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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef LINUX_MM_INLINE_H3#define LINUX_MM_INLINE_H4 5#include <linux/atomic.h>6#include <linux/huge_mm.h>7#include <linux/mm_types.h>8#include <linux/swap.h>9#include <linux/string.h>10#include <linux/userfaultfd_k.h>11#include <linux/swapops.h>12 13/**14 * folio_is_file_lru - Should the folio be on a file LRU or anon LRU?15 * @folio: The folio to test.16 *17 * We would like to get this info without a page flag, but the state18 * needs to survive until the folio is last deleted from the LRU, which19 * could be as far down as __page_cache_release.20 *21 * Return: An integer (not a boolean!) used to sort a folio onto the22 * right LRU list and to account folios correctly.23 * 1 if @folio is a regular filesystem backed page cache folio24 * or a lazily freed anonymous folio (e.g. via MADV_FREE).25 * 0 if @folio is a normal anonymous folio, a tmpfs folio or otherwise26 * ram or swap backed folio.27 */28static inline int folio_is_file_lru(struct folio *folio)29{30 return !folio_test_swapbacked(folio);31}32 33static inline int page_is_file_lru(struct page *page)34{35 return folio_is_file_lru(page_folio(page));36}37 38static __always_inline void __update_lru_size(struct lruvec *lruvec,39 enum lru_list lru, enum zone_type zid,40 long nr_pages)41{42 struct pglist_data *pgdat = lruvec_pgdat(lruvec);43 44 lockdep_assert_held(&lruvec->lru_lock);45 WARN_ON_ONCE(nr_pages != (int)nr_pages);46 47 __mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);48 __mod_zone_page_state(&pgdat->node_zones[zid],49 NR_ZONE_LRU_BASE + lru, nr_pages);50}51 52static __always_inline void update_lru_size(struct lruvec *lruvec,53 enum lru_list lru, enum zone_type zid,54 long nr_pages)55{56 __update_lru_size(lruvec, lru, zid, nr_pages);57#ifdef CONFIG_MEMCG58 mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages);59#endif60}61 62/**63 * __folio_clear_lru_flags - Clear page lru flags before releasing a page.64 * @folio: The folio that was on lru and now has a zero reference.65 */66static __always_inline void __folio_clear_lru_flags(struct folio *folio)67{68 VM_BUG_ON_FOLIO(!folio_test_lru(folio), folio);69 70 __folio_clear_lru(folio);71 72 /* this shouldn't happen, so leave the flags to bad_page() */73 if (folio_test_active(folio) && folio_test_unevictable(folio))74 return;75 76 __folio_clear_active(folio);77 __folio_clear_unevictable(folio);78}79 80/**81 * folio_lru_list - Which LRU list should a folio be on?82 * @folio: The folio to test.83 *84 * Return: The LRU list a folio should be on, as an index85 * into the array of LRU lists.86 */87static __always_inline enum lru_list folio_lru_list(struct folio *folio)88{89 enum lru_list lru;90 91 VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);92 93 if (folio_test_unevictable(folio))94 return LRU_UNEVICTABLE;95 96 lru = folio_is_file_lru(folio) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;97 if (folio_test_active(folio))98 lru += LRU_ACTIVE;99 100 return lru;101}102 103#ifdef CONFIG_LRU_GEN104 105#ifdef CONFIG_LRU_GEN_ENABLED106static inline bool lru_gen_enabled(void)107{108 DECLARE_STATIC_KEY_TRUE(lru_gen_caps[NR_LRU_GEN_CAPS]);109 110 return static_branch_likely(&lru_gen_caps[LRU_GEN_CORE]);111}112#else113static inline bool lru_gen_enabled(void)114{115 DECLARE_STATIC_KEY_FALSE(lru_gen_caps[NR_LRU_GEN_CAPS]);116 117 return static_branch_unlikely(&lru_gen_caps[LRU_GEN_CORE]);118}119#endif120 121static inline bool lru_gen_in_fault(void)122{123 return current->in_lru_fault;124}125 