1 #ifndef __LINUX_COMPILER_H
2 #define __LINUX_COMPILER_H
7 # define __user __attribute__((noderef, address_space(1)))
8 # define __kernel __attribute__((address_space(0)))
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)
18 # define __percpu __attribute__((noderef, address_space(3)))
19 #ifdef CONFIG_SPARSE_RCU_POINTER
20 # define __rcu __attribute__((noderef, address_space(4)))
24 extern void __chk_user_ptr(const volatile void __user *);
25 extern void __chk_io_ptr(const volatile void __iomem *);
33 # define __chk_user_ptr(x) (void)0
34 # define __chk_io_ptr(x) (void)0
35 # define __builtin_warning(x, y...) (1)
36 # define __acquires(x)
37 # define __releases(x)
38 # define __acquire(x) (void)0
39 # define __release(x) (void)0
40 # define __cond_lock(x,c) (c)
45 /* Indirect macros required for expanded argument pasting, eg. __LINE__. */
46 #define ___PASTE(a,b) a##b
47 #define __PASTE(a,b) ___PASTE(a,b)
52 #include <linux/compiler-gcc.h>
55 #define notrace __attribute__((no_instrument_function))
57 /* Intel compiler defines __GNUC__. So we will overwrite implementations
58 * coming from above header files here
60 #ifdef __INTEL_COMPILER
61 # include <linux/compiler-intel.h>
65 * Generic compiler-dependent macros required for kernel
66 * build go below this comment. Actual compiler/compiler version
67 * specific implementations come from the above header files
70 struct ftrace_branch_data {
76 unsigned long correct;
77 unsigned long incorrect;
83 unsigned long miss_hit[2];
88 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
89 * to disable branch tracing on a per file basis.
91 #if defined(CONFIG_TRACE_BRANCH_PROFILING) \
92 && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
93 void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
95 #define likely_notrace(x) __builtin_expect(!!(x), 1)
96 #define unlikely_notrace(x) __builtin_expect(!!(x), 0)
98 #define __branch_check__(x, expect) ({ \
100 static struct ftrace_branch_data \
101 __attribute__((__aligned__(4))) \
102 __attribute__((section("_ftrace_annotated_branch"))) \
108 ______r = likely_notrace(x); \
109 ftrace_likely_update(&______f, ______r, expect); \
114 * Using __builtin_constant_p(x) to ignore cases where the return
115 * value is always the same. This idea is taken from a similar patch
116 * written by Daniel Walker.
119 # define likely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
122 # define unlikely(x) (__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
125 #ifdef CONFIG_PROFILE_ALL_BRANCHES
127 * "Define 'is'", Bill Clinton
128 * "Define 'if'", Steven Rostedt
130 #define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
131 #define __trace_if(cond) \
132 if (__builtin_constant_p((cond)) ? !!(cond) : \
135 static struct ftrace_branch_data \
136 __attribute__((__aligned__(4))) \
137 __attribute__((section("_ftrace_branch"))) \
143 ______r = !!(cond); \
144 ______f.miss_hit[______r]++; \
147 #endif /* CONFIG_PROFILE_ALL_BRANCHES */
150 # define likely(x) __builtin_expect(!!(x), 1)
151 # define unlikely(x) __builtin_expect(!!(x), 0)
154 /* Optimization barrier */
156 # define barrier() __memory_barrier()
159 /* Unreachable code */
161 # define unreachable() do { } while (1)
165 # define RELOC_HIDE(ptr, off) \
166 ({ unsigned long __ptr; \
167 __ptr = (unsigned long) (ptr); \
168 (typeof(ptr)) (__ptr + (off)); })
171 /* Not-quite-unique ID. */
173 # define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
176 #endif /* __KERNEL__ */
178 #endif /* __ASSEMBLY__ */
182 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
183 * warning for each use, in hopes of speeding the functions removal.
185 * int __deprecated foo(void)
188 # define __deprecated /* unimplemented */
192 #define __deprecated_for_modules __deprecated
194 #define __deprecated_for_modules
201 #ifndef CONFIG_ENABLE_MUST_CHECK
205 #ifndef CONFIG_ENABLE_WARN_DEPRECATED
207 #undef __deprecated_for_modules
209 #define __deprecated_for_modules
213 * Allow us to avoid 'defined but not used' warnings on functions and data,
214 * as well as force them to be emitted to the assembly file.
216 * As of gcc 3.4, static functions that are not marked with attribute((used))
217 * may be elided from the assembly file. As of gcc 3.4, static data not so
218 * marked will not be elided, but this may change in a future gcc version.
220 * NOTE: Because distributions shipped with a backported unit-at-a-time
221 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
222 * for gcc >=3.3 instead of 3.4.
224 * In prior versions of gcc, such functions and data would be emitted, but
225 * would be warned about except with attribute((unused)).
227 * Mark functions that are referenced only in inline assembly as __used so
228 * the code is emitted even though it appears to be unreferenced.
231 # define __used /* unimplemented */
234 #ifndef __maybe_unused
235 # define __maybe_unused /* unimplemented */
238 #ifndef __always_unused
239 # define __always_unused /* unimplemented */
247 * Rather then using noinline to prevent stack consumption, use
248 * noinline_for_stack instead. For documentation reasons.
250 #define noinline_for_stack noinline
252 #ifndef __always_inline
253 #define __always_inline inline
256 #endif /* __KERNEL__ */
259 * From the GCC manual:
261 * Many functions do not examine any values except their arguments,
262 * and have no effects except the return value. Basically this is
263 * just slightly more strict class than the `pure' attribute above,
264 * since function is not allowed to read global memory.
266 * Note that a function that has pointer arguments and examines the
267 * data pointed to must _not_ be declared `const'. Likewise, a
268 * function that calls a non-`const' function usually must not be
269 * `const'. It does not make sense for a `const' function to return
272 #ifndef __attribute_const__
273 # define __attribute_const__ /* unimplemented */
277 * Tell gcc if a function is cold. The compiler will assume any path
278 * directly leading to the call is unlikely.
285 /* Simple shorthand for a section definition */
287 # define __section(S) __attribute__ ((__section__(#S)))
294 /* Are two types/vars the same type (ignoring qualifiers)? */
296 # define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
299 /* Compile time object size, -1 for unknown */
300 #ifndef __compiletime_object_size
301 # define __compiletime_object_size(obj) -1
303 #ifndef __compiletime_warning
304 # define __compiletime_warning(message)
306 #ifndef __compiletime_error
307 # define __compiletime_error(message)
309 #ifndef __linktime_error
310 # define __linktime_error(message)
313 * Prevent the compiler from merging or refetching accesses. The compiler
314 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
315 * but only when the compiler is aware of some particular ordering. One way
316 * to make the compiler aware of ordering is to put the two invocations of
317 * ACCESS_ONCE() in different C statements.
319 * This macro does absolutely -nothing- to prevent the CPU from reordering,
320 * merging, or refetching absolutely anything at any time. Its main intended
321 * use is to mediate communication between process-level code and irq/NMI
322 * handlers, all running on the same CPU.
324 #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
326 #endif /* __LINUX_COMPILER_H */