1/*-
2 * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. Berkeley Software Design Inc's name may not be used to endorse or
13 *    promote products derived from this software without specific prior
14 *    written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 *	from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
29 * $FreeBSD: stable/11/sys/sys/mutex.h 327413 2017-12-31 05:06:35Z mjg $
30 */
31
32#ifndef _SYS_MUTEX_H_
33#define _SYS_MUTEX_H_
34
35#include <sys/queue.h>
36#include <sys/_lock.h>
37#include <sys/_mutex.h>
38
39#ifdef _KERNEL
40#include <sys/pcpu.h>
41#include <sys/lock_profile.h>
42#include <sys/lockstat.h>
43#include <machine/atomic.h>
44#include <machine/cpufunc.h>
45
46/*
47 * Mutex types and options passed to mtx_init().  MTX_QUIET and MTX_DUPOK
48 * can also be passed in.
49 */
50#define	MTX_DEF		0x00000000	/* DEFAULT (sleep) lock */
51#define MTX_SPIN	0x00000001	/* Spin lock (disables interrupts) */
52#define MTX_RECURSE	0x00000004	/* Option: lock allowed to recurse */
53#define	MTX_NOWITNESS	0x00000008	/* Don't do any witness checking. */
54#define MTX_NOPROFILE   0x00000020	/* Don't profile this lock */
55#define	MTX_NEW		0x00000040	/* Don't check for double-init */
56
57/*
58 * Option flags passed to certain lock/unlock routines, through the use
59 * of corresponding mtx_{lock,unlock}_flags() interface macros.
60 */
61#define	MTX_QUIET	LOP_QUIET	/* Don't log a mutex event */
62#define	MTX_DUPOK	LOP_DUPOK	/* Don't log a duplicate acquire */
63
64/*
65 * State bits kept in mutex->mtx_lock, for the DEFAULT lock type. None of this,
66 * with the exception of MTX_UNOWNED, applies to spin locks.
67 */
68#define	MTX_UNOWNED	0x00000000	/* Cookie for free mutex */
69#define	MTX_RECURSED	0x00000001	/* lock recursed (for MTX_DEF only) */
70#define	MTX_CONTESTED	0x00000002	/* lock contested (for MTX_DEF only) */
71#define	MTX_DESTROYED	0x00000004	/* lock destroyed */
72#define	MTX_FLAGMASK	(MTX_RECURSED | MTX_CONTESTED | MTX_DESTROYED)
73
74/*
75 * Prototypes
76 *
77 * NOTE: Functions prepended with `_' (underscore) are exported to other parts
78 *	 of the kernel via macros, thus allowing us to use the cpp LOCK_FILE
79 *	 and LOCK_LINE or for hiding the lock cookie crunching to the
80 *	 consumers. These functions should not be called directly by any
81 *	 code using the API. Their macros cover their functionality.
82 *	 Functions with a `_' suffix are the entrypoint for the common
83 *	 KPI covering both compat shims and fast path case.  These can be
84 *	 used by consumers willing to pass options, file and line
85 *	 informations, in an option-independent way.
