[merged mm-stable] mm-remove-devmap-related-functions-and-page-table-bits.patch removed from -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

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The quilt patch titled
     Subject: mm: remove devmap related functions and page table bits
has been removed from the -mm tree.  Its filename was
     mm-remove-devmap-related-functions-and-page-table-bits.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Alistair Popple <apopple@nvidia.com>
Subject: mm: remove devmap related functions and page table bits
Date: Thu, 19 Jun 2025 18:58:03 +1000

Now that DAX and all other reference counts to ZONE_DEVICE pages are
managed normally there is no need for the special devmap PTE/PMD/PUD page
table bits.  So drop all references to these, freeing up a software
defined page table bit on architectures supporting it.

Link: https://lkml.kernel.org/r/6389398c32cc9daa3dfcaa9f79c7972525d310ce.1750323463.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: Will Deacon <will@kernel.org> # arm64
Acked-by: David Hildenbrand <david@redhat.com>
Suggested-by: Chunyan Zhang <zhang.lyra@gmail.com>
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Inki Dae <m.szyprowski@samsung.com>
Cc: John Groves <john@groves.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/mm/arch_pgtable_helpers.rst     |    6 -
 arch/arm64/Kconfig                            |    1 
 arch/arm64/include/asm/pgtable-prot.h         |    1 
 arch/arm64/include/asm/pgtable.h              |   24 ------
 arch/loongarch/Kconfig                        |    1 
 arch/loongarch/include/asm/pgtable-bits.h     |    6 -
 arch/loongarch/include/asm/pgtable.h          |   19 -----
 arch/powerpc/Kconfig                          |    1 
 arch/powerpc/include/asm/book3s/64/hash-4k.h  |    6 -
 arch/powerpc/include/asm/book3s/64/hash-64k.h |    7 -
 arch/powerpc/include/asm/book3s/64/pgtable.h  |   53 --------------
 arch/powerpc/include/asm/book3s/64/radix.h    |   14 ---
 arch/riscv/Kconfig                            |    1 
 arch/riscv/include/asm/pgtable-64.h           |   16 ----
 arch/riscv/include/asm/pgtable-bits.h         |    1 
 arch/riscv/include/asm/pgtable.h              |   22 -----
 arch/x86/Kconfig                              |    1 
 arch/x86/include/asm/pgtable.h                |   51 -------------
 arch/x86/include/asm/pgtable_types.h          |    5 -
 include/linux/mm.h                            |    7 -
 include/linux/pgtable.h                       |   19 -----
 mm/Kconfig                                    |    4 -
 mm/debug_vm_pgtable.c                         |   59 ----------------
 mm/hmm.c                                      |    3 
 mm/madvise.c                                  |    8 +-
 25 files changed, 17 insertions(+), 319 deletions(-)

--- a/arch/arm64/include/asm/pgtable.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/arm64/include/asm/pgtable.h
@@ -190,7 +190,6 @@ static inline pteval_t __phys_to_pte_val
 #define pte_user(pte)		(!!(pte_val(pte) & PTE_USER))
 #define pte_user_exec(pte)	(!(pte_val(pte) & PTE_UXN))
 #define pte_cont(pte)		(!!(pte_val(pte) & PTE_CONT))
-#define pte_devmap(pte)		(!!(pte_val(pte) & PTE_DEVMAP))
 #define pte_tagged(pte)		((pte_val(pte) & PTE_ATTRINDX_MASK) == \
 				 PTE_ATTRINDX(MT_NORMAL_TAGGED))
 
@@ -372,11 +371,6 @@ static inline pmd_t pmd_mkcont(pmd_t pmd
 	return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
 }
 
-static inline pte_t pte_mkdevmap(pte_t pte)
-{
-	return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL));
-}
-
 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP
 static inline int pte_uffd_wp(pte_t pte)
 {
@@ -653,14 +647,6 @@ static inline pmd_t pmd_mkhuge(pmd_t pmd
 	return __pmd((pmd_val(pmd) & ~mask) | val);
 }
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#define pmd_devmap(pmd)		pte_devmap(pmd_pte(pmd))
-#endif
-static inline pmd_t pmd_mkdevmap(pmd_t pmd)
-{
-	return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP)));
-}
-
 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
 #define pmd_special(pte)	(!!((pmd_val(pte) & PTE_SPECIAL)))
 static inline pmd_t pmd_mkspecial(pmd_t pmd)
@@ -1302,16 +1288,6 @@ static inline int pmdp_set_access_flags(
 	return __ptep_set_access_flags(vma, address, (pte_t *)pmdp,
 							pmd_pte(entry), dirty);
 }
-
-static inline int pud_devmap(pud_t pud)
-{
-	return 0;
-}
-
-static inline int pgd_devmap(pgd_t pgd)
-{
-	return 0;
-}
 #endif
 
