1 #ifndef __LINUX_COMPILER_H 2 #define __LINUX_COMPILER_H 3 4 #ifndef __ASSEMBLY__ 5 6 #ifdef __CHECKER__ 7 # define __user __attribute__((noderef, address_space(1))) 8 # define __kernel __attribute__((address_space(0))) 9 # define __safe __attribute__((safe)) 10 # define __force __attribute__((force)) 11 # define __nocast __attribute__((nocast)) 12 # define __iomem __attribute__((noderef, address_space(2))) 13 # define __acquires(x) __attribute__((context(x,0,1))) 14 # define __releases(x) __attribute__((context(x,1,0))) 15 # define __acquire(x) __context__(x,1) 16 # define __release(x) __context__(x,-1) 17 # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) 18 # define __percpu __attribute__((noderef, address_space(3))) 19 extern void __chk_user_ptr(const volatile void __user *); 20 extern void __chk_io_ptr(const volatile void __iomem *); 21 #else 22 # define __user 23 # define __kernel 24 # define __safe 25 # define __force 26 # define __nocast 27 # define __iomem 28 # define __chk_user_ptr(x) (void)0 29 # define __chk_io_ptr(x) (void)0 30 # define __builtin_warning(x, y...) (1) 31 # define __acquires(x) 32 # define __releases(x) 33 # define __acquire(x) (void)0 34 # define __release(x) (void)0 35 # define __cond_lock(x,c) (c) 36 # define __percpu 37 #endif 38 39 #ifdef __KERNEL__ 40 41 #ifdef __GNUC__ 42 #include <linux/compiler-gcc.h> 43 #endif 44 45 #define notrace __attribute__((no_instrument_function)) 46 47 /* Intel compiler defines __GNUC__. So we will overwrite implementations 48 * coming from above header files here 49 */ 50 #ifdef __INTEL_COMPILER 51 # include <linux/compiler-intel.h> 52 #endif 53 54 /* 55 * Generic compiler-dependent macros required for kernel 56 * build go below this comment. Actual compiler/compiler version 57 * specific implementations come from the above header files 58 */ 59 60 struct ftrace_branch_data { 61 const char *func; 62 const char *file; 63 unsigned line; 64 union { 65 struct { 66 unsigned long correct; 67 unsigned long incorrect; 68 }; 69 struct { 70 unsigned long miss; 71 unsigned long hit; 72 }; 73 unsigned long miss_hit[2]; 74 }; 75 }; 76 77 /* 78 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code 79 * to disable branch tracing on a per file basis. 80 */ 81 #if defined(CONFIG_TRACE_BRANCH_PROFILING) \ 82 && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__) 83 void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); 84 85 #define likely_notrace(x) __builtin_expect(!!(x), 1) 86 #define unlikely_notrace(x) __builtin_expect(!!(x), 0) 87 88 #define __branch_check__(x, expect) ({ \ 89 int ______r; \ 90 static struct ftrace_branch_data \ 91 __attribute__((__aligned__(4))) \ 92 __attribute__((section("_ftrace_annotated_branch"))) \ 93 ______f = { \ 94 .func = __func__, \ 95 .file = __FILE__, \ 96 .line = __LINE__, \ 97 }; \ 98 ______r = likely_notrace(x); \ 99 ftrace_likely_update(&______f, ______r, expect); \ 100 ______r; \ 101 }) 102 103 /* 104 * Using __builtin_constant_p(x) to ignore cases where the return 105 * value is always the same. This idea is taken from a similar patch 106 * written by Daniel Walker. 107 */ 108 # ifndef likely 109 # define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1)) 110 # endif 111 # ifndef unlikely 112 # define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0)) 113 # endif 114 115 #ifdef CONFIG_PROFILE_ALL_BRANCHES 116 /* 117 * "Define 'is'", Bill Clinton 118 * "Define 'if'", Steven Rostedt 119 */ 120 #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) ) 121 #define __trace_if(cond) \ 122 if (__builtin_constant_p((cond)) ? !!(cond) : \ 123 ({ \ 124 int ______r; \ 125 static struct ftrace_branch_data \ 126 __attribute__((__aligned__(4))) \ 127 __attribute__((section("_ftrace_branch"))) \ 128 ______f = { \ 129 .func = __func__, \ 130 .file = __FILE__, \ 131 .line = __LINE__, \ 132 }; \ 133 ______r = !!(cond); \ 134 ______f.miss_hit[______r]++; \ 135 ______r; \ 136 })) 137 #endif /* CONFIG_PROFILE_ALL_BRANCHES */ 138 139 #else 140 # define likely(x) __builtin_expect(!!(x), 1) 141 # define unlikely(x) __builtin_expect(!!(x), 0) 142 #endif 143 144 /* Optimization barrier */ 145 #ifndef barrier 146 # define barrier() __memory_barrier() 147 #endif 148 149 /* Unreachable code */ 150 #ifndef unreachable 151 # define unreachable() do { } while (1) 152 #endif 153 154 #ifndef RELOC_HIDE 155 # define RELOC_HIDE(ptr, off) \ 156 ({ unsigned long __ptr; \ 157 __ptr = (unsigned long) (ptr); \ 158 (typeof(ptr)) (__ptr + (off)); }) 159 #endif 160 161 #endif /* __KERNEL__ */ 162 163 #endif /* __ASSEMBLY__ */ 164 165 #ifdef __KERNEL__ 166 /* 167 * Allow us to mark functions as 'deprecated' and have gcc emit a nice 168 * warning for each use, in hopes of speeding the functions removal. 