1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* include/asm-generic/tlb.h 3 * 4 * Generic TLB shootdown code 5 * 6 * Copyright 2001 Red Hat, Inc. 7 * Based on code from mm/memory.c Copyright Linus Torvalds and others. 8 * 9 * Copyright 2011 Red Hat, Inc., Peter Zijlstra 10 */ 11 #ifndef _ASM_GENERIC__TLB_H 12 #define _ASM_GENERIC__TLB_H 13 14 #include <linux/mmu_notifier.h> 15 #include <linux/swap.h> 16 #include <linux/hugetlb_inline.h> 17 #include <asm/tlbflush.h> 18 #include <asm/cacheflush.h> 19 20 /* 21 * Blindly accessing user memory from NMI context can be dangerous 22 * if we're in the middle of switching the current user task or switching 23 * the loaded mm. 24 */ 25 #ifndef nmi_uaccess_okay 26 # define nmi_uaccess_okay() true 27 #endif 28 29 #ifdef CONFIG_MMU 30 31 /* 32 * Generic MMU-gather implementation. 33 * 34 * The mmu_gather data structure is used by the mm code to implement the 35 * correct and efficient ordering of freeing pages and TLB invalidations. 36 * 37 * This correct ordering is: 38 * 39 * 1) unhook page 40 * 2) TLB invalidate page 41 * 3) free page 42 * 43 * That is, we must never free a page before we have ensured there are no live 44 * translations left to it. Otherwise it might be possible to observe (or 45 * worse, change) the page content after it has been reused. 46 * 47 * The mmu_gather API consists of: 48 * 49 * - tlb_gather_mmu() / tlb_gather_mmu_fullmm() / tlb_finish_mmu() 50 * 51 * start and finish a mmu_gather 52 * 53 * Finish in particular will issue a (final) TLB invalidate and free 54 * all (remaining) queued pages. 55 * 56 * - tlb_start_vma() / tlb_end_vma(); marks the start / end of a VMA 57 * 58 * Defaults to flushing at tlb_end_vma() to reset the range; helps when 59 * there's large holes between the VMAs. 60 * 61 * - tlb_remove_table() 62 * 63 * tlb_remove_table() is the basic primitive to free page-table directories 64 * (__p*_free_tlb()). In it's most primitive form it is an alias for 65 * tlb_remove_page() below, for when page directories are pages and have no 66 * additional constraints. 67 * 68 * See also MMU_GATHER_TABLE_FREE and MMU_GATHER_RCU_TABLE_FREE. 69 * 70 * - tlb_remove_page() / tlb_remove_page_size() 71 * - __tlb_remove_folio_pages() / __tlb_remove_page_size() 72 * - __tlb_remove_folio_pages_size() 73 * 74 * __tlb_remove_folio_pages_size() is the basic primitive that queues pages 75 * for freeing. It will return a boolean indicating if the queue is (now) 76 * full and a call to tlb_flush_mmu() is required. 77 * 78 * tlb_remove_page() and tlb_remove_page_size() imply the call to 79 * tlb_flush_mmu() when required and has no return value. 80 * 81 * __tlb_remove_folio_pages() is similar to __tlb_remove_page_size(), 82 * however, instead of removing a single page, assume PAGE_SIZE and remove 83 * the given number of consecutive pages that are all part of the 84 * same (large) folio. 85 * 86 * - tlb_change_page_size() 87 * 88 * call before __tlb_remove_page*() to set the current page-size; implies a 89 * possible tlb_flush_mmu() call. 90 * 91 * - tlb_flush_mmu() / tlb_flush_mmu_tlbonly() 92 * 93 * tlb_flush_mmu_tlbonly() - does the TLB invalidate (and resets 94 * related state, like the range) 95 * 96 * tlb_flush_mmu() - in addition to the above TLB invalidate, also frees 97 * whatever pages are still batched. 