 #ifdef CONFIG_PAGE_TABLE_CHECK
--- a/arch/arm64/include/asm/pgtable-prot.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/arm64/include/asm/pgtable-prot.h
@@ -17,7 +17,6 @@
 #define PTE_SWP_EXCLUSIVE	(_AT(pteval_t, 1) << 2)	 /* only for swp ptes */
 #define PTE_DIRTY		(_AT(pteval_t, 1) << 55)
 #define PTE_SPECIAL		(_AT(pteval_t, 1) << 56)
-#define PTE_DEVMAP		(_AT(pteval_t, 1) << 57)
 
 /*
  * PTE_PRESENT_INVALID=1 & PTE_VALID=0 indicates that the pte's fields should be
--- a/arch/arm64/Kconfig~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/arm64/Kconfig
@@ -44,7 +44,6 @@ config ARM64
 	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PTDUMP
-	select ARCH_HAS_PTE_DEVMAP
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_HW_PTE_YOUNG
 	select ARCH_HAS_SETUP_DMA_OPS
--- a/arch/loongarch/include/asm/pgtable-bits.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/loongarch/include/asm/pgtable-bits.h
@@ -22,7 +22,6 @@
 #define	_PAGE_PFN_SHIFT		12
 #define	_PAGE_SWP_EXCLUSIVE_SHIFT 23
 #define	_PAGE_PFN_END_SHIFT	48
-#define	_PAGE_DEVMAP_SHIFT	59
 #define	_PAGE_PRESENT_INVALID_SHIFT 60
 #define	_PAGE_NO_READ_SHIFT	61
 #define	_PAGE_NO_EXEC_SHIFT	62
@@ -36,7 +35,6 @@
 #define _PAGE_MODIFIED		(_ULCAST_(1) << _PAGE_MODIFIED_SHIFT)
 #define _PAGE_PROTNONE		(_ULCAST_(1) << _PAGE_PROTNONE_SHIFT)
 #define _PAGE_SPECIAL		(_ULCAST_(1) << _PAGE_SPECIAL_SHIFT)
-#define _PAGE_DEVMAP		(_ULCAST_(1) << _PAGE_DEVMAP_SHIFT)
 
 /* We borrow bit 23 to store the exclusive marker in swap PTEs. */
 #define _PAGE_SWP_EXCLUSIVE	(_ULCAST_(1) << _PAGE_SWP_EXCLUSIVE_SHIFT)
@@ -76,8 +74,8 @@
 #define __READABLE	(_PAGE_VALID)
 #define __WRITEABLE	(_PAGE_DIRTY | _PAGE_WRITE)
 
-#define _PAGE_CHG_MASK	(_PAGE_MODIFIED | _PAGE_SPECIAL | _PAGE_DEVMAP | _PFN_MASK | _CACHE_MASK | _PAGE_PLV)
-#define _HPAGE_CHG_MASK	(_PAGE_MODIFIED | _PAGE_SPECIAL | _PAGE_DEVMAP | _PFN_MASK | _CACHE_MASK | _PAGE_PLV | _PAGE_HUGE)
+#define _PAGE_CHG_MASK	(_PAGE_MODIFIED | _PAGE_SPECIAL | _PFN_MASK | _CACHE_MASK | _PAGE_PLV)
+#define _HPAGE_CHG_MASK	(_PAGE_MODIFIED | _PAGE_SPECIAL | _PFN_MASK | _CACHE_MASK | _PAGE_PLV | _PAGE_HUGE)
 
 #define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_NO_READ | \
 				 _PAGE_USER | _CACHE_CC)
--- a/arch/loongarch/include/asm/pgtable.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/loongarch/include/asm/pgtable.h
@@ -409,9 +409,6 @@ static inline int pte_special(pte_t pte)
 static inline pte_t pte_mkspecial(pte_t pte)	{ pte_val(pte) |= _PAGE_SPECIAL; return pte; }
 #endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 
-static inline int pte_devmap(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_DEVMAP); }
-static inline pte_t pte_mkdevmap(pte_t pte)	{ pte_val(pte) |= _PAGE_DEVMAP; return pte; }
-
 #define pte_accessible pte_accessible
 static inline unsigned long pte_accessible(struct mm_struct *mm, pte_t a)
 {
@@ -540,17 +537,6 @@ static inline pmd_t pmd_mkyoung(pmd_t pm
 	return pmd;
 }
 
