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2 * virtual page mapping and translated block handling
4 * Copyright (c) 2003 Fabrice Bellard
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
31 //#define DEBUG_TB_INVALIDATE
34 /* make various TB consistency checks */
35 //#define DEBUG_TB_CHECK
37 /* threshold to flush the translated code buffer */
38 #define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
40 #define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64)
42 TranslationBlock tbs
[CODE_GEN_MAX_BLOCKS
];
43 TranslationBlock
*tb_hash
[CODE_GEN_HASH_SIZE
];
46 uint8_t code_gen_buffer
[CODE_GEN_BUFFER_SIZE
];
47 uint8_t *code_gen_ptr
;
49 /* XXX: pack the flags in the low bits of the pointer ? */
50 typedef struct PageDesc
{
52 TranslationBlock
*first_tb
;
56 #define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS)
58 #define L1_SIZE (1 << L1_BITS)
59 #define L2_SIZE (1 << L2_BITS)
61 static void tb_invalidate_page(unsigned long address
);
63 unsigned long real_host_page_size
;
64 unsigned long host_page_bits
;
65 unsigned long host_page_size
;
66 unsigned long host_page_mask
;
68 static PageDesc
*l1_map
[L1_SIZE
];
72 /* NOTE: we can always suppose that host_page_size >=
74 real_host_page_size
= getpagesize();
75 if (host_page_size
== 0)
76 host_page_size
= real_host_page_size
;
77 if (host_page_size
< TARGET_PAGE_SIZE
)
78 host_page_size
= TARGET_PAGE_SIZE
;
80 while ((1 << host_page_bits
) < host_page_size
)
82 host_page_mask
= ~(host_page_size
- 1);
85 /* dump memory mappings */
86 void page_dump(FILE *f
)
88 unsigned long start
, end
;
89 int i
, j
, prot
, prot1
;
92 fprintf(f
, "%-8s %-8s %-8s %s\n",
93 "start", "end", "size", "prot");
97 for(i
= 0; i
<= L1_SIZE
; i
++) {
102 for(j
= 0;j
< L2_SIZE
; j
++) {
108 end
= (i
<< (32 - L1_BITS
)) | (j
<< TARGET_PAGE_BITS
);
110 fprintf(f
, "%08lx-%08lx %08lx %c%c%c\n",
111 start
, end
, end
- start
,
112 prot
& PAGE_READ
? 'r' : '-',
113 prot
& PAGE_WRITE
? 'w' : '-',
114 prot
& PAGE_EXEC
? 'x' : '-');
128 static inline PageDesc
*page_find_alloc(unsigned int index
)
132 lp
= &l1_map
[index
>> L2_BITS
];
135 /* allocate if not found */
136 p
= malloc(sizeof(PageDesc
) * L2_SIZE
);
137 memset(p
, 0, sizeof(PageDesc
) * L2_SIZE
);
140 return p
+ (index
& (L2_SIZE
- 1));
143 static inline PageDesc
*page_find(unsigned int index
)
147 p
= l1_map
[index
>> L2_BITS
];
150 return p
+ (index
& (L2_SIZE
- 1));
153 int page_get_flags(unsigned long address
)
157 p
= page_find(address
>> TARGET_PAGE_BITS
);
163 /* modify the flags of a page and invalidate the code if
164 necessary. The flag PAGE_WRITE_ORG is positionned automatically
165 depending on PAGE_WRITE */
166 void page_set_flags(unsigned long start
, unsigned long end
, int flags
)
171 start
= start
& TARGET_PAGE_MASK
;
172 end
= TARGET_PAGE_ALIGN(end
);
173 if (flags
& PAGE_WRITE
)
174 flags
|= PAGE_WRITE_ORG
;
175 for(addr
= start
; addr
< end
; addr
+= TARGET_PAGE_SIZE
) {
176 p
= page_find_alloc(addr
>> TARGET_PAGE_BITS
);
177 /* if the write protection is set, then we invalidate the code
179 if (!(p
->flags
& PAGE_WRITE
) &&
