/*
 *  SH4 emulation
 *
 *  Copyright (c) 2005 Samuel Tardieu
 *
 * 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 <inttypes.h>
#include <signal.h>

#include "cpu.h"
#include "exec-all.h"
#include "hw/sh_intc.h"

#if defined(CONFIG_USER_ONLY)

void do_interrupt (CPUState *env)
{
  env->exception_index = -1;
}

int cpu_sh4_handle_mmu_fault(CPUState * env, target_ulong address, int rw,
                             int mmu_idx, int is_softmmu)
{
    env->tea = address;
    env->exception_index = 0;
    switch (rw) {
    case 0:
        env->exception_index = 0x0a0;
        break;
    case 1:
        env->exception_index = 0x0c0;
        break;
    case 2:
        env->exception_index = 0x0a0;
        break;
    }
    return 1;
}

target_phys_addr_t cpu_get_phys_page_debug(CPUState * env, target_ulong addr)
{
    return addr;
}

int cpu_sh4_is_cached(CPUSH4State * env, target_ulong addr)
{
    /* For user mode, only U0 area is cachable. */
    return !(addr & 0x80000000);
}

#else /* !CONFIG_USER_ONLY */

#define MMU_OK                   0
#define MMU_ITLB_MISS            (-1)
#define MMU_ITLB_MULTIPLE        (-2)
#define MMU_ITLB_VIOLATION       (-3)
#define MMU_DTLB_MISS_READ       (-4)
#define MMU_DTLB_MISS_WRITE      (-5)
#define MMU_DTLB_INITIAL_WRITE   (-6)
#define MMU_DTLB_VIOLATION_READ  (-7)
#define MMU_DTLB_VIOLATION_WRITE (-8)
#define MMU_DTLB_MULTIPLE        (-9)
#define MMU_DTLB_MISS            (-10)
#define MMU_IADDR_ERROR          (-11)
#define MMU_DADDR_ERROR_READ     (-12)
#define MMU_DADDR_ERROR_WRITE    (-13)

void do_interrupt(CPUState * env)
{
    int do_irq = env->interrupt_request & CPU_INTERRUPT_HARD;
    int do_exp, irq_vector = env->exception_index;

    /* prioritize exceptions over interrupts */

    do_exp = env->exception_index != -1;
    do_irq = do_irq && (env->exception_index == -1);

    if (env->sr & SR_BL) {
        if (do_exp && env->exception_index != 0x1e0) {
            env->exception_index = 0x000; /* masked exception -> reset */
        }
        if (do_irq && !env->intr_at_halt) {
            return; /* masked */
        }
        env->intr_at_halt = 0;
    }

    if (do_irq) {
        irq_vector = sh_intc_get_pending_vector(env->intc_handle,
                                                (env->sr >> 4) & 0xf);
        if (irq_vector == -1) {
            return; /* masked */
        }
    }

    if (qemu_loglevel_mask(CPU_LOG_INT)) {
        const char *expname;
        switch (env->exception_index) {
        case 0x0e0:
            expname = "addr_error";
            break;
        case 0x040:
            expname = "tlb_miss";
            break;
        case 0x0a0:
            expname = "tlb_violation";
            break;
        case 0x180:
            expname = "illegal_instruction";
            break;
        case 0x1a0:
            expname = "slot_illegal_instruction";
            break;
        case 0x800:
            expname = "fpu_disable";
            break;
        case 0x820:
            expname = "slot_fpu";
            break;
        case 0x100:
            expname = "data_write";
            break;
        case 0x060:
            expname = "dtlb_miss_write";
            break;
        case 0x0c0:
            expname = "dtlb_violation_write";
            break;
        case 0x120:
            expname = "fpu_exception";
            break;
        case 0x080:
            expname = "initial_page_write";
            break;
        case 0x160:
            expname = "trapa";
            break;
        default:
            expname = do_irq ? "interrupt" : "???";
            break;
        }
        qemu_log("exception 0x%03x [%s] raised\n",
                  irq_vector, expname);
        log_cpu_state(env, 0);
    }

    env->ssr = env->sr;
    env->spc = env->pc;
    env->sgr = env->gregs[15];
    env->sr |= SR_BL | SR_MD | SR_RB;

    if (env->flags & (DELAY_SLOT | DELAY_SLOT_CONDITIONAL)) {
        /* Branch instruction should be executed again before delay slot. */
        env->spc -= 2;
        /* Clear flags for exception/interrupt routine. */
        env->flags &= ~(DELAY_SLOT | DELAY_SLOT_CONDITIONAL | DELAY_SLOT_TRUE);
    }
    if (env->flags & DELAY_SLOT_CLEARME)
        env->flags = 0;

