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/*
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* virtual page mapping and translated block handling
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*
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* Copyright (c) 2003 Fabrice Bellard
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <stdlib.h> |
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#include <stdio.h> |
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#include <stdarg.h> |
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#include <string.h> |
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#include <errno.h> |
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#include <unistd.h> |
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#include <inttypes.h> |
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#include <sys/mman.h> |
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#include "cpu-i386.h" |
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#include "exec.h" |
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//#define DEBUG_TB_INVALIDATE
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#define DEBUG_FLUSH
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/* make various TB consistency checks */
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//#define DEBUG_TB_CHECK
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/* threshold to flush the translated code buffer */
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#define CODE_GEN_BUFFER_MAX_SIZE (CODE_GEN_BUFFER_SIZE - CODE_GEN_MAX_SIZE)
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#define CODE_GEN_MAX_BLOCKS (CODE_GEN_BUFFER_SIZE / 64) |
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TranslationBlock tbs[CODE_GEN_MAX_BLOCKS]; |
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TranslationBlock *tb_hash[CODE_GEN_HASH_SIZE]; |
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int nb_tbs;
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/* any access to the tbs or the page table must use this lock */
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spinlock_t tb_lock = SPIN_LOCK_UNLOCKED; |
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uint8_t code_gen_buffer[CODE_GEN_BUFFER_SIZE]; |
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uint8_t *code_gen_ptr; |
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/* XXX: pack the flags in the low bits of the pointer ? */
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typedef struct PageDesc { |
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unsigned long flags; |
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TranslationBlock *first_tb; |
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} PageDesc; |
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#define L2_BITS 10 |
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#define L1_BITS (32 - L2_BITS - TARGET_PAGE_BITS) |
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#define L1_SIZE (1 << L1_BITS) |
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#define L2_SIZE (1 << L2_BITS) |
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static void tb_invalidate_page(unsigned long address); |
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unsigned long real_host_page_size; |
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unsigned long host_page_bits; |
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unsigned long host_page_size; |
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unsigned long host_page_mask; |
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static PageDesc *l1_map[L1_SIZE];
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|
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void page_init(void) |
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{ |
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/* NOTE: we can always suppose that host_page_size >=
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TARGET_PAGE_SIZE */
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real_host_page_size = getpagesize(); |
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if (host_page_size == 0) |
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host_page_size = real_host_page_size; |
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if (host_page_size < TARGET_PAGE_SIZE)
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host_page_size = TARGET_PAGE_SIZE; |
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host_page_bits = 0;
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while ((1 << host_page_bits) < host_page_size) |
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host_page_bits++; |
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host_page_mask = ~(host_page_size - 1);
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} |
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/* dump memory mappings */
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void page_dump(FILE *f)
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{ |
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unsigned long start, end; |
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int i, j, prot, prot1;
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PageDesc *p; |
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fprintf(f, "%-8s %-8s %-8s %s\n",
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"start", "end", "size", "prot"); |
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start = -1;
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end = -1;
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prot = 0;
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for(i = 0; i <= L1_SIZE; i++) { |
