xref: /openbmc/qemu/accel/tcg/cputlb.c (revision 09a274d8)
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 2.1 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 "qemu/osdep.h"
21 #include "qemu/main-loop.h"
22 #include "cpu.h"
23 #include "exec/exec-all.h"
24 #include "exec/memory.h"
25 #include "exec/address-spaces.h"
26 #include "exec/cpu_ldst.h"
27 #include "exec/cputlb.h"
28 #include "exec/memory-internal.h"
29 #include "exec/ram_addr.h"
30 #include "tcg/tcg.h"
31 #include "qemu/error-report.h"
32 #include "exec/log.h"
33 #include "exec/helper-proto.h"
34 #include "qemu/atomic.h"
35 #include "qemu/atomic128.h"
36 
37 /* DEBUG defines, enable DEBUG_TLB_LOG to log to the CPU_LOG_MMU target */
38 /* #define DEBUG_TLB */
39 /* #define DEBUG_TLB_LOG */
40 
41 #ifdef DEBUG_TLB
42 # define DEBUG_TLB_GATE 1
43 # ifdef DEBUG_TLB_LOG
44 #  define DEBUG_TLB_LOG_GATE 1
45 # else
46 #  define DEBUG_TLB_LOG_GATE 0
47 # endif
48 #else
49 # define DEBUG_TLB_GATE 0
50 # define DEBUG_TLB_LOG_GATE 0
51 #endif
52 
53 #define tlb_debug(fmt, ...) do { \
54     if (DEBUG_TLB_LOG_GATE) { \
55         qemu_log_mask(CPU_LOG_MMU, "%s: " fmt, __func__, \
56                       ## __VA_ARGS__); \
57     } else if (DEBUG_TLB_GATE) { \
58         fprintf(stderr, "%s: " fmt, __func__, ## __VA_ARGS__); \
59     } \
60 } while (0)
61 
62 #define assert_cpu_is_self(cpu) do {                              \
63         if (DEBUG_TLB_GATE) {                                     \
64             g_assert(!(cpu)->created || qemu_cpu_is_self(cpu));   \
65         }                                                         \
66     } while (0)
67 
68 /* run_on_cpu_data.target_ptr should always be big enough for a
69  * target_ulong even on 32 bit builds */
70 QEMU_BUILD_BUG_ON(sizeof(target_ulong) > sizeof(run_on_cpu_data));
71 
72 /* We currently can't handle more than 16 bits in the MMUIDX bitmask.
73  */
74 QEMU_BUILD_BUG_ON(NB_MMU_MODES > 16);
75 #define ALL_MMUIDX_BITS ((1 << NB_MMU_MODES) - 1)
76 
77 static inline size_t sizeof_tlb(CPUArchState *env, uintptr_t mmu_idx)
78 {
79     return env->tlb_mask[mmu_idx] + (1 << CPU_TLB_ENTRY_BITS);
80 }
81 
82 static void tlb_window_reset(CPUTLBWindow *window, int64_t ns,
83                              size_t max_entries)
84 {
85     window->begin_ns = ns;
86     window->max_entries = max_entries;
87 }
88 
89 static void tlb_dyn_init(CPUArchState *env)
90 {
91     int i;
92 
93     for (i = 0; i < NB_MMU_MODES; i++) {
94         CPUTLBDesc *desc = &env->tlb_d[i];
95         size_t n_entries = 1 << CPU_TLB_DYN_DEFAULT_BITS;
96 
97         tlb_window_reset(&desc->window, get_clock_realtime(), 0);
98         desc->n_used_entries = 0;
99         env->tlb_mask[i] = (n_entries - 1) << CPU_TLB_ENTRY_BITS;
100         env->tlb_table[i] = g_new(CPUTLBEntry, n_entries);
101         env->iotlb[i] = g_new(CPUIOTLBEntry, n_entries);
102     }
103 }
104 
105 /**
106  * tlb_mmu_resize_locked() - perform TLB resize bookkeeping; resize if necessary
107  * @env: CPU that owns the TLB
108  * @mmu_idx: MMU index of the TLB
109  *
110  * Called with tlb_lock_held.
111  *
112  * We have two main constraints when resizing a TLB: (1) we only resize it
113  * on a TLB flush (otherwise we'd have to take a perf hit by either rehashing
114  * the array or unnecessarily flushing it), which means we do not control how
115  * frequently the resizing can occur; (2) we don't have access to the guest's
116  * future scheduling decisions, and therefore have to decide the magnitude of
117  * the resize based on past observations.
118  *
119  * In general, a memory-hungry process can benefit greatly from an appropriately
120  * sized TLB, since a guest TLB miss is very expensive. This doesn't mean that
121  * we just have to make the TLB as large as possible; while an oversized TLB
122  * results in minimal TLB miss rates, it also takes longer to be flushed
123  * (flushes can be _very_ frequent), and the reduced locality can also hurt
124  * performance.
125  *
126  * To achieve near-optimal performance for all kinds of workloads, we:
127  *
128  * 1. Aggressively increase the size of the TLB when the use rate of the
129  * TLB being flushed is high, since it is likely that in the near future this
130  * memory-hungry process will execute again, and its memory hungriness will
131  * probably be similar.
132  *
133  * 2. Slowly reduce the size of the TLB as the use rate declines over a
134  * reasonably large time window. The rationale is that if in such a time window
135  * we have not observed a high TLB use rate, it is likely that we won't observe
136  * it in the near future. In that case, once a time window expires we downsize
137  * the TLB to match the maximum use rate observed in the window.
138  *
139  * 3. Try to keep the maximum use rate in a time window in the 30-70% range,
140  * since in that range performance is likely near-optimal. Recall that the TLB
141  * is direct mapped, so we want the use rate to be low (or at least not too
142  * high), since otherwise we are likely to have a significant amount of
143  * conflict misses.
144  */
145 static void tlb_mmu_resize_locked(CPUArchState *env, int mmu_idx)
146 {
147     CPUTLBDesc *desc = &env->tlb_d[mmu_idx];
148     size_t old_size = tlb_n_entries(env, mmu_idx);
149     size_t rate;
150     size_t new_size = old_size;
151     int64_t now = get_clock_realtime();
152     int64_t window_len_ms = 100;
153     int64_t window_len_ns = window_len_ms * 1000 * 1000;
154     bool window_expired = now > desc->window.begin_ns + window_len_ns;
155 
156     if (desc->n_used_entries > desc->window.max_entries) {
157         desc->window.max_entries = desc->n_used_entries;
158     }
159     rate = desc->window.max_entries * 100 / old_size;
160 
161     if (rate > 70) {
162         new_size = MIN(old_size << 1, 1 << CPU_TLB_DYN_MAX_BITS);
163     } else if (rate < 30 && window_expired) {
164         size_t ceil = pow2ceil(desc->window.max_entries);
165         size_t expected_rate = desc->window.max_entries * 100 / ceil;
166 
167         /*
168          * Avoid undersizing when the max number of entries seen is just below
169          * a pow2. For instance, if max_entries == 1025, the expected use rate
170          * would be 1025/2048==50%. However, if max_entries == 1023, we'd get
171          * 1023/1024==99.9% use rate, so we'd likely end up doubling the size
172          * later. Thus, make sure that the expected use rate remains below 70%.
