1 | /* |
2 | * Copyright (c) 1998-2010 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 | #define IOKIT_ENABLE_SHARED_PTR |
30 | |
31 | #if !defined(__LP64__) |
32 | |
33 | #include <IOKit/IOCommandQueue.h> |
34 | #include <IOKit/IOWorkLoop.h> |
35 | #include <IOKit/IOTimeStamp.h> |
36 | #include <IOKit/IOKitDebug.h> |
37 | #include <libkern/c++/OSSharedPtr.h> |
38 | |
39 | #include <mach/sync_policy.h> |
40 | |
41 | #if IOKITSTATS |
42 | |
43 | #define IOStatisticsInitializeCounter() \ |
44 | IOStatistics::setCounterType(reserved->counter, kIOStatisticsCommandQueueCounter) |
45 | |
46 | #define IOStatisticsActionCall() \ |
47 | IOStatistics::countCommandQueueActionCall(reserved->counter) |
48 | |
49 | #else |
50 | |
51 | #define IOStatisticsInitializeCounter() |
52 | #define IOStatisticsActionCall() |
53 | |
54 | #endif /* IOKITSTATS */ |
55 | |
56 | #define NUM_FIELDS_IN_COMMAND 4 |
57 | typedef struct commandEntryTag { |
58 | void *f[NUM_FIELDS_IN_COMMAND]; |
59 | } commandEntryT; |
60 | |
61 | #define super IOEventSource |
62 | |
63 | OSDefineMetaClassAndStructors(IOCommandQueue, IOEventSource) |
64 | |
65 | /*[ |
66 | * Instance Methods |
67 | * |
68 | * initWithNext:owner:action:size: |
69 | * - initWithNext: (IOEventSource *) inNext |
70 | * owner: (id) inOwner |
71 | * action: (SEL) inAction |
72 | * size: (int) inSize; |
73 | * |
74 | * Primary initialiser for the IOCommandQueue class. Returns an |
75 | * IOCommandQueue object that is initialised with the next object in |
76 | * the chain and the owner and action. On return the signalWorkAvailableIMP |
77 | * has been cached for this function. |
78 | * |
79 | * If the object fails to initialise for some reason then [self free] will |
80 | * be called and nil will be returned. |
81 | * |
82 | * See also: initWithNext:owner:action:(IOEventSource) |
83 | * ]*/ |
84 | bool |
85 | IOCommandQueue::init(OSObject *inOwner, |
86 | IOCommandQueueAction inAction, |
87 | int inSize) |
88 | { |
89 | if (!super::init(inOwner, (IOEventSourceAction) inAction)) { |
90 | return false; |
91 | } |
92 | |
93 | if (KERN_SUCCESS |
94 | != semaphore_create(kernel_task, &producerSema, SYNC_POLICY_FIFO, inSize)) { |
95 | return false; |
96 | } |
97 | |
98 | size = inSize + 1; /* Allocate one more entry than needed */ |
99 | |
100 | queue = (void *)kalloc_type(commandEntryT, size, Z_WAITOK_ZERO); |
101 | if (!queue) { |
102 | return false; |
103 | } |
104 | |
105 | producerLock = IOLockAlloc(); |
106 | if (!producerLock) { |
107 | return false; |
108 | } |
109 | |
110 | producerIndex = consumerIndex = 0; |
111 | |
112 | IOStatisticsInitializeCounter(); |
113 | |
114 | return true; |
115 | } |
116 | |
117 | OSSharedPtr<IOCommandQueue> |
118 | IOCommandQueue::commandQueue(OSObject *inOwner, |
119 | IOCommandQueueAction inAction, |
120 | int inSize) |
121 | { |
122 | OSSharedPtr<IOCommandQueue> me = OSMakeShared<IOCommandQueue>(); |
123 | |
124 | if (me && !me->init(inOwner, inAction, inSize)) { |
125 | me.reset(); |
126 | return nullptr; |
127 | } |
128 | |
129 | return me; |
130 | } |
131 | |
132 | /*[ |
133 | * free |
134 | * - free |
135 | * |
136 | * Mandatory free of the object independent of the current retain count. |
137 | * Returns nil. |
138 | * ]*/ |
139 | void |
140 | IOCommandQueue::free() |
141 | { |
142 | if (queue) { |
143 | kfree_type(commandEntryT, size, queue); |
144 | } |
145 | if (producerSema) { |
146 | semaphore_destroy(kernel_task, producerSema); |
147 | } |
148 | if (producerLock) { |
149 | IOLockFree(producerLock); |
150 | } |
151 | |
152 | super::free(); |
153 | } |
154 | |
155 | #if NUM_FIELDS_IN_COMMAND != 4 |
156 | #error IOCommandQueue::checkForWork needs to be updated for new command size |
157 | #endif |
158 | |
159 | bool |
160 | IOCommandQueue::checkForWork() |
161 | { |
162 | void *field0, *field1, *field2, *field3; |
163 | bool trace = (gIOKitTrace & kIOTraceCommandGates) ? true : false; |
164 | |
165 | if (!enabled || consumerIndex == producerIndex) { |
166 | return false; |
167 | } |
168 | |
169 | { |
170 | commandEntryT *q = (commandEntryT *) queue; |
171 | int localIndex = consumerIndex; |
172 | |
173 | field0 = q[localIndex].f[0]; field1 = q[localIndex].f[1]; |
174 | field2 = q[localIndex].f[2]; field3 = q[localIndex].f[3]; |
175 | semaphore_signal(producerSema); |
176 | } |
177 | |
178 | if (++consumerIndex >= size) { |
179 | consumerIndex = 0; |
180 | } |
181 | |
182 | if (trace) { |
183 | IOTimeStampStartConstant(IODBG_CMDQ(IOCMDQ_ACTION), |
