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
__volatile_read(const volatile void * x,int size,void * result)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
__volatile_write(volatile void * var,int size,void * value)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