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Rev | Author | Line No. | Line |
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1408 | serge | 1 | #ifndef __LINUX_COMPILER_H |
2 | #define __LINUX_COMPILER_H |
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3 | |||
4 | #ifndef __ASSEMBLY__ |
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5 | |||
6 | #ifdef __CHECKER__ |
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7 | # define __user __attribute__((noderef, address_space(1))) |
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1964 | serge | 8 | # define __kernel __attribute__((address_space(0))) |
1408 | serge | 9 | # define __safe __attribute__((safe)) |
10 | # define __force __attribute__((force)) |
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11 | # define __nocast __attribute__((nocast)) |
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12 | # define __iomem __attribute__((noderef, address_space(2))) |
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3243 | Serge | 13 | # define __must_hold(x) __attribute__((context(x,1,1))) |
1408 | serge | 14 | # define __acquires(x) __attribute__((context(x,0,1))) |
15 | # define __releases(x) __attribute__((context(x,1,0))) |
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16 | # define __acquire(x) __context__(x,1) |
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17 | # define __release(x) __context__(x,-1) |
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18 | # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) |
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1964 | serge | 19 | # define __percpu __attribute__((noderef, address_space(3))) |
6082 | serge | 20 | # define __pmem __attribute__((noderef, address_space(5))) |
1964 | serge | 21 | #ifdef CONFIG_SPARSE_RCU_POINTER |
22 | # define __rcu __attribute__((noderef, address_space(4))) |
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7143 | serge | 23 | #else /* CONFIG_SPARSE_RCU_POINTER */ |
1964 | serge | 24 | # define __rcu |
7143 | serge | 25 | #endif /* CONFIG_SPARSE_RCU_POINTER */ |
26 | # define __private __attribute__((noderef)) |
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1408 | serge | 27 | extern void __chk_user_ptr(const volatile void __user *); |
28 | extern void __chk_io_ptr(const volatile void __iomem *); |
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7143 | serge | 29 | # define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member)) |
30 | #else /* __CHECKER__ */ |
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1408 | serge | 31 | # define __user |
32 | # define __kernel |
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33 | # define __safe |
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34 | # define __force |
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35 | # define __nocast |
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36 | # define __iomem |
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37 | # define __chk_user_ptr(x) (void)0 |
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38 | # define __chk_io_ptr(x) (void)0 |
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39 | # define __builtin_warning(x, y...) (1) |
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3243 | Serge | 40 | # define __must_hold(x) |
1408 | serge | 41 | # define __acquires(x) |
42 | # define __releases(x) |
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43 | # define __acquire(x) (void)0 |
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44 | # define __release(x) (void)0 |
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45 | # define __cond_lock(x,c) (c) |
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1964 | serge | 46 | # define __percpu |
47 | # define __rcu |
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6082 | serge | 48 | # define __pmem |
7143 | serge | 49 | # define __private |
50 | # define ACCESS_PRIVATE(p, member) ((p)->member) |
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51 | #endif /* __CHECKER__ */ |
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1408 | serge | 52 | |
3243 | Serge | 53 | /* Indirect macros required for expanded argument pasting, eg. __LINE__. */ |
54 | #define ___PASTE(a,b) a##b |
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55 | #define __PASTE(a,b) ___PASTE(a,b) |
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56 | |||
1408 | serge | 57 | #ifdef __KERNEL__ |
58 | |||
59 | #ifdef __GNUC__ |
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60 | #include |
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61 | #endif |
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62 | |||
6082 | serge | 63 | #if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__) |
64 | #define notrace __attribute__((hotpatch(0,0))) |
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65 | #else |
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1408 | serge | 66 | #define notrace __attribute__((no_instrument_function)) |
6082 | serge | 67 | #endif |
1408 | serge | 68 | |
69 | /* Intel compiler defines __GNUC__. So we will overwrite implementations |
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70 | * coming from above header files here |
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71 | */ |
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72 | #ifdef __INTEL_COMPILER |
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73 | # include |
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74 | #endif |
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75 | |||
5056 | serge | 76 | /* Clang compiler defines __GNUC__. So we will overwrite implementations |
77 | * coming from above header files here |
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78 | */ |
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79 | #ifdef __clang__ |
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80 | #include |
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81 | #endif |
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82 | |||
1408 | serge | 83 | /* |
84 | * Generic compiler-dependent macros required for kernel |
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85 | * build go below this comment. Actual compiler/compiler version |
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86 | * specific implementations come from the above header files |
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87 | */ |
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88 | |||
89 | struct ftrace_branch_data { |
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90 | const char *func; |
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91 | const char *file; |
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92 | unsigned line; |
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93 | union { |
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94 | struct { |
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95 | unsigned long correct; |
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96 | unsigned long incorrect; |
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97 | }; |
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98 | struct { |
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99 | unsigned long miss; |