173          * (and since we double the size, that means the lowest rate we'd
174          * expect to get is 35%, which is still in the 30-70% range where
175          * we consider that the size is appropriate.)
176          */
177         if (expected_rate > 70) {
178             ceil *= 2;
179         }
180         new_size = MAX(ceil, 1 << CPU_TLB_DYN_MIN_BITS);
181     }
182 
183     if (new_size == old_size) {
184         if (window_expired) {
185             tlb_window_reset(&desc->window, now, desc->n_used_entries);
186         }
187         return;
188     }
189 
190     g_free(env->tlb_table[mmu_idx]);
191     g_free(env->iotlb[mmu_idx]);
192 
193     tlb_window_reset(&desc->window, now, 0);
194     /* desc->n_used_entries is cleared by the caller */
195     env->tlb_mask[mmu_idx] = (new_size - 1) << CPU_TLB_ENTRY_BITS;
196     env->tlb_table[mmu_idx] = g_try_new(CPUTLBEntry, new_size);
197     env->iotlb[mmu_idx] = g_try_new(CPUIOTLBEntry, new_size);
198     /*
199      * If the allocations fail, try smaller sizes. We just freed some
200      * memory, so going back to half of new_size has a good chance of working.
201      * Increased memory pressure elsewhere in the system might cause the
202      * allocations to fail though, so we progressively reduce the allocation
203      * size, aborting if we cannot even allocate the smallest TLB we support.
204      */
205     while (env->tlb_table[mmu_idx] == NULL || env->iotlb[mmu_idx] == NULL) {
206         if (new_size == (1 << CPU_TLB_DYN_MIN_BITS)) {
207             error_report("%s: %s", __func__, strerror(errno));
208             abort();
209         }
210         new_size = MAX(new_size >> 1, 1 << CPU_TLB_DYN_MIN_BITS);
211         env->tlb_mask[mmu_idx] = (new_size - 1) << CPU_TLB_ENTRY_BITS;
212 
213         g_free(env->tlb_table[mmu_idx]);
214         g_free(env->iotlb[mmu_idx]);
215         env->tlb_table[mmu_idx] = g_try_new(CPUTLBEntry, new_size);
216         env->iotlb[mmu_idx] = g_try_new(CPUIOTLBEntry, new_size);
217     }
218 }
219 
220 static inline void tlb_table_flush_by_mmuidx(CPUArchState *env, int mmu_idx)
221 {
222     tlb_mmu_resize_locked(env, mmu_idx);
223     memset(env->tlb_table[mmu_idx], -1, sizeof_tlb(env, mmu_idx));
224     env->tlb_d[mmu_idx].n_used_entries = 0;
225 }
226 
227 static inline void tlb_n_used_entries_inc(CPUArchState *env, uintptr_t mmu_idx)
228 {
229     env->tlb_d[mmu_idx].n_used_entries++;
230 }
231 
232 static inline void tlb_n_used_entries_dec(CPUArchState *env, uintptr_t mmu_idx)
233 {
234     env->tlb_d[mmu_idx].n_used_entries--;
235 }
236 
237 void tlb_init(CPUState *cpu)
238 {
239     CPUArchState *env = cpu->env_ptr;
240 
241     qemu_spin_init(&env->tlb_c.lock);
242 
243     /* Ensure that cpu_reset performs a full flush.  */
244     env->tlb_c.dirty = ALL_MMUIDX_BITS;
245 
246     tlb_dyn_init(env);
247 }
248 
249 /* flush_all_helper: run fn across all cpus
250  *
251  * If the wait flag is set then the src cpu's helper will be queued as
252  * "safe" work and the loop exited creating a synchronisation point
253  * where all queued work will be finished before execution starts
254  * again.
255  */
256 static void flush_all_helper(CPUState *src, run_on_cpu_func fn,
257                              run_on_cpu_data d)
258 {
259     CPUState *cpu;
260 
261     CPU_FOREACH(cpu) {
262         if (cpu != src) {
263             async_run_on_cpu(cpu, fn, d);
264         }
265     }
266 }
267 
268 void tlb_flush_counts(size_t *pfull, size_t *ppart, size_t *pelide)
269 {
270     CPUState *cpu;
271     size_t full = 0, part = 0, elide = 0;
272 
273     CPU_FOREACH(cpu) {
274         CPUArchState *env = cpu->env_ptr;
275 
276         full += atomic_read(&env->tlb_c.full_flush_count);
277         part += atomic_read(&env->tlb_c.part_flush_count);
278         elide += atomic_read(&env->tlb_c.elide_flush_count);
279     }
280     *pfull = full;
281     *ppart = part;
282     *pelide = elide;
283 }
284 
285 static void tlb_flush_one_mmuidx_locked(CPUArchState *env, int mmu_idx)
286 {
287     tlb_table_flush_by_mmuidx(env, mmu_idx);
288     memset(env->tlb_v_table[mmu_idx], -1, sizeof(env->tlb_v_table[0]));
289     env->tlb_d[mmu_idx].large_page_addr = -1;
290     env->tlb_d[mmu_idx].large_page_mask = -1;
291     env->tlb_d[mmu_idx].vindex = 0;
292 }
293 
294 static void tlb_flush_by_mmuidx_async_work(CPUState *cpu, run_on_cpu_data data)
295 {
296     CPUArchState *env = cpu->env_ptr;
297     uint16_t asked = data.host_int;
298     uint16_t all_dirty, work, to_clean;
299 
300     assert_cpu_is_self(cpu);
301 
302     tlb_debug("mmu_idx:0x%04" PRIx16 "\n", asked);
303 
304     qemu_spin_lock(&env->tlb_c.lock);
305 
306     all_dirty = env->tlb_c.dirty;
307     to_clean = asked & all_dirty;
308     all_dirty &= ~to_clean;
309     env->tlb_c.dirty = all_dirty;
310 
311     for (work = to_clean; work != 0; work &= work - 1) {
312         int mmu_idx = ctz32(work);
313         tlb_flush_one_mmuidx_locked(env, mmu_idx);
314     }
315 
316     qemu_spin_unlock(&env->tlb_c.lock);
317 
318     cpu_tb_jmp_cache_clear(cpu);
319 
320     if (to_clean == ALL_MMUIDX_BITS) {
