Current File : //usr/lib/modules/6.8.0-45-generic/build/include/linux/mm_inline.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef LINUX_MM_INLINE_H
#define LINUX_MM_INLINE_H
#include <linux/atomic.h>
#include <linux/huge_mm.h>
#include <linux/mm_types.h>
#include <linux/swap.h>
#include <linux/string.h>
#include <linux/userfaultfd_k.h>
#include <linux/swapops.h>
/**
* folio_is_file_lru - Should the folio be on a file LRU or anon LRU?
* @folio: The folio to test.
*
* We would like to get this info without a page flag, but the state
* needs to survive until the folio is last deleted from the LRU, which
* could be as far down as __page_cache_release.
*
* Return: An integer (not a boolean!) used to sort a folio onto the
* right LRU list and to account folios correctly.
* 1 if @folio is a regular filesystem backed page cache folio
* or a lazily freed anonymous folio (e.g. via MADV_FREE).
* 0 if @folio is a normal anonymous folio, a tmpfs folio or otherwise
* ram or swap backed folio.
*/
static inline int folio_is_file_lru(struct folio *folio)
{
return !folio_test_swapbacked(folio);
}
static inline int page_is_file_lru(struct page *page)
{
return folio_is_file_lru(page_folio(page));
}
static __always_inline void __update_lru_size(struct lruvec *lruvec,
enum lru_list lru, enum zone_type zid,
long nr_pages)
{
struct pglist_data *pgdat = lruvec_pgdat(lruvec);
lockdep_assert_held(&lruvec->lru_lock);
WARN_ON_ONCE(nr_pages != (int)nr_pages);
__mod_lruvec_state(lruvec, NR_LRU_BASE + lru, nr_pages);
__mod_zone_page_state(&pgdat->node_zones[zid],
NR_ZONE_LRU_BASE + lru, nr_pages);
}
static __always_inline void update_lru_size(struct lruvec *lruvec,
enum lru_list lru, enum zone_type zid,
long nr_pages)
{
__update_lru_size(lruvec, lru, zid, nr_pages);
#ifdef CONFIG_MEMCG
mem_cgroup_update_lru_size(lruvec, lru, zid, nr_pages);
#endif
}
/**
* __folio_clear_lru_flags - Clear page lru flags before releasing a page.
* @folio: The folio that was on lru and now has a zero reference.
*/
static __always_inline void __folio_clear_lru_flags(struct folio *folio)
{
VM_BUG_ON_FOLIO(!folio_test_lru(folio), folio);
__folio_clear_lru(folio);
/* this shouldn't happen, so leave the flags to bad_page() */
if (folio_test_active(folio) && folio_test_unevictable(folio))
return;
__folio_clear_active(folio);
__folio_clear_unevictable(folio);
}
/**
* folio_lru_list - Which LRU list should a folio be on?
* @folio: The folio to test.
*
* Return: The LRU list a folio should be on, as an index
* into the array of LRU lists.
*/
static __always_inline enum lru_list folio_lru_list(struct folio *folio)
{
enum lru_list lru;
VM_BUG_ON_FOLIO(folio_test_active(folio) && folio_test_unevictable(folio), folio);
if (folio_test_unevictable(folio))
return LRU_UNEVICTABLE;
lru = folio_is_file_lru(folio) ? LRU_INACTIVE_FILE : LRU_INACTIVE_ANON;
if (folio_test_active(folio))
lru += LRU_ACTIVE;
return lru;
}
#ifdef CONFIG_LRU_GEN
#ifdef CONFIG_LRU_GEN_ENABLED
static inline bool lru_gen_enabled(void)
{
DECLARE_STATIC_KEY_TRUE(lru_gen_caps[NR_LRU_GEN_CAPS]);
return static_branch_likely(&lru_gen_caps[LRU_GEN_CORE]);
}
#else
static inline bool lru_gen_enabled(void)
{
DECLARE_STATIC_KEY_FALSE(lru_gen_caps[NR_LRU_GEN_CAPS]);
return static_branch_unlikely(&lru_gen_caps[LRU_GEN_CORE]);
}
#endif
static inline bool lru_gen_in_fault(void)
{
return current->in_lru_fault;
}
static inline int lru_gen_from_seq(unsigned long seq)
{
return seq % MAX_NR_GENS;
}
static inline int lru_hist_from_seq(unsigned long seq)
{
return seq % NR_HIST_GENS;
}
static inline int lru_tier_from_refs(int refs)
{
VM_WARN_ON_ONCE(refs > BIT(LRU_REFS_WIDTH));
/* see the comment in folio_lru_refs() */
return order_base_2(refs + 1);
}
static inline int folio_lru_refs(struct folio *folio)
{
unsigned long flags = READ_ONCE(folio->flags);
bool workingset = flags & BIT(PG_workingset);
/*
* Return the number of accesses beyond PG_referenced, i.e., N-1 if the
* total number of accesses is N>1, since N=0,1 both map to the first
* tier. lru_tier_from_refs() will account for this off-by-one. Also see
* the comment on MAX_NR_TIERS.
