linux/include/asm-generic/pgtable-nopmd.h
Mike Rapoport 974b9b2c68 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>
2020-06-09 09:39:14 -07:00

72 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _PGTABLE_NOPMD_H
#define _PGTABLE_NOPMD_H
#ifndef __ASSEMBLY__
#include <asm-generic/pgtable-nopud.h>
struct mm_struct;
#define __PAGETABLE_PMD_FOLDED 1
/*
* Having the pmd type consist of a pud gets the size right, and allows
* us to conceptually access the pud entry that this pmd is folded into
* without casting.
*/
typedef struct { pud_t pud; } pmd_t;
#define PMD_SHIFT PUD_SHIFT
#define PTRS_PER_PMD 1
#define PMD_SIZE (1UL << PMD_SHIFT)
#define PMD_MASK (~(PMD_SIZE-1))
/*
* The "pud_xxx()" functions here are trivial for a folded two-level
* setup: the pmd is never bad, and a pmd always exists (as it's folded
* into the pud entry)
*/
static inline int pud_none(pud_t pud) { return 0; }
static inline int pud_bad(pud_t pud) { return 0; }
static inline int pud_present(pud_t pud) { return 1; }
static inline void pud_clear(pud_t *pud) { }
#define pmd_ERROR(pmd) (pud_ERROR((pmd).pud))
#define pud_populate(mm, pmd, pte) do { } while (0)
/*
* (pmds are folded into puds so this doesn't get actually called,
* but the define is needed for a generic inline function.)
*/
#define set_pud(pudptr, pudval) set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
static inline pmd_t * pmd_offset(pud_t * pud, unsigned long address)
{
return (pmd_t *)pud;
}
#define pmd_offset pmd_offset
#define pmd_val(x) (pud_val((x).pud))
#define __pmd(x) ((pmd_t) { __pud(x) } )
#define pud_page(pud) (pmd_page((pmd_t){ pud }))
#define pud_page_vaddr(pud) (pmd_page_vaddr((pmd_t){ pud }))
/*
* allocating and freeing a pmd is trivial: the 1-entry pmd is
* inside the pud, so has no extra memory associated with it.
*/
#define pmd_alloc_one(mm, address) NULL
static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
{
}
#define pmd_free_tlb(tlb, x, a) do { } while (0)
#undef pmd_addr_end
#define pmd_addr_end(addr, end) (end)
#endif /* __ASSEMBLY__ */
#endif /* _PGTABLE_NOPMD_H */