180 (flags
& PAGE_WRITE
) &&
182 tb_invalidate_page(addr
);
188 void cpu_x86_tblocks_init(void)
191 code_gen_ptr
= code_gen_buffer
;
195 /* set to NULL all the 'first_tb' fields in all PageDescs */
196 static void page_flush_tb(void)
201 for(i
= 0; i
< L1_SIZE
; i
++) {
204 for(j
= 0; j
< L2_SIZE
; j
++)
205 p
[j
].first_tb
= NULL
;
210 /* flush all the translation blocks */
215 printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
216 code_gen_ptr
- code_gen_buffer
,
218 (code_gen_ptr
- code_gen_buffer
) / nb_tbs
);
221 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++)
224 code_gen_ptr
= code_gen_buffer
;
225 /* XXX: flush processor icache at this point */
228 #ifdef DEBUG_TB_CHECK
230 static void tb_invalidate_check(unsigned long address
)
232 TranslationBlock
*tb
;
234 address
&= TARGET_PAGE_MASK
;
235 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++) {
236 for(tb
= tb_hash
[i
]; tb
!= NULL
; tb
= tb
->hash_next
) {
237 if (!(address
+ TARGET_PAGE_SIZE
<= tb
->pc
||
238 address
>= tb
->pc
+ tb
->size
)) {
239 printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n",
240 address
, tb
->pc
, tb
->size
);
246 /* verify that all the pages have correct rights for code */
247 static void tb_page_check(void)
249 TranslationBlock
*tb
;
250 int i
, flags1
, flags2
;
252 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++) {
253 for(tb
= tb_hash
[i
]; tb
!= NULL
; tb
= tb
->hash_next
) {
254 flags1
= page_get_flags(tb
->pc
);
255 flags2
= page_get_flags(tb
->pc
+ tb
->size
- 1);
256 if ((flags1
& PAGE_WRITE
) || (flags2
& PAGE_WRITE
)) {
257 printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
258 tb
->pc
, tb
->size
, flags1
, flags2
);
266 /* invalidate one TB */
267 static inline void tb_remove(TranslationBlock
**ptb
, TranslationBlock
*tb
,
270 TranslationBlock
*tb1
;
274 *ptb
= *(TranslationBlock
**)((char *)tb1
+ next_offset
);
277 ptb
= (TranslationBlock
**)((char *)tb1
+ next_offset
);
281 static inline void tb_invalidate(TranslationBlock
*tb
, int parity
)
284 unsigned int page_index1
, page_index2
;
287 /* remove the TB from the hash list */
288 h
= tb_hash_func(tb
->pc
);
289 tb_remove(&tb_hash
[h
], tb
,
290 offsetof(TranslationBlock
, hash_next
));
291 /* remove the TB from the page list */
292 page_index1
= tb
->pc
>> TARGET_PAGE_BITS
;
293 if ((page_index1
& 1) == parity
) {
294 p
= page_find(page_index1
);
295 tb_remove(&p
->first_tb
, tb
,
296 offsetof(TranslationBlock
, page_next
[page_index1
& 1]));
298 page_index2
= (tb
->pc
+ tb
->size
- 1) >> TARGET_PAGE_BITS
;
299 if ((page_index2
& 1) == parity
) {
300 p
= page_find(page_index2
);
301 tb_remove(&p
->first_tb
, tb
,
302 offsetof(TranslationBlock
, page_next
[page_index2
& 1]));
306 /* invalidate all TBs which intersect with the target page starting at addr */
307 static void tb_invalidate_page(unsigned long address
)
309 TranslationBlock
*tb_next
, *tb
;
310 unsigned int page_index
;
311 int parity1
, parity2
;
313 #ifdef DEBUG_TB_INVALIDATE
314 printf("tb_invalidate_page: %lx\n", address
);
317 page_index
= address
>> TARGET_PAGE_BITS
;
318 p
= page_find(page_index
