diff options
Diffstat (limited to 'include/asm-x86/pgtable.h')
| -rw-r--r-- | include/asm-x86/pgtable.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/include/asm-x86/pgtable.h b/include/asm-x86/pgtable.h index 1330e7487da1..85f851a0b998 100644 --- a/include/asm-x86/pgtable.h +++ b/include/asm-x86/pgtable.h @@ -357,6 +357,26 @@ void set_pte_vaddr(unsigned long vaddr, pte_t pte); # include "pgtable_64.h" #endif +/* + * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD] + * + * this macro returns the index of the entry in the pgd page which would + * control the given virtual address + */ +#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1)) + +/* + * pgd_offset() returns a (pgd_t *) + * pgd_index() is used get the offset into the pgd page's array of pgd_t's; + */ +#define pgd_offset(mm, address) ((mm)->pgd + pgd_index((address))) +/* + * 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)) + + #define KERNEL_PGD_BOUNDARY pgd_index(PAGE_OFFSET) #define KERNEL_PGD_PTRS (PTRS_PER_PGD - KERNEL_PGD_BOUNDARY) |