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-rw-r--r--include/linux/swapops.h124
1 files changed, 111 insertions, 13 deletions
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index d356ab4047f7..fe220df499f1 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -13,10 +13,10 @@
* 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 seven
+ * 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 two bits: see swp_to_radix_entry().
+ * 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.
*/
@@ -26,6 +26,8 @@
/* 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_wp(pte))
@@ -194,6 +196,7 @@ static inline bool is_writable_device_exclusive_entry(swp_entry_t entry)
static inline int is_migration_entry(swp_entry_t entry)
{
return unlikely(swp_type(entry) == SWP_MIGRATION_READ ||
+ swp_type(entry) == SWP_MIGRATION_READ_EXCLUSIVE ||
swp_type(entry) == SWP_MIGRATION_WRITE);
}
@@ -202,11 +205,26 @@ static inline int is_writable_migration_entry(swp_entry_t entry)
return unlikely(swp_type(entry) == SWP_MIGRATION_WRITE);
}
+static inline int is_readable_migration_entry(swp_entry_t entry)
+{
+ return unlikely(swp_type(entry) == SWP_MIGRATION_READ);
+}
+
+static inline int is_readable_exclusive_migration_entry(swp_entry_t entry)
+{
+ return unlikely(swp_type(entry) == SWP_MIGRATION_READ_EXCLUSIVE);
+}
+
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);
@@ -224,6 +242,11 @@ 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);
@@ -244,9 +267,92 @@ static inline int is_writable_migration_entry(swp_entry_t entry)
{
return 0;
}
+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)
+{
+ return swp_entry(SWP_PTE_MARKER, marker);
+}
+
+static inline bool is_pte_marker_entry(swp_entry_t entry)
+{
+ return swp_type(entry) == SWP_PTE_MARKER;
+}
+
+static inline pte_marker pte_marker_get(swp_entry_t entry)
+{
+ return swp_offset(entry) & PTE_MARKER_MASK;
+}
+
+static inline bool is_pte_marker(pte_t pte)
+{
+ return is_swap_pte(pte) && is_pte_marker_entry(pte_to_swp_entry(pte));
+}
+
+#else /* CONFIG_PTE_MARKER */
+
+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);
+}
+
+static inline bool is_pte_marker_entry(swp_entry_t entry)
+{
+ return false;
+}
+
+static inline pte_marker pte_marker_get(swp_entry_t entry)
+{
+ return 0;
+}
+
+static inline bool is_pte_marker(pte_t pte)
+{
+ return false;
+}
+
+#endif /* CONFIG_PTE_MARKER */
+
+static inline pte_t make_pte_marker(pte_marker marker)
+{
+ return swp_entry_to_pte(make_pte_marker_entry(marker));
+}
+
+/*
+ * 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
+ * should be seen as a none pte; it's just that we have stored some information
+ * onto the none pte so it becomes not-none any more.
+ *
+ * It should be used when the pte is file-backed, ram-based and backing
+ * userspace pages, like shmem. It is not needed upon pgtables that do not
+ * support pte markers at all. For example, it's not needed on anonymous
+ * 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)
+{
+ return pte_none(pte) || is_pte_marker(pte);
+}
+
static inline struct page *pfn_swap_entry_to_page(swp_entry_t entry)
{
struct page *p = pfn_to_page(swp_offset(entry));
@@ -274,7 +380,7 @@ static inline bool is_pfn_swap_entry(swp_entry_t entry)
struct page_vma_mapped_walk;
#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
-extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
+extern int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
struct page *page);
extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw,
@@ -304,10 +410,10 @@ static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
static inline int is_pmd_migration_entry(pmd_t pmd)
{
- return !pmd_present(pmd) && is_migration_entry(pmd_to_swp_entry(pmd));
+ return is_swap_pmd(pmd) && is_migration_entry(pmd_to_swp_entry(pmd));
}
#else
-static inline void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
+static inline int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
struct page *page)
{
BUILD_BUG();
@@ -387,18 +493,10 @@ static inline void num_poisoned_pages_inc(void)
}
#endif
-#if defined(CONFIG_MEMORY_FAILURE) || defined(CONFIG_MIGRATION) || \
- defined(CONFIG_DEVICE_PRIVATE)
static inline int non_swap_entry(swp_entry_t entry)
{
return swp_type(entry) >= MAX_SWAPFILES;
}
-#else
-static inline int non_swap_entry(swp_entry_t entry)
-{
- return 0;
-}
-#endif
#endif /* CONFIG_MMU */
#endif /* _LINUX_SWAPOPS_H */