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>

3 files changed, 15 insertions, 42 deletions

diff --git a/arch/riscv/include/asm/pgtable-64.h b/arch/riscv/include/asm/pgtable-64.h
index b15f70a1fdfa..f3b0da64c6c8 100644
--- a/arch/riscv/include/asm/pgtable-64.h
+++ b/arch/riscv/include/asm/pgtable-64.h
@@ -70,13 +70,6 @@ static inline struct page *pud_page(pud_t pud)
 	return pfn_to_page(pud_val(pud) >> _PAGE_PFN_SHIFT);
 }
 
-#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);
-}
-
 static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot)
 {
 	return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 8e3606fd580e..eaea1f717010 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -173,16 +173,6 @@ static inline unsigned long _pgd_pfn(pgd_t pgd)
 	return pgd_val(pgd) >> _PAGE_PFN_SHIFT;
 }
 
-#define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
-
-/* Locate an entry in the page global directory */
-static inline pgd_t *pgd_offset(const struct mm_struct *mm, unsigned long addr)
-{
-	return mm->pgd + pgd_index(addr);
-}
-/* Locate an entry in the kernel page global directory */
-#define pgd_offset_k(addr)      pgd_offset(&init_mm, (addr))
-
 static inline struct page *pmd_page(pmd_t pmd)
 {
 	return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
@@ -209,16 +199,6 @@ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
 
 #define mk_pte(page, prot)       pfn_pte(page_to_pfn(page), prot)
 
-#define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
-
-static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long addr)
-{
-	return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(addr);
-}
-
-#define pte_offset_map(dir, addr)	pte_offset_kernel((dir), (addr))
-#define pte_unmap(pte)			((void)(pte))
-
 static inline int pte_present(pte_t pte)
 {
 	return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index 57797862f363..9996f49959bd 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -235,12 +235,12 @@ static void __init create_pte_mapping(pte_t *ptep,
 				      uintptr_t va, phys_addr_t pa,
 				      phys_addr_t sz, pgprot_t prot)
 {
-	uintptr_t pte_index = pte_index(va);
+	uintptr_t pte_idx = pte_index(va);
 
 	BUG_ON(sz != PAGE_SIZE);
 
-	if (pte_none(ptep[pte_index]))
-		ptep[pte_index] = pfn_pte(PFN_DOWN(pa), prot);
+	if (pte_none(ptep[pte_idx]))
+		ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
 }
 
 #ifndef __PAGETABLE_PMD_FOLDED
@@ -283,21 +283,21 @@ static void __init create_pmd_mapping(pmd_t *pmdp,
 {
 	pte_t *ptep;
 	phys_addr_t pte_phys;
-	uintptr_t pmd_index = pmd_index(va);
+	uintptr_t pmd_idx = pmd_index(va);
 
 	if (sz == PMD_SIZE) {
-		if (pmd_none(pmdp[pmd_index]))
-			pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pa), prot);
+		if (pmd_none(pmdp[pmd_idx]))
+			pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
 		return;
 	}
 
-	if (pmd_none(pmdp[pmd_index])) {
+	if (pmd_none(pmdp[pmd_idx])) {
 		pte_phys = alloc_pte(va);
-		pmdp[pmd_index] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
+		pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
 		ptep = get_pte_virt(pte_phys);
 		memset(ptep, 0, PAGE_SIZE);
 	} else {
-		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_index]));
+		pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
 		ptep = get_pte_virt(pte_phys);
 	}
 
@@ -325,21 +325,21 @@ static void __init create_pgd_mapping(pgd_t *pgdp,
 {
 	pgd_next_t *nextp;
 	phys_addr_t next_phys;
-	uintptr_t pgd_index = pgd_index(va);
+	uintptr_t pgd_idx = pgd_index(va);
 
 	if (sz == PGDIR_SIZE) {
-		if (pgd_val(pgdp[pgd_index]) == 0)
-			pgdp[pgd_index] = pfn_pgd(PFN_DOWN(pa), prot);
+		if (pgd_val(pgdp[pgd_idx]) == 0)
+			pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
 		return;
 	}
 
-	if (pgd_val(pgdp[pgd_index]) == 0) {
+	if (pgd_val(pgdp[pgd_idx]) == 0) {
 		next_phys = alloc_pgd_next(va);
-		pgdp[pgd_index] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
+		pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
 		nextp = get_pgd_next_virt(next_phys);
 		memset(nextp, 0, PAGE_SIZE);
 	} else {
-		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_index]));
+		next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
 		nextp = get_pgd_next_virt(next_phys);
 	}