321         atomic_set(&env->tlb_c.full_flush_count,
322                    env->tlb_c.full_flush_count + 1);
323     } else {
324         atomic_set(&env->tlb_c.part_flush_count,
325                    env->tlb_c.part_flush_count + ctpop16(to_clean));
326         if (to_clean != asked) {
327             atomic_set(&env->tlb_c.elide_flush_count,
328                        env->tlb_c.elide_flush_count +
329                        ctpop16(asked & ~to_clean));
330         }
331     }
332 }
333 
334 void tlb_flush_by_mmuidx(CPUState *cpu, uint16_t idxmap)
335 {
336     tlb_debug("mmu_idx: 0x%" PRIx16 "\n", idxmap);
337 
338     if (cpu->created && !qemu_cpu_is_self(cpu)) {
339         async_run_on_cpu(cpu, tlb_flush_by_mmuidx_async_work,
340                          RUN_ON_CPU_HOST_INT(idxmap));
341     } else {
342         tlb_flush_by_mmuidx_async_work(cpu, RUN_ON_CPU_HOST_INT(idxmap));
343     }
344 }
345 
346 void tlb_flush(CPUState *cpu)
347 {
348     tlb_flush_by_mmuidx(cpu, ALL_MMUIDX_BITS);
349 }
350 
351 void tlb_flush_by_mmuidx_all_cpus(CPUState *src_cpu, uint16_t idxmap)
352 {
353     const run_on_cpu_func fn = tlb_flush_by_mmuidx_async_work;
354 
355     tlb_debug("mmu_idx: 0x%"PRIx16"\n", idxmap);
356 
357     flush_all_helper(src_cpu, fn, RUN_ON_CPU_HOST_INT(idxmap));
358     fn(src_cpu, RUN_ON_CPU_HOST_INT(idxmap));
359 }
360 
361 void tlb_flush_all_cpus(CPUState *src_cpu)
362 {
363     tlb_flush_by_mmuidx_all_cpus(src_cpu, ALL_MMUIDX_BITS);
364 }
365 
366 void tlb_flush_by_mmuidx_all_cpus_synced(CPUState *src_cpu, uint16_t idxmap)
367 {
368     const run_on_cpu_func fn = tlb_flush_by_mmuidx_async_work;
369 
370     tlb_debug("mmu_idx: 0x%"PRIx16"\n", idxmap);
371 
372     flush_all_helper(src_cpu, fn, RUN_ON_CPU_HOST_INT(idxmap));
373     async_safe_run_on_cpu(src_cpu, fn, RUN_ON_CPU_HOST_INT(idxmap));
374 }
375 
376 void tlb_flush_all_cpus_synced(CPUState *src_cpu)
377 {
378     tlb_flush_by_mmuidx_all_cpus_synced(src_cpu, ALL_MMUIDX_BITS);
379 }
380 
381 static inline bool tlb_hit_page_anyprot(CPUTLBEntry *tlb_entry,
382                                         target_ulong page)
383 {
384     return tlb_hit_page(tlb_entry->addr_read, page) ||
385            tlb_hit_page(tlb_addr_write(tlb_entry), page) ||
386            tlb_hit_page(tlb_entry->addr_code, page);
387 }
388 
389 /**
390  * tlb_entry_is_empty - return true if the entry is not in use
391  * @te: pointer to CPUTLBEntry
392  */
393 static inline bool tlb_entry_is_empty(const CPUTLBEntry *te)
394 {
395     return te->addr_read == -1 && te->addr_write == -1 && te->addr_code == -1;
396 }
397 
398 /* Called with tlb_c.lock held */
399 static inline bool tlb_flush_entry_locked(CPUTLBEntry *tlb_entry,
400                                           target_ulong page)
401 {
402     if (tlb_hit_page_anyprot(tlb_entry, page)) {
403         memset(tlb_entry, -1, sizeof(*tlb_entry));
404         return true;
405     }
406     return false;
407 }
408 
409 /* Called with tlb_c.lock held */
410 static inline void tlb_flush_vtlb_page_locked(CPUArchState *env, int mmu_idx,
411                                               target_ulong page)
412 {
413     int k;
414 
415     assert_cpu_is_self(ENV_GET_CPU(env));
416     for (k = 0; k < CPU_VTLB_SIZE; k++) {
417         if (tlb_flush_entry_locked(&env->tlb_v_table[mmu_idx][k], page)) {
418             tlb_n_used_entries_dec(env, mmu_idx);
419         }
420     }
421 }
422 
423 static void tlb_flush_page_locked(CPUArchState *env, int midx,
424                                   target_ulong page)
425 {
426     target_ulong lp_addr = env->tlb_d[midx].large_page_addr;
427     target_ulong lp_mask = env->tlb_d[midx].large_page_mask;
428 
429     /* Check if we need to flush due to large pages.  */
430     if ((page & lp_mask) == lp_addr) {
431         tlb_debug("forcing full flush midx %d ("
432                   TARGET_FMT_lx "/" TARGET_FMT_lx ")\n",
433                   midx, lp_addr, lp_mask);
434         tlb_flush_one_mmuidx_locked(env, midx);
435     } else {
436         if (tlb_flush_entry_locked(tlb_entry(env, midx, page), page)) {
437             tlb_n_used_entries_dec(env, midx);
438         }
439         tlb_flush_vtlb_page_locked(env, midx, page);
440     }
441 }
442 
443 /* As we are going to hijack the bottom bits of the page address for a
444  * mmuidx bit mask we need to fail to build if we can't do that
445  */
446 QEMU_BUILD_BUG_ON(NB_MMU_MODES > TARGET_PAGE_BITS_MIN);
447 
448 static void tlb_flush_page_by_mmuidx_async_work(CPUState *cpu,
449                                                 run_on_cpu_data data)
450 {
451     CPUArchState *env = cpu->env_ptr;
452     target_ulong addr_and_mmuidx = (target_ulong) data.target_ptr;
453     target_ulong addr = addr_and_mmuidx & TARGET_PAGE_MASK;
454     unsigned long mmu_idx_bitmap = addr_and_mmuidx & ALL_MMUIDX_BITS;
455     int mmu_idx;
456 
457     assert_cpu_is_self(cpu);
458 
459     tlb_debug("page addr:" TARGET_FMT_lx " mmu_map:0x%lx\n",
460               addr, mmu_idx_bitmap);
461 
462     qemu_spin_lock(&env->tlb_c.lock);
463     for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
464         if (test_bit(mmu_idx, &mmu_idx_bitmap)) {
