1 /* $NetBSD: compiler.h,v 1.6 2021/12/19 11:26:57 riastradh Exp $ */ 2 3 /*- 4 * Copyright (c) 2018 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 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 #ifndef _LINUX_COMPILER_H_ 33 #define _LINUX_COMPILER_H_ 34 35 #include <sys/atomic.h> 36 #include <sys/cdefs.h> 37 38 #include <linux/stddef.h> 39 40 #include <asm/barrier.h> 41 42 #define __printf __printflike 43 #define __user 44 #if __GNUC_PREREQ__(4,0) /* not sure when but this will work */ 45 #define __must_check __attribute__((warn_unused_result)) 46 #else 47 #define __must_check /* nothing */ 48 #endif 49 #define __always_unused __unused 50 #define __maybe_unused __unused 51 #define noinline __noinline 52 #define __deprecated /* nothing */ 53 54 #define barrier() __insn_barrier() 55 #define likely(X) __predict_true(X) 56 #define unlikely(X) __predict_false(X) 57 #define __same_type(X,Y) \ 58 __builtin_types_compatible_p(__typeof__(X), __typeof__(Y)) 59 #define __must_be_array(X) \ 60 BUILD_BUG_ON_ZERO(__same_type((X), &(X)[0])) 61 62 #define READ_ONCE(X) ({ \ 63 typeof(X) __read_once_tmp = (X); \ 64 membar_datadep_consumer(); \ 65 __read_once_tmp; \ 66 }) 67 68 #define WRITE_ONCE(X, V) ({ \ 69 typeof(X) __write_once_tmp = (V); \ 70 (X) = __write_once_tmp; \ 71 __write_once_tmp; \ 72 }) 73 74 #define smp_store_mb(X, V) do { \ 75 WRITE_ONCE(X, V); \ 76 smp_mb(); \ 77 } while (0) 78 79 #define smp_store_release(X, V) do { \ 80 typeof(X) __smp_store_release_tmp = (V); \ 81 membar_exit(); \ 82 (X) = __write_once_tmp; \ 83 } while (0) 84 85 #endif /* _LINUX_COMPILER_H_ */ 86