[PATCH]: powerpc/pseries: mutex lock to serialze EEH event processing
DORMANTno replies
From: Linas Vepstas <hidden>
Date: 2006-03-29 21:29:31
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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 <redacted> ---- 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)