diff options
Diffstat (limited to 'include/linux/swapops.h')
| -rw-r--r-- | include/linux/swapops.h | 215 |
1 files changed, 140 insertions, 75 deletions
diff --git a/include/linux/swapops.h b/include/linux/swapops.h index a3d435bf9f97..b982dd614572 100644 --- a/include/linux/swapops.h +++ b/include/linux/swapops.h @@ -8,6 +8,10 @@ #ifdef CONFIG_MMU +#ifdef CONFIG_SWAP +#include <linux/swapfile.h> +#endif /* CONFIG_SWAP */ + /* * swapcache pages are stored in the swapper_space radix tree. We want to * get good packing density in that tree, so the index should be dense in @@ -23,6 +27,47 @@ #define SWP_TYPE_SHIFT (BITS_PER_XA_VALUE - MAX_SWAPFILES_SHIFT) #define SWP_OFFSET_MASK ((1UL << SWP_TYPE_SHIFT) - 1) +/* + * Definitions only for PFN swap entries (see is_pfn_swap_entry()). To + * store PFN, we only need SWP_PFN_BITS bits. Each of the pfn swap entries + * can use the extra bits to store other information besides PFN. + */ +#ifdef MAX_PHYSMEM_BITS +#define SWP_PFN_BITS (MAX_PHYSMEM_BITS - PAGE_SHIFT) +#else /* MAX_PHYSMEM_BITS */ +#define SWP_PFN_BITS min_t(int, \ + sizeof(phys_addr_t) * 8 - PAGE_SHIFT, \ + SWP_TYPE_SHIFT) +#endif /* MAX_PHYSMEM_BITS */ +#define SWP_PFN_MASK (BIT(SWP_PFN_BITS) - 1) + +/** + * Migration swap entry specific bitfield definitions. Layout: + * + * |----------+--------------------| + * | swp_type | swp_offset | + * |----------+--------+-+-+-------| + * | | resv |D|A| PFN | + * |----------+--------+-+-+-------| + * + * @SWP_MIG_YOUNG_BIT: Whether the page used to have young bit set (bit A) + * @SWP_MIG_DIRTY_BIT: Whether the page used to have dirty bit set (bit D) + * + * Note: A/D bits will be stored in migration entries iff there're enough + * free bits in arch specific swp offset. By default we'll ignore A/D bits + * when migrating a page. Please refer to migration_entry_supports_ad() + * for more information. If there're more bits besides PFN and A/D bits, + * they should be reserved and always be zeros. + */ +#define SWP_MIG_YOUNG_BIT (SWP_PFN_BITS) +#define SWP_MIG_DIRTY_BIT (SWP_PFN_BITS + 1) +#define SWP_MIG_TOTAL_BITS (SWP_PFN_BITS + 2) + +#define SWP_MIG_YOUNG BIT(SWP_MIG_YOUNG_BIT) +#define SWP_MIG_DIRTY BIT(SWP_MIG_DIRTY_BIT) + +static inline bool is_pfn_swap_entry(swp_entry_t entry); + /* Clear all flags but only keep swp_entry_t related information */ static inline pte_t pte_swp_clear_flags(pte_t pte) { @@ -64,6 +109,17 @@ static inline pgoff_t swp_offset(swp_entry_t entry) return entry.val & SWP_OFFSET_MASK; } +/* + * This should only be called upon a pfn swap entry to get the PFN stored + * in the swap entry. Please refers to is_pfn_swap_entry() for definition + * of pfn swap entry. + */ +static inline unsigned long swp_offset_pfn(swp_entry_t entry) +{ + VM_BUG_ON(!is_pfn_swap_entry(entry)); + return swp_offset(entry) & SWP_PFN_MASK; +} + /* check whether a pte points to a swap entry */ static inline int is_swap_pte(pte_t pte) { @@ -108,16 +164,6 @@ static inline void *swp_to_radix_entry(swp_entry_t entry) return xa_mk_value(entry.val); } -static inline swp_entry_t make_swapin_error_entry(struct page *page) -{ - return swp_entry(SWP_SWAPIN_ERROR, page_to_pfn(page)); -} - -static inline int is_swapin_error_entry(swp_entry_t entry) -{ - return swp_type(entry) == SWP_SWAPIN_ERROR; -} - #if IS_ENABLED(CONFIG_DEVICE_PRIVATE) static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset) { @@ -240,6 +286,52 @@ static inline swp_entry_t make_writable_migration_entry(pgoff_t offset) return swp_entry(SWP_MIGRATION_WRITE, offset); } +/* + * Returns whether the host