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![Andrew Morton](/assets/img/avatar_default.png)
fix CONFIG_MMU=n build Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
606 lines
17 KiB
C
606 lines
17 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef LINUX_MM_INLINE_H
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#define LINUX_MM_INLINE_H
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#include <linux/atomic.h>
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#include <linux/huge_mm.h>
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#include <linux/swap.h>
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#include <linux/string.h>
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#include <linux/userfaultfd_k.h>
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#include <linux/swapops.h>
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/**
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* folio_is_file_lru - Should the folio be on a file LRU or anon LRU?
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* @folio: The folio to test.
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*
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* We would like to get this info without a page flag, but the state
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* needs to survive until the folio is last deleted from the LRU, which
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* could be as far down as __page_cache_release.
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*
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* Return: An integer (not a boolean!) used to sort a folio onto the
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* right LRU list and to account folios correctly.
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* 1 if @folio is a regular filesystem backed page cache folio
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* or a lazily freed anonymous folio (e.g. via MADV_FREE).
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* 0 if @folio is a normal anonymous folio, a tmpfs folio or otherwise
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* ram or swap backed folio.
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*/
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static inline int folio_is_file_lru(struct folio *folio)
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{
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return !folio_test_swapbacked(folio);
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}
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static inline int page_is_file_lru(struct page *page)
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{
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return folio_is_file_lru(page_folio(page));
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}
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static __always_inline void __update_lru_size(struct lruvec *lruvec,
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enum lru_list lru, enum zone_type zid,
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long nr_pages)
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{
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struct pglist_data *pgdat = lruvec_pgdat(lruvec);
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lockdep_assert_held(&lruvec->lru_lock);
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WARN_ON_ONCE(nr_pages != (int)nr_pages);
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__mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
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__mod_zone_page_state(&pgdat->node_zones[zid],
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NR_ZONE_LRU_BASE + lru, nr_pages);
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}
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static __always_inline void update_lru_size(struct lruvec *lruvec,
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enum lru_list lru, enum zone_type zid,
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long nr_pages)
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{
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__update_lru_size(lruvec, lru, zid, nr_pages);
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#ifdef CONFIG_MEMCG
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mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages);
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#endif
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}
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/**
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* __folio_clear_lru_flags - Clear page lru flags before releasing a page.
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* @folio: The folio that was on lru and now has a zero reference.
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*/
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static __always_inline void __folio_clear_lru_flags(struct folio *folio)
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{
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VM_BUG_ON_FOLIO(!folio_test_lru(folio), folio);
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__folio_clear_lru(folio);
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/* this shouldn't happen, so leave the flags to bad_page() */
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if (folio_test_active(folio) && folio_test_unevictable(folio))
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return;
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__folio_clear_active(folio);
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__folio_clear_unevictable(folio);
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}
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/**
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* folio_lru_list - Which LRU list should a folio be on?
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* @folio: The folio to test.
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*
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* Return: The LRU list a folio should be on, as an index
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* into the array of LRU lists.
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*/
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static __always_inline enum lru_list folio_lru_list(struct folio *folio)
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{
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enum lru_list lru;
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VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);
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if (folio_test_unevictable(folio))
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return LRU_UNEVICTABLE;
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lru = folio_is_file_lru(folio) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
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if (folio_test_active(folio))
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lru += LRU_ACTIVE;
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return lru;
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}
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#ifdef CONFIG_LRU_GEN
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#ifdef CONFIG_LRU_GEN_ENABLED
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static inline bool lru_gen_enabled(void)
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{
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DECLARE_STATIC_KEY_TRUE(lru_gen_caps[NR_LRU_GEN_CAPS]);
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return static_branch_likely(&lru_gen_caps[LRU_GEN_CORE]);
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}
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#else
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static inline bool lru_gen_enabled(void)
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{
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DECLARE_STATIC_KEY_FALSE(lru_gen_caps[NR_LRU_GEN_CAPS]);
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return static_branch_unlikely(&lru_gen_caps[LRU_GEN_CORE]);
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}
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#endif
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static inline bool lru_gen_in_fault(void)
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{
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return current->in_lru_fault;
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}
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static inline int lru_gen_from_seq(unsigned long seq)
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{
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return seq % MAX_NR_GENS;
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}
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static inline int lru_hist_from_seq(unsigned long seq)
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{
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return seq % NR_HIST_GENS;
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}
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static inline int lru_tier_from_refs(int refs)
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{
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VM_WARN_ON_ONCE(refs > BIT(LRU_REFS_WIDTH));
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/* see the comment in folio_lru_refs() */
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return order_base_2(refs + 1);
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}
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static inline int folio_lru_refs(struct folio *folio)
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{
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unsigned long flags = READ_ONCE(folio->flags);
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bool workingset = flags & BIT(PG_workingset);
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/*
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* Return the number of accesses beyond PG_referenced, i.e., N-1 if the
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* total number of accesses is N>1, since N=0,1 both map to the first
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* tier. lru_tier_from_refs() will account for this off-by-one. Also see
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* the comment on MAX_NR_TIERS.