126static inline int lru_gen_from_seq(unsigned long seq)127{128 return seq % MAX_NR_GENS;129}130 131static inline int lru_hist_from_seq(unsigned long seq)132{133 return seq % NR_HIST_GENS;134}135 136static inline int lru_tier_from_refs(int refs)137{138 VM_WARN_ON_ONCE(refs > BIT(LRU_REFS_WIDTH));139 140 /* see the comment in folio_lru_refs() */141 return order_base_2(refs + 1);142}143 144static inline int folio_lru_refs(struct folio *folio)145{146 unsigned long flags = READ_ONCE(folio->flags);147 bool workingset = flags & BIT(PG_workingset);148 149 /*150 * Return the number of accesses beyond PG_referenced, i.e., N-1 if the151 * total number of accesses is N>1, since N=0,1 both map to the first152 * tier. lru_tier_from_refs() will account for this off-by-one. Also see153 * the comment on MAX_NR_TIERS.154 */155 return ((flags & LRU_REFS_MASK) >> LRU_REFS_PGOFF) + workingset;156}157 158static inline int folio_lru_gen(struct folio *folio)159{160 unsigned long flags = READ_ONCE(folio->flags);161 162 return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;163}164 165static inline bool lru_gen_is_active(struct lruvec *lruvec, int gen)166{167 unsigned long max_seq = lruvec->lrugen.max_seq;168 169 VM_WARN_ON_ONCE(gen >= MAX_NR_GENS);170 171 /* see the comment on MIN_NR_GENS */172 return gen == lru_gen_from_seq(max_seq) || gen == lru_gen_from_seq(max_seq - 1);173}174 175static inline void lru_gen_update_size(struct lruvec *lruvec, struct folio *folio,176 int old_gen, int new_gen)177{178 int type = folio_is_file_lru(folio);179 int zone = folio_zonenum(folio);180 int delta = folio_nr_pages(folio);181 enum lru_list lru = type * LRU_INACTIVE_FILE;182 struct lru_gen_folio *lrugen = &lruvec->lrugen;183 184 VM_WARN_ON_ONCE(old_gen != -1 && old_gen >= MAX_NR_GENS);185 VM_WARN_ON_ONCE(new_gen != -1 && new_gen >= MAX_NR_GENS);186 VM_WARN_ON_ONCE(old_gen == -1 && new_gen == -1);187 188 if (old_gen >= 0)189 WRITE_ONCE(lrugen->nr_pages[old_gen][type][zone],190 lrugen->nr_pages[old_gen][type][zone] - delta);191 if (new_gen >= 0)192 WRITE_ONCE(lrugen->nr_pages[new_gen][type][zone],193 lrugen->nr_pages[new_gen][type][zone] + delta);194 195 /* addition */196 if (old_gen < 0) {197 if (lru_gen_is_active(lruvec, new_gen))198 lru += LRU_ACTIVE;199 __update_lru_size(lruvec, lru, zone, delta);200 return;201 }202 203 /* deletion */204 if (new_gen < 0) {205 if (lru_gen_is_active(lruvec, old_gen))206 lru += LRU_ACTIVE;207 __update_lru_size(lruvec, lru, zone, -delta);208 return;209 }210 211 /* promotion */212 if (!lru_gen_is_active(lruvec, old_gen) && lru_gen_is_active(lruvec, new_gen)) {213 __update_lru_size(lruvec, lru, zone, -delta);214 __update_lru_size(lruvec, lru + LRU_ACTIVE, zone, delta);215 }216 217 /* demotion requires isolation, e.g., lru_deactivate_fn() */218 VM_WARN_ON_ONCE(lru_gen_is_active(lruvec, old_gen) && !lru_gen_is_active(lruvec, new_gen));219}220 221static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)222{223 unsigned long seq;224 unsigned long flags;225 int gen = folio_lru_gen(folio);226 int type = folio_is_file_lru(folio);227 int zone = folio_zonenum(folio);228 struct lru_gen_folio *lrugen = &lruvec->lrugen;229 230 VM_WARN_ON_ONCE_FOLIO(gen != -1, folio);231 232 if (folio_test_unevictable(folio) || !lrugen->enabled)233 return false;234 /*235 * There are four common cases for this page:236 * 1. If it's hot, i.e., freshly faulted in, add it to the youngest237 * generation, and it's protected over the rest below.238 * 2. If it can't be evicted immediately, i.e., a dirty page pending239 * writeback, add