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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)))
8# define __kernel /* default address space */
9# 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)
Al Viroc47ffe32007-07-26 17:35:29 +010018extern void __chk_user_ptr(const volatile void __user *);
19extern void __chk_io_ptr(const volatile void __iomem *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#else
21# define __user
22# define __kernel
23# define __safe
24# define __force
25# define __nocast
26# define __iomem
27# define __chk_user_ptr(x) (void)0
28# define __chk_io_ptr(x) (void)0
29# define __builtin_warning(x, y...) (1)
30# define __acquires(x)
31# define __releases(x)
32# define __acquire(x) (void)0
33# define __release(x) (void)0
Josh Triplettdcc8e552006-09-29 02:01:03 -070034# define __cond_lock(x,c) (c)
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#endif
36
37#ifdef __KERNEL__
38
Linus Torvaldsf153b822009-01-02 09:23:03 -080039#ifdef __GNUC__
40#include <linux/compiler-gcc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#endif
42
Steven Rostedt28614882008-08-14 22:47:18 -040043#define notrace __attribute__((no_instrument_function))
44
Linus Torvalds1da177e2005-04-16 15:20:36 -070045/* Intel compiler defines __GNUC__. So we will overwrite implementations
46 * coming from above header files here
47 */
48#ifdef __INTEL_COMPILER
49# include <linux/compiler-intel.h>
50#endif
51
52/*
53 * Generic compiler-dependent macros required for kernel
54 * build go below this comment. Actual compiler/compiler version
55 * specific implementations come from the above header files
56 */
57
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050058struct ftrace_branch_data {
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050059 const char *func;
60 const char *file;
61 unsigned line;
Steven Rostedt2bcd5212008-11-21 01:30:54 -050062 union {
63 struct {
64 unsigned long correct;
65 unsigned long incorrect;
66 };
67 struct {
68 unsigned long miss;
69 unsigned long hit;
70 };
Witold Baryluk97e7e4f2009-03-17 21:15:44 +010071 unsigned long miss_hit[2];
Steven Rostedt2bcd5212008-11-21 01:30:54 -050072 };
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050073};
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050074
75/*
76 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
77 * to disable branch tracing on a per file basis.
78 */
Bart Van Assched9ad8bc2009-04-05 16:20:02 +020079#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
80 && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050081void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050082
83#define likely_notrace(x) __builtin_expect(!!(x), 1)
84#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
85
Steven Rostedt45b79742008-11-21 00:40:40 -050086#define __branch_check__(x, expect) ({ \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050087 int ______r; \
Steven Rostedt2ed84ee2008-11-12 15:24:24 -050088 static struct ftrace_branch_data \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050089 __attribute__((__aligned__(4))) \
Steven Rostedt45b79742008-11-21 00:40:40 -050090 __attribute__((section("_ftrace_annotated_branch"))) \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050091 ______f = { \
92 .func = __func__, \
93 .file = __FILE__, \
94 .line = __LINE__, \
95 }; \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050096 ______r = likely_notrace(x); \
Steven Rostedt45b79742008-11-21 00:40:40 -050097 ftrace_likely_update(&______f, ______r, expect); \
Steven Rostedt1f0d69a2008-11-12 00:14:39 -050098 ______r; \
99 })
100
101/*
102 * Using __builtin_constant_p(x) to ignore cases where the return
103 * value is always the same. This idea is taken from a similar patch
104 * written by Daniel Walker.
105 */
106# ifndef likely
Steven Rostedt45b79742008-11-21 00:40:40 -0500107# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500108# endif
109# ifndef unlikely
Steven Rostedt45b79742008-11-21 00:40:40 -0500110# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500111# endif
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500112
113#ifdef CONFIG_PROFILE_ALL_BRANCHES
114/*
115 * "Define 'is'", Bill Clinton
116 * "Define 'if'", Steven Rostedt
117 */
Linus Torvaldsab3c9c62009-04-07 07:59:41 -0700118#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
119#define __trace_if(cond) \
120 if (__builtin_constant_p((cond)) ? !!(cond) : \
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500121 ({ \
122 int ______r; \
123 static struct ftrace_branch_data \
124 __attribute__((__aligned__(4))) \
125 __attribute__((section("_ftrace_branch"))) \
126 ______f = { \
127 .func = __func__, \
128 .file = __FILE__, \
129 .line = __LINE__, \
130 }; \
131 ______r = !!(cond); \
Witold Baryluk97e7e4f2009-03-17 21:15:44 +0100132 ______f.miss_hit[______r]++; \
Steven Rostedt2bcd5212008-11-21 01:30:54 -0500133 ______r; \
134 }))
135#endif /* CONFIG_PROFILE_ALL_BRANCHES */
136
Steven Rostedt1f0d69a2008-11-12 00:14:39 -0500137#else
138# define likely(x) __builtin_expect(!!(x), 1)
139# define unlikely(x) __builtin_expect(!!(x), 0)
140#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
142/* Optimization barrier */
143#ifndef barrier
144# define barrier() __memory_barrier()
145#endif
146
147#ifndef RELOC_HIDE
148# define RELOC_HIDE(ptr, off) \
149 ({ unsigned long __ptr; \
150 __ptr = (unsigned long) (ptr); \
151 (typeof(ptr)) (__ptr + (off)); })
152#endif
153
154#endif /* __KERNEL__ */
155
156#endif /* __ASSEMBLY__ */
157
David Woodhouse4f79c3f2006-05-02 10:41:25 +0100158#ifdef __KERNEL__
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159/*
160 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
161 * warning for each use, in hopes of speeding the functions removal.
