/*

 *  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, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#include <stdarg.h>

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include <inttypes.h>

#include <signal.h>

#include <assert.h>

#include "cpu.h"

#include "exec-all.h"

enum {

    TLBRET_DIRTY = -4,

    TLBRET_INVALID = -3,

    TLBRET_NOMATCH = -2,

    TLBRET_BADADDR = -1,

    TLBRET_MATCH = 0

};

/* no MMU emulation */

int no_mmu_map_address (CPUState *env, target_ulong *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 (CPUState *env, target_ulong *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 (CPUState *env, target_ulong *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 | ~(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 match */

            int n = !!(address & mask & ~(mask >> 1));

            /* Check access rights */

            if (!(n ? tlb->V1 : tlb->V0))

                return TLBRET_INVALID;

            if (rw == 0 || (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 (CPUState *env, target_ulong *physical,

                                int *prot, target_ulong 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;

#if 0

    if (logfile) {

        fprintf(logfile, "user mode %d h %08x\n",

                user_mode, env->hflags);

    }

#endif

    if (address <= (int32_t)0x7FFFFFFFUL) {

        /* 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, 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, 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, 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, address, rw, access_type);

	} else {

	    ret = TLBRET_BADADDR;

	}

#endif

    } else if (address < (int32_t)0xA0000000UL) {

        /* kseg0 */

        if (kernel_mode) {

            *physical = address - (int32_t)0x80000000UL;

            *prot = PAGE_READ | PAGE_WRITE;

        } else {

            ret = TLBRET_BADADDR;

        }

    } else if (address < (int32_t)0xC0000000UL) {

        /* kseg1 */

        if (kernel_mode) {

            *physical = address - (int32_t)0xA0000000UL;

            *prot = PAGE_READ | PAGE_WRITE;

        } else {

            ret = TLBRET_BADADDR;

        }

    } else if (address < (int32_t)0xE0000000UL) {

        /* sseg (kseg2) */

        if (supervisor_mode || kernel_mode) {

            ret = env->tlb->map_address(env, physical, prot, 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, address, rw, access_type);

        } else {

            ret = TLBRET_BADADDR;

        }

    }

#if 0

    if (logfile) {

        fprintf(logfile, TARGET_FMT_lx " %d %d => " TARGET_FMT_lx " %d (%d)\n",

		address, rw, access_type, *physical, *prot, ret);

    }

#endif

    return ret;

}

target_phys_addr_t cpu_get_phys_page_debug(CPUState *env, target_ulong addr)

{

    if (env->user_mode_only)

        return addr;

    else {

        target_ulong phys_addr;

        int prot;

        if (get_physical_address(env, &phys_addr, &prot, addr, 0, ACCESS_INT) != 0)

            return -1;

        return phys_addr;

    }

}

int cpu_mips_handle_mmu_fault (CPUState *env, target_ulong address, int rw,

                               int mmu_idx, int is_softmmu)

{

    target_ulong physical;

    int prot;

    int exception = 0, error_code = 0;

    int access_type;

    int ret = 0;

    if (logfile) {

#if 0

        cpu_dump_state(env, logfile, fprintf, 0);

#endif

        fprintf(logfile, "%s pc " TARGET_FMT_lx " ad " TARGET_FMT_lx " rw %d mmu_idx %d smmu %d\n",

                __func__, env->active_tc.PC, address, rw, mmu_idx, is_softmmu);

    }

    rw &= 1;

    /* data access */

    /* XXX: put correct access by using cpu_restore_state()

       correctly */

    access_type = ACCESS_INT;

    if (env->user_mode_only) {

        /* user mode only emulation */

        ret = TLBRET_NOMATCH;

        goto do_fault;

    }

    ret = get_physical_address(env, &physical, &prot,

                               address, rw, access_type);

    if (logfile) {

        fprintf(logfile, "%s address=" TARGET_FMT_lx " ret %d physical " TARGET_FMT_lx " prot %d\n",

                __func__, address, ret, physical, prot);

    }

    if (ret == TLBRET_MATCH) {

       ret = tlb_set_page(env, address & TARGET_PAGE_MASK,

                          physical & TARGET_PAGE_MASK, prot,

                          mmu_idx, is_softmmu);

    } else if (ret < 0) {

    do_fault:

        switch (ret) {

        default:

        case TLBRET_BADADDR:

            /* Reference to kernel address from user mode or supervisor mode */

            /* Reference to supervisor address from user mode */

            if (rw)

                exception = EXCP_AdES;

            else

                exception = EXCP_AdEL;

            break;

        case TLBRET_NOMATCH:

            /* No TLB match for a mapped address */

            if (rw)

                exception = EXCP_TLBS;

            else

                exception = EXCP_TLBL;

            error_code = 1;

            break;

        case TLBRET_INVALID:

            /* TLB match with no valid bit */

            if (rw)

                exception = EXCP_TLBS;

            else

                exception = EXCP_TLBL;

            break;

        case TLBRET_DIRTY:

            /* TLB match but 'D' bit is cleared */

            exception = EXCP_LTLBL;

            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 & (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

        env->exception_index = exception;

        env->error_code = error_code;

        ret = 1;

    }

    return ret;

