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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))) | |
e0fdb0e0 | 8 | # define __kernel __attribute__((address_space(0))) |
1da177e4 LT |
9 | # define __safe __attribute__((safe)) |
10 | # define __force __attribute__((force)) | |
11 | # define __nocast __attribute__((nocast)) | |
12 | # define __iomem __attribute__((noderef, address_space(2))) | |
8529091e | 13 | # define __must_hold(x) __attribute__((context(x,1,1))) |
c902e0a0 JT |
14 | # define __acquires(x) __attribute__((context(x,0,1))) |
15 | # define __releases(x) __attribute__((context(x,1,0))) | |
16 | # define __acquire(x) __context__(x,1) | |
17 | # define __release(x) __context__(x,-1) | |
dcc8e559 | 18 | # define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0) |
e0fdb0e0 | 19 | # define __percpu __attribute__((noderef, address_space(3))) |
ca5ecddf PM |
20 | #ifdef CONFIG_SPARSE_RCU_POINTER |
21 | # define __rcu __attribute__((noderef, address_space(4))) | |
22 | #else | |
71d1d5c7 | 23 | # define __rcu |
ca5ecddf | 24 | #endif |
c47ffe3d AV |
25 | extern void __chk_user_ptr(const volatile void __user *); |
26 | extern void __chk_io_ptr(const volatile void __iomem *); | |
1da177e4 LT |
27 | #else |
28 | # define __user | |
29 | # define __kernel | |
30 | # define __safe | |
31 | # define __force | |
32 | # define __nocast | |
33 | # define __iomem | |
34 | # define __chk_user_ptr(x) (void)0 | |
35 | # define __chk_io_ptr(x) (void)0 | |
36 | # define __builtin_warning(x, y...) (1) | |
8529091e | 37 | # define __must_hold(x) |
1da177e4 LT |
38 | # define __acquires(x) |
39 | # define __releases(x) | |
40 | # define __acquire(x) (void)0 | |
41 | # define __release(x) (void)0 | |
dcc8e559 | 42 | # define __cond_lock(x,c) (c) |
e0fdb0e0 | 43 | # define __percpu |
71d1d5c7 | 44 | # define __rcu |
1da177e4 LT |
45 | #endif |
46 | ||
6f33d587 RR |
47 | /* Indirect macros required for expanded argument pasting, eg. __LINE__. */ |
48 | #define ___PASTE(a,b) a##b | |
49 | #define __PASTE(a,b) ___PASTE(a,b) | |
50 | ||
1da177e4 LT |
51 | #ifdef __KERNEL__ |
52 | ||
f153b821 LT |
53 | #ifdef __GNUC__ |
54 | #include <linux/compiler-gcc.h> | |
1da177e4 LT |
55 | #endif |
56 | ||
28614889 SR |
57 | #define notrace __attribute__((no_instrument_function)) |
58 | ||
1da177e4 LT |
59 | /* Intel compiler defines __GNUC__. So we will overwrite implementations |
60 | * coming from above header files here | |
61 | */ | |
62 | #ifdef __INTEL_COMPILER | |
63 | # include <linux/compiler-intel.h> | |
64 | #endif | |
65 | ||
565cbdc2 MC |
66 | /* Clang compiler defines __GNUC__. So we will overwrite implementations |
67 | * coming from above header files here | |
68 | */ | |
69 | #ifdef __clang__ | |
70 | #include <linux/compiler-clang.h> | |
71 | #endif | |
72 | ||
1da177e4 LT |
73 | /* |
74 | * Generic compiler-dependent macros required for kernel | |
75 | * build go below this comment. Actual compiler/compiler version | |
76 | * specific implementations come from the above header files | |
77 | */ | |
78 | ||
2ed84eeb | 79 | struct ftrace_branch_data { |
1f0d69a9 SR |
80 | const char *func; |
81 | const char *file; | |
82 | unsigned line; | |
2bcd521a SR |
83 | union { |
84 | struct { | |
85 | unsigned long correct; | |
86 | unsigned long incorrect; | |
87 | }; | |
88 | struct { | |
89 | unsigned long miss; | |
90 | unsigned long hit; | |
91 | }; | |
97e7e4f3 | 92 | unsigned long miss_hit[2]; |
2bcd521a | 93 | }; |
1f0d69a9 | 94 | }; |
2ed84eeb SR |
95 | |
96 | /* | |
97 | * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code | |
98 | * to disable branch tracing on a per file basis. | |
99 | */ | |
d9ad8bc0 BVA |
100 | #if defined(CONFIG_TRACE_BRANCH_PROFILING) \ |
101 | && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__) | |
