diff options
Diffstat (limited to 'arch/x86/include/asm/pgtable_64.h')
| -rw-r--r-- | arch/x86/include/asm/pgtable_64.h | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index 2ee781114d34..7e8ec7ae10fa 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -140,18 +140,32 @@ static inline int pgd_large(pgd_t pgd) { return 0; } #define pte_offset_map(dir, address) pte_offset_kernel((dir), (address)) #define pte_unmap(pte) ((void)(pte))/* NOP */ -/* Encode and de-code a swap entry */ +/* + * Encode and de-code a swap entry + * + * | ... | 11| 10| 9|8|7|6|5| 4| 3|2|1|0| <- bit number + * | ... |SW3|SW2|SW1|G|L|D|A|CD|WT|U|W|P| <- bit names + * | OFFSET (14->63) | TYPE (10-13) |0|X|X|X| X| X|X|X|0| <- swp entry + * + * G (8) is aliased and used as a PROT_NONE indicator for + * !present ptes. We need to start storing swap entries above + * there. We also need to avoid using A and D because of an + * erratum where they can be incorrectly set by hardware on + * non-present PTEs. + */ +#define SWP_TYPE_FIRST_BIT (_PAGE_BIT_PROTNONE + 1) #define SWP_TYPE_BITS 5 -#define SWP_OFFSET_SHIFT (_PAGE_BIT_PROTNONE + 1) +/* Place the offset above the type: */ +#define SWP_OFFSET_FIRST_BIT (SWP_TYPE_FIRST_BIT + SWP_TYPE_BITS + 1) #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS) -#define __swp_type(x) (((x).val >> (_PAGE_BIT_PRESENT + 1)) \ +#define __swp_type(x) (((x).val >> (SWP_TYPE_FIRST_BIT)) \ & ((1U << SWP_TYPE_BITS) - 1)) -#define __swp_offset(x) ((x).val >> SWP_OFFSET_SHIFT) +#define __swp_offset(x) ((x).val >> SWP_OFFSET_FIRST_BIT) #define __swp_entry(type, offset) ((swp_entry_t) { \ - ((type) << (_PAGE_BIT_PRESENT + 1)) \ - | ((offset) << SWP_OFFSET_SHIFT) }) + ((type) << (SWP_TYPE_FIRST_BIT)) \ + | ((offset) << SWP_OFFSET_FIRST_BIT) }) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val((pte)) }) #define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val }) |