/**

  * $Id: mem.c,v 1.2 2005-12-11 12:00:03 nkeynes Exp $

  * mem.c is responsible for creating and maintaining the overall system memory

  * map, as visible from the SH4 processor. 

  *

  * Copyright (c) 2005 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 <sys/mman.h>

 #include <assert.h>

 #include <stdint.h>

 #include <stdlib.h>

 #include <stdio.h>

 #include <unistd.h>

 #include <fcntl.h>

 #include <errno.h>

 #include <string.h>

 #include <zlib.h>

 #include "dream.h"

 #include "mem.h"

 #include "mmio.h"

 #include "dreamcast.h"

 char **page_map = NULL;

 struct mem_region mem_rgn[MAX_MEM_REGIONS];

 struct mmio_region *io_rgn[MAX_IO_REGIONS];

 struct mmio_region *P4_io[4096];

 int num_io_rgns = 1, num_mem_rgns = 0;

 void *mem_alloc_pages( int n )

 {

     void *mem = mmap( NULL, n * 4096,

                       PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0 );

     if( mem == MAP_FAILED ) {

         ERROR( "Memory allocation failure! (%s)", strerror(errno) );

         return NULL;

     }

     return mem;

 }

 void mem_init( void )

 {

     page_map = mmap( NULL, sizeof(char *) * PAGE_TABLE_ENTRIES,

                      PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0 );

     if( page_map == MAP_FAILED ) {

         ERROR( "Unable to allocate page map! (%s)", strerror(errno) );

         page_map = NULL;

         return;

     }

     memset( page_map, 0, sizeof(uint32_t) * PAGE_TABLE_ENTRIES );

 }

 void mem_reset( void )

 {

     /* Restore all mmio registers to their initial settings */

     int i, j;

     for( i=1; i<num_io_rgns; i++ ) {

         for( j=0; io_rgn[i]->ports[j].id != NULL; j++ ) {

             if( io_rgn[i]->ports[j].def_val != UNDEFINED &&

                 io_rgn[i]->ports[j].def_val != *io_rgn[i]->ports[j].val ) {

                 io_rgn[i]->io_write( io_rgn[i]->ports[j].offset,

                                     io_rgn[i]->ports[j].def_val );

             }

         }

     }

 }

 struct mem_region *mem_map_region( void *mem, uint32_t base, uint32_t size,

                                    char *name, int flags )

 {

     int i;

     mem_rgn[num_mem_rgns].base = base;

     mem_rgn[num_mem_rgns].size = size;

     mem_rgn[num_mem_rgns].flags = flags;

     mem_rgn[num_mem_rgns].name = name;

     mem_rgn[num_mem_rgns].mem = mem;

     num_mem_rgns++;

     for( i=0; i<size>>PAGE_BITS; i++ )

         page_map[(base>>PAGE_BITS)+i] = mem + (i<<PAGE_BITS);

     return &mem_rgn[num_mem_rgns-1];

 }

 void *mem_create_ram_region( uint32_t base, uint32_t size, char *name )

 {

     char *mem;

     assert( (base&0xFFFFF000) == base ); /* must be page aligned */

     assert( (size&0x00000FFF) == 0 );

     assert( num_mem_rgns < MAX_MEM_REGIONS );

     assert( page_map != NULL );

     mem = mem_alloc_pages( size>>PAGE_BITS );

     mem_map_region( mem, base, size, name, 6 );

     return mem;

 }

 void *mem_load_rom( char *file, uint32_t base, uint32_t size, uint32_t crc )

 {

     char buf[512], *mem;

     int fd;

     uint32_t calc_crc;

     snprintf( buf, 512, "%s/%s",BIOS_PATH, file );

     fd = open( buf, O_RDONLY );

     if( fd == -1 ) {

         ERROR( "Bios file not found: %s", buf );

         return NULL;

     }

     mem = mmap( NULL, size, PROT_READ, MAP_PRIVATE, fd, 0 );

     if( mem == MAP_FAILED ) {

         ERROR( "Unable to map bios file: %s (%s)", file, strerror(errno) );

         close(fd);

         return NULL;

     }

     mem_map_region( mem, base, size, file, 4 );

     /* CRC check */

     calc_crc = crc32(0L, mem, size);

     if( calc_crc != crc ) {

         WARN( "Bios CRC Mismatch in %s: %08X (expected %08X)",

               file, calc_crc, crc);

     }

     return mem;

 }

 char *mem_get_region_by_name( char *name )

 {

     int i;

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

         if( strcmp( mem_rgn[i].name, name ) == 0 )

             return mem_rgn[i].mem;

     }

     return NULL;

 }

 void register_io_region( struct mmio_region *io )

 {

     int i;

     assert(io);

     io->mem = mem_alloc_pages(2);

     io->save_mem = io->mem + PAGE_SIZE;

     io->index = (struct mmio_port **)malloc(1024*sizeof(struct mmio_port *));

     io->trace_flag = 1;

     memset( io->index, 0, 1024*sizeof(struct mmio_port *) );

     for( i=0; io->ports[i].id != NULL; i++ ) {

         io->ports[i].val = (uint32_t *)(io->mem + io->ports[i].offset);

         *io->ports[i].val = io->ports[i].def_val;

         io->index[io->ports[i].offset>>2] = &io->ports[i];

     }

     memcpy( io->save_mem, io->mem, PAGE_SIZE );

     if( (io->base & 0xFF000000) == 0xFF000000 ) {

         /* P4 area (on-chip I/O channels */

         P4_io[(io->base&0x1FFFFFFF)>>19] = io;

     } else {

         page_map[io->base>>12] = (char *)num_io_rgns;

     }

     io_rgn[num_io_rgns] = io;

     num_io_rgns++;

 }

 void register_io_regions( struct mmio_region **io )

 {

     while( *io ) register_io_region( *io++ );

 }

 int mem_has_page( uint32_t addr )

 {

     char *page = page_map[ (addr & 0x1FFFFFFF) >> 12 ];

     return page != NULL;

 }

 char *mem_get_page( uint32_t addr )

 {

     char *page = page_map[ (addr & 0x1FFFFFFF) >> 12 ];

     return page;

 }

 char *mem_get_region( uint32_t addr )

 {

     char *page = page_map[ (addr & 0x1FFFFFFF) >> 12 ];

     if( ((uint32_t)page) < MAX_IO_REGIONS ) { /* IO Region */

         return NULL;

     } else {

         return page+(addr&0xFFF);

     }

 }