/*
 * arch/sh/kernel/traps_64.c
 *
 * Copyright (C) 2000, 2001  Paolo Alberelli
 * Copyright (C) 2003, 2004  Paul Mundt
 * Copyright (C) 2003, 2004  Richard Curnow
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
#include <linux/sysctl.h>
#include <linux/module.h>
#include <linux/perf_event.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/atomic.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/fpu.h>

#undef DEBUG_EXCEPTION
#ifdef DEBUG_EXCEPTION
/* implemented in ../lib/dbg.c */
extern void show_excp_regs(char *fname, int trapnr, int signr,
                           struct pt_regs *regs);
#else
#define show_excp_regs(a, b, c, d)
#endif

static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
                unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk);

#define DO_ERROR(trapnr, signr, str, name, tsk) \
asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \
{ \
        do_unhandled_exception(trapnr, signr, str, __stringify(name), error_code, regs, current); \
}

static DEFINE_SPINLOCK(die_lock);

void die(const char * str, struct pt_regs * regs, long err)
{
        console_verbose();
        spin_lock_irq(&die_lock);
        printk("%s: %lx\n", str, (err & 0xffffff));
        show_regs(regs);
        spin_unlock_irq(&die_lock);
        do_exit(SIGSEGV);
}

static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
{
        if (!user_mode(regs))
                die(str, regs, err);
}

static void die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
{
        if (!user_mode(regs)) {
                const struct exception_table_entry *fixup;
                fixup = search_exception_tables(regs->pc);
                if (fixup) {
                        regs->pc = fixup->fixup;
                        return;
                }
                die(str, regs, err);
        }
}

DO_ERROR(13, SIGILL,  "illegal slot instruction", illegal_slot_inst, current)
DO_ERROR(87, SIGSEGV, "address error (exec)", address_error_exec, current)


/* Implement misaligned load/store handling for kernel (and optionally for user
   mode too).  Limitation : only SHmedia mode code is handled - there is no
   handling at all for misaligned accesses occurring in SHcompact code yet. */

static int misaligned_fixup(struct pt_regs *regs);

asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs)
{
        if (misaligned_fixup(regs) < 0) {
                do_unhandled_exception(7, SIGSEGV, "address error(load)",
                                "do_address_error_load",
                                error_code, regs, current);
        }
        return;
}

asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs)
{
        if (misaligned_fixup(regs) < 0) {
                do_unhandled_exception(8, SIGSEGV, "address error(store)",
                                "do_address_error_store",
                                error_code, regs, current);
        }
        return;
}

#if defined(CONFIG_SH64_ID2815_WORKAROUND)

#define OPCODE_INVALID      0
#define OPCODE_USER_VALID   1
#define OPCODE_PRIV_VALID   2

/* getcon/putcon - requires checking which control register is referenced. */
#define OPCODE_CTRL_REG     3

/* Table of valid opcodes for SHmedia mode.
   Form a 10-bit value by concatenating the major/minor opcodes i.e.
   opcode[31:26,20:16].  The 6 MSBs of this value index into the following
   array.  The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to
   LSBs==4'b0000 etc). */
static unsigned long shmedia_opcode_table[64] = {
        0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015,
        0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000,
        0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000,
        0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000,
        0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
        0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
        0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
        0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000
};

void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
{
        /* Workaround SH5-101 cut2 silicon defect #2815 :
           in some situations, inter-mode branches from SHcompact -> SHmedia
           which should take ITLBMISS or EXECPROT exceptions at the target
           falsely take RESINST at the target instead. */

        unsigned long opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
        unsigned long pc, aligned_pc;
        int get_user_error;
        int trapnr = 12;
        int signr = SIGILL;
        char *exception_name = "reserved_instruction";

