Now that our assembler supports the xsave family of instructions, use them

natively rather than hand-assembled versions.  For xgetbv/xsetbv, add a
wrapper API to deal with xcr* registers: rxcr() and load_xcr().

Reviewed by:	kib
MFC after:	1 month

1 files changed, 19 insertions, 0 deletions

diff --git a/sys/amd64/include/cpufunc.h b/sys/amd64/include/cpufunc.h
index 927d00f..829efc1 100644
--- a/sys/amd64/include/cpufunc.h
+++ b/sys/amd64/include/cpufunc.h
@@ -418,6 +418,25 @@ rcr4(void)
 	return (data);
 }
 
+static __inline u_long
+rxcr(u_int reg)
+{
+	u_int low, high;
+
+	__asm __volatile("xgetbv" : "=a" (low), "=d" (high) : "c" (reg));
+	return (low | ((uint64_t)high << 32));
+}
+
+static __inline void
+load_xcr(u_int reg, u_long val)
+{
+	u_int low, high;
+
+	low = val;
+	high = val >> 32;
+	__asm __volatile("xsetbv" : : "c" (reg), "a" (low), "d" (high));
+}
+
 /*
  * Global TLB flush (except for thise for pages marked PG_G)
  */