/**

  * $Id$

  * 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 */

 }

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

 {

     mem_write_fn_t writefn = ext_address_space[(addr&0x1FFFFFFF)>>12]->write_long;

     uint32_t *p = (uint32_t *)src;

     sh4addr_t end = addr + 32;

     while( addr < end ) {

         writefn(addr, *p);

         addr += 4;

         p += 4;

     }

 }

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

 {

     mem_read_fn_t readfn = ext_address_space[(addr&0x1FFFFFFF)>>12]->read_long;

     uint32_t *p = (uint32_t *)dest;

     sh4addr_t end = addr + 32;

     while( addr < end ) {

         *p = readfn(addr);

         addr += 4;

         p += 4;

     }

 }

 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;

     if( io->fn.write_burst == NULL )

         io->fn.write_burst = default_write_burst;

     if( io->fn.read_burst == NULL )

         io->fn.read_burst = default_read_burst;

     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 );

     }

 }