*/
return ((flags & LRU_REFS_MASK) >> LRU_REFS_PGOFF) + workingset;
}
static inline int folio_lru_gen(struct folio *folio)
{
unsigned long flags = READ_ONCE(folio->flags);
return ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
}
static inline bool lru_gen_is_active(struct lruvec *lruvec, int gen)
{
unsigned long max_seq = lruvec->lrugen.max_seq;
VM_WARN_ON_ONCE(gen >= MAX_NR_GENS);
/* see the comment on MIN_NR_GENS */
return gen == lru_gen_from_seq(max_seq) || gen == lru_gen_from_seq(max_seq - 1);
}
static inline void lru_gen_update_size(struct lruvec *lruvec, struct folio *folio,
int old_gen, int new_gen)
{
int type = folio_is_file_lru(folio);
int zone = folio_zonenum(folio);
int delta = folio_nr_pages(folio);
enum lru_list lru = type * LRU_INACTIVE_FILE;
struct lru_gen_folio *lrugen = &lruvec->lrugen;
VM_WARN_ON_ONCE(old_gen != -1 && old_gen >= MAX_NR_GENS);
VM_WARN_ON_ONCE(new_gen != -1 && new_gen >= MAX_NR_GENS);
VM_WARN_ON_ONCE(old_gen == -1 && new_gen == -1);
if (old_gen >= 0)
WRITE_ONCE(lrugen->nr_pages[old_gen][type][zone],
lrugen->nr_pages[old_gen][type][zone] - delta);
if (new_gen >= 0)
WRITE_ONCE(lrugen->nr_pages[new_gen][type][zone],
lrugen->nr_pages[new_gen][type][zone] + delta);
/* addition */
if (old_gen < 0) {
if (lru_gen_is_active(lruvec, new_gen))
lru += LRU_ACTIVE;
__update_lru_size(lruvec, lru, zone, delta);
return;
}
/* deletion */
if (new_gen < 0) {
if (lru_gen_is_active(lruvec, old_gen))
lru += LRU_ACTIVE;
__update_lru_size(lruvec, lru, zone, -delta);
return;
}
/* promotion */
if (!lru_gen_is_active(lruvec, old_gen) && lru_gen_is_active(lruvec, new_gen)) {
__update_lru_size(lruvec, lru, zone, -delta);
__update_lru_size(lruvec, lru + LRU_ACTIVE, zone, delta);
}
/* demotion requires isolation, e.g., lru_deactivate_fn() */
VM_WARN_ON_ONCE(lru_gen_is_active(lruvec, old_gen) && !lru_gen_is_active(lruvec, new_gen));
}
static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
{
unsigned long seq;
unsigned long flags;
int gen = folio_lru_gen(folio);
int type = folio_is_file_lru(folio);
int zone = folio_zonenum(folio);
struct lru_gen_folio *lrugen = &lruvec->lrugen;
VM_WARN_ON_ONCE_FOLIO(gen != -1, folio);
if (folio_test_unevictable(folio) || !lrugen->enabled)
return false;
/*
* There are four common cases for this page:
* 1. If it's hot, i.e., freshly faulted in, add it to the youngest
* generation, and it's protected over the rest below.
* 2. If it can't be evicted immediately, i.e., a dirty page pending
* writeback, add it to the second youngest generation.
* 3. If it should be evicted first, e.g., cold and clean from
* folio_rotate_reclaimable(), add it to the oldest generation.
* 4. Everything else falls between 2 & 3 above and is added to the
* second oldest generation if it's considered inactive, or the
* oldest generation otherwise. See lru_gen_is_active().
