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lxdream.org :: lxdream/src/sh4/xltcache.c
lxdream 0.9.1
released Jun 29
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filename src/sh4/xltcache.c
changeset 366:6fb0d05152d7
prev359:c588dce7ebde
next376:8c7587af5a5d
author nkeynes
date Tue Sep 04 08:32:44 2007 +0000 (14 years ago)
permissions -rw-r--r--
last change Add method to retrieve the size of a block, given the code pointer (useful
for eg disassembling the block)
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     1 /**
     2  * $Id: xltcache.c,v 1.2 2007-09-04 08:32:44 nkeynes Exp $
     3  * 
     4  * Translation cache management. This part is architecture independent.
     5  *
     6  * Copyright (c) 2005 Nathan Keynes.
     7  *
     8  * This program is free software; you can redistribute it and/or modify
     9  * it under the terms of the GNU General Public License as published by
    10  * the Free Software Foundation; either version 2 of the License, or
    11  * (at your option) any later version.
    12  *
    13  * This program is distributed in the hope that it will be useful,
    14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16  * GNU General Public License for more details.
    17  */
    19 #include "sh4/xltcache.h"
    20 #include "dreamcast.h"
    21 #include <sys/mman.h>
    22 #include <assert.h>
    24 #define XLAT_LUT_PAGE_BITS 12
    25 #define XLAT_LUT_TOTAL_BITS 28
    26 #define XLAT_LUT_PAGE(addr) (((addr)>>13) & 0xFFFF)
    27 #define XLAT_LUT_ENTRY(addr) (((addr)&0x1FFE) >> 1)
    29 #define XLAT_LUT_PAGES (1<<(XLAT_LUT_TOTAL_BITS-XLAT_LUT_PAGE_BITS))
    30 #define XLAT_LUT_PAGE_ENTRIES (1<<XLAT_LUT_PAGE_BITS)
    31 #define XLAT_LUT_PAGE_SIZE (XLAT_LUT_PAGE_ENTRIES * sizeof(void *))
    33 #define XLAT_LUT_ENTRY_EMPTY (void *)0
    34 #define XLAT_LUT_ENTRY_USED  (void *)1
    36 #define NEXT(block) ( (xlat_cache_block_t)&((block)->code[(block)->size]))
    37 #define BLOCK_FOR_CODE(code) (((xlat_cache_block_t)code)-1)
    38 #define IS_ENTRY_POINT(ent) (ent > XLAT_LUT_ENTRY_USED)
    39 #define IS_ENTRY_USED(ent) (ent != XLAT_LUT_ENTRY_EMPTY)
    41 #define MIN_BLOCK_SIZE 32
    42 #define MIN_TOTAL_SIZE (sizeof(struct xlat_cache_block)+MIN_BLOCK_SIZE)
    44 #define BLOCK_INACTIVE 0
    45 #define BLOCK_ACTIVE 1
    46 #define BLOCK_USED 2
    48 xlat_cache_block_t xlat_new_cache;
    49 xlat_cache_block_t xlat_new_cache_ptr;
    50 xlat_cache_block_t xlat_new_create_ptr;
    51 xlat_cache_block_t xlat_temp_cache;
    52 xlat_cache_block_t xlat_temp_cache_ptr;
    53 xlat_cache_block_t xlat_old_cache;
    54 xlat_cache_block_t xlat_old_cache_ptr;
    55 static void ***xlat_lut;
    56 static void **xlat_lut2; /* second-tier page info */
    58 void xlat_cache_init() 
    59 {
    60     xlat_new_cache = mmap( NULL, XLAT_NEW_CACHE_SIZE, PROT_EXEC|PROT_READ|PROT_WRITE,
    61 			   MAP_PRIVATE|MAP_ANONYMOUS, -1, 0 );
    62     xlat_temp_cache = mmap( NULL, XLAT_TEMP_CACHE_SIZE, PROT_EXEC|PROT_READ|PROT_WRITE,
    63 			   MAP_PRIVATE|MAP_ANONYMOUS, -1, 0 );
    64     xlat_old_cache = mmap( NULL, XLAT_OLD_CACHE_SIZE, PROT_EXEC|PROT_READ|PROT_WRITE,
    65 			   MAP_PRIVATE|MAP_ANONYMOUS, -1, 0 );
    66     xlat_new_cache_ptr = xlat_new_cache;
