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1da177e4 LT |
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))) | |
c902e0a0 JT |
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) | |
dcc8e559 | 17 | # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) |
c47ffe3d AV |
18 | extern void __chk_user_ptr(const volatile void __user *); |
19 | extern void __chk_io_ptr(const volatile void __iomem *); | |
1da177e4 LT |
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 | |
dcc8e559 | 34 | # define __cond_lock(x,c) (c) |
1da177e4 LT |
35 | #endif |
36 | ||
37 | #ifdef __KERNEL__ | |
38 | ||
21124a82 | 39 | #if __GNUC__ >= 4 |
1da177e4 | 40 | # include <linux/compiler-gcc4.h> |
53569ab7 | 41 | #elif __GNUC__ == 3 && __GNUC_MINOR__ >= 2 |
1da177e4 | 42 | # include <linux/compiler-gcc3.h> |
1da177e4 LT |
43 | #else |
44 | # error Sorry, your compiler is too old/not recognized. | |
45 | #endif | |
46 | ||
28614889 SR |
47 | #define notrace __attribute__((no_instrument_function)) |
48 | ||
1da177e4 LT |
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 | ||
2b7d0390 IM |
62 | /* |
63 | * Note: DISABLE_UNLIKELY_PROFILE can be used by special lowlevel code | |
64 | * to disable branch tracing on a per file basis. | |
65 | */ | |
66 | #if defined(CONFIG_TRACE_UNLIKELY_PROFILE) && !defined(DISABLE_UNLIKELY_PROFILE) | |
1f0d69a9 SR |
67 | struct ftrace_likely_data { |
68 | const char *func; | |
69 | const char *file; | |
70 | unsigned line; | |
71 | unsigned long correct; | |
72 | unsigned long incorrect; | |
73 | }; | |
74 | void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect); | |
75 | ||
76 | #define likely_notrace(x) __builtin_expect(!!(x), 1) | |
77 | #define unlikely_notrace(x) __builtin_expect(!!(x), 0) | |
78 | ||
79 | #define likely_check(x) ({ \ | |
80 | int ______r; \ | |
81 | static struct ftrace_likely_data \ | |
82 | __attribute__((__aligned__(4))) \ | |
83 | __attribute__((section("_ftrace_likely"))) \ | |
84 | ______f = { \ | |
85 | .func = __func__, \ | |
86 | .file = __FILE__, \ | |
87 | .line = __LINE__, \ | |
88 | }; \ | |
89 | ______f.line = __LINE__; \ | |
90 | ______r = likely_notrace(x); \ | |
91 | ftrace_likely_update(&______f, ______r, 1); \ | |
92 | ______r; \ | |
93 | }) | |
94 | #define unlikely_check(x) ({ \ | |
95 | int ______r; \ | |
96 | static struct ftrace_likely_data \ | |
97 | __attribute__((__aligned__(4))) \ | |
98 | __attribute__((section("_ftrace_unlikely"))) \ | |
99 | ______f = { \ | |
100 | .func = __func__, \ | |
101 | .file = __FILE__, \ | |
102 | .line = __LINE__, \ | |
103 | }; \ | |
104 | ______f.line = __LINE__; \ | |
105 | ______r = unlikely_notrace(x); \ | |
106 | ftrace_likely_update(&______f, ______r, 0); \ | |
107 | ______r; \ | |
108 | }) | |
109 | ||
110 | /* | |
111 | * Using __builtin_constant_p(x) to ignore cases where the return | |
112 | * value is always the same. This idea is taken from a similar patch | |
113 | * written by Daniel Walker. | |
114 | */ | |
115 | # ifndef likely | |
116 | # define likely(x) (__builtin_constant_p(x) ? !!(x) : likely_check(x)) | |
117 | # endif | |
118 | # ifndef unlikely | |
119 | # define unlikely(x) (__builtin_constant_p(x) ? !!(x) : unlikely_check(x)) | |
120 | # endif | |
121 | #else | |
122 | # define likely(x) __builtin_expect(!!(x), 1) | |
123 | # define unlikely(x) __builtin_expect(!!(x), 0) | |
124 | #endif | |
1da177e4 LT |
125 | |
126 | /* Optimization barrier */ | |
127 | #ifndef barrier | |
128 | # define barrier() __memory_barrier() | |
129 | #endif | |
130 | ||
131 | #ifndef RELOC_HIDE | |
132 | # define RELOC_HIDE(ptr, off) \ | |
133 | ({ unsigned long __ptr; \ | |
134 | __ptr = (unsigned long) (ptr); \ | |
135 | (typeof(ptr)) (__ptr + (off)); }) | |
136 | #endif | |
137 | ||
138 | #endif /* __KERNEL__ */ | |
139 | ||
140 | #endif /* __ASSEMBLY__ */ | |
141 | ||
4f79c3ff | 142 | #ifdef __KERNEL__ |
1da177e4 LT |
143 | /* |
144 | * Allow us to mark functions as 'deprecated' and have gcc emit a nice | |
145 | * warning for each use, in hopes of speeding the functions removal. | |
146 | * Usage is: | |
147 | * int __deprecated foo(void) | |
148 | */ | |
149 | #ifndef __deprecated | |
150 | # define __deprecated /* unimplemented */ | |
151 | #endif | |
152 | ||
512345be PM |
153 | #ifdef MODULE |
154 | #define __deprecated_for_modules __deprecated | |
155 | #else | |
156 | #define __deprecated_for_modules | |
157 | #endif | |
158 | ||