        pc = regs->pc;
        if ((pc & 3) == 1) {
                /* SHmedia : check for defect.  This requires executable vmas
                   to be readable too. */
                aligned_pc = pc & ~3;
                if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
                        get_user_error = -EFAULT;
                } else {
                        get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
                }
                if (get_user_error >= 0) {
                        unsigned long index, shift;
                        unsigned long major, minor, combined;
                        unsigned long reserved_field;
                        reserved_field = opcode & 0xf; /* These bits are currently reserved as zero in all valid opcodes */
                        major = (opcode >> 26) & 0x3f;
                        minor = (opcode >> 16) & 0xf;
                        combined = (major << 4) | minor;
                        index = major;
                        shift = minor << 1;
                        if (reserved_field == 0) {
                                int opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3;
                                switch (opcode_state) {
                                        case OPCODE_INVALID:
                                                /* Trap. */
                                                break;
                                        case OPCODE_USER_VALID:
                                                /* Restart the instruction : the branch to the instruction will now be from an RTE
                                                   not from SHcompact so the silicon defect won't be triggered. */
                                                return;
                                        case OPCODE_PRIV_VALID:
                                                if (!user_mode(regs)) {
                                                        /* Should only ever get here if a module has
                                                           SHcompact code inside it.  If so, the same fix up is needed. */
                                                        return; /* same reason */
                                                }
                                                /* Otherwise, user mode trying to execute a privileged instruction -
                                                   fall through to trap. */
                                                break;
                                        case OPCODE_CTRL_REG:
                                                /* If in privileged mode, return as above. */
                                                if (!user_mode(regs)) return;
                                                /* In user mode ... */
                                                if (combined == 0x9f) { /* GETCON */
                                                        unsigned long regno = (opcode >> 20) & 0x3f;
                                                        if (regno >= 62) {
                                                                return;
                                                        }
                                                        /* Otherwise, reserved or privileged control register, => trap */
                                                } else if (combined == 0x1bf) { /* PUTCON */
                                                        unsigned long regno = (opcode >> 4) & 0x3f;
                                                        if (regno >= 62) {
                                                                return;
                                                        }
                                                        /* Otherwise, reserved or privileged control register, => trap */
                                                } else {
                                                        /* Trap */
                                                }
                                                break;
                                        default:
                                                /* Fall through to trap. */
                                                break;
                                }
                        }
                        /* fall through to normal resinst processing */
                } else {
                        /* Error trying to read opcode.  This typically means a
                           real fault, not a RESINST any more.  So change the
                           codes. */
                        trapnr = 87;
                        exception_name = "address error (exec)";
                        signr = SIGSEGV;
                }
        }

        do_unhandled_exception(trapnr, signr, exception_name, "do_reserved_inst", error_code, regs, current);
}

#else /* CONFIG_SH64_ID2815_WORKAROUND */

/* If the workaround isn't needed, this is just a straightforward reserved
   instruction */
DO_ERROR(12, SIGILL,  "reserved instruction", reserved_inst, current)

#endif /* CONFIG_SH64_ID2815_WORKAROUND */

/* Called with interrupts disabled */
asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs)
{
        show_excp_regs(__func__, -1, -1, regs);
        die_if_kernel("exception", regs, ex);
}

int do_unknown_trapa(unsigned long scId, struct pt_regs *regs)
{
        /* Syscall debug */
        printk("System call ID error: [0x1#args:8 #syscall:16  0x%lx]\n", scId);

        die_if_kernel("unknown trapa", regs, scId);

        return -ENOSYS;
}

void show_stack(struct task_struct *tsk, unsigned long *sp)
{
#ifdef CONFIG_KALLSYMS
        extern void sh64_unwind(struct pt_regs *regs);
        struct pt_regs *regs;

        regs = tsk ? tsk->thread.kregs : NULL;

        sh64_unwind(regs);
#else
        printk(KERN_ERR "Can't backtrace on sh64 without CONFIG_KALLSYMS\n");
#endif
}

void show_task(unsigned long *sp)
{
        show_stack(NULL, sp);
}

void dump_stack(void)
{
        show_task(NULL);
}
/* Needed by any user of WARN_ON in view of the defn in include/asm-sh/bug.h */
EXPORT_SYMBOL(dump_stack);

