1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2021 Vladimir Kondratyev <wulf@FreeBSD.org> 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 unmodified, this list of conditions, and the following 11 * disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #ifndef _LINUXKPI_ASM_BARRIER_H_ 29 #define _LINUXKPI_ASM_BARRIER_H_ 30 31 #include <sys/types.h> 32 #include <machine/atomic.h> 33 34 #include <asm/atomic.h> 35 #include <linux/compiler.h> 36 37 /* TODO: Check other archs for atomic_thread_fence_* useability */ 38 #if defined(__amd64__) || defined(__i386__) 39 #define smp_mb() atomic_thread_fence_seq_cst() 40 #define smp_wmb() atomic_thread_fence_rel() 41 #define smp_rmb() atomic_thread_fence_acq() 42 #define smp_store_mb(x, v) do { (void)xchg(&(x), v); } while (0) 43 #endif 44 45 #ifndef smp_mb 46 #define smp_mb() mb() 47 #endif 48 #ifndef smp_wmb 49 #define smp_wmb() wmb() 50 #endif 51 #ifndef smp_rmb 52 #define smp_rmb() rmb() 53 #endif 54 #ifndef smp_store_mb 55 #define smp_store_mb(x, v) do { WRITE_ONCE(x, v); smp_mb(); } while (0) 56 #endif 57 58 #define smp_mb__before_atomic() barrier() 59 #define smp_mb__after_atomic() barrier() 60 61 #define smp_store_release(p, v) do { smp_mb(); WRITE_ONCE(*p, v); } while (0) 62 #define smp_load_acquire(p) ({ typeof(*p) _v = READ_ONCE(*p); smp_mb(); _v; }) 63 64 #endif /* _LINUXKPI_ASM_BARRIER_H_ */ 65