[SCSI] libsas: replace event locks with atomic bitops
Dan Williams [Fri, 18 Nov 2011 01:59:49 +0000 (17:59 -0800)]
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>

drivers/scsi/libsas/sas_discover.c
drivers/scsi/libsas/sas_event.c
drivers/scsi/libsas/sas_init.c
drivers/scsi/libsas/sas_internal.h
drivers/scsi/libsas/sas_phy.c
drivers/scsi/libsas/sas_port.c
include/scsi/libsas.h

index dc52b1f..ed04118 100644 (file)
@@ -295,8 +295,7 @@ static void sas_discover_domain(struct work_struct *work)
                container_of(work, struct sas_discovery_event, work);
        struct asd_sas_port *port = ev->port;
 
-       sas_begin_event(DISCE_DISCOVER_DOMAIN, &port->disc.disc_event_lock,
-                       &port->disc.pending);
+       clear_bit(DISCE_DISCOVER_DOMAIN, &port->disc.pending);
 
        if (port->port_dev)
                return;
@@ -355,8 +354,7 @@ static void sas_revalidate_domain(struct work_struct *work)
                container_of(work, struct sas_discovery_event, work);
        struct asd_sas_port *port = ev->port;
 
-       sas_begin_event(DISCE_REVALIDATE_DOMAIN, &port->disc.disc_event_lock,
-                       &port->disc.pending);
+       clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
 
        SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
                    task_pid_nr(current));
@@ -379,8 +377,7 @@ int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
 
        BUG_ON(ev >= DISC_NUM_EVENTS);
 
-       sas_queue_event(ev, &disc->disc_event_lock, &disc->pending,
-                       &disc->disc_work[ev].work, port->ha);
+       sas_queue_event(ev, &disc->pending, &disc->disc_work[ev].work, port->ha);
 
        return 0;
 }
@@ -400,7 +397,6 @@ void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
                [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
        };
 
-       spin_lock_init(&disc->disc_event_lock);
        disc->pending = 0;
        for (i = 0; i < DISC_NUM_EVENTS; i++) {
                INIT_WORK(&disc->disc_work[i].work, sas_event_fns[i]);
index 9db30fb..9c084bc 100644 (file)
@@ -30,7 +30,7 @@ static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event event)
 {
        BUG_ON(event >= HA_NUM_EVENTS);
 
-       sas_queue_event(event, &sas_ha->event_lock, &sas_ha->pending,
+       sas_queue_event(event, &sas_ha->pending,
                        &sas_ha->ha_events[event].work, sas_ha);
 }
 
@@ -40,7 +40,7 @@ static void notify_port_event(struct asd_sas_phy *phy, enum port_event event)
 
        BUG_ON(event >= PORT_NUM_EVENTS);
 
-       sas_queue_event(event, &ha->event_lock, &phy->port_events_pending,
+       sas_queue_event(event, &phy->port_events_pending,
                        &phy->port_events[event].work, ha);
 }
 
@@ -50,7 +50,7 @@ static void notify_phy_event(struct asd_sas_phy *phy, enum phy_event event)
 
        BUG_ON(event >= PHY_NUM_EVENTS);
 
-       sas_queue_event(event, &ha->event_lock, &phy->phy_events_pending,
+       sas_queue_event(event, &phy->phy_events_pending,
                        &phy->phy_events[event].work, ha);
 }
 
@@ -62,8 +62,6 @@ int sas_init_events(struct sas_ha_struct *sas_ha)
 
        int i;
 
-       spin_lock_init(&sas_ha->event_lock);
-
        for (i = 0; i < HA_NUM_EVENTS; i++) {
                INIT_WORK(&sas_ha->ha_events[i].work, sas_ha_event_fns[i]);
                sas_ha->ha_events[i].ha = sas_ha;
index d81c3b1..a435876 100644 (file)
@@ -97,8 +97,7 @@ void sas_hae_reset(struct work_struct *work)
                container_of(work, struct sas_ha_event, work);
        struct sas_ha_struct *ha = ev->ha;
 
-       sas_begin_event(HAE_RESET, &ha->event_lock,
-                       &ha->pending);
+       clear_bit(HAE_RESET, &ha->pending);
 }
 
 int sas_register_ha(struct sas_ha_struct *sas_ha)
index 0d43408..7fe4ede 100644 (file)
@@ -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,
index e0f5018..dcfd4a9 100644 (file)
@@ -36,8 +36,7 @@ static void sas_phye_loss_of_signal(struct work_struct *work)
                container_of(work, struct asd_sas_event, work);
        struct asd_sas_phy *phy = ev->phy;
 
-       sas_begin_event(PHYE_LOSS_OF_SIGNAL, &phy->ha->event_lock,
-                       &phy->phy_events_pending);
+       clear_bit(PHYE_LOSS_OF_SIGNAL, &phy->phy_events_pending);
        phy->error = 0;
        sas_deform_port(phy, 1);
 }
@@ -48,8 +47,7 @@ static void sas_phye_oob_done(struct work_struct *work)
                container_of(work, struct asd_sas_event, work);
        struct asd_sas_phy *phy = ev->phy;
 
