mm: consolidate pte_index() and pte_offset_*() definitions

All architectures define pte_index() as

	(address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)

and all architectures define pte_offset_kernel() as an entry in the array
of PTEs indexed by the pte_index().

For the most architectures the pte_offset_kernel() implementation relies
on the availability of pmd_page_vaddr() that converts a PMD entry value to
the virtual address of the page containing PTEs array.

Let's move x86 definitions of the PTE accessors to the generic place in
<linux/pgtable.h> and then simply drop the respective definitions from the
other architectures.

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

The generic implementation of pte_offset_kernel() can be overridden by an
architecture and alpha makes use of this because it has special ordering
requirements for its version of pte_offset_kernel().

[rppt@linux.ibm.com: v2]
  Link: http://lkml.kernel.org/r/20200514170327.31389-11-rppt@kernel.org
[rppt@linux.ibm.com: update]
  Link: http://lkml.kernel.org/r/20200514170327.31389-12-rppt@kernel.org
[rppt@linux.ibm.com: update]
  Link: http://lkml.kernel.org/r/20200514170327.31389-13-rppt@kernel.org
[akpm@linux-foundation.org: fix x86 warning]
[sfr@canb.auug.org.au: fix powerpc build]
  Link: http://lkml.kernel.org/r/20200607153443.GB738695@linux.ibm.com

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-10-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/include/asm/pgtable.h

@@ -276,15 +276,6 @@ extern inline pte_t pte_mkwrite(pte_t pte)	{ pte_val(pte) &= ~_PAGE_FOW; return
 extern inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= __DIRTY_BITS; return pte; }
 extern inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= __ACCESS_BITS; return pte; }
 
-#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))
-
-/* to find an entry in a kernel page-table-directory */
-#define pgd_offset_k(address) pgd_offset(&init_mm, (address))
-
-/* to find an entry in a page-table-directory. */
-#define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
-#define pgd_offset(mm, address)	((mm)->pgd+pgd_index(address))
-
 /*
  * The smp_read_barrier_depends() in the following functions are required to
  * order the load of *dir (the pointer in the top level page table) with any
@@ -305,6 +296,7 @@ extern inline pmd_t * pmd_offset(pud_t * dir, unsigned long address)
 	smp_read_barrier_depends(); /* see above */
 	return ret;
 }
+#define pmd_offset pmd_offset
 
 /* Find an entry in the third-level page table.. */
 extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address)
@@ -314,9 +306,7 @@ extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address)
 	smp_read_barrier_depends(); /* see above */
 	return ret;
 }
-
-#define pte_offset_map(dir,addr)	pte_offset_kernel((dir),(addr))
-#define pte_unmap(pte)			do { } while (0)
+#define pte_offset_kernel pte_offset_kernel
 
 extern pgd_t swapper_pg_dir[1024];
 

arch/arc/include/asm/pgtable.h

@@ -248,9 +248,6 @@
 extern char empty_zero_page[PAGE_SIZE];
 #define ZERO_PAGE(vaddr)	(virt_to_page(empty_zero_page))
 
-#define pte_unmap(pte)		do { } while (0)
-#define pte_unmap_nested(pte)		do { } while (0)
-
 #define set_pte(pteptr, pteval)	((*(pteptr)) = (pteval))
 #define set_pmd(pmdptr, pmdval)	(*(pmdptr) = pmdval)
 
@@ -282,18 +279,6 @@ static inline void pmd_set(pmd_t *pmdp, pte_t *ptep)
 
 /* Don't use virt_to_pfn for macros below: could cause truncations for PAE40*/
 #define pte_pfn(pte)		(pte_val(pte) >> PAGE_SHIFT)
-#define __pte_index(addr)	(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
-
-/*
- * pte_offset gets a @ptr to PMD entry (PGD in our 2-tier paging system)
- * and returns ptr to PTE entry corresponding to @addr
- */
-#define pte_offset(dir, addr) ((pte_t *)(pmd_page_vaddr(*dir)) +\
-					 __pte_index(addr))
-
-/* No mapping of Page Tables in high mem etc, so following same as above */
-#define pte_offset_kernel(dir, addr)		pte_offset(dir, addr)
-#define pte_offset_map(dir, addr)		pte_offset(dir, addr)
 
