/**************************************************************************
**
** $FreeBSD: src/sys/pci/ncr.c,v 1.155.2.3 2001/03/05 13:09:10 obrien Exp $
**
**  Device driver for the   NCR 53C8XX   PCI-SCSI-Controller Family.
**
**-------------------------------------------------------------------------
**
**  Written for 386bsd and FreeBSD by
**      Wolfgang Stanglmeier    <wolf@cologne.de>
**      Stefan Esser            <se@mi.Uni-Koeln.de>
**
**-------------------------------------------------------------------------
**
** Copyright (c) 1994 Wolfgang Stanglmeier.  All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**
***************************************************************************
*/

#define NCR_DATE "pl30 98/1/1"

#define NCR_VERSION     (2)
#define MAX_UNITS       (16)

#define NCR_GETCC_WITHMSG

#if (defined(__DragonFly__) || defined (__FreeBSD__)) && defined(_KERNEL)
#include "opt_ncr.h"
#endif

/*==========================================================
**
**      Configuration and Debugging
**
**      May be overwritten in <arch/conf/xxxx>
**
**==========================================================
*/

/*
**    SCSI address of this device.
**    The boot routines should have set it.
**    If not, use this.
*/

#ifndef SCSI_NCR_MYADDR
#define SCSI_NCR_MYADDR      (7)
#endif /* SCSI_NCR_MYADDR */

/*
**    The default synchronous period factor
**    (0=asynchronous)
**    If maximum synchronous frequency is defined, use it instead.
*/

#ifndef SCSI_NCR_MAX_SYNC

#ifndef SCSI_NCR_DFLT_SYNC
#define SCSI_NCR_DFLT_SYNC   (12)
#endif /* SCSI_NCR_DFLT_SYNC */

#else

#if     SCSI_NCR_MAX_SYNC == 0
#define SCSI_NCR_DFLT_SYNC 0
#else
#define SCSI_NCR_DFLT_SYNC (250000 / SCSI_NCR_MAX_SYNC)
#endif

#endif

/*
**    The minimal asynchronous pre-scaler period (ns)
**    Shall be 40.
*/

#ifndef SCSI_NCR_MIN_ASYNC
#define SCSI_NCR_MIN_ASYNC   (40)
#endif /* SCSI_NCR_MIN_ASYNC */

/*
**    The maximal bus with (in log2 byte)
**    (0=8 bit, 1=16 bit)
*/

#ifndef SCSI_NCR_MAX_WIDE
#define SCSI_NCR_MAX_WIDE   (1)
#endif /* SCSI_NCR_MAX_WIDE */

/*==========================================================
**
**      Configuration and Debugging
**
**==========================================================
*/

/*
**    Number of targets supported by the driver.
**    n permits target numbers 0..n-1.
**    Default is 7, meaning targets #0..#6.
**    #7 .. is myself.
*/

#define MAX_TARGET  (16)

/*
**    Number of logic units supported by the driver.
**    n enables logic unit numbers 0..n-1.
**    The common SCSI devices require only
**    one lun, so take 1 as the default.
*/

#ifndef MAX_LUN
#define MAX_LUN     (8)
#endif  /* MAX_LUN */

/*
**    The maximum number of jobs scheduled for starting.
**    There should be one slot per target, and one slot
**    for each tag of each target in use.
*/

#define MAX_START   (256)

/*
**    The maximum number of segments a transfer is split into.
*/

#define MAX_SCATTER (33)

/*
**    The maximum transfer length (should be >= 64k).
**    MUST NOT be greater than (MAX_SCATTER-1) * PAGE_SIZE.
*/

#define MAX_SIZE  ((MAX_SCATTER-1) * (long) PAGE_SIZE)

/*
**      other
*/

#define NCR_SNOOP_TIMEOUT (1000000)

/*==========================================================
**
**      Include files
**
**==========================================================
*/

#include <sys/param.h>
#include <sys/time.h>

#ifdef _KERNEL
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/buf.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/bus.h>
#include <sys/thread2.h>
#include <machine/clock.h>
#include <machine/md_var.h>
#include <sys/rman.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#endif

#include <bus/pci/pcivar.h>
#include <bus/pci/pcireg.h>
#include "ncrreg.h"

#include <bus/cam/cam.h>
#include <bus/cam/cam_ccb.h>
#include <bus/cam/cam_sim.h>
#include <bus/cam/cam_xpt.h>
#include <bus/cam/cam_xpt_sim.h>
#include <bus/cam/cam_xpt_periph.h>
#include <bus/cam/cam_debug.h>


#include <bus/cam/scsi/scsi_all.h>
#include <bus/cam/scsi/scsi_message.h>

/*==========================================================
**
**      Debugging tags
**
**==========================================================
*/

#define DEBUG_ALLOC    (0x0001)
#define DEBUG_PHASE    (0x0002)
#define DEBUG_POLL     (0x0004)
#define DEBUG_QUEUE    (0x0008)
#define DEBUG_RESULT   (0x0010)
#define DEBUG_SCATTER  (0x0020)
#define DEBUG_SCRIPT   (0x0040)
#define DEBUG_TINY     (0x0080)
#define DEBUG_TIMING   (0x0100)
#define DEBUG_NEGO     (0x0200)
#define DEBUG_TAGS     (0x0400)
#define DEBUG_FREEZE   (0x0800)
#define DEBUG_RESTART  (0x1000)

/*
**    Enable/Disable debug messages.
**    Can be changed at runtime too.
*/
#ifdef SCSI_NCR_DEBUG
        #define DEBUG_FLAGS ncr_debug
#else /* SCSI_NCR_DEBUG */
        #define SCSI_NCR_DEBUG  0
        #define DEBUG_FLAGS     0
#endif /* SCSI_NCR_DEBUG */



/*==========================================================
**
**      assert ()
**
**==========================================================
**
**      modified copy from 386bsd:/usr/include/sys/assert.h
**
**----------------------------------------------------------
*/

#ifdef DIAGNOSTIC
#define assert(expression) {                                    \
        if (!(expression)) {                                    \
                (void)kprintf("assertion \"%s\" failed: "       \
                             "file \"%s\", line %d\n",          \
                             #expression, __FILE__, __LINE__);  \
             Debugger("");                                      \
        }                                                       \
}
#else
#define assert(expression) {                                    \
        if (!(expression)) {                                    \
                (void)kprintf("assertion \"%s\" failed: "       \
                             "file \"%s\", line %d\n",          \
                             #expression, __FILE__, __LINE__);  \
        }                                                       \
}
#endif

/*==========================================================
**
**      Access to the controller chip.
**
**==========================================================
*/

#define INB(r) bus_space_read_1(np->bst, np->bsh, offsetof(struct ncr_reg, r))
#define INW(r) bus_space_read_2(np->bst, np->bsh, offsetof(struct ncr_reg, r))
#define INL(r) bus_space_read_4(np->bst, np->bsh, offsetof(struct ncr_reg, r))

#define OUTB(r, val) bus_space_write_1(np->bst, np->bsh, \
                                       offsetof(struct ncr_reg, r), val)
#define OUTW(r, val) bus_space_write_2(np->bst, np->bsh, \
                                       offsetof(struct ncr_reg, r), val)
#define OUTL(r, val) bus_space_write_4(np->bst, np->bsh, \
                                       offsetof(struct ncr_reg, r), val)
#define OUTL_OFF(o, val) bus_space_write_4(np->bst, np->bsh, o, val)

#define INB_OFF(o) bus_space_read_1(np->bst, np->bsh, o)
#define INW_OFF(o) bus_space_read_2(np->bst, np->bsh, o)
#define INL_OFF(o) bus_space_read_4(np->bst, np->bsh, o)

#define READSCRIPT_OFF(base, off)                                       \
    (base ? *((volatile u_int32_t *)((volatile char *)base + (off))) :  \
    bus_space_read_4(np->bst2, np->bsh2, off))

#define WRITESCRIPT_OFF(base, off, val)                                 \
    do {                                                                \
        if (base)                                                       \
                *((volatile u_int32_t *)                                \
                        ((volatile char *)base + (off))) = (val);       \
        else                                                            \
                bus_space_write_4(np->bst2, np->bsh2, off, val);        \
    } while (0)

#define READSCRIPT(r) \
    READSCRIPT_OFF(np->script, offsetof(struct script, r))

#define WRITESCRIPT(r, val) \
    WRITESCRIPT_OFF(np->script, offsetof(struct script, r), val)

/*
**      Set bit field ON, OFF 
*/

#define OUTONB(r, m)    OUTB(r, INB(r) | (m))
#define OUTOFFB(r, m)   OUTB(r, INB(r) & ~(m))
#define OUTONW(r, m)    OUTW(r, INW(r) | (m))
#define OUTOFFW(r, m)   OUTW(r, INW(r) & ~(m))
#define OUTONL(r, m)    OUTL(r, INL(r) | (m))
#define OUTOFFL(r, m)   OUTL(r, INL(r) & ~(m))

/*==========================================================
**
**      Command control block states.
**
**==========================================================
*/

#define HS_IDLE         (0)
#define HS_BUSY         (1)
#define HS_NEGOTIATE    (2)     /* sync/wide data transfer*/
#define HS_DISCONNECT   (3)     /* Disconnected by target */

#define HS_COMPLETE     (4)
#define HS_SEL_TIMEOUT  (5)     /* Selection timeout      */
#define HS_RESET        (6)     /* SCSI reset        */
#define HS_ABORTED      (7)     /* Transfer aborted       */
#define HS_TIMEOUT      (8)     /* Software timeout       */
#define HS_FAIL         (9)     /* SCSI or PCI bus errors */
#define HS_UNEXPECTED   (10)    /* Unexpected disconnect  */
#define HS_STALL        (11)    /* QUEUE FULL or BUSY     */

#define HS_DONEMASK     (0xfc)

/*==========================================================
**
**      Software Interrupt Codes
**
**==========================================================
*/

#define SIR_SENSE_RESTART       (1)
#define SIR_SENSE_FAILED        (2)
#define SIR_STALL_RESTART       (3)
#define SIR_STALL_QUEUE         (4)
#define SIR_NEGO_SYNC           (5)
#define SIR_NEGO_WIDE           (6)
#define SIR_NEGO_FAILED         (7)
#define SIR_NEGO_PROTO          (8)
#define SIR_REJECT_RECEIVED     (9)
#define SIR_REJECT_SENT         (10)
#define SIR_IGN_RESIDUE         (11)
#define SIR_MISSING_SAVE        (12)
#define SIR_MAX                 (12)

/*==========================================================
**
**      Extended error codes.
**      xerr_status field of struct nccb.
**
**==========================================================
*/

#define XE_OK           (0)
#define XE_EXTRA_DATA   (1)     /* unexpected data phase */
#define XE_BAD_PHASE    (2)     /* illegal phase (4/5)   */

/*==========================================================
**
**      Negotiation status.
**      nego_status field       of struct nccb.
**
**==========================================================
*/

#define NS_SYNC         (1)
#define NS_WIDE         (2)

/*==========================================================
**
**      XXX These are no longer used.  Remove once the
**          script is updated.
**      "Special features" of targets.
**      quirks field of struct tcb.
**      actualquirks field of struct nccb.
**
**==========================================================
*/

#define QUIRK_AUTOSAVE  (0x01)
#define QUIRK_NOMSG     (0x02)
#define QUIRK_NOSYNC    (0x10)
#define QUIRK_NOWIDE16  (0x20)
#define QUIRK_NOTAGS    (0x40)
#define QUIRK_UPDATE    (0x80)

/*==========================================================
**
**      Misc.
**
**==========================================================
*/

#define CCB_MAGIC       (0xf2691ad2)
#define MAX_TAGS        (32)            /* hard limit */

/*==========================================================
**
**      OS dependencies.
**
**==========================================================
*/

#define PRINT_ADDR(ccb) xpt_print_path((ccb)->ccb_h.path)

/*==========================================================
**
**      Declaration of structs.
**
**==========================================================
*/

struct tcb;
struct lcb;
struct nccb;
struct ncb;
struct script;

typedef struct ncb * ncb_p;
typedef struct tcb * tcb_p;
typedef struct lcb * lcb_p;
typedef struct nccb * nccb_p;

struct link {
        ncrcmd  l_cmd;
        ncrcmd  l_paddr;
};

struct  usrcmd {
        u_long  target;
        u_long  lun;
        u_long  data;
        u_long  cmd;
};

#define UC_SETSYNC      10
#define UC_SETTAGS      11
#define UC_SETDEBUG     12
#define UC_SETORDER     13
#define UC_SETWIDE      14
#define UC_SETFLAG      15

#define UF_TRACE        (0x01)

/*---------------------------------------
**
**      Timestamps for profiling
**
**---------------------------------------
*/

/* Type of the kernel variable `ticks'.  XXX should be declared with the var. */
typedef int ticks_t;

struct tstamp {
        ticks_t start;
        ticks_t end;
        ticks_t select;
        ticks_t command;
        ticks_t data;
        ticks_t status;
        ticks_t disconnect;
};

/*
**      profiling data (per device)
*/

struct profile {
        u_long  num_trans;
        u_long  num_bytes;
        u_long  num_disc;
        u_long  num_break;
        u_long  num_int;
        u_long  num_fly;
        u_long  ms_setup;
        u_long  ms_data;
        u_long  ms_disc;
        u_long  ms_post;
};

/*==========================================================
**
**      Declaration of structs:         target control block
**
**==========================================================
*/

#define NCR_TRANS_CUR           0x01    /* Modify current neogtiation status */
#define NCR_TRANS_ACTIVE        0x03    /* Assume this is the active target */
#define NCR_TRANS_GOAL          0x04    /* Modify negotiation goal */
#define NCR_TRANS_USER          0x08    /* Modify user negotiation settings */

struct ncr_transinfo {
        u_int8_t width;
        u_int8_t period;
        u_int8_t offset;
};

struct ncr_target_tinfo {
        /* Hardware version of our sync settings */
        u_int8_t disc_tag;
#define         NCR_CUR_DISCENB 0x01
#define         NCR_CUR_TAGENB  0x02
#define         NCR_USR_DISCENB 0x04
#define         NCR_USR_TAGENB  0x08
        u_int8_t sval;
        struct   ncr_transinfo current;
        struct   ncr_transinfo goal;
        struct   ncr_transinfo user;
        /* Hardware version of our wide settings */
        u_int8_t wval;
};

struct tcb {
        /*
        **      during reselection the ncr jumps to this point
        **      with SFBR set to the encoded target number
        **      with bit 7 set.
        **      if it's not this target, jump to the next.
        **
        **      JUMP  IF (SFBR != #target#)
        **      @(next tcb)
        */

        struct link   jump_tcb;

        /*
        **      load the actual values for the sxfer and the scntl3
        **      register (sync/wide mode).
        **
        **      SCR_COPY (1);
        **      @(sval field of this tcb)
        **      @(sxfer register)
        **      SCR_COPY (1);
        **      @(wval field of this tcb)
        **      @(scntl3 register)
        */

        ncrcmd  getscr[6];

        /*
        **      if next message is "identify"
        **      then load the message to SFBR,
        **      else load 0 to SFBR.
        **
        **      CALL
        **      <RESEL_LUN>
        */

        struct link   call_lun;

        /*
        **      now look for the right lun.
        **
        **      JUMP
        **      @(first nccb of this lun)
        */

        struct link   jump_lcb;

        /*
        **      pointer to interrupted getcc nccb
        */

        nccb_p   hold_cp;

        /*
        **      pointer to nccb used for negotiating.
        **      Avoid to start a nego for all queued commands 
        **      when tagged command queuing is enabled.
        */

        nccb_p   nego_cp;

        /*
        **      statistical data
        */

        u_long  transfers;
        u_long  bytes;

        /*
        **      user settable limits for sync transfer
        **      and tagged commands.
        */

        struct   ncr_target_tinfo tinfo;

        /*
        **      the lcb's of this tcb
        */

        lcb_p   lp[MAX_LUN];
};

/*==========================================================
**
**      Declaration of structs:         lun control block
**
**==========================================================
*/

struct lcb {
        /*
        **      during reselection the ncr jumps to this point
        **      with SFBR set to the "Identify" message.
        **      if it's not this lun, jump to the next.
        **
        **      JUMP  IF (SFBR != #lun#)
        **      @(next lcb of this target)
        */

        struct link     jump_lcb;

        /*
        **      if next message is "simple tag",
        **      then load the tag to SFBR,
        **      else load 0 to SFBR.
        **
        **      CALL
        **      <RESEL_TAG>
        */

        struct link     call_tag;

        /*
        **      now look for the right nccb.
        **
        **      JUMP
        **      @(first nccb of this lun)
        */

        struct link     jump_nccb;

        /*
        **      start of the nccb chain
        */

        nccb_p  next_nccb;

        /*
        **      Control of tagged queueing
        */

        u_char          reqnccbs;
        u_char          reqlink;
        u_char          actlink;
        u_char          usetags;
        u_char          lasttag;
};

/*==========================================================
**
**      Declaration of structs:     COMMAND control block
**
**==========================================================
**
**      This substructure is copied from the nccb to a
**      global address after selection (or reselection)
**      and copied back before disconnect.
**
**      These fields are accessible to the script processor.
**
**----------------------------------------------------------
*/

struct head {
        /*
        **      Execution of a nccb starts at this point.
        **      It's a jump to the "SELECT" label
        **      of the script.
        **
        **      After successful selection the script
        **      processor overwrites it with a jump to
        **      the IDLE label of the script.
        */

        struct link     launch;

        /*
        **      Saved data pointer.
        **      Points to the position in the script
        **      responsible for the actual transfer
        **      of data.
        **      It's written after reception of a
        **      "SAVE_DATA_POINTER" message.
        **      The goalpointer points after
        **      the last transfer command.
        */

        u_int32_t       savep;
        u_int32_t       lastp;
        u_int32_t       goalp;

        /*
        **      The virtual address of the nccb
        **      containing this header.
        */

        nccb_p  cp;

        /*
        **      space for some timestamps to gather
        **      profiling data about devices and this driver.
        */

        struct tstamp   stamp;

        /*
        **      status fields.
        */

        u_char          status[8];
};

/*
**      The status bytes are used by the host and the script processor.
**
**      The first four byte are copied to the scratchb register
**      (declared as scr0..scr3 in ncr_reg.h) just after the select/reselect,
**      and copied back just after disconnecting.
**      Inside the script the XX_REG are used.
**
**      The last four bytes are used inside the script by "COPY" commands.
**      Because source and destination must have the same alignment
**      in a longword, the fields HAVE to be at the choosen offsets.
**              xerr_st (4)     0       (0x34)  scratcha
**              sync_st (5)     1       (0x05)  sxfer
**              wide_st (7)     3       (0x03)  scntl3
*/

/*
**      First four bytes (script)
*/
#define  QU_REG scr0
#define  HS_REG scr1
#define  HS_PRT nc_scr1
#define  SS_REG scr2
#define  PS_REG scr3

/*
**      First four bytes (host)
*/
#define  actualquirks  phys.header.status[0]
#define  host_status   phys.header.status[1]
#define  s_status      phys.header.status[2]
#define  parity_status phys.header.status[3]

/*
**      Last four bytes (script)
*/
#define  xerr_st       header.status[4] /* MUST be ==0 mod 4 */
#define  sync_st       header.status[5] /* MUST be ==1 mod 4 */
#define  nego_st       header.status[6]
#define  wide_st       header.status[7] /* MUST be ==3 mod 4 */

/*
**      Last four bytes (host)
*/
#define  xerr_status   phys.xerr_st
#define  sync_status   phys.sync_st
#define  nego_status   phys.nego_st
#define  wide_status   phys.wide_st

/*==========================================================
**
**      Declaration of structs:     Data structure block
**
**==========================================================
**
**      During execution of a nccb by the script processor,
**      the DSA (data structure address) register points
**      to this substructure of the nccb.
**      This substructure contains the header with
**      the script-processor-changable data and
**      data blocks for the indirect move commands.
**
**----------------------------------------------------------
*/

struct dsb {

        /*
        **      Header.
        **      Has to be the first entry,
        **      because it's jumped to by the
        **      script processor
        */

        struct head     header;

        /*
        **      Table data for Script
        */

        struct scr_tblsel  select;
        struct scr_tblmove smsg  ;
        struct scr_tblmove smsg2 ;
        struct scr_tblmove cmd   ;
        struct scr_tblmove scmd  ;
        struct scr_tblmove sense ;
        struct scr_tblmove data [MAX_SCATTER];
};

/*==========================================================
**
**      Declaration of structs:     Command control block.
**
**==========================================================
**
**      During execution of a nccb by the script processor,
**      the DSA (data structure address) register points
**      to this substructure of the nccb.
**      This substructure contains the header with
**      the script-processor-changable data and then
**      data blocks for the indirect move commands.
**
**----------------------------------------------------------
*/


struct nccb {
        /*
        **      This filler ensures that the global header is 
        **      cache line size aligned.
        */
        ncrcmd  filler[4];

        /*
        **      during reselection the ncr jumps to this point.
        **      If a "SIMPLE_TAG" message was received,
        **      then SFBR is set to the tag.
        **      else SFBR is set to 0
        **      If looking for another tag, jump to the next nccb.
        **
        **      JUMP  IF (SFBR != #TAG#)
        **      @(next nccb of this lun)
        */

        struct link             jump_nccb;

        /*
        **      After execution of this call, the return address
        **      (in  the TEMP register) points to the following
        **      data structure block.
        **      So copy it to the DSA register, and start
        **      processing of this data structure.
        **
        **      CALL
        **      <RESEL_TMP>
        */

        struct link             call_tmp;

        /*
        **      This is the data structure which is
        **      to be executed by the script processor.
        */

        struct dsb              phys;

        /*
        **      If a data transfer phase is terminated too early
        **      (after reception of a message (i.e. DISCONNECT)),
        **      we have to prepare a mini script to transfer
        **      the rest of the data.
        */

        ncrcmd                  patch[8];

        /*
        **      The general SCSI driver provides a
        **      pointer to a control block.
        */

        union   ccb *ccb;

        /*
        **      We prepare a message to be sent after selection,
        **      and a second one to be sent after getcc selection.
        **      Contents are IDENTIFY and SIMPLE_TAG.
        **      While negotiating sync or wide transfer,
        **      a SDTM or WDTM message is appended.
        */

        u_char                  scsi_smsg [8];
        u_char                  scsi_smsg2[8];

        /*
        **      Lock this nccb.
        **      Flag is used while looking for a free nccb.
        */

        u_long          magic;

        /*
        **      Physical address of this instance of nccb
        */

        u_long          p_nccb;

        /*
        **      Completion time out for this job.
        **      It's set to time of start + allowed number of seconds.
        */

        time_t          tlimit;

        /*
        **      All nccbs of one hostadapter are chained.
        */

        nccb_p          link_nccb;

        /*
        **      All nccbs of one target/lun are chained.
        */

        nccb_p          next_nccb;

        /*
        **      Sense command
        */

        u_char          sensecmd[6];

        /*
        **      Tag for this transfer.
        **      It's patched into jump_nccb.
        **      If it's not zero, a SIMPLE_TAG
        **      message is included in smsg.
        */

        u_char                  tag;
};

#define CCB_PHYS(cp,lbl)        (cp->p_nccb + offsetof(struct nccb, lbl))

/*==========================================================
**
**      Declaration of structs:     NCR device descriptor
**
**==========================================================
*/

struct ncb {
        /*
        **      The global header.
        **      Accessible to both the host and the
        **      script-processor.
        **      We assume it is cache line size aligned.
        */
        struct head     header;

        int     unit;

        /*-----------------------------------------------
        **      Scripts ..
        **-----------------------------------------------
        **
        **      During reselection the ncr jumps to this point.
        **      The SFBR register is loaded with the encoded target id.
        **
        **      Jump to the first target.
        **
        **      JUMP
        **      @(next tcb)
        */
        struct link     jump_tcb;

        /*-----------------------------------------------
        **      Configuration ..
        **-----------------------------------------------
        **
        **      virtual and physical addresses
        **      of the 53c810 chip.
        */
        int             reg_rid;
        struct resource *reg_res;
        bus_space_tag_t bst;
        bus_space_handle_t bsh;

        int             sram_rid;
        struct resource *sram_res;
        bus_space_tag_t bst2;
        bus_space_handle_t bsh2;

        struct resource *irq_res;
        void            *irq_handle;

        /*
        **      Scripts instance virtual address.
        */
        struct script   *script;
        struct scripth  *scripth;

        /*
        **      Scripts instance physical address.
        */
        u_long          p_script;
        u_long          p_scripth;

        /*
        **      The SCSI address of the host adapter.
        */
        u_char          myaddr;

        /*
        **      timing parameters
        */
        u_char          minsync;        /* Minimum sync period factor   */
        u_char          maxsync;        /* Maximum sync period factor   */
        u_char          maxoffs;        /* Max scsi offset              */
        u_char          clock_divn;     /* Number of clock divisors     */
        u_long          clock_khz;      /* SCSI clock frequency in KHz  */
        u_long          features;       /* Chip features map            */
        u_char          multiplier;     /* Clock multiplier (1,2,4)     */

        u_char          maxburst;       /* log base 2 of dwords burst   */

        /*
        **      BIOS supplied PCI bus options
        */
        u_char          rv_scntl3;
        u_char          rv_dcntl;
        u_char          rv_dmode;
        u_char          rv_ctest3;
        u_char          rv_ctest4;
        u_char          rv_ctest5;
        u_char          rv_gpcntl;
        u_char          rv_stest2;

        /*-----------------------------------------------
        **      CAM SIM information for this instance
        **-----------------------------------------------
        */

        struct          cam_sim  *sim;
        struct          cam_path *path;

        /*-----------------------------------------------
        **      Job control
        **-----------------------------------------------
        **
        **      Commands from user
        */
        struct usrcmd   user;

        /*
        **      Target data
        */
        struct tcb      target[MAX_TARGET];

        /*
        **      Start queue.
        */
        u_int32_t       squeue [MAX_START];
        u_short         squeueput;

        /*
        **      Timeout handler
        */
        time_t          heartbeat;
        u_short         ticks;
        u_short         latetime;
        time_t          lasttime;
        struct          callout timeout_ch;

        /*-----------------------------------------------
        **      Debug and profiling
        **-----------------------------------------------
        **
        **      register dump
        */
        struct ncr_reg  regdump;
        time_t          regtime;

        /*
        **      Profiling data
        */
        struct profile  profile;
        u_long          disc_phys;
        u_long          disc_ref;