465             tlb_flush_page_locked(env, mmu_idx, addr);
466         }
467     }
468     qemu_spin_unlock(&env->tlb_c.lock);
469 
470     tb_flush_jmp_cache(cpu, addr);
471 }
472 
473 void tlb_flush_page_by_mmuidx(CPUState *cpu, target_ulong addr, uint16_t idxmap)
474 {
475     target_ulong addr_and_mmu_idx;
476 
477     tlb_debug("addr: "TARGET_FMT_lx" mmu_idx:%" PRIx16 "\n", addr, idxmap);
478 
479     /* This should already be page aligned */
480     addr_and_mmu_idx = addr & TARGET_PAGE_MASK;
481     addr_and_mmu_idx |= idxmap;
482 
483     if (!qemu_cpu_is_self(cpu)) {
484         async_run_on_cpu(cpu, tlb_flush_page_by_mmuidx_async_work,
485                          RUN_ON_CPU_TARGET_PTR(addr_and_mmu_idx));
486     } else {
487         tlb_flush_page_by_mmuidx_async_work(
488             cpu, RUN_ON_CPU_TARGET_PTR(addr_and_mmu_idx));
489     }
490 }
491 
492 void tlb_flush_page(CPUState *cpu, target_ulong addr)
493 {
494     tlb_flush_page_by_mmuidx(cpu, addr, ALL_MMUIDX_BITS);
495 }
496 
497 void tlb_flush_page_by_mmuidx_all_cpus(CPUState *src_cpu, target_ulong addr,
498                                        uint16_t idxmap)
499 {
500     const run_on_cpu_func fn = tlb_flush_page_by_mmuidx_async_work;
501     target_ulong addr_and_mmu_idx;
502 
503     tlb_debug("addr: "TARGET_FMT_lx" mmu_idx:%"PRIx16"\n", addr, idxmap);
504 
505     /* This should already be page aligned */
506     addr_and_mmu_idx = addr & TARGET_PAGE_MASK;
507     addr_and_mmu_idx |= idxmap;
508 
509     flush_all_helper(src_cpu, fn, RUN_ON_CPU_TARGET_PTR(addr_and_mmu_idx));
510     fn(src_cpu, RUN_ON_CPU_TARGET_PTR(addr_and_mmu_idx));
511 }
512 
513 void tlb_flush_page_all_cpus(CPUState *src, target_ulong addr)
514 {
515     tlb_flush_page_by_mmuidx_all_cpus(src, addr, ALL_MMUIDX_BITS);
516 }
517 
518 void tlb_flush_page_by_mmuidx_all_cpus_synced(CPUState *src_cpu,
519                                               target_ulong addr,
520                                               uint16_t idxmap)
521 {
522     const run_on_cpu_func fn = tlb_flush_page_by_mmuidx_async_work;
523     target_ulong addr_and_mmu_idx;
524 
525     tlb_debug("addr: "TARGET_FMT_lx" mmu_idx:%"PRIx16"\n", addr, idxmap);
526 
527     /* This should already be page aligned */
528     addr_and_mmu_idx = addr & TARGET_PAGE_MASK;
529     addr_and_mmu_idx |= idxmap;
530 
531     flush_all_helper(src_cpu, fn, RUN_ON_CPU_TARGET_PTR(addr_and_mmu_idx));
532     async_safe_run_on_cpu(src_cpu, fn, RUN_ON_CPU_TARGET_PTR(addr_and_mmu_idx));
533 }
534 
535 void tlb_flush_page_all_cpus_synced(CPUState *src, target_ulong addr)
536 {
537     tlb_flush_page_by_mmuidx_all_cpus_synced(src, addr, ALL_MMUIDX_BITS);
538 }
539 
540 /* update the TLBs so that writes to code in the virtual page 'addr'
541    can be detected */
542 void tlb_protect_code(ram_addr_t ram_addr)
543 {
544     cpu_physical_memory_test_and_clear_dirty(ram_addr, TARGET_PAGE_SIZE,
545                                              DIRTY_MEMORY_CODE);
546 }
547 
548 /* update the TLB so that writes in physical page 'phys_addr' are no longer
549    tested for self modifying code */
550 void tlb_unprotect_code(ram_addr_t ram_addr)
551 {
552     cpu_physical_memory_set_dirty_flag(ram_addr, DIRTY_MEMORY_CODE);
553 }
554 
555 
556 /*
557  * Dirty write flag handling
558  *
559  * When the TCG code writes to a location it looks up the address in
560  * the TLB and uses that data to compute the final address. If any of
561  * the lower bits of the address are set then the slow path is forced.
562  * There are a number of reasons to do this but for normal RAM the
563  * most usual is detecting writes to code regions which may invalidate
564  * generated code.
565  *
566  * Other vCPUs might be reading their TLBs during guest execution, so we update
567  * te->addr_write with atomic_set. We don't need to worry about this for
568  * oversized guests as MTTCG is disabled for them.
569  *
570  * Called with tlb_c.lock held.
571  */
572 static void tlb_reset_dirty_range_locked(CPUTLBEntry *tlb_entry,
573                                          uintptr_t start, uintptr_t length)
574 {
575     uintptr_t addr = tlb_entry->addr_write;
576 
577     if ((addr & (TLB_INVALID_MASK | TLB_MMIO | TLB_NOTDIRTY)) == 0) {
578         addr &= TARGET_PAGE_MASK;
579         addr += tlb_entry->addend;
580         if ((addr - start) < length) {
581 #if TCG_OVERSIZED_GUEST
582             tlb_entry->addr_write |= TLB_NOTDIRTY;
583 #else
584             atomic_set(&tlb_entry->addr_write,
585                        tlb_entry->addr_write | TLB_NOTDIRTY);
586 #endif
587         }
588     }
589 }
590 
591 /*
592  * Called with tlb_c.lock held.
593  * Called only from the vCPU context, i.e. the TLB's owner thread.
594  */
595 static inline void copy_tlb_helper_locked(CPUTLBEntry *d, const CPUTLBEntry *s)
596 {
597     *d = *s;
598 }
599 
600 /* This is a cross vCPU call (i.e. another vCPU resetting the flags of
601  * the target vCPU).
602  * We must take tlb_c.lock to avoid racing with another vCPU update. The only
603  * thing actually updated is the target TLB entry ->addr_write flags.