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if (i < L1_SIZE)
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p = l1_map[i]; |
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else
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p = NULL;
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for(j = 0;j < L2_SIZE; j++) { |
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if (!p)
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prot1 = 0;
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else
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prot1 = p[j].flags; |
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if (prot1 != prot) {
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end = (i << (32 - L1_BITS)) | (j << TARGET_PAGE_BITS);
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if (start != -1) { |
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fprintf(f, "%08lx-%08lx %08lx %c%c%c\n",
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start, end, end - start, |
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prot & PAGE_READ ? 'r' : '-', |
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prot & PAGE_WRITE ? 'w' : '-', |
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prot & PAGE_EXEC ? 'x' : '-'); |
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} |
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if (prot1 != 0) |
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start = end; |
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else
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start = -1;
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prot = prot1; |
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} |
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if (!p)
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break;
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} |
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} |
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} |
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static inline PageDesc *page_find_alloc(unsigned int index) |
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{ |
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PageDesc **lp, *p; |
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lp = &l1_map[index >> L2_BITS]; |
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p = *lp; |
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if (!p) {
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/* allocate if not found */
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p = malloc(sizeof(PageDesc) * L2_SIZE);
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memset(p, 0, sizeof(PageDesc) * L2_SIZE); |
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*lp = p; |
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} |
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return p + (index & (L2_SIZE - 1)); |
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} |
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static inline PageDesc *page_find(unsigned int index) |
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{ |
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PageDesc *p; |
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p = l1_map[index >> L2_BITS]; |
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if (!p)
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return 0; |
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return p + (index & (L2_SIZE - 1)); |
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} |
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int page_get_flags(unsigned long address) |
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{ |
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PageDesc *p; |
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p = page_find(address >> TARGET_PAGE_BITS); |
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if (!p)
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return 0; |
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return p->flags;
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} |
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/* modify the flags of a page and invalidate the code if
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necessary. The flag PAGE_WRITE_ORG is positionned automatically
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depending on PAGE_WRITE */
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void page_set_flags(unsigned long start, unsigned long end, int flags) |
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{ |
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PageDesc *p; |
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unsigned long addr; |
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start = start & TARGET_PAGE_MASK; |
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end = TARGET_PAGE_ALIGN(end); |
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if (flags & PAGE_WRITE)
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flags |= PAGE_WRITE_ORG; |
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spin_lock(&tb_lock); |
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for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
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p = page_find_alloc(addr >> TARGET_PAGE_BITS); |
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/* if the write protection is set, then we invalidate the code
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inside */
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if (!(p->flags & PAGE_WRITE) &&
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(flags & PAGE_WRITE) && |
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p->first_tb) { |