        /*
        **      Head of list of all nccbs for this controller.
        */
        nccb_p          link_nccb;
        
        /*
        **      message buffers.
        **      Should be longword aligned,
        **      because they're written with a
        **      COPY script command.
        */
        u_char          msgout[8];
        u_char          msgin [8];
        u_int32_t       lastmsg;

        /*
        **      Buffer for STATUS_IN phase.
        */
        u_char          scratch;

        /*
        **      controller chip dependent maximal transfer width.
        */
        u_char          maxwide;

#ifdef NCR_IOMAPPED
        /*
        **      address of the ncr control registers in io space
        */
        pci_port_t      port;
#endif
};

#define NCB_SCRIPT_PHYS(np,lbl) (np->p_script + offsetof (struct script, lbl))
#define NCB_SCRIPTH_PHYS(np,lbl) (np->p_scripth + offsetof (struct scripth,lbl))

/*==========================================================
**
**
**      Script for NCR-Processor.
**
**      Use ncr_script_fill() to create the variable parts.
**      Use ncr_script_copy_and_bind() to make a copy and
**      bind to physical addresses.
**
**
**==========================================================
**
**      We have to know the offsets of all labels before
**      we reach them (for forward jumps).
**      Therefore we declare a struct here.
**      If you make changes inside the script,
**      DONT FORGET TO CHANGE THE LENGTHS HERE!
**
**----------------------------------------------------------
*/

/*
**      Script fragments which are loaded into the on-board RAM 
**      of 825A, 875 and 895 chips.
*/
struct script {
        ncrcmd  start           [  7];
        ncrcmd  start0          [  2];
        ncrcmd  start1          [  3];
        ncrcmd  startpos        [  1];
        ncrcmd  trysel          [  8];
        ncrcmd  skip            [  8];
        ncrcmd  skip2           [  3];
        ncrcmd  idle            [  2];
        ncrcmd  select          [ 18];
        ncrcmd  prepare         [  4];
        ncrcmd  loadpos         [ 14];
        ncrcmd  prepare2        [ 24];
        ncrcmd  setmsg          [  5];
        ncrcmd  clrack          [  2];
        ncrcmd  dispatch        [ 33];
        ncrcmd  no_data         [ 17];
        ncrcmd  checkatn        [ 10];
        ncrcmd  command         [ 15];
        ncrcmd  status          [ 27];
        ncrcmd  msg_in          [ 26];
        ncrcmd  msg_bad         [  6];
        ncrcmd  complete        [ 13];
        ncrcmd  cleanup         [ 12];
        ncrcmd  cleanup0        [  9];
        ncrcmd  signal          [ 12];
        ncrcmd  save_dp         [  5];
        ncrcmd  restore_dp      [  5];
        ncrcmd  disconnect      [ 12];
        ncrcmd  disconnect0     [  5];
        ncrcmd  disconnect1     [ 23];
        ncrcmd  msg_out         [  9];
        ncrcmd  msg_out_done    [  7];
        ncrcmd  badgetcc        [  6];
        ncrcmd  reselect        [  8];
        ncrcmd  reselect1       [  8];
        ncrcmd  reselect2       [  8];
        ncrcmd  resel_tmp       [  5];
        ncrcmd  resel_lun       [ 18];
        ncrcmd  resel_tag       [ 24];
        ncrcmd  data_in         [MAX_SCATTER * 4 + 7];
        ncrcmd  data_out        [MAX_SCATTER * 4 + 7];
};

/*
**      Script fragments which stay in main memory for all chips.
*/
struct scripth {
        ncrcmd  tryloop         [MAX_START*5+2];
        ncrcmd  msg_parity      [  6];
        ncrcmd  msg_reject      [  8];
        ncrcmd  msg_ign_residue [ 32];
        ncrcmd  msg_extended    [ 18];
        ncrcmd  msg_ext_2       [ 18];
        ncrcmd  msg_wdtr        [ 27];
        ncrcmd  msg_ext_3       [ 18];
        ncrcmd  msg_sdtr        [ 27];
        ncrcmd  msg_out_abort   [ 10];
        ncrcmd  getcc           [  4];
        ncrcmd  getcc1          [  5];
#ifdef NCR_GETCC_WITHMSG
        ncrcmd  getcc2          [ 29];
#else
        ncrcmd  getcc2          [ 14];
#endif
        ncrcmd  getcc3          [  6];
        ncrcmd  aborttag        [  4];
        ncrcmd  abort           [ 22];
        ncrcmd  snooptest       [  9];
        ncrcmd  snoopend        [  2];
};

/*==========================================================
**
**
**      Function headers.
**
**
**==========================================================
*/

#ifdef _KERNEL
static  nccb_p  ncr_alloc_nccb  (ncb_p np, u_long target, u_long lun);
static  void    ncr_complete    (ncb_p np, nccb_p cp);
static  int     ncr_delta       (int * from, int * to);
static  void    ncr_exception   (ncb_p np);
static  void    ncr_free_nccb   (ncb_p np, nccb_p cp);
static  void    ncr_freeze_devq (ncb_p np, struct cam_path *path);
static  void    ncr_selectclock (ncb_p np, u_char scntl3);
static  void    ncr_getclock    (ncb_p np, u_char multiplier);
static  nccb_p  ncr_get_nccb    (ncb_p np, u_long t,u_long l);
#if 0
static  u_int32_t ncr_info      (int unit);
#endif
static  void    ncr_init        (ncb_p np, char * msg, u_long code);
static  void    ncr_intr        (void *vnp);
static  void    ncr_int_ma      (ncb_p np, u_char dstat);
static  void    ncr_int_sir     (ncb_p np);
static  void    ncr_int_sto     (ncb_p np);
#if 0
static  void    ncr_min_phys    (struct buf *bp);
#endif
static  void    ncr_poll        (struct cam_sim *sim);
static  void    ncb_profile     (ncb_p np, nccb_p cp);
static  void    ncr_script_copy_and_bind
                                (ncb_p np, ncrcmd *src, ncrcmd *dst, int len);
static  void    ncr_script_fill (struct script * scr, struct scripth *scrh);
static  int     ncr_scatter     (struct dsb* phys, vm_offset_t vaddr,
                                 vm_size_t datalen);
static  void    ncr_getsync     (ncb_p np, u_char sfac, u_char *fakp,
                                 u_char *scntl3p);
static  void    ncr_setsync     (ncb_p np, nccb_p cp,u_char scntl3,u_char sxfer,
                                 u_char period);
static  void    ncr_setwide     (ncb_p np, nccb_p cp, u_char wide, u_char ack);
static  int     ncr_show_msg    (u_char * msg);
static  int     ncr_snooptest   (ncb_p np);
static  void    ncr_action      (struct cam_sim *sim, union ccb *ccb);
static  void    ncr_timeout     (void *arg);
static  void    ncr_wakeup      (ncb_p np, u_long code);

static  int     ncr_probe       (device_t dev);
static  int     ncr_attach      (device_t dev);

#endif /* _KERNEL */

/*==========================================================
**
**
**      Global static data.
**
**
**==========================================================
*/

#ifdef _KERNEL

static int ncr_debug = SCSI_NCR_DEBUG;
SYSCTL_INT(_debug, OID_AUTO, ncr_debug, CTLFLAG_RW, &ncr_debug, 0,
    "Driver debug flags");

static int ncr_cache; /* to be aligned _NOT_ static */

/*==========================================================
**
**
**      Global static data:     auto configure
**
**
**==========================================================
*/

#define NCR_810_ID      (0x00011000ul)
#define NCR_815_ID      (0x00041000ul)
#define NCR_820_ID      (0x00021000ul)
#define NCR_825_ID      (0x00031000ul)
#define NCR_860_ID      (0x00061000ul)
#define NCR_875_ID      (0x000f1000ul)
#define NCR_875_ID2     (0x008f1000ul)
#define NCR_885_ID      (0x000d1000ul)
#define NCR_895_ID      (0x000c1000ul)
#define NCR_896_ID      (0x000b1000ul)
#define NCR_895A_ID     (0x00121000ul)
#define NCR_1510D_ID    (0x000a1000ul)


static char *ncr_name (ncb_p np)
{
        static char name[10];
        ksnprintf(name, sizeof(name), "ncr%d", np->unit);
        return (name);
}

/*==========================================================
**
**
**      Scripts for NCR-Processor.
**
**      Use ncr_script_bind for binding to physical addresses.
**
**
**==========================================================
**
**      NADDR generates a reference to a field of the controller data.
**      PADDR generates a reference to another part of the script.
**      RADDR generates a reference to a script processor register.
**      FADDR generates a reference to a script processor register
**              with offset.
**
**----------------------------------------------------------
*/

#define RELOC_SOFTC     0x40000000
#define RELOC_LABEL     0x50000000
#define RELOC_REGISTER  0x60000000
#define RELOC_KVAR      0x70000000
#define RELOC_LABELH    0x80000000
#define RELOC_MASK      0xf0000000

#define NADDR(label)    (RELOC_SOFTC | offsetof(struct ncb, label))
#define PADDR(label)    (RELOC_LABEL | offsetof(struct script, label))
#define PADDRH(label)   (RELOC_LABELH | offsetof(struct scripth, label))
#define RADDR(label)    (RELOC_REGISTER | REG(label))
#define FADDR(label,ofs)(RELOC_REGISTER | ((REG(label))+(ofs)))
#define KVAR(which)     (RELOC_KVAR | (which))

#define KVAR_SECOND                     (0)
#define KVAR_TICKS                      (1)
#define KVAR_NCR_CACHE                  (2)

#define SCRIPT_KVAR_FIRST               (0)
#define SCRIPT_KVAR_LAST                (3)

/*
 * Kernel variables referenced in the scripts.
 * THESE MUST ALL BE ALIGNED TO A 4-BYTE BOUNDARY.
 */
static void *script_kvars[] =
        { &time_uptime, &ticks, &ncr_cache };

static  struct script script0 = {
/*--------------------------< START >-----------------------*/ {
        /*
        **      Claim to be still alive ...
        */
        SCR_COPY (sizeof (((struct ncb *)0)->heartbeat)),
                KVAR (KVAR_SECOND),
                NADDR (heartbeat),
        /*
        **      Make data structure address invalid.
        **      clear SIGP.
        */
        SCR_LOAD_REG (dsa, 0xff),
                0,
        SCR_FROM_REG (ctest2),
                0,
}/*-------------------------< START0 >----------------------*/,{
        /*
        **      Hook for interrupted GetConditionCode.
        **      Will be patched to ... IFTRUE by
        **      the interrupt handler.
        */
        SCR_INT ^ IFFALSE (0),
                SIR_SENSE_RESTART,

}/*-------------------------< START1 >----------------------*/,{
        /*
        **      Hook for stalled start queue.
        **      Will be patched to IFTRUE by the interrupt handler.
        */
        SCR_INT ^ IFFALSE (0),
                SIR_STALL_RESTART,
        /*
        **      Then jump to a certain point in tryloop.
        **      Due to the lack of indirect addressing the code
        **      is self modifying here.
        */
        SCR_JUMP,
}/*-------------------------< STARTPOS >--------------------*/,{
                PADDRH(tryloop),

}/*-------------------------< TRYSEL >----------------------*/,{
        /*
        **      Now:
        **      DSA: Address of a Data Structure
        **      or   Address of the IDLE-Label.
        **
        **      TEMP:   Address of a script, which tries to
        **              start the NEXT entry.
        **
        **      Save the TEMP register into the SCRATCHA register.
        **      Then copy the DSA to TEMP and RETURN.
        **      This is kind of an indirect jump.
        **      (The script processor has NO stack, so the
        **      CALL is actually a jump and link, and the
        **      RETURN is an indirect jump.)
        **
        **      If the slot was empty, DSA contains the address
        **      of the IDLE part of this script. The processor
        **      jumps to IDLE and waits for a reselect.
        **      It will wake up and try the same slot again
        **      after the SIGP bit becomes set by the host.
        **
        **      If the slot was not empty, DSA contains
        **      the address of the phys-part of a nccb.
        **      The processor jumps to this address.
        **      phys starts with head,
        **      head starts with launch,
        **      so actually the processor jumps to
        **      the lauch part.
        **      If the entry is scheduled for execution,
        **      then launch contains a jump to SELECT.
        **      If it's not scheduled, it contains a jump to IDLE.
        */
        SCR_COPY (4),
                RADDR (temp),
                RADDR (scratcha),
        SCR_COPY (4),
                RADDR (dsa),
                RADDR (temp),
        SCR_RETURN,
                0

}/*-------------------------< SKIP >------------------------*/,{
        /*
        **      This entry has been canceled.
        **      Next time use the next slot.
        */
        SCR_COPY (4),
                RADDR (scratcha),
                PADDR (startpos),
        /*
        **      patch the launch field.
        **      should look like an idle process.
        */
        SCR_COPY_F (4),
                RADDR (dsa),
                PADDR (skip2),
        SCR_COPY (8),
                PADDR (idle),
}/*-------------------------< SKIP2 >-----------------------*/,{
                0,
        SCR_JUMP,
                PADDR(start),
}/*-------------------------< IDLE >------------------------*/,{
        /*
        **      Nothing to do?
        **      Wait for reselect.
        */
        SCR_JUMP,
                PADDR(reselect),

}/*-------------------------< SELECT >----------------------*/,{
        /*
        **      DSA     contains the address of a scheduled
        **              data structure.
        **
        **      SCRATCHA contains the address of the script,
        **              which starts the next entry.
        **
        **      Set Initiator mode.
        **
        **      (Target mode is left as an exercise for the reader)
        */

        SCR_CLR (SCR_TRG),
                0,
        SCR_LOAD_REG (HS_REG, 0xff),
                0,

        /*
        **      And try to select this target.
        */
        SCR_SEL_TBL_ATN ^ offsetof (struct dsb, select),
                PADDR (reselect),

        /*
        **      Now there are 4 possibilities:
        **
        **      (1) The ncr looses arbitration.
        **      This is ok, because it will try again,
        **      when the bus becomes idle.
        **      (But beware of the timeout function!)
        **
        **      (2) The ncr is reselected.
        **      Then the script processor takes the jump
        **      to the RESELECT label.
        **
        **      (3) The ncr completes the selection.
        **      Then it will execute the next statement.
        **
        **      (4) There is a selection timeout.
        **      Then the ncr should interrupt the host and stop.
        **      Unfortunately, it seems to continue execution
        **      of the script. But it will fail with an
        **      IID-interrupt on the next WHEN.
        */

        SCR_JUMPR ^ IFTRUE (WHEN (SCR_MSG_IN)),
                0,

        /*
        **      Send the IDENTIFY and SIMPLE_TAG messages
        **      (and the MSG_EXT_SDTR message)
        */
        SCR_MOVE_TBL ^ SCR_MSG_OUT,
                offsetof (struct dsb, smsg),
#ifdef undef /* XXX better fail than try to deal with this ... */
        SCR_JUMPR ^ IFTRUE (WHEN (SCR_MSG_OUT)),
                -16,
#endif
        SCR_CLR (SCR_ATN),
                0,
        SCR_COPY (1),
                RADDR (sfbr),
                NADDR (lastmsg),
        /*
        **      Selection complete.
        **      Next time use the next slot.
        */
        SCR_COPY (4),
                RADDR (scratcha),
                PADDR (startpos),
}/*-------------------------< PREPARE >----------------------*/,{
        /*
        **      The ncr doesn't have an indirect load
        **      or store command. So we have to
        **      copy part of the control block to a
        **      fixed place, where we can access it.
        **
        **      We patch the address part of a
        **      COPY command with the DSA-register.
        */
        SCR_COPY_F (4),
                RADDR (dsa),
                PADDR (loadpos),
        /*
        **      then we do the actual copy.
        */
        SCR_COPY (sizeof (struct head)),
        /*
        **      continued after the next label ...
        */

}/*-------------------------< LOADPOS >---------------------*/,{
                0,
                NADDR (header),
        /*
        **      Mark this nccb as not scheduled.
        */
        SCR_COPY (8),
                PADDR (idle),
                NADDR (header.launch),
        /*
        **      Set a time stamp for this selection
        */
        SCR_COPY (sizeof (ticks)),
                KVAR (KVAR_TICKS),
                NADDR (header.stamp.select),
        /*
        **      load the savep (saved pointer) into
        **      the TEMP register (actual pointer)
        */
        SCR_COPY (4),
                NADDR (header.savep),
                RADDR (temp),
        /*
        **      Initialize the status registers
        */
        SCR_COPY (4),
                NADDR (header.status),
                RADDR (scr0),

}/*-------------------------< PREPARE2 >---------------------*/,{
        /*
        **      Load the synchronous mode register
        */
        SCR_COPY (1),
                NADDR (sync_st),
                RADDR (sxfer),
        /*
        **      Load the wide mode and timing register
        */
        SCR_COPY (1),
                NADDR (wide_st),
                RADDR (scntl3),
        /*
        **      Initialize the msgout buffer with a NOOP message.
        */
        SCR_LOAD_REG (scratcha, MSG_NOOP),
                0,
        SCR_COPY (1),
                RADDR (scratcha),
                NADDR (msgout),
        SCR_COPY (1),
                RADDR (scratcha),
                NADDR (msgin),
        /*
        **      Message in phase ?
        */
        SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                PADDR (dispatch),
        /*
        **      Extended or reject message ?
        */
        SCR_FROM_REG (sbdl),
                0,
        SCR_JUMP ^ IFTRUE (DATA (MSG_EXTENDED)),
                PADDR (msg_in),
        SCR_JUMP ^ IFTRUE (DATA (MSG_MESSAGE_REJECT)),
                PADDRH (msg_reject),
        /*
        **      normal processing
        */
        SCR_JUMP,
                PADDR (dispatch),
}/*-------------------------< SETMSG >----------------------*/,{
        SCR_COPY (1),
                RADDR (scratcha),
                NADDR (msgout),
        SCR_SET (SCR_ATN),
                0,
}/*-------------------------< CLRACK >----------------------*/,{
        /*
        **      Terminate possible pending message phase.
        */
        SCR_CLR (SCR_ACK),
                0,

}/*-----------------------< DISPATCH >----------------------*/,{
        SCR_FROM_REG (HS_REG),
                0,
        SCR_INT ^ IFTRUE (DATA (HS_NEGOTIATE)),
                SIR_NEGO_FAILED,
        /*
        **      remove bogus output signals
        */
        SCR_REG_REG (socl, SCR_AND, CACK|CATN),
                0,
        SCR_RETURN ^ IFTRUE (WHEN (SCR_DATA_OUT)),
                0,
        SCR_RETURN ^ IFTRUE (IF (SCR_DATA_IN)),
                0,
        SCR_JUMP ^ IFTRUE (IF (SCR_MSG_OUT)),
                PADDR (msg_out),
        SCR_JUMP ^ IFTRUE (IF (SCR_MSG_IN)),
                PADDR (msg_in),
        SCR_JUMP ^ IFTRUE (IF (SCR_COMMAND)),
                PADDR (command),
        SCR_JUMP ^ IFTRUE (IF (SCR_STATUS)),
                PADDR (status),
        /*
        **      Discard one illegal phase byte, if required.
        */
        SCR_LOAD_REG (scratcha, XE_BAD_PHASE),
                0,
        SCR_COPY (1),
                RADDR (scratcha),
                NADDR (xerr_st),
        SCR_JUMPR ^ IFFALSE (IF (SCR_ILG_OUT)),
                8,
        SCR_MOVE_ABS (1) ^ SCR_ILG_OUT,
                NADDR (scratch),
        SCR_JUMPR ^ IFFALSE (IF (SCR_ILG_IN)),
                8,
        SCR_MOVE_ABS (1) ^ SCR_ILG_IN,
                NADDR (scratch),
        SCR_JUMP,
                PADDR (dispatch),

}/*-------------------------< NO_DATA >--------------------*/,{
        /*
        **      The target wants to tranfer too much data
        **      or in the wrong direction.
        **      Remember that in extended error.
        */
        SCR_LOAD_REG (scratcha, XE_EXTRA_DATA),
                0,
        SCR_COPY (1),
                RADDR (scratcha),
                NADDR (xerr_st),
        /*
        **      Discard one data byte, if required.
        */
        SCR_JUMPR ^ IFFALSE (WHEN (SCR_DATA_OUT)),
                8,
        SCR_MOVE_ABS (1) ^ SCR_DATA_OUT,
                NADDR (scratch),
        SCR_JUMPR ^ IFFALSE (IF (SCR_DATA_IN)),
                8,
        SCR_MOVE_ABS (1) ^ SCR_DATA_IN,
                NADDR (scratch),
        /*
        **      .. and repeat as required.
        */
        SCR_CALL,
                PADDR (dispatch),
        SCR_JUMP,
                PADDR (no_data),
}/*-------------------------< CHECKATN >--------------------*/,{
        /*
        **      If AAP (bit 1 of scntl0 register) is set
        **      and a parity error is detected,
        **      the script processor asserts ATN.
        **
        **      The target should switch to a MSG_OUT phase
        **      to get the message.
        */
        SCR_FROM_REG (socl),
                0,
        SCR_JUMP ^ IFFALSE (MASK (CATN, CATN)),
                PADDR (dispatch),
        /*
        **      count it
        */
        SCR_REG_REG (PS_REG, SCR_ADD, 1),
                0,
        /*
        **      Prepare a MSG_INITIATOR_DET_ERR message
        **      (initiator detected error).
        **      The target should retry the transfer.
        */
        SCR_LOAD_REG (scratcha, MSG_INITIATOR_DET_ERR),
                0,
        SCR_JUMP,
                PADDR (setmsg),

}/*-------------------------< COMMAND >--------------------*/,{
        /*
        **      If this is not a GETCC transfer ...
        */
        SCR_FROM_REG (SS_REG),
                0,
/*<<<*/ SCR_JUMPR ^ IFTRUE (DATA (SCSI_STATUS_CHECK_COND)),
                28,
        /*
        **      ... set a timestamp ...
        */
        SCR_COPY (sizeof (ticks)),
                KVAR (KVAR_TICKS),
                NADDR (header.stamp.command),
        /*
        **      ... and send the command
        */
        SCR_MOVE_TBL ^ SCR_COMMAND,
                offsetof (struct dsb, cmd),
        SCR_JUMP,
                PADDR (dispatch),
        /*
        **      Send the GETCC command
        */
/*>>>*/ SCR_MOVE_TBL ^ SCR_COMMAND,
                offsetof (struct dsb, scmd),
        SCR_JUMP,
                PADDR (dispatch),

}/*-------------------------< STATUS >--------------------*/,{
        /*
        **      set the timestamp.
        */
        SCR_COPY (sizeof (ticks)),
                KVAR (KVAR_TICKS),
                NADDR (header.stamp.status),
        /*
        **      If this is a GETCC transfer,
        */
        SCR_FROM_REG (SS_REG),
                0,
/*<<<*/ SCR_JUMPR ^ IFFALSE (DATA (SCSI_STATUS_CHECK_COND)),
                40,
        /*
        **      get the status
        */
        SCR_MOVE_ABS (1) ^ SCR_STATUS,
                NADDR (scratch),
        /*
        **      Save status to scsi_status.
        **      Mark as complete.
        **      And wait for disconnect.
        */
        SCR_TO_REG (SS_REG),
                0,
        SCR_REG_REG (SS_REG, SCR_OR, SCSI_STATUS_SENSE),
                0,
        SCR_LOAD_REG (HS_REG, HS_COMPLETE),
                0,
        SCR_JUMP,
                PADDR (checkatn),
        /*
        **      If it was no GETCC transfer,
        **      save the status to scsi_status.
        */
/*>>>*/ SCR_MOVE_ABS (1) ^ SCR_STATUS,
                NADDR (scratch),
        SCR_TO_REG (SS_REG),
                0,
        /*
        **      if it was no check condition ...
        */
        SCR_JUMP ^ IFTRUE (DATA (SCSI_STATUS_CHECK_COND)),
                PADDR (checkatn),
        /*
        **      ... mark as complete.
        */
        SCR_LOAD_REG (HS_REG, HS_COMPLETE),
                0,
        SCR_JUMP,
                PADDR (checkatn),

}/*-------------------------< MSG_IN >--------------------*/,{
        /*
        **      Get the first byte of the message
        **      and save it to SCRATCHA.
        **
        **      The script processor doesn't negate the
        **      ACK signal after this transfer.
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin[0]),
        /*
        **      Check for message parity error.
        */
        SCR_TO_REG (scratcha),
                0,
        SCR_FROM_REG (socl),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                PADDRH (msg_parity),
        SCR_FROM_REG (scratcha),
                0,
        /*
        **      Parity was ok, handle this message.
        */
        SCR_JUMP ^ IFTRUE (DATA (MSG_CMDCOMPLETE)),
                PADDR (complete),
        SCR_JUMP ^ IFTRUE (DATA (MSG_SAVEDATAPOINTER)),
                PADDR (save_dp),
        SCR_JUMP ^ IFTRUE (DATA (MSG_RESTOREPOINTERS)),
                PADDR (restore_dp),
        SCR_JUMP ^ IFTRUE (DATA (MSG_DISCONNECT)),
                PADDR (disconnect),
        SCR_JUMP ^ IFTRUE (DATA (MSG_EXTENDED)),
                PADDRH (msg_extended),
        SCR_JUMP ^ IFTRUE (DATA (MSG_NOOP)),
                PADDR (clrack),
        SCR_JUMP ^ IFTRUE (DATA (MSG_MESSAGE_REJECT)),
                PADDRH (msg_reject),
        SCR_JUMP ^ IFTRUE (DATA (MSG_IGN_WIDE_RESIDUE)),
                PADDRH (msg_ign_residue),
        /*
        **      Rest of the messages left as
        **      an exercise ...
        **
        **      Unimplemented messages:
        **      fall through to MSG_BAD.
        */
}/*-------------------------< MSG_BAD >------------------*/,{
        /*
        **      unimplemented message - reject it.
        */
        SCR_INT,
                SIR_REJECT_SENT,
        SCR_LOAD_REG (scratcha, MSG_MESSAGE_REJECT),
                0,
        SCR_JUMP,
                PADDR (setmsg),