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100 | unsigned long hit; |
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101 | }; |
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102 | unsigned long miss_hit[2]; |
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103 | }; |
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104 | }; |
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105 | |||
106 | /* |
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107 | * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code |
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108 | * to disable branch tracing on a per file basis. |
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109 | */ |
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110 | #if defined(CONFIG_TRACE_BRANCH_PROFILING) \ |
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111 | && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__) |
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112 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); |
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113 | |||
114 | #define likely_notrace(x) __builtin_expect(!!(x), 1) |
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115 | #define unlikely_notrace(x) __builtin_expect(!!(x), 0) |
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116 | |||
117 | #define __branch_check__(x, expect) ({ \ |
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118 | int ______r; \ |
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119 | static struct ftrace_branch_data \ |
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120 | __attribute__((__aligned__(4))) \ |
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121 | __attribute__((section("_ftrace_annotated_branch"))) \ |
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122 | ______f = { \ |
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123 | .func = __func__, \ |
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124 | .file = __FILE__, \ |
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125 | .line = __LINE__, \ |
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126 | }; \ |
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127 | ______r = likely_notrace(x); \ |
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128 | ftrace_likely_update(&______f, ______r, expect); \ |
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129 | ______r; \ |
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130 | }) |
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131 | |||
132 | /* |
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133 | * Using __builtin_constant_p(x) to ignore cases where the return |
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134 | * value is always the same. This idea is taken from a similar patch |
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135 | * written by Daniel Walker. |
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136 | */ |
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137 | # ifndef likely |
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138 | # define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1)) |
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139 | # endif |
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140 | # ifndef unlikely |
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141 | # define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0)) |
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142 | # endif |
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143 | |||
144 | #ifdef CONFIG_PROFILE_ALL_BRANCHES |
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145 | /* |
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146 | * "Define 'is'", Bill Clinton |
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147 | * "Define 'if'", Steven Rostedt |
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148 | */ |
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149 | #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) ) |
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150 | #define __trace_if(cond) \ |
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6295 | serge | 151 | if (__builtin_constant_p(!!(cond)) ? !!(cond) : \ |
1408 | serge | 152 | ({ \ |
153 | int ______r; \ |
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154 | static struct ftrace_branch_data \ |
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155 | __attribute__((__aligned__(4))) \ |
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156 | __attribute__((section("_ftrace_branch"))) \ |
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157 | ______f = { \ |
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158 | .func = __func__, \ |
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159 | .file = __FILE__, \ |
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160 | .line = __LINE__, \ |
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161 | }; \ |
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162 | ______r = !!(cond); \ |
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163 | ______f.miss_hit[______r]++; \ |
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164 | ______r; \ |
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165 | })) |
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166 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ |
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167 | |||
168 | #else |
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169 | # define likely(x) __builtin_expect(!!(x), 1) |
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170 | # define unlikely(x) __builtin_expect(!!(x), 0) |
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171 | #endif |
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172 | |||
173 | /* Optimization barrier */ |
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174 | #ifndef barrier |
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175 | # define barrier() __memory_barrier() |
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176 | #endif |
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177 | |||
6082 | serge | 178 | #ifndef barrier_data |
179 | # define barrier_data(ptr) barrier() |
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180 | #endif |
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181 | |||
1408 | serge | 182 | /* Unreachable code */ |
183 | #ifndef unreachable |
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184 | # define unreachable() do { } while (1) |
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185 | #endif |
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186 | |||
187 | #ifndef RELOC_HIDE |
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188 | # define RELOC_HIDE(ptr, off) \ |
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189 | ({ unsigned long __ptr; \ |
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190 | __ptr = (unsigned long) (ptr); \ |
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191 | (typeof(ptr)) (__ptr + (off)); }) |
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192 | #endif |
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193 | |||
5056 | serge | 194 | #ifndef OPTIMIZER_HIDE_VAR |
195 | #define OPTIMIZER_HIDE_VAR(var) barrier() |
