/*
 * Copyright (c) 1997, 1998, 2000 Justin T. Gibbs.
 * Copyright (c) 1997, 1998, 1999 Kenneth D. Merry.
 * 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,
 *    without modification, immediately at the beginning of the file.
 * 2. 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 *
 * $FreeBSD: src/sys/cam/scsi/scsi_pass.c,v 1.19 2000/01/17 06:27:37 mjacob Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/types.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/caps.h>
#include <sys/conf.h>
#include <sys/errno.h>
#include <sys/devicestat.h>
#include <sys/buf2.h>

#include "../cam.h"
#include "../cam_ccb.h"
#include "../cam_extend.h"
#include "../cam_periph.h"
#include "../cam_queue.h"
#include "../cam_xpt_periph.h"
#include "../cam_debug.h"
#include "../cam_sim.h"

#include "scsi_all.h"
#include "scsi_message.h"
#include "scsi_da.h"
#include "scsi_pass.h"

typedef enum {
        PASS_FLAG_OPEN                  = 0x01,
        PASS_FLAG_LOCKED                = 0x02,
        PASS_FLAG_INVALID               = 0x04
} pass_flags;

typedef enum {
        PASS_STATE_NORMAL
} pass_state;

typedef enum {
        PASS_CCB_POLLED,
        PASS_CCB_BUFFER_IO,
        PASS_CCB_WAITING
} pass_ccb_types;

#define ccb_type        ppriv_field0
#define ccb_bio         ppriv_ptr1

struct pass_softc {
        pass_state      state;
        pass_flags      flags;
        u_int8_t        pd_type;
        union ccb       saved_ccb;
        struct devstat  device_stats;
};

static  d_open_t        passopen;
static  d_close_t       passclose;
static  d_ioctl_t       passioctl;

static  periph_init_t   passinit;
static  periph_ctor_t   passregister;
static  periph_oninv_t  passoninvalidate;
static  periph_dtor_t   passcleanup;
static  periph_start_t  passstart;
static  void            passasync(void *callback_arg, u_int32_t code,
                                  struct cam_path *path, void *arg);
static  void            passdone(struct cam_periph *periph, 
                                 union ccb *done_ccb);
static  int             passerror(union ccb *ccb, u_int32_t cam_flags, 
                                  u_int32_t sense_flags);
static  int             passsendccb(struct cam_periph *periph, union ccb *ccb,
                                    union ccb *inccb);

static struct periph_driver passdriver =
{
        passinit, "pass",
        TAILQ_HEAD_INITIALIZER(passdriver.units), /* generation */ 0
};

PERIPHDRIVER_DECLARE(pass, passdriver);

static struct dev_ops pass_ops = {
        { "pass", 0, D_MPSAFE },
        .d_open =       passopen,
        .d_close =      passclose,
        .d_ioctl =      passioctl,
};

static struct extend_array *passperiphs;

static void
passinit(void)
{
        cam_status status;

        /*
         * Create our extend array for storing the devices we attach to.
         */
        passperiphs = cam_extend_new();
        if (passperiphs == NULL) {
                kprintf("passm: Failed to alloc extend array!\n");
                return;
        }

        /*
         * Install a global async callback.  This callback will
         * receive async callbacks like "new device found".
         */
        status = xpt_register_async(AC_FOUND_DEVICE, passasync, NULL, NULL);

        if (status != CAM_REQ_CMP) {
                kprintf("pass: Failed to attach master async callback "
                       "due to status 0x%x!\n", status);
        }
        
}

static void
passoninvalidate(struct cam_periph *periph)
{
        struct pass_softc *softc;

        softc = (struct pass_softc *)periph->softc;

        /*
         * De-register any async callbacks.
         */
        xpt_register_async(0, passasync, periph, periph->path);

        softc->flags |= PASS_FLAG_INVALID;

        if (bootverbose) {
                xpt_print(periph->path, "lost device\n");
        }

}

static void
passcleanup(struct cam_periph *periph)
{
        struct pass_softc *softc;

        softc = (struct pass_softc *)periph->softc;

        devstat_remove_entry(&softc->device_stats);

        cam_extend_release(passperiphs, periph->unit_number);

        if (bootverbose) {
                xpt_print(periph->path, "removing device entry\n");
        }
        dev_ops_remove_minor(&pass_ops, periph->unit_number);
        kfree(softc, M_DEVBUF);
}

static void
passasync(void *callback_arg, u_int32_t code,
          struct cam_path *path, void *arg)
{
        struct cam_periph *periph;

        periph = (struct cam_periph *)callback_arg;

        switch (code) {
        case AC_FOUND_DEVICE:
        {
                struct ccb_getdev *cgd;
                cam_status status;
 
                cgd = (struct ccb_getdev *)arg;
                if (cgd == NULL)
                        break;