2ed84eeb | 102 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); |
1f0d69a9 SR |
103 | |
104 | #define likely_notrace(x) __builtin_expect(!!(x), 1) | |
105 | #define unlikely_notrace(x) __builtin_expect(!!(x), 0) | |
106 | ||
45b79749 | 107 | #define __branch_check__(x, expect) ({ \ |
1f0d69a9 | 108 | int ______r; \ |
2ed84eeb | 109 | static struct ftrace_branch_data \ |
1f0d69a9 | 110 | __attribute__((__aligned__(4))) \ |
45b79749 | 111 | __attribute__((section("_ftrace_annotated_branch"))) \ |
1f0d69a9 SR |
112 | ______f = { \ |
113 | .func = __func__, \ | |
114 | .file = __FILE__, \ | |
115 | .line = __LINE__, \ | |
116 | }; \ | |
1f0d69a9 | 117 | ______r = likely_notrace(x); \ |
45b79749 | 118 | ftrace_likely_update(&______f, ______r, expect); \ |
1f0d69a9 SR |
119 | ______r; \ |
120 | }) | |
121 | ||
122 | /* | |
123 | * Using __builtin_constant_p(x) to ignore cases where the return | |
124 | * value is always the same. This idea is taken from a similar patch | |
125 | * written by Daniel Walker. | |
126 | */ | |
127 | # ifndef likely | |
45b79749 | 128 | # define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1)) |
1f0d69a9 SR |
129 | # endif |
130 | # ifndef unlikely | |
45b79749 | 131 | # define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0)) |
1f0d69a9 | 132 | # endif |
2bcd521a SR |
133 | |
134 | #ifdef CONFIG_PROFILE_ALL_BRANCHES | |
135 | /* | |
136 | * "Define 'is'", Bill Clinton | |
137 | * "Define 'if'", Steven Rostedt | |
138 | */ | |
ab3c9c68 LT |
139 | #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) ) |
140 | #define __trace_if(cond) \ | |
141 | if (__builtin_constant_p((cond)) ? !!(cond) : \ | |
2bcd521a SR |
142 | ({ \ |
143 | int ______r; \ | |
144 | static struct ftrace_branch_data \ | |
145 | __attribute__((__aligned__(4))) \ | |
146 | __attribute__((section("_ftrace_branch"))) \ | |
147 | ______f = { \ | |
148 | .func = __func__, \ | |
149 | .file = __FILE__, \ | |
150 | .line = __LINE__, \ | |
151 | }; \ | |
152 | ______r = !!(cond); \ | |
97e7e4f3 | 153 | ______f.miss_hit[______r]++; \ |
2bcd521a SR |
154 | ______r; \ |
155 | })) | |
156 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ | |
157 | ||
1f0d69a9 SR |
158 | #else |
159 | # define likely(x) __builtin_expect(!!(x), 1) | |
160 | # define unlikely(x) __builtin_expect(!!(x), 0) | |
161 | #endif | |
1da177e4 LT |
162 | |
163 | /* Optimization barrier */ | |
164 | #ifndef barrier | |
165 | # define barrier() __memory_barrier() | |
166 | #endif | |
167 | ||
38938c87 DD |
168 | /* Unreachable code */ |
169 | #ifndef unreachable | |
170 | # define unreachable() do { } while (1) | |
171 | #endif | |
172 | ||
1da177e4 LT |
173 | #ifndef RELOC_HIDE |
174 | # define RELOC_HIDE(ptr, off) \ | |
175 | ({ unsigned long __ptr; \ | |
176 | __ptr = (unsigned long) (ptr); \ | |
177 | (typeof(ptr)) (__ptr + (off)); }) | |
178 | #endif | |
179 | ||
fe8c8a12 CEB |
180 | #ifndef OPTIMIZER_HIDE_VAR |
181 | #define OPTIMIZER_HIDE_VAR(var) barrier() | |
182 | #endif | |
183 | ||
6f33d587 RR |
184 | /* Not-quite-unique ID. */ |
185 | #ifndef __UNIQUE_ID | |
186 | # define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__) | |
187 | #endif | |
188 | ||
230fa253 CB |
189 | #include <uapi/linux/types.h> |
190 | ||
191 | static __always_inline void data_access_exceeds_word_size(void) | |
192 | #ifdef __compiletime_warning | |
193 | __compiletime_warning("data access exceeds word size and won't be atomic") | |
194 | #endif | |
195 | ; | |
196 | ||
197 | static __always_inline void data_access_exceeds_word_size(void) | |
198 | { | |
199 | } | |
200 | ||
201 | static __always_inline void __read_once_size(volatile void *p, void *res, int size) | |
202 | { | |
203 | switch (size) { | |
204 | case 1: *(__u8 *)res = *(volatile __u8 *)p; break; | |
