cputlb.c 10.9 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
/*
 *  Common CPU TLB handling
 *
 *  Copyright (c) 2003 Fabrice Bellard
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"
#include "cpu.h"
22 23 24
#include "exec/exec-all.h"
#include "exec/memory.h"
#include "exec/address-spaces.h"
25

26
#include "exec/cputlb.h"
27

28
#include "exec/memory-internal.h"
29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56

//#define DEBUG_TLB
//#define DEBUG_TLB_CHECK

/* statistics */
int tlb_flush_count;

static const CPUTLBEntry s_cputlb_empty_entry = {
    .addr_read  = -1,
    .addr_write = -1,
    .addr_code  = -1,
    .addend     = -1,
};

/* NOTE:
 * If flush_global is true (the usual case), flush all tlb entries.
 * If flush_global is false, flush (at least) all tlb entries not
 * marked global.
 *
 * Since QEMU doesn't currently implement a global/not-global flag
 * for tlb entries, at the moment tlb_flush() will also flush all
 * tlb entries in the flush_global == false case. This is OK because
 * CPU architectures generally permit an implementation to drop
 * entries from the TLB at any time, so flushing more entries than
 * required is only an efficiency issue, not a correctness issue.
 */
void tlb_flush(CPUArchState *env, int flush_global)
{
57
    CPUState *cpu = ENV_GET_CPU(env);
58 59 60 61 62 63 64
    int i;

#if defined(DEBUG_TLB)
    printf("tlb_flush:\n");
#endif
    /* must reset current TB so that interrupts cannot modify the
       links while we are modifying them */
65
    cpu->current_tb = NULL;
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

    for (i = 0; i < CPU_TLB_SIZE; i++) {
        int mmu_idx;

        for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
            env->tlb_table[mmu_idx][i] = s_cputlb_empty_entry;
        }
    }

    memset(env->tb_jmp_cache, 0, TB_JMP_CACHE_SIZE * sizeof (void *));

    env->tlb_flush_addr = -1;
    env->tlb_flush_mask = 0;
    tlb_flush_count++;
}

static inline void tlb_flush_entry(CPUTLBEntry *tlb_entry, target_ulong addr)
{
    if (addr == (tlb_entry->addr_read &
                 (TARGET_PAGE_MASK | TLB_INVALID_MASK)) ||
        addr == (tlb_entry->addr_write &
                 (TARGET_PAGE_MASK | TLB_INVALID_MASK)) ||
        addr == (tlb_entry->addr_code &
                 (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
        *tlb_entry = s_cputlb_empty_entry;
    }
}

void tlb_flush_page(CPUArchState *env, target_ulong addr)
{
96
    CPUState *cpu = ENV_GET_CPU(env);
97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114
    int i;
    int mmu_idx;

#if defined(DEBUG_TLB)
    printf("tlb_flush_page: " TARGET_FMT_lx "\n", addr);
#endif
    /* Check if we need to flush due to large pages.  */
    if ((addr & env->tlb_flush_mask) == env->tlb_flush_addr) {
#if defined(DEBUG_TLB)
        printf("tlb_flush_page: forced full flush ("
               TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
               env->tlb_flush_addr, env->tlb_flush_mask);
#endif
        tlb_flush(env, 1);
        return;
    }
    /* must reset current TB so that interrupts cannot modify the
       links while we are modifying them */
115
    cpu->current_tb = NULL;
116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241

    addr &= TARGET_PAGE_MASK;
    i = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
    for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
        tlb_flush_entry(&env->tlb_table[mmu_idx][i], addr);
    }

    tb_flush_jmp_cache(env, addr);
}

/* update the TLBs so that writes to code in the virtual page 'addr'
   can be detected */
void tlb_protect_code(ram_addr_t ram_addr)
{
    cpu_physical_memory_reset_dirty(ram_addr,
                                    ram_addr + TARGET_PAGE_SIZE,
                                    CODE_DIRTY_FLAG);
}