604  */
605 void tlb_reset_dirty(CPUState *cpu, ram_addr_t start1, ram_addr_t length)
606 {
607     CPUArchState *env;
608 
609     int mmu_idx;
610 
611     env = cpu->env_ptr;
612     qemu_spin_lock(&env->tlb_c.lock);
613     for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
614         unsigned int i;
615         unsigned int n = tlb_n_entries(env, mmu_idx);
616 
617         for (i = 0; i < n; i++) {
618             tlb_reset_dirty_range_locked(&env->tlb_table[mmu_idx][i], start1,
619                                          length);
620         }
621 
622         for (i = 0; i < CPU_VTLB_SIZE; i++) {
623             tlb_reset_dirty_range_locked(&env->tlb_v_table[mmu_idx][i], start1,
624                                          length);
625         }
626     }
627     qemu_spin_unlock(&env->tlb_c.lock);
628 }
629 
630 /* Called with tlb_c.lock held */
631 static inline void tlb_set_dirty1_locked(CPUTLBEntry *tlb_entry,
632                                          target_ulong vaddr)
633 {
634     if (tlb_entry->addr_write == (vaddr | TLB_NOTDIRTY)) {
635         tlb_entry->addr_write = vaddr;
636     }
637 }
638 
639 /* update the TLB corresponding to virtual page vaddr
640    so that it is no longer dirty */
641 void tlb_set_dirty(CPUState *cpu, target_ulong vaddr)
642 {
643     CPUArchState *env = cpu->env_ptr;
644     int mmu_idx;
645 
646     assert_cpu_is_self(cpu);
647 
648     vaddr &= TARGET_PAGE_MASK;
649     qemu_spin_lock(&env->tlb_c.lock);
650     for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
651         tlb_set_dirty1_locked(tlb_entry(env, mmu_idx, vaddr), vaddr);
652     }
653 
654     for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) {
655         int k;
656         for (k = 0; k < CPU_VTLB_SIZE; k++) {
657             tlb_set_dirty1_locked(&env->tlb_v_table[mmu_idx][k], vaddr);
658         }
659     }
660     qemu_spin_unlock(&env->tlb_c.lock);
661 }
662 
663 /* Our TLB does not support large pages, so remember the area covered by
664    large pages and trigger a full TLB flush if these are invalidated.  */
665 static void tlb_add_large_page(CPUArchState *env, int mmu_idx,
666                                target_ulong vaddr, target_ulong size)
667 {
668     target_ulong lp_addr = env->tlb_d[mmu_idx].large_page_addr;
669     target_ulong lp_mask = ~(size - 1);
670 
671     if (lp_addr == (target_ulong)-1) {
672         /* No previous large page.  */
673         lp_addr = vaddr;
674     } else {
675         /* Extend the existing region to include the new page.
676            This is a compromise between unnecessary flushes and
677            the cost of maintaining a full variable size TLB.  */
678         lp_mask &= env->tlb_d[mmu_idx].large_page_mask;
679         while (((lp_addr ^ vaddr) & lp_mask) != 0) {
680             lp_mask <<= 1;
681         }
682     }
683     env->tlb_d[mmu_idx].large_page_addr = lp_addr & lp_mask;
684     env->tlb_d[mmu_idx].large_page_mask = lp_mask;
685 }
686 
687 /* Add a new TLB entry. At most one entry for a given virtual address
688  * is permitted. Only a single TARGET_PAGE_SIZE region is mapped, the
689  * supplied size is only used by tlb_flush_page.
690  *
691  * Called from TCG-generated code, which is under an RCU read-side
692  * critical section.
693  */
694 void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
695                              hwaddr paddr, MemTxAttrs attrs, int prot,
696                              int mmu_idx, target_ulong size)
697 {
698     CPUArchState *env = cpu->env_ptr;
699     MemoryRegionSection *section;
700     unsigned int index;
701     target_ulong address;
702     target_ulong code_address;
703     uintptr_t addend;
704     CPUTLBEntry *te, tn;
705     hwaddr iotlb, xlat, sz, paddr_page;
706     target_ulong vaddr_page;
707     int asidx = cpu_asidx_from_attrs(cpu, attrs);
708 
709     assert_cpu_is_self(cpu);
710 
711     if (size <= TARGET_PAGE_SIZE) {
712         sz = TARGET_PAGE_SIZE;
713     } else {
714         tlb_add_large_page(env, mmu_idx, vaddr, size);
715         sz = size;
716     }
717     vaddr_page = vaddr & TARGET_PAGE_MASK;
718     paddr_page = paddr & TARGET_PAGE_MASK;
719 
720     section = address_space_translate_for_iotlb(cpu, asidx, paddr_page,
721                                                 &xlat, &sz, attrs, &prot);
722     assert(sz >= TARGET_PAGE_SIZE);
723 
724     tlb_debug("vaddr=" TARGET_FMT_lx " paddr=0x" TARGET_FMT_plx
725               " prot=%x idx=%d\n",
726               vaddr, paddr, prot, mmu_idx);
727 
728     address = vaddr_page;
729     if (size < TARGET_PAGE_SIZE) {
730         /*
731          * Slow-path the TLB entries; we will repeat the MMU check and TLB
732          * fill on every access.
733          */
734         address |= TLB_RECHECK;
735     }
736     if (!memory_region_is_ram(section->mr) &&
737         !memory_region_is_romd(section->mr)) {
738         /* IO memory case */
739         address |= TLB_MMIO;
740         addend = 0;
741     } else {
742         /* TLB_MMIO for rom/romd handled below */
743         addend = (uintptr_t)memory_region_get_ram_ptr(section->mr) + xlat;
744     }
745 
746     code_address = address;
747     iotlb = memory_region_section_get_iotlb(cpu, section, vaddr_page,
748                                             paddr_page, xlat, prot, &address);
749 
750     index = tlb_index(env, mmu_idx, vaddr_page);
751     te = tlb_entry(env, mmu_idx, vaddr_page);
752 
753     /*
754      * Hold the TLB lock for the rest of the function. We could acquire/release
755      * the lock several times in the function, but it is faster to amortize the
756      * acquisition cost by acquiring it just once. Note that this leads to
757      * a longer critical section, but this is not a concern since the TLB lock
758      * is unlikely to be contended.
759      */
760     qemu_spin_lock(&env->tlb_c.lock);
761 
762     /* Note that the tlb is no longer clean.  */
763     env->tlb_c.dirty |= 1 << mmu_idx;
764 
765     /* Make sure there's no cached translation for the new page.  */
766     tlb_flush_vtlb_page_locked(env, mmu_idx, vaddr_page);
767 
768     /*
769      * Only evict the old entry to the victim tlb if it's for a
770      * different page; otherwise just overwrite the stale data.
771      */
772     if (!tlb_hit_page_anyprot(te, vaddr_page) && !tlb_entry_is_empty(te)) {
773         unsigned vidx = env->tlb_d[mmu_idx].vindex++ % CPU_VTLB_SIZE;
774         CPUTLBEntry *tv = &env->tlb_v_table[mmu_idx][vidx];
775 
776         /* Evict the old entry into the victim tlb.  */
777         copy_tlb_helper_locked(tv, te);
778         env->iotlb_v[mmu_idx][vidx] = env->iotlb[mmu_idx][index];
779         tlb_n_used_entries_dec(env, mmu_idx);
780     }
781 
782     /* refill the tlb */
783     /*
784      * At this point iotlb contains a physical section number in the lower
785      * TARGET_PAGE_BITS, and either
786      *  + the ram_addr_t of the page base of the target RAM (if NOTDIRTY or ROM)
787      *  + the offset within section->mr of the page base (otherwise)
788      * We subtract the vaddr_page (which is page aligned and thus won't
789      * disturb the low bits) to give an offset which can be added to the
790      * (non-page-aligned) vaddr of the eventual memory access to get
791      * the MemoryRegion offset for the access. Note that the vaddr we
792      * subtract here is that of the page base, and not the same as the
793      * vaddr we add back in io_readx()/io_writex()/get_page_addr_code().