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*/
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return ((flags & LRU_REFS_MASK) >> LRU_REFS_PGOFF) + workingset;
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}
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static inline int folio_lru_gen(struct folio *folio)
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{
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unsigned long flags = READ_ONCE(folio->flags);
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return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
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}
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static inline bool lru_gen_is_active(struct lruvec *lruvec, int gen)
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{
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unsigned long max_seq = lruvec->lrugen.max_seq;
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VM_WARN_ON_ONCE(gen >= MAX_NR_GENS);
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/* see the comment on MIN_NR_GENS */
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return gen == lru_gen_from_seq(max_seq) || gen == lru_gen_from_seq(max_seq - 1);
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}
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static inline void lru_gen_update_size(struct lruvec *lruvec, struct folio *folio,
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int old_gen, int new_gen)
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{
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int type = folio_is_file_lru(folio);
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int zone = folio_zonenum(folio);
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int delta = folio_nr_pages(folio);
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enum lru_list lru = type * LRU_INACTIVE_FILE;
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struct lru_gen_folio *lrugen = &lruvec->lrugen;
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VM_WARN_ON_ONCE(old_gen != -1 && old_gen >= MAX_NR_GENS);
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VM_WARN_ON_ONCE(new_gen != -1 && new_gen >= MAX_NR_GENS);
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VM_WARN_ON_ONCE(old_gen == -1 && new_gen == -1);
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if (old_gen >= 0)
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WRITE_ONCE(lrugen->nr_pages[old_gen][type][zone],
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lrugen->nr_pages[old_gen][type][zone] - delta);
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if (new_gen >= 0)
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WRITE_ONCE(lrugen->nr_pages[new_gen][type][zone],
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lrugen->nr_pages[new_gen][type][zone] + delta);
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/* addition */
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if (old_gen < 0) {
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if (lru_gen_is_active(lruvec, new_gen))
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lru += LRU_ACTIVE;
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__update_lru_size(lruvec, lru, zone, delta);
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return;
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}
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/* deletion */
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if (new_gen < 0) {
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if (lru_gen_is_active(lruvec, old_gen))
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lru += LRU_ACTIVE;
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__update_lru_size(lruvec, lru, zone, -delta);
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return;
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}
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/* promotion */
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if (!lru_gen_is_active(lruvec, old_gen) && lru_gen_is_active(lruvec, new_gen)) {
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__update_lru_size(lruvec, lru, zone, -delta);
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__update_lru_size(lruvec, lru + LRU_ACTIVE, zone, delta);
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}
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/* demotion requires isolation, e.g., lru_deactivate_fn() */
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VM_WARN_ON_ONCE(lru_gen_is_active(lruvec, old_gen) && !lru_gen_is_active(lruvec, new_gen));
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}
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static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
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{
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unsigned long seq;
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unsigned long flags;
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int gen = folio_lru_gen(folio);
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int type = folio_is_file_lru(folio);
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int zone = folio_zonenum(folio);
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struct lru_gen_folio *lrugen = &lruvec->lrugen;
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VM_WARN_ON_ONCE_FOLIO(gen != -1, folio);
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if (folio_test_unevictable(folio) || !lrugen->enabled)
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return false;
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/*
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* There are three common cases for this page:
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* 1. If it's hot, e.g., freshly faulted in or previously hot and
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* migrated, add it to the youngest generation.