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196 | #endif |
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197 | |||
3480 | Serge | 198 | /* Not-quite-unique ID. */ |
199 | #ifndef __UNIQUE_ID |
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200 | # define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__) |
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201 | #endif |
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202 | |||
5270 | serge | 203 | #include |
204 | |||
6082 | serge | 205 | #define __READ_ONCE_SIZE \ |
206 | ({ \ |
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207 | switch (size) { \ |
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208 | case 1: *(__u8 *)res = *(volatile __u8 *)p; break; \ |
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209 | case 2: *(__u16 *)res = *(volatile __u16 *)p; break; \ |
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210 | case 4: *(__u32 *)res = *(volatile __u32 *)p; break; \ |
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211 | case 8: *(__u64 *)res = *(volatile __u64 *)p; break; \ |
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212 | default: \ |
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213 | barrier(); \ |
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214 | __builtin_memcpy((void *)res, (const void *)p, size); \ |
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215 | barrier(); \ |
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216 | } \ |
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217 | }) |
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5270 | serge | 218 | |
6082 | serge | 219 | static __always_inline |
220 | void __read_once_size(const volatile void *p, void *res, int size) |
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5270 | serge | 221 | { |
6082 | serge | 222 | __READ_ONCE_SIZE; |
5270 | serge | 223 | } |
224 | |||
6082 | serge | 225 | #ifdef CONFIG_KASAN |
226 | /* |
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227 | * This function is not 'inline' because __no_sanitize_address confilcts |
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228 | * with inlining. Attempt to inline it may cause a build failure. |
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229 | * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368 |
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230 | * '__maybe_unused' allows us to avoid defined-but-not-used warnings. |
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231 | */ |
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232 | static __no_sanitize_address __maybe_unused |
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233 | void __read_once_size_nocheck(const volatile void *p, void *res, int size) |
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5270 | serge | 234 | { |
6082 | serge | 235 | __READ_ONCE_SIZE; |
236 | } |
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237 | #else |
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238 | static __always_inline |
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239 | void __read_once_size_nocheck(const volatile void *p, void *res, int size) |
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240 | { |
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241 | __READ_ONCE_SIZE; |
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242 | } |
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5270 | serge | 243 | #endif |
244 | |||
6082 | serge | 245 | static __always_inline void __write_once_size(volatile void *p, void *res, int size) |
5270 | serge | 246 | { |
247 | switch (size) { |
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248 | case 1: *(volatile __u8 *)p = *(__u8 *)res; break; |
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249 | case 2: *(volatile __u16 *)p = *(__u16 *)res; break; |
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250 | case 4: *(volatile __u32 *)p = *(__u32 *)res; break; |
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251 | case 8: *(volatile __u64 *)p = *(__u64 *)res; break; |
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252 | default: |
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253 | barrier(); |
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254 | __builtin_memcpy((void *)p, (const void *)res, size); |
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255 | barrier(); |
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256 | } |
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257 | } |
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258 | |||
259 | /* |
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260 | * Prevent the compiler from merging or refetching reads or writes. The |
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261 | * compiler is also forbidden from reordering successive instances of |
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6082 | serge | 262 | * READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the |
5270 | serge | 263 | * compiler is aware of some particular ordering. One way to make the |
264 | * compiler aware of ordering is to put the two invocations of READ_ONCE, |
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6082 | serge | 265 | * WRITE_ONCE or ACCESS_ONCE() in different C statements. |
5270 | serge | 266 | * |
267 | * In contrast to ACCESS_ONCE these two macros will also work on aggregate |
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268 | * data types like structs or unions. If the size of the accessed data |
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269 | * type exceeds the word size of the machine (e.g., 32 bits or 64 bits) |
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7143 | serge | 270 | * READ_ONCE() and WRITE_ONCE() will fall back to memcpy(). There's at |
271 | * least two memcpy()s: one for the __builtin_memcpy() and then one for |
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272 | * the macro doing the copy of variable - '__u' allocated on the stack. |
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5270 | serge | 273 | * |
274 | * Their two major use cases are: (1) Mediating communication between |
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275 | * process-level code and irq/NMI handlers, all running on the same CPU, |
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276 | * and (2) Ensuring that the compiler does not fold, spindle, or otherwise |
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277 | * mutilate accesses that either do not require ordering or that interact |
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278 | * with an explicit memory barrier or atomic instruction that provides the |
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279 | * required ordering. |
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280 | */ |
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281 | |||
6082 | serge | 282 | #define __READ_ONCE(x, check) \ |
283 | ({ \ |
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284 | union { typeof(x) __val; char __c[1]; } __u; \ |
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285 | if (check) \ |
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286 | __read_once_size(&(x), __u.__c, sizeof(x)); \ |