794      */
795     env->iotlb[mmu_idx][index].addr = iotlb - vaddr_page;
796     env->iotlb[mmu_idx][index].attrs = attrs;
797 
798     /* Now calculate the new entry */
799     tn.addend = addend - vaddr_page;
800     if (prot & PAGE_READ) {
801         tn.addr_read = address;
802     } else {
803         tn.addr_read = -1;
804     }
805 
806     if (prot & PAGE_EXEC) {
807         tn.addr_code = code_address;
808     } else {
809         tn.addr_code = -1;
810     }
811 
812     tn.addr_write = -1;
813     if (prot & PAGE_WRITE) {
814         if ((memory_region_is_ram(section->mr) && section->readonly)
815             || memory_region_is_romd(section->mr)) {
816             /* Write access calls the I/O callback.  */
817             tn.addr_write = address | TLB_MMIO;
818         } else if (memory_region_is_ram(section->mr)
819                    && cpu_physical_memory_is_clean(
820                        memory_region_get_ram_addr(section->mr) + xlat)) {
821             tn.addr_write = address | TLB_NOTDIRTY;
822         } else {
823             tn.addr_write = address;
824         }
825         if (prot & PAGE_WRITE_INV) {
826             tn.addr_write |= TLB_INVALID_MASK;
827         }
828     }
829 
830     copy_tlb_helper_locked(te, &tn);
831     tlb_n_used_entries_inc(env, mmu_idx);
832     qemu_spin_unlock(&env->tlb_c.lock);
833 }
834 
835 /* Add a new TLB entry, but without specifying the memory
836  * transaction attributes to be used.
837  */
838 void tlb_set_page(CPUState *cpu, target_ulong vaddr,
839                   hwaddr paddr, int prot,
840                   int mmu_idx, target_ulong size)
841 {
842     tlb_set_page_with_attrs(cpu, vaddr, paddr, MEMTXATTRS_UNSPECIFIED,
843                             prot, mmu_idx, size);
844 }
845 
846 static inline ram_addr_t qemu_ram_addr_from_host_nofail(void *ptr)
847 {
848     ram_addr_t ram_addr;
849 
850     ram_addr = qemu_ram_addr_from_host(ptr);
851     if (ram_addr == RAM_ADDR_INVALID) {
852         error_report("Bad ram pointer %p", ptr);
853         abort();
854     }
855     return ram_addr;
856 }
857 
858 static uint64_t io_readx(CPUArchState *env, CPUIOTLBEntry *iotlbentry,
859                          int mmu_idx,
860                          target_ulong addr, uintptr_t retaddr,
861                          bool recheck, MMUAccessType access_type, int size)
862 {
863     CPUState *cpu = ENV_GET_CPU(env);
864     hwaddr mr_offset;
865     MemoryRegionSection *section;
866     MemoryRegion *mr;
867     uint64_t val;
868     bool locked = false;
869     MemTxResult r;
870 
871     if (recheck) {
872         /*
873          * This is a TLB_RECHECK access, where the MMU protection
874          * covers a smaller range than a target page, and we must
875          * repeat the MMU check here. This tlb_fill() call might
876          * longjump out if this access should cause a guest exception.
877          */
878         CPUTLBEntry *entry;
879         target_ulong tlb_addr;
880 
881         tlb_fill(cpu, addr, size, MMU_DATA_LOAD, mmu_idx, retaddr);
882 
883         entry = tlb_entry(env, mmu_idx, addr);
884         tlb_addr = entry->addr_read;
885         if (!(tlb_addr & ~(TARGET_PAGE_MASK | TLB_RECHECK))) {
886             /* RAM access */
887             uintptr_t haddr = addr + entry->addend;
888 
889             return ldn_p((void *)haddr, size);
890         }
891         /* Fall through for handling IO accesses */
892     }
893 
894     section = iotlb_to_section(cpu, iotlbentry->addr, iotlbentry->attrs);
895     mr = section->mr;
896     mr_offset = (iotlbentry->addr & TARGET_PAGE_MASK) + addr;
897     cpu->mem_io_pc = retaddr;
898     if (mr != &io_mem_rom && mr != &io_mem_notdirty && !cpu->can_do_io) {
899         cpu_io_recompile(cpu, retaddr);
900     }
901 
902     cpu->mem_io_vaddr = addr;
903     cpu->mem_io_access_type = access_type;
904 
905     if (mr->global_locking && !qemu_mutex_iothread_locked()) {
906         qemu_mutex_lock_iothread();
907         locked = true;
908     }
909     r = memory_region_dispatch_read(mr, mr_offset,
910                                     &val, size, iotlbentry->attrs);
911     if (r != MEMTX_OK) {
912         hwaddr physaddr = mr_offset +
913             section->offset_within_address_space -
914             section->offset_within_region;
915 
916         cpu_transaction_failed(cpu, physaddr, addr, size, access_type,
917                                mmu_idx, iotlbentry->attrs, r, retaddr);
918     }
919     if (locked) {
920         qemu_mutex_unlock_iothread();
921     }
922 
923     return val;
924 }
925 
926 static void io_writex(CPUArchState *env, CPUIOTLBEntry *iotlbentry,
927                       int mmu_idx,
928                       uint64_t val, target_ulong addr,
929                       uintptr_t retaddr, bool recheck, int size)
930 {
931     CPUState *cpu = ENV_GET_CPU(env);
932     hwaddr mr_offset;
933     MemoryRegionSection *section;
934     MemoryRegion *mr;
935     bool locked = false;
936     MemTxResult r;
937 
938     if (recheck) {
939         /*
940          * This is a TLB_RECHECK access, where the MMU protection
941          * covers a smaller range than a target page, and we must
942          * repeat the MMU check here. This tlb_fill() call might
943          * longjump out if this access should cause a guest exception.
