157 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			157 lines
		
	
	
		
			4.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * eeh_event.c
 | |
|  *
 | |
|  * 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/mutex.h>
 | |
| #include <linux/pci.h>
 | |
| #include <linux/workqueue.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.
 | |
|  */
 | |
| 
 | |
| /* 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);
 | |
| 
 | |
| /**
 | |
|  * 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 pci_dn *pdn;
 | |
| 
 | |
| 	daemonize ("eehd");
 | |
| 	set_current_state(TASK_INTERRUPTIBLE);
 | |
| 
 | |
| 	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);
 | |
| 	eeh_mark_slot(event->dn, EEH_MODE_RECOVERING);
 | |
| 
 | |
| 	printk(KERN_INFO "EEH: Detected PCI bus error on device %s\n",
 | |
| 	       pci_name(event->dev));
 | |
| 
 | |
| 	pdn = handle_eeh_events(event);
 | |
| 
 | |
| 	eeh_clear_slot(event->dn, EEH_MODE_RECOVERING);
 | |
| 	pci_dev_put(event->dev);
 | |
| 	kfree(event);
 | |
| 	mutex_unlock(&eeh_event_mutex);
 | |
| 
 | |
| 	/* If there are no new errors after an hour, clear the counter. */
 | |
| 	if (pdn && pdn->eeh_freeze_count>0) {
 | |
| 		msleep_interruptible (3600*1000);
 | |
| 		if (pdn->eeh_freeze_count>0)
 | |
| 			pdn->eeh_freeze_count--;
 | |
| 	}
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * eeh_thread_launcher
 | |
|  * @dummy - unused
 | |
|  */
 | |
| static void eeh_thread_launcher(struct work_struct *dummy)
 | |
| {
 | |
| 	if (kernel_thread(eeh_event_handler, NULL, CLONE_KERNEL) < 0)
 | |
| 		printk(KERN_ERR "Failed to start EEH daemon\n");
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * eeh_send_failure_event - generate a PCI error event
 | |
|  * @dev pci device
 | |
|  *
 | |
|  * 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 device_node *dn,
 | |
|                             struct pci_dev *dev)
 | |
| {
 | |
| 	unsigned long flags;
 | |
| 	struct eeh_event *event;
 | |
| 	const char *location;
 | |
| 
 | |
| 	if (!mem_init_done) {
 | |
| 		printk(KERN_ERR "EEH: event during early boot not handled\n");
 | |
| 		location = of_get_property(dn, "ibm,loc-code", NULL);
 | |
| 		printk(KERN_ERR "EEH: device node = %s\n", dn->full_name);
 | |
| 		printk(KERN_ERR "EEH: PCI location = %s\n", location);
 | |
| 		return 1;
 | |
| 	}
 | |
| 	event = kmalloc(sizeof(*event), GFP_ATOMIC);
 | |
| 	if (event == NULL) {
 | |
| 		printk (KERN_ERR "EEH: out of memory, event not handled\n");
 | |
| 		return 1;
 | |
|  	}
 | |
| 
 | |
| 	if (dev)
 | |
| 		pci_dev_get(dev);
 | |
| 
 | |
| 	event->dn = dn;
 | |
| 	event->dev = dev;
 | |
| 
 | |
| 	/* 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;
 | |
| }
 | |
| 
 | |
| /********************** END OF FILE ******************************/
 |