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>
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index eb9ddd8..e22a9a9 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -61,6 +61,11 @@
return;
}
+ if (cpu_has_xsave) {
+ xsave_cntxt_init();
+ return;
+ }
+
if (cpu_has_fxsr)
xstate_size = sizeof(struct i387_fxsave_struct);
#ifdef CONFIG_X86_32
@@ -83,6 +88,13 @@
write_cr0(oldcr0 & ~(X86_CR0_TS|X86_CR0_EM)); /* clear TS and EM */
+ /*
+ * Boot processor to setup the FP and extended state context info.
+ */
+ if (!smp_processor_id())
+ init_thread_xstate();
+ xsave_init();
+
mxcsr_feature_mask_init();
/* clean state in init */
current_thread_info()->status = 0;