944          */
945         CPUTLBEntry *entry;
946         target_ulong tlb_addr;
947 
948         tlb_fill(cpu, addr, size, MMU_DATA_STORE, mmu_idx, retaddr);
949 
950         entry = tlb_entry(env, mmu_idx, addr);
951         tlb_addr = tlb_addr_write(entry);
952         if (!(tlb_addr & ~(TARGET_PAGE_MASK | TLB_RECHECK))) {
953             /* RAM access */
954             uintptr_t haddr = addr + entry->addend;
955 
956             stn_p((void *)haddr, size, val);
957             return;
958         }
959         /* Fall through for handling IO accesses */
960     }
961 
962     section = iotlb_to_section(cpu, iotlbentry->addr, iotlbentry->attrs);
963     mr = section->mr;
964     mr_offset = (iotlbentry->addr & TARGET_PAGE_MASK) + addr;
965     if (mr != &io_mem_rom && mr != &io_mem_notdirty && !cpu->can_do_io) {
966         cpu_io_recompile(cpu, retaddr);
967     }
968     cpu->mem_io_vaddr = addr;
969     cpu->mem_io_pc = retaddr;
970 
971     if (mr->global_locking && !qemu_mutex_iothread_locked()) {
972         qemu_mutex_lock_iothread();
973         locked = true;
974     }
975     r = memory_region_dispatch_write(mr, mr_offset,
976                                      val, size, iotlbentry->attrs);
977     if (r != MEMTX_OK) {
978         hwaddr physaddr = mr_offset +
979             section->offset_within_address_space -
980             section->offset_within_region;
981 
982         cpu_transaction_failed(cpu, physaddr, addr, size, MMU_DATA_STORE,
983                                mmu_idx, iotlbentry->attrs, r, retaddr);
984     }
985     if (locked) {
986         qemu_mutex_unlock_iothread();
987     }
988 }
989 
990 /* Return true if ADDR is present in the victim tlb, and has been copied
991    back to the main tlb.  */
992 static bool victim_tlb_hit(CPUArchState *env, size_t mmu_idx, size_t index,
993                            size_t elt_ofs, target_ulong page)
994 {
995     size_t vidx;
996 
997     assert_cpu_is_self(ENV_GET_CPU(env));
998     for (vidx = 0; vidx < CPU_VTLB_SIZE; ++vidx) {
999         CPUTLBEntry *vtlb = &env->tlb_v_table[mmu_idx][vidx];
1000         target_ulong cmp;
1001 
1002         /* elt_ofs might correspond to .addr_write, so use atomic_read */
1003 #if TCG_OVERSIZED_GUEST
1004         cmp = *(target_ulong *)((uintptr_t)vtlb + elt_ofs);
1005 #else
1006         cmp = atomic_read((target_ulong *)((uintptr_t)vtlb + elt_ofs));
1007 #endif
1008 
1009         if (cmp == page) {
1010             /* Found entry in victim tlb, swap tlb and iotlb.  */
1011             CPUTLBEntry tmptlb, *tlb = &env->tlb_table[mmu_idx][index];
1012 
1013             qemu_spin_lock(&env->tlb_c.lock);
1014             copy_tlb_helper_locked(&tmptlb, tlb);
1015             copy_tlb_helper_locked(tlb, vtlb);
1016             copy_tlb_helper_locked(vtlb, &tmptlb);
1017             qemu_spin_unlock(&env->tlb_c.lock);
1018 
1019             CPUIOTLBEntry tmpio, *io = &env->iotlb[mmu_idx][index];
1020             CPUIOTLBEntry *vio = &env->iotlb_v[mmu_idx][vidx];
1021             tmpio = *io; *io = *vio; *vio = tmpio;
1022             return true;
1023         }
1024     }
1025     return false;
1026 }
1027 
1028 /* Macro to call the above, with local variables from the use context.  */
1029 #define VICTIM_TLB_HIT(TY, ADDR) \
1030   victim_tlb_hit(env, mmu_idx, index, offsetof(CPUTLBEntry, TY), \
1031                  (ADDR) & TARGET_PAGE_MASK)
1032 
1033 /* NOTE: this function can trigger an exception */
1034 /* NOTE2: the returned address is not exactly the physical address: it
1035  * is actually a ram_addr_t (in system mode; the user mode emulation
1036  * version of this function returns a guest virtual address).
1037  */
1038 tb_page_addr_t get_page_addr_code(CPUArchState *env, target_ulong addr)
1039 {
1040     uintptr_t mmu_idx = cpu_mmu_index(env, true);
1041     uintptr_t index = tlb_index(env, mmu_idx, addr);
1042     CPUTLBEntry *entry = tlb_entry(env, mmu_idx, addr);
1043     void *p;
1044 
1045     if (unlikely(!tlb_hit(entry->addr_code, addr))) {
1046         if (!VICTIM_TLB_HIT(addr_code, addr)) {
1047             tlb_fill(ENV_GET_CPU(env), addr, 0, MMU_INST_FETCH, mmu_idx, 0);
1048             index = tlb_index(env, mmu_idx, addr);
1049             entry = tlb_entry(env, mmu_idx, addr);
1050         }
1051         assert(tlb_hit(entry->addr_code, addr));
1052     }
1053 
1054     if (unlikely(entry->addr_code & (TLB_RECHECK | TLB_MMIO))) {
1055         /*
1056          * Return -1 if we can't translate and execute from an entire
1057          * page of RAM here, which will cause us to execute by loading
1058          * and translating one insn at a time, without caching:
1059          *  - TLB_RECHECK: means the MMU protection covers a smaller range
1060          *    than a target page, so we must redo the MMU check every insn
1061          *  - TLB_MMIO: region is not backed by RAM
1062          */
1063         return -1;
1064     }
1065 
1066     p = (void *)((uintptr_t)addr + entry->addend);
1067     return qemu_ram_addr_from_host_nofail(p);
1068 }
1069 
1070 /* Probe for whether the specified guest write access is permitted.
1071  * If it is not permitted then an exception will be taken in the same
1072  * way as if this were a real write access (and we will not return).
1073  * Otherwise the function will return, and there will be a valid
1074  * entry in the TLB for this access.
1075  */
1076 void probe_write(CPUArchState *env, target_ulong addr, int size, int mmu_idx,
1077                  uintptr_t retaddr)
1078 {
1079     uintptr_t index = tlb_index(env, mmu_idx, addr);
1080     CPUTLBEntry *entry = tlb_entry(env, mmu_idx, addr);
1081 
1082     if (!tlb_hit(tlb_addr_write(entry), addr)) {
1083         /* TLB entry is for a different page */
1084         if (!VICTIM_TLB_HIT(addr_write, addr)) {
1085             tlb_fill(ENV_GET_CPU(env), addr, size, MMU_DATA_STORE,
1086                      mmu_idx, retaddr);
1087         }
1088     }
1089 }
1090 
1091 /* Probe for a read-modify-write atomic operation.  Do not allow unaligned
1092  * operations, or io operations to proceed.  Return the host address.  */
1093 static void *atomic_mmu_lookup(CPUArchState *env, target_ulong addr,
1094                                TCGMemOpIdx oi, uintptr_t retaddr,
1095                                NotDirtyInfo *ndi)
1096 {
1097     size_t mmu_idx = get_mmuidx(oi);
1098     uintptr_t index = tlb_index(env, mmu_idx, addr);
1099     CPUTLBEntry *tlbe = tlb_entry(env, mmu_idx, addr);
1100     target_ulong tlb_addr = tlb_addr_write(tlbe);
1101     TCGMemOp mop = get_memop(oi);
1102     int a_bits = get_alignment_bits(mop);
1103     int s_bits = mop & MO_SIZE;
1104     void *hostaddr;
1105 
1106     /* Adjust the given return address.  */
1107     retaddr -= GETPC_ADJ;
1108 
1109     /* Enforce guest required alignment.  */
1110     if (unlikely(a_bits > 0 && (addr & ((1 << a_bits) - 1)))) {
1111         /* ??? Maybe indicate atomic op to cpu_unaligned_access */
1112         cpu_unaligned_access(ENV_GET_CPU(env), addr, MMU_DATA_STORE,
1113                              mmu_idx, retaddr);
1114     }
1115 
1116     /* Enforce qemu required alignment.  */
1117     if (unlikely(addr & ((1 << s_bits) - 1))) {
1118         /* We get here if guest alignment was not requested,
1119            or was not enforced by cpu_unaligned_access above.