-static inline int pmd_devmap(pmd_t pmd)
-{
-	return !!(pmd_val(pmd) & _PAGE_DEVMAP);
-}
-
-static inline pmd_t pmd_mkdevmap(pmd_t pmd)
-{
-	pmd_val(pmd) |= _PAGE_DEVMAP;
-	return pmd;
-}
-
 static inline struct page *pmd_page(pmd_t pmd)
 {
 	if (pmd_trans_huge(pmd))
@@ -606,11 +592,6 @@ static inline long pmd_protnone(pmd_t pm
 #define pmd_leaf(pmd)		((pmd_val(pmd) & _PAGE_HUGE) != 0)
 #define pud_leaf(pud)		((pud_val(pud) & _PAGE_HUGE) != 0)
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-#define pud_devmap(pud)		(0)
-#define pgd_devmap(pgd)		(0)
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-
 /*
  * We provide our own get_unmapped area to cope with the virtual aliasing
  * constraints placed on us by the cache architecture.
--- a/arch/loongarch/Kconfig~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/loongarch/Kconfig
@@ -25,7 +25,6 @@ config LOONGARCH
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_PREEMPT_LAZY
-	select ARCH_HAS_PTE_DEVMAP
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SET_DIRECT_MAP
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -168,12 +168,6 @@ extern pmd_t hash__pmdp_huge_get_and_cle
 extern int hash__has_transparent_hugepage(void);
 #endif
 
-static inline pmd_t hash__pmd_mkdevmap(pmd_t pmd)
-{
-	BUG();
-	return pmd;
-}
-
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_BOOK3S_64_HASH_4K_H */
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -259,7 +259,7 @@ static inline void mark_hpte_slot_valid(
  */
 static inline int hash__pmd_trans_huge(pmd_t pmd)
 {
-	return !!((pmd_val(pmd) & (_PAGE_PTE | H_PAGE_THP_HUGE | _PAGE_DEVMAP)) ==
+	return !!((pmd_val(pmd) & (_PAGE_PTE | H_PAGE_THP_HUGE)) ==
 		  (_PAGE_PTE | H_PAGE_THP_HUGE));
 }
 
@@ -281,11 +281,6 @@ extern pmd_t hash__pmdp_huge_get_and_cle
 extern int hash__has_transparent_hugepage(void);
 #endif /*  CONFIG_TRANSPARENT_HUGEPAGE */
 
-static inline pmd_t hash__pmd_mkdevmap(pmd_t pmd)
-{
-	return __pmd(pmd_val(pmd) | (_PAGE_PTE | H_PAGE_THP_HUGE | _PAGE_DEVMAP));
-}
-
 #endif	/* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_BOOK3S_64_HASH_64K_H */
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -88,7 +88,6 @@
 
 #define _PAGE_SOFT_DIRTY	_RPAGE_SW3 /* software: software dirty tracking */
 #define _PAGE_SPECIAL		_RPAGE_SW2 /* software: special page */
-#define _PAGE_DEVMAP		_RPAGE_SW1 /* software: ZONE_DEVICE page */
 
 /*
  * Drivers request for cache inhibited pte mapping using _PAGE_NO_CACHE
@@ -109,7 +108,7 @@
  */
 #define _HPAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
 			 _PAGE_ACCESSED | H_PAGE_THP_HUGE | _PAGE_PTE | \
-			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
+			 _PAGE_SOFT_DIRTY)
 /*
  * user access blocked by key
  */
@@ -123,7 +122,7 @@
  */
 #define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
 			 _PAGE_ACCESSED | _PAGE_SPECIAL | _PAGE_PTE |	\
-			 _PAGE_SOFT_DIRTY | _PAGE_DEVMAP)
+			 _PAGE_SOFT_DIRTY)
 
 /*
  * We define 2 sets of base prot bits, one for basic pages (ie,
@@ -609,24 +608,6 @@ static inline pte_t pte_mkhuge(pte_t pte
 	return pte;
 }
 