98 * 99 * - mmu_gather::fullmm 100 * 101 * A flag set by tlb_gather_mmu_fullmm() to indicate we're going to free 102 * the entire mm; this allows a number of optimizations. 103 * 104 * - We can ignore tlb_{start,end}_vma(); because we don't 105 * care about ranges. Everything will be shot down. 106 * 107 * - (RISC) architectures that use ASIDs can cycle to a new ASID 108 * and delay the invalidation until ASID space runs out. 109 * 110 * - mmu_gather::need_flush_all 111 * 112 * A flag that can be set by the arch code if it wants to force 113 * flush the entire TLB irrespective of the range. For instance 114 * x86-PAE needs this when changing top-level entries. 115 * 116 * And allows the architecture to provide and implement tlb_flush(): 117 * 118 * tlb_flush() may, in addition to the above mentioned mmu_gather fields, make 119 * use of: 120 * 121 * - mmu_gather::start / mmu_gather::end 122 * 123 * which provides the range that needs to be flushed to cover the pages to 124 * be freed. 125 * 126 * - mmu_gather::freed_tables 127 * 128 * set when we freed page table pages 129 * 130 * - tlb_get_unmap_shift() / tlb_get_unmap_size() 131 * 132 * returns the smallest TLB entry size unmapped in this range. 133 * 134 * If an architecture does not provide tlb_flush() a default implementation 135 * based on flush_tlb_range() will be used, unless MMU_GATHER_NO_RANGE is 136 * specified, in which case we'll default to flush_tlb_mm(). 137 * 138 * Additionally there are a few opt-in features: 139 * 140 * MMU_GATHER_PAGE_SIZE 141 * 142 * This ensures we call tlb_flush() every time tlb_change_page_size() actually 143 * changes the size and provides mmu_gather::page_size to tlb_flush(). 144 * 145 * This might be useful if your architecture has size specific TLB 146 * invalidation instructions. 147 * 148 * MMU_GATHER_TABLE_FREE 149 * 150 * This provides tlb_remove_table(), to be used instead of tlb_remove_page() 151 * for page directores (__p*_free_tlb()). 152 * 153 * Useful if your architecture has non-page page directories. 154 * 155 * When used, an architecture is expected to provide __tlb_remove_table() or 156 * use the generic __tlb_remove_table(), which does the actual freeing of these 157 * pages. 158 * 159 * MMU_GATHER_RCU_TABLE_FREE 160 * 161 * Like MMU_GATHER_TABLE_FREE, and adds semi-RCU semantics to the free (see 162 * comment below). 163 * 164 * Useful if your architecture doesn't use IPIs for remote TLB invalidates 165 * and therefore doesn't naturally serialize with software page-table walkers. 166 * 167 * MMU_GATHER_NO_FLUSH_CACHE 168 * 169 * Indicates the architecture has flush_cache_range() but it needs *NOT* be called 170 * before unmapping a VMA. 171 * 172 * NOTE: strictly speaking we shouldn't have this knob and instead rely on 173 * flush_cache_range() being a NOP, except Sparc64 seems to be 174 * different here. 175 * 176 * MMU_GATHER_MERGE_VMAS 177 * 178 * Indicates the architecture wants to merge ranges over VMAs; typical when 179 * multiple range invalidates are more expensive than a full invalidate. 180 * 181 * MMU_GATHER_NO_RANGE 182 * 183 * Use this if your architecture lacks an efficient flush_tlb_range(). This 184 * option implies MMU_GATHER_MERGE_VMAS above. 185 * 186 * MMU_GATHER_NO_GATHER 187 * 188 * If the option is set the mmu_gather will not track individual pages for 189 * delayed page free anymore. A platform that enables the option needs to 190 * provide its own implementation of the __tlb_remove_page_size() function to 191 * free pages. 