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
40#if defined(__x86_64__)
41/* Synthetic event if none is specified, for backwards compatibility only. */
42static bool IOLockSleep_NO_EVENT __attribute__((used)) = 0;
43#endif
44
45void IOLockInitWithState( IOLock * lock, IOLockState state)
46{
47 if( state == kIOLockStateLocked)
48 lck_mtx_lock( lock);
49}
50
51IOLock * IOLockAlloc( void )
52{
53 return( lck_mtx_alloc_init(IOLockGroup, LCK_ATTR_NULL) );
54}
55
56void IOLockFree( IOLock * lock)
57{
58 lck_mtx_free( lock, IOLockGroup);
59}
60
61lck_mtx_t * IOLockGetMachLock( IOLock * lock)
62{
63 return( (lck_mtx_t *)lock);
64}
65
66int IOLockSleep( IOLock * lock, void *event, UInt32 interType)
67{
68 return (int) lck_mtx_sleep(lock, LCK_SLEEP_PROMOTED_PRI, (event_t) event, (wait_interrupt_t) interType);
69}
70
71int IOLockSleepDeadline( IOLock * lock, void *event,
72 AbsoluteTime deadline, UInt32 interType)
73{
74 return (int) lck_mtx_sleep_deadline(lock, LCK_SLEEP_PROMOTED_PRI, (event_t) event,
75 (wait_interrupt_t) interType, __OSAbsoluteTime(deadline));
76}
77
78void IOLockWakeup(IOLock * lock, void *event, bool oneThread)
79{
80 thread_wakeup_prim((event_t) event, oneThread, THREAD_AWAKENED);
81}
82
83
84#if defined(__x86_64__)
85/*
86 * For backwards compatibility, kexts built against pre-Darwin 14 headers will bind at runtime to this function,
87 * which supports a NULL event,
88 */
89int IOLockSleep_legacy_x86_64( IOLock * lock, void *event, UInt32 interType) __asm("_IOLockSleep");
90int IOLockSleepDeadline_legacy_x86_64( IOLock * lock, void *event,
91 AbsoluteTime deadline, UInt32 interType) __asm("_IOLockSleepDeadline");
92void IOLockWakeup_legacy_x86_64(IOLock * lock, void *event, bool oneThread) __asm("_IOLockWakeup");
93
94int IOLockSleep_legacy_x86_64( IOLock * lock, void *event, UInt32 interType)
95{
96 if (event == NULL)
97 event = (void *)&IOLockSleep_NO_EVENT;
98
99 return IOLockSleep(lock, event, interType);
100}
101
102int IOLockSleepDeadline_legacy_x86_64( IOLock * lock, void *event,
103 AbsoluteTime deadline, UInt32 interType)
104{
105 if (event == NULL)
106 event = (void *)&IOLockSleep_NO_EVENT;
107
108 return IOLockSleepDeadline(lock, event, deadline, interType);
109}
110
111void IOLockWakeup_legacy_x86_64(IOLock * lock, void *event, bool oneThread)
112{
113 if (event == NULL)
114 event = (void *)&IOLockSleep_NO_EVENT;
115
116 IOLockWakeup(lock, event, oneThread);
117}
118#endif /* defined(__x86_64__) */
119
120
121struct _IORecursiveLock {
122 lck_mtx_t mutex;
123 lck_grp_t *group;
124 thread_t thread;
125 UInt32 count;
126};
127
128IORecursiveLock * IORecursiveLockAllocWithLockGroup( lck_grp_t * lockGroup )
129{
130 _IORecursiveLock * lock;
131
132 if( lockGroup == 0 )
133 return( 0 );
134
135 lock = IONew( _IORecursiveLock, 1 );
136 if( !lock )
137 return( 0 );
138
139 lck_mtx_init( &lock->mutex, lockGroup, LCK_ATTR_NULL );
140 lock->group = lockGroup;
141 lock->thread = 0;
142 lock->count = 0;
143
144 return( (IORecursiveLock *) lock );
145}
146
147
148IORecursiveLock * IORecursiveLockAlloc( void )
149{
150 return IORecursiveLockAllocWithLockGroup( IOLockGroup );
151}
152
153void IORecursiveLockFree( IORecursiveLock * _lock )
154{
155 _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
156
157 lck_mtx_destroy(&lock->mutex, lock->group);
158 IODelete( lock, _IORecursiveLock, 1 );
159}
160
161lck_mtx_t * IORecursiveLockGetMachLock( IORecursiveLock * lock )
162{
163 return( &lock->mutex );
164}
165
166void IORecursiveLockLock( IORecursiveLock * _lock)
167{
168 _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
169
170 if( lock->thread == IOThreadSelf())
171 lock->count++;
172 else {
173 lck_mtx_lock( &lock->mutex );
174 assert( lock->thread == 0 );
175 assert( lock->count == 0 );
176 lock->thread = IOThreadSelf();
177 lock->count = 1;
178 }
179}
180
