powernotification-r0drv.c

Last change on this file was 106061, checked in by vboxsync, 2 months ago
Copyright year updates by scm.
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1	/* $Id: powernotification-r0drv.c 106061 2024-09-16 14:03:52Z vboxsync $ */
2	/** @file
3	* IPRT - Power Management, Ring-0 Driver, Event Notifications.
4	*/
5
6	/*
7	* Copyright (C) 2008-2024 Oracle and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* The contents of this file may alternatively be used under the terms
26	* of the Common Development and Distribution License Version 1.0
27	* (CDDL), a copy of it is provided in the "COPYING.CDDL" file included
28	* in the VirtualBox distribution, in which case the provisions of the
29	* CDDL are applicable instead of those of the GPL.
30	*
31	* You may elect to license modified versions of this file under the
32	* terms and conditions of either the GPL or the CDDL or both.
33	*
34	* SPDX-License-Identifier: GPL-3.0-only OR CDDL-1.0
35	*/
36
37
38	/*********************************************************************************************************************************
39	* Header Files *
40	*********************************************************************************************************************************/
41	#include <iprt/power.h>
42	#include "internal/iprt.h"
43
44	#include <iprt/asm.h>
45	#if defined(RT_ARCH_AMD64) \|\| defined(RT_ARCH_X86)
46	# include <iprt/asm-amd64-x86.h>
47	#endif
48	#include <iprt/assert.h>
49	#include <iprt/err.h>
50	#include <iprt/mem.h>
51	#include <iprt/spinlock.h>
52	#include <iprt/string.h>
53	#include <iprt/thread.h>
54	#include "r0drv/mp-r0drv.h"
55	#include "r0drv/power-r0drv.h"
56
57
58	/*********************************************************************************************************************************
59	* Structures and Typedefs *
60	*********************************************************************************************************************************/
61	/**
62	* Notification registration record tracking
63	* RTPowerRegisterNotification() calls.
64	*/
65	typedef struct RTPOWERNOTIFYREG
66	{
67	/** Pointer to the next record. */
68	struct RTPOWERNOTIFYREG * volatile pNext;
69	/** The callback. */
70	PFNRTPOWERNOTIFICATION pfnCallback;
71	/** The user argument. */
72	void *pvUser;
73	/** Bit mask indicating whether we've done this callback or not. */
74	uint8_t bmDone[sizeof(void *)];
75	} RTPOWERNOTIFYREG;
76	/** Pointer to a registration record. */
77	typedef RTPOWERNOTIFYREG *PRTPOWERNOTIFYREG;
78
79
80	/*********************************************************************************************************************************
81	* Global Variables *
82	*********************************************************************************************************************************/
83	/** The spinlock protecting the list. */
84	static RTSPINLOCK volatile g_hRTPowerNotifySpinLock = NIL_RTSPINLOCK;
85	/** List of callbacks, in registration order. */
86	static PRTPOWERNOTIFYREG volatile g_pRTPowerCallbackHead = NULL;
87	/** The current done bit. */
88	static uint32_t volatile g_iRTPowerDoneBit;
89	/** The list generation.
90	* This is increased whenever the list has been modified. The callback routine
91	* make use of this to avoid having restart at the list head after each callback. */
92	static uint32_t volatile g_iRTPowerGeneration;
93
94
95
96
97	RTDECL(int) RTPowerSignalEvent(RTPOWEREVENT enmEvent)
98	{
99	PRTPOWERNOTIFYREG pCur;
100	RTSPINLOCK hSpinlock;
101
102	/*
103	* This is a little bit tricky as we cannot be holding the spinlock
104	* while calling the callback. This means that the list might change
105	* while we're walking it, and that multiple events might be running
106	* concurrently (depending on the OS).
107	*
108	* So, the first measure is to employ a 32-bitmask for each
109	* record where we'll use a bit that rotates for each call to
110	* this function to indicate which records that has been
111	* processed. This will take care of both changes to the list
112	* and a reasonable amount of concurrent events.
113	*
114	* In order to avoid having to restart the list walks for every
115	* callback we make, we'll make use a list generation number that is
116	* incremented everytime the list is changed. So, if it remains
117	* unchanged over a callback we can safely continue the iteration.