1120            We might widen the access and emulate, but for now
1121            mark an exception and exit the cpu loop.  */
1122         goto stop_the_world;
1123     }
1124 
1125     /* Check TLB entry and enforce page permissions.  */
1126     if (!tlb_hit(tlb_addr, addr)) {
1127         if (!VICTIM_TLB_HIT(addr_write, addr)) {
1128             tlb_fill(ENV_GET_CPU(env), addr, 1 << s_bits, MMU_DATA_STORE,
1129                      mmu_idx, retaddr);
1130             index = tlb_index(env, mmu_idx, addr);
1131             tlbe = tlb_entry(env, mmu_idx, addr);
1132         }
1133         tlb_addr = tlb_addr_write(tlbe) & ~TLB_INVALID_MASK;
1134     }
1135 
1136     /* Notice an IO access or a needs-MMU-lookup access */
1137     if (unlikely(tlb_addr & (TLB_MMIO | TLB_RECHECK))) {
1138         /* There's really nothing that can be done to
1139            support this apart from stop-the-world.  */
1140         goto stop_the_world;
1141     }
1142 
1143     /* Let the guest notice RMW on a write-only page.  */
1144     if (unlikely(tlbe->addr_read != (tlb_addr & ~TLB_NOTDIRTY))) {
1145         tlb_fill(ENV_GET_CPU(env), addr, 1 << s_bits, MMU_DATA_LOAD,
1146                  mmu_idx, retaddr);
1147         /* Since we don't support reads and writes to different addresses,
1148            and we do have the proper page loaded for write, this shouldn't
1149            ever return.  But just in case, handle via stop-the-world.  */
1150         goto stop_the_world;
1151     }
1152 
1153     hostaddr = (void *)((uintptr_t)addr + tlbe->addend);
1154 
1155     ndi->active = false;
1156     if (unlikely(tlb_addr & TLB_NOTDIRTY)) {
1157         ndi->active = true;
1158         memory_notdirty_write_prepare(ndi, ENV_GET_CPU(env), addr,
1159                                       qemu_ram_addr_from_host_nofail(hostaddr),
1160                                       1 << s_bits);
1161     }
1162 
1163     return hostaddr;
1164 
1165  stop_the_world:
1166     cpu_loop_exit_atomic(ENV_GET_CPU(env), retaddr);
1167 }
1168 
1169 #ifdef TARGET_WORDS_BIGENDIAN
1170 # define TGT_BE(X)  (X)
1171 # define TGT_LE(X)  BSWAP(X)
1172 #else
1173 # define TGT_BE(X)  BSWAP(X)
1174 # define TGT_LE(X)  (X)
1175 #endif
1176 
1177 #define MMUSUFFIX _mmu
1178 
1179 #define DATA_SIZE 1
1180 #include "softmmu_template.h"
1181 
1182 #define DATA_SIZE 2
1183 #include "softmmu_template.h"
1184 
1185 #define DATA_SIZE 4
1186 #include "softmmu_template.h"
1187 
1188 #define DATA_SIZE 8
1189 #include "softmmu_template.h"
1190 
1191 /* First set of helpers allows passing in of OI and RETADDR.  This makes
1192    them callable from other helpers.  */
1193 
1194 #define EXTRA_ARGS     , TCGMemOpIdx oi, uintptr_t retaddr
1195 #define ATOMIC_NAME(X) \
1196     HELPER(glue(glue(glue(atomic_ ## X, SUFFIX), END), _mmu))
1197 #define ATOMIC_MMU_DECLS NotDirtyInfo ndi
1198 #define ATOMIC_MMU_LOOKUP atomic_mmu_lookup(env, addr, oi, retaddr, &ndi)
1199 #define ATOMIC_MMU_CLEANUP                              \
1200     do {                                                \
1201         if (unlikely(ndi.active)) {                     \
1202             memory_notdirty_write_complete(&ndi);       \
1203         }                                               \
1204     } while (0)
1205 
1206 #define DATA_SIZE 1
1207 #include "atomic_template.h"
1208 
1209 #define DATA_SIZE 2
1210 #include "atomic_template.h"
1211 
1212 #define DATA_SIZE 4
1213 #include "atomic_template.h"
1214 
1215 #ifdef CONFIG_ATOMIC64
1216 #define DATA_SIZE 8
1217 #include "atomic_template.h"
1218 #endif
1219 
1220 #if HAVE_CMPXCHG128 || HAVE_ATOMIC128
1221 #define DATA_SIZE 16
1222 #include "atomic_template.h"
1223 #endif
1224 
1225 /* Second set of helpers are directly callable from TCG as helpers.  */
1226 
1227 #undef EXTRA_ARGS
1228 #undef ATOMIC_NAME
1229 #undef ATOMIC_MMU_LOOKUP
1230 #define EXTRA_ARGS         , TCGMemOpIdx oi
1231 #define ATOMIC_NAME(X)     HELPER(glue(glue(atomic_ ## X, SUFFIX), END))
1232 #define ATOMIC_MMU_LOOKUP  atomic_mmu_lookup(env, addr, oi, GETPC(), &ndi)
1233 
1234 #define DATA_SIZE 1
1235 #include "atomic_template.h"
1236 
1237 #define DATA_SIZE 2
1238 #include "atomic_template.h"
1239 
1240 #define DATA_SIZE 4
1241 #include "atomic_template.h"
1242 
1243 #ifdef CONFIG_ATOMIC64
1244 #define DATA_SIZE 8
1245 #include "atomic_template.h"
1246 #endif
1247 
1248 /* Code access functions.  */
1249 
1250 #undef MMUSUFFIX
1251 #define MMUSUFFIX _cmmu
1252 #undef GETPC
1253 #define GETPC() ((uintptr_t)0)
1254 #define SOFTMMU_CODE_ACCESS
1255 
1256 #define DATA_SIZE 1
1257 #include "softmmu_template.h"
1258 
1259 #define DATA_SIZE 2
1260 #include "softmmu_template.h"
1261 
1262 #define DATA_SIZE 4
1263 #include "softmmu_template.h"
1264 
1265 #define DATA_SIZE 8
1266 #include "softmmu_template.h"
1267