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#include <linux/radix-tree.h>#include <linux/bug.h>#include <linux/mm_types.h>#include <linux/swap.h>
#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 * the low-order bits. * * We arrange the `type' and `offset' fields so that `type' is at the six * high-order bits of the swp_entry_t and `offset' is right-aligned in the * remaining bits. Although `type' itself needs only five bits, we allow for * shmem/tmpfs to shift it all up a further one bit: see swp_to_radix_entry(). * * swp_entry_t's are *never* stored anywhere in their arch-dependent format. */#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 leafeant_has_pfn()). 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)
/* Clear all flags but only keep swp_entry_t related information */static inline pte_t pte_swp_clear_flags(pte_t pte){ if (pte_swp_exclusive(pte)) pte = pte_swp_clear_exclusive(pte); if (pte_swp_soft_dirty(pte)) pte = pte_swp_clear_soft_dirty(pte); if (pte_swp_uffd(pte)) pte = pte_swp_clear_uffd(pte); return pte;}
/* * Store a type+offset into a swp_entry_t in an arch-independent format */static inline swp_entry_t swp_entry(unsigned long type, pgoff_t offset){ swp_entry_t ret;
ret.val = (type << SWP_TYPE_SHIFT) | (offset & SWP_OFFSET_MASK); return ret;}
/* * Extract the `type' field from a swp_entry_t. The swp_entry_t is in * arch-independent format */static inline unsigned swp_type(swp_entry_t entry){ return (entry.val >> SWP_TYPE_SHIFT);}
/* * Extract the `offset' field from a swp_entry_t. The swp_entry_t is in * arch-independent format */static inline pgoff_t swp_offset(swp_entry_t entry){ return entry.val & SWP_OFFSET_MASK;}
/* * Convert the arch-independent representation of a swp_entry_t into the * arch-dependent pte representation. */static inline pte_t swp_entry_to_pte(swp_entry_t entry){ swp_entry_t arch_entry;
arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); return __swp_entry_to_pte(arch_entry);}
static inline swp_entry_t radix_to_swp_entry(void *arg){ swp_entry_t entry;
entry.val = xa_to_value(arg); return entry;}
static inline void *swp_to_radix_entry(swp_entry_t entry){ return xa_mk_value(entry.val);}
#if IS_ENABLED(CONFIG_DEVICE_PRIVATE)static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset){ return swp_entry(SWP_DEVICE_READ, offset);}
static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset){ return swp_entry(SWP_DEVICE_WRITE, offset);}
static inline swp_entry_t make_device_exclusive_entry(pgoff_t offset){ return swp_entry(SWP_DEVICE_EXCLUSIVE, offset);}
#else /* CONFIG_DEVICE_PRIVATE */static inline swp_entry_t make_readable_device_private_entry(pgoff_t offset){ return swp_entry(0, 0);}
static inline swp_entry_t make_writable_device_private_entry(pgoff_t offset){ return swp_entry(0, 0);}
static inline swp_entry_t make_device_exclusive_entry(pgoff_t offset){ return swp_entry(0, 0);}
#endif /* CONFIG_DEVICE_PRIVATE */
#ifdef CONFIG_MIGRATION
static inline swp_entry_t make_readable_migration_entry(pgoff_t offset){ return swp_entry(SWP_MIGRATION_READ, offset);}
static inline swp_entry_t make_readable_exclusive_migration_entry(pgoff_t offset){ return swp_entry(SWP_MIGRATION_READ_EXCLUSIVE, offset);}
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 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;}
extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, unsigned long address);extern void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, pte_t *pte);#else /* CONFIG_MIGRATION */static inline swp_entry_t make_readable_migration_entry(pgoff_t offset){ return swp_entry(0, 0);}
static inline swp_entry_t make_readable_exclusive_migration_entry(pgoff_t offset){ return swp_entry(0, 0);}
static inline swp_entry_t make_writable_migration_entry(pgoff_t offset){ return swp_entry(0, 0);}
static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd, unsigned long address) { }static inline void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, pte_t *pte) { }
static inline swp_entry_t make_migration_entry_young(swp_entry_t entry){ return entry;}
static inline swp_entry_t make_migration_entry_dirty(swp_entry_t entry){ return entry;}
#endif /* CONFIG_MIGRATION */
#ifdef CONFIG_MEMORY_FAILURE
/* * Support for hardware poisoned pages */static inline swp_entry_t make_hwpoison_entry(struct page *page){ BUG_ON(!PageLocked(page)); return swp_entry(SWP_HWPOISON, page_to_pfn(page));}
static inline int is_hwpoison_entry(swp_entry_t entry){ return swp_type(entry) == SWP_HWPOISON;}
#else
static inline swp_entry_t make_hwpoison_entry(struct page *page){ return swp_entry(0, 0);}
static inline int is_hwpoison_entry(swp_entry_t swp){ return 0;}#endif
typedef unsigned long pte_marker;
#define PTE_MARKER_UFFD_WP BIT(0)/* * "Poisoned" here is meant in the very general sense of "future accesses are * invalid", instead of referring very specifically to hardware memory errors. * This marker is meant to represent any of various different causes of this. * * Note that, when encountered by the faulting logic, PTEs with this marker will * result in VM_FAULT_HWPOISON and thus regardless trigger hardware memory error * logic. */#define PTE_MARKER_POISONED BIT(1)/* * Indicates that, on fault, this PTE will case a SIGSEGV signal to be * sent. This means guard markers behave in effect as if the region were mapped * PROT_NONE, rather than if they were a memory hole or equivalent. */#define PTE_MARKER_GUARD BIT(2)#define PTE_MARKER_MASK (BIT(3) - 1)
static inline swp_entry_t make_pte_marker_entry(pte_marker marker){ return swp_entry(SWP_PTE_MARKER, 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_poisoned_swp_entry(void){ return make_pte_marker_entry(PTE_MARKER_POISONED);}
static inline swp_entry_t make_guard_swp_entry(void){ return make_pte_marker_entry(PTE_MARKER_GUARD);}
struct page_vma_mapped_walk;
#ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVESextern int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, struct page *page);
void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct folio *folio);
extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd);
static inline pmd_t swp_entry_to_pmd(swp_entry_t entry){ swp_entry_t arch_entry;
arch_entry = __swp_entry(swp_type(entry), swp_offset(entry)); return __swp_entry_to_pmd(arch_entry);}
#else /* CONFIG_ARCH_HAS_PMD_SOFTLEAVES */static inline int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, struct page *page){ BUILD_BUG();}
static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct folio *folio){ BUILD_BUG();}
static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { }
static inline pmd_t swp_entry_to_pmd(swp_entry_t entry){ return __pmd(0);}
#endif /* CONFIG_ARCH_HAS_PMD_SOFTLEAVES */
#endif /* CONFIG_MMU */#endif /* _LINUX_SWAPOPS_H */