[src/trunk]: src/sys/arch/arm/arm32 Add clrex when we get an abort.

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

details:   https://anonhg.NetBSD.org/src/rev/c98129477aa8
branches:  trunk
changeset: 794361:c98129477aa8
user:      matt <matt%NetBSD.org@localhost>
date:      Thu Mar 13 01:45:35 2014 +0000

description:
Add clrex when we get an abort.
Simplify undefined_entry to use the undefined stack to do transfer to the
undefined handler.

diffstat:

 sys/arch/arm/arm32/exception.S |  38 ++++++++++++++++++++++++++++++--------
 1 files changed, 30 insertions(+), 8 deletions(-)

diffs (81 lines):

diff -r 57d93f287fae -r c98129477aa8 sys/arch/arm/arm32/exception.S
--- a/sys/arch/arm/arm32/exception.S    Thu Mar 13 01:45:33 2014 +0000
+++ b/sys/arch/arm/arm32/exception.S    Thu Mar 13 01:45:35 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exception.S,v 1.21 2014/03/05 02:12:24 matt Exp $      */
+/*     $NetBSD: exception.S,v 1.22 2014/03/13 01:45:35 matt Exp $      */
 
 /*
  * Copyright (c) 1994-1997 Mark Brinicombe.
@@ -51,7 +51,7 @@
 
 #include <arm/locore.h>
 
-       RCSID("$NetBSD: exception.S,v 1.21 2014/03/05 02:12:24 matt Exp $")
+       RCSID("$NetBSD: exception.S,v 1.22 2014/03/13 01:45:35 matt Exp $")
 
        .text   
        .align  0
@@ -102,6 +102,14 @@
 #endif
         sub     lr, lr, #0x00000004     /* Adjust the lr */
 
+#ifdef _ARM_ARCH_7
+       /*
+        * After taking a Data Abort exception, the state of the exclusive
+        * monitors is UNKNOWN. Therefore ARM strongly recommends that the
+        * abort handling software performs a CLREX instruction
+        */
+       clrex
+#endif
        PUSHFRAMEINSVC
        ENABLE_ALIGNMENT_FAULTS
 
@@ -140,6 +148,14 @@
 #endif
         sub     lr, lr, #0x00000008     /* Adjust the lr */
 
+#ifdef _ARM_ARCH_7
+       /*
+        * After taking a Data Abort exception, the state of the exclusive
+        * monitors is UNKNOWN. Therefore ARM strongly recommends that the
+        * abort handling software performs a CLREX instruction
+        */
+       clrex
+#endif
        PUSHFRAMEINSVC                  /* Push trap frame and switch */
                                        /* to SVC32 mode */
        ENABLE_ALIGNMENT_FAULTS
@@ -178,6 +194,14 @@
  *     it like a Data Abort.
  */
 ASENTRY_NP(address_exception_entry)
+#ifdef _ARM_ARCH_7
+       /*
+        * After taking a Data Abort exception, the state of the exclusive
+        * monitors is UNKNOWN. Therefore ARM strongly recommends that the
+        * abort handling software performs a CLREX instruction
+        */
+       clrex
+#endif
        push    {r0-r3,ip,lr}
        mrs     r1, cpsr
        mrs     r2, spsr
@@ -220,13 +244,11 @@
  *     look like direct entry from the vector.
  */
 ASENTRY_NP(undefined_entry)
-       stmfd   sp!, {r0, r1}
+       str     r0, [sp, #-8]!
        GET_CURCPU(r0)
-       ldr     r1, [sp], #0x0004
-       str     r1, [r0, #CI_UNDEFSAVE]!
-       ldr     r1, [sp], #0x0004
-       str     r1, [r0, #0x0004]
-       ldmia   r0, {r0, r1, pc}
+       ldr     r0, [r0, #CI_UNDEFSAVE+8]
+       str     r0, [sp, #4]
+       pop     {r0, pc}
 ASEND(undefined_entry)
 
 /*