diff options
Diffstat (limited to 'lib/libutils/ext/arch/arm/atomic_a32.S')
| -rw-r--r-- | lib/libutils/ext/arch/arm/atomic_a32.S | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/lib/libutils/ext/arch/arm/atomic_a32.S b/lib/libutils/ext/arch/arm/atomic_a32.S new file mode 100644 index 0000000..c9b562b --- /dev/null +++ b/lib/libutils/ext/arch/arm/atomic_a32.S @@ -0,0 +1,50 @@ +/* + * Copyright (c) 2015-2016, Linaro Limited + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <asm.S> + +/* uint32_t atomic_inc32(uint32_t *v); */ +FUNC atomic_inc32 , : + ldrex r1, [r0] + add r1, r1, #1 + strex r2, r1, [r0] + cmp r2, #0 + bne atomic_inc32 + mov r0, r1 + bx lr +END_FUNC atomic_inc32 + +/* uint32_t atomic_dec32(uint32_t *v); */ +FUNC atomic_dec32 , : + ldrex r1, [r0] + sub r1, r1, #1 + strex r2, r1, [r0] + cmp r2, #0 + bne atomic_dec32 + mov r0, r1 + bx lr +END_FUNC atomic_dec32 |