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 #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0)
  41
  42 static enum cpuhp_state g_rtR0MpOnline;
  43
  44 /*
  45  * Linux 4.10 completely removed CPU notifiers. So let's switch to CPU hotplug
  46  * notification.
  47  */
  48
  49 static int rtR0MpNotificationLinuxOnline(unsigned int cpu)
  50 {
  51     RTCPUID idCpu = RTMpCpuIdFromSetIndex(cpu);
  52     rtMpNotificationDoCallbacks(RTMPEVENT_ONLINE, idCpu);
  53     return 0;
  54 }
  55
  56 static int rtR0MpNotificationLinuxOffline(unsigned int cpu)
  57 {
  58     RTCPUID idCpu = RTMpCpuIdFromSetIndex(cpu);
  59     rtMpNotificationDoCallbacks(RTMPEVENT_OFFLINE, idCpu);
  60     return 0;
  61 }
  62
  63 DECLHIDDEN(int) rtR0MpNotificationNativeInit(void)
  64 {
  65     int rc;
  66     IPRT_LINUX_SAVE_EFL_AC();
  67     rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "vboxdrv:online",
  68                                    rtR0MpNotificationLinuxOnline, rtR0MpNotificationLinuxOffline);
  69     IPRT_LINUX_RESTORE_EFL_AC();
  70     /*
  71      * cpuhp_setup_state_nocalls() returns a positive state number for
  72      * CPUHP_AP_ONLINE_DYN or -ENOSPC if there is no free slot available
  73      * (see cpuhp_reserve_state / definition of CPUHP_AP_ONLINE_DYN).
  74      */
  75     AssertMsgReturn(rc > 0, ("%d\n", rc), RTErrConvertFromErrno(rc));
  76     g_rtR0MpOnline = rc;
  77     return VINF_SUCCESS;
  78 }
  79
  80
  81 DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void)
  82 {
  83     IPRT_LINUX_SAVE_EFL_AC();
  84     cpuhp_remove_state_nocalls(g_rtR0MpOnline);
  85     IPRT_LINUX_RESTORE_EFL_AC();
  86 }
  87
  88 #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 71) && defined(CONFIG_SMP)
  89
  90 static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu);
  91
  92 /**
  93  * The notifier block we use for registering the callback.
  94  */
  95 static struct notifier_block g_NotifierBlock =
  96 {
  97     .notifier_call = rtMpNotificationLinuxCallback,
  98     .next = NULL,
  99     .priority = 0
 100 };
 101
 102 # ifdef CPU_DOWN_FAILED
 103 /**
 104  * The set of CPUs we've seen going offline recently.
 105  */
 106 static RTCPUSET g_MpPendingOfflineSet;
 107 # endif
 108
 109
 110 /**
 111  * The native callback.
 112  *
 113  * @returns NOTIFY_DONE.
 114  * @param   pNotifierBlock  Pointer to g_NotifierBlock.
 115  * @param   ulNativeEvent   The native event.
 116  * @param   pvCpu           The cpu id cast into a pointer value.
 117  *
 118  * @remarks This can fire with preemption enabled and on any CPU.
 119  */
 120 static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu)
 121 {
 122     bool fProcessEvent = false;
 123     RTCPUID idCpu      = (uintptr_t)pvCpu;
 124     NOREF(pNotifierBlock);
 125
 126     /*
 127      * Note that redhat/CentOS ported _some_ of the FROZEN macros
 128      * back to their 2.6.18-92.1.10.el5 kernel but actually don't
 129      * use them. Thus we have to test for both CPU_TASKS_FROZEN and
 130      * the individual event variants.
 131      */
 132     switch (ulNativeEvent)
 133     {
 134         /*
 135          * Pick up online events or failures to go offline.
 136          * Ignore failure events for CPUs we didn't see go offline.