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tb_invalidate_page(addr); |
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} |
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p->flags = flags; |
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} |
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spin_unlock(&tb_lock); |
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} |
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void cpu_x86_tblocks_init(void) |
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{ |
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if (!code_gen_ptr) {
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code_gen_ptr = code_gen_buffer; |
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} |
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} |
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/* set to NULL all the 'first_tb' fields in all PageDescs */
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static void page_flush_tb(void) |
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{ |
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int i, j;
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PageDesc *p; |
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for(i = 0; i < L1_SIZE; i++) { |
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p = l1_map[i]; |
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if (p) {
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for(j = 0; j < L2_SIZE; j++) |
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p[j].first_tb = NULL;
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} |
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} |
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} |
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/* flush all the translation blocks */
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/* XXX: tb_flush is currently not thread safe */
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void tb_flush(void) |
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{ |
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int i;
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#ifdef DEBUG_FLUSH
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printf("qemu: flush code_size=%d nb_tbs=%d avg_tb_size=%d\n",
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code_gen_ptr - code_gen_buffer, |
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nb_tbs, |
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(code_gen_ptr - code_gen_buffer) / nb_tbs); |
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#endif
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nb_tbs = 0;
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for(i = 0;i < CODE_GEN_HASH_SIZE; i++) |
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tb_hash[i] = NULL;
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page_flush_tb(); |
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code_gen_ptr = code_gen_buffer; |
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/* XXX: flush processor icache at this point if cache flush is
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expensive */
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} |
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#ifdef DEBUG_TB_CHECK
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static void tb_invalidate_check(unsigned long address) |
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{ |
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TranslationBlock *tb; |
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int i;
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address &= TARGET_PAGE_MASK; |
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for(i = 0;i < CODE_GEN_HASH_SIZE; i++) { |
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for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) { |
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if (!(address + TARGET_PAGE_SIZE <= tb->pc ||
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address >= tb->pc + tb->size)) { |
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printf("ERROR invalidate: address=%08lx PC=%08lx size=%04x\n",
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address, tb->pc, tb->size); |
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} |
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} |
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} |
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} |
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/* verify that all the pages have correct rights for code */
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static void tb_page_check(void) |
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{ |
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TranslationBlock *tb; |
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int i, flags1, flags2;
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for(i = 0;i < CODE_GEN_HASH_SIZE; i++) { |
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for(tb = tb_hash[i]; tb != NULL; tb = tb->hash_next) { |
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flags1 = page_get_flags(tb->pc); |
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flags2 = page_get_flags(tb->pc + tb->size - 1);
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if ((flags1 & PAGE_WRITE) || (flags2 & PAGE_WRITE)) {
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printf("ERROR page flags: PC=%08lx size=%04x f1=%x f2=%x\n",
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tb->pc, tb->size, flags1, flags2); |
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} |
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} |