}/*-------------------------< COMPLETE >-----------------*/,{
        /*
        **      Complete message.
        **
        **      If it's not the get condition code,
        **      copy TEMP register to LASTP in header.
        */
        SCR_FROM_REG (SS_REG),
                0,
/*<<<*/ SCR_JUMPR ^ IFTRUE (MASK (SCSI_STATUS_SENSE, SCSI_STATUS_SENSE)),
                12,
        SCR_COPY (4),
                RADDR (temp),
                NADDR (header.lastp),
/*>>>*/ /*
        **      When we terminate the cycle by clearing ACK,
        **      the target may disconnect immediately.
        **
        **      We don't want to be told of an
        **      "unexpected disconnect",
        **      so we disable this feature.
        */
        SCR_REG_REG (scntl2, SCR_AND, 0x7f),
                0,
        /*
        **      Terminate cycle ...
        */
        SCR_CLR (SCR_ACK|SCR_ATN),
                0,
        /*
        **      ... and wait for the disconnect.
        */
        SCR_WAIT_DISC,
                0,
}/*-------------------------< CLEANUP >-------------------*/,{
        /*
        **      dsa:    Pointer to nccb
        **            or xxxxxxFF (no nccb)
        **
        **      HS_REG:   Host-Status (<>0!)
        */
        SCR_FROM_REG (dsa),
                0,
        SCR_JUMP ^ IFTRUE (DATA (0xff)),
                PADDR (signal),
        /*
        **      dsa is valid.
        **      save the status registers
        */
        SCR_COPY (4),
                RADDR (scr0),
                NADDR (header.status),
        /*
        **      and copy back the header to the nccb.
        */
        SCR_COPY_F (4),
                RADDR (dsa),
                PADDR (cleanup0),
        SCR_COPY (sizeof (struct head)),
                NADDR (header),
}/*-------------------------< CLEANUP0 >--------------------*/,{
                0,

        /*
        **      If command resulted in "check condition"
        **      status and is not yet completed,
        **      try to get the condition code.
        */
        SCR_FROM_REG (HS_REG),
                0,
/*<<<*/ SCR_JUMPR ^ IFFALSE (MASK (0, HS_DONEMASK)),
                16,
        SCR_FROM_REG (SS_REG),
                0,
        SCR_JUMP ^ IFTRUE (DATA (SCSI_STATUS_CHECK_COND)),
                PADDRH(getcc2),
}/*-------------------------< SIGNAL >----------------------*/,{
        /*
        **      if status = queue full,
        **      reinsert in startqueue and stall queue.
        */
/*>>>*/ SCR_FROM_REG (SS_REG),
                0,
        SCR_INT ^ IFTRUE (DATA (SCSI_STATUS_QUEUE_FULL)),
                SIR_STALL_QUEUE,
        /*
        **      And make the DSA register invalid.
        */
        SCR_LOAD_REG (dsa, 0xff), /* invalid */
                0,
        /*
        **      if job completed ...
        */
        SCR_FROM_REG (HS_REG),
                0,
        /*
        **      ... signal completion to the host
        */
        SCR_INT_FLY ^ IFFALSE (MASK (0, HS_DONEMASK)),
                0,
        /*
        **      Auf zu neuen Schandtaten!
        */
        SCR_JUMP,
                PADDR(start),

}/*-------------------------< SAVE_DP >------------------*/,{
        /*
        **      SAVE_DP message:
        **      Copy TEMP register to SAVEP in header.
        */
        SCR_COPY (4),
                RADDR (temp),
                NADDR (header.savep),
        SCR_JUMP,
                PADDR (clrack),
}/*-------------------------< RESTORE_DP >---------------*/,{
        /*
        **      RESTORE_DP message:
        **      Copy SAVEP in header to TEMP register.
        */
        SCR_COPY (4),
                NADDR (header.savep),
                RADDR (temp),
        SCR_JUMP,
                PADDR (clrack),

}/*-------------------------< DISCONNECT >---------------*/,{
        /*
        **      If QUIRK_AUTOSAVE is set,
        **      do an "save pointer" operation.
        */
        SCR_FROM_REG (QU_REG),
                0,
/*<<<*/ SCR_JUMPR ^ IFFALSE (MASK (QUIRK_AUTOSAVE, QUIRK_AUTOSAVE)),
                12,
        /*
        **      like SAVE_DP message:
        **      Copy TEMP register to SAVEP in header.
        */
        SCR_COPY (4),
                RADDR (temp),
                NADDR (header.savep),
/*>>>*/ /*
        **      Check if temp==savep or temp==goalp:
        **      if not, log a missing save pointer message.
        **      In fact, it's a comparison mod 256.
        **
        **      Hmmm, I hadn't thought that I would be urged to
        **      write this kind of ugly self modifying code.
        **
        **      It's unbelievable, but the ncr53c8xx isn't able
        **      to subtract one register from another.
        */
        SCR_FROM_REG (temp),
                0,
        /*
        **      You are not expected to understand this ..
        **
        **      CAUTION: only little endian architectures supported! XXX
        */
        SCR_COPY_F (1),
                NADDR (header.savep),
                PADDR (disconnect0),
}/*-------------------------< DISCONNECT0 >--------------*/,{
/*<<<*/ SCR_JUMPR ^ IFTRUE (DATA (1)),
                20,
        /*
        **      neither this
        */
        SCR_COPY_F (1),
                NADDR (header.goalp),
                PADDR (disconnect1),
}/*-------------------------< DISCONNECT1 >--------------*/,{
        SCR_INT ^ IFFALSE (DATA (1)),
                SIR_MISSING_SAVE,
/*>>>*/

        /*
        **      DISCONNECTing  ...
        **
        **      disable the "unexpected disconnect" feature,
        **      and remove the ACK signal.
        */
        SCR_REG_REG (scntl2, SCR_AND, 0x7f),
                0,
        SCR_CLR (SCR_ACK|SCR_ATN),
                0,
        /*
        **      Wait for the disconnect.
        */
        SCR_WAIT_DISC,
                0,
        /*
        **      Profiling:
        **      Set a time stamp,
        **      and count the disconnects.
        */
        SCR_COPY (sizeof (ticks)),
                KVAR (KVAR_TICKS),
                NADDR (header.stamp.disconnect),
        SCR_COPY (4),
                NADDR (disc_phys),
                RADDR (temp),
        SCR_REG_REG (temp, SCR_ADD, 0x01),
                0,
        SCR_COPY (4),
                RADDR (temp),
                NADDR (disc_phys),
        /*
        **      Status is: DISCONNECTED.
        */
        SCR_LOAD_REG (HS_REG, HS_DISCONNECT),
                0,
        SCR_JUMP,
                PADDR (cleanup),

}/*-------------------------< MSG_OUT >-------------------*/,{
        /*
        **      The target requests a message.
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_OUT,
                NADDR (msgout),
        SCR_COPY (1),
                RADDR (sfbr),
                NADDR (lastmsg),
        /*
        **      If it was no ABORT message ...
        */
        SCR_JUMP ^ IFTRUE (DATA (MSG_ABORT)),
                PADDRH (msg_out_abort),
        /*
        **      ... wait for the next phase
        **      if it's a message out, send it again, ...
        */
        SCR_JUMP ^ IFTRUE (WHEN (SCR_MSG_OUT)),
                PADDR (msg_out),
}/*-------------------------< MSG_OUT_DONE >--------------*/,{
        /*
        **      ... else clear the message ...
        */
        SCR_LOAD_REG (scratcha, MSG_NOOP),
                0,
        SCR_COPY (4),
                RADDR (scratcha),
                NADDR (msgout),
        /*
        **      ... and process the next phase
        */
        SCR_JUMP,
                PADDR (dispatch),

}/*------------------------< BADGETCC >---------------------*/,{
        /*
        **      If SIGP was set, clear it and try again.
        */
        SCR_FROM_REG (ctest2),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CSIGP,CSIGP)),
                PADDRH (getcc2),
        SCR_INT,
                SIR_SENSE_FAILED,
}/*-------------------------< RESELECT >--------------------*/,{
        /*
        **      This NOP will be patched with LED OFF
        **      SCR_REG_REG (gpreg, SCR_OR, 0x01)
        */
        SCR_NO_OP,
                0,

        /*
        **      make the DSA invalid.
        */
        SCR_LOAD_REG (dsa, 0xff),
                0,
        SCR_CLR (SCR_TRG),
                0,
        /*
        **      Sleep waiting for a reselection.
        **      If SIGP is set, special treatment.
        **
        **      Zu allem bereit ..
        */
        SCR_WAIT_RESEL,
                PADDR(reselect2),
}/*-------------------------< RESELECT1 >--------------------*/,{
        /*
        **      This NOP will be patched with LED ON
        **      SCR_REG_REG (gpreg, SCR_AND, 0xfe)
        */
        SCR_NO_OP,
                0,
        /*
        **      ... zu nichts zu gebrauchen ?
        **
        **      load the target id into the SFBR
        **      and jump to the control block.
        **
        **      Look at the declarations of
        **      - struct ncb
        **      - struct tcb
        **      - struct lcb
        **      - struct nccb
        **      to understand what's going on.
        */
        SCR_REG_SFBR (ssid, SCR_AND, 0x8F),
                0,
        SCR_TO_REG (sdid),
                0,
        SCR_JUMP,
                NADDR (jump_tcb),
}/*-------------------------< RESELECT2 >-------------------*/,{
        /*
        **      This NOP will be patched with LED ON
        **      SCR_REG_REG (gpreg, SCR_AND, 0xfe)
        */
        SCR_NO_OP,
                0,
        /*
        **      If it's not connected :(
        **      -> interrupted by SIGP bit.
        **      Jump to start.
        */
        SCR_FROM_REG (ctest2),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CSIGP,CSIGP)),
                PADDR (start),
        SCR_JUMP,
                PADDR (reselect),

}/*-------------------------< RESEL_TMP >-------------------*/,{
        /*
        **      The return address in TEMP
        **      is in fact the data structure address,
        **      so copy it to the DSA register.
        */
        SCR_COPY (4),
                RADDR (temp),
                RADDR (dsa),
        SCR_JUMP,
                PADDR (prepare),

}/*-------------------------< RESEL_LUN >-------------------*/,{
        /*
        **      come back to this point
        **      to get an IDENTIFY message
        **      Wait for a msg_in phase.
        */
/*<<<*/ SCR_JUMPR ^ IFFALSE (WHEN (SCR_MSG_IN)),
                48,
        /*
        **      message phase
        **      It's not a sony, it's a trick:
        **      read the data without acknowledging it.
        */
        SCR_FROM_REG (sbdl),
                0,
/*<<<*/ SCR_JUMPR ^ IFFALSE (MASK (MSG_IDENTIFYFLAG, 0x98)),
                32,
        /*
        **      It WAS an Identify message.
        **      get it and ack it!
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin),
        SCR_CLR (SCR_ACK),
                0,
        /*
        **      Mask out the lun.
        */
        SCR_REG_REG (sfbr, SCR_AND, 0x07),
                0,
        SCR_RETURN,
                0,
        /*
        **      No message phase or no IDENTIFY message:
        **      return 0.
        */
/*>>>*/ SCR_LOAD_SFBR (0),
                0,
        SCR_RETURN,
                0,

}/*-------------------------< RESEL_TAG >-------------------*/,{
        /*
        **      come back to this point
        **      to get a SIMPLE_TAG message
        **      Wait for a MSG_IN phase.
        */
/*<<<*/ SCR_JUMPR ^ IFFALSE (WHEN (SCR_MSG_IN)),
                64,
        /*
        **      message phase
        **      It's a trick - read the data
        **      without acknowledging it.
        */
        SCR_FROM_REG (sbdl),
                0,
/*<<<*/ SCR_JUMPR ^ IFFALSE (DATA (MSG_SIMPLE_Q_TAG)),
                48,
        /*
        **      It WAS a SIMPLE_TAG message.
        **      get it and ack it!
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin),
        SCR_CLR (SCR_ACK),
                0,
        /*
        **      Wait for the second byte (the tag)
        */
/*<<<*/ SCR_JUMPR ^ IFFALSE (WHEN (SCR_MSG_IN)),
                24,
        /*
        **      Get it and ack it!
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin),
        SCR_CLR (SCR_ACK|SCR_CARRY),
                0,
        SCR_RETURN,
                0,
        /*
        **      No message phase or no SIMPLE_TAG message
        **      or no second byte: return 0.
        */
/*>>>*/ SCR_LOAD_SFBR (0),
                0,
        SCR_SET (SCR_CARRY),
                0,
        SCR_RETURN,
                0,

}/*-------------------------< DATA_IN >--------------------*/,{
/*
**      Because the size depends on the
**      #define MAX_SCATTER parameter,
**      it is filled in at runtime.
**
**      SCR_JUMP ^ IFFALSE (WHEN (SCR_DATA_IN)),
**              PADDR (no_data),
**      SCR_COPY (sizeof (ticks)),
**              KVAR (KVAR_TICKS),
**              NADDR (header.stamp.data),
**      SCR_MOVE_TBL ^ SCR_DATA_IN,
**              offsetof (struct dsb, data[ 0]),
**
**  ##===========< i=1; i<MAX_SCATTER >=========
**  ||  SCR_CALL ^ IFFALSE (WHEN (SCR_DATA_IN)),
**  ||          PADDR (checkatn),
**  ||  SCR_MOVE_TBL ^ SCR_DATA_IN,
**  ||          offsetof (struct dsb, data[ i]),
**  ##==========================================
**
**      SCR_CALL,
**              PADDR (checkatn),
**      SCR_JUMP,
**              PADDR (no_data),
*/
0
}/*-------------------------< DATA_OUT >-------------------*/,{
/*
**      Because the size depends on the
**      #define MAX_SCATTER parameter,
**      it is filled in at runtime.
**
**      SCR_JUMP ^ IFFALSE (WHEN (SCR_DATA_OUT)),
**              PADDR (no_data),
**      SCR_COPY (sizeof (ticks)),
**              KVAR (KVAR_TICKS),
**              NADDR (header.stamp.data),
**      SCR_MOVE_TBL ^ SCR_DATA_OUT,
**              offsetof (struct dsb, data[ 0]),
**
**  ##===========< i=1; i<MAX_SCATTER >=========
**  ||  SCR_CALL ^ IFFALSE (WHEN (SCR_DATA_OUT)),
**  ||          PADDR (dispatch),
**  ||  SCR_MOVE_TBL ^ SCR_DATA_OUT,
**  ||          offsetof (struct dsb, data[ i]),
**  ##==========================================
**
**      SCR_CALL,
**              PADDR (dispatch),
**      SCR_JUMP,
**              PADDR (no_data),
**
**---------------------------------------------------------
*/
(u_long)0

}/*--------------------------------------------------------*/
};


static  struct scripth scripth0 = {
/*-------------------------< TRYLOOP >---------------------*/{
/*
**      Load an entry of the start queue into dsa
**      and try to start it by jumping to TRYSEL.
**
**      Because the size depends on the
**      #define MAX_START parameter, it is filled
**      in at runtime.
**
**-----------------------------------------------------------
**
**  ##===========< I=0; i<MAX_START >===========
**  ||  SCR_COPY (4),
**  ||          NADDR (squeue[i]),
**  ||          RADDR (dsa),
**  ||  SCR_CALL,
**  ||          PADDR (trysel),
**  ##==========================================
**
**      SCR_JUMP,
**              PADDRH(tryloop),
**
**-----------------------------------------------------------
*/
0
}/*-------------------------< MSG_PARITY >---------------*/,{
        /*
        **      count it
        */
        SCR_REG_REG (PS_REG, SCR_ADD, 0x01),
                0,
        /*
        **      send a "message parity error" message.
        */
        SCR_LOAD_REG (scratcha, MSG_PARITY_ERROR),
                0,
        SCR_JUMP,
                PADDR (setmsg),
}/*-------------------------< MSG_MESSAGE_REJECT >---------------*/,{
        /*
        **      If a negotiation was in progress,
        **      negotiation failed.
        */
        SCR_FROM_REG (HS_REG),
                0,
        SCR_INT ^ IFTRUE (DATA (HS_NEGOTIATE)),
                SIR_NEGO_FAILED,
        /*
        **      else make host log this message
        */
        SCR_INT ^ IFFALSE (DATA (HS_NEGOTIATE)),
                SIR_REJECT_RECEIVED,
        SCR_JUMP,
                PADDR (clrack),

}/*-------------------------< MSG_IGN_RESIDUE >----------*/,{
        /*
        **      Terminate cycle
        */
        SCR_CLR (SCR_ACK),
                0,
        SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                PADDR (dispatch),
        /*
        **      get residue size.
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin[1]),
        /*
        **      Check for message parity error.
        */
        SCR_TO_REG (scratcha),
                0,
        SCR_FROM_REG (socl),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                PADDRH (msg_parity),
        SCR_FROM_REG (scratcha),
                0,
        /*
        **      Size is 0 .. ignore message.
        */
        SCR_JUMP ^ IFTRUE (DATA (0)),
                PADDR (clrack),
        /*
        **      Size is not 1 .. have to interrupt.
        */
/*<<<*/ SCR_JUMPR ^ IFFALSE (DATA (1)),
                40,
        /*
        **      Check for residue byte in swide register
        */
        SCR_FROM_REG (scntl2),
                0,
/*<<<*/ SCR_JUMPR ^ IFFALSE (MASK (WSR, WSR)),
                16,
        /*
        **      There IS data in the swide register.
        **      Discard it.
        */
        SCR_REG_REG (scntl2, SCR_OR, WSR),
                0,
        SCR_JUMP,
                PADDR (clrack),
        /*
        **      Load again the size to the sfbr register.
        */
/*>>>*/ SCR_FROM_REG (scratcha),
                0,
/*>>>*/ SCR_INT,
                SIR_IGN_RESIDUE,
        SCR_JUMP,
                PADDR (clrack),

}/*-------------------------< MSG_EXTENDED >-------------*/,{
        /*
        **      Terminate cycle
        */
        SCR_CLR (SCR_ACK),
                0,
        SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                PADDR (dispatch),
        /*
        **      get length.
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin[1]),
        /*
        **      Check for message parity error.
        */
        SCR_TO_REG (scratcha),
                0,
        SCR_FROM_REG (socl),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                PADDRH (msg_parity),
        SCR_FROM_REG (scratcha),
                0,
        /*
        */
        SCR_JUMP ^ IFTRUE (DATA (3)),
                PADDRH (msg_ext_3),
        SCR_JUMP ^ IFFALSE (DATA (2)),
                PADDR (msg_bad),
}/*-------------------------< MSG_EXT_2 >----------------*/,{
        SCR_CLR (SCR_ACK),
                0,
        SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                PADDR (dispatch),
        /*
        **      get extended message code.
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin[2]),
        /*
        **      Check for message parity error.
        */
        SCR_TO_REG (scratcha),
                0,
        SCR_FROM_REG (socl),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                PADDRH (msg_parity),
        SCR_FROM_REG (scratcha),
                0,
        SCR_JUMP ^ IFTRUE (DATA (MSG_EXT_WDTR)),
                PADDRH (msg_wdtr),
        /*
        **      unknown extended message
        */
        SCR_JUMP,
                PADDR (msg_bad)
}/*-------------------------< MSG_WDTR >-----------------*/,{
        SCR_CLR (SCR_ACK),
                0,
        SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                PADDR (dispatch),
        /*
        **      get data bus width
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin[3]),
        SCR_FROM_REG (socl),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                PADDRH (msg_parity),
        /*
        **      let the host do the real work.
        */
        SCR_INT,
                SIR_NEGO_WIDE,
        /*
        **      let the target fetch our answer.
        */
        SCR_SET (SCR_ATN),
                0,
        SCR_CLR (SCR_ACK),
                0,

        SCR_INT ^ IFFALSE (WHEN (SCR_MSG_OUT)),
                SIR_NEGO_PROTO,
        /*
        **      Send the MSG_EXT_WDTR
        */
        SCR_MOVE_ABS (4) ^ SCR_MSG_OUT,
                NADDR (msgout),
        SCR_CLR (SCR_ATN),
                0,
        SCR_COPY (1),
                RADDR (sfbr),
                NADDR (lastmsg),
        SCR_JUMP,
                PADDR (msg_out_done),

}/*-------------------------< MSG_EXT_3 >----------------*/,{
        SCR_CLR (SCR_ACK),
                0,
        SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                PADDR (dispatch),
        /*
        **      get extended message code.
        */
        SCR_MOVE_ABS (1) ^ SCR_MSG_IN,
                NADDR (msgin[2]),
        /*
        **      Check for message parity error.
        */
        SCR_TO_REG (scratcha),
                0,
        SCR_FROM_REG (socl),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                PADDRH (msg_parity),
        SCR_FROM_REG (scratcha),
                0,
        SCR_JUMP ^ IFTRUE (DATA (MSG_EXT_SDTR)),
                PADDRH (msg_sdtr),
        /*
        **      unknown extended message
        */
        SCR_JUMP,
                PADDR (msg_bad)

}/*-------------------------< MSG_SDTR >-----------------*/,{
        SCR_CLR (SCR_ACK),
                0,
        SCR_JUMP ^ IFFALSE (WHEN (SCR_MSG_IN)),
                PADDR (dispatch),
        /*
        **      get period and offset
        */
        SCR_MOVE_ABS (2) ^ SCR_MSG_IN,
                NADDR (msgin[3]),
        SCR_FROM_REG (socl),
                0,
        SCR_JUMP ^ IFTRUE (MASK (CATN, CATN)),
                PADDRH (msg_parity),
        /*
        **      let the host do the real work.
        */
        SCR_INT,
                SIR_NEGO_SYNC,
        /*
        **      let the target fetch our answer.
        */
        SCR_SET (SCR_ATN),
                0,
        SCR_CLR (SCR_ACK),
                0,

        SCR_INT ^ IFFALSE (WHEN (SCR_MSG_OUT)),
                SIR_NEGO_PROTO,
        /*
        **      Send the MSG_EXT_SDTR
        */
        SCR_MOVE_ABS (5) ^ SCR_MSG_OUT,
                NADDR (msgout),
        SCR_CLR (SCR_ATN),
                0,
        SCR_COPY (1),
                RADDR (sfbr),
                NADDR (lastmsg),
        SCR_JUMP,
                PADDR (msg_out_done),

}/*-------------------------< MSG_OUT_ABORT >-------------*/,{
        /*
        **      After ABORT message,
        **
        **      expect an immediate disconnect, ...
        */
        SCR_REG_REG (scntl2, SCR_AND, 0x7f),
                0,
        SCR_CLR (SCR_ACK|SCR_ATN),
                0,
        SCR_WAIT_DISC,
                0,
        /*
        **      ... and set the status to "ABORTED"
        */
        SCR_LOAD_REG (HS_REG, HS_ABORTED),
                0,
        SCR_JUMP,
                PADDR (cleanup),

}/*-------------------------< GETCC >-----------------------*/,{
        /*
        **      The ncr doesn't have an indirect load
        **      or store command. So we have to
        **      copy part of the control block to a
        **      fixed place, where we can modify it.
        **
        **      We patch the address part of a COPY command
        **      with the address of the dsa register ...
        */
        SCR_COPY_F (4),
                RADDR (dsa),
                PADDRH (getcc1),
        /*
        **      ... then we do the actual copy.
        */
        SCR_COPY (sizeof (struct head)),
}/*-------------------------< GETCC1 >----------------------*/,{
                0,
                NADDR (header),
        /*
        **      Initialize the status registers
        */
        SCR_COPY (4),
                NADDR (header.status),
                RADDR (scr0),
}/*-------------------------< GETCC2 >----------------------*/,{
        /*
        **      Get the condition code from a target.
        **
        **      DSA points to a data structure.
        **      Set TEMP to the script location
        **      that receives the condition code.
        **
        **      Because there is no script command
        **      to load a longword into a register,
        **      we use a CALL command.
        */
/*<<<*/ SCR_CALLR,
                24,
        /*
        **      Get the condition code.
        */
        SCR_MOVE_TBL ^ SCR_DATA_IN,
                offsetof (struct dsb, sense),
        /*
        **      No data phase may follow!
        */
        SCR_CALL,
                PADDR (checkatn),
        SCR_JUMP,
                PADDR (no_data),
/*>>>*/

        /*
        **      The CALL jumps to this point.
        **      Prepare for a RESTORE_POINTER message.
        **      Save the TEMP register into the saved pointer.
        */
        SCR_COPY (4),
                RADDR (temp),
                NADDR (header.savep),
        /*
        **      Load scratcha, because in case of a selection timeout,
        **      the host will expect a new value for startpos in
        **      the scratcha register.
        */
        SCR_COPY (4),
                PADDR (startpos),
                RADDR (scratcha),
#ifdef NCR_GETCC_WITHMSG
        /*
        **      If QUIRK_NOMSG is set, select without ATN.
        **      and don't send a message.
        */
        SCR_FROM_REG (QU_REG),
                0,
        SCR_JUMP ^ IFTRUE (MASK (QUIRK_NOMSG, QUIRK_NOMSG)),
                PADDRH(getcc3),
        /*
        **      Then try to connect to the target.
        **      If we are reselected, special treatment
        **      of the current job is required before
        **      accepting the reselection.
        */
        SCR_SEL_TBL_ATN ^ offsetof (struct dsb, select),
                PADDR(badgetcc),
        /*
        **      Send the IDENTIFY message.
        **      In case of short transfer, remove ATN.
        */
        SCR_MOVE_TBL ^ SCR_MSG_OUT,
                offsetof (struct dsb, smsg2),
        SCR_CLR (SCR_ATN),
                0,
        /*
        **      save the first byte of the message.
        */
        SCR_COPY (1),
                RADDR (sfbr),
                NADDR (lastmsg),
        SCR_JUMP,
                PADDR (prepare2),

