Archipelago » qemu

/*

 *  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 = -1;

    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;

}

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;

    cpu_abort(env, "Unhandled itlb_replacement");

}

/* 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 */

        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 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) {

                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_EXEC;

        }

    } else {

        n = find_utlb_entry(env, address, use_asid);

        if (n >= 0) {

            matching = &env->utlb[n];

            if (!(env->sr & SR_MD) && !(matching->pr & 2)) {

                n = (rw == 1) ? MMU_DTLB_VIOLATION_WRITE :

                    MMU_DTLB_VIOLATION_READ;

            } else if ((rw == 1) && !(matching->pr & 1)) {

                n = MMU_DTLB_VIOLATION_WRITE;

            } else if ((rw == 1) & !matching->d) {

                n = MMU_DTLB_INITIAL_WRITE;

            } else {

                *prot = PAGE_READ;

                if ((matching->pr & 1) && matching->d) {

                    *prot |= PAGE_WRITE;

                }

            }

        } else if (n == MMU_DTLB_MISS) {

            n = (rw == 1) ? MMU_DTLB_MISS_WRITE :

                MMU_DTLB_MISS_READ;

        }

    }

    if (n >= 0) {

        n = MMU_OK;

        *physical = ((matching->ppn << 10) & ~(matching->size - 1)) |

            (address & (matching->size - 1));

    }

    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 | PAGE_EXEC;

        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 | PAGE_EXEC;

        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;

    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:

            cpu_abort(env, "Unhandled MMU fault");

        }

        return 1;

    }

    address &= TARGET_PAGE_MASK;

    physical &= TARGET_PAGE_MASK;

    tlb_set_page(env, address, physical, prot, mmu_idx, TARGET_PAGE_SIZE);

    return 0;

}

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;

        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:

        cpu_abort(env, "Unhandled load_tlb");

        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_invalidate_tlb(CPUSH4State *s)

{

    int i;

    /* UTLB */

    for (i = 0; i < UTLB_SIZE; i++) {

        tlb_t * entry = &s->utlb[i];

        entry->v = 0;

    }

    /* ITLB */

    for (i = 0; i < UTLB_SIZE; i++) {

        tlb_t * entry = &s->utlb[i];

        entry->v = 0;

    }

    tlb_flush(s, 1);

}

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;

            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