/**

  * $Id$

  * 

  * 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

     }

 }