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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 | ||
61f55214 HC |
57 | #ifdef CC_USING_HOTPATCH |
58 | #define notrace __attribute__((hotpatch(0,0))) | |
59 | #else | |
28614889 | 60 | #define notrace __attribute__((no_instrument_function)) |
61f55214 | 61 | #endif |
28614889 | 62 | |
1da177e4 LT |
63 | /* Intel compiler defines __GNUC__. So we will overwrite implementations |
64 | * coming from above header files here | |
65 | */ | |
66 | #ifdef __INTEL_COMPILER | |
67 | # include <linux/compiler-intel.h> | |
68 | #endif | |
69 | ||
565cbdc2 MC |
70 | /* Clang compiler defines __GNUC__. So we will overwrite implementations |
71 | * coming from above header files here | |
72 | */ | |
73 | #ifdef __clang__ | |
74 | #include <linux/compiler-clang.h> | |
75 | #endif | |
76 | ||
1da177e4 LT |
77 | /* |
78 | * Generic compiler-dependent macros required for kernel | |
79 | * build go below this comment. Actual compiler/compiler version | |
80 | * specific implementations come from the above header files | |
81 | */ | |
82 | ||
2ed84eeb | 83 | struct ftrace_branch_data { |
1f0d69a9 SR |
84 | const char *func; |
85 | const char *file; | |
86 | unsigned line; | |
2bcd521a SR |
87 | union { |
88 | struct { | |
89 | unsigned long correct; | |
90 | unsigned long incorrect; | |
91 | }; | |
92 | struct { | |
93 | unsigned long miss; | |
94 | unsigned long hit; | |
95 | }; | |
97e7e4f3 | 96 | unsigned long miss_hit[2]; |
2bcd521a | 97 | }; |
1f0d69a9 | 98 | }; |
2ed84eeb SR |
99 | |
100 | /* | |
101 | * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code | |
102 | * to disable branch tracing on a per file basis. | |
103 | */ | |
d9ad8bc0 BVA |
104 | #if defined(CONFIG_TRACE_BRANCH_PROFILING) \ |
105 | && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__) | |
2ed84eeb | 106 | void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); |
1f0d69a9 SR |
107 | |
108 | #define likely_notrace(x) __builtin_expect(!!(x), 1) | |
109 | #define unlikely_notrace(x) __builtin_expect(!!(x), 0) | |
110 | ||
45b79749 | 111 | #define __branch_check__(x, expect) ({ \ |
1f0d69a9 | 112 | int ______r; \ |
2ed84eeb | 113 | static struct ftrace_branch_data \ |
1f0d69a9 | 114 | __attribute__((__aligned__(4))) \ |
45b79749 | 115 | __attribute__((section("_ftrace_annotated_branch"))) \ |
1f0d69a9 SR |
116 | ______f = { \ |
117 | .func = __func__, \ | |
118 | .file = __FILE__, \ | |
119 | .line = __LINE__, \ | |
120 | }; \ | |
1f0d69a9 | 121 | ______r = likely_notrace(x); \ |
45b79749 | 122 | ftrace_likely_update(&______f, ______r, expect); \ |
1f0d69a9 SR |
123 | ______r; \ |
124 | }) | |
125 | ||
126 | /* | |
127 | * Using __builtin_constant_p(x) to ignore cases where the return | |
128 | * value is always the same. This idea is taken from a similar patch | |
129 | * written by Daniel Walker. | |
130 | */ | |
131 | # ifndef likely | |
45b79749 | 132 | # define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1)) |
1f0d69a9 SR |
133 | # endif |
134 | # ifndef unlikely | |
45b79749 | 135 | # define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0)) |
1f0d69a9 | 136 | # endif |
2bcd521a SR |
137 | |
138 | #ifdef CONFIG_PROFILE_ALL_BRANCHES | |
139 | /* | |
140 | * "Define 'is'", Bill Clinton | |
141 | * "Define 'if'", Steven Rostedt | |
142 | */ | |
ab3c9c68 LT |
143 | #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) ) |
144 | #define __trace_if(cond) \ | |