 /* Zoo of pte_xxx function */
 #define pte_read(pte)		(pte_val(pte) & _PAGE_READ)
@@ -331,13 +316,6 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 	set_pte(ptep, pteval);
 }
 
-/*
- * All kernel related VM pages are in init's mm.
- */
-#define pgd_offset_k(address)	pgd_offset(&init_mm, address)
-#define pgd_index(addr)		((addr) >> PGDIR_SHIFT)
-#define pgd_offset(mm, addr)	(((mm)->pgd)+pgd_index(addr))
-
 /*
  * Macro to quickly access the PGD entry, utlising the fact that some
  * arch may cache the pointer to Page Directory of "current" task

arch/arm/include/asm/pgtable-2level.h

@@ -187,6 +187,7 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 {
 	return (pmd_t *)pud;
 }
+#define pmd_offset pmd_offset
 
 #define pmd_large(pmd)		(pmd_val(pmd) & 2)
 #define pmd_leaf(pmd)		(pmd_val(pmd) & 2)

arch/arm/include/asm/pgtable-3level.h

@@ -133,13 +133,6 @@ static inline pmd_t *pud_page_vaddr(pud_t pud)
 	return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
 }
 
-/* Find an entry in the second-level page table.. */
-#define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
-static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
-{
-	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
-}
-
 #define pmd_bad(pmd)		(!(pmd_val(pmd) & 2))
 
 #define copy_pmd(pmdpd,pmdps)		\

arch/arm/include/asm/pgtable-nommu.h

@@ -22,7 +22,6 @@
 #define pgd_bad(pgd)		(0)
 #define pgd_clear(pgdp)
 #define kern_addr_valid(addr)	(1)
-#define	pmd_offset(a, b)	((void *)0)
 /* FIXME */
 /*
  * PMD_SHIFT determines the size of the area a second-level page table can map

arch/arm/include/asm/pgtable.h

@@ -166,14 +166,6 @@ extern struct page *empty_zero_page;
 
 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 
-/* to find an entry in a page-table-directory */
-#define pgd_index(addr)		((addr) >> PGDIR_SHIFT)
-
-#define pgd_offset(mm, addr)	((mm)->pgd + pgd_index(addr))
-
-/* to find an entry in a kernel page-table-directory */
-#define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
-
 #define pmd_none(pmd)		(!pmd_val(pmd))
 
 static inline pte_t *pmd_page_vaddr(pmd_t pmd)
@@ -183,21 +175,6 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd)
 
 #define pmd_page(pmd)		pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 
-#ifndef CONFIG_HIGHPTE
-#define __pte_map(pmd)		pmd_page_vaddr(*(pmd))
-#define __pte_unmap(pte)	do { } while (0)
-#else
-#define __pte_map(pmd)		(pte_t *)kmap_atomic(pmd_page(*(pmd)))
-#define __pte_unmap(pte)	kunmap_atomic(pte)
-#endif
-
-#define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
-
-#define pte_offset_kernel(pmd,addr)	(pmd_page_vaddr(*(pmd)) + pte_index(addr))
-
-#define pte_offset_map(pmd,addr)	(__pte_map(pmd) + pte_index(addr))
-#define pte_unmap(pte)			__pte_unmap(pte)
-
 #define pte_pfn(pte)		((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
 #define pfn_pte(pfn,prot)	__pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 

arch/arm64/include/asm/pgtable.h

@@ -506,15 +506,13 @@ static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
 	return __pmd_to_phys(pmd);
 }
 
-static inline void pte_unmap(pte_t *pte) { }
+static inline unsigned long pmd_page_vaddr(pmd_t pmd)
+{
+	return (unsigned long)__va(pmd_page_paddr(pmd));
+}
 
 /* Find an entry in the third-level page table. */
-#define pte_index(addr)		(((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
-
 #define pte_offset_phys(dir,addr)	(pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
-#define pte_offset_kernel(dir,addr)	((pte_t *)__va(pte_offset_phys((dir), (addr))))
-
-#define pte_offset_map(dir,addr)	pte_offset_kernel((dir), (addr))
 