it to the second youngest generation.240 * 3. If it should be evicted first, e.g., cold and clean from241 * folio_rotate_reclaimable(), add it to the oldest generation.242 * 4. Everything else falls between 2 & 3 above and is added to the243 * second oldest generation if it's considered inactive, or the244 * oldest generation otherwise. See lru_gen_is_active().245 */246 if (folio_test_active(folio))247 seq = lrugen->max_seq;248 else if ((type == LRU_GEN_ANON && !folio_test_swapcache(folio)) ||249 (folio_test_reclaim(folio) &&250 (folio_test_dirty(folio) || folio_test_writeback(folio))))251 seq = lrugen->max_seq - 1;252 else if (reclaiming || lrugen->min_seq[type] + MIN_NR_GENS >= lrugen->max_seq)253 seq = lrugen->min_seq[type];254 else255 seq = lrugen->min_seq[type] + 1;256 257 gen = lru_gen_from_seq(seq);258 flags = (gen + 1UL) << LRU_GEN_PGOFF;259 /* see the comment on MIN_NR_GENS about PG_active */260 set_mask_bits(&folio->flags, LRU_GEN_MASK | BIT(PG_active), flags);261 262 lru_gen_update_size(lruvec, folio, -1, gen);263 /* for folio_rotate_reclaimable() */264 if (reclaiming)265 list_add_tail(&folio->lru, &lrugen->folios[gen][type][zone]);266 else267 list_add(&folio->lru, &lrugen->folios[gen][type][zone]);268 269 return true;270}271 272static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)273{274 unsigned long flags;275 int gen = folio_lru_gen(folio);276 277 if (gen < 0)278 return false;279 280 VM_WARN_ON_ONCE_FOLIO(folio_test_active(folio), folio);281 VM_WARN_ON_ONCE_FOLIO(folio_test_unevictable(folio), folio);282 283 /* for folio_migrate_flags() */284 flags = !reclaiming && lru_gen_is_active(lruvec, gen) ? BIT(PG_active) : 0;285 flags = set_mask_bits(&folio->flags, LRU_GEN_MASK, flags);286 gen = ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;287 288 lru_gen_update_size(lruvec, folio, gen, -1);289 list_del(&folio->lru);290 291 return true;292}293 294#else /* !CONFIG_LRU_GEN */295 296static inline bool lru_gen_enabled(void)297{298 return false;299}300 301static inline bool lru_gen_in_fault(void)302{303 return false;304}305 306static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)307{308 return false;309}310 311static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)312{313 return false;314}315 316#endif /* CONFIG_LRU_GEN */317 318static __always_inline319void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)320{321 enum lru_list lru = folio_lru_list(folio);322 323 if (lru_gen_add_folio(lruvec, folio, false))324 return;325 326 update_lru_size(lruvec, lru, folio_zonenum(folio),327 folio_nr_pages(folio));328 if (lru != LRU_UNEVICTABLE)329 list_add(&folio->lru, &lruvec->lists[lru]);330}331 332static __always_inline333void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)334{335 enum lru_list lru = folio_lru_list(folio);336 337 if (lru_gen_add_folio(lruvec, folio, true))338 return;339 340 update_lru_size(lruvec, lru, folio_zonenum(folio),341 folio_nr_pages(folio));342 /* This is not expected to be used on LRU_UNEVICTABLE */343 list_add_tail(&folio->lru, &lruvec->lists[lru]);344}345 346static __always_inline347void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)348{349 enum lru_list lru = folio_lru_list(folio);350 351 if (lru_gen_del_folio(lruvec, folio, false))352 return;353 354 if (lru != LRU_UNEVICTABLE)355 list_del(&folio->lru);356 update_lru_size(lruvec, lru, folio_zonenum(folio),357 -folio_nr_pages(folio));358}359 360#ifdef CONFIG_ANON_VMA_NAME361/* mmap_lock should be read-locked */362static inline void anon_vma_name_get(struct anon_vma_name *anon_name)363{364 