                /*
                 * Don't complain if a valid peripheral is already attached.
                 */
                periph = cam_periph_find(cgd->ccb_h.path, "pass");
                if (periph && (periph->flags & CAM_PERIPH_INVALID) == 0)
                        break;

                /*
                 * Allocate a peripheral instance for
                 * this device and start the probe
                 * process.
                 */
                status = cam_periph_alloc(passregister, passoninvalidate,
                                          passcleanup, passstart, "pass",
                                          CAM_PERIPH_BIO, cgd->ccb_h.path,
                                          passasync, AC_FOUND_DEVICE, cgd);

                if (status != CAM_REQ_CMP && status != CAM_REQ_INPROG) {
                        const struct cam_status_entry *entry;

                        entry = cam_fetch_status_entry(status);

                        kprintf("passasync: Unable to attach new device "
                                "due to status %#x: %s\n", status, entry ?
                                entry->status_text : "Unknown");
                }

                break;
        }
        default:
                cam_periph_async(periph, code, path, arg);
                break;
        }
}

static cam_status
passregister(struct cam_periph *periph, void *arg)
{
        struct pass_softc *softc;
        struct ccb_getdev *cgd;
        int    no_tags;

        cgd = (struct ccb_getdev *)arg;
        if (periph == NULL) {
                kprintf("passregister: periph was NULL!!\n");
                return(CAM_REQ_CMP_ERR);
        }

        if (cgd == NULL) {
                kprintf("passregister: no getdev CCB, can't register device\n");
                return(CAM_REQ_CMP_ERR);
        }

        softc = kmalloc(sizeof(*softc), M_DEVBUF, M_INTWAIT | M_ZERO);
        softc->state = PASS_STATE_NORMAL;
        softc->pd_type = SID_TYPE(&cgd->inq_data);

        periph->softc = softc;
        cam_extend_set(passperiphs, periph->unit_number, periph);

        /*
         * We pass in 0 for a blocksize, since we don't 
         * know what the blocksize of this device is, if 
         * it even has a blocksize.
         */
        CAM_SIM_UNLOCK(periph->sim);
        no_tags = (cgd->inq_data.flags & SID_CmdQue) == 0;
        devstat_add_entry(&softc->device_stats, "pass", periph->unit_number, 0,
                          DEVSTAT_NO_BLOCKSIZE
                          | (no_tags ? DEVSTAT_NO_ORDERED_TAGS : 0),
                          softc->pd_type |
                          DEVSTAT_TYPE_IF_SCSI |
                          DEVSTAT_TYPE_PASS,
                          DEVSTAT_PRIORITY_PASS);

        /* Register the device */
        make_dev(&pass_ops, periph->unit_number, UID_ROOT,
                  GID_OPERATOR, 0600, "%s%d", periph->periph_name,
                  periph->unit_number);
        CAM_SIM_LOCK(periph->sim);
        /*
         * Add an async callback so that we get
         * notified if this device goes away.
         */
        xpt_register_async(AC_LOST_DEVICE, passasync, periph, periph->path);

#if 0
        if (bootverbose)
                xpt_announce_periph(periph, NULL);
#endif

        return(CAM_REQ_CMP);
}

static int
passopen(struct dev_open_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct cam_periph *periph;
        struct pass_softc *softc;
        int unit, error;

        /*
         * Disallow CAM access if RESTRICTEDROOT
         */
        if (caps_priv_check_self(SYSCAP_RESTRICTEDROOT))
                return (EPERM);

        error = 0; /* default to no error */

        /* unit = dkunit(dev); */
        /* XXX KDM fix this */
        unit = minor(dev) & 0xff;

        periph = cam_extend_get(passperiphs, unit);

        if (cam_periph_acquire(periph) != CAM_REQ_CMP)
                return (ENXIO);

        cam_periph_lock(periph);

        softc = (struct pass_softc *)periph->softc;

        if (softc->flags & PASS_FLAG_INVALID) {
                cam_periph_unlock(periph);
                cam_periph_release(periph);
                return(ENXIO);
        }

