6 files changed, 55 insertions, 27 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 5fdb63ad94b7..92f7e78a096c 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -284,9 +284,10 @@ static int smp_ata_check_ready(struct ata_link *link)
 	struct ata_port *ap = link->ap;
 	struct domain_device *dev = ap->private_data;
 	struct domain_device *ex_dev = dev->parent;
-	struct sas_phy *phy = sas_find_local_phy(dev);
+	struct sas_phy *phy = sas_get_local_phy(dev);
 
 	res = sas_get_phy_attached_sas_addr(ex_dev, phy->number, addr);
+	sas_put_local_phy(phy);
 	/* break the wait early if the expander is unreachable,
 	 * otherwise keep polling
 	 */
@@ -319,10 +320,10 @@ static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
 			      unsigned long deadline)
 {
 	int ret = 0, res;
+	struct sas_phy *phy;
 	struct ata_port *ap = link->ap;
 	int (*check_ready)(struct ata_link *link);
 	struct domain_device *dev = ap->private_data;
-	struct sas_phy *phy = sas_find_local_phy(dev);
 	struct sas_internal *i = dev_to_sas_internal(dev);
 
 	res = i->dft->lldd_I_T_nexus_reset(dev);
@@ -330,10 +331,12 @@ static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
 	if (res != TMF_RESP_FUNC_COMPLETE)
 		SAS_DPRINTK("%s: Unable to reset ata device?\n", __func__);
 
+	phy = sas_get_local_phy(dev);
 	if (scsi_is_sas_phy_local(phy))
 		check_ready = local_ata_check_ready;
 	else
 		check_ready = smp_ata_check_ready;
+	sas_put_local_phy(phy);
 
 	ret = ata_wait_after_reset(link, deadline, check_ready);
 	if (ret && ret != -EAGAIN)
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index c56cc6400819..789b50861bb9 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -147,6 +147,7 @@ static int sas_get_port_device(struct asd_sas_port *port)
 	memset(port->disc.eeds_a, 0, SAS_ADDR_SIZE);
 	memset(port->disc.eeds_b, 0, SAS_ADDR_SIZE);
 	port->disc.max_level = 0;
+	sas_device_set_phy(dev, port->port);
 
 	dev->rphy = rphy;
 
@@ -234,6 +235,9 @@ void sas_free_device(struct kref *kref)
 	if (dev->parent)
 		sas_put_device(dev->parent);
 
+	sas_port_put_phy(dev->phy);
+	dev->phy = NULL;
+
 	/* remove the phys and ports, everything else should be gone */
 	if (dev->dev_type == EDGE_DEV || dev->dev_type == FANOUT_DEV)
 		kfree(dev->ex_dev.ex_phy);
@@ -308,6 +312,26 @@ void sas_unregister_domain_devices(struct asd_sas_port *port)
 
 }
 
+void sas_device_set_phy(struct domain_device *dev, struct sas_port *port)
+{
+	struct sas_ha_struct *ha;
+	struct sas_phy *new_phy;
+
+	if (!dev)
+		return;
+
+	ha = dev->port->ha;
+	new_phy = sas_port_get_phy(port);
+
+	/* pin and record last seen phy */
+	spin_lock_irq(&ha->phy_port_lock);
+	if (new_phy) {
+		sas_port_put_phy(dev->phy);
+		dev->phy = new_phy;
+	}
+	spin_unlock_irq(&ha->phy_port_lock);
+}
+
 /* ---------- Discovery and Revalidation ---------- */
 
 /**
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 6fb1f3afd1e0..68a80a00f73f 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -723,6 +723,7 @@ static struct domain_device *sas_ex_discover_end_dev(
 		}
 	}
 	sas_ex_get_linkrate(parent, child, phy);
+	sas_device_set_phy(child, phy->port);
 
 #ifdef CONFIG_SCSI_SAS_ATA
 	if ((phy->attached_tproto & SAS_PROTOCOL_STP) || phy->attached_sata_dev) {
@@ -1810,7 +1811,7 @@ static void sas_unregister_devs_sas_addr(struct domain_device *parent,
 {
 	struct expander_device *ex_dev = &parent->ex_dev;
 	struct ex_phy *phy = &ex_dev->ex_phy[phy_id];
-	struct domain_device *child, *n;
+	struct domain_device *child, *n, *found = NULL;
 	if (last) {
 		list_for_each_entry_safe(child, n,
 			&ex_dev->children, siblings) {
@@ -1822,6 +1823,7 @@ static void sas_unregister_devs_sas_addr(struct domain_device *parent,
 					sas_unregister_ex_tree(parent->port, child);
 				else
 					sas_unregister_dev(parent->port, child);
+				found = child;
 				break;
 			}
 		}
@@ -1830,6 +1832,7 @@ static void sas_unregister_devs_sas_addr(struct domain_device *parent,
 	memset(phy->attached_sas_addr, 0, SAS_ADDR_SIZE);
 	if (phy->port) {
 		sas_port_delete_phy(phy->port, phy->phy);
+		sas_device_set_phy(found, phy->port);
 		if (phy->port->num_phys == 0)
 			sas_port_delete(phy->port);
 		phy->port = NULL;
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index a9a3bb94c1bc..c8febc71c40d 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -87,6 +87,7 @@ int sas_smp_phy_control(struct domain_device *dev, int phy_id,
 			enum phy_func phy_func, struct sas_phy_linkrates *);
 int sas_smp_get_phy_events(struct sas_phy *phy);
 
