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-rw-r--r--arch/x86/include/asm/cacheflush.h54
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,
43 memcpy(dst, src, len); 43 memcpy(dst, src, len);
44} 44}
45 45
46#define PG_non_WB PG_arch_1 46#define PG_WC PG_arch_1
47PAGEFLAG(NonWB, non_WB) 47PAGEFLAG(WC, WC)
48
49#ifdef CONFIG_X86_PAT
50/*
51 * X86 PAT uses page flags WC and Uncached together to keep track of
52 * memory type of pages that have backing page struct. X86 PAT supports 3
53 * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and
54 * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not
55 * been changed from its default (value of -1 used to denote this).
56 * Note we do not support _PAGE_CACHE_UC here.
57 *
58 * Caller must hold memtype_lock for atomicity.
59 */
60static inline unsigned long get_page_memtype(struct page *pg)
61{
62 if (!PageUncached(pg) && !PageWC(pg))
63 return -1;
64 else if (!PageUncached(pg) && PageWC(pg))
65 return _PAGE_CACHE_WC;
66 else if (PageUncached(pg) && !PageWC(pg))
67 return _PAGE_CACHE_UC_MINUS;
68 else
69 return _PAGE_CACHE_WB;
70}
71
72static inline void set_page_memtype(struct page *pg, unsigned long memtype)
73{
74 switch (memtype) {
75 case _PAGE_CACHE_WC:
76 ClearPageUncached(pg);
77 SetPageWC(pg);
78 break;
79 case _PAGE_CACHE_UC_MINUS:
80 SetPageUncached(pg);
81 ClearPageWC(pg);
82 break;
83 case _PAGE_CACHE_WB:
84 SetPageUncached(pg);
85 SetPageWC(pg);
86 break;
87 default:
88 case -1:
89 ClearPageUncached(pg);
90 ClearPageWC(pg);
91 break;
92 }
93}
94#else
95static inline unsigned long get_page_memtype(struct page *pg) { return -1; }
96static inline void set_page_memtype(struct page *pg, unsigned long memtype) { }
97#endif
48 98
49/* 99/*
50 * The set_memory_* API can be used to change various attributes of a virtual 100 * The set_memory_* API can be used to change various attributes of a virtual