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Diffstat (limited to 'arch/x86/include/asm/cacheflush.h')
-rw-r--r--arch/x86/include/asm/cacheflush.h44
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; }
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