powernotification-r0drv.c@ 67979

Last change on this file since 67979 was 62477, checked in by vboxsync, 8 years ago
(C) 2016
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1	/* $Id: powernotification-r0drv.c 62477 2016-07-22 18:27:37Z vboxsync $ */
2	/** @file
3	* IPRT - Power Management, Ring-0 Driver, Event Notifications.
4	*/
5
6	/*
7	* Copyright (C) 2008-2016 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* The contents of this file may alternatively be used under the terms
18	* of the Common Development and Distribution License Version 1.0
19	* (CDDL) only, as it comes in the "COPYING.CDDL" file of the
20	* VirtualBox OSE distribution, in which case the provisions of the
21	* CDDL are applicable instead of those of the GPL.
22	*
23	* You may elect to license modified versions of this file under the
24	* terms and conditions of either the GPL or the CDDL or both.
25	*/
26
27
28	/*********************************************************************************************************************************
29	* Header Files *
30	*********************************************************************************************************************************/
31	#include <iprt/power.h>
32	#include "internal/iprt.h"
33
34	#include <iprt/asm.h>
35	#if defined(RT_ARCH_AMD64) \|\| defined(RT_ARCH_X86)
36	# include <iprt/asm-amd64-x86.h>
37	#endif
38	#include <iprt/assert.h>
39	#include <iprt/err.h>
40	#include <iprt/mem.h>
41	#include <iprt/spinlock.h>
42	#include <iprt/string.h>
43	#include <iprt/thread.h>
44	#include "r0drv/mp-r0drv.h"
45	#include "r0drv/power-r0drv.h"
46
47
48	/*********************************************************************************************************************************
49	* Structures and Typedefs *
50	*********************************************************************************************************************************/
51	/**
52	* Notification registration record tracking
53	* RTPowerRegisterNotification() calls.
54	*/
55	typedef struct RTPOWERNOTIFYREG
56	{
57	/** Pointer to the next record. */
58	struct RTPOWERNOTIFYREG * volatile pNext;
59	/** The callback. */
60	PFNRTPOWERNOTIFICATION pfnCallback;
61	/** The user argument. */
62	void *pvUser;
63	/** Bit mask indicating whether we've done this callback or not. */
64	uint8_t bmDone[sizeof(void *)];
65	} RTPOWERNOTIFYREG;
66	/** Pointer to a registration record. */
67	typedef RTPOWERNOTIFYREG *PRTPOWERNOTIFYREG;
68
69
70	/*********************************************************************************************************************************
71	* Global Variables *
72	*********************************************************************************************************************************/
73	/** The spinlock protecting the list. */
74	static RTSPINLOCK volatile g_hRTPowerNotifySpinLock = NIL_RTSPINLOCK;
75	/** List of callbacks, in registration order. */
76	static PRTPOWERNOTIFYREG volatile g_pRTPowerCallbackHead = NULL;
77	/** The current done bit. */
78	static uint32_t volatile g_iRTPowerDoneBit;
79	/** The list generation.
80	* This is increased whenever the list has been modified. The callback routine
81	* make use of this to avoid having restart at the list head after each callback. */
82	static uint32_t volatile g_iRTPowerGeneration;
83
84
85
86
87	RTDECL(int) RTPowerSignalEvent(RTPOWEREVENT enmEvent)
88	{
89	PRTPOWERNOTIFYREG pCur;
90	RTSPINLOCK hSpinlock;
91
92	/*
93	* This is a little bit tricky as we cannot be holding the spinlock
94	* while calling the callback. This means that the list might change
95	* while we're walking it, and that multiple events might be running
96	* concurrently (depending on the OS).
97	*
98	* So, the first measure is to employ a 32-bitmask for each
99	* record where we'll use a bit that rotates for each call to
100	* this function to indicate which records that has been
101	* processed. This will take care of both changes to the list
102	* and a reasonable amount of concurrent events.
103	*
104	* In order to avoid having to restart the list walks for every
105	* callback we make, we'll make use a list generation number that is
106	* incremented everytime the list is changed. So, if it remains
107	* unchanged over a callback we can safely continue the iteration.
