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Rev Author Line No. Line
1408 serge 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)))
1964 serge 8
# define __kernel	__attribute__((address_space(0)))
1408 serge 9
# define __safe		__attribute__((safe))
10
# define __force	__attribute__((force))
11
# define __nocast	__attribute__((nocast))
12
# define __iomem	__attribute__((noderef, address_space(2)))
3243 Serge 13
# define __must_hold(x)	__attribute__((context(x,1,1)))
1408 serge 14
# define __acquires(x)	__attribute__((context(x,0,1)))
15
# define __releases(x)	__attribute__((context(x,1,0)))
16
# define __acquire(x)	__context__(x,1)
17
# define __release(x)	__context__(x,-1)
18
# define __cond_lock(x,c)	((c) ? ({ __acquire(x); 1; }) : 0)
1964 serge 19
# define __percpu	__attribute__((noderef, address_space(3)))
6082 serge 20
# define __pmem		__attribute__((noderef, address_space(5)))
1964 serge 21
#ifdef CONFIG_SPARSE_RCU_POINTER
22
# define __rcu		__attribute__((noderef, address_space(4)))
7143 serge 23
#else /* CONFIG_SPARSE_RCU_POINTER */
1964 serge 24
# define __rcu
7143 serge 25
#endif /* CONFIG_SPARSE_RCU_POINTER */
26
# define __private	__attribute__((noderef))
1408 serge 27
extern void __chk_user_ptr(const volatile void __user *);
28
extern void __chk_io_ptr(const volatile void __iomem *);
7143 serge 29
# define ACCESS_PRIVATE(p, member) (*((typeof((p)->member) __force *) &(p)->member))
30
#else /* __CHECKER__ */
1408 serge 31
# define __user
32
# define __kernel
33
# define __safe
34
# define __force
35
# define __nocast
36
# define __iomem
37
# define __chk_user_ptr(x) (void)0
38
# define __chk_io_ptr(x) (void)0
39
# define __builtin_warning(x, y...) (1)
3243 Serge 40
# define __must_hold(x)
1408 serge 41
# define __acquires(x)
42
# define __releases(x)
43
# define __acquire(x) (void)0
44
# define __release(x) (void)0
45
# define __cond_lock(x,c) (c)
1964 serge 46
# define __percpu
47
# define __rcu
6082 serge 48
# define __pmem
7143 serge 49
# define __private
50
# define ACCESS_PRIVATE(p, member) ((p)->member)
51
#endif /* __CHECKER__ */
1408 serge 52
 
3243 Serge 53
/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
54
#define ___PASTE(a,b) a##b
55
#define __PASTE(a,b) ___PASTE(a,b)
56
 
1408 serge 57
#ifdef __KERNEL__
58
 
59
#ifdef __GNUC__
60
#include 
61
#endif
62
 
6082 serge 63
#if defined(CC_USING_HOTPATCH) && !defined(__CHECKER__)
64
#define notrace __attribute__((hotpatch(0,0)))
65
#else
1408 serge 66
#define notrace __attribute__((no_instrument_function))
6082 serge 67
#endif
1408 serge 68
 
69
/* Intel compiler defines __GNUC__. So we will overwrite implementations
70
 * coming from above header files here
71
 */
72
#ifdef __INTEL_COMPILER
73
# include 
74
#endif
75
 
5056 serge 76
/* Clang compiler defines __GNUC__. So we will overwrite implementations
77
 * coming from above header files here
78
 */
79
#ifdef __clang__
80
#include 
81
#endif
82
 
1408 serge 83
/*
84
 * Generic compiler-dependent macros required for kernel
85
 * build go below this comment. Actual compiler/compiler version
86
 * specific implementations come from the above header files
87
 */
88
 
89
struct ftrace_branch_data {
90
	const char *func;
91
	const char *file;
92
	unsigned line;
93
	union {
94
		struct {
95
			unsigned long correct;
96
			unsigned long incorrect;
97
		};
98
		struct {
99
			unsigned long miss;
100
			unsigned long hit;
101
		};
102
		unsigned long miss_hit[2];
103
	};
104
};
105
 
106
/*
107
 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
108
 * to disable branch tracing on a per file basis.
109
 */
110
#if defined(CONFIG_TRACE_BRANCH_PROFILING) \
111
    && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
112
void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
113
 
114
#define likely_notrace(x)	__builtin_expect(!!(x), 1)
115
#define unlikely_notrace(x)	__builtin_expect(!!(x), 0)
116
 
