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