-       sas_begin_event(PHYE_OOB_DONE, &phy->ha->event_lock,
-                       &phy->phy_events_pending);
+       clear_bit(PHYE_OOB_DONE, &phy->phy_events_pending);
        phy->error = 0;
 }
 
@@ -63,8 +61,7 @@ static void sas_phye_oob_error(struct work_struct *work)
        struct sas_internal *i =
                to_sas_internal(sas_ha->core.shost->transportt);
 
-       sas_begin_event(PHYE_OOB_ERROR, &phy->ha->event_lock,
-                       &phy->phy_events_pending);
+       clear_bit(PHYE_OOB_ERROR, &phy->phy_events_pending);
 
        sas_deform_port(phy, 1);
 
@@ -95,8 +92,7 @@ static void sas_phye_spinup_hold(struct work_struct *work)
        struct sas_internal *i =
                to_sas_internal(sas_ha->core.shost->transportt);
 
-       sas_begin_event(PHYE_SPINUP_HOLD, &phy->ha->event_lock,
-                       &phy->phy_events_pending);
+       clear_bit(PHYE_SPINUP_HOLD, &phy->phy_events_pending);
 
        phy->error = 0;
        i->dft->lldd_control_phy(phy, PHY_FUNC_RELEASE_SPINUP_HOLD, NULL);
index 42fd1f2..a47c7a7 100644 (file)
@@ -213,8 +213,7 @@ void sas_porte_bytes_dmaed(struct work_struct *work)
                container_of(work, struct asd_sas_event, work);
        struct asd_sas_phy *phy = ev->phy;
 
-       sas_begin_event(PORTE_BYTES_DMAED, &phy->ha->event_lock,
-                       &phy->port_events_pending);
+       clear_bit(PORTE_BYTES_DMAED, &phy->port_events_pending);
 
        sas_form_port(phy);
 }
@@ -227,8 +226,7 @@ void sas_porte_broadcast_rcvd(struct work_struct *work)
        unsigned long flags;
        u32 prim;
 
-       sas_begin_event(PORTE_BROADCAST_RCVD, &phy->ha->event_lock,
-                       &phy->port_events_pending);
+       clear_bit(PORTE_BROADCAST_RCVD, &phy->port_events_pending);
 
        spin_lock_irqsave(&phy->sas_prim_lock, flags);
        prim = phy->sas_prim;
@@ -244,8 +242,7 @@ void sas_porte_link_reset_err(struct work_struct *work)
                container_of(work, struct asd_sas_event, work);
        struct asd_sas_phy *phy = ev->phy;
 
-       sas_begin_event(PORTE_LINK_RESET_ERR, &phy->ha->event_lock,
-                       &phy->port_events_pending);
+       clear_bit(PORTE_LINK_RESET_ERR, &phy->port_events_pending);
 
        sas_deform_port(phy, 1);
 }
@@ -256,8 +253,7 @@ void sas_porte_timer_event(struct work_struct *work)
                container_of(work, struct asd_sas_event, work);
        struct asd_sas_phy *phy = ev->phy;
 
-       sas_begin_event(PORTE_TIMER_EVENT, &phy->ha->event_lock,
-                       &phy->port_events_pending);
+       clear_bit(PORTE_TIMER_EVENT, &phy->port_events_pending);
 
        sas_deform_port(phy, 1);
 }
@@ -268,8 +264,7 @@ void sas_porte_hard_reset(struct work_struct *work)
                container_of(work, struct asd_sas_event, work);
        struct asd_sas_phy *phy = ev->phy;
 
-       sas_begin_event(PORTE_HARD_RESET, &phy->ha->event_lock,
-                       &phy->port_events_pending);
+       clear_bit(PORTE_HARD_RESET, &phy->port_events_pending);
 
        sas_deform_port(phy, 1);
 }
index 7ecb5c1..de63a66 100644 (file)
@@ -215,7 +215,6 @@ struct sas_discovery_event {
 };
 
 struct sas_discovery {
-       spinlock_t disc_event_lock;
        struct sas_discovery_event disc_work[DISC_NUM_EVENTS];
        unsigned long    pending;
        u8     fanout_sas_addr[8];
@@ -272,7 +271,6 @@ struct asd_sas_event {
  */
 struct asd_sas_phy {
 /* private: */
-       /* protected by ha->event_lock */
        struct asd_sas_event   port_events[PORT_NUM_EVENTS];
        struct asd_sas_event   phy_events[PHY_NUM_EVENTS];
 
@@ -337,7 +335,6 @@ enum sas_ha_state {
 
 struct sas_ha_struct {
 /* private: */
-       spinlock_t       event_lock;
        struct sas_ha_event ha_events[HA_NUM_EVENTS];
        unsigned long    pending;