-static inline pte_t pte_mkdevmap(pte_t pte)
-{
-	return __pte_raw(pte_raw(pte) | cpu_to_be64(_PAGE_SPECIAL | _PAGE_DEVMAP));
-}
-
-/*
- * This is potentially called with a pmd as the argument, in which case it's not
- * safe to check _PAGE_DEVMAP unless we also confirm that _PAGE_PTE is set.
- * That's because the bit we use for _PAGE_DEVMAP is not reserved for software
- * use in page directory entries (ie. non-ptes).
- */
-static inline int pte_devmap(pte_t pte)
-{
-	__be64 mask = cpu_to_be64(_PAGE_DEVMAP | _PAGE_PTE);
-
-	return (pte_raw(pte) & mask) == mask;
-}
-
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	/* FIXME!! check whether this need to be a conditional */
@@ -1379,36 +1360,6 @@ static inline bool arch_needs_pgtable_de
 }
 extern void serialize_against_pte_lookup(struct mm_struct *mm);
 
-
-static inline pmd_t pmd_mkdevmap(pmd_t pmd)
-{
-	if (radix_enabled())
-		return radix__pmd_mkdevmap(pmd);
-	return hash__pmd_mkdevmap(pmd);
-}
-
-static inline pud_t pud_mkdevmap(pud_t pud)
-{
-	if (radix_enabled())
-		return radix__pud_mkdevmap(pud);
-	BUG();
-	return pud;
-}
-
-static inline int pmd_devmap(pmd_t pmd)
-{
-	return pte_devmap(pmd_pte(pmd));
-}
-
-static inline int pud_devmap(pud_t pud)
-{
-	return pte_devmap(pud_pte(pud));
-}
-
-static inline int pgd_devmap(pgd_t pgd)
-{
-	return 0;
-}
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
--- a/arch/powerpc/include/asm/book3s/64/radix.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/powerpc/include/asm/book3s/64/radix.h
@@ -264,7 +264,7 @@ static inline int radix__p4d_bad(p4d_t p
 
 static inline int radix__pmd_trans_huge(pmd_t pmd)
 {
-	return (pmd_val(pmd) & (_PAGE_PTE | _PAGE_DEVMAP)) == _PAGE_PTE;
+	return (pmd_val(pmd) & _PAGE_PTE) == _PAGE_PTE;
 }
 
 static inline pmd_t radix__pmd_mkhuge(pmd_t pmd)
@@ -274,7 +274,7 @@ static inline pmd_t radix__pmd_mkhuge(pm
 
 static inline int radix__pud_trans_huge(pud_t pud)
 {
-	return (pud_val(pud) & (_PAGE_PTE | _PAGE_DEVMAP)) == _PAGE_PTE;
+	return (pud_val(pud) & _PAGE_PTE) == _PAGE_PTE;
 }
 
 static inline pud_t radix__pud_mkhuge(pud_t pud)
@@ -315,16 +315,6 @@ static inline int radix__has_transparent
 }
 #endif
 
-static inline pmd_t radix__pmd_mkdevmap(pmd_t pmd)
-{
-	return __pmd(pmd_val(pmd) | (_PAGE_PTE | _PAGE_DEVMAP));
-}
-
-static inline pud_t radix__pud_mkdevmap(pud_t pud)
-{
-	return __pud(pud_val(pud) | (_PAGE_PTE | _PAGE_DEVMAP));
-}
-
 struct vmem_altmap;
 struct dev_pagemap;
 extern int __meminit radix__vmemmap_create_mapping(unsigned long start,
--- a/arch/powerpc/Kconfig~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/powerpc/Kconfig
@@ -149,7 +149,6 @@ config PPC
 	select ARCH_HAS_PMEM_API
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PTDUMP
-	select ARCH_HAS_PTE_DEVMAP		if PPC_BOOK3S_64
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
 	select ARCH_HAS_SET_MEMORY
--- a/arch/riscv/include/asm/pgtable-64.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/riscv/include/asm/pgtable-64.h
@@ -397,24 +397,8 @@ static inline struct page *pgd_page(pgd_
 p4d_t *p4d_offset(pgd_t *pgd, unsigned long address);
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static inline int pte_devmap(pte_t pte);
 static inline pte_t pmd_pte(pmd_t pmd);
 static inline pte_t pud_pte(pud_t pud);
-
-static inline int pmd_devmap(pmd_t pmd)
-{
-	return pte_devmap(pmd_pte(pmd));
-}
-
-static inline int pud_devmap(pud_t pud)
-{
-	return pte_devmap(pud_pte(pud));
-}
-
-static inline int pgd_devmap(pgd_t pgd)
-{
-	return 0;
-}
 #endif
 