192 * 193 * This is useful if your architecture already flushes TLB entries in the 194 * various ptep_get_and_clear() functions. 195 */ 196 197 #ifdef CONFIG_MMU_GATHER_TABLE_FREE 198 199 struct mmu_table_batch { 200 #ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE 201 struct rcu_head rcu; 202 #endif 203 unsigned int nr; 204 void *tables[]; 205 }; 206 207 #define MAX_TABLE_BATCH \ 208 ((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *)) 209 210 #ifndef __HAVE_ARCH_TLB_REMOVE_TABLE 211 static inline void __tlb_remove_table(void *table) 212 { 213 struct ptdesc *ptdesc = (struct ptdesc *)table; 214 215 pagetable_dtor_free(ptdesc); 216 } 217 #endif 218 219 extern void tlb_remove_table(struct mmu_gather *tlb, void *table); 220 221 #else /* !CONFIG_MMU_GATHER_TABLE_FREE */ 222 223 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page); 224 /* 225 * Without MMU_GATHER_TABLE_FREE the architecture is assumed to have page based 226 * page directories and we can use the normal page batching to free them. 227 */ 228 static inline void tlb_remove_table(struct mmu_gather *tlb, void *table) 229 { 230 struct page *page = (struct page *)table; 231 232 pagetable_dtor(page_ptdesc(page)); 233 tlb_remove_page(tlb, page); 234 } 235 #endif /* CONFIG_MMU_GATHER_TABLE_FREE */ 236 237 #ifdef CONFIG_MMU_GATHER_RCU_TABLE_FREE 238 /* 239 * This allows an architecture that does not use the linux page-tables for 240 * hardware to skip the TLBI when freeing page tables. 241 */ 242 #ifndef tlb_needs_table_invalidate 243 #define tlb_needs_table_invalidate() (true) 244 #endif 245 246 void tlb_remove_table_sync_one(void); 247 248 #else 249 250 #ifdef tlb_needs_table_invalidate 251 #error tlb_needs_table_invalidate() requires MMU_GATHER_RCU_TABLE_FREE 252 #endif 253 254 static inline void tlb_remove_table_sync_one(void) { } 255 256 #endif /* CONFIG_MMU_GATHER_RCU_TABLE_FREE */ 257 258 259 #ifndef CONFIG_MMU_GATHER_NO_GATHER 260 /* 261 * If we can't allocate a page to make a big batch of page pointers 262 * to work on, then just handle a few from the on-stack structure. 263 */ 264 #define MMU_GATHER_BUNDLE 8 265 266 struct mmu_gather_batch { 267 struct mmu_gather_batch *next; 268 unsigned int nr; 269 unsigned int max; 270 struct encoded_page *encoded_pages[]; 271 }; 272 273 #define MAX_GATHER_BATCH \ 274 ((PAGE_SIZE - sizeof(struct mmu_gather_batch)) / sizeof(void *)) 275 276 /* 277 * Limit the maximum number of mmu_gather batches to reduce a risk of soft 278 * lockups for non-preemptible kernels on huge machines when a lot of memory 279 * is zapped during unmapping. 280 * 10K pages freed at once should be safe even without a preemption point. 281 */ 282 #define MAX_GATHER_BATCH_COUNT (10000UL/MAX_GATHER_BATCH) 283 284 extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, 285 bool delay_rmap, int page_size); 286 bool __tlb_remove_folio_pages(struct mmu_gather *tlb, struct page *page, 287 unsigned int nr_pages, bool delay_rmap); 288 289 #ifdef CONFIG_SMP 290 /* 291 * This both sets 'delayed_rmap', and returns true. It would be an inline 292 * function, except we define it before the 'struct mmu_gather'. 