lkml.org 
[lkml]   [2006]   [Mar]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
Subject[PATCH]: powerpc/pseries: mutex lock to serialze EEH event processing
From

Paul,
Please review/apply/forward upstream. Seems I forgot to do this before.
--linas

[PATCH]: powerpc/pseries: mutex lock to serialze EEH event processing

This patch forces the processing of EEH PCI events to be serialized,
using a very simple mutex lock. This serialization is required to
avoid races involving additional PCI device failures that may occur
during the recovery hase of a previous failure.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>

----
arch/powerpc/platforms/pseries/eeh_event.c | 30 +++++++++++++++++------------
1 files changed, 18 insertions(+), 12 deletions(-)
Index: linux-2.6.16-git6/arch/powerpc/platforms/pseries/eeh_event.c
===================================================================
--- linux-2.6.16-git6.orig/arch/powerpc/platforms/pseries/eeh_event.c 2006-03-28 17:44:38.000000000 -0600
+++ linux-2.6.16-git6/arch/powerpc/platforms/pseries/eeh_event.c 2006-03-29 14:45:42.522111515 -0600
@@ -19,7 +19,9 @@
*/

#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>

@@ -37,14 +39,18 @@ LIST_HEAD(eeh_eventlist);
static void eeh_thread_launcher(void *);
DECLARE_WORK(eeh_event_wq, eeh_thread_launcher, NULL);

+/* Serialize reset sequences for a given pci device */
+DEFINE_MUTEX(eeh_event_mutex);
+
/**
- * 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.
- *
+ * 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)
{
@@ -64,23 +70,24 @@ static int eeh_event_handler(void * dumm
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;

+ /* 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));

handle_eeh_events(event);

eeh_clear_slot(event->dn, EEH_MODE_RECOVERING);
-
pci_dev_put(event->dev);
kfree(event);
+ mutex_unlock(&eeh_event_mutex);
}

return 0;
@@ -88,7 +95,6 @@ static int eeh_event_handler(void * dumm

/**
* eeh_thread_launcher
- *
* @dummy - unused
*/
static void eeh_thread_launcher(void *dummy)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2006-03-29 23:31    [from the cache]
©2003-2011 Jasper Spaans