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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
32 //#define DEBUG_TB_INVALIDATE
35 /* make various TB consistency checks */
36 //#define DEBUG_TB_CHECK
38 /* threshold to flush the translated code buffer */
39 #define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
41 #define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64)
43 TranslationBlock tbs
[CODE_GEN_MAX_BLOCKS
];
44 TranslationBlock
*tb_hash
[CODE_GEN_HASH_SIZE
];
46 /* any access to the tbs or the page table must use this lock */
47 spinlock_t tb_lock
= SPIN_LOCK_UNLOCKED
;
49 uint8_t code_gen_buffer
[CODE_GEN_BUFFER_SIZE
];
50 uint8_t *code_gen_ptr
;
52 /* XXX: pack the flags in the low bits of the pointer ? */
53 typedef struct PageDesc
{
55 TranslationBlock
*first_tb
;
59 #define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS)
61 #define L1_SIZE (1 << L1_BITS)
62 #define L2_SIZE (1 << L2_BITS)
64 static void tb_invalidate_page(unsigned long address
);
66 unsigned long real_host_page_size
;
67 unsigned long host_page_bits
;
68 unsigned long host_page_size
;
69 unsigned long host_page_mask
;
71 static PageDesc
*l1_map
[L1_SIZE
];
73 static void page_init(void)
75 /* NOTE: we can always suppose that host_page_size >=
77 real_host_page_size
= getpagesize();
78 if (host_page_size
== 0)
79 host_page_size
= real_host_page_size
;
80 if (host_page_size
< TARGET_PAGE_SIZE
)
81 host_page_size
= TARGET_PAGE_SIZE
;
83 while ((1 << host_page_bits
) < host_page_size
)
85 host_page_mask
= ~(host_page_size
- 1);
88 /* dump memory mappings */
89 void page_dump(FILE *f
)
91 unsigned long start
, end
;
92 int i
, j
, prot
, prot1
;
95 fprintf(f
, "%-8s %-8s %-8s %s\n",
96 "start", "end", "size", "prot");
100 for(i
= 0; i
<= L1_SIZE
; i
++) {
105 for(j
= 0;j
< L2_SIZE
; j
++) {
111 end
= (i
<< (32 - L1_BITS
)) | (j
<< TARGET_PAGE_BITS
);
113 fprintf(f
, "%08lx-%08lx %08lx %c%c%c\n",
114 start
, end
, end
- start
,
115 prot
& PAGE_READ
? 'r' : '-',
116 prot
& PAGE_WRITE
? 'w' : '-',
117 prot
& PAGE_EXEC
? 'x' : '-');
131 static inline PageDesc
*page_find_alloc(unsigned int index
)
135 lp
= &l1_map
[index
>> L2_BITS
];
138 /* allocate if not found */
139 p
= malloc(sizeof(PageDesc
) * L2_SIZE
);
140 memset(p
, 0, sizeof(PageDesc
) * L2_SIZE
);
143 return p
+ (index
& (L2_SIZE
- 1));
146 static inline PageDesc
*page_find(unsigned int index
)
150 p
= l1_map
[index
>> L2_BITS
];
153 return p
+ (index
& (L2_SIZE
- 1));
156 int page_get_flags(unsigned long address
)
160 p
= page_find(address
>> TARGET_PAGE_BITS
);
166 /* modify the flags of a page and invalidate the code if
167 necessary. The flag PAGE_WRITE_ORG is positionned automatically
168 depending on PAGE_WRITE */
169 void page_set_flags(unsigned long start
, unsigned long end
, int flags
)
174 start
= start
& TARGET_PAGE_MASK
;
175 end
= TARGET_PAGE_ALIGN(end
);
176 if (flags
& PAGE_WRITE
)
177 flags
|= PAGE_WRITE_ORG
;
179 for(addr
= start
; addr
< end
; addr
+= TARGET_PAGE_SIZE
) {
180 p
= page_find_alloc(addr
>> TARGET_PAGE_BITS
);
181 /* if the write protection is set, then we invalidate the code
183 if (!(p
->flags
& PAGE_WRITE
) &&
184 (flags
& PAGE_WRITE
) &&
186 tb_invalidate_page(addr
);
190 spin_unlock(&tb_lock
);
193 void cpu_exec_init(void)
196 code_gen_ptr
= code_gen_buffer
;
201 /* set to NULL all the 'first_tb' fields in all PageDescs */
202 static void page_flush_tb(void)
207 for(i
= 0; i
< L1_SIZE
; i
++) {
210 for(j
= 0; j
< L2_SIZE
; j
++)
211 p
[j
].first_tb
= NULL
;
216 /* flush all the translation blocks */
217 /* XXX: tb_flush is currently not thread safe */
222 printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
223 code_gen_ptr
- code_gen_buffer
,
225 (code_gen_ptr
- code_gen_buffer
) / nb_tbs
);
228 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++)
231 code_gen_ptr
= code_gen_buffer
;
