diff options
Diffstat (limited to 'core/arch/arm/kernel/spin_lock_a32.S')
| -rw-r--r-- | core/arch/arm/kernel/spin_lock_a32.S | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/core/arch/arm/kernel/spin_lock_a32.S b/core/arch/arm/kernel/spin_lock_a32.S new file mode 100644 index 0000000..52d8e9f --- /dev/null +++ b/core/arch/arm/kernel/spin_lock_a32.S @@ -0,0 +1,85 @@ +/* + * Copyright (c) 2016, Linaro Limited + * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2014, STMicroelectronics International N.V. + * 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. + * + * Neither the name of ARM nor the names of its contributors may be used + * to endorse or promote products derived from this software without specific + * prior written permission. + * + * 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> +#include <kernel/spinlock.h> +#include <kernel/unwind.h> + +/* void __cpu_spin_lock(unsigned int *lock) */ +FUNC __cpu_spin_lock , : +UNWIND( .fnstart) + mov r2, #SPINLOCK_LOCK +1: + ldrex r1, [r0] + cmp r1, #SPINLOCK_UNLOCK + wfene + strexeq r1, r2, [r0] + cmpeq r1, #0 + bne 1b + dmb + bx lr +UNWIND( .fnend) +END_FUNC __cpu_spin_lock + +/* int __cpu_spin_trylock(unsigned int *lock) - return 0 on success */ +FUNC __cpu_spin_trylock , : +UNWIND( .fnstart) + mov r2, #SPINLOCK_LOCK + mov r1, r0 +1: + ldrex r0, [r1] + cmp r0, #0 + bne 1f + strex r0, r2, [r1] + cmp r0, #0 + bne 1b + dmb + bx lr +1: + clrex + dmb + bx lr +UNWIND( .fnend) +END_FUNC __cpu_spin_trylock + +/* void __cpu_spin_unlock(unsigned int *lock) */ +FUNC __cpu_spin_unlock , : +UNWIND( .fnstart) + dmb + mov r1, #SPINLOCK_UNLOCK + str r1, [r0] + dsb + sev + bx lr +UNWIND( .fnend) +END_FUNC __cpu_spin_unlock |