118	*/
119	uint32_t iDone = ASMAtomicIncU32(&g_iRTPowerDoneBit);
120	iDone %= RT_SIZEOFMEMB(RTPOWERNOTIFYREG, bmDone) * 8;
121
122	hSpinlock = g_hRTPowerNotifySpinLock;
123	if (hSpinlock == NIL_RTSPINLOCK)
124	return VERR_ACCESS_DENIED;
125	RTSpinlockAcquire(hSpinlock);
126
127	/* Clear the bit. */
128	for (pCur = g_pRTPowerCallbackHead; pCur; pCur = pCur->pNext)
129	ASMAtomicBitClear(&pCur->bmDone[0], iDone);
130
131	/* Iterate the records and perform the callbacks. */
132	do
133	{
134	uint32_t const iGeneration = ASMAtomicUoReadU32(&g_iRTPowerGeneration);
135
136	pCur = g_pRTPowerCallbackHead;
137	while (pCur)
138	{
139	if (!ASMAtomicBitTestAndSet(&pCur->bmDone[0], iDone))
140	{
141	PFNRTPOWERNOTIFICATION pfnCallback = pCur->pfnCallback;
142	void *pvUser = pCur->pvUser;
143	pCur = pCur->pNext;
144	RTSpinlockRelease(g_hRTPowerNotifySpinLock);
145
146	pfnCallback(enmEvent, pvUser);
147
148	/* carefully require the lock here, see RTR0MpNotificationTerm(). */
149	hSpinlock = g_hRTPowerNotifySpinLock;
150	if (hSpinlock == NIL_RTSPINLOCK)
151	return VERR_ACCESS_DENIED;
152	RTSpinlockAcquire(hSpinlock);
153	if (ASMAtomicUoReadU32(&g_iRTPowerGeneration) != iGeneration)
154	break;
155	}
156	else
157	pCur = pCur->pNext;
158	}
159	} while (pCur);
160
161	RTSpinlockRelease(hSpinlock);
162	return VINF_SUCCESS;
163	}
164	RT_EXPORT_SYMBOL(RTPowerSignalEvent);
165
166
167	RTDECL(int) RTPowerNotificationRegister(PFNRTPOWERNOTIFICATION pfnCallback, void *pvUser)
168	{
169	PRTPOWERNOTIFYREG pCur;
170	PRTPOWERNOTIFYREG pNew;
171
172	/*
173	* Validation.
174	*/
175	AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
176	AssertReturn(g_hRTPowerNotifySpinLock != NIL_RTSPINLOCK, VERR_WRONG_ORDER);
177	RT_ASSERT_PREEMPTIBLE();
178
179	RTSpinlockAcquire(g_hRTPowerNotifySpinLock);
180	for (pCur = g_pRTPowerCallbackHead; pCur; pCur = pCur->pNext)
181	if ( pCur->pvUser == pvUser
182	&& pCur->pfnCallback == pfnCallback)
183	break;
184	RTSpinlockRelease(g_hRTPowerNotifySpinLock);
185	AssertMsgReturn(!pCur, ("pCur=%p pfnCallback=%p pvUser=%p\n", pCur, pfnCallback, pvUser), VERR_ALREADY_EXISTS);
186
187	/*
188	* Allocate a new record and attempt to insert it.