    67     xlat_temp_cache_ptr = xlat_temp_cache;
    68     xlat_old_cache_ptr = xlat_old_cache;
    69     xlat_new_create_ptr = xlat_new_cache;
    71     xlat_lut = mmap( NULL, XLAT_LUT_PAGES*sizeof(void *), PROT_READ|PROT_WRITE,
    72 		     MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
    73     memset( xlat_lut, 0, XLAT_LUT_PAGES*sizeof(void *) );
    75     xlat_flush_cache();
    76 }
    78 /**
    79  * Reset the cache structure to its default state
    80  */
    81 void xlat_flush_cache() 
    82 {
    83     xlat_cache_block_t tmp;
    84     int i;
    85     xlat_new_cache_ptr = xlat_new_cache;
    86     xlat_new_cache_ptr->active = 0;
    87     xlat_new_cache_ptr->size = XLAT_NEW_CACHE_SIZE - 2*sizeof(struct xlat_cache_block);
    88     tmp = NEXT(xlat_new_cache_ptr);
    89     tmp->active = 1;
    90     tmp->size = 0;
    91     xlat_temp_cache_ptr = xlat_temp_cache;
    92     xlat_temp_cache_ptr->active = 0;
    93     xlat_temp_cache_ptr->size = XLAT_TEMP_CACHE_SIZE - 2*sizeof(struct xlat_cache_block);
    94     tmp = NEXT(xlat_temp_cache_ptr);
    95     tmp->active = 1;
    96     tmp->size = 0;
    97     xlat_old_cache_ptr = xlat_old_cache;
    98     xlat_old_cache_ptr->active = 0;
    99     xlat_old_cache_ptr->size = XLAT_OLD_CACHE_SIZE - 2*sizeof(struct xlat_cache_block);
   100     tmp = NEXT(xlat_old_cache_ptr);
   101     tmp->active = 1;
   102     tmp->size = 0;
   103     for( i=0; i<XLAT_LUT_PAGES; i++ ) {
   104 	if( xlat_lut[i] != NULL ) {
   105 	    memset( xlat_lut[i], 0, XLAT_LUT_PAGE_SIZE );
   106 	}
   107     }
   108 }
   110 void xlat_flush_page( sh4addr_t address )
   111 {
   112     int i;
   113     void **page = xlat_lut[XLAT_LUT_PAGE(address)];
   114     for( i=0; i<XLAT_LUT_PAGE_ENTRIES; i++ ) {
   115 	if( IS_ENTRY_POINT(page[i]) ) {
   116 	    BLOCK_FOR_CODE(page[i])->active = 0;
   117 	}
   118 	page[i] = NULL;
   119     }
   120 }
   122 void *xlat_get_code( sh4addr_t address )
   123 {
   124     void **page = xlat_lut[XLAT_LUT_PAGE(address)];
   125     if( page == NULL ) {
   126 	return NULL;
   127     }
   128     return page[XLAT_LUT_ENTRY(address)];
   129 }
   131 uint32_t xlat_get_block_size( void *block )
   132 {
   133     xlat_cache_block_t xlt = (xlat_cache_block_t)(((char *)block)-sizeof(struct xlat_cache_block));
   134     return xlt->size;
   135 }
   137 /**
   138  * Cut the specified block so that it has the given size, with the remaining data
   139  * forming a new free block. If the free block would be less than the minimum size,
   140  * the cut is not performed.
   141  * @return the next block after the (possibly cut) block.
   142  */
   143 static inline xlat_cache_block_t xlat_cut_block( xlat_cache_block_t block, int cutsize )
   144 {
   145     if( block->size > cutsize + MIN_TOTAL_SIZE ) {
   146 	int oldsize = block->size;
   147 	block->size = cutsize;
   148 	xlat_cache_block_t next = NEXT(block);
   149 	next->active = 0;
   150 	next->size = oldsize - cutsize - sizeof(struct xlat_cache_block);
   151 	return next;
   152     } else {
   153 	return NEXT(block);
   154     }
   155 }
   157 /**
   158  * Promote a block in temp space (or elsewhere for that matter) to old space.
   159  *
   160  * @param block to promote.
