cputlb.c

   1 /*
   2  *  Common CPU TLB handling
   3  *
   4  *  Copyright (c) 2003 Fabrice Bellard
   5  *
   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.
  10  *
  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.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "config.h"
  21 #include "cpu.h"
  22 #include "exec/exec-all.h"
  23 #include "exec/memory.h"
  24 #include "exec/address-spaces.h"
  25
  26 #include "exec/cputlb.h"
  27
  28 #include "exec/memory-internal.h"
  29
  30 //#define DEBUG_TLB
  31 //#define DEBUG_TLB_CHECK
  32
  33 /* statistics */
  34 int tlb_flush_count;
  35
  36 static const CPUTLBEntry s_cputlb_empty_entry = {
  37     .addr_read  = -1,
  38     .addr_write = -1,
  39     .addr_code  = -1,
  40     .addend     = -1,
  41 };
  42
  43 /* NOTE:
  44  * If flush_global is true (the usual case), flush all tlb entries.
  45  * If flush_global is false, flush (at least) all tlb entries not
  46  * marked global.
  47  *
  48  * Since QEMU doesn't currently implement a global/not-global flag
  49  * for tlb entries, at the moment tlb_flush() will also flush all
  50  * tlb entries in the flush_global == false case. This is OK because
  51  * CPU architectures generally permit an implementation to drop
  52  * entries from the TLB at any time, so flushing more entries than
  53  * required is only an efficiency issue, not a correctness issue.
  54  */
  55 void tlb_flush(CPUArchState *env, int flush_global)
  56 {
  57     CPUState *cpu = ENV_GET_CPU(env);
  58     int i;
  59
  60 #if defined(DEBUG_TLB)
  61     printf("tlb_flush:\n");
  62 #endif
  63     /* must reset current TB so that interrupts cannot modify the
  64        links while we are modifying them */
  65     cpu->current_tb = NULL;
  66
  67     for (i = 0; i < CPU_TLB_SIZE; i++) {
  68         int mmu_idx;
  69
  70         for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
  71             env->tlb_table[mmu_idx][i] = s_cputlb_empty_entry;
  72         }
  73     }
  74
  75     memset(env->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof (void *));
  76
  77     env->tlb_flush_addr = -1;
  78     env->tlb_flush_mask = 0;
  79     tlb_flush_count++;
  80 }
  81
  82 static inline void tlb_flush_entry(CPUTLBEntry *tlb_entry, target_ulong addr)
  83 {
  84     if (addr == (tlb_entry->addr_read &
  85                  (TARGET_PAGE_MASK | TLB_INVALID_MASK)) ||
  86         addr == (tlb_entry->addr_write &
  87                  (TARGET_PAGE_MASK | TLB_INVALID_MASK)) ||
  88         addr == (tlb_entry->addr_code &
  89                  (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
  90         *tlb_entry = s_cputlb_empty_entry;
  91     }
  92 }
  93
  94 void tlb_flush_page(CPUArchState *env, target_ulong addr)
  95 {
  96     CPUState *cpu = ENV_GET_CPU(env);
  97     int i;
  98     int mmu_idx;
  99
 100 #if defined(DEBUG_TLB)
 101     printf("tlb_flush_page: " TARGET_FMT_lx "\n", addr);
 102 #endif
 103     /* Check if we need to flush due to large pages.  */
 104     if ((addr & env->tlb_flush_mask) == env->tlb_flush_addr) {
 105 #if defined(DEBUG_TLB)
 106         printf("tlb_flush_page: forced full flush ("
 107                TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
 108                env->tlb_flush_addr, env->tlb_flush_mask);
 109 #endif
 110         tlb_flush(env, 1);
 111         return;
 112     }
 113     /* must reset current TB so that interrupts cannot modify the
 114        links while we are modifying them */
 115     cpu->current_tb = NULL;
 116
 117     addr &= TARGET_PAGE_MASK;
 118     i = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
 119     for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
 120         tlb_flush_entry(&env->tlb_table[mmu_idx][i], addr);
 121     }
 122
 123     tb_flush_jmp_cache(env, addr);
 124 }
 125
