/* $NetBSD: membar_ops.S,v 1.8 2022/04/09 23:32:52 riastradh Exp $ */ /*- * Copyright (c) 2007 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Jason R. Thorpe, and by Andrew Doran. * * 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" #ifdef _KERNEL_OPT #include "opt_multiprocessor.h" #endif .text /* * These assume Total Store Order (TSO), which may reorder * store-before-load but nothing else. Hence, only membar_sync (and * its deprecated alias membar_enter) must issue anything -- * specifically, an LDSTUB, which (along with SWAP) is the only * instruction that implies a sequential consistency barrier. * * If we ran with Partial Store Order (PSO), we would also need to * issue STBAR for membar_release (load/store-before-store) and * membar_producer (store-before-store). */ ENTRY(_membar_acquire) retl nop END(_membar_acquire) ATOMIC_OP_ALIAS(membar_acquire,_membar_acquire) ENTRY(_membar_release) retl nop END(_membar_release) ATOMIC_OP_ALIAS(membar_release,_membar_release) ENTRY(_membar_sync) retl #if !defined(_KERNEL) || defined(MULTIPROCESSOR) ldstub [%sp - 4], %g0 #else nop #endif END(_membar_sync) ATOMIC_OP_ALIAS(membar_sync,_membar_sync) ATOMIC_OP_ALIAS(membar_producer,_membar_release) STRONG_ALIAS(_membar_producer,_membar_release) ATOMIC_OP_ALIAS(membar_consumer,_membar_acquire) STRONG_ALIAS(_membar_consumer,_membar_acquire) ATOMIC_OP_ALIAS(membar_enter,_membar_sync) STRONG_ALIAS(_membar_enter,_membar_sync) ATOMIC_OP_ALIAS(membar_exit,_membar_release) STRONG_ALIAS(_membar_exit,_membar_release) |