diff options
Diffstat (limited to 'arch/x86/include/asm/cacheflush.h')
| -rw-r--r-- | arch/x86/include/asm/cacheflush.h | 54 |
1 files changed, 52 insertions, 2 deletions
diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index e55dfc1ad453..b54f6afe7ec4 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/arch/x86/include/asm/cacheflush.h @@ -43,8 +43,58 @@ static inline void copy_from_user_page(struct vm_area_struct *vma, memcpy(dst, src, len); } -#define PG_non_WB PG_arch_1 -PAGEFLAG(NonWB, non_WB) +#define PG_WC PG_arch_1 +PAGEFLAG(WC, WC) + +#ifdef CONFIG_X86_PAT +/* + * X86 PAT uses page flags WC and Uncached together to keep track of + * memory type of pages that have backing page struct. X86 PAT supports 3 + * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and + * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not + * been changed from its default (value of -1 used to denote this). + * Note we do not support _PAGE_CACHE_UC here. + * + * Caller must hold memtype_lock for atomicity. + */ +static inline unsigned long get_page_memtype(struct page *pg) +{ + if (!PageUncached(pg) && !PageWC(pg)) + return -1; + else if (!PageUncached(pg) && PageWC(pg)) + return _PAGE_CACHE_WC; + else if (PageUncached(pg) && !PageWC(pg)) + return _PAGE_CACHE_UC_MINUS; + else + return _PAGE_CACHE_WB; +} + +static inline void set_page_memtype(struct page *pg, unsigned long memtype) +{ + switch (memtype) { + case _PAGE_CACHE_WC: + ClearPageUncached(pg); + SetPageWC(pg); + break; + case _PAGE_CACHE_UC_MINUS: + SetPageUncached(pg); + ClearPageWC(pg); + break; + case _PAGE_CACHE_WB: + SetPageUncached(pg); + SetPageWC(pg); + break; + default: + case -1: + ClearPageUncached(pg); + ClearPageWC(pg); + break; + } +} +#else +static inline unsigned long get_page_memtype(struct page *pg) { return -1; } +static inline void set_page_memtype(struct page *pg, unsigned long memtype) { } +#endif /* * The set_memory_* API can be used to change various attributes of a virtual |