mlx4: Use port management change event instead of smp_snoop

The port management change event can replace smp_snoop.  If the
capability bit for this event is set in dev-caps, the event is used
(by the driver setting the PORT_MNG_CHG_EVENT bit in the async event
mask in the MAP_EQ fw command).  In this case, when the driver passes
incoming SMP PORT_INFO SET mads to the FW, the FW generates port
management change events to signal any changes to the driver.

If the FW generates these events, smp_snoop shouldn't be invoked in
ib_process_mad(), or duplicate events will occur (once from the
FW-generated event, and once from smp_snoop).

In the case where the FW does not generate port management change
events smp_snoop needs to be invoked to create these events.  The flow
in smp_snoop has been modified to make use of the same procedures as
in the fw-generated-event event case to generate the port management
events (LID change, Client-rereg, Pkey change, and/or GID change).

Port management change event handling required changing the
mlx4_ib_event and mlx4_dispatch_event prototypes; the "param" argument
(last argument) had to be changed to unsigned long in order to
accomodate passing the EQE pointer.

We also needed to move the definition of struct mlx4_eqe from
net/mlx4.h to file device.h -- to make it available to the IB driver,
to handle port management change events.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

3 files changed, 122 insertions, 34 deletions

diff --git a/drivers/infiniband/hw/mlx4/mad.c b/drivers/infiniband/hw/mlx4/mad.c
index 84786a9fb64..58c45fb5bd3 100644
--- a/drivers/infiniband/hw/mlx4/mad.c
+++ b/drivers/infiniband/hw/mlx4/mad.c
@@ -147,47 +147,49 @@ static void update_sm_ah(struct mlx4_ib_dev *dev, u8 port_num