#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 "sh4core.h"

#include "mem.h"

#include "dreamcast.h"

#define OC_BASE 0x1C000000

#define OC_TOP  0x20000000

#ifdef ENABLE_WATCH

#define CHECK_READ_WATCH( addr, size ) \

    if( mem_is_watched(addr,size,WATCH_READ) != NULL ) { \

        WARN( "Watch triggered at %08X by %d byte read", addr, size ); \

        dreamcast_stop(); \

    }

#define CHECK_WRITE_WATCH( addr, size, val )                  \

    if( mem_is_watched(addr,size,WATCH_WRITE) != NULL ) { \

        WARN( "Watch triggered at %08X by %d byte write <= %0*X", addr, size, size*2, val ); \

        dreamcast_stop(); \

    }

#else

#define CHECK_READ_WATCH( addr, size )

#define CHECK_WRITE_WATCH( addr, size )

#endif

#define TRANSLATE_VIDEO_64BIT_ADDRESS(a)  ( (((a)&0x00FFFFF8)>>1)|(((a)&0x00000004)<<20)|((a)&0x03)|0x05000000 );

static char **page_map = NULL;

static char *cache = 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 );

    cache = mem_alloc_pages(2);

}

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;

}

#define OCRAM_START (0x1C000000>>PAGE_BITS)

#define OCRAM_END   (0x20000000>>PAGE_BITS)

void mem_set_cache_mode( int mode )

{

    uint32_t i;

    switch( mode ) {

        case MEM_OC_INDEX0: /* OIX=0 */

            for( i=OCRAM_START; i<OCRAM_END; i++ )

                page_map[i] = cache + ((i&0x02)<<(PAGE_BITS-1));

            break;

        case MEM_OC_INDEX1: /* OIX=1 */

            for( i=OCRAM_START; i<OCRAM_END; i++ )

                page_map[i] = cache + ((i&0x02000000)>>(25-PAGE_BITS));

            break;

        default: /* disabled */

            for( i=OCRAM_START; i<OCRAM_END; i++ )

                page_map[i] = NULL;

            break;

    }

}

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++ );

}

#define TRACE_IO( str, p, r, ... ) if(io_rgn[(uint32_t)p]->trace_flag) \

TRACE( str " [%s.%s: %s]", __VA_ARGS__, \

    MMIO_NAME_BYNUM((uint32_t)p), MMIO_REGID_BYNUM((uint32_t)p, r), \

    MMIO_REGDESC_BYNUM((uint32_t)p, r) )

int32_t mem_read_p4( uint32_t addr )

{

    struct mmio_region *io = P4_io[(addr&0x1FFFFFFF)>>19];

    if( !io ) {

        ERROR( "Attempted read from unknown P4 region: %08X", addr );

        return 0;

    } else {

        return io->io_read( addr&0xFFF );

    }    

}

void mem_write_p4( uint32_t addr, int32_t val )

{

    struct mmio_region *io = P4_io[(addr&0x1FFFFFFF)>>19];

    if( !io ) {

        if( (addr & 0xFC000000) == 0xE0000000 ) {

            /* Store queue */

            SH4_WRITE_STORE_QUEUE( addr, val );

        } else {

            ERROR( "Attempted write to unknown P4 region: %08X", addr );

        }

    } else {

        io->io_write( addr&0xFFF, val );

    }

}

int mem_has_page( uint32_t addr )

{

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

    return page != NULL;

}

int32_t mem_read_phys_word( uint32_t addr )

{

    char *page;

    if( addr > 0xE0000000 ) /* P4 Area, handled specially */

        return SIGNEXT16(mem_read_p4( addr ));

    if( (addr&0x1F800000) == 0x04000000 ) {

        addr = TRANSLATE_VIDEO_64BIT_ADDRESS(addr);

    }

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

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

        if( page == NULL ) {

            ERROR( "Attempted word read to missing page: %08X",

                   addr );

            return 0;

        }

        return SIGNEXT16(io_rgn[(uint32_t)page]->io_read(addr&0xFFF));

    } else {

        return SIGNEXT16(*(int16_t *)(page+(addr&0xFFF)));

    }

}

int32_t mem_read_long( uint32_t addr )

{

    char *page;

    CHECK_READ_WATCH(addr,4);

    if( addr > 0xE0000000 ) /* P4 Area, handled specially */

        return mem_read_p4( addr );

    if( (addr&0x1F800000) == 0x04000000 ) {

        addr = TRANSLATE_VIDEO_64BIT_ADDRESS(addr);

    }

    if( IS_MMU_ENABLED() ) {

        ERROR( "user-mode & mmu translation not implemented, aborting", NULL );

        sh4_stop();

        return 0;

    }

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

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

        int32_t val;

        if( page == NULL ) {

            ERROR( "Attempted long read to missing page: %08X", addr );

            return 0;

        }

        val = io_rgn[(uint32_t)page]->io_read(addr&0xFFF);

        TRACE_IO( "Long read %08X <= %08X", page, (addr&0xFFF), val, addr );

        return val;

    } else {

        return *(int32_t *)(page+(addr&0xFFF));

    }

}

int32_t mem_read_word( uint32_t addr )

{

    char *page;

    CHECK_READ_WATCH(addr,2);

    if( addr > 0xE0000000 ) /* P4 Area, handled specially */

        return SIGNEXT16(mem_read_p4( addr ));

    if( (addr&0x1F800000) == 0x04000000 ) {

        addr = TRANSLATE_VIDEO_64BIT_ADDRESS(addr);