 #endif /* _ASM_RISCV_PGTABLE_64_H */
--- a/arch/riscv/include/asm/pgtable-bits.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/riscv/include/asm/pgtable-bits.h
@@ -19,7 +19,6 @@
 #define _PAGE_SOFT      (3 << 8)    /* Reserved for software */
 
 #define _PAGE_SPECIAL   (1 << 8)    /* RSW: 0x1 */
-#define _PAGE_DEVMAP    (1 << 9)    /* RSW, devmap */
 #define _PAGE_TABLE     _PAGE_PRESENT
 
 /*
--- a/arch/riscv/include/asm/pgtable.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/riscv/include/asm/pgtable.h
@@ -409,13 +409,6 @@ static inline int pte_special(pte_t pte)
 	return pte_val(pte) & _PAGE_SPECIAL;
 }
 
-#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
-static inline int pte_devmap(pte_t pte)
-{
-	return pte_val(pte) & _PAGE_DEVMAP;
-}
-#endif
-
 /* static inline pte_t pte_rdprotect(pte_t pte) */
 
 static inline pte_t pte_wrprotect(pte_t pte)
@@ -457,11 +450,6 @@ static inline pte_t pte_mkspecial(pte_t
 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
 }
 
-static inline pte_t pte_mkdevmap(pte_t pte)
-{
-	return __pte(pte_val(pte) | _PAGE_DEVMAP);
-}
-
 static inline pte_t pte_mkhuge(pte_t pte)
 {
 	return pte;
@@ -790,11 +778,6 @@ static inline pmd_t pmd_mkdirty(pmd_t pm
 	return pte_pmd(pte_mkdirty(pmd_pte(pmd)));
 }
 
-static inline pmd_t pmd_mkdevmap(pmd_t pmd)
-{
-	return pte_pmd(pte_mkdevmap(pmd_pte(pmd)));
-}
-
 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
 static inline bool pmd_special(pmd_t pmd)
 {
@@ -946,11 +929,6 @@ static inline pud_t pud_mkhuge(pud_t pud
 	return pud;
 }
 
-static inline pud_t pud_mkdevmap(pud_t pud)
-{
-	return pte_pud(pte_mkdevmap(pud_pte(pud)));
-}
-
 static inline int pudp_set_access_flags(struct vm_area_struct *vma,
 					unsigned long address, pud_t *pudp,
 					pud_t entry, int dirty)
--- a/arch/riscv/Kconfig~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/riscv/Kconfig
@@ -46,7 +46,6 @@ config RISCV
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
 	select ARCH_HAS_PTDUMP if MMU
-	select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SET_DIRECT_MAP if MMU
 	select ARCH_HAS_SET_MEMORY if MMU
--- a/arch/x86/include/asm/pgtable.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/x86/include/asm/pgtable.h
@@ -301,16 +301,15 @@ static inline bool pmd_leaf(pmd_t pte)
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-/* NOTE: when predicate huge page, consider also pmd_devmap, or use pmd_leaf */
 static inline int pmd_trans_huge(pmd_t pmd)
 {
-	return (pmd_val(pmd) & (_PAGE_PSE|_PAGE_DEVMAP)) == _PAGE_PSE;
+	return (pmd_val(pmd) & _PAGE_PSE) == _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;
+	return (pud_val(pud) & _PAGE_PSE) == _PAGE_PSE;
 }
 #endif
 
@@ -320,24 +319,6 @@ static inline int has_transparent_hugepa
 	return boot_cpu_has(X86_FEATURE_PSE);
 }
 
-#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
-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
-
 #ifdef CONFIG_ARCH_SUPPORTS_PMD_PFNMAP
 static inline bool pmd_special(pmd_t pmd)
 {
@@ -361,12 +342,6 @@ static inline pud_t pud_mkspecial(pud_t
 	return pud_set_flags(pud, _PAGE_SPECIAL);
 }
 #endif	/* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */
-
-static inline int pgd_devmap(pgd_t pgd)
-{
-	return 0;
-}
-#endif
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 static inline pte_t pte_set_flags(pte_t pte, pteval_t set)
@@ -527,11 +502,6 @@ static inline pte_t pte_mkspecial(pte_t
 	return pte_set_flags(pte, _PAGE_SPECIAL);
 }
 
-static inline pte_t pte_mkdevmap(pte_t pte)
-{
-	return pte_set_flags(pte, _PAGE_SPECIAL|_PAGE_DEVMAP);
-}
-
 /* See comments above mksaveddirty_shift() */
 static inline pmd_t pmd_mksaveddirty(pmd_t pmd)
 {
@@ -603,11 +573,6 @@ static inline pmd_t pmd_mkwrite_shstk(pm
 	return pmd_set_flags(pmd, _PAGE_DIRTY);
 }
 
