diff --git a/arch/Kconfig b/arch/Kconfig
index 89e0b4f..40ed4e2 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -545,6 +545,9 @@ config HAVE_IRQ_TIME_ACCOUNTING
 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
 	bool
 
+config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+	bool
+
 config HAVE_ARCH_HUGE_VMAP
 	bool
 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index e487493..2c4a6ab 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -105,6 +105,7 @@ config X86
 	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
+	select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
 	select HAVE_ARCH_VMAP_STACK		if X86_64
 	select HAVE_ARCH_WITHIN_STACK_FRAMES
 	select HAVE_CC_STACKPROTECTOR
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 1eea6ca..1b5c172 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -475,6 +475,17 @@ static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 			    native_pmd_val(pmd));
 }
 
+static inline void set_pud_at(struct mm_struct *mm, unsigned long addr,
+			      pud_t *pudp, pud_t pud)
+{
+	if (sizeof(pudval_t) > sizeof(long))
+		/* 5 arg words */
+		pv_mmu_ops.set_pud_at(mm, addr, pudp, pud);
+	else
+		PVOP_VCALL4(pv_mmu_ops.set_pud_at, mm, addr, pudp,
+			    native_pud_val(pud));
+}
+
 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 {
 	pmdval_t val = native_pmd_val(pmd);
diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h
index bb2de45..b060f96 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -249,6 +249,8 @@ struct pv_mmu_ops {
 	void (*set_pmd)(pmd_t *pmdp, pmd_t pmdval);
 	void (*set_pmd_at)(struct mm_struct *mm, unsigned long addr,
 			   pmd_t *pmdp, pmd_t pmdval);
+	void (*set_pud_at)(struct mm_struct *mm, unsigned long addr,
+			   pud_t *pudp, pud_t pudval);
 	void (*pte_update)(struct mm_struct *mm, unsigned long addr,
 			   pte_t *ptep);
 
diff --git a/arch/x86/include/asm/pgtable-2level.h b/arch/x86/include/asm/pgtable-2level.h
index fd74a11..a8b96e7 100644
--- a/arch/x86/include/asm/pgtable-2level.h
+++ b/arch/x86/include/asm/pgtable-2level.h
@@ -21,6 +21,10 @@ static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd)
 	*pmdp = pmd;
 }
 
+static inline void native_set_pud(pud_t *pudp, pud_t pud)
+{
+}
+
 static inline void native_set_pte_atomic(pte_t *ptep, pte_t pte)
 {
 	native_set_pte(ptep, pte);
@@ -31,6 +35,10 @@ static inline void native_pmd_clear(pmd_t *pmdp)
 	native_set_pmd(pmdp, __pmd(0));
 }
 
+static inline void native_pud_clear(pud_t *pudp)
+{
+}
+
 static inline void native_pte_clear(struct mm_struct *mm,
 				    unsigned long addr, pte_t *xp)
 {
@@ -55,6 +63,15 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp)
 #define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
 #endif
 
+#ifdef CONFIG_SMP
+static inline pud_t native_pudp_get_and_clear(pud_t *xp)
+{
+	return __pud(xchg((pudval_t *)xp, 0));
+}
+#else
+#define native_pudp_get_and_clear(xp) native_local_pudp_get_and_clear(xp)
+#endif
+
 /* Bit manipulation helper on pte/pgoff entry */
 static inline unsigned long pte_bitop(unsigned long value, unsigned int rightshift,
 				      unsigned long mask, unsigned int leftshift)
diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h
index cdaa58c..be759ff 100644
--- a/arch/x86/include/asm/pgtable-3level.h
+++ b/arch/x86/include/asm/pgtable-3level.h
@@ -176,6 +176,30 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *pmdp)
 #define native_pmdp_get_and_clear(xp) native_local_pmdp_get_and_clear(xp)
 #endif
 
+#ifdef CONFIG_SMP
+union split_pud {
+	struct {
+		u32 pud_low;
+		u32 pud_high;
+	};
+	pud_t pud;
+};
+
+static inline pud_t native_pudp_get_and_clear(pud_t *pudp)
+{
+	union split_pud res, *orig = (union split_pud *)pudp;
+
+	/* xchg acts as a barrier before setting of the high bits */
+	res.pud_low = xchg(&orig->pud_low, 0);
+	res.pud_high = orig->pud_high;
+	orig->pud_high = 0;
+
+	return res.pud;
+}
+#else
+#define native_pudp_get_and_clear(xp) native_local_pudp_get_and_clear(xp)
+#endif
+
 /* Encode and de-code a swap entry */
 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > 5)
 #define __swp_type(x)			(((x).val) & 0x1f)
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 437feb4..1cfb36b 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -46,6 +46,7 @@ extern struct mm_struct *pgd_page_get_mm(struct page *page);
 #define set_pte(ptep, pte)		native_set_pte(ptep, pte)
 #define set_pte_at(mm, addr, ptep, pte)	native_set_pte_at(mm, addr, ptep, pte)
 #define set_pmd_at(mm, addr, pmdp, pmd)	native_set_pmd_at(mm, addr, pmdp, pmd)
+#define set_pud_at(mm, addr, pudp, pud)	native_set_pud_at(mm, addr, pudp, pud)
 
 #define set_pte_atomic(ptep, pte)					\
 	native_set_pte_atomic(ptep, pte)
@@ -128,6 +129,16 @@ static inline int pmd_young(pmd_t pmd)
 	return pmd_flags(pmd) & _PAGE_ACCESSED;
 }
 