    if (do_exp) {
        env->expevt = env->exception_index;
        switch (env->exception_index) {
        case 0x000:
        case 0x020:
        case 0x140:
            env->sr &= ~SR_FD;
            env->sr |= 0xf << 4; /* IMASK */
            env->pc = 0xa0000000;
            break;
        case 0x040:
        case 0x060:
            env->pc = env->vbr + 0x400;
            break;
        case 0x160:
            env->spc += 2; /* special case for TRAPA */
            /* fall through */
        default:
            env->pc = env->vbr + 0x100;
            break;
        }
        return;
    }

    if (do_irq) {
        env->intevt = irq_vector;
        env->pc = env->vbr + 0x600;
        return;
    }
}

static void update_itlb_use(CPUState * env, int itlbnb)
{
    uint8_t or_mask = 0, and_mask = (uint8_t) - 1;

    switch (itlbnb) {
    case 0:
        and_mask = 0x1f;
        break;
    case 1:
        and_mask = 0xe7;
        or_mask = 0x80;
        break;
    case 2:
        and_mask = 0xfb;
        or_mask = 0x50;
        break;
    case 3:
        or_mask = 0x2c;
        break;
    }

    env->mmucr &= (and_mask << 24) | 0x00ffffff;
    env->mmucr |= (or_mask << 24);
}

static int itlb_replacement(CPUState * env)
{
    if ((env->mmucr & 0xe0000000) == 0xe0000000)
        return 0;
    if ((env->mmucr & 0x98000000) == 0x18000000)
        return 1;
    if ((env->mmucr & 0x54000000) == 0x04000000)
        return 2;
    if ((env->mmucr & 0x2c000000) == 0x00000000)
        return 3;
    assert(0);
}

/* Find the corresponding entry in the right TLB
   Return entry, MMU_DTLB_MISS or MMU_DTLB_MULTIPLE
*/
static int find_tlb_entry(CPUState * env, target_ulong address,
                          tlb_t * entries, uint8_t nbtlb, int use_asid)
{
    int match = MMU_DTLB_MISS;
    uint32_t start, end;
    uint8_t asid;
    int i;

    asid = env->pteh & 0xff;

    for (i = 0; i < nbtlb; i++) {
        if (!entries[i].v)
            continue;           /* Invalid entry */
        if (!entries[i].sh && use_asid && entries[i].asid != asid)
            continue;           /* Bad ASID */
#if 0
        switch (entries[i].sz) {
        case 0:
            size = 1024;        /* 1kB */
            break;
        case 1:
            size = 4 * 1024;    /* 4kB */
            break;
        case 2:
            size = 64 * 1024;   /* 64kB */
            break;
        case 3:
            size = 1024 * 1024; /* 1MB */
            break;
        default:
            assert(0);
        }
#endif
        start = (entries[i].vpn << 10) & ~(entries[i].size - 1);
        end = start + entries[i].size - 1;
        if (address >= start && address <= end) {       /* Match */
            if (match != MMU_DTLB_MISS)
                return MMU_DTLB_MULTIPLE;       /* Multiple match */
            match = i;
        }
    }
    return match;
}

static int same_tlb_entry_exists(const tlb_t * haystack, uint8_t nbtlb,
                                 const tlb_t * needle)
{
    int i;
    for (i = 0; i < nbtlb; i++)
        if (!memcmp(&haystack[i], needle, sizeof(tlb_t)))
            return 1;
    return 0;
}

static void increment_urc(CPUState * env)
{
    uint8_t urb, urc;

    /* Increment URC */
    urb = ((env->mmucr) >> 18) & 0x3f;
    urc = ((env->mmucr) >> 10) & 0x3f;
    urc++;
    if ((urb > 0 && urc > urb) || urc > (UTLB_SIZE - 1))
        urc = 0;
    env->mmucr = (env->mmucr & 0xffff03ff) | (urc << 10);
}

