Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
/* Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009
   Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#ifndef _LOWLEVELLOCK_H
#define _LOWLEVELLOCK_H	1

#ifndef __ASSEMBLER__
#include <time.h>
#include <sys/param.h>
#include <bits/pthreadtypes.h>
#include <bits/kernel-features.h>
#endif

#define FUTEX_WAIT		0
#define FUTEX_WAKE		1
#define FUTEX_CMP_REQUEUE	4
#define FUTEX_WAKE_OP		5
#define FUTEX_LOCK_PI		6
#define FUTEX_UNLOCK_PI		7
#define FUTEX_TRYLOCK_PI	8
#define FUTEX_WAIT_BITSET	9
#define FUTEX_WAKE_BITSET	10
#define FUTEX_PRIVATE_FLAG	128
#define FUTEX_CLOCK_REALTIME	256

#define FUTEX_BITSET_MATCH_ANY	0xffffffff

#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE	((4 << 24) | 1)

/* Values for 'private' parameter of locking macros.  Yes, the
   definition seems to be backwards.  But it is not.  The bit will be
   reversed before passing to the system call.  */
#define LLL_PRIVATE    0
#define LLL_SHARED     FUTEX_PRIVATE_FLAG


#if !defined NOT_IN_libc || defined IS_IN_rtld
/* In libc.so or ld.so all futexes are private.  */
# ifdef __ASSUME_PRIVATE_FUTEX
#  define __lll_private_flag(fl, private) \
  ((fl) | FUTEX_PRIVATE_FLAG)
# else
#  define __lll_private_flag(fl, private) \
  ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))
# endif
#else
# ifdef __ASSUME_PRIVATE_FUTEX
#  define __lll_private_flag(fl, private) \
  (((fl) | FUTEX_PRIVATE_FLAG) ^ (private))
# else
#  define __lll_private_flag(fl, private) \
  (__builtin_constant_p (private)					      \
   ? ((private) == 0							      \
      ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex))	      \
      : (fl))								      \
   : ((fl) | (((private) ^ FUTEX_PRIVATE_FLAG)				      \
	      & THREAD_GETMEM (THREAD_SELF, header.private_futex))))
# endif
#endif

#ifndef __ASSEMBLER__

/* Initializer for compatibility lock.  */
#define LLL_LOCK_INITIALIZER		(0)
#define LLL_LOCK_INITIALIZER_LOCKED	(1)
#define LLL_LOCK_INITIALIZER_WAITERS	(2)

extern int __lll_lock_wait_private (int val, int *__futex)
  attribute_hidden;
extern int __lll_lock_wait (int val, int *__futex, int private)
  attribute_hidden;
extern int __lll_timedlock_wait (int val, int *__futex,
				 const struct timespec *abstime, int private)
  attribute_hidden;
extern int __lll_robust_lock_wait (int val, int *__futex, int private)
  attribute_hidden;
extern int __lll_robust_timedlock_wait (int val, int *__futex,
					const struct timespec *abstime,
					int private)
  attribute_hidden;
extern int __lll_unlock_wake_private (int *__futex) attribute_hidden;
extern int __lll_unlock_wake (int *__futex, int private) attribute_hidden;

#define lll_trylock(futex) \
  ({ unsigned char __ret; \
     __asm__ __volatile__ ("\
	.align 2\n\
	mova 1f,r0\n\
	nop\n\
	mov r15,r1\n\
	mov #-8,r15\n\
     0: mov.l @%1,r2\n\
	cmp/eq r2,%3\n\
	bf 1f\n\
	mov.l %2,@%1\n\
     1: mov r1,r15\n\
	mov #-1,%0\n\
	negc %0,%0"\
	: "=r" (__ret) \
	: "r" (&(futex)), \
	  "r" (LLL_LOCK_INITIALIZER_LOCKED), \
	  "r" (LLL_LOCK_INITIALIZER) \
	: "r0", "r1", "r2", "t", "memory"); \
     __ret; })

#define lll_robust_trylock(futex, id)	\
  ({ unsigned char __ret; \
     __asm__ __volatile__ ("\
	.align 2\n\
	mova 1f,r0\n\
	nop\n\
	mov r15,r1\n\
	mov #-8,r15\n\
     0: mov.l @%1,r2\n\
	cmp/eq r2,%3\n\
	bf 1f\n\
	mov.l %2,@%1\n\
     1: mov r1,r15\n\
	mov #-1,%0\n\
	negc %0,%0"\
	: "=r" (__ret) \
	: "r" (&(futex)), \
	  "r" (id), \
	  "r" (LLL_LOCK_INITIALIZER) \
	: "r0", "r1", "r2", "t", "memory"); \
     __ret; })

#define lll_cond_trylock(futex) \
  ({ unsigned char __ret; \
     __asm__ __volatile__ ("\
	.align 2\n\
	mova 1f,r0\n\
	nop\n\
	mov r15,r1\n\
	mov #-8,r15\n\
     0: mov.l @%1,r2\n\
	cmp/eq r2,%3\n\
	bf 1f\n\
	mov.l %2,@%1\n\
     1: mov r1,r15\n\
	mov #-1,%0\n\
	negc %0,%0"\
	: "=r" (__ret) \
	: "r" (&(futex)), \
	  "r" (LLL_LOCK_INITIALIZER_WAITERS), \
	  "r" (LLL_LOCK_INITIALIZER) \
	: "r0", "r1", "r2", "t", "memory"); \
     __ret; })

