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-rw-r--r--src/VBox/Runtime/r0drv/mpnotification-r0drv.c322
1 files changed, 322 insertions, 0 deletions
diff --git a/src/VBox/Runtime/r0drv/mpnotification-r0drv.c b/src/VBox/Runtime/r0drv/mpnotification-r0drv.c
new file mode 100644
index 00000000..ee90dca4
--- /dev/null
+++ b/src/VBox/Runtime/r0drv/mpnotification-r0drv.c
@@ -0,0 +1,322 @@
+/* $Id: mpnotification-r0drv.c $ */
+/** @file
+ * IPRT - Multiprocessor, Ring-0 Driver, Event Notifications.
+ */
+
+/*
+ * Copyright (C) 2008-2019 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+
+/*********************************************************************************************************************************
+* Header Files *
+*********************************************************************************************************************************/
+#include <iprt/mp.h>
+#include "internal/iprt.h"
+
+#include <iprt/asm.h>
+#if defined(RT_ARCH_AMD64) || defined(RT_ARCH_X86)
+# include <iprt/asm-amd64-x86.h>
+#endif
+#include <iprt/assert.h>
+#include <iprt/err.h>
+#include <iprt/mem.h>
+#include <iprt/spinlock.h>
+#include <iprt/string.h>
+#include <iprt/thread.h>
+#include "r0drv/mp-r0drv.h"
+
+
+/*********************************************************************************************************************************
+* Structures and Typedefs *
+*********************************************************************************************************************************/
+/**
+ * Notification registration record tracking
+ * RTMpRegisterNotification() calls.
+ */
+typedef struct RTMPNOTIFYREG
+{
+ /** Pointer to the next record. */
+ struct RTMPNOTIFYREG * volatile pNext;
+ /** The callback. */
+ PFNRTMPNOTIFICATION pfnCallback;
+ /** The user argument. */
+ void *pvUser;
+ /** Bit mask indicating whether we've done this callback or not. */
+ uint8_t bmDone[sizeof(void *)];
+} RTMPNOTIFYREG;
+/** Pointer to a registration record. */
+typedef RTMPNOTIFYREG *PRTMPNOTIFYREG;
+
+
+/*********************************************************************************************************************************
+* Global Variables *
+*********************************************************************************************************************************/
+/** The spinlock protecting the list. */
+static RTSPINLOCK volatile g_hRTMpNotifySpinLock = NIL_RTSPINLOCK;
+/** List of callbacks, in registration order. */
+static PRTMPNOTIFYREG volatile g_pRTMpCallbackHead = NULL;
+/** The current done bit. */
+static uint32_t volatile g_iRTMpDoneBit;
+/** The list generation.
+ * This is increased whenever the list has been modified. The callback routine
+ * make use of this to avoid having restart at the list head after each callback. */
+static uint32_t volatile g_iRTMpGeneration;
+
+
+
+
+/**
+ * This is called by the native code.
+ *
+ * @param idCpu The CPU id the event applies to.
+ * @param enmEvent The event.
+ */
+DECLHIDDEN(void) rtMpNotificationDoCallbacks(RTMPEVENT enmEvent, RTCPUID idCpu)
+{
+ PRTMPNOTIFYREG pCur;
+ RTSPINLOCK hSpinlock;
+
+ /*
+ * This is a little bit tricky as we cannot be holding the spinlock
+ * while calling the callback. This means that the list might change
+ * while we're walking it, and that multiple events might be running
+ * concurrently (depending on the OS).
+ *
+ * So, the first measure is to employ a 32-bitmask for each
+ * record where we'll use a bit that rotates for each call to
+ * this function to indicate which records that has been
+ * processed. This will take care of both changes to the list
+ * and a reasonable amount of concurrent events.
+ *
+ * In order to avoid having to restart the list walks for every
+ * callback we make, we'll make use a list generation number that is
+ * incremented everytime the list is changed. So, if it remains
+ * unchanged over a callback we can safely continue the iteration.