#endif
}/*-------------------------< GETCC3 >----------------------*/,{
        /*
        **      Try to connect to the target.
        **      If we are reselected, special treatment
        **      of the current job is required before
        **      accepting the reselection.
        **
        **      Silly target won't accept a message.
        **      Select without ATN.
        */
        SCR_SEL_TBL ^ offsetof (struct dsb, select),
                PADDR(badgetcc),
        /*
        **      Force error if selection timeout
        */
        SCR_JUMPR ^ IFTRUE (WHEN (SCR_MSG_IN)),
                0,
        /*
        **      don't negotiate.
        */
        SCR_JUMP,
                PADDR (prepare2),
}/*-------------------------< ABORTTAG >-------------------*/,{
        /*
        **      Abort a bad reselection.
        **      Set the message to ABORT vs. ABORT_TAG
        */
        SCR_LOAD_REG (scratcha, MSG_ABORT_TAG),
                0,
        SCR_JUMPR ^ IFFALSE (CARRYSET),
                8,
}/*-------------------------< ABORT >----------------------*/,{
        SCR_LOAD_REG (scratcha, MSG_ABORT),
                0,
        SCR_COPY (1),
                RADDR (scratcha),
                NADDR (msgout),
        SCR_SET (SCR_ATN),
                0,
        SCR_CLR (SCR_ACK),
                0,
        /*
        **      and send it.
        **      we expect an immediate disconnect
        */
        SCR_REG_REG (scntl2, SCR_AND, 0x7f),
                0,
        SCR_MOVE_ABS (1) ^ SCR_MSG_OUT,
                NADDR (msgout),
        SCR_COPY (1),
                RADDR (sfbr),
                NADDR (lastmsg),
        SCR_CLR (SCR_ACK|SCR_ATN),
                0,
        SCR_WAIT_DISC,
                0,
        SCR_JUMP,
                PADDR (start),
}/*-------------------------< SNOOPTEST >-------------------*/,{
        /*
        **      Read the variable.
        */
        SCR_COPY (4),
                KVAR (KVAR_NCR_CACHE),
                RADDR (scratcha),
        /*
        **      Write the variable.
        */
        SCR_COPY (4),
                RADDR (temp),
                KVAR (KVAR_NCR_CACHE),
        /*
        **      Read back the variable.
        */
        SCR_COPY (4),
                KVAR (KVAR_NCR_CACHE),
                RADDR (temp),
}/*-------------------------< SNOOPEND >-------------------*/,{
        /*
        **      And stop.
        */
        SCR_INT,
                99,
}/*--------------------------------------------------------*/
};


/*==========================================================
**
**
**      Fill in #define dependent parts of the script
**
**
**==========================================================
*/

static void
ncr_script_fill (struct script * scr, struct scripth * scrh)
{
        int     i;
        ncrcmd  *p;

        p = scrh->tryloop;
        for (i=0; i<MAX_START; i++) {
                *p++ =SCR_COPY (4);
                *p++ =NADDR (squeue[i]);
                *p++ =RADDR (dsa);
                *p++ =SCR_CALL;
                *p++ =PADDR (trysel);
        }
        *p++ =SCR_JUMP;
        *p++ =PADDRH(tryloop);

        assert ((char *)p == (char *)&scrh->tryloop + sizeof (scrh->tryloop));

        p = scr->data_in;

        *p++ =SCR_JUMP ^ IFFALSE (WHEN (SCR_DATA_IN));
        *p++ =PADDR (no_data);
        *p++ =SCR_COPY (sizeof (ticks));
        *p++ =(ncrcmd) KVAR (KVAR_TICKS);
        *p++ =NADDR (header.stamp.data);
        *p++ =SCR_MOVE_TBL ^ SCR_DATA_IN;
        *p++ =offsetof (struct dsb, data[ 0]);

        for (i=1; i<MAX_SCATTER; i++) {
                *p++ =SCR_CALL ^ IFFALSE (WHEN (SCR_DATA_IN));
                *p++ =PADDR (checkatn);
                *p++ =SCR_MOVE_TBL ^ SCR_DATA_IN;
                *p++ =offsetof (struct dsb, data[i]);
        }

        *p++ =SCR_CALL;
        *p++ =PADDR (checkatn);
        *p++ =SCR_JUMP;
        *p++ =PADDR (no_data);

        assert ((char *)p == (char *)&scr->data_in + sizeof (scr->data_in));

        p = scr->data_out;

        *p++ =SCR_JUMP ^ IFFALSE (WHEN (SCR_DATA_OUT));
        *p++ =PADDR (no_data);
        *p++ =SCR_COPY (sizeof (ticks));
        *p++ =(ncrcmd) KVAR (KVAR_TICKS);
        *p++ =NADDR (header.stamp.data);
        *p++ =SCR_MOVE_TBL ^ SCR_DATA_OUT;
        *p++ =offsetof (struct dsb, data[ 0]);

        for (i=1; i<MAX_SCATTER; i++) {
                *p++ =SCR_CALL ^ IFFALSE (WHEN (SCR_DATA_OUT));
                *p++ =PADDR (dispatch);
                *p++ =SCR_MOVE_TBL ^ SCR_DATA_OUT;
                *p++ =offsetof (struct dsb, data[i]);
        }

        *p++ =SCR_CALL;
        *p++ =PADDR (dispatch);
        *p++ =SCR_JUMP;
        *p++ =PADDR (no_data);

        assert ((char *)p == (char *)&scr->data_out + sizeof (scr->data_out));
}

/*==========================================================
**
**
**      Copy and rebind a script.
**
**
**==========================================================
*/

static void ncr_script_copy_and_bind (ncb_p np, ncrcmd *src, ncrcmd *dst, int len)
{
        ncrcmd  opcode, new, old, tmp1, tmp2;
        ncrcmd  *start, *end;
        int relocs, offset;

        start = src;
        end = src + len/4;
        offset = 0;

        while (src < end) {

                opcode = *src++;
                WRITESCRIPT_OFF(dst, offset, opcode);
                offset += 4;

                /*
                **      If we forget to change the length
                **      in struct script, a field will be
                **      padded with 0. This is an illegal
                **      command.
                */

                if (opcode == 0) {
                        kprintf ("%s: ERROR0 IN SCRIPT at %d.\n",
                                ncr_name(np), (int) (src-start-1));
                        DELAY (1000000);
                }

                if (DEBUG_FLAGS & DEBUG_SCRIPT)
                        kprintf ("%p:  <%x>\n",
                                (src-1), (unsigned)opcode);

                /*
                **      We don't have to decode ALL commands
                */
                switch (opcode >> 28) {

                case 0xc:
                        /*
                        **      COPY has TWO arguments.
                        */
                        relocs = 2;
                        tmp1 = src[0];
                        if ((tmp1 & RELOC_MASK) == RELOC_KVAR)
                                tmp1 = 0;
                        tmp2 = src[1];
                        if ((tmp2 & RELOC_MASK) == RELOC_KVAR)
                                tmp2 = 0;
                        if ((tmp1 ^ tmp2) & 3) {
                                kprintf ("%s: ERROR1 IN SCRIPT at %d.\n",
                                        ncr_name(np), (int) (src-start-1));
                                DELAY (1000000);
                        }
                        /*
                        **      If PREFETCH feature not enabled, remove 
                        **      the NO FLUSH bit if present.
                        */
                        if ((opcode & SCR_NO_FLUSH) && !(np->features&FE_PFEN))
                                WRITESCRIPT_OFF(dst, offset - 4,
                                    (opcode & ~SCR_NO_FLUSH));
                        break;

                case 0x0:
                        /*
                        **      MOVE (absolute address)
                        */
                        relocs = 1;
                        break;

                case 0x8:
                        /*
                        **      JUMP / CALL
                        **      dont't relocate if relative :-)
                        */
                        if (opcode & 0x00800000)
                                relocs = 0;
                        else
                                relocs = 1;
                        break;

                case 0x4:
                case 0x5:
                case 0x6:
                case 0x7:
                        relocs = 1;
                        break;

                default:
                        relocs = 0;
                        break;
                }

                if (relocs) {
                        while (relocs--) {
                                old = *src++;

                                switch (old & RELOC_MASK) {
                                case RELOC_REGISTER:
                                        new = (old & ~RELOC_MASK) + rman_get_start(np->reg_res);
                                        break;
                                case RELOC_LABEL:
                                        new = (old & ~RELOC_MASK) + np->p_script;
                                        break;
                                case RELOC_LABELH:
                                        new = (old & ~RELOC_MASK) + np->p_scripth;
                                        break;
                                case RELOC_SOFTC:
                                        new = (old & ~RELOC_MASK) + vtophys(np);
                                        break;
                                case RELOC_KVAR:
                                        if (((old & ~RELOC_MASK) <
                                             SCRIPT_KVAR_FIRST) ||
                                            ((old & ~RELOC_MASK) >
                                             SCRIPT_KVAR_LAST))
                                                panic("ncr KVAR out of range");
                                        new = vtophys(script_kvars[old &
                                            ~RELOC_MASK]);
                                        break;
                                case 0:
                                        /* Don't relocate a 0 address. */
                                        if (old == 0) {
                                                new = old;
                                                break;
                                        }
                                        /* fall through */
                                default:
                                        panic("ncr_script_copy_and_bind: weird relocation %x @ %d", old, (int)(src - start));
                                        break;
                                }

                                WRITESCRIPT_OFF(dst, offset, new);
                                offset += 4;
                        }
                } else {
                        WRITESCRIPT_OFF(dst, offset, *src++);
                        offset += 4;
                }

        }
}

/*==========================================================
**
**
**      Auto configuration.
**
**
**==========================================================
*/

#if 0
/*----------------------------------------------------------
**
**      Reduce the transfer length to the max value
**      we can transfer safely.
**
**      Reading a block greater then MAX_SIZE from the
**      raw (character) device exercises a memory leak
**      in the vm subsystem. This is common to ALL devices.
**      We have submitted a description of this bug to
**      <FreeBSD-bugs@freefall.cdrom.com>.
**      It should be fixed in the current release.
**
**----------------------------------------------------------
*/

void ncr_min_phys (struct  buf *bp)
{
        if ((unsigned long)bp->b_bcount > MAX_SIZE) bp->b_bcount = MAX_SIZE;
}

#endif

#if 0
/*----------------------------------------------------------
**
**      Maximal number of outstanding requests per target.
**
**----------------------------------------------------------
*/

u_int32_t ncr_info (int unit)
{
        return (1);   /* may be changed later */
}

#endif

/*----------------------------------------------------------
**
**      NCR chip devices table and chip look up function.
**      Features bit are defined in ncrreg.h. Is it the 
**      right place?
**
**----------------------------------------------------------
*/
typedef struct {
        unsigned long   device_id;
        unsigned short  minrevid;
        char           *name;
        unsigned char   maxburst;
        unsigned char   maxoffs;
        unsigned char   clock_divn;
        unsigned int    features;
} ncr_chip;

static ncr_chip ncr_chip_table[] = {
 {NCR_810_ID, 0x00,     "ncr 53c810 fast10 scsi",               4,  8, 4,
 FE_ERL}
 ,
 {NCR_810_ID, 0x10,     "ncr 53c810a fast10 scsi",              4,  8, 4,
 FE_ERL|FE_LDSTR|FE_PFEN|FE_BOF}
 ,
 {NCR_815_ID, 0x00,     "ncr 53c815 fast10 scsi",               4,  8, 4,
 FE_ERL|FE_BOF}
 ,
 {NCR_820_ID, 0x00,     "ncr 53c820 fast10 wide scsi",          4,  8, 4,
 FE_WIDE|FE_ERL}
 ,
 {NCR_825_ID, 0x00,     "ncr 53c825 fast10 wide scsi",          4,  8, 4,
 FE_WIDE|FE_ERL|FE_BOF}
 ,
 {NCR_825_ID, 0x10,     "ncr 53c825a fast10 wide scsi",         7,  8, 4,
 FE_WIDE|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
 ,
 {NCR_860_ID, 0x00,     "ncr 53c860 fast20 scsi",               4,  8, 5,
 FE_ULTRA|FE_CLK80|FE_CACHE_SET|FE_LDSTR|FE_PFEN}
 ,
 {NCR_875_ID, 0x00,     "ncr 53c875 fast20 wide scsi",          7, 16, 5,
 FE_WIDE|FE_ULTRA|FE_CLK80|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
 ,
 {NCR_875_ID, 0x02,     "ncr 53c875 fast20 wide scsi",          7, 16, 5,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
 ,
 {NCR_875_ID2, 0x00,    "ncr 53c875j fast20 wide scsi",         7, 16, 5,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
 ,
 {NCR_885_ID, 0x00,     "ncr 53c885 fast20 wide scsi",          7, 16, 5,
 FE_WIDE|FE_ULTRA|FE_DBLR|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
 ,
 {NCR_895_ID, 0x00,     "ncr 53c895 fast40 wide scsi",          7, 31, 7,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
 ,
 {NCR_896_ID, 0x00,     "ncr 53c896 fast40 wide scsi",          7, 31, 7,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
 ,
 {NCR_895A_ID, 0x00,    "ncr 53c895a fast40 wide scsi",         7, 31, 7,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
 ,
 {NCR_1510D_ID, 0x00,   "ncr 53c1510d fast40 wide scsi",        7, 31, 7,
 FE_WIDE|FE_ULTRA2|FE_QUAD|FE_CACHE_SET|FE_DFS|FE_LDSTR|FE_PFEN|FE_RAM}
};

static int ncr_chip_lookup(u_long device_id, u_char revision_id)
{
        int i, found;
        
        found = -1;
        for (i = 0; i < NELEM(ncr_chip_table); i++) {
                if (device_id   == ncr_chip_table[i].device_id &&
                    ncr_chip_table[i].minrevid <= revision_id) {
                        if (found < 0 || 
                            ncr_chip_table[found].minrevid 
                              < ncr_chip_table[i].minrevid) {
                                found = i;
                        }
                }
        }
        return found;
}

/*----------------------------------------------------------
**
**      Probe the hostadapter.
**
**----------------------------------------------------------
*/



static  int ncr_probe (device_t dev)
{
        int i;

        i = ncr_chip_lookup(pci_get_devid(dev), pci_get_revid(dev));
        if (i >= 0) {
                device_set_desc(dev, ncr_chip_table[i].name);
                return (-1000); /* Allows to use both ncr and sym */
        }

        return (ENXIO);
}



/*==========================================================
**
**      NCR chip clock divisor table.
**      Divisors are multiplied by 10,000,000 in order to make 
**      calculations more simple.
**
**==========================================================
*/

#define _5M 5000000
static u_long div_10M[] =
        {2*_5M, 3*_5M, 4*_5M, 6*_5M, 8*_5M, 12*_5M, 16*_5M};

/*===============================================================
**
**      NCR chips allow burst lengths of 2, 4, 8, 16, 32, 64, 128 
**      transfers. 32,64,128 are only supported by 875 and 895 chips.
**      We use log base 2 (burst length) as internal code, with 
**      value 0 meaning "burst disabled".
**
**===============================================================
*/

/*
 *      Burst length from burst code.
 */
#define burst_length(bc) (!(bc))? 0 : 1 << (bc)

/*
 *      Burst code from io register bits.
 */
#define burst_code(dmode, ctest4, ctest5) \
        (ctest4) & 0x80? 0 : (((dmode) & 0xc0) >> 6) + ((ctest5) & 0x04) + 1

/*
 *      Set initial io register bits from burst code.
 */
static void
ncr_init_burst(ncb_p np, u_char bc)
{
        np->rv_ctest4   &= ~0x80;
        np->rv_dmode    &= ~(0x3 << 6);
        np->rv_ctest5   &= ~0x4;

        if (!bc) {
                np->rv_ctest4   |= 0x80;
        }
        else {
                --bc;
                np->rv_dmode    |= ((bc & 0x3) << 6);
                np->rv_ctest5   |= (bc & 0x4);
        }
}

/*==========================================================
**
**
**      Auto configuration:  attach and init a host adapter.
**
**
**==========================================================
*/


static int
ncr_attach (device_t dev)
{
        ncb_p np = (struct ncb*) device_get_softc(dev);
        u_char   rev = 0;
        u_long   period;
        int      i, rid;
        u_int8_t usrsync;
        u_int8_t usrwide;
        struct cam_devq *devq;

        /*
        **      allocate and initialize structures.
        */

        np->unit = device_get_unit(dev);

        /*
        **      Try to map the controller chip to
        **      virtual and physical memory.
        */

        np->reg_rid = 0x14;
        np->reg_res = bus_alloc_resource(dev, SYS_RES_MEMORY, &np->reg_rid,
                                         0, ~0, 1, RF_ACTIVE);
        if (!np->reg_res) {
                device_printf(dev, "could not map memory\n");
                return ENXIO;
        }

        /*
        **      Make the controller's registers available.
        **      Now the INB INW INL OUTB OUTW OUTL macros
        **      can be used safely.
        */

        np->bst = rman_get_bustag(np->reg_res);
        np->bsh = rman_get_bushandle(np->reg_res);


#ifdef NCR_IOMAPPED
        /*
        **      Try to map the controller chip into iospace.
        */

        if (!pci_map_port (config_id, 0x10, &np->port))
                return;
#endif


        /*
        **      Save some controller register default values
        */

        np->rv_scntl3   = INB(nc_scntl3) & 0x77;
        np->rv_dmode    = INB(nc_dmode)  & 0xce;
        np->rv_dcntl    = INB(nc_dcntl)  & 0xa9;
        np->rv_ctest3   = INB(nc_ctest3) & 0x01;
        np->rv_ctest4   = INB(nc_ctest4) & 0x88;
        np->rv_ctest5   = INB(nc_ctest5) & 0x24;
        np->rv_gpcntl   = INB(nc_gpcntl);
        np->rv_stest2   = INB(nc_stest2) & 0x20;

        if (bootverbose >= 2) {
                kprintf ("\tBIOS values:  SCNTL3:%02x DMODE:%02x  DCNTL:%02x\n",
                        np->rv_scntl3, np->rv_dmode, np->rv_dcntl);
                kprintf ("\t              CTEST3:%02x CTEST4:%02x CTEST5:%02x\n",
                        np->rv_ctest3, np->rv_ctest4, np->rv_ctest5);
        }

        np->rv_dcntl  |= NOCOM;

        /*
        **      Do chip dependent initialization.
        */

        rev = pci_get_revid(dev);

        /*
        **      Get chip features from chips table.
        */
        i = ncr_chip_lookup(pci_get_devid(dev), rev);

        if (i >= 0) {
                np->maxburst    = ncr_chip_table[i].maxburst;
                np->maxoffs     = ncr_chip_table[i].maxoffs;
                np->clock_divn  = ncr_chip_table[i].clock_divn;
                np->features    = ncr_chip_table[i].features;
        } else {        /* Should'nt happen if probe() is ok */
                np->maxburst    = 4;
                np->maxoffs     = 8;
                np->clock_divn  = 4;
                np->features    = FE_ERL;
        }

        np->maxwide     = np->features & FE_WIDE ? 1 : 0;
        np->clock_khz   = np->features & FE_CLK80 ? 80000 : 40000;
        if      (np->features & FE_QUAD)        np->multiplier = 4;
        else if (np->features & FE_DBLR)        np->multiplier = 2;
        else                                    np->multiplier = 1;

        /*
        **      Get the frequency of the chip's clock.
        **      Find the right value for scntl3.
        */
        if (np->features & (FE_ULTRA|FE_ULTRA2))
                ncr_getclock(np, np->multiplier);

#ifdef NCR_TEKRAM_EEPROM
        if (bootverbose) {
                kprintf ("%s: Tekram EEPROM read %s\n",
                        ncr_name(np),
                        read_tekram_eeprom (np, NULL) ?
                        "succeeded" : "failed");
        }
#endif /* NCR_TEKRAM_EEPROM */

        /*
         *      If scntl3 != 0, we assume BIOS is present.
         */
        if (np->rv_scntl3)
                np->features |= FE_BIOS;

        /*
         * Divisor to be used for async (timer pre-scaler).
         */
        i = np->clock_divn - 1;
        while (i >= 0) {
                --i;
                if (10ul * SCSI_NCR_MIN_ASYNC * np->clock_khz > div_10M[i]) {
                        ++i;
                        break;
                }
        }
        np->rv_scntl3 = i+1;

        /*
         * Minimum synchronous period factor supported by the chip.
         * Btw, 'period' is in tenths of nanoseconds.
         */

        period = (4 * div_10M[0] + np->clock_khz - 1) / np->clock_khz;
        if      (period <= 250)         np->minsync = 10;
        else if (period <= 303)         np->minsync = 11;
        else if (period <= 500)         np->minsync = 12;
        else                            np->minsync = (period + 40 - 1) / 40;

        /*
         * Check against chip SCSI standard support (SCSI-2,ULTRA,ULTRA2).
         */

        if      (np->minsync < 25 && !(np->features & (FE_ULTRA|FE_ULTRA2)))
                np->minsync = 25;
        else if (np->minsync < 12 && !(np->features & FE_ULTRA2))
                np->minsync = 12;

        /*
         * Maximum synchronous period factor supported by the chip.
         */

        period = (11 * div_10M[np->clock_divn - 1]) / (4 * np->clock_khz);
        np->maxsync = period > 2540 ? 254 : period / 10;

        /*
         * Now, some features available with Symbios compatible boards.
         * LED support through GPIO0 and DIFF support.
         */

#ifdef  SCSI_NCR_SYMBIOS_COMPAT
        if (!(np->rv_gpcntl & 0x01))
                np->features |= FE_LED0;
#if 0   /* Not safe enough without NVRAM support or user settable option */
        if (!(INB(nc_gpreg) & 0x08))
                np->features |= FE_DIFF;
#endif
#endif  /* SCSI_NCR_SYMBIOS_COMPAT */

        /*
         * Prepare initial IO registers settings.
         * Trust BIOS only if we believe we have one and if we want to.
         */
#ifdef  SCSI_NCR_TRUST_BIOS
        if (!(np->features & FE_BIOS)) {
#else
        if (1) {
#endif
                np->rv_dmode = 0;
                np->rv_dcntl = NOCOM;
                np->rv_ctest3 = 0;
                np->rv_ctest4 = MPEE;
                np->rv_ctest5 = 0;
                np->rv_stest2 = 0;

                if (np->features & FE_ERL)
                        np->rv_dmode    |= ERL;   /* Enable Read Line */
                if (np->features & FE_BOF)
                        np->rv_dmode    |= BOF;   /* Burst Opcode Fetch */
                if (np->features & FE_ERMP)
                        np->rv_dmode    |= ERMP;  /* Enable Read Multiple */
                if (np->features & FE_CLSE)
                        np->rv_dcntl    |= CLSE;  /* Cache Line Size Enable */
                if (np->features & FE_WRIE)
                        np->rv_ctest3   |= WRIE;  /* Write and Invalidate */
                if (np->features & FE_PFEN)
                        np->rv_dcntl    |= PFEN;  /* Prefetch Enable */
                if (np->features & FE_DFS)
                        np->rv_ctest5   |= DFS;   /* Dma Fifo Size */
                if (np->features & FE_DIFF)     
                        np->rv_stest2   |= 0x20;  /* Differential mode */
                ncr_init_burst(np, np->maxburst); /* Max dwords burst length */
        } else {
                np->maxburst =
                        burst_code(np->rv_dmode, np->rv_ctest4, np->rv_ctest5);
        }

        /*
        **      Get on-chip SRAM address, if supported
        */
        if ((np->features & FE_RAM) && sizeof(struct script) <= 4096) {
                np->sram_rid = 0x18;
                np->sram_res = bus_alloc_resource(dev, SYS_RES_MEMORY,
                                                  &np->sram_rid,
                                                  0, ~0, 1, RF_ACTIVE);
        }

        /*
        **      Allocate structure for script relocation.
        */
        if (np->sram_res != NULL) {
                np->script = NULL;
                np->p_script = rman_get_start(np->sram_res);
                np->bst2 = rman_get_bustag(np->sram_res);
                np->bsh2 = rman_get_bushandle(np->sram_res);
        } else if (sizeof (struct script) > PAGE_SIZE) {
                np->script  = (struct script*) kmem_alloc_contig
                        (round_page(sizeof (struct script)), 
                         0, 0xffffffff, PAGE_SIZE);
        } else {
                np->script  = (struct script *)
                        kmalloc (sizeof (struct script), M_DEVBUF, M_WAITOK);
        }

        /* XXX JGibbs - Use contigmalloc */
        if (sizeof (struct scripth) > PAGE_SIZE) {
                np->scripth = (struct scripth*) kmem_alloc_contig
                        (round_page(sizeof (struct scripth)), 
                         0, 0xffffffff, PAGE_SIZE);
        } else 
                {
                np->scripth = (struct scripth *)
                        kmalloc (sizeof (struct scripth), M_DEVBUF, M_WAITOK);
        }

#ifdef SCSI_NCR_PCI_CONFIG_FIXUP
        /*
        **      If cache line size is enabled, check PCI config space and 
        **      try to fix it up if necessary.
        */
#ifdef PCIR_CACHELNSZ   /* To be sure that new PCI stuff is present */
        {
                u_char cachelnsz = pci_read_config(dev, PCIR_CACHELNSZ, 1);
                u_short command  = pci_read_config(dev, PCIR_COMMAND, 2);

                if (!cachelnsz) {
                        cachelnsz = 8;
                        kprintf("%s: setting PCI cache line size register to %d.\n",
                                ncr_name(np), (int)cachelnsz);
                        pci_write_config(dev, PCIR_CACHELNSZ, cachelnsz, 1);
                }

                if (!(command & (1<<4))) {
                        command |= (1<<4);
                        kprintf("%s: setting PCI command write and invalidate.\n",
                                ncr_name(np));
                        pci_write_config(dev, PCIR_COMMAND, command, 2);
                }
        }
#endif /* PCIR_CACHELNSZ */

#endif /* SCSI_NCR_PCI_CONFIG_FIXUP */

        /* Initialize per-target user settings */
        usrsync = 0;
        if (SCSI_NCR_DFLT_SYNC) {
                usrsync = SCSI_NCR_DFLT_SYNC;
                if (usrsync > np->maxsync)
                        usrsync = np->maxsync;
                if (usrsync < np->minsync)
                        usrsync = np->minsync;
        }

        usrwide = (SCSI_NCR_MAX_WIDE);
        if (usrwide > np->maxwide) usrwide=np->maxwide;

        for (i=0;i<MAX_TARGET;i++) {
                tcb_p tp = &np->target[i];

                tp->tinfo.user.period = usrsync;
                tp->tinfo.user.offset = usrsync != 0 ? np->maxoffs : 0;
                tp->tinfo.user.width = usrwide;
                tp->tinfo.disc_tag = NCR_CUR_DISCENB
                                   | NCR_CUR_TAGENB
                                   | NCR_USR_DISCENB
                                   | NCR_USR_TAGENB;
        }

        /*
        **      Bells and whistles   ;-)
        */
        if (bootverbose)
                kprintf("%s: minsync=%d, maxsync=%d, maxoffs=%d, %d dwords burst, %s dma fifo\n",
                ncr_name(np), np->minsync, np->maxsync, np->maxoffs,
                burst_length(np->maxburst),
                (np->rv_ctest5 & DFS) ? "large" : "normal");

