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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
Andi Kleen21124a82007-05-21 14:31:46 +020039#if __GNUC__ >= 4
Linus Torvalds1da177e2005-04-16 15:20:36 -070040# include <linux/compiler-gcc4.h>
Alistair John Strachan53569ab2006-12-12 19:28:50 +010041#elif __GNUC__ == 3 && __GNUC_MINOR__ >= 2
Linus Torvalds1da177e2005-04-16 15:20:36 -070042# include <linux/compiler-gcc3.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#else
44# error Sorry, your compiler is too old/not recognized.
45#endif
46
47/* 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
60#define likely(x) __builtin_expect(!!(x), 1)
61#define unlikely(x) __builtin_expect(!!(x), 0)
62
63/* Optimization barrier */
64#ifndef barrier
65# define barrier() __memory_barrier()
66#endif
67
68#ifndef RELOC_HIDE
69# define RELOC_HIDE(ptr, off) \
70 ({ unsigned long __ptr; \
71 __ptr = (unsigned long) (ptr); \
72 (typeof(ptr)) (__ptr + (off)); })
73#endif
74
75#endif /* __KERNEL__ */
76
77#endif /* __ASSEMBLY__ */
78
David Woodhouse4f79c3f2006-05-02 10:41:25 +010079#ifdef __KERNEL__
Linus Torvalds1da177e2005-04-16 15:20:36 -070080/*
81 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
82 * warning for each use, in hopes of speeding the functions removal.
83 * Usage is:
84 * int __deprecated foo(void)
85 */
86#ifndef __deprecated
87# define __deprecated /* unimplemented */
88#endif
89
Paul E. McKenney512345b2005-05-01 08:59:03 -070090#ifdef MODULE
91#define __deprecated_for_modules __deprecated
92#else
93#define __deprecated_for_modules
94#endif
95
Linus Torvalds1da177e2005-04-16 15:20:36 -070096#ifndef __must_check
97#define __must_check
98#endif
99
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700100#ifndef CONFIG_ENABLE_MUST_CHECK
101#undef __must_check
102#define __must_check
103#endif
Jeff Garzikde488442007-10-25 04:06:13 -0400104#ifndef CONFIG_ENABLE_WARN_DEPRECATED
105#undef __deprecated
106#undef __deprecated_for_modules
107#define __deprecated
108#define __deprecated_for_modules
109#endif
Andrew Mortoncebc04b2006-08-14 22:43:18 -0700110
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111/*
112 * Allow us to avoid 'defined but not used' warnings on functions and data,
113 * as well as force them to be emitted to the assembly file.
114 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700115 * As of gcc 3.4, static functions that are not marked with attribute((used))
116 * may be elided from the assembly file. As of gcc 3.4, static data not so
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 * marked will not be elided, but this may change in a future gcc version.
118 *
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700119 * NOTE: Because distributions shipped with a backported unit-at-a-time
120 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
121 * for gcc >=3.3 instead of 3.4.
122 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 * In prior versions of gcc, such functions and data would be emitted, but
124 * would be warned about except with attribute((unused)).
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700125 *
126 * Mark functions that are referenced only in inline assembly as __used so
127 * the code is emitted even though it appears to be unreferenced.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 */
David Rientjes0d7ebbb2007-05-09 02:35:27 -0700129#ifndef __used
130# define __used /* unimplemented */
131#endif
132
133#ifndef __maybe_unused
134# define __maybe_unused /* unimplemented */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135#endif
136
David Woodhouse423bc7b2006-05-04 00:41:02 +0100137#ifndef noinline
138#define noinline
139#endif
140
Andrew Morton735c4fb2008-03-04 14:28:40 -0800141/*
142 * Rather then using noinline to prevent stack consumption, use
143 * noinline_for_stack instead. For documentaiton reasons.
144 */
145#define noinline_for_stack noinline
146
David Woodhouse423bc7b2006-05-04 00:41:02 +0100147#ifndef __always_inline
148#define __always_inline inline
149#endif
150
151#endif /* __KERNEL__ */
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153/*
154 * From the GCC manual:
155 *
156 * Many functions do not examine any values except their arguments,
157 * and have no effects except the return value. Basically this is
158 * just slightly more strict class than the `pure' attribute above,
159 * since function is not allowed to read global memory.
160 *
161 * Note that a function that has pointer arguments and examines the
162 * data pointed to must _not_ be declared `const'. Likewise, a
163 * function that calls a non-`const' function usually must not be
164 * `const'. It does not make sense for a `const' function to return
165 * `void'.
166 */
167#ifndef __attribute_const__
168# define __attribute_const__ /* unimplemented */
169#endif
170
Andi Kleena586df02007-07-21 17:10:00 +0200171/*
172 * Tell gcc if a function is cold. The compiler will assume any path
173 * directly leading to the call is unlikely.
174 */
175
176#ifndef __cold
177#define __cold
178#endif
179
Sam Ravnborgf3fe8662008-01-20 18:54:48 +0100180/* Simple shorthand for a section definition */
181#ifndef __section
182# define __section(S) __attribute__ ((__section__(#S)))
183#endif
184
Linus Torvalds9c3cdc12008-05-10 19:51:16 -0700185/*
186 * Prevent the compiler from merging or refetching accesses. The compiler
187 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
188 * but only when the compiler is aware of some particular ordering. One way
189 * to make the compiler aware of ordering is to put the two invocations of
190 * ACCESS_ONCE() in different C statements.
191 *
192 * This macro does absolutely -nothing- to prevent the CPU from reordering,
193 * merging, or refetching absolutely anything at any time.
194 */
195#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
196
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197#endif /* __LINUX_COMPILER_H */