-static inline pmd_t pmd_mkdevmap(pmd_t pmd)
-{
-	return pmd_set_flags(pmd, _PAGE_DEVMAP);
-}
-
 static inline pmd_t pmd_mkhuge(pmd_t pmd)
 {
 	return pmd_set_flags(pmd, _PAGE_PSE);
@@ -673,11 +638,6 @@ static inline pud_t pud_mkdirty(pud_t pu
 	return pud_mksaveddirty(pud);
 }
 
-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);
@@ -1008,13 +968,6 @@ static inline int pte_present(pte_t a)
 	return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE);
 }
 
-#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
-static inline int pte_devmap(pte_t a)
-{
-	return (pte_flags(a) & _PAGE_DEVMAP) == _PAGE_DEVMAP;
-}
-#endif
-
 #define pte_accessible pte_accessible
 static inline bool pte_accessible(struct mm_struct *mm, pte_t a)
 {
--- a/arch/x86/include/asm/pgtable_types.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/x86/include/asm/pgtable_types.h
@@ -34,7 +34,6 @@
 #define _PAGE_BIT_UFFD_WP	_PAGE_BIT_SOFTW2 /* userfaultfd wrprotected */
 #define _PAGE_BIT_SOFT_DIRTY	_PAGE_BIT_SOFTW3 /* software dirty tracking */
 #define _PAGE_BIT_KERNEL_4K	_PAGE_BIT_SOFTW3 /* page must not be converted to large */
-#define _PAGE_BIT_DEVMAP	_PAGE_BIT_SOFTW4
 
 #ifdef CONFIG_X86_64
 #define _PAGE_BIT_SAVED_DIRTY	_PAGE_BIT_SOFTW5 /* Saved Dirty bit (leaf) */
@@ -121,11 +120,9 @@
 
 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
 #define _PAGE_NX	(_AT(pteval_t, 1) << _PAGE_BIT_NX)
-#define _PAGE_DEVMAP	(_AT(u64, 1) << _PAGE_BIT_DEVMAP)
 #define _PAGE_SOFTW4	(_AT(pteval_t, 1) << _PAGE_BIT_SOFTW4)
 #else
 #define _PAGE_NX	(_AT(pteval_t, 0))
-#define _PAGE_DEVMAP	(_AT(pteval_t, 0))
 #define _PAGE_SOFTW4	(_AT(pteval_t, 0))
 #endif
 
@@ -154,7 +151,7 @@
 #define _COMMON_PAGE_CHG_MASK	(PTE_PFN_MASK | _PAGE_PCD | _PAGE_PWT |	\
 				 _PAGE_SPECIAL | _PAGE_ACCESSED |	\
 				 _PAGE_DIRTY_BITS | _PAGE_SOFT_DIRTY |	\
-				 _PAGE_DEVMAP | _PAGE_CC | _PAGE_UFFD_WP)
+				 _PAGE_CC | _PAGE_UFFD_WP)
 #define _PAGE_CHG_MASK	(_COMMON_PAGE_CHG_MASK | _PAGE_PAT)
 #define _HPAGE_CHG_MASK (_COMMON_PAGE_CHG_MASK | _PAGE_PSE | _PAGE_PAT_LARGE)
 
