root/arch/parisc/kernel/unaligned.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *    Unaligned memory access handler
 *
 *    Copyright (C) 2001 Randolph Chung <tausq@debian.org>
 *    Copyright (C) 2022 Helge Deller <deller@gmx.de>
 *    Significantly tweaked by LaMont Jones <lamont@debian.org>
 */

#include <linux/sched/signal.h>
#include <linux/signal.h>
#include <linux/ratelimit.h>
#include <linux/uaccess.h>
#include <linux/sysctl.h>
#include <linux/unaligned.h>
#include <linux/perf_event.h>
#include <asm/hardirq.h>
#include <asm/traps.h>
#include "unaligned.h"

/* #define DEBUG_UNALIGNED 1 */

#ifdef DEBUG_UNALIGNED
#define DPRINTF(fmt, args...) do { printk(KERN_DEBUG "%s:%d:%s ", __FILE__, __LINE__, __func__ ); printk(KERN_DEBUG fmt, ##args ); } while (0)
#else
#define DPRINTF(fmt, args...)
#endif

#define RFMT "0x%08lx"

/* 1111 1100 0000 0000 0001 0011 1100 0000 */
#define OPCODE1(a,b,c)  ((a)<<26|(b)<<12|(c)<<6) 
#define OPCODE2(a,b)    ((a)<<26|(b)<<1)
#define OPCODE3(a,b)    ((a)<<26|(b)<<2)
#define OPCODE4(a)      ((a)<<26)
#define OPCODE1_MASK    OPCODE1(0x3f,1,0xf)
#define OPCODE2_MASK    OPCODE2(0x3f,1)
#define OPCODE3_MASK    OPCODE3(0x3f,1)
#define OPCODE4_MASK    OPCODE4(0x3f)

/* skip LDB - never unaligned (index) */
#define OPCODE_LDH_I    OPCODE1(0x03,0,0x1)
#define OPCODE_LDW_I    OPCODE1(0x03,0,0x2)
#define OPCODE_LDD_I    OPCODE1(0x03,0,0x3)
#define OPCODE_LDDA_I   OPCODE1(0x03,0,0x4)
#define OPCODE_LDCD_I   OPCODE1(0x03,0,0x5)
#define OPCODE_LDWA_I   OPCODE1(0x03,0,0x6)
#define OPCODE_LDCW_I   OPCODE1(0x03,0,0x7)
/* skip LDB - never unaligned (short) */
#define OPCODE_LDH_S    OPCODE1(0x03,1,0x1)
#define OPCODE_LDW_S    OPCODE1(0x03,1,0x2)
#define OPCODE_LDD_S    OPCODE1(0x03,1,0x3)
#define OPCODE_LDDA_S   OPCODE1(0x03,1,0x4)
#define OPCODE_LDCD_S   OPCODE1(0x03,1,0x5)
#define OPCODE_LDWA_S   OPCODE1(0x03,1,0x6)
#define OPCODE_LDCW_S   OPCODE1(0x03,1,0x7)
/* skip STB - never unaligned */
#define OPCODE_STH      OPCODE1(0x03,1,0x9)
#define OPCODE_STW      OPCODE1(0x03,1,0xa)
#define OPCODE_STD      OPCODE1(0x03,1,0xb)
/* skip STBY - never unaligned */
/* skip STDBY - never unaligned */
#define OPCODE_STWA     OPCODE1(0x03,1,0xe)
#define OPCODE_STDA     OPCODE1(0x03,1,0xf)

#define OPCODE_FLDWX    OPCODE1(0x09,0,0x0)
#define OPCODE_FLDWXR   OPCODE1(0x09,0,0x1)
#define OPCODE_FSTWX    OPCODE1(0x09,0,0x8)
#define OPCODE_FSTWXR   OPCODE1(0x09,0,0x9)
#define OPCODE_FLDWS    OPCODE1(0x09,1,0x0)
#define OPCODE_FLDWSR   OPCODE1(0x09,1,0x1)
#define OPCODE_FSTWS    OPCODE1(0x09,1,0x8)
#define OPCODE_FSTWSR   OPCODE1(0x09,1,0x9)
#define OPCODE_FLDDX    OPCODE1(0x0b,0,0x0)
#define OPCODE_FSTDX    OPCODE1(0x0b,0,0x8)
#define OPCODE_FLDDS    OPCODE1(0x0b,1,0x0)
#define OPCODE_FSTDS    OPCODE1(0x0b,1,0x8)