}

static const char * const excp_names[EXCP_LAST + 1] = {

    [EXCP_RESET] = "reset",

    [EXCP_SRESET] = "soft reset",

    [EXCP_DSS] = "debug single step",

    [EXCP_DINT] = "debug interrupt",

    [EXCP_NMI] = "non-maskable interrupt",

    [EXCP_MCHECK] = "machine check",

    [EXCP_EXT_INTERRUPT] = "interrupt",

    [EXCP_DFWATCH] = "deferred watchpoint",

    [EXCP_DIB] = "debug instruction breakpoint",

    [EXCP_IWATCH] = "instruction fetch watchpoint",

    [EXCP_AdEL] = "address error load",

    [EXCP_AdES] = "address error store",

    [EXCP_TLBF] = "TLB refill",

    [EXCP_IBE] = "instruction bus error",

    [EXCP_DBp] = "debug breakpoint",

    [EXCP_SYSCALL] = "syscall",

    [EXCP_BREAK] = "break",

    [EXCP_CpU] = "coprocessor unusable",

    [EXCP_RI] = "reserved instruction",

    [EXCP_OVERFLOW] = "arithmetic overflow",

    [EXCP_TRAP] = "trap",

    [EXCP_FPE] = "floating point",

    [EXCP_DDBS] = "debug data break store",

    [EXCP_DWATCH] = "data watchpoint",

    [EXCP_LTLBL] = "TLB modify",

    [EXCP_TLBL] = "TLB load",

    [EXCP_TLBS] = "TLB store",

    [EXCP_DBE] = "data bus error",

    [EXCP_DDBL] = "debug data break load",

    [EXCP_THREAD] = "thread",

    [EXCP_MDMX] = "MDMX",

    [EXCP_C2E] = "precise coprocessor 2",

    [EXCP_CACHE] = "cache error",

};

void do_interrupt (CPUState *env)

{

    if (!env->user_mode_only) {

        target_ulong offset;

        int cause = -1;

        const char *name;

        if (logfile && env->exception_index != EXCP_EXT_INTERRUPT) {

            if (env->exception_index < 0 || env->exception_index > EXCP_LAST)

                name = "unknown";

            else

                name = excp_names[env->exception_index];

            fprintf(logfile, "%s enter: PC " TARGET_FMT_lx " EPC " TARGET_FMT_lx " %s exception\n",

                    __func__, env->active_tc.PC, env->CP0_EPC, name);

        }

        if (env->exception_index == EXCP_EXT_INTERRUPT &&

            (env->hflags & MIPS_HFLAG_DM))

            env->exception_index = EXCP_DINT;

        offset = 0x180;

        switch (env->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;

            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:

            if (env->hflags & MIPS_HFLAG_BMASK) {

                /* If the exception was raised from a delay slot,

                   come back to the jump.  */

                env->CP0_DEPC = env->active_tc.PC - 4;

                env->hflags &= ~MIPS_HFLAG_BMASK;

            } else {

                env->CP0_DEPC = env->active_tc.PC;

            }

 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 &= ~(1 << CP0Ca_BD);

            env->active_tc.PC = (int32_t)0xBFC00480;

            break;

        case EXCP_RESET:

            cpu_reset(env);

            break;

        case EXCP_SRESET:

            env->CP0_Status |= (1 << CP0St_SR);

            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:

            if (env->hflags & MIPS_HFLAG_BMASK) {

                /* If the exception was raised from a delay slot,

                   come back to the jump.  */

                env->CP0_ErrorEPC = env->active_tc.PC - 4;

                env->hflags &= ~MIPS_HFLAG_BMASK;

            } else {

                env->CP0_ErrorEPC = env->active_tc.PC;

            }

            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 &= ~(1 << CP0Ca_BD);

            env->active_tc.PC = (int32_t)0xBFC00000;

            break;

        case EXCP_EXT_INTERRUPT:

            cause = 0;

            if (env->CP0_Cause & (1 << CP0Ca_IV))

                offset = 0x200;

            goto set_EPC;

        case EXCP_LTLBL:

            cause = 1;

            goto set_EPC;

        case EXCP_TLBL:

            cause = 2;

            if (env->error_code == 1 && !(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))

                    offset = 0x080;

                else

#endif

                    offset = 0x000;

            }

            goto set_EPC;

        case EXCP_TLBS:

            cause = 3;

            if (env->error_code == 1 && !(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))

                    offset = 0x080;

                else

#endif

                    offset = 0x000;

            }

            goto set_EPC;

        case EXCP_AdEL:

            cause = 4;

            goto set_EPC;

        case EXCP_AdES:

            cause = 5;

            goto set_EPC;

        case EXCP_IBE:

            cause = 6;

            goto set_EPC;

        case EXCP_DBE:

            cause = 7;

            goto set_EPC;

        case EXCP_SYSCALL:

            cause = 8;

            goto set_EPC;

        case EXCP_BREAK:

            cause = 9;

            goto set_EPC;

        case EXCP_RI:

            cause = 10;

            goto set_EPC;

        case EXCP_CpU:

            cause = 11;

            env->CP0_Cause = (env->CP0_Cause & ~(0x3 << CP0Ca_CE)) |

                             (env->error_code << CP0Ca_CE);

            goto set_EPC;

        case EXCP_OVERFLOW:

            cause = 12;

            goto set_EPC;

        case EXCP_TRAP:

            cause = 13;

            goto set_EPC;

        case EXCP_FPE:

            cause = 15;

            goto set_EPC;

        case EXCP_C2E:

            cause = 18;

            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_CACHE:

            cause = 30;

            if (env->CP0_Status & (1 << CP0St_BEV)) {

                offset = 0x100;