/*
 *  MIPS emulation helpers for qemu.
 *
 *  Copyright (c) 2004-2005 Jocelyn Mayer
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "unicorn/platform.h"
#include <signal.h>

#include "cpu.h"
#include "exec/cpu_ldst.h"

enum {
    TLBRET_XI = -6,
    TLBRET_RI = -5,
    TLBRET_DIRTY = -4,
    TLBRET_INVALID = -3,
    TLBRET_NOMATCH = -2,
    TLBRET_BADADDR = -1,
    TLBRET_MATCH = 0
};

#if !defined(CONFIG_USER_ONLY)

/* no MMU emulation */
int no_mmu_map_address (CPUMIPSState *env, hwaddr *physical, int *prot,
                        target_ulong address, int rw, int access_type)
{
    *physical = address;
    *prot = PAGE_READ | PAGE_WRITE;
    return TLBRET_MATCH;
}

/* fixed mapping MMU emulation */
int fixed_mmu_map_address (CPUMIPSState *env, hwaddr *physical, int *prot,
                           target_ulong address, int rw, int access_type)
{
    if (address <= (int32_t)0x7FFFFFFFUL) {
        if (!(env->CP0_Status & (1 << CP0St_ERL)))
            *physical = address + 0x40000000UL;
        else
            *physical = address;
    } else if (address <= (int32_t)0xBFFFFFFFUL)
        *physical = address & 0x1FFFFFFF;
    else
        *physical = address;

    *prot = PAGE_READ | PAGE_WRITE;
    return TLBRET_MATCH;
}

/* MIPS32/MIPS64 R4000-style MMU emulation */
int r4k_map_address (CPUMIPSState *env, hwaddr *physical, int *prot,
                     target_ulong address, int rw, int access_type)
{
    uint8_t ASID = env->CP0_EntryHi & 0xFF;
    int i;

    for (i = 0; i < env->tlb->tlb_in_use; i++) {
        r4k_tlb_t *tlb = &env->tlb->mmu.r4k.tlb[i];
        /* 1k pages are not supported. */
        target_ulong mask = tlb->PageMask | ~(((unsigned int)TARGET_PAGE_MASK) << 1);
        target_ulong tag = address & ~mask;
        target_ulong VPN = tlb->VPN & ~mask;
#if defined(TARGET_MIPS64)
        tag &= env->SEGMask;
#endif

        /* Check ASID, virtual page number & size */
        if ((tlb->G == 1 || tlb->ASID == ASID) && VPN == tag && !tlb->EHINV) {
            /* TLB match */
            int n = !!(address & mask & ~(mask >> 1));
            /* Check access rights */
            if (!(n ? tlb->V1 : tlb->V0)) {
                return TLBRET_INVALID;
            }
            if (rw == MMU_INST_FETCH && (n ? tlb->XI1 : tlb->XI0)) {
                return TLBRET_XI;
            }
            if (rw == MMU_DATA_LOAD && (n ? tlb->RI1 : tlb->RI0)) {
                return TLBRET_RI;
            }
            if (rw != MMU_DATA_STORE || (n ? tlb->D1 : tlb->D0)) {
                *physical = tlb->PFN[n] | (address & (mask >> 1));
                *prot = PAGE_READ;
                if (n ? tlb->D1 : tlb->D0)
                    *prot |= PAGE_WRITE;
                return TLBRET_MATCH;
            }
            return TLBRET_DIRTY;
        }
    }
    return TLBRET_NOMATCH;
}

static int get_physical_address (CPUMIPSState *env, hwaddr *physical,
                                int *prot, target_ulong real_address,
                                int rw, int access_type)
{
    /* User mode can only access useg/xuseg */
    int user_mode = (env->hflags & MIPS_HFLAG_MODE) == MIPS_HFLAG_UM;
    int supervisor_mode = (env->hflags & MIPS_HFLAG_MODE) == MIPS_HFLAG_SM;
    int kernel_mode = !user_mode && !supervisor_mode;
#if defined(TARGET_MIPS64)
    int UX = (env->CP0_Status & (1 << CP0St_UX)) != 0;
    int SX = (env->CP0_Status & (1 << CP0St_SX)) != 0;
    int KX = (env->CP0_Status & (1 << CP0St_KX)) != 0;
#endif
    int ret = TLBRET_MATCH;
    /* effective address (modified for KVM T&E kernel segments) */
    target_ulong address = real_address;

