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linux/arch/sh/include/asm/pgtable_pmd.h
Matt Fleming 5d9b4b19f1 sh: Definitions for 3-level page table layout
If using 64-bit PTEs and 4K pages then each page table has 512 entries
(as opposed to 1024 entries with 32-bit PTEs). Unlike MIPS, SH follows
the convention that all structures in the page table (pgd_t, pmd_t,
pgprot_t, etc) must be the same size. Therefore, 64-bit PTEs require
64-bit PGD entries, etc. Using 2-levels of page tables and 64-bit PTEs
it is only possible to map 1GB of virtual address space.

In order to map all 4GB of virtual address space we need to adopt a
3-level page table layout. This actually works out better for
CONFIG_SUPERH32 because we only waste 2 PGD entries on the P1 and P2
areas (which are untranslated) instead of 256.

Signed-off-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2009-12-17 14:31:20 +09:00

56 lines
1.4 KiB
C

#ifndef __ASM_SH_PGTABLE_PMD_H
#define __ASM_SH_PGTABLE_PMD_H
#include <asm-generic/pgtable-nopud.h>
/*
* Some cores need a 3-level page table layout, for example when using
* 64-bit PTEs and 4K pages.
*/
#define PTE_MAGNITUDE 3 /* 64-bit PTEs on extended mode SH-X2 TLB */
/* PGD bits */
#define PGDIR_SHIFT 30
#define PTRS_PER_PGD 4
#define USER_PTRS_PER_PGD 2
/* PMD bits */
#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT - 3))
#define PMD_SIZE (1UL << PMD_SHIFT)
#define PMD_MASK (~(PMD_SIZE-1))
#define PTRS_PER_PMD (PAGE_SIZE / sizeof(pmd_t))
#define pmd_ERROR(e) \
printk("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e))
typedef struct { unsigned long long pmd; } pmd_t;
#define pmd_val(x) ((x).pmd)
#define __pmd(x) ((pmd_t) { (x) } )
static inline unsigned long pud_page_vaddr(pud_t pud)
{
return pud_val(pud);
}
#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
{
return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
}
#define pud_none(x) (!pud_val(x))
#define pud_present(x) (pud_val(x))
#define pud_clear(xp) do { set_pud(xp, __pud(0)); } while (0)
#define pud_bad(x) (pud_val(x) & ~PAGE_MASK)
/*
* (puds are folded into pgds so this doesn't get actually called,
* but the define is needed for a generic inline function.)
*/
#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while(0)
#endif /* __ASM_SH_PGTABLE_PMD_H */