+ */
+ uint32_t iDone = ASMAtomicIncU32(&g_iRTMpDoneBit);
+ iDone %= RT_SIZEOFMEMB(RTMPNOTIFYREG, bmDone) * 8;
+
+ hSpinlock = g_hRTMpNotifySpinLock;
+ if (hSpinlock == NIL_RTSPINLOCK)
+ return;
+ RTSpinlockAcquire(hSpinlock);
+
+ /* Clear the bit. */
+ for (pCur = g_pRTMpCallbackHead; pCur; pCur = pCur->pNext)
+ ASMAtomicBitClear(&pCur->bmDone[0], iDone);
+
+ /* Iterate the records and perform the callbacks. */
+ do
+ {
+ uint32_t const iGeneration = ASMAtomicUoReadU32(&g_iRTMpGeneration);
+
+ pCur = g_pRTMpCallbackHead;
+ while (pCur)
+ {
+ if (!ASMAtomicBitTestAndSet(&pCur->bmDone[0], iDone))
+ {
+ PFNRTMPNOTIFICATION pfnCallback = pCur->pfnCallback;
+ void *pvUser = pCur->pvUser;
+ pCur = pCur->pNext;
+ RTSpinlockRelease(g_hRTMpNotifySpinLock);
+
+ pfnCallback(enmEvent, idCpu, pvUser);
+
+ /* carefully require the lock here, see RTR0MpNotificationTerm(). */
+ hSpinlock = g_hRTMpNotifySpinLock;
+ if (hSpinlock == NIL_RTSPINLOCK)
+ return;
+ RTSpinlockAcquire(hSpinlock);
+ if (ASMAtomicUoReadU32(&g_iRTMpGeneration) != iGeneration)
+ break;
+ }
+ else
+ pCur = pCur->pNext;
+ }
+ } while (pCur);
+
+ RTSpinlockRelease(hSpinlock);
+}
+
+
+
+RTDECL(int) RTMpNotificationRegister(PFNRTMPNOTIFICATION pfnCallback, void *pvUser)
+{
+ PRTMPNOTIFYREG pCur;
+ PRTMPNOTIFYREG pNew;
+
+ /*
+ * Validation.
+ */
+ AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
+ AssertReturn(g_hRTMpNotifySpinLock != NIL_RTSPINLOCK, VERR_WRONG_ORDER);
+ RT_ASSERT_PREEMPTIBLE();
+
+ RTSpinlockAcquire(g_hRTMpNotifySpinLock);
+ for (pCur = g_pRTMpCallbackHead; pCur; pCur = pCur->pNext)
+ if ( pCur->pvUser == pvUser
+ && pCur->pfnCallback == pfnCallback)
+ break;
+ RTSpinlockRelease(g_hRTMpNotifySpinLock);
+ AssertMsgReturn(!pCur, ("pCur=%p pfnCallback=%p pvUser=%p\n", pCur, pfnCallback, pvUser), VERR_ALREADY_EXISTS);
+
+ /*
+ * Allocate a new record and attempt to insert it.
+ */
+ pNew = (PRTMPNOTIFYREG)RTMemAlloc(sizeof(*pNew));
+ if (!pNew)
+ return VERR_NO_MEMORY;
+
+ pNew->pNext = NULL;
+ pNew->pfnCallback = pfnCallback;
+ pNew->pvUser = pvUser;
+ memset(&pNew->bmDone[0], 0xff, sizeof(pNew->bmDone));
+
+ RTSpinlockAcquire(g_hRTMpNotifySpinLock);
+
+ pCur = g_pRTMpCallbackHead;
+ if (!pCur)
+ g_pRTMpCallbackHead = pNew;
+ else
+ {
+ for (pCur = g_pRTMpCallbackHead; ; pCur = pCur->pNext)
+ if ( pCur->pvUser == pvUser
+ && pCur->pfnCallback == pfnCallback)
+ break;
+ else if (!pCur->pNext)
+ {
+ pCur->pNext = pNew;
+ pCur = NULL;
+ break;
+ }
+ }
+
+ ASMAtomicIncU32(&g_iRTMpGeneration);
+
+ RTSpinlockRelease(g_hRTMpNotifySpinLock);
+
+ /* duplicate? */
+ if (pCur)
+ {
+ RTMemFree(pCur);
+ AssertMsgFailedReturn(("pCur=%p pfnCallback=%p pvUser=%p\n", pCur, pfnCallback, pvUser), VERR_ALREADY_EXISTS);
+ }
+
+ return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTMpNotificationRegister);
+
+
+RTDECL(int) RTMpNotificationDeregister(PFNRTMPNOTIFICATION pfnCallback, void *pvUser)
+{
+ PRTMPNOTIFYREG pPrev;
+ PRTMPNOTIFYREG pCur;
+
+ /*
+ * Validation.
