diff options
Diffstat (limited to 'arch/x86/include/asm/pgtable_64.h')
| -rw-r--r-- | arch/x86/include/asm/pgtable_64.h | 38 |
1 files changed, 27 insertions, 11 deletions
diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index acb6970e7bcf..f773d5e6c8cc 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -188,7 +188,7 @@ extern void sync_global_pgds(unsigned long start, unsigned long end); * * | ... | 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 (9-13) |0|0|X|X| X| X|X|SD|0| <- swp entry + * | TYPE (59-63) | ~OFFSET (9-58) |0|0|X|X| X| X|X|SD|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 @@ -201,20 +201,34 @@ extern void sync_global_pgds(unsigned long start, unsigned long end); * * Bit 7 in swp entry should be 0 because pmd_present checks not only P, * but also L and G. + * + * The offset is inverted by a binary not operation to make the high + * physical bits set. */ -#define SWP_TYPE_FIRST_BIT (_PAGE_BIT_PROTNONE + 1) -#define SWP_TYPE_BITS 5 -/* Place the offset above the type: */ -#define SWP_OFFSET_FIRST_BIT (SWP_TYPE_FIRST_BIT + SWP_TYPE_BITS) +#define SWP_TYPE_BITS 5 + +#define SWP_OFFSET_FIRST_BIT (_PAGE_BIT_PROTNONE + 1) + +/* We always extract/encode the offset by shifting it all the way up, and then down again */ +#define SWP_OFFSET_SHIFT (SWP_OFFSET_FIRST_BIT+SWP_TYPE_BITS) #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > SWP_TYPE_BITS) -#define __swp_type(x) (((x).val >> (SWP_TYPE_FIRST_BIT)) \ - & ((1U << SWP_TYPE_BITS) - 1)) -#define __swp_offset(x) ((x).val >> SWP_OFFSET_FIRST_BIT) -#define __swp_entry(type, offset) ((swp_entry_t) { \ - ((type) << (SWP_TYPE_FIRST_BIT)) \ - | ((offset) << SWP_OFFSET_FIRST_BIT) }) +/* Extract the high bits for type */ +#define __swp_type(x) ((x).val >> (64 - SWP_TYPE_BITS)) + +/* Shift up (to get rid of type), then down to get value */ +#define __swp_offset(x) (~(x).val << SWP_TYPE_BITS >> SWP_OFFSET_SHIFT) + +/* + * Shift the offset up "too far" by TYPE bits, then down again + * The offset is inverted by a binary not operation to make the high + * physical bits set. + */ +#define __swp_entry(type, offset) ((swp_entry_t) { \ + (~(unsigned long)(offset) << SWP_OFFSET_SHIFT >> SWP_TYPE_BITS) \ + | ((unsigned long)(type) << (64-SWP_TYPE_BITS)) }) + #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val((pte)) }) #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val((pmd)) }) #define __swp_entry_to_pte(x) ((pte_t) { .pte = (x).val }) @@ -258,5 +272,7 @@ static inline bool gup_fast_permitted(unsigned long start, int nr_pages, return true; } +#include <asm/pgtable-invert.h> + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_X86_PGTABLE_64_H */ |