86 *
87 * [See below for descriptions]
88 *
89 */
90void	_mtx_init(volatile uintptr_t *c, const char *name, const char *type,
91	    int opts);
92void	_mtx_destroy(volatile uintptr_t *c);
93void	mtx_sysinit(void *arg);
94int	_mtx_trylock_flags_int(struct mtx *m, int opts LOCK_FILE_LINE_ARG_DEF);
95int	_mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file,
96	    int line);
97void	mutex_init(void);
98#if LOCK_DEBUG > 0
99void	__mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v, int opts,
100	    const char *file, int line);
101void	__mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v, int opts,
102	    const char *file, int line);
103#else
104void	__mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v);
105void	__mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v);
106#endif
107
108#ifdef SMP
109#if LOCK_DEBUG > 0
110void	_mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v, int opts,
111	    const char *file, int line);
112#else
113void	_mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v);
114#endif
115#endif
116void	__mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file,
117	    int line);
118void	__mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file,
119	    int line);
120void	__mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file,
121	     int line);
122int	__mtx_trylock_spin_flags(volatile uintptr_t *c, int opts,
123	     const char *file, int line);
124void	__mtx_unlock_spin_flags(volatile uintptr_t *c, int opts,
125	    const char *file, int line);
126#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
127void	__mtx_assert(const volatile uintptr_t *c, int what, const char *file,
128	    int line);
129#endif
130void	thread_lock_flags_(struct thread *, int, const char *, int);
131#if LOCK_DEBUG > 0
132void	_thread_lock(struct thread *td, int opts, const char *file, int line);
133#else
134void	_thread_lock(struct thread *);
135#endif
136
137#if defined(LOCK_PROFILING) || defined(KLD_MODULE)
138#define	thread_lock(tdp)						\
139	thread_lock_flags_((tdp), 0, __FILE__, __LINE__)
140#elif LOCK_DEBUG > 0
141#define	thread_lock(tdp)						\
142	_thread_lock((tdp), 0, __FILE__, __LINE__)
143#else
144#define	thread_lock(tdp)						\
145	_thread_lock((tdp))
146#endif
147
148#if LOCK_DEBUG > 0
149#define	thread_lock_flags(tdp, opt)					\
150	thread_lock_flags_((tdp), (opt), __FILE__, __LINE__)
151#else
152#define	thread_lock_flags(tdp, opt)					\
153	_thread_lock(tdp)
154#endif
155
156#define	thread_unlock(tdp)						\
157       mtx_unlock_spin((tdp)->td_lock)
158
159/*
160 * Top-level macros to provide lock cookie once the actual mtx is passed.
161 * They will also prevent passing a malformed object to the mtx KPI by
162 * failing compilation as the mtx_lock reserved member will not be found.
163 */
164#define	mtx_init(m, n, t, o)						\
165	_mtx_init(&(m)->mtx_lock, n, t, o)
166#define	mtx_destroy(m)							\
167	_mtx_destroy(&(m)->mtx_lock)
168#define	mtx_trylock_flags_(m, o, f, l)					\
169	_mtx_trylock_flags_(&(m)->mtx_lock, o, f, l)
170#if LOCK_DEBUG > 0
171#define	_mtx_lock_sleep(m, v, o, f, l)					\
172	__mtx_lock_sleep(&(m)->mtx_lock, v, o, f, l)
173#define	_mtx_unlock_sleep(m, v, o, f, l)				\
174	__mtx_unlock_sleep(&(m)->mtx_lock, v, o, f, l)
175#else
176#define	_mtx_lock_sleep(m, v, o, f, l)					\
177	__mtx_lock_sleep(&(m)->mtx_lock, v)
178#define	_mtx_unlock_sleep(m, v, o, f, l)				\
179	__mtx_unlock_sleep(&(m)->mtx_lock, v)
180#endif
181#ifdef SMP
182#if LOCK_DEBUG > 0
183#define	_mtx_lock_spin(m, v, o, f, l)					\
184	_mtx_lock_spin_cookie(&(m)->mtx_lock, v, o, f, l)
185#else
186#define	_mtx_lock_spin(m, v, o, f, l)					\
187	_mtx_lock_spin_cookie(&(m)->mtx_lock, v)
188#endif
189#endif
190#define	_mtx_lock_flags(m, o, f, l)					\
191	__mtx_lock_flags(&(m)->mtx_lock, o, f, l)
192#define	_mtx_unlock_flags(m, o, f, l)					\
193	__mtx_unlock_flags(&(m)->mtx_lock, o, f, l)
194#define	_mtx_lock_spin_flags(m, o, f, l)				\
195	__mtx_lock_spin_flags(&(m)->mtx_lock, o, f, l)
196#define	_mtx_trylock_spin_flags(m, o, f, l)				\
197	__mtx_trylock_spin_flags(&(m)->mtx_lock, o, f, l)
198#define	_mtx_unlock_spin_flags(m, o, f, l)				\
199	__mtx_unlock_spin_flags(&(m)->mtx_lock, o, f, l)