#define OPCODE_LDD_L    OPCODE2(0x14,0)
#define OPCODE_FLDD_L   OPCODE2(0x14,1)
#define OPCODE_STD_L    OPCODE2(0x1c,0)
#define OPCODE_FSTD_L   OPCODE2(0x1c,1)

#define OPCODE_LDW_M    OPCODE3(0x17,1)
#define OPCODE_FLDW_L   OPCODE3(0x17,0)
#define OPCODE_FSTW_L   OPCODE3(0x1f,0)
#define OPCODE_STW_M    OPCODE3(0x1f,1)

#define OPCODE_LDH_L    OPCODE4(0x11)
#define OPCODE_LDW_L    OPCODE4(0x12)
#define OPCODE_LDWM     OPCODE4(0x13)
#define OPCODE_STH_L    OPCODE4(0x19)
#define OPCODE_STW_L    OPCODE4(0x1A)
#define OPCODE_STWM     OPCODE4(0x1B)

#define MAJOR_OP(i) (((i)>>26)&0x3f)
#define R1(i) (((i)>>21)&0x1f)
#define R2(i) (((i)>>16)&0x1f)
#define R3(i) ((i)&0x1f)
#define FR3(i) ((((i)&0x1f)<<1)|(((i)>>6)&1))
#define IM(i,n) (((i)>>1&((1<<(n-1))-1))|((i)&1?((0-1L)<<(n-1)):0))
#define IM5_2(i) IM((i)>>16,5)
#define IM5_3(i) IM((i),5)
#define IM14(i) IM((i),14)

#define ERR_NOTHANDLED  -1

int unaligned_enabled __read_mostly = 1;
int no_unaligned_warning __read_mostly;

static int emulate_ldh(struct pt_regs *regs, int toreg)
{
        unsigned long saddr = regs->ior;
        unsigned long val = 0, temp1;
        ASM_EXCEPTIONTABLE_VAR(ret);

        DPRINTF("load " RFMT ":" RFMT " to r%d for 2 bytes\n", 
                regs->isr, regs->ior, toreg);

        __asm__ __volatile__  (
"       mtsp    %4, %%sr1\n"
"1:     ldbs    0(%%sr1,%3), %2\n"
"2:     ldbs    1(%%sr1,%3), %0\n"
"       depw    %2, 23, 24, %0\n"
"3:     \n"
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b, "%1")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b, "%1")
        : "+r" (val), "+r" (ret), "=&r" (temp1)
        : "r" (saddr), "r" (regs->isr) );

        DPRINTF("val = " RFMT "\n", val);

        if (toreg)
                regs->gr[toreg] = val;

        return ret;
}

static int emulate_ldw(struct pt_regs *regs, int toreg, int flop)
{
        unsigned long saddr = regs->ior;
        unsigned long val = 0, temp1, temp2;
        ASM_EXCEPTIONTABLE_VAR(ret);

        DPRINTF("load " RFMT ":" RFMT " to r%d for 4 bytes\n", 
                regs->isr, regs->ior, toreg);

        __asm__ __volatile__  (
"       zdep    %4,28,2,%2\n"           /* r19=(ofs&3)*8 */
"       mtsp    %5, %%sr1\n"
"       depw    %%r0,31,2,%4\n"
"1:     ldw     0(%%sr1,%4),%0\n"
"2:     ldw     4(%%sr1,%4),%3\n"
"       subi    32,%2,%2\n"
"       mtctl   %2,11\n"
"       vshd    %0,%3,%0\n"
"3:     \n"
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b, "%1")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b, "%1")
        : "+r" (val), "+r" (ret), "=&r" (temp1), "=&r" (temp2)
        : "r" (saddr), "r" (regs->isr) );

        DPRINTF("val = " RFMT "\n", val);

        if (flop)
                ((__u32*)(regs->fr))[toreg] = val;
        else if (toreg)
                regs->gr[toreg] = val;

        return ret;
}
static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
{
        unsigned long saddr = regs->ior;
        unsigned long shift, temp1;
        __u64 val = 0;
        ASM_EXCEPTIONTABLE_VAR(ret);