169 * Usage is: 170 * int __deprecated foo(void) 171 */ 172 #ifndef __deprecated 173 # define __deprecated /* unimplemented */ 174 #endif 175 176 #ifdef MODULE 177 #define __deprecated_for_modules __deprecated 178 #else 179 #define __deprecated_for_modules 180 #endif 181 182 #ifndef __must_check 183 #define __must_check 184 #endif 185 186 #ifndef CONFIG_ENABLE_MUST_CHECK 187 #undef __must_check 188 #define __must_check 189 #endif 190 #ifndef CONFIG_ENABLE_WARN_DEPRECATED 191 #undef __deprecated 192 #undef __deprecated_for_modules 193 #define __deprecated 194 #define __deprecated_for_modules 195 #endif 196 197 /* 198 * Allow us to avoid 'defined but not used' warnings on functions and data, 199 * as well as force them to be emitted to the assembly file. 200 * 201 * As of gcc 3.4, static functions that are not marked with attribute((used)) 202 * may be elided from the assembly file. As of gcc 3.4, static data not so 203 * marked will not be elided, but this may change in a future gcc version. 204 * 205 * NOTE: Because distributions shipped with a backported unit-at-a-time 206 * compiler in gcc 3.3, we must define __used to be __attribute__((used)) 207 * for gcc >=3.3 instead of 3.4. 208 * 209 * In prior versions of gcc, such functions and data would be emitted, but 210 * would be warned about except with attribute((unused)). 211 * 212 * Mark functions that are referenced only in inline assembly as __used so 213 * the code is emitted even though it appears to be unreferenced. 214 */ 215 #ifndef __used 216 # define __used /* unimplemented */ 217 #endif 218 219 #ifndef __maybe_unused 220 # define __maybe_unused /* unimplemented */ 221 #endif 222 223 #ifndef __always_unused 224 # define __always_unused /* unimplemented */ 225 #endif 226 227 #ifndef noinline 228 #define noinline 229 #endif 230 231 /* 232 * Rather then using noinline to prevent stack consumption, use 233 * noinline_for_stack instead. For documentaiton reasons. 234 */ 235 #define noinline_for_stack noinline 236 237 #ifndef __always_inline 238 #define __always_inline inline 239 #endif 240 241 #endif /* __KERNEL__ */ 242 243 /* 244 * From the GCC manual: 245 * 246 * Many functions do not examine any values except their arguments, 247 * and have no effects except the return value. Basically this is 248 * just slightly more strict class than the `pure' attribute above, 249 * since function is not allowed to read global memory. 250 * 251 * Note that a function that has pointer arguments and examines the 252 * data pointed to must _not_ be declared `const'. Likewise, a 253 * function that calls a non-`const' function usually must not be 254 * `const'. It does not make sense for a `const' function to return 255 * `void'. 256 */ 257 #ifndef __attribute_const__ 258 # define __attribute_const__ /* unimplemented */ 259 #endif 260 261 /* 262 * Tell gcc if a function is cold. The compiler will assume any path 263 * directly leading to the call is unlikely. 264 */ 265 266 #ifndef __cold 267 #define __cold 268 #endif 269 270 /* Simple shorthand for a section definition */ 271 #ifndef __section 272 # define __section(S) __attribute__ ((__section__(#S))) 273 #endif 274 275 /* Are two types/vars the same type (ignoring qualifiers)? */ 276 #ifndef __same_type 277 # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) 278 #endif 279 280 /* Compile time object size, -1 for unknown */ 281 #ifndef __compiletime_object_size 282 # define __compiletime_object_size(obj) -1 283 #endif 284 #ifndef __compiletime_warning 285 # define __compiletime_warning(message) 286 #endif 287 #ifndef __compiletime_error 288 # define __compiletime_error(message) 289 #endif 290 291 /* 292 * Prevent the compiler from merging or refetching accesses. The compiler 293 * is also forbidden from reordering successive instances of ACCESS_ONCE(), 294 * but only when the compiler is aware of some particular ordering. One way 295 * to make the compiler aware of ordering is to put the two invocations of 296 * ACCESS_ONCE() in different C statements. 297 * 298 * This macro does absolutely -nothing- to prevent the CPU from reordering, 299 * merging, or refetching absolutely anything at any time. Its main intended 300 * use is to mediate communication between process-level code and irq/NMI 301 * handlers, all running on the same CPU. 302 */ 303 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) 304 305 #endif /* __LINUX_COMPILER_H */ 306