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287 | else \ |
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288 | __read_once_size_nocheck(&(x), __u.__c, sizeof(x)); \ |
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289 | __u.__val; \ |
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290 | }) |
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291 | #define READ_ONCE(x) __READ_ONCE(x, 1) |
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5270 | serge | 292 | |
6082 | serge | 293 | /* |
294 | * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need |
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295 | * to hide memory access from KASAN. |
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296 | */ |
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297 | #define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0) |
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5270 | serge | 298 | |
6082 | serge | 299 | #define WRITE_ONCE(x, val) \ |
300 | ({ \ |
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301 | union { typeof(x) __val; char __c[1]; } __u = \ |
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302 | { .__val = (__force typeof(x)) (val) }; \ |
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303 | __write_once_size(&(x), __u.__c, sizeof(x)); \ |
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304 | __u.__val; \ |
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305 | }) |
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306 | |||
6936 | serge | 307 | /** |
308 | * smp_cond_acquire() - Spin wait for cond with ACQUIRE ordering |
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309 | * @cond: boolean expression to wait for |
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310 | * |
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311 | * Equivalent to using smp_load_acquire() on the condition variable but employs |
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312 | * the control dependency of the wait to reduce the barrier on many platforms. |
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313 | * |
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314 | * The control dependency provides a LOAD->STORE order, the additional RMB |
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315 | * provides LOAD->LOAD order, together they provide LOAD->{LOAD,STORE} order, |
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316 | * aka. ACQUIRE. |
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317 | */ |
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318 | #define smp_cond_acquire(cond) do { \ |
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319 | while (!(cond)) \ |
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320 | cpu_relax(); \ |
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321 | smp_rmb(); /* ctrl + rmb := acquire */ \ |
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322 | } while (0) |
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323 | |||
1408 | serge | 324 | #endif /* __KERNEL__ */ |
325 | |||
326 | #endif /* __ASSEMBLY__ */ |
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327 | |||
328 | #ifdef __KERNEL__ |
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329 | /* |
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330 | * Allow us to mark functions as 'deprecated' and have gcc emit a nice |
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331 | * warning for each use, in hopes of speeding the functions removal. |
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332 | * Usage is: |
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333 | * int __deprecated foo(void) |
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334 | */ |
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335 | #ifndef __deprecated |
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336 | # define __deprecated /* unimplemented */ |
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337 | #endif |
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338 | |||
339 | #ifdef MODULE |
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340 | #define __deprecated_for_modules __deprecated |
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341 | #else |
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342 | #define __deprecated_for_modules |
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343 | #endif |
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344 | |||
345 | #ifndef __must_check |
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346 | #define __must_check |
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347 | #endif |
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348 | |||
349 | #ifndef CONFIG_ENABLE_MUST_CHECK |
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350 | #undef __must_check |
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351 | #define __must_check |
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352 | #endif |
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353 | #ifndef CONFIG_ENABLE_WARN_DEPRECATED |
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354 | #undef __deprecated |
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355 | #undef __deprecated_for_modules |
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356 | #define __deprecated |
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357 | #define __deprecated_for_modules |
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358 | #endif |
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359 | |||
360 | /* |
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361 | * Allow us to avoid 'defined but not used' warnings on functions and data, |
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362 | * as well as force them to be emitted to the assembly file. |
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363 | * |
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364 | * As of gcc 3.4, static functions that are not marked with attribute((used)) |
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365 | * may be elided from the assembly file. As of gcc 3.4, static data not so |
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366 | * marked will not be elided, but this may change in a future gcc version. |
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367 | * |
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368 | * NOTE: Because distributions shipped with a backported unit-at-a-time |
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369 | * compiler in gcc 3.3, we must define __used to be __attribute__((used)) |
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370 | * for gcc >=3.3 instead of 3.4. |
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371 | * |
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372 | * In prior versions of gcc, such functions and data would be emitted, but |
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373 | * would be warned about except with attribute((unused)). |
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374 | * |
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375 | * Mark functions that are referenced only in inline assembly as __used so |
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376 | * the code is emitted even though it appears to be unreferenced. |