static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
                unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk)
{
        show_excp_regs(fn_name, trapnr, signr, regs);
        tsk->thread.error_code = error_code;
        tsk->thread.trap_no = trapnr;

        if (user_mode(regs))
                force_sig(signr, tsk);

        die_if_no_fixup(str, regs, error_code);
}

static int read_opcode(unsigned long long pc, unsigned long *result_opcode, int from_user_mode)
{
        int get_user_error;
        unsigned long aligned_pc;
        unsigned long opcode;

        if ((pc & 3) == 1) {
                /* SHmedia */
                aligned_pc = pc & ~3;
                if (from_user_mode) {
                        if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
                                get_user_error = -EFAULT;
                        } else {
                                get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
                                *result_opcode = opcode;
                        }
                        return get_user_error;
                } else {
                        /* If the fault was in the kernel, we can either read
                         * this directly, or if not, we fault.
                        */
                        *result_opcode = *(unsigned long *) aligned_pc;
                        return 0;
                }
        } else if ((pc & 1) == 0) {
                /* SHcompact */
                /* TODO : provide handling for this.  We don't really support
                   user-mode SHcompact yet, and for a kernel fault, this would
                   have to come from a module built for SHcompact.  */
                return -EFAULT;
        } else {
                /* misaligned */
                return -EFAULT;
        }
}

static int address_is_sign_extended(__u64 a)
{
        __u64 b;
#if (NEFF == 32)
        b = (__u64)(__s64)(__s32)(a & 0xffffffffUL);
        return (b == a) ? 1 : 0;
#else
#error "Sign extend check only works for NEFF==32"
#endif
}

static int generate_and_check_address(struct pt_regs *regs,
                                      __u32 opcode,
                                      int displacement_not_indexed,
                                      int width_shift,
                                      __u64 *address)
{
        /* return -1 for fault, 0 for OK */

        __u64 base_address, addr;
        int basereg;

        basereg = (opcode >> 20) & 0x3f;
        base_address = regs->regs[basereg];
        if (displacement_not_indexed) {
                __s64 displacement;
                displacement = (opcode >> 10) & 0x3ff;
                displacement = ((displacement << 54) >> 54); /* sign extend */
                addr = (__u64)((__s64)base_address + (displacement << width_shift));
        } else {
                __u64 offset;
                int offsetreg;
                offsetreg = (opcode >> 10) & 0x3f;
                offset = regs->regs[offsetreg];
                addr = base_address + offset;
        }

        /* Check sign extended */
        if (!address_is_sign_extended(addr)) {
                return -1;
        }

        /* Check accessible.  For misaligned access in the kernel, assume the
           address is always accessible (and if not, just fault when the
           load/store gets done.) */
        if (user_mode(regs)) {
                if (addr >= TASK_SIZE) {
                        return -1;
                }
                /* Do access_ok check later - it depends on whether it's a load or a store. */
        }

        *address = addr;
        return 0;
}

static int user_mode_unaligned_fixup_count = 10;
static int user_mode_unaligned_fixup_enable = 1;
static int kernel_mode_unaligned_fixup_count = 32;

static void misaligned_kernel_word_load(__u64 address, int do_sign_extend, __u64 *result)
{
        unsigned short x;
        unsigned char *p, *q;
        p = (unsigned char *) (int) address;
        q = (unsigned char *) &x;
        q[0] = p[0];
        q[1] = p[1];

        if (do_sign_extend) {
                *result = (__u64)(__s64) *(short *) &x;
        } else {
                *result = (__u64) x;
        }
}

static void misaligned_kernel_word_store(__u64 address, __u64 value)
{
        unsigned short x;
        unsigned char *p, *q;
        p = (unsigned char *) (int) address;
        q = (unsigned char *) &x;

        x = (__u16) value;
        p[0] = q[0];
        p[1] = q[1];
}

static int misaligned_load(struct pt_regs *regs,
                           __u32 opcode,
                           int displacement_not_indexed,
                           int width_shift,
                           int do_sign_extend)
{
        /* Return -1 for a fault, 0 for OK */
        int error;
        int destreg;
        __u64 address;