        DPRINTF("load " RFMT ":" RFMT " to r%d for 8 bytes\n", 
                regs->isr, regs->ior, toreg);

        if (!IS_ENABLED(CONFIG_64BIT) && !flop)
                return ERR_NOTHANDLED;

#ifdef CONFIG_64BIT
        __asm__ __volatile__  (
"       depd,z  %2,60,3,%3\n"           /* shift=(ofs&7)*8 */
"       mtsp    %5, %%sr1\n"
"       depd    %%r0,63,3,%2\n"
"1:     ldd     0(%%sr1,%2),%0\n"
"2:     ldd     8(%%sr1,%2),%4\n"
"       subi    64,%3,%3\n"
"       mtsar   %3\n"
"       shrpd   %0,%4,%%sar,%0\n"
"3:     \n"
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b, "%1")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b, "%1")
        : "+r" (val), "+r" (ret), "+r" (saddr), "=&r" (shift), "=&r" (temp1)
        : "r" (regs->isr) );
#else
        __asm__ __volatile__  (
"       zdep    %2,29,2,%3\n"           /* shift=(ofs&3)*8 */
"       mtsp    %5, %%sr1\n"
"       dep     %%r0,31,2,%2\n"
"1:     ldw     0(%%sr1,%2),%0\n"
"2:     ldw     4(%%sr1,%2),%R0\n"
"3:     ldw     8(%%sr1,%2),%4\n"
"       subi    32,%3,%3\n"
"       mtsar   %3\n"
"       vshd    %0,%R0,%0\n"
"       vshd    %R0,%4,%R0\n"
"4:     \n"
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 4b, "%1")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 4b, "%1")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 4b, "%1")
        : "+r" (val), "+r" (ret), "+r" (saddr), "=&r" (shift), "=&r" (temp1)
        : "r" (regs->isr) );
#endif

        DPRINTF("val = 0x%llx\n", val);

        if (flop)
                regs->fr[toreg] = val;
        else if (toreg)
                regs->gr[toreg] = val;

        return ret;
}

static int emulate_sth(struct pt_regs *regs, int frreg)
{
        unsigned long val = regs->gr[frreg], temp1;
        ASM_EXCEPTIONTABLE_VAR(ret);

        if (!frreg)
                val = 0;

        DPRINTF("store r%d (" RFMT ") to " RFMT ":" RFMT " for 2 bytes\n", frreg,
                val, regs->isr, regs->ior);

        __asm__ __volatile__ (
"       mtsp %4, %%sr1\n"
"       extrw,u %2, 23, 8, %1\n"
"1:     stb %1, 0(%%sr1, %3)\n"
"2:     stb %2, 1(%%sr1, %3)\n"
"3:     \n"
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b, "%0")
        : "+r" (ret), "=&r" (temp1)
        : "r" (val), "r" (regs->ior), "r" (regs->isr) );

        return ret;
}

static int emulate_stw(struct pt_regs *regs, int frreg, int flop)
{
        unsigned long val;
        ASM_EXCEPTIONTABLE_VAR(ret);

        if (flop)
                val = ((__u32*)(regs->fr))[frreg];
        else if (frreg)
                val = regs->gr[frreg];
        else
                val = 0;

        DPRINTF("store r%d (" RFMT ") to " RFMT ":" RFMT " for 4 bytes\n", frreg,
                val, regs->isr, regs->ior);


        __asm__ __volatile__ (
"       mtsp %3, %%sr1\n"
"       zdep    %2, 28, 2, %%r19\n"
"       dep     %%r0, 31, 2, %2\n"
"       mtsar   %%r19\n"
"       depwi,z -2, %%sar, 32, %%r19\n"
"1:     ldw     0(%%sr1,%2),%%r20\n"
"2:     ldw     4(%%sr1,%2),%%r21\n"
"       vshd    %%r0, %1, %%r22\n"
"       vshd    %1, %%r0, %%r1\n"
"       and     %%r20, %%r19, %%r20\n"
"       andcm   %%r21, %%r19, %%r21\n"
"       or      %%r22, %%r20, %%r20\n"
"       or      %%r1, %%r21, %%r21\n"
"       stw     %%r20,0(%%sr1,%2)\n"
"       stw     %%r21,4(%%sr1,%2)\n"
"3:     \n"
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b, "%0")
        : "+r" (ret)
        : "r" (val), "r" (regs->ior), "r" (regs->isr)
        : "r19", "r20", "r21", "r22", "r1" );

        return ret;
}
static int emulate_std(struct pt_regs *regs, int frreg, int flop)
{
        __u64 val;
        ASM_EXCEPTIONTABLE_VAR(ret);

        if (flop)
                val = regs->fr[frreg];
        else if (frreg)
                val = regs->gr[frreg];
        else
                val = 0;