205 | case 2: *(__u16 *)res = *(volatile __u16 *)p; break; | |
206 | case 4: *(__u32 *)res = *(volatile __u32 *)p; break; | |
207 | #ifdef CONFIG_64BIT | |
208 | case 8: *(__u64 *)res = *(volatile __u64 *)p; break; | |
209 | #endif | |
210 | default: | |
211 | barrier(); | |
212 | __builtin_memcpy((void *)res, (const void *)p, size); | |
213 | data_access_exceeds_word_size(); | |
214 | barrier(); | |
215 | } | |
216 | } | |
217 | ||
43239cbe | 218 | static __always_inline void __write_once_size(volatile void *p, void *res, int size) |
230fa253 CB |
219 | { |
220 | switch (size) { | |
221 | case 1: *(volatile __u8 *)p = *(__u8 *)res; break; | |
222 | case 2: *(volatile __u16 *)p = *(__u16 *)res; break; | |
223 | case 4: *(volatile __u32 *)p = *(__u32 *)res; break; | |
224 | #ifdef CONFIG_64BIT | |
225 | case 8: *(volatile __u64 *)p = *(__u64 *)res; break; | |
226 | #endif | |
227 | default: | |
228 | barrier(); | |
229 | __builtin_memcpy((void *)p, (const void *)res, size); | |
230 | data_access_exceeds_word_size(); | |
231 | barrier(); | |
232 | } | |
233 | } | |
234 | ||
235 | /* | |
236 | * Prevent the compiler from merging or refetching reads or writes. The | |
237 | * compiler is also forbidden from reordering successive instances of | |
43239cbe | 238 | * READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the |
230fa253 CB |
239 | * compiler is aware of some particular ordering. One way to make the |
240 | * compiler aware of ordering is to put the two invocations of READ_ONCE, | |
43239cbe | 241 | * WRITE_ONCE or ACCESS_ONCE() in different C statements. |
230fa253 CB |
242 | * |
243 | * In contrast to ACCESS_ONCE these two macros will also work on aggregate | |
244 | * data types like structs or unions. If the size of the accessed data | |
245 | * type exceeds the word size of the machine (e.g., 32 bits or 64 bits) | |
43239cbe | 246 | * READ_ONCE() and WRITE_ONCE() will fall back to memcpy and print a |
230fa253 CB |
247 | * compile-time warning. |
248 | * | |
249 | * Their two major use cases are: (1) Mediating communication between | |
250 | * process-level code and irq/NMI handlers, all running on the same CPU, | |
251 | * and (2) Ensuring that the compiler does not fold, spindle, or otherwise | |
252 | * mutilate accesses that either do not require ordering or that interact | |
253 | * with an explicit memory barrier or atomic instruction that provides the | |
254 | * required ordering. | |
255 | */ | |
256 | ||
257 | #define READ_ONCE(x) \ | |
258 | ({ typeof(x) __val; __read_once_size(&x, &__val, sizeof(__val)); __val; }) | |
259 | ||
43239cbe CB |
260 | #define WRITE_ONCE(x, val) \ |
261 | ({ typeof(x) __val; __val = val; __write_once_size(&x, &__val, sizeof(__val)); __val; }) | |
230fa253 | 262 | |
1da177e4 LT |
263 | #endif /* __KERNEL__ */ |
264 | ||
265 | #endif /* __ASSEMBLY__ */ | |
266 | ||
4f79c3ff | 267 | #ifdef __KERNEL__ |
1da177e4 LT |
268 | /* |
269 | * Allow us to mark functions as 'deprecated' and have gcc emit a nice | |
270 | * warning for each use, in hopes of speeding the functions removal. | |
271 | * Usage is: | |
272 | * int __deprecated foo(void) | |
273 | */ | |
274 | #ifndef __deprecated | |
275 | # define __deprecated /* unimplemented */ | |
276 | #endif | |
277 | ||
512345be PM |
278 | #ifdef MODULE |
279 | #define __deprecated_for_modules __deprecated | |
280 | #else | |
281 | #define __deprecated_for_modules | |
282 | #endif | |
283 | ||
1da177e4 LT |
284 | #ifndef __must_check |
285 | #define __must_check | |
286 | #endif | |
287 | ||
cebc04ba AM |
288 | #ifndef CONFIG_ENABLE_MUST_CHECK |
289 | #undef __must_check | |
290 | #define __must_check | |
291 | #endif | |
de488443 JG |
292 | #ifndef CONFIG_ENABLE_WARN_DEPRECATED |
293 | #undef __deprecated | |