        error = generate_and_check_address(regs, opcode,
                        displacement_not_indexed, width_shift, &address);
        if (error < 0) {
                return error;
        }

        perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, 0, regs, address);

        destreg = (opcode >> 4) & 0x3f;
        if (user_mode(regs)) {
                __u64 buffer;

                if (!access_ok(VERIFY_READ, (unsigned long) address, 1UL<<width_shift)) {
                        return -1;
                }

                if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
                        return -1; /* fault */
                }
                switch (width_shift) {
                case 1:
                        if (do_sign_extend) {
                                regs->regs[destreg] = (__u64)(__s64) *(__s16 *) &buffer;
                        } else {
                                regs->regs[destreg] = (__u64) *(__u16 *) &buffer;
                        }
                        break;
                case 2:
                        regs->regs[destreg] = (__u64)(__s64) *(__s32 *) &buffer;
                        break;
                case 3:
                        regs->regs[destreg] = buffer;
                        break;
                default:
                        printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
                                width_shift, (unsigned long) regs->pc);
                        break;
                }
        } else {
                /* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
                __u64 lo, hi;

                switch (width_shift) {
                case 1:
                        misaligned_kernel_word_load(address, do_sign_extend, &regs->regs[destreg]);
                        break;
                case 2:
                        asm ("ldlo.l %1, 0, %0" : "=r" (lo) : "r" (address));
                        asm ("ldhi.l %1, 3, %0" : "=r" (hi) : "r" (address));
                        regs->regs[destreg] = lo | hi;
                        break;
                case 3:
                        asm ("ldlo.q %1, 0, %0" : "=r" (lo) : "r" (address));
                        asm ("ldhi.q %1, 7, %0" : "=r" (hi) : "r" (address));
                        regs->regs[destreg] = lo | hi;
                        break;

                default:
                        printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
                                width_shift, (unsigned long) regs->pc);
                        break;
                }
        }

        return 0;

}

static int misaligned_store(struct pt_regs *regs,
                            __u32 opcode,
                            int displacement_not_indexed,
                            int width_shift)
{
        /* Return -1 for a fault, 0 for OK */
        int error;
        int srcreg;
        __u64 address;

        error = generate_and_check_address(regs, opcode,
                        displacement_not_indexed, width_shift, &address);
        if (error < 0) {
                return error;
        }

        perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, 0, regs, address);

        srcreg = (opcode >> 4) & 0x3f;
        if (user_mode(regs)) {
                __u64 buffer;

                if (!access_ok(VERIFY_WRITE, (unsigned long) address, 1UL<<width_shift)) {
                        return -1;
                }

                switch (width_shift) {
                case 1:
                        *(__u16 *) &buffer = (__u16) regs->regs[srcreg];
                        break;
                case 2:
                        *(__u32 *) &buffer = (__u32) regs->regs[srcreg];
                        break;
                case 3:
                        buffer = regs->regs[srcreg];
                        break;
                default:
                        printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
                                width_shift, (unsigned long) regs->pc);
                        break;
                }

                if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
                        return -1; /* fault */
                }
        } else {
                /* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
                __u64 val = regs->regs[srcreg];

                switch (width_shift) {
                case 1:
                        misaligned_kernel_word_store(address, val);
                        break;
                case 2:
                        asm ("stlo.l %1, 0, %0" : : "r" (val), "r" (address));
                        asm ("sthi.l %1, 3, %0" : : "r" (val), "r" (address));
                        break;
                case 3:
                        asm ("stlo.q %1, 0, %0" : : "r" (val), "r" (address));
                        asm ("sthi.q %1, 7, %0" : : "r" (val), "r" (address));
                        break;

                default:
                        printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
                                width_shift, (unsigned long) regs->pc);
                        break;
                }
        }

        return 0;

