[SCSI] libsas: replace event locks with atomic bitops

The locks only served to make sure the pending event bitmask was updated
consistently.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 7 insertions, 25 deletions

diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 0d43408196f9..7fe4eded2866 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -92,36 +92,18 @@ static inline int sas_smp_host_handler(struct Scsi_Host *shost,
 }
 #endif
 
-static inline void sas_queue_event(int event, spinlock_t *lock,
-                                   unsigned long *pending,
+static inline void sas_queue_event(int event, unsigned long *pending,
                                    struct work_struct *work,
                                    struct sas_ha_struct *sas_ha)
 {
-        unsigned long flags;
+        if (!test_and_set_bit(event, pending)) {
+                unsigned long flags;
 
-        spin_lock_irqsave(lock, flags);
-        if (test_bit(event, pending)) {
-                spin_unlock_irqrestore(lock, flags);
-                return;
+                spin_lock_irqsave(&sas_ha->state_lock, flags);
+                if (sas_ha->state != SAS_HA_UNREGISTERED)
+                        scsi_queue_work(sas_ha->core.shost, work);
+                spin_unlock_irqrestore(&sas_ha->state_lock, flags);
         }
-        __set_bit(event, pending);
-        spin_unlock_irqrestore(lock, flags);
-
-        spin_lock_irqsave(&sas_ha->state_lock, flags);
-        if (sas_ha->state != SAS_HA_UNREGISTERED) {
-                scsi_queue_work(sas_ha->core.shost, work);
-        }
-        spin_unlock_irqrestore(&sas_ha->state_lock, flags);
-}
-
-static inline void sas_begin_event(int event, spinlock_t *lock,
-                                   unsigned long *pending)
-{
-        unsigned long flags;
-
-        spin_lock_irqsave(lock, flags);
-        __clear_bit(event, pending);
-        spin_unlock_irqrestore(lock, flags);
 }
 
 static inline void sas_fill_in_rphy(struct domain_device *dev,