145 | if (__builtin_constant_p((cond)) ? !!(cond) : \ | |
2bcd521a SR |
146 | ({ \ |
147 | int ______r; \ | |
148 | static struct ftrace_branch_data \ | |
149 | __attribute__((__aligned__(4))) \ | |
150 | __attribute__((section("_ftrace_branch"))) \ | |
151 | ______f = { \ | |
152 | .func = __func__, \ | |
153 | .file = __FILE__, \ | |
154 | .line = __LINE__, \ | |
155 | }; \ | |
156 | ______r = !!(cond); \ | |
97e7e4f3 | 157 | ______f.miss_hit[______r]++; \ |
2bcd521a SR |
158 | ______r; \ |
159 | })) | |
160 | #endif /* CONFIG_PROFILE_ALL_BRANCHES */ | |
161 | ||
1f0d69a9 SR |
162 | #else |
163 | # define likely(x) __builtin_expect(!!(x), 1) | |
164 | # define unlikely(x) __builtin_expect(!!(x), 0) | |
165 | #endif | |
1da177e4 LT |
166 | |
167 | /* Optimization barrier */ | |
168 | #ifndef barrier | |
169 | # define barrier() __memory_barrier() | |
170 | #endif | |
171 | ||
38938c87 DD |
172 | /* Unreachable code */ |
173 | #ifndef unreachable | |
174 | # define unreachable() do { } while (1) | |
175 | #endif | |
176 | ||
1da177e4 LT |
177 | #ifndef RELOC_HIDE |
178 | # define RELOC_HIDE(ptr, off) \ | |
179 | ({ unsigned long __ptr; \ | |
180 | __ptr = (unsigned long) (ptr); \ | |
181 | (typeof(ptr)) (__ptr + (off)); }) | |
182 | #endif | |
183 | ||
fe8c8a12 CEB |
184 | #ifndef OPTIMIZER_HIDE_VAR |
185 | #define OPTIMIZER_HIDE_VAR(var) barrier() | |
186 | #endif | |
187 | ||
6f33d587 RR |
188 | /* Not-quite-unique ID. */ |
189 | #ifndef __UNIQUE_ID | |
190 | # define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__) | |
191 | #endif | |
192 | ||
230fa253 CB |
193 | #include <uapi/linux/types.h> |
194 | ||
dd369297 | 195 | static __always_inline void __read_once_size(const volatile void *p, void *res, int size) |
230fa253 CB |
196 | { |
197 | switch (size) { | |
198 | case 1: *(__u8 *)res = *(volatile __u8 *)p; break; | |
199 | case 2: *(__u16 *)res = *(volatile __u16 *)p; break; | |
200 | case 4: *(__u32 *)res = *(volatile __u32 *)p; break; | |
230fa253 | 201 | case 8: *(__u64 *)res = *(volatile __u64 *)p; break; |
230fa253 CB |
202 | default: |
203 | barrier(); | |
204 | __builtin_memcpy((void *)res, (const void *)p, size); | |
230fa253 CB |
205 | barrier(); |
206 | } | |
207 | } | |
208 | ||
43239cbe | 209 | static __always_inline void __write_once_size(volatile void *p, void *res, int size) |
230fa253 CB |
210 | { |
211 | switch (size) { | |
212 | case 1: *(volatile __u8 *)p = *(__u8 *)res; break; | |
213 | case 2: *(volatile __u16 *)p = *(__u16 *)res; break; | |
214 | case 4: *(volatile __u32 *)p = *(__u32 *)res; break; | |
230fa253 | 215 | case 8: *(volatile __u64 *)p = *(__u64 *)res; break; |
230fa253 CB |
216 | default: |
217 | barrier(); | |
218 | __builtin_memcpy((void *)p, (const void *)res, size); | |
230fa253 CB |
219 | barrier(); |
220 | } | |
221 | } | |
222 | ||
223 | /* | |
224 | * Prevent the compiler from merging or refetching reads or writes. The | |
225 | * compiler is also forbidden from reordering successive instances of | |
43239cbe | 226 | * READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the |
230fa253 CB |
227 | * compiler is aware of some particular ordering. One way to make the |
228 | * compiler aware of ordering is to put the two invocations of READ_ONCE, | |
43239cbe | 229 | * WRITE_ONCE or ACCESS_ONCE() in different C statements. |
230fa253 CB |
230 | * |
231 | * In contrast to ACCESS_ONCE these two macros will also work on aggregate | |