117
#define __branch_check__(x, expect) ({					\
118
			int ______r;					\
119
			static struct ftrace_branch_data		\
120
				__attribute__((__aligned__(4)))		\
121
				__attribute__((section("_ftrace_annotated_branch"))) \
122
				______f = {				\
123
				.func = __func__,			\
124
				.file = __FILE__,			\
125
				.line = __LINE__,			\
126
			};						\
127
			______r = likely_notrace(x);			\
128
			ftrace_likely_update(&______f, ______r, expect); \
129
			______r;					\
130
		})
131
 
132
/*
133
 * Using __builtin_constant_p(x) to ignore cases where the return
134
 * value is always the same.  This idea is taken from a similar patch
135
 * written by Daniel Walker.
136
 */
137
# ifndef likely
138
#  define likely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
139
# endif
140
# ifndef unlikely
141
#  define unlikely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
142
# endif
143
 
144
#ifdef CONFIG_PROFILE_ALL_BRANCHES
145
/*
146
 * "Define 'is'", Bill Clinton
147
 * "Define 'if'", Steven Rostedt
148
 */
149
#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) )
150
#define __trace_if(cond) \
6295 serge 151
	if (__builtin_constant_p(!!(cond)) ? !!(cond) :			\
1408 serge 152
	({								\
153
		int ______r;						\
154
		static struct ftrace_branch_data			\
155
			__attribute__((__aligned__(4)))			\
156
			__attribute__((section("_ftrace_branch")))	\
157
			______f = {					\
158
				.func = __func__,			\
159
				.file = __FILE__,			\
160
				.line = __LINE__,			\
161
			};						\
162
		______r = !!(cond);					\
163
		______f.miss_hit[______r]++;					\
164
		______r;						\
165
	}))
166
#endif /* CONFIG_PROFILE_ALL_BRANCHES */
167
 
168
#else
169
# define likely(x)	__builtin_expect(!!(x), 1)
170
# define unlikely(x)	__builtin_expect(!!(x), 0)
171
#endif
172
 
173
/* Optimization barrier */
174
#ifndef barrier
175
# define barrier() __memory_barrier()
176
#endif
177
 
6082 serge 178
#ifndef barrier_data
179
# define barrier_data(ptr) barrier()
180
#endif
181
 
1408 serge 182
/* Unreachable code */
183
#ifndef unreachable
184
# define unreachable() do { } while (1)
185
#endif
186
 
187
#ifndef RELOC_HIDE
188
# define RELOC_HIDE(ptr, off)					\
189
  ({ unsigned long __ptr;					\
190
     __ptr = (unsigned long) (ptr);				\
191
    (typeof(ptr)) (__ptr + (off)); })
192
#endif
193
 
5056 serge 194
#ifndef OPTIMIZER_HIDE_VAR
195
#define OPTIMIZER_HIDE_VAR(var) barrier()
196
#endif
197
 
3480 Serge 198
/* Not-quite-unique ID. */
199
#ifndef __UNIQUE_ID
200
# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
201
#endif
202
 
5270 serge 203
#include 
204
 
6082 serge 205
#define __READ_ONCE_SIZE						\
206
({									\
207
	switch (size) {							\
208
	case 1: *(__u8 *)res = *(volatile __u8 *)p; break;		\
209
	case 2: *(__u16 *)res = *(volatile __u16 *)p; break;		\
210
	case 4: *(__u32 *)res = *(volatile __u32 *)p; break;		\
211
	case 8: *(__u64 *)res = *(volatile __u64 *)p; break;		\
212
	default:							\
213
		barrier();						\
214
		__builtin_memcpy((void *)res, (const void *)p, size);	\
215
		barrier();						\
216
	}								\
217
})
5270 serge 218
 
6082 serge 219
static __always_inline
220
void __read_once_size(const volatile void *p, void *res, int size)
5270 serge 221
{
6082 serge 222
	__READ_ONCE_SIZE;
5270 serge 223
}
224
 
6082 serge 225
#ifdef CONFIG_KASAN
226
/*
227
 * This function is not 'inline' because __no_sanitize_address confilcts
228
 * with inlining. Attempt to inline it may cause a build failure.
229
 * 	https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368
230
 * '__maybe_unused' allows us to avoid defined-but-not-used warnings.
231
 */
232
static __no_sanitize_address __maybe_unused
233
void __read_once_size_nocheck(const volatile void *p, void *res, int size)
5270 serge 234
{
6082 serge 235
	__READ_ONCE_SIZE;
236
}
237
#else
238
static __always_inline
239
void __read_once_size_nocheck(const volatile void *p, void *res, int size)
240
{
241
	__READ_ONCE_SIZE;
242
}
5270 serge 243
#endif
244
 