108	*/
109	uint32_t iDone = ASMAtomicIncU32(&g_iRTPowerDoneBit);
110	iDone %= RT_SIZEOFMEMB(RTPOWERNOTIFYREG, bmDone) * 8;
111
112	hSpinlock = g_hRTPowerNotifySpinLock;
113	if (hSpinlock == NIL_RTSPINLOCK)
114	return VERR_ACCESS_DENIED;
115	RTSpinlockAcquire(hSpinlock);
116
117	/* Clear the bit. */
118	for (pCur = g_pRTPowerCallbackHead; pCur; pCur = pCur->pNext)
119	ASMAtomicBitClear(&pCur->bmDone[0], iDone);
120
121	/* Iterate the records and perform the callbacks. */
122	do
123	{
124	uint32_t const iGeneration = ASMAtomicUoReadU32(&g_iRTPowerGeneration);
125
126	pCur = g_pRTPowerCallbackHead;
127	while (pCur)
128	{
129	if (!ASMAtomicBitTestAndSet(&pCur->bmDone[0], iDone))
130	{
131	PFNRTPOWERNOTIFICATION pfnCallback = pCur->pfnCallback;
132	void *pvUser = pCur->pvUser;
133	pCur = pCur->pNext;
134	RTSpinlockRelease(g_hRTPowerNotifySpinLock);
135
136	pfnCallback(enmEvent, pvUser);
137
138	/* carefully require the lock here, see RTR0MpNotificationTerm(). */
139	hSpinlock = g_hRTPowerNotifySpinLock;
140	if (hSpinlock == NIL_RTSPINLOCK)
141	return VERR_ACCESS_DENIED;
142	RTSpinlockAcquire(hSpinlock);
143	if (ASMAtomicUoReadU32(&g_iRTPowerGeneration) != iGeneration)
144	break;
145	}
146	else
147	pCur = pCur->pNext;
148	}
149	} while (pCur);
150
151	RTSpinlockRelease(hSpinlock);
152	return VINF_SUCCESS;
153	}
154	RT_EXPORT_SYMBOL(RTPowerSignalEvent);
155
156
157	RTDECL(int) RTPowerNotificationRegister(PFNRTPOWERNOTIFICATION pfnCallback, void *pvUser)
158	{
159	PRTPOWERNOTIFYREG pCur;
160	PRTPOWERNOTIFYREG pNew;
161
162	/*
163	* Validation.
164	*/
165	AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
166	AssertReturn(g_hRTPowerNotifySpinLock != NIL_RTSPINLOCK, VERR_WRONG_ORDER);
167	RT_ASSERT_PREEMPTIBLE();
168
169	RTSpinlockAcquire(g_hRTPowerNotifySpinLock);
170	for (pCur = g_pRTPowerCallbackHead; pCur; pCur = pCur->pNext)
171	if ( pCur->pvUser == pvUser
172	&& pCur->pfnCallback == pfnCallback)
173	break;
174	RTSpinlockRelease(g_hRTPowerNotifySpinLock);
175	AssertMsgReturn(!pCur, ("pCur=%p pfnCallback=%p pvUser=%p\n", pCur, pfnCallback, pvUser), VERR_ALREADY_EXISTS);
176
177	/*
178	* Allocate a new record and attempt to insert it.
179	*/
180	pNew = (PRTPOWERNOTIFYREG)RTMemAlloc(sizeof(*pNew));
181	if (!pNew)
182	return VERR_NO_MEMORY;
183
184	pNew->pNext = NULL;
185	pNew->pfnCallback = pfnCallback;
186	pNew->pvUser = pvUser;
187	memset(&pNew->bmDone[0], 0xff, sizeof(pNew->bmDone));
188
189	RTSpinlockAcquire(g_hRTPowerNotifySpinLock);
190
191	pCur = g_pRTPowerCallbackHead;
192	if (!pCur)
193	g_pRTPowerCallbackHead = pNew;
194	else
195	{
196	for (pCur = g_pRTPowerCallbackHead; ; pCur = pCur->pNext)
197	if ( pCur->pvUser == pvUser
198	&& pCur->pfnCallback == pfnCallback)
199	break;
200	else if (!pCur->pNext)
201	{
202	pCur->pNext = pNew;
203	pCur = NULL;
204	break;
205	}
206	}
207
208	ASMAtomicIncU32(&g_iRTPowerGeneration);
209
210	RTSpinlockRelease(g_hRTPowerNotifySpinLock);
211
212	/* duplicate? */
213	if (pCur)
214	{
215	RTMemFree(pCur);
216	AssertMsgFailedReturn(("pCur=%p pfnCallback=%p pvUser=%p\n", pCur, pfnCallback, pvUser), VERR_ALREADY_EXISTS);
217	}
218
219	return VINF_SUCCESS;
220	}
221	RT_EXPORT_SYMBOL(RTPowerNotificationRegister);
222
223
224	RTDECL(int) RTPowerNotificationDeregister(PFNRTPOWERNOTIFICATION pfnCallback, void *pvUser)
225	{
226	PRTPOWERNOTIFYREG pPrev;
227	PRTPOWERNOTIFYREG pCur;
228
229	/*
230	* Validation.
