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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
66/*
67 * Generic compiler-dependent macros required for kernel
68 * build go below this comment. Actual compiler/compiler version
69 * specific implementations come from the above header files
70 */
71
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050072struct ftrace_branch_data {
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050073 const char *func;
74 const char *file;
75 unsigned line;
Steven Rostedt2bcd5212008-11-21 01:30:54 -050076 union {
77 struct {
78 unsigned long correct;
79 unsigned long incorrect;
80 };
81 struct {
82 unsigned long miss;
83 unsigned long hit;
84 };
Witold Baryluk97e7e4f2009-03-17 21:15:44 +010085 unsigned long miss_hit[2];
Steven Rostedt2bcd5212008-11-21 01:30:54 -050086 };
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050087};
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050088
89/*
90 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
91 * to disable branch tracing on a per file basis.
92 */
Bart Van Assched9ad8bc2009-04-05 16:20:02 +020093#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
94 && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050095void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050096
97#define likely_notrace(x) __builtin_expect(!!(x), 1)
98#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
99
Steven Rostedt45b79742008-11-21 00:40:40 -0500100#define __branch_check__(x, expect) ({ \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500101 int ______r; \
Steven Rostedt2ed84ee2008-11-12 15:24:24 -0500102 static struct ftrace_branch_data \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500103 __attribute__((__aligned__(4))) \
Steven Rostedt45b79742008-11-21 00:40:40 -0500104 __attribute__((section("_ftrace_annotated_branch"))) \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500105 ______f = { \
106 .func = __func__, \
107 .file = __FILE__, \
108 .line = __LINE__, \
109 }; \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500110 ______r = likely_notrace(x); \
Steven Rostedt45b79742008-11-21 00:40:40 -0500111 ftrace_likely_update(&______f, ______r, expect); \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500112 ______r; \
113 })
114
115/*
116 * Using __builtin_constant_p(x) to ignore cases where the return
117 * value is always the same. This idea is taken from a similar patch
118 * written by Daniel Walker.
119 */
120# ifndef likely
Steven Rostedt45b79742008-11-21 00:40:40 -0500121# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500122# endif
123# ifndef unlikely
Steven Rostedt45b79742008-11-21 00:40:40 -0500124# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500125# endif
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500126
127#ifdef CONFIG_PROFILE_ALL_BRANCHES
128/*
129 * "Define 'is'", Bill Clinton
130 * "Define 'if'", Steven Rostedt
131 */
Linus Torvaldsab3c9c62009-04-07 07:59:41 -0700132#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
133#define __trace_if(cond) \
134 if (__builtin_constant_p((cond)) ? !!(cond) : \
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500135 ({ \
136 int ______r; \
137 static struct ftrace_branch_data \
138 __attribute__((__aligned__(4))) \
139 __attribute__((section("_ftrace_branch"))) \
140 ______f = { \
141 .func = __func__, \
142 .file = __FILE__, \
143 .line = __LINE__, \
144 }; \
145 ______r = !!(cond); \
Witold Baryluk97e7e4f2009-03-17 21:15:44 +0100146 ______f.miss_hit[______r]++; \
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500147 ______r; \
148 }))
149#endif /* CONFIG_PROFILE_ALL_BRANCHES */
150
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500151#else
152# define likely(x) __builtin_expect(!!(x), 1)
153# define unlikely(x) __builtin_expect(!!(x), 0)
154#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156/* Optimization barrier */
157#ifndef barrier
158# define barrier() __memory_barrier()
159#endif
160
David Daney38938c82009-12-04 17:44:50 -0800161/* Unreachable code */
162#ifndef unreachable
163# define unreachable() do { } while (1)
164#endif
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166#ifndef RELOC_HIDE
167# define RELOC_HIDE(ptr, off) \
168 ({ unsigned long __ptr; \
169 __ptr = (unsigned long) (ptr); \
170 (typeof(ptr)) (__ptr + (off)); })
171#endif
172
Rusty Russell6f33d582012-11-22 12:30:25 +1030173/* Not-quite-unique ID. */
174#ifndef __UNIQUE_ID
175# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
176#endif
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178#endif /* __KERNEL__ */
179
180#endif /* __ASSEMBLY__ */
181
David Woodhouse4f79c3f2006-05-02 10:41:25 +0100182#ifdef __KERNEL__
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183/*
184 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
185 * warning for each use, in hopes of speeding the functions removal.