293 */ 294 #define tlb_delay_rmap(tlb) (((tlb)->delayed_rmap = 1), true) 295 extern void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma); 296 #endif 297 298 #endif 299 300 /* 301 * We have a no-op version of the rmap removal that doesn't 302 * delay anything. That is used on S390, which flushes remote 303 * TLBs synchronously, and on UP, which doesn't have any 304 * remote TLBs to flush and is not preemptible due to this 305 * all happening under the page table lock. 306 */ 307 #ifndef tlb_delay_rmap 308 #define tlb_delay_rmap(tlb) (false) 309 static inline void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma) { } 310 #endif 311 312 /* 313 * struct mmu_gather is an opaque type used by the mm code for passing around 314 * any data needed by arch specific code for tlb_remove_page. 315 */ 316 struct mmu_gather { 317 struct mm_struct *mm; 318 319 #ifdef CONFIG_MMU_GATHER_TABLE_FREE 320 struct mmu_table_batch *batch; 321 #endif 322 323 unsigned long start; 324 unsigned long end; 325 /* 326 * we are in the middle of an operation to clear 327 * a full mm and can make some optimizations 328 */ 329 unsigned int fullmm : 1; 330 331 /* 332 * we have performed an operation which 333 * requires a complete flush of the tlb 334 */ 335 unsigned int need_flush_all : 1; 336 337 /* 338 * we have removed page directories 339 */ 340 unsigned int freed_tables : 1; 341 342 /* 343 * Do we have pending delayed rmap removals? 344 */ 345 unsigned int delayed_rmap : 1; 346 347 /* 348 * at which levels have we cleared entries? 349 */ 350 unsigned int cleared_ptes : 1; 351 unsigned int cleared_pmds : 1; 352 unsigned int cleared_puds : 1; 353 unsigned int cleared_p4ds : 1; 354 355 /* 356 * tracks VM_EXEC | VM_HUGETLB in tlb_start_vma 357 */ 358 unsigned int vma_exec : 1; 359 unsigned int vma_huge : 1; 360 unsigned int vma_pfn : 1; 361 362 unsigned int batch_count; 363 364 #ifndef CONFIG_MMU_GATHER_NO_GATHER 365 struct mmu_gather_batch *active; 366 struct mmu_gather_batch local; 367 struct page *__pages[MMU_GATHER_BUNDLE]; 368 369 #ifdef CONFIG_MMU_GATHER_PAGE_SIZE 370 unsigned int page_size; 371 #endif 372 #endif 373 }; 374 375 void tlb_flush_mmu(struct mmu_gather *tlb); 376 377 static inline void __tlb_adjust_range(struct mmu_gather *tlb, 378 unsigned long address, 379 unsigned int range_size) 380 { 381 tlb->start = min(tlb->start, address); 382 tlb->end = max(tlb->end, address + range_size); 383 } 384 385 static inline void __tlb_reset_range(struct mmu_gather *tlb) 386 { 387 if (tlb->fullmm) { 388 tlb->start = tlb->end = ~0; 389 } else { 390 tlb->start = TASK_SIZE; 391 tlb->end = 0; 392 } 393 tlb->freed_tables = 0; 394 tlb->cleared_ptes = 0; 395 tlb->cleared_pmds = 0; 396 tlb->cleared_puds = 0; 397 tlb->cleared_p4ds = 0; 398 /* 399 * Do not reset mmu_gather::vma_* fields here, we do not 400 * call into tlb_start_vma() again to set them if there is an 401 * intermediate flush. 402 */ 403 } 404 405 #ifdef CONFIG_MMU_GATHER_NO_RANGE 406 407 #if defined(tlb_flush) 408 #error MMU_GATHER_NO_RANGE relies on default tlb_flush() 409 #endif 410 411 /* 412 * When an architecture does not have efficient means of range flushing TLBs 413 * there is no point in doing intermediate flushes on tlb_end_vma() to keep the 414 * range small. We equally don't have to worry about page granularity or other 415 * things. 416 * 417 * All we need to do is issue a full flush for any !0 range. 