1/*
2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: stable/11/lib/libthr/thread/thr_umtx.c 319430 2017-06-01 14:49:53Z vangyzen $");
29
30#include "thr_private.h"
31#include "thr_umtx.h"
32
33#ifndef HAS__UMTX_OP_ERR
34int _umtx_op_err(void *obj, int op, u_long val, void *uaddr, void *uaddr2)
35{
36
37	if (_umtx_op(obj, op, val, uaddr, uaddr2) == -1)
38		return (errno);
39	return (0);
40}
41#endif
42
43void
44_thr_umutex_init(struct umutex *mtx)
45{
46	static const struct umutex default_mtx = DEFAULT_UMUTEX;
47
48	*mtx = default_mtx;
49}
50
51void
52_thr_urwlock_init(struct urwlock *rwl)
53{
54	static const struct urwlock default_rwl = DEFAULT_URWLOCK;
55
56	*rwl = default_rwl;
57}
58
59int
60__thr_umutex_lock(struct umutex *mtx, uint32_t id)
61{
62	uint32_t owner;
63
64	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) != 0)
65		return	(_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0));
66
67	for (;;) {
68		owner = mtx->m_owner;
69		if ((owner & ~UMUTEX_CONTESTED) == 0 &&
70		     atomic_cmpset_acq_32(&mtx->m_owner, owner, id | owner))
71			return (0);
72		if (owner == UMUTEX_RB_OWNERDEAD &&
73		     atomic_cmpset_acq_32(&mtx->m_owner, owner,
74		     id | UMUTEX_CONTESTED))
75			return (EOWNERDEAD);
76		if (owner == UMUTEX_RB_NOTRECOV)
77			return (ENOTRECOVERABLE);
78
79		/* wait in kernel */
80		_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
81	}
82}
83
84#define SPINLOOPS 1000
85
86int
87__thr_umutex_lock_spin(struct umutex *mtx, uint32_t id)
88{
89	uint32_t owner;
90	int count;
91
92	if (!_thr_is_smp)
93		return (__thr_umutex_lock(mtx, id));
94	if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) != 0)
95		return	(_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0));
96
97	for (;;) {
98		count = SPINLOOPS;
99		while (count--) {
100			owner = mtx->m_owner;
101			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
102			    atomic_cmpset_acq_32(&mtx->m_owner, owner,
103			    id | owner))
104				return (0);
105			if (__predict_false(owner == UMUTEX_RB_OWNERDEAD) &&
106			    atomic_cmpset_acq_32(&mtx->m_owner, owner,
107			    id | UMUTEX_CONTESTED))
108				return (EOWNERDEAD);
109			if (__predict_false(owner == UMUTEX_RB_NOTRECOV))
110				return (ENOTRECOVERABLE);
111			CPU_SPINWAIT;
112		}
113
114		/* wait in kernel */
115		_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
116	}
117}
118
119int
120__thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
121	const struct timespec *abstime)
122{
123	struct _umtx_time *tm_p, timeout;
124	size_t tm_size;
125	uint32_t owner;
126	int ret;
127
128	if (abstime == NULL) {
129		tm_p = NULL;
130		tm_size = 0;
131	} else {
132		timeout._clockid = CLOCK_REALTIME;
133		timeout._flags = UMTX_ABSTIME;
134		timeout._timeout = *abstime;
135		tm_p = &timeout;
136		tm_size = sizeof(timeout);
137	}
138
139	for (;;) {
140		if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT |
141		    UMUTEX_PRIO_INHERIT)) == 0) {
142			/* try to lock it */
143			owner = mtx->m_owner;
144			if ((owner & ~UMUTEX_CONTESTED) == 0 &&
145			     atomic_cmpset_acq_32(&mtx->m_owner, owner,
146			     id | owner))
147				return (0);
148			if (__predict_false(owner == UMUTEX_RB_OWNERDEAD) &&
149			     atomic_cmpset_acq_32(&mtx->m_owner, owner,
150			     id | UMUTEX_CONTESTED))
151				return (EOWNERDEAD);
152			if (__predict_false(owner == UMUTEX_RB_NOTRECOV))
153				return (ENOTRECOVERABLE);
154			/* wait in kernel */
155			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0,
156			    (void *)tm_size, __DECONST(void *, tm_p));
157		} else {
158			ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0,
159			    (void *)tm_size, __DECONST(void *, tm_p));
160			if (ret == 0 || ret == EOWNERDEAD ||
161			    ret == ENOTRECOVERABLE)
162				break;
163		}
164		if (ret == ETIMEDOUT)
165			break;
166	}
167	return (ret);
168}
169
170int
171__thr_umutex_unlock(struct umutex *mtx)
172{
173
174	return (_umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0));
175}
176
177int
178__thr_umutex_trylock(struct umutex *mtx)
179{
180
181	return (_umtx_op_err(mtx, UMTX_OP_MUTEX_TRYLOCK, 0, 0, 0));
182}
183
184int
185__thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
186    uint32_t *oldceiling)
187{
188
189	return (_umtx_op_err(mtx, UMTX_OP_SET_CEILING, ceiling, oldceiling, 0));
190}
191
192int