}

/* Never need to fix up misaligned FPU accesses within the kernel since that's a real
   error. */
static int misaligned_fpu_load(struct pt_regs *regs,
                           __u32 opcode,
                           int displacement_not_indexed,
                           int width_shift,
                           int do_paired_load)
{
        /* Return -1 for a fault, 0 for OK */
        int error;
        int destreg;
        __u64 address;

        error = generate_and_check_address(regs, opcode,
                        displacement_not_indexed, width_shift, &address);
        if (error < 0) {
                return error;
        }

        perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, 0, regs, address);

        destreg = (opcode >> 4) & 0x3f;
        if (user_mode(regs)) {
                __u64 buffer;
                __u32 buflo, bufhi;

                if (!access_ok(VERIFY_READ, (unsigned long) address, 1UL<<width_shift)) {
                        return -1;
                }

                if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
                        return -1; /* fault */
                }
                /* 'current' may be the current owner of the FPU state, so
                   context switch the registers into memory so they can be
                   indexed by register number. */
                if (last_task_used_math == current) {
                        enable_fpu();
                        save_fpu(current);
                        disable_fpu();
                        last_task_used_math = NULL;
                        regs->sr |= SR_FD;
                }

                buflo = *(__u32*) &buffer;
                bufhi = *(1 + (__u32*) &buffer);

                switch (width_shift) {
                case 2:
                        current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
                        break;
                case 3:
                        if (do_paired_load) {
                                current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
                                current->thread.xstate->hardfpu.fp_regs[destreg+1] = bufhi;
                        } else {
#if defined(CONFIG_CPU_LITTLE_ENDIAN)
                                current->thread.xstate->hardfpu.fp_regs[destreg] = bufhi;
                                current->thread.xstate->hardfpu.fp_regs[destreg+1] = buflo;
#else
                                current->thread.xstate->hardfpu.fp_regs[destreg] = buflo;
                                current->thread.xstate->hardfpu.fp_regs[destreg+1] = bufhi;
#endif
                        }
                        break;
                default:
                        printk("Unexpected width_shift %d in misaligned_fpu_load, PC=%08lx\n",
                                width_shift, (unsigned long) regs->pc);
                        break;
                }
                return 0;
        } else {
                die ("Misaligned FPU load inside kernel", regs, 0);
                return -1;
        }


}

static int misaligned_fpu_store(struct pt_regs *regs,
                           __u32 opcode,
                           int displacement_not_indexed,
                           int width_shift,
                           int do_paired_load)
{
        /* Return -1 for a fault, 0 for OK */
        int error;
        int srcreg;
        __u64 address;

        error = generate_and_check_address(regs, opcode,
                        displacement_not_indexed, width_shift, &address);
        if (error < 0) {
                return error;
        }

        perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, 0, regs, address);

        srcreg = (opcode >> 4) & 0x3f;
        if (user_mode(regs)) {
                __u64 buffer;
                /* Initialise these to NaNs. */
                __u32 buflo=0xffffffffUL, bufhi=0xffffffffUL;

                if (!access_ok(VERIFY_WRITE, (unsigned long) address, 1UL<<width_shift)) {
                        return -1;
                }

                /* 'current' may be the current owner of the FPU state, so
                   context switch the registers into memory so they can be
                   indexed by register number. */
                if (last_task_used_math == current) {
                        enable_fpu();
                        save_fpu(current);
                        disable_fpu();
                        last_task_used_math = NULL;
                        regs->sr |= SR_FD;
                }

                switch (width_shift) {
                case 2:
                        buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
                        break;
                case 3:
                        if (do_paired_load) {
                                buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
                                bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
                        } else {
#if defined(CONFIG_CPU_LITTLE_ENDIAN)
                                bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg];
                                buflo = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
#else
                                buflo = current->thread.xstate->hardfpu.fp_regs[srcreg];
                                bufhi = current->thread.xstate->hardfpu.fp_regs[srcreg+1];
#endif
                        }
                        break;
                default:
                        printk("Unexpected width_shift %d in misaligned_fpu_store, PC=%08lx\n",
                                width_shift, (unsigned long) regs->pc);
                        break;
                }

