[src/trunk]: src/sys/arch/arm/arm32 Add a clrex/dmb to irq path as recommende...

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

details:   https://anonhg.NetBSD.org/src/rev/cca86356d43e
branches:  trunk
changeset: 338641:cca86356d43e
user:      matt <matt%NetBSD.org@localhost>
date:      Tue Jun 02 14:06:16 2015 +0000

description:
Add a clrex/dmb to irq path as recommended by ARM.

diffstat:

 sys/arch/arm/arm32/irq_dispatch.S |  12 +++++++++++-
 1 files changed, 11 insertions(+), 1 deletions(-)

diffs (33 lines):

diff -r 900b5f6f1d6a -r cca86356d43e sys/arch/arm/arm32/irq_dispatch.S
--- a/sys/arch/arm/arm32/irq_dispatch.S Tue Jun 02 14:02:39 2015 +0000
+++ b/sys/arch/arm/arm32/irq_dispatch.S Tue Jun 02 14:06:16 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: irq_dispatch.S,v 1.15 2013/08/18 06:28:18 matt Exp $   */
+/*     $NetBSD: irq_dispatch.S,v 1.16 2015/06/02 14:06:16 matt Exp $   */
 
 /*
  * Copyright (c) 2002 Fujitsu Component Limited
@@ -97,6 +97,11 @@
        PUSHFRAMEINSVC                  /* Push an interrupt frame */
        ENABLE_ALIGNMENT_FAULTS         /* finishes with curcpu() in r4 */
 
+#ifdef _ARM_ARCH_7
+       clrex                           /* force all strex to fail */
+       dmb                             /* synchronize memory writes */
+#endif
+
        /*
         * Increment the interrupt nesting depth and call the interrupt
         * dispatch routine.  We've pushed a frame, so we can safely use
@@ -153,6 +158,11 @@
        add     r1, r6, #1
        str     r1, [r4, #CI_INTR_DEPTH]
 
+#ifdef _ARM_ARCH_7
+       clrex                           /* force all strex to fail */
+       dmb                             /* synchronize memory writes */
+#endif
+
        mov     r0, sp                  /* arg for dispatcher */
        bl      ARM_IRQ_HANDLER