156 lines
4.4 KiB
C
156 lines
4.4 KiB
C
/*
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* eeh_event.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Copyright (c) 2005 Linas Vepstas <linas@linas.org>
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*/
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#include <linux/list.h>
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#include <linux/pci.h>
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#include <asm/eeh_event.h>
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/** Overview:
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* EEH error states may be detected within exception handlers;
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* however, the recovery processing needs to occur asynchronously
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* in a normal kernel context and not an interrupt context.
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* This pair of routines creates an event and queues it onto a
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* work-queue, where a worker thread can drive recovery.
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*/
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/* EEH event workqueue setup. */
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static spinlock_t eeh_eventlist_lock = SPIN_LOCK_UNLOCKED;
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LIST_HEAD(eeh_eventlist);
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static void eeh_thread_launcher(void *);
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DECLARE_WORK(eeh_event_wq, eeh_thread_launcher, NULL);
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/**
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* eeh_panic - call panic() for an eeh event that cannot be handled.
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* The philosophy of this routine is that it is better to panic and
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* halt the OS than it is to risk possible data corruption by
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* oblivious device drivers that don't know better.
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*
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* @dev pci device that had an eeh event
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* @reset_state current reset state of the device slot
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*/
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static void eeh_panic(struct pci_dev *dev, int reset_state)
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{
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/*
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* Since the panic_on_oops sysctl is used to halt the system
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* in light of potential corruption, we can use it here.
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*/
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if (panic_on_oops) {
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panic("EEH: MMIO failure (%d) on device:%s\n", reset_state,
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pci_name(dev));
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}
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else {
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printk(KERN_INFO "EEH: Ignored MMIO failure (%d) on device:%s\n",
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reset_state, pci_name(dev));
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}
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}
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/**
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* eeh_event_handler - dispatch EEH events. The detection of a frozen
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* slot can occur inside an interrupt, where it can be hard to do
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* anything about it. The goal of this routine is to pull these
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* detection events out of the context of the interrupt handler, and
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* re-dispatch them for processing at a later time in a normal context.
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*
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* @dummy - unused
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*/
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static int eeh_event_handler(void * dummy)
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{
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unsigned long flags;
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struct eeh_event *event;
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daemonize ("eehd");
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while (1) {
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set_current_state(TASK_INTERRUPTIBLE);
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spin_lock_irqsave(&eeh_eventlist_lock, flags);
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event = NULL;
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if (!list_empty(&eeh_eventlist)) {
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event = list_entry(eeh_eventlist.next, struct eeh_event, list);
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list_del(&event->list);
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}
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spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
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if (event == NULL)
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break;
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printk(KERN_INFO "EEH: Detected PCI bus error on device %s\n",
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pci_name(event->dev));
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eeh_panic (event->dev, event->state);
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kfree(event);
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}
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return 0;
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}
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/**
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* eeh_thread_launcher
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*
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* @dummy - unused
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*/
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static void eeh_thread_launcher(void *dummy)
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{
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if (kernel_thread(eeh_event_handler, NULL, CLONE_KERNEL) < 0)
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printk(KERN_ERR "Failed to start EEH daemon\n");
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}
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/**
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* eeh_send_failure_event - generate a PCI error event
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* @dev pci device
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*
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* This routine can be called within an interrupt context;
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* the actual event will be delivered in a normal context
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* (from a workqueue).
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*/
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int eeh_send_failure_event (struct device_node *dn,
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struct pci_dev *dev,
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int state,
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int time_unavail)
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{
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unsigned long flags;
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struct eeh_event *event;
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event = kmalloc(sizeof(*event), GFP_ATOMIC);
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if (event == NULL) {
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printk (KERN_ERR "EEH: out of memory, event not handled\n");
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return 1;
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}
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if (dev)
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pci_dev_get(dev);
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event->dn = dn;
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event->dev = dev;
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event->state = state;
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event->time_unavail = time_unavail;
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/* We may or may not be called in an interrupt context */
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spin_lock_irqsave(&eeh_eventlist_lock, flags);
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list_add(&event->list, &eeh_eventlist);
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spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
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schedule_work(&eeh_event_wq);
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return 0;
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}
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/********************** END OF FILE ******************************/
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