blob: ee7239ea1583482b16bfa0b46ebd45714c7babd6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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)))
Rusty Russelle0fdb0e2009-10-29 22:34:15 +09008# define __kernel __attribute__((address_space(0)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07009# define __safe __attribute__((safe))
10# define __force __attribute__((force))
11# define __nocast __attribute__((nocast))
12# define __iomem __attribute__((noderef, address_space(2)))
Josh Triplett85290912012-12-17 16:03:24 -080013# define __must_hold(x) __attribute__((context(x,1,1)))
Josh Triplettc902e0a2006-09-30 23:28:21 -070014# 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)
Josh Triplettdcc8e552006-09-29 02:01:03 -070018# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
Rusty Russelle0fdb0e2009-10-29 22:34:15 +090019# define __percpu __attribute__((noderef, address_space(3)))
Paul E. McKenneyca5ecdd2010-04-28 14:39:09 -070020#ifdef CONFIG_SPARSE_RCU_POINTER
21# define __rcu __attribute__((noderef, address_space(4)))
22#else
Paul E. McKenney71d1d5c2010-05-11 16:13:14 -070023# define __rcu
Paul E. McKenneyca5ecdd2010-04-28 14:39:09 -070024#endif
Al Viroc47ffe32007-07-26 17:35:29 +010025extern void __chk_user_ptr(const volatile void __user *);
26extern void __chk_io_ptr(const volatile void __iomem *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#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)
Josh Triplett85290912012-12-17 16:03:24 -080037# define __must_hold(x)
Linus Torvalds1da177e2005-04-16 15:20:36 -070038# define __acquires(x)
39# define __releases(x)
40# define __acquire(x) (void)0
41# define __release(x) (void)0
Josh Triplettdcc8e552006-09-29 02:01:03 -070042# define __cond_lock(x,c) (c)
Rusty Russelle0fdb0e2009-10-29 22:34:15 +090043# define __percpu
Paul E. McKenney71d1d5c2010-05-11 16:13:14 -070044# define __rcu
Linus Torvalds1da177e2005-04-16 15:20:36 -070045#endif
46
Rusty Russell6f33d582012-11-22 12:30:25 +103047/* 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#ifdef __KERNEL__
52
Linus Torvaldsf153b822009-01-02 09:23:03 -080053#ifdef __GNUC__
54#include <linux/compiler-gcc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#endif
56
Steven Rostedt28614882008-08-14 22:47:18 -040057#define notrace __attribute__((no_instrument_function))
58
Linus Torvalds1da177e2005-04-16 15:20:36 -070059/* 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
Mark Charlebois565cbdc2012-11-20 22:13:10 +010066/* 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070073/*
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
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050079struct ftrace_branch_data {
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050080 const char *func;
81 const char *file;
82 unsigned line;
Steven Rostedt2bcd5212008-11-21 01:30:54 -050083 union {
84 struct {
85 unsigned long correct;
86 unsigned long incorrect;
87 };
88 struct {
89 unsigned long miss;
90 unsigned long hit;
91 };
Witold Baryluk97e7e4f2009-03-17 21:15:44 +010092 unsigned long miss_hit[2];
Steven Rostedt2bcd5212008-11-21 01:30:54 -050093 };
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050094};
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050095
96/*
97 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
98 * to disable branch tracing on a per file basis.