+static inline int pud_dirty(pud_t pud)
+{
+	return pud_flags(pud) & _PAGE_DIRTY;
+}
+
+static inline int pud_young(pud_t pud)
+{
+	return pud_flags(pud) & _PAGE_ACCESSED;
+}
+
 static inline int pte_write(pte_t pte)
 {
 	return pte_flags(pte) & _PAGE_RW;
@@ -181,6 +192,13 @@ static inline int pmd_trans_huge(pmd_t pmd)
 	return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE;
 }
 
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline int pud_trans_huge(pud_t pud)
+{
+	return (pud_val(pud) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE;
+}
+#endif
+
 #define has_transparent_hugepage has_transparent_hugepage
 static inline int has_transparent_hugepage(void)
 {
@@ -192,6 +210,18 @@ static inline int pmd_devmap(pmd_t pmd)
 {
 	return !!(pmd_val(pmd) & _PAGE_DEVMAP);
 }
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline int pud_devmap(pud_t pud)
+{
+	return !!(pud_val(pud) & _PAGE_DEVMAP);
+}
+#else
+static inline int pud_devmap(pud_t pud)
+{
+	return 0;
+}
+#endif
 #endif
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
@@ -333,6 +363,65 @@ static inline pmd_t pmd_mknotpresent(pmd_t pmd)
 	return pmd_clear_flags(pmd, _PAGE_PRESENT | _PAGE_PROTNONE);
 }
 
+static inline pud_t pud_set_flags(pud_t pud, pudval_t set)
+{
+	pudval_t v = native_pud_val(pud);
+
+	return __pud(v | set);
+}
+
+static inline pud_t pud_clear_flags(pud_t pud, pudval_t clear)
+{
+	pudval_t v = native_pud_val(pud);
+
+	return __pud(v & ~clear);
+}
+
+static inline pud_t pud_mkold(pud_t pud)
+{
+	return pud_clear_flags(pud, _PAGE_ACCESSED);
+}
+
+static inline pud_t pud_mkclean(pud_t pud)
+{
+	return pud_clear_flags(pud, _PAGE_DIRTY);
+}
+
+static inline pud_t pud_wrprotect(pud_t pud)
+{
+	return pud_clear_flags(pud, _PAGE_RW);
+}
+
+static inline pud_t pud_mkdirty(pud_t pud)
+{
+	return pud_set_flags(pud, _PAGE_DIRTY | _PAGE_SOFT_DIRTY);
+}
+
+static inline pud_t pud_mkdevmap(pud_t pud)
+{
+	return pud_set_flags(pud, _PAGE_DEVMAP);
+}
+
+static inline pud_t pud_mkhuge(pud_t pud)
+{
+	return pud_set_flags(pud, _PAGE_PSE);
+}
+
+static inline pud_t pud_mkyoung(pud_t pud)
+{
+	return pud_set_flags(pud, _PAGE_ACCESSED);
+}
+
+static inline pud_t pud_mkwrite(pud_t pud)
+{
+	return pud_set_flags(pud, _PAGE_RW);
+}
+
+static inline pud_t pud_mknotpresent(pud_t pud)
+{
+	return pud_clear_flags(pud, _PAGE_PRESENT | _PAGE_PROTNONE);
+}
+
 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
 static inline int pte_soft_dirty(pte_t pte)
 {
@@ -344,6 +433,11 @@ static inline int pmd_soft_dirty(pmd_t pmd)
 	return pmd_flags(pmd) & _PAGE_SOFT_DIRTY;
 }
 
+static inline int pud_soft_dirty(pud_t pud)
+{
+	return pud_flags(pud) & _PAGE_SOFT_DIRTY;
+}
+
 static inline pte_t pte_mksoft_dirty(pte_t pte)
 {
 	return pte_set_flags(pte, _PAGE_SOFT_DIRTY);
@@ -354,6 +448,11 @@ static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
 	return pmd_set_flags(pmd, _PAGE_SOFT_DIRTY);
 }
 
+static inline pud_t pud_mksoft_dirty(pud_t pud)
+{
+	return pud_set_flags(pud, _PAGE_SOFT_DIRTY);
+}
+
 static inline pte_t pte_clear_soft_dirty(pte_t pte)
 {
 	return pte_clear_flags(pte, _PAGE_SOFT_DIRTY);
@@ -364,6 +463,11 @@ static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
 	return pmd_clear_flags(pmd, _PAGE_SOFT_DIRTY);
 }
 
+static inline pud_t pud_clear_soft_dirty(pud_t pud)
+{
+	return pud_clear_flags(pud, _PAGE_SOFT_DIRTY);
+}
+
 #endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
 
 /*
@@ -392,6 +496,12 @@ static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
 		     massage_pgprot(pgprot));
 }
 
+static inline pud_t pfn_pud(unsigned long page_nr, pgprot_t pgprot)
+{
+	return __pud(((phys_addr_t)page_nr << PAGE_SHIFT) |
+		     massage_pgprot(pgprot));
+}
+
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	pteval_t val = pte_val(pte);
@@ -771,6 +881,14 @@ static inline pmd_t native_local_pmdp_get_and_clear(pmd_t *pmdp)
 	return res;
 }
 
+static inline pud_t native_local_pudp_get_and_clear(pud_t *pudp)
+{
+	pud_t res = *pudp;
+
+	native_pud_clear(pudp);
+	return res;
+}
+
 static inline void native_set_pte_at(struct mm_struct *mm, unsigned long addr,
 				     pte_t *ptep , pte_t pte)
 {
@@ -783,6 +901,12 @@ static inline void native_set_pmd_at(struct mm_struct *mm, unsigned long addr,
 	native_set_pmd(pmdp, pmd);
 }
 
