x86, pat: Generalize the use of page flag PG_uncached

Only IA64 was using PG_uncached as of now. We now intend to use this bit
in x86 as well, to keep track of memory type of those addresses that
have page struct for them. So, generalize the use of that bit across
ia64 and x86.

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>

3 files changed, 10 insertions, 2 deletions

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 170042b420d4..e6246119932a 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -112,6 +112,10 @@ config IA64_UNCACHED_ALLOCATOR
         bool
         select GENERIC_ALLOCATOR
 
+config ARCH_USES_PG_UNCACHED
+        def_bool y
+        depends on IA64_UNCACHED_ALLOCATOR
+
 config AUDIT_ARCH
         bool
         default y
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c07f72205909..8e1595382196 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1414,6 +1414,10 @@ config X86_PAT
 
           If unsure, say Y.
 
+config ARCH_USES_PG_UNCACHED
+        def_bool y
+        depends on X86_PAT
+
 config EFI
         bool "EFI runtime service support"
         depends on ACPI
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index e2e5ce543595..2b87acfc5f87 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -99,7 +99,7 @@ enum pageflags {
 #ifdef CONFIG_HAVE_MLOCKED_PAGE_BIT
         PG_mlocked,             /* Page is vma mlocked */
 #endif
-#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
+#ifdef CONFIG_ARCH_USES_PG_UNCACHED
         PG_uncached,            /* Page has been mapped as uncached */
 #endif
         __NR_PAGEFLAGS,
@@ -257,7 +257,7 @@ PAGEFLAG_FALSE(Mlocked)
         SETPAGEFLAG_NOOP(Mlocked) TESTCLEARFLAG_FALSE(Mlocked)
 #endif
 
-#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR
+#ifdef CONFIG_ARCH_USES_PG_UNCACHED
 PAGEFLAG(Uncached, uncached)
 #else
 PAGEFLAG_FALSE(Uncached)