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