has large enough swap offset field to support + * carrying over pgtable A/D bits for page migrations. The result is + * pretty much arch specific. + */ +static inline bool migration_entry_supports_ad(void) +{ +#ifdef CONFIG_SWAP + return swap_migration_ad_supported; +#else /* CONFIG_SWAP */ + return false; +#endif /* CONFIG_SWAP */ +} + +static inline swp_entry_t make_migration_entry_young(swp_entry_t entry) +{ + if (migration_entry_supports_ad()) + return swp_entry(swp_type(entry), + swp_offset(entry) | SWP_MIG_YOUNG); + return entry; +} + +static inline bool is_migration_entry_young(swp_entry_t entry) +{ + if (migration_entry_supports_ad()) + return swp_offset(entry) & SWP_MIG_YOUNG; + /* Keep the old behavior of aging page after migration */ + return false; +} + +static inline swp_entry_t make_migration_entry_dirty(swp_entry_t entry) +{ + if (migration_entry_supports_ad()) + return swp_entry(swp_type(entry), + swp_offset(entry) | SWP_MIG_DIRTY); + return entry; +} + +static inline bool is_migration_entry_dirty(swp_entry_t entry) +{ + if (migration_entry_supports_ad()) + return swp_offset(entry) & SWP_MIG_DIRTY; + /* Keep the old behavior of clean page after migration */ + return false; +} + extern void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, spinlock_t *ptl); extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, @@ -247,8 +339,8 @@ extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, #ifdef CONFIG_HUGETLB_PAGE extern void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl); extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte); -#endif -#else +#endif /* CONFIG_HUGETLB_PAGE */ +#else /* CONFIG_MIGRATION */ static inline swp_entry_t make_readable_migration_entry(pgoff_t offset) { return swp_entry(0, 0); @@ -276,7 +368,7 @@ static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, #ifdef CONFIG_HUGETLB_PAGE static inline void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) { } static inline void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte) { } -#endif +#endif /* CONFIG_HUGETLB_PAGE */ static inline int is_writable_migration_entry(swp_entry_t entry) { return 0; @@ -286,66 +378,69 @@ static inline int is_readable_migration_entry(swp_entry_t entry) return 0; } -#endif - -typedef unsigned long pte_marker; - -#define PTE_MARKER_UFFD_WP BIT(0) -#define PTE_MARKER_MASK (PTE_MARKER_UFFD_WP) - -#ifdef CONFIG_PTE_MARKER - -static inline swp_entry_t make_pte_marker_entry(pte_marker marker) +static inline swp_entry_t make_migration_entry_young(swp_entry_t entry) { - return swp_entry(SWP_PTE_MARKER, marker); + return entry; } -static inline bool is_pte_marker_entry(swp_entry_t entry) +static inline bool is_migration_entry_young(swp_entry_t entry) { - return swp_type(entry) == SWP_PTE_MARKER; + return false; } -static inline pte_marker pte_marker_get(swp_entry_t entry) +static inline swp_entry_t make_migration_entry_dirty(swp_entry_t entry) { - return swp_offset(entry) & PTE_MARKER_MASK; + return entry; } -static inline bool is_pte_marker(pte_t pte) +static inline bool is_migration_entry_dirty(swp_entry_t entry) { - return is_swap_pte(pte) && is_pte_marker_entry(pte_to_swp_entry(pte)); + return false; } +#endif /* CONFIG_MIGRATION */ + +typedef unsigned long pte_marker; -#else /* CONFIG_PTE_MARKER */ +#define PTE_MARKER_UFFD_WP BIT(0) +#define PTE_MARKER_SWAPIN_ERROR BIT(1) +#define PTE_MARKER_MASK (BIT(2) - 1) static inline swp_entry_t make_pte_marker_entry(pte_marker marker) { - /* This should never be called if !CONFIG_PTE_MARKER */ - WARN_ON_ONCE(1); - return