x86: PAT: change pgprot_noncached to uc_minus instead of strong uc - v3

Impact: mm behavior change.

Make pgprot_noncached uc_minus instead of strong UC. This will make
pgprot_noncached to be in line with ioremap_nocache() and all the other
APIs that map page uc_minus on uc request.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 7dcd94c2904477d2d22c72405c0803e60c50752e..6968d4f6be3e138c6d35d0107753429fcd4135e7 100644 (file)
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -158,6 +158,14 @@
 #define PGD_IDENT_ATTR  0x001          /* PRESENT (no other attributes) */
 #endif
 
+/*
+ * Macro to mark a page protection value as UC-
+ */
+#define pgprot_noncached(prot)                                 \
+       ((boot_cpu_data.x86 > 3)                                \
+        ? (__pgprot(pgprot_val(prot) | _PAGE_CACHE_UC_MINUS))  \
+        : (prot))
+
 #ifndef __ASSEMBLY__
 
 /*

diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
index f9d5889b336be5eb5d9f575d22ac512be7d63f7e..72b020deb46b9352a5365410b2011e55b4c56021 100644 (file)
--- a/arch/x86/include/asm/pgtable_32.h
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -100,15 +100,6 @@ extern unsigned long pg0[];
 # include <asm/pgtable-2level.h>
 #endif
 
-/*
- * Macro to mark a page protection value as "uncacheable".
- * On processors which do not support it, this is a no-op.
- */
-#define pgprot_noncached(prot)                                 \
-       ((boot_cpu_data.x86 > 3)                                \
-        ? (__pgprot(pgprot_val(prot) | _PAGE_PCD | _PAGE_PWT)) \
-        : (prot))
-
 /*
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.

diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 545a0e042bb2d44268d7a240e97b2c14309568b9..4798a4033e3a7a05b920ba792af9f22541f48318 100644 (file)
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -176,12 +176,6 @@ static inline int pmd_bad(pmd_t pmd)
 
 #define pages_to_mb(x) ((x) >> (20 - PAGE_SHIFT))   /* FIXME: is this right? */
 
-/*
- * Macro to mark a page protection value as "uncacheable".
- */
-#define pgprot_noncached(prot)                                 \
-       (__pgprot(pgprot_val((prot)) | _PAGE_PCD | _PAGE_PWT))
-
 /*
  * Conversion functions: convert a page and protection to a page entry,
  * and a page entry and page directory to the page they refer to.