/*
 * 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/sched/debug.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 <linux/uaccess.h>
#include <asm/io.h>
#include <asm/alignment.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/fpu.h>

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

        if ((pc & 3) == 1) {
                /* SHmedia */
                aligned_pc = pc & ~3;
                if (from_user_mode) {
                        if (!access_ok(VERIFY_READ, aligned_pc, sizeof(insn_size_t))) {
                                get_user_error = -EFAULT;
                        } else {
                                get_user_error = __get_user(opcode, (insn_size_t *)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 = *(insn_size_t *)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
}

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

        switch (1 << width_shift) {
        case 1: inc_unaligned_byte_access(); break;
        case 2: inc_unaligned_word_access(); break;
        case 4: inc_unaligned_dword_access(); break;
        case 8: inc_unaligned_multi_access(); break;
        }

        basereg = (opcode >> 20) & 0x3f;
        base_address = regs->regs[basereg];
        if (displacement_not_indexed) {
                __s64 displacement;
                displacement = (opcode >> 10) & 0x3ff;
                displacement = sign_extend64(displacement, 9);
                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)) {
                inc_unaligned_user_access();

                if (addr >= TASK_SIZE)
                        return -1;
        } else
                inc_unaligned_kernel_access();

        *address = addr;

        perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, addr);
        unaligned_fixups_notify(current, opcode, regs);

        return 0;
}

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,
                           insn_size_t 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;

        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,
                            insn_size_t 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;

        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,
                           insn_size_t 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;

        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,
                           insn_size_t 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;

        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)
{
        insn_size_t opcode;
        int error;
        int major, minor;
        unsigned int user_action;

        user_action = unaligned_user_action();
        if (!(user_action & UM_FIXUP))
                return -1;

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

        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 void do_unhandled_exception(int signr, char *str, unsigned long error,
                                   struct pt_regs *regs)
{
        if (user_mode(regs))
                force_sig(signr, current);

        die_if_no_fixup(str, regs, error);
}

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

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

#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
};

/* 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. */
void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
{
        insn_size_t opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
        unsigned long pc, aligned_pc;
        unsigned long index, shift;
        unsigned long major, minor, combined;
        unsigned long reserved_field;
        int opcode_state;
        int get_user_error;
        int signr = SIGILL;
        char *exception_name = "reserved_instruction";

        pc = regs->pc;

        /* SHcompact is not handled */
        if (unlikely((pc & 3) == 0))
                goto out;

        /* SHmedia : check for defect.  This requires executable vmas
           to be readable too. */
        aligned_pc = pc & ~3;
        if (!access_ok(VERIFY_READ, aligned_pc, sizeof(insn_size_t)))
                get_user_error = -EFAULT;
        else
                get_user_error = __get_user(opcode, (insn_size_t *)aligned_pc);

        if (get_user_error < 0) {
                /*
                 * Error trying to read opcode.  This typically means a
                 * real fault, not a RESINST any more.  So change the
                 * codes.
                 */
                exception_name = "address error (exec)";
                signr = SIGSEGV;
                goto out;
        }

        /* These bits are currently reserved as zero in all valid opcodes */
        reserved_field = opcode & 0xf;
        if (unlikely(reserved_field))
                goto out;       /* invalid opcode */

        major = (opcode >> 26) & 0x3f;
        minor = (opcode >> 16) & 0xf;
        combined = (major << 4) | minor;
        index = major;
        shift = minor << 1;
        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;

                        /* reserved/privileged control register => trap */
                } else if (combined == 0x1bf) { /* PUTCON */
                        unsigned long regno = (opcode >> 4) & 0x3f;

                        if (regno >= 62)
                                return;

                        /* reserved/privileged control register => trap */
                }

                break;
        default:
                /* Fall through to trap. */
                break;
        }

out:
        do_unhandled_exception(signr, exception_name, error_code, regs);
}

#else /* CONFIG_SH64_ID2815_WORKAROUND */

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

#endif /* CONFIG_SH64_ID2815_WORKAROUND */

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

asmlinkage 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;
}

/* 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. */

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

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

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