/**

 * $Id$

 * 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.

 */

#define MODULE mem_module

#include <sys/types.h>

#include <sys/mman.h>

#include <sys/stat.h>

#include <glib/gstrfuncs.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"

#ifndef PAGE_SIZE

#define PAGE_SIZE 4096

#endif

sh4ptr_t *page_map = NULL;

mem_region_fn_t *ext_address_space = NULL;

extern struct mem_region_fn mem_region_unmapped; 

static int mem_load(FILE *f);

static void mem_save(FILE *f);

struct dreamcast_module mem_module =

{ "MEM", mem_init, mem_reset, NULL, NULL, NULL, mem_save, mem_load };

struct mem_region mem_rgn[MAX_MEM_REGIONS];

struct mmio_region *io_rgn[MAX_IO_REGIONS];

struct mmio_region *P4_io[4096];

uint32_t num_io_rgns = 0, num_mem_rgns = 0;

DEFINE_HOOK( mem_page_remapped_hook, mem_page_remapped_hook_t );

static void mem_page_remapped( sh4addr_t addr, mem_region_fn_t fn )

{

    CALL_HOOKS( mem_page_remapped_hook, addr, fn );

}

/********************* The "unmapped" address space ********************/

/* Always reads as 0, writes have no effect */

int32_t FASTCALL unmapped_read_long( sh4addr_t addr )

{

    return 0;

}

void FASTCALL unmapped_write_long( sh4addr_t addr, uint32_t val )

{

}

void FASTCALL unmapped_read_burst( unsigned char *dest, sh4addr_t addr )

{

    memset( dest, 0, 32 );

}

void FASTCALL unmapped_write_burst( sh4addr_t addr, unsigned char *src )

{

}

void FASTCALL unmapped_prefetch( sh4addr_t addr )

{

    /* No effect */

}

struct mem_region_fn mem_region_unmapped = { 

        unmapped_read_long, unmapped_write_long, 

        unmapped_read_long, unmapped_write_long, 

        unmapped_read_long, unmapped_write_long, 

        unmapped_read_burst, unmapped_write_burst,

        unmapped_prefetch, unmapped_read_long }; 

void *mem_alloc_pages( int n )

{

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

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

    if( mem == MAP_FAILED ) {

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

        return NULL;

    }

    return mem;

}

void mem_unprotect( void *region, uint32_t size )

{

    /* Force page alignment */

    uintptr_t i = (uintptr_t)region;

    uintptr_t mask = ~(PAGE_SIZE-1);

    void *ptr = (void *)(i & mask);

    size_t len = (i & (PAGE_SIZE-1)) + size;

    len = (len + (PAGE_SIZE-1)) & mask;

    int status = mprotect( ptr, len, PROT_READ|PROT_WRITE|PROT_EXEC );

    assert( status == 0 );

}

void mem_init( void )

{

    int i;

    mem_region_fn_t *ptr;

    page_map = (sh4ptr_t *)mmap( NULL, sizeof(sh4ptr_t) * LXDREAM_PAGE_TABLE_ENTRIES,

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

    if( page_map == MAP_FAILED ) {

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

    }

    memset( page_map, 0, sizeof(sh4ptr_t) * LXDREAM_PAGE_TABLE_ENTRIES );

    ext_address_space = (mem_region_fn_t *) mmap( NULL, sizeof(mem_region_fn_t) * LXDREAM_PAGE_TABLE_ENTRIES,

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

    if( ext_address_space == MAP_FAILED ) {

        FATAL( "Unable to allocate external memory map (%s)", strerror(errno) );

    }

    for( ptr = ext_address_space, i = LXDREAM_PAGE_TABLE_ENTRIES; i > 0; ptr++, i-- ) {

        *ptr = &mem_region_unmapped;

    }

}

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

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

            }

        }

    }

}

static void mem_save( FILE *f ) 

{

    int i, num_ram_regions = 0;

    uint32_t len;

    /* All RAM regions (ROM and non-memory regions don't need to be saved)

     * Flash is questionable - for now we save it too */

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

        if( mem_rgn[i].flags == MEM_FLAG_RAM ) {

            num_ram_regions++;

        }

    }

    fwrite( &num_ram_regions, sizeof(num_ram_regions), 1, f );