 137          */
 138 # ifdef CPU_DOWN_FAILED
 139         case CPU_DOWN_FAILED:
 140 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_FAILED_FROZEN)
 141         case CPU_DOWN_FAILED_FROZEN:
 142 #  endif
 143             if (!RTCpuSetIsMember(&g_MpPendingOfflineSet, idCpu))
 144                 break;      /* fProcessEvents = false */
 145         /* fall thru */
 146 # endif
 147         case CPU_ONLINE:
 148 # if defined(CPU_TASKS_FROZEN) && defined(CPU_ONLINE_FROZEN)
 149         case CPU_ONLINE_FROZEN:
 150 # endif
 151 # ifdef CPU_DOWN_FAILED
 152             RTCpuSetDel(&g_MpPendingOfflineSet, idCpu);
 153 # endif
 154             fProcessEvent = true;
 155             break;
 156
 157         /*
 158          * Pick the earliest possible offline event.
 159          * The only important thing here is that we get the event and that
 160          * it's exactly one.
 161          */
 162 # ifdef CPU_DOWN_PREPARE
 163         case CPU_DOWN_PREPARE:
 164 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_PREPARE_FROZEN)
 165         case CPU_DOWN_PREPARE_FROZEN:
 166 #  endif
 167             fProcessEvent = true;
 168 # else
 169         case CPU_DEAD:
 170 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DEAD_FROZEN)
 171         case CPU_DEAD_FROZEN:
 172 #  endif
 173             /* Don't process CPU_DEAD notifications. */
 174 # endif
 175 # ifdef CPU_DOWN_FAILED
 176             RTCpuSetAdd(&g_MpPendingOfflineSet, idCpu);
 177 # endif
 178             break;
 179     }
 180
 181     if (!fProcessEvent)
 182         return NOTIFY_DONE;
 183
 184     switch (ulNativeEvent)
 185     {
 186 # ifdef CPU_DOWN_FAILED
 187         case CPU_DOWN_FAILED:
 188 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_FAILED_FROZEN)
 189         case CPU_DOWN_FAILED_FROZEN:
 190 #  endif
 191 # endif
 192         case CPU_ONLINE:
 193 # if defined(CPU_TASKS_FROZEN) && defined(CPU_ONLINE_FROZEN)
 194         case CPU_ONLINE_FROZEN:
 195 # endif
 196             rtMpNotificationDoCallbacks(RTMPEVENT_ONLINE, idCpu);
 197             break;
 198
 199 # ifdef CPU_DOWN_PREPARE
 200         case CPU_DOWN_PREPARE:
 201 #  if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_PREPARE_FROZEN)
 202         case CPU_DOWN_PREPARE_FROZEN:
 203 #  endif
 204             rtMpNotificationDoCallbacks(RTMPEVENT_OFFLINE, idCpu);
 205             break;
 206 # endif
 207     }
 208
 209     return NOTIFY_DONE;
 210 }
 211
 212
 213 DECLHIDDEN(int) rtR0MpNotificationNativeInit(void)
 214 {
 215     int rc;
 216     IPRT_LINUX_SAVE_EFL_AC();
 217
 218 # ifdef CPU_DOWN_FAILED
 219     RTCpuSetEmpty(&g_MpPendingOfflineSet);
 220 # endif
 221
 222     rc = register_cpu_notifier(&g_NotifierBlock);
 223     IPRT_LINUX_RESTORE_EFL_AC();
 224     AssertMsgReturn(!rc, ("%d\n", rc), RTErrConvertFromErrno(rc));
 225     return VINF_SUCCESS;
 226 }
 227
 228
 229 DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void)
 230 {
 231     IPRT_LINUX_SAVE_EFL_AC();
 232     unregister_cpu_notifier(&g_NotifierBlock);
 233     IPRT_LINUX_RESTORE_EFL_AC();
 234 }
 235
 236 #else   /* Not supported / Not needed */
 237
 238 DECLHIDDEN(int) rtR0MpNotificationNativeInit(void)
 239 {
 240     return VINF_SUCCESS;
 241 }
 242
 243 DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void)
 244 {
 245 }
 246
 247 #endif  /* Not supported / Not needed */
 248