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];
45 /* any access to the tbs or the page table must use this lock */
46 spinlock_t tb_lock = SPIN_LOCK_UNLOCKED;
48 uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE];
49 uint8_t *code_gen_ptr;
51 /* XXX: pack the flags in the low bits of the pointer ? */
52 typedef struct PageDesc {
54 TranslationBlock *first_tb;
58 #define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS)
60 #define L1_SIZE (1 << L1_BITS)
61 #define L2_SIZE (1 << L2_BITS)
63 static void tb_invalidate_page(unsigned long address);
65 unsigned long real_host_page_size;
66 unsigned long host_page_bits;
67 unsigned long host_page_size;
68 unsigned long host_page_mask;
70 static PageDesc *l1_map[L1_SIZE];
74 /* NOTE: we can always suppose that host_page_size >=
76 real_host_page_size = getpagesize();
77 if (host_page_size == 0)
78 host_page_size = real_host_page_size;
79 if (host_page_size < TARGET_PAGE_SIZE)
80 host_page_size = TARGET_PAGE_SIZE;
82 while ((1 << host_page_bits) < host_page_size)
84 host_page_mask = ~(host_page_size - 1);
87 /* dump memory mappings */
88 void page_dump(FILE *f)
90 unsigned long start, end;
91 int i, j, prot, prot1;
94 fprintf(f, "%-8s %-8s %-8s %s\n",
95 "start", "end", "size", "prot");
99 for(i = 0; i <= L1_SIZE; i++) {
104 for(j = 0;j < L2_SIZE; j++) {
110 end = (i << (32 - L1_BITS)) | (j << TARGET_PAGE_BITS);
112 fprintf(f, "%08lx-%08lx %08lx %c%c%c\n",
113 start, end, end - start,
114 prot & PAGE_READ ? 'r' : '-',
115 prot & PAGE_WRITE ? 'w' : '-',
116 prot & PAGE_EXEC ? 'x' : '-');
130 static inline PageDesc *page_find_alloc(unsigned int index)
134 lp = &l1_map[index >> L2_BITS];
137 /* allocate if not found */
138 p = malloc(sizeof(PageDesc) * L2_SIZE);
139 memset(p, 0, sizeof(PageDesc) * L2_SIZE);
142 return p + (index & (L2_SIZE - 1));
145 static inline PageDesc *page_find(unsigned int index)
149 p = l1_map[index >> L2_BITS];
152 return p + (index & (L2_SIZE - 1));
155 int page_get_flags(unsigned long address)
159 p = page_find(address >> TARGET_PAGE_BITS);
165 /* modify the flags of a page and invalidate the code if
166 necessary. The flag PAGE_WRITE_ORG is positionned automatically
167 depending on PAGE_WRITE */
168 void page_set_flags(unsigned long start, unsigned long end, int flags)
173 start = start & TARGET_PAGE_MASK;
174 end = TARGET_PAGE_ALIGN(end);
175 if (flags & PAGE_WRITE)
176 flags |= PAGE_WRITE_ORG;
178 for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
179 p = page_find_alloc(addr >> TARGET_PAGE_BITS);
180 /* if the write protection is set, then we invalidate the code
182 if (!(p->flags & PAGE_WRITE) &&
183 (flags & PAGE_WRITE) &&
185 tb_invalidate_page(addr);
189 spin_unlock(&tb_lock);
192 void cpu_x86_tblocks_init(void)
195 code_gen_ptr = code_gen_buffer;
199 /* set to NULL all the 'first_tb' fields in all PageDescs */
200 static void page_flush_tb(void)
205 for(i = 0; i < L1_SIZE; i++) {
208 for(j = 0; j < L2_SIZE; j++)
209 p[j].first_tb = NULL;
214 /* flush all the translation blocks */
219 printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
220 code_gen_ptr - code_gen_buffer,
222 (code_gen_ptr - code_gen_buffer) / nb_tbs);
225 for(i = 0;i < CODE_GEN_HASH_SIZE; i++)
228 code_gen_ptr = code_gen_buffer;
229 /* XXX: flush processor icache at this point */
232 #ifdef DEBUG_TB_CHECK
234 static void tb_invalidate_check(unsigned long address)
236 TranslationBlock *tb;
238 address &= TARGET_PAGE_MASK;
239 for(i = 0;i < CODE_GEN_HASH_SIZE; i++) {
240 for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) {
241 if (!(address + TARGET_PAGE_SIZE <= tb->pc ||
242 address >= tb->pc + tb->size)) {
243 printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n",
244 address, tb->pc, tb->size);
250 /* verify that all the pages have correct rights for code */
251 static void tb_page_check(void)
253 TranslationBlock *tb;
254 int i, flags1, flags2;
256 for(i = 0;i < CODE_GEN_HASH_SIZE; i++) {
257 for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) {
258 flags1 = page_get_flags(tb->pc);
259 flags2 = page_get_flags(tb->pc + tb->size - 1);
260 if ((flags1 & PAGE_WRITE) || (flags2 & PAGE_WRITE)) {
261 printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
262 tb->pc, tb->size, flags1, flags2);
270 /* invalidate one TB */
271 static inline void tb_remove(TranslationBlock **ptb, TranslationBlock *tb,