swp_entry(0, 0); + return swp_entry(SWP_PTE_MARKER, marker); } static inline bool is_pte_marker_entry(swp_entry_t entry) { - return false; + return swp_type(entry) == SWP_PTE_MARKER; } static inline pte_marker pte_marker_get(swp_entry_t entry) { - return 0; + return swp_offset(entry) & PTE_MARKER_MASK; } static inline bool is_pte_marker(pte_t pte) { - return false; + return is_swap_pte(pte) && is_pte_marker_entry(pte_to_swp_entry(pte)); } -#endif /* CONFIG_PTE_MARKER */ - static inline pte_t make_pte_marker(pte_marker marker) { return swp_entry_to_pte(make_pte_marker_entry(marker)); } +static inline swp_entry_t make_swapin_error_entry(void) +{ + return make_pte_marker_entry(PTE_MARKER_SWAPIN_ERROR); +} + +static inline int is_swapin_error_entry(swp_entry_t entry) +{ + return is_pte_marker_entry(entry) && + (pte_marker_get(entry) & PTE_MARKER_SWAPIN_ERROR); +} + /* * This is a special version to check pte_none() just to cover the case when * the pte is a pte marker. It existed because in many cases the pte marker @@ -358,9 +453,6 @@ static inline pte_t make_pte_marker(pte_marker marker) * memory, kernel-only memory (including when the system is during-boot), * non-ram based generic file-system. It's fine to be used even there, but the * extra pte marker check will be pure overhead. - * - * For systems configured with !CONFIG_PTE_MARKER this will be automatically - * optimized to pte_none(). */ static inline int pte_none_mostly(pte_t pte) { @@ -369,7 +461,7 @@ static inline int pte_none_mostly(pte_t pte) static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry) { - struct page *p = pfn_to_page(swp_offset(entry)); + struct page *p = pfn_to_page(swp_offset_pfn(entry)); /* * Any use of migration entries may only occur while the @@ -387,6 +479,9 @@ static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry) */ static inline bool is_pfn_swap_entry(swp_entry_t entry) { + /* Make sure the swp offset can always store the needed fields */ + BUILD_BUG_ON(SWP_TYPE_SHIFT < SWP_PFN_BITS); + return is_migration_entry(entry) || is_device_private_entry(entry) || is_device_exclusive_entry(entry); } @@ -426,7 +521,7 @@ static inline int is_pmd_migration_entry(pmd_t pmd) { return is_swap_pmd(pmd) && is_migration_entry(pmd_to_swp_entry(pmd)); } -#else +#else /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ static inline int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, struct page *page) { @@ -455,12 +550,10 @@ static inline int is_pmd_migration_entry(pmd_t pmd) { return 0; } -#endif +#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ #ifdef CONFIG_MEMORY_FAILURE -extern atomic_long_t num_poisoned_pages __read_mostly; - /* * Support for hardware poisoned pages */ @@ -475,26 +568,6 @@ static inline int is_hwpoison_entry(swp_entry_t entry) return swp_type(entry) == SWP_HWPOISON; } -static inline unsigned long hwpoison_entry_to_pfn(swp_entry_t entry) -{ - return swp_offset(entry); -} - -static inline void num_poisoned_pages_inc(void) -{ - atomic_long_inc(&num_poisoned_pages); -} - -static inline void num_poisoned_pages_dec(void) -{ - atomic_long_dec(&num_poisoned_pages); -} - -static inline void num_poisoned_pages_sub(long i) -{ - atomic_long_sub(i, &num_poisoned_pages); -} - #else static inline swp_entry_t make_hwpoison_entry(struct page *page) @@ -506,14 +579,6 @@ static inline int is_hwpoison_entry(swp_entry_t swp) { return 0; } - -static inline void num_poisoned_pages_inc(void) -{ -} - -static inline void num_poisoned_pages_sub(long i) -{ -} #endif static inline int non_swap_entry(swp_entry_t entry) |