#if 0
    qemu_log("user mode %d h %08x\n", user_mode, env->hflags);
#endif

#define USEG_LIMIT      0x7FFFFFFFUL
#define KSEG0_BASE      0x80000000UL
#define KSEG1_BASE      0xA0000000UL
#define KSEG2_BASE      0xC0000000UL
#define KSEG3_BASE      0xE0000000UL

#define KVM_KSEG0_BASE  0x40000000UL
#define KVM_KSEG2_BASE  0x60000000UL

    if (address <= USEG_LIMIT) {
        /* useg */
        if (env->CP0_Status & (1 << CP0St_ERL)) {
            *physical = address & 0xFFFFFFFF;
            *prot = PAGE_READ | PAGE_WRITE;
        } else {
            ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
        }
#if defined(TARGET_MIPS64)
    } else if (address < 0x4000000000000000ULL) {
        /* xuseg */
        if (UX && address <= (0x3FFFFFFFFFFFFFFFULL & env->SEGMask)) {
            ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
        } else {
            ret = TLBRET_BADADDR;
        }
    } else if (address < 0x8000000000000000ULL) {
        /* xsseg */
        if ((supervisor_mode || kernel_mode) &&
            SX && address <= (0x7FFFFFFFFFFFFFFFULL & env->SEGMask)) {
            ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
        } else {
            ret = TLBRET_BADADDR;
        }
    } else if (address < 0xC000000000000000ULL) {
        /* xkphys */
        if (kernel_mode && KX &&
            (address & 0x07FFFFFFFFFFFFFFULL) <= env->PAMask) {
            *physical = address & env->PAMask;
            *prot = PAGE_READ | PAGE_WRITE;
        } else {
            ret = TLBRET_BADADDR;
        }
    } else if (address < 0xFFFFFFFF80000000ULL) {
        /* xkseg */
        if (kernel_mode && KX &&
            address <= (0xFFFFFFFF7FFFFFFFULL & env->SEGMask)) {
            ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
        } else {
            ret = TLBRET_BADADDR;
        }
#endif
    } else if (address < (int32_t)KSEG1_BASE) {
        /* kseg0 */
        if (kernel_mode) {
            *physical = address - (int32_t)KSEG0_BASE;
            *prot = PAGE_READ | PAGE_WRITE;
        } else {
            ret = TLBRET_BADADDR;
        }
    } else if (address < (int32_t)KSEG2_BASE) {
        /* kseg1 */
        if (kernel_mode) {
            *physical = address - (int32_t)KSEG1_BASE;
            *prot = PAGE_READ | PAGE_WRITE;
        } else {
            ret = TLBRET_BADADDR;
        }
    } else if (address < (int32_t)KSEG3_BASE) {
        /* sseg (kseg2) */
        if (supervisor_mode || kernel_mode) {
            ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
        } else {
            ret = TLBRET_BADADDR;
        }
    } else {
        /* kseg3 */
        /* XXX: debug segment is not emulated */
        if (kernel_mode) {
            ret = env->tlb->map_address(env, physical, prot, real_address, rw, access_type);
        } else {
            ret = TLBRET_BADADDR;
        }
    }
#if 0
    qemu_log(TARGET_FMT_lx " %d %d => %" HWADDR_PRIx " %d (%d)\n",
            address, rw, access_type, *physical, *prot, ret);
#endif

    return ret;
}
#endif

static void raise_mmu_exception(CPUMIPSState *env, target_ulong address,
                                int rw, int tlb_error)
{
    CPUState *cs = CPU(mips_env_get_cpu(env));
    int exception = 0, error_code = 0;