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* 2. If it's cold but can't be evicted immediately, i.e., an anon page
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* not in swapcache or a dirty page pending writeback, add it to the
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* second oldest generation.
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* 3. Everything else (clean, cold) is added to the oldest generation.
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*/
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if (folio_test_active(folio))
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seq = lrugen->max_seq;
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else if ((type == LRU_GEN_ANON && !folio_test_swapcache(folio)) ||
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(folio_test_reclaim(folio) &&
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(folio_test_dirty(folio) || folio_test_writeback(folio))))
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seq = lrugen->min_seq[type] + 1;
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else
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seq = lrugen->min_seq[type];
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gen = lru_gen_from_seq(seq);
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flags = (gen + 1UL) << LRU_GEN_PGOFF;
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/* see the comment on MIN_NR_GENS about PG_active */
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set_mask_bits(&folio->flags, LRU_GEN_MASK | BIT(PG_active), flags);
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lru_gen_update_size(lruvec, folio, -1, gen);
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/* for folio_rotate_reclaimable() */
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if (reclaiming)
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list_add_tail(&folio->lru, &lrugen->folios[gen][type][zone]);
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else
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list_add(&folio->lru, &lrugen->folios[gen][type][zone]);
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return true;
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}
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static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
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{
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unsigned long flags;
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int gen = folio_lru_gen(folio);
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if (gen < 0)
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return false;
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VM_WARN_ON_ONCE_FOLIO(folio_test_active(folio), folio);
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VM_WARN_ON_ONCE_FOLIO(folio_test_unevictable(folio), folio);
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/* for folio_migrate_flags() */
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flags = !reclaiming && lru_gen_is_active(lruvec, gen) ? BIT(PG_active) : 0;
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flags = set_mask_bits(&folio->flags, LRU_GEN_MASK, flags);
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gen = ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
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lru_gen_update_size(lruvec, folio, gen, -1);
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list_del(&folio->lru);
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return true;
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}
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#else /* !CONFIG_LRU_GEN */
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static inline bool lru_gen_enabled(void)
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{
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return false;
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}
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static inline bool lru_gen_in_fault(void)
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{
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return false;
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}
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static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
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{
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return false;
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}
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static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
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{
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return false;
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}
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#endif /* CONFIG_LRU_GEN */
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static __always_inline
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void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
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{
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enum lru_list lru = folio_lru_list(folio);
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if (lru_gen_add_folio(lruvec, folio, false))
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return;
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update_lru_size(lruvec, lru, folio_zonenum(folio),
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folio_nr_pages(folio));
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if (lru != LRU_UNEVICTABLE)
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list_add(&folio->lru, &lruvec->lists[lru]);
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}
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static __always_inline
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void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
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{
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enum lru_list lru = folio_lru_list(folio);
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if (lru_gen_add_folio(lruvec, folio, true))
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return;
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update_lru_size(lruvec, lru, folio_zonenum(folio),
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folio_nr_pages(folio));
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/* This is not expected to be used on LRU_UNEVICTABLE */
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list_add_tail(&folio->lru, &lruvec->lists[lru]);
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}
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static __always_inline
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void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
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{
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enum lru_list lru = folio_lru_list(folio);
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if (lru_gen_del_folio(lruvec, folio, false))
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return;
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if (lru != LRU_UNEVICTABLE)
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list_del(&folio->lru);
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update_lru_size(lruvec, lru, folio_zonenum(folio),
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-folio_nr_pages(folio));
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}
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#ifdef CONFIG_ANON_VMA_NAME
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/*
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* mmap_lock should be read-locked when calling anon_vma_name(). Caller should
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* either keep holding the lock while using the returned pointer or it should
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* raise anon_vma_name refcount before releasing the lock.
