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1 | /* $Id: powernotification-r0drv.c $ */ |
2 | /** @file | |
3 | * IPRT - Power Management, Ring-0 Driver, Event Notifications. | |
4 | */ | |
5 | ||
6 | /* | |
6d209b23 | 7 | * Copyright (C) 2008-2017 Oracle Corporation |
056a1eb7 SF |
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 |