232 | * data types like structs or unions. If the size of the accessed data | |
233 | * type exceeds the word size of the machine (e.g., 32 bits or 64 bits) | |
43239cbe | 234 | * READ_ONCE() and WRITE_ONCE() will fall back to memcpy and print a |
230fa253 CB |
235 | * compile-time warning. |
236 | * | |
237 | * Their two major use cases are: (1) Mediating communication between | |
238 | * process-level code and irq/NMI handlers, all running on the same CPU, | |
239 | * and (2) Ensuring that the compiler does not fold, spindle, or otherwise | |
240 | * mutilate accesses that either do not require ordering or that interact | |
241 | * with an explicit memory barrier or atomic instruction that provides the | |
242 | * required ordering. | |
243 | */ | |
244 | ||
245 | #define READ_ONCE(x) \ | |
dd369297 | 246 | ({ union { typeof(x) __val; char __c[1]; } __u; __read_once_size(&(x), __u.__c, sizeof(x)); __u.__val; }) |
230fa253 | 247 | |
43239cbe | 248 | #define WRITE_ONCE(x, val) \ |
dd369297 | 249 | ({ typeof(x) __val = (val); __write_once_size(&(x), &__val, sizeof(__val)); __val; }) |
230fa253 | 250 | |
1da177e4 LT |
251 | #endif /* __KERNEL__ */ |
252 | ||
253 | #endif /* __ASSEMBLY__ */ | |
254 | ||
4f79c3ff | 255 | #ifdef __KERNEL__ |
1da177e4 LT |
256 | /* |
257 | * Allow us to mark functions as 'deprecated' and have gcc emit a nice | |
258 | * warning for each use, in hopes of speeding the functions removal. | |
259 | * Usage is: | |
260 | * int __deprecated foo(void) | |
261 | */ | |
262 | #ifndef __deprecated | |
263 | # define __deprecated /* unimplemented */ | |
264 | #endif | |
265 | ||
512345be PM |
266 | #ifdef MODULE |
267 | #define __deprecated_for_modules __deprecated | |
268 | #else | |
269 | #define __deprecated_for_modules | |
270 | #endif | |
271 | ||
1da177e4 LT |
272 | #ifndef __must_check |
273 | #define __must_check | |
274 | #endif | |
275 | ||
cebc04ba AM |
276 | #ifndef CONFIG_ENABLE_MUST_CHECK |
277 | #undef __must_check | |
278 | #define __must_check | |
279 | #endif | |
de488443 JG |
280 | #ifndef CONFIG_ENABLE_WARN_DEPRECATED |
281 | #undef __deprecated | |
282 | #undef __deprecated_for_modules | |
283 | #define __deprecated | |
284 | #define __deprecated_for_modules | |
285 | #endif | |
cebc04ba | 286 | |
1da177e4 LT |
287 | /* |
288 | * Allow us to avoid 'defined but not used' warnings on functions and data, | |
289 | * as well as force them to be emitted to the assembly file. | |
290 | * | |
0d7ebbbc DR |
291 | * As of gcc 3.4, static functions that are not marked with attribute((used)) |
292 | * may be elided from the assembly file. As of gcc 3.4, static data not so | |
1da177e4 LT |
293 | * marked will not be elided, but this may change in a future gcc version. |
294 | * | |
0d7ebbbc DR |
295 | * NOTE: Because distributions shipped with a backported unit-at-a-time |
296 | * compiler in gcc 3.3, we must define __used to be __attribute__((used)) | |
297 | * for gcc >=3.3 instead of 3.4. | |
298 | * | |
1da177e4 LT |
299 | * In prior versions of gcc, such functions and data would be emitted, but |
300 | * would be warned about except with attribute((unused)). | |
0d7ebbbc DR |
301 | * |
302 | * Mark functions that are referenced only in inline assembly as __used so | |
303 | * the code is emitted even though it appears to be unreferenced. | |
1da177e4 | 304 | */ |
0d7ebbbc DR |
305 | #ifndef __used |
306 | # define __used /* unimplemented */ | |
307 | #endif | |
308 | ||
