Subject: [PATCH 11/12] mm: consolidate pud_index() and pud_offset() definitions

From: Mike Rapoport <[email-masked]>
Date: Tue, 12 May 2020 21:44:21 +0300

From: Mike Rapoport <[email-masked]>

All architectures that have at least four-level page tables define
pud_offset() as an entry in the array of PUDs indexed by the pud_index(),
where pud_index() is

	(address >> PUD_SHIFT) & (PTRS_PER_PUD - 1)

For the most architectures the pud_offset() implementation relies on
the availability of pud_page_vaddr() that converts a PUD entry value to the
virtual address of the page containing PUD array.

Let's use such implementation as a generic and drop most of the definitions
of pud_index() and pud_offset() in <asm/pgtable.h> files.

The architectures that didn't provide pud_page_vaddr() are updated to
have that defined.

The generic implementation can be overridden by an architecture and this
ability is currently in use by there architectures:
* s390 has custom definitions of all page table accessors

Signed-off-by: Mike Rapoport <[email-masked]>
---
 arch/arm64/include/asm/pgtable.h                |  8 +++++---
 arch/csky/include/asm/pgtable.h                 |  2 --
 arch/ia64/include/asm/pgtable.h                 |  6 ------
 arch/mips/include/asm/pgtable-32.h              |  1 -
 arch/mips/include/asm/pgtable-64.h              |  7 -------
 arch/powerpc/include/asm/book3s/64/pgtable.h    |  4 ----
 arch/powerpc/include/asm/nohash/64/pgtable-4k.h |  4 ----
 arch/s390/include/asm/pgtable.h                 |  1 +
 arch/sh/include/asm/pgtable_32.h                |  2 --
 arch/sh/include/asm/pgtable_64.h                |  2 --
 arch/sparc/include/asm/pgtable_64.h             |  5 -----
 arch/x86/include/asm/pgtable.h                  | 11 -----------
 include/asm-generic/pgtable-nopud.h             |  1 +
 include/linux/pgtable.h                         | 16 ++++++++++++++++
 14 files changed, 23 insertions(+), 47 deletions(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index d0175335a2f2..c0155814b374 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -626,11 +626,13 @@ static inline phys_addr_t p4d_page_paddr(p4d_t p4d)
 	return __p4d_to_phys(p4d);
 }
 
-/* Find an entry in the frst-level page table. */
-#define pud_index(addr)		(((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
+static inline unsigned long p4d_page_vaddr(p4d_t p4d)
+{
+	return (unsigned long)__va(p4d_page_paddr(p4d));
+}
 
+/* Find an entry in the frst-level page table. */
 #define pud_offset_phys(dir, addr)	(p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t))
-#define pud_offset(dir, addr)		((pud_t *)__va(pud_offset_phys((dir), (addr))))
 
 #define pud_set_fixmap(addr)		((pud_t *)set_fixmap_offset(FIX_PUD, addr))
 #define pud_set_fixmap_offset(p4d, addr)	pud_set_fixmap(pud_offset_phys(p4d, addr))
diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
index dc613f20e2e1..c5ab20970857 100644
--- a/arch/csky/include/asm/pgtable.h
+++ b/arch/csky/include/asm/pgtable.h
@@ -220,8 +220,6 @@ static inline pte_t pte_mkyoung(pte_t pte)
 	return pte;
 }
 
-#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
-
 /* to find an entry in a kernel page-table-directory */
 #define pgd_offset_k(address)	pgd_offset(&init_mm, address)
 
diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
index d75d981e6ee1..4c24e5e18bff 100644
--- a/arch/ia64/include/asm/pgtable.h
+++ b/arch/ia64/include/asm/pgtable.h
@@ -383,12 +383,6 @@ pgd_offset (const struct mm_struct *mm, unsigned long address)
    here.  */
 #define pgd_offset_gate(mm, addr)	pgd_offset_k(addr)
 