        DPRINTF("store r%d (0x%016llx) to " RFMT ":" RFMT " for 8 bytes\n", frreg, 
                val,  regs->isr, regs->ior);

        if (!IS_ENABLED(CONFIG_64BIT) && !flop)
                return ERR_NOTHANDLED;

#ifdef CONFIG_64BIT
        __asm__ __volatile__ (
"       mtsp %3, %%sr1\n"
"       depd,z  %2, 60, 3, %%r19\n"
"       depd    %%r0, 63, 3, %2\n"
"       mtsar   %%r19\n"
"       depdi,z -2, %%sar, 64, %%r19\n"
"1:     ldd     0(%%sr1,%2),%%r20\n"
"2:     ldd     8(%%sr1,%2),%%r21\n"
"       shrpd   %%r0, %1, %%sar, %%r22\n"
"       shrpd   %1, %%r0, %%sar, %%r1\n"
"       and     %%r20, %%r19, %%r20\n"
"       andcm   %%r21, %%r19, %%r21\n"
"       or      %%r22, %%r20, %%r20\n"
"       or      %%r1, %%r21, %%r21\n"
"3:     std     %%r20,0(%%sr1,%2)\n"
"4:     std     %%r21,8(%%sr1,%2)\n"
"5:     \n"
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 5b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 5b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 5b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(4b, 5b, "%0")
        : "+r" (ret)
        : "r" (val), "r" (regs->ior), "r" (regs->isr)
        : "r19", "r20", "r21", "r22", "r1" );
#else
    {
        __asm__ __volatile__ (
"       mtsp    %3, %%sr1\n"
"       zdep    %R1, 29, 2, %%r19\n"
"       dep     %%r0, 31, 2, %2\n"
"       mtsar   %%r19\n"
"       zvdepi  -2, 32, %%r19\n"
"1:     ldw     0(%%sr1,%2),%%r20\n"
"2:     ldw     8(%%sr1,%2),%%r21\n"
"       vshd    %1, %R1, %%r1\n"
"       vshd    %%r0, %1, %1\n"
"       vshd    %R1, %%r0, %R1\n"
"       and     %%r20, %%r19, %%r20\n"
"       andcm   %%r21, %%r19, %%r21\n"
"       or      %1, %%r20, %1\n"
"       or      %R1, %%r21, %R1\n"
"3:     stw     %1,0(%%sr1,%2)\n"
"4:     stw     %%r1,4(%%sr1,%2)\n"
"5:     stw     %R1,8(%%sr1,%2)\n"
"6:     \n"
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 6b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 6b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 6b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(4b, 6b, "%0")
        ASM_EXCEPTIONTABLE_ENTRY_EFAULT(5b, 6b, "%0")
        : "+r" (ret)
        : "r" (val), "r" (regs->ior), "r" (regs->isr)
        : "r19", "r20", "r21", "r1" );
    }
#endif

        return ret;
}

void handle_unaligned(struct pt_regs *regs)
{
        static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
        unsigned long newbase = R1(regs->iir)?regs->gr[R1(regs->iir)]:0;
        int modify = 0;
        int ret = ERR_NOTHANDLED;

        __inc_irq_stat(irq_unaligned_count);
        perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, regs->ior);

        /* log a message with pacing */
        if (user_mode(regs)) {
                if (current->thread.flags & PARISC_UAC_SIGBUS) {
                        goto force_sigbus;
                }

                if (!(current->thread.flags & PARISC_UAC_NOPRINT) &&
                        __ratelimit(&ratelimit)) {
                        printk(KERN_WARNING "%s(%d): unaligned access to " RFMT
                                " at ip " RFMT " (iir " RFMT ")\n",
                                current->comm, task_pid_nr(current), regs->ior,
                                regs->iaoq[0], regs->iir);
#ifdef DEBUG_UNALIGNED
                        show_regs(regs);
#endif          
                }

                if (!unaligned_enabled)
                        goto force_sigbus;
        } else {
                static DEFINE_RATELIMIT_STATE(kernel_ratelimit, 5 * HZ, 5);
                if (!(current->thread.flags & PARISC_UAC_NOPRINT) &&
                        !no_unaligned_warning &&
                        __ratelimit(&kernel_ratelimit))
                        pr_warn("Kernel: unaligned access to " RFMT " in %pS "
                                        "(iir " RFMT ")\n",
                                regs->ior, (void *)regs->iaoq[0], regs->iir);
        }

