[src/trunk]: src/sys/arch/x86/x86 Reorder the code a little. On Xen, return e...

[maxv <maxv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/661ac9cfbbc3
branches:  trunk
changeset: 320107:661ac9cfbbc3
user:      maxv <maxv%NetBSD.org@localhost>
date:      Sat Jun 23 10:02:39 2018 +0000

description:
Reorder the code a little. On Xen, return earlier, we don't need to do
the XSAVE-related initialization if we don't support XSAVE.

diffstat:

 sys/arch/x86/x86/identcpu.c |  15 +++++++--------
 1 files changed, 7 insertions(+), 8 deletions(-)

diffs (51 lines):

diff -r ba601762eeba -r 661ac9cfbbc3 sys/arch/x86/x86/identcpu.c
--- a/sys/arch/x86/x86/identcpu.c       Sat Jun 23 09:51:34 2018 +0000
+++ b/sys/arch/x86/x86/identcpu.c       Sat Jun 23 10:02:39 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: identcpu.c,v 1.75 2018/06/23 09:51:34 maxv Exp $       */
+/*     $NetBSD: identcpu.c,v 1.76 2018/06/23 10:02:39 maxv Exp $       */
 
 /*-
  * Copyright (c) 1999, 2000, 2001, 2006, 2007, 2008 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: identcpu.c,v 1.75 2018/06/23 09:51:34 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: identcpu.c,v 1.76 2018/06/23 10:02:39 maxv Exp $");
 
 #include "opt_xen.h"
 
@@ -795,6 +795,11 @@
 
        x86_fpu_save = FPU_SAVE_FXSAVE;
 
+#ifdef XEN
+       /* We don't support XSAVE on Xen. */
+       return;
+#endif
+
        /* See if xsave (for AVX) is supported */
        if ((ci->ci_feat_val[1] & CPUID2_XSAVE) == 0)
                return;
@@ -802,7 +807,6 @@
        x86_fpu_save = FPU_SAVE_XSAVE;
 
 #if 0 /* XXX PR 52966 */
-       /* xsaveopt ought to be faster than xsave */
        x86_cpuid2(0xd, 1, descs);
        if (descs[0] & CPUID_PES1_XSAVEOPT)
                x86_fpu_save = FPU_SAVE_XSAVEOPT;
@@ -813,12 +817,7 @@
        if (descs[2] > 512)
                x86_fpu_save_size = descs[2];
 
-#ifdef XEN
-       /* Don't use xsave, force fxsave with x86_xsave_features = 0. */
-       x86_fpu_save = FPU_SAVE_FXSAVE;
-#else
        x86_xsave_features = (uint64_t)descs[3] << 32 | descs[0];
-#endif
 }
 
 void