eeh_event.c

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/*
 * 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 <[email protected]>
 */

#include <linux/delay.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/kthread.h>
#include <asm/eeh_event.h>
#include <asm/ppc-pci.h>

/* EEH event workqueue setup. */
static DEFINE_SPINLOCK(eeh_eventlist_lock);
LIST_HEAD(eeh_eventlist);
static void eeh_thread_launcher(struct work_struct *);
DECLARE_WORK(eeh_event_wq, eeh_thread_launcher);

/* Serialize reset sequences for a given pci device */
DEFINE_MUTEX(eeh_event_mutex);

static int eeh_event_handler(void * dummy)
{
    unsigned long flags;
    struct eeh_event *event;
    struct eeh_pe *pe;

    spin_lock_irqsave(&eeh_eventlist_lock, flags);
    event = NULL;

    /* Unqueue the event, get ready to process. */
    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 == NULL)
        return 0;

    /* Serialize processing of EEH events */
    mutex_lock(&eeh_event_mutex);
    pe = event->pe;
    eeh_pe_state_mark(pe, EEH_PE_RECOVERING);
    pr_info("EEH: Detected PCI bus error on PHB#%d-PE#%x\n",
        pe->phb->global_number, pe->addr);

    set_current_state(TASK_INTERRUPTIBLE);  /* Don't add to load average */
    eeh_handle_event(pe);
    eeh_pe_state_clear(pe, EEH_PE_RECOVERING);

    kfree(event);
    mutex_unlock(&eeh_event_mutex);

    /* If there are no new errors after an hour, clear the counter. */
    if (pe && pe->freeze_count > 0) {
        msleep_interruptible(3600*1000);
        if (pe->freeze_count > 0)
            pe->freeze_count--;

    }

    return 0;
}

static void eeh_thread_launcher(struct work_struct *dummy)
{
    if (IS_ERR(kthread_run(eeh_event_handler, NULL, "eehd")))
        printk(KERN_ERR "Failed to start EEH daemon\n");
}

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);

    schedule_work(&eeh_event_wq);

    return 0;
}