v4.19.13 snapshot.
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
new file mode 100644
index 0000000..fdcb459
--- /dev/null
+++ b/include/linux/huge_mm.h
@@ -0,0 +1,364 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_HUGE_MM_H
+#define _LINUX_HUGE_MM_H
+
+#include <linux/sched/coredump.h>
+#include <linux/mm_types.h>
+
+#include <linux/fs.h> /* only for vma_is_dax() */
+
+extern vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf);
+extern int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr,
+ struct vm_area_struct *vma);
+extern void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd);
+extern int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm,
+ pud_t *dst_pud, pud_t *src_pud, unsigned long addr,
+ struct vm_area_struct *vma);
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+extern void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud);
+#else
+static inline void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
+{
+}
+#endif
+
+extern vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf, pmd_t orig_pmd);
+extern struct page *follow_trans_huge_pmd(struct vm_area_struct *vma,
+ unsigned long addr,
+ pmd_t *pmd,
+ unsigned int flags);
+extern bool madvise_free_huge_pmd(struct mmu_gather *tlb,
+ struct vm_area_struct *vma,
+ pmd_t *pmd, unsigned long addr, unsigned long next);
+extern int zap_huge_pmd(struct mmu_gather *tlb,
+ struct vm_area_struct *vma,
+ pmd_t *pmd, unsigned long addr);
+extern int zap_huge_pud(struct mmu_gather *tlb,
+ struct vm_area_struct *vma,
+ pud_t *pud, unsigned long addr);
+extern int mincore_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, unsigned long end,
+ unsigned char *vec);
+extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
+ unsigned long new_addr, unsigned long old_end,
+ pmd_t *old_pmd, pmd_t *new_pmd);
+extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long addr, pgprot_t newprot,
+ int prot_numa);
+vm_fault_t vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
+ pmd_t *pmd, pfn_t pfn, bool write);
+vm_fault_t vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
+ pud_t *pud, pfn_t pfn, bool write);
+enum transparent_hugepage_flag {
+ TRANSPARENT_HUGEPAGE_FLAG,
+ TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG,
+ TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG,
+ TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG,
+ TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG,
+ TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG,
+ TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG,
+ TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG,
+#ifdef CONFIG_DEBUG_VM
+ TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG,
+#endif
+};
+
+struct kobject;
+struct kobj_attribute;
+
+extern ssize_t single_hugepage_flag_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t count,
+ enum transparent_hugepage_flag flag);
+extern ssize_t single_hugepage_flag_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf,
+ enum transparent_hugepage_flag flag);
+extern struct kobj_attribute shmem_enabled_attr;
+
+#define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
+#define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define HPAGE_PMD_SHIFT PMD_SHIFT
+#define HPAGE_PMD_SIZE ((1UL) << HPAGE_PMD_SHIFT)
+#define HPAGE_PMD_MASK (~(HPAGE_PMD_SIZE - 1))
+
+#define HPAGE_PUD_SHIFT PUD_SHIFT
+#define HPAGE_PUD_SIZE ((1UL) << HPAGE_PUD_SHIFT)
+#define HPAGE_PUD_MASK (~(HPAGE_PUD_SIZE - 1))
+
+extern bool is_vma_temporary_stack(struct vm_area_struct *vma);
+
+extern unsigned long transparent_hugepage_flags;
+
+static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
+{
+ if (vma->vm_flags & VM_NOHUGEPAGE)
+ return false;
+
+ if (is_vma_temporary_stack(vma))
+ return false;
+
+ if (test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
+ return false;
+
+ if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG))
+ return true;
+
+ if (vma_is_dax(vma))
+ return true;
+
+ if (transparent_hugepage_flags &
+ (1 << TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG))
+ return !!(vma->vm_flags & VM_HUGEPAGE);
+
+ return false;
+}
+
+#define transparent_hugepage_use_zero_page() \
+ (transparent_hugepage_flags & \
+ (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))
+#ifdef CONFIG_DEBUG_VM
+#define transparent_hugepage_debug_cow() \
+ (transparent_hugepage_flags & \
+ (1<<TRANSPARENT_HUGEPAGE_DEBUG_COW_FLAG))
+#else /* CONFIG_DEBUG_VM */
+#define transparent_hugepage_debug_cow() 0
+#endif /* CONFIG_DEBUG_VM */
+
+extern unsigned long thp_get_unmapped_area(struct file *filp,
+ unsigned long addr, unsigned long len, unsigned long pgoff,
+ unsigned long flags);
+
+extern void prep_transhuge_page(struct page *page);
+extern void free_transhuge_page(struct page *page);
+
+bool can_split_huge_page(struct page *page, int *pextra_pins);
+int split_huge_page_to_list(struct page *page, struct list_head *list);
+static inline int split_huge_page(struct page *page)
+{
+ return split_huge_page_to_list(page, NULL);
+}
+void deferred_split_huge_page(struct page *page);
+
+void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long address, bool freeze, struct page *page);
+
+#define split_huge_pmd(__vma, __pmd, __address) \
+ do { \
+ pmd_t *____pmd = (__pmd); \
