/**

 * $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);

    }

}