412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * IPRT - Multiprocessor, Ring-0 Driver, Event Notifications.
c58f1213e628a545081c70e26c6b67a841cff880vboxsync * Copyright (C) 2008-2013 Oracle Corporation
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * This file is part of VirtualBox Open Source Edition (OSE), as
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * available from http://www.virtualbox.org. This file is free software;
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * you can redistribute it and/or modify it under the terms of the GNU
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * General Public License (GPL) as published by the Free Software
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * Foundation, in version 2 as it comes in the "COPYING" file of the
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * The contents of this file may alternatively be used under the terms
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * of the Common Development and Distribution License Version 1.0
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * VirtualBox OSE distribution, in which case the provisions of the
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * CDDL are applicable instead of those of the GPL.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * You may elect to license modified versions of this file under the
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * terms and conditions of either the GPL or the CDDL or both.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync/*******************************************************************************
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync* Header Files *
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync*******************************************************************************/
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync/*******************************************************************************
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync* Structures and Typedefs *
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync*******************************************************************************/
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * Notification registration record tracking
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * RTMpRegisterNotification() calls.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync /** Pointer to the next record. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync /** The callback. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync /** The user argument. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync /** Bit mask indicating whether we've done this callback or not. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync/** Pointer to a registration record. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync/*******************************************************************************
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync* Global Variables *
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync*******************************************************************************/
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync/** The spinlock protecting the list. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsyncstatic RTSPINLOCK volatile g_hRTMpNotifySpinLock = NIL_RTSPINLOCK;
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync/** List of callbacks, in registration order. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsyncstatic PRTMPNOTIFYREG volatile g_pRTMpCallbackHead = NULL;
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync/** The current done bit. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync/** The list generation.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * This is increased whenever the list has been modified. The callback routine
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * make use of this to avoid having restart at the list head after each callback. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * This is called by the native code.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * @param idCpu The CPU id the event applies to.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * @param enmEvent The event.
5eda82e218d35ae0691febd531e1bfc0324cc4a6vboxsyncDECLHIDDEN(void) rtMpNotificationDoCallbacks(RTMPEVENT enmEvent, RTCPUID idCpu)
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * This is a little bit tricky as we cannot be holding the spinlock
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * while calling the callback. This means that the list might change
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * while we're walking it, and that multiple events might be running
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * concurrently (depending on the OS).
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * So, the first measure is to employ a 32-bitmask for each
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * record where we'll use a bit that rotates for each call to
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * this function to indicate which records that has been
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * processed. This will take care of both changes to the list
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * and a reasonable amount of concurrent events.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * In order to avoid having to restart the list walks for every
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * callback we make, we'll make use a list generation number that is
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * incremented everytime the list is changed. So, if it remains
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * unchanged over a callback we can safely continue the iteration.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync /* Clear the bit. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync for (pCur = g_pRTMpCallbackHead; pCur; pCur = pCur->pNext)
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync /* Iterate the records and perform the callbacks. */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync uint32_t const iGeneration = ASMAtomicUoReadU32(&g_iRTMpGeneration);
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync if (!ASMAtomicBitTestAndSet(&pCur->bmDone[0], iDone))
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync PFNRTMPNOTIFICATION pfnCallback = pCur->pfnCallback;
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync /* carefully require the lock here, see RTR0MpNotificationTerm(). */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync if (ASMAtomicUoReadU32(&g_iRTMpGeneration) != iGeneration)
412ad5bac323727b4073056113e1d8e0faf60db3vboxsyncRTDECL(int) RTMpNotificationRegister(PFNRTMPNOTIFICATION pfnCallback, void *pvUser)
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * Validation.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync AssertReturn(g_hRTMpNotifySpinLock != NIL_RTSPINLOCK, VERR_WRONG_ORDER);
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync for (pCur = g_pRTMpCallbackHead; pCur; pCur = pCur->pNext)
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync AssertMsgReturn(!pCur, ("pCur=%p pfnCallback=%p pvUser=%p\n", pCur, pfnCallback, pvUser), VERR_ALREADY_EXISTS);
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * Allocate a new record and attempt to insert it.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync memset(&pNew->bmDone[0], 0xff, sizeof(pNew->bmDone));
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync for (pCur = g_pRTMpCallbackHead; ; pCur = pCur->pNext)
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync /* duplicate? */
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync AssertMsgFailedReturn(("pCur=%p pfnCallback=%p pvUser=%p\n", pCur, pfnCallback, pvUser), VERR_ALREADY_EXISTS);
412ad5bac323727b4073056113e1d8e0faf60db3vboxsyncRTDECL(int) RTMpNotificationDeregister(PFNRTMPNOTIFICATION pfnCallback, void *pvUser)
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * Validation.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync AssertReturn(g_hRTMpNotifySpinLock != NIL_RTSPINLOCK, VERR_WRONG_ORDER);
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * Find and unlink the record from the list.
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync for (pCur = g_pRTMpCallbackHead; pCur; pCur = pCur->pNext)
412ad5bac323727b4073056113e1d8e0faf60db3vboxsync * Invalidate and free the record.
4904fa0280dc21e724cf7eaac5c959534b47b9b9vboxsync int rc = RTSpinlockCreate((PRTSPINLOCK)&g_hRTMpNotifySpinLock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTR0Mp");
7b6f8773dac1008543c95f9a606db09ebe3c97cavboxsync /* pick up the list and the spinlock. */
81cfcb51c89626fd5d331d92dcec81c94a5e9d2fvboxsync ASMAtomicWriteHandle(&g_hRTMpNotifySpinLock, NIL_RTSPINLOCK);
7b6f8773dac1008543c95f9a606db09ebe3c97cavboxsync /* free the list. */