/* $NetBSD: atomic_dec_32.S,v 1.5.28.1 2021/08/11 17:05:42 martin Exp $ */ /*- * Copyright (c) 2008 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Matt Thomas * * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 "atomic_op_asm.h" #if defined(_ARM_ARCH_6) ENTRY_NP(_atomic_dec_32) 1: ldrex r3, [r0] /* load old value (return value) */ subs r3, r3, #1 /* calculate new value */ strex r2, r3, [r0] /* try to store */ cmp r2, #0 /* succeed? */ bne 1b /* no, try again? */ RET /* return new value */ END(_atomic_dec_32) ATOMIC_OP_ALIAS(atomic_dec_32,_atomic_dec_32) ATOMIC_OP_ALIAS(atomic_dec_uint,_atomic_dec_32) ATOMIC_OP_ALIAS(atomic_dec_ulong,_atomic_dec_32) ATOMIC_OP_ALIAS(atomic_dec_ptr,_atomic_dec_32) STRONG_ALIAS(_atomic_dec_uint,_atomic_dec_32) STRONG_ALIAS(_atomic_dec_ulong,_atomic_dec_32) STRONG_ALIAS(_atomic_dec_ptr,_atomic_dec_32) ENTRY_NP(_atomic_dec_32_nv) mov ip, r0 /* need r0 for return value */ 1: ldrex r0, [ip] /* load old value */ subs r0, r0, #1 /* calculate new value (return value) */ strex r2, r0, [ip] /* try to store */ cmp r2, #0 /* succeed? */ bne 1b /* no, try again? */ RET /* return new value */ END(_atomic_dec_32_nv) ATOMIC_OP_ALIAS(atomic_dec_32_nv,_atomic_dec_32_nv) ATOMIC_OP_ALIAS(atomic_dec_uint_nv,_atomic_dec_32_nv) ATOMIC_OP_ALIAS(atomic_dec_ulong_nv,_atomic_dec_32_nv) ATOMIC_OP_ALIAS(atomic_dec_ptr_nv,_atomic_dec_32_nv) STRONG_ALIAS(_atomic_dec_uint_nv,_atomic_dec_32_nv) STRONG_ALIAS(_atomic_dec_ulong_nv,_atomic_dec_32_nv) STRONG_ALIAS(_atomic_dec_ptr_nv,_atomic_dec_32_nv) #endif /* _ARM_ARCH_6 */