200#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
201#define	_mtx_assert(m, w, f, l)						\
202	__mtx_assert(&(m)->mtx_lock, w, f, l)
203#endif
204
205#define	mtx_recurse	lock_object.lo_data
206
207/* Very simple operations on mtx_lock. */
208
209/* Try to obtain mtx_lock once. */
210#define _mtx_obtain_lock(mp, tid)					\
211	atomic_cmpset_acq_ptr(&(mp)->mtx_lock, MTX_UNOWNED, (tid))
212
213#define _mtx_obtain_lock_fetch(mp, vp, tid)				\
214	atomic_fcmpset_acq_ptr(&(mp)->mtx_lock, vp, (tid))
215
216/* Try to release mtx_lock if it is unrecursed and uncontested. */
217#define _mtx_release_lock(mp, tid)					\
218	atomic_cmpset_rel_ptr(&(mp)->mtx_lock, (tid), MTX_UNOWNED)
219
220/* Release mtx_lock quickly, assuming we own it. */
221#define _mtx_release_lock_quick(mp)					\
222	atomic_store_rel_ptr(&(mp)->mtx_lock, MTX_UNOWNED)
223
224#define	_mtx_release_lock_fetch(mp, vp)					\
225	atomic_fcmpset_rel_ptr(&(mp)->mtx_lock, (vp), MTX_UNOWNED)
226
227/*
228 * Full lock operations that are suitable to be inlined in non-debug
229 * kernels.  If the lock cannot be acquired or released trivially then
230 * the work is deferred to another function.
231 */
232
233/* Lock a normal mutex. */
234#define __mtx_lock(mp, tid, opts, file, line) do {			\
235	uintptr_t _tid = (uintptr_t)(tid);				\
236	uintptr_t _v = MTX_UNOWNED;					\
237									\
238	if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__acquire) ||\
239	    !_mtx_obtain_lock_fetch((mp), &_v, _tid)))			\
240		_mtx_lock_sleep((mp), _v, (opts), (file), (line));	\
241} while (0)
242
243/*
244 * Lock a spin mutex.  For spinlocks, we handle recursion inline (it
245 * turns out that function calls can be significantly expensive on
246 * some architectures).  Since spin locks are not _too_ common,
247 * inlining this code is not too big a deal.
248 */
249#ifdef SMP
250#define __mtx_lock_spin(mp, tid, opts, file, line) do {			\
251	uintptr_t _tid = (uintptr_t)(tid);				\
252	uintptr_t _v = MTX_UNOWNED;					\
253									\
254	spinlock_enter();						\
255	if (__predict_false(LOCKSTAT_PROFILE_ENABLED(spin__acquire) ||	\
256	    !_mtx_obtain_lock_fetch((mp), &_v, _tid))) 			\
257		_mtx_lock_spin((mp), _v, (opts), (file), (line)); 	\
258} while (0)
259#define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__  ({	\
260	uintptr_t _tid = (uintptr_t)(tid);				\
261	int _ret;							\
262									\
263	spinlock_enter();						\
264	if (((mp)->mtx_lock != MTX_UNOWNED || !_mtx_obtain_lock((mp), _tid))) {\
265		spinlock_exit();					\
266		_ret = 0;						\
267	} else {							\
268		LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire,	\
269		    mp, 0, 0, file, line);				\
270		_ret = 1;						\
271	}								\
272	_ret;								\
273})
274#else /* SMP */
275#define __mtx_lock_spin(mp, tid, opts, file, line) do {			\
276	uintptr_t _tid = (uintptr_t)(tid);				\
277									\
278	spinlock_enter();						\
279	if ((mp)->mtx_lock == _tid)					\
280		(mp)->mtx_recurse++;					\
281	else {								\
282		KASSERT((mp)->mtx_lock == MTX_UNOWNED, ("corrupt spinlock")); \
283		(mp)->mtx_lock = _tid;					\
284	}								\
285} while (0)
286#define __mtx_trylock_spin(mp, tid, opts, file, line) __extension__  ({	\
287	uintptr_t _tid = (uintptr_t)(tid);				\
288	int _ret;							\
289									\
290	spinlock_enter();						\
291	if ((mp)->mtx_lock != MTX_UNOWNED) {				\
292		spinlock_exit();					\
293		_ret = 0;						\
294	} else {							\
295		(mp)->mtx_lock = _tid;					\
296		_ret = 1;						\
297	}								\
298	_ret;								\
299})
300#endif /* SMP */
301
302/* Unlock a normal mutex. */
303#define __mtx_unlock(mp, tid, opts, file, line) do {			\
304	uintptr_t _v = (uintptr_t)(tid);				\
305									\
306	if (__predict_false(LOCKSTAT_PROFILE_ENABLED(adaptive__release) ||\
307	    !_mtx_release_lock_fetch((mp), &_v)))			\
308		_mtx_unlock_sleep((mp), _v, (opts), (file), (line));	\
309} while (0)
310
311/*
312 * Unlock a spin mutex.  For spinlocks, we can handle everything
313 * inline, as it's pretty simple and a function call would be too
314 * expensive (at least on some architectures).  Since spin locks are
315 * not _too_ common, inlining this code is not too big a deal.