    }

    if( IS_MMU_ENABLED() ) {

        ERROR( "user-mode & mmu translation not implemented, aborting", NULL );

        sh4_stop();

        return 0;

    }

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

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

        int32_t val;

        if( page == NULL ) {

            ERROR( "Attempted word read to missing page: %08X", addr );

            return 0;

        }

        val = SIGNEXT16(io_rgn[(uint32_t)page]->io_read(addr&0xFFF));

        TRACE_IO( "Word read %04X <= %08X", page, (addr&0xFFF), val&0xFFFF, addr );

        return val;

    } else {

        return SIGNEXT16(*(int16_t *)(page+(addr&0xFFF)));

    }

}

int32_t mem_read_byte( uint32_t addr )

{

    char *page;

    CHECK_READ_WATCH(addr,1);

    if( addr > 0xE0000000 ) /* P4 Area, handled specially */

        return SIGNEXT8(mem_read_p4( addr ));

    if( (addr&0x1F800000) == 0x04000000 ) {

        addr = TRANSLATE_VIDEO_64BIT_ADDRESS(addr);

    }

    if( IS_MMU_ENABLED() ) {

        ERROR( "user-mode & mmu translation not implemented, aborting", NULL );

        sh4_stop();

        return 0;

    }

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

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

        int32_t val;

        if( page == NULL ) {

            ERROR( "Attempted byte read to missing page: %08X", addr );

            return 0;

        }

        val = SIGNEXT8(io_rgn[(uint32_t)page]->io_read(addr&0xFFF));

        TRACE_IO( "Byte read %02X <= %08X", page, (addr&0xFFF), val&0xFF, addr );

        return val;

    } else {

        return SIGNEXT8(*(int8_t *)(page+(addr&0xFFF)));

    }

}

void mem_write_long( uint32_t addr, uint32_t val )

{

    char *page;

    CHECK_WRITE_WATCH(addr,4,val);

    if( addr > 0xE0000000 ) {

        mem_write_p4( addr, val );

        return;

    }

    if( (addr&0x1F800000) == 0x04000000 ) {

        addr = TRANSLATE_VIDEO_64BIT_ADDRESS(addr);

    }

    if( IS_MMU_ENABLED() ) {

        ERROR( "user-mode & mmu translation not implemented, aborting", NULL );

        sh4_stop();

        return;

    }

    if( (addr&0x1FFFFFFF) < 0x200000 ) {

        ERROR( "Attempted write to read-only memory: %08X => %08X", val, addr);

        sh4_stop();

        return;

    }

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

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

        if( page == NULL ) {

            ERROR( "Long write to missing page: %08X => %08X", val, addr );

            return;

        }

        TRACE_IO( "Long write %08X => %08X", page, (addr&0xFFF), val, addr );

        io_rgn[(uint32_t)page]->io_write(addr&0xFFF, val);

    } else {

        *(uint32_t *)(page+(addr&0xFFF)) = val;

    }

}

void mem_write_word( uint32_t addr, uint32_t val )

{

    char *page;

    CHECK_WRITE_WATCH(addr,2,val);

    if( addr > 0xE0000000 ) {

        mem_write_p4( addr, (int16_t)val );

        return;

    }

    if( (addr&0x1F800000) == 0x04000000 ) {

        addr = TRANSLATE_VIDEO_64BIT_ADDRESS(addr);

    }

    if( IS_MMU_ENABLED() ) {

        ERROR( "user-mode & mmu translation not implemented, aborting", NULL );

        sh4_stop();

        return;

    }

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

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

        if( page == NULL ) {

            ERROR( "Attempted word write to missing page: %08X", addr );

            return;

        }

        TRACE_IO( "Word write %04X => %08X", page, (addr&0xFFF), val&0xFFFF, addr );

        io_rgn[(uint32_t)page]->io_write(addr&0xFFF, val);

    } else {

        *(uint16_t *)(page+(addr&0xFFF)) = val;

    }

}

void mem_write_byte( uint32_t addr, uint32_t val )

{

    char *page;

    CHECK_WRITE_WATCH(addr,1,val);

    if( addr > 0xE0000000 ) {

        mem_write_p4( addr, (int8_t)val );

        return;

    }

    if( (addr&0x1F800000) == 0x04000000 ) {

        addr = TRANSLATE_VIDEO_64BIT_ADDRESS(addr);

    }

    if( IS_MMU_ENABLED() ) {

        ERROR( "user-mode & mmu translation not implemented, aborting", NULL );

        sh4_stop();

        return;

    }

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

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

        if( page == NULL ) {

            ERROR( "Attempted byte write to missing page: %08X", addr );

            return;

        }

        TRACE_IO( "Byte write %02X => %08X", page, (addr&0xFFF), val&0xFF, addr );

        io_rgn[(uint32_t)page]->io_write( (addr&0xFFF), val);

    } else {

        *(uint8_t *)(page+(addr&0xFFF)) = val;

    }

}

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);

    }

}

/* FIXME: Handle all the many special cases when the range doesn't fall cleanly

 * into the same memory black

 */

void mem_copy_from_sh4( char *dest, uint32_t srcaddr, size_t count ) {

    char *src = mem_get_region(srcaddr);

    memcpy( dest, src, count );

}

void mem_copy_to_sh4( uint32_t destaddr, char *src, size_t count ) {

    char *dest = mem_get_region(destaddr);

    memcpy( dest, src, count );

}