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} |
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} |
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void tb_jmp_check(TranslationBlock *tb)
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{ |
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TranslationBlock *tb1; |
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unsigned int n1; |
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/* suppress any remaining jumps to this TB */
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tb1 = tb->jmp_first; |
278 |
for(;;) {
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n1 = (long)tb1 & 3; |
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tb1 = (TranslationBlock *)((long)tb1 & ~3); |
281 |
if (n1 == 2) |
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break;
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tb1 = tb1->jmp_next[n1]; |
284 |
} |
285 |
/* check end of list */
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if (tb1 != tb) {
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printf("ERROR: jmp_list from 0x%08lx\n", (long)tb); |
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} |
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} |
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#endif
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/* invalidate one TB */
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static inline void tb_remove(TranslationBlock **ptb, TranslationBlock *tb, |
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int next_offset)
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{ |
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TranslationBlock *tb1; |
298 |
for(;;) {
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tb1 = *ptb; |
300 |
if (tb1 == tb) {
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*ptb = *(TranslationBlock **)((char *)tb1 + next_offset);
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break;
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} |
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ptb = (TranslationBlock **)((char *)tb1 + next_offset);
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} |
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} |
307 |
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static inline void tb_jmp_remove(TranslationBlock *tb, int n) |
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{ |
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TranslationBlock *tb1, **ptb; |
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unsigned int n1; |
312 |
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ptb = &tb->jmp_next[n]; |
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tb1 = *ptb; |
315 |
if (tb1) {
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/* find tb(n) in circular list */
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for(;;) {
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tb1 = *ptb; |
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n1 = (long)tb1 & 3; |
320 |
tb1 = (TranslationBlock *)((long)tb1 & ~3); |
321 |
if (n1 == n && tb1 == tb)
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break;
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if (n1 == 2) { |
324 |
ptb = &tb1->jmp_first; |
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} else {
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ptb = &tb1->jmp_next[n1]; |
327 |
} |
328 |
} |
329 |
/* now we can suppress tb(n) from the list */
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*ptb = tb->jmp_next[n]; |
331 |
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tb->jmp_next[n] = NULL;
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} |
334 |
} |
335 |
|
336 |
/* reset the jump entry 'n' of a TB so that it is not chained to
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another TB */
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static inline void tb_reset_jump(TranslationBlock *tb, int n) |
339 |
{ |
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tb_set_jmp_target(tb, n, (unsigned long)(tb->tc_ptr + tb->tb_next_offset[n])); |
341 |
} |
342 |
|
343 |
static inline void tb_invalidate(TranslationBlock *tb, int parity) |
344 |
{ |
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PageDesc *p; |
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unsigned int page_index1, page_index2; |
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unsigned int h, n1; |
348 |
TranslationBlock *tb1, *tb2; |
349 |
|
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/* remove the TB from the hash list */
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h = tb_hash_func(tb->pc); |
352 |
tb_remove(&tb_hash[h], tb, |
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offsetof(TranslationBlock, hash_next)); |
354 |
/* remove the TB from the page list */
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page_index1 = tb->pc >> TARGET_PAGE_BITS; |
356 |
if ((page_index1 & 1) == parity) { |
357 |
p = page_find(page_index1); |
358 |
tb_remove(&p->first_tb, tb, |
359 |
offsetof(TranslationBlock, page_next[page_index1 & 1]));
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360 |
} |
361 |
page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS;
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362 |
if ((page_index2 & 1) == parity) { |
363 |
p = page_find(page_index2); |
364 |
tb_remove(&p->first_tb, tb, |
365 |
offsetof(TranslationBlock, page_next[page_index2 & 1]));
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366 |
} |
367 |
|
368 |
/* suppress this TB from the two jump lists */
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369 |
tb_jmp_remove(tb, 0);
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370 |
