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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 Triplettc902e0a2006-09-30 23:28:21 -070013# 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)
Josh Triplettdcc8e552006-09-29 02:01:03 -070017# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
Rusty Russelle0fdb0e2009-10-29 22:34:15 +090018# define __percpu __attribute__((noderef, address_space(3)))
Al Viroc47ffe32007-07-26 17:35:29 +010019extern void __chk_user_ptr(const volatile void __user *);
20extern void __chk_io_ptr(const volatile void __iomem *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#else
22# define __user
23# define __kernel
24# define __safe
25# define __force
26# define __nocast
27# define __iomem
28# define __chk_user_ptr(x) (void)0
29# define __chk_io_ptr(x) (void)0
30# define __builtin_warning(x, y...) (1)
31# define __acquires(x)
32# define __releases(x)
33# define __acquire(x) (void)0
34# define __release(x) (void)0
Josh Triplettdcc8e552006-09-29 02:01:03 -070035# define __cond_lock(x,c) (c)
Rusty Russelle0fdb0e2009-10-29 22:34:15 +090036# define __percpu
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#endif
38
39#ifdef __KERNEL__
40
Linus Torvaldsf153b822009-01-02 09:23:03 -080041#ifdef __GNUC__
42#include <linux/compiler-gcc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#endif
44
Steven Rostedt28614882008-08-14 22:47:18 -040045#define notrace __attribute__((no_instrument_function))
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047/* Intel compiler defines __GNUC__. So we will overwrite implementations
48 * coming from above header files here
49 */
50#ifdef __INTEL_COMPILER
51# include <linux/compiler-intel.h>
52#endif
53
54/*
55 * Generic compiler-dependent macros required for kernel
56 * build go below this comment. Actual compiler/compiler version
57 * specific implementations come from the above header files
58 */
59
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050060struct ftrace_branch_data {
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050061 const char *func;
62 const char *file;
63 unsigned line;
Steven Rostedt2bcd5212008-11-21 01:30:54 -050064 union {
65 struct {
66 unsigned long correct;
67 unsigned long incorrect;
68 };
69 struct {
70 unsigned long miss;
71 unsigned long hit;
72 };
Witold Baryluk97e7e4f2009-03-17 21:15:44 +010073 unsigned long miss_hit[2];
Steven Rostedt2bcd5212008-11-21 01:30:54 -050074 };
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050075};
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050076
77/*
78 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
79 * to disable branch tracing on a per file basis.
80 */
Bart Van Assched9ad8bc2009-04-05 16:20:02 +020081#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
82 && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050083void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050084
85#define likely_notrace(x) __builtin_expect(!!(x), 1)
86#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
87
Steven Rostedt45b79742008-11-21 00:40:40 -050088#define __branch_check__(x, expect) ({ \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050089 int ______r; \
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050090 static struct ftrace_branch_data \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050091 __attribute__((__aligned__(4))) \
Steven Rostedt45b79742008-11-21 00:40:40 -050092 __attribute__((section("_ftrace_annotated_branch"))) \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050093 ______f = { \
94 .func = __func__, \
95 .file = __FILE__, \
96 .line = __LINE__, \
97 }; \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050098 ______r = likely_notrace(x); \
Steven Rostedt45b79742008-11-21 00:40:40 -050099 ftrace_likely_update(&______f, ______r, expect); \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500100 ______r; \
101 })
102
103/*
104 * Using __builtin_constant_p(x) to ignore cases where the return
105 * value is always the same. This idea is taken from a similar patch
106 * written by Daniel Walker.
107 */
108# ifndef likely
Steven Rostedt45b79742008-11-21 00:40:40 -0500109# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500110# endif
111# ifndef unlikely
Steven Rostedt45b79742008-11-21 00:40:40 -0500112# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500113# endif
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500114
115#ifdef CONFIG_PROFILE_ALL_BRANCHES
116/*
117 * "Define 'is'", Bill Clinton
118 * "Define 'if'", Steven Rostedt
119 */
Linus Torvaldsab3c9c62009-04-07 07:59:41 -0700120#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
121#define __trace_if(cond) \
122 if (__builtin_constant_p((cond)) ? !!(cond) : \
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500123 ({ \
124 int ______r; \
125 static struct ftrace_branch_data \
126 __attribute__((__aligned__(4))) \
127 __attribute__((section("_ftrace_branch"))) \
128 ______f = { \
129 .func = __func__, \
130 .file = __FILE__, \
131 .line = __LINE__, \
132 }; \
133 ______r = !!(cond); \
Witold Baryluk97e7e4f2009-03-17 21:15:44 +0100134 ______f.miss_hit[______r]++; \
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500135 ______r; \
136 }))
137#endif /* CONFIG_PROFILE_ALL_BRANCHES */
138
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500139#else
140# define likely(x) __builtin_expect(!!(x), 1)
141# define unlikely(x) __builtin_expect(!!(x), 0)
142#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144/* Optimization barrier */
145#ifndef barrier
146# define barrier() __memory_barrier()
147#endif
148
149#ifndef RELOC_HIDE
150# define RELOC_HIDE(ptr, off) \
151 ({ unsigned long __ptr; \
152 __ptr = (unsigned long) (ptr); \
153 (typeof(ptr)) (__ptr + (off)); })
154#endif
155
156#endif /* __KERNEL__ */
157
158#endif /* __ASSEMBLY__ */
159
David Woodhouse4f79c3f2006-05-02 10:41:25 +0100160#ifdef __KERNEL__
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161/*
162 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
163 * warning for each use, in hopes of speeding the functions removal.