+ if (is_swap_pmd(*____pmd) || pmd_trans_huge(*____pmd) \
+ || pmd_devmap(*____pmd)) \
+ __split_huge_pmd(__vma, __pmd, __address, \
+ false, NULL); \
+ } while (0)
+
+
+void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address,
+ bool freeze, struct page *page);
+
+void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long address);
+
+#define split_huge_pud(__vma, __pud, __address) \
+ do { \
+ pud_t *____pud = (__pud); \
+ if (pud_trans_huge(*____pud) \
+ || pud_devmap(*____pud)) \
+ __split_huge_pud(__vma, __pud, __address); \
+ } while (0)
+
+extern int hugepage_madvise(struct vm_area_struct *vma,
+ unsigned long *vm_flags, int advice);
+extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end,
+ long adjust_next);
+extern spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd,
+ struct vm_area_struct *vma);
+extern spinlock_t *__pud_trans_huge_lock(pud_t *pud,
+ struct vm_area_struct *vma);
+
+static inline int is_swap_pmd(pmd_t pmd)
+{
+ return !pmd_none(pmd) && !pmd_present(pmd);
+}
+
+/* mmap_sem must be held on entry */
+static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
+ struct vm_area_struct *vma)
+{
+ VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
+ if (is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || pmd_devmap(*pmd))
+ return __pmd_trans_huge_lock(pmd, vma);
+ else
+ return NULL;
+}
+static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
+ struct vm_area_struct *vma)
+{
+ VM_BUG_ON_VMA(!rwsem_is_locked(&vma->vm_mm->mmap_sem), vma);
+ if (pud_trans_huge(*pud) || pud_devmap(*pud))
+ return __pud_trans_huge_lock(pud, vma);
+ else
+ return NULL;
+}
+static inline int hpage_nr_pages(struct page *page)
+{
+ if (unlikely(PageTransHuge(page)))
+ return HPAGE_PMD_NR;
+ return 1;
+}
+
+struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
+ pmd_t *pmd, int flags);
+struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
+ pud_t *pud, int flags);
+
+extern vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
+
+extern struct page *huge_zero_page;
+
+static inline bool is_huge_zero_page(struct page *page)
+{
+ return READ_ONCE(huge_zero_page) == page;
+}
+
+static inline bool is_huge_zero_pmd(pmd_t pmd)
+{
+ return is_huge_zero_page(pmd_page(pmd));
+}
+
+static inline bool is_huge_zero_pud(pud_t pud)
+{
+ return false;
+}
+
+struct page *mm_get_huge_zero_page(struct mm_struct *mm);
+void mm_put_huge_zero_page(struct mm_struct *mm);
+
+#define mk_huge_pmd(page, prot) pmd_mkhuge(mk_pmd(page, prot))
+
+static inline bool thp_migration_supported(void)
+{
+ return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION);
+}
+
+#else /* CONFIG_TRANSPARENT_HUGEPAGE */
+#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
+#define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
+#define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
+
+#define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
+#define HPAGE_PUD_MASK ({ BUILD_BUG(); 0; })
+#define HPAGE_PUD_SIZE ({ BUILD_BUG(); 0; })
+
+#define hpage_nr_pages(x) 1
+
+static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma)
+{
+ return false;
+}
+
+static inline void prep_transhuge_page(struct page *page) {}
+
+#define transparent_hugepage_flags 0UL
+
+#define thp_get_unmapped_area NULL
+
+static inline bool
+can_split_huge_page(struct page *page, int *pextra_pins)
+{
+ BUILD_BUG();
+ return false;
+}
+static inline int
+split_huge_page_to_list(struct page *page, struct list_head *list)
+{
+ return 0;
+}
+static inline int split_huge_page(struct page *page)
+{
+ return 0;
+}
+static inline void deferred_split_huge_page(struct page *page) {}
+#define split_huge_pmd(__vma, __pmd, __address) \
+ do { } while (0)
+
+static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
+ unsigned long address, bool freeze, struct page *page) {}
+static inline void split_huge_pmd_address(struct vm_area_struct *vma,
+ unsigned long address, bool freeze, struct page *page) {}
+
+#define split_huge_pud(__vma, __pmd, __address) \
+ do { } while (0)
+
+static inline int hugepage_madvise(struct vm_area_struct *vma,
+ unsigned long *vm_flags, int advice)
+{
+ BUG();
+ return 0;
+}
+static inline void vma_adjust_trans_huge(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end,
+ long adjust_next)
+{
+}
+static inline int is_swap_pmd(pmd_t pmd)
+{
+ return 0;
+}
+static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
+ struct vm_area_struct *vma)
+{
+ return NULL;
+}
+static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
+ struct vm_area_struct *vma)
+{
+ return NULL;
+}
+
+static inline vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf,
+ pmd_t orig_pmd)
+{
+ return 0;
+}
+
+static inline bool is_huge_zero_page(struct page *page)
+{
+ return false;
+}
+
+static inline bool is_huge_zero_pud(pud_t pud)
+{
+ return false;
+}
+
+static inline void mm_put_huge_zero_page(struct mm_struct *mm)
+{
+ return;
+}
+
+static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t *pmd, int flags)
+{
+ return NULL;
+}
+
+static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
+ unsigned long addr, pud_t *pud, int flags)
+{
+ return NULL;
+}
+
+static inline bool thp_migration_supported(void)
+{
+ return false;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#endif /* _LINUX_HUGE_MM_H */