initial_commit

1 files changed, 157 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/eeh_event.c b/arch/powerpc/platforms/pseries/eeh_event.c
new file mode 100644
index 00000000..2ec500c1
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/eeh_event.c
@@ -0,0 +1,157 @@
+/*
+ * 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/slab.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",
+	       eeh_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 ******************************/