/**

 * $Id$

 * 

 * 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 "xlat/x86/x86op.h"

#if SIZEOF_VOID_P == 8

#define XLAT(addr_space, reg) \

    MOVQ_imm64_r64( (uintptr_t)addr_space, REG_RAX ); \

    MOVP_sib_rptr( 3, reg, REG_RAX, 0, reg );

#define ADDP_imms_ptr(imm,p) \

    MOVQ_imm64_r64((uintptr_t)p, REG_EAX ); \

    ADDL_imms_r32disp(imm, REG_EAX, 0);

#else

#define XLAT(addr_space, reg) \

    MOVP_sib_rptr( 2, reg, -1, (uintptr_t)addr_space, reg ); 

#define ADDP_imms_ptr(imm,p) \

    ADDL_imms_r32disp(imm, -1, (uintptr_t)p);

#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;

    struct mem_region_fn **addr_space;

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

    uint8_t **fn;

    int inc = writable ? 1 : 2; 

    int i;

    xlat_output = page->code;

    if( (ppn & 0x1FFFFFFF) >= 0x1C000000 ) {

        /* SH4 control region */

        ppn |= 0xE0000000;

        addr_space = sh4_address_space;

    } else {

        addr_space = ext_address_space;

    }

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

    for( i=0; i<10; i+= inc, fn += inc, out += inc ) {

        *out = xlat_output;

        if( i != 9 ) { /* read_byte_for_write doesn't increment mmu_urc, everything else does */

            ADDP_imms_ptr(1, &mmu_urc);

        }

        ADDL_imms_r32( ppn-vpn, REG_ARG1 ); // 6

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

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

            int rel = (*fn - xlat_output);

            JMP_prerel( rel ); // 5

        } else {

            MOVL_r32_r32( REG_ARG1, REG_ECX ); // 2

            SHRL_imm_r32( 12, REG_ECX );  // 3

            XLAT(addr_space, REG_ECX);                   // 14

            JMP_r32disp(REG_ECX, (((uintptr_t)out) - ((uintptr_t)&page->fn)) );    // 3

        }

    }

    page->fn.prefetch = unmapped_prefetch; // FIXME

}

void mmu_utlb_init_storequeue_vtable( struct utlb_entry *ent, struct utlb_page_entry *page )

{

    uint32_t mask = ent->mask;

    uint32_t vpn = ent->vpn & mask;

    uint32_t ppn = ent->ppn & mask;

    xlat_output = page->code;

    memcpy( page, &p4_region_storequeue, sizeof(struct mem_region_fn) );

    page->fn.prefetch = (mem_prefetch_fn_t)xlat_output;

    ADDP_imms_ptr(1, &mmu_urc);

    ADDL_imms_r32( ppn-vpn, REG_ARG1 );

    int rel = ((uint8_t *)ccn_storequeue_prefetch_tlb) - xlat_output;

    JMP_prerel( rel );

}

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<9; i++, out++ ) {

        *out = xlat_output;

        MOVL_r32_r32( REG_ARG1, REG_ECX );

        SHRL_imm_r32( 10, REG_ECX );

        ANDL_imms_r32( 0x3, REG_ECX );

        XLAT( (uintptr_t)&entry->subpages[0], REG_ECX );

        JMP_r32disp(REG_ECX, (((uintptr_t)out) - ((uintptr_t)&entry->fn)) );    // 3

    }

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

    for( i=0; i<9; i++, out++ ) {

        *out = xlat_output;

        MOVL_r32_r32( REG_ARG1, REG_ECX );

        SHRL_imm_r32( 10, REG_ECX );

        ANDL_imms_r32( 0x3, REG_ECX );

        XLAT( (uintptr_t)&entry->user_subpages[0], REG_ECX );

        JMP_r32disp(REG_ECX, (((uintptr_t)out) - ((uintptr_t)&entry->user_fn)) );    // 3

    }

}