-#if CONFIG_PGTABLE_LEVELS == 4
-/* Find an entry in the second-level page table.. */
-#define pud_offset(dir,addr) \
-	((pud_t *) p4d_page_vaddr(*(dir)) + (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
-#endif
-
 /* atomic versions of the some PTE manipulations: */
 
 static inline int
diff --git a/arch/mips/include/asm/pgtable-32.h b/arch/mips/include/asm/pgtable-32.h
index 05b51c344939..9c0e7a5ffc75 100644
--- a/arch/mips/include/asm/pgtable-32.h
+++ b/arch/mips/include/asm/pgtable-32.h
@@ -199,7 +199,6 @@ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
 #define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
-#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
 
 /* to find an entry in a page-table-directory */
 #define pgd_offset(mm, addr)	((mm)->pgd + pgd_index(addr))
diff --git a/arch/mips/include/asm/pgtable-64.h b/arch/mips/include/asm/pgtable-64.h
index 21fb55510d35..38170fdac5bf 100644
--- a/arch/mips/include/asm/pgtable-64.h
+++ b/arch/mips/include/asm/pgtable-64.h
@@ -172,8 +172,6 @@
 
 extern pte_t invalid_pte_table[PTRS_PER_PTE];
 
-#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
-
 #ifndef __PAGETABLE_PUD_FOLDED
 /*
  * For 4-level pagetables we defines these ourselves, for 3-level the
@@ -222,11 +220,6 @@ static inline unsigned long p4d_page_vaddr(p4d_t p4d)
 
 #define p4d_index(address)	(((address) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
 
-static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
-{
-	return (pud_t *)p4d_page_vaddr(*p4d) + pud_index(address);
-}
-
 static inline void set_p4d(p4d_t *p4d, p4d_t p4dval)
 {
 	*p4d = p4dval;
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index fbb5d12c6214..fffe28d52c02 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1009,7 +1009,6 @@ extern struct page *p4d_page(p4d_t p4d);
 #define p4d_page_vaddr(p4d)	__va(p4d_val(p4d) & ~P4D_MASKED_BITS)
 
 #define pgd_index(address) (((address) >> (PGDIR_SHIFT)) & (PTRS_PER_PGD - 1))
-#define pud_index(address) (((address) >> (PUD_SHIFT)) & (PTRS_PER_PUD - 1))
 
 /*
  * Find an entry in a page-table-directory.  We combine the address region
@@ -1018,9 +1017,6 @@ extern struct page *p4d_page(p4d_t p4d);
 
 #define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))
 
-#define pud_offset(p4dp, addr)	\
-	(((pud_t *) p4d_page_vaddr(*(p4dp))) + pud_index(addr))
-
 /* to find an entry in a kernel page-table-directory */
 /* This now only contains the vmalloc pages */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
diff --git a/arch/powerpc/include/asm/nohash/64/pgtable-4k.h b/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
index 81b1c54e3cf1..fe2f4c9acd9e 100644
--- a/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable-4k.h
@@ -78,10 +78,6 @@ extern struct page *p4d_page(p4d_t p4d);
 
 #endif /* !__ASSEMBLY__ */
 
-#define pud_offset(p4dp, addr)	\
-  (((pud_t *) p4d_page_vaddr(*(p4dp))) + \
-    (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1)))
-
 #define pud_ERROR(e) \
 	pr_err("%s:%d: bad pud %08lx.\n", __FILE__, __LINE__, pud_val(e))
 
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index c162e50c7689..e1eef67a0877 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1274,6 +1274,7 @@ static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
 		return (pud_t *) p4d_deref(*p4d) + pud_index(address);
 	return (pud_t *) p4d;
 }
+#define pud_offset pud_offset
 