        /* handle modification - OK, it's ugly, see the instruction manual */
        switch (MAJOR_OP(regs->iir))
        {
        case 0x03:
        case 0x09:
        case 0x0b:
                if (regs->iir&0x20)
                {
                        modify = 1;
                        if (regs->iir&0x1000)           /* short loads */
                                if (regs->iir&0x200)
                                        newbase += IM5_3(regs->iir);
                                else
                                        newbase += IM5_2(regs->iir);
                        else if (regs->iir&0x2000)      /* scaled indexed */
                        {
                                int shift=0;
                                switch (regs->iir & OPCODE1_MASK)
                                {
                                case OPCODE_LDH_I:
                                        shift= 1; break;
                                case OPCODE_LDW_I:
                                        shift= 2; break;
                                case OPCODE_LDD_I:
                                case OPCODE_LDDA_I:
                                        shift= 3; break;
                                }
                                newbase += (R2(regs->iir)?regs->gr[R2(regs->iir)]:0)<<shift;
                        } else                          /* simple indexed */
                                newbase += (R2(regs->iir)?regs->gr[R2(regs->iir)]:0);
                }
                break;
        case 0x13:
        case 0x1b:
                modify = 1;
                newbase += IM14(regs->iir);
                break;
        case 0x14:
        case 0x1c:
                if (regs->iir&8)
                {
                        modify = 1;
                        newbase += IM14(regs->iir&~0xe);
                }
                break;
        case 0x16:
        case 0x1e:
                modify = 1;
                newbase += IM14(regs->iir&6);
                break;
        case 0x17:
        case 0x1f:
                if (regs->iir&4)
                {
                        modify = 1;
                        newbase += IM14(regs->iir&~4);
                }
                break;
        }

        /* TODO: make this cleaner... */
        switch (regs->iir & OPCODE1_MASK)
        {
        case OPCODE_LDH_I:
        case OPCODE_LDH_S:
                ret = emulate_ldh(regs, R3(regs->iir));
                break;

        case OPCODE_LDW_I:
        case OPCODE_LDWA_I:
        case OPCODE_LDW_S:
        case OPCODE_LDWA_S:
                ret = emulate_ldw(regs, R3(regs->iir), 0);
                break;

        case OPCODE_STH:
                ret = emulate_sth(regs, R2(regs->iir));
                break;

        case OPCODE_STW:
        case OPCODE_STWA:
                ret = emulate_stw(regs, R2(regs->iir), 0);
                break;

#ifdef CONFIG_64BIT
        case OPCODE_LDD_I:
        case OPCODE_LDDA_I:
        case OPCODE_LDD_S:
        case OPCODE_LDDA_S:
                ret = emulate_ldd(regs, R3(regs->iir), 0);
                break;

        case OPCODE_STD:
        case OPCODE_STDA:
                ret = emulate_std(regs, R2(regs->iir), 0);
                break;
#endif

        case OPCODE_FLDWX:
        case OPCODE_FLDWS:
        case OPCODE_FLDWXR:
        case OPCODE_FLDWSR:
                ret = emulate_ldw(regs, FR3(regs->iir), 1);
                break;

        case OPCODE_FLDDX:
        case OPCODE_FLDDS:
                ret = emulate_ldd(regs, R3(regs->iir), 1);
                break;

        case OPCODE_FSTWX:
        case OPCODE_FSTWS:
        case OPCODE_FSTWXR:
        case OPCODE_FSTWSR:
                ret = emulate_stw(regs, FR3(regs->iir), 1);
                break;

        case OPCODE_FSTDX:
        case OPCODE_FSTDS:
                ret = emulate_std(regs, R3(regs->iir), 1);
                break;