164 * Usage is:
165 * int __deprecated foo(void)
166 */
167#ifndef __deprecated
168# define __deprecated /* unimplemented */
169#endif
170
Paul E. McKenney512345b2005-05-01 08:59:03 -0700171#ifdef MODULE
172#define __deprecated_for_modules __deprecated
173#else
174#define __deprecated_for_modules
175#endif
176
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177#ifndef __must_check
178#define __must_check
179#endif
180
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700181#ifndef CONFIG_ENABLE_MUST_CHECK
182#undef __must_check
183#define __must_check
184#endif
Jeff Garzikde488442007-10-25 04:06:13 -0400185#ifndef CONFIG_ENABLE_WARN_DEPRECATED
186#undef __deprecated
187#undef __deprecated_for_modules
188#define __deprecated
189#define __deprecated_for_modules
190#endif
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192/*
193 * Allow us to avoid 'defined but not used' warnings on functions and data,
194 * as well as force them to be emitted to the assembly file.
195 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700196 * As of gcc 3.4, static functions that are not marked with attribute((used))
197 * may be elided from the assembly file. As of gcc 3.4, static data not so
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 * marked will not be elided, but this may change in a future gcc version.
199 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700200 * NOTE: Because distributions shipped with a backported unit-at-a-time
201 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
202 * for gcc >=3.3 instead of 3.4.
203 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 * In prior versions of gcc, such functions and data would be emitted, but
205 * would be warned about except with attribute((unused)).
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700206 *
207 * Mark functions that are referenced only in inline assembly as __used so
208 * the code is emitted even though it appears to be unreferenced.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 */
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700210#ifndef __used
211# define __used /* unimplemented */
212#endif
213
214#ifndef __maybe_unused
215# define __maybe_unused /* unimplemented */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216#endif
217
David Woodhouse423bc7b2006-05-04 00:41:02 +0100218#ifndef noinline
219#define noinline
220#endif
221
Andrew Morton735c4fb2008-03-04 14:28:40 -0800222/*
223 * Rather then using noinline to prevent stack consumption, use
224 * noinline_for_stack instead. For documentaiton reasons.
225 */
226#define noinline_for_stack noinline
227
David Woodhouse423bc7b2006-05-04 00:41:02 +0100228#ifndef __always_inline
229#define __always_inline inline
230#endif
231
232#endif /* __KERNEL__ */
233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234/*
235 * From the GCC manual:
236 *
237 * Many functions do not examine any values except their arguments,
238 * and have no effects except the return value. Basically this is
239 * just slightly more strict class than the `pure' attribute above,
240 * since function is not allowed to read global memory.
241 *
242 * Note that a function that has pointer arguments and examines the
243 * data pointed to must _not_ be declared `const'. Likewise, a
244 * function that calls a non-`const' function usually must not be
245 * `const'. It does not make sense for a `const' function to return
246 * `void'.
247 */
248#ifndef __attribute_const__
249# define __attribute_const__ /* unimplemented */
250#endif
251
Andi Kleena586df02007-07-21 17:10:00 +0200252/*
253 * Tell gcc if a function is cold. The compiler will assume any path
254 * directly leading to the call is unlikely.
255 */
256
257#ifndef __cold
258#define __cold
259#endif
260
Sam Ravnborgf3fe8662008-01-20 18:54:48 +0100261/* Simple shorthand for a section definition */
262#ifndef __section
263# define __section(S) __attribute__ ((__section__(#S)))
264#endif
265
Rusty Russelld2c123c2009-06-12 21:46:56 -0600266/* Are two types/vars the same type (ignoring qualifiers)? */
267#ifndef __same_type
268# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
269#endif
270
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700271/*
272 * Prevent the compiler from merging or refetching accesses. The compiler
273 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
274 * but only when the compiler is aware of some particular ordering. One way
275 * to make the compiler aware of ordering is to put the two invocations of
276 * ACCESS_ONCE() in different C statements.
277 *
278 * This macro does absolutely -nothing- to prevent the CPU from reordering,
Paul E. McKenneyded00a52008-08-17 12:50:36 -0700279 * merging, or refetching absolutely anything at any time. Its main intended
280 * use is to mediate communication between process-level code and irq/NMI
281 * handlers, all running on the same CPU.
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700282 */
283#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
284
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285#endif /* __LINUX_COMPILER_H */