From 8c33fd11e3a21a15af35b5831f1516faf53094f1 Mon Sep 17 00:00:00 2001 From: Linas Vepstas Date: Wed, 29 Mar 2006 15:29:18 -0600 Subject: [PATCH] [PATCH] powerpc/pseries: mutex lock to serialize EEH event processing This 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 phase of a previous failure. Signed-off-by: Linas Vepstas Signed-off-by: Paul Mackerras --- arch/powerpc/platforms/pseries/eeh_event.c | 30 +++++++++++++--------- 1 file changed, 18 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/platforms/pseries/eeh_event.c b/arch/powerpc/platforms/pseries/eeh_event.c index 9a9961f2748..a1bda6f96fd 100644 --- a/arch/powerpc/platforms/pseries/eeh_event.c +++ b/arch/powerpc/platforms/pseries/eeh_event.c @@ -19,7 +19,9 @@ */ #include +#include #include +#include #include #include @@ -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 * dummy) 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 * dummy) /** * eeh_thread_launcher - * * @dummy - unused */ static void eeh_thread_launcher(void *dummy) -- 2.20.1