Archipelago » qemu

/*

 *  Software MMU support

 * 

 *  Copyright (c) 2003 Fabrice Bellard

 *

 * 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

 */

#define DATA_SIZE (1 << SHIFT)

#if DATA_SIZE == 8

#define SUFFIX q

#define DATA_TYPE uint64_t

#elif DATA_SIZE == 4

#define SUFFIX l

#define DATA_TYPE uint32_t

#elif DATA_SIZE == 2

#define SUFFIX w

#define DATA_TYPE uint16_t

#elif DATA_SIZE == 1

#define SUFFIX b

#define DATA_TYPE uint8_t

#else

#error unsupported data size

#endif

static DATA_TYPE glue(slow_ld, SUFFIX)(unsigned long addr, void *retaddr);

static void glue(slow_st, SUFFIX)(unsigned long addr, DATA_TYPE val,

                                  void *retaddr);

static inline DATA_TYPE glue(io_read, SUFFIX)(unsigned long physaddr, 

                                              unsigned long tlb_addr)

{

    DATA_TYPE res;

    int index;

    index = (tlb_addr >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);

#if SHIFT <= 2

    res = io_mem_read[index][SHIFT](physaddr);

#else

#ifdef TARGET_WORDS_BIGENDIAN

    res = (uint64_t)io_mem_read[index][2](physaddr) << 32;

    res |= io_mem_read[index][2](physaddr + 4);

#else

    res = io_mem_read[index][2](physaddr);

    res |= (uint64_t)io_mem_read[index][2](physaddr + 4) << 32;

#endif

#endif /* SHIFT > 2 */

    return res;

}

static inline void glue(io_write, SUFFIX)(unsigned long physaddr, 

                                          DATA_TYPE val,

                                          unsigned long tlb_addr)

{

    int index;

    index = (tlb_addr >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1);

#if SHIFT <= 2

    io_mem_write[index][SHIFT](physaddr, val);

#else

#ifdef TARGET_WORDS_BIGENDIAN

    io_mem_write[index][2](physaddr, val >> 32);

    io_mem_write[index][2](physaddr + 4, val);

#else

    io_mem_write[index][2](physaddr, val);

    io_mem_write[index][2](physaddr + 4, val >> 32);

#endif

#endif /* SHIFT > 2 */

}

/* handle all cases except unaligned access which span two pages */

DATA_TYPE REGPARM(1) glue(glue(__ld, SUFFIX), _mmu)(unsigned long addr)

{

    DATA_TYPE res;

    int is_user, index;

    unsigned long physaddr, tlb_addr;

    void *retaddr;

    /* test if there is match for unaligned or IO access */

    /* XXX: could done more in memory macro in a non portable way */

    is_user = ((env->hflags & HF_CPL_MASK) == 3);

    index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);

 redo:

    tlb_addr = env->tlb_read[is_user][index].address;

    if ((addr & TARGET_PAGE_MASK) == (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {

        physaddr = addr + env->tlb_read[is_user][index].addend;

        if (tlb_addr & ~TARGET_PAGE_MASK) {

            /* IO access */

            if ((addr & (DATA_SIZE - 1)) != 0)

                goto do_unaligned_access;

            res = glue(io_read, SUFFIX)(physaddr, tlb_addr);

        } else if (((addr & 0xfff) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {

            /* slow unaligned access (it spans two pages or IO) */

        do_unaligned_access:

            retaddr = __builtin_return_address(0);

            res = glue(slow_ld, SUFFIX)(addr, retaddr);

        } else {

            /* unaligned access in the same page */

            res = glue(glue(ldu, SUFFIX), _raw)((uint8_t *)physaddr);

        }

    } else {

        /* the page is not in the TLB : fill it */

        retaddr = __builtin_return_address(0);

        tlb_fill(addr, 0, retaddr);

        goto redo;

    }

    return res;

}

/* handle all unaligned cases */

static DATA_TYPE glue(slow_ld, SUFFIX)(unsigned long addr, void *retaddr)

{

    DATA_TYPE res, res1, res2;

    int is_user, index, shift;

    unsigned long physaddr, tlb_addr, addr1, addr2;

    is_user = ((env->hflags & HF_CPL_MASK) == 3);

    index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);

 redo:

    tlb_addr = env->tlb_read[is_user][index].address;

    if ((addr & TARGET_PAGE_MASK) == (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {

        physaddr = addr + env->tlb_read[is_user][index].addend;

        if (tlb_addr & ~TARGET_PAGE_MASK) {

            /* IO access */

            if ((addr & (DATA_SIZE - 1)) != 0)

                goto do_unaligned_access;

            res = glue(io_read, SUFFIX)(physaddr, tlb_addr);