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*/
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extern struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma);
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extern struct anon_vma_name *anon_vma_name_alloc(const char *name);
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extern void anon_vma_name_free(struct kref *kref);
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/* mmap_lock should be read-locked */
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static inline void anon_vma_name_get(struct anon_vma_name *anon_name)
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{
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if (anon_name)
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kref_get(&anon_name->kref);
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}
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static inline void anon_vma_name_put(struct anon_vma_name *anon_name)
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{
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if (anon_name)
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kref_put(&anon_name->kref, anon_vma_name_free);
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}
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static inline
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struct anon_vma_name *anon_vma_name_reuse(struct anon_vma_name *anon_name)
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{
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/* Prevent anon_name refcount saturation early on */
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if (kref_read(&anon_name->kref) < REFCOUNT_MAX) {
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anon_vma_name_get(anon_name);
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return anon_name;
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}
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return anon_vma_name_alloc(anon_name->name);
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}
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static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
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struct vm_area_struct *new_vma)
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{
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struct anon_vma_name *anon_name = anon_vma_name(orig_vma);
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if (anon_name)
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new_vma->anon_name = anon_vma_name_reuse(anon_name);
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}
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static inline void free_anon_vma_name(struct vm_area_struct *vma)
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{
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/*
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* Not using anon_vma_name because it generates a warning if mmap_lock
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* is not held, which might be the case here.
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*/
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anon_vma_name_put(vma->anon_name);
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}
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static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
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struct anon_vma_name *anon_name2)
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{
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if (anon_name1 == anon_name2)
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return true;
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return anon_name1 && anon_name2 &&
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!strcmp(anon_name1->name, anon_name2->name);
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}
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#else /* CONFIG_ANON_VMA_NAME */
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static inline struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma)
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{
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return NULL;
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}
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static inline struct anon_vma_name *anon_vma_name_alloc(const char *name)
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{
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return NULL;
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}
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static inline void anon_vma_name_get(struct anon_vma_name *anon_name) {}
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static inline void anon_vma_name_put(struct anon_vma_name *anon_name) {}
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static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
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struct vm_area_struct *new_vma) {}
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static inline void free_anon_vma_name(struct vm_area_struct *vma) {}
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static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
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struct anon_vma_name *anon_name2)
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{
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return true;
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}
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#endif /* CONFIG_ANON_VMA_NAME */
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static inline void init_tlb_flush_pending(struct mm_struct *mm)
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{
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atomic_set(&mm->tlb_flush_pending, 0);
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}
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static inline void inc_tlb_flush_pending(struct mm_struct *mm)
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{
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atomic_inc(&mm->tlb_flush_pending);
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/*
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* The only time this value is relevant is when there are indeed pages
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* to flush. And we'll only flush pages after changing them, which
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* requires the PTL.
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*
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* So the ordering here is:
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*
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* atomic_inc(&mm->tlb_flush_pending);
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* spin_lock(&ptl);
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* ...
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* set_pte_at();
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* spin_unlock(&ptl);
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*
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* spin_lock(&ptl)
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* mm_tlb_flush_pending();
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* ....
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* spin_unlock(&ptl);
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|
*
|
|
* flush_tlb_range();
|
|
* atomic_dec(&mm->tlb_flush_pending);
|
|
*
|
|
* Where the increment if constrained by the PTL unlock, it thus
|
|
* ensures that the increment is visible if the PTE modification is
|
|
* visible. After all, if there is no PTE modification, nobody cares
|
|
* about TLB flushes either.
|
|
*
|
|
* This very much relies on users (mm_tlb_flush_pending() and
|
|
* mm_tlb_flush_nested()) only caring about _specific_ PTEs (and
|
|
* therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc
|
|
* locks (PPC) the unlock of one doesn't order against the lock of
|
|
* another PTL.
|
|
*
|
|
* The decrement is ordered by the flush_tlb_range(), such that
|
|
* mm_tlb_flush_pending() will not return false unless all flushes have
|
|
* completed.
|
|
*/
|
|
}
|
|
|
|
static inline void dec_tlb_flush_pending(struct mm_struct *mm)
|
|
{
|
|
/*
|
|
* See inc_tlb_flush_pending().
|
|
*
|
|
* This cannot be smp_mb__before_atomic() because smp_mb() simply does
|
|
* not order against TLB invalidate completion, which is what we need.
|
|
*
|
|
* Therefore we must rely on tlb_flush_*() to guarantee order.
|
|
*/
|
|
atomic_dec(&mm->tlb_flush_pending);
|
|
}
|
|
|
|
static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
|
|
{
|
|
/*
|
|
* Must be called after having acquired the PTL; orders against that
|
|
* PTLs release and therefore ensures that if we observe the modified
|
|
* PTE we must also observe the increment from inc_tlb_flush_pending().
