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, 5 insertions, 10 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 22757203828d..19d603bd1f36 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1229,7 +1229,6 @@ static inline pte_t mk_pte(struct page *page, pgprot_t pgprot)
 #define p4d_index(address) (((address) >> P4D_SHIFT) & (PTRS_PER_P4D-1))
 #define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
-#define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
 
 #define pmd_deref(pmd) (pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN)
 #define pud_deref(pud) (pud_val(pud) & _REGION_ENTRY_ORIGIN)
@@ -1260,7 +1259,6 @@ static inline pgd_t *pgd_offset_raw(pgd_t *pgd, unsigned long address)
 }
 
 #define pgd_offset(mm, address) pgd_offset_raw(READ_ONCE((mm)->pgd), address)
-#define pgd_offset_k(address) pgd_offset(&init_mm, address)
 
 static inline p4d_t *p4d_offset(pgd_t *pgd, unsigned long address)
 {
@@ -1275,6 +1273,7 @@ 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)
 {
@@ -1282,17 +1281,13 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
 		return (pmd_t *) pud_deref(*pud) + pmd_index(address);
 	return (pmd_t *) pud;
 }
+#define pmd_offset pmd_offset
 
-static inline pte_t *pte_offset(pmd_t *pmd, unsigned long address)
+static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 {
-	return (pte_t *) pmd_deref(*pmd) + pte_index(address);
+	return (unsigned long) pmd_deref(pmd);
 }
 
-#define pte_offset_kernel(pmd, address) pte_offset(pmd, address)
-#define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
-
-static inline void pte_unmap(pte_t *pte) { }
-
 static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
 {
 	return end <= current->mm->context.asce_limit;
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index 397944b9906b..c5c52ec2b46f 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -85,7 +85,7 @@ static int walk_pte_level(pmd_t *pmdp, unsigned long addr, unsigned long end,
 {
 	pte_t *ptep, new;
 
-	ptep = pte_offset(pmdp, addr);
+	ptep = pte_offset_kernel(pmdp, addr);
 	do {
 		new = *ptep;
 		if (pte_none(new))