/* Find itlb entry - update itlb from utlb if necessary and asked for
   Return entry, MMU_ITLB_MISS, MMU_ITLB_MULTIPLE or MMU_DTLB_MULTIPLE
   Update the itlb from utlb if update is not 0
*/
static int find_itlb_entry(CPUState * env, target_ulong address,
                           int use_asid, int update)
{
    int e, n;

    e = find_tlb_entry(env, address, env->itlb, ITLB_SIZE, use_asid);
    if (e == MMU_DTLB_MULTIPLE)
        e = MMU_ITLB_MULTIPLE;
    else if (e == MMU_DTLB_MISS && update) {
        e = find_tlb_entry(env, address, env->utlb, UTLB_SIZE, use_asid);
        if (e >= 0) {
            tlb_t * ientry;
            n = itlb_replacement(env);
            ientry = &env->itlb[n];
            if (ientry->v) {
                if (!same_tlb_entry_exists(env->utlb, UTLB_SIZE, ientry))
                    tlb_flush_page(env, ientry->vpn << 10);
            }
            *ientry = env->utlb[e];
            e = n;
        } else if (e == MMU_DTLB_MISS)
            e = MMU_ITLB_MISS;
    } else if (e == MMU_DTLB_MISS)
        e = MMU_ITLB_MISS;
    if (e >= 0)
        update_itlb_use(env, e);
    return e;
}

/* Find utlb entry
   Return entry, MMU_DTLB_MISS, MMU_DTLB_MULTIPLE */
static int find_utlb_entry(CPUState * env, target_ulong address, int use_asid)
{
    /* per utlb access */
    increment_urc(env);

    /* Return entry */
    return find_tlb_entry(env, address, env->utlb, UTLB_SIZE, use_asid);
}

/* Match address against MMU
   Return MMU_OK, MMU_DTLB_MISS_READ, MMU_DTLB_MISS_WRITE,
   MMU_DTLB_INITIAL_WRITE, MMU_DTLB_VIOLATION_READ,
   MMU_DTLB_VIOLATION_WRITE, MMU_ITLB_MISS,
   MMU_ITLB_MULTIPLE, MMU_ITLB_VIOLATION,
   MMU_IADDR_ERROR, MMU_DADDR_ERROR_READ, MMU_DADDR_ERROR_WRITE.
*/
static int get_mmu_address(CPUState * env, target_ulong * physical,
                           int *prot, target_ulong address,
                           int rw, int access_type)
{
    int use_asid, n;
    tlb_t *matching = NULL;

    use_asid = (env->mmucr & MMUCR_SV) == 0 || (env->sr & SR_MD) == 0;

    if (rw == 2) {
        n = find_itlb_entry(env, address, use_asid, 1);
        if (n >= 0) {
            matching = &env->itlb[n];
            if ((env->sr & SR_MD) & !(matching->pr & 2))
                n = MMU_ITLB_VIOLATION;
            else
                *prot = PAGE_READ;
        }
    } else {
        n = find_utlb_entry(env, address, use_asid);
        if (n >= 0) {
            matching = &env->utlb[n];
            switch ((matching->pr << 1) | ((env->sr & SR_MD) ? 1 : 0)) {
            case 0:             /* 000 */
            case 2:             /* 010 */
                n = (rw == 1) ? MMU_DTLB_VIOLATION_WRITE :
                    MMU_DTLB_VIOLATION_READ;
                break;
            case 1:             /* 001 */
            case 4:             /* 100 */
            case 5:             /* 101 */
                if (rw == 1)
                    n = MMU_DTLB_VIOLATION_WRITE;
                else
                    *prot = PAGE_READ;
                break;
            case 3:             /* 011 */
            case 6:             /* 110 */
            case 7:             /* 111 */
                *prot = (rw == 1)? PAGE_WRITE : PAGE_READ;
                break;
            }
        } else if (n == MMU_DTLB_MISS) {
            n = (rw == 1) ? MMU_DTLB_MISS_WRITE :
                MMU_DTLB_MISS_READ;
        }
    }
    if (n >= 0) {
        *physical = ((matching->ppn << 10) & ~(matching->size - 1)) |
            (address & (matching->size - 1));
        if ((rw == 1) & !matching->d)
            n = MMU_DTLB_INITIAL_WRITE;
        else
            n = MMU_OK;
    }
    return n;
}

static int get_physical_address(CPUState * env, target_ulong * physical,
                                int *prot, target_ulong address,
                                int rw, int access_type)
{
    /* P1, P2 and P4 areas do not use translation */
    if ((address >= 0x80000000 && address < 0xc0000000) ||
        address >= 0xe0000000) {
        if (!(env->sr & SR_MD)
            && (address < 0xe0000000 || address > 0xe4000000)) {
            /* Unauthorized access in user mode (only store queues are available) */
            fprintf(stderr, "Unauthorized access\n");
            if (rw == 0)
                return MMU_DADDR_ERROR_READ;
            else if (rw == 1)
                return MMU_DADDR_ERROR_WRITE;
            else
                return MMU_IADDR_ERROR;
        }
        if (address >= 0x80000000 && address < 0xc0000000) {
            /* Mask upper 3 bits for P1 and P2 areas */
            *physical = address & 0x1fffffff;
        } else {
            *physical = address;
        }
        *prot = PAGE_READ | PAGE_WRITE;
        return MMU_OK;
    }

