diff options
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/cacheflush.h | 44 |
1 files changed, 25 insertions, 19 deletions
diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h index 634c40a739a6..c70068d05f70 100644 --- a/arch/x86/include/asm/cacheflush.h +++ b/arch/x86/include/asm/cacheflush.h @@ -44,9 +44,6 @@ static inline void copy_from_user_page(struct vm_area_struct *vma, memcpy(dst, src, len); } -#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 @@ -55,16 +52,24 @@ PAGEFLAG(WC, WC) * _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. */ + +#define _PGMT_DEFAULT 0 +#define _PGMT_WC (1UL << PG_arch_1) +#define _PGMT_UC_MINUS (1UL << PG_uncached) +#define _PGMT_WB (1UL << PG_uncached | 1UL << PG_arch_1) +#define _PGMT_MASK (1UL << PG_uncached | 1UL << PG_arch_1) +#define _PGMT_CLEAR_MASK (~_PGMT_MASK) + static inline unsigned long get_page_memtype(struct page *pg) { - if (!PageUncached(pg) && !PageWC(pg)) + unsigned long pg_flags = pg->flags & _PGMT_MASK; + + if (pg_flags == _PGMT_DEFAULT) return -1; - else if (!PageUncached(pg) && PageWC(pg)) + else if (pg_flags == _PGMT_WC) return _PAGE_CACHE_WC; - else if (PageUncached(pg) && !PageWC(pg)) + else if (pg_flags == _PGMT_UC_MINUS) return _PAGE_CACHE_UC_MINUS; else return _PAGE_CACHE_WB; @@ -72,25 +77,26 @@ static inline unsigned long get_page_memtype(struct page *pg) static inline void set_page_memtype(struct page *pg, unsigned long memtype) { + unsigned long memtype_flags = _PGMT_DEFAULT; + unsigned long old_flags; + unsigned long new_flags; + switch (memtype) { case _PAGE_CACHE_WC: - ClearPageUncached(pg); - SetPageWC(pg); + memtype_flags = _PGMT_WC; break; case _PAGE_CACHE_UC_MINUS: - SetPageUncached(pg); - ClearPageWC(pg); + memtype_flags = _PGMT_UC_MINUS; break; case _PAGE_CACHE_WB: - SetPageUncached(pg); - SetPageWC(pg); - break; - default: - case -1: - ClearPageUncached(pg); - ClearPageWC(pg); + memtype_flags = _PGMT_WB; break; } + + do { + old_flags = pg->flags; + new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags; + } while (cmpxchg(&pg->flags, old_flags, new_flags) != old_flags); } #else static inline unsigned long get_page_memtype(struct page *pg) { return -1; } |