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377 | */ |
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378 | #ifndef __used |
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379 | # define __used /* unimplemented */ |
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380 | #endif |
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381 | |||
382 | #ifndef __maybe_unused |
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383 | # define __maybe_unused /* unimplemented */ |
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384 | #endif |
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385 | |||
386 | #ifndef __always_unused |
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387 | # define __always_unused /* unimplemented */ |
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388 | #endif |
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389 | |||
390 | #ifndef noinline |
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391 | #define noinline |
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392 | #endif |
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393 | |||
394 | /* |
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395 | * Rather then using noinline to prevent stack consumption, use |
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3031 | serge | 396 | * noinline_for_stack instead. For documentation reasons. |
1408 | serge | 397 | */ |
398 | #define noinline_for_stack noinline |
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399 | |||
400 | #ifndef __always_inline |
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401 | #define __always_inline inline |
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402 | #endif |
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403 | |||
404 | #endif /* __KERNEL__ */ |
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405 | |||
406 | /* |
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407 | * From the GCC manual: |
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408 | * |
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409 | * Many functions do not examine any values except their arguments, |
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410 | * and have no effects except the return value. Basically this is |
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411 | * just slightly more strict class than the `pure' attribute above, |
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412 | * since function is not allowed to read global memory. |
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413 | * |
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414 | * Note that a function that has pointer arguments and examines the |
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415 | * data pointed to must _not_ be declared `const'. Likewise, a |
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416 | * function that calls a non-`const' function usually must not be |
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417 | * `const'. It does not make sense for a `const' function to return |
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418 | * `void'. |
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419 | */ |
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420 | #ifndef __attribute_const__ |
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421 | # define __attribute_const__ /* unimplemented */ |
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422 | #endif |
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423 | |||
424 | /* |
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425 | * Tell gcc if a function is cold. The compiler will assume any path |
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426 | * directly leading to the call is unlikely. |
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427 | */ |
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428 | |||
429 | #ifndef __cold |
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430 | #define __cold |
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431 | #endif |
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432 | |||
433 | /* Simple shorthand for a section definition */ |
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434 | #ifndef __section |
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435 | # define __section(S) __attribute__ ((__section__(#S))) |
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436 | #endif |
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437 | |||
3031 | serge | 438 | #ifndef __visible |
439 | #define __visible |
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440 | #endif |
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441 | |||
6082 | serge | 442 | /* |
443 | * Assume alignment of return value. |
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444 | */ |
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445 | #ifndef __assume_aligned |
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446 | #define __assume_aligned(a, ...) |
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447 | #endif |
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448 | |||
449 | |||
1408 | serge | 450 | /* Are two types/vars the same type (ignoring qualifiers)? */ |
451 | #ifndef __same_type |
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452 | # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) |
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453 | #endif |
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454 | |||
5056 | serge | 455 | /* Is this type a native word size -- useful for atomic operations */ |
456 | #ifndef __native_word |
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6082 | serge | 457 | # define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) |
5056 | serge | 458 | #endif |
459 | |||
1408 | serge | 460 | /* Compile time object size, -1 for unknown */ |
461 | #ifndef __compiletime_object_size |
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462 | # define __compiletime_object_size(obj) -1 |
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463 | #endif |
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464 | #ifndef __compiletime_warning |
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465 | # define __compiletime_warning(message) |
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466 | #endif |
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467 | #ifndef __compiletime_error |
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468 | # define __compiletime_error(message) |
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5056 | serge | 469 | /* |
470 | * Sparse complains of variable sized arrays due to the temporary variable in |
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471 | * __compiletime_assert. Unfortunately we can't just expand it out to make |
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472 | * sparse see a constant array size without breaking compiletime_assert on old |
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473 | * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether. |
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474 | */ |
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475 | # ifndef __CHECKER__ |