309 | #ifndef __maybe_unused | |
310 | # define __maybe_unused /* unimplemented */ | |
1da177e4 LT |
311 | #endif |
312 | ||
7b2a3513 LZ |
313 | #ifndef __always_unused |
314 | # define __always_unused /* unimplemented */ | |
315 | #endif | |
316 | ||
423bc7b2 DW |
317 | #ifndef noinline |
318 | #define noinline | |
319 | #endif | |
320 | ||
735c4fb9 AM |
321 | /* |
322 | * Rather then using noinline to prevent stack consumption, use | |
e6be0c9e | 323 | * noinline_for_stack instead. For documentation reasons. |
735c4fb9 AM |
324 | */ |
325 | #define noinline_for_stack noinline | |
326 | ||
423bc7b2 DW |
327 | #ifndef __always_inline |
328 | #define __always_inline inline | |
329 | #endif | |
330 | ||
331 | #endif /* __KERNEL__ */ | |
332 | ||
1da177e4 LT |
333 | /* |
334 | * From the GCC manual: | |
335 | * | |
336 | * Many functions do not examine any values except their arguments, | |
337 | * and have no effects except the return value. Basically this is | |
338 | * just slightly more strict class than the `pure' attribute above, | |
339 | * since function is not allowed to read global memory. | |
340 | * | |
341 | * Note that a function that has pointer arguments and examines the | |
342 | * data pointed to must _not_ be declared `const'. Likewise, a | |
343 | * function that calls a non-`const' function usually must not be | |
344 | * `const'. It does not make sense for a `const' function to return | |
345 | * `void'. | |
346 | */ | |
347 | #ifndef __attribute_const__ | |
348 | # define __attribute_const__ /* unimplemented */ | |
349 | #endif | |
350 | ||
a586df06 AK |
351 | /* |
352 | * Tell gcc if a function is cold. The compiler will assume any path | |
353 | * directly leading to the call is unlikely. | |
354 | */ | |
355 | ||
356 | #ifndef __cold | |
357 | #define __cold | |
358 | #endif | |
359 | ||
f3fe866d SR |
360 | /* Simple shorthand for a section definition */ |
361 | #ifndef __section | |
362 | # define __section(S) __attribute__ ((__section__(#S))) | |
363 | #endif | |
364 | ||
9a858dc7 AK |
365 | #ifndef __visible |
366 | #define __visible | |
367 | #endif | |
368 | ||
d2c123c2 RR |
369 | /* Are two types/vars the same type (ignoring qualifiers)? */ |
370 | #ifndef __same_type | |
371 | # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b)) | |
372 | #endif | |
373 | ||
47933ad4 PZ |
374 | /* Is this type a native word size -- useful for atomic operations */ |
375 | #ifndef __native_word | |
536fa402 | 376 | # define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) |
47933ad4 PZ |
377 | #endif |
378 | ||
9f0cf4ad AV |
379 | /* Compile time object size, -1 for unknown */ |
380 | #ifndef __compiletime_object_size | |
381 | # define __compiletime_object_size(obj) -1 | |
382 | #endif | |
4a312769 AV |
383 | #ifndef __compiletime_warning |
384 | # define __compiletime_warning(message) | |
385 | #endif | |
63312b6a AV |
386 | #ifndef __compiletime_error |
387 | # define __compiletime_error(message) | |
2c0d259e JH |
388 | /* |
389 | * Sparse complains of variable sized arrays due to the temporary variable in | |
390 | * __compiletime_assert. Unfortunately we can't just expand it out to make | |
391 | * sparse see a constant array size without breaking compiletime_assert on old | |
392 | * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether. | |
393 | */ | |
394 | # ifndef __CHECKER__ | |
395 | # define __compiletime_error_fallback(condition) \ | |