294 | #undef __deprecated_for_modules | |
295 | #define __deprecated | |
296 | #define __deprecated_for_modules | |
297 | #endif | |
cebc04ba | 298 | |
1da177e4 LT |
299 | /* |
300 | * Allow us to avoid 'defined but not used' warnings on functions and data, | |
301 | * as well as force them to be emitted to the assembly file. | |
302 | * | |
0d7ebbbc DR |
303 | * As of gcc 3.4, static functions that are not marked with attribute((used)) |
304 | * may be elided from the assembly file. As of gcc 3.4, static data not so | |
1da177e4 LT |
305 | * marked will not be elided, but this may change in a future gcc version. |
306 | * | |
0d7ebbbc DR |
307 | * NOTE: Because distributions shipped with a backported unit-at-a-time |
308 | * compiler in gcc 3.3, we must define __used to be __attribute__((used)) | |
309 | * for gcc >=3.3 instead of 3.4. | |
310 | * | |
1da177e4 LT |
311 | * In prior versions of gcc, such functions and data would be emitted, but |
312 | * would be warned about except with attribute((unused)). | |
0d7ebbbc DR |
313 | * |
314 | * Mark functions that are referenced only in inline assembly as __used so | |
315 | * the code is emitted even though it appears to be unreferenced. | |
1da177e4 | 316 | */ |
0d7ebbbc DR |
317 | #ifndef __used |
318 | # define __used /* unimplemented */ | |
319 | #endif | |
320 | ||
321 | #ifndef __maybe_unused | |
322 | # define __maybe_unused /* unimplemented */ | |
1da177e4 LT |
323 | #endif |
324 | ||
7b2a3513 LZ |
325 | #ifndef __always_unused |
326 | # define __always_unused /* unimplemented */ | |
327 | #endif | |
328 | ||
423bc7b2 DW |
329 | #ifndef noinline |
330 | #define noinline | |
331 | #endif | |
332 | ||
735c4fb9 AM |
333 | /* |
334 | * Rather then using noinline to prevent stack consumption, use | |
e6be0c9e | 335 | * noinline_for_stack instead. For documentation reasons. |
735c4fb9 AM |
336 | */ |
337 | #define noinline_for_stack noinline | |
338 | ||
423bc7b2 DW |
339 | #ifndef __always_inline |
340 | #define __always_inline inline | |
341 | #endif | |
342 | ||
343 | #endif /* __KERNEL__ */ | |
344 | ||
1da177e4 LT |
345 | /* |
346 | * From the GCC manual: | |
347 | * | |
348 | * Many functions do not examine any values except their arguments, | |
349 | * and have no effects except the return value. Basically this is | |
350 | * just slightly more strict class than the `pure' attribute above, | |
351 | * since function is not allowed to read global memory. | |
352 | * | |
353 | * Note that a function that has pointer arguments and examines the | |
354 | * data pointed to must _not_ be declared `const'. Likewise, a | |
355 | * function that calls a non-`const' function usually must not be | |
356 | * `const'. It does not make sense for a `const' function to return | |
357 | * `void'. | |
358 | */ | |
359 | #ifndef __attribute_const__ | |
360 | # define __attribute_const__ /* unimplemented */ | |
361 | #endif | |
362 | ||
a586df06 AK |
363 | /* |
364 | * Tell gcc if a function is cold. The compiler will assume any path | |
365 | * directly leading to the call is unlikely. | |
366 | */ | |
367 | ||
368 | #ifndef __cold | |
369 | #define __cold | |
370 | #endif | |
371 | ||
f3fe866d SR |
372 | /* Simple shorthand for a section definition */ |
373 | #ifndef __section | |
374 | # define __section(S) __attribute__ ((__section__(#S))) | |
375 | #endif | |
376 | ||
9a858dc7 AK |
377 | #ifndef __visible |
378 | #define __visible | |
379 | #endif | |
380 | ||
d2c123c2 RR |
381 | /* Are two types/vars the same type (ignoring qualifiers)? */ |
382 | #ifndef __same_type | |
383 | # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) | |
384 | #endif | |
385 | ||
47933ad4 PZ |
386 | /* Is this type a native word size -- useful for atomic operations */ |
387 | #ifndef __native_word | |