    if (rw == MMU_INST_FETCH) {
        error_code |= EXCP_INST_NOTAVAIL;
    }

    switch (tlb_error) {
    default:
    case TLBRET_BADADDR:
        /* Reference to kernel address from user mode or supervisor mode */
        /* Reference to supervisor address from user mode */
        if (rw == MMU_DATA_STORE) {
            exception = EXCP_AdES;
        } else {
            exception = EXCP_AdEL;
        }
        break;
    case TLBRET_NOMATCH:
        /* No TLB match for a mapped address */
        if (rw == MMU_DATA_STORE) {
            exception = EXCP_TLBS;
        } else {
            exception = EXCP_TLBL;
        }
        error_code |= EXCP_TLB_NOMATCH;
        break;
    case TLBRET_INVALID:
        /* TLB match with no valid bit */
        if (rw == MMU_DATA_STORE) {
            exception = EXCP_TLBS;
        } else {
            exception = EXCP_TLBL;
        }
        break;
    case TLBRET_DIRTY:
        /* TLB match but 'D' bit is cleared */
        exception = EXCP_LTLBL;
        break;
    case TLBRET_XI:
        /* Execute-Inhibit Exception */
        if (env->CP0_PageGrain & (1 << CP0PG_IEC)) {
            exception = EXCP_TLBXI;
        } else {
            exception = EXCP_TLBL;
        }
        break;
    case TLBRET_RI:
        /* Read-Inhibit Exception */
        if (env->CP0_PageGrain & (1 << CP0PG_IEC)) {
            exception = EXCP_TLBRI;
        } else {
            exception = EXCP_TLBL;
        }
        break;
    }
    /* Raise exception */
    env->CP0_BadVAddr = address;
    env->CP0_Context = (env->CP0_Context & ~0x007fffff) |
                       ((address >> 9) & 0x007ffff0);
    env->CP0_EntryHi =
        (env->CP0_EntryHi & 0xFF) | (address & (((unsigned int)TARGET_PAGE_MASK) << 1));
#if defined(TARGET_MIPS64)
    env->CP0_EntryHi &= env->SEGMask;
    env->CP0_XContext = (env->CP0_XContext & ((~0ULL) << (env->SEGBITS - 7))) |
                        ((address & 0xC00000000000ULL) >> (55 - env->SEGBITS)) |
                        ((address & ((1ULL << env->SEGBITS) - 1) & 0xFFFFFFFFFFFFE000ULL) >> 9);
#endif
    cs->exception_index = exception;
    env->error_code = error_code;
}

#if !defined(CONFIG_USER_ONLY)
hwaddr mips_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
{
    MIPSCPU *cpu = MIPS_CPU(cs->uc, cs);
    hwaddr phys_addr;
    int prot;

    if (get_physical_address(&cpu->env, &phys_addr, &prot, addr, 0,
                             ACCESS_INT) != 0) {
        return -1;
    }
    return phys_addr;
}
#endif

int mips_cpu_handle_mmu_fault(CPUState *cs, vaddr address, int rw,
                              int mmu_idx)
{
    MIPSCPU *cpu = MIPS_CPU(cs->uc, cs);
    CPUMIPSState *env = &cpu->env;
#if !defined(CONFIG_USER_ONLY)
    hwaddr physical;
    int prot;
    int access_type;
#endif
    int ret = 0;

#if 0
    log_cpu_state(cs, 0);
#endif
    qemu_log("%s pc " TARGET_FMT_lx " ad %" VADDR_PRIx " rw %d mmu_idx %d\n",
              __func__, env->active_tc.PC, address, rw, mmu_idx);

    /* data access */
#if !defined(CONFIG_USER_ONLY)
    /* XXX: put correct access by using cpu_restore_state()
       correctly */
    access_type = ACCESS_INT;
    ret = get_physical_address(env, &physical, &prot,
                               address, rw, access_type);
    qemu_log("%s address=%" VADDR_PRIx " ret %d physical " TARGET_FMT_plx
             " prot %d\n",
             __func__, address, ret, physical, prot);
    if (ret == TLBRET_MATCH) {
      if (mmu_idx < 0 || mmu_idx >= NB_MMU_MODES) {
        raise_mmu_exception(env, address, rw, ret);
        ret = 1;
      } else {
        tlb_set_page(cs, address & TARGET_PAGE_MASK,
                     physical & TARGET_PAGE_MASK, prot | PAGE_EXEC,
                     mmu_idx, TARGET_PAGE_SIZE);
        ret = 0;
      }
    } else if (ret < 0)
#endif
    {
        raise_mmu_exception(env, address, rw, ret);
        ret = 1;
    }

    return ret;
}

#if !defined(CONFIG_USER_ONLY)
hwaddr cpu_mips_translate_address(CPUMIPSState *env, target_ulong address, int rw)
{
    hwaddr physical;
    int prot;
    int access_type;
    int ret = 0;