 126 /* update the TLBs so that writes to code in the virtual page 'addr'
 127    can be detected */
 128 void tlb_protect_code(ram_addr_t ram_addr)
 129 {
 130     cpu_physical_memory_reset_dirty(ram_addr,
 131                                     ram_addr + TARGET_PAGE_SIZE,
 132                                     CODE_DIRTY_FLAG);
 133 }
 134
 135 /* update the TLB so that writes in physical page 'phys_addr' are no longer
 136    tested for self modifying code */
 137 void tlb_unprotect_code_phys(CPUArchState *env, ram_addr_t ram_addr,
 138                              target_ulong vaddr)
 139 {
 140     cpu_physical_memory_set_dirty_flags(ram_addr, CODE_DIRTY_FLAG);
 141 }
 142
 143 static bool tlb_is_dirty_ram(CPUTLBEntry *tlbe)
 144 {
 145     return (tlbe->addr_write & (TLB_INVALID_MASK|TLB_MMIO|TLB_NOTDIRTY)) == 0;
 146 }
 147
 148 void tlb_reset_dirty_range(CPUTLBEntry *tlb_entry, uintptr_t start,
 149                            uintptr_t length)
 150 {
 151     uintptr_t addr;
 152
 153     if (tlb_is_dirty_ram(tlb_entry)) {
 154         addr = (tlb_entry->addr_write & TARGET_PAGE_MASK) + tlb_entry->addend;
 155         if ((addr - start) < length) {
 156             tlb_entry->addr_write |= TLB_NOTDIRTY;
 157         }
 158     }
 159 }
 160
 161 static inline ram_addr_t qemu_ram_addr_from_host_nofail(void *ptr)
 162 {
 163     ram_addr_t ram_addr;
 164
 165     if (qemu_ram_addr_from_host(ptr, &ram_addr) == NULL) {
 166         fprintf(stderr, "Bad ram pointer %p\n", ptr);
 167         abort();
 168     }
 169     return ram_addr;
 170 }
 171
 172 static inline void tlb_update_dirty(CPUTLBEntry *tlb_entry)
 173 {
 174     ram_addr_t ram_addr;
 175     void *p;
 176
 177     if (tlb_is_dirty_ram(tlb_entry)) {
 178         p = (void *)(uintptr_t)((tlb_entry->addr_write & TARGET_PAGE_MASK)
 179             + tlb_entry->addend);
 180         ram_addr = qemu_ram_addr_from_host_nofail(p);
 181         if (!cpu_physical_memory_is_dirty(ram_addr)) {
 182             tlb_entry->addr_write |= TLB_NOTDIRTY;
 183         }
 184     }
 185 }
 186
 187 void cpu_tlb_reset_dirty_all(ram_addr_t start1, ram_addr_t length)
 188 {
 189     CPUArchState *env;
 190
 191     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 192         int mmu_idx;
 193
 194         for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
 195             unsigned int i;
 196
 197             for (i = 0; i < CPU_TLB_SIZE; i++) {
 198                 tlb_reset_dirty_range(&env->tlb_table[mmu_idx][i],
 199                                       start1, length);
 200             }
 201         }
 202     }
 203 }
 204
 205 static inline void tlb_set_dirty1(CPUTLBEntry *tlb_entry, target_ulong vaddr)
 206 {
 207     if (tlb_entry->addr_write == (vaddr | TLB_NOTDIRTY)) {
 208         tlb_entry->addr_write = vaddr;
 209     }
 210 }
 211
 212 /* update the TLB corresponding to virtual page vaddr
 213    so that it is no longer dirty */
 214 void tlb_set_dirty(CPUArchState *env, target_ulong vaddr)
 215 {
 216     int i;
 217     int mmu_idx;
 218
 219     vaddr &= TARGET_PAGE_MASK;
 220     i = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
 221     for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
 222         tlb_set_dirty1(&env->tlb_table[mmu_idx][i], vaddr);
 223     }
 224 }
 225
 226 /* Our TLB does not support large pages, so remember the area covered by
 227    large pages and trigger a full TLB flush if these are invalidated.  */
 228 static void tlb_add_large_page(CPUArchState *env, target_ulong vaddr,
 229                                target_ulong size)
 230 {
 231     target_ulong mask = ~(size - 1);
 232
 233     if (env->tlb_flush_addr == (target_ulong)-1) {
 234         env->tlb_flush_addr = vaddr & mask;
 235         env->tlb_flush_mask = mask;
 236         return;
 237     }
 238     /* Extend the existing region to include the new page.