388 | # define __native_word(t) (sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) | |
389 | #endif | |
390 | ||
9f0cf4ad AV |
391 | /* Compile time object size, -1 for unknown */ |
392 | #ifndef __compiletime_object_size | |
393 | # define __compiletime_object_size(obj) -1 | |
394 | #endif | |
4a312769 AV |
395 | #ifndef __compiletime_warning |
396 | # define __compiletime_warning(message) | |
397 | #endif | |
63312b6a AV |
398 | #ifndef __compiletime_error |
399 | # define __compiletime_error(message) | |
2c0d259e JH |
400 | /* |
401 | * Sparse complains of variable sized arrays due to the temporary variable in | |
402 | * __compiletime_assert. Unfortunately we can't just expand it out to make | |
403 | * sparse see a constant array size without breaking compiletime_assert on old | |
404 | * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether. | |
405 | */ | |
406 | # ifndef __CHECKER__ | |
407 | # define __compiletime_error_fallback(condition) \ | |
9a8ab1c3 | 408 | do { ((void)sizeof(char[1 - 2 * condition])); } while (0) |
2c0d259e JH |
409 | # endif |
410 | #endif | |
411 | #ifndef __compiletime_error_fallback | |
c361d3e5 | 412 | # define __compiletime_error_fallback(condition) do { } while (0) |
63312b6a | 413 | #endif |
c361d3e5 | 414 | |
9a8ab1c3 DS |
415 | #define __compiletime_assert(condition, msg, prefix, suffix) \ |
416 | do { \ | |
417 | bool __cond = !(condition); \ | |
418 | extern void prefix ## suffix(void) __compiletime_error(msg); \ | |
419 | if (__cond) \ | |
420 | prefix ## suffix(); \ | |
421 | __compiletime_error_fallback(__cond); \ | |
422 | } while (0) | |
423 | ||
424 | #define _compiletime_assert(condition, msg, prefix, suffix) \ | |
425 | __compiletime_assert(condition, msg, prefix, suffix) | |
426 | ||
427 | /** | |
428 | * compiletime_assert - break build and emit msg if condition is false | |
429 | * @condition: a compile-time constant condition to check | |
430 | * @msg: a message to emit if condition is false | |
431 | * | |
432 | * In tradition of POSIX assert, this macro will break the build if the | |
433 | * supplied condition is *false*, emitting the supplied error message if the | |
434 | * compiler has support to do so. | |
435 | */ | |
436 | #define compiletime_assert(condition, msg) \ | |
437 | _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) | |
438 | ||
47933ad4 PZ |
439 | #define compiletime_assert_atomic_type(t) \ |
440 | compiletime_assert(__native_word(t), \ | |
441 | "Need native word sized stores/loads for atomicity.") | |
442 | ||
9c3cdc1f LT |
443 | /* |
444 | * Prevent the compiler from merging or refetching accesses. The compiler | |
445 | * is also forbidden from reordering successive instances of ACCESS_ONCE(), | |
446 | * but only when the compiler is aware of some particular ordering. One way | |
447 | * to make the compiler aware of ordering is to put the two invocations of | |
448 | * ACCESS_ONCE() in different C statements. | |
449 | * | |
450 | * This macro does absolutely -nothing- to prevent the CPU from reordering, | |
ded00a56 PM |
451 | * merging, or refetching absolutely anything at any time. Its main intended |
452 | * use is to mediate communication between process-level code and irq/NMI | |
453 | * handlers, all running on the same CPU. | |
9c3cdc1f LT |
454 | */ |
455 | #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) | |
456 | ||
324670b6 MH |
457 | /* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */ |
458 | #ifdef CONFIG_KPROBES | |
459 | # define __kprobes __attribute__((__section__(".kprobes.text"))) | |
376e2424 | 460 | # define nokprobe_inline __always_inline |
324670b6 MH |
461 | #else |
462 | # define __kprobes | |
376e2424 | 463 | # define nokprobe_inline inline |
324670b6 | 464 | #endif |
1da177e4 | 465 | #endif /* __LINUX_COMPILER_H */ |