186 * Usage is:
187 * int __deprecated foo(void)
188 */
189#ifndef __deprecated
190# define __deprecated /* unimplemented */
191#endif
192
Paul E. McKenney512345b2005-05-01 08:59:03 -0700193#ifdef MODULE
194#define __deprecated_for_modules __deprecated
195#else
196#define __deprecated_for_modules
197#endif
198
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199#ifndef __must_check
200#define __must_check
201#endif
202
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700203#ifndef CONFIG_ENABLE_MUST_CHECK
204#undef __must_check
205#define __must_check
206#endif
Jeff Garzikde488442007-10-25 04:06:13 -0400207#ifndef CONFIG_ENABLE_WARN_DEPRECATED
208#undef __deprecated
209#undef __deprecated_for_modules
210#define __deprecated
211#define __deprecated_for_modules
212#endif
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214/*
215 * Allow us to avoid 'defined but not used' warnings on functions and data,
216 * as well as force them to be emitted to the assembly file.
217 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700218 * As of gcc 3.4, static functions that are not marked with attribute((used))
219 * may be elided from the assembly file. As of gcc 3.4, static data not so
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 * marked will not be elided, but this may change in a future gcc version.
221 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700222 * NOTE: Because distributions shipped with a backported unit-at-a-time
223 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
224 * for gcc >=3.3 instead of 3.4.
225 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 * In prior versions of gcc, such functions and data would be emitted, but
227 * would be warned about except with attribute((unused)).
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700228 *
229 * Mark functions that are referenced only in inline assembly as __used so
230 * the code is emitted even though it appears to be unreferenced.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 */
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700232#ifndef __used
233# define __used /* unimplemented */
234#endif
235
236#ifndef __maybe_unused
237# define __maybe_unused /* unimplemented */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238#endif
239
Li Zefan7b2a3512009-11-02 08:50:52 +0800240#ifndef __always_unused
241# define __always_unused /* unimplemented */
242#endif
243
David Woodhouse423bc7b2006-05-04 00:41:02 +0100244#ifndef noinline
245#define noinline
246#endif
247
Andrew Morton735c4fb2008-03-04 14:28:40 -0800248/*
249 * Rather then using noinline to prevent stack consumption, use
Alexander Steine6be0c92012-02-23 13:42:30 +0100250 * noinline_for_stack instead. For documentation reasons.
Andrew Morton735c4fb2008-03-04 14:28:40 -0800251 */
252#define noinline_for_stack noinline
253
David Woodhouse423bc7b2006-05-04 00:41:02 +0100254#ifndef __always_inline
255#define __always_inline inline
256#endif
257
258#endif /* __KERNEL__ */
259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260/*
261 * From the GCC manual:
262 *
263 * Many functions do not examine any values except their arguments,
264 * and have no effects except the return value. Basically this is
265 * just slightly more strict class than the `pure' attribute above,
266 * since function is not allowed to read global memory.
267 *
268 * Note that a function that has pointer arguments and examines the
269 * data pointed to must _not_ be declared `const'. Likewise, a
270 * function that calls a non-`const' function usually must not be
271 * `const'. It does not make sense for a `const' function to return
272 * `void'.
273 */
274#ifndef __attribute_const__
275# define __attribute_const__ /* unimplemented */
276#endif
277
Andi Kleena586df02007-07-21 17:10:00 +0200278/*
279 * Tell gcc if a function is cold. The compiler will assume any path
280 * directly leading to the call is unlikely.