231	*/
232	AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
233	AssertReturn(g_hRTPowerNotifySpinLock != NIL_RTSPINLOCK, VERR_WRONG_ORDER);
234	RT_ASSERT_INTS_ON();
235
236	/*
237	* Find and unlink the record from the list.
238	*/
239	RTSpinlockAcquire(g_hRTPowerNotifySpinLock);
240	pPrev = NULL;
241	for (pCur = g_pRTPowerCallbackHead; pCur; pCur = pCur->pNext)
242	{
243	if ( pCur->pvUser == pvUser
244	&& pCur->pfnCallback == pfnCallback)
245	break;
246	pPrev = pCur;
247	}
248	if (pCur)
249	{
250	if (pPrev)
251	pPrev->pNext = pCur->pNext;
252	else
253	g_pRTPowerCallbackHead = pCur->pNext;
254	ASMAtomicIncU32(&g_iRTPowerGeneration);
255	}
256	RTSpinlockRelease(g_hRTPowerNotifySpinLock);
257
258	if (!pCur)
259	return VERR_NOT_FOUND;
260
261	/*
262	* Invalidate and free the record.
263	*/
264	pCur->pNext = NULL;
265	pCur->pfnCallback = NULL;
266	RTMemFree(pCur);
267
268	return VINF_SUCCESS;
269	}
270	RT_EXPORT_SYMBOL(RTPowerNotificationDeregister);
271
272
273	DECLHIDDEN(int) rtR0PowerNotificationInit(void)
274	{
275	int rc = RTSpinlockCreate((PRTSPINLOCK)&g_hRTPowerNotifySpinLock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTR0Power");
276	if (RT_SUCCESS(rc))
277	{
278	/** @todo OS specific init here */
279	return rc;
280	#if 0
281	RTSpinlockDestroy(g_hRTPowerNotifySpinLock);
282	g_hRTPowerNotifySpinLock = NIL_RTSPINLOCK;
283	#endif
284	}
285	return rc;
286	}
287
288
289	DECLHIDDEN(void) rtR0PowerNotificationTerm(void)
290	{
291	PRTPOWERNOTIFYREG pHead;
292	RTSPINLOCK hSpinlock = g_hRTPowerNotifySpinLock;
293	AssertReturnVoid(hSpinlock != NIL_RTSPINLOCK);
294
295	/** @todo OS specific term here */
296
297	/* pick up the list and the spinlock. */
298	RTSpinlockAcquire(hSpinlock);
299	ASMAtomicWriteHandle(&g_hRTPowerNotifySpinLock, NIL_RTSPINLOCK);
300	pHead = g_pRTPowerCallbackHead;
301	g_pRTPowerCallbackHead = NULL;
302	ASMAtomicIncU32(&g_iRTPowerGeneration);
303	RTSpinlockRelease(hSpinlock);
304
305	/* free the list. */
306	while (pHead)
307	{
308	PRTPOWERNOTIFYREG pFree = pHead;
309	pHead = pHead->pNext;
310
311	pFree->pNext = NULL;
312	pFree->pfnCallback = NULL;
313	RTMemFree(pFree);
314	}
315
316	RTSpinlockDestroy(hSpinlock);
317	}
318

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source: vbox/trunk/src/VBox/Runtime/r0drv/powernotification-r0drv.c@ 67979

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