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>

2 files changed, 15 insertions, 56 deletions

diff --git a/arch/um/include/asm/pgtable-3level.h b/arch/um/include/asm/pgtable-3level.h
index 8a3b689e0f86..36f452957cef 100644
--- a/arch/um/include/asm/pgtable-3level.h
+++ b/arch/um/include/asm/pgtable-3level.h
@@ -89,10 +89,6 @@ static inline void pud_clear (pud_t *pud)
 #define pud_page(pud) phys_to_page(pud_val(pud) & PAGE_MASK)
 #define pud_page_vaddr(pud) ((unsigned long) __va(pud_val(pud) & PAGE_MASK))
 
-/* Find an entry in the second-level page table.. */
-#define pmd_offset(pud, address) ((pmd_t *) pud_page_vaddr(*(pud)) + \
-			pmd_index(address))
-
 static inline unsigned long pte_pfn(pte_t pte)
 {
 	return phys_to_pfn(pte_val(pte));
diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
index 9618a0b8088c..def376194dce 100644
--- a/arch/um/include/asm/pgtable.h
+++ b/arch/um/include/asm/pgtable.h
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-/* 
+/*
  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Copyright 2003 PathScale, Inc.
  * Derived from include/asm-i386/pgtable.h
@@ -131,7 +131,7 @@ static inline int pte_none(pte_t pte)
  * Undefined behaviour if not..
  */
 static inline int pte_read(pte_t pte)
-{ 
+{
 	return((pte_get_bits(pte, _PAGE_USER)) &&
 	       !(pte_get_bits(pte, _PAGE_PROTNONE)));
 }
@@ -163,7 +163,7 @@ static inline int pte_newpage(pte_t pte)
 }
 
 static inline int pte_newprot(pte_t pte)
-{ 
+{
 	return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 }
 
@@ -185,31 +185,31 @@ static inline pte_t pte_mkclean(pte_t pte)
 	return(pte);
 }
 
-static inline pte_t pte_mkold(pte_t pte)	
-{ 
+static inline pte_t pte_mkold(pte_t pte)
+{
 	pte_clear_bits(pte, _PAGE_ACCESSED);
 	return(pte);
 }
 
 static inline pte_t pte_wrprotect(pte_t pte)
-{ 
+{
 	if (likely(pte_get_bits(pte, _PAGE_RW)))
 		pte_clear_bits(pte, _PAGE_RW);
 	else
 		return pte;
-	return(pte_mknewprot(pte)); 
+	return(pte_mknewprot(pte));
 }
 
 static inline pte_t pte_mkread(pte_t pte)
-{ 
+{
 	if (unlikely(pte_get_bits(pte, _PAGE_USER)))
 		return pte;
 	pte_set_bits(pte, _PAGE_USER);
-	return(pte_mknewprot(pte)); 
+	return(pte_mknewprot(pte));
 }
 
 static inline pte_t pte_mkdirty(pte_t pte)
-{ 
+{
 	pte_set_bits(pte, _PAGE_DIRTY);
 	return(pte);
 }
@@ -220,20 +220,20 @@ static inline pte_t pte_mkyoung(pte_t pte)
 	return(pte);
 }
 
-static inline pte_t pte_mkwrite(pte_t pte)	
+static inline pte_t pte_mkwrite(pte_t pte)
 {
 	if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
 		return pte;
 	pte_set_bits(pte, _PAGE_RW);
-	return(pte_mknewprot(pte)); 
+	return(pte_mknewprot(pte));
 }
 
-static inline pte_t pte_mkuptodate(pte_t pte)	
+static inline pte_t pte_mkuptodate(pte_t pte)
 {
 	pte_clear_bits(pte, _PAGE_NEWPAGE);
 	if(pte_present(pte))
 		pte_clear_bits(pte, _PAGE_NEWPROT);
-	return(pte); 
+	return(pte);
 }
 
 static inline pte_t pte_mknewpage(pte_t pte)
@@ -288,53 +288,16 @@ static inline int pte_same(pte_t pte_a, pte_t pte_b)
 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 {
 	pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
-	return pte; 
+	return pte;
 }
 
 /*
- * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
- *
- * this macro returns the index of the entry in the pgd page which would
- * control the given virtual address
- */
-#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
-
-/*
- * pgd_offset() returns a (pgd_t *)
- * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
- */
-#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
-
-/*
- * a shortcut which implies the use of the kernel's pgd, instead
- * of a process's
- */
-#define pgd_offset_k(address) pgd_offset(&init_mm, address)
-
-/*
  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
  *
  * this macro returns the index of the entry in the pmd page which would
  * control the given virtual address
  */
 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
-#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
-
-#define pmd_page_vaddr(pmd) \
-	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
-
-/*
- * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
- *
- * this macro returns the index of the entry in the pte page which would
- * control the given virtual address
- */
-#define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
-#define pte_offset_kernel(dir, address) \
-	((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
-#define pte_offset_map(dir, address) \
-	((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
-#define pte_unmap(pte) do { } while (0)
 
 struct mm_struct;
 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);