[src/trunk]: src/sys/arch/powerpc/powerpc Don't reload the FPU register if th...

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

details:   https://anonhg.NetBSD.org/src/rev/fe26378ade80
branches:  trunk
changeset: 809361:fe26378ade80
user:      matt <matt%NetBSD.org@localhost>
date:      Mon Jul 06 01:55:50 2015 +0000

description:
Don't reload the FPU register if this is just a re-enable.

diffstat:

 sys/arch/powerpc/powerpc/fpu.c |  20 +++++++++++---------
 1 files changed, 11 insertions(+), 9 deletions(-)

diffs (43 lines):

diff -r 999fbad5721e -r fe26378ade80 sys/arch/powerpc/powerpc/fpu.c
--- a/sys/arch/powerpc/powerpc/fpu.c    Mon Jul 06 00:21:51 2015 +0000
+++ b/sys/arch/powerpc/powerpc/fpu.c    Mon Jul 06 01:55:50 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: fpu.c,v 1.35 2014/05/16 00:48:41 rmind Exp $   */
+/*     $NetBSD: fpu.c,v 1.36 2015/07/06 01:55:50 matt Exp $    */
 
 /*
  * Copyright (C) 1996 Wolfgang Solfrank.
@@ -32,7 +32,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.35 2014/05/16 00:48:41 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fpu.c,v 1.36 2015/07/06 01:55:50 matt Exp $");
 
 #include "opt_multiprocessor.h"
 
@@ -84,15 +84,17 @@
                memset(&pcb->pcb_fpu, 0, sizeof(pcb->pcb_fpu));
        }
 
-       const register_t msr = mfmsr();
-        mtmsr((msr & ~PSL_EE) | PSL_FP);
-       __asm volatile ("isync");
+       if ((flags & PCU_REENABLE) == 0) {
+               const register_t msr = mfmsr();
+               mtmsr((msr & ~PSL_EE) | PSL_FP);
+               __asm volatile ("isync");
 
-       fpu_load_from_fpreg(&pcb->pcb_fpu);
-       __asm volatile ("sync");
+               fpu_load_from_fpreg(&pcb->pcb_fpu);
+               __asm volatile ("sync");
 
-       mtmsr(msr);
-       __asm volatile ("isync");
+               mtmsr(msr);
+               __asm volatile ("isync");
+       }
 
        curcpu()->ci_ev_fpusw.ev_count++;
        l->l_md.md_utf->tf_srr1 |= PSL_FP|(pcb->pcb_flags & (PCB_FE0|PCB_FE1));