/**

 * $Id$

 * 

 * x86-specific MMU code - this emits simple TLB stubs for TLB indirection.

  *

 * Copyright (c) 2008 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 */

#include "lxdream.h"

#include "mem.h"

#include "sh4/sh4core.h"

#include "sh4/sh4mmio.h"

#include "sh4/sh4trans.h"

#include "sh4/mmu.h"

#include "sh4/x86op.h"

#if SIZEOF_VOID_P == 8

#define ARG1 R_EDI

#define ARG2 R_ESI

#define DECODE() \

    MOV_imm64_r32((uintptr_t)ext_address_space, R_EAX);     /* movq ptr, %rax */ \

    REXW(); OP(0x8B); OP(0x0C); OP(0xC8)                    /* movq [%rax + %rcx*8], %rcx */

#else

#define ARG1 R_EAX

#define ARG2 R_EDX

#define DECODE() \

    MOV_r32disp32x4_r32( R_ECX, (uintptr_t)ext_address_space, R_ECX );

#endif

void mmu_utlb_init_vtable( struct utlb_entry *ent, struct utlb_page_entry *page, gboolean writable )

{

    uint32_t mask = ent->mask;

    uint32_t vpn = ent->vpn & mask;

    uint32_t ppn = ent->ppn & mask;

    int inc = writable ? 1 : 2; 

    int i;

    xlat_output = page->code;

    uint8_t **fn = (uint8_t **)ext_address_space[ppn>>12];

    uint8_t **out = (uint8_t **)&page->fn;

    for( i=0; i<8; i+= inc, fn += inc, out += inc ) {

        *out = xlat_output;

#if SIZEOF_VOID_P == 8

        MOV_imm64_r32((uintptr_t)&mmu_urc, R_EAX );

        OP(0x83); OP(0x00); OP(0x01); // ADD #1, [RAX]

#else 

        OP(0x83); MODRM_r32_disp32(0, (uintptr_t)&mmu_urc); OP(0x01); // ADD #1, mmu_urc

#endif

        ADD_imm32_r32( ppn-vpn, ARG1 ); // 6

        if( ent->mask >= 0xFFFFF000 ) {

            // Maps to a single page, so jump directly there

            int rel = (*fn - xlat_output);

            JMP_rel( rel ); // 5

        } else {

            MOV_r32_r32( ARG1, R_ECX ); // 2

            SHR_imm8_r32( 12, R_ECX );  // 3

            DECODE();                   // 14

            JMP_r32disp8(R_ECX, (((uintptr_t)out) - ((uintptr_t)&page->fn)) );    // 3

        }

    }

}

void mmu_utlb_1k_init_vtable( struct utlb_1k_entry *entry )

{

    xlat_output = entry->code;

    int i;

    uint8_t **out = (uint8_t **)&entry->fn;

    for( i=0; i<8; i++, out++ ) {

        *out = xlat_output;

        MOV_r32_r32( ARG1, R_ECX );

        SHR_imm8_r32( 10, R_ECX );

        AND_imm8s_r32( 0x3, R_ECX );

#if SIZEOF_VOID_P == 8

        MOV_imm64_r32( (uintptr_t)&entry->subpages[0], R_EAX );

        REXW(); OP(0x8B); OP(0x0C); OP(0xC8);                   /* movq [%rax + %rcx*8], %rcx */

#else

        MOV_r32disp32x4_r32( R_ECX, ((uintptr_t)&entry->subpages[0]), R_ECX );

#endif                

        JMP_r32disp8(R_ECX, (((uintptr_t)out) - ((uintptr_t)&entry->fn)) );    // 3

    }

    out = (uint8_t **)&entry->user_fn;

    for( i=0; i<8; i++, out++ ) {

        *out = xlat_output;

        MOV_r32_r32( ARG1, R_ECX );

        SHR_imm8_r32( 10, R_ECX );

        AND_imm8s_r32( 0x3, R_ECX );

#if SIZEOF_VOID_P == 8

        MOV_imm64_r32( (uintptr_t)&entry->user_subpages[0], R_EAX );

        REXW(); OP(0x8B); OP(0x0C); OP(0xC8);                   /* movq [%rax + %rcx*8], %rcx */

#else

        MOV_r32disp32x4_r32( R_ECX, ((uintptr_t)&entry->user_subpages[0]), R_ECX );

#endif                

        JMP_r32disp8(R_ECX, (((uintptr_t)out) - ((uintptr_t)&entry->user_fn)) );    // 3

    }

}