   161  */
   162 static void xlat_promote_to_old_space( xlat_cache_block_t block )
   163 {
   164     int allocation = -sizeof(struct xlat_cache_block);
   165     int size = block->size;
   166     xlat_cache_block_t curr = xlat_old_cache_ptr;
   167     xlat_cache_block_t start_block = curr;
   168     do {
   169 	allocation += curr->size + sizeof(struct xlat_cache_block);
   170 	curr = NEXT(curr);
   171 	if( allocation > size ) {
   172 	    break; /* done */
   173 	}
   174 	if( curr->size == 0 ) { /* End-of-cache Sentinel */
   175 	    /* Leave what we just released as free space and start again from the
   176 	     * top of the cache
   177 	     */
   178 	    start_block->active = 0;
   179 	    start_block->size = allocation;
   180 	    allocation = -sizeof(struct xlat_cache_block);
   181 	    start_block = curr = xlat_old_cache;
   182 	}
   183     } while(1);
   184     start_block->active = 1;
   185     start_block->size = allocation;
   186     start_block->lut_entry = block->lut_entry;
   187     *block->lut_entry = &start_block->code;
   188     memcpy( start_block->code, block->code, block->size );
   189     xlat_old_cache_ptr = xlat_cut_block(start_block, size );
   190     if( xlat_old_cache_ptr->size == 0 ) {
   191 	xlat_old_cache_ptr = xlat_old_cache;
   192     }
   193 }
   195 /**
   196  * Similarly to the above method, promotes a block to temp space.
   197  * TODO: Try to combine these - they're nearly identical
   198  */
   199 void xlat_promote_to_temp_space( xlat_cache_block_t block )
   200 {
   201     int size = block->size;
   202     int allocation = -sizeof(struct xlat_cache_block);
   203     xlat_cache_block_t curr = xlat_temp_cache_ptr;
   204     xlat_cache_block_t start_block = curr;
   205     do {
   206 	if( curr->active == BLOCK_USED ) {
   207 	    xlat_promote_to_old_space( curr );
   208 	}
   209 	allocation += curr->size + sizeof(struct xlat_cache_block);
   210 	curr = NEXT(curr);
   211 	if( allocation > size ) {
   212 	    break; /* done */
   213 	}
   214 	if( curr->size == 0 ) { /* End-of-cache Sentinel */
   215 	    /* Leave what we just released as free space and start again from the
   216 	     * top of the cache
   217 	     */
   218 	    start_block->active = 0;
   219 	    start_block->size = allocation;
   220 	    allocation = -sizeof(struct xlat_cache_block);
   221 	    start_block = curr = xlat_temp_cache;
   222 	}
   223     } while(1);
   224     start_block->active = 1;
   225     start_block->size = allocation;
   226     start_block->lut_entry = block->lut_entry;
   227     *block->lut_entry = &start_block->code;
   228     memcpy( start_block->code, block->code, block->size );
   229     xlat_temp_cache_ptr = xlat_cut_block(start_block, size );
   230     if( xlat_temp_cache_ptr->size == 0 ) {
   231 	xlat_temp_cache_ptr = xlat_temp_cache;
   232     }
   234 }
   236 /**
   237  * Returns the next block in the new cache list that can be written to by the
   238  * translator. If the next block is active, it is evicted first.
   239  */
   240 xlat_cache_block_t xlat_start_block( sh4addr_t address )
   241 {
   242     if( xlat_new_cache_ptr->size == 0 ) {
   243 	xlat_new_cache_ptr = xlat_new_cache;
   244     }
   246     if( xlat_new_cache_ptr->active ) {
   247 	xlat_promote_to_temp_space( xlat_new_cache_ptr );
   248     }
   249     xlat_new_create_ptr = xlat_new_cache_ptr;
   250     xlat_new_create_ptr->active = 1;
   251     xlat_new_cache_ptr = NEXT(xlat_new_cache_ptr);
   253     /* Add the LUT entry for the block */
   254     if( xlat_lut[XLAT_LUT_PAGE(address)] == NULL ) {
   255 	xlat_lut[XLAT_LUT_PAGE(address)] =
   256 	    mmap( NULL, XLAT_LUT_PAGE_SIZE, PROT_READ|PROT_WRITE,
   257 		  MAP_PRIVATE|MAP_ANONYMOUS, -1, 0 );