 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
 {
diff --git a/arch/sh/include/asm/pgtable_32.h b/arch/sh/include/asm/pgtable_32.h
index 3023943ce731..ccc032e89f75 100644
--- a/arch/sh/include/asm/pgtable_32.h
+++ b/arch/sh/include/asm/pgtable_32.h
@@ -415,8 +415,6 @@ static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 /* to find an entry in a kernel page-table-directory */
 #define pgd_offset_k(address)	pgd_offset(&init_mm, address)
 
-#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
-
 #ifdef CONFIG_X2TLB
 #define pte_ERROR(e) \
 	printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, \
diff --git a/arch/sh/include/asm/pgtable_64.h b/arch/sh/include/asm/pgtable_64.h
index 8d5948f92caf..60aef1191784 100644
--- a/arch/sh/include/asm/pgtable_64.h
+++ b/arch/sh/include/asm/pgtable_64.h
@@ -51,8 +51,6 @@ static __inline__ void set_pte(pte_t *pteptr, pte_t pteval)
 /* To find an entry in a kernel PGD. */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
-#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
-
 /*
  * PMD level access routines. Same notes as above.
  */
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 2da1cec60f4e..f546ea46d41b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -896,11 +896,6 @@ static inline unsigned long pud_pfn(pud_t pud)
 /* to find an entry in a kernel page-table-directory */
 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
-/* Find an entry in the third-level page table.. */
-#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
-#define pud_offset(p4dp, address)	\
-	((pud_t *) p4d_page_vaddr(*(p4dp)) + pud_index(address))
-
 /* We cannot include <linux/mm_types.h> at this point yet: */
 extern struct mm_struct init_mm;
 
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 35e3bf86df20..97efdc62e740 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -895,11 +895,6 @@ static inline int pud_large(pud_t pud)
 }
 #endif	/* CONFIG_PGTABLE_LEVELS > 2 */
 
-static inline unsigned long pud_index(unsigned long address)
-{
-	return (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
-}
-
 #if CONFIG_PGTABLE_LEVELS > 3
 static inline int p4d_none(p4d_t p4d)
 {
@@ -922,12 +917,6 @@ static inline unsigned long p4d_page_vaddr(p4d_t p4d)
  */
 #define p4d_page(p4d)	pfn_to_page(p4d_pfn(p4d))
 
-/* Find an entry in the third-level page table.. */
-static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
-{
-	return (pud_t *)p4d_page_vaddr(*p4d) + pud_index(address);
-}
-
 static inline int p4d_bad(p4d_t p4d)
 {
 	unsigned long ignore_flags = _KERNPG_TABLE | _PAGE_USER;
diff --git a/include/asm-generic/pgtable-nopud.h b/include/asm-generic/pgtable-nopud.h
index ad05c1684bfc..a9d751fbda9e 100644
--- a/include/asm-generic/pgtable-nopud.h
+++ b/include/asm-generic/pgtable-nopud.h
@@ -43,6 +43,7 @@ static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
 {
 	return (pud_t *)p4d;
 }
+#define pud_offset pud_offset
 
 #define pud_val(x)				(p4d_val((x).p4d))
 #define __pud(x)				((pud_t) { __p4d(x) })
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 14cfeb3443c5..3a78ef38eda6 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -53,6 +53,14 @@ static inline unsigned long pmd_index(unsigned long address)
 #define pmd_index pmd_index
 #endif
 
+#ifndef pud_index
+static inline unsigned long pud_index(unsigned long address)
+{
+	return (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
+}
+#define pud_index pud_index
+#endif
+
 #ifndef pte_offset_kernel
 static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
 {
@@ -80,6 +88,14 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
 #define pmd_offset pmd_offset
 #endif
 
+#ifndef pud_offset
+static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
+{
+	return (pud_t *)p4d_page_vaddr(*p4d) + pud_index(address);
+}
+#define pud_offset pud_offset
+#endif
+
 /* FIXME: */
 static inline pmd_t *pmd_off(struct mm_struct *mm, unsigned long va)
 {
-- 
2.26.1