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6082 | serge | 476 | # define __compiletime_error_fallback(condition) \ |
3480 | Serge | 477 | do { ((void)sizeof(char[1 - 2 * condition])); } while (0) |
5056 | serge | 478 | # endif |
479 | #endif |
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480 | #ifndef __compiletime_error_fallback |
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3480 | Serge | 481 | # define __compiletime_error_fallback(condition) do { } while (0) |
1408 | serge | 482 | #endif |
3480 | Serge | 483 | |
484 | #define __compiletime_assert(condition, msg, prefix, suffix) \ |
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485 | do { \ |
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486 | bool __cond = !(condition); \ |
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487 | extern void prefix ## suffix(void) __compiletime_error(msg); \ |
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488 | if (__cond) \ |
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489 | prefix ## suffix(); \ |
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490 | __compiletime_error_fallback(__cond); \ |
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491 | } while (0) |
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492 | |||
493 | #define _compiletime_assert(condition, msg, prefix, suffix) \ |
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494 | __compiletime_assert(condition, msg, prefix, suffix) |
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495 | |||
496 | /** |
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497 | * compiletime_assert - break build and emit msg if condition is false |
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498 | * @condition: a compile-time constant condition to check |
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499 | * @msg: a message to emit if condition is false |
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500 | * |
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501 | * In tradition of POSIX assert, this macro will break the build if the |
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502 | * supplied condition is *false*, emitting the supplied error message if the |
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503 | * compiler has support to do so. |
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504 | */ |
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505 | #define compiletime_assert(condition, msg) \ |
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506 | _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) |
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507 | |||
5056 | serge | 508 | #define compiletime_assert_atomic_type(t) \ |
509 | compiletime_assert(__native_word(t), \ |
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510 | "Need native word sized stores/loads for atomicity.") |
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511 | |||
1408 | serge | 512 | /* |
513 | * Prevent the compiler from merging or refetching accesses. The compiler |
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514 | * is also forbidden from reordering successive instances of ACCESS_ONCE(), |
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515 | * but only when the compiler is aware of some particular ordering. One way |
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516 | * to make the compiler aware of ordering is to put the two invocations of |
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517 | * ACCESS_ONCE() in different C statements. |
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518 | * |
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6082 | serge | 519 | * ACCESS_ONCE will only work on scalar types. For union types, ACCESS_ONCE |
520 | * on a union member will work as long as the size of the member matches the |
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521 | * size of the union and the size is smaller than word size. |
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522 | * |
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523 | * The major use cases of ACCESS_ONCE used to be (1) Mediating communication |
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524 | * between process-level code and irq/NMI handlers, all running on the same CPU, |
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525 | * and (2) Ensuring that the compiler does not fold, spindle, or otherwise |
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526 | * mutilate accesses that either do not require ordering or that interact |
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527 | * with an explicit memory barrier or atomic instruction that provides the |
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528 | * required ordering. |
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529 | * |
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530 | * If possible use READ_ONCE()/WRITE_ONCE() instead. |
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1408 | serge | 531 | */ |
6082 | serge | 532 | #define __ACCESS_ONCE(x) ({ \ |
533 | __maybe_unused typeof(x) __var = (__force typeof(x)) 0; \ |
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534 | (volatile typeof(x) *)&(x); }) |
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535 | #define ACCESS_ONCE(x) (*__ACCESS_ONCE(x)) |
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1408 | serge | 536 | |
6082 | serge | 537 | /** |
538 | * lockless_dereference() - safely load a pointer for later dereference |
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539 | * @p: The pointer to load |
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540 | * |
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541 | * Similar to rcu_dereference(), but for situations where the pointed-to |
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542 | * object's lifetime is managed by something other than RCU. That |
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543 | * "something other" might be reference counting or simple immortality. |
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544 | */ |
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545 | #define lockless_dereference(p) \ |
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546 | ({ \ |
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547 | typeof(p) _________p1 = READ_ONCE(p); \ |
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548 | smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ |
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549 | (_________p1); \ |
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550 | }) |
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551 | |||
4103 | Serge | 552 | /* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */ |
553 | #ifdef CONFIG_KPROBES |
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554 | # define __kprobes __attribute__((__section__(".kprobes.text"))) |
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5056 | serge | 555 | # define nokprobe_inline __always_inline |
4103 | Serge | 556 | #else |
557 | # define __kprobes |
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5056 | serge | 558 | # define nokprobe_inline inline |
4103 | Serge | 559 | #endif |
1408 | serge | 560 | #endif /* __LINUX_COMPILER_H */ |