   258 	memset( xlat_lut[XLAT_LUT_PAGE(address)], 0, XLAT_LUT_PAGE_SIZE );
   259     }
   261     if( IS_ENTRY_POINT(xlat_lut[XLAT_LUT_PAGE(address)][XLAT_LUT_ENTRY(address)]) ) {
   262 	xlat_cache_block_t oldblock = BLOCK_FOR_CODE(xlat_lut[XLAT_LUT_PAGE(address)][XLAT_LUT_ENTRY(address)]);
   263 	oldblock->active = 0;
   264     }
   266     xlat_lut[XLAT_LUT_PAGE(address)][XLAT_LUT_ENTRY(address)] = 
   267 	&xlat_new_create_ptr->code;
   268     xlat_new_create_ptr->lut_entry = xlat_lut[XLAT_LUT_PAGE(address)] + XLAT_LUT_ENTRY(address);
   270     return xlat_new_create_ptr;
   271 }
   273 xlat_cache_block_t xlat_extend_block()
   274 {
   275     if( xlat_new_cache_ptr->size == 0 ) {
   276 	/* Migrate to the front of the cache to keep it contiguous */
   277 	xlat_new_create_ptr->active = 0;
   278 	char *olddata = xlat_new_create_ptr->code;
   279 	int oldsize = xlat_new_create_ptr->size;
   280 	int size = oldsize + MIN_BLOCK_SIZE; /* minimum expansion */
   281 	void **lut_entry = xlat_new_create_ptr->lut_entry;
   282 	int allocation = -sizeof(struct xlat_cache_block);
   283 	xlat_new_cache_ptr = xlat_new_cache;
   284 	do {
   285 	    if( xlat_new_cache_ptr->active ) {
   286 		xlat_promote_to_temp_space( xlat_new_cache_ptr );
   287 	    }
   288 	    allocation += xlat_new_cache_ptr->size + sizeof(struct xlat_cache_block);
   289 	    xlat_new_cache_ptr = NEXT(xlat_new_cache_ptr);
   290 	} while( allocation < size );
   291 	xlat_new_create_ptr = xlat_new_cache;
   292 	xlat_new_create_ptr->active = 1;
   293 	xlat_new_create_ptr->size = allocation;
   294 	xlat_new_create_ptr->lut_entry = lut_entry;
   295 	*lut_entry = &xlat_new_create_ptr->code;
   296 	memmove( xlat_new_create_ptr->code, olddata, oldsize );
   297     } else {
   298 	if( xlat_new_cache_ptr->active ) {
   299 	    xlat_promote_to_temp_space( xlat_new_cache_ptr );
   300 	}
   301 	xlat_new_create_ptr->size += xlat_new_cache_ptr->size + sizeof(struct xlat_cache_block);
   302 	xlat_new_cache_ptr = NEXT(xlat_new_cache_ptr);
   303     }
   304     return xlat_new_create_ptr;
   306 }
   308 void xlat_commit_block( uint32_t destsize, uint32_t srcsize )
   309 {
   310     void **ptr = xlat_new_create_ptr->lut_entry;
   311     void **endptr = ptr + (srcsize>>2);
   312     while( ptr < endptr ) {
   313 	if( *ptr == NULL ) {
   314 	    *ptr = XLAT_LUT_ENTRY_USED;
   315 	}
   316 	ptr++;
   317     }
   319     xlat_new_cache_ptr = xlat_cut_block( xlat_new_create_ptr, destsize );
   320 }
   322 void xlat_delete_block( xlat_cache_block_t block ) 
   323 {
   324     block->active = 0;
   325     *block->lut_entry = NULL;
   326 }
   328 void xlat_check_cache_integrity( xlat_cache_block_t cache, xlat_cache_block_t ptr, int size )
   329 {
   330     int foundptr = 0;
   331     xlat_cache_block_t tail = 
   332 	(xlat_cache_block_t)(((char *)cache) + size - sizeof(struct xlat_cache_block));
   334     assert( tail->active == 1 );
   335     assert( tail->size == 0 ); 
   336     while( cache < tail ) {
   337 	assert( cache->active >= 0 && cache->active <= 2 );
   338 	assert( cache->size >= 0 && cache->size < size );
   339 	if( cache == ptr ) {
   340 	    foundptr = 1;
   341 	}
   342 	cache = NEXT(cache);
   343     }
   344     assert( cache == tail );
   345     assert( foundptr == 1 );
   346 }
   348 void xlat_check_integrity( )
   349 {
   350     xlat_check_cache_integrity( xlat_new_cache, xlat_new_cache_ptr, XLAT_NEW_CACHE_SIZE );
   351     xlat_check_cache_integrity( xlat_temp_cache, xlat_temp_cache_ptr, XLAT_TEMP_CACHE_SIZE );
   352     xlat_check_cache_integrity( xlat_old_cache, xlat_old_cache_ptr, XLAT_OLD_CACHE_SIZE );
   353 }
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