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, 26 insertions, 0 deletions

diff --git a/include/asm-x86/xsave.h b/include/asm-x86/xsave.h
new file mode 100644
index 000000000000..6d70e62c6bdc
--- /dev/null
+++ b/include/asm-x86/xsave.h
@@ -0,0 +1,26 @@
+#ifndef __ASM_X86_XSAVE_H
+#define __ASM_X86_XSAVE_H
+
+#include <asm/processor.h>
+#include <asm/i387.h>
+
+#define XSTATE_FP       0x1
+#define XSTATE_SSE      0x2
+
+#define XSTATE_FPSSE    (XSTATE_FP | XSTATE_SSE)
+
+#define FXSAVE_SIZE     512
+
+/*
+ * These are the features that the OS can handle currently.
+ */
+#define XCNTXT_LMASK    (XSTATE_FP | XSTATE_SSE)
+#define XCNTXT_HMASK    0x0
+
+extern unsigned int xstate_size, pcntxt_hmask, pcntxt_lmask;
+extern struct xsave_struct *init_xstate_buf;
+
+extern void xsave_cntxt_init(void);
+extern void xsave_init(void);
+
+#endif