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/pci.h>
23 #include <asm/eeh_event.h>
24 #include <asm/ppc-pci.h>
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.
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);
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.
49 static int eeh_event_handler(void * dummy)
52 struct eeh_event *event;
57 set_current_state(TASK_INTERRUPTIBLE);
59 spin_lock_irqsave(&eeh_eventlist_lock, flags);
62 /* Unqueue the event, get ready to process. */
63 if (!list_empty(&eeh_eventlist)) {
64 event = list_entry(eeh_eventlist.next, struct eeh_event, list);
65 list_del(&event->list);
69 eeh_mark_slot(event->dn, EEH_MODE_RECOVERING);
71 spin_unlock_irqrestore(&eeh_eventlist_lock, flags);
75 printk(KERN_INFO "EEH: Detected PCI bus error on device %s\n",
76 pci_name(event->dev));
78 handle_eeh_events(event);
80 eeh_clear_slot(event->dn, EEH_MODE_RECOVERING);
82 pci_dev_put(event->dev);
94 static void eeh_thread_launcher(void *dummy)
96 if (kernel_thread(eeh_event_handler, NULL, CLONE_KERNEL) < 0)
97 printk(KERN_ERR "Failed to start EEH daemon\n");
101 * eeh_send_failure_event - generate a PCI error event
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).
108 int eeh_send_failure_event (struct device_node *dn,
110 enum pci_channel_state state,
114 struct eeh_event *event;
116 event = kmalloc(sizeof(*event), GFP_ATOMIC);
118 printk (KERN_ERR "EEH: out of memory, event not handled\n");
127 event->state = state;
128 event->time_unavail = time_unavail;
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);
135 schedule_work(&eeh_event_wq);
140 /********************** END OF FILE ******************************/