linux/include/asm-generic/pgtable-nopmd.h
Dave McCracken 46a82b2d55 [PATCH] Standardize pxx_page macros
One of the changes necessary for shared page tables is to standardize the
pxx_page macros.  pte_page and pmd_page have always returned the struct
page associated with their entry, while pte_page_kernel and pmd_page_kernel
have returned the kernel virtual address.  pud_page and pgd_page, on the
other hand, return the kernel virtual address.

Shared page tables needs pud_page and pgd_page to return the actual page
structures.  There are very few actual users of these functions, so it is
simple to standardize their usage.

Since this is basic cleanup, I am submitting these changes as a standalone
patch.  Per Hugh Dickins' comments about it, I am also changing the
pxx_page_kernel macros to pxx_page_vaddr to clarify their meaning.

Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26 08:48:51 -07:00

66 lines
1.8 KiB
C

#ifndef _PGTABLE_NOPMD_H
#define _PGTABLE_NOPMD_H
#ifndef __ASSEMBLY__
#include <asm-generic/pgtable-nopud.h>
#define __PAGETABLE_PMD_FOLDED
/*
* 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_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
#define pmd_free(x) do { } while (0)
#define __pmd_free_tlb(tlb, x) do { } while (0)
#undef pmd_addr_end
#define pmd_addr_end(addr, end) (end)
#endif /* __ASSEMBLY__ */
#endif /* _PGTABLE_NOPMD_H */