#define lll_lock(futex, private) \
  (void) ({ int __ret, *__futex = &(futex); \
	    __asm__ __volatile__ ("\
		.align 2\n\
		mova 1f,r0\n\
		nop\n\
		mov r15,r1\n\
		mov #-8,r15\n\
	     0: mov.l @%2,%0\n\
		tst %0,%0\n\
		bf 1f\n\
		mov.l %1,@%2\n\
	     1: mov r1,r15"\
		: "=&r" (__ret) : "r" (1), "r" (__futex) \
		: "r0", "r1", "t", "memory"); \
	    if (__ret) \
	      { \
		if (__builtin_constant_p (private) \
		    && (private) == LLL_PRIVATE) \
		  __lll_lock_wait_private (__ret, __futex); \
	        else \
		  __lll_lock_wait (__ret, __futex, (private));	\
	      } \
    })

#define lll_robust_lock(futex, id, private) \
  ({ int __ret, *__futex = &(futex); \
     __asm__ __volatile__ ("\
	.align 2\n\
	mova 1f,r0\n\
	nop\n\
	mov r15,r1\n\
	mov #-8,r15\n\
      0: mov.l @%2,%0\n\
	tst %0,%0\n\
	bf 1f\n\
	mov.l %1,@%2\n\
      1: mov r1,r15"\
	: "=&r" (__ret) : "r" (id), "r" (__futex) \
	: "r0", "r1", "t", "memory"); \
     if (__ret) \
       __ret = __lll_robust_lock_wait (__ret, __futex, private); \
     __ret; })

/* Special version of lll_mutex_lock which causes the unlock function to
   always wakeup waiters.  */
#define lll_cond_lock(futex, private) \
  (void) ({ int __ret, *__futex = &(futex); \
	    __asm__ __volatile__ ("\
		.align 2\n\
		mova 1f,r0\n\
		nop\n\
		mov r15,r1\n\
		mov #-8,r15\n\
	     0: mov.l @%2,%0\n\
		tst %0,%0\n\
		bf 1f\n\
		mov.l %1,@%2\n\
	     1: mov r1,r15"\
		: "=&r" (__ret) : "r" (2), "r" (__futex) \
		: "r0", "r1", "t", "memory"); \
	    if (__ret) \
	      __lll_lock_wait (__ret, __futex, private); })

#define lll_robust_cond_lock(futex, id, private) \
  ({ int __ret, *__futex = &(futex); \
     __asm__ __volatile__ ("\
	.align 2\n\
	mova 1f,r0\n\
	nop\n\
	mov r15,r1\n\
	mov #-8,r15\n\
     0: mov.l @%2,%0\n\
	tst %0,%0\n\
	bf 1f\n\
	mov.l %1,@%2\n\
     1: mov r1,r15"\
	: "=&r" (__ret) : "r" (id | FUTEX_WAITERS), "r" (__futex) \
	: "r0", "r1", "t", "memory"); \
      if (__ret) \
	__ret = __lll_robust_lock_wait (__ret, __futex, private); \
      __ret; })

#define lll_timedlock(futex, timeout, private) \
  ({ int __ret, *__futex = &(futex); \
     __asm__ __volatile__ ("\
	.align 2\n\
	mova 1f,r0\n\
	nop\n\
	mov r15,r1\n\
	mov #-8,r15\n\
     0: mov.l @%2,%0\n\
	tst %0,%0\n\
	bf 1f\n\
	mov.l %1,@%2\n\
     1: mov r1,r15"\
	: "=&r" (__ret) : "r" (1), "r" (__futex) \
	: "r0", "r1", "t", "memory"); \
    if (__ret) \
      __ret = __lll_timedlock_wait (__ret, __futex, timeout, private); \
    __ret; })

#define lll_robust_timedlock(futex, timeout, id, private) \
  ({ int __ret, *__futex = &(futex); \
     __asm__ __volatile__ ("\
	.align 2\n\
	mova 1f,r0\n\
	nop\n\
	mov r15,r1\n\
	mov #-8,r15\n\
     0: mov.l @%2,%0\n\
	tst %0,%0\n\
	bf 1f\n\
	mov.l %1,@%2\n\
     1: mov r1,r15"\
	: "=&r" (__ret) : "r" (id), "r" (__futex) \
	: "r0", "r1", "t", "memory"); \
    if (__ret) \
      __ret = __lll_robust_timedlock_wait (__ret, __futex, \
					      timeout, private); \
    __ret; })