+static inline void native_set_pud_at(struct mm_struct *mm, unsigned long addr,
+				     pud_t *pudp, pud_t pud)
+{
+	native_set_pud(pudp, pud);
+}
+
 #ifndef CONFIG_PARAVIRT
 /*
  * Rules for using pte_update - it must be called after any PTE update which
@@ -861,10 +985,15 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm,
 extern int pmdp_set_access_flags(struct vm_area_struct *vma,
 				 unsigned long address, pmd_t *pmdp,
 				 pmd_t entry, int dirty);
+extern int pudp_set_access_flags(struct vm_area_struct *vma,
+				 unsigned long address, pud_t *pudp,
+				 pud_t entry, int dirty);
 
 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 extern int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 				     unsigned long addr, pmd_t *pmdp);
+extern int pudp_test_and_clear_young(struct vm_area_struct *vma,
+				     unsigned long addr, pud_t *pudp);
 
 #define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
 extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
@@ -884,6 +1013,13 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long
 	return native_pmdp_get_and_clear(pmdp);
 }
 
+#define __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
+static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
+					unsigned long addr, pud_t *pudp)
+{
+	return native_pudp_get_and_clear(pudp);
+}
+
 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 				      unsigned long addr, pmd_t *pmdp)
@@ -932,6 +1068,10 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
 		unsigned long addr, pmd_t *pmd)
 {
 }
+static inline void update_mmu_cache_pud(struct vm_area_struct *vma,
+		unsigned long addr, pud_t *pud)
+{
+}
 
 #ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
 static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 62b77592..73c7ccc 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -106,6 +106,21 @@ static inline void native_pud_clear(pud_t *pud)
 	native_set_pud(pud, native_make_pud(0));
 }
 
+static inline pud_t native_pudp_get_and_clear(pud_t *xp)
+{
+#ifdef CONFIG_SMP
+	return native_make_pud(xchg(&xp->pud, 0));
+#else
+	/* native_local_pudp_get_and_clear,
+	 * but duplicated because of cyclic dependency
+	 */
+	pud_t ret = *xp;
+
+	native_pud_clear(xp);
+	return ret;
+#endif
+}
+
 static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd)
 {
 	*pgdp = pgd;
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index a1bfba0..4797e87 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -425,6 +425,7 @@ struct pv_mmu_ops pv_mmu_ops __ro_after_init = {
 	.pmd_clear = native_pmd_clear,
 #endif
 	.set_pud = native_set_pud,
+	.set_pud_at = native_set_pud_at,
 
 	.pmd_val = PTE_IDENT,
 	.make_pmd = PTE_IDENT,
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index 3feec5a..6cbdff2 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -445,6 +445,26 @@ int pmdp_set_access_flags(struct vm_area_struct *vma,
 
 	return changed;
 }
+
+int pudp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
+			  pud_t *pudp, pud_t entry, int dirty)
+{
+	int changed = !pud_same(*pudp, entry);
+
+	VM_BUG_ON(address & ~HPAGE_PUD_MASK);
+
+	if (changed && dirty) {
+		*pudp = entry;
+		/*
+		 * We had a write-protection fault here and changed the pud
+		 * to to more permissive. No need to flush the TLB for that,
+		 * #PF is architecturally guaranteed to do that and in the
+		 * worst-case we'll generate a spurious fault.
+		 */
+	}
+
+	return changed;
+}
 #endif
 
 int ptep_test_and_clear_young(struct vm_area_struct *vma,
@@ -474,6 +494,17 @@ int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 
 	return ret;
 }
+int pudp_test_and_clear_young(struct vm_area_struct *vma,
+			      unsigned long addr, pud_t *pudp)
+{
+	int ret = 0;
+
+	if (pud_young(*pudp))
+		ret = test_and_clear_bit(_PAGE_BIT_ACCESSED,
+					 (unsigned long *)pudp);
+
+	return ret;
+}
 #endif
 
 int ptep_clear_flush_young(struct vm_area_struct *vma,
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index 18af2bc..a0aba0f 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -36,6 +36,9 @@ extern int ptep_set_access_flags(struct vm_area_struct *vma,
 extern int pmdp_set_access_flags(struct vm_area_struct *vma,
 				 unsigned long address, pmd_t *pmdp,
 				 pmd_t entry, int dirty);
+extern int pudp_set_access_flags(struct vm_area_struct *vma,
+				 unsigned long address, pud_t *pudp,
+				 pud_t entry, int dirty);
 #else
 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
 					unsigned long address, pmd_t *pmdp,
@@ -44,6 +47,13 @@ static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
 	BUILD_BUG();
 	return 0;
 }
+static inline int pudp_set_access_flags(struct vm_area_struct *vma,
+					unsigned long address, pud_t *pudp,
+					pud_t entry, int dirty)
+{
+	BUILD_BUG();
+	return 0;
+}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #endif
 
@@ -121,8 +131,8 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 }
 #endif
 
-#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 					    unsigned long address,
 					    pmd_t *pmdp)
@@ -131,20 +141,40 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 	pmd_clear(pmdp);
 	return pmd;
 }
+#endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */
+#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
+static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
+					    unsigned long address,
+					    pud_t *pudp)
+{
+	pud_t pud = *pudp;
+
+	pud_clear(pudp);
+	return pud;
+}
+#endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-#endif
 
-#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
 static inline pmd_t pmdp_huge_get_and_clear_full(struct mm_struct *mm,
 					    unsigned long address, pmd_t *pmdp,
 					    int full)
 {
 	return pmdp_huge_get_and_clear(mm, address, pmdp);
 }
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #endif
 
