/**

 * $Id$

 * 

 * Translation cache support (architecture independent)

 *

 * 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 "dream.h"

#include "mem.h"

#ifndef lxdream_xltcache_H

#define lxdream_xltcache_H 1

/**

 * For now, recovery is purely a matter of mapping native pc => sh4 pc,

 * and updating sh4r.pc & sh4r.slice_cycles accordingly. In future more

 * detailed recovery may be required if the translator optimizes more

 * agressively.

 *

 * The recovery table contains (at least) one entry per abortable instruction,

 * 

 */

typedef struct xlat_recovery_record {

    uint32_t xlat_offset;    // native (translated) pc 

    uint32_t sh4_icount;     // instruction number of the corresponding SH4 instruction

                             // (0 = first instruction, 1 = second instruction, ... )

} *xlat_recovery_record_t;

struct xlat_cache_block {

    int active;  /* 0 = deleted, 1 = normal. 2 = accessed (temp-space only) */

    uint32_t size;

    void **lut_entry; /* For deletion */

    void *chain;

    void *use_list;

    uint32_t xlat_sh4_mode; /* comparison with sh4r.xlat_sh4_mode */

    uint32_t recover_table_offset; // Offset from code[0] of the recovery table;

    uint32_t recover_table_size;

    unsigned char code[0];

} __attribute__((packed));

typedef struct xlat_cache_block *xlat_cache_block_t;

#define XLAT_BLOCK_FOR_CODE(code) (((xlat_cache_block_t)code)-1)

#define XLAT_BLOCK_MODE(code) (XLAT_BLOCK_FOR_CODE(code)->xlat_sh4_mode)

#define XLAT_BLOCK_CHAIN(code) (XLAT_BLOCK_FOR_CODE(code)->chain)

#define XLAT_RECOVERY_TABLE(code) ((xlat_recovery_record_t)(((char *)code) + XLAT_BLOCK_FOR_CODE(code)->recover_table_offset))

/**

 * Initialize the translation cache

 */

void xlat_cache_init(void);

/**

 * Returns the next block in the new cache list that can be written to by the

 * translator.

 */

xlat_cache_block_t xlat_start_block(sh4addr_t address);

/**

 * Increases the current block size (only valid between calls to xlat_start_block()

 * and xlat_commit_block()). 

 * @return the new block, which may be different from the old block.

 */

xlat_cache_block_t xlat_extend_block( uint32_t newSize );

/**

 * Commit the current translation block

 * @param destsize final size of the translation in bytes.

 * @param startpc PC at the start of the translation block.

 * @param endpc PC at the end of the translation block (i.e. the address of the

 *  next instruction after the block).

 */

void xlat_commit_block( uint32_t destsize, sh4addr_t startpc, sh4addr_t endpc );

/**

 * Dump the disassembly of the specified code block to a stream

 * (primarily for debugging purposes)

 * @param out The stream to write the output to

 * @param code a translated block

 */

void xlat_disasm_block( FILE *out, void *code );

/**

 * Delete (deactivate) the specified block from the cache. Caller is responsible

 * for ensuring that there really is a block there.

 */

void xlat_delete_block( xlat_cache_block_t block );

/**

 * Retrieve the entry point for the translated code corresponding to the given

 * SH4 address, or NULL if there is no code for that address.

 */

void * FASTCALL xlat_get_code( sh4addr_t address );

/**

 * Retrieve the pre-instruction recovery record corresponding to the given

 * native address, or NULL if there is no recovery code for the address.

 * @param code The code block containing the recovery table.

 * @param native_pc A pointer that must be within the currently executing 

 * return the first record before or equal to the given pc.

 * translation block.

 */

struct xlat_recovery_record *xlat_get_pre_recovery( void *code, void *native_pc );

/**

 * Retrieve the entry point for the translated code corresponding to the given

 * SH4 virtual address, or NULL if there is no code for the address. 

 * If the virtual address cannot be resolved, this method will raise a TLB miss 

 * exception, and return NULL.

 */

void * FASTCALL xlat_get_code_by_vma( sh4vma_t address );

/**

 * Retrieve the address of the lookup table entry corresponding to the

 * given SH4 address.

 */

void ** FASTCALL xlat_get_lut_entry( sh4addr_t address );

/**

 * Retrieve the current host address of the running translated code block.

 * @return the host PC, or null if there is no currently executing translated

 * block (or the stack is corrupted)

 * Note: the implementation of this method is host (and calling-convention) specific.

 * @param block_start start of the block the PC should be in

 * @param block_size size of the code block in bytes.

 */

void *xlat_get_native_pc( void *block_start, uint32_t block_size );

/**

 * Retrieve the size of the block starting at the specified pointer. If the

 * pointer is not a valid code block, the return value is undefined.

 */

uint32_t FASTCALL xlat_get_block_size( void *ptr );

/**

 * Retrieve the size of the code in the block starting at the specified 

 * pointer. Effectively this is xlat_get_block_size() minus the size of

 * the recovery table. If the pointer is not a valid code block, the 

 * return value is undefined.

 */

uint32_t FASTCALL xlat_get_code_size( void *ptr );

/**

 * Flush the code cache for the page containing the given address

 */

void FASTCALL xlat_flush_page( sh4addr_t address );

void FASTCALL xlat_invalidate_word( sh4addr_t address );

void FASTCALL xlat_invalidate_long( sh4addr_t address );

/**

 * Invalidate the code cache for a memory region

 */

void FASTCALL xlat_invalidate_block( sh4addr_t address, size_t bytes );

/**

 * Flush the entire code cache. This isn't as cheap as one might like

 */

void xlat_flush_cache();

/**

 * Test if the given pointer is within the translation cache, and (is likely)

 * the start of a code block

 */

gboolean xlat_is_code_pointer( void *p );

/**

 * Check the internal integrity of the cache

 */

void xlat_check_integrity();

/**

 * Short record with block + pc, used for activity dumps

 */

typedef struct xlat_block_ref {

    xlat_cache_block_t block;

    uint32_t pc;

} *xlat_block_ref_t;

/**

 * Fetch the top numRecords translated blocks by number of executions (requires block

 * profiling to be turned on in order to give meaningful results).

 * @param topN Number of blocks to print.

 * @return the number of records retrieved

 */

unsigned int xlat_get_cache_blocks_by_activity( xlat_block_ref_t records, size_t numRecords );

void xlat_dump_cache_by_activity( unsigned int topN );

#endif /* lxdream_xltcache_H */