        } else if (((addr & 0xfff) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {

        do_unaligned_access:

            /* slow unaligned access (it spans two pages) */

            addr1 = addr & ~(DATA_SIZE - 1);

            addr2 = addr1 + DATA_SIZE;

            res1 = glue(slow_ld, SUFFIX)(addr1, retaddr);

            res2 = glue(slow_ld, SUFFIX)(addr2, retaddr);

            shift = (addr & (DATA_SIZE - 1)) * 8;

#ifdef TARGET_WORDS_BIGENDIAN

            res = (res1 << shift) | (res2 >> ((DATA_SIZE * 8) - shift));

#else

            res = (res1 >> shift) | (res2 << ((DATA_SIZE * 8) - shift));

#endif

        } else {

            /* unaligned/aligned access in the same page */

            res = glue(glue(ldu, SUFFIX), _raw)((uint8_t *)physaddr);

        }

    } else {

        /* the page is not in the TLB : fill it */

        tlb_fill(addr, 0, retaddr);

        goto redo;

    }

    return res;

}

void REGPARM(2) glue(glue(__st, SUFFIX), _mmu)(unsigned long addr, DATA_TYPE val)

{

    unsigned long physaddr, tlb_addr;

    void *retaddr;

    int is_user, index;

    is_user = ((env->hflags & HF_CPL_MASK) == 3);

    index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);

 redo:

    tlb_addr = env->tlb_write[is_user][index].address;

    if ((addr & TARGET_PAGE_MASK) == (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {

        physaddr = addr + env->tlb_read[is_user][index].addend;

        if (tlb_addr & ~TARGET_PAGE_MASK) {

            /* IO access */

            if ((addr & (DATA_SIZE - 1)) != 0)

                goto do_unaligned_access;

            glue(io_write, SUFFIX)(physaddr, val, tlb_addr);

        } else if (((addr & 0xfff) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {

        do_unaligned_access:

            retaddr = __builtin_return_address(0);

            glue(slow_st, SUFFIX)(addr, val, retaddr);

        } else {

            /* aligned/unaligned access in the same page */

            glue(glue(st, SUFFIX), _raw)((uint8_t *)physaddr, val);

        }

    } else {

        /* the page is not in the TLB : fill it */

        retaddr = __builtin_return_address(0);

        tlb_fill(addr, 1, retaddr);

        goto redo;

    }

}

/* handles all unaligned cases */

static void glue(slow_st, SUFFIX)(unsigned long addr, DATA_TYPE val,

                                  void *retaddr)

{

    unsigned long physaddr, tlb_addr;

    int is_user, index, i;

    is_user = ((env->hflags & HF_CPL_MASK) == 3);

    index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);

 redo:

    tlb_addr = env->tlb_write[is_user][index].address;

    if ((addr & TARGET_PAGE_MASK) == (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {

        physaddr = addr + env->tlb_read[is_user][index].addend;

        if (tlb_addr & ~TARGET_PAGE_MASK) {

            /* IO access */

            if ((addr & (DATA_SIZE - 1)) != 0)

                goto do_unaligned_access;

            glue(io_write, SUFFIX)(physaddr, val, tlb_addr);

        } else if (((addr & 0xfff) + DATA_SIZE - 1) >= TARGET_PAGE_SIZE) {

        do_unaligned_access:

            /* XXX: not efficient, but simple */

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

#ifdef TARGET_WORDS_BIGENDIAN

                slow_stb(addr + i, val >> (((DATA_SIZE - 1) * 8) - (i * 8)), retaddr);

#else

                slow_stb(addr + i, val >> (i * 8), retaddr);

#endif

            }

        } else {

            /* aligned/unaligned access in the same page */

            glue(glue(st, SUFFIX), _raw)((uint8_t *)physaddr, val);

        }

    } else {

        /* the page is not in the TLB : fill it */

        tlb_fill(addr, 1, retaddr);

        goto redo;

    }

}

#undef SHIFT

#undef DATA_TYPE

#undef SUFFIX

#undef DATA_SIZE