        case OPCODE_LDCD_I:
        case OPCODE_LDCW_I:
        case OPCODE_LDCD_S:
        case OPCODE_LDCW_S:
                ret = ERR_NOTHANDLED;   /* "undefined", but lets kill them. */
                break;
        }
        switch (regs->iir & OPCODE2_MASK)
        {
        case OPCODE_FLDD_L:
                ret = emulate_ldd(regs,R2(regs->iir),1);
                break;
        case OPCODE_FSTD_L:
                ret = emulate_std(regs, R2(regs->iir),1);
                break;
#ifdef CONFIG_64BIT
        case OPCODE_LDD_L:
                ret = emulate_ldd(regs, R2(regs->iir),0);
                break;
        case OPCODE_STD_L:
                ret = emulate_std(regs, R2(regs->iir),0);
                break;
#endif
        }
        switch (regs->iir & OPCODE3_MASK)
        {
        case OPCODE_FLDW_L:
                ret = emulate_ldw(regs, R2(regs->iir), 1);
                break;
        case OPCODE_LDW_M:
                ret = emulate_ldw(regs, R2(regs->iir), 0);
                break;

        case OPCODE_FSTW_L:
                ret = emulate_stw(regs, R2(regs->iir),1);
                break;
        case OPCODE_STW_M:
                ret = emulate_stw(regs, R2(regs->iir),0);
                break;
        }
        switch (regs->iir & OPCODE4_MASK)
        {
        case OPCODE_LDH_L:
                ret = emulate_ldh(regs, R2(regs->iir));
                break;
        case OPCODE_LDW_L:
        case OPCODE_LDWM:
                ret = emulate_ldw(regs, R2(regs->iir),0);
                break;
        case OPCODE_STH_L:
                ret = emulate_sth(regs, R2(regs->iir));
                break;
        case OPCODE_STW_L:
        case OPCODE_STWM:
                ret = emulate_stw(regs, R2(regs->iir),0);
                break;
        }

        if (ret == 0 && modify && R1(regs->iir))
                regs->gr[R1(regs->iir)] = newbase;


        if (ret == ERR_NOTHANDLED)
                printk(KERN_CRIT "Not-handled unaligned insn 0x%08lx\n", regs->iir);

        DPRINTF("ret = %d\n", ret);

        if (ret)
        {
                /*
                 * The unaligned handler failed.
                 * If we were called by __get_user() or __put_user() jump
                 * to it's exception fixup handler instead of crashing.
                 */
                if (!user_mode(regs) && fixup_exception(regs))
                        return;

                printk(KERN_CRIT "Unaligned handler failed, ret = %d\n", ret);
                die_if_kernel("Unaligned data reference", regs, 28);

                if (ret == -EFAULT)
                {
                        force_sig_fault(SIGSEGV, SEGV_MAPERR,
                                        (void __user *)regs->ior);
                }
                else
                {
force_sigbus:
                        /* couldn't handle it ... */
                        force_sig_fault(SIGBUS, BUS_ADRALN,
                                        (void __user *)regs->ior);
                }
                
                return;
        }

        /* else we handled it, let life go on. */
        regs->gr[0]|=PSW_N;
}

/*
 * NB: check_unaligned() is only used for PCXS processors right
 * now, so we only check for PA1.1 encodings at this point.
 */

int
check_unaligned(struct pt_regs *regs)
{
        unsigned long align_mask;

        /* Get alignment mask */

        align_mask = 0UL;
        switch (regs->iir & OPCODE1_MASK) {

        case OPCODE_LDH_I:
        case OPCODE_LDH_S:
        case OPCODE_STH:
                align_mask = 1UL;
                break;

        case OPCODE_LDW_I:
        case OPCODE_LDWA_I:
        case OPCODE_LDW_S:
        case OPCODE_LDWA_S:
        case OPCODE_STW:
        case OPCODE_STWA:
                align_mask = 3UL;
                break;

        default:
                switch (regs->iir & OPCODE4_MASK) {
                case OPCODE_LDH_L:
                case OPCODE_STH_L:
                        align_mask = 1UL;
                        break;
                case OPCODE_LDW_L:
                case OPCODE_LDWM:
                case OPCODE_STW_L:
                case OPCODE_STWM:
                        align_mask = 3UL;
                        break;
                }
                break;
        }

        return (int)(regs->ior & align_mask);
}