316 *
317 * Since we always perform a spinlock_enter() when attempting to acquire a
318 * spin lock, we need to always perform a matching spinlock_exit() when
319 * releasing a spin lock.  This includes the recursion cases.
320 */
321#ifdef SMP
322#define __mtx_unlock_spin(mp) do {					\
323	if (mtx_recursed((mp)))						\
324		(mp)->mtx_recurse--;					\
325	else {								\
326		LOCKSTAT_PROFILE_RELEASE_LOCK(spin__release, mp);	\
327		_mtx_release_lock_quick((mp));				\
328	}								\
329	spinlock_exit();						\
330} while (0)
331#else /* SMP */
332#define __mtx_unlock_spin(mp) do {					\
333	if (mtx_recursed((mp)))						\
334		(mp)->mtx_recurse--;					\
335	else {								\
336		LOCKSTAT_PROFILE_RELEASE_LOCK(spin__release, mp);	\
337		(mp)->mtx_lock = MTX_UNOWNED;				\
338	}								\
339	spinlock_exit();						\
340} while (0)
341#endif /* SMP */
342
343/*
344 * Exported lock manipulation interface.
345 *
346 * mtx_lock(m) locks MTX_DEF mutex `m'
347 *
348 * mtx_lock_spin(m) locks MTX_SPIN mutex `m'
349 *
350 * mtx_unlock(m) unlocks MTX_DEF mutex `m'
351 *
352 * mtx_unlock_spin(m) unlocks MTX_SPIN mutex `m'
353 *
354 * mtx_lock_spin_flags(m, opts) and mtx_lock_flags(m, opts) locks mutex `m'
355 *     and passes option flags `opts' to the "hard" function, if required.
356 *     With these routines, it is possible to pass flags such as MTX_QUIET
357 *     to the appropriate lock manipulation routines.
358 *
359 * mtx_trylock(m) attempts to acquire MTX_DEF mutex `m' but doesn't sleep if
360 *     it cannot. Rather, it returns 0 on failure and non-zero on success.
361 *     It does NOT handle recursion as we assume that if a caller is properly
362 *     using this part of the interface, he will know that the lock in question
363 *     is _not_ recursed.
364 *
365 * mtx_trylock_flags(m, opts) is used the same way as mtx_trylock() but accepts
366 *     relevant option flags `opts.'
367 *
368 * mtx_trylock_spin(m) attempts to acquire MTX_SPIN mutex `m' but doesn't
369 *     spin if it cannot.  Rather, it returns 0 on failure and non-zero on
370 *     success.  It always returns failure for recursed lock attempts.
371 *
372 * mtx_initialized(m) returns non-zero if the lock `m' has been initialized.
373 *
374 * mtx_owned(m) returns non-zero if the current thread owns the lock `m'
375 *
376 * mtx_recursed(m) returns non-zero if the lock `m' is presently recursed.