        /*
        **      Print some complementary information that can be helpfull.
        */
        if (bootverbose)
                kprintf("%s: %s, %s IRQ driver%s\n",
                        ncr_name(np),
                        np->rv_stest2 & 0x20 ? "differential" : "single-ended",
                        np->rv_dcntl & IRQM ? "totem pole" : "open drain",
                        np->sram_res ? ", using on-chip SRAM" : "");
                        
        /*
        **      Patch scripts to physical addresses
        */
        ncr_script_fill (&script0, &scripth0);

        if (np->script)
                np->p_script    = vtophys(np->script);
        np->p_scripth   = vtophys(np->scripth);

        ncr_script_copy_and_bind (np, (ncrcmd *) &script0,
                        (ncrcmd *) np->script, sizeof(struct script));

        ncr_script_copy_and_bind (np, (ncrcmd *) &scripth0,
                (ncrcmd *) np->scripth, sizeof(struct scripth));

        /*
        **    Patch the script for LED support.
        */

        if (np->features & FE_LED0) {
                WRITESCRIPT(reselect[0],  SCR_REG_REG(gpreg, SCR_OR,  0x01));
                WRITESCRIPT(reselect1[0], SCR_REG_REG(gpreg, SCR_AND, 0xfe));
                WRITESCRIPT(reselect2[0], SCR_REG_REG(gpreg, SCR_AND, 0xfe));
        }

        /*
        **      init data structure
        */

        np->jump_tcb.l_cmd      = SCR_JUMP;
        np->jump_tcb.l_paddr    = NCB_SCRIPTH_PHYS (np, abort);

        /*
        **  Get SCSI addr of host adapter (set by bios?).
        */

        np->myaddr = INB(nc_scid) & 0x07;
        if (!np->myaddr) np->myaddr = SCSI_NCR_MYADDR;

#ifdef NCR_DUMP_REG
        /*
        **      Log the initial register contents
        */
        {
                int reg;
                for (reg=0; reg<256; reg+=4) {
                        if (reg%16==0) kprintf ("reg[%2x]", reg);
                        kprintf (" %08x", (int)pci_conf_read (config_id, reg));
                        if (reg%16==12) kprintf ("\n");
                }
        }
#endif /* NCR_DUMP_REG */

        /*
        **      Reset chip.
        */

        OUTB (nc_istat,  SRST);
        DELAY (1000);
        OUTB (nc_istat,  0   );


        /*
        **      Now check the cache handling of the pci chipset.
        */

        if (ncr_snooptest (np)) {
                kprintf ("CACHE INCORRECTLY CONFIGURED.\n");
                return EINVAL;
        }

        /*
        **      Install the interrupt handler.
        */

        rid = 0;
        np->irq_res = bus_alloc_resource(dev, SYS_RES_IRQ, &rid, 0, ~0, 1,
                                         RF_SHAREABLE | RF_ACTIVE);
        if (np->irq_res == NULL) {
                device_printf(dev,
                              "interruptless mode: reduced performance.\n");
        } else {
                bus_setup_intr(dev, np->irq_res, 0,
                               ncr_intr, np, &np->irq_handle, NULL);
        }

        /*
        ** Create the device queue.  We only allow MAX_START-1 concurrent
        ** transactions so we can be sure to have one element free in our
        ** start queue to reset to the idle loop.
        */
        devq = cam_simq_alloc(MAX_START - 1);
        if (devq == NULL)
                return ENOMEM;

        /*
        **      Now tell the generic SCSI layer
        **      about our bus.
        */
        np->sim = cam_sim_alloc(ncr_action, ncr_poll, "ncr", np, np->unit,
                                &sim_mplock, 1, MAX_TAGS, devq);
        cam_simq_release(devq);
        if (np->sim == NULL)
                return ENOMEM;

        
        if (xpt_bus_register(np->sim, 0) != CAM_SUCCESS) {
                cam_sim_free(np->sim);
                return ENOMEM;
        }
        
        if (xpt_create_path(&np->path, /*periph*/NULL,
                            cam_sim_path(np->sim), CAM_TARGET_WILDCARD,
                            CAM_LUN_WILDCARD) != CAM_REQ_CMP) {
                xpt_bus_deregister(cam_sim_path(np->sim));
                cam_sim_free(np->sim);
                return ENOMEM;
        }

        /*
        **      start the timeout daemon
        */
        callout_init(&np->timeout_ch);
        ncr_timeout (np);
        np->lasttime=0;

        return 0;
}

/*==========================================================
**
**
**      Process pending device interrupts.
**
**
**==========================================================
*/

static void
ncr_intr(void *vnp)
{
        ncb_p np = vnp;
        crit_enter();

        if (DEBUG_FLAGS & DEBUG_TINY) kprintf ("[");

        if (INB(nc_istat) & (INTF|SIP|DIP)) {
                /*
                **      Repeat until no outstanding ints
                */
                do {
                        ncr_exception (np);
                } while (INB(nc_istat) & (INTF|SIP|DIP));

                np->ticks = 100;
        }

        if (DEBUG_FLAGS & DEBUG_TINY) kprintf ("]\n");

        crit_exit();
}

/*==========================================================
**
**
**      Start execution of a SCSI command.
**      This is called from the generic SCSI driver.
**
**
**==========================================================
*/

static void
ncr_action (struct cam_sim *sim, union ccb *ccb)
{
        ncb_p np;

        np = (ncb_p) cam_sim_softc(sim);

        switch (ccb->ccb_h.func_code) {
        /* Common cases first */
        case XPT_SCSI_IO:       /* Execute the requested I/O operation */
        {
                nccb_p cp;
                lcb_p lp;
                tcb_p tp;
                struct ccb_scsiio *csio;
                u_int8_t *msgptr;
                u_int msglen;
                u_int msglen2;
                int segments;
                u_int8_t nego;
                u_int8_t idmsg;
                int qidx;
                
                tp = &np->target[ccb->ccb_h.target_id];
                csio = &ccb->csio;

                crit_enter();

                /*
                 * Last time we need to check if this CCB needs to
                 * be aborted.
                 */
                if ((ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_INPROG) {
                        xpt_done(ccb);
                        crit_exit();
                        return;
                }
                ccb->ccb_h.status |= CAM_SIM_QUEUED;

                /*---------------------------------------------------
                **
                **      Assign an nccb / bind ccb
                **
                **----------------------------------------------------
                */
                cp = ncr_get_nccb (np, ccb->ccb_h.target_id,
                                   ccb->ccb_h.target_lun);
                if (cp == NULL) {
                        /* XXX JGibbs - Freeze SIMQ */
                        ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
                        xpt_done(ccb);
                        crit_exit();
                        return;
                }
                
                cp->ccb = ccb;
                
                /*---------------------------------------------------
                **
                **      timestamp
                **
                **----------------------------------------------------
                */
                /*
                ** XXX JGibbs - Isn't this expensive
                **              enough to be conditionalized??
                */

                bzero (&cp->phys.header.stamp, sizeof (struct tstamp));
                cp->phys.header.stamp.start = ticks;

                nego = 0;
                if (tp->nego_cp == NULL) {
                        
                        if (tp->tinfo.current.width
                         != tp->tinfo.goal.width) {
                                tp->nego_cp = cp;
                                nego = NS_WIDE;
                        } else if ((tp->tinfo.current.period
                                    != tp->tinfo.goal.period)
                                || (tp->tinfo.current.offset
                                    != tp->tinfo.goal.offset)) {
                                tp->nego_cp = cp;
                                nego = NS_SYNC;
                        }
                }

                /*---------------------------------------------------
                **
                **      choose a new tag ...
                **
                **----------------------------------------------------
                */
                lp = tp->lp[ccb->ccb_h.target_lun];

                if ((ccb->ccb_h.flags & CAM_TAG_ACTION_VALID) != 0
                 && (ccb->csio.tag_action != CAM_TAG_ACTION_NONE)
                 && (nego == 0)) {
                        /*
                        **      assign a tag to this nccb
                        */
                        while (!cp->tag) {
                                nccb_p cp2 = lp->next_nccb;
                                lp->lasttag = lp->lasttag % 255 + 1;
                                while (cp2 && cp2->tag != lp->lasttag)
                                        cp2 = cp2->next_nccb;
                                if (cp2) continue;
                                cp->tag=lp->lasttag;
                                if (DEBUG_FLAGS & DEBUG_TAGS) {
                                        PRINT_ADDR(ccb);
                                        kprintf ("using tag #%d.\n", cp->tag);
                                }
                        }
                } else {
                        cp->tag=0;
                }

                /*----------------------------------------------------
                **
                **      Build the identify / tag / sdtr message
                **
                **----------------------------------------------------
                */
                idmsg = MSG_IDENTIFYFLAG | ccb->ccb_h.target_lun;
                if (tp->tinfo.disc_tag & NCR_CUR_DISCENB)
                        idmsg |= MSG_IDENTIFY_DISCFLAG;

                msgptr = cp->scsi_smsg;
                msglen = 0;
                msgptr[msglen++] = idmsg;

                if (cp->tag) {
                        msgptr[msglen++] = ccb->csio.tag_action;
                        msgptr[msglen++] = cp->tag;
                }

                switch (nego) {
                case NS_SYNC:
                        msgptr[msglen++] = MSG_EXTENDED;
                        msgptr[msglen++] = MSG_EXT_SDTR_LEN;
                        msgptr[msglen++] = MSG_EXT_SDTR;
                        msgptr[msglen++] = tp->tinfo.goal.period;
                        msgptr[msglen++] = tp->tinfo.goal.offset;
                        if (DEBUG_FLAGS & DEBUG_NEGO) {
                                PRINT_ADDR(ccb);
                                kprintf ("sync msgout: ");
                                ncr_show_msg (&cp->scsi_smsg [msglen-5]);
                                kprintf (".\n");
                        };
                        break;
                case NS_WIDE:
                        msgptr[msglen++] = MSG_EXTENDED;
                        msgptr[msglen++] = MSG_EXT_WDTR_LEN;
                        msgptr[msglen++] = MSG_EXT_WDTR;
                        msgptr[msglen++] = tp->tinfo.goal.width;
                        if (DEBUG_FLAGS & DEBUG_NEGO) {
                                PRINT_ADDR(ccb);
                                kprintf ("wide msgout: ");
                                ncr_show_msg (&cp->scsi_smsg [msglen-4]);
                                kprintf (".\n");
                        };
                        break;
                }

                /*----------------------------------------------------
                **
                **      Build the identify message for getcc.
                **
                **----------------------------------------------------
                */

                cp->scsi_smsg2 [0] = idmsg;
                msglen2 = 1;

                /*----------------------------------------------------
                **
                **      Build the data descriptors
                **
                **----------------------------------------------------
                */

                /* XXX JGibbs - Handle other types of I/O */
                if ((ccb->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_NONE) {
                        segments = ncr_scatter(&cp->phys,
                                               (vm_offset_t)csio->data_ptr,
                                               (vm_size_t)csio->dxfer_len);

                        if (segments < 0) {
                                ccb->ccb_h.status = CAM_REQ_TOO_BIG;
                                ncr_free_nccb(np, cp);
                                crit_exit();
                                xpt_done(ccb);
                                return;
                        }
                        if ((ccb->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
                                cp->phys.header.savep = NCB_SCRIPT_PHYS (np, data_in);
                                cp->phys.header.goalp = cp->phys.header.savep +20 +segments*16;
                        } else { /* CAM_DIR_OUT */
                                cp->phys.header.savep = NCB_SCRIPT_PHYS (np, data_out);
                                cp->phys.header.goalp = cp->phys.header.savep +20 +segments*16;
                        }
                } else {
                        cp->phys.header.savep = NCB_SCRIPT_PHYS (np, no_data);
                        cp->phys.header.goalp = cp->phys.header.savep;
                }

                cp->phys.header.lastp = cp->phys.header.savep;


                /*----------------------------------------------------
                **
                **      fill in nccb
                **
                **----------------------------------------------------
                **
                **
                **      physical -> virtual backlink
                **      Generic SCSI command
                */
                cp->phys.header.cp              = cp;
                /*
                **      Startqueue
                */
                cp->phys.header.launch.l_paddr  = NCB_SCRIPT_PHYS (np, select);
                cp->phys.header.launch.l_cmd    = SCR_JUMP;
                /*
                **      select
                */
                cp->phys.select.sel_id          = ccb->ccb_h.target_id;
                cp->phys.select.sel_scntl3      = tp->tinfo.wval;
                cp->phys.select.sel_sxfer       = tp->tinfo.sval;
                /*
                **      message
                */
                cp->phys.smsg.addr              = CCB_PHYS (cp, scsi_smsg);
                cp->phys.smsg.size              = msglen;
        
                cp->phys.smsg2.addr             = CCB_PHYS (cp, scsi_smsg2);
                cp->phys.smsg2.size             = msglen2;
                /*
                **      command
                */
                /* XXX JGibbs - Support other command types */
                cp->phys.cmd.addr               = vtophys (csio->cdb_io.cdb_bytes);
                cp->phys.cmd.size               = csio->cdb_len;
                /*
                **      sense command
                */
                cp->phys.scmd.addr              = CCB_PHYS (cp, sensecmd);
                cp->phys.scmd.size              = 6;
                /*
                **      patch requested size into sense command
                */
                cp->sensecmd[0]                 = 0x03;
                cp->sensecmd[1]                 = ccb->ccb_h.target_lun << 5;
                cp->sensecmd[4]                 = csio->sense_len;
                /*
                **      sense data
                */
                cp->phys.sense.addr             = vtophys (&csio->sense_data);
                cp->phys.sense.size             = csio->sense_len;
                /*
                **      status
                */
                cp->actualquirks                = QUIRK_NOMSG;
                cp->host_status                 = nego ? HS_NEGOTIATE : HS_BUSY;
                cp->s_status                    = SCSI_STATUS_ILLEGAL;
                cp->parity_status               = 0;
        
                cp->xerr_status                 = XE_OK;
                cp->sync_status                 = tp->tinfo.sval;
                cp->nego_status                 = nego;
                cp->wide_status                 = tp->tinfo.wval;

                /*----------------------------------------------------
                **
                **      Critical region: start this job.
                **
                **----------------------------------------------------
                */

                /*
                **      reselect pattern and activate this job.
                */

                cp->jump_nccb.l_cmd     = (SCR_JUMP ^ IFFALSE (DATA (cp->tag)));
                cp->tlimit              = time_uptime
                                        + ccb->ccb_h.timeout / 1000 + 2;
                cp->magic               = CCB_MAGIC;

                /*
                **      insert into start queue.
                */

                qidx = np->squeueput + 1;
                if (qidx >= MAX_START)
                        qidx = 0;
                np->squeue [qidx         ] = NCB_SCRIPT_PHYS (np, idle);
                np->squeue [np->squeueput] = CCB_PHYS (cp, phys);
                np->squeueput = qidx;

                if(DEBUG_FLAGS & DEBUG_QUEUE)
                        kprintf("%s: queuepos=%d tryoffset=%d.\n",
                               ncr_name (np), np->squeueput,
                               (unsigned)(READSCRIPT(startpos[0]) - 
                               (NCB_SCRIPTH_PHYS (np, tryloop))));

                /*
                **      Script processor may be waiting for reselect.
                **      Wake it up.
                */
                OUTB (nc_istat, SIGP);

                /*
                **      and reenable interrupts
                */
                crit_exit();
                break;
        }
        case XPT_RESET_DEV:     /* Bus Device Reset the specified SCSI device */
        case XPT_EN_LUN:                /* Enable LUN as a target */
        case XPT_TARGET_IO:             /* Execute target I/O request */
        case XPT_ACCEPT_TARGET_IO:      /* Accept Host Target Mode CDB */
        case XPT_CONT_TARGET_IO:        /* Continue Host Target I/O Connection*/
        case XPT_ABORT:                 /* Abort the specified CCB */
                /* XXX Implement */
                ccb->ccb_h.status = CAM_REQ_INVALID;
                xpt_done(ccb);
                break;
        case XPT_SET_TRAN_SETTINGS:
        {
                struct  ccb_trans_settings *cts = &ccb->cts;
                tcb_p   tp;
                u_int   update_type;
                struct ccb_trans_settings_scsi *scsi =
                    &cts->proto_specific.scsi;
                struct ccb_trans_settings_spi *spi =
                    &cts->xport_specific.spi;

                update_type = 0;
                if (cts->type == CTS_TYPE_CURRENT_SETTINGS)
                        update_type |= NCR_TRANS_GOAL;
                if (cts->type == CTS_TYPE_USER_SETTINGS)
                        update_type |= NCR_TRANS_USER;

                crit_enter();
                tp = &np->target[ccb->ccb_h.target_id];
                /* Tag and disc enables */
                if ((spi->valid & CTS_SPI_VALID_DISC) != 0) {
                        if (update_type & NCR_TRANS_GOAL) {
                                if ((spi->flags & CTS_SPI_FLAGS_DISC_ENB) != 0)
                                        tp->tinfo.disc_tag |= NCR_CUR_DISCENB;
                                else
                                        tp->tinfo.disc_tag &= ~NCR_CUR_DISCENB;
                        }

                        if (update_type & NCR_TRANS_USER) {
                                if ((spi->flags & CTS_SPI_FLAGS_DISC_ENB) != 0)
                                        tp->tinfo.disc_tag |= NCR_USR_DISCENB;
                                else
                                        tp->tinfo.disc_tag &= ~NCR_USR_DISCENB;
                        }

                }

                if ((scsi->valid & CTS_SCSI_VALID_TQ) != 0) {
                        if (update_type & NCR_TRANS_GOAL) {
                                if ((scsi->flags & CTS_SCSI_FLAGS_TAG_ENB) != 0)
                                        tp->tinfo.disc_tag |= NCR_CUR_TAGENB;
                                else
                                        tp->tinfo.disc_tag &= ~NCR_CUR_TAGENB;
                        }

                        if (update_type & NCR_TRANS_USER) {
                                if ((scsi->flags & CTS_SCSI_FLAGS_TAG_ENB) != 0)
                                        tp->tinfo.disc_tag |= NCR_USR_TAGENB;
                                else
                                        tp->tinfo.disc_tag &= ~NCR_USR_TAGENB;
                        }
                }

                /* Filter bus width and sync negotiation settings */
                if ((spi->valid & CTS_SPI_VALID_BUS_WIDTH) != 0) {
                        if (spi->bus_width > np->maxwide)
                                spi->bus_width = np->maxwide;
                }

                if (((spi->valid & CTS_SPI_VALID_SYNC_RATE) != 0)
                 || ((spi->valid & CTS_SPI_VALID_SYNC_OFFSET) != 0)) {
                        if ((spi->valid & CTS_SPI_VALID_SYNC_RATE) != 0) {
                                if (spi->sync_period != 0
                                 && (spi->sync_period < np->minsync))
                                        spi->sync_period = np->minsync;
                        }
                        if ((spi->valid & CTS_SPI_VALID_SYNC_OFFSET) != 0) {
                                if (spi->sync_offset == 0)
                                        spi->sync_period = 0;
                                if (spi->sync_offset > np->maxoffs)
                                        spi->sync_offset = np->maxoffs;
                        }
                }
                if ((update_type & NCR_TRANS_USER) != 0) {
                        if ((spi->valid & CTS_SPI_VALID_SYNC_RATE) != 0)
                                tp->tinfo.user.period = spi->sync_period;
                        if ((spi->valid & CTS_SPI_VALID_SYNC_OFFSET) != 0)
                                tp->tinfo.user.offset = spi->sync_offset;
                        if ((spi->valid & CTS_SPI_VALID_BUS_WIDTH) != 0)
                                tp->tinfo.user.width = spi->bus_width;
                }
                if ((update_type & NCR_TRANS_GOAL) != 0) {
                        if ((spi->valid & CTS_SPI_VALID_SYNC_RATE) != 0)
                                tp->tinfo.goal.period = spi->sync_period;

                        if ((spi->valid & CTS_SPI_VALID_SYNC_OFFSET) != 0)
                                tp->tinfo.goal.offset = spi->sync_offset;

                        if ((spi->valid & CTS_SPI_VALID_BUS_WIDTH) != 0)
                                tp->tinfo.goal.width = spi->bus_width;
                }
                crit_exit();
                ccb->ccb_h.status = CAM_REQ_CMP;
                xpt_done(ccb);
                break;
        }
        case XPT_GET_TRAN_SETTINGS:
        /* Get default/user set transfer settings for the target */
        {
                struct  ccb_trans_settings *cts = &ccb->cts;
                struct  ncr_transinfo *tinfo;
                tcb_p   tp = &np->target[ccb->ccb_h.target_id];
                struct ccb_trans_settings_scsi *scsi =
                    &cts->proto_specific.scsi;
                struct ccb_trans_settings_spi *spi =
                    &cts->xport_specific.spi;

                cts->protocol = PROTO_SCSI;
                cts->protocol_version = SCSI_REV_2;
                cts->transport = XPORT_SPI;
                cts->transport_version = 2;

                crit_enter();
                if (cts->type == CTS_TYPE_CURRENT_SETTINGS) {
                        tinfo = &tp->tinfo.current;
                        if (tp->tinfo.disc_tag & NCR_CUR_DISCENB)
                                spi->flags |= CTS_SPI_FLAGS_DISC_ENB;
                        else
                                spi->flags &= ~CTS_SPI_FLAGS_DISC_ENB;

                        if (tp->tinfo.disc_tag & NCR_CUR_TAGENB)
                                scsi->flags |= CTS_SCSI_FLAGS_TAG_ENB;
                        else
                                scsi->flags &= ~CTS_SCSI_FLAGS_TAG_ENB;
                } else {
                        tinfo = &tp->tinfo.user;
                        if (tp->tinfo.disc_tag & NCR_USR_DISCENB)
                                spi->flags |= CTS_SPI_FLAGS_DISC_ENB;
                        else
                                spi->flags &= ~CTS_SPI_FLAGS_DISC_ENB;

                        if (tp->tinfo.disc_tag & NCR_USR_TAGENB)
                                scsi->flags |= CTS_SCSI_FLAGS_TAG_ENB;
                        else
                                scsi->flags &= ~CTS_SCSI_FLAGS_TAG_ENB;
                }

                spi->sync_period = tinfo->period;
                spi->sync_offset = tinfo->offset;
                spi->bus_width = tinfo->width;

                crit_exit();
                spi->valid = CTS_SPI_VALID_SYNC_RATE
                           | CTS_SPI_VALID_SYNC_OFFSET
                           | CTS_SPI_VALID_BUS_WIDTH
                           | CTS_SPI_VALID_DISC;
                scsi->valid = CTS_SCSI_VALID_TQ;

                ccb->ccb_h.status = CAM_REQ_CMP;
                xpt_done(ccb);
                break;
        }
        case XPT_CALC_GEOMETRY:
        {
                struct    ccb_calc_geometry *ccg;
                u_int32_t size_mb;
                u_int32_t secs_per_cylinder;
                int       extended;

                /* XXX JGibbs - I'm sure the NCR uses a different strategy,
                 *              but it should be able to deal with Adaptec
                 *              geometry too.
                 */
                extended = 1;
                ccg = &ccb->ccg;
                size_mb = ccg->volume_size
                        / ((1024L * 1024L) / ccg->block_size);
                
                if (size_mb > 1024 && extended) {
                        ccg->heads = 255;
                        ccg->secs_per_track = 63;
                } else {
                        ccg->heads = 64;
                        ccg->secs_per_track = 32;
                }
                secs_per_cylinder = ccg->heads * ccg->secs_per_track;
                ccg->cylinders = ccg->volume_size / secs_per_cylinder;
                ccb->ccb_h.status = CAM_REQ_CMP;
                xpt_done(ccb);
                break;
        }
        case XPT_RESET_BUS:             /* Reset the specified SCSI bus */
        {
                OUTB (nc_scntl1, CRST);
                ccb->ccb_h.status = CAM_REQ_CMP;
                DELAY(10000);   /* Wait until our interrupt handler sees it */ 
                xpt_done(ccb);
                break;
        }
        case XPT_TERM_IO:               /* Terminate the I/O process */
                /* XXX Implement */
                ccb->ccb_h.status = CAM_REQ_INVALID;
                xpt_done(ccb);
                break;
        case XPT_PATH_INQ:              /* Path routing inquiry */
        {
                struct ccb_pathinq *cpi = &ccb->cpi;
                
                cpi->version_num = 1; /* XXX??? */
                cpi->hba_inquiry = PI_SDTR_ABLE|PI_TAG_ABLE;
                if ((np->features & FE_WIDE) != 0)
                        cpi->hba_inquiry |= PI_WIDE_16;
                cpi->target_sprt = 0;
                cpi->hba_misc = 0;
                cpi->hba_eng_cnt = 0;
                cpi->max_target = (np->features & FE_WIDE) ? 15 : 7;
                cpi->max_lun = MAX_LUN - 1;
                cpi->initiator_id = np->myaddr;
                cpi->bus_id = cam_sim_bus(sim);
                cpi->base_transfer_speed = 3300;
                strncpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
                strncpy(cpi->hba_vid, "Symbios", HBA_IDLEN);
                strncpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
                cpi->unit_number = cam_sim_unit(sim);
                cpi->transport = XPORT_SPI;
                cpi->transport_version = 2;
                cpi->protocol = PROTO_SCSI;
                cpi->protocol_version = SCSI_REV_2;
                cpi->ccb_h.status = CAM_REQ_CMP;
                xpt_done(ccb);
                break;
        }
        default:
                ccb->ccb_h.status = CAM_REQ_INVALID;
                xpt_done(ccb);
                break;
        }
}

/*==========================================================
**
**
**      Complete execution of a SCSI command.
**      Signal completion to the generic SCSI driver.
**
**
**==========================================================
*/

static void
ncr_complete (ncb_p np, nccb_p cp)
{
        union ccb *ccb;
        tcb_p tp;

        /*
        **      Sanity check
        */

        if (!cp || (cp->magic!=CCB_MAGIC) || !cp->ccb) return;
        cp->magic = 1;
        cp->tlimit= 0;

        /*
        **      No Reselect anymore.
        */
        cp->jump_nccb.l_cmd = (SCR_JUMP);

        /*
        **      No starting.
        */
        cp->phys.header.launch.l_paddr= NCB_SCRIPT_PHYS (np, idle);

        /*
        **      timestamp
        */
        ncb_profile (np, cp);

        if (DEBUG_FLAGS & DEBUG_TINY)
                kprintf ("CCB=%x STAT=%x/%x\n", (int)(intptr_t)cp & 0xfff,
                        cp->host_status,cp->s_status);

        ccb = cp->ccb;
        cp->ccb = NULL;
        tp = &np->target[ccb->ccb_h.target_id];