418 */ 419 static inline void tlb_flush(struct mmu_gather *tlb) 420 { 421 if (tlb->end) 422 flush_tlb_mm(tlb->mm); 423 } 424 425 #else /* CONFIG_MMU_GATHER_NO_RANGE */ 426 427 #ifndef tlb_flush 428 /* 429 * When an architecture does not provide its own tlb_flush() implementation 430 * but does have a reasonably efficient flush_vma_range() implementation 431 * use that. 432 */ 433 static inline void tlb_flush(struct mmu_gather *tlb) 434 { 435 if (tlb->fullmm || tlb->need_flush_all) { 436 flush_tlb_mm(tlb->mm); 437 } else if (tlb->end) { 438 struct vm_area_struct vma = { 439 .vm_mm = tlb->mm, 440 .vm_flags = (tlb->vma_exec ? VM_EXEC : 0) | 441 (tlb->vma_huge ? VM_HUGETLB : 0), 442 }; 443 444 flush_tlb_range(&vma, tlb->start, tlb->end); 445 } 446 } 447 #endif 448 449 #endif /* CONFIG_MMU_GATHER_NO_RANGE */ 450 451 static inline void 452 tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) 453 { 454 /* 455 * flush_tlb_range() implementations that look at VM_HUGETLB (tile, 456 * mips-4k) flush only large pages. 457 * 458 * flush_tlb_range() implementations that flush I-TLB also flush D-TLB 459 * (tile, xtensa, arm), so it's ok to just add VM_EXEC to an existing 460 * range. 461 * 462 * We rely on tlb_end_vma() to issue a flush, such that when we reset 463 * these values the batch is empty. 464 */ 465 tlb->vma_huge = is_vm_hugetlb_page(vma); 466 tlb->vma_exec = !!(vma->vm_flags & VM_EXEC); 467 tlb->vma_pfn = !!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)); 468 } 469 470 static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) 471 { 472 /* 473 * Anything calling __tlb_adjust_range() also sets at least one of 474 * these bits. 475 */ 476 if (!(tlb->freed_tables || tlb->cleared_ptes || tlb->cleared_pmds || 477 tlb->cleared_puds || tlb->cleared_p4ds)) 478 return; 479 480 tlb_flush(tlb); 481 __tlb_reset_range(tlb); 482 } 483 484 static inline void tlb_remove_page_size(struct mmu_gather *tlb, 485 struct page *page, int page_size) 486 { 487 if (__tlb_remove_page_size(tlb, page, false, page_size)) 488 tlb_flush_mmu(tlb); 489 } 490 491 static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page) 492 { 493 return tlb_remove_page_size(tlb, page, PAGE_SIZE); 494 } 495 496 static inline void tlb_remove_ptdesc(struct mmu_gather *tlb, void *pt) 497 { 498 tlb_remove_table(tlb, pt); 499 } 500 501 /* Like tlb_remove_ptdesc, but for page-like page directories. */ 502 static inline void tlb_remove_page_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt) 503 { 504 tlb_remove_page(tlb, ptdesc_page(pt)); 505 } 506 507 static inline void tlb_change_page_size(struct mmu_gather *tlb, 508 unsigned int page_size) 509 { 510 #ifdef CONFIG_MMU_GATHER_PAGE_SIZE 511 if (tlb->page_size && tlb->page_size != page_size) { 512 if (!tlb->fullmm && !tlb->need_flush_all) 513 tlb_flush_mmu(tlb); 514 } 515 516 tlb->page_size = page_size; 517 #endif 518 } 519 520 static inline unsigned long tlb_get_unmap_shift(struct mmu_gather *tlb) 521 { 522 if (tlb->cleared_ptes) 523 return PAGE_SHIFT; 524 if (tlb->cleared_pmds) 525 return PMD_SHIFT; 526 if (tlb->cleared_puds) 527 return PUD_SHIFT; 528 if (tlb->cleared_p4ds) 529 return P4D_SHIFT; 530 531 return PAGE_SHIFT; 532 } 533 534 static inline unsigned long tlb_get_unmap_size(struct mmu_gather *tlb) 535 { 536 return 1UL << tlb_get_unmap_shift(tlb); 537 } 538 539 /* 540 * In the case of tlb vma handling, we can optimise these away in the 541 * case where we're doing a full MM flush. When we're doing a munmap, 542 * the vmas are adjusted to only cover the region to be torn down. 543 */ 544 static inline void tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) 545 { 546 if (tlb->fullmm) 547 return; 548 549 tlb_update_vma_flags(tlb, vma); 550 #ifndef CONFIG_MMU_GATHER_NO_FLUSH_CACHE 551 flush_cache_range(vma, vma->vm_start, vma->vm_end); 552 #endif 553 } 554 555 static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) 556 { 557 if (tlb->fullmm) 558 return; 559 560 /* 561 * VM_PFNMAP is more fragile because the core mm will not track the 562 * page mapcount -- there might not be page-frames for these PFNs after 563 * all. Force flush TLBs for such ranges to avoid munmap() vs 564 * unmap_mapping_range() races. 565 */ 566 if (tlb->vma_pfn || !IS_ENABLED(CONFIG_MMU_GATHER_MERGE_VMAS)) { 567 /* 568 * Do a TLB flush and reset the range at VMA boundaries; this avoids 569 * the ranges growing with the unused space between consecutive VMAs. 570 */ 571 tlb_flush_mmu_tlbonly(tlb); 572 } 573 } 574 575 /* 576 * tlb_flush_{pte|pmd|pud|p4d}_range() adjust the tlb->start and tlb->end, 577 * and set corresponding cleared_*. 578 */ 579 static inline void tlb_flush_pte_range(struct mmu_gather *tlb, 580 unsigned long address, unsigned long size) 581 { 582 __tlb_adjust_range(tlb, address, size); 583 tlb->cleared_ptes = 1; 584 } 585 586 static inline void tlb_flush_pmd_range(struct mmu_gather *tlb, 587 unsigned long address, unsigned long size) 588 { 589 __tlb_adjust_range(tlb, address, size); 590 tlb->cleared_pmds = 1; 591 } 592 593 static inline void tlb_flush_pud_range(struct mmu_gather *tlb, 594 unsigned long address, unsigned long size) 595 { 596 __tlb_adjust_range(tlb, address, size); 597 tlb->cleared_puds = 1; 598 } 599 600 static inline void tlb_flush_p4d_range(struct mmu_gather *tlb, 601 unsigned long address, unsigned long size) 602 { 603 __tlb_adjust_range(tlb, address, size); 604 tlb->cleared_p4ds = 1; 605 } 606 607 #ifndef __tlb_remove_tlb_entry 608 static inline void __tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long address) 609 { 610 } 611 #endif 612 613 /** 614 * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation. 615 * 616 * Record the fact that pte's were really unmapped by updating the range, 617 * so we can later optimise away the tlb invalidate. This helps when 618 * userspace is unmapping already-unmapped pages, which happens quite a lot. 619 */ 620 #define tlb_remove_tlb_entry(tlb, ptep, address) \ 621 do { \ 622 tlb_flush_pte_range(tlb, address, PAGE_SIZE); \ 623 __tlb_remove_tlb_entry(tlb, ptep, address); \ 624 } while (0) 625 626 /** 627 * tlb_remove_tlb_entries - remember unmapping of multiple consecutive ptes for 628 * later tlb invalidation. 629 * 630 * Similar to tlb_remove_tlb_entry(), but remember unmapping of multiple 631 * consecutive ptes instead of only a single one. 632 */ 633 static inline void tlb_remove_tlb_entries(struct mmu_gather *tlb, 634 pte_t *ptep, unsigned int nr, unsigned long address) 635 { 636 tlb_flush_pte_range(tlb, address, PAGE_SIZE * nr); 637 for (;;) { 638 __tlb_remove_tlb_entry(tlb, ptep, address); 639 if (--nr == 0) 640 break; 641 ptep++; 642 address += PAGE_SIZE; 643 } 644 } 645 646 #define tlb_remove_huge_tlb_entry(h, tlb, ptep, address) \ 647 do { \ 648 unsigned long _sz = huge_page_size(h); \ 649 if (_sz >= P4D_SIZE) \ 650 tlb_flush_p4d_range(tlb, address, _sz); \ 651 else if (_sz >= PUD_SIZE) \ 652 tlb_flush_pud_range(tlb, address, _sz); \ 653 else if (_sz >= PMD_SIZE) \ 