377 */
378#define mtx_lock(m)		mtx_lock_flags((m), 0)
379#define mtx_lock_spin(m)	mtx_lock_spin_flags((m), 0)
380#define mtx_trylock(m)		mtx_trylock_flags((m), 0)
381#define mtx_trylock_spin(m)	mtx_trylock_spin_flags((m), 0)
382#define mtx_unlock(m)		mtx_unlock_flags((m), 0)
383#define mtx_unlock_spin(m)	mtx_unlock_spin_flags((m), 0)
384
385struct mtx_pool;
386
387struct mtx_pool *mtx_pool_create(const char *mtx_name, int pool_size, int opts);
388void mtx_pool_destroy(struct mtx_pool **poolp);
389struct mtx *mtx_pool_find(struct mtx_pool *pool, void *ptr);
390struct mtx *mtx_pool_alloc(struct mtx_pool *pool);
391#define mtx_pool_lock(pool, ptr)					\
392	mtx_lock(mtx_pool_find((pool), (ptr)))
393#define mtx_pool_lock_spin(pool, ptr)					\
394	mtx_lock_spin(mtx_pool_find((pool), (ptr)))
395#define mtx_pool_unlock(pool, ptr)					\
396	mtx_unlock(mtx_pool_find((pool), (ptr)))
397#define mtx_pool_unlock_spin(pool, ptr)					\
398	mtx_unlock_spin(mtx_pool_find((pool), (ptr)))
399
400/*
401 * mtxpool_sleep is a general purpose pool of sleep mutexes.
402 */
403extern struct mtx_pool *mtxpool_sleep;
404
405#ifndef LOCK_DEBUG
406#error LOCK_DEBUG not defined, include <sys/lock.h> before <sys/mutex.h>
407#endif
408#if LOCK_DEBUG > 0 || defined(MUTEX_NOINLINE)
409#define	mtx_lock_flags_(m, opts, file, line)				\
410	_mtx_lock_flags((m), (opts), (file), (line))
411#define	mtx_unlock_flags_(m, opts, file, line)				\
412	_mtx_unlock_flags((m), (opts), (file), (line))
413#define	mtx_lock_spin_flags_(m, opts, file, line)			\
414	_mtx_lock_spin_flags((m), (opts), (file), (line))
415#define	mtx_trylock_spin_flags_(m, opts, file, line)			\
416	_mtx_trylock_spin_flags((m), (opts), (file), (line))
417#define	mtx_unlock_spin_flags_(m, opts, file, line)			\
418	_mtx_unlock_spin_flags((m), (opts), (file), (line))
419#else	/* LOCK_DEBUG == 0 && !MUTEX_NOINLINE */
420#define	mtx_lock_flags_(m, opts, file, line)				\
421	__mtx_lock((m), curthread, (opts), (file), (line))
422#define	mtx_unlock_flags_(m, opts, file, line)				\
423	__mtx_unlock((m), curthread, (opts), (file), (line))
424#define	mtx_lock_spin_flags_(m, opts, file, line)			\
425	__mtx_lock_spin((m), curthread, (opts), (file), (line))
426#define	mtx_trylock_spin_flags_(m, opts, file, line)			\
427	__mtx_trylock_spin((m), curthread, (opts), (file), (line))
428#define	mtx_unlock_spin_flags_(m, opts, file, line)			\
429	__mtx_unlock_spin((m))
430#endif	/* LOCK_DEBUG > 0 || MUTEX_NOINLINE */
431
432#ifdef INVARIANTS
433#define	mtx_assert_(m, what, file, line)				\
434	_mtx_assert((m), (what), (file), (line))
435
436#define GIANT_REQUIRED	mtx_assert_(&Giant, MA_OWNED, __FILE__, __LINE__)
437
438#else	/* INVARIANTS */
439#define mtx_assert_(m, what, file, line)	(void)0
440#define GIANT_REQUIRED
441#endif	/* INVARIANTS */
442
443#define	mtx_lock_flags(m, opts)						\
444	mtx_lock_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
445#define	mtx_unlock_flags(m, opts)					\
446	mtx_unlock_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
447#define	mtx_lock_spin_flags(m, opts)					\
448	mtx_lock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
449#define	mtx_unlock_spin_flags(m, opts)					\
450	mtx_unlock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
451#define mtx_trylock_flags(m, opts)					\
452	mtx_trylock_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
453#define mtx_trylock_spin_flags(m, opts)					\
454	mtx_trylock_spin_flags_((m), (opts), LOCK_FILE, LOCK_LINE)
455#define	mtx_assert(m, what)						\
456	mtx_assert_((m), (what), __FILE__, __LINE__)
457
458#define	mtx_sleep(chan, mtx, pri, wmesg, timo)				\
459	_sleep((chan), &(mtx)->lock_object, (pri), (wmesg),		\
460	    tick_sbt * (timo), 0, C_HARDCLOCK)
461
462#define	MTX_READ_VALUE(m)	((m)->mtx_lock)
463
464#define	mtx_initialized(m)	lock_initialized(&(m)->lock_object)
465
466#define lv_mtx_owner(v)	((struct thread *)((v) & ~MTX_FLAGMASK))
467
468#define mtx_owner(m)	lv_mtx_owner(MTX_READ_VALUE(m))
469
470#define mtx_owned(m)	(mtx_owner(m) == curthread)
471
472#define mtx_recursed(m)	((m)->mtx_recurse != 0)
473
474#define mtx_name(m)	((m)->lock_object.lo_name)
475
476/*
477 * Global locks.
