root/sys/arch/sparc/sparc/bsd_fdintr.s
/*      $NetBSD: bsd_fdintr.s,v 1.28 2010/12/20 00:25:43 matt Exp $ */

/*
 * Copyright (c) 1995 Paul Kranenburg
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Paul Kranenburg.
 * 4. 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.
 *
 */

#ifndef FDC_C_HANDLER
#include "assym.h"
#include <machine/param.h>
#include <machine/asm.h>
#include <machine/intr.h>
#include <machine/psl.h>
#include <sparc/sparc/intreg.h>
#include <sparc/sparc/auxreg.h>
#include <sparc/sparc/vaddrs.h>
#include <sparc/dev/fdreg.h>
#include <sparc/dev/fdvar.h>

#define FD_SET_SWINTR_4C                                \
        sethi   %hi(INTRREG_VA), %l5;                   \
        ldub    [%l5 + %lo(INTRREG_VA)], %l6;           \
        or      %l6, IE_L4, %l6;                        \
        stb     %l6, [%l5 + %lo(INTRREG_VA)]

! raise(0,IPL_SOFTFDC)  ! NOTE: CPU#0
#define FD_SET_SWINTR_4M                                \
        sethi   %hi(PINTR_SINTRLEV(IPL_SOFTFDC)), %l5;  \
        set     ICR_PI_SET, %l6;                        \
        st      %l5, [%l6]

/* set software interrupt */
#if (defined(SUN4) || defined(SUN4C)) && !defined(SUN4M)
#define FD_SET_SWINTR   FD_SET_SWINTR_4C
#elif !(defined(SUN4) || defined(SUN4C)) && defined(SUN4M)
#define FD_SET_SWINTR   FD_SET_SWINTR_4M
#else
#define FD_SET_SWINTR                                   \
        sethi   %hi(_C_LABEL(cputyp)), %l5;             \
        ld      [%l5 + %lo(_C_LABEL(cputyp))], %l5;     \
        cmp     %l5, CPU_SUN4M;                         \
        be      8f;                                     \
        FD_SET_SWINTR_4C;                               \
        ba,a    9f;                                     \
8:                                                      \
        FD_SET_SWINTR_4M;                               \
9:
#endif

! flip TC bit in auxreg
! assumes %l6 remains unchanged between ASSERT and DEASSERT
#define FD_ASSERT_TC_4C                                 \
        sethi   %hi(AUXREG_VA), %l6;                    \
        ldub    [%l6 + %lo(AUXREG_VA) + 3], %l7;        \
        or      %l7, AUXIO4C_MB1|AUXIO4C_FTC, %l7;      \
        stb     %l7, [%l6 + %lo(AUXREG_VA) + 3];

#define FD_DEASSERT_TC_4C                               \
        ldub    [%l6 + %lo(AUXREG_VA) + 3], %l7;        \
        andn    %l7, AUXIO4C_FTC, %l7;                  \
        or      %l7, AUXIO4C_MB1, %l7;                  \
        stb     %l7, [%l6 + %lo(AUXREG_VA) + 3];

! flip TC bit in auxreg
#define FD_ASSERT_TC_4M                                 \
        sethi   %hi(AUXREG_VA), %l6;                    \
        ldub    [%l6 + %lo(AUXREG_VA) + 3], %l7;        \
        or      %l7, AUXIO4M_MB1|AUXIO4M_FTC, %l7;      \
        stb     %l7, [%l6 + %lo(AUXREG_VA) + 3];