--- a/arch/x86/Kconfig~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/arch/x86/Kconfig
@@ -101,7 +101,6 @@ config X86
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_PMEM_API		if X86_64
 	select ARCH_HAS_PREEMPT_LAZY
-	select ARCH_HAS_PTE_DEVMAP		if X86_64
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_HW_PTE_YOUNG
 	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
--- a/Documentation/mm/arch_pgtable_helpers.rst~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/Documentation/mm/arch_pgtable_helpers.rst
@@ -30,8 +30,6 @@ PTE Page Table Helpers
 +---------------------------+--------------------------------------------------+
 | pte_protnone              | Tests a PROT_NONE PTE                            |
 +---------------------------+--------------------------------------------------+
-| pte_devmap                | Tests a ZONE_DEVICE mapped PTE                   |
-+---------------------------+--------------------------------------------------+
 | pte_soft_dirty            | Tests a soft dirty PTE                           |
 +---------------------------+--------------------------------------------------+
 | pte_swp_soft_dirty        | Tests a soft dirty swapped PTE                   |
@@ -104,8 +102,6 @@ PMD Page Table Helpers
 +---------------------------+--------------------------------------------------+
 | pmd_protnone              | Tests a PROT_NONE PMD                            |
 +---------------------------+--------------------------------------------------+
-| pmd_devmap                | Tests a ZONE_DEVICE mapped PMD                   |
-+---------------------------+--------------------------------------------------+
 | pmd_soft_dirty            | Tests a soft dirty PMD                           |
 +---------------------------+--------------------------------------------------+
 | pmd_swp_soft_dirty        | Tests a soft dirty swapped PMD                   |
@@ -177,8 +173,6 @@ PUD Page Table Helpers
 +---------------------------+--------------------------------------------------+
 | pud_write                 | Tests a writable PUD                             |
 +---------------------------+--------------------------------------------------+
-| pud_devmap                | Tests a ZONE_DEVICE mapped PUD                   |
-+---------------------------+--------------------------------------------------+
 | pud_mkyoung               | Creates a young PUD                              |
 +---------------------------+--------------------------------------------------+
 | pud_mkold                 | Creates an old PUD                               |
--- a/include/linux/mm.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/include/linux/mm.h
@@ -2704,13 +2704,6 @@ static inline pud_t pud_mkspecial(pud_t
 }
 #endif	/* CONFIG_ARCH_SUPPORTS_PUD_PFNMAP */
 
-#ifndef CONFIG_ARCH_HAS_PTE_DEVMAP
-static inline int pte_devmap(pte_t pte)
-{
-	return 0;
-}
-#endif
-
 extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
 			       spinlock_t **ptl);
 static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
--- a/include/linux/pgtable.h~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/include/linux/pgtable.h
@@ -1643,21 +1643,6 @@ static inline int pud_write(pud_t pud)
 }
 #endif /* pud_write */
 
-#if !defined(CONFIG_ARCH_HAS_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE)
-static inline int pmd_devmap(pmd_t pmd)
-{
-	return 0;
-}
-static inline int pud_devmap(pud_t pud)
-{
-	return 0;
-}
-static inline int pgd_devmap(pgd_t pgd)
-{
-	return 0;
-}
-#endif
-
 #if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \
 	!defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
 static inline int pud_trans_huge(pud_t pud)
@@ -1912,8 +1897,8 @@ typedef unsigned int pgtbl_mod_mask;
  * - It should contain a huge PFN, which points to a huge page larger than
  *   PAGE_SIZE of the platform.  The PFN format isn't important here.
  *
- * - It should cover all kinds of huge mappings (e.g., pXd_trans_huge(),
- *   pXd_devmap(), or hugetlb mappings).
+ * - It should cover all kinds of huge mappings (i.e. pXd_trans_huge()
+ *   or hugetlb mappings).
  */
 #ifndef pgd_leaf
 #define pgd_leaf(x)	false
--- a/mm/debug_vm_pgtable.c~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/mm/debug_vm_pgtable.c
@@ -348,12 +348,6 @@ static void __init pud_advanced_tests(st
 	vaddr &= HPAGE_PUD_MASK;
 
 	pud = pfn_pud(args->pud_pfn, args->page_prot);
-	/*
-	 * Some architectures have debug checks to make sure
-	 * huge pud mapping are only found with devmap entries
-	 * For now test with only devmap entries.
-	 */
-	pud = pud_mkdevmap(pud);
 	set_pud_at(args->mm, vaddr, args->pudp, pud);
 	flush_dcache_page(page);
 	pudp_set_wrprotect(args->mm, vaddr, args->pudp);
@@ -366,7 +360,6 @@ static void __init pud_advanced_tests(st
 	WARN_ON(!pud_none(pud));
 #endif /* __PAGETABLE_PMD_FOLDED */
 	pud = pfn_pud(args->pud_pfn, args->page_prot);
-	pud = pud_mkdevmap(pud);
 	pud = pud_wrprotect(pud);
 	pud = pud_mkclean(pud);
 	set_pud_at(args->mm, vaddr, args->pudp, pud);
@@ -384,7 +377,6 @@ static void __init pud_advanced_tests(st
 #endif /* __PAGETABLE_PMD_FOLDED */
 