if (anon_name)365 kref_get(&anon_name->kref);366}367 368static inline void anon_vma_name_put(struct anon_vma_name *anon_name)369{370 if (anon_name)371 kref_put(&anon_name->kref, anon_vma_name_free);372}373 374static inline375struct anon_vma_name *anon_vma_name_reuse(struct anon_vma_name *anon_name)376{377 /* Prevent anon_name refcount saturation early on */378 if (kref_read(&anon_name->kref) < REFCOUNT_MAX) {379 anon_vma_name_get(anon_name);380 return anon_name;381 382 }383 return anon_vma_name_alloc(anon_name->name);384}385 386static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,387 struct vm_area_struct *new_vma)388{389 struct anon_vma_name *anon_name = anon_vma_name(orig_vma);390 391 if (anon_name)392 new_vma->anon_name = anon_vma_name_reuse(anon_name);393}394 395static inline void free_anon_vma_name(struct vm_area_struct *vma)396{397 /*398 * Not using anon_vma_name because it generates a warning if mmap_lock399 * is not held, which might be the case here.400 */401 anon_vma_name_put(vma->anon_name);402}403 404static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,405 struct anon_vma_name *anon_name2)406{407 if (anon_name1 == anon_name2)408 return true;409 410 return anon_name1 && anon_name2 &&411 !strcmp(anon_name1->name, anon_name2->name);412}413 414#else /* CONFIG_ANON_VMA_NAME */415static inline void anon_vma_name_get(struct anon_vma_name *anon_name) {}416static inline void anon_vma_name_put(struct anon_vma_name *anon_name) {}417static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,418 struct vm_area_struct *new_vma) {}419static inline void free_anon_vma_name(struct vm_area_struct *vma) {}420 421static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,422 struct anon_vma_name *anon_name2)423{424 return true;425}426 427#endif /* CONFIG_ANON_VMA_NAME */428 429static inline void init_tlb_flush_pending(struct mm_struct *mm)430{431 atomic_set(&mm->tlb_flush_pending, 0);432}433 434static inline void inc_tlb_flush_pending(struct mm_struct *mm)435{436 atomic_inc(&mm->tlb_flush_pending);437 /*438 * The only time this value is relevant is when there are indeed pages439 * to flush. And we'll only flush pages after changing them, which440 * requires the PTL.441 *442 * So the ordering here is:443 *444 * atomic_inc(&mm->tlb_flush_pending);445 * spin_lock(&ptl);446 * ...447 * set_pte_at();448 * spin_unlock(&ptl);449 *450 * spin_lock(&ptl)451 * mm_tlb_flush_pending();452 * ....453 * spin_unlock(&ptl);454 *455 * flush_tlb_range();456 * atomic_dec(&mm->tlb_flush_pending);457 *458 * Where the increment if constrained by the PTL unlock, it thus459 * ensures that the increment is visible if the PTE modification is460 * visible. After all, if there is no PTE modification, nobody cares461 * about TLB flushes either.462 *463 * This very much relies on users (mm_tlb_flush_pending() and464 * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and465 * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc466 * locks (PPC) the unlock of one doesn't order against the lock of467 * another PTL.468 *469 * The decrement is ordered by the flush_tlb_range(), such that470 * mm_tlb_flush_pending() will not return false unless all flushes have471 * completed.472 */473}474 475static inline void dec_tlb_flush_pending(struct mm_struct *mm)476{477 /*478 * See inc_tlb_flush_pending().479 *480 * This cannot be smp_mb__before_atomic() because smp_mb() simply does481 * not order against TLB invalidate completion, which is what we need.482 *483 * Therefore we must rely on tlb_flush_*() to guarantee order.484 */485 