/**

  * $Id$

  * 

  * 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

 /**

  * Exception table record - this is filled out by the codegen used by the codegen (to backpatch)

  * and linker (for longjmp recover)

  */;

 typedef struct xlat_exception_record {

     uint32_t xlat_pc_offset;  // Native PC exception source (relative to start of code block)

     uint32_t xlat_exc_offset; // Exception entry point (relative to start of code block)

 } *xlat_exception_record_t;

 typedef struct xlat_exception_table {

     xlat_exception_record_t exc;

     size_t next_record;

     size_t table_size;

 } *xlat_exception_table_t;

 /**

  * 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 */

     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) 

 /**

  * 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 addr target address (for the lookup table)

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

  * @param srcsize size of the original data that was translated in bytes

  */

 void xlat_commit_block( uint32_t destsize, uint32_t srcsize );

 /**

  * 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();

 /**

  * Check the internal integrity of the cache

  */

 void xlat_check_integrity();

 #endif /* lxdream_xltcache_H */