1da177e4 LT |
159 | #ifndef __must_check |
160 | #define __must_check | |
161 | #endif | |
162 | ||
cebc04ba AM |
163 | #ifndef CONFIG_ENABLE_MUST_CHECK |
164 | #undef __must_check | |
165 | #define __must_check | |
166 | #endif | |
de488443 JG |
167 | #ifndef CONFIG_ENABLE_WARN_DEPRECATED |
168 | #undef __deprecated | |
169 | #undef __deprecated_for_modules | |
170 | #define __deprecated | |
171 | #define __deprecated_for_modules | |
172 | #endif | |
cebc04ba | 173 | |
1da177e4 LT |
174 | /* |
175 | * Allow us to avoid 'defined but not used' warnings on functions and data, | |
176 | * as well as force them to be emitted to the assembly file. | |
177 | * | |
0d7ebbbc DR |
178 | * As of gcc 3.4, static functions that are not marked with attribute((used)) |
179 | * may be elided from the assembly file. As of gcc 3.4, static data not so | |
1da177e4 LT |
180 | * marked will not be elided, but this may change in a future gcc version. |
181 | * | |
0d7ebbbc DR |
182 | * NOTE: Because distributions shipped with a backported unit-at-a-time |
183 | * compiler in gcc 3.3, we must define __used to be __attribute__((used)) | |
184 | * for gcc >=3.3 instead of 3.4. | |
185 | * | |
1da177e4 LT |
186 | * In prior versions of gcc, such functions and data would be emitted, but |
187 | * would be warned about except with attribute((unused)). | |
0d7ebbbc DR |
188 | * |
189 | * Mark functions that are referenced only in inline assembly as __used so | |
190 | * the code is emitted even though it appears to be unreferenced. | |
1da177e4 | 191 | */ |
0d7ebbbc DR |
192 | #ifndef __used |
193 | # define __used /* unimplemented */ | |
194 | #endif | |
195 | ||
196 | #ifndef __maybe_unused | |
197 | # define __maybe_unused /* unimplemented */ | |
1da177e4 LT |
198 | #endif |
199 | ||
423bc7b2 DW |
200 | #ifndef noinline |
201 | #define noinline | |
202 | #endif | |
203 | ||
735c4fb9 AM |
204 | /* |
205 | * Rather then using noinline to prevent stack consumption, use | |
206 | * noinline_for_stack instead. For documentaiton reasons. | |
207 | */ | |
208 | #define noinline_for_stack noinline | |
209 | ||
423bc7b2 DW |
210 | #ifndef __always_inline |
211 | #define __always_inline inline | |
212 | #endif | |
213 | ||
214 | #endif /* __KERNEL__ */ | |
215 | ||
1da177e4 LT |
216 | /* |
217 | * From the GCC manual: | |
218 | * | |
219 | * Many functions do not examine any values except their arguments, | |
220 | * and have no effects except the return value. Basically this is | |
221 | * just slightly more strict class than the `pure' attribute above, | |
222 | * since function is not allowed to read global memory. | |
223 | * | |
224 | * Note that a function that has pointer arguments and examines the | |
225 | * data pointed to must _not_ be declared `const'. Likewise, a | |
226 | * function that calls a non-`const' function usually must not be | |
227 | * `const'. It does not make sense for a `const' function to return | |
228 | * `void'. | |
229 | */ | |
230 | #ifndef __attribute_const__ | |
231 | # define __attribute_const__ /* unimplemented */ | |
232 | #endif | |
233 | ||
a586df06 AK |
234 | /* |
235 | * Tell gcc if a function is cold. The compiler will assume any path | |
236 | * directly leading to the call is unlikely. | |
237 | */ | |
238 | ||
239 | #ifndef __cold | |
240 | #define __cold | |
241 | #endif | |
242 | ||
f3fe866d SR |
243 | /* Simple shorthand for a section definition */ |
244 | #ifndef __section | |
245 | # define __section(S) __attribute__ ((__section__(#S))) | |
246 | #endif | |
247 | ||
9c3cdc1f LT |
248 | /* |
249 | * Prevent the compiler from merging or refetching accesses. The compiler | |
250 | * is also forbidden from reordering successive instances of ACCESS_ONCE(), | |
251 | * but only when the compiler is aware of some particular ordering. One way | |
252 | * to make the compiler aware of ordering is to put the two invocations of | |
253 | * ACCESS_ONCE() in different C statements. | |
254 | * | |
255 | * This macro does absolutely -nothing- to prevent the CPU from reordering, | |
ded00a56 PM |
256 | * merging, or refetching absolutely anything at any time. Its main intended |
257 | * use is to mediate communication between process-level code and irq/NMI | |
258 | * handlers, all running on the same CPU. | |
9c3cdc1f LT |
259 | */ |
260 | #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) | |
261 | ||
1da177e4 | 262 | #endif /* __LINUX_COMPILER_H */ |