162 * Usage is:
163 * int __deprecated foo(void)
164 */
165#ifndef __deprecated
166# define __deprecated /* unimplemented */
167#endif
168
Paul E. McKenney512345b2005-05-01 08:59:03 -0700169#ifdef MODULE
170#define __deprecated_for_modules __deprecated
171#else
172#define __deprecated_for_modules
173#endif
174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175#ifndef __must_check
176#define __must_check
177#endif
178
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700179#ifndef CONFIG_ENABLE_MUST_CHECK
180#undef __must_check
181#define __must_check
182#endif
Jeff Garzikde488442007-10-25 04:06:13 -0400183#ifndef CONFIG_ENABLE_WARN_DEPRECATED
184#undef __deprecated
185#undef __deprecated_for_modules
186#define __deprecated
187#define __deprecated_for_modules
188#endif
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190/*
191 * Allow us to avoid 'defined but not used' warnings on functions and data,
192 * as well as force them to be emitted to the assembly file.
193 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700194 * As of gcc 3.4, static functions that are not marked with attribute((used))
195 * may be elided from the assembly file. As of gcc 3.4, static data not so
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 * marked will not be elided, but this may change in a future gcc version.
197 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700198 * NOTE: Because distributions shipped with a backported unit-at-a-time
199 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
200 * for gcc >=3.3 instead of 3.4.
201 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 * In prior versions of gcc, such functions and data would be emitted, but
203 * would be warned about except with attribute((unused)).
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700204 *
205 * Mark functions that are referenced only in inline assembly as __used so
206 * the code is emitted even though it appears to be unreferenced.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 */
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700208#ifndef __used
209# define __used /* unimplemented */
210#endif
211
212#ifndef __maybe_unused
213# define __maybe_unused /* unimplemented */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214#endif
215
David Woodhouse423bc7b2006-05-04 00:41:02 +0100216#ifndef noinline
217#define noinline
218#endif
219
Andrew Morton735c4fb2008-03-04 14:28:40 -0800220/*
221 * Rather then using noinline to prevent stack consumption, use
222 * noinline_for_stack instead. For documentaiton reasons.
223 */
224#define noinline_for_stack noinline
225
David Woodhouse423bc7b2006-05-04 00:41:02 +0100226#ifndef __always_inline
227#define __always_inline inline
228#endif
229
230#endif /* __KERNEL__ */
231
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232/*
233 * From the GCC manual:
234 *
235 * Many functions do not examine any values except their arguments,
236 * and have no effects except the return value. Basically this is
237 * just slightly more strict class than the `pure' attribute above,
238 * since function is not allowed to read global memory.
239 *
240 * Note that a function that has pointer arguments and examines the
241 * data pointed to must _not_ be declared `const'. Likewise, a
242 * function that calls a non-`const' function usually must not be
243 * `const'. It does not make sense for a `const' function to return
244 * `void'.
245 */
246#ifndef __attribute_const__
247# define __attribute_const__ /* unimplemented */
248#endif
249
Andi Kleena586df02007-07-21 17:10:00 +0200250/*
251 * Tell gcc if a function is cold. The compiler will assume any path
252 * directly leading to the call is unlikely.
253 */
254
255#ifndef __cold
256#define __cold
257#endif
258
Sam Ravnborgf3fe8662008-01-20 18:54:48 +0100259/* Simple shorthand for a section definition */
260#ifndef __section
261# define __section(S) __attribute__ ((__section__(#S)))
262#endif
263
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700264/*
265 * Prevent the compiler from merging or refetching accesses. The compiler
266 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
267 * but only when the compiler is aware of some particular ordering. One way
268 * to make the compiler aware of ordering is to put the two invocations of
269 * ACCESS_ONCE() in different C statements.
270 *
271 * This macro does absolutely -nothing- to prevent the CPU from reordering,
Paul E. McKenneyded00a52008-08-17 12:50:36 -0700272 * merging, or refetching absolutely anything at any time. Its main intended
273 * use is to mediate communication between process-level code and irq/NMI
274 * handlers, all running on the same CPU.
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700275 */
276#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
277
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278#endif /* __LINUX_COMPILER_H */