[src/trunk]: src/sys/arch/alpha/alpha When completing a FP trap, only load th...

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

details:   https://anonhg.NetBSD.org/src/rev/b06c63e6bdf7
branches:  trunk
changeset: 329310:b06c63e6bdf7
user:      matt <matt%NetBSD.org@localhost>
date:      Mon May 19 06:55:54 2014 +0000

description:
When completing a FP trap, only load the FPU if we don't already own it.
While the FPU is on, disable kernel preemption.

diffstat:

 sys/arch/alpha/alpha/fp_complete.c |  12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diffs (52 lines):

diff -r a5872edd4b2e -r b06c63e6bdf7 sys/arch/alpha/alpha/fp_complete.c
--- a/sys/arch/alpha/alpha/fp_complete.c        Mon May 19 05:48:14 2014 +0000
+++ b/sys/arch/alpha/alpha/fp_complete.c        Mon May 19 06:55:54 2014 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: fp_complete.c,v 1.19 2014/05/18 11:04:51 martin Exp $ */
+/* $NetBSD: fp_complete.c,v 1.20 2014/05/19 06:55:54 matt Exp $ */
 
 /*-
  * Copyright (c) 2001 Ross Harvey
@@ -35,7 +35,7 @@
 
 #include <sys/cdefs.h>                 /* RCS ID & Copyright macro defns */
 
-__KERNEL_RCSID(0, "$NetBSD: fp_complete.c,v 1.19 2014/05/18 11:04:51 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fp_complete.c,v 1.20 2014/05/19 06:55:54 matt Exp $");
 
 #include "opt_compat_osf1.h"
 
@@ -408,11 +408,13 @@
        if ((md_flags & MDLWP_FP_C) == fp_c)
                return;
        l->l_md.md_flags = (md_flags & ~MDLWP_FP_C) | fp_c;
+       kpreempt_disable();
        if (md_flags & MDLWP_FPACTIVE) {
                alpha_pal_wrfen(1);
                fp_c_to_fpcr(l);
                alpha_pal_wrfen(0);
        }
+       kpreempt_enable();
 }
 
 uint64_t
@@ -586,7 +588,10 @@
                this_cannot_happen(6, -1);
                return SIGSEGV;
        }
-       fpu_load();
+       kpreempt_disable();
+       if ((curlwp->l_md.md_flags & MDLWP_FPACTIVE) == 0) {
+               fpu_load();
+       }
        alpha_pal_wrfen(1);
        /*
         * If necessary, lie about the dynamic rounding mode so emulation
@@ -612,6 +617,7 @@
        alpha_write_fpcr(fp_c_to_fpcr_1(orig_fpcr, md_flags));
        needsig = changed_flags & FP_C_TO_NETBSD_MASK(md_flags);
        alpha_pal_wrfen(0);
+       kpreempt_enable();
        if (__predict_false(needsig)) {
                *ucode = needsig;
                return SIGFPE;