    /* data access */
    access_type = ACCESS_INT;
    ret = get_physical_address(env, &physical, &prot,
                               address, rw, access_type);
    if (ret != TLBRET_MATCH) {
        raise_mmu_exception(env, address, rw, ret);
        return -1LL;
    } else {
        return physical;
    }
}
#endif

static const char * const excp_names[EXCP_LAST + 1] = {
    "reset",
    "soft reset",
    "debug single step",
    "debug interrupt",
    "debug data break load",
    "debug data break store",
    "non-maskable interrupt",
    "machine check",
    "interrupt",
    "deferred watchpoint",
    "debug instruction breakpoint",
    "instruction fetch watchpoint",
    "address error load",
    "address error store",
    "TLB refill",
    "instruction bus error",
    "debug breakpoint",
    "syscall",
    "break",
    "coprocessor unusable",
    "reserved instruction",
    "arithmetic overflow",
    "trap",
    "floating point",
    "data watchpoint",
    "TLB modify",
    "TLB load",
    "TLB store",
    "data bus error",
    "thread",
    "MDMX",
    "precise coprocessor 2",
    "cache error",
    "DSP disabled",
    "MSA disabled",
    "MSA floating point",
    "TLB execute-inhibit",
    "TLB read-inhibit",
};

target_ulong exception_resume_pc (CPUMIPSState *env)
{
    target_ulong bad_pc;
    target_ulong isa_mode;

    isa_mode = !!(env->hflags & MIPS_HFLAG_M16);
    bad_pc = env->active_tc.PC | isa_mode;
    if (env->hflags & MIPS_HFLAG_BMASK) {
        /* If the exception was raised from a delay slot, come back to
           the jump.  */
        bad_pc -= (env->hflags & MIPS_HFLAG_B16 ? 2 : 4);
    }

    return bad_pc;
}

#if !defined(CONFIG_USER_ONLY)
static void set_hflags_for_handler (CPUMIPSState *env)
{
    /* Exception handlers are entered in 32-bit mode.  */
    env->hflags &= ~(MIPS_HFLAG_M16);
    /* ...except that microMIPS lets you choose.  */
    if (env->insn_flags & ASE_MICROMIPS) {
        env->hflags |= (!!(env->CP0_Config3
                           & (1 << CP0C3_ISA_ON_EXC))
                        << MIPS_HFLAG_M16_SHIFT);
    }
}

static inline void set_badinstr_registers(CPUMIPSState *env)
{
    if (env->hflags & MIPS_HFLAG_M16) {
        /* TODO: add BadInstr support for microMIPS */
        return;
    }
    if (env->CP0_Config3 & (1 << CP0C3_BI)) {
        env->CP0_BadInstr = cpu_ldl_code(env, env->active_tc.PC);
    }
    if ((env->CP0_Config3 & (1 << CP0C3_BP)) &&
        (env->hflags & MIPS_HFLAG_BMASK)) {
        env->CP0_BadInstrP = cpu_ldl_code(env, env->active_tc.PC - 4);
    }
}
#endif

void mips_cpu_do_interrupt(CPUState *cs)
{
#if !defined(CONFIG_USER_ONLY)
    MIPSCPU *cpu = MIPS_CPU(cs->uc, cs);
    CPUMIPSState *env = &cpu->env;
    bool update_badinstr = 0;
    target_ulong offset;
    int cause = -1;
    const char *name;

    if (qemu_log_enabled() && cs->exception_index != EXCP_EXT_INTERRUPT) {
        if (cs->exception_index < 0 || cs->exception_index > EXCP_LAST) {
            name = "unknown";
        } else {
            name = excp_names[cs->exception_index];
        }