181boolean_t IORecursiveLockTryLock( IORecursiveLock * _lock)
182{
183 _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
184
185 if( lock->thread == IOThreadSelf()) {
186 lock->count++;
187 return( true );
188 } else {
189 if( lck_mtx_try_lock( &lock->mutex )) {
190 assert( lock->thread == 0 );
191 assert( lock->count == 0 );
192 lock->thread = IOThreadSelf();
193 lock->count = 1;
194 return( true );
195 }
196 }
197 return( false );
198}
199
200void IORecursiveLockUnlock( IORecursiveLock * _lock)
201{
202 _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
203
204 assert( lock->thread == IOThreadSelf() );
205
206 if( 0 == (--lock->count)) {
207 lock->thread = 0;
208 lck_mtx_unlock( &lock->mutex );
209 }
210}
211
212boolean_t IORecursiveLockHaveLock( const IORecursiveLock * _lock)
213{
214 _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
215
216 return( lock->thread == IOThreadSelf());
217}
218
219int IORecursiveLockSleep(IORecursiveLock *_lock, void *event, UInt32 interType)
220{
221 _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
222 UInt32 count = lock->count;
223 int res;
224
225 assert(lock->thread == IOThreadSelf());
226
227 lock->count = 0;
228 lock->thread = 0;
229 res = lck_mtx_sleep(&lock->mutex, LCK_SLEEP_PROMOTED_PRI, (event_t) event, (wait_interrupt_t) interType);
230
231 // Must re-establish the recursive lock no matter why we woke up
232 // otherwise we would potentially leave the return path corrupted.
233 assert(lock->thread == 0);
234 assert(lock->count == 0);
235 lock->thread = IOThreadSelf();
236 lock->count = count;
237 return res;
238}
239
240int IORecursiveLockSleepDeadline( IORecursiveLock * _lock, void *event,
241 AbsoluteTime deadline, UInt32 interType)
242{
243 _IORecursiveLock * lock = (_IORecursiveLock *)_lock;
244 UInt32 count = lock->count;
245 int res;
246
247 assert(lock->thread == IOThreadSelf());
248
249 lock->count = 0;
250 lock->thread = 0;
251 res = lck_mtx_sleep_deadline(&lock->mutex, LCK_SLEEP_PROMOTED_PRI, (event_t) event,
252 (wait_interrupt_t) interType, __OSAbsoluteTime(deadline));
253
254 // Must re-establish the recursive lock no matter why we woke up
255 // otherwise we would potentially leave the return path corrupted.
256 assert(lock->thread == 0);
257 assert(lock->count == 0);
258 lock->thread = IOThreadSelf();
259 lock->count = count;
260 return res;
261}
262
263void IORecursiveLockWakeup(IORecursiveLock *, void *event, bool oneThread)
264{
265 thread_wakeup_prim((event_t) event, oneThread, THREAD_AWAKENED);
266}
267
268/*
269 * Complex (read/write) lock operations
270 */
271
272IORWLock * IORWLockAlloc( void )
273{
274 return( lck_rw_alloc_init(IOLockGroup, LCK_ATTR_NULL) );
275}
276
277void IORWLockFree( IORWLock * lock)
278{
279 lck_rw_free( lock, IOLockGroup);
280}
281
282lck_rw_t * IORWLockGetMachLock( IORWLock * lock)
283{
284 return( (lck_rw_t *)lock);
285}
286
287
288/*
289 * Spin locks
290 */
291
292IOSimpleLock * IOSimpleLockAlloc( void )
293{
294 return( lck_spin_alloc_init( IOLockGroup, LCK_ATTR_NULL) );
295}
296
297void IOSimpleLockInit( IOSimpleLock * lock)
298{
299 lck_spin_init( lock, IOLockGroup, LCK_ATTR_NULL);
300}
301
302void IOSimpleLockFree( IOSimpleLock * lock )
303{
304 lck_spin_free( lock, IOLockGroup);
305}
306
307lck_spin_t * IOSimpleLockGetMachLock( IOSimpleLock * lock)
308{
309 return( (lck_spin_t *)lock);
310}
311
312#ifndef IOLOCKS_INLINE
313/*
314 * Lock assertions
315 */
316
317void
318IOLockAssert(IOLock * lock, IOLockAssertState type)
319{
320 LCK_MTX_ASSERT(lock, type);
321}
322
323void
324IORWLockAssert(IORWLock * lock, IORWLockAssertState type)
325{
326 LCK_RW_ASSERT(lock, type);
327}
328
329void
330IOSimpleLockAssert(IOSimpleLock *lock, IOSimpleLockAssertState type)
331{
332 LCK_SPIN_ASSERT(l, type);
333}
334#endif /* !IOLOCKS_INLINE */
335
336} /* extern "C" */
337
338
339