x86, xsave: enable xsave/xrstor on cpus with xsave support

Enables xsave/xrstor by turning on cr4.osxsave on cpu's which have
the xsave support. For now, features that OS supports/enabled are
FP and SSE.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 80ab20d4fa39..fabbcb7020fb 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -712,6 +712,14 @@ void __cpuinit cpu_init(void)
         current_thread_info()->status = 0;
         clear_used_math();
         mxcsr_feature_mask_init();
+
+        /*
+         * Boot processor to setup the FP and extended state context info.
+         */
+        if (!smp_processor_id())
+                init_thread_xstate();
+
+        xsave_init();
 }
 
 #ifdef CONFIG_HOTPLUG_CPU