+#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR_FULL
+static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm,
+					    unsigned long address, pud_t *pudp,
+					    int full)
+{
+	return pudp_huge_get_and_clear(mm, address, pudp);
+}
+#endif
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
 #ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
 static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
 					    unsigned long address, pte_t *ptep,
@@ -181,6 +211,9 @@ extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
 extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
 			      unsigned long address,
 			      pmd_t *pmdp);
+extern pud_t pudp_huge_clear_flush(struct vm_area_struct *vma,
+			      unsigned long address,
+			      pud_t *pudp);
 #endif
 
 #ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
@@ -208,6 +241,23 @@ static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #endif
+#ifndef __HAVE_ARCH_PUDP_SET_WRPROTECT
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline void pudp_set_wrprotect(struct mm_struct *mm,
+				      unsigned long address, pud_t *pudp)
+{
+	pud_t old_pud = *pudp;
+
+	set_pud_at(mm, address, pudp, pud_wrprotect(old_pud));
+}
+#else
+static inline void pudp_set_wrprotect(struct mm_struct *mm,
+				      unsigned long address, pud_t *pudp)
+{
+	BUILD_BUG();
+}
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+#endif
 
 #ifndef pmdp_collapse_flush
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
@@ -273,12 +323,23 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 {
 	return pmd_val(pmd_a) == pmd_val(pmd_b);
 }
+
+static inline int pud_same(pud_t pud_a, pud_t pud_b)
+{
+	return pud_val(pud_a) == pud_val(pud_b);
+}
 #else /* CONFIG_TRANSPARENT_HUGEPAGE */
 static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
 {
 	BUILD_BUG();
 	return 0;
 }
+
+static inline int pud_same(pud_t pud_a, pud_t pud_b)
+{
+	BUILD_BUG();
+	return 0;
+}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #endif
 
@@ -640,6 +701,15 @@ static inline int pmd_write(pmd_t pmd)
 #endif /* __HAVE_ARCH_PMD_WRITE */
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
+#if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \
+	(defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
+	 !defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
+static inline int pud_trans_huge(pud_t pud)
+{
+	return 0;
+}
+#endif
+
 #ifndef pmd_read_atomic
 static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
 {
@@ -785,8 +855,10 @@ static inline int pmd_clear_huge(pmd_t *pmd)
  * e.g. see arch/arc: flush_pmd_tlb_range
  */
 #define flush_pmd_tlb_range(vma, addr, end)	flush_tlb_range(vma, addr, end)
+#define flush_pud_tlb_range(vma, addr, end)	flush_tlb_range(vma, addr, end)
 #else
 #define flush_pmd_tlb_range(vma, addr, end)	BUILD_BUG()
+#define flush_pud_tlb_range(vma, addr, end)	BUILD_BUG()
 #endif
 #endif
 
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index 7eed8cf..4329bc6 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -232,6 +232,20 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
 		__tlb_remove_pmd_tlb_entry(tlb, pmdp, address);		\
 	} while (0)
 
+/**
+ * tlb_remove_pud_tlb_entry - remember a pud mapping for later tlb
+ * invalidation. This is a nop so far, because only x86 needs it.
+ */
+#ifndef __tlb_remove_pud_tlb_entry
+#define __tlb_remove_pud_tlb_entry(tlb, pudp, address) do {} while (0)
+#endif
+
+#define tlb_remove_pud_tlb_entry(tlb, pudp, address)			\
+	do {								\
+		__tlb_adjust_range(tlb, address, HPAGE_PUD_SIZE);	\
+		__tlb_remove_pud_tlb_entry(tlb, pudp, address);		\
+	} while (0)
+
 /*
  * For things like page tables caches (ie caching addresses "inside" the
  * page tables, like x86 does), for legacy reasons, flushing an
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 97e478d..a530742 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -6,6 +6,18 @@ 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 int 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,
@@ -17,6 +29,9 @@ extern bool madvise_free_huge_pmd(struct mmu_gather *tlb,
 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);
@@ -26,8 +41,10 @@ extern bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 extern int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 			unsigned long addr, pgprot_t newprot,
 			int prot_numa);
-int vmf_insert_pfn_pmd(struct vm_area_struct *, unsigned long addr, pmd_t *,
-			pfn_t pfn, bool write);
+int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
+			pmd_t *pmd, pfn_t pfn, bool write);
+int 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,
@@ -57,13 +74,14 @@ extern struct kobj_attribute shmem_enabled_attr;
 #define HPAGE_PMD_NR (1<<HPAGE_PMD_ORDER)
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr,
-		pmd_t *pmd, int flags);
-
 #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);
 
 #define transparent_hugepage_enabled(__vma)				\
@@ -117,6 +135,17 @@ void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 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,
@@ -125,6 +154,8 @@ extern void vma_adjust_trans_huge(struct vm_area_struct *vma,
 				    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);
 /* mmap_sem must be held on entry */
 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 		struct vm_area_struct *vma)
@@ -135,6 +166,15 @@ static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 	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)))
@@ -142,6 +182,11 @@ static inline int hpage_nr_pages(struct page *page)
 	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 int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd);
 
 extern struct page *huge_zero_page;
@@ -156,6 +201,11 @@ 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);
 
@@ -166,6 +216,10 @@ void mm_put_huge_zero_page(struct mm_struct *mm);
 #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
 
