11859 need swapgs mitigation
Reviewed by: Robert Mustacchi <rm@fingolfin.org>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Robert Mustacchi <rm@fingolfin.org>

@@ -21,10 +21,14 @@
 /*
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
+/*
+ * Copyright 2019 Joyent, Inc.
+ */
+
 /
 / In-line functions for amd64 kernels.
 /
 
 /

@@ -187,18 +191,10 @@
 
         .inline __set_gs, 0
         movw    %di, %gs
         .end
 
-        /*
-         * OPTERON_ERRATUM_88 requires mfence
-         */
-        .inline __swapgs, 0
-        mfence
-        swapgs
-        .end
-
 /*
  * prefetch 64 bytes
  */
 
         .inline prefetch_read_many,8