9a8ab1c3 | 396 | do { ((void)sizeof(char[1 - 2 * condition])); } while (0) |
2c0d259e JH |
397 | # endif |
398 | #endif | |
399 | #ifndef __compiletime_error_fallback | |
c361d3e5 | 400 | # define __compiletime_error_fallback(condition) do { } while (0) |
63312b6a | 401 | #endif |
c361d3e5 | 402 | |
9a8ab1c3 DS |
403 | #define __compiletime_assert(condition, msg, prefix, suffix) \ |
404 | do { \ | |
405 | bool __cond = !(condition); \ | |
406 | extern void prefix ## suffix(void) __compiletime_error(msg); \ | |
407 | if (__cond) \ | |
408 | prefix ## suffix(); \ | |
409 | __compiletime_error_fallback(__cond); \ | |
410 | } while (0) | |
411 | ||
412 | #define _compiletime_assert(condition, msg, prefix, suffix) \ | |
413 | __compiletime_assert(condition, msg, prefix, suffix) | |
414 | ||
415 | /** | |
416 | * compiletime_assert - break build and emit msg if condition is false | |
417 | * @condition: a compile-time constant condition to check | |
418 | * @msg: a message to emit if condition is false | |
419 | * | |
420 | * In tradition of POSIX assert, this macro will break the build if the | |
421 | * supplied condition is *false*, emitting the supplied error message if the | |
422 | * compiler has support to do so. | |
423 | */ | |
424 | #define compiletime_assert(condition, msg) \ | |
425 | _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) | |
426 | ||
47933ad4 PZ |
427 | #define compiletime_assert_atomic_type(t) \ |
428 | compiletime_assert(__native_word(t), \ | |
429 | "Need native word sized stores/loads for atomicity.") | |
430 | ||
9c3cdc1f LT |
431 | /* |
432 | * Prevent the compiler from merging or refetching accesses. The compiler | |
433 | * is also forbidden from reordering successive instances of ACCESS_ONCE(), | |
434 | * but only when the compiler is aware of some particular ordering. One way | |
435 | * to make the compiler aware of ordering is to put the two invocations of | |
436 | * ACCESS_ONCE() in different C statements. | |
437 | * | |
927609d6 CB |
438 | * ACCESS_ONCE will only work on scalar types. For union types, ACCESS_ONCE |
439 | * on a union member will work as long as the size of the member matches the | |
440 | * size of the union and the size is smaller than word size. | |
441 | * | |
442 | * The major use cases of ACCESS_ONCE used to be (1) Mediating communication | |
443 | * between process-level code and irq/NMI handlers, all running on the same CPU, | |
444 | * and (2) Ensuring that the compiler does not fold, spindle, or otherwise | |
445 | * mutilate accesses that either do not require ordering or that interact | |
446 | * with an explicit memory barrier or atomic instruction that provides the | |
447 | * required ordering. | |
448 | * | |
449 | * If possible use READ_ONCE/ASSIGN_ONCE instead. | |
9c3cdc1f | 450 | */ |
927609d6 | 451 | #define __ACCESS_ONCE(x) ({ \ |
c5b19946 | 452 | __maybe_unused typeof(x) __var = (__force typeof(x)) 0; \ |
927609d6 CB |
453 | (volatile typeof(x) *)&(x); }) |
454 | #define ACCESS_ONCE(x) (*__ACCESS_ONCE(x)) | |
9c3cdc1f | 455 | |
324670b6 MH |
456 | /* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */ |
457 | #ifdef CONFIG_KPROBES | |
458 | # define __kprobes __attribute__((__section__(".kprobes.text"))) | |
376e2424 | 459 | # define nokprobe_inline __always_inline |
324670b6 MH |
460 | #else |
461 | # define __kprobes | |
376e2424 | 462 | # define nokprobe_inline inline |
324670b6 | 463 | #endif |
1da177e4 | 464 | #endif /* __LINUX_COMPILER_H */ |