#define lll_unlock(futex, private) \
  (void) ({ int __ret, *__futex = &(futex); \
	    __asm__ __volatile__ ("\
		.align 2\n\
		mova 1f,r0\n\
		mov r15,r1\n\
		mov #-6,r15\n\
	     0: mov.l @%1,%0\n\
		add #-1,%0\n\
		mov.l %0,@%1\n\
	     1: mov r1,r15"\
		: "=&r" (__ret) : "r" (__futex) \
		: "r0", "r1", "memory"); \
	    if (__ret) \
	      { \
		if (__builtin_constant_p (private) \
		    && (private) == LLL_PRIVATE) \
		  __lll_unlock_wake_private (__futex); \
	        else \
		  __lll_unlock_wake (__futex, (private)); \
	      } \
    })

#define lll_robust_unlock(futex, private) \
  (void) ({ int __ret, *__futex = &(futex); \
	    __asm__ __volatile__ ("\
		.align 2\n\
		mova 1f,r0\n\
		mov r15,r1\n\
		mov #-6,r15\n\
	     0: mov.l @%1,%0\n\
		and %2,%0\n\
		mov.l %0,@%1\n\
	     1: mov r1,r15"\
		: "=&r" (__ret) : "r" (__futex), "r" (FUTEX_WAITERS) \
		: "r0", "r1", "memory");	\
	    if (__ret) \
	      __lll_unlock_wake (__futex, private); })

#define lll_robust_dead(futex, private)		       \
  (void) ({ int __ignore, *__futex = &(futex); \
	    __asm__ __volatile__ ("\
		.align 2\n\
		mova 1f,r0\n\
		mov r15,r1\n\
		mov #-6,r15\n\
	     0: mov.l @%1,%0\n\
		or %2,%0\n\
		mov.l %0,@%1\n\
	     1: mov r1,r15"\
		: "=&r" (__ignore) : "r" (__futex), "r" (FUTEX_OWNER_DIED) \
		: "r0", "r1", "memory");	\
	    lll_futex_wake (__futex, 1, private); })

# ifdef NEED_SYSCALL_INST_PAD
#  define SYSCALL_WITH_INST_PAD "\
	trapa #0x14; or r0,r0; or r0,r0; or r0,r0; or r0,r0; or r0,r0"
# else
#  define SYSCALL_WITH_INST_PAD "\
	trapa #0x14"
# endif

#define lll_futex_wait(futex, val, private) \
  lll_futex_timed_wait (futex, val, NULL, private)


#define lll_futex_timed_wait(futex, val, timeout, private) \
  ({									      \
    int __status;							      \
    register unsigned long __r3 __asm__ ("r3") = SYS_futex;			      \
    register unsigned long __r4 __asm__ ("r4") = (unsigned long) (futex);	      \
    register unsigned long __r5 __asm__ ("r5")				      \
      = __lll_private_flag (FUTEX_WAIT, private);			      \
    register unsigned long __r6 __asm__ ("r6") = (unsigned long) (val);	      \
    register unsigned long __r7 __asm__ ("r7") = (unsigned long) (timeout);   \
    __asm__ __volatile__ (SYSCALL_WITH_INST_PAD				      \
		      : "=z" (__status)					      \
		      : "r" (__r3), "r" (__r4), "r" (__r5),		      \
			"r" (__r6), "r" (__r7)				      \
		      : "memory", "t");					      \
    __status;								      \
  })


#define lll_futex_wake(futex, nr, private) \
  do {									      \
    int __ignore;							      \
    register unsigned long __r3 __asm__ ("r3") = SYS_futex;			      \
    register unsigned long __r4 __asm__ ("r4") = (unsigned long) (futex);	      \
    register unsigned long __r5 __asm__ ("r5")				      \
      = __lll_private_flag (FUTEX_WAKE, private);			      \
    register unsigned long __r6 __asm__ ("r6") = (unsigned long) (nr);	      \
    register unsigned long __r7 __asm__ ("r7") = 0;				      \
    __asm__ __volatile__ (SYSCALL_WITH_INST_PAD				      \
		      : "=z" (__ignore)					      \
		      : "r" (__r3), "r" (__r4), "r" (__r5),		      \
			"r" (__r6), "r" (__r7)				      \
		      : "memory", "t");					      \
  } while (0)


#define lll_islocked(futex) \
  (futex != LLL_LOCK_INITIALIZER)

/* The kernel notifies a process with uses CLONE_CLEARTID via futex
   wakeup when the clone terminates.  The memory location contains the
   thread ID while the clone is running and is reset to zero
   afterwards.  */

#define lll_wait_tid(tid) \
  do {									      \
    __typeof (tid) __tid;						      \
    while ((__tid = (tid)) != 0)						      \
      lll_futex_wait (&(tid), __tid, LLL_SHARED);			      \
  } while (0)

extern int __lll_timedwait_tid (int *tid, const struct timespec *abstime)
     attribute_hidden;
#define lll_timedwait_tid(tid, abstime) \
  ({									      \
    int __ret = 0;							      \
    if (tid != 0)							      \
      {									      \
	if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000)	      \
	  __ret = EINVAL;						      \
	else								      \
	  __ret = __lll_timedwait_tid (&tid, abstime);		      \
      }									      \
    __ret; })

#endif  /* !__ASSEMBLER__ */

#endif  /* lowlevellock.h */