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.
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.
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
18 * Copyright (c) 2005 Linas Vepstas <linas@linas.org>
21 #include <linux/list.h>
22 #include <linux/mutex.h>
23 #include <linux/pci.h>
24 #include <linux/workqueue.h>
25 #include <asm/eeh_event.h>
26 #include <asm/ppc-pci.h>
29 * EEH error states may be detected within exception handlers;
30 * however, the recovery processing needs to occur asynchronously
31 * in a normal kernel context and not an interrupt context.
32 * This pair of routines creates an event and queues it onto a
33 * work-queue, where a worker thread can drive recovery.
36 /* EEH event workqueue setup. */
37 static spinlock_t eeh_eventlist_lock
= SPIN_LOCK_UNLOCKED
;
38 LIST_HEAD(eeh_eventlist
);
39 static void eeh_thread_launcher(void *);
40 DECLARE_WORK(eeh_event_wq
, eeh_thread_launcher
, NULL
);
42 /* Serialize reset sequences for a given pci device */
43 DEFINE_MUTEX(eeh_event_mutex
);
46 * eeh_event_handler - dispatch EEH events.
49 * The detection of a frozen slot can occur inside an interrupt,
50 * where it can be hard to do anything about it. The goal of this
51 * routine is to pull these detection events out of the context
52 * of the interrupt handler, and re-dispatch them for processing
53 * at a later time in a normal context.
55 static int eeh_event_handler(void * dummy
)
58 struct eeh_event
*event
;
63 set_current_state(TASK_INTERRUPTIBLE
);
65 spin_lock_irqsave(&eeh_eventlist_lock
, flags
);
68 /* Unqueue the event, get ready to process. */
69 if (!list_empty(&eeh_eventlist
)) {
70 event
= list_entry(eeh_eventlist
.next
, struct eeh_event
, list
);
71 list_del(&event
->list
);
73 spin_unlock_irqrestore(&eeh_eventlist_lock
, flags
);
78 /* Serialize processing of EEH events */
79 mutex_lock(&eeh_event_mutex
);
80 eeh_mark_slot(event
->dn
, EEH_MODE_RECOVERING
);
82 printk(KERN_INFO
"EEH: Detected PCI bus error on device %s\n",
83 pci_name(event
->dev
));
85 handle_eeh_events(event
);
87 eeh_clear_slot(event
->dn
, EEH_MODE_RECOVERING
);
88 pci_dev_put(event
->dev
);
90 mutex_unlock(&eeh_event_mutex
);
100 static void eeh_thread_launcher(void *dummy
)
102 if (kernel_thread(eeh_event_handler
, NULL
, CLONE_KERNEL
) < 0)
103 printk(KERN_ERR
"Failed to start EEH daemon\n");
107 * eeh_send_failure_event - generate a PCI error event
110 * This routine can be called within an interrupt context;
111 * the actual event will be delivered in a normal context
112 * (from a workqueue).
114 int eeh_send_failure_event (struct device_node
*dn
,
116 enum pci_channel_state state
,
120 struct eeh_event
*event
;
123 if (!mem_init_done
) {
124 printk(KERN_ERR
"EEH: event during early boot not handled\n");
125 location
= (char *) get_property(dn
, "ibm,loc-code", NULL
);
126 printk(KERN_ERR
"EEH: device node = %s\n", dn
->full_name
);
127 printk(KERN_ERR
"EEH: PCI location = %s\n", location
);
130 event
= kmalloc(sizeof(*event
), GFP_ATOMIC
);
132 printk (KERN_ERR
"EEH: out of memory, event not handled\n");
141 event
->state
= state
;
142 event
->time_unavail
= time_unavail
;
144 /* We may or may not be called in an interrupt context */
145 spin_lock_irqsave(&eeh_eventlist_lock
, flags
);
146 list_add(&event
->list
, &eeh_eventlist
);
147 spin_unlock_irqrestore(&eeh_eventlist_lock
, flags
);
149 schedule_work(&eeh_event_wq
);
154 /********************** END OF FILE ******************************/