[src/trunk]: src/sys/arch/x86/x86 Force a reload of CW in fpu_set_default_cw(...

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

details:   https://anonhg.NetBSD.org/src/rev/88f5ea385646
branches:  trunk
changeset: 359421:88f5ea385646
user:      maxv <maxv%NetBSD.org@localhost>
date:      Fri Feb 09 08:58:01 2018 +0000

description:
Force a reload of CW in fpu_set_default_cw(). This function is used only
in COMPAT_FREEBSD, it really needs to die.

diffstat:

 sys/arch/x86/x86/fpu.c |  17 +++++++++++++----
 1 files changed, 13 insertions(+), 4 deletions(-)

diffs (40 lines):

diff -r 0bfbb1fda0e4 -r 88f5ea385646 sys/arch/x86/x86/fpu.c
--- a/sys/arch/x86/x86/fpu.c    Fri Feb 09 08:54:11 2018 +0000
+++ b/sys/arch/x86/x86/fpu.c    Fri Feb 09 08:58:01 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fpu.c,v 1.27 2017/11/11 11:00:46 maxv Exp $    */
+/*     $NetBSD: fpu.c,v 1.28 2018/02/09 08:58:01 maxv Exp $    */
 
 /*
  * Copyright (c) 2008 The NetBSD Foundation, Inc.  All
@@ -96,7 +96,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.27 2017/11/11 11:00:46 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.28 2018/02/09 08:58:01 maxv Exp $");
 
 #include "opt_multiprocessor.h"
 
@@ -534,10 +534,19 @@
        union savefpu *fpu_save = process_fpframe(l);
        struct pcb *pcb = lwp_getpcb(l);
 
-       if (i386_use_fxsave)
+       if (i386_use_fxsave) {
                fpu_save->sv_xmm.fx_cw = x87_cw;
-       else
+
+               /* Force a reload of CW */
+               if ((x87_cw != __INITIAL_NPXCW__) &&
+                   (x86_fpu_save == FPU_SAVE_XSAVE ||
+                   x86_fpu_save == FPU_SAVE_XSAVEOPT)) {
+                       fpu_save->sv_xsave_hdr.xsh_xstate_bv |=
+                           XCR0_X87;
+               }
+       } else {
                fpu_save->sv_87.s87_cw = x87_cw;
+       }
        pcb->pcb_fpu_dflt_cw = x87_cw;
 }