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1#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)))
e0fdb0e0 8# define __kernel __attribute__((address_space(0)))
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9# define __safe __attribute__((safe))
10# define __force __attribute__((force))
11# define __nocast __attribute__((nocast))
12# define __iomem __attribute__((noderef, address_space(2)))
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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)
dcc8e559 17# define __cond_lock(x,c) ((c) ? ({ __acquire(x); 1; }) : 0)
e0fdb0e0 18# define __percpu __attribute__((noderef, address_space(3)))
71d1d5c7 19# define __rcu
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20extern void __chk_user_ptr(const volatile void __user *);
21extern void __chk_io_ptr(const volatile void __iomem *);
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22#else
23# define __user
24# define __kernel
25# define __safe
26# define __force
27# define __nocast
28# define __iomem
29# define __chk_user_ptr(x) (void)0
30# define __chk_io_ptr(x) (void)0
31# define __builtin_warning(x, y...) (1)
32# define __acquires(x)
33# define __releases(x)
34# define __acquire(x) (void)0
35# define __release(x) (void)0
dcc8e559 36# define __cond_lock(x,c) (c)
e0fdb0e0 37# define __percpu
71d1d5c7 38# define __rcu
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39#endif
40
41#ifdef __KERNEL__
42
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43#ifdef __GNUC__
44#include <linux/compiler-gcc.h>
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45#endif
46
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47#define notrace __attribute__((no_instrument_function))
48
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49/* Intel compiler defines __GNUC__. So we will overwrite implementations
50 * coming from above header files here
51 */
52#ifdef __INTEL_COMPILER
53# include <linux/compiler-intel.h>
54#endif
55
56/*
57 * Generic compiler-dependent macros required for kernel
58 * build go below this comment. Actual compiler/compiler version
59 * specific implementations come from the above header files
60 */
61
2ed84eeb 62struct ftrace_branch_data {
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63 const char *func;
64 const char *file;
65 unsigned line;
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66 union {
67 struct {
68 unsigned long correct;
69 unsigned long incorrect;
70 };
71 struct {
72 unsigned long miss;
73 unsigned long hit;
74 };
97e7e4f3 75 unsigned long miss_hit[2];
2bcd521a 76 };
1f0d69a9 77};
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78
79/*
80 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
81 * to disable branch tracing on a per file basis.
82 */
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83#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
84 && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
2ed84eeb 85void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
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86
87#define likely_notrace(x) __builtin_expect(!!(x), 1)
88#define unlikely_notrace(x) __builtin_expect(!!(x), 0)
89
45b79749 90#define __branch_check__(x, expect) ({ \
1f0d69a9 91 int ______r; \
2ed84eeb 92 static struct ftrace_branch_data \
1f0d69a9 93 __attribute__((__aligned__(4))) \
45b79749 94 __attribute__((section("_ftrace_annotated_branch"))) \
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95 ______f = { \
96 .func = __func__, \
97 .file = __FILE__, \
98 .line = __LINE__, \
99 }; \
1f0d69a9 100 ______r = likely_notrace(x); \
45b79749 101 ftrace_likely_update(&______f, ______r, expect); \
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102 ______r; \
103 })
104
105/*
106 * Using __builtin_constant_p(x) to ignore cases where the return
107 * value is always the same. This idea is taken from a similar patch
108 * written by Daniel Walker.
109 */
110# ifndef likely
45b79749 111# define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
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112# endif
113# ifndef unlikely
45b79749 114# define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
1f0d69a9 115# endif
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116
117#ifdef CONFIG_PROFILE_ALL_BRANCHES
118/*
119 * "Define 'is'", Bill Clinton
120 * "Define 'if'", Steven Rostedt
121 */
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122#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
123#define __trace_if(cond) \
124 if (__builtin_constant_p((cond)) ? !!(cond) : \
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125 ({ \
126 int ______r; \
127 static struct ftrace_branch_data \
128 __attribute__((__aligned__(4))) \
129 __attribute__((section("_ftrace_branch"))) \
130 ______f = { \
131 .func = __func__, \
132 .file = __FILE__, \
133 .line = __LINE__, \
134 }; \
135 ______r = !!(cond); \
97e7e4f3 136 ______f.miss_hit[______r]++; \
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137 ______r; \
138 }))
139#endif /* CONFIG_PROFILE_ALL_BRANCHES */
140
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141#else
142# define likely(x) __builtin_expect(!!(x), 1)
143# define unlikely(x) __builtin_expect(!!(x), 0)
144#endif
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145
146/* Optimization barrier */
147#ifndef barrier
148# define barrier() __memory_barrier()
149#endif
150
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151/* Unreachable code */
152#ifndef unreachable
153# define unreachable() do { } while (1)
154#endif
155
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156#ifndef RELOC_HIDE
157# define RELOC_HIDE(ptr, off) \
158 ({ unsigned long __ptr; \
159 __ptr = (unsigned long) (ptr); \
160 (typeof(ptr)) (__ptr + (off)); })
161#endif
162
163#endif /* __KERNEL__ */
164
165#endif /* __ASSEMBLY__ */
166
4f79c3ff 167#ifdef __KERNEL__
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168/*
169 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
170 * warning for each use, in hopes of speeding the functions removal.