/* update the TLB so that writes in physical page 'phys_addr' are no longer
   tested for self modifying code */
void tlb_unprotect_code_phys(CPUArchState *env, ram_addr_t ram_addr,
                             target_ulong vaddr)
{
    cpu_physical_memory_set_dirty_flags(ram_addr, CODE_DIRTY_FLAG);
}

static bool tlb_is_dirty_ram(CPUTLBEntry *tlbe)
{
    return (tlbe->addr_write & (TLB_INVALID_MASK|TLB_MMIO|TLB_NOTDIRTY)) == 0;
}

void tlb_reset_dirty_range(CPUTLBEntry *tlb_entry, uintptr_t start,
                           uintptr_t length)
{
    uintptr_t addr;

    if (tlb_is_dirty_ram(tlb_entry)) {
        addr = (tlb_entry->addr_write & TARGET_PAGE_MASK) + tlb_entry->addend;
        if ((addr - start) < length) {
            tlb_entry->addr_write |= TLB_NOTDIRTY;
        }
    }
}

static inline void tlb_update_dirty(CPUTLBEntry *tlb_entry)
{
    ram_addr_t ram_addr;
    void *p;

    if (tlb_is_dirty_ram(tlb_entry)) {
        p = (void *)(uintptr_t)((tlb_entry->addr_write & TARGET_PAGE_MASK)
            + tlb_entry->addend);
        ram_addr = qemu_ram_addr_from_host_nofail(p);
        if (!cpu_physical_memory_is_dirty(ram_addr)) {
            tlb_entry->addr_write |= TLB_NOTDIRTY;
        }
    }
}

void cpu_tlb_reset_dirty_all(ram_addr_t start1, ram_addr_t length)
{
    CPUArchState *env;

    for (env = first_cpu; env != NULL; env = env->next_cpu) {
        int mmu_idx;

        for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
            unsigned int i;

            for (i = 0; i < CPU_TLB_SIZE; i++) {
                tlb_reset_dirty_range(&env->tlb_table[mmu_idx][i],
                                      start1, length);
            }
        }
    }
}

static inline void tlb_set_dirty1(CPUTLBEntry *tlb_entry, target_ulong vaddr)
{
    if (tlb_entry->addr_write == (vaddr | TLB_NOTDIRTY)) {
        tlb_entry->addr_write = vaddr;
    }
}

/* update the TLB corresponding to virtual page vaddr
   so that it is no longer dirty */
void tlb_set_dirty(CPUArchState *env, target_ulong vaddr)
{
    int i;
    int mmu_idx;

    vaddr &= TARGET_PAGE_MASK;
    i = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
    for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
        tlb_set_dirty1(&env->tlb_table[mmu_idx][i], vaddr);
    }
}

/* Our TLB does not support large pages, so remember the area covered by
   large pages and trigger a full TLB flush if these are invalidated.  */
static void tlb_add_large_page(CPUArchState *env, target_ulong vaddr,
                               target_ulong size)
{
    target_ulong mask = ~(size - 1);

    if (env->tlb_flush_addr == (target_ulong)-1) {
        env->tlb_flush_addr = vaddr & mask;
        env->tlb_flush_mask = mask;
        return;
    }
    /* Extend the existing region to include the new page.
       This is a compromise between unnecessary flushes and the cost
       of maintaining a full variable size TLB.  */
    mask &= env->tlb_flush_mask;
    while (((env->tlb_flush_addr ^ vaddr) & mask) != 0) {
        mask <<= 1;
    }
    env->tlb_flush_addr &= mask;
    env->tlb_flush_mask = mask;
}

/* Add a new TLB entry. At most one entry for a given virtual address
   is permitted. Only a single TARGET_PAGE_SIZE region is mapped, the
   supplied size is only used by tlb_flush_page.  */
void tlb_set_page(CPUArchState *env, target_ulong vaddr,
242
                  hwaddr paddr, int prot,
243 244 245 246 247 248 249 250
                  int mmu_idx, target_ulong size)
{
    MemoryRegionSection *section;
    unsigned int index;
    target_ulong address;
    target_ulong code_address;
    uintptr_t addend;
    CPUTLBEntry *te;
251
    hwaddr iotlb, xlat, sz;
252 253 254 255 256

    assert(size >= TARGET_PAGE_SIZE);
    if (size != TARGET_PAGE_SIZE) {
        tlb_add_large_page(env, vaddr, size);
    }
257 258 259 260 261 262

    sz = size;
    section = address_space_translate(&address_space_memory, paddr, &xlat, &sz,
                                      false);
    assert(sz >= TARGET_PAGE_SIZE);