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

        if( mem_rgn[i].flags == MEM_FLAG_RAM ) {

            fwrite_string( mem_rgn[i].name, f );

            fwrite( &mem_rgn[i].base, sizeof(uint32_t), 1, f );

            fwrite( &mem_rgn[i].flags, sizeof(uint32_t), 1, f );

            fwrite( &mem_rgn[i].size, sizeof(uint32_t), 1, f );

            fwrite_gzip( mem_rgn[i].mem, mem_rgn[i].size, 1, f );

        }

    }

    /* All MMIO regions */

    fwrite( &num_io_rgns, sizeof(num_io_rgns), 1, f );

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

        fwrite_string( io_rgn[i]->id, f );

        fwrite( &io_rgn[i]->base, sizeof( uint32_t ), 1, f );

        len = 4096;

        fwrite( &len, sizeof(len), 1, f );

        fwrite_gzip( io_rgn[i]->mem, len, 1, f );

    }

}

static int mem_load( FILE *f )

{

    char tmp[64];

    uint32_t len;

    uint32_t base, size;

    uint32_t flags;

    int i, j;

    int mem_region_loaded[MAX_MEM_REGIONS];

    /* All RAM regions */

    memset( mem_region_loaded, 0, sizeof(mem_region_loaded) );

    fread( &len, sizeof(len), 1, f );

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

        fread_string( tmp, sizeof(tmp), f );

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

            if( strcasecmp( mem_rgn[j].name, tmp ) == 0 ) {

                fread( &base, sizeof(base), 1, f );

                fread( &flags, sizeof(flags), 1, f );

                fread( &size, sizeof(size), 1, f );

                if( base != mem_rgn[j].base ||

                    flags != mem_rgn[j].flags ||

                    size != mem_rgn[j].size ) {

                    ERROR( "Bad memory block %d %s (not mapped to expected region)", i, tmp );

                    return -1;

                }

                if( flags != MEM_FLAG_RAM ) {

                    ERROR( "Unexpected memory block %d %s (Not a RAM region)", i, tmp );

                    return -1;

                }

                fread_gzip( mem_rgn[j].mem, size, 1, f );

                mem_region_loaded[j] = 1;

                break;

            }

        }

    }

    /* Make sure we got all the memory regions we expected */

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

        if( mem_rgn[i].flags == MEM_FLAG_RAM &&

            mem_region_loaded[i] == 0 ) {

            ERROR( "Missing memory block %s (not found in save state)", mem_rgn[i].name );

            return -1;

        }

    }

    /* All MMIO regions */

    fread( &len, sizeof(len), 1, f );

    if( len != num_io_rgns ) {

        ERROR( "Unexpected IO region count %d (expected %d)", len, num_io_rgns );

        return -1;

    }

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

        fread_string( tmp, sizeof(tmp), f );

        fread( &base, sizeof(base), 1, f );

        fread( &size, sizeof(size), 1, f );

        if( strcmp( io_rgn[i]->id, tmp ) != 0 ||

                base != io_rgn[i]->base ||

                size != 4096 ) {

            ERROR( "Bad MMIO region %d %s", i, tmp );

            return -1;

        }

        fread_gzip( io_rgn[i]->mem, size, 1, f );

    }

    return 0;

}

int mem_save_block( const gchar *file, uint32_t start, uint32_t length )

{

    sh4ptr_t region;

    int len = 4096, total = 0;

    uint32_t addr = start;

    FILE *f = fopen(file,"w");

    if( f == NULL )

        return errno;

    while( total < length ) {

        region = mem_get_region(addr);

        len = 4096 - (addr & 0x0FFF);

        if( len > (length-total) ) 

            len = (length-total);

        if( fwrite( region, len, 1, f ) != 1 ) {

            ERROR( "Unexpected error writing blocks: %d (%s)", len, strerror(errno) );

            break;

        }

        addr += len;

        total += len;

    }

    fclose( f );

    DEBUG( "Saved %d of %d bytes to %08X", total, length, start );

    return 0;

}

int mem_load_block( const gchar *file, uint32_t start, uint32_t length )

{

    sh4ptr_t region;

    int len = 4096, total = 0;

    uint32_t addr = start;

    struct stat st;

    FILE *f = fopen(file,"r");

    if( f == NULL ) {

        WARN( "Unable to load file '%s': %s", file, strerror(errno) );

        return -1;

    }

    fstat( fileno(f), &st );

    if( length == 0 || length == -1 || length > st.st_size )

        length = st.st_size;

    while( total < length ) {

        region = mem_get_region(addr);

        len = 4096 - (addr & 0x0FFF);

        if( len > (length-total) ) 

            len = (length-total);

        if( fread( region, len, 1, f ) != 1 ) {

            ERROR( "Unexpected error reading: %d (%s)", len, strerror(errno) );

            break;

