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, 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"

#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)

void do_interrupt(CPUState * env)

{

    if (loglevel & 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 = "???";

            break;

        }

        fprintf(logfile, "exception 0x%03x [%s] raised\n",

                env->exception_index, expname);

        cpu_dump_state(env, logfile, fprintf, 0);

    }

    env->ssr = env->sr;

    env->spc = env->spc;

    env->sgr = env->gregs[15];

    env->sr |= SR_BL | SR_MD | SR_RB;

    env->expevt = env->exception_index & 0x7ff;

    switch (env->exception_index) {

    case 0x040:

    case 0x060:

    case 0x080:

        env->pc = env->vbr + 0x400;

        break;

    case 0x140:

        env->pc = 0xa0000000;

        break;

    default:

        env->pc = env->vbr + 0x100;

        break;

    }

}

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 = 0x7f;

        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);

    env->mmucr |= (or_mask << 24);

}

static int itlb_replacement(CPUState * env)

{

    if ((env->mmucr & 0xe0000000) == 0xe0000000)

        return 0;

    if ((env->mmucr & 0x98000000) == 0x08000000)

        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 (use_asid && entries[i].asid != asid && !entries[i].sh)

            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 != -1)

                return MMU_DTLB_MULTIPLE;        /* Multiple match */

            match = i;

        }

    }

    return match;

}

/* 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

*/

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) {

            n = itlb_replacement(env);

            env->itlb[n] = env->utlb[e];

            e = n;

        }

    }

    if (e >= 0)

        update_itlb_use(env, e);

    return e;

}

/* Find utlb entry

   Return entry, MMU_DTLB_MISS, MMU_DTLB_MULTIPLE */

int find_utlb_entry(CPUState * env, target_ulong address, int use_asid)

{

    uint8_t urb, urc;

    /* Increment URC */

    urb = ((env->mmucr) >> 18) & 0x3f;

    urc = ((env->mmucr) >> 10) & 0x3f;

    urc++;

    if (urc == urb || urc == UTLB_SIZE - 1)

        urc = 0;

    env->mmucr = (env->mmucr & 0xffff03ff) | (urc << 10);

    /* 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

*/

static int get_mmu_address(CPUState * env, target_ulong * physical,

                           int *prot, target_ulong address,

                           int rw, int access_type)

{

    int use_asid, is_code, n;

    tlb_t *matching = NULL;

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

    is_code = env->pc == address;        /* Hack */

    /* Use a hack to find if this is an instruction or data access */

    if (env->pc == address && !(rw & PAGE_WRITE)) {

        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 & PAGE_WRITE) ? MMU_DTLB_VIOLATION_WRITE :

                    MMU_DTLB_VIOLATION_READ;

                break;

            case 1:                /* 001 */

            case 4:                /* 100 */

            case 5:                /* 101 */

                if (rw & PAGE_WRITE)

                    n = MMU_DTLB_VIOLATION_WRITE;

                else

                    *prot = PAGE_READ;

                break;

            case 3:                /* 011 */

            case 6:                /* 110 */

            case 7:                /* 111 */

                *prot = rw & (PAGE_READ | PAGE_WRITE);

                break;

            }

        } else if (n == MMU_DTLB_MISS) {

            n = (rw & PAGE_WRITE) ? MMU_DTLB_MISS_WRITE :

                MMU_DTLB_MISS_READ;

        }

    }

    if (n >= 0) {

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

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

        if ((rw & PAGE_WRITE) & !matching->d)

            n = MMU_DTLB_INITIAL_WRITE;

        else

            n = MMU_OK;

    }

    return n;

}

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");

            return (rw & PAGE_WRITE) ? MMU_DTLB_MISS_WRITE :

                MMU_DTLB_MISS_READ;

        }

        /* Mask upper 3 bits */

        *physical = address & 0x1FFFFFFF;

        *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 is_user, int is_softmmu)

{

    target_ulong physical, page_offset, page_size;

    int prot, ret, access_type;

    /* XXXXX */

#if 0

    fprintf(stderr, "%s pc %08x ad %08x rw %d is_user %d smmu %d\n",

            __func__, env->pc, address, rw, is_user, is_softmmu);

#endif

    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;

        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, is_user, is_softmmu);

}