 #define transparent_hugepage_enabled(__vma) 0
@@ -194,6 +248,9 @@ static inline void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 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)
 {
@@ -211,6 +268,11 @@ static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 {
 	return NULL;
 }
+static inline spinlock_t *pud_trans_huge_lock(pud_t *pud,
+		struct vm_area_struct *vma)
+{
+	return NULL;
+}
 
 static inline int do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t orig_pmd)
 {
@@ -222,6 +284,11 @@ 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;
@@ -232,6 +299,12 @@ static inline struct page *follow_devmap_pmd(struct vm_area_struct *vma,
 {
 	return NULL;
 }
+
+static inline struct page *follow_devmap_pud(struct vm_area_struct *vma,
+		unsigned long addr, pud_t *pud, int flags)
+{
+	return NULL;
+}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #endif /* _LINUX_HUGE_MM_H */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 19d6f71..5282729 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -420,6 +420,10 @@ static inline int pmd_devmap(pmd_t pmd)
 {
 	return 0;
 }
+static inline int pud_devmap(pud_t pud)
+{
+	return 0;
+}
 #endif
 
 /*
@@ -1198,6 +1202,10 @@ void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
 
 /**
  * mm_walk - callbacks for walk_page_range
+ * @pud_entry: if set, called for each non-empty PUD (2nd-level) entry
+ *	       this handler should only handle pud_trans_huge() puds.
+ *	       the pmd_entry or pte_entry callbacks will be used for
+ *	       regular PUDs.
  * @pmd_entry: if set, called for each non-empty PMD (3rd-level) entry
  *	       this handler is required to be able to handle
  *	       pmd_trans_huge() pmds.  They may simply choose to
@@ -1217,6 +1225,8 @@ void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
  * (see the comment on walk_page_range() for more details)
  */
 struct mm_walk {
+	int (*pud_entry)(pud_t *pud, unsigned long addr,
+			 unsigned long next, struct mm_walk *walk);
 	int (*pmd_entry)(pmd_t *pmd, unsigned long addr,
 			 unsigned long next, struct mm_walk *walk);
 	int (*pte_entry)(pte_t *pte, unsigned long addr,
@@ -1800,8 +1810,26 @@ static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
 	return ptl;
 }
 
-extern void __init pagecache_init(void);
+/*
+ * No scalability reason to split PUD locks yet, but follow the same pattern
+ * as the PMD locks to make it easier if we decide to.  The VM should not be
+ * considered ready to switch to split PUD locks yet; there may be places
+ * which need to be converted from page_table_lock.
+ */
+static inline spinlock_t *pud_lockptr(struct mm_struct *mm, pud_t *pud)
+{
+	return &mm->page_table_lock;
+}
+
+static inline spinlock_t *pud_lock(struct mm_struct *mm, pud_t *pud)
+{
+	spinlock_t *ptl = pud_lockptr(mm, pud);
+
+	spin_lock(ptl);
+	return ptl;
+}
 
+extern void __init pagecache_init(void);
 extern void free_area_init(unsigned long * zones_size);
 extern void free_area_init_node(int nid, unsigned long * zones_size,
 		unsigned long zone_start_pfn, unsigned long *zholes_size);
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index a1a210d..51891fb 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -381,6 +381,19 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
 	___pmd;								\
 })
 
+#define pudp_huge_clear_flush_notify(__vma, __haddr, __pud)		\
+({									\
+	unsigned long ___haddr = __haddr & HPAGE_PUD_MASK;		\
+	struct mm_struct *___mm = (__vma)->vm_mm;			\
+	pud_t ___pud;							\
+									\
+	___pud = pudp_huge_clear_flush(__vma, __haddr, __pud);		\
+	mmu_notifier_invalidate_range(___mm, ___haddr,			\
+				      ___haddr + HPAGE_PUD_SIZE);	\
+									\
+	___pud;								\
+})
+
 #define pmdp_huge_get_and_clear_notify(__mm, __haddr, __pmd)		\
 ({									\
 	unsigned long ___haddr = __haddr & HPAGE_PMD_MASK;		\
@@ -475,6 +488,7 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
 #define pmdp_clear_young_notify pmdp_test_and_clear_young
 #define	ptep_clear_flush_notify ptep_clear_flush
 #define pmdp_huge_clear_flush_notify pmdp_huge_clear_flush
+#define pudp_huge_clear_flush_notify pudp_huge_clear_flush
 #define pmdp_huge_get_and_clear_notify pmdp_huge_get_and_clear
 #define set_pte_at_notify set_pte_at
 
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index 033fc7b..a49b325 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -90,6 +90,13 @@ static inline pmd_t pfn_t_pmd(pfn_t pfn, pgprot_t pgprot)
 {
 	return pfn_pmd(pfn_t_to_pfn(pfn), pgprot);
 }
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot)
+{
+	return pfn_pud(pfn_t_to_pfn(pfn), pgprot);
+}
+#endif
 #endif
 
 #ifdef __HAVE_ARCH_PTE_DEVMAP
@@ -106,5 +113,10 @@ static inline bool pfn_t_devmap(pfn_t pfn)
 }
 pte_t pte_mkdevmap(pte_t pte);
 pmd_t pmd_mkdevmap(pmd_t pmd);
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
+	defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
+pud_t pud_mkdevmap(pud_t pud);
 #endif
+#endif /* __HAVE_ARCH_PTE_DEVMAP */
+
 #endif /* _LINUX_PFN_T_H_ */
diff --git a/mm/gup.c b/mm/gup.c
index 40abe4c..1e67461 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -253,6 +253,13 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
 			return page;
 		return no_page_table(vma, flags);
 	}
+	if (pud_devmap(*pud)) {
+		ptl = pud_lock(mm, pud);
+		page = follow_devmap_pud(vma, address, pud, flags);
+		spin_unlock(ptl);
+		if (page)
+			return page;
+	}
 	if (unlikely(pud_bad(*pud)))
 		return no_page_table(vma, flags);
 