                *(__u32*) &buffer = buflo;
                *(1 + (__u32*) &buffer) = bufhi;
                if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
                        return -1; /* fault */
                }
                return 0;
        } else {
                die ("Misaligned FPU load inside kernel", regs, 0);
                return -1;
        }
}

static int misaligned_fixup(struct pt_regs *regs)
{
        unsigned long opcode;
        int error;
        int major, minor;

        if (!user_mode_unaligned_fixup_enable)
                return -1;

        error = read_opcode(regs->pc, &opcode, user_mode(regs));
        if (error < 0) {
                return error;
        }
        major = (opcode >> 26) & 0x3f;
        minor = (opcode >> 16) & 0xf;

        if (user_mode(regs) && (user_mode_unaligned_fixup_count > 0)) {
                --user_mode_unaligned_fixup_count;
                /* Only do 'count' worth of these reports, to remove a potential DoS against syslog */
                printk("Fixing up unaligned userspace access in \"%s\" pid=%d pc=0x%08x ins=0x%08lx\n",
                       current->comm, task_pid_nr(current), (__u32)regs->pc, opcode);
        } else if (!user_mode(regs) && (kernel_mode_unaligned_fixup_count > 0)) {
                --kernel_mode_unaligned_fixup_count;
                if (in_interrupt()) {
                        printk("Fixing up unaligned kernelspace access in interrupt pc=0x%08x ins=0x%08lx\n",
                               (__u32)regs->pc, opcode);
                } else {
                        printk("Fixing up unaligned kernelspace access in \"%s\" pid=%d pc=0x%08x ins=0x%08lx\n",
                               current->comm, task_pid_nr(current), (__u32)regs->pc, opcode);
                }
        }


        switch (major) {
                case (0x84>>2): /* LD.W */
                        error = misaligned_load(regs, opcode, 1, 1, 1);
                        break;
                case (0xb0>>2): /* LD.UW */
                        error = misaligned_load(regs, opcode, 1, 1, 0);
                        break;
                case (0x88>>2): /* LD.L */
                        error = misaligned_load(regs, opcode, 1, 2, 1);
                        break;
                case (0x8c>>2): /* LD.Q */
                        error = misaligned_load(regs, opcode, 1, 3, 0);
                        break;

                case (0xa4>>2): /* ST.W */
                        error = misaligned_store(regs, opcode, 1, 1);
                        break;
                case (0xa8>>2): /* ST.L */
                        error = misaligned_store(regs, opcode, 1, 2);
                        break;
                case (0xac>>2): /* ST.Q */
                        error = misaligned_store(regs, opcode, 1, 3);
                        break;

                case (0x40>>2): /* indexed loads */
                        switch (minor) {
                                case 0x1: /* LDX.W */
                                        error = misaligned_load(regs, opcode, 0, 1, 1);
                                        break;
                                case 0x5: /* LDX.UW */
                                        error = misaligned_load(regs, opcode, 0, 1, 0);
                                        break;
                                case 0x2: /* LDX.L */
                                        error = misaligned_load(regs, opcode, 0, 2, 1);
                                        break;
                                case 0x3: /* LDX.Q */
                                        error = misaligned_load(regs, opcode, 0, 3, 0);
                                        break;
                                default:
                                        error = -1;
                                        break;
                        }
                        break;

                case (0x60>>2): /* indexed stores */
                        switch (minor) {
                                case 0x1: /* STX.W */
                                        error = misaligned_store(regs, opcode, 0, 1);
                                        break;
                                case 0x2: /* STX.L */
                                        error = misaligned_store(regs, opcode, 0, 2);
                                        break;
                                case 0x3: /* STX.Q */
                                        error = misaligned_store(regs, opcode, 0, 3);
                                        break;
                                default:
                                        error = -1;
                                        break;
                        }
                        break;

