1/* $NetBSD: rump_atomic_cas_up.c,v 1.1 2010/11/22 10:50:51 pooka Exp $ */ 2 3/*- 4 * Copyright (c) 2010 Antti Kantee. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS 16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS 19 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 * POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__KERNEL_RCSID(0, "$NetBSD: rump_atomic_cas_up.c,v 1.1 2010/11/22 10:50:51 pooka Exp $"); 30 31/* 32 * Uniprocessor version of atomic CAS. Since there is no preemption 33 * in rump, this is a piece of cake. 34 */ 35 36#include <sys/types.h> 37 38uint32_t rump_cas_32_up(volatile uint32_t *ptr, uint32_t, uint32_t); 39 40uint32_t 41rump_cas_32_up(volatile uint32_t *ptr, uint32_t old, uint32_t new) 42{ 43 uint32_t ret; 44 45 ret = *ptr; 46 if (__predict_true(ret == old)) { 47 *ptr = new; 48 } 49 50 return ret; 51} 52 53__strong_alias(atomic_cas_32,rump_cas_32_up) 54__strong_alias(_atomic_cas_32,rump_cas_32_up) 55__strong_alias(atomic_cas_uint,rump_cas_32_up) 56__strong_alias(_atomic_cas_uint,rump_cas_32_up) 57__strong_alias(atomic_cas_ulong,rump_cas_32_up) 58__strong_alias(_atomic_cas_ulong,rump_cas_32_up) 59__strong_alias(atomic_cas_ptr,rump_cas_32_up) 60__strong_alias(_atomic_cas_ptr,rump_cas_32_up) 61__strong_alias(atomic_cas_32_ni,rump_cas_32_up) 62__strong_alias(_atomic_cas_32_ni,rump_cas_32_up) 63__strong_alias(atomic_cas_uint_ni,rump_cas_32_up) 64__strong_alias(_atomic_cas_uint_ni,rump_cas_32_up) 65__strong_alias(atomic_cas_ulong_ni,rump_cas_32_up) 66__strong_alias(_atomic_cas_ulong_ni,rump_cas_32_up) 67__strong_alias(atomic_cas_ptr_ni,rump_cas_32_up) 68__strong_alias(_atomic_cas_ptr_ni,rump_cas_32_up) 69