263 264
#if defined(DEBUG_TLB)
    printf("tlb_set_page: vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
265 266
           " prot=%x idx=%d\n",
           vaddr, paddr, prot, mmu_idx);
267 268 269
#endif

    address = vaddr;
270 271
    if (!memory_region_is_ram(section->mr) && !memory_region_is_romd(section->mr)) {
        /* IO memory case */
272
        address |= TLB_MMIO;
273 274 275
        addend = 0;
    } else {
        /* TLB_MMIO for rom/romd handled below */
276
        addend = (uintptr_t)memory_region_get_ram_ptr(section->mr) + xlat;
277 278 279
    }

    code_address = address;
280 281
    iotlb = memory_region_section_get_iotlb(env, section, vaddr, paddr, xlat,
                                            prot, &address);
282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299

    index = (vaddr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
    env->iotlb[mmu_idx][index] = iotlb - vaddr;
    te = &env->tlb_table[mmu_idx][index];
    te->addend = addend - vaddr;
    if (prot & PAGE_READ) {
        te->addr_read = address;
    } else {
        te->addr_read = -1;
    }

    if (prot & PAGE_EXEC) {
        te->addr_code = code_address;
    } else {
        te->addr_code = -1;
    }
    if (prot & PAGE_WRITE) {
        if ((memory_region_is_ram(section->mr) && section->readonly)
300
            || memory_region_is_romd(section->mr)) {
301 302 303
            /* Write access calls the I/O callback.  */
            te->addr_write = address | TLB_MMIO;
        } else if (memory_region_is_ram(section->mr)
304
                   && !cpu_physical_memory_is_dirty(section->mr->ram_addr + xlat)) {
305 306 307 308 309 310 311 312 313 314 315
            te->addr_write = address | TLB_NOTDIRTY;
        } else {
            te->addr_write = address;
        }
    } else {
        te->addr_write = -1;
    }
}

/* NOTE: this function can trigger an exception */
/* NOTE2: the returned address is not exactly the physical address: it
316 317 318
 * is actually a ram_addr_t (in system mode; the user mode emulation
 * version of this function returns a guest virtual address).
 */
319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350
tb_page_addr_t get_page_addr_code(CPUArchState *env1, target_ulong addr)
{
    int mmu_idx, page_index, pd;
    void *p;
    MemoryRegion *mr;

    page_index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
    mmu_idx = cpu_mmu_index(env1);
    if (unlikely(env1->tlb_table[mmu_idx][page_index].addr_code !=
                 (addr & TARGET_PAGE_MASK))) {
        cpu_ldub_code(env1, addr);
    }
    pd = env1->iotlb[mmu_idx][page_index] & ~TARGET_PAGE_MASK;
    mr = iotlb_to_region(pd);
    if (memory_region_is_unassigned(mr)) {
#if defined(TARGET_ALPHA) || defined(TARGET_MIPS) || defined(TARGET_SPARC)
        cpu_unassigned_access(env1, addr, 0, 1, 0, 4);
#else
        cpu_abort(env1, "Trying to execute code outside RAM or ROM at 0x"
                  TARGET_FMT_lx "\n", addr);
#endif
    }
    p = (void *)((uintptr_t)addr + env1->tlb_table[mmu_idx][page_index].addend);
    return qemu_ram_addr_from_host_nofail(p);
}

#define MMUSUFFIX _cmmu
#undef GETPC
#define GETPC() ((uintptr_t)0)
#define SOFTMMU_CODE_ACCESS

#define SHIFT 0
351
#include "exec/softmmu_template.h"
352 353

#define SHIFT 1
354
#include "exec/softmmu_template.h"
355 356

#define SHIFT 2
357
#include "exec/softmmu_template.h"
358 359

#define SHIFT 3
360
#include "exec/softmmu_template.h"
361 362

#undef env