x86: PAT infrastructure patch
Sets up pat_init() infrastructure.
PAT MSR has following setting.
PAT
|PCD
||PWT
|||
000 WB _PAGE_CACHE_WB
001 WC _PAGE_CACHE_WC
010 UC- _PAGE_CACHE_UC_MINUS
011 UC _PAGE_CACHE_UC
We are effectively changing WT from boot time setting to WC.
UC_MINUS is used to provide backward compatibility to existing /dev/mem
users(X).
reserve_memtype and free_memtype are new interfaces for maintaining alias-free
mapping. It is currently implemented in a simple way with a linked list and
not optimized. reserve and free tracks the effective memory type, as a result
of PAT and MTRR setting rather than what is actually requested in PAT.
pat_init piggy backs on mtrr_init as the rules for setting both pat and mtrr
are same.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 9ab9889..20941d2 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -1,4 +1,5 @@
-obj-y := init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o
+obj-y := init_$(BITS).o fault.o ioremap.o extable.o pageattr.o mmap.o \
+ pat.o
obj-$(CONFIG_X86_32) += pgtable_32.o