 #define pte_set_fixmap(addr)		((pte_t *)set_fixmap_offset(FIX_PTE, addr))
 #define pte_set_fixmap_offset(pmd, addr)	pte_set_fixmap(pte_offset_phys(pmd, addr))
@@ -568,11 +566,13 @@ static inline phys_addr_t pud_page_paddr(pud_t pud)
 	return __pud_to_phys(pud);
 }
 
-/* Find an entry in the second-level page table. */
-#define pmd_index(addr)		(((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
+static inline unsigned long pud_page_vaddr(pud_t pud)
+{
+	return (unsigned long)__va(pud_page_paddr(pud));
+}
 
+/* Find an entry in the second-level page table. */
 #define pmd_offset_phys(dir, addr)	(pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t))
-#define pmd_offset(dir, addr)		((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
 
 #define pmd_set_fixmap(addr)		((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
 #define pmd_set_fixmap_offset(pud, addr)	pmd_set_fixmap(pmd_offset_phys(pud, addr))
@@ -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))
@@ -657,16 +659,6 @@ static inline phys_addr_t p4d_page_paddr(p4d_t p4d)
 
 #define pgd_ERROR(pgd)		__pgd_error(__FILE__, __LINE__, pgd_val(pgd))
 
-/* to find an entry in a page-table-directory */
-#define pgd_index(addr)		(((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
-
-#define pgd_offset_raw(pgd, addr)	((pgd) + pgd_index(addr))
-
-#define pgd_offset(mm, addr)	(pgd_offset_raw((mm)->pgd, (addr)))
-
-/* to find an entry in a kernel page-table-directory */
-#define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
-
 #define pgd_set_fixmap(addr)	((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
 #define pgd_clear_fixmap()	clear_fixmap(FIX_PGD)
 

arch/arm64/kernel/hibernate.c

@@ -188,7 +188,7 @@ static int trans_pgd_map_page(pgd_t *trans_pgd, void *page,
 	pmd_t *pmdp;
 	pte_t *ptep;
 
-	pgdp = pgd_offset_raw(trans_pgd, dst_addr);
+	pgdp = pgd_offset_pgd(trans_pgd, dst_addr);
 	if (pgd_none(READ_ONCE(*pgdp))) {
 		pudp = (void *)get_safe_page(GFP_ATOMIC);
 		if (!pudp)
@@ -490,7 +490,7 @@ static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start,
 	unsigned long addr = start;
 	pgd_t *src_pgdp = pgd_offset_k(start);
 
-	dst_pgdp = pgd_offset_raw(dst_pgdp, start);
+	dst_pgdp = pgd_offset_pgd(dst_pgdp, start);
 	do {
 		next = pgd_addr_end(addr, end);
 		if (pgd_none(READ_ONCE(*src_pgdp)))

arch/arm64/mm/kasan_init.c

@@ -190,7 +190,7 @@ void __init kasan_copy_shadow(pgd_t *pgdir)
 
 	pgdp = pgd_offset_k(KASAN_SHADOW_START);
 	pgdp_end = pgd_offset_k(KASAN_SHADOW_END);
-	pgdp_new = pgd_offset_raw(pgdir, KASAN_SHADOW_START);
+	pgdp_new = pgd_offset_pgd(pgdir, KASAN_SHADOW_START);
 	do {
 		set_pgd(pgdp_new, READ_ONCE(*pgdp));
 	} while (pgdp++, pgdp_new++, pgdp != pgdp_end);

arch/arm64/mm/mmu.c

@@ -341,7 +341,7 @@ static void __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
 				 int flags)
 {
 	unsigned long addr, end, next;
-	pgd_t *pgdp = pgd_offset_raw(pgdir, virt);
+	pgd_t *pgdp = pgd_offset_pgd(pgdir, virt);
 
 	/*
 	 * If the virtual and physical address don't have the same offset
@@ -663,13 +663,13 @@ static void __init map_kernel(pgd_t *pgdp)
 			   &vmlinux_initdata, 0, VM_NO_GUARD);
 	map_kernel_segment(pgdp, _data, _end, PAGE_KERNEL, &vmlinux_data, 0, 0);
 