atomic_dec(&mm->tlb_flush_pending);486}487 488static inline bool mm_tlb_flush_pending(struct mm_struct *mm)489{490 /*491 * Must be called after having acquired the PTL; orders against that492 * PTLs release and therefore ensures that if we observe the modified493 * PTE we must also observe the increment from inc_tlb_flush_pending().494 *495 * That is, it only guarantees to return true if there is a flush496 * pending for _this_ PTL.497 */498 return atomic_read(&mm->tlb_flush_pending);499}500 501static inline bool mm_tlb_flush_nested(struct mm_struct *mm)502{503 /*504 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL505 * for which there is a TLB flush pending in order to guarantee506 * we've seen both that PTE modification and the increment.507 *508 * (no requirement on actually still holding the PTL, that is irrelevant)509 */510 return atomic_read(&mm->tlb_flush_pending) > 1;511}512 513#ifdef CONFIG_MMU514/*515 * Computes the pte marker to copy from the given source entry into dst_vma.516 * If no marker should be copied, returns 0.517 * The caller should insert a new pte created with make_pte_marker().518 */519static inline pte_marker copy_pte_marker(520 swp_entry_t entry, struct vm_area_struct *dst_vma)521{522 pte_marker srcm = pte_marker_get(entry);523 /* Always copy error entries. */524 pte_marker dstm = srcm & PTE_MARKER_POISONED;525 526 /* Only copy PTE markers if UFFD register matches. */527 if ((srcm & PTE_MARKER_UFFD_WP) && userfaultfd_wp(dst_vma))528 dstm |= PTE_MARKER_UFFD_WP;529 530 return dstm;531}532#endif533 534/*535 * If this pte is wr-protected by uffd-wp in any form, arm the special pte to536 * replace a none pte. NOTE! This should only be called when *pte is already537 * cleared so we will never accidentally replace something valuable. Meanwhile538 * none pte also means we are not demoting the pte so tlb flushed is not needed.539 * E.g., when pte cleared the caller should have taken care of the tlb flush.540 *541 * Must be called with pgtable lock held so that no thread will see the none542 * pte, and if they see it, they'll fault and serialize at the pgtable lock.543 *544 * This function is a no-op if PTE_MARKER_UFFD_WP is not enabled.545 */546static inline void547pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr,548 pte_t *pte, pte_t pteval)549{550#ifdef CONFIG_PTE_MARKER_UFFD_WP551 bool arm_uffd_pte = false;552 553 /* The current status of the pte should be "cleared" before calling */554 WARN_ON_ONCE(!pte_none(ptep_get(pte)));555 556 /*557 * NOTE: userfaultfd_wp_unpopulated() doesn't need this whole558 * thing, because when zapping either it means it's dropping the559 * page, or in TTU where the present pte will be quickly replaced560 * with a swap pte. There's no way of leaking the bit.561 */562 if (vma_is_anonymous(vma) || !userfaultfd_wp(vma))563 return;564 565 /* A uffd-wp wr-protected normal pte */566 if (unlikely(pte_present(pteval) && pte_uffd_wp(pteval)))567 arm_uffd_pte = true;568 569 /*570 * A uffd-wp wr-protected swap pte. Note: this should even cover an571 * existing pte marker with uffd-wp bit set.572 */573 if (unlikely(pte_swp_uffd_wp_any(pteval)))574 arm_uffd_pte = true;575 576 if (unlikely(arm_uffd_pte))577 set_pte_at(vma->vm_mm, addr, pte,578 make_pte_marker(PTE_MARKER_UFFD_WP));579#endif580}581 582static inline bool vma_has_recency(struct vm_area_struct *vma)583{584 if (vma->vm_flags & (VM_SEQ_READ | VM_RAND_READ))585 return false;586 587 if (vma->vm_file && (vma->vm_file->f_mode & FMODE_NOREUSE))588 return false;589 590 return true;591}592 593#endif594