654 tlb_flush_pmd_range(tlb, address, _sz); \ 655 else \ 656 tlb_flush_pte_range(tlb, address, _sz); \ 657 __tlb_remove_tlb_entry(tlb, ptep, address); \ 658 } while (0) 659 660 /** 661 * tlb_remove_pmd_tlb_entry - remember a pmd mapping for later tlb invalidation 662 * This is a nop so far, because only x86 needs it. 663 */ 664 #ifndef __tlb_remove_pmd_tlb_entry 665 #define __tlb_remove_pmd_tlb_entry(tlb, pmdp, address) do {} while (0) 666 #endif 667 668 #define tlb_remove_pmd_tlb_entry(tlb, pmdp, address) \ 669 do { \ 670 tlb_flush_pmd_range(tlb, address, HPAGE_PMD_SIZE); \ 671 __tlb_remove_pmd_tlb_entry(tlb, pmdp, address); \ 672 } while (0) 673 674 /** 675 * tlb_remove_pud_tlb_entry - remember a pud mapping for later tlb 676 * invalidation. This is a nop so far, because only x86 needs it. 677 */ 678 #ifndef __tlb_remove_pud_tlb_entry 679 #define __tlb_remove_pud_tlb_entry(tlb, pudp, address) do {} while (0) 680 #endif 681 682 #define tlb_remove_pud_tlb_entry(tlb, pudp, address) \ 683 do { \ 684 tlb_flush_pud_range(tlb, address, HPAGE_PUD_SIZE); \ 685 __tlb_remove_pud_tlb_entry(tlb, pudp, address); \ 686 } while (0) 687 688 /* 689 * For things like page tables caches (ie caching addresses "inside" the 690 * page tables, like x86 does), for legacy reasons, flushing an 691 * individual page had better flush the page table caches behind it. This 692 * is definitely how x86 works, for example. And if you have an 693 * architected non-legacy page table cache (which I'm not aware of 694 * anybody actually doing), you're going to have some architecturally 695 * explicit flushing for that, likely *separate* from a regular TLB entry 696 * flush, and thus you'd need more than just some range expansion.. 697 * 698 * So if we ever find an architecture 699 * that would want something that odd, I think it is up to that 700 * architecture to do its own odd thing, not cause pain for others 701 * http://lkml.kernel.org/r/CA+55aFzBggoXtNXQeng5d_mRoDnaMBE5Y+URs+PHR67nUpMtaw@mail.gmail.com 702 * 703 * For now w.r.t page table cache, mark the range_size as PAGE_SIZE 704 */ 705 706 #ifndef pte_free_tlb 707 #define pte_free_tlb(tlb, ptep, address) \ 708 do { \ 709 tlb_flush_pmd_range(tlb, address, PAGE_SIZE); \ 710 tlb->freed_tables = 1; \ 711 __pte_free_tlb(tlb, ptep, address); \ 712 } while (0) 713 #endif 714 715 #ifndef pmd_free_tlb 716 #define pmd_free_tlb(tlb, pmdp, address) \ 717 do { \ 718 tlb_flush_pud_range(tlb, address, PAGE_SIZE); \ 719 tlb->freed_tables = 1; \ 720 __pmd_free_tlb(tlb, pmdp, address); \ 721 } while (0) 722 #endif 723 724 #ifndef pud_free_tlb 725 #define pud_free_tlb(tlb, pudp, address) \ 726 do { \ 727 tlb_flush_p4d_range(tlb, address, PAGE_SIZE); \ 728 tlb->freed_tables = 1; \ 729 __pud_free_tlb(tlb, pudp, address); \ 730 } while (0) 731 #endif 732 733 #ifndef p4d_free_tlb 734 #define p4d_free_tlb(tlb, pudp, address) \ 735 do { \ 736 __tlb_adjust_range(tlb, address, PAGE_SIZE); \ 737 tlb->freed_tables = 1; \ 738 __p4d_free_tlb(tlb, pudp, address); \ 739 } while (0) 740 #endif 741 742 #ifndef pte_needs_flush 743 static inline bool pte_needs_flush(pte_t oldpte, pte_t newpte) 744 { 745 return true; 746 } 747 #endif 748 749 #ifndef huge_pmd_needs_flush 750 static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd) 751 { 752 return true; 753 } 754 #endif 755 756 #endif /* CONFIG_MMU */ 757 758 #endif /* _ASM_GENERIC__TLB_H */ 759