11.3Sskrll/* $NetBSD: atomic_cas_16.S,v 1.3 2021/07/28 07:32:20 skrll Exp $ */ 21.1Smatt/*- 31.1Smatt * Copyright (c) 2013 The NetBSD Foundation, Inc. 41.1Smatt * All rights reserved. 51.1Smatt * 61.1Smatt * This code is derived from software contributed to The NetBSD Foundation 71.1Smatt * by Matt Thomas <matt@3am-software.com> 81.1Smatt * 91.1Smatt * Redistribution and use in source and binary forms, with or without 101.1Smatt * modification, are permitted provided that the following conditions 111.1Smatt * are met: 121.1Smatt * 1. Redistributions of source code must retain the above copyright 131.1Smatt * notice, this list of conditions and the following disclaimer. 141.1Smatt * 2. Redistributions in binary form must reproduce the above copyright 151.1Smatt * notice, this list of conditions and the following disclaimer in the 161.1Smatt * documentation and/or other materials provided with the distribution. 171.1Smatt * 181.1Smatt * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 191.1Smatt * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 201.1Smatt * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 211.1Smatt * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 221.1Smatt * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 231.1Smatt * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 241.1Smatt * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 251.1Smatt * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 261.1Smatt * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 271.1Smatt * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 281.1Smatt * POSSIBILITY OF SUCH DAMAGE. 291.1Smatt */ 301.1Smatt 311.1Smatt#include "atomic_op_asm.h" 321.1Smatt 331.1Smatt#if defined(_ARM_ARCH_6) 341.3Sskrll 351.1Smatt/* 361.1Smatt * ARMv6 has load-exclusive/store-exclusive which works for both user 371.1Smatt * and kernel. 381.1Smatt */ 391.1SmattENTRY_NP(_atomic_cas_16) 401.1Smatt mov ip, r0 /* we need r0 for return value */ 411.1Smatt1: 421.1Smatt ldrexh r0, [ip] /* load old value */ 431.1Smatt cmp r0, r1 /* compare? */ 441.1Smatt#ifdef __thumb__ 451.1Smatt bne 2f 461.1Smatt#else 471.1Smatt RETc(ne) /* return if different */ 481.1Smatt#endif 491.1Smatt strexh r3, r2, [ip] /* store new value */ 501.1Smatt cmp r3, #0 /* succeed? */ 511.1Smatt bne 1b /* nope, try again. */ 521.1Smatt2: RET /* return. */ 531.1SmattEND(_atomic_cas_16) 541.1Smatt 551.1SmattATOMIC_OP_ALIAS(atomic_cas_16,_atomic_cas_16) 561.1SmattSTRONG_ALIAS(_atomic_cas_short,_atomic_cas_16) 571.1SmattSTRONG_ALIAS(_atomic_cas_ushort,_atomic_cas_16) 581.3Sskrll 591.3SskrllENTRY_NP(__sync_val_compare_and_swap_2) 601.3Sskrll push {r4, lr} 611.3Sskrll DMB 621.3Sskrll bl _atomic_cas_16 631.3Sskrll DMB 641.3Sskrll pop {r4, pc} 651.3SskrllEND(__sync_val_compare_and_swap_2) 661.1Smatt 671.1Smatt#endif /* _ARM_ARCH_6 */ 68