tb_jmp_remove(tb, 1);
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371 |
|
372 |
/* suppress any remaining jumps to this TB */
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373 |
tb1 = tb->jmp_first; |
374 |
for(;;) {
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375 |
n1 = (long)tb1 & 3; |
376 |
if (n1 == 2) |
377 |
break;
|
378 |
tb1 = (TranslationBlock *)((long)tb1 & ~3); |
379 |
tb2 = tb1->jmp_next[n1]; |
380 |
tb_reset_jump(tb1, n1); |
381 |
tb1->jmp_next[n1] = NULL;
|
382 |
tb1 = tb2; |
383 |
} |
384 |
tb->jmp_first = (TranslationBlock *)((long)tb | 2); /* fail safe */ |
385 |
} |
386 |
|
387 |
/* invalidate all TBs which intersect with the target page starting at addr */
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388 |
static void tb_invalidate_page(unsigned long address) |
389 |
{ |
390 |
TranslationBlock *tb_next, *tb; |
391 |
unsigned int page_index; |
392 |
int parity1, parity2;
|
393 |
PageDesc *p; |
394 |
#ifdef DEBUG_TB_INVALIDATE
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395 |
printf("tb_invalidate_page: %lx\n", address);
|
396 |
#endif
|
397 |
|
398 |
page_index = address >> TARGET_PAGE_BITS; |
399 |
p = page_find(page_index); |
400 |
if (!p)
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401 |
return;
|
402 |
tb = p->first_tb; |
403 |
parity1 = page_index & 1;
|
404 |
parity2 = parity1 ^ 1;
|
405 |
while (tb != NULL) { |
406 |
tb_next = tb->page_next[parity1]; |
407 |
tb_invalidate(tb, parity2); |
408 |
tb = tb_next; |
409 |
} |
410 |
p->first_tb = NULL;
|
411 |
} |
412 |
|
413 |
/* add the tb in the target page and protect it if necessary */
|
414 |
static inline void tb_alloc_page(TranslationBlock *tb, unsigned int page_index) |
415 |
{ |
416 |
PageDesc *p; |
417 |
unsigned long host_start, host_end, addr, page_addr; |
418 |
int prot;
|
419 |
|
420 |
p = page_find_alloc(page_index); |
421 |
tb->page_next[page_index & 1] = p->first_tb;
|
422 |
p->first_tb = tb; |
423 |
if (p->flags & PAGE_WRITE) {
|
424 |
/* force the host page as non writable (writes will have a
|
425 |
page fault + mprotect overhead) */
|
426 |
page_addr = (page_index << TARGET_PAGE_BITS); |
427 |
host_start = page_addr & host_page_mask; |
428 |
host_end = host_start + host_page_size; |
429 |
prot = 0;
|
430 |
for(addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE)
|
431 |
prot |= page_get_flags(addr); |
432 |
mprotect((void *)host_start, host_page_size,
|
433 |
(prot & PAGE_BITS) & ~PAGE_WRITE); |
434 |
#ifdef DEBUG_TB_INVALIDATE
|
435 |
printf("protecting code page: 0x%08lx\n",
|
436 |
host_start); |
437 |
#endif
|
438 |
p->flags &= ~PAGE_WRITE; |
439 |
#ifdef DEBUG_TB_CHECK
|
440 |
tb_page_check(); |
441 |
#endif
|
442 |
} |
443 |
} |
444 |
|
445 |
/* Allocate a new translation block. Flush the translation buffer if
|
446 |
too many translation blocks or too much generated code. */
|
447 |
TranslationBlock *tb_alloc(unsigned long pc) |
448 |
{ |
449 |
TranslationBlock *tb; |
450 |
|
451 |
if (nb_tbs >= CODE_GEN_MAX_BLOCKS ||
|
452 |
(code_gen_ptr - code_gen_buffer) >= CODE_GEN_BUFFER_MAX_SIZE) |
453 |
return NULL; |
454 |
tb = &tbs[nb_tbs++]; |
455 |
tb->pc = pc; |
456 |
return tb;
|
457 |
} |
458 |
|
459 |
/* link the tb with the other TBs */
|
460 |
void tb_link(TranslationBlock *tb)
|
461 |
{ |
462 |
unsigned int page_index1, page_index2; |
463 |
|
464 |
/* add in the page list */
|
465 |
page_index1 = tb->pc >> TARGET_PAGE_BITS; |
466 |
tb_alloc_page(tb, page_index1); |
467 |
page_index2 = (tb->pc + tb->size - 1) >> TARGET_PAGE_BITS;
|
468 |
if (page_index2 != page_index1) {
|
469 |
tb_alloc_page(tb, page_index2); |
470 |
} |
471 |
tb->jmp_first = (TranslationBlock *)((long)tb | 2); |
472 |
tb->jmp_next[0] = NULL; |
473 |
tb->jmp_next[1] = NULL; |
474 |
|
475 |
/* init original jump addresses */
|
476 |
if (tb->tb_next_offset[0] != 0xffff) |
477 |
tb_reset_jump(tb, 0);
|
478 |
if (tb->tb_next_offset[1] != 0xffff) |
479 |
tb_reset_jump(tb, 1);
|
480 |
} |
481 |
|
482 |
/* called from signal handler: invalidate the code and unprotect the
|
483 |
page. Return TRUE if the fault was succesfully handled. */
|
484 |
int page_unprotect(unsigned long address) |
485 |
{ |
486 |
unsigned int page_index, prot, pindex; |
487 |
PageDesc *p, *p1; |
488 |
unsigned long host_start, host_end, addr; |
489 |
|
490 |
host_start = address & host_page_mask; |
491 |
page_index = host_start >> TARGET_PAGE_BITS; |
492 |
p1 = page_find(page_index); |
493 |
if (!p1)
|
494 |
return 0; |
495 |
host_end = host_start + host_page_size; |
496 |
p = p1; |
497 |
prot = 0;
|
498 |
for(addr = host_start;addr < host_end; addr += TARGET_PAGE_SIZE) {
|
499 |
prot |= p->flags; |
500 |
p++; |
501 |
} |
502 |
/* if the page was really writable, then we change its
|
503 |
protection back to writable */
|
504 |
if (prot & PAGE_WRITE_ORG) {
|
505 |
mprotect((void *)host_start, host_page_size,
|
506 |
(prot & PAGE_BITS) | PAGE_WRITE); |
507 |
pindex = (address - host_start) >> TARGET_PAGE_BITS; |
508 |
p1[pindex].flags |= PAGE_WRITE; |
509 |
/* and since the content will be modified, we must invalidate
|
510 |
the corresponding translated code. */
|
511 |
tb_invalidate_page(address); |
512 |
#ifdef DEBUG_TB_CHECK
|
513 |
tb_invalidate_check(address); |
514 |
#endif
|
515 |
return 1; |
516 |
} else {
|
517 |
return 0; |
518 |
} |
519 |
} |
520 |
|
521 |
/* call this function when system calls directly modify a memory area */
|
522 |
void page_unprotect_range(uint8_t *data, unsigned long data_size) |
523 |
{ |
524 |
unsigned long start, end, addr; |
525 |
|
526 |
start = (unsigned long)data; |
527 |
end = start + data_size; |
528 |
start &= TARGET_PAGE_MASK; |
529 |
end = TARGET_PAGE_ALIGN(end); |
530 |
for(addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
|
531 |
page_unprotect(addr); |
532 |
} |
533 |
} |