);
322 parity1
= page_index
& 1;
323 parity2
= parity1
^ 1;
325 tb_next
= tb
->page_next
[parity1
];
326 tb_invalidate(tb
, parity2
);
332 /* add the tb in the target page and protect it if necessary */
333 static inline void tb_alloc_page(TranslationBlock
*tb
, unsigned int page_index
)
336 unsigned long host_start
, host_end
, addr
, page_addr
;
339 p
= page_find_alloc(page_index
);
340 tb
->page_next
[page_index
& 1] = p
->first_tb
;
342 if (p
->flags
& PAGE_WRITE
) {
343 /* force the host page as non writable (writes will have a
344 page fault + mprotect overhead) */
345 page_addr
= (page_index
<< TARGET_PAGE_BITS
);
346 host_start
= page_addr
& host_page_mask
;
347 host_end
= host_start
+ host_page_size
;
349 for(addr
= host_start
; addr
< host_end
; addr
+= TARGET_PAGE_SIZE
)
350 prot
|= page_get_flags(addr
);
351 mprotect((void *)host_start
, host_page_size
,
352 (prot
& PAGE_BITS
) & ~PAGE_WRITE
);
353 #ifdef DEBUG_TB_INVALIDATE
354 printf("protecting code page: 0x%08lx\n",
357 p
->flags
&= ~PAGE_WRITE
;
358 #ifdef DEBUG_TB_CHECK
364 /* Allocate a new translation block. Flush the translation buffer if
365 too many translation blocks or too much generated code. */
366 TranslationBlock
*tb_alloc(unsigned long pc
,
369 TranslationBlock
*tb
;
370 unsigned int page_index1
, page_index2
;
372 if (nb_tbs
>= CODE_GEN_MAX_BLOCKS
||
373 (code_gen_ptr
- code_gen_buffer
) >= CODE_GEN_BUFFER_MAX_SIZE
)
379 /* add in the page list */
380 page_index1
= pc
>> TARGET_PAGE_BITS
;
381 tb_alloc_page(tb
, page_index1
);
382 page_index2
= (pc
+ size
- 1) >> TARGET_PAGE_BITS
;
383 if (page_index2
!= page_index1
) {
384 tb_alloc_page(tb
, page_index2
);
389 /* called from signal handler: invalidate the code and unprotect the
390 page. Return TRUE if the fault was succesfully handled. */
391 int page_unprotect(unsigned long address
)
393 unsigned int page_index
, prot
;
395 unsigned long host_start
, host_end
, addr
;
397 page_index
= address
>> TARGET_PAGE_BITS
;
398 p
= page_find(page_index
);
401 if ((p
->flags
& (PAGE_WRITE_ORG
| PAGE_WRITE
)) == PAGE_WRITE_ORG
) {
402 /* if the page was really writable, then we change its
403 protection back to writable */
404 host_start
= address
& host_page_mask
;
405 host_end
= host_start
+ host_page_size
;
407 for(addr
= host_start
; addr
< host_end
; addr
+= TARGET_PAGE_SIZE
)
408 prot
|= page_get_flags(addr
);
409 mprotect((void *)host_start
, host_page_size
,
410 (prot
& PAGE_BITS
) | PAGE_WRITE
);
411 p
->flags
|= PAGE_WRITE
;
413 /* and since the content will be modified, we must invalidate
414 the corresponding translated code. */
415 tb_invalidate_page(address
);
416 #ifdef DEBUG_TB_CHECK
417 tb_invalidate_check(address
);
425 /* call this function when system calls directly modify a memory area */
426 void page_unprotect_range(uint8_t *data
, unsigned long data_size
)
428 unsigned long start
, end
, addr
;
430 start
= (unsigned long)data
;
431 end
= start
+ data_size
;
432 start
&= TARGET_PAGE_MASK
;
433 end
= TARGET_PAGE_ALIGN(end
);
434 for(addr
= start
; addr
< end
; addr
+= TARGET_PAGE_SIZE
) {
435 page_unprotect(addr
);