#define FD_DEASSERT_TC_4M

/*
 * flip TC bit in auxreg
 * assumes %l5 remains unchanged between ASSERT and DEASSERT
 */
#if (defined(SUN4) || defined(SUN4C)) && !defined(SUN4M)
#define FD_ASSERT_TC            FD_ASSERT_TC_4C
#define FD_DEASSERT_TC          FD_DEASSERT_TC_4C
#elif !(defined(SUN4) || defined(SUN4C)) && defined(SUN4M)
#define FD_ASSERT_TC            FD_ASSERT_TC_4M
#define FD_DEASSERT_TC          FD_DEASSERT_TC_4M
#else
#define FD_ASSERT_TC                                    \
        sethi   %hi(_C_LABEL(cputyp)), %l5;             \
        ld      [%l5 + %lo(_C_LABEL(cputyp))], %l5;     \
        cmp     %l5, CPU_SUN4M;                         \
        be      8f;                                     \
         nop;                                           \
        FD_ASSERT_TC_4C;                                \
        ba,a    9f;                                     \
8:                                                      \
        FD_ASSERT_TC_4M;                                \
9:
#define FD_DEASSERT_TC                                  \
        cmp     %l5, CPU_SUN4M;                         \
        be      8f;                                     \
         nop;                                           \
        FD_DEASSERT_TC_4C;                              \
        ba,a    9f;                                     \
8:                                                      \
        FD_DEASSERT_TC_4M;                              \
9:
#endif


/* Timeout waiting for chip ready */
#define POLL_TIMO       100000

/*
 * register mnemonics. note overlapping assignments.
 */
#define R_fdc   %l0
#define R_msr   %l1
#define R_fifo  %l2
#define R_buf   %l3
#define R_tc    %l4
#define R_stat  %l3
#define R_nstat %l4
#define R_stcnt %l5
/* use %l6 and %l7 as short-term temporaries */


        .seg    "data"
        .align  8
/* A save haven for three precious registers */
save_l:
        .word   0
        .word   0
        .word   0
/* Pointer to a `struct fdcio', set in fd.c */
        .global _C_LABEL(fdciop)
_C_LABEL(fdciop):
        .word   0

        .seg    "text"
        .align  4

_ENTRY(_C_LABEL(fdchwintr))
        set     save_l, %l7
        std     %l0, [%l7]
        st      %l2, [%l7 + 8]

        ! tally interrupt (curcpu()->cpu_data.cpu_nintr++)
        INCR64X(CPUINFO_VA+CPUINFO_NINTR, %l4, %l5, %l7)

        ! load fdc, if it's NULL there's nothing to do: schedule soft interrupt
        sethi   %hi(_C_LABEL(fdciop)), %l7
        ld      [%l7 + %lo(_C_LABEL(fdciop))], R_fdc

        ! tally interrupt (fdcio_intrcnt.ev_count++)
        ldd     [R_fdc + FDC_EVCNT], %l6
        addcc   %l7, 1, %l7
        addx    %l6, 0, %l6
        std     %l6, [R_fdc + FDC_EVCNT]

        /*
         * load chips register addresses
         * NOTE: we ignore the bus tag here and assume the bus handle
         *       is the virtual address of the chip's registers.
         */
        ld      [R_fdc + FDC_REG_HANDLE], %l7   ! get chip registers bus handle
        ld      [R_fdc + FDC_REG_MSR], R_msr    ! get chip MSR reg addr
        add     R_msr, %l7, R_msr
        ld      [R_fdc + FDC_REG_FIFO], R_fifo  ! get chip FIFO reg addr
        add     R_fifo, %l7, R_fifo
        !!ld    [R_fdc + FDC_REG_DOR], R_dor    ! get chip DOR reg addr
        !!add   R_dor, %l7, R_dor

        ! find out what we are supposed to do
        ld      [R_fdc + FDC_ITASK], %l7        ! get task from fdc
        cmp     %l7, FDC_ITASK_SENSEI
        be      sensei
         !nop
        cmp     %l7, FDC_ITASK_RESULT
        be      resultphase
         !nop
        cmp     %l7, FDC_ITASK_DMA
        bne,a   ssi                             ! a spurious interrupt
         mov    FDC_ISTATUS_SPURIOUS, %l7       ! set status and post sw intr

        ! pseudo DMA
        ld      [R_fdc + FDC_TC], R_tc          ! residual count
        ld      [R_fdc + FDC_DATA], R_buf       ! IO buffer

        ldub    [R_msr], %l7                    ! get MSR value
nextc:
        btst    NE7_RQM, %l7                    ! room in fifo?
        bnz,a   0f
         btst   NE7_NDM, %l7                    ! execution finished?