171 * Usage is:
172 * int __deprecated foo(void)
173 */
174#ifndef __deprecated
175# define __deprecated /* unimplemented */
176#endif
177
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178#ifdef MODULE
179#define __deprecated_for_modules __deprecated
180#else
181#define __deprecated_for_modules
182#endif
183
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184#ifndef __must_check
185#define __must_check
186#endif
187
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188#ifndef CONFIG_ENABLE_MUST_CHECK
189#undef __must_check
190#define __must_check
191#endif
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192#ifndef CONFIG_ENABLE_WARN_DEPRECATED
193#undef __deprecated
194#undef __deprecated_for_modules
195#define __deprecated
196#define __deprecated_for_modules
197#endif
cebc04ba 198
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199/*
200 * Allow us to avoid 'defined but not used' warnings on functions and data,
201 * as well as force them to be emitted to the assembly file.
202 *
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203 * As of gcc 3.4, static functions that are not marked with attribute((used))
204 * may be elided from the assembly file. As of gcc 3.4, static data not so
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205 * marked will not be elided, but this may change in a future gcc version.
206 *
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207 * NOTE: Because distributions shipped with a backported unit-at-a-time
208 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
209 * for gcc >=3.3 instead of 3.4.
210 *
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211 * In prior versions of gcc, such functions and data would be emitted, but
212 * would be warned about except with attribute((unused)).
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213 *
214 * Mark functions that are referenced only in inline assembly as __used so
215 * the code is emitted even though it appears to be unreferenced.
1da177e4 216 */
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217#ifndef __used
218# define __used /* unimplemented */
219#endif
220
221#ifndef __maybe_unused
222# define __maybe_unused /* unimplemented */
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223#endif
224
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225#ifndef __always_unused
226# define __always_unused /* unimplemented */
227#endif
228
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229#ifndef noinline
230#define noinline
231#endif
232
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233/*
234 * Rather then using noinline to prevent stack consumption, use
235 * noinline_for_stack instead. For documentaiton reasons.
236 */
237#define noinline_for_stack noinline
238
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239#ifndef __always_inline
240#define __always_inline inline
241#endif
242
243#endif /* __KERNEL__ */
244
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245/*
246 * From the GCC manual:
247 *
248 * Many functions do not examine any values except their arguments,
249 * and have no effects except the return value. Basically this is
250 * just slightly more strict class than the `pure' attribute above,
251 * since function is not allowed to read global memory.
252 *
253 * Note that a function that has pointer arguments and examines the
254 * data pointed to must _not_ be declared `const'. Likewise, a
255 * function that calls a non-`const' function usually must not be
256 * `const'. It does not make sense for a `const' function to return
257 * `void'.
258 */
259#ifndef __attribute_const__
260# define __attribute_const__ /* unimplemented */
261#endif
262
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263/*
264 * Tell gcc if a function is cold. The compiler will assume any path
265 * directly leading to the call is unlikely.
266 */
267
268#ifndef __cold
269#define __cold
270#endif
271
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272/* Simple shorthand for a section definition */
273#ifndef __section
274# define __section(S) __attribute__ ((__section__(#S)))
275#endif
276
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277/* Are two types/vars the same type (ignoring qualifiers)? */
278#ifndef __same_type
279# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
280#endif
281
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282/* Compile time object size, -1 for unknown */
283#ifndef __compiletime_object_size
284# define __compiletime_object_size(obj) -1
285#endif
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286#ifndef __compiletime_warning
287# define __compiletime_warning(message)
288#endif
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289#ifndef __compiletime_error
290# define __compiletime_error(message)
291#endif
4a312769 292
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293/*
294 * Prevent the compiler from merging or refetching accesses. The compiler
295 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
296 * but only when the compiler is aware of some particular ordering. One way
297 * to make the compiler aware of ordering is to put the two invocations of
298 * ACCESS_ONCE() in different C statements.
299 *
300 * This macro does absolutely -nothing- to prevent the CPU from reordering,
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301 * merging, or refetching absolutely anything at any time. Its main intended
302 * use is to mediate communication between process-level code and irq/NMI
303 * handlers, all running on the same CPU.
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304 */
305#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
306
1da177e4 307#endif /* __LINUX_COMPILER_H */