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 5f3ad65c..de9ba1e 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -755,6 +755,60 @@ int vmf_insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr,
 }
 EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd);
 
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma)
+{
+	if (likely(vma->vm_flags & VM_WRITE))
+		pud = pud_mkwrite(pud);
+	return pud;
+}
+
+static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
+		pud_t *pud, pfn_t pfn, pgprot_t prot, bool write)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	pud_t entry;
+	spinlock_t *ptl;
+
+	ptl = pud_lock(mm, pud);
+	entry = pud_mkhuge(pfn_t_pud(pfn, prot));
+	if (pfn_t_devmap(pfn))
+		entry = pud_mkdevmap(entry);
+	if (write) {
+		entry = pud_mkyoung(pud_mkdirty(entry));
+		entry = maybe_pud_mkwrite(entry, vma);
+	}
+	set_pud_at(mm, addr, pud, entry);
+	update_mmu_cache_pud(vma, addr, pud);
+	spin_unlock(ptl);
+}
+
+int vmf_insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr,
+			pud_t *pud, pfn_t pfn, bool write)
+{
+	pgprot_t pgprot = vma->vm_page_prot;
+	/*
+	 * If we had pud_special, we could avoid all these restrictions,
+	 * but we need to be consistent with PTEs and architectures that
+	 * can't support a 'special' bit.
+	 */
+	BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)));
+	BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) ==
+						(VM_PFNMAP|VM_MIXEDMAP));
+	BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));
+	BUG_ON(!pfn_t_devmap(pfn));
+
+	if (addr < vma->vm_start || addr >= vma->vm_end)
+		return VM_FAULT_SIGBUS;
+
+	track_pfn_insert(vma, &pgprot, pfn);
+
+	insert_pfn_pud(vma, addr, pud, pfn, pgprot, write);
+	return VM_FAULT_NOPAGE;
+}
+EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud);
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+
 static void touch_pmd(struct vm_area_struct *vma, unsigned long addr,
 		pmd_t *pmd)
 {
@@ -885,6 +939,123 @@ int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm,
 	return ret;
 }
 
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void touch_pud(struct vm_area_struct *vma, unsigned long addr,
+		pud_t *pud)
+{
+	pud_t _pud;
+
+	/*
+	 * We should set the dirty bit only for FOLL_WRITE but for now
+	 * the dirty bit in the pud is meaningless.  And if the dirty
+	 * bit will become meaningful and we'll only set it with
+	 * FOLL_WRITE, an atomic set_bit will be required on the pud to
+	 * set the young bit, instead of the current set_pud_at.
+	 */
+	_pud = pud_mkyoung(pud_mkdirty(*pud));
+	if (pudp_set_access_flags(vma, addr & HPAGE_PUD_MASK,
+				pud, _pud,  1))
+		update_mmu_cache_pud(vma, addr, pud);
+}
+
+struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr,
+		pud_t *pud, int flags)
+{
+	unsigned long pfn = pud_pfn(*pud);
+	struct mm_struct *mm = vma->vm_mm;
+	struct dev_pagemap *pgmap;
+	struct page *page;
+
+	assert_spin_locked(pud_lockptr(mm, pud));
+
+	if (flags & FOLL_WRITE && !pud_write(*pud))
+		return NULL;
+
+	if (pud_present(*pud) && pud_devmap(*pud))
+		/* pass */;
+	else
+		return NULL;
+
+	if (flags & FOLL_TOUCH)
+		touch_pud(vma, addr, pud);
+
+	/*
+	 * device mapped pages can only be returned if the
+	 * caller will manage the page reference count.
+	 */
+	if (!(flags & FOLL_GET))
+		return ERR_PTR(-EEXIST);
+
+	pfn += (addr & ~PUD_MASK) >> PAGE_SHIFT;
+	pgmap = get_dev_pagemap(pfn, NULL);
+	if (!pgmap)
+		return ERR_PTR(-EFAULT);
+	page = pfn_to_page(pfn);
+	get_page(page);
+	put_dev_pagemap(pgmap);
+
+	return page;
+}
+
+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)
+{
+	spinlock_t *dst_ptl, *src_ptl;
+	pud_t pud;
+	int ret;
+
+	dst_ptl = pud_lock(dst_mm, dst_pud);
+	src_ptl = pud_lockptr(src_mm, src_pud);
+	spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
+
+	ret = -EAGAIN;
+	pud = *src_pud;
+	if (unlikely(!pud_trans_huge(pud) && !pud_devmap(pud)))
+		goto out_unlock;
+
+	/*
+	 * When page table lock is held, the huge zero pud should not be
+	 * under splitting since we don't split the page itself, only pud to
+	 * a page table.
+	 */
+	if (is_huge_zero_pud(pud)) {
+		/* No huge zero pud yet */
+	}
+
+	pudp_set_wrprotect(src_mm, addr, src_pud);
+	pud = pud_mkold(pud_wrprotect(pud));
+	set_pud_at(dst_mm, addr, dst_pud, pud);
+
+	ret = 0;
+out_unlock:
+	spin_unlock(src_ptl);
+	spin_unlock(dst_ptl);
+	return ret;
+}
+
+void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud)
+{
+	pud_t entry;
+	unsigned long haddr;
+	bool write = vmf->flags & FAULT_FLAG_WRITE;
+
+	vmf->ptl = pud_lock(vmf->vma->vm_mm, vmf->pud);
+	if (unlikely(!pud_same(*vmf->pud, orig_pud)))
+		goto unlock;
+
+	entry = pud_mkyoung(orig_pud);
+	if (write)
+		entry = pud_mkdirty(entry);
+	haddr = vmf->address & HPAGE_PUD_MASK;
+	if (pudp_set_access_flags(vmf->vma, haddr, vmf->pud, entry, write))
+		update_mmu_cache_pud(vmf->vma, vmf->address, vmf->pud);
+
+unlock:
+	spin_unlock(vmf->ptl);
+}
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+
 void huge_pmd_set_accessed(struct vm_fault *vmf, pmd_t orig_pmd)
 {
 	pmd_t entry;
@@ -1599,6 +1770,84 @@ spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma)
 	return NULL;
 }
 