6082 serge 245
static __always_inline void __write_once_size(volatile void *p, void *res, int size)
5270 serge 246
{
247
	switch (size) {
248
	case 1: *(volatile __u8 *)p = *(__u8 *)res; break;
249
	case 2: *(volatile __u16 *)p = *(__u16 *)res; break;
250
	case 4: *(volatile __u32 *)p = *(__u32 *)res; break;
251
	case 8: *(volatile __u64 *)p = *(__u64 *)res; break;
252
	default:
253
		barrier();
254
		__builtin_memcpy((void *)p, (const void *)res, size);
255
		barrier();
256
	}
257
}
258
 
259
/*
260
 * Prevent the compiler from merging or refetching reads or writes. The
261
 * compiler is also forbidden from reordering successive instances of
6082 serge 262
 * READ_ONCE, WRITE_ONCE and ACCESS_ONCE (see below), but only when the
5270 serge 263
 * compiler is aware of some particular ordering.  One way to make the
264
 * compiler aware of ordering is to put the two invocations of READ_ONCE,
6082 serge 265
 * WRITE_ONCE or ACCESS_ONCE() in different C statements.
5270 serge 266
 *
267
 * In contrast to ACCESS_ONCE these two macros will also work on aggregate
268
 * data types like structs or unions. If the size of the accessed data
269
 * type exceeds the word size of the machine (e.g., 32 bits or 64 bits)
7143 serge 270
 * READ_ONCE() and WRITE_ONCE() will fall back to memcpy(). There's at
271
 * least two memcpy()s: one for the __builtin_memcpy() and then one for
272
 * the macro doing the copy of variable - '__u' allocated on the stack.
5270 serge 273
 *
274
 * Their two major use cases are: (1) Mediating communication between
275
 * process-level code and irq/NMI handlers, all running on the same CPU,
276
 * and (2) Ensuring that the compiler does not  fold, spindle, or otherwise
277
 * mutilate accesses that either do not require ordering or that interact
278
 * with an explicit memory barrier or atomic instruction that provides the
279
 * required ordering.
280
 */
281
 
6082 serge 282
#define __READ_ONCE(x, check)						\
283
({									\
284
	union { typeof(x) __val; char __c[1]; } __u;			\
285
	if (check)							\
286
		__read_once_size(&(x), __u.__c, sizeof(x));		\
287
	else								\
288
		__read_once_size_nocheck(&(x), __u.__c, sizeof(x));	\
289
	__u.__val;							\
290
})
291
#define READ_ONCE(x) __READ_ONCE(x, 1)
5270 serge 292
 
6082 serge 293
/*
294
 * Use READ_ONCE_NOCHECK() instead of READ_ONCE() if you need
295
 * to hide memory access from KASAN.
296
 */
297
#define READ_ONCE_NOCHECK(x) __READ_ONCE(x, 0)
5270 serge 298
 
6082 serge 299
#define WRITE_ONCE(x, val) \
300
({							\
301
	union { typeof(x) __val; char __c[1]; } __u =	\
302
		{ .__val = (__force typeof(x)) (val) }; \
303
	__write_once_size(&(x), __u.__c, sizeof(x));	\
304
	__u.__val;					\
305
})
306
 
6936 serge 307
/**
308
 * smp_cond_acquire() - Spin wait for cond with ACQUIRE ordering
309
 * @cond: boolean expression to wait for
310
 *
311
 * Equivalent to using smp_load_acquire() on the condition variable but employs
312
 * the control dependency of the wait to reduce the barrier on many platforms.
313
 *
314
 * The control dependency provides a LOAD->STORE order, the additional RMB
315
 * provides LOAD->LOAD order, together they provide LOAD->{LOAD,STORE} order,
316
 * aka. ACQUIRE.
317
 */
318
#define smp_cond_acquire(cond)	do {		\
319
	while (!(cond))				\
320
		cpu_relax();			\
321
	smp_rmb(); /* ctrl + rmb := acquire */	\
322
} while (0)
323
 