+ */
+ AssertPtrReturn(pfnCallback, VERR_INVALID_POINTER);
+ AssertReturn(g_hRTMpNotifySpinLock != NIL_RTSPINLOCK, VERR_WRONG_ORDER);
+ RT_ASSERT_INTS_ON();
+
+ /*
+ * Find and unlink the record from the list.
+ */
+ RTSpinlockAcquire(g_hRTMpNotifySpinLock);
+ pPrev = NULL;
+ for (pCur = g_pRTMpCallbackHead; pCur; pCur = pCur->pNext)
+ {
+ if ( pCur->pvUser == pvUser
+ && pCur->pfnCallback == pfnCallback)
+ break;
+ pPrev = pCur;
+ }
+ if (pCur)
+ {
+ if (pPrev)
+ pPrev->pNext = pCur->pNext;
+ else
+ g_pRTMpCallbackHead = pCur->pNext;
+ ASMAtomicIncU32(&g_iRTMpGeneration);
+ }
+ RTSpinlockRelease(g_hRTMpNotifySpinLock);
+
+ if (!pCur)
+ return VERR_NOT_FOUND;
+
+ /*
+ * Invalidate and free the record.
+ */
+ pCur->pNext = NULL;
+ pCur->pfnCallback = NULL;
+ RTMemFree(pCur);
+
+ return VINF_SUCCESS;
+}
+RT_EXPORT_SYMBOL(RTMpNotificationDeregister);
+
+
+DECLHIDDEN(int) rtR0MpNotificationInit(void)
+{
+ int rc = RTSpinlockCreate((PRTSPINLOCK)&g_hRTMpNotifySpinLock, RTSPINLOCK_FLAGS_INTERRUPT_SAFE, "RTR0Mp");
+ if (RT_SUCCESS(rc))
+ {
+ rc = rtR0MpNotificationNativeInit();
+ if (RT_SUCCESS(rc))
+ return rc;
+
+ RTSpinlockDestroy(g_hRTMpNotifySpinLock);
+ g_hRTMpNotifySpinLock = NIL_RTSPINLOCK;
+ }
+ return rc;
+}
+
+
+DECLHIDDEN(void) rtR0MpNotificationTerm(void)
+{
+ PRTMPNOTIFYREG pHead;
+ RTSPINLOCK hSpinlock = g_hRTMpNotifySpinLock;
+ AssertReturnVoid(hSpinlock != NIL_RTSPINLOCK);
+
+ rtR0MpNotificationNativeTerm();
+
+ /* pick up the list and the spinlock. */
+ RTSpinlockAcquire(hSpinlock);
+ ASMAtomicWriteHandle(&g_hRTMpNotifySpinLock, NIL_RTSPINLOCK);
+ pHead = g_pRTMpCallbackHead;
+ g_pRTMpCallbackHead = NULL;
+ ASMAtomicIncU32(&g_iRTMpGeneration);
+ RTSpinlockRelease(hSpinlock);
+
+ /* free the list. */
+ while (pHead)
+ {
+ PRTMPNOTIFYREG pFree = pHead;
+ pHead = pHead->pNext;
+
+ pFree->pNext = NULL;
+ pFree->pfnCallback = NULL;
+ RTMemFree(pFree);
+ }
+
+ RTSpinlockDestroy(hSpinlock);
+}
+
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