|
|
*
|
|
* That is, it only guarantees to return true if there is a flush
|
|
* pending for _this_ PTL.
|
|
*/
|
|
return atomic_read(&mm->tlb_flush_pending);
|
|
}
|
|
|
|
static inline bool mm_tlb_flush_nested(struct mm_struct *mm)
|
|
{
|
|
/*
|
|
* Similar to mm_tlb_flush_pending(), we must have acquired the PTL
|
|
* for which there is a TLB flush pending in order to guarantee
|
|
* we've seen both that PTE modification and the increment.
|
|
*
|
|
* (no requirement on actually still holding the PTL, that is irrelevant)
|
|
*/
|
|
return atomic_read(&mm->tlb_flush_pending) > 1;
|
|
}
|
|
|
|
#ifdef CONFIG_MMU
|
|
/*
|
|
* Computes the pte marker to copy from the given source entry into dst_vma.
|
|
* If no marker should be copied, returns 0.
|
|
* The caller should insert a new pte created with make_pte_marker().
|
|
*/
|
|
static inline pte_marker copy_pte_marker(
|
|
swp_entry_t entry, struct vm_area_struct *dst_vma)
|
|
{
|
|
pte_marker srcm = pte_marker_get(entry);
|
|
/* Always copy error entries. */
|
|
pte_marker dstm = srcm & PTE_MARKER_POISONED;
|
|
|
|
/* Only copy PTE markers if UFFD register matches. */
|
|
if ((srcm & PTE_MARKER_UFFD_WP) && userfaultfd_wp(dst_vma))
|
|
dstm |= PTE_MARKER_UFFD_WP;
|
|
|
|
return dstm;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* If this pte is wr-protected by uffd-wp in any form, arm the special pte to
|
|
* replace a none pte. NOTE! This should only be called when *pte is already
|
|
* cleared so we will never accidentally replace something valuable. Meanwhile
|
|
* none pte also means we are not demoting the pte so tlb flushed is not needed.
|
|
* E.g., when pte cleared the caller should have taken care of the tlb flush.
|
|
*
|
|
* Must be called with pgtable lock held so that no thread will see the none
|
|
* pte, and if they see it, they'll fault and serialize at the pgtable lock.
|
|
*
|
|
* This function is a no-op if PTE_MARKER_UFFD_WP is not enabled.
|
|
*/
|
|
static inline void
|
|
pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr,
|
|
pte_t *pte, pte_t pteval)
|
|
{
|
|
#ifdef CONFIG_PTE_MARKER_UFFD_WP
|
|
bool arm_uffd_pte = false;
|
|
|
|
/* The current status of the pte should be "cleared" before calling */
|
|
WARN_ON_ONCE(!pte_none(ptep_get(pte)));
|
|
|
|
/*
|
|
* NOTE: userfaultfd_wp_unpopulated() doesn't need this whole
|
|
* thing, because when zapping either it means it's dropping the
|
|
* page, or in TTU where the present pte will be quickly replaced
|
|
* with a swap pte. There's no way of leaking the bit.
|
|
*/
|
|
if (vma_is_anonymous(vma) || !userfaultfd_wp(vma))
|
|
return;
|
|
|
|
/* A uffd-wp wr-protected normal pte */
|
|
if (unlikely(pte_present(pteval) && pte_uffd_wp(pteval)))
|
|
arm_uffd_pte = true;
|
|
|
|
/*
|
|
* A uffd-wp wr-protected swap pte. Note: this should even cover an
|
|
* existing pte marker with uffd-wp bit set.
|
|
*/
|
|
if (unlikely(pte_swp_uffd_wp_any(pteval)))
|
|
arm_uffd_pte = true;
|
|
|
|
if (unlikely(arm_uffd_pte))
|
|
set_pte_at(vma->vm_mm, addr, pte,
|
|
make_pte_marker(PTE_MARKER_UFFD_WP));
|
|
#endif
|
|
}
|
|
|
|
static inline bool vma_has_recency(struct vm_area_struct *vma)
|
|
{
|
|
if (vma->vm_flags & (VM_SEQ_READ | VM_RAND_READ))
|
|
return false;
|
|
|
|
if (vma->vm_file && (vma->vm_file->f_mode & FMODE_NOREUSE))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
#endif
|