1/*
2 * Copyright (c) 1998-2007 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29#include <IOKit/system.h>
30
31#include <IOKit/IOReturn.h>
32#include <IOKit/IOLib.h>
33#include <IOKit/assert.h>
34
35#include <IOKit/IOLocksPrivate.h>
36
37extern "C" {
38#include <kern/locks.h>
39
40void	IOLockInitWithState( IOLock * lock, IOLockState state)
41{
42    if( state == kIOLockStateLocked)
43        lck_mtx_lock( lock);
44}
45
46IOLock * IOLockAlloc( void )
47{
48    return( lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL) );
49}
50
51void	IOLockFree( IOLock * lock)
52{
53    lck_mtx_free( lock, IOLockGroup);
54}
55
56lck_mtx_t * IOLockGetMachLock( IOLock * lock)
57{
58    return( (lck_mtx_t *)lock);
59}
60
61int	IOLockSleep( IOLock * lock, void *event, UInt32 interType)
62{
63    return (int) lck_mtx_sleep(lock, LCK_SLEEP_DEFAULT, (event_t) event, (wait_interrupt_t) interType);
64}
65
66int	IOLockSleepDeadline( IOLock * lock, void *event,
67                                AbsoluteTime deadline, UInt32 interType)
68{
69    return (int) lck_mtx_sleep_deadline(lock, LCK_SLEEP_DEFAULT, (event_t) event,
70    					(wait_interrupt_t) interType, __OSAbsoluteTime(deadline));
71}
72
73void	IOLockWakeup(IOLock * lock, void *event, bool oneThread)
74{
75	thread_wakeup_prim((event_t) event, oneThread, THREAD_AWAKENED);
76}
77
78
79struct _IORecursiveLock {
80	lck_mtx_t	*mutex;
81	lck_grp_t	*group;
82	thread_t	thread;
83	UInt32		count;
84};
85
86IORecursiveLock * IORecursiveLockAllocWithLockGroup( lck_grp_t * lockGroup )
87{
88    _IORecursiveLock * lock;
89
90    if( lockGroup == 0 )
91        return( 0 );
92
93    lock = IONew( _IORecursiveLock, 1 );
94    if( !lock )
95        return( 0 );
96
97    lock->mutex = lck_mtx_alloc_init( lockGroup, LCK_ATTR_NULL );
98    if( lock->mutex ) {
99		lock->group = lockGroup;
100        lock->thread = 0;
101        lock->count  = 0;
102    } else {
103        IODelete( lock, _IORecursiveLock, 1 );
104        lock = 0;
105    }
106
107    return( (IORecursiveLock *) lock );
108}
109
110
111IORecursiveLock * IORecursiveLockAlloc( void )
112{
113    return IORecursiveLockAllocWithLockGroup( IOLockGroup );
114}
115
116void IORecursiveLockFree( IORecursiveLock * _lock )
117{
118    _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
119
120    lck_mtx_free( lock->mutex, lock->group );
121    IODelete( lock, _IORecursiveLock, 1 );
122}
123
124lck_mtx_t * IORecursiveLockGetMachLock( IORecursiveLock * lock )
125{
126    return( lock->mutex );
127}
128
129void IORecursiveLockLock( IORecursiveLock * _lock)
130{
131    _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
132
133    if( lock->thread == IOThreadSelf())
134        lock->count++;
135    else {
136        lck_mtx_lock( lock->mutex );
137        assert( lock->thread == 0 );
138        assert( lock->count == 0 );
139        lock->thread = IOThreadSelf();
140        lock->count = 1;
141    }
142}
143
144boolean_t IORecursiveLockTryLock( IORecursiveLock * _lock)
145{
146    _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
147
148    if( lock->thread == IOThreadSelf()) {
149        lock->count++;
150	return( true );
151    } else {
152        if( lck_mtx_try_lock( lock->mutex )) {
153            assert( lock->thread == 0 );
154            assert( lock->count == 0 );
155            lock->thread = IOThreadSelf();
156            lock->count = 1;
157            return( true );
158	}
159    }
160    return( false );
161}
162
163void IORecursiveLockUnlock( IORecursiveLock * _lock)
164{
165    _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
166
167    assert( lock->thread == IOThreadSelf() );
168
169    if( 0 == (--lock->count)) {
170        lock->thread = 0;
171        lck_mtx_unlock( lock->mutex );
172    }
173}
174
175boolean_t IORecursiveLockHaveLock( const IORecursiveLock * _lock)
176{
177    _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
178
179    return( lock->thread == IOThreadSelf());
180}
181
182int IORecursiveLockSleep(IORecursiveLock *_lock, void *event, UInt32 interType)
183{
184    _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
185    UInt32 count = lock->count;
186    int res;
187
188    assert(lock->thread == IOThreadSelf());
189
190    lock->count = 0;
191    lock->thread = 0;
192    res = lck_mtx_sleep(lock->mutex, LCK_SLEEP_DEFAULT, (event_t) event, (wait_interrupt_t) interType);
193
194    // Must re-establish the recursive lock no matter why we woke up
195    // otherwise we would potentially leave the return path corrupted.
196    assert(lock->thread == 0);
197    assert(lock->count == 0);
198    lock->thread = IOThreadSelf();
199    lock->count = count;
200    return res;
201}
202
203int	IORecursiveLockSleepDeadline( IORecursiveLock * _lock, void *event,
204                                  AbsoluteTime deadline, UInt32 interType)
205{
206    _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
207    UInt32 count = lock->count;
208    int res;
209
210    assert(lock->thread == IOThreadSelf());
211
212    lock->count = 0;
213    lock->thread = 0;
214    res = lck_mtx_sleep_deadline(lock->mutex, LCK_SLEEP_DEFAULT, (event_t) event,
215								 (wait_interrupt_t) interType, __OSAbsoluteTime(deadline));
216
217    // Must re-establish the recursive lock no matter why we woke up
218    // otherwise we would potentially leave the return path corrupted.
219    assert(lock->thread == 0);
220    assert(lock->count == 0);
221    lock->thread = IOThreadSelf();
222    lock->count = count;
223    return res;
224}
225
226void IORecursiveLockWakeup(IORecursiveLock *, void *event, bool oneThread)
227{
228    thread_wakeup_prim((event_t) event, oneThread, THREAD_AWAKENED);
229}
230
231/*
232 * Complex (read/write) lock operations
233 */
234
235IORWLock * IORWLockAlloc( void )
236{
237    return(  lck_rw_alloc_init(IOLockGroup, LCK_ATTR_NULL)  );
238}
239
240void	IORWLockFree( IORWLock * lock)
241{
242    lck_rw_free( lock, IOLockGroup);
243}
244
245lck_rw_t * IORWLockGetMachLock( IORWLock * lock)
246{
247    return( (lck_rw_t *)lock);
248}
249
250
251/*
252 * Spin locks
253 */
254
255IOSimpleLock * IOSimpleLockAlloc( void )
256{
257    return( lck_spin_alloc_init( IOLockGroup, LCK_ATTR_NULL) );
258}
259
260void IOSimpleLockInit( IOSimpleLock * lock)
261{
262    lck_spin_init( lock, IOLockGroup, LCK_ATTR_NULL);
263}
264
265void IOSimpleLockFree( IOSimpleLock * lock )
266{
267    lck_spin_free( lock, IOLockGroup);
268}
269
270lck_spin_t * IOSimpleLockGetMachLock( IOSimpleLock * lock)
271{
272    return( (lck_spin_t *)lock);
273}
274
275} /* extern "C" */
276
277
278