diff options
| -rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 73 | ||||
| -rw-r--r-- | arch/x86/mm/init.c | 29 |
2 files changed, 101 insertions, 1 deletions
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 07789647bf33..512464227c09 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -128,12 +128,34 @@ _PAGE_SOFT_DIRTY | _PAGE_NUMA) #define _HPAGE_CHG_MASK (_PAGE_CHG_MASK | _PAGE_PSE | _PAGE_NUMA) -#define _PAGE_CACHE_MASK (_PAGE_PCD | _PAGE_PWT) #define _PAGE_CACHE_WB (0) #define _PAGE_CACHE_WC (_PAGE_PWT) #define _PAGE_CACHE_UC_MINUS (_PAGE_PCD) #define _PAGE_CACHE_UC (_PAGE_PCD | _PAGE_PWT) +/* + * The cache modes defined here are used to translate between pure SW usage + * and the HW defined cache mode bits and/or PAT entries. + * + * The resulting bits for PWT, PCD and PAT should be chosen in a way + * to have the WB mode at index 0 (all bits clear). This is the default + * right now and likely would break too much if changed. + */ +#ifndef __ASSEMBLY__ +enum page_cache_mode { + _PAGE_CACHE_MODE_WB = 0, + _PAGE_CACHE_MODE_WC = 1, + _PAGE_CACHE_MODE_UC_MINUS = 2, + _PAGE_CACHE_MODE_UC = 3, + _PAGE_CACHE_MODE_WT = 4, + _PAGE_CACHE_MODE_WP = 5, + _PAGE_CACHE_MODE_NUM = 8 +}; +#endif + +#define _PAGE_CACHE_MASK (_PAGE_PAT | _PAGE_PCD | _PAGE_PWT) +#define _PAGE_NOCACHE (cachemode2protval(_PAGE_CACHE_MODE_UC)) + #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED) #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | \ _PAGE_ACCESSED | _PAGE_NX) @@ -341,6 +363,55 @@ static inline pmdval_t pmdnuma_flags(pmd_t pmd) #define pgprot_val(x) ((x).pgprot) #define __pgprot(x) ((pgprot_t) { (x) } ) +extern uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM]; +extern uint8_t __pte2cachemode_tbl[8]; + +#define __pte2cm_idx(cb) \ + ((((cb) >> (_PAGE_BIT_PAT - 2)) & 4) | \ + (((cb) >> (_PAGE_BIT_PCD - 1)) & 2) | \ + (((cb) >> _PAGE_BIT_PWT) & 1)) + +static inline unsigned long cachemode2protval(enum page_cache_mode pcm) +{ + if (likely(pcm == 0)) + return 0; + return __cachemode2pte_tbl[pcm]; +} +static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm) +{ + return __pgprot(cachemode2protval(pcm)); +} +static inline enum page_cache_mode pgprot2cachemode(pgprot_t pgprot) +{ + unsigned long masked; + + masked = pgprot_val(pgprot) & _PAGE_CACHE_MASK; + if (likely(masked == 0)) + return 0; + return __pte2cachemode_tbl[__pte2cm_idx(masked)]; +} +static inline pgprot_t pgprot_4k_2_large(pgprot_t pgprot) +{ + pgprot_t new; + unsigned long val; + + val = pgprot_val(pgprot); + pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) | + ((val & _PAGE_PAT) << (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT)); + return new; +} +static inline pgprot_t pgprot_large_2_4k(pgprot_t pgprot) +{ + pgprot_t new; + unsigned long val; + + val = pgprot_val(pgprot); + pgprot_val(new) = (val & ~(_PAGE_PAT | _PAGE_PAT_LARGE)) | + ((val & _PAGE_PAT_LARGE) >> + (_PAGE_BIT_PAT_LARGE - _PAGE_BIT_PAT)); + return new; +} + typedef struct page *pgtable_t; diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 66dba36f2343..a9776ba475d4 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -27,6 +27,35 @@ #include "mm_internal.h" +/* + * Tables translating between page_cache_type_t and pte encoding. + * Minimal supported modes are defined statically, modified if more supported + * cache modes are available. + * Index into __cachemode2pte_tbl is the cachemode. + * Index into __pte2cachemode_tbl are the caching attribute bits of the pte + * (_PAGE_PWT, _PAGE_PCD, _PAGE_PAT) at index bit positions 0, 1, 2. + */ +uint16_t __cachemode2pte_tbl[_PAGE_CACHE_MODE_NUM] = { + [_PAGE_CACHE_MODE_WB] = 0, + [_PAGE_CACHE_MODE_WC] = _PAGE_PWT, + [_PAGE_CACHE_MODE_UC_MINUS] = _PAGE_PCD, + [_PAGE_CACHE_MODE_UC] = _PAGE_PCD | _PAGE_PWT, + [_PAGE_CACHE_MODE_WT] = _PAGE_PCD, + [_PAGE_CACHE_MODE_WP] = _PAGE_PCD, +}; +EXPORT_SYMBOL_GPL(__cachemode2pte_tbl); +uint8_t __pte2cachemode_tbl[8] = { + [__pte2cm_idx(0)] = _PAGE_CACHE_MODE_WB, + [__pte2cm_idx(_PAGE_PWT)] = _PAGE_CACHE_MODE_WC, + [__pte2cm_idx(_PAGE_PCD)] = _PAGE_CACHE_MODE_UC_MINUS, + [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD)] = _PAGE_CACHE_MODE_UC, + [__pte2cm_idx(_PAGE_PAT)] = _PAGE_CACHE_MODE_WB, + [__pte2cm_idx(_PAGE_PWT | _PAGE_PAT)] = _PAGE_CACHE_MODE_WC, + [__pte2cm_idx(_PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC_MINUS, + [__pte2cm_idx(_PAGE_PWT | _PAGE_PCD | _PAGE_PAT)] = _PAGE_CACHE_MODE_UC, +}; +EXPORT_SYMBOL_GPL(__pte2cachemode_tbl); + static unsigned long __initdata pgt_buf_start; static unsigned long __initdata pgt_buf_end; static unsigned long __initdata pgt_buf_top; |