mpnotification-r0drv-linux.c revision f2054a43ed4a624a04100921b1de7ec86974ddcf
/* $Id$ */
/** @file
* IPRT - Multiprocessor Event Notifications, Ring-0 Driver, Linux.
*/
/*
* Copyright (C) 2008 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 "the-linux-kernel.h"
#include "internal/iprt.h"
#include <iprt/mp.h>
#include <iprt/err.h>
#include <iprt/cpuset.h>
#include <iprt/thread.h>
#include "r0drv/mp-r0drv.h"
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 71) && defined(CONFIG_SMP)
/*******************************************************************************
* Internal Functions *
*******************************************************************************/
static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu);
/*******************************************************************************
* Global Variables *
*******************************************************************************/
/**
* The notifier block we use for registering the callback.
*/
static struct notifier_block g_NotifierBlock =
{
.notifier_call = rtMpNotificationLinuxCallback,
.next = NULL,
.priority = 0
};
# ifdef CPU_DOWN_FAILED
/**
* The set of CPUs we've seen going offline recently.
*/
static RTCPUSET g_MpPendingOfflineSet;
# endif
/**
* Notification wrapper that updates CPU states and invokes our notification
* callbacks.
*
* @param idCpu The CPU Id.
* @param pvUser1 Pointer to the notifier_block (unused).
* @param pvUser2 The notification event.
* @remarks This can be invoked in interrupt context.
*/
static void rtMpNotificationLinuxOnCurrentCpu(RTCPUID idCpu, void *pvUser1, void *pvUser2)
{
unsigned long ulNativeEvent = *(unsigned long *)pvUser2;
NOREF(pvUser1);
AssertRelease(!RTThreadPreemptIsEnabled(NIL_RTTHREAD));
AssertRelease(idCpu == RTMpCpuId()); /* ASSUMES iCpu == RTCPUID */
/*
* Note that redhat/CentOS ported _some_ of the FROZEN macros
* back to their 2.6.18-92.1.10.el5 kernel but actually don't
* use them. Thus we have to test for both CPU_TASKS_FROZEN and
* the individual event variants.
*/
/* ASSUMES iCpu == RTCPUID */
switch (ulNativeEvent)
{
/*
* Pick up online events or failures to go offline.
* Ignore failure events for CPUs we didn't see go offline.
*/
# ifdef CPU_DOWN_FAILED
case CPU_DOWN_FAILED:
# if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_FAILED_FROZEN)
case CPU_DOWN_FAILED_FROZEN:
# endif
if (!RTCpuSetIsMember(&g_MpPendingOfflineSet, idCpu))
return;
/* fall thru */
# endif
case CPU_ONLINE:
# if defined(CPU_TASKS_FROZEN) && defined(CPU_ONLINE_FROZEN)
case CPU_ONLINE_FROZEN:
# endif
# ifdef CPU_DOWN_FAILED
RTCpuSetDel(&g_MpPendingOfflineSet, idCpu);
# endif
rtMpNotificationDoCallbacks(RTMPEVENT_ONLINE, idCpu);
break;
/*
* Pick the earliest possible offline event.
* The only important thing here is that we get the event and that
* it's exactly one.
*/
# ifdef CPU_DOWN_PREPARE
case CPU_DOWN_PREPARE:
# if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_PREPARE_FROZEN)
case CPU_DOWN_PREPARE_FROZEN:
# endif
# else
case CPU_DEAD:
# if defined(CPU_TASKS_FROZEN) && defined(CPU_DEAD_FROZEN)
case CPU_DEAD_FROZEN:
# endif
# endif
rtMpNotificationDoCallbacks(RTMPEVENT_OFFLINE, idCpu);
# ifdef CPU_DOWN_FAILED
RTCpuSetAdd(&g_MpPendingOfflineSet, idCpu);
# endif
break;
}
}
/**
* The native callback.
*
* @returns NOTIFY_DONE.
* @param pNotifierBlock Pointer to g_NotifierBlock.
* @param ulNativeEvent The native event.
* @param pvCpu The cpu id cast into a pointer value.
* @remarks This can fire with preemption enabled and on any CPU.
*/
static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu)
{
int rc;
RTCPUID idCpu = (uintptr_t)pvCpu;
NOREF(pNotifierBlock);
/*
* Reschedule the callbacks to fire on the specific CPU with preemption disabled.
*/
rc = RTMpOnSpecific(idCpu, rtMpNotificationLinuxOnCurrentCpu, pNotifierBlock, &ulNativeEvent);
Assert(RT_SUCCESS(rc));
return NOTIFY_DONE;
}
DECLHIDDEN(int) rtR0MpNotificationNativeInit(void)
{
int rc;
# ifdef CPU_DOWN_FAILED
RTCpuSetEmpty(&g_MpPendingOfflineSet);
# endif
rc = register_cpu_notifier(&g_NotifierBlock);
AssertMsgReturn(!rc, ("%d\n", rc), RTErrConvertFromErrno(rc));
return VINF_SUCCESS;
}
DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void)
{
unregister_cpu_notifier(&g_NotifierBlock);
}
#else /* Not supported / Not needed */
DECLHIDDEN(int) rtR0MpNotificationNativeInit(void)
{
return VINF_SUCCESS;
}
DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void)
{
}
#endif /* Not supported / Not needed */