        /*
        **      We do not queue more than 1 nccb per target 
        **      with negotiation at any time. If this nccb was 
        **      used for negotiation, clear this info in the tcb.
        */

        if (cp == tp->nego_cp)
                tp->nego_cp = NULL;

        /*
        **      Check for parity errors.
        */
        /* XXX JGibbs - What about reporting them??? */

        if (cp->parity_status) {
                PRINT_ADDR(ccb);
                kprintf ("%d parity error(s), fallback.\n", cp->parity_status);
                /*
                **      fallback to asynch transfer.
                */
                tp->tinfo.goal.period = 0;
                tp->tinfo.goal.offset = 0;
        }

        /*
        **      Check for extended errors.
        */

        if (cp->xerr_status != XE_OK) {
                PRINT_ADDR(ccb);
                switch (cp->xerr_status) {
                case XE_EXTRA_DATA:
                        kprintf ("extraneous data discarded.\n");
                        break;
                case XE_BAD_PHASE:
                        kprintf ("illegal scsi phase (4/5).\n");
                        break;
                default:
                        kprintf ("extended error %d.\n", cp->xerr_status);
                        break;
                }
                if (cp->host_status==HS_COMPLETE)
                        cp->host_status = HS_FAIL;
        }

        /*
        **      Check the status.
        */
        if (cp->host_status == HS_COMPLETE) {

                if (cp->s_status == SCSI_STATUS_OK) {

                        /*
                        **      All went well.
                        */
                        /* XXX JGibbs - Properly calculate residual */

                        tp->bytes     += ccb->csio.dxfer_len;
                        tp->transfers ++;

                        ccb->ccb_h.status = CAM_REQ_CMP;
                } else if ((cp->s_status & SCSI_STATUS_SENSE) != 0) {

                        /*
                         * XXX Could be TERMIO too.  Should record
                         * original status.
                         */
                        ccb->csio.scsi_status = SCSI_STATUS_CHECK_COND;
                        cp->s_status &= ~SCSI_STATUS_SENSE;
                        if (cp->s_status == SCSI_STATUS_OK) {
                                ccb->ccb_h.status =
                                    CAM_AUTOSNS_VALID|CAM_SCSI_STATUS_ERROR;
                        } else {
                                ccb->ccb_h.status = CAM_AUTOSENSE_FAIL;
                        }
                } else {
                        ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR;                      
                        ccb->csio.scsi_status = cp->s_status;
                }
                
                
        } else if (cp->host_status == HS_SEL_TIMEOUT) {

                /*
                **   Device failed selection
                */
                ccb->ccb_h.status = CAM_SEL_TIMEOUT;

        } else if (cp->host_status == HS_TIMEOUT) {

                /*
                **   No response
                */
                ccb->ccb_h.status = CAM_CMD_TIMEOUT;
        } else if (cp->host_status == HS_STALL) {
                ccb->ccb_h.status = CAM_REQUEUE_REQ;
        } else {

                /*
                **  Other protocol messes
                */
                PRINT_ADDR(ccb);
                kprintf ("COMMAND FAILED (%x %x) @%p.\n",
                        cp->host_status, cp->s_status, cp);

                ccb->ccb_h.status = CAM_CMD_TIMEOUT;
        }

        if ((ccb->ccb_h.status & CAM_STATUS_MASK) != CAM_REQ_CMP) {
                xpt_freeze_devq(ccb->ccb_h.path, /*count*/1);
                ccb->ccb_h.status |= CAM_DEV_QFRZN;
        }

        /*
        **      Free this nccb
        */
        ncr_free_nccb (np, cp);

        /*
        **      signal completion to generic driver.
        */
        xpt_done (ccb);
}

/*==========================================================
**
**
**      Signal all (or one) control block done.
**
**
**==========================================================
*/

static void
ncr_wakeup (ncb_p np, u_long code)
{
        /*
        **      Starting at the default nccb and following
        **      the links, complete all jobs with a
        **      host_status greater than "disconnect".
        **
        **      If the "code" parameter is not zero,
        **      complete all jobs that are not IDLE.
        */

        nccb_p cp = np->link_nccb;
        while (cp) {
                switch (cp->host_status) {

                case HS_IDLE:
                        break;

                case HS_DISCONNECT:
                        if(DEBUG_FLAGS & DEBUG_TINY) kprintf ("D");
                        /* fall through */

                case HS_BUSY:
                case HS_NEGOTIATE:
                        if (!code) break;
                        cp->host_status = code;

                        /* fall through */

                default:
                        ncr_complete (np, cp);
                        break;
                }
                cp = cp -> link_nccb;
        }
}

static void
ncr_freeze_devq (ncb_p np, struct cam_path *path)
{
        nccb_p  cp;
        int     i;
        int     count;
        int     firstskip;
        /*
        **      Starting at the first nccb and following
        **      the links, complete all jobs that match
        **      the passed in path and are in the start queue.
        */

        cp = np->link_nccb;
        count = 0;
        firstskip = 0;
        while (cp) {
                switch (cp->host_status) {

                case HS_BUSY:
                case HS_NEGOTIATE:
                        if ((cp->phys.header.launch.l_paddr
                            == NCB_SCRIPT_PHYS (np, select))
                         && (xpt_path_comp(path, cp->ccb->ccb_h.path) >= 0)) {

                                /* Mark for removal from the start queue */
                                for (i = 1; i < MAX_START; i++) {
                                        int idx;

                                        idx = np->squeueput - i;
                                
                                        if (idx < 0)
                                                idx = MAX_START + idx;
                                        if (np->squeue[idx]
                                         == CCB_PHYS(cp, phys)) {
                                                np->squeue[idx] =
                                                    NCB_SCRIPT_PHYS (np, skip);
                                                if (i > firstskip)
                                                        firstskip = i;
                                                break;
                                        }
                                }
                                cp->host_status=HS_STALL;
                                ncr_complete (np, cp);
                                count++;
                        }
                        break;
                default:
                        break;
                }
                cp = cp->link_nccb;
        }

        if (count > 0) {
                int j;
                int bidx;

                /* Compress the start queue */
                j = 0;
                bidx = np->squeueput;
                i = np->squeueput - firstskip;
                if (i < 0)
                        i = MAX_START + i;
                for (;;) {

                        bidx = i - j;
                        if (bidx < 0)
                                bidx = MAX_START + bidx;
                        
                        if (np->squeue[i] == NCB_SCRIPT_PHYS (np, skip)) {
                                j++;
                        } else if (j != 0) {
                                np->squeue[bidx] = np->squeue[i];
                                if (np->squeue[bidx]
                                 == NCB_SCRIPT_PHYS(np, idle))
                                        break;
                        }
                        i = (i + 1) % MAX_START;
                }
                np->squeueput = bidx;
        }
}

/*==========================================================
**
**
**      Start NCR chip.
**
**
**==========================================================
*/

static void
ncr_init(ncb_p np, char * msg, u_long code)
{
        int     i;

        /*
        **      Reset chip.
        */

        OUTB (nc_istat,  SRST);
        DELAY (1000);
        OUTB (nc_istat, 0);

        /*
        **      Message.
        */

        if (msg) kprintf ("%s: restart (%s).\n", ncr_name (np), msg);

        /*
        **      Clear Start Queue
        */

        for (i=0;i<MAX_START;i++)
                np -> squeue [i] = NCB_SCRIPT_PHYS (np, idle);

        /*
        **      Start at first entry.
        */

        np->squeueput = 0;
        WRITESCRIPT(startpos[0], NCB_SCRIPTH_PHYS (np, tryloop));
        WRITESCRIPT(start0  [0], SCR_INT ^ IFFALSE (0));

        /*
        **      Wakeup all pending jobs.
        */

        ncr_wakeup (np, code);

        /*
        **      Init chip.
        */

        OUTB (nc_istat,  0x00   );      /*  Remove Reset, abort ...          */
        OUTB (nc_scntl0, 0xca   );      /*  full arb., ena parity, par->ATN  */
        OUTB (nc_scntl1, 0x00   );      /*  odd parity, and remove CRST!!    */
        ncr_selectclock(np, np->rv_scntl3); /* Select SCSI clock             */
        OUTB (nc_scid  , RRE|np->myaddr);/*  host adapter SCSI address       */
        OUTW (nc_respid, 1ul<<np->myaddr);/*  id to respond to               */
        OUTB (nc_istat , SIGP   );      /*  Signal Process                   */
        OUTB (nc_dmode , np->rv_dmode); /* XXX modify burstlen ??? */
        OUTB (nc_dcntl , np->rv_dcntl);
        OUTB (nc_ctest3, np->rv_ctest3);
        OUTB (nc_ctest5, np->rv_ctest5);
        OUTB (nc_ctest4, np->rv_ctest4);/*  enable master parity checking    */
        OUTB (nc_stest2, np->rv_stest2|EXT); /* Extended Sreq/Sack filtering */
        OUTB (nc_stest3, TE     );      /*  TolerANT enable                  */
        OUTB (nc_stime0, 0x0b   );      /*  HTH = disabled, STO = 0.1 sec.   */

        if (bootverbose >= 2) {
                kprintf ("\tACTUAL values:SCNTL3:%02x DMODE:%02x  DCNTL:%02x\n",
                        np->rv_scntl3, np->rv_dmode, np->rv_dcntl);
                kprintf ("\t              CTEST3:%02x CTEST4:%02x CTEST5:%02x\n",
                        np->rv_ctest3, np->rv_ctest4, np->rv_ctest5);
        }

        /*
        **    Enable GPIO0 pin for writing if LED support.
        */

        if (np->features & FE_LED0) {
                OUTOFFB (nc_gpcntl, 0x01);
        }

        /*
        **      Fill in target structure.
        */
        for (i=0;i<MAX_TARGET;i++) {
                tcb_p tp = &np->target[i];

                tp->tinfo.sval    = 0;
                tp->tinfo.wval    = np->rv_scntl3;

                tp->tinfo.current.period = 0;
                tp->tinfo.current.offset = 0;
                tp->tinfo.current.width = MSG_EXT_WDTR_BUS_8_BIT;
        }

        /*
        **      enable ints
        */

        OUTW (nc_sien , STO|HTH|MA|SGE|UDC|RST);
        OUTB (nc_dien , MDPE|BF|ABRT|SSI|SIR|IID);

        /*
        **    Start script processor.
        */

        OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, start));

        /*
         * Notify the XPT of the event
         */
        if (code == HS_RESET)
                xpt_async(AC_BUS_RESET, np->path, NULL);
}

static void
ncr_poll(struct cam_sim *sim)
{       
        ncr_intr(cam_sim_softc(sim));  
}


/*==========================================================
**
**      Get clock factor and sync divisor for a given 
**      synchronous factor period.
**      Returns the clock factor (in sxfer) and scntl3 
**      synchronous divisor field.
**
**==========================================================
*/

static void ncr_getsync(ncb_p np, u_char sfac, u_char *fakp, u_char *scntl3p)
{
        u_long  clk = np->clock_khz;    /* SCSI clock frequency in kHz  */
        int     div = np->clock_divn;   /* Number of divisors supported */
        u_long  fak;                    /* Sync factor in sxfer         */
        u_long  per;                    /* Period in tenths of ns       */
        u_long  kpc;                    /* (per * clk)                  */

        /*
        **      Compute the synchronous period in tenths of nano-seconds
        */
        if      (sfac <= 10)    per = 250;
        else if (sfac == 11)    per = 303;
        else if (sfac == 12)    per = 500;
        else                    per = 40 * sfac;

        /*
        **      Look for the greatest clock divisor that allows an 
        **      input speed faster than the period.
        */
        kpc = per * clk;
        while (--div >= 0)
                if (kpc >= (div_10M[div] * 4)) break;

        /*
        **      Calculate the lowest clock factor that allows an output 
        **      speed not faster than the period.
        */
        fak = (kpc - 1) / div_10M[div] + 1;

#if 0   /* You can #if 1 if you think this optimization is useful */

        per = (fak * div_10M[div]) / clk;

        /*
        **      Why not to try the immediate lower divisor and to choose 
        **      the one that allows the fastest output speed ?
        **      We dont want input speed too much greater than output speed.
        */
        if (div >= 1 && fak < 6) {
                u_long fak2, per2;
                fak2 = (kpc - 1) / div_10M[div-1] + 1;
                per2 = (fak2 * div_10M[div-1]) / clk;
                if (per2 < per && fak2 <= 6) {
                        fak = fak2;
                        per = per2;
                        --div;
                }
        }
#endif

        if (fak < 4) fak = 4;   /* Should never happen, too bad ... */

        /*
        **      Compute and return sync parameters for the ncr
        */
        *fakp           = fak - 4;
        *scntl3p        = ((div+1) << 4) + (sfac < 25 ? 0x80 : 0);
}

/*==========================================================
**
**      Switch sync mode for current job and its target
**
**==========================================================
*/

static void
ncr_setsync(ncb_p np, nccb_p cp, u_char scntl3, u_char sxfer, u_char period)
{
        union   ccb *ccb;
        struct  ccb_trans_settings *neg;
        tcb_p   tp;
        int     div;
        u_int   target = INB (nc_sdid) & 0x0f;
        u_int   period_10ns;

        assert (cp);
        if (!cp) return;

        ccb = cp->ccb;
        assert (ccb);
        if (!ccb) return;
        assert (target == ccb->ccb_h.target_id);

        tp = &np->target[target];

        if (!scntl3 || !(sxfer & 0x1f))
                scntl3 = np->rv_scntl3;
        scntl3 = (scntl3 & 0xf0) | (tp->tinfo.wval & EWS)
               | (np->rv_scntl3 & 0x07);

        /*
        **      Deduce the value of controller sync period from scntl3.
        **      period is in tenths of nano-seconds.
        */

        div = ((scntl3 >> 4) & 0x7);
        if ((sxfer & 0x1f) && div)
                period_10ns =
                    (((sxfer>>5)+4)*div_10M[div-1])/np->clock_khz;
        else
                period_10ns = 0;

        tp->tinfo.goal.period = period;
        tp->tinfo.goal.offset = sxfer & 0x1f;
        tp->tinfo.current.period = period;
        tp->tinfo.current.offset = sxfer & 0x1f;

        /*
        **       Stop there if sync parameters are unchanged
        */
        if (tp->tinfo.sval == sxfer && tp->tinfo.wval == scntl3) return;
        tp->tinfo.sval = sxfer;
        tp->tinfo.wval = scntl3;

        if (sxfer & 0x1f) {
                /*
                **  Disable extended Sreq/Sack filtering
                */
                if (period_10ns <= 2000) OUTOFFB (nc_stest2, EXT);
        }

        /*
        ** Tell the SCSI layer about the
        ** new transfer parameters.
        */
        neg = &xpt_alloc_ccb()->cts;
        neg->protocol = PROTO_SCSI;
        neg->protocol_version = SCSI_REV_2;
        neg->transport = XPORT_SPI;
        neg->transport_version = 2;
        neg->xport_specific.spi.sync_period = period;
        neg->xport_specific.spi.sync_offset = sxfer & 0x1f;
        neg->xport_specific.spi.valid = CTS_SPI_VALID_SYNC_RATE
                | CTS_SPI_VALID_SYNC_OFFSET;
        xpt_setup_ccb(&neg->ccb_h, ccb->ccb_h.path, /*priority*/1);
        xpt_async(AC_TRANSFER_NEG, ccb->ccb_h.path, neg);
        
        /*
        **      set actual value and sync_status
        */
        OUTB (nc_sxfer, sxfer);
        np->sync_st = sxfer;
        OUTB (nc_scntl3, scntl3);
        np->wide_st = scntl3;

        /*
        **      patch ALL nccbs of this target.
        */
        for (cp = np->link_nccb; cp; cp = cp->link_nccb) {
                if (!cp->ccb) continue;
                if (cp->ccb->ccb_h.target_id != target) continue;
                cp->sync_status = sxfer;
                cp->wide_status = scntl3;
        }

        xpt_free_ccb(&neg->ccb_h);
}

/*==========================================================
**
**      Switch wide mode for current job and its target
**      SCSI specs say: a SCSI device that accepts a WDTR 
**      message shall reset the synchronous agreement to 
**      asynchronous mode.
**
**==========================================================
*/

static void ncr_setwide (ncb_p np, nccb_p cp, u_char wide, u_char ack)
{
        union   ccb *ccb;
        struct  ccb_trans_settings *neg;
        u_int   target = INB (nc_sdid) & 0x0f;
        tcb_p   tp;
        u_char  scntl3;
        u_char  sxfer;

        assert (cp);
        if (!cp) return;

        ccb = cp->ccb;
        assert (ccb);
        if (!ccb) return;
        assert (target == ccb->ccb_h.target_id);

        tp = &np->target[target];
        tp->tinfo.current.width = wide;
        tp->tinfo.goal.width = wide;
        tp->tinfo.current.period = 0;
        tp->tinfo.current.offset = 0;

        scntl3 = (tp->tinfo.wval & (~EWS)) | (wide ? EWS : 0);

        sxfer = ack ? 0 : tp->tinfo.sval;

        /*
        **       Stop there if sync/wide parameters are unchanged
        */
        if (tp->tinfo.sval == sxfer && tp->tinfo.wval == scntl3) return;
        tp->tinfo.sval = sxfer;
        tp->tinfo.wval = scntl3;

        /* Tell the SCSI layer about the new transfer params */
        neg = &xpt_alloc_ccb()->cts;

        neg->protocol = PROTO_SCSI;
        neg->protocol_version = SCSI_REV_2;
        neg->transport = XPORT_SPI;
        neg->transport_version = 2;
        neg->xport_specific.spi.bus_width = (scntl3 & EWS) ?
            MSG_EXT_WDTR_BUS_16_BIT : MSG_EXT_WDTR_BUS_8_BIT;
        neg->xport_specific.spi.sync_period = 0;
        neg->xport_specific.spi.sync_offset = 0;
        neg->xport_specific.spi.valid = CTS_SPI_VALID_SYNC_RATE
                | CTS_SPI_VALID_SYNC_OFFSET
                | CTS_SPI_VALID_BUS_WIDTH;
        xpt_setup_ccb(&neg->ccb_h, ccb->ccb_h.path, /*priority*/1);
        xpt_async(AC_TRANSFER_NEG, ccb->ccb_h.path, neg);

        /*
        **      set actual value and sync_status
        */
        OUTB (nc_sxfer, sxfer);
        np->sync_st = sxfer;
        OUTB (nc_scntl3, scntl3);
        np->wide_st = scntl3;

        /*
        **      patch ALL nccbs of this target.
        */
        for (cp = np->link_nccb; cp; cp = cp->link_nccb) {
                if (!cp->ccb) continue;
                if (cp->ccb->ccb_h.target_id != target) continue;
                cp->sync_status = sxfer;
                cp->wide_status = scntl3;
        }

        xpt_free_ccb(&neg->ccb_h);
}

/*==========================================================
**
**
**      ncr timeout handler.
**
**
**==========================================================
**
**      Misused to keep the driver running when
**      interrupts are not configured correctly.
**
**----------------------------------------------------------
*/

static void
ncr_timeout (void *arg)
{
        ncb_p   np = arg;
        time_t  thistime = time_uptime;
        ticks_t step  = np->ticks;
        long t;
        nccb_p cp;

        if (np->lasttime != thistime) {
                /*
                **      block ncr interrupts
                */
                crit_enter();
                np->lasttime = thistime;

                /*----------------------------------------------------
                **
                **      handle ncr chip timeouts
                **
                **      Assumption:
                **      We have a chance to arbitrate for the
                **      SCSI bus at least every 10 seconds.
                **
                **----------------------------------------------------
                */

                t = thistime - np->heartbeat;

                if (t<2) np->latetime=0; else np->latetime++;

                if (np->latetime>2) {
                        /*
                        **      If there are no requests, the script
                        **      processor will sleep on SEL_WAIT_RESEL.
                        **      But we have to check whether it died.
                        **      Let's try to wake it up.
                        */
                        OUTB (nc_istat, SIGP);
                }

                /*----------------------------------------------------
                **
                **      handle nccb timeouts
                **
                **----------------------------------------------------
                */

                for (cp=np->link_nccb; cp; cp=cp->link_nccb) {
                        /*
                        **      look for timed out nccbs.
                        */
                        if (!cp->host_status) continue;
                        if (cp->tlimit > thistime) continue;

                        /*
                        **      Disable reselect.
                        **      Remove it from startqueue.
                        */
                        cp->jump_nccb.l_cmd = (SCR_JUMP);
                        if (cp->phys.header.launch.l_paddr ==
                                NCB_SCRIPT_PHYS (np, select)) {
                                kprintf ("%s: timeout nccb=%p (skip)\n",
                                        ncr_name (np), cp);
                                cp->phys.header.launch.l_paddr
                                = NCB_SCRIPT_PHYS (np, skip);
                        }

                        switch (cp->host_status) {

                        case HS_BUSY:
                        case HS_NEGOTIATE:
                                /* fall through */
                        case HS_DISCONNECT:
                                cp->host_status=HS_TIMEOUT;
                        }
                        cp->tag = 0;

                        /*
                        **      wakeup this nccb.
                        */
                        ncr_complete (np, cp);
                }
                crit_exit();
        }

        callout_reset(&np->timeout_ch, step ? step : 1, ncr_timeout, np);

        if (INB(nc_istat) & (INTF|SIP|DIP)) {

                /*
                **      Process pending interrupts.
                */

                crit_enter();
                if (DEBUG_FLAGS & DEBUG_TINY) kprintf ("{");
                ncr_exception (np);
                if (DEBUG_FLAGS & DEBUG_TINY) kprintf ("}");
                crit_exit();
        }
}

/*==========================================================
**
**      log message for real hard errors
**
**      "ncr0 targ 0?: ERROR (ds:si) (so-si-sd) (sxfer/scntl3) @ name (dsp:dbc)."
**      "             reg: r0 r1 r2 r3 r4 r5 r6 ..... rf."
**
**      exception register:
**              ds:     dstat
**              si:     sist
**
**      SCSI bus lines:
**              so:     control lines as driver by NCR.
**              si:     control lines as seen by NCR.
**              sd:     scsi data lines as seen by NCR.
**
**      wide/fastmode:
**              sxfer:  (see the manual)
**              scntl3: (see the manual)
**
**      current script command:
**              dsp:    script adress (relative to start of script).
**              dbc:    first word of script command.
**
**      First 16 register of the chip:
**              r0..rf
**
**==========================================================
*/

static void ncr_log_hard_error(ncb_p np, u_short sist, u_char dstat)
{
        u_int32_t dsp;
        int     script_ofs;
        int     script_size;
        char    *script_name;
        u_char  *script_base;
        int     i;

        dsp     = INL (nc_dsp);

        if (np->p_script < dsp && 
            dsp <= np->p_script + sizeof(struct script)) {
                script_ofs      = dsp - np->p_script;
                script_size     = sizeof(struct script);
                script_base     = (u_char *) np->script;
                script_name     = "script";
        }
        else if (np->p_scripth < dsp && 
                 dsp <= np->p_scripth + sizeof(struct scripth)) {
                script_ofs      = dsp - np->p_scripth;
                script_size     = sizeof(struct scripth);
                script_base     = (u_char *) np->scripth;
                script_name     = "scripth";
        } else {
                script_ofs      = dsp;
                script_size     = 0;
                script_base     = NULL;
                script_name     = "mem";
        }

        kprintf ("%s:%d: ERROR (%x:%x) (%x-%x-%x) (%x/%x) @ (%s %x:%08x).\n",
                ncr_name (np), (unsigned)INB (nc_sdid)&0x0f, dstat, sist,
                (unsigned)INB (nc_socl), (unsigned)INB (nc_sbcl), (unsigned)INB (nc_sbdl),
                (unsigned)INB (nc_sxfer),(unsigned)INB (nc_scntl3), script_name, script_ofs,
                (unsigned)INL (nc_dbc));

        if (((script_ofs & 3) == 0) &&
            (unsigned)script_ofs < script_size) {
                kprintf ("%s: script cmd = %08x\n", ncr_name(np),
                        (int)READSCRIPT_OFF(script_base, script_ofs));
        }

        kprintf ("%s: regdump:", ncr_name(np));
        for (i=0; i<16;i++)
            kprintf (" %02x", (unsigned)INB_OFF(i));
        kprintf (".\n");
}

/*==========================================================
**
**
**      ncr chip exception handler.
**
**
**==========================================================
*/

static void ncr_exception (ncb_p np)
{
        u_char  istat, dstat;
        u_short sist;

        /*
        **      interrupt on the fly ?
        */
        while ((istat = INB (nc_istat)) & INTF) {
                if (DEBUG_FLAGS & DEBUG_TINY) kprintf ("F ");
                OUTB (nc_istat, INTF);
                np->profile.num_fly++;
                ncr_wakeup (np, 0);
        }
        if (!(istat & (SIP|DIP))) {
                return;
        }

        /*
        **      Steinbach's Guideline for Systems Programming:
        **      Never test for an error condition you don't know how to handle.
        */

        sist  = (istat & SIP) ? INW (nc_sist)  : 0;
        dstat = (istat & DIP) ? INB (nc_dstat) : 0;
        np->profile.num_int++;

        if (DEBUG_FLAGS & DEBUG_TINY)
                kprintf ("<%d|%x:%x|%x:%x>",
                        INB(nc_scr0),
                        dstat,sist,
                        (unsigned)INL(nc_dsp),
                        (unsigned)INL(nc_dbc));
        if ((dstat==DFE) && (sist==PAR)) return;

/*==========================================================
**
**      First the normal cases.
**
**==========================================================
*/
        /*-------------------------------------------
        **      SCSI reset
        **-------------------------------------------
        */

        if (sist & RST) {
                ncr_init (np, bootverbose ? "scsi reset" : NULL, HS_RESET);
                return;
        }

        /*-------------------------------------------
        **      selection timeout
        **
        **      IID excluded from dstat mask!
        **      (chip bug)
        **-------------------------------------------
        */

        if ((sist  & STO) &&
                !(sist  & (GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                !(dstat & (MDPE|BF|ABRT|SIR))) {
                ncr_int_sto (np);
                return;
        }

        /*-------------------------------------------
        **      Phase mismatch.
        **-------------------------------------------
        */

        if ((sist  & MA) &&
                !(sist  & (STO|GEN|HTH|SGE|UDC|RST|PAR)) &&
                !(dstat & (MDPE|BF|ABRT|SIR|IID))) {
                ncr_int_ma (np, dstat);
                return;
        }