        qemu_log("%s enter: PC " TARGET_FMT_lx " EPC " TARGET_FMT_lx " %s exception\n",
                 __func__, env->active_tc.PC, env->CP0_EPC, name);
    }
    if (cs->exception_index == EXCP_EXT_INTERRUPT &&
        (env->hflags & MIPS_HFLAG_DM)) {
        cs->exception_index = EXCP_DINT;
    }
    offset = 0x180;
    switch (cs->exception_index) {
    case EXCP_DSS:
        env->CP0_Debug |= 1 << CP0DB_DSS;
        /* Debug single step cannot be raised inside a delay slot and
           resume will always occur on the next instruction
           (but we assume the pc has always been updated during
           code translation). */
        env->CP0_DEPC = env->active_tc.PC | !!(env->hflags & MIPS_HFLAG_M16);
        goto enter_debug_mode;
    case EXCP_DINT:
        env->CP0_Debug |= 1 << CP0DB_DINT;
        goto set_DEPC;
    case EXCP_DIB:
        env->CP0_Debug |= 1 << CP0DB_DIB;
        goto set_DEPC;
    case EXCP_DBp:
        env->CP0_Debug |= 1 << CP0DB_DBp;
        goto set_DEPC;
    case EXCP_DDBS:
        env->CP0_Debug |= 1 << CP0DB_DDBS;
        goto set_DEPC;
    case EXCP_DDBL:
        env->CP0_Debug |= 1 << CP0DB_DDBL;
    set_DEPC:
        env->CP0_DEPC = exception_resume_pc(env);
        env->hflags &= ~MIPS_HFLAG_BMASK;
 enter_debug_mode:
        env->hflags |= MIPS_HFLAG_DM | MIPS_HFLAG_64 | MIPS_HFLAG_CP0;
        env->hflags &= ~(MIPS_HFLAG_KSU);
        /* EJTAG probe trap enable is not implemented... */
        if (!(env->CP0_Status & (1 << CP0St_EXL)))
            env->CP0_Cause &= ~(1U << CP0Ca_BD);
        env->active_tc.PC = (int32_t)0xBFC00480;
        set_hflags_for_handler(env);
        break;
    case EXCP_RESET:
        cpu_reset(CPU(cpu));
        break;
    case EXCP_SRESET:
        env->CP0_Status |= (1 << CP0St_SR);
        /* memset CP0_WatchLo which is fixed size array. */
        memset(env->CP0_WatchLo, 0, sizeof(env->CP0_WatchLo));
        goto set_error_EPC;
    case EXCP_NMI:
        env->CP0_Status |= (1 << CP0St_NMI);
 set_error_EPC:
        env->CP0_ErrorEPC = exception_resume_pc(env);
        env->hflags &= ~MIPS_HFLAG_BMASK;
        env->CP0_Status |= (1 << CP0St_ERL) | (1 << CP0St_BEV);
        env->hflags |= MIPS_HFLAG_64 | MIPS_HFLAG_CP0;
        env->hflags &= ~(MIPS_HFLAG_KSU);
        if (!(env->CP0_Status & (1 << CP0St_EXL)))
            env->CP0_Cause &= ~(1U << CP0Ca_BD);
        env->active_tc.PC = (int32_t)0xBFC00000;
        set_hflags_for_handler(env);
        break;
    case EXCP_EXT_INTERRUPT:
        cause = 0;
        if (env->CP0_Cause & (1 << CP0Ca_IV))
            offset = 0x200;

        if (env->CP0_Config3 & ((1 << CP0C3_VInt) | (1 << CP0C3_VEIC))) {
            /* Vectored Interrupts.  */
            unsigned int spacing;
            unsigned int vector;
            unsigned int pending = (env->CP0_Cause & CP0Ca_IP_mask) >> 8;

            pending &= env->CP0_Status >> 8;
            /* Compute the Vector Spacing.  */
            spacing = (env->CP0_IntCtl >> CP0IntCtl_VS) & ((1 << 6) - 1);
            spacing <<= 5;

            if (env->CP0_Config3 & (1 << CP0C3_VInt)) {
                /* For VInt mode, the MIPS computes the vector internally.  */
                for (vector = 7; vector > 0; vector--) {
                    if (pending & (1 << vector)) {
                        /* Found it.  */
                        break;
                    }
                }
            } else {
                /* For VEIC mode, the external interrupt controller feeds the
                   vector through the CP0Cause IP lines.  */
                vector = pending;
            }
            offset = 0x200 + vector * spacing;
        }
        goto set_EPC;
    case EXCP_LTLBL:
        cause = 1;
        update_badinstr = !(env->error_code & EXCP_INST_NOTAVAIL);
        goto set_EPC;
    case EXCP_TLBL:
        cause = 2;
        update_badinstr = !(env->error_code & EXCP_INST_NOTAVAIL);
        if ((env->error_code & EXCP_TLB_NOMATCH) &&
            !(env->CP0_Status & (1 << CP0St_EXL))) {
#if defined(TARGET_MIPS64)
            int R = env->CP0_BadVAddr >> 62;
            int UX = (env->CP0_Status & (1 << CP0St_UX)) != 0;
            int SX = (env->CP0_Status & (1 << CP0St_SX)) != 0;
            int KX = (env->CP0_Status & (1 << CP0St_KX)) != 0;