    /* If MMU is disabled, return the corresponding physical page */
    if (!env->mmucr & MMUCR_AT) {
        *physical = address & 0x1FFFFFFF;
        *prot = PAGE_READ | PAGE_WRITE;
        return MMU_OK;
    }

    /* We need to resort to the MMU */
    return get_mmu_address(env, physical, prot, address, rw, access_type);
}

int cpu_sh4_handle_mmu_fault(CPUState * env, target_ulong address, int rw,
                             int mmu_idx, int is_softmmu)
{
    target_ulong physical, page_offset, page_size;
    int prot, ret, access_type;

    access_type = ACCESS_INT;
    ret =
        get_physical_address(env, &physical, &prot, address, rw,
                             access_type);

    if (ret != MMU_OK) {
        env->tea = address;
        switch (ret) {
        case MMU_ITLB_MISS:
        case MMU_DTLB_MISS_READ:
            env->exception_index = 0x040;
            break;
        case MMU_DTLB_MULTIPLE:
        case MMU_ITLB_MULTIPLE:
            env->exception_index = 0x140;
            break;
        case MMU_ITLB_VIOLATION:
            env->exception_index = 0x0a0;
            break;
        case MMU_DTLB_MISS_WRITE:
            env->exception_index = 0x060;
            break;
        case MMU_DTLB_INITIAL_WRITE:
            env->exception_index = 0x080;
            break;
        case MMU_DTLB_VIOLATION_READ:
            env->exception_index = 0x0a0;
            break;
        case MMU_DTLB_VIOLATION_WRITE:
            env->exception_index = 0x0c0;
            break;
        case MMU_IADDR_ERROR:
        case MMU_DADDR_ERROR_READ:
            env->exception_index = 0x0c0;
            break;
        case MMU_DADDR_ERROR_WRITE:
            env->exception_index = 0x100;
            break;
        default:
            assert(0);
        }
        return 1;
    }

    page_size = TARGET_PAGE_SIZE;
    page_offset =
        (address - (address & TARGET_PAGE_MASK)) & ~(page_size - 1);
    address = (address & TARGET_PAGE_MASK) + page_offset;
    physical = (physical & TARGET_PAGE_MASK) + page_offset;

    return tlb_set_page(env, address, physical, prot, mmu_idx, is_softmmu);
}

target_phys_addr_t cpu_get_phys_page_debug(CPUState * env, target_ulong addr)
{
    target_ulong physical;
    int prot;

    get_physical_address(env, &physical, &prot, addr, 0, 0);
    return physical;
}

void cpu_load_tlb(CPUSH4State * env)
{
    int n = cpu_mmucr_urc(env->mmucr);
    tlb_t * entry = &env->utlb[n];

    if (entry->v) {
        /* Overwriting valid entry in utlb. */
        target_ulong address = entry->vpn << 10;
        if (!same_tlb_entry_exists(env->itlb, ITLB_SIZE, entry)) {
            tlb_flush_page(env, address);
        }
    }

    /* Take values into cpu status from registers. */
    entry->asid = (uint8_t)cpu_pteh_asid(env->pteh);
    entry->vpn  = cpu_pteh_vpn(env->pteh);
    entry->v    = (uint8_t)cpu_ptel_v(env->ptel);
    entry->ppn  = cpu_ptel_ppn(env->ptel);
    entry->sz   = (uint8_t)cpu_ptel_sz(env->ptel);
    switch (entry->sz) {
    case 0: /* 00 */
        entry->size = 1024; /* 1K */
        break;
    case 1: /* 01 */
        entry->size = 1024 * 4; /* 4K */
        break;
    case 2: /* 10 */
        entry->size = 1024 * 64; /* 64K */
        break;
    case 3: /* 11 */
        entry->size = 1024 * 1024; /* 1M */
        break;
    default:
        assert(0);
        break;
    }
    entry->sh   = (uint8_t)cpu_ptel_sh(env->ptel);
    entry->c    = (uint8_t)cpu_ptel_c(env->ptel);
    entry->pr   = (uint8_t)cpu_ptel_pr(env->ptel);
    entry->d    = (uint8_t)cpu_ptel_d(env->ptel);
    entry->wt   = (uint8_t)cpu_ptel_wt(env->ptel);
    entry->sa   = (uint8_t)cpu_ptea_sa(env->ptea);
    entry->tc   = (uint8_t)cpu_ptea_tc(env->ptea);
}