99 */
Bart Van Assched9ad8bc2009-04-05 16:20:02 +0200100#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
101 && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
Steven Rostedt2ed84ee2008-11-12 15:24:24 -0500102void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500103
104#define likely_notrace(x) __builtin_expect(!!(x), 1)
105#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
106
Steven Rostedt45b79742008-11-21 00:40:40 -0500107#define __branch_check__(x, expect) ({ \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500108 int ______r; \
Steven Rostedt2ed84ee2008-11-12 15:24:24 -0500109 static struct ftrace_branch_data \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500110 __attribute__((__aligned__(4))) \
Steven Rostedt45b79742008-11-21 00:40:40 -0500111 __attribute__((section("_ftrace_annotated_branch"))) \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500112 ______f = { \
113 .func = __func__, \
114 .file = __FILE__, \
115 .line = __LINE__, \
116 }; \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500117 ______r = likely_notrace(x); \
Steven Rostedt45b79742008-11-21 00:40:40 -0500118 ftrace_likely_update(&______f, ______r, expect); \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500119 ______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
Steven Rostedt45b79742008-11-21 00:40:40 -0500128# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500129# endif
130# ifndef unlikely
Steven Rostedt45b79742008-11-21 00:40:40 -0500131# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500132# endif
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500133
134#ifdef CONFIG_PROFILE_ALL_BRANCHES
135/*
136 * "Define 'is'", Bill Clinton
137 * "Define 'if'", Steven Rostedt
138 */
Linus Torvaldsab3c9c62009-04-07 07:59:41 -0700139#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
140#define __trace_if(cond) \
141 if (__builtin_constant_p((cond)) ? !!(cond) : \
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500142 ({ \
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); \
Witold Baryluk97e7e4f2009-03-17 21:15:44 +0100153 ______f.miss_hit[______r]++; \
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500154 ______r; \
155 }))
156#endif /* CONFIG_PROFILE_ALL_BRANCHES */
157
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500158#else
159# define likely(x) __builtin_expect(!!(x), 1)
160# define unlikely(x) __builtin_expect(!!(x), 0)
161#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162
163/* Optimization barrier */
164#ifndef barrier
165# define barrier() __memory_barrier()
166#endif
167
David Daney38938c82009-12-04 17:44:50 -0800168/* Unreachable code */
169#ifndef unreachable
170# define unreachable() do { } while (1)
171#endif
172
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173#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
Cesar Eduardo Barrosfe8c8a12013-11-25 22:00:41 -0200180#ifndef OPTIMIZER_HIDE_VAR
181#define OPTIMIZER_HIDE_VAR(var) barrier()
182#endif
183
Rusty Russell6f33d582012-11-22 12:30:25 +1030184/* Not-quite-unique ID. */
185#ifndef __UNIQUE_ID
186# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
187#endif
188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189#endif /* __KERNEL__ */
190
191#endif /* __ASSEMBLY__ */
192
David Woodhouse4f79c3f2006-05-02 10:41:25 +0100193#ifdef __KERNEL__
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194/*
195 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
196 * warning for each use, in hopes of speeding the functions removal.
197 * Usage is:
198 * int __deprecated foo(void)
199 */
200#ifndef __deprecated
201# define __deprecated /* unimplemented */
202#endif
203
Paul E. McKenney512345b2005-05-01 08:59:03 -0700204#ifdef MODULE
205#define __deprecated_for_modules __deprecated
206#else
207#define __deprecated_for_modules
208#endif
209
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210#ifndef __must_check
211#define __must_check
212#endif
213
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700214#ifndef CONFIG_ENABLE_MUST_CHECK
215#undef __must_check
216#define __must_check
217#endif
Jeff Garzikde488442007-10-25 04:06:13 -0400218#ifndef CONFIG_ENABLE_WARN_DEPRECATED
219#undef __deprecated
220#undef __deprecated_for_modules
221#define __deprecated
222#define __deprecated_for_modules
223#endif
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700224
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225/*
226 * Allow us to avoid 'defined but not used' warnings on functions and data,
227 * as well as force them to be emitted to the assembly file.
228 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700229 * As of gcc 3.4, static functions that are not marked with attribute((used))
230 * may be elided from the assembly file. As of gcc 3.4, static data not so
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 * marked will not be elided, but this may change in a future gcc version.
232 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700233 * NOTE: Because distributions shipped with a backported unit-at-a-time
234 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
235 * for gcc >=3.3 instead of 3.4.
236 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 * In prior versions of gcc, such functions and data would be emitted, but
238 * would be warned about except with attribute((unused)).
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700239 *
240 * Mark functions that are referenced only in inline assembly as __used so
241 * the code is emitted even though it appears to be unreferenced.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 */
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700243#ifndef __used
244# define __used /* unimplemented */
245#endif
246
247#ifndef __maybe_unused
248# define __maybe_unused /* unimplemented */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249#endif
250
Li Zefan7b2a3512009-11-02 08:50:52 +0800251#ifndef __always_unused
252# define __always_unused /* unimplemented */
253#endif
254
David Woodhouse423bc7b2006-05-04 00:41:02 +0100255#ifndef noinline
256#define noinline
257#endif
258
Andrew Morton735c4fb2008-03-04 14:28:40 -0800259/*
260 * Rather then using noinline to prevent stack consumption, use
Alexander Steine6be0c92012-02-23 13:42:30 +0100261 * noinline_for_stack instead. For documentation reasons.
Andrew Morton735c4fb2008-03-04 14:28:40 -0800262 */
263#define noinline_for_stack noinline
264
David Woodhouse423bc7b2006-05-04 00:41:02 +0100265#ifndef __always_inline
266#define __always_inline inline
267#endif
268
269#endif /* __KERNEL__ */
270
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271/*
272 * From the GCC manual:
273 *
274 * Many functions do not examine any values except their arguments,
275 * and have no effects except the return value. Basically this is
276 * just slightly more strict class than the `pure' attribute above,
277 * since function is not allowed to read global memory.