            if (((R == 0 && UX) || (R == 1 && SX) || (R == 3 && KX)) &&
                (!(env->insn_flags & (INSN_LOONGSON2E | INSN_LOONGSON2F))))
                offset = 0x080;
            else
#endif
                offset = 0x000;
        }
        goto set_EPC;
    case EXCP_TLBS:
        cause = 3;
        update_badinstr = 1;
        if ((env->error_code & EXCP_TLB_NOMATCH) &&
            !(env->CP0_Status & (1 << CP0St_EXL))) {
#if defined(TARGET_MIPS64)
            int R = env->CP0_BadVAddr >> 62;
            int UX = (env->CP0_Status & (1 << CP0St_UX)) != 0;
            int SX = (env->CP0_Status & (1 << CP0St_SX)) != 0;
            int KX = (env->CP0_Status & (1 << CP0St_KX)) != 0;

            if (((R == 0 && UX) || (R == 1 && SX) || (R == 3 && KX)) &&
                (!(env->insn_flags & (INSN_LOONGSON2E | INSN_LOONGSON2F))))
                offset = 0x080;
            else
#endif
                offset = 0x000;
        }
        goto set_EPC;
    case EXCP_AdEL:
        cause = 4;
        update_badinstr = !(env->error_code & EXCP_INST_NOTAVAIL);
        goto set_EPC;
    case EXCP_AdES:
        cause = 5;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_IBE:
        cause = 6;
        goto set_EPC;
    case EXCP_DBE:
        cause = 7;
        goto set_EPC;
    case EXCP_SYSCALL:
        cause = 8;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_BREAK:
        cause = 9;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_RI:
        cause = 10;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_CpU:
        cause = 11;
        update_badinstr = 1;
        env->CP0_Cause = (env->CP0_Cause & ~(0x3 << CP0Ca_CE)) |
                         (env->error_code << CP0Ca_CE);
        goto set_EPC;
    case EXCP_OVERFLOW:
        cause = 12;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_TRAP:
        cause = 13;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_MSAFPE:
        cause = 14;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_FPE:
        cause = 15;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_C2E:
        cause = 18;
        goto set_EPC;
    case EXCP_TLBRI:
        cause = 19;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_TLBXI:
        cause = 20;
        goto set_EPC;
    case EXCP_MSADIS:
        cause = 21;
        update_badinstr = 1;
        goto set_EPC;
    case EXCP_MDMX:
        cause = 22;
        goto set_EPC;
    case EXCP_DWATCH:
        cause = 23;
        /* XXX: TODO: manage defered watch exceptions */
        goto set_EPC;
    case EXCP_MCHECK:
        cause = 24;
        goto set_EPC;
    case EXCP_THREAD:
        cause = 25;
        goto set_EPC;
    case EXCP_DSPDIS:
        cause = 26;
        goto set_EPC;
    case EXCP_CACHE:
        cause = 30;
        if (env->CP0_Status & (1 << CP0St_BEV)) {
            offset = 0x100;
        } else {
            offset = 0x20000100;
        }
 set_EPC:
        if (!(env->CP0_Status & (1 << CP0St_EXL))) {
            env->CP0_EPC = exception_resume_pc(env);
            if (update_badinstr) {
                set_badinstr_registers(env);
            }
            if (env->hflags & MIPS_HFLAG_BMASK) {
                env->CP0_Cause |= (1U << CP0Ca_BD);
            } else {
                env->CP0_Cause &= ~(1U << CP0Ca_BD);
            }
            env->CP0_Status |= (1 << CP0St_EXL);
            env->hflags |= MIPS_HFLAG_64 | MIPS_HFLAG_CP0;
            env->hflags &= ~(MIPS_HFLAG_KSU);
        }
        env->hflags &= ~MIPS_HFLAG_BMASK;
        if (env->CP0_Status & (1 << CP0St_BEV)) {
            env->active_tc.PC = (int32_t)0xBFC00200;
        } else {
            env->active_tc.PC = (int32_t)(env->CP0_EBase & ~0x3ff);
        }
        env->active_tc.PC += offset;
        set_hflags_for_handler(env);
        env->CP0_Cause = (env->CP0_Cause & ~(0x1f << CP0Ca_EC)) | (cause << CP0Ca_EC);
        break;
    default:
        qemu_log("Invalid MIPS exception %d. Exiting\n", cs->exception_index);
        printf("Invalid MIPS exception %d. Exiting\n", cs->exception_index);
        exit(1);
    }
    if (qemu_log_enabled() && cs->exception_index != EXCP_EXT_INTERRUPT) {
        qemu_log("%s: PC " TARGET_FMT_lx " EPC " TARGET_FMT_lx " cause %d\n"
                "    S %08x C %08x A " TARGET_FMT_lx " D " TARGET_FMT_lx "\n",
                __func__, env->active_tc.PC, env->CP0_EPC, cause,
                env->CP0_Status, env->CP0_Cause, env->CP0_BadVAddr,
                env->CP0_DEPC);
    }
#endif
    cs->exception_index = EXCP_NONE;
}