                case (0x94>>2): /* FLD.S */
                        error = misaligned_fpu_load(regs, opcode, 1, 2, 0);
                        break;
                case (0x98>>2): /* FLD.P */
                        error = misaligned_fpu_load(regs, opcode, 1, 3, 1);
                        break;
                case (0x9c>>2): /* FLD.D */
                        error = misaligned_fpu_load(regs, opcode, 1, 3, 0);
                        break;
                case (0x1c>>2): /* floating indexed loads */
                        switch (minor) {
                        case 0x8: /* FLDX.S */
                                error = misaligned_fpu_load(regs, opcode, 0, 2, 0);
                                break;
                        case 0xd: /* FLDX.P */
                                error = misaligned_fpu_load(regs, opcode, 0, 3, 1);
                                break;
                        case 0x9: /* FLDX.D */
                                error = misaligned_fpu_load(regs, opcode, 0, 3, 0);
                                break;
                        default:
                                error = -1;
                                break;
                        }
                        break;
                case (0xb4>>2): /* FLD.S */
                        error = misaligned_fpu_store(regs, opcode, 1, 2, 0);
                        break;
                case (0xb8>>2): /* FLD.P */
                        error = misaligned_fpu_store(regs, opcode, 1, 3, 1);
                        break;
                case (0xbc>>2): /* FLD.D */
                        error = misaligned_fpu_store(regs, opcode, 1, 3, 0);
                        break;
                case (0x3c>>2): /* floating indexed stores */
                        switch (minor) {
                        case 0x8: /* FSTX.S */
                                error = misaligned_fpu_store(regs, opcode, 0, 2, 0);
                                break;
                        case 0xd: /* FSTX.P */
                                error = misaligned_fpu_store(regs, opcode, 0, 3, 1);
                                break;
                        case 0x9: /* FSTX.D */
                                error = misaligned_fpu_store(regs, opcode, 0, 3, 0);
                                break;
                        default:
                                error = -1;
                                break;
                        }
                        break;

                default:
                        /* Fault */
                        error = -1;
                        break;
        }

        if (error < 0) {
                return error;
        } else {
                regs->pc += 4; /* Skip the instruction that's just been emulated */
                return 0;
        }

}

static ctl_table unaligned_table[] = {
        {
                .procname       = "kernel_reports",
                .data           = &kernel_mode_unaligned_fixup_count,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "user_reports",
                .data           = &user_mode_unaligned_fixup_count,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec
        },
        {
                .procname       = "user_enable",
                .data           = &user_mode_unaligned_fixup_enable,
                .maxlen         = sizeof(int),
                .mode           = 0644,
                .proc_handler   = proc_dointvec},
        {}
};

static ctl_table unaligned_root[] = {
        {
                .procname       = "unaligned_fixup",
                .mode           = 0555,
                .child          = unaligned_table
        },
        {}
};

static ctl_table sh64_root[] = {
        {
                .procname       = "sh64",
                .mode           = 0555,
                .child          = unaligned_root
        },
        {}
};
static struct ctl_table_header *sysctl_header;
static int __init init_sysctl(void)
{
        sysctl_header = register_sysctl_table(sh64_root);
        return 0;
}

__initcall(init_sysctl);


asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs)
{
        u64 peek_real_address_q(u64 addr);
        u64 poke_real_address_q(u64 addr, u64 val);
        unsigned long long DM_EXP_CAUSE_PHY = 0x0c100010;
        unsigned long long exp_cause;
        /* It's not worth ioremapping the debug module registers for the amount
           of access we make to them - just go direct to their physical
           addresses. */
        exp_cause = peek_real_address_q(DM_EXP_CAUSE_PHY);
        if (exp_cause & ~4) {
                printk("DM.EXP_CAUSE had unexpected bits set (=%08lx)\n",
                        (unsigned long)(exp_cause & 0xffffffff));
        }
        show_state();
        /* Clear all DEBUGINT causes */
        poke_real_address_q(DM_EXP_CAUSE_PHY, 0x0);
}

void __cpuinit per_cpu_trap_init(void)
{
        /* Nothing to do for now, VBR initialization later. */
}