        /*
         * Don't allow access when we're running at a high securelevel.
         */
        if (securelevel > 1) {
                cam_periph_unlock(periph);
                cam_periph_release(periph);
                return(EPERM);
        }

        /*
         * Only allow read-write access.
         */
        if (((ap->a_oflags & FWRITE) == 0) || ((ap->a_oflags & FREAD) == 0)) {
                cam_periph_unlock(periph);
                cam_periph_release(periph);
                return(EPERM);
        }

        /*
         * We don't allow nonblocking access.
         */
        if ((ap->a_oflags & O_NONBLOCK) != 0) {
                xpt_print(periph->path, "can't do nonblocking access\n");
                cam_periph_unlock(periph);
                cam_periph_release(periph);
                return(EINVAL);
        }

        if ((softc->flags & PASS_FLAG_OPEN) == 0) {
                softc->flags |= PASS_FLAG_OPEN;
        } else {
                /* Device closes aren't symmertical, so fix up the refcount */
                cam_periph_release(periph);
        }

        cam_periph_unlock(periph);

        return (error);
}

static int
passclose(struct dev_close_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct  cam_periph *periph;
        struct  pass_softc *softc;
        int     unit;

        /* unit = dkunit(dev); */
        /* XXX KDM fix this */
        unit = minor(dev) & 0xff;

        periph = cam_extend_get(passperiphs, unit);
        if (periph == NULL)
                return (ENXIO); 

        cam_periph_lock(periph);

        softc = (struct pass_softc *)periph->softc;
        softc->flags &= ~PASS_FLAG_OPEN;

        cam_periph_unlock(periph);
        cam_periph_release(periph);

        return (0);
}

static void
passstart(struct cam_periph *periph, union ccb *start_ccb)
{
        struct pass_softc *softc;

        softc = (struct pass_softc *)periph->softc;

        switch (softc->state) {
        case PASS_STATE_NORMAL:
                start_ccb->ccb_h.ccb_type = PASS_CCB_WAITING;
                SLIST_INSERT_HEAD(&periph->ccb_list, &start_ccb->ccb_h,
                                  periph_links.sle);
                periph->immediate_priority = CAM_PRIORITY_NONE;
                wakeup(&periph->ccb_list);
                break;
        }
}

static void
passdone(struct cam_periph *periph, union ccb *done_ccb)
{ 
        struct ccb_scsiio *csio;

        csio = &done_ccb->csio;

        switch (csio->ccb_h.ccb_type) {
        case PASS_CCB_WAITING:
                /* Caller will release the CCB */
                wakeup(&done_ccb->ccb_h.cbfcnp);
                return;
        case PASS_CCB_POLLED:
                /* polled, caller releases ccb */
                wakeup(&done_ccb->ccb_h.cbfcnp);
                return;
        }
        xpt_release_ccb(done_ccb);
}

static int
passioctl(struct dev_ioctl_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        caddr_t addr = ap->a_data;
        struct  cam_periph *periph;
        u_int8_t unit;
        int      error;


        /* unit = dkunit(dev); */
        /* XXX KDM fix this */
        unit = minor(dev) & 0xff;

        periph = cam_extend_get(passperiphs, unit);

        if (periph == NULL)
                return(ENXIO);

        cam_periph_lock(periph);

        error = 0;

        switch (ap->a_cmd) {

        case CAMIOCOMMAND:
        {
                union ccb *inccb;
                union ccb *ccb;
                int ccb_malloced;

                inccb = (union ccb *)addr;

                /*
                 * Some CCB types, like scan bus and scan lun can only go
                 * through the transport layer device.
                 */
                if (inccb->ccb_h.func_code & XPT_FC_XPT_ONLY) {
                        xpt_print(periph->path, "CCB function code %#x is "
                            "restricted to the XPT device\n",
                            inccb->ccb_h.func_code);
                        error = ENODEV;
                        break;
                }

                /*
                 * Non-immediate CCBs need a CCB from the per-device pool
                 * of CCBs, which is scheduled by the transport layer.
                 * Immediate CCBs and user-supplied CCBs should just be
                 * malloced.
                 */
                if ((inccb->ccb_h.func_code & XPT_FC_QUEUED)
                 && ((inccb->ccb_h.func_code & XPT_FC_USER_CCB) == 0)) {
                        ccb = cam_periph_getccb(periph,
                                                inccb->ccb_h.pinfo.priority);
                        ccb_malloced = 0;
                } else {
                        ccb = xpt_alloc_ccb();

