platform_bionic/libc/private/bionic_atomic_gcc_builtin.h
Serban Constantinescu 845c778fa6 ARM: Change dmb domain for bionic_atomic_barrier()
This patch changes the domain that the memory barrier operates on. Assumes
that the scope of bionic_atomic_barrier() does not include device memory,
memory shared with the GPU or any other memory external to the processor
cluster.

Change-Id: I291e741c98a64c86f3a3cf99811bbf1e714ac9aa
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>
2013-12-19 11:39:01 -08:00

50 lines
1.7 KiB
C

/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef BIONIC_ATOMIC_GCC_BUILTIN_H
#define BIONIC_ATOMIC_GCC_BUILTIN_H
/*
* This header file is used by default if we don't have optimized atomic
* routines for a given platform. See bionic_atomic_arm.h and
* bionic_atomic_x86.h for examples.
*
* Note that the GCC builtins include barriers that aren't present in
* the architecture-specific assembler versions.
*/
__ATOMIC_INLINE__ void __bionic_memory_barrier() {
__sync_synchronize();
}
__ATOMIC_INLINE__ int __bionic_cmpxchg(int32_t old_value, int32_t new_value, volatile int32_t* ptr) {
/* We must return 0 on success. */
return __sync_val_compare_and_swap(ptr, old_value, new_value) != old_value;
}
__ATOMIC_INLINE__ int32_t __bionic_swap(int32_t new_value, volatile int32_t* ptr) {
int32_t old_value;
do {
old_value = *ptr;
} while (__sync_val_compare_and_swap(ptr, old_value, new_value) != old_value);
return old_value;
}
__ATOMIC_INLINE__ int32_t __bionic_atomic_dec(volatile int32_t* ptr) {
/* We must return the old value. */
return __sync_fetch_and_add(ptr, -1);
}
#endif /* BIONIC_ATOMIC_GCC_BUILTIN_H */