bool mips_cpu_exec_interrupt(CPUState *cs, int interrupt_request)   // qq
{
    if (interrupt_request & CPU_INTERRUPT_HARD) {
        MIPSCPU *cpu = MIPS_CPU(cs->uc, cs);
        CPUMIPSState *env = &cpu->env;

        if (cpu_mips_hw_interrupts_pending(env)) {
            /* Raise it */
            cs->exception_index = EXCP_EXT_INTERRUPT;
            env->error_code = 0;
            mips_cpu_do_interrupt(cs);
            return true;
        }
    }
    return false;
}

#if !defined(CONFIG_USER_ONLY)
void r4k_invalidate_tlb (CPUMIPSState *env, int idx, int use_extra)
{
    MIPSCPU *cpu = mips_env_get_cpu(env);
    CPUState *cs;
    r4k_tlb_t *tlb;
    target_ulong addr;
    target_ulong end;
    uint8_t ASID = env->CP0_EntryHi & 0xFF;
    target_ulong mask;

    tlb = &env->tlb->mmu.r4k.tlb[idx];
    /* The qemu TLB is flushed when the ASID changes, so no need to
       flush these entries again.  */
    if (tlb->G == 0 && tlb->ASID != ASID) {
        return;
    }

    if (use_extra && env->tlb->tlb_in_use < MIPS_TLB_MAX) {
        /* For tlbwr, we can shadow the discarded entry into
           a new (fake) TLB entry, as long as the guest can not
           tell that it's there.  */
        env->tlb->mmu.r4k.tlb[env->tlb->tlb_in_use] = *tlb;
        env->tlb->tlb_in_use++;
        return;
    }

    /* 1k pages are not supported. */
    mask = tlb->PageMask | ~(((unsigned int)TARGET_PAGE_MASK) << 1);
    if (tlb->V0) {
        cs = CPU(cpu);
        addr = tlb->VPN & ~mask;
#if defined(TARGET_MIPS64)
        if (addr >= (0xFFFFFFFF80000000ULL & env->SEGMask)) {
            addr |= 0x3FFFFF0000000000ULL;
        }
#endif
        end = addr | (mask >> 1);
        while (addr < end) {
            tlb_flush_page(cs, addr);
            addr += TARGET_PAGE_SIZE;
        }
    }
    if (tlb->V1) {
        cs = CPU(cpu);
        addr = (tlb->VPN & ~mask) | ((mask >> 1) + 1);
#if defined(TARGET_MIPS64)
        if (addr >= (0xFFFFFFFF80000000ULL & env->SEGMask)) {
            addr |= 0x3FFFFF0000000000ULL;
        }
#endif
        end = addr | mask;
        while (addr - 1 < end) {
            tlb_flush_page(cs, addr);
            addr += TARGET_PAGE_SIZE;
        }
    }
}
#endif