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