478 */
479extern struct mtx Giant;
480extern struct mtx blocked_lock;
481
482/*
483 * Giant lock manipulation and clean exit macros.
484 * Used to replace return with an exit Giant and return.
485 *
486 * Note that DROP_GIANT*() needs to be paired with PICKUP_GIANT()
487 * The #ifndef is to allow lint-like tools to redefine DROP_GIANT.
488 */
489#ifndef DROP_GIANT
490#define DROP_GIANT()							\
491do {									\
492	int _giantcnt = 0;						\
493	WITNESS_SAVE_DECL(Giant);					\
494									\
495	if (mtx_owned(&Giant)) {					\
496		WITNESS_SAVE(&Giant.lock_object, Giant);		\
497		for (_giantcnt = 0; mtx_owned(&Giant) &&		\
498		    !SCHEDULER_STOPPED(); _giantcnt++)			\
499			mtx_unlock(&Giant);				\
500	}
501
502#define PICKUP_GIANT()							\
503	PARTIAL_PICKUP_GIANT();						\
504} while (0)
505
506#define PARTIAL_PICKUP_GIANT()						\
507	mtx_assert(&Giant, MA_NOTOWNED);				\
508	if (_giantcnt > 0) {						\
509		while (_giantcnt--)					\
510			mtx_lock(&Giant);				\
511		WITNESS_RESTORE(&Giant.lock_object, Giant);		\
512	}
513#endif
514
515struct mtx_args {
516	void		*ma_mtx;
517	const char 	*ma_desc;
518	int		 ma_opts;
519};
520
521#define	MTX_SYSINIT(name, mtx, desc, opts)				\
522	static struct mtx_args name##_args = {				\
523		(mtx),							\
524		(desc),							\
525		(opts)							\
526	};								\
527	SYSINIT(name##_mtx_sysinit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
528	    mtx_sysinit, &name##_args);					\
529	SYSUNINIT(name##_mtx_sysuninit, SI_SUB_LOCK, SI_ORDER_MIDDLE,	\
530	    _mtx_destroy, __DEVOLATILE(void *, &(mtx)->mtx_lock))
531
532/*
533 * The INVARIANTS-enabled mtx_assert() functionality.
534 *
535 * The constants need to be defined for INVARIANT_SUPPORT infrastructure
536 * support as _mtx_assert() itself uses them and the latter implies that
537 * _mtx_assert() must build.
538 */
539#if defined(INVARIANTS) || defined(INVARIANT_SUPPORT)
540#define MA_OWNED	LA_XLOCKED
541#define MA_NOTOWNED	LA_UNLOCKED
542#define MA_RECURSED	LA_RECURSED
543#define MA_NOTRECURSED	LA_NOTRECURSED
544#endif
545
546/*
547 * Common lock type names.
548 */
549#define	MTX_NETWORK_LOCK	"network driver"
550
551#endif	/* _KERNEL */
552#endif	/* _SYS_MUTEX_H_ */
553