274 TranslationBlock *tb1;
278 *ptb = *(TranslationBlock **)((char *)tb1 + next_offset);
281 ptb = (TranslationBlock **)((char *)tb1 + next_offset);
285 static inline void tb_invalidate(TranslationBlock *tb, int parity)
288 unsigned int page_index1, page_index2;
291 /* remove the TB from the hash list */
292 h = tb_hash_func(tb->pc);
293 tb_remove(&tb_hash[h], tb,
294 offsetof(TranslationBlock, hash_next));
295 /* remove the TB from the page list */
296 page_index1 = tb->pc >> TARGET_PAGE_BITS;
297 if ((page_index1 & 1) == parity) {
298 p = page_find(page_index1);
299 tb_remove(&p->first_tb, tb,
300 offsetof(TranslationBlock, page_next[page_index1 & 1]));
302 page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS;
303 if ((page_index2 & 1) == parity) {
304 p = page_find(page_index2);
305 tb_remove(&p->first_tb, tb,
306 offsetof(TranslationBlock, page_next[page_index2 & 1]));
310 /* invalidate all TBs which intersect with the target page starting at addr */
311 static void tb_invalidate_page(unsigned long address)
313 TranslationBlock *tb_next, *tb;
314 unsigned int page_index;
315 int parity1, parity2;
317 #ifdef DEBUG_TB_INVALIDATE
318 printf("tb_invalidate_page: %lx\n", address);
321 page_index = address >> TARGET_PAGE_BITS;
322 p = page_find(page_index);
326 parity1 = page_index & 1;
327 parity2 = parity1 ^ 1;
329 tb_next = tb->page_next[parity1];
330 tb_invalidate(tb, parity2);
336 /* add the tb in the target page and protect it if necessary */
337 static inline void tb_alloc_page(TranslationBlock *tb, unsigned int page_index)
340 unsigned long host_start, host_end, addr, page_addr;
343 p = page_find_alloc(page_index);
344 tb->page_next[page_index & 1] = p->first_tb;
346 if (p->flags & PAGE_WRITE) {
347 /* force the host page as non writable (writes will have a
348 page fault + mprotect overhead) */
349 page_addr = (page_index << TARGET_PAGE_BITS);
350 host_start = page_addr & host_page_mask;
351 host_end = host_start + host_page_size;
353 for(addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE)
354 prot |= page_get_flags(addr);
355 mprotect((void *)host_start, host_page_size,
356 (prot & PAGE_BITS) & ~PAGE_WRITE);
357 #ifdef DEBUG_TB_INVALIDATE
358 printf("protecting code page: 0x%08lx\n",
361 p->flags &= ~PAGE_WRITE;
362 #ifdef DEBUG_TB_CHECK
368 /* Allocate a new translation block. Flush the translation buffer if
369 too many translation blocks or too much generated code. */
370 TranslationBlock *tb_alloc(unsigned long pc,
373 TranslationBlock *tb;
374 unsigned int page_index1, page_index2;
376 if (nb_tbs >= CODE_GEN_MAX_BLOCKS ||
377 (code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE)
383 /* add in the page list */
384 page_index1 = pc >> TARGET_PAGE_BITS;
385 tb_alloc_page(tb, page_index1);
386 page_index2 = (pc + size - 1) >> TARGET_PAGE_BITS;
387 if (page_index2 != page_index1) {
388 tb_alloc_page(tb, page_index2);
393 /* called from signal handler: invalidate the code and unprotect the
394 page. Return TRUE if the fault was succesfully handled. */
395 int page_unprotect(unsigned long address)
397 unsigned int page_index, prot, pindex;
399 unsigned long host_start, host_end, addr;
401 host_start = address & host_page_mask;
402 page_index = host_start >> TARGET_PAGE_BITS;
403 p1 = page_find(page_index);
406 host_end = host_start + host_page_size;
409 for(addr = host_start;addr < host_end; addr += TARGET_PAGE_SIZE) {
413 /* if the page was really writable, then we change its
414 protection back to writable */
415 if (prot & PAGE_WRITE_ORG) {
416 mprotect((void *)host_start, host_page_size,
417 (prot & PAGE_BITS) | PAGE_WRITE);
418 pindex = (address - host_start) >> TARGET_PAGE_BITS;
419 p1[pindex].flags |= PAGE_WRITE;
420 /* and since the content will be modified, we must invalidate
421 the corresponding translated code. */
422 tb_invalidate_page(address);
423 #ifdef DEBUG_TB_CHECK
424 tb_invalidate_check(address);
432 /* call this function when system calls directly modify a memory area */
433 void page_unprotect_range(uint8_t *data, unsigned long data_size)
435 unsigned long start, end, addr;
437 start = (unsigned long)data;
438 end = start + data_size;
439 start &= TARGET_PAGE_MASK;
440 end = TARGET_PAGE_ALIGN(end);
441 for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
442 page_unprotect(addr);