232 /* XXX: flush processor icache at this point if cache flush is
236 #ifdef DEBUG_TB_CHECK
238 static void tb_invalidate_check(unsigned long address
)
240 TranslationBlock
*tb
;
242 address
&= TARGET_PAGE_MASK
;
243 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++) {
244 for(tb
= tb_hash
[i
]; tb
!= NULL
; tb
= tb
->hash_next
) {
245 if (!(address
+ TARGET_PAGE_SIZE
<= tb
->pc
||
246 address
>= tb
->pc
+ tb
->size
)) {
247 printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n",
248 address
, tb
->pc
, tb
->size
);
254 /* verify that all the pages have correct rights for code */
255 static void tb_page_check(void)
257 TranslationBlock
*tb
;
258 int i
, flags1
, flags2
;
260 for(i
= 0;i
< CODE_GEN_HASH_SIZE
; i
++) {
261 for(tb
= tb_hash
[i
]; tb
!= NULL
; tb
= tb
->hash_next
) {
262 flags1
= page_get_flags(tb
->pc
);
263 flags2
= page_get_flags(tb
->pc
+ tb
->size
- 1);
264 if ((flags1
& PAGE_WRITE
) || (flags2
& PAGE_WRITE
)) {
265 printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
266 tb
->pc
, tb
->size
, flags1
, flags2
);
272 void tb_jmp_check(TranslationBlock
*tb
)
274 TranslationBlock
*tb1
;
277 /* suppress any remaining jumps to this TB */
281 tb1
= (TranslationBlock
*)((long)tb1
& ~3);
284 tb1
= tb1
->jmp_next
[n1
];
286 /* check end of list */
288 printf("ERROR: jmp_list from 0x%08lx\n", (long)tb
);
294 /* invalidate one TB */
295 static inline void tb_remove(TranslationBlock
**ptb
, TranslationBlock
*tb
,
298 TranslationBlock
*tb1
;
302 *ptb
= *(TranslationBlock
**)((char *)tb1
+ next_offset
);
305 ptb
= (TranslationBlock
**)((char *)tb1
+ next_offset
);
309 static inline void tb_jmp_remove(TranslationBlock
*tb
, int n
)
311 TranslationBlock
*tb1
, **ptb
;
314 ptb
= &tb
->jmp_next
[n
];
317 /* find tb(n) in circular list */
321 tb1
= (TranslationBlock
*)((long)tb1
& ~3);
322 if (n1
== n
&& tb1
== tb
)
325 ptb
= &tb1
->jmp_first
;
327 ptb
= &tb1
->jmp_next
[n1
];
330 /* now we can suppress tb(n) from the list */
331 *ptb
= tb
->jmp_next
[n
];
333 tb
->jmp_next
[n
] = NULL
;
337 /* reset the jump entry 'n' of a TB so that it is not chained to
339 static inline void tb_reset_jump(TranslationBlock
*tb
, int n
)
341 tb_set_jmp_target(tb
, n
, (unsigned long)(tb
->tc_ptr
+ tb
->tb_next_offset
[n
]));
344 static inline void tb_invalidate(TranslationBlock
*tb
, int parity
)
347 unsigned int page_index1
, page_index2
;
349 TranslationBlock
*tb1
, *tb2
;
351 /* remove the TB from the hash list */
352 h
= tb_hash_func(tb
->pc
);
353 tb_remove(&tb_hash
[h
], tb
,
354 offsetof(TranslationBlock
, hash_next
));
355 /* remove the TB from the page list */
356 page_index1
= tb
->pc
>> TARGET_PAGE_BITS
;
357 if ((page_index1
& 1) == parity
) {
358 p
= page_find(page_index1
);
359 tb_remove(&p
->first_tb
, tb
,
360 offsetof(TranslationBlock
, page_next
[page_index1
& 1]));
362 page_index2
= (tb
->pc
+ tb
->size
- 1) >> TARGET_PAGE_BITS
;
363 if ((page_index2
& 1) == parity
) {
364 p
= page_find(page_index2
);
365 tb_remove(&p
->first_tb
, tb
,
366 offsetof(TranslationBlock
, page_next
[page_index2
& 1]));
369 /* suppress this TB from the two jump lists */
370 tb_jmp_remove(tb
, 0);
371 tb_jmp_remove(tb
, 1);
373 /* suppress any remaining jumps to this TB */
379 tb1
= (TranslationBlock
*)((long)tb1
& ~3);
380 tb2
= tb1
->jmp_next
[n1
];
381 tb_reset_jump(tb1
, n1
);
382 tb1
->jmp_next
[n1
] = NULL
;
385 tb
->jmp_first
= (TranslationBlock
*)((long)tb
| 2); /* fail safe */
388 /* invalidate all TBs which intersect with the target page starting at addr */
389 static void tb_invalidate_page(unsigned long address
)
391 TranslationBlock
*tb_next
, *tb
;
392 unsigned int page_index
;
393 int parity1
, parity2
;
395 #ifdef DEBUG_TB_INVALIDATE
396 printf("tb_invalidate_page: %lx\n", address
);
399 page_index
= address
>> TARGET_PAGE_BITS
;
400 p
= page_find(page_index
);
404 parity1
= page_index
& 1;
405 parity2
= parity1
^ 1;
407 tb_next
