blob: 5be3dab4a69547bf6bb378a45d73e553166c5b12 [file] [log] [blame]
Graeme Russ95ffaba2010-04-24 00:05:49 +10001#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)))
13# 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)
17# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
18extern void __chk_user_ptr(const volatile void __user *);
19extern void __chk_io_ptr(const volatile void __iomem *);
20#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
34# define __cond_lock(x,c) (c)
35#endif
36
37#ifdef __KERNEL__
38
39#ifdef __GNUC__
40#include <linux/compiler-gcc.h>
41#endif
42
43#define notrace __attribute__((no_instrument_function))
44
45/* 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
58struct ftrace_branch_data {
59 const char *func;
60 const char *file;
61 unsigned line;
62 union {
63 struct {
64 unsigned long correct;
65 unsigned long incorrect;
66 };
67 struct {
68 unsigned long miss;
69 unsigned long hit;
70 };
71 unsigned long miss_hit[2];
72 };
73};
74
75/*
76 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
77 * to disable branch tracing on a per file basis.
78 */
79#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
80 && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
81void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
82
83#define likely_notrace(x) __builtin_expect(!!(x), 1)
84#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
85
86#define __branch_check__(x, expect) ({ \
87 int ______r; \
88 static struct ftrace_branch_data \
89 __attribute__((__aligned__(4))) \
90 __attribute__((section("_ftrace_annotated_branch"))) \
91 ______f = { \
92 .func = __func__, \
93 .file = __FILE__, \
94 .line = __LINE__, \
95 }; \
96 ______r = likely_notrace(x); \
97 ftrace_likely_update(&______f, ______r, expect); \
98 ______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
107# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
108# endif
109# ifndef unlikely
110# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
111# endif
112
113#ifdef CONFIG_PROFILE_ALL_BRANCHES
114/*
115 * "Define 'is'", Bill Clinton
116 * "Define 'if'", Steven Rostedt
117 */
118#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
119#define __trace_if(cond) \
120 if (__builtin_constant_p((cond)) ? !!(cond) : \
121 ({ \
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); \
132 ______f.miss_hit[______r]++; \
133 ______r; \
134 }))
135#endif /* CONFIG_PROFILE_ALL_BRANCHES */
136
137#else
138# define likely(x) __builtin_expect(!!(x), 1)
139# define unlikely(x) __builtin_expect(!!(x), 0)
140#endif
141
142/* Optimization barrier */
143#ifndef barrier
144# define barrier() __memory_barrier()
145#endif
146
147/* Unreachable code */
148#ifndef unreachable
149# define unreachable() do { } while (1)
150#endif
151
152#ifndef RELOC_HIDE
153# define RELOC_HIDE(ptr, off) \
154 ({ unsigned long __ptr; \
155 __ptr = (unsigned long) (ptr); \
156 (typeof(ptr)) (__ptr + (off)); })
157#endif
158
159#endif /* __KERNEL__ */
160
161#endif /* __ASSEMBLY__ */
162
163#ifdef __KERNEL__
164/*
165 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
166 * warning for each use, in hopes of speeding the functions removal.
167 * Usage is:
168 * int __deprecated foo(void)
169 */
170#ifndef __deprecated
171# define __deprecated /* unimplemented */
172#endif
173
174#ifdef MODULE
175#define __deprecated_for_modules __deprecated
176#else
177#define __deprecated_for_modules
178#endif
179
180#ifndef __must_check
181#define __must_check
182#endif
183
184#ifndef CONFIG_ENABLE_MUST_CHECK
185#undef __must_check
186#define __must_check
187#endif
188#ifndef CONFIG_ENABLE_WARN_DEPRECATED
189#undef __deprecated
190#undef __deprecated_for_modules
191#define __deprecated
192#define __deprecated_for_modules
193#endif
194
195/*
196 * Allow us to avoid 'defined but not used' warnings on functions and data,
197 * as well as force them to be emitted to the assembly file.
198 *
199 * As of gcc 3.4, static functions that are not marked with attribute((used))
200 * may be elided from the assembly file. As of gcc 3.4, static data not so
201 * marked will not be elided, but this may change in a future gcc version.
202 *
203 * NOTE: Because distributions shipped with a backported unit-at-a-time
204 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
205 * for gcc >=3.3 instead of 3.4.
206 *
207 * In prior versions of gcc, such functions and data would be emitted, but
208 * would be warned about except with attribute((unused)).
209 *
210 * Mark functions that are referenced only in inline assembly as __used so
211 * the code is emitted even though it appears to be unreferenced.
212 */
213#ifndef __used
214# define __used /* unimplemented */
215#endif
216
217#ifndef __maybe_unused
218# define __maybe_unused /* unimplemented */
219#endif
220
221#ifndef __always_unused
222# define __always_unused /* unimplemented */
223#endif
224
225#ifndef noinline
226#define noinline
227#endif
228
229/*
230 * Rather then using noinline to prevent stack consumption, use
231 * noinline_for_stack instead. For documentaiton reasons.
232 */
233#define noinline_for_stack noinline
234
235#ifndef __always_inline
236#define __always_inline inline
237#endif
238
239#endif /* __KERNEL__ */
240
241/*
242 * From the GCC manual:
243 *
244 * Many functions do not examine any values except their arguments,
245 * and have no effects except the return value. Basically this is
246 * just slightly more strict class than the `pure' attribute above,
247 * since function is not allowed to read global memory.
248 *
249 * Note that a function that has pointer arguments and examines the
250 * data pointed to must _not_ be declared `const'. Likewise, a
251 * function that calls a non-`const' function usually must not be
252 * `const'. It does not make sense for a `const' function to return
253 * `void'.
254 */
255#ifndef __attribute_const__
256# define __attribute_const__ /* unimplemented */
257#endif
258
259/*
260 * Tell gcc if a function is cold. The compiler will assume any path
261 * directly leading to the call is unlikely.
262 */
263
264#ifndef __cold
265#define __cold
266#endif
267
268/* Simple shorthand for a section definition */
269#ifndef __section
270# define __section(S) __attribute__ ((__section__(#S)))
271#endif
272
273/* Are two types/vars the same type (ignoring qualifiers)? */
274#ifndef __same_type
275# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
276#endif
277
278/* Compile time object size, -1 for unknown */
279#ifndef __compiletime_object_size
280# define __compiletime_object_size(obj) -1
281#endif
282#ifndef __compiletime_warning
283# define __compiletime_warning(message)
284#endif
285#ifndef __compiletime_error
286# define __compiletime_error(message)
287#endif
288
289/*
290 * Prevent the compiler from merging or refetching accesses. The compiler
291 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
292 * but only when the compiler is aware of some particular ordering. One way
293 * to make the compiler aware of ordering is to put the two invocations of
294 * ACCESS_ONCE() in different C statements.
295 *
296 * This macro does absolutely -nothing- to prevent the CPU from reordering,
297 * merging, or refetching absolutely anything at any time. Its main intended
298 * use is to mediate communication between process-level code and irq/NMI
299 * handlers, all running on the same CPU.
300 */
301#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
302
303#endif /* __LINUX_COMPILER_H */