        /*----------------------------------------
        **      move command with length 0
        **----------------------------------------
        */

        if ((dstat & IID) &&
                !(sist  & (STO|GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                !(dstat & (MDPE|BF|ABRT|SIR)) &&
                ((INL(nc_dbc) & 0xf8000000) == SCR_MOVE_TBL)) {
                /*
                **      Target wants more data than available.
                **      The "no_data" script will do it.
                */
                OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, no_data));
                return;
        }

        /*-------------------------------------------
        **      Programmed interrupt
        **-------------------------------------------
        */

        if ((dstat & SIR) &&
                !(sist  & (STO|GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                !(dstat & (MDPE|BF|ABRT|IID)) &&
                (INB(nc_dsps) <= SIR_MAX)) {
                ncr_int_sir (np);
                return;
        }

        /*========================================
        **      log message for real hard errors
        **========================================
        */

        ncr_log_hard_error(np, sist, dstat);

        /*========================================
        **      do the register dump
        **========================================
        */

        if (time_uptime - np->regtime > 10) {
                int i;
                np->regtime = time_uptime;
                for (i=0; i<sizeof(np->regdump); i++)
                        ((volatile char*)&np->regdump)[i] = INB_OFF(i);
                np->regdump.nc_dstat = dstat;
                np->regdump.nc_sist  = sist;
        }


        /*----------------------------------------
        **      clean up the dma fifo
        **----------------------------------------
        */

        if ( (INB(nc_sstat0) & (ILF|ORF|OLF)   ) ||
             (INB(nc_sstat1) & (FF3210) ) ||
             (INB(nc_sstat2) & (ILF1|ORF1|OLF1)) ||     /* wide .. */
             !(dstat & DFE)) {
                kprintf ("%s: have to clear fifos.\n", ncr_name (np));
                OUTB (nc_stest3, TE|CSF);       /* clear scsi fifo */
                OUTB (nc_ctest3, np->rv_ctest3 | CLF);
                                                /* clear dma fifo  */
        }

        /*----------------------------------------
        **      handshake timeout
        **----------------------------------------
        */

        if (sist & HTH) {
                kprintf ("%s: handshake timeout\n", ncr_name(np));
                OUTB (nc_scntl1, CRST);
                DELAY (1000);
                OUTB (nc_scntl1, 0x00);
                OUTB (nc_scr0, HS_FAIL);
                OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, cleanup));
                return;
        }

        /*----------------------------------------
        **      unexpected disconnect
        **----------------------------------------
        */

        if ((sist  & UDC) &&
                !(sist  & (STO|GEN|HTH|MA|SGE|RST|PAR)) &&
                !(dstat & (MDPE|BF|ABRT|SIR|IID))) {
                OUTB (nc_scr0, HS_UNEXPECTED);
                OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, cleanup));
                return;
        }

        /*----------------------------------------
        **      cannot disconnect
        **----------------------------------------
        */

        if ((dstat & IID) &&
                !(sist  & (STO|GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                !(dstat & (MDPE|BF|ABRT|SIR)) &&
                ((INL(nc_dbc) & 0xf8000000) == SCR_WAIT_DISC)) {
                /*
                **      Unexpected data cycle while waiting for disconnect.
                */
                if (INB(nc_sstat2) & LDSC) {
                        /*
                        **      It's an early reconnect.
                        **      Let's continue ...
                        */
                        OUTB (nc_dcntl, np->rv_dcntl | STD);
                        /*
                        **      info message
                        */
                        kprintf ("%s: INFO: LDSC while IID.\n",
                                ncr_name (np));
                        return;
                }
                kprintf ("%s: target %d doesn't release the bus.\n",
                        ncr_name (np), INB (nc_sdid)&0x0f);
                /*
                **      return without restarting the NCR.
                **      timeout will do the real work.
                */
                return;
        }

        /*----------------------------------------
        **      single step
        **----------------------------------------
        */

        if ((dstat & SSI) &&
                !(sist  & (STO|GEN|HTH|MA|SGE|UDC|RST|PAR)) &&
                !(dstat & (MDPE|BF|ABRT|SIR|IID))) {
                OUTB (nc_dcntl, np->rv_dcntl | STD);
                return;
        }

/*
**      @RECOVER@ HTH, SGE, ABRT.
**
**      We should try to recover from these interrupts.
**      They may occur if there are problems with synch transfers, or 
**      if targets are switched on or off while the driver is running.
*/

        if (sist & SGE) {
                /* clear scsi offsets */
                OUTB (nc_ctest3, np->rv_ctest3 | CLF);
        }

        /*
        **      Freeze controller to be able to read the messages.
        */

        if (DEBUG_FLAGS & DEBUG_FREEZE) {
                int i;
                unsigned char val;
                for (i=0; i<0x60; i++) {
                        switch (i%16) {

                        case 0:
                                kprintf ("%s: reg[%d0]: ",
                                        ncr_name(np),i/16);
                                break;
                        case 4:
                        case 8:
                        case 12:
                                kprintf (" ");
                                break;
                        }
                        val = bus_space_read_1(np->bst, np->bsh, i);
                        kprintf (" %x%x", val/16, val%16);
                        if (i%16==15) kprintf (".\n");
                }

                callout_stop(&np->timeout_ch);

                kprintf ("%s: halted!\n", ncr_name(np));
                /*
                **      don't restart controller ...
                */
                OUTB (nc_istat,  SRST);
                return;
        }

#ifdef NCR_FREEZE
        /*
        **      Freeze system to be able to read the messages.
        */
        kprintf ("ncr: fatal error: system halted - press reset to reboot ...");
        crit_enter();
        for (;;);
#endif

        /*
        **      sorry, have to kill ALL jobs ...
        */

        ncr_init (np, "fatal error", HS_FAIL);
}

/*==========================================================
**
**      ncr chip exception handler for selection timeout
**
**==========================================================
**
**      There seems to be a bug in the 53c810.
**      Although a STO-Interrupt is pending,
**      it continues executing script commands.
**      But it will fail and interrupt (IID) on
**      the next instruction where it's looking
**      for a valid phase.
**
**----------------------------------------------------------
*/

static void ncr_int_sto (ncb_p np)
{
        u_long dsa, scratcha, diff;
        nccb_p cp;
        if (DEBUG_FLAGS & DEBUG_TINY) kprintf ("T");

        /*
        **      look for nccb and set the status.
        */

        dsa = INL (nc_dsa);
        cp = np->link_nccb;
        while (cp && (CCB_PHYS (cp, phys) != dsa))
                cp = cp->link_nccb;

        if (cp) {
                cp-> host_status = HS_SEL_TIMEOUT;
                ncr_complete (np, cp);
        }

        /*
        **      repair start queue
        */

        scratcha = INL (nc_scratcha);
        diff = scratcha - NCB_SCRIPTH_PHYS (np, tryloop);

/*      assert ((diff <= MAX_START * 20) && !(diff % 20));*/

        if ((diff <= MAX_START * 20) && !(diff % 20)) {
                WRITESCRIPT(startpos[0], scratcha);
                OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, start));
                return;
        }
        ncr_init (np, "selection timeout", HS_FAIL);
}

/*==========================================================
**
**
**      ncr chip exception handler for phase errors.
**
**
**==========================================================
**
**      We have to construct a new transfer descriptor,
**      to transfer the rest of the current block.
**
**----------------------------------------------------------
*/

static void ncr_int_ma (ncb_p np, u_char dstat)
{
        u_int32_t       dbc;
        u_int32_t       rest;
        u_int32_t       dsa;
        u_int32_t       dsp;
        u_int32_t       nxtdsp;
        volatile void   *vdsp_base;
        size_t          vdsp_off;
        u_int32_t       oadr, olen;
        u_int32_t       *tblp, *newcmd;
        u_char  cmd, sbcl, ss0, ss2, ctest5;
        u_short delta;
        nccb_p  cp;

        dsp = INL (nc_dsp);
        dsa = INL (nc_dsa);
        dbc = INL (nc_dbc);
        ss0 = INB (nc_sstat0);
        ss2 = INB (nc_sstat2);
        sbcl= INB (nc_sbcl);

        cmd = dbc >> 24;
        rest= dbc & 0xffffff;

        ctest5 = (np->rv_ctest5 & DFS) ? INB (nc_ctest5) : 0;
        if (ctest5 & DFS)
                delta=(((ctest5<<8) | (INB (nc_dfifo) & 0xff)) - rest) & 0x3ff;
        else
                delta=(INB (nc_dfifo) - rest) & 0x7f;


        /*
        **      The data in the dma fifo has not been transfered to
        **      the target -> add the amount to the rest
        **      and clear the data.
        **      Check the sstat2 register in case of wide transfer.
        */

        if (!(dstat & DFE)) rest += delta;
        if (ss0 & OLF) rest++;
        if (ss0 & ORF) rest++;
        if (INB(nc_scntl3) & EWS) {
                if (ss2 & OLF1) rest++;
                if (ss2 & ORF1) rest++;
        }
        OUTB (nc_ctest3, np->rv_ctest3 | CLF);  /* clear dma fifo  */
        OUTB (nc_stest3, TE|CSF);               /* clear scsi fifo */

        /*
        **      locate matching cp
        */
        cp = np->link_nccb;
        while (cp && (CCB_PHYS (cp, phys) != dsa))
                cp = cp->link_nccb;

        if (!cp) {
            kprintf ("%s: SCSI phase error fixup: CCB already dequeued (%p)\n", 
                    ncr_name (np), (void *) np->header.cp);
            return;
        }
        if (cp != np->header.cp) {
            kprintf ("%s: SCSI phase error fixup: CCB address mismatch "
                    "(%p != %p) np->nccb = %p\n", 
                    ncr_name (np), (void *)cp, (void *)np->header.cp,
                    (void *)np->link_nccb);
/*          return;*/
        }

        /*
        **      find the interrupted script command,
        **      and the address at which to continue.
        */

        if (dsp == vtophys (&cp->patch[2])) {
                vdsp_base = cp;
                vdsp_off = offsetof(struct nccb, patch[0]);
                nxtdsp = READSCRIPT_OFF(vdsp_base, vdsp_off + 3*4);
        } else if (dsp == vtophys (&cp->patch[6])) {
                vdsp_base = cp;
                vdsp_off = offsetof(struct nccb, patch[4]);
                nxtdsp = READSCRIPT_OFF(vdsp_base, vdsp_off + 3*4);
        } else if (dsp > np->p_script &&
                   dsp <= np->p_script + sizeof(struct script)) {
                vdsp_base = np->script;
                vdsp_off = dsp - np->p_script - 8;
                nxtdsp = dsp;
        } else {
                vdsp_base = np->scripth;
                vdsp_off = dsp - np->p_scripth - 8;
                nxtdsp = dsp;
        }

        /*
        **      log the information
        */
        if (DEBUG_FLAGS & (DEBUG_TINY|DEBUG_PHASE)) {
                kprintf ("P%x%x ",cmd&7, sbcl&7);
                kprintf ("RL=%d D=%d SS0=%x ",
                        (unsigned) rest, (unsigned) delta, ss0);
        }
        if (DEBUG_FLAGS & DEBUG_PHASE) {
                kprintf ("\nCP=%p CP2=%p DSP=%x NXT=%x VDSP=%p CMD=%x ",
                        cp, np->header.cp,
                        dsp,
                        nxtdsp, (volatile char*)vdsp_base+vdsp_off, cmd);
        }

        /*
        **      get old startaddress and old length.
        */

        oadr = READSCRIPT_OFF(vdsp_base, vdsp_off + 1*4);

        if (cmd & 0x10) {       /* Table indirect */
                tblp = (u_int32_t *) ((char*) &cp->phys + oadr);
                olen = tblp[0];
                oadr = tblp[1];
        } else {
                tblp = NULL;
                olen = READSCRIPT_OFF(vdsp_base, vdsp_off) & 0xffffff;
        }

        if (DEBUG_FLAGS & DEBUG_PHASE) {
                kprintf ("OCMD=%x\nTBLP=%p OLEN=%lx OADR=%lx\n",
                        (unsigned) (READSCRIPT_OFF(vdsp_base, vdsp_off) >> 24),
                        (void *) tblp,
                        (u_long) olen,
                        (u_long) oadr);
        }

        /*
        **      if old phase not dataphase, leave here.
        */

        if (cmd != (READSCRIPT_OFF(vdsp_base, vdsp_off) >> 24)) {
                PRINT_ADDR(cp->ccb);
                kprintf ("internal error: cmd=%02x != %02x=(vdsp[0] >> 24)\n",
                        (unsigned)cmd,
                        (unsigned)READSCRIPT_OFF(vdsp_base, vdsp_off) >> 24);
                
                return;
        }
        if (cmd & 0x06) {
                PRINT_ADDR(cp->ccb);
                kprintf ("phase change %x-%x %d@%08x resid=%d.\n",
                        cmd&7, sbcl&7, (unsigned)olen,
                        (unsigned)oadr, (unsigned)rest);

                OUTB (nc_dcntl, np->rv_dcntl | STD);
                return;
        }

        /*
        **      choose the correct patch area.
        **      if savep points to one, choose the other.
        */

        newcmd = cp->patch;
        if (cp->phys.header.savep == vtophys (newcmd)) newcmd+=4;

        /*
        **      fillin the commands
        */

        newcmd[0] = ((cmd & 0x0f) << 24) | rest;
        newcmd[1] = oadr + olen - rest;
        newcmd[2] = SCR_JUMP;
        newcmd[3] = nxtdsp;

        if (DEBUG_FLAGS & DEBUG_PHASE) {
                PRINT_ADDR(cp->ccb);
                kprintf ("newcmd[%d] %x %x %x %x.\n",
                        (int)(newcmd - cp->patch),
                        (unsigned)newcmd[0],
                        (unsigned)newcmd[1],
                        (unsigned)newcmd[2],
                        (unsigned)newcmd[3]);
        }
        /*
        **      fake the return address (to the patch).
        **      and restart script processor at dispatcher.
        */
        np->profile.num_break++;
        OUTL (nc_temp, vtophys (newcmd));
        if ((cmd & 7) == 0)
                OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, dispatch));
        else
                OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, checkatn));
}

/*==========================================================
**
**
**      ncr chip exception handler for programmed interrupts.
**
**
**==========================================================
*/

static int ncr_show_msg (u_char * msg)
{
        u_char i;
        kprintf ("%x",*msg);
        if (*msg==MSG_EXTENDED) {
                for (i=1;i<8;i++) {
                        if (i-1>msg[1]) break;
                        kprintf ("-%x",msg[i]);
                }
                return (i+1);
        } else if ((*msg & 0xf0) == 0x20) {
                kprintf ("-%x",msg[1]);
                return (2);
        }
        return (1);
}

static void ncr_int_sir (ncb_p np)
{
        u_char scntl3;
        u_char chg, ofs, per, fak, wide;
        u_char num = INB (nc_dsps);
        nccb_p  cp=NULL;
        u_long  dsa;
        u_int   target = INB (nc_sdid) & 0x0f;
        tcb_p   tp     = &np->target[target];
        int     i;
        if (DEBUG_FLAGS & DEBUG_TINY) kprintf ("I#%d", num);

        switch (num) {
        case SIR_SENSE_RESTART:
        case SIR_STALL_RESTART:
                break;

        default:
                /*
                **      lookup the nccb
                */
                dsa = INL (nc_dsa);
                cp = np->link_nccb;
                while (cp && (CCB_PHYS (cp, phys) != dsa))
                        cp = cp->link_nccb;

                assert (cp);
                if (!cp)
                        goto out;
                assert (cp == np->header.cp);
                if (cp != np->header.cp)
                        goto out;
        }

        switch (num) {

/*--------------------------------------------------------------------
**
**      Processing of interrupted getcc selects
**
**--------------------------------------------------------------------
*/

        case SIR_SENSE_RESTART:
                /*------------------------------------------
                **      Script processor is idle.
                **      Look for interrupted "check cond"
                **------------------------------------------
                */

                if (DEBUG_FLAGS & DEBUG_RESTART)
                        kprintf ("%s: int#%d",ncr_name (np),num);
                cp = (nccb_p) 0;
                for (i=0; i<MAX_TARGET; i++) {
                        if (DEBUG_FLAGS & DEBUG_RESTART) kprintf (" t%d", i);
                        tp = &np->target[i];
                        if (DEBUG_FLAGS & DEBUG_RESTART) kprintf ("+");
                        cp = tp->hold_cp;
                        if (!cp) continue;
                        if (DEBUG_FLAGS & DEBUG_RESTART) kprintf ("+");
                        if ((cp->host_status==HS_BUSY) &&
                                (cp->s_status==SCSI_STATUS_CHECK_COND))
                                break;
                        if (DEBUG_FLAGS & DEBUG_RESTART) kprintf ("- (remove)");
                        tp->hold_cp = cp = (nccb_p) 0;
                }

                if (cp) {
                        if (DEBUG_FLAGS & DEBUG_RESTART)
                                kprintf ("+ restart job ..\n");
                        OUTL (nc_dsa, CCB_PHYS (cp, phys));
                        OUTL (nc_dsp, NCB_SCRIPTH_PHYS (np, getcc));
                        return;
                }

                /*
                **      no job, resume normal processing
                */
                if (DEBUG_FLAGS & DEBUG_RESTART) kprintf (" -- remove trap\n");
                WRITESCRIPT(start0[0], SCR_INT ^ IFFALSE (0));
                break;

        case SIR_SENSE_FAILED:
                /*-------------------------------------------
                **      While trying to select for
                **      getting the condition code,
                **      a target reselected us.
                **-------------------------------------------
                */
                if (DEBUG_FLAGS & DEBUG_RESTART) {
                        PRINT_ADDR(cp->ccb);
                        kprintf ("in getcc reselect by t%d.\n",
                                INB(nc_ssid) & 0x0f);
                }

                /*
                **      Mark this job
                */
                cp->host_status = HS_BUSY;
                cp->s_status = SCSI_STATUS_CHECK_COND;
                np->target[cp->ccb->ccb_h.target_id].hold_cp = cp;

                /*
                **      And patch code to restart it.
                */
                WRITESCRIPT(start0[0], SCR_INT);
                break;

/*-----------------------------------------------------------------------------
**
**      Was Sie schon immer ueber transfermode negotiation wissen wollten ...
**
**      We try to negotiate sync and wide transfer only after
**      a successfull inquire command. We look at byte 7 of the
**      inquire data to determine the capabilities if the target.
**
**      When we try to negotiate, we append the negotiation message
**      to the identify and (maybe) simple tag message.
**      The host status field is set to HS_NEGOTIATE to mark this
**      situation.
**
**      If the target doesn't answer this message immidiately
**      (as required by the standard), the SIR_NEGO_FAIL interrupt
**      will be raised eventually.
**      The handler removes the HS_NEGOTIATE status, and sets the
**      negotiated value to the default (async / nowide).
**
**      If we receive a matching answer immediately, we check it
**      for validity, and set the values.
**
**      If we receive a Reject message immediately, we assume the
**      negotiation has failed, and fall back to standard values.
**
**      If we receive a negotiation message while not in HS_NEGOTIATE
**      state, it's a target initiated negotiation. We prepare a
**      (hopefully) valid answer, set our parameters, and send back 
**      this answer to the target.
**
**      If the target doesn't fetch the answer (no message out phase),
**      we assume the negotiation has failed, and fall back to default
**      settings.
**
**      When we set the values, we adjust them in all nccbs belonging 
**      to this target, in the controller's register, and in the "phys"
**      field of the controller's struct ncb.
**
**      Possible cases:            hs  sir   msg_in value  send   goto
**      We try try to negotiate:
**      -> target doesnt't msgin   NEG FAIL  noop   defa.  -      dispatch
**      -> target rejected our msg NEG FAIL  reject defa.  -      dispatch
**      -> target answered  (ok)   NEG SYNC  sdtr   set    -      clrack
**      -> target answered (!ok)   NEG SYNC  sdtr   defa.  REJ--->msg_bad
**      -> target answered  (ok)   NEG WIDE  wdtr   set    -      clrack
**      -> target answered (!ok)   NEG WIDE  wdtr   defa.  REJ--->msg_bad
**      -> any other msgin         NEG FAIL  noop   defa.  -      dispatch
**
**      Target tries to negotiate:
**      -> incoming message        --- SYNC  sdtr   set    SDTR   -
**      -> incoming message        --- WIDE  wdtr   set    WDTR   -
**      We sent our answer:
**      -> target doesn't msgout   --- PROTO ?      defa.  -      dispatch
**
**-----------------------------------------------------------------------------
*/

        case SIR_NEGO_FAILED:
                /*-------------------------------------------------------
                **
                **      Negotiation failed.
                **      Target doesn't send an answer message,
                **      or target rejected our message.
                **
                **      Remove negotiation request.
                **
                **-------------------------------------------------------
                */
                OUTB (HS_PRT, HS_BUSY);

                /* fall through */

        case SIR_NEGO_PROTO:
                /*-------------------------------------------------------
                **
                **      Negotiation failed.
                **      Target doesn't fetch the answer message.
                **
                **-------------------------------------------------------
                */

                if (DEBUG_FLAGS & DEBUG_NEGO) {
                        PRINT_ADDR(cp->ccb);
                        kprintf ("negotiation failed sir=%x status=%x.\n",
                                num, cp->nego_status);
                }

                /*
                **      any error in negotiation:
                **      fall back to default mode.
                */
                switch (cp->nego_status) {

                case NS_SYNC:
                        ncr_setsync (np, cp, 0, 0xe0, 0);
                        break;

                case NS_WIDE:
                        ncr_setwide (np, cp, 0, 0);
                        break;

                }
                np->msgin [0] = MSG_NOOP;
                np->msgout[0] = MSG_NOOP;
                cp->nego_status = 0;
                OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, dispatch));
                break;

        case SIR_NEGO_SYNC:
                /*
                **      Synchronous request message received.
                */

                if (DEBUG_FLAGS & DEBUG_NEGO) {
                        PRINT_ADDR(cp->ccb);
                        kprintf ("sync msgin: ");
                        (void) ncr_show_msg (np->msgin);
                        kprintf (".\n");
                }

                /*
                **      get requested values.
                */

                chg = 0;
                per = np->msgin[3];
                ofs = np->msgin[4];
                if (ofs==0) per=255;

                /*
                **      check values against driver limits.
                */
                if (per < np->minsync)
                        {chg = 1; per = np->minsync;}
                if (per < tp->tinfo.user.period)
                        {chg = 1; per = tp->tinfo.user.period;}
                if (ofs > tp->tinfo.user.offset)
                        {chg = 1; ofs = tp->tinfo.user.offset;}

                /*
                **      Check against controller limits.
                */

                fak     = 7;
                scntl3  = 0;
                if (ofs != 0) {
                        ncr_getsync(np, per, &fak, &scntl3);
                        if (fak > 7) {
                                chg = 1;
                                ofs = 0;
                        }
                }
                if (ofs == 0) {
                        fak     = 7;
                        per     = 0;
                        scntl3  = 0;
                }

                if (DEBUG_FLAGS & DEBUG_NEGO) {
                        PRINT_ADDR(cp->ccb);
                        kprintf ("sync: per=%d scntl3=0x%x ofs=%d fak=%d chg=%d.\n",
                                per, scntl3, ofs, fak, chg);
                }

                if (INB (HS_PRT) == HS_NEGOTIATE) {
                        OUTB (HS_PRT, HS_BUSY);
                        switch (cp->nego_status) {

                        case NS_SYNC:
                                /*
                                **      This was an answer message
                                */
                                if (chg) {
                                        /*
                                        **      Answer wasn't acceptable.
                                        */
                                        ncr_setsync (np, cp, 0, 0xe0, 0);
                                        OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, msg_bad));
                                } else {
                                        /*
                                        **      Answer is ok.
                                        */
                                        ncr_setsync (np,cp,scntl3,(fak<<5)|ofs, per);
                                        OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, clrack));
                                }
                                return;

                        case NS_WIDE:
                                ncr_setwide (np, cp, 0, 0);
                                break;
                        }
                }

                /*
                **      It was a request. Set value and
                **      prepare an answer message
                */

                ncr_setsync (np, cp, scntl3, (fak<<5)|ofs, per);

                np->msgout[0] = MSG_EXTENDED;
                np->msgout[1] = 3;
                np->msgout[2] = MSG_EXT_SDTR;
                np->msgout[3] = per;
                np->msgout[4] = ofs;

                cp->nego_status = NS_SYNC;

                if (DEBUG_FLAGS & DEBUG_NEGO) {
                        PRINT_ADDR(cp->ccb);
                        kprintf ("sync msgout: ");
                        (void) ncr_show_msg (np->msgout);
                        kprintf (".\n");
                }

                if (!ofs) {
                        OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, msg_bad));
                        return;
                }
                np->msgin [0] = MSG_NOOP;

                break;

        case SIR_NEGO_WIDE:
                /*
                **      Wide request message received.
                */
                if (DEBUG_FLAGS & DEBUG_NEGO) {
                        PRINT_ADDR(cp->ccb);
                        kprintf ("wide msgin: ");
                        (void) ncr_show_msg (np->msgin);
                        kprintf (".\n");
                }

                /*
                **      get requested values.
                */

                chg  = 0;
                wide = np->msgin[3];

                /*
                **      check values against driver limits.
                */

                if (wide > tp->tinfo.user.width)
                        {chg = 1; wide = tp->tinfo.user.width;}

                if (DEBUG_FLAGS & DEBUG_NEGO) {
                        PRINT_ADDR(cp->ccb);
                        kprintf ("wide: wide=%d chg=%d.\n", wide, chg);
                }

                if (INB (HS_PRT) == HS_NEGOTIATE) {
                        OUTB (HS_PRT, HS_BUSY);
                        switch (cp->nego_status) {

                        case NS_WIDE:
                                /*
                                **      This was an answer message
                                */
                                if (chg) {
                                        /*
                                        **      Answer wasn't acceptable.
                                        */
                                        ncr_setwide (np, cp, 0, 1);
                                        OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, msg_bad));
                                } else {
                                        /*
                                        **      Answer is ok.
                                        */
                                        ncr_setwide (np, cp, wide, 1);
                                        OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, clrack));
                                }
                                return;

                        case NS_SYNC:
                                ncr_setsync (np, cp, 0, 0xe0, 0);
                                break;
                        }
                }