1408 serge 324
#endif /* __KERNEL__ */
325
 
326
#endif /* __ASSEMBLY__ */
327
 
328
#ifdef __KERNEL__
329
/*
330
 * Allow us to mark functions as 'deprecated' and have gcc emit a nice
331
 * warning for each use, in hopes of speeding the functions removal.
332
 * Usage is:
333
 * 		int __deprecated foo(void)
334
 */
335
#ifndef __deprecated
336
# define __deprecated		/* unimplemented */
337
#endif
338
 
339
#ifdef MODULE
340
#define __deprecated_for_modules __deprecated
341
#else
342
#define __deprecated_for_modules
343
#endif
344
 
345
#ifndef __must_check
346
#define __must_check
347
#endif
348
 
349
#ifndef CONFIG_ENABLE_MUST_CHECK
350
#undef __must_check
351
#define __must_check
352
#endif
353
#ifndef CONFIG_ENABLE_WARN_DEPRECATED
354
#undef __deprecated
355
#undef __deprecated_for_modules
356
#define __deprecated
357
#define __deprecated_for_modules
358
#endif
359
 
360
/*
361
 * Allow us to avoid 'defined but not used' warnings on functions and data,
362
 * as well as force them to be emitted to the assembly file.
363
 *
364
 * As of gcc 3.4, static functions that are not marked with attribute((used))
365
 * may be elided from the assembly file.  As of gcc 3.4, static data not so
366
 * marked will not be elided, but this may change in a future gcc version.
367
 *
368
 * NOTE: Because distributions shipped with a backported unit-at-a-time
369
 * compiler in gcc 3.3, we must define __used to be __attribute__((used))
370
 * for gcc >=3.3 instead of 3.4.
371
 *
372
 * In prior versions of gcc, such functions and data would be emitted, but
373
 * would be warned about except with attribute((unused)).
374
 *
375
 * Mark functions that are referenced only in inline assembly as __used so
376
 * the code is emitted even though it appears to be unreferenced.
377
 */
378
#ifndef __used
379
# define __used			/* unimplemented */
380
#endif
381
 
382
#ifndef __maybe_unused
383
# define __maybe_unused		/* unimplemented */
384
#endif
385
 
386
#ifndef __always_unused
387
# define __always_unused	/* unimplemented */
388
#endif
389
 
390
#ifndef noinline
391
#define noinline
392
#endif
393
 
394
/*
395
 * Rather then using noinline to prevent stack consumption, use
3031 serge 396
 * noinline_for_stack instead.  For documentation reasons.
1408 serge 397
 */
398
#define noinline_for_stack noinline
399
 
400
#ifndef __always_inline
401
#define __always_inline inline
402
#endif
403
 
404
#endif /* __KERNEL__ */
405
 
406
/*
407
 * From the GCC manual:
408
 *
409
 * Many functions do not examine any values except their arguments,
410
 * and have no effects except the return value.  Basically this is
411
 * just slightly more strict class than the `pure' attribute above,
412
 * since function is not allowed to read global memory.
413
 *
414
 * Note that a function that has pointer arguments and examines the
415
 * data pointed to must _not_ be declared `const'.  Likewise, a
416
 * function that calls a non-`const' function usually must not be
417
 * `const'.  It does not make sense for a `const' function to return
418
 * `void'.
419
 */
420
#ifndef __attribute_const__
421
# define __attribute_const__	/* unimplemented */
422
#endif
423
 
424
/*
425
 * Tell gcc if a function is cold. The compiler will assume any path
426
 * directly leading to the call is unlikely.
427
 */
428
 
429
#ifndef __cold
430
#define __cold
431
#endif
432
 
433
/* Simple shorthand for a section definition */
434
#ifndef __section
435
# define __section(S) __attribute__ ((__section__(#S)))
436
#endif
437
 
3031 serge 438
#ifndef __visible
439
#define __visible
440
#endif
441
 
6082 serge 442
/*
443
 * Assume alignment of return value.
444
 */
445
#ifndef __assume_aligned
446
#define __assume_aligned(a, ...)
447
#endif
448
 
449
 
1408 serge 450
/* Are two types/vars the same type (ignoring qualifiers)? */
451
#ifndef __same_type
452
# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
453
#endif
454
 
5056 serge 455
/* Is this type a native word size -- useful for atomic operations */
456
#ifndef __native_word
6082 serge 457
# define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
5056 serge 458
#endif
459
 
