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

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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>
This commit is contained in:
Mike Rapoport
2020-06-08 21:33:10 -07:00
committed by Linus Torvalds
parent e05c7b1f2b
commit 974b9b2c68
55 changed files with 228 additions and 860 deletions
Download Patch File Download Diff File Expand all files Collapse all files

91
include/linux/pgtable.h
View File

@@ -28,6 +28,97 @@
#define USER_PGTABLES_CEILING 0UL
#endif
/*
* A page table page can be thought of an array like this: pXd_t[PTRS_PER_PxD]
*
* The pXx_index() functions return the index of the entry in the page
* table page which would control the given virtual address
*
* As these functions may be used by the same code for different levels of
* the page table folding, they are always available, regardless of
* CONFIG_PGTABLE_LEVELS value. For the folded levels they simply return 0
* because in such cases PTRS_PER_PxD equals 1.
*/
static inline unsigned long pte_index(unsigned long address)
{
return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
}
#ifndef pmd_index
static inline unsigned long pmd_index(unsigned long address)
{
return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
}
#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 pgd_index
/* Must be a compile-time constant, so implement it as a macro */
#define pgd_index(a) (((a) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
#endif
#ifndef pte_offset_kernel
static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
{
return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
}
#define pte_offset_kernel pte_offset_kernel
#endif
#if defined(CONFIG_HIGHPTE)
#define pte_offset_map(dir, address) \
((pte_t *)kmap_atomic(pmd_page(*(dir))) + \
pte_index((address)))
#define pte_unmap(pte) kunmap_atomic((pte))
#else
#define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
#define pte_unmap(pte) ((void)(pte)) /* NOP */
#endif
/* Find an entry in the second-level page table.. */
#ifndef pmd_offset
static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(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
static inline pgd_t *pgd_offset_pgd(pgd_t *pgd, unsigned long address)
{
return (pgd + pgd_index(address));
};
/*
* a shortcut to get a pgd_t in a given mm
*/
#ifndef pgd_offset
#define pgd_offset(mm, address) pgd_offset_pgd((mm)->pgd, (address))
#endif
/*
* 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))
/*
* In many cases it is known that a virtual address is mapped at PMD or PTE
* level, so instead of traversing all the page table levels, we can get a