        }

        addr += len;

        total += len;

    }

    fclose( f );

    DEBUG( "Loaded %d of %d bytes to %08X", total, length, start );

    return 0;

}

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

                                   const char *name, mem_region_fn_t fn, int flags, 

                                   uint32_t repeat_offset, uint32_t repeat_until )

{

    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;

    mem_rgn[num_mem_rgns].fn = fn;

    fn->prefetch = unmapped_prefetch;

    fn->read_byte_for_write = fn->read_byte;

    num_mem_rgns++;

    do {

        for( i=0; i<size>>LXDREAM_PAGE_BITS; i++ ) {

            if( mem != NULL ) {

                page_map[(base>>LXDREAM_PAGE_BITS)+i] = ((unsigned char *)mem) + (i<<LXDREAM_PAGE_BITS);

            }

            ext_address_space[(base>>LXDREAM_PAGE_BITS)+i] = fn;

            mem_page_remapped( base + (i<<LXDREAM_PAGE_BITS), fn );

        }

        base += repeat_offset;	

    } while( base <= repeat_until );

    return &mem_rgn[num_mem_rgns-1];

}

gboolean mem_load_rom( void *output, const gchar *file, uint32_t size, uint32_t crc )

{

    if( file != NULL && file[0] != '\0' ) {

        FILE *f = fopen(file,"r");

        struct stat st;

        uint32_t calc_crc;

        if( f == NULL ) {

            ERROR( "Unable to load file '%s': %s", file, strerror(errno) );

            return FALSE;

        }

        fstat( fileno(f), &st );

        if( st.st_size != size ) {

            ERROR( "File '%s' is invalid, expected %d bytes but was %d bytes long.", file, size, st.st_size );

            fclose(f);

            return FALSE;

        }

        if( fread( output, 1, size, f ) != size ) { 

            ERROR( "Failed to load file '%s': %s", file, strerror(errno) );

            fclose(f);

            return FALSE;

        }

        /* CRC check only if we loaded something */

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

        if( calc_crc != crc ) {

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

                   file, calc_crc, crc);

        }

        /* Even if the CRC fails, continue normally */

        return TRUE;

    }

    return FALSE;

}

sh4ptr_t mem_get_region_by_name( const 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 + LXDREAM_PAGE_SIZE;

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

    io->trace_flag = 0;

    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, LXDREAM_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] = (sh4ptr_t)(uintptr_t)num_io_rgns;

        ext_address_space[io->base>>12] = &io->fn;

        mem_page_remapped( io->base, &io->fn );

    }

    io_rgn[num_io_rgns] = io;

    num_io_rgns++;

}

void register_io_regions( struct mmio_region **io )

{

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

}

gboolean mem_has_page( uint32_t addr )

{

    return ext_address_space[ (addr&0x1FFFFFFF)>>12 ] != &mem_region_unmapped;

}

sh4ptr_t mem_get_region( uint32_t addr )

{

    sh4ptr_t page = page_map[ (addr & 0x1FFFFFFF) >> 12 ];

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

        return NULL;

    } else {

        return page+(addr&0xFFF);

    }

}

void mem_write_long( sh4addr_t addr, uint32_t value )

{

    ext_address_space[(addr&0x1FFFFFFF)>>12]->write_long(addr, value);

}

static struct mmio_region *mem_get_io_region_by_name( const gchar *name )

{

    int i;

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

        if( strcasecmp(io_rgn[i]->id, name) == 0 ) {

            return io_rgn[i];

        }

    }

    return NULL;

}

void mem_set_trace( const gchar *tracelist, gboolean flag )

{

    if( tracelist != NULL ) {

        gchar ** tracev = g_strsplit_set( tracelist, ",:; \t\r\n", 0 );

        int i;

        for( i=0; tracev[i] != NULL; i++ ) {

            // Special case "all" - trace everything

            if( strcasecmp(tracev[i], "all") == 0 ) {

                int j;

                for( j=0; j<num_io_rgns; j++ ) {

                    io_rgn[j]->trace_flag = flag ? 1 : 0;

                }

                break;

            }

            struct mmio_region *region = mem_get_io_region_by_name( tracev[i] );

            if( region == NULL ) {

                WARN( "Unknown IO region '%s'", tracev[i] );

            } else {

                region->trace_flag = flag ? 1 : 0;

            }

        }

        g_strfreev( tracev );

    }

}