-	if (!READ_ONCE(pgd_val(*pgd_offset_raw(pgdp, FIXADDR_START)))) {
+	if (!READ_ONCE(pgd_val(*pgd_offset_pgd(pgdp, FIXADDR_START)))) {
 		/*
 		 * The fixmap falls in a separate pgd to the kernel, and doesn't
 		 * live in the carveout for the swapper_pg_dir. We can simply
 		 * re-use the existing dir for the fixmap.
 		 */
-		set_pgd(pgd_offset_raw(pgdp, FIXADDR_START),
+		set_pgd(pgd_offset_pgd(pgdp, FIXADDR_START),
 			READ_ONCE(*pgd_offset_k(FIXADDR_START)));
 	} else if (CONFIG_PGTABLE_LEVELS > 3) {
 		pgd_t *bm_pgdp;
@@ -682,7 +682,7 @@ static void __init map_kernel(pgd_t *pgdp)
 		 * entry instead.
 		 */
 		BUG_ON(!IS_ENABLED(CONFIG_ARM64_16K_PAGES));
-		bm_pgdp = pgd_offset_raw(pgdp, FIXADDR_START);
+		bm_pgdp = pgd_offset_pgd(pgdp, FIXADDR_START);
 		bm_p4dp = p4d_offset(bm_pgdp, FIXADDR_START);
 		bm_pudp = pud_set_fixmap_offset(bm_p4dp, FIXADDR_START);
 		pud_populate(&init_mm, bm_pudp, lm_alias(bm_pmd));

arch/c6x/include/asm/pgtable.h

@@ -26,7 +26,6 @@
 #define pgd_clear(pgdp)
 #define kern_addr_valid(addr) (1)
 
-#define pmd_offset(a, b)	((void *)0)
 #define pmd_none(x)		(!pmd_val(x))
 #define pmd_present(x)		(pmd_val(x))
 #define pmd_clear(xp)		do { set_pmd(xp, __pmd(0)); } while (0)

arch/csky/include/asm/pgtable.h

@@ -32,13 +32,6 @@
 #define pgd_ERROR(e) \
 	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
 
-/* Find an entry in the third-level page table.. */
-#define __pte_offset_t(address) \
-	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
-#define pte_offset_kernel(dir, address) \
-	(pmd_page_vaddr(*(dir)) + __pte_offset_t(address))
-#define pte_offset_map(dir, address) \
-	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset_t(address))
 #define pmd_page(pmd)	(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
 #define pte_clear(mm, addr, ptep)	set_pte((ptep), \
 	(((unsigned int) addr & PAGE_OFFSET) ? __pte(_PAGE_GLOBAL) : __pte(0)))
@@ -54,8 +47,6 @@
 #define _PAGE_CHG_MASK	(PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED | \
 			 _CACHE_MASK)
 
-#define pte_unmap(pte)	((void)(pte))
-
 #define __swp_type(x)			(((x).val >> 4) & 0xff)
 #define __swp_offset(x)			((x).val >> 12)
 #define __swp_entry(type, offset)	((swp_entry_t) {((type) << 4) | \
@@ -229,14 +220,6 @@ static inline pte_t pte_mkyoung(pte_t pte)
 	return pte;
 }
 
-#define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
-#define pmd_index(address)	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
-
-/* to find an entry in a kernel page-table-directory */
-#define pgd_offset_k(address)	pgd_offset(&init_mm, address)
-
-#define pgd_index(address)	((address) >> PGDIR_SHIFT)
-
 #define __HAVE_PHYS_MEM_ACCESS_PROT
 struct file;
 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
@@ -280,19 +263,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 		     (pgprot_val(newprot)));
 }
 
-/* to find an entry in a page-table-directory */
-static inline pgd_t *pgd_offset(struct mm_struct *mm, unsigned long address)
-{
-	return mm->pgd + pgd_index(address);
-}
-
-/* Find an entry in the third-level page table.. */
-static inline pte_t *pte_offset(pmd_t *dir, unsigned long address)
-{
-	return (pte_t *) (pmd_page_vaddr(*dir)) +
-		((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
-}
-
 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 extern void paging_init(void);