 	pud = pfn_pud(args->pud_pfn, args->page_prot);
-	pud = pud_mkdevmap(pud);
 	pud = pud_mkyoung(pud);
 	set_pud_at(args->mm, vaddr, args->pudp, pud);
 	flush_dcache_page(page);
@@ -693,53 +685,6 @@ static void __init pmd_protnone_tests(st
 static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
-#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
-static void __init pte_devmap_tests(struct pgtable_debug_args *args)
-{
-	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
-
-	pr_debug("Validating PTE devmap\n");
-	WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
-}
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void __init pmd_devmap_tests(struct pgtable_debug_args *args)
-{
-	pmd_t pmd;
-
-	if (!has_transparent_hugepage())
-		return;
-
-	pr_debug("Validating PMD devmap\n");
-	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
-	WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
-}
-
-#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-static void __init pud_devmap_tests(struct pgtable_debug_args *args)
-{
-	pud_t pud;
-
-	if (!has_transparent_pud_hugepage())
-		return;
-
-	pr_debug("Validating PUD devmap\n");
-	pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
-	WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
-}
-#else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
-static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
-#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
-#else  /* CONFIG_TRANSPARENT_HUGEPAGE */
-static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
-static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-#else
-static void __init pte_devmap_tests(struct pgtable_debug_args *args) { }
-static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
-static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
-#endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
-
 static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args)
 {
 	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
@@ -1333,10 +1278,6 @@ static int __init debug_vm_pgtable(void)
 	pte_protnone_tests(&args);
 	pmd_protnone_tests(&args);
 
-	pte_devmap_tests(&args);
-	pmd_devmap_tests(&args);
-	pud_devmap_tests(&args);
-
 	pte_soft_dirty_tests(&args);
 	pmd_soft_dirty_tests(&args);
 	pte_swap_soft_dirty_tests(&args);
--- a/mm/hmm.c~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/mm/hmm.c
@@ -405,8 +405,7 @@ again:
 	return 0;
 }
 
-#if defined(CONFIG_ARCH_HAS_PTE_DEVMAP) && \
-    defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
+#if defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
 static inline unsigned long pud_to_hmm_pfn_flags(struct hmm_range *range,
 						 pud_t pud)
 {
--- a/mm/Kconfig~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/mm/Kconfig
@@ -1117,9 +1117,6 @@ config ARCH_HAS_CURRENT_STACK_POINTER
 	  register alias named "current_stack_pointer", this config can be
 	  selected.
 
-config ARCH_HAS_PTE_DEVMAP
-	bool
-
 config ARCH_HAS_ZONE_DMA_SET
 	bool
 
@@ -1137,7 +1134,6 @@ config ZONE_DEVICE
 	depends on MEMORY_HOTPLUG
 	depends on MEMORY_HOTREMOVE
 	depends on SPARSEMEM_VMEMMAP
-	depends on ARCH_HAS_PTE_DEVMAP
 	select XARRAY_MULTI
 
 	help
--- a/mm/madvise.c~mm-remove-devmap-related-functions-and-page-table-bits
+++ a/mm/madvise.c
@@ -1069,7 +1069,7 @@ static int guard_install_pud_entry(pud_t
 	pud_t pudval = pudp_get(pud);
 
 	/* If huge return >0 so we abort the operation + zap. */
-	return pud_trans_huge(pudval) || pud_devmap(pudval);
+	return pud_trans_huge(pudval);
 }
 
 static int guard_install_pmd_entry(pmd_t *pmd, unsigned long addr,
@@ -1078,7 +1078,7 @@ static int guard_install_pmd_entry(pmd_t
 	pmd_t pmdval = pmdp_get(pmd);
 
 	/* If huge return >0 so we abort the operation + zap. */
-	return pmd_trans_huge(pmdval) || pmd_devmap(pmdval);
+	return pmd_trans_huge(pmdval);
 }
 
 static int guard_install_pte_entry(pte_t *pte, unsigned long addr,
@@ -1189,7 +1189,7 @@ static int guard_remove_pud_entry(pud_t
 	pud_t pudval = pudp_get(pud);
 
 	/* If huge, cannot have guard pages present, so no-op - skip. */
-	if (pud_trans_huge(pudval) || pud_devmap(pudval))
+	if (pud_trans_huge(pudval))
 		walk->action = ACTION_CONTINUE;
 
 	return 0;
@@ -1201,7 +1201,7 @@ static int guard_remove_pmd_entry(pmd_t
 	pmd_t pmdval = pmdp_get(pmd);
 
 	/* If huge, cannot have guard pages present, so no-op - skip. */
-	if (pmd_trans_huge(pmdval) || pmd_devmap(pmdval))
+	if (pmd_trans_huge(pmdval))
 		walk->action = ACTION_CONTINUE;
 
 	return 0;
_

Patches currently in -mm which might be from apopple@nvidia.com are