1408 serge 460
/* Compile time object size, -1 for unknown */
461
#ifndef __compiletime_object_size
462
# define __compiletime_object_size(obj) -1
463
#endif
464
#ifndef __compiletime_warning
465
# define __compiletime_warning(message)
466
#endif
467
#ifndef __compiletime_error
468
# define __compiletime_error(message)
5056 serge 469
/*
470
 * Sparse complains of variable sized arrays due to the temporary variable in
471
 * __compiletime_assert. Unfortunately we can't just expand it out to make
472
 * sparse see a constant array size without breaking compiletime_assert on old
473
 * versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
474
 */
475
# ifndef __CHECKER__
6082 serge 476
#  define __compiletime_error_fallback(condition) \
3480 Serge 477
	do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
5056 serge 478
# endif
479
#endif
480
#ifndef __compiletime_error_fallback
3480 Serge 481
# define __compiletime_error_fallback(condition) do { } while (0)
1408 serge 482
#endif
3480 Serge 483
 
484
#define __compiletime_assert(condition, msg, prefix, suffix)		\
485
	do {								\
486
		bool __cond = !(condition);				\
487
		extern void prefix ## suffix(void) __compiletime_error(msg); \
488
		if (__cond)						\
489
			prefix ## suffix();				\
490
		__compiletime_error_fallback(__cond);			\
491
	} while (0)
492
 
493
#define _compiletime_assert(condition, msg, prefix, suffix) \
494
	__compiletime_assert(condition, msg, prefix, suffix)
495
 
496
/**
497
 * compiletime_assert - break build and emit msg if condition is false
498
 * @condition: a compile-time constant condition to check
499
 * @msg:       a message to emit if condition is false
500
 *
501
 * In tradition of POSIX assert, this macro will break the build if the
502
 * supplied condition is *false*, emitting the supplied error message if the
503
 * compiler has support to do so.
504
 */
505
#define compiletime_assert(condition, msg) \
506
	_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
507
 
5056 serge 508
#define compiletime_assert_atomic_type(t)				\
509
	compiletime_assert(__native_word(t),				\
510
		"Need native word sized stores/loads for atomicity.")
511
 
1408 serge 512
/*
513
 * Prevent the compiler from merging or refetching accesses.  The compiler
514
 * is also forbidden from reordering successive instances of ACCESS_ONCE(),
515
 * but only when the compiler is aware of some particular ordering.  One way
516
 * to make the compiler aware of ordering is to put the two invocations of
517
 * ACCESS_ONCE() in different C statements.
518
 *
6082 serge 519
 * ACCESS_ONCE will only work on scalar types. For union types, ACCESS_ONCE
520
 * on a union member will work as long as the size of the member matches the
521
 * size of the union and the size is smaller than word size.
522
 *
523
 * The major use cases of ACCESS_ONCE used to be (1) Mediating communication
524
 * between process-level code and irq/NMI handlers, all running on the same CPU,
525
 * and (2) Ensuring that the compiler does not  fold, spindle, or otherwise
526
 * mutilate accesses that either do not require ordering or that interact
527
 * with an explicit memory barrier or atomic instruction that provides the
528
 * required ordering.
529
 *
530
 * If possible use READ_ONCE()/WRITE_ONCE() instead.
1408 serge 531
 */
6082 serge 532
#define __ACCESS_ONCE(x) ({ \
533
	 __maybe_unused typeof(x) __var = (__force typeof(x)) 0; \
534
	(volatile typeof(x) *)&(x); })
535
#define ACCESS_ONCE(x) (*__ACCESS_ONCE(x))
1408 serge 536
 
6082 serge 537
/**
538
 * lockless_dereference() - safely load a pointer for later dereference
539
 * @p: The pointer to load
540
 *
541
 * Similar to rcu_dereference(), but for situations where the pointed-to
542
 * object's lifetime is managed by something other than RCU.  That
543
 * "something other" might be reference counting or simple immortality.
544
 */
545
#define lockless_dereference(p) \
546
({ \
547
	typeof(p) _________p1 = READ_ONCE(p); \
548
	smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
549
	(_________p1); \
550
})
551
 
4103 Serge 552
/* Ignore/forbid kprobes attach on very low level functions marked by this attribute: */
553
#ifdef CONFIG_KPROBES
554
# define __kprobes	__attribute__((__section__(".kprobes.text")))
5056 serge 555
# define nokprobe_inline	__always_inline
4103 Serge 556
#else
557
# define __kprobes
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# define nokprobe_inline	inline
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#endif
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#endif /* __LINUX_COMPILER_H */