void cpu_sh4_write_mmaped_utlb_addr(CPUSH4State *s, target_phys_addr_t addr,
                                    uint32_t mem_value)
{
    int associate = addr & 0x0000080;
    uint32_t vpn = (mem_value & 0xfffffc00) >> 10;
    uint8_t d = (uint8_t)((mem_value & 0x00000200) >> 9);
    uint8_t v = (uint8_t)((mem_value & 0x00000100) >> 8);
    uint8_t asid = (uint8_t)(mem_value & 0x000000ff);
    int use_asid = (s->mmucr & MMUCR_SV) == 0 || (s->sr & SR_MD) == 0;

    if (associate) {
        int i;
        tlb_t * utlb_match_entry = NULL;
        int needs_tlb_flush = 0;

        /* search UTLB */
        for (i = 0; i < UTLB_SIZE; i++) {
            tlb_t * entry = &s->utlb[i];
            if (!entry->v)
                continue;

            if (entry->vpn == vpn
                && (!use_asid || entry->asid == asid || entry->sh)) {
                if (utlb_match_entry) {
                    /* Multiple TLB Exception */
                    s->exception_index = 0x140;
                    s->tea = addr;
                    break;
                }
                if (entry->v && !v)
                    needs_tlb_flush = 1;
                entry->v = v;
                entry->d = d;
                utlb_match_entry = entry;
            }
            increment_urc(s); /* per utlb access */
        }

        /* search ITLB */
        for (i = 0; i < ITLB_SIZE; i++) {
            tlb_t * entry = &s->itlb[i];
            if (entry->vpn == vpn
                && (!use_asid || entry->asid == asid || entry->sh)) {
                if (entry->v && !v)
                    needs_tlb_flush = 1;
                if (utlb_match_entry)
                    *entry = *utlb_match_entry;
                else
                    entry->v = v;
                break;
            }
        }

        if (needs_tlb_flush)
            tlb_flush_page(s, vpn << 10);
        
    } else {
        int index = (addr & 0x00003f00) >> 8;
        tlb_t * entry = &s->utlb[index];
        if (entry->v) {
            /* Overwriting valid entry in utlb. */
            target_ulong address = entry->vpn << 10;
            if (!same_tlb_entry_exists(s->itlb, ITLB_SIZE, entry)) {
                tlb_flush_page(s, address);
            }
        }
        entry->asid = asid;
        entry->vpn = vpn;
        entry->d = d;
        entry->v = v;
        increment_urc(s);
    }
}

int cpu_sh4_is_cached(CPUSH4State * env, target_ulong addr)
{
    int n;
    int use_asid = (env->mmucr & MMUCR_SV) == 0 || (env->sr & SR_MD) == 0;

    /* check area */
    if (env->sr & SR_MD) {
        /* For previledged mode, P2 and P4 area is not cachable. */
        if ((0xA0000000 <= addr && addr < 0xC0000000) || 0xE0000000 <= addr)
            return 0;
    } else {
        /* For user mode, only U0 area is cachable. */
        if (0x80000000 <= addr)
            return 0;
    }

    /*
     * TODO : Evaluate CCR and check if the cache is on or off.
     *        Now CCR is not in CPUSH4State, but in SH7750State.
     *        When you move the ccr inot CPUSH4State, the code will be
     *        as follows.
     */
#if 0
    /* check if operand cache is enabled or not. */
    if (!(env->ccr & 1))
        return 0;
#endif

    /* if MMU is off, no check for TLB. */
    if (env->mmucr & MMUCR_AT)
        return 1;

    /* check TLB */
    n = find_tlb_entry(env, addr, env->itlb, ITLB_SIZE, use_asid);
    if (n >= 0)
        return env->itlb[n].c;

    n = find_tlb_entry(env, addr, env->utlb, UTLB_SIZE, use_asid);
    if (n >= 0)
        return env->utlb[n].c;

    return 0;
}

#endif