1/* $NetBSD: atomic_sub_64.S,v 1.2 2014/03/04 16:15:28 matt Exp $ */ 2 3/*- 4 * Copyright (c) 2013 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matt Thomas <matt@3am-software.com> 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include "atomic_op_asm.h" 33 34#ifdef _ARM_ARCH_6 35 36ENTRY_NP(_atomic_sub_64_nv) 37 push {r3,r4} /* save temporary */ 38 mov ip, r0 /* need r0 for return value */ 39#ifndef __ARM_EABI__ 40 mov r3, r2 41 mov r2, r1 42#endif 431: ldrexd r0, [ip] /* load old value */ 44 subs LO, LO, NLO /* calculate new value lo */ 45 sbcs HI, HI, NHI /* calculate new value hi */ 46 strexd r4, r0, [ip] /* try to store */ 47 cmp r4, #0 /* succeed? */ 48 bne 1b /* no, try again? */ 49#ifdef _ARM_ARCH_7 50 dmb 51#else 52 mcr p15, 0, r4, c7, c10, 5 /* data memory barrier */ 53#endif 54 pop {r3,r4} /* restore temporary */ 55 RET /* return new value */ 56END(_atomic_sub_64_nv) 57 58STRONG_ALIAS(_atomic_sub_64,_atomic_sub_64_nv) 59ATOMIC_OP_ALIAS(atomic_sub_64_nv,_atomic_sub_64_nv) 60ATOMIC_OP_ALIAS(atomic_sub_64,_atomic_sub_64) 61CRT_ALIAS(__sync_sub_and_fetch_8,_atomic_sub_64_nv) 62 63#endif /* _ARM_ARCH_6 */ 64