1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013-2016 Mellanox Technologies, Ltd. 6 * Copyright (c) 2015-2020 François Tigeot <ftigeot@wolfpond.org> 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice unmodified, this list of conditions, and the following 14 * 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #ifndef _LINUX_COMPILER_H_ 32 #define _LINUX_COMPILER_H_ 33 34 #include <sys/cdefs.h> 35 36 #define __user 37 #define __kernel 38 #define __safe 39 #define __force 40 #define __nocast 41 #define __iomem 42 #define __chk_user_ptr(x) 0 43 #define __chk_io_ptr(x) 0 44 #define __builtin_warning(x, y...) (1) 45 #define __acquires(x) 46 #define __releases(x) 47 #define __acquire(x) 0 48 #define __release(x) 0 49 #define __cond_lock(x,c) (c) 50 #define __bitwise 51 #define __devinitdata 52 #define __init 53 #define __devinit 54 #define __devexit 55 #define __exit 56 #define __stringify(x) #x 57 #define __attribute_const__ __attribute__((__const__)) 58 #undef __always_inline 59 #define __always_inline inline 60 #define noinline __attribute__((noinline)) 61 62 #define likely(x) __builtin_expect(!!(x), 1) 63 #define unlikely(x) __builtin_expect(!!(x), 0) 64 #define typeof(x) __typeof(x) 65 66 #define __maybe_unused __unused 67 #define __always_unused __unused 68 #define __malloc 69 #define __must_check __heedresult 70 71 #define __printf(a,b) __printflike(a,b) 72 73 74 #define barrier() cpu_ccfence() 75 76 #ifdef _KERNEL /* This file is included by kdump(1) */ 77 78 #include <sys/param.h> 79 80 /* 81 * The READ_ONCE() and WRITE_ONCE() macros force volatile accesses to 82 * various data types. 83 * Their complexity is caused by the necessity to work-around 84 * compiler cleverness and bugs. 85 * Some GCC versions drop the volatile modifier if the variable used 86 * is not of a scalar type. 87 */ 88 static inline void 89 __volatile_read(const volatile void *x, int size, void *result) 90 { 91 switch(size) { 92 case 8: 93 *(uint64_t *)result = *(const volatile uint64_t *)x; 94 break; 95 case 4: 96 *(uint32_t *)result = *(const volatile uint32_t *)x; 97 break; 98 case 2: 99 *(uint16_t *)result = *(const volatile uint16_t *)x; 100 break; 101 case 1: 102 *(uint8_t *)result = *(const volatile uint8_t *)x; 103 break; 104 default: 105 panic("__volatile_read called with size %d\n", size); 106 } 107 } 108 109 static inline void 110 __volatile_write(volatile void *var, int size, void *value) 111 { 112 switch(size) { 113 case 8: 114 *(volatile uint64_t *)var = *(uint64_t *)value; 115 break; 116 case 4: 117 *(volatile uint32_t *)var = *(uint32_t *)value; 118 break; 119 case 2: 120 *(volatile uint16_t *)var = *(uint16_t *)value; 121 break; 122 case 1: 123 *(volatile uint8_t *)var = *(uint8_t *)value; 124 break; 125 default: 126 panic("__volatile_write called with size %d\n", size); 127 } 128 129 } 130 131 #define READ_ONCE(x) ({ \ 132 union { \ 133 __typeof(x) initial_type; \ 134 uint8_t nc_type; \ 135 } result; \ 136 \ 137 result.nc_type = 0; \ 138 __volatile_read(&(x), sizeof(x), &result.nc_type); \ 139 result.initial_type; \ 140 }) 141 142 #define WRITE_ONCE(var, value) ({ \ 143 union { \ 144 __typeof(var) initial_type; \ 145 uint8_t nc_type; \ 146 } result; \ 147 \ 148 result.initial_type = value; \ 149 __volatile_write(&(var), sizeof(var), &result.nc_type); \ 150 result.initial_type; \ 151 }) 152 153 #define __rcu 154 155 /* Workaround to protect from the 'DEBUG' kernel config option */ 156 #undef DEBUG 157 158 #endif /* __KERNEL__ */ 159 160 #define GCC_VERSION \ 161 (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) 162 163 #ifndef unreachable 164 #define unreachable() \ 165 do { \ 166 __asm __volatile(""); \ 167 __builtin_unreachable(); \ 168 } while (0) 169 #endif 170 171 #endif /* _LINUX_COMPILER_H_ */ 172