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merge from open-source master

This commit is contained in:
Jean-Baptiste Queru 2009-09-15 07:52:20 -07:00
parent f647a3c8aa 2f1013e6e4
commit 3e42572835
1 changed files with 11 additions and 5 deletions
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16
libcutils/atomic-android-arm.S
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@ -17,8 +17,7 @@
#include <machine/cpu-features.h>
/*
* NOTE: these atomic operations are SMP safe on all architectures,
* except swap(), see below.
* NOTE: these atomic operations are SMP safe on all architectures.
*/
.text
@ -213,11 +212,18 @@ android_atomic_or:
* output: r0 = old value
*/
/* FIXME: this is not safe on SMP systems
* a general way to do it is to use kernel_cmpxchg */
/* replaced swp instruction with ldrex/strex for ARMv6 & ARMv7 */
android_atomic_swap:
#if defined (_ARM_HAVE_LDREX_STREX)
1: ldrex r2, [r1]
strex r3, r0, [r1]
teq r3, #0
bne 1b
mov r0, r2
mcr p15, 0, r0, c7, c10, 5 /* or, use dmb */
#else
swp r0, r0, [r1]
#endif
bx lr
/*