+/*
+ * Returns true if a given pud maps a thp, false otherwise.
+ *
+ * Note that if it returns true, this routine returns without unlocking page
+ * table lock. So callers must unlock it.
+ */
+spinlock_t *__pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma)
+{
+	spinlock_t *ptl;
+
+	ptl = pud_lock(vma->vm_mm, pud);
+	if (likely(pud_trans_huge(*pud) || pud_devmap(*pud)))
+		return ptl;
+	spin_unlock(ptl);
+	return NULL;
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma,
+		 pud_t *pud, unsigned long addr)
+{
+	pud_t orig_pud;
+	spinlock_t *ptl;
+
+	ptl = __pud_trans_huge_lock(pud, vma);
+	if (!ptl)
+		return 0;
+	/*
+	 * For architectures like ppc64 we look at deposited pgtable
+	 * when calling pudp_huge_get_and_clear. So do the
+	 * pgtable_trans_huge_withdraw after finishing pudp related
+	 * operations.
+	 */
+	orig_pud = pudp_huge_get_and_clear_full(tlb->mm, addr, pud,
+			tlb->fullmm);
+	tlb_remove_pud_tlb_entry(tlb, pud, addr);
+	if (vma_is_dax(vma)) {
+		spin_unlock(ptl);
+		/* No zero page support yet */
+	} else {
+		/* No support for anonymous PUD pages yet */
+		BUG();
+	}
+	return 1;
+}
+
+static void __split_huge_pud_locked(struct vm_area_struct *vma, pud_t *pud,
+		unsigned long haddr)
+{
+	VM_BUG_ON(haddr & ~HPAGE_PUD_MASK);
+	VM_BUG_ON_VMA(vma->vm_start > haddr, vma);
+	VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PUD_SIZE, vma);
+	VM_BUG_ON(!pud_trans_huge(*pud) && !pud_devmap(*pud));
+
+	count_vm_event(THP_SPLIT_PMD);
+
+	pudp_huge_clear_flush_notify(vma, haddr, pud);
+}
+
+void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud,
+		unsigned long address)
+{
+	spinlock_t *ptl;
+	struct mm_struct *mm = vma->vm_mm;
+	unsigned long haddr = address & HPAGE_PUD_MASK;
+
+	mmu_notifier_invalidate_range_start(mm, haddr, haddr + HPAGE_PUD_SIZE);
+	ptl = pud_lock(mm, pud);
+	if (unlikely(!pud_trans_huge(*pud) && !pud_devmap(*pud)))
+		goto out;
+	__split_huge_pud_locked(vma, pud, haddr);
+
+out:
+	spin_unlock(ptl);
+	mmu_notifier_invalidate_range_end(mm, haddr, haddr + HPAGE_PUD_SIZE);
+}
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+
 static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
 		unsigned long haddr, pmd_t *pmd)
 {
diff --git a/mm/memory.c b/mm/memory.c
index a2acf9e..c55b799 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1001,7 +1001,7 @@ static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src
 		next = pmd_addr_end(addr, end);
 		if (pmd_trans_huge(*src_pmd) || pmd_devmap(*src_pmd)) {
 			int err;
-			VM_BUG_ON(next-addr != HPAGE_PMD_SIZE);
+			VM_BUG_ON_VMA(next-addr != HPAGE_PMD_SIZE, vma);
 			err = copy_huge_pmd(dst_mm, src_mm,
 					    dst_pmd, src_pmd, addr, vma);
 			if (err == -ENOMEM)
@@ -1032,6 +1032,18 @@ static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src
 	src_pud = pud_offset(src_pgd, addr);
 	do {
 		next = pud_addr_end(addr, end);
+		if (pud_trans_huge(*src_pud) || pud_devmap(*src_pud)) {
+			int err;
+
+			VM_BUG_ON_VMA(next-addr != HPAGE_PUD_SIZE, vma);
+			err = copy_huge_pud(dst_mm, src_mm,
+					    dst_pud, src_pud, addr, vma);
+			if (err == -ENOMEM)
+				return -ENOMEM;
+			if (!err)
+				continue;
+			/* fall through */
+		}
 		if (pud_none_or_clear_bad(src_pud))
 			continue;
 		if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud,
@@ -1269,9 +1281,19 @@ static inline unsigned long zap_pud_range(struct mmu_gather *tlb,
 	pud = pud_offset(pgd, addr);
 	do {
 		next = pud_addr_end(addr, end);
+		if (pud_trans_huge(*pud) || pud_devmap(*pud)) {
+			if (next - addr != HPAGE_PUD_SIZE) {
+				VM_BUG_ON_VMA(!rwsem_is_locked(&tlb->mm->mmap_sem), vma);
+				split_huge_pud(vma, pud, addr);
+			} else if (zap_huge_pud(tlb, vma, pud, addr))
+				goto next;
+			/* fall through */
+		}
 		if (pud_none_or_clear_bad(pud))
 			continue;
 		next = zap_pmd_range(tlb, vma, pud, addr, next, details);
+next:
+		cond_resched();
 	} while (pud++, addr = next, addr != end);
 
 	return addr;
@@ -3497,6 +3519,30 @@ static inline bool vma_is_accessible(struct vm_area_struct *vma)
 	return vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE);
 }
 
