ubuntu/vbox/r0drv/linux/mpnotification-r0drv-linux.c

   1 /* $Id: mpnotification-r0drv-linux.c $ */
   2 /** @file
   3  * IPRT - Multiprocessor Event Notifications, Ring-0 Driver, Linux.
   4  */
   5
   6 /*
   7  * Copyright (C) 2008-2016 Oracle Corporation
   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 "the-linux-kernel.h"
  32 #include "internal/iprt.h"
  33
  34 #include <iprt/asm-amd64-x86.h>
  35 #include <iprt/err.h>
  36 #include <iprt/cpuset.h>
  37 #include <iprt/thread.h>
  38 #include "r0drv/mp-r0drv.h"
  39
  40
  41 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 71) && defined(CONFIG_SMP)
  42
  43
  44 /*********************************************************************************************************************************
  45 *   Internal Functions                                                                                                           *
  46 *********************************************************************************************************************************/
  47 static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu);
  48
  49
  50 /*********************************************************************************************************************************
  51 *   Global Variables                                                                                                             *
  52 *********************************************************************************************************************************/
  53 /**
  54  * The notifier block we use for registering the callback.
  55  */
  56 static struct notifier_block g_NotifierBlock =
  57 {
  58     .notifier_call = rtMpNotificationLinuxCallback,
  59     .next = NULL,
  60     .priority = 0
  61 };
  62
  63 # ifdef CPU_DOWN_FAILED
  64 /**
  65  * The set of CPUs we've seen going offline recently.
  66  */
  67 static RTCPUSET g_MpPendingOfflineSet;
  68 # endif
  69
  70
  71 /**
  72  * The native callback.
  73  *
  74  * @returns NOTIFY_DONE.
  75  * @param   pNotifierBlock  Pointer to g_NotifierBlock.
  76  * @param   ulNativeEvent   The native event.
  77  * @param   pvCpu           The cpu id cast into a pointer value.
  78  *
  79  * @remarks This can fire with preemption enabled and on any CPU.
  80  */
  81 static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu)
  82 {
  83     bool fProcessEvent = false;
  84     RTCPUID idCpu      = (uintptr_t)pvCpu;
  85     NOREF(pNotifierBlock);
  86
  87     /*
  88      * Note that redhat/CentOS ported _some_ of the FROZEN macros
  89      * back to their 2.6.18-92.1.10.el5 kernel but actually don't
  90      * use them. Thus we have to test for both CPU_TASKS_FROZEN and
  91      * the individual event variants.
  92      */
  93     switch (ulNativeEvent)
  94     {
  95         /*
  96          * Pick up online events or failures to go offline.
  97          * Ignore failure events for CPUs we didn't see go offline.
  98          */
  99 # ifdef CPU_DOWN_FAILED
 100         case CPU_DOWN_FAILED:
 101 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_FAILED_FROZEN)
 102         case CPU_DOWN_FAILED_FROZEN:
 103 #  endif
 104             if (!RTCpuSetIsMember(&g_MpPendingOfflineSet, idCpu))
 105                 break;      /* fProcessEvents = false */
 106         /* fall thru */
 107 # endif
 108         case CPU_ONLINE:
 109 # if defined(CPU_TASKS_FROZEN) && defined(CPU_ONLINE_FROZEN)
 110         case CPU_ONLINE_FROZEN:
 111 # endif
 112 # ifdef CPU_DOWN_FAILED
 113             RTCpuSetDel(&g_MpPendingOfflineSet, idCpu);
 114 # endif
 115             fProcessEvent = true;
 116             break;
 117
 118         /*
 119          * Pick the earliest possible offline event.
 120          * The only important thing here is that we get the event and that
 121          * it's exactly one.
 122          */
 123 # ifdef CPU_DOWN_PREPARE
 124         case CPU_DOWN_PREPARE:
 125 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_PREPARE_FROZEN)
 126         case CPU_DOWN_PREPARE_FROZEN:
 127 #  endif
 128             fProcessEvent = true;
 129 # else
 130         case CPU_DEAD:
 131 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DEAD_FROZEN)
 132         case CPU_DEAD_FROZEN:
 133 #  endif
 134             /* Don't process CPU_DEAD notifications. */
 135 # endif
 136 # ifdef CPU_DOWN_FAILED
 137             RTCpuSetAdd(&g_MpPendingOfflineSet, idCpu);
 138 # endif
 139             break;
 140     }
 141
 142     if (!fProcessEvent)
 143         return NOTIFY_DONE;
 144
 145     switch (ulNativeEvent)
 146     {
 147 # ifdef CPU_DOWN_FAILED
 148         case CPU_DOWN_FAILED:
 149 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_FAILED_FROZEN)
 150         case CPU_DOWN_FAILED_FROZEN:
 151 #  endif
 152 # endif
 153         case CPU_ONLINE:
 154 # if defined(CPU_TASKS_FROZEN) && defined(CPU_ONLINE_FROZEN)
 155         case CPU_ONLINE_FROZEN:
 156 # endif
 157             rtMpNotificationDoCallbacks(RTMPEVENT_ONLINE, idCpu);
 158             break;
 159
 160 # ifdef CPU_DOWN_PREPARE
 161         case CPU_DOWN_PREPARE:
 162 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_PREPARE_FROZEN)
 163         case CPU_DOWN_PREPARE_FROZEN:
 164 #  endif
 165             rtMpNotificationDoCallbacks(RTMPEVENT_OFFLINE, idCpu);
 166             break;
 167 # endif
 168     }
 169
 170     return NOTIFY_DONE;
 171 }
 172
 173
 174 DECLHIDDEN(int) rtR0MpNotificationNativeInit(void)
 175 {
 176     int rc;
 177     IPRT_LINUX_SAVE_EFL_AC();
 178
 179 # ifdef CPU_DOWN_FAILED
 180     RTCpuSetEmpty(&g_MpPendingOfflineSet);
 181 # endif
 182
 183     rc = register_cpu_notifier(&g_NotifierBlock);
 184     IPRT_LINUX_RESTORE_EFL_AC();
 185     AssertMsgReturn(!rc, ("%d\n", rc), RTErrConvertFromErrno(rc));
 186     return VINF_SUCCESS;
 187 }
 188
 189
 190 DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void)
 191 {
 192     IPRT_LINUX_SAVE_EFL_AC();
 193     unregister_cpu_notifier(&g_NotifierBlock);
 194     IPRT_LINUX_RESTORE_EFL_AC();
 195 }
 196
 197 #else   /* Not supported / Not needed */
 198
 199 DECLHIDDEN(int) rtR0MpNotificationNativeInit(void)
 200 {
 201     return VINF_SUCCESS;
 202 }
 203
 204 DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void)
 205 {
 206 }
 207
 208 #endif  /* Not supported / Not needed */
 209