278 *
279 * Note that a function that has pointer arguments and examines the
280 * data pointed to must _not_ be declared `const'. Likewise, a
281 * function that calls a non-`const' function usually must not be
282 * `const'. It does not make sense for a `const' function to return
283 * `void'.
284 */
285#ifndef __attribute_const__
286# define __attribute_const__ /* unimplemented */
287#endif
288
Andi Kleena586df02007-07-21 17:10:00 +0200289/*
290 * Tell gcc if a function is cold. The compiler will assume any path
291 * directly leading to the call is unlikely.
292 */
293
294#ifndef __cold
295#define __cold
296#endif
297
Sam Ravnborgf3fe8662008-01-20 18:54:48 +0100298/* Simple shorthand for a section definition */
299#ifndef __section
300# define __section(S) __attribute__ ((__section__(#S)))
301#endif
302
Andi Kleen9a858dc2012-09-17 14:09:15 -0700303#ifndef __visible
304#define __visible
305#endif
306
Rusty Russelld2c123c2009-06-12 21:46:56 -0600307/* Are two types/vars the same type (ignoring qualifiers)? */
308#ifndef __same_type
309# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
310#endif
311
Peter Zijlstra47933ad2013-11-06 14:57:36 +0100312/* Is this type a native word size -- useful for atomic operations */
313#ifndef __native_word
314# define __native_word(t) (sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
315#endif
316
Arjan van de Ven9f0cf4a2009-09-26 14:33:01 +0200317/* Compile time object size, -1 for unknown */
318#ifndef __compiletime_object_size
319# define __compiletime_object_size(obj) -1
320#endif
Arjan van de Ven4a312762009-09-30 13:05:23 +0200321#ifndef __compiletime_warning
322# define __compiletime_warning(message)
323#endif
Arjan van de Ven63312b62009-10-02 07:50:50 -0700324#ifndef __compiletime_error
325# define __compiletime_error(message)
Daniel Santosc361d3e2013-02-21 16:41:54 -0800326# define __compiletime_error_fallback(condition) \
Daniel Santos9a8ab1c2013-02-21 16:41:55 -0800327 do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
Daniel Santosc361d3e2013-02-21 16:41:54 -0800328#else
329# define __compiletime_error_fallback(condition) do { } while (0)
Arjan van de Ven63312b62009-10-02 07:50:50 -0700330#endif
Daniel Santosc361d3e2013-02-21 16:41:54 -0800331
Daniel Santos9a8ab1c2013-02-21 16:41:55 -0800332#define __compiletime_assert(condition, msg, prefix, suffix) \
333 do { \
334 bool __cond = !(condition); \
335 extern void prefix ## suffix(void) __compiletime_error(msg); \
336 if (__cond) \
337 prefix ## suffix(); \
338 __compiletime_error_fallback(__cond); \
339 } while (0)
340
341#define _compiletime_assert(condition, msg, prefix, suffix) \
342 __compiletime_assert(condition, msg, prefix, suffix)
343
344/**
345 * compiletime_assert - break build and emit msg if condition is false
346 * @condition: a compile-time constant condition to check
347 * @msg: a message to emit if condition is false
348 *
349 * In tradition of POSIX assert, this macro will break the build if the
350 * supplied condition is *false*, emitting the supplied error message if the
351 * compiler has support to do so.
352 */
353#define compiletime_assert(condition, msg) \
354 _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
355
Peter Zijlstra47933ad2013-11-06 14:57:36 +0100356#define compiletime_assert_atomic_type(t) \
357 compiletime_assert(__native_word(t), \
358 "Need native word sized stores/loads for atomicity.")
359
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700360/*
361 * Prevent the compiler from merging or refetching accesses. The compiler
362 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
363 * but only when the compiler is aware of some particular ordering. One way
364 * to make the compiler aware of ordering is to put the two invocations of
365 * ACCESS_ONCE() in different C statements.
366 *
367 * This macro does absolutely -nothing- to prevent the CPU from reordering,
Paul E. McKenneyded00a52008-08-17 12:50:36 -0700368 * merging, or refetching absolutely anything at any time. Its main intended
369 * use is to mediate communication between process-level code and irq/NMI
370 * handlers, all running on the same CPU.
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700371 */
372#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
373
Masami Hiramatsu324670b2013-04-04 19:40:50 +0900374/* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
375#ifdef CONFIG_KPROBES
376# define __kprobes __attribute__((__section__(".kprobes.text")))
377#else
378# define __kprobes
379#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380#endif /* __LINUX_COMPILER_H */