[deliverable/linux.git] / arch / powerpc / platforms / pseries / eeh_event.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/list.h>
#include <linux/pci.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 spinlock_t eeh_eventlist_lock = SPIN_LOCK_UNLOCKED;
LIST_HEAD(eeh_eventlist);
static void eeh_thread_launcher(void *);
DECLARE_WORK(eeh_event_wq, eeh_thread_launcher, NULL);

/**
 * eeh_event_handler - dispatch EEH events.  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.
 *
 * @dummy - unused
 */
static int eeh_event_handler(void * dummy)
{
	unsigned long flags;
	struct eeh_event	*event;

	daemonize ("eehd");

	while (1) {
		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);
		}
		
		if (event)
			eeh_mark_slot(event->dn, EEH_MODE_RECOVERING);

		spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
		if (event == NULL)
			break;

		printk(KERN_INFO "EEH: Detected PCI bus error on device %s\n",
		       pci_name(event->dev));

		handle_eeh_events(event);

		eeh_clear_slot(event->dn, EEH_MODE_RECOVERING);

		pci_dev_put(event->dev);
		kfree(event);
	}

	return 0;
}

/**
 * eeh_thread_launcher
 *
 * @dummy - unused
 */
static void eeh_thread_launcher(void *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,
                            enum pci_channel_state state,
                            int time_unavail)
{
	unsigned long flags;
	struct eeh_event *event;

	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;
	event->state = state;
	event->time_unavail = time_unavail;

	/* 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 ******************************/
Commit	Line	Data
172ca926 LV	1	/*
	2	* eeh_event.c
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	17	*
	18	* Copyright (c) 2005 Linas Vepstas <linas@linas.org>
	19	*/
	20
	21	#include <linux/list.h>
	22	#include <linux/pci.h>
	23	#include <asm/eeh_event.h>
77bd7415	24	#include <asm/ppc-pci.h>
172ca926 LV	25
	26	/** Overview:
	27	* EEH error states may be detected within exception handlers;
	28	* however, the recovery processing needs to occur asynchronously
	29	* in a normal kernel context and not an interrupt context.
	30	* This pair of routines creates an event and queues it onto a
	31	* work-queue, where a worker thread can drive recovery.
	32	*/
	33
	34	/* EEH event workqueue setup. */
	35	static spinlock_t eeh_eventlist_lock = SPIN_LOCK_UNLOCKED;
	36	LIST_HEAD(eeh_eventlist);
	37	static void eeh_thread_launcher(void *);
	38	DECLARE_WORK(eeh_event_wq, eeh_thread_launcher, NULL);
	39
172ca926 LV	40	/**
	41	* eeh_event_handler - dispatch EEH events. The detection of a frozen
	42	* slot can occur inside an interrupt, where it can be hard to do
	43	* anything about it. The goal of this routine is to pull these
	44	* detection events out of the context of the interrupt handler, and
	45	* re-dispatch them for processing at a later time in a normal context.
	46	*
	47	* @dummy - unused
	48	*/
	49	static int eeh_event_handler(void * dummy)
	50	{
	51	unsigned long flags;
	52	struct eeh_event *event;
	53
	54	daemonize ("eehd");
	55
	56	while (1) {
	57	set_current_state(TASK_INTERRUPTIBLE);
	58
	59	spin_lock_irqsave(&eeh_eventlist_lock, flags);
	60	event = NULL;
77bd7415 LV	61
77bd7415 LV	62	/* Unqueue the event, get ready to process. */
172ca926 LV	63	if (!list_empty(&eeh_eventlist)) {
	64	event = list_entry(eeh_eventlist.next, struct eeh_event, list);
	65	list_del(&event->list);
	66	}
77bd7415 LV	67
	68	if (event)
	69	eeh_mark_slot(event->dn, EEH_MODE_RECOVERING);
	70
172ca926 LV	71	spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
	72	if (event == NULL)
	73	break;
	74
	75	printk(KERN_INFO "EEH: Detected PCI bus error on device %s\n",
	76	pci_name(event->dev));
	77
77bd7415 LV	78	handle_eeh_events(event);
	79
	80	eeh_clear_slot(event->dn, EEH_MODE_RECOVERING);
172ca926	81
77bd7415	82	pci_dev_put(event->dev);
172ca926 LV	83	kfree(event);
	84	}
	85
	86	return 0;
	87	}
	88
	89	/**
	90	* eeh_thread_launcher
	91	*
	92	* @dummy - unused
	93	*/
	94	static void eeh_thread_launcher(void *dummy)
	95	{
	96	if (kernel_thread(eeh_event_handler, NULL, CLONE_KERNEL) < 0)
	97	printk(KERN_ERR "Failed to start EEH daemon\n");
	98	}
	99
	100	/**
	101	* eeh_send_failure_event - generate a PCI error event
	102	* @dev pci device
	103	*
	104	* This routine can be called within an interrupt context;
	105	* the actual event will be delivered in a normal context
	106	* (from a workqueue).
	107	*/
	108	int eeh_send_failure_event (struct device_node *dn,
	109	struct pci_dev *dev,
77bd7415	110	enum pci_channel_state state,
172ca926 LV	111	int time_unavail)
	112	{
	113	unsigned long flags;
	114	struct eeh_event *event;
	115
	116	event = kmalloc(sizeof(*event), GFP_ATOMIC);
	117	if (event == NULL) {
	118	printk (KERN_ERR "EEH: out of memory, event not handled\n");
	119	return 1;
	120	}
	121
	122	if (dev)
	123	pci_dev_get(dev);
	124
	125	event->dn = dn;
	126	event->dev = dev;
	127	event->state = state;
	128	event->time_unavail = time_unavail;
	129
	130	/* We may or may not be called in an interrupt context */
	131	spin_lock_irqsave(&eeh_eventlist_lock, flags);
	132	list_add(&event->list, &eeh_eventlist);
	133	spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
	134
	135	schedule_work(&eeh_event_wq);
	136
	137	return 0;
	138	}
	139
	140	/******************** END OF FILE ****************************/