184 | VM_KERNEL_ADDRHIDE(action), VM_KERNEL_ADDRHIDE(owner)); |
185 | } |
186 | |
187 | IOStatisticsActionCall(); |
188 | (*(IOCommandQueueAction) action)(owner, field0, field1, field2, field3); |
189 | |
190 | if (trace) { |
191 | IOTimeStampEndConstant(IODBG_CMDQ(IOCMDQ_ACTION), |
192 | VM_KERNEL_ADDRHIDE(action), VM_KERNEL_ADDRHIDE(owner)); |
193 | } |
194 | |
195 | return consumerIndex != producerIndex; |
196 | } |
197 | |
198 | /*[ |
199 | * enqueueSleep:command: |
200 | * - (kern_return_t) enqueueSleepRaw: (BOOL) gotoSleep |
201 | * field0: (void *) field0 field1: (void *) field1 |
202 | * field2: (void *) field2 field3: (void *) field3; |
203 | * |
204 | * Key method that enqueues the four input fields onto the command queue |
205 | * and calls signalWorkAvailable to indicate that work is available to the |
206 | * consumer. This routine is safe against multiple threaded producers. |
207 | * |
208 | * A family of convenience functions have been provided to assist with the |
209 | * enqueueing of an method selector and an integer tag. This relies on the |
210 | * IODevice rawCommandOccurred... command to forward on the requests. |
211 | * |
212 | * See also: signalWorkAvailable, checkForWork |
213 | * ]*/ |
214 | #if NUM_FIELDS_IN_COMMAND != 4 |
215 | #error IOCommandQueue::enqueueCommand needs to be updated |
216 | #endif |
217 | |
218 | kern_return_t |
219 | IOCommandQueue::enqueueCommand(bool gotoSleep, |
220 | void *field0, void *field1, |
221 | void *field2, void *field3) |
222 | { |
223 | kern_return_t rtn = KERN_SUCCESS; |
224 | int retry; |
225 | |
226 | /* Make sure there is room in the queue before doing anything else */ |
227 | |
228 | if (gotoSleep) { |
229 | retry = 0; |
230 | do{ |
231 | rtn = semaphore_wait(producerSema); |
232 | } while ((KERN_SUCCESS != rtn) |
233 | && (KERN_OPERATION_TIMED_OUT != rtn) |
234 | && (KERN_SEMAPHORE_DESTROYED != rtn) |
235 | && (KERN_TERMINATED != rtn) |
236 | && ((retry++) < 4)); |
237 | } else { |
238 | rtn = semaphore_timedwait(producerSema, MACH_TIMESPEC_ZERO); |
239 | } |
240 | |
241 | if (KERN_SUCCESS != rtn) { |
242 | return rtn; |
243 | } |
244 | |
245 | /* Block other producers */ |
246 | IOTakeLock(producerLock); |
247 | |
248 | /* |
249 | * Make sure that we update the current producer entry before we |
250 | * increment the producer pointer. This avoids a nasty race as the |
251 | * test for work is producerIndex != consumerIndex and a signal. |
252 | */ |
253 | { |
254 | commandEntryT *q = (commandEntryT *) queue; |
255 | int localIndex = producerIndex; |
256 | |
257 | q[localIndex].f[0] = field0; q[localIndex].f[1] = field1; |
258 | q[localIndex].f[2] = field2; q[localIndex].f[3] = field3; |
259 | } |
260 | if (++producerIndex >= size) { |
261 | producerIndex = 0; |
262 | } |
263 | |
264 | /* Clear to allow other producers to go now */ |
265 | IOUnlock(producerLock); |
266 | |
267 | /* |
268 | * Right we have created some new work, we had better make sure that |
269 | * we notify the work loop that it has to test producerIndex. |
270 | */ |
271 | signalWorkAvailable(); |
272 | return rtn; |
273 | } |
274 | |
275 | int |
276 | IOCommandQueue::performAndFlush(OSObject *target, |
277 | IOCommandQueueAction inAction) |
278 | { |
279 | int numEntries; |
280 | kern_return_t rtn; |
281 | |
282 | // Set the defaults if necessary |
283 | if (!target) { |
284 | target = owner; |
285 | } |
286 | if (!inAction) { |
287 | inAction = (IOCommandQueueAction) action; |
288 | } |
289 | |
290 | // Lock out the producers first |
291 | do { |
292 | rtn = semaphore_timedwait(producerSema, MACH_TIMESPEC_ZERO); |
293 | } while (rtn == KERN_SUCCESS); |
294 | |
295 | // now step over all remaining entries in the command queue |
296 | for (numEntries = 0; consumerIndex != producerIndex;) { |
297 | void *field0, *field1, *field2, *field3; |
298 | |
299 | { |
300 | commandEntryT *q = (commandEntryT *) queue; |
301 | int localIndex = consumerIndex; |
302 | |
303 | field0 = q[localIndex].f[0]; field1 = q[localIndex].f[1]; |
304 | field2 = q[localIndex].f[2]; field3 = q[localIndex].f[3]; |
305 | } |
306 | |
307 | if (++consumerIndex >= size) { |
308 | consumerIndex = 0; |
309 | } |
310 | |
311 | (*inAction)(target, field0, field1, field2, field3); |
312 | } |
313 | |
314 | // finally refill the producer semaphore to size - 1 |
315 | for (int i = 1; i < size; i++) { |
316 | semaphore_signal(producerSema); |
317 | } |
318 | |
319 | return numEntries; |
320 | } |
321 | |
322 | #endif /* !defined(__LP64__) */ |
323 | |