x86: add linux kernel support for YMM state

Impact: save/restore Intel-AVX state properly between tasks

Intel Advanced Vector Extensions (AVX) introduce 256-bit vector processing
capability. More about AVX at http://software.intel.com/sites/avx

Add OS support for YMM state management using xsave/xrstor infrastructure
to support AVX.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1239402084.27006.8057.camel@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 08e9a1a..727acc1 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -7,6 +7,7 @@
 
 #define XSTATE_FP	0x1
 #define XSTATE_SSE	0x2
+#define XSTATE_YMM	0x4
 
 #define XSTATE_FPSSE	(XSTATE_FP | XSTATE_SSE)
 
@@ -15,7 +16,7 @@
 /*
  * These are the features that the OS can handle currently.
  */
-#define XCNTXT_MASK	(XSTATE_FP | XSTATE_SSE)
+#define XCNTXT_MASK	(XSTATE_FP | XSTATE_SSE | XSTATE_YMM)
 
 #ifdef CONFIG_X86_64
 #define REX_PREFIX	"0x48, "