281 */
282
283#ifndef __cold
284#define __cold
285#endif
286
Sam Ravnborgf3fe8662008-01-20 18:54:48 +0100287/* Simple shorthand for a section definition */
288#ifndef __section
289# define __section(S) __attribute__ ((__section__(#S)))
290#endif
291
Andi Kleen9a858dc2012-09-17 14:09:15 -0700292#ifndef __visible
293#define __visible
294#endif
295
Rusty Russelld2c123c2009-06-12 21:46:56 -0600296/* Are two types/vars the same type (ignoring qualifiers)? */
297#ifndef __same_type
298# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
299#endif
300
Peter Zijlstra47933ad2013-11-06 14:57:36 +0100301/* Is this type a native word size -- useful for atomic operations */
302#ifndef __native_word
303# define __native_word(t) (sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
304#endif
305
Arjan van de Ven9f0cf4a2009-09-26 14:33:01 +0200306/* Compile time object size, -1 for unknown */
307#ifndef __compiletime_object_size
308# define __compiletime_object_size(obj) -1
309#endif
Arjan van de Ven4a312762009-09-30 13:05:23 +0200310#ifndef __compiletime_warning
311# define __compiletime_warning(message)
312#endif
Arjan van de Ven63312b62009-10-02 07:50:50 -0700313#ifndef __compiletime_error
314# define __compiletime_error(message)
Daniel Santosc361d3e2013-02-21 16:41:54 -0800315# define __compiletime_error_fallback(condition) \
Daniel Santos9a8ab1c2013-02-21 16:41:55 -0800316 do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
Daniel Santosc361d3e2013-02-21 16:41:54 -0800317#else
318# define __compiletime_error_fallback(condition) do { } while (0)
Arjan van de Ven63312b62009-10-02 07:50:50 -0700319#endif
Daniel Santosc361d3e2013-02-21 16:41:54 -0800320
Daniel Santos9a8ab1c2013-02-21 16:41:55 -0800321#define __compiletime_assert(condition, msg, prefix, suffix) \
322 do { \
323 bool __cond = !(condition); \
324 extern void prefix ## suffix(void) __compiletime_error(msg); \
325 if (__cond) \
326 prefix ## suffix(); \
327 __compiletime_error_fallback(__cond); \
328 } while (0)
329
330#define _compiletime_assert(condition, msg, prefix, suffix) \
331 __compiletime_assert(condition, msg, prefix, suffix)
332
333/**
334 * compiletime_assert - break build and emit msg if condition is false
335 * @condition: a compile-time constant condition to check
336 * @msg: a message to emit if condition is false
337 *
338 * In tradition of POSIX assert, this macro will break the build if the
339 * supplied condition is *false*, emitting the supplied error message if the
340 * compiler has support to do so.
341 */
342#define compiletime_assert(condition, msg) \
343 _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
344
Peter Zijlstra47933ad2013-11-06 14:57:36 +0100345#define compiletime_assert_atomic_type(t) \
346 compiletime_assert(__native_word(t), \
347 "Need native word sized stores/loads for atomicity.")
348
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700349/*
350 * Prevent the compiler from merging or refetching accesses. The compiler
351 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
352 * but only when the compiler is aware of some particular ordering. One way
353 * to make the compiler aware of ordering is to put the two invocations of
354 * ACCESS_ONCE() in different C statements.
355 *
356 * This macro does absolutely -nothing- to prevent the CPU from reordering,
Paul E. McKenneyded00a52008-08-17 12:50:36 -0700357 * merging, or refetching absolutely anything at any time. Its main intended
358 * use is to mediate communication between process-level code and irq/NMI
359 * handlers, all running on the same CPU.
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700360 */
361#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
362
Masami Hiramatsu324670b2013-04-04 19:40:50 +0900363/* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
364#ifdef CONFIG_KPROBES
365# define __kprobes __attribute__((__section__(".kprobes.text")))
366#else
367# define __kprobes
368#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369#endif /* __LINUX_COMPILER_H */