/* $Id: mpnotification-r0drv-linux.c 82968 2020-02-04 10:35:17Z vboxsync $ */ /** @file * IPRT - Multiprocessor Event Notifications, Ring-0 Driver, Linux. */ /* * Copyright (C) 2008-2020 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 #include #include #include #include "r0drv/mp-r0drv.h" #if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 10, 0) static enum cpuhp_state g_rtR0MpOnline; /* * Linux 4.10 completely removed CPU notifiers. So let's switch to CPU hotplug * notification. */ static int rtR0MpNotificationLinuxOnline(unsigned int cpu) { RTCPUID idCpu = RTMpCpuIdFromSetIndex(cpu); rtMpNotificationDoCallbacks(RTMPEVENT_ONLINE, idCpu); return 0; } static int rtR0MpNotificationLinuxOffline(unsigned int cpu) { RTCPUID idCpu = RTMpCpuIdFromSetIndex(cpu); rtMpNotificationDoCallbacks(RTMPEVENT_OFFLINE, idCpu); return 0; } DECLHIDDEN(int) rtR0MpNotificationNativeInit(void) { int rc; IPRT_LINUX_SAVE_EFL_AC(); rc = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "vboxdrv:online", rtR0MpNotificationLinuxOnline, rtR0MpNotificationLinuxOffline); IPRT_LINUX_RESTORE_EFL_AC(); /* * cpuhp_setup_state_nocalls() returns a positive state number for * CPUHP_AP_ONLINE_DYN or -ENOSPC if there is no free slot available * (see cpuhp_reserve_state / definition of CPUHP_AP_ONLINE_DYN). */ AssertMsgReturn(rc > 0, ("%d\n", rc), RTErrConvertFromErrno(rc)); g_rtR0MpOnline = rc; return VINF_SUCCESS; } DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void) { IPRT_LINUX_SAVE_EFL_AC(); cpuhp_remove_state_nocalls(g_rtR0MpOnline); IPRT_LINUX_RESTORE_EFL_AC(); } #elif LINUX_VERSION_CODE >= KERNEL_VERSION(2, 5, 71) && defined(CONFIG_SMP) static int rtMpNotificationLinuxCallback(struct notifier_block *pNotifierBlock, unsigned long ulNativeEvent, void *pvCpu); /** * 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 /** * 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) { bool fProcessEvent = false; RTCPUID idCpu = (uintptr_t)pvCpu; NOREF(pNotifierBlock); /* * 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. */ 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)) break; /* fProcessEvents = false */ /* 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 fProcessEvent = true; 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 fProcessEvent = true; # else case CPU_DEAD: # if defined(CPU_TASKS_FROZEN) && defined(CPU_DEAD_FROZEN) case CPU_DEAD_FROZEN: # endif /* Don't process CPU_DEAD notifications. */ # endif # ifdef CPU_DOWN_FAILED RTCpuSetAdd(&g_MpPendingOfflineSet, idCpu); # endif break; } if (!fProcessEvent) return NOTIFY_DONE; switch (ulNativeEvent) { # ifdef CPU_DOWN_FAILED case CPU_DOWN_FAILED: # if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_FAILED_FROZEN) case CPU_DOWN_FAILED_FROZEN: # endif # endif case CPU_ONLINE: # if defined(CPU_TASKS_FROZEN) && defined(CPU_ONLINE_FROZEN) case CPU_ONLINE_FROZEN: # endif rtMpNotificationDoCallbacks(RTMPEVENT_ONLINE, idCpu); break; # ifdef CPU_DOWN_PREPARE case CPU_DOWN_PREPARE: # if defined(CPU_TASKS_FROZEN) && defined(CPU_DOWN_PREPARE_FROZEN) case CPU_DOWN_PREPARE_FROZEN: # endif rtMpNotificationDoCallbacks(RTMPEVENT_OFFLINE, idCpu); break; # endif } return NOTIFY_DONE; } DECLHIDDEN(int) rtR0MpNotificationNativeInit(void) { int rc; IPRT_LINUX_SAVE_EFL_AC(); # ifdef CPU_DOWN_FAILED RTCpuSetEmpty(&g_MpPendingOfflineSet); # endif rc = register_cpu_notifier(&g_NotifierBlock); IPRT_LINUX_RESTORE_EFL_AC(); AssertMsgReturn(!rc, ("%d\n", rc), RTErrConvertFromErrno(rc)); return VINF_SUCCESS; } DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void) { IPRT_LINUX_SAVE_EFL_AC(); unregister_cpu_notifier(&g_NotifierBlock); IPRT_LINUX_RESTORE_EFL_AC(); } #else /* Not supported / Not needed */ DECLHIDDEN(int) rtR0MpNotificationNativeInit(void) { return VINF_SUCCESS; } DECLHIDDEN(void) rtR0MpNotificationNativeTerm(void) { } #endif /* Not supported / Not needed */