                        if (ccb != NULL)
                                xpt_setup_ccb(&ccb->ccb_h, periph->path,
                                              inccb->ccb_h.pinfo.priority);
                        ccb_malloced = 1;
                }

                if (ccb == NULL) {
                        xpt_print(periph->path, "unable to allocate CCB\n");
                        error = ENOMEM;
                        break;
                }

                ccb->ccb_h.ccb_type = PASS_CCB_POLLED;
                error = passsendccb(periph, ccb, inccb);

                if (ccb_malloced)
                        xpt_free_ccb(&ccb->ccb_h);
                else
                        xpt_release_ccb(ccb);

                break;
        }
        default:
                error = cam_periph_ioctl(periph, ap->a_cmd, addr, passerror);
                break;
        }

        cam_periph_unlock(periph);
        return(error);
}

/*
 * Generally, "ccb" should be the CCB supplied by the kernel.  "inccb"
 * should be the CCB that is copied in from the user.
 */
static int
passsendccb(struct cam_periph *periph, union ccb *ccb, union ccb *inccb)
{
        struct pass_softc *softc;
        struct cam_periph_map_info mapinfo;
        int error, need_unmap;

        softc = (struct pass_softc *)periph->softc;

        need_unmap = 0;

        /*
         * There are some fields in the CCB header that need to be
         * preserved, the rest we get from the user.
         */
        xpt_merge_ccb(ccb, inccb);

        /*
         * There's no way for the user to have a completion
         * function, so we put our own completion function in here.
         */
        ccb->ccb_h.cbfcnp = passdone;

        /*
         * We only attempt to map the user memory into kernel space
         * if they haven't passed in a physical memory pointer,
         * and if there is actually an I/O operation to perform.
         * Right now cam_periph_mapmem() only supports SCSI and device
         * match CCBs.  For the SCSI CCBs, we only pass the CCB in if
         * there's actually data to map.  cam_periph_mapmem() will do the
         * right thing, even if there isn't data to map, but since CCBs
         * without data are a reasonably common occurance (e.g. test unit
         * ready), it will save a few cycles if we check for it here.
         */
        if (((ccb->ccb_h.flags & CAM_DATA_PHYS) == 0)
         && (((ccb->ccb_h.func_code == XPT_SCSI_IO)
            && ((ccb->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_NONE))
          || (ccb->ccb_h.func_code == XPT_DEV_MATCH))) {

                bzero(&mapinfo, sizeof(mapinfo));

                /*
                 * cam_periph_mapmem calls into proc and vm functions that can
                 * sleep as well as trigger I/O, so we can't hold the lock.
                 * Dropping it here is reasonably safe.
                 */
                cam_periph_unlock(periph);
                error = cam_periph_mapmem(ccb, &mapinfo); 
                cam_periph_lock(periph);

                /*
                 * cam_periph_mapmem returned an error, we can't continue.
                 * Return the error to the user.
                 */
                if (error)
                        return(error);

                /*
                 * We successfully mapped the memory in, so we need to
                 * unmap it when the transaction is done.
                 */
                need_unmap = 1;
        }

        /*
         * If the user wants us to perform any error recovery, then honor
         * that request.  Otherwise, it's up to the user to perform any
         * error recovery.
         */
        error = cam_periph_runccb(ccb,
                                  (ccb->ccb_h.flags & CAM_PASS_ERR_RECOVER) ?
                                  passerror : NULL,
                                  /* cam_flags */ CAM_RETRY_SELTO,
                                  /* sense_flags */SF_RETRY_UA,
                                  &softc->device_stats);

        if (need_unmap != 0)
                cam_periph_unmapmem(ccb, &mapinfo);

        ccb->ccb_h.cbfcnp = NULL;
        ccb->ccb_h.periph_priv = inccb->ccb_h.periph_priv;
        bcopy(ccb, inccb, sizeof(union ccb));

        return(error);
}

static int
passerror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
{
        struct cam_periph *periph;
        struct pass_softc *softc;

        periph = xpt_path_periph(ccb->ccb_h.path);
        softc = (struct pass_softc *)periph->softc;
        
        return(cam_periph_error(ccb, cam_flags, sense_flags, 
                                 &softc->saved_ccb));
}