[PATCH 12/12] mm: Remove devmap related functions and page table bits

From: Alistair Popple
Date: Tue Sep 10 2024 - 00:20:53 EST

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.

Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
Acked-by: Will Deacon <will@xxxxxxxxxx> # arm64
---
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/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 | 52 +------------------
arch/powerpc/include/asm/book3s/64/radix.h | 14 +-----
arch/x86/Kconfig | 1 +-
arch/x86/include/asm/pgtable.h | 50 +-----------------
arch/x86/include/asm/pgtable_types.h | 5 +--
include/linux/mm.h | 7 +--
include/linux/pfn_t.h | 20 +-------
include/linux/pgtable.h | 19 +------
mm/Kconfig | 4 +-
mm/debug_vm_pgtable.c | 59 +--------------------
mm/hmm.c | 3 +-
18 files changed, 11 insertions(+), 269 deletions(-)

diff --git a/Documentation/mm/arch_pgtable_helpers.rst b/Documentation/mm/arch_pgtable_helpers.rst
index af24516..c88c7fa 100644
--- a/Documentation/mm/arch_pgtable_helpers.rst
+++ b/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 |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 6494848..b6d9c29 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -36,7 +36,6 @@ config ARM64
select ARCH_HAS_MEMBARRIER_SYNC_CORE
select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
- select ARCH_HAS_PTE_DEVMAP
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_HW_PTE_YOUNG
select ARCH_HAS_SETUP_DMA_OPS
diff --git a/arch/arm64/include/asm/pgtable-prot.h b/arch/arm64/include/asm/pgtable-prot.h
index b11cfb9..043b102 100644
--- a/arch/arm64/include/asm/pgtable-prot.h
+++ b/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
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 7a4f560..d21b6c9 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -107,7 +107,6 @@ static inline pteval_t __phys_to_pte_val(phys_addr_t phys)
#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))

@@ -269,11 +268,6 @@ 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)
{
@@ -569,14 +563,6 @@ static inline int pmd_trans_huge(pmd_t pmd)

#define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))

-#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)));
-}
-
#define __pmd_to_phys(pmd) __pte_to_phys(pmd_pte(pmd))
#define __phys_to_pmd_val(phys) __phys_to_pte_val(phys)
#define pmd_pfn(pmd) ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT)
@@ -1136,16 +1122,6 @@ static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
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
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d7b09b0..8094e48 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -144,7 +144,6 @@ config PPC
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
select ARCH_HAS_PHYS_TO_DMA
select ARCH_HAS_PMEM_API
- 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
diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index c654c37..d23244b 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -140,12 +140,6 @@ extern pmd_t hash__pmdp_huge_get_and_clear(struct mm_struct *mm,
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 */
diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
index 0bf6fd0..0fb5b7d 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
@@ -259,7 +259,7 @@ static inline void mark_hpte_slot_valid(unsigned char *hpte_slot_array,
*/
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_clear(struct mm_struct *mm,
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 */
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 5da92ba..9bf54b5 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/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,
@@ -635,24 +634,6 @@ 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 */
@@ -1406,35 +1387,6 @@ static inline bool arch_needs_pgtable_deposit(void)
}
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 */

diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index 8f55ff7..df23a82 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -264,7 +264,7 @@ static inline int radix__p4d_bad(p4d_t p4d)

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(pmd_t pmd)

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_pud_hugepage(void)
}
#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,
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b74b9ee..9177fe3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -91,7 +91,6 @@ config X86
select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
select ARCH_HAS_PMEM_API if X86_64
- 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
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 8d12bfa..b576a14 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -280,16 +280,15 @@ 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

@@ -299,29 +298,6 @@ static inline int has_transparent_hugepage(void)
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
-
-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)
@@ -482,11 +458,6 @@ static inline pte_t pte_mkspecial(pte_t pte)
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);
-}
-
static inline pmd_t pmd_set_flags(pmd_t pmd, pmdval_t set)
{
pmdval_t v = native_pmd_val(pmd);
@@ -572,11 +543,6 @@ static inline pmd_t pmd_mkwrite_shstk(pmd_t pmd)
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);
@@ -656,11 +622,6 @@ static inline pud_t pud_mkdirty(pud_t pud)
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);
@@ -988,13 +949,6 @@ 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)
{
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 2f32113..37c250f 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -33,7 +33,6 @@
#define _PAGE_BIT_CPA_TEST _PAGE_BIT_SOFTW1
#define _PAGE_BIT_UFFD_WP _PAGE_BIT_SOFTW2 /* userfaultfd wrprotected */
#define _PAGE_BIT_SOFT_DIRTY _PAGE_BIT_SOFTW3 /* software dirty tracking */
-#define _PAGE_BIT_DEVMAP _PAGE_BIT_SOFTW4

#ifdef CONFIG_X86_64
#define _PAGE_BIT_SAVED_DIRTY _PAGE_BIT_SOFTW5 /* Saved Dirty bit */
@@ -117,11 +116,9 @@

#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

@@ -148,7 +145,7 @@
#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)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 592b992..5976276 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2624,13 +2624,6 @@ static inline pte_t pte_mkspecial(pte_t pte)
}
#endif

-#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,
diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h
index 2d91482..0100ad8 100644
--- a/include/linux/pfn_t.h
+++ b/include/linux/pfn_t.h
@@ -97,26 +97,6 @@ static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot)
#endif
#endif

-#ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
-static inline bool pfn_t_devmap(pfn_t pfn)
-{
- const u64 flags = PFN_DEV|PFN_MAP;
-
- return (pfn.val & flags) == flags;
-}
-#else
-static inline bool pfn_t_devmap(pfn_t pfn)
-{
- return false;
-}
-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 /* CONFIG_ARCH_HAS_PTE_DEVMAP */
-
#ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
static inline bool pfn_t_special(pfn_t pfn)
{
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index a68e279..f3a95e3 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1616,21 +1616,6 @@ 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)
@@ -1885,8 +1870,8 @@ 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
diff --git a/mm/Kconfig b/mm/Kconfig
index 8078a4b..58402d7 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1017,9 +1017,6 @@ 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

@@ -1037,7 +1034,6 @@ 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
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index e4969fb..1262148 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -348,12 +348,6 @@ static void __init pud_advanced_tests(struct pgtable_debug_args *args)
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(struct pgtable_debug_args *args)
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(struct pgtable_debug_args *args)
#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(struct pgtable_debug_args *args)
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);
@@ -1341,10 +1286,6 @@ 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);
diff --git a/mm/hmm.c b/mm/hmm.c
index 1b85ed6..4fca141 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -395,8 +395,7 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp,
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)
{
--
git-series 0.9.1