                /*
                **      It was a request, set value and
                **      prepare an answer message
                */

                ncr_setwide (np, cp, wide, 1);

                np->msgout[0] = MSG_EXTENDED;
                np->msgout[1] = 2;
                np->msgout[2] = MSG_EXT_WDTR;
                np->msgout[3] = wide;

                np->msgin [0] = MSG_NOOP;

                cp->nego_status = NS_WIDE;

                if (DEBUG_FLAGS & DEBUG_NEGO) {
                        PRINT_ADDR(cp->ccb);
                        kprintf ("wide msgout: ");
                        (void) ncr_show_msg (np->msgout);
                        kprintf (".\n");
                }
                break;

/*--------------------------------------------------------------------
**
**      Processing of special messages
**
**--------------------------------------------------------------------
*/

        case SIR_REJECT_RECEIVED:
                /*-----------------------------------------------
                **
                **      We received a MSG_MESSAGE_REJECT message.
                **
                **-----------------------------------------------
                */

                PRINT_ADDR(cp->ccb);
                kprintf ("MSG_MESSAGE_REJECT received (%x:%x).\n",
                        (unsigned)np->lastmsg, np->msgout[0]);
                break;

        case SIR_REJECT_SENT:
                /*-----------------------------------------------
                **
                **      We received an unknown message
                **
                **-----------------------------------------------
                */

                PRINT_ADDR(cp->ccb);
                kprintf ("MSG_MESSAGE_REJECT sent for ");
                (void) ncr_show_msg (np->msgin);
                kprintf (".\n");
                break;

/*--------------------------------------------------------------------
**
**      Processing of special messages
**
**--------------------------------------------------------------------
*/

        case SIR_IGN_RESIDUE:
                /*-----------------------------------------------
                **
                **      We received an IGNORE RESIDUE message,
                **      which couldn't be handled by the script.
                **
                **-----------------------------------------------
                */

                PRINT_ADDR(cp->ccb);
                kprintf ("MSG_IGN_WIDE_RESIDUE received, but not yet implemented.\n");
                break;

        case SIR_MISSING_SAVE:
                /*-----------------------------------------------
                **
                **      We received an DISCONNECT message,
                **      but the datapointer wasn't saved before.
                **
                **-----------------------------------------------
                */

                PRINT_ADDR(cp->ccb);
                kprintf ("MSG_DISCONNECT received, but datapointer not saved:\n"
                        "\tdata=%x save=%x goal=%x.\n",
                        (unsigned) INL (nc_temp),
                        (unsigned) np->header.savep,
                        (unsigned) np->header.goalp);
                break;

/*--------------------------------------------------------------------
**
**      Processing of a "SCSI_STATUS_QUEUE_FULL" status.
**
**      XXX JGibbs - We should do the same thing for BUSY status.
**
**      The current command has been rejected,
**      because there are too many in the command queue.
**      We have started too many commands for that target.
**
**--------------------------------------------------------------------
*/
        case SIR_STALL_QUEUE:
                cp->xerr_status = XE_OK;
                cp->host_status = HS_COMPLETE;
                cp->s_status = SCSI_STATUS_QUEUE_FULL;
                ncr_freeze_devq(np, cp->ccb->ccb_h.path);
                ncr_complete(np, cp);

                /* FALL THROUGH */

        case SIR_STALL_RESTART:
                /*-----------------------------------------------
                **
                **      Enable selecting again,
                **      if NO disconnected jobs.
                **
                **-----------------------------------------------
                */
                /*
                **      Look for a disconnected job.
                */
                cp = np->link_nccb;
                while (cp && cp->host_status != HS_DISCONNECT)
                        cp = cp->link_nccb;

                /*
                **      if there is one, ...
                */
                if (cp) {
                        /*
                        **      wait for reselection
                        */
                        OUTL (nc_dsp, NCB_SCRIPT_PHYS (np, reselect));
                        return;
                }

                /*
                **      else remove the interrupt.
                */

                kprintf ("%s: queue empty.\n", ncr_name (np));
                WRITESCRIPT(start1[0], SCR_INT ^ IFFALSE (0));
                break;
        }

out:
        OUTB (nc_dcntl, np->rv_dcntl | STD);
}

/*==========================================================
**
**
**      Acquire a control block
**
**
**==========================================================
*/

static  nccb_p ncr_get_nccb
        (ncb_p np, u_long target, u_long lun)
{
        lcb_p lp;
        nccb_p cp = NULL;

        /* Keep our timeout handler out */
        crit_enter();
        
        /*
        **      Lun structure available ?
        */

        lp = np->target[target].lp[lun];
        if (lp) {
                cp = lp->next_nccb;

                /*
                **      Look for free CCB
                */

                while (cp && cp->magic) {
                        cp = cp->next_nccb;
                }
        }

        /*
        **      if nothing available, create one.
        */

        if (cp == NULL)
                cp = ncr_alloc_nccb(np, target, lun);

        if (cp != NULL) {
                if (cp->magic) {
                        kprintf("%s: Bogus free cp found\n", ncr_name(np));
                        crit_exit();
                        return (NULL);
                }
                cp->magic = 1;
        }
        crit_exit();
        return (cp);
}

/*==========================================================
**
**
**      Release one control block
**
**
**==========================================================
*/

static void ncr_free_nccb (ncb_p np, nccb_p cp)
{
        /*
        **    sanity
        */

        assert (cp != NULL);

        cp -> host_status = HS_IDLE;
        cp -> magic = 0;
}

/*==========================================================
**
**
**      Allocation of resources for Targets/Luns/Tags.
**
**
**==========================================================
*/

static nccb_p
ncr_alloc_nccb (ncb_p np, u_long target, u_long lun)
{
        tcb_p tp;
        lcb_p lp;
        nccb_p cp;

        assert (np != NULL);

        if (target>=MAX_TARGET) return(NULL);
        if (lun   >=MAX_LUN   ) return(NULL);

        tp=&np->target[target];

        if (!tp->jump_tcb.l_cmd) {

                /*
                **      initialize it.
                */
                tp->jump_tcb.l_cmd   = (SCR_JUMP^IFFALSE (DATA (0x80 + target)));
                tp->jump_tcb.l_paddr = np->jump_tcb.l_paddr;

                tp->getscr[0] =
                        (np->features & FE_PFEN)? SCR_COPY(1) : SCR_COPY_F(1);
                tp->getscr[1] = vtophys (&tp->tinfo.sval);
                tp->getscr[2] = rman_get_start(np->reg_res) + offsetof (struct ncr_reg, nc_sxfer);
                tp->getscr[3] =
                        (np->features & FE_PFEN)? SCR_COPY(1) : SCR_COPY_F(1);
                tp->getscr[4] = vtophys (&tp->tinfo.wval);
                tp->getscr[5] = rman_get_start(np->reg_res) + offsetof (struct ncr_reg, nc_scntl3);

                assert (((offsetof(struct ncr_reg, nc_sxfer) ^
                         (offsetof(struct tcb ,tinfo)
                        + offsetof(struct ncr_target_tinfo, sval))) & 3) == 0);
                assert (((offsetof(struct ncr_reg, nc_scntl3) ^
                         (offsetof(struct tcb, tinfo)
                        + offsetof(struct ncr_target_tinfo, wval))) &3) == 0);

                tp->call_lun.l_cmd   = (SCR_CALL);
                tp->call_lun.l_paddr = NCB_SCRIPT_PHYS (np, resel_lun);

                tp->jump_lcb.l_cmd   = (SCR_JUMP);
                tp->jump_lcb.l_paddr = NCB_SCRIPTH_PHYS (np, abort);
                np->jump_tcb.l_paddr = vtophys (&tp->jump_tcb);
        }

        /*
        **      Logic unit control block
        */
        lp = tp->lp[lun];
        if (!lp) {
                /*
                **      Allocate a lcb
                */
                lp = kmalloc (sizeof (struct lcb), M_DEVBUF, M_WAITOK | M_ZERO);

                /*
                **      Initialize it
                */
                lp->jump_lcb.l_cmd   = (SCR_JUMP ^ IFFALSE (DATA (lun)));
                lp->jump_lcb.l_paddr = tp->jump_lcb.l_paddr;

                lp->call_tag.l_cmd   = (SCR_CALL);
                lp->call_tag.l_paddr = NCB_SCRIPT_PHYS (np, resel_tag);

                lp->jump_nccb.l_cmd   = (SCR_JUMP);
                lp->jump_nccb.l_paddr = NCB_SCRIPTH_PHYS (np, aborttag);

                lp->actlink = 1;

                /*
                **   Chain into LUN list
                */
                tp->jump_lcb.l_paddr = vtophys (&lp->jump_lcb);
                tp->lp[lun] = lp;

        }

        /*
        **      Allocate a nccb
        */
        cp = kmalloc (sizeof (struct nccb), M_DEVBUF, M_WAITOK | M_ZERO);

        if (DEBUG_FLAGS & DEBUG_ALLOC) { 
                kprintf ("new nccb @%p.\n", cp);
        }

        /*
        **      Fill in physical addresses
        */

        cp->p_nccb           = vtophys (cp);

        /*
        **      Chain into reselect list
        */
        cp->jump_nccb.l_cmd   = SCR_JUMP;
        cp->jump_nccb.l_paddr = lp->jump_nccb.l_paddr;
        lp->jump_nccb.l_paddr = CCB_PHYS (cp, jump_nccb);
        cp->call_tmp.l_cmd   = SCR_CALL;
        cp->call_tmp.l_paddr = NCB_SCRIPT_PHYS (np, resel_tmp);

        /*
        **      Chain into wakeup list
        */
        cp->link_nccb      = np->link_nccb;
        np->link_nccb      = cp;

        /*
        **      Chain into CCB list
        */
        cp->next_nccb   = lp->next_nccb;
        lp->next_nccb   = cp;

        return (cp);
}

/*==========================================================
**
**
**      Build Scatter Gather Block
**
**
**==========================================================
**
**      The transfer area may be scattered among
**      several non adjacent physical pages.
**
**      We may use MAX_SCATTER blocks.
**
**----------------------------------------------------------
*/

static  int     ncr_scatter
        (struct dsb* phys, vm_offset_t vaddr, vm_size_t datalen)
{
        u_long  paddr, pnext;

        u_short segment  = 0;
        u_long  segsize, segaddr;
        u_long  size, csize    = 0;
        u_long  chunk = MAX_SIZE;
        int     free;

        bzero (&phys->data, sizeof (phys->data));
        if (!datalen) return (0);

        paddr = vtophys (vaddr);

        /*
        **      insert extra break points at a distance of chunk.
        **      We try to reduce the number of interrupts caused
        **      by unexpected phase changes due to disconnects.
        **      A typical harddisk may disconnect before ANY block.
        **      If we wanted to avoid unexpected phase changes at all
        **      we had to use a break point every 512 bytes.
        **      Of course the number of scatter/gather blocks is
        **      limited.
        */

        free = MAX_SCATTER - 1;

        if (vaddr & PAGE_MASK) free -= datalen / PAGE_SIZE;

        if (free>1)
                while ((chunk * free >= 2 * datalen) && (chunk>=1024))
                        chunk /= 2;

        if(DEBUG_FLAGS & DEBUG_SCATTER)
                kprintf("ncr?:\tscattering virtual=%p size=%d chunk=%d.\n",
                       (void *) vaddr, (unsigned) datalen, (unsigned) chunk);

        /*
        **   Build data descriptors.
        */
        while (datalen && (segment < MAX_SCATTER)) {

                /*
                **      this segment is empty
                */
                segsize = 0;
                segaddr = paddr;
                pnext   = paddr;

                if (!csize) csize = chunk;

                while ((datalen) && (paddr == pnext) && (csize)) {

                        /*
                        **      continue this segment
                        */
                        pnext = (paddr & (~PAGE_MASK)) + PAGE_SIZE;

                        /*
                        **      Compute max size
                        */

                        size = pnext - paddr;           /* page size */
                        if (size > datalen) size = datalen;  /* data size */
                        if (size > csize  ) size = csize  ;  /* chunksize */

                        segsize += size;
                        vaddr   += size;
                        csize   -= size;
                        datalen -= size;
                        paddr    = vtophys (vaddr);
                }

                if(DEBUG_FLAGS & DEBUG_SCATTER)
                        kprintf ("\tseg #%d  addr=%x  size=%d  (rest=%d).\n",
                        segment,
                        (unsigned) segaddr,
                        (unsigned) segsize,
                        (unsigned) datalen);

                phys->data[segment].addr = segaddr;
                phys->data[segment].size = segsize;
                segment++;
        }

        if (datalen) {
                kprintf("ncr?: scatter/gather failed (residue=%d).\n",
                        (unsigned) datalen);
                return (-1);
        }

        return (segment);
}

/*==========================================================
**
**
**      Test the pci bus snoop logic :-(
**
**      Has to be called with interrupts disabled.
**
**
**==========================================================
*/

#ifndef NCR_IOMAPPED
static int ncr_regtest (struct ncb* np)
{
        volatile u_int32_t data;
        /*
        **      ncr registers may NOT be cached.
        **      write 0xffffffff to a read only register area,
        **      and try to read it back.
        */
        data = 0xffffffff;
        OUTL_OFF(offsetof(struct ncr_reg, nc_dstat), data);
        data = INL_OFF(offsetof(struct ncr_reg, nc_dstat));
#if 1
        if (data == 0xffffffff) {
#else
        if ((data & 0xe2f0fffd) != 0x02000080) {
#endif
                kprintf ("CACHE TEST FAILED: reg dstat-sstat2 readback %x.\n",
                        (unsigned) data);
                return (0x10);
        }
        return (0);
}
#endif

static int ncr_snooptest (struct ncb* np)
{
        u_int32_t ncr_rd, ncr_wr, ncr_bk, host_rd, host_wr, pc;
        int     i, err=0;
#ifndef NCR_IOMAPPED
        err |= ncr_regtest (np);
        if (err) return (err);
#endif
        /*
        **      init
        */
        pc  = NCB_SCRIPTH_PHYS (np, snooptest);
        host_wr = 1;
        ncr_wr  = 2;
        /*
        **      Set memory and register.
        */
        ncr_cache = host_wr;
        OUTL (nc_temp, ncr_wr);
        /*
        **      Start script (exchange values)
        */
        OUTL (nc_dsp, pc);
        /*
        **      Wait 'til done (with timeout)
        */
        for (i=0; i<NCR_SNOOP_TIMEOUT; i++)
                if (INB(nc_istat) & (INTF|SIP|DIP))
                        break;
        /*
        **      Save termination position.
        */
        pc = INL (nc_dsp);
        /*
        **      Read memory and register.
        */
        host_rd = ncr_cache;
        ncr_rd  = INL (nc_scratcha);
        ncr_bk  = INL (nc_temp);
        /*
        **      Reset ncr chip
        */
        OUTB (nc_istat,  SRST);
        DELAY (1000);
        OUTB (nc_istat,  0   );
        /*
        **      check for timeout
        */
        if (i>=NCR_SNOOP_TIMEOUT) {
                kprintf ("CACHE TEST FAILED: timeout.\n");
                return (0x20);
        }
        /*
        **      Check termination position.
        */
        if (pc != NCB_SCRIPTH_PHYS (np, snoopend)+8) {
                kprintf ("CACHE TEST FAILED: script execution failed.\n");
                kprintf ("start=%08lx, pc=%08lx, end=%08lx\n", 
                        (u_long) NCB_SCRIPTH_PHYS (np, snooptest), (u_long) pc,
                        (u_long) NCB_SCRIPTH_PHYS (np, snoopend) +8);
                return (0x40);
        }
        /*
        **      Show results.
        */
        if (host_wr != ncr_rd) {
                kprintf ("CACHE TEST FAILED: host wrote %d, ncr read %d.\n",
                        (int) host_wr, (int) ncr_rd);
                err |= 1;
        }
        if (host_rd != ncr_wr) {
                kprintf ("CACHE TEST FAILED: ncr wrote %d, host read %d.\n",
                        (int) ncr_wr, (int) host_rd);
                err |= 2;
        }
        if (ncr_bk != ncr_wr) {
                kprintf ("CACHE TEST FAILED: ncr wrote %d, read back %d.\n",
                        (int) ncr_wr, (int) ncr_bk);
                err |= 4;
        }
        return (err);
}

/*==========================================================
**
**
**      Profiling the drivers and targets performance.
**
**
**==========================================================
*/

/*
**      Compute the difference in milliseconds.
**/

static  int ncr_delta (int *from, int *to)
{
        if (!from) return (-1);
        if (!to)   return (-2);
        return ((to - from) * 1000 / hz);
}

#define PROFILE  cp->phys.header.stamp
static  void ncb_profile (ncb_p np, nccb_p cp)
{
        int co, da, st, en, di, se, post,work,disc;
        u_long diff;

        PROFILE.end = ticks;

        st = ncr_delta (&PROFILE.start,&PROFILE.status);
        if (st<0) return;       /* status  not reached  */

        da = ncr_delta (&PROFILE.start,&PROFILE.data);
        if (da<0) return;       /* No data transfer phase */

        co = ncr_delta (&PROFILE.start,&PROFILE.command);
        if (co<0) return;       /* command not executed */

        en = ncr_delta (&PROFILE.start,&PROFILE.end),
        di = ncr_delta (&PROFILE.start,&PROFILE.disconnect),
        se = ncr_delta (&PROFILE.start,&PROFILE.select);
        post = en - st;

        /*
        **      @PROFILE@  Disconnect time invalid if multiple disconnects
        */

        if (di>=0) disc = se-di; else  disc = 0;

        work = (st - co) - disc;

        diff = (np->disc_phys - np->disc_ref) & 0xff;
        np->disc_ref += diff;

        np->profile.num_trans   += 1;
        if (cp->ccb)
                np->profile.num_bytes   += cp->ccb->csio.dxfer_len;
        np->profile.num_disc    += diff;
        np->profile.ms_setup    += co;
        np->profile.ms_data     += work;
        np->profile.ms_disc     += disc;
        np->profile.ms_post     += post;
}
#undef PROFILE

/*==========================================================
**
**      Determine the ncr's clock frequency.
**      This is essential for the negotiation
**      of the synchronous transfer rate.
**
**==========================================================
**
**      Note: we have to return the correct value.
**      THERE IS NO SAVE DEFAULT VALUE.
**
**      Most NCR/SYMBIOS boards are delivered with a 40 Mhz clock.
**      53C860 and 53C875 rev. 1 support fast20 transfers but 
**      do not have a clock doubler and so are provided with a 
**      80 MHz clock. All other fast20 boards incorporate a doubler 
**      and so should be delivered with a 40 MHz clock.
**      The future fast40 chips (895/895) use a 40 Mhz base clock 
**      and provide a clock quadrupler (160 Mhz). The code below 
**      tries to deal as cleverly as possible with all this stuff.
**
**----------------------------------------------------------
*/

/*
 *      Select NCR SCSI clock frequency
 */
static void ncr_selectclock(ncb_p np, u_char scntl3)
{
        if (np->multiplier < 2) {
                OUTB(nc_scntl3, scntl3);
                return;
        }

        if (bootverbose >= 2)
                kprintf ("%s: enabling clock multiplier\n", ncr_name(np));

        OUTB(nc_stest1, DBLEN);    /* Enable clock multiplier             */
        if (np->multiplier > 2) {  /* Poll bit 5 of stest4 for quadrupler */
                int i = 20;
                while (!(INB(nc_stest4) & LCKFRQ) && --i > 0)
                        DELAY(20);
                if (!i)
                        kprintf("%s: the chip cannot lock the frequency\n", ncr_name(np));
        } else                  /* Wait 20 micro-seconds for doubler    */
                DELAY(20);
        OUTB(nc_stest3, HSC);           /* Halt the scsi clock          */
        OUTB(nc_scntl3, scntl3);
        OUTB(nc_stest1, (DBLEN|DBLSEL));/* Select clock multiplier      */
        OUTB(nc_stest3, 0x00);          /* Restart scsi clock           */
}

/*
 *      calculate NCR SCSI clock frequency (in KHz)
 */
static unsigned
ncrgetfreq (ncb_p np, int gen)
{
        int ms = 0;
        /*
         * Measure GEN timer delay in order 
         * to calculate SCSI clock frequency
         *
         * This code will never execute too
         * many loop iterations (if DELAY is 
         * reasonably correct). It could get
         * too low a delay (too high a freq.)
         * if the CPU is slow executing the 
         * loop for some reason (an NMI, for
         * example). For this reason we will
         * if multiple measurements are to be 
         * performed trust the higher delay 
         * (lower frequency returned).
         */
        OUTB (nc_stest1, 0);    /* make sure clock doubler is OFF           */
        OUTW (nc_sien , 0);     /* mask all scsi interrupts                 */
        (void) INW (nc_sist);   /* clear pending scsi interrupt             */
        OUTB (nc_dien , 0);     /* mask all dma interrupts                  */
        (void) INW (nc_sist);   /* another one, just to be sure :)          */
        OUTB (nc_scntl3, 4);    /* set pre-scaler to divide by 3            */
        OUTB (nc_stime1, 0);    /* disable general purpose timer            */
        OUTB (nc_stime1, gen);  /* set to nominal delay of (1<<gen) * 125us */
        while (!(INW(nc_sist) & GEN) && ms++ < 1000)
                DELAY(1000);    /* count ms                                 */
        OUTB (nc_stime1, 0);    /* disable general purpose timer            */
        OUTB (nc_scntl3, 0);
        /*
         * Set prescaler to divide by whatever "0" means.
         * "0" ought to choose divide by 2, but appears
         * to set divide by 3.5 mode in my 53c810 ...
         */
        OUTB (nc_scntl3, 0);

        if (bootverbose >= 2)
                kprintf ("\tDelay (GEN=%d): %u msec\n", gen, ms);
        /*
         * adjust for prescaler, and convert into KHz 
         */
        return ms ? ((1 << gen) * 4440) / ms : 0;
}

static void ncr_getclock (ncb_p np, u_char multiplier)
{
        unsigned char scntl3;
        unsigned char stest1;
        scntl3 = INB(nc_scntl3);
        stest1 = INB(nc_stest1);
          
        np->multiplier = 1;

        if (multiplier > 1) {
                np->multiplier  = multiplier;
                np->clock_khz   = 40000 * multiplier;
        } else {
                if ((scntl3 & 7) == 0) {
                        unsigned f1, f2;
                        /* throw away first result */
                        (void) ncrgetfreq (np, 11);
                        f1 = ncrgetfreq (np, 11);
                        f2 = ncrgetfreq (np, 11);

                        if (bootverbose >= 2)
                          kprintf ("\tNCR clock is %uKHz, %uKHz\n", f1, f2);
                        if (f1 > f2) f1 = f2;   /* trust lower result   */
                        if (f1 > 45000) {
                                scntl3 = 5;     /* >45Mhz: assume 80MHz */
                        } else {
                                scntl3 = 3;     /* <45Mhz: assume 40MHz */
                        }
                }
                else if ((scntl3 & 7) == 5)
                        np->clock_khz = 80000;  /* Probably a 875 rev. 1 ? */
        }
}

/*=========================================================================*/

#ifdef NCR_TEKRAM_EEPROM

struct tekram_eeprom_dev {
  u_char        devmode;
#define TKR_PARCHK      0x01
#define TKR_TRYSYNC     0x02
#define TKR_ENDISC      0x04
#define TKR_STARTUNIT   0x08
#define TKR_USETAGS     0x10
#define TKR_TRYWIDE     0x20
  u_char        syncparam;      /* max. sync transfer rate (table ?) */
  u_char        filler1;
  u_char        filler2;
};


struct tekram_eeprom {
  struct tekram_eeprom_dev 
                dev[16];
  u_char        adaptid;
  u_char        adaptmode;
#define TKR_ADPT_GT2DRV 0x01
#define TKR_ADPT_GT1GB  0x02
#define TKR_ADPT_RSTBUS 0x04
#define TKR_ADPT_ACTNEG 0x08
#define TKR_ADPT_NOSEEK 0x10
#define TKR_ADPT_MORLUN 0x20
  u_char        delay;          /* unit ? ( table ??? ) */
  u_char        tags;           /* use 4 times as many ... */
  u_char        filler[60];
};

static void
tekram_write_bit (ncb_p np, int bit)
{
        u_char val = 0x10 + ((bit & 1) << 1);

        DELAY(10);
        OUTB (nc_gpreg, val);
        DELAY(10);
        OUTB (nc_gpreg, val | 0x04);
        DELAY(10);
        OUTB (nc_gpreg, val);
        DELAY(10);
}

static int
tekram_read_bit (ncb_p np)
{
        OUTB (nc_gpreg, 0x10);
        DELAY(10);
        OUTB (nc_gpreg, 0x14);
        DELAY(10);
        return INB (nc_gpreg) & 1;
}

static u_short
read_tekram_eeprom_reg (ncb_p np, int reg)
{
        int bit;
        u_short result = 0;
        int cmd = 0x80 | reg;

        OUTB (nc_gpreg, 0x10);

        tekram_write_bit (np, 1);
        for (bit = 7; bit >= 0; bit--)
        {
                tekram_write_bit (np, cmd >> bit);
        }

        for (bit = 0; bit < 16; bit++)
        {
                result <<= 1;
                result |= tekram_read_bit (np);
        }

        OUTB (nc_gpreg, 0x00);
        return result;
}

static int 
read_tekram_eeprom(ncb_p np, struct tekram_eeprom *buffer)
{
        u_short *p = (u_short *) buffer;
        u_short sum = 0;
        int i;

        if (INB (nc_gpcntl) != 0x09)
        {
                return 0;
        }
        for (i = 0; i < 64; i++)
        {
                u_short val;
if((i&0x0f) == 0) kprintf ("%02x:", i*2);
                val = read_tekram_eeprom_reg (np, i);
                if (p)
                        *p++ = val;
                sum += val;
if((i&0x01) == 0x00) kprintf (" ");
                kprintf ("%02x%02x", val & 0xff, (val >> 8) & 0xff);
if((i&0x0f) == 0x0f) kprintf ("\n");
        }
kprintf ("Sum = %04x\n", sum);
        return sum == 0x1234;
}
#endif /* NCR_TEKRAM_EEPROM */

static device_method_t ncr_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         ncr_probe),
        DEVMETHOD(device_attach,        ncr_attach),

        DEVMETHOD_END
};

static driver_t ncr_driver = {
        "ncr",
        ncr_methods,
        sizeof(struct ncb),
};

static devclass_t ncr_devclass;

DRIVER_MODULE(if_ncr, pci, ncr_driver, ncr_devclass, NULL, NULL);

/*=========================================================================*/
#endif /* _KERNEL */