 239        This is a compromise between unnecessary flushes and the cost
 240        of maintaining a full variable size TLB.  */
 241     mask &= env->tlb_flush_mask;
 242     while (((env->tlb_flush_addr ^ vaddr) & mask) != 0) {
 243         mask <<= 1;
 244     }
 245     env->tlb_flush_addr &= mask;
 246     env->tlb_flush_mask = mask;
 247 }
 248
 249 /* Add a new TLB entry. At most one entry for a given virtual address
 250    is permitted. Only a single TARGET_PAGE_SIZE region is mapped, the
 251    supplied size is only used by tlb_flush_page.  */
 252 void tlb_set_page(CPUArchState *env, target_ulong vaddr,
 253                   hwaddr paddr, int prot,
 254                   int mmu_idx, target_ulong size)
 255 {
 256     MemoryRegionSection *section;
 257     unsigned int index;
 258     target_ulong address;
 259     target_ulong code_address;
 260     uintptr_t addend;
 261     CPUTLBEntry *te;
 262     hwaddr iotlb, xlat, sz;
 263
 264     assert(size >= TARGET_PAGE_SIZE);
 265     if (size != TARGET_PAGE_SIZE) {
 266         tlb_add_large_page(env, vaddr, size);
 267     }
 268
 269     sz = size;
 270     section = address_space_translate_for_iotlb(&address_space_memory, paddr,
 271                                                 &xlat, &sz);
 272     assert(sz >= TARGET_PAGE_SIZE);
 273
 274 #if defined(DEBUG_TLB)
 275     printf("tlb_set_page: vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
 276            " prot=%x idx=%d\n",
 277            vaddr, paddr, prot, mmu_idx);
 278 #endif
 279
 280     address = vaddr;
 281     if (!memory_region_is_ram(section->mr) && !memory_region_is_romd(section->mr)) {
 282         /* IO memory case */
 283         address |= TLB_MMIO;
 284         addend = 0;
 285     } else {
 286         /* TLB_MMIO for rom/romd handled below */
 287         addend = (uintptr_t)memory_region_get_ram_ptr(section->mr) + xlat;
 288     }
 289
 290     code_address = address;
 291     iotlb = memory_region_section_get_iotlb(env, section, vaddr, paddr, xlat,
 292                                             prot, &address);
 293
 294     index = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
 295     env->iotlb[mmu_idx][index] = iotlb - vaddr;
 296     te = &env->tlb_table[mmu_idx][index];
 297     te->addend = addend - vaddr;
 298     if (prot & PAGE_READ) {
 299         te->addr_read = address;
 300     } else {
 301         te->addr_read = -1;
 302     }
 303
 304     if (prot & PAGE_EXEC) {
 305         te->addr_code = code_address;
 306     } else {
 307         te->addr_code = -1;
 308     }
 309     if (prot & PAGE_WRITE) {
 310         if ((memory_region_is_ram(section->mr) && section->readonly)
 311             || memory_region_is_romd(section->mr)) {
 312             /* Write access calls the I/O callback.  */
 313             te->addr_write = address | TLB_MMIO;
 314         } else if (memory_region_is_ram(section->mr)
 315                    && !cpu_physical_memory_is_dirty(section->mr->ram_addr + xlat)) {
 316             te->addr_write = address | TLB_NOTDIRTY;
 317         } else {
 318             te->addr_write = address;
 319         }
 320     } else {
 321         te->addr_write = -1;
 322     }
 323 }
 324
 325 /* NOTE: this function can trigger an exception */
 326 /* NOTE2: the returned address is not exactly the physical address: it
 327  * is actually a ram_addr_t (in system mode; the user mode emulation
 328  * version of this function returns a guest virtual address).
 329  */
 330 tb_page_addr_t get_page_addr_code(CPUArchState *env1, target_ulong addr)
 331 {
 332     int mmu_idx, page_index, pd;
 333     void *p;
 334     MemoryRegion *mr;
 335
 336     page_index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
 337     mmu_idx = cpu_mmu_index(env1);
 338     if (unlikely(env1->tlb_table[mmu_idx][page_index].addr_code !=
 339                  (addr & TARGET_PAGE_MASK))) {
 340         cpu_ldub_code(env1, addr);
 341     }
 342     pd = env1->iotlb[mmu_idx][page_index] & ~TARGET_PAGE_MASK;
 343     mr = iotlb_to_region(pd);
 344     if (memory_region_is_unassigned(mr)) {
 345         CPUState *cpu = ENV_GET_CPU(env1);
 346         CPUClass *cc = CPU_GET_CLASS(cpu);
 347
 348         if (cc->do_unassigned_access) {
 349             cc->do_unassigned_access(cpu, addr, false, true, 0, 4);
 350         } else {
 351             cpu_abort(env1, "Trying to execute code outside RAM or ROM at 0x"
 352                       TARGET_FMT_lx "\n", addr);
 353         }
 354     }
 355     p = (void *)((uintptr_t)addr + env1->tlb_table[mmu_idx][page_index].addend);
 356     return qemu_ram_addr_from_host_nofail(p);
 357 }
 358
 359 #define MMUSUFFIX _cmmu
 360 #undef GETPC
 361 #define GETPC() ((uintptr_t)0)
 362 #define SOFTMMU_CODE_ACCESS
 363
 364 #define SHIFT 0
 365 #include "exec/softmmu_template.h"
 366
 367 #define SHIFT 1
 368 #include "exec/softmmu_template.h"
 369
 370 #define SHIFT 2
 371 #include "exec/softmmu_template.h"
 372
 373 #define SHIFT 3
 374 #include "exec/softmmu_template.h"
 375
 376 #undef env