*/
if (folio_test_active(folio))
seq = lrugen->max_seq;
else if ((type == LRU_GEN_ANON && !folio_test_swapcache(folio)) ||
(folio_test_reclaim(folio) &&
(folio_test_dirty(folio) || folio_test_writeback(folio))))
seq = lrugen->max_seq - 1;
else if (reclaiming || lrugen->min_seq[type] + MIN_NR_GENS >= lrugen->max_seq)
seq = lrugen->min_seq[type];
else
seq = lrugen->min_seq[type] + 1;
gen = lru_gen_from_seq(seq);
flags = (gen + 1UL) << LRU_GEN_PGOFF;
/* see the comment on MIN_NR_GENS about PG_active */
set_mask_bits(&folio->flags, LRU_GEN_MASK | BIT(PG_active), flags);
lru_gen_update_size(lruvec, folio, -1, gen);
/* for folio_rotate_reclaimable() */
if (reclaiming)
list_add_tail(&folio->lru, &lrugen->folios[gen][type][zone]);
else
list_add(&folio->lru, &lrugen->folios[gen][type][zone]);
return true;
}
static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
{
unsigned long flags;
int gen = folio_lru_gen(folio);
if (gen < 0)
return false;
VM_WARN_ON_ONCE_FOLIO(folio_test_active(folio), folio);
VM_WARN_ON_ONCE_FOLIO(folio_test_unevictable(folio), folio);
/* for folio_migrate_flags() */
flags = !reclaiming && lru_gen_is_active(lruvec, gen) ? BIT(PG_active) : 0;
flags = set_mask_bits(&folio->flags, LRU_GEN_MASK, flags);
gen = ((flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
lru_gen_update_size(lruvec, folio, gen, -1);
list_del(&folio->lru);
return true;
}
#else /* !CONFIG_LRU_GEN */
static inline bool lru_gen_enabled(void)
{
return false;
}
static inline bool lru_gen_in_fault(void)
{
return false;
}
static inline bool lru_gen_add_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
{
return false;
}
static inline bool lru_gen_del_folio(struct lruvec *lruvec, struct folio *folio, bool reclaiming)
{
return false;
}
#endif /* CONFIG_LRU_GEN */
static __always_inline
void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
{
enum lru_list lru = folio_lru_list(folio);
if (lru_gen_add_folio(lruvec, folio, false))
return;
update_lru_size(lruvec, lru, folio_zonenum(folio),
folio_nr_pages(folio));
if (lru != LRU_UNEVICTABLE)
list_add(&folio->lru, &lruvec->lists[lru]);
}
static __always_inline
void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
{
enum lru_list lru = folio_lru_list(folio);
if (lru_gen_add_folio(lruvec, folio, true))
return;
update_lru_size(lruvec, lru, folio_zonenum(folio),
folio_nr_pages(folio));
/* This is not expected to be used on LRU_UNEVICTABLE */
list_add_tail(&folio->lru, &lruvec->lists[lru]);
}
static __always_inline
void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
{
enum lru_list lru = folio_lru_list(folio);
if (lru_gen_del_folio(lruvec, folio, false))
return;
if (lru != LRU_UNEVICTABLE)
list_del(&folio->lru);
update_lru_size(lruvec, lru, folio_zonenum(folio),
-folio_nr_pages(folio));
}
#ifdef CONFIG_ANON_VMA_NAME
/* mmap_lock should be read-locked */
static inline void anon_vma_name_get(struct anon_vma_name *anon_name)
{
if (anon_name)
kref_get(&anon_name->kref);
}
static inline void anon_vma_name_put(struct anon_vma_name *anon_name)
{
if (anon_name)
kref_put(&anon_name->kref, anon_vma_name_free);
}
static inline
struct anon_vma_name *anon_vma_name_reuse(struct anon_vma_name *anon_name)
{
/* Prevent anon_name refcount saturation early on */
if (kref_read(&anon_name->kref) < REFCOUNT_MAX) {
anon_vma_name_get(anon_name);
return anon_name;
}
return anon_vma_name_alloc(anon_name->name);
}
static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
struct vm_area_struct *new_vma)
{
struct anon_vma_name *anon_name = anon_vma_name(orig_vma);
if (anon_name)
new_vma->anon_name = anon_vma_name_reuse(anon_name);
}
static inline void free_anon_vma_name(struct vm_area_struct *vma)
{
/*
* Not using anon_vma_name because it generates a warning if mmap_lock
* is not held, which might be the case here.
*/
anon_vma_name_put(vma->anon_name);
}
static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
struct anon_vma_name *anon_name2)
{
if (anon_name1 == anon_name2)
return true;
return anon_name1 && anon_name2 &&
!strcmp(anon_name1->name, anon_name2->name);
}
#else /* CONFIG_ANON_VMA_NAME */
static inline void anon_vma_name_get(struct anon_vma_name *anon_name) {}
static inline void anon_vma_name_put(struct anon_vma_name *anon_name) {}
static inline void dup_anon_vma_name(struct vm_area_struct *orig_vma,
struct vm_area_struct *new_vma) {}
static inline void free_anon_vma_name(struct vm_area_struct *vma) {}
static inline bool anon_vma_name_eq(struct anon_vma_name *anon_name1,
struct anon_vma_name *anon_name2)
{
return true;
}
#endif /* CONFIG_ANON_VMA_NAME */
static inline void init_tlb_flush_pending(struct mm_struct *mm)
{
atomic_set(&mm->tlb_flush_pending, 0);
}
static inline void inc_tlb_flush_pending(struct mm_struct *mm)
{
atomic_inc(&mm->tlb_flush_pending);
/*
* The only time this value is relevant is when there are indeed pages
* to flush. And we'll only flush pages after changing them, which
* requires the PTL.
*
* So the ordering here is:
*
* atomic_inc(&mm->tlb_flush_pending);
* spin_lock(&ptl);
* ...
* set_pte_at();
* spin_unlock(&ptl);
*
* spin_lock(&ptl)
* mm_tlb_flush_pending();
* ....
* spin_unlock(&ptl);
*
* 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
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