        ! we filled/emptied the FIFO; update fdc->sc_buf & fdc->sc_tc
        st      R_tc, [R_fdc + FDC_TC]
        b       x
        st      R_buf, [R_fdc + FDC_DATA]

0:
        bz      resultphase

        tst     R_tc
        bnz     0f
         nop

        !! panic("fdc: overrun")
        sethi   %hi(.Lpanic_msg), %o0
        call    _C_LABEL(panic)
         or     %lo(.Lpanic_msg), %o0, %o0
        /* NOTREACHED */

0:      btst    NE7_DIO, %l7                    ! IO direction
        bz      1f
         deccc  R_tc
        ldub    [R_fifo], %l7                   ! reading:
        b       2f
        stb     %l7, [R_buf]                    !    *fdc->sc_bufp = *reg_fifo

1:
        ldub    [R_buf], %l7                    ! writing:
        stb     %l7, [R_fifo]                   !    *reg_fifo = *fdc->sc_bufp
2:
        inc     R_buf                           ! fdc->sc_bufp++
        bne,a   nextc                           ! if (--fdc->sc_tc) goto ...
         ldub   [R_msr], %l7                    ! get MSR value

        ! xfer done: update fdc->sc_buf & fdc->sc_tc, mark istate DONE
        st      R_tc, [R_fdc + FDC_TC]
        st      R_buf, [R_fdc + FDC_DATA]

        ! flip TC bit in auxreg
        FD_ASSERT_TC
        nop; nop; nop                           ! XXX
        FD_DEASSERT_TC
        b,a     x


sensei:
        ldub    [R_msr], %l7
        set     POLL_TIMO, %l6
1:      deccc   %l6                             ! timeout?
        be,a    ssi                             ! if so, set status
         mov    FDC_ISTATUS_ERROR, %l7          ! and post sw interrupt
        and     %l7, (NE7_RQM | NE7_DIO | NE7_CB), %l7
        cmp     %l7, NE7_RQM
        bne,a   1b                              ! loop till chip ready
         ldub   [R_msr], %l7
        mov     NE7CMD_SENSEI, %l7
        stb     %l7, [R_fifo]

resultphase:
        ! prepare for result phase
        add     R_fdc, FDC_STATUS, R_stat       ! &fdc->sc_status[0]
        mov     -1, %l7
        st      %l7, [R_fdc + FDC_NSTAT]        ! fdc->sc_nstat = -1;

resultphase1:
        clr     R_stcnt
        ldub    [R_msr], %l7
        set     POLL_TIMO, %l6
1:      deccc   %l6                             ! timeout?
        be,a    ssi                             ! if so, set status
         mov    FDC_ISTATUS_ERROR, %l7          ! and post sw interrupt
        and     %l7, (NE7_RQM | NE7_DIO | NE7_CB), %l7
        cmp     %l7, NE7_RQM
        be      3f                              ! done
        cmp     %l7, (NE7_RQM | NE7_DIO | NE7_CB)
        bne,a   1b                              ! loop till chip ready
         ldub   [R_msr], %l7

        cmp     R_stcnt, FDC_NSTATUS            ! status overrun?
        bge     2f                              ! if so, load but dont store
        ldub    [R_fifo], %l7                   ! load the status byte
        stb     %l7, [R_stat]
        inc     R_stat
        inc     R_stcnt
2:      b       1b
         ldub   [R_msr], %l7

3:
        ! got status, update sc_nstat and mark istate DONE
        st      R_stcnt, [R_fdc + FDC_NSTAT]
        mov     FDC_ISTATUS_DONE, %l7

ssi:
        ! set software interrupt
        ! enter here with status in %l7
        ! SMP: consider which CPU to ping?
        st      %l7, [R_fdc + FDC_ISTATUS]
        FD_SET_SWINTR

x:
        /*
         * Restore psr -- note: psr delay honored by pc restore loads.
         */
        set     save_l, %l7
        ldd     [%l7], %l0
        mov     %l0, %psr
         nop
        ld      [%l7 + 8], %l2
        jmp     %l1
        rett    %l2


.Lpanic_msg:
        .asciz  "fdc: overrun"
#endif