| /* |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| * |
| * Copyright (c) 2005 Linas Vepstas <linas@linas.org> |
| */ |
| |
| #include <linux/delay.h> |
| #include <linux/list.h> |
| #include <linux/sched.h> |
| #include <linux/semaphore.h> |
| #include <linux/pci.h> |
| #include <linux/slab.h> |
| #include <linux/kthread.h> |
| #include <asm/eeh_event.h> |
| #include <asm/ppc-pci.h> |
| |
| /** Overview: |
| * EEH error states may be detected within exception handlers; |
| * however, the recovery processing needs to occur asynchronously |
| * in a normal kernel context and not an interrupt context. |
| * This pair of routines creates an event and queues it onto a |
| * work-queue, where a worker thread can drive recovery. |
| */ |
| |
| static DEFINE_SPINLOCK(eeh_eventlist_lock); |
| static DECLARE_COMPLETION(eeh_eventlist_event); |
| static LIST_HEAD(eeh_eventlist); |
| |
| /** |
| * eeh_event_handler - Dispatch EEH events. |
| * @dummy - unused |
| * |
| * The detection of a frozen slot can occur inside an interrupt, |
| * where it can be hard to do anything about it. The goal of this |
| * routine is to pull these detection events out of the context |
| * of the interrupt handler, and re-dispatch them for processing |
| * at a later time in a normal context. |
| */ |
| static int eeh_event_handler(void * dummy) |
| { |
| unsigned long flags; |
| struct eeh_event *event; |
| struct eeh_pe *pe; |
| |
| while (!kthread_should_stop()) { |
| if (wait_for_completion_interruptible(&eeh_eventlist_event)) |
| break; |
| |
| /* Fetch EEH event from the queue */ |
| spin_lock_irqsave(&eeh_eventlist_lock, flags); |
| event = NULL; |
| if (!list_empty(&eeh_eventlist)) { |
| event = list_entry(eeh_eventlist.next, |
| struct eeh_event, list); |
| list_del(&event->list); |
| } |
| spin_unlock_irqrestore(&eeh_eventlist_lock, flags); |
| if (!event) |
| continue; |
| |
| /* We might have event without binding PE */ |
| pe = event->pe; |
| if (pe) { |
| if (pe->type & EEH_PE_PHB) |
| pr_info("EEH: Detected error on PHB#%x\n", |
| pe->phb->global_number); |
| else |
| pr_info("EEH: Detected PCI bus error on " |
| "PHB#%x-PE#%x\n", |
| pe->phb->global_number, pe->addr); |
| eeh_handle_normal_event(pe); |
| } else { |
| eeh_handle_special_event(); |
| } |
| |
| kfree(event); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * eeh_event_init - Start kernel thread to handle EEH events |
| * |
| * This routine is called to start the kernel thread for processing |
| * EEH event. |
| */ |
| int eeh_event_init(void) |
| { |
| struct task_struct *t; |
| int ret = 0; |
| |
| t = kthread_run(eeh_event_handler, NULL, "eehd"); |
| if (IS_ERR(t)) { |
| ret = PTR_ERR(t); |
| pr_err("%s: Failed to start EEH daemon (%d)\n", |
| __func__, ret); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * eeh_send_failure_event - Generate a PCI error event |
| * @pe: EEH PE |
| * |
| * This routine can be called within an interrupt context; |
| * the actual event will be delivered in a normal context |
| * (from a workqueue). |
| */ |
| int eeh_send_failure_event(struct eeh_pe *pe) |
| { |
| unsigned long flags; |
| struct eeh_event *event; |
| |
| event = kzalloc(sizeof(*event), GFP_ATOMIC); |
| if (!event) { |
| pr_err("EEH: out of memory, event not handled\n"); |
| return -ENOMEM; |
| } |
| event->pe = pe; |
| |
| /* We may or may not be called in an interrupt context */ |
| spin_lock_irqsave(&eeh_eventlist_lock, flags); |
| list_add(&event->list, &eeh_eventlist); |
| spin_unlock_irqrestore(&eeh_eventlist_lock, flags); |
| |
| /* For EEH deamon to knick in */ |
| complete(&eeh_eventlist_event); |
| |
| return 0; |
| } |
| |
| /** |
| * eeh_remove_event - Remove EEH event from the queue |
| * @pe: Event binding to the PE |
| * @force: Event will be removed unconditionally |
| * |
| * On PowerNV platform, we might have subsequent coming events |
| * is part of the former one. For that case, those subsequent |
| * coming events are totally duplicated and unnecessary, thus |
| * they should be removed. |
| */ |
| void eeh_remove_event(struct eeh_pe *pe, bool force) |
| { |
| unsigned long flags; |
| struct eeh_event *event, *tmp; |
| |
| /* |
| * If we have NULL PE passed in, we have dead IOC |
| * or we're sure we can report all existing errors |
| * by the caller. |
| * |
| * With "force", the event with associated PE that |
| * have been isolated, the event won't be removed |
| * to avoid event lost. |
| */ |
| spin_lock_irqsave(&eeh_eventlist_lock, flags); |
| list_for_each_entry_safe(event, tmp, &eeh_eventlist, list) { |
| if (!force && event->pe && |
| (event->pe->state & EEH_PE_ISOLATED)) |
| continue; |
| |
| if (!pe) { |
| list_del(&event->list); |
| kfree(event); |
| } else if (pe->type & EEH_PE_PHB) { |
| if (event->pe && event->pe->phb == pe->phb) { |
| list_del(&event->list); |
| kfree(event); |
| } |
| } else if (event->pe == pe) { |
| list_del(&event->list); |
| kfree(event); |
| } |
| } |
| spin_unlock_irqrestore(&eeh_eventlist_lock, flags); |
| } |