189	*/
190	pNew = (PRTPOWERNOTIFYREG)RTMemAlloc(sizeof(*pNew));
191	if (!pNew)
192	return VERR_NO_MEMORY;
193
194	pNew->pNext = NULL;
195	pNew->pfnCallback = pfnCallback;
196	pNew->pvUser = pvUser;
197	memset(&pNew->bmDone[0], 0xff, sizeof(pNew->bmDone));
198
199	RTSpinlockAcquire(g_hRTPowerNotifySpinLock);
200
201	pCur = g_pRTPowerCallbackHead;
202	if (!pCur)
203	g_pRTPowerCallbackHead = pNew;
204	else
205	{
206	for (pCur = g_pRTPowerCallbackHead; ; pCur = pCur->pNext)
207	if ( pCur->pvUser == pvUser
208	&& pCur->pfnCallback == pfnCallback)
209	break;
210	else if (!pCur->pNext)
211	{
212	pCur->pNext = pNew;
213	pCur = NULL;
214	break;
215	}
216	}
217
218	ASMAtomicIncU32(&g_iRTPowerGeneration);
219
220	RTSpinlockRelease(g_hRTPowerNotifySpinLock);
221
222	/* duplicate? */
223	if (pCur)
224	{
225	RTMemFree(pCur);
226	AssertMsgFailedReturn(("pCur=%p pfnCallback=%p pvUser=%p\n", pCur, pfnCallback, pvUser), VERR_ALREADY_EXISTS);
227	}
228
229	return VINF_SUCCESS;
230	}
231	RT_EXPORT_SYMBOL(RTPowerNotificationRegister);
232
233
234	RTDECL(int) RTPowerNotificationDeregister(PFNRTPOWERNOTIFICATION pfnCallback, void *pvUser)
235	{
236	PRTPOWERNOTIFYREG pPrev;
237	PRTPOWERNOTIFYREG pCur;
238
239	/*
240	* Validation.
241	*/
242	AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
243	AssertReturn(g_hRTPowerNotifySpinLock != NIL_RTSPINLOCK, VERR_WRONG_ORDER);
244	RT_ASSERT_INTS_ON();
245
246	/*
247	* Find and unlink the record from the list.
248	*/
249	RTSpinlockAcquire(g_hRTPowerNotifySpinLock);
250	pPrev = NULL;
251	for (pCur = g_pRTPowerCallbackHead; pCur; pCur = pCur->pNext)
252	{
253	if ( pCur->pvUser == pvUser
254	&& pCur->pfnCallback == pfnCallback)
255	break;
256	pPrev = pCur;
257	}
258	if (pCur)
259	{
260	if (pPrev)
261	pPrev->pNext = pCur->pNext;
262	else
263	g_pRTPowerCallbackHead = pCur->pNext;
264	ASMAtomicIncU32(&g_iRTPowerGeneration);
265	}
266	RTSpinlockRelease(g_hRTPowerNotifySpinLock);
267
268	if (!pCur)
269	return VERR_NOT_FOUND;
270
271	/*
272	* Invalidate and free the record.
273	*/
274	pCur->pNext = NULL;
275	pCur->pfnCallback = NULL;
276	RTMemFree(pCur);
277
278	return VINF_SUCCESS;
279	}
280	RT_EXPORT_SYMBOL(RTPowerNotificationDeregister);
281
282
283	DECLHIDDEN(int) rtR0PowerNotificationInit(void)
284	{
285	int rc = RTSpinlockCreate((PRTSPINLOCK)&g_hRTPowerNotifySpinLock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTR0Power");
286	if (RT_SUCCESS(rc))
287	{
288	/** @todo OS specific init here */
289	return rc;
290	#if 0
291	RTSpinlockDestroy(g_hRTPowerNotifySpinLock);
292	g_hRTPowerNotifySpinLock = NIL_RTSPINLOCK;
293	#endif
294	}
295	return rc;
296	}
297
298
299	DECLHIDDEN(void) rtR0PowerNotificationTerm(void)
300	{
301	PRTPOWERNOTIFYREG pHead;
302	RTSPINLOCK hSpinlock = g_hRTPowerNotifySpinLock;
303	AssertReturnVoid(hSpinlock != NIL_RTSPINLOCK);
304
305	/** @todo OS specific term here */
306
307	/* pick up the list and the spinlock. */
308	RTSpinlockAcquire(hSpinlock);
309	ASMAtomicWriteHandle(&g_hRTPowerNotifySpinLock, NIL_RTSPINLOCK);
310	pHead = g_pRTPowerCallbackHead;
311	g_pRTPowerCallbackHead = NULL;
312	ASMAtomicIncU32(&g_iRTPowerGeneration);
313	RTSpinlockRelease(hSpinlock);
314
315	/* free the list. */
316	while (pHead)
317	{
318	PRTPOWERNOTIFYREG pFree = pHead;
319	pHead = pHead->pNext;
320
321	pFree->pNext = NULL;
322	pFree->pfnCallback = NULL;
323	RTMemFree(pFree);
324	}
325
326	RTSpinlockDestroy(hSpinlock);
327	}
328

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

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