+void sas_device_set_phy(struct domain_device *dev, struct sas_port *port);
 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy);
 struct domain_device *sas_ex_to_ata(struct domain_device *ex_dev, int phy_id);
 int sas_get_phy_attached_sas_addr(struct domain_device *dev, int phy_id,
diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c
index 2980bde4e34a..31adcd1b4191 100644
--- a/drivers/scsi/libsas/sas_port.c
+++ b/drivers/scsi/libsas/sas_port.c
@@ -108,9 +108,6 @@ static void sas_form_port(struct asd_sas_phy *phy)
 	port->num_phys++;
 	port->phy_mask |= (1U << phy->id);
 
-	if (!port->phy)
-		port->phy = phy->phy;
-
 	if (*(u64 *)port->attached_sas_addr == 0) {
 		port->class = phy->class;
 		memcpy(port->attached_sas_addr, phy->attached_sas_addr,
@@ -175,8 +172,10 @@ void sas_deform_port(struct asd_sas_phy *phy, int gone)
 		sas_unregister_domain_devices(port);
 		sas_port_delete(port->port);
 		port->port = NULL;
-	} else
+	} else {
 		sas_port_delete_phy(port->port, phy->phy);
+		sas_device_set_phy(dev, port->port);
+	}
 
 	if (si->dft->lldd_port_deformed)
 		si->dft->lldd_port_deformed(phy);
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 5cc44fddfe95..94ef76316c31 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -439,30 +439,26 @@ static int sas_recover_I_T(struct domain_device *dev)
 	return res;
 }
 
-/* Find the sas_phy that's attached to this device */
-struct sas_phy *sas_find_local_phy(struct domain_device *dev)
+/* take a reference on the last known good phy for this device */
+struct sas_phy *sas_get_local_phy(struct domain_device *dev)
 {
-	struct domain_device *pdev = dev->parent;
-	struct ex_phy *exphy = NULL;
-	int i;
+	struct sas_ha_struct *ha = dev->port->ha;
+	struct sas_phy *phy;
+	unsigned long flags;
 
-	/* Directly attached device */
-	if (!pdev)
-		return dev->port->phy;
+	/* a published domain device always has a valid phy, it may be
+	 * stale, but it is never NULL
+	 */
+	BUG_ON(!dev->phy);
 
-	/* Otherwise look in the expander */
-	for (i = 0; i < pdev->ex_dev.num_phys; i++)
-		if (!memcmp(dev->sas_addr,
-			    pdev->ex_dev.ex_phy[i].attached_sas_addr,
-			    SAS_ADDR_SIZE)) {
-			exphy = &pdev->ex_dev.ex_phy[i];
-			break;
-		}
+	spin_lock_irqsave(&ha->phy_port_lock, flags);
+	phy = dev->phy;
+	get_device(&phy->dev);
+	spin_unlock_irqrestore(&ha->phy_port_lock, flags);
 
-	BUG_ON(!exphy);
-	return exphy->phy;
+	return phy;
 }
-EXPORT_SYMBOL_GPL(sas_find_local_phy);
+EXPORT_SYMBOL_GPL(sas_get_local_phy);
 
 /* Attempt to send a LUN reset message to a device */
 int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
@@ -489,7 +485,7 @@ int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
 int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
 {
 	struct domain_device *dev = cmd_to_domain_dev(cmd);
-	struct sas_phy *phy = sas_find_local_phy(dev);
+	struct sas_phy *phy = sas_get_local_phy(dev);
 	int res;
 
 	res = sas_phy_reset(phy, 1);
@@ -497,6 +493,8 @@ int sas_eh_bus_reset_handler(struct scsi_cmnd *cmd)
 		SAS_DPRINTK("Bus reset of %s failed 0x%x\n",
 			    kobject_name(&phy->dev.kobj),
 			    res);
+	sas_put_local_phy(phy);
+
 	if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
 		return SUCCESS;