= tb
->page_next
[parity1
];
408 tb_invalidate(tb
, parity2
);
414 /* add the tb in the target page and protect it if necessary */
415 static inline void tb_alloc_page(TranslationBlock
*tb
, unsigned int page_index
)
418 unsigned long host_start
, host_end
, addr
, page_addr
;
421 p
= page_find_alloc(page_index
);
422 tb
->page_next
[page_index
& 1] = p
->first_tb
;
424 if (p
->flags
& PAGE_WRITE
) {
425 /* force the host page as non writable (writes will have a
426 page fault + mprotect overhead) */
427 page_addr
= (page_index
<< TARGET_PAGE_BITS
);
428 host_start
= page_addr
& host_page_mask
;
429 host_end
= host_start
+ host_page_size
;
431 for(addr
= host_start
; addr
< host_end
; addr
+= TARGET_PAGE_SIZE
)
432 prot
|= page_get_flags(addr
);
433 mprotect((void *)host_start
, host_page_size
,
434 (prot
& PAGE_BITS
) & ~PAGE_WRITE
);
435 #ifdef DEBUG_TB_INVALIDATE
436 printf("protecting code page: 0x%08lx\n",
439 p
->flags
&= ~PAGE_WRITE
;
440 #ifdef DEBUG_TB_CHECK
446 /* Allocate a new translation block. Flush the translation buffer if
447 too many translation blocks or too much generated code. */
448 TranslationBlock
*tb_alloc(unsigned long pc
)
450 TranslationBlock
*tb
;
452 if (nb_tbs
>= CODE_GEN_MAX_BLOCKS
||
453 (code_gen_ptr
- code_gen_buffer
) >= CODE_GEN_BUFFER_MAX_SIZE
)
460 /* link the tb with the other TBs */
461 void tb_link(TranslationBlock
*tb
)
463 unsigned int page_index1
, page_index2
;
465 /* add in the page list */
466 page_index1
= tb
->pc
>> TARGET_PAGE_BITS
;
467 tb_alloc_page(tb
, page_index1
);
468 page_index2
= (tb
->pc
+ tb
->size
- 1) >> TARGET_PAGE_BITS
;
469 if (page_index2
!= page_index1
) {
470 tb_alloc_page(tb
, page_index2
);
472 tb
->jmp_first
= (TranslationBlock
*)((long)tb
| 2);
473 tb
->jmp_next
[0] = NULL
;
474 tb
->jmp_next
[1] = NULL
;
476 /* init original jump addresses */
477 if (tb
->tb_next_offset
[0] != 0xffff)
478 tb_reset_jump(tb
, 0);
479 if (tb
->tb_next_offset
[1] != 0xffff)
480 tb_reset_jump(tb
, 1);
483 /* called from signal handler: invalidate the code and unprotect the
484 page. Return TRUE if the fault was succesfully handled. */
485 int page_unprotect(unsigned long address
)
487 unsigned int page_index
, prot
, pindex
;
489 unsigned long host_start
, host_end
, addr
;
491 host_start
= address
& host_page_mask
;
492 page_index
= host_start
>> TARGET_PAGE_BITS
;
493 p1
= page_find(page_index
);
496 host_end
= host_start
+ host_page_size
;
499 for(addr
= host_start
;addr
< host_end
; addr
+= TARGET_PAGE_SIZE
) {
503 /* if the page was really writable, then we change its
504 protection back to writable */
505 if (prot
& PAGE_WRITE_ORG
) {
506 mprotect((void *)host_start
, host_page_size
,
507 (prot
& PAGE_BITS
) | PAGE_WRITE
);
508 pindex
= (address
- host_start
) >> TARGET_PAGE_BITS
;
509 p1
[pindex
].flags
|= PAGE_WRITE
;
510 /* and since the content will be modified, we must invalidate
511 the corresponding translated code. */
512 tb_invalidate_page(address
);
513 #ifdef DEBUG_TB_CHECK
514 tb_invalidate_check(address
);
522 /* call this function when system calls directly modify a memory area */
523 void page_unprotect_range(uint8_t *data
, unsigned long data_size
)
525 unsigned long start
, end
, addr
;
527 start
= (unsigned long)data
;
528 end
= start
+ data_size
;
529 start
&= TARGET_PAGE_MASK
;
530 end
= TARGET_PAGE_ALIGN(end
);
531 for(addr
= start
; addr
< end
; addr
+= TARGET_PAGE_SIZE
) {
532 page_unprotect(addr
);
536 /* find the TB 'tb' such that tb[0].tc_ptr <= tc_ptr <
537 tb[1].tc_ptr. Return NULL if not found */
538 TranslationBlock
*tb_find_pc(unsigned long tc_ptr
)
542 TranslationBlock
*tb
;
546 if (tc_ptr
< (unsigned long)code_gen_buffer
||
547 tc_ptr
>= (unsigned long)code_gen_ptr
)
549 /* binary search (cf Knuth) */
552 while (m_min
<= m_max
) {
553 m
= (m_min
+ m_max
) >> 1;
555 v
= (unsigned long)tb
->tc_ptr
;
558 else if (tc_ptr
< v
) {