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 #if __GNUC__ >= 4 40 # include <linux/compiler-gcc4.h> 41 #elif __GNUC__ == 3 && __GNUC_MINOR__ >= 2 42 # include <linux/compiler-gcc3.h> 43 #else 44 # error Sorry, your compiler is too old/not recognized. 45 #endif 46 47 #define notrace __attribute__((no_instrument_function)) 48 49 /* Intel compiler defines __GNUC__. So we will overwrite implementations 50 * coming from above header files here 51 */ 52 #ifdef __INTEL_COMPILER 53 # include <linux/compiler-intel.h> 54 #endif 55 56 /* 57 * Generic compiler-dependent macros required for kernel 58 * build go below this comment. Actual compiler/compiler version 59 * specific implementations come from the above header files 60 */ 61 62 #define likely(x) __builtin_expect(!!(x), 1) 63 #define unlikely(x) __builtin_expect(!!(x), 0) 64 65 /* Optimization barrier */ 66 #ifndef barrier 67 # define barrier() __memory_barrier() 68 #endif 69 70 #ifndef RELOC_HIDE 71 # define RELOC_HIDE(ptr, off) \ 72 ({ unsigned long __ptr; \ 73 __ptr = (unsigned long) (ptr); \ 74 (typeof(ptr)) (__ptr + (off)); }) 75 #endif 76 77 #endif /* __KERNEL__ */ 78 79 #endif /* __ASSEMBLY__ */ 80 81 #ifdef __KERNEL__ 82 /* 83 * Allow us to mark functions as 'deprecated' and have gcc emit a nice 84 * warning for each use, in hopes of speeding the functions removal. 85 * Usage is: 86 * int __deprecated foo(void) 87 */ 88 #ifndef __deprecated 89 # define __deprecated /* unimplemented */ 90 #endif 91 92 #ifdef MODULE 93 #define __deprecated_for_modules __deprecated 94 #else 95 #define __deprecated_for_modules 96 #endif 97 98 #ifndef __must_check 99 #define __must_check 100 #endif 101 102 #ifndef CONFIG_ENABLE_MUST_CHECK 103 #undef __must_check 104 #define __must_check 105 #endif 106 #ifndef CONFIG_ENABLE_WARN_DEPRECATED 107 #undef __deprecated 108 #undef __deprecated_for_modules 109 #define __deprecated 110 #define __deprecated_for_modules 111 #endif 112 113 /* 114 * Allow us to avoid 'defined but not used' warnings on functions and data, 115 * as well as force them to be emitted to the assembly file. 116 * 117 * As of gcc 3.4, static functions that are not marked with attribute((used)) 118 * may be elided from the assembly file. As of gcc 3.4, static data not so 119 * marked will not be elided, but this may change in a future gcc version. 120 * 121 * NOTE: Because distributions shipped with a backported unit-at-a-time 122 * compiler in gcc 3.3, we must define __used to be __attribute__((used)) 123 * for gcc >=3.3 instead of 3.4. 124 * 125 * In prior versions of gcc, such functions and data would be emitted, but 126 * would be warned about except with attribute((unused)). 127 * 128 * Mark functions that are referenced only in inline assembly as __used so 129 * the code is emitted even though it appears to be unreferenced. 130 */ 131 #ifndef __used 132 # define __used /* unimplemented */ 133 #endif 134 135 #ifndef __maybe_unused 136 # define __maybe_unused /* unimplemented */ 137 #endif 138 139 #ifndef noinline 140 #define noinline 141 #endif 142 143 /* 144 * Rather then using noinline to prevent stack consumption, use 145 * noinline_for_stack instead. For documentaiton reasons. 146 */ 147 #define noinline_for_stack noinline 148 149 #ifndef __always_inline 150 #define __always_inline inline 151 #endif 152 153 #endif /* __KERNEL__ */ 154 155 /* 156 * From the GCC manual: 157 * 158 * Many functions do not examine any values except their arguments, 159 * and have no effects except the return value. Basically this is 160 * just slightly more strict class than the `pure' attribute above, 161 * since function is not allowed to read global memory. 162 * 163 * Note that a function that has pointer arguments and examines the 164 * data pointed to must _not_ be declared `const'. Likewise, a 165 * function that calls a non-`const' function usually must not be 166 * `const'. It does not make sense for a `const' function to return 167 * `void'. 168 */ 169 #ifndef __attribute_const__ 170 # define __attribute_const__ /* unimplemented */ 171 #endif 172 173 /* 174 * Tell gcc if a function is cold. The compiler will assume any path 175 * directly leading to the call is unlikely. 176 */ 177 178 #ifndef __cold 179 #define __cold 180 #endif 181 182 /* Simple shorthand for a section definition */ 183 #ifndef __section 184 # define __section(S) __attribute__ ((__section__(#S))) 185 #endif 186 187 /* 188 * Prevent the compiler from merging or refetching accesses. The compiler 189 * is also forbidden from reordering successive instances of ACCESS_ONCE(), 190 * but only when the compiler is aware of some particular ordering. One way 191 * to make the compiler aware of ordering is to put the two invocations of 192 * ACCESS_ONCE() in different C statements. 193 * 194 * This macro does absolutely -nothing- to prevent the CPU from reordering, 195 * merging, or refetching absolutely anything at any time. Its main intended 196 * use is to mediate communication between process-level code and irq/NMI 197 * handlers, all running on the same CPU. 198 */ 199 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) 200 201 #endif /* __LINUX_COMPILER_H */ 202