193_thr_umtx_wait(volatile long *mtx, long id, const struct timespec *timeout)
194{
195
196	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
197	    timeout->tv_nsec <= 0)))
198		return (ETIMEDOUT);
199	return (_umtx_op_err(__DEVOLATILE(void *, mtx), UMTX_OP_WAIT, id, 0,
200	    __DECONST(void*, timeout)));
201}
202
203int
204_thr_umtx_wait_uint(volatile u_int *mtx, u_int id,
205    const struct timespec *timeout, int shared)
206{
207
208	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
209	    timeout->tv_nsec <= 0)))
210		return (ETIMEDOUT);
211	return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
212	    UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id, 0,
213	    __DECONST(void*, timeout)));
214}
215
216int
217_thr_umtx_timedwait_uint(volatile u_int *mtx, u_int id, int clockid,
218    const struct timespec *abstime, int shared)
219{
220	struct _umtx_time *tm_p, timeout;
221	size_t tm_size;
222
223	if (abstime == NULL) {
224		tm_p = NULL;
225		tm_size = 0;
226	} else {
227		timeout._clockid = clockid;
228		timeout._flags = UMTX_ABSTIME;
229		timeout._timeout = *abstime;
230		tm_p = &timeout;
231		tm_size = sizeof(timeout);
232	}
233
234	return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
235	    UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id,
236	    (void *)tm_size, __DECONST(void *, tm_p)));
237}
238
239int
240_thr_umtx_wake(volatile void *mtx, int nr_wakeup, int shared)
241{
242
243	return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
244	    UMTX_OP_WAKE : UMTX_OP_WAKE_PRIVATE, nr_wakeup, 0, 0));
245}
246
247void
248_thr_ucond_init(struct ucond *cv)
249{
250
251	bzero(cv, sizeof(struct ucond));
252}
253
254int
255_thr_ucond_wait(struct ucond *cv, struct umutex *m,
256	const struct timespec *timeout, int flags)
257{
258	struct pthread *curthread;
259
260	if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
261	    timeout->tv_nsec <= 0))) {
262		curthread = _get_curthread();
263		_thr_umutex_unlock(m, TID(curthread));
264                return (ETIMEDOUT);
265	}
266	return (_umtx_op_err(cv, UMTX_OP_CV_WAIT, flags, m,
267	    __DECONST(void*, timeout)));
268}
269
270int
271_thr_ucond_signal(struct ucond *cv)
272{
273
274	if (!cv->c_has_waiters)
275		return (0);
276	return (_umtx_op_err(cv, UMTX_OP_CV_SIGNAL, 0, NULL, NULL));
277}
278
279int
280_thr_ucond_broadcast(struct ucond *cv)
281{
282
283	if (!cv->c_has_waiters)
284		return (0);
285	return (_umtx_op_err(cv, UMTX_OP_CV_BROADCAST, 0, NULL, NULL));
286}
287
288int
289__thr_rwlock_rdlock(struct urwlock *rwlock, int flags,
290	const struct timespec *tsp)
291{
292	struct _umtx_time timeout, *tm_p;
293	size_t tm_size;
294
295	if (tsp == NULL) {
296		tm_p = NULL;
297		tm_size = 0;
298	} else {
299		timeout._timeout = *tsp;
300		timeout._flags = UMTX_ABSTIME;
301		timeout._clockid = CLOCK_REALTIME;
302		tm_p = &timeout;
303		tm_size = sizeof(timeout);
304	}
305	return (_umtx_op_err(rwlock, UMTX_OP_RW_RDLOCK, flags,
306	    (void *)tm_size, tm_p));
307}
308
309int
310__thr_rwlock_wrlock(struct urwlock *rwlock, const struct timespec *tsp)
311{
312	struct _umtx_time timeout, *tm_p;
313	size_t tm_size;
314
315	if (tsp == NULL) {
316		tm_p = NULL;
317		tm_size = 0;
318	} else {
319		timeout._timeout = *tsp;
320		timeout._flags = UMTX_ABSTIME;
321		timeout._clockid = CLOCK_REALTIME;
322		tm_p = &timeout;
323		tm_size = sizeof(timeout);
324	}
325	return (_umtx_op_err(rwlock, UMTX_OP_RW_WRLOCK, 0, (void *)tm_size,
326	    tm_p));
327}
328
329int
330__thr_rwlock_unlock(struct urwlock *rwlock)
331{
332
333	return (_umtx_op_err(rwlock, UMTX_OP_RW_UNLOCK, 0, NULL, NULL));
334}
335
336void
337_thr_rwl_rdlock(struct urwlock *rwlock)
338{
339	int ret;
340
341	for (;;) {
342		if (_thr_rwlock_tryrdlock(rwlock, URWLOCK_PREFER_READER) == 0)
343			return;
344		ret = __thr_rwlock_rdlock(rwlock, URWLOCK_PREFER_READER, NULL);
345		if (ret == 0)
346			return;
347		if (ret != EINTR)
348			PANIC("rdlock error");
349	}
350}
351
352void
353_thr_rwl_wrlock(struct urwlock *rwlock)
354{
355	int ret;
356
357	for (;;) {
358		if (_thr_rwlock_trywrlock(rwlock) == 0)
359			return;
360		ret = __thr_rwlock_wrlock(rwlock, NULL);
361		if (ret == 0)
362			return;
363		if (ret != EINTR)
364			PANIC("wrlock error");
365	}
366}
367
368void
369_thr_rwl_unlock(struct urwlock *rwlock)
370{
371
372	if (_thr_rwlock_unlock(rwlock))
373		PANIC("unlock error");
374}
375