+static int create_huge_pud(struct vm_fault *vmf)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	/* No support for anonymous transparent PUD pages yet */
+	if (vma_is_anonymous(vmf->vma))
+		return VM_FAULT_FALLBACK;
+	if (vmf->vma->vm_ops->huge_fault)
+		return vmf->vma->vm_ops->huge_fault(vmf);
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+	return VM_FAULT_FALLBACK;
+}
+
+static int wp_huge_pud(struct vm_fault *vmf, pud_t orig_pud)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	/* No support for anonymous transparent PUD pages yet */
+	if (vma_is_anonymous(vmf->vma))
+		return VM_FAULT_FALLBACK;
+	if (vmf->vma->vm_ops->huge_fault)
+		return vmf->vma->vm_ops->huge_fault(vmf);
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+	return VM_FAULT_FALLBACK;
+}
+
 /*
  * These routines also need to handle stuff like marking pages dirty
  * and/or accessed for architectures that don't do it in hardware (most
@@ -3612,14 +3658,41 @@ static int __handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
 	};
 	struct mm_struct *mm = vma->vm_mm;
 	pgd_t *pgd;
-	pud_t *pud;
 	int ret;
 
 	pgd = pgd_offset(mm, address);
-	pud = pud_alloc(mm, pgd, address);
-	if (!pud)
+
+	vmf.pud = pud_alloc(mm, pgd, address);
+	if (!vmf.pud)
 		return VM_FAULT_OOM;
-	vmf.pmd = pmd_alloc(mm, pud, address);
+	if (pud_none(*vmf.pud) && transparent_hugepage_enabled(vma)) {
+		vmf.flags |= FAULT_FLAG_SIZE_PUD;
+		ret = create_huge_pud(&vmf);
+		if (!(ret & VM_FAULT_FALLBACK))
+			return ret;
+	} else {
+		pud_t orig_pud = *vmf.pud;
+
+		barrier();
+		if (pud_trans_huge(orig_pud) || pud_devmap(orig_pud)) {
+			unsigned int dirty = flags & FAULT_FLAG_WRITE;
+
+			vmf.flags |= FAULT_FLAG_SIZE_PUD;
+
+			/* NUMA case for anonymous PUDs would go here */
+
+			if (dirty && !pud_write(orig_pud)) {
+				ret = wp_huge_pud(&vmf, orig_pud);
+				if (!(ret & VM_FAULT_FALLBACK))
+					return ret;
+			} else {
+				huge_pud_set_accessed(&vmf, orig_pud);
+				return 0;
+			}
+		}
+	}
+
+	vmf.pmd = pmd_alloc(mm, vmf.pud, address);
 	if (!vmf.pmd)
 		return VM_FAULT_OOM;
 	if (pmd_none(*vmf.pmd) && transparent_hugepage_enabled(vma)) {
@@ -3746,13 +3819,14 @@ int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address)
  */
 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 {
+	spinlock_t *ptl;
 	pmd_t *new = pmd_alloc_one(mm, address);
 	if (!new)
 		return -ENOMEM;
 
 	smp_wmb(); /* See comment in __pte_alloc */
 
-	spin_lock(&mm->page_table_lock);
+	ptl = pud_lock(mm, pud);
 #ifndef __ARCH_HAS_4LEVEL_HACK
 	if (!pud_present(*pud)) {
 		mm_inc_nr_pmds(mm);
@@ -3766,7 +3840,7 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
 	} else /* Another has populated it */
 		pmd_free(mm, new);
 #endif /* __ARCH_HAS_4LEVEL_HACK */
-	spin_unlock(&mm->page_table_lock);
+	spin_unlock(ptl);
 	return 0;
 }
 #endif /* __PAGETABLE_PMD_FOLDED */
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 2072444..0376157 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -78,14 +78,32 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
 
 	pud = pud_offset(pgd, addr);
 	do {
+ again:
 		next = pud_addr_end(addr, end);
-		if (pud_none_or_clear_bad(pud)) {
+		if (pud_none(*pud) || !walk->vma) {
 			if (walk->pte_hole)
 				err = walk->pte_hole(addr, next, walk);
 			if (err)
 				break;
 			continue;
 		}
+
+		if (walk->pud_entry) {
+			spinlock_t *ptl = pud_trans_huge_lock(pud, walk->vma);
+
+			if (ptl) {
+				err = walk->pud_entry(pud, addr, next, walk);
+				spin_unlock(ptl);
+				if (err)
+					break;
+				continue;
+			}
+		}
+
+		split_huge_pud(walk->vma, pud, addr);
+		if (pud_none(*pud))
+			goto again;
+
 		if (walk->pmd_entry || walk->pte_entry)
 			err = walk_pmd_range(pud, addr, next, walk);
 		if (err)
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 71c5f91..4ed5908 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -123,6 +123,20 @@ pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
 	flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
 	return pmd;
 }
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+pud_t pudp_huge_clear_flush(struct vm_area_struct *vma, unsigned long address,
+			    pud_t *pudp)
+{
+	pud_t pud;
+
+	VM_BUG_ON(address & ~HPAGE_PUD_MASK);
+	VM_BUG_ON(!pud_trans_huge(*pudp) && !pud_devmap(*pudp));
+	pud = pudp_huge_get_and_clear(vma->vm_mm, address, pudp);
+	flush_pud_tlb_range(vma, address, address + HPAGE_PUD_SIZE);
+	return pud;
+}
+#endif
 #endif
 
 #ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
