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 }; 72 }; 73 74 /* 75 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code 76 * to disable branch tracing on a per file basis. 77 */ 78 #if defined(CONFIG_TRACE_BRANCH_PROFILING) && !defined(DISABLE_BRANCH_PROFILING) 79 void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); 80 81 #define likely_notrace(x) __builtin_expect(!!(x), 1) 82 #define unlikely_notrace(x) __builtin_expect(!!(x), 0) 83 84 #define __branch_check__(x, expect) ({ \ 85 int ______r; \ 86 static struct ftrace_branch_data \ 87 __attribute__((__aligned__(4))) \ 88 __attribute__((section("_ftrace_annotated_branch"))) \ 89 ______f = { \ 90 .func = __func__, \ 91 .file = __FILE__, \ 92 .line = __LINE__, \ 93 }; \ 94 ______r = likely_notrace(x); \ 95 ftrace_likely_update(&______f, ______r, expect); \ 96 ______r; \ 97 }) 98 99 /* 100 * Using __builtin_constant_p(x) to ignore cases where the return 101 * value is always the same. This idea is taken from a similar patch 102 * written by Daniel Walker. 103 */ 104 # ifndef likely 105 # define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1)) 106 # endif 107 # ifndef unlikely 108 # define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0)) 109 # endif 110 111 #ifdef CONFIG_PROFILE_ALL_BRANCHES 112 /* 113 * "Define 'is'", Bill Clinton 114 * "Define 'if'", Steven Rostedt 115 */ 116 #define if(cond) if (__builtin_constant_p((cond)) ? !!(cond) : \ 117 ({ \ 118 int ______r; \ 119 static struct ftrace_branch_data \ 120 __attribute__((__aligned__(4))) \ 121 __attribute__((section("_ftrace_branch"))) \ 122 ______f = { \ 123 .func = __func__, \ 124 .file = __FILE__, \ 125 .line = __LINE__, \ 126 }; \ 127 ______r = !!(cond); \ 128 if (______r) \ 129 ______f.hit++; \ 130 else \ 131 ______f.miss++; \ 132 ______r; \ 133 })) 134 #endif /* CONFIG_PROFILE_ALL_BRANCHES */ 135 136 #else 137 # define likely(x) __builtin_expect(!!(x), 1) 138 # define unlikely(x) __builtin_expect(!!(x), 0) 139 #endif 140 141 /* Optimization barrier */ 142 #ifndef barrier 143 # define barrier() __memory_barrier() 144 #endif 145 146 #ifndef RELOC_HIDE 147 # define RELOC_HIDE(ptr, off) \ 148 ({ unsigned long __ptr; \ 149 __ptr = (unsigned long) (ptr); \ 150 (typeof(ptr)) (__ptr + (off)); }) 151 #endif 152 153 #endif /* __KERNEL__ */ 154 155 #endif /* __ASSEMBLY__ */ 156 157 #ifdef __KERNEL__ 158 /* 159 * Allow us to mark functions as 'deprecated' and have gcc emit a nice 160 * warning for each use, in hopes of speeding the functions removal. 161 * Usage is: 162 * int __deprecated foo(void) 163 */ 164 #ifndef __deprecated 165 # define __deprecated /* unimplemented */ 166 #endif 167 168 #ifdef MODULE 169 #define __deprecated_for_modules __deprecated 170 #else 171 #define __deprecated_for_modules 172 #endif 173 174 #ifndef __must_check 175 #define __must_check 176 #endif 177 178 #ifndef CONFIG_ENABLE_MUST_CHECK 179 #undef __must_check 180 #define __must_check 181 #endif 182 #ifndef CONFIG_ENABLE_WARN_DEPRECATED 183 #undef __deprecated 184 #undef __deprecated_for_modules 185 #define __deprecated 186 #define __deprecated_for_modules 187 #endif 188 189 /* 190 * Allow us to avoid 'defined but not used' warnings on functions and data, 191 * as well as force them to be emitted to the assembly file. 192 * 193 * As of gcc 3.4, static functions that are not marked with attribute((used)) 194 * may be elided from the assembly file. As of gcc 3.4, static data not so 195 * marked will not be elided, but this may change in a future gcc version. 196 * 197 * NOTE: Because distributions shipped with a backported unit-at-a-time 198 * compiler in gcc 3.3, we must define __used to be __attribute__((used)) 199 * for gcc >=3.3 instead of 3.4. 200 * 201 * In prior versions of gcc, such functions and data would be emitted, but 202 * would be warned about except with attribute((unused)). 203 * 204 * Mark functions that are referenced only in inline assembly as __used so 205 * the code is emitted even though it appears to be unreferenced. 206 */ 207 #ifndef __used 208 # define __used /* unimplemented */ 209 #endif 210 211 #ifndef __maybe_unused 212 # define __maybe_unused /* unimplemented */ 213 #endif 214 215 #ifndef noinline 216 #define noinline 217 #endif 218 219 /* 220 * Rather then using noinline to prevent stack consumption, use 221 * noinline_for_stack instead. For documentaiton reasons. 222 */ 223 #define noinline_for_stack noinline 224 225 #ifndef __always_inline 226 #define __always_inline inline 227 #endif 228 229 #endif /* __KERNEL__ */ 230 231 /* 232 * From the GCC manual: 233 * 234 * Many functions do not examine any values except their arguments, 235 * and have no effects except the return value. Basically this is 236 * just slightly more strict class than the `pure' attribute above, 237 * since function is not allowed to read global memory. 238 * 239 * Note that a function that has pointer arguments and examines the 240 * data pointed to must _not_ be declared `const'. Likewise, a 241 * function that calls a non-`const' function usually must not be 242 * `const'. It does not make sense for a `const' function to return 243 * `void'. 244 */ 245 #ifndef __attribute_const__ 246 # define __attribute_const__ /* unimplemented */ 247 #endif 248 249 /* 250 * Tell gcc if a function is cold. The compiler will assume any path 251 * directly leading to the call is unlikely. 252 */ 253 254 #ifndef __cold 255 #define __cold 256 #endif 257 258 /* Simple shorthand for a section definition */ 259 #ifndef __section 260 # define __section(S) __attribute__ ((__section__(#S))) 261 #endif 262 263 /* 264 * Prevent the compiler from merging or refetching accesses. The compiler 265 * is also forbidden from reordering successive instances of ACCESS_ONCE(), 266 * but only when the compiler is aware of some particular ordering. One way 267 * to make the compiler aware of ordering is to put the two invocations of 268 * ACCESS_ONCE() in different C statements. 269 * 270 * This macro does absolutely -nothing- to prevent the CPU from reordering, 271 * merging, or refetching absolutely anything at any time. Its main intended 272 * use is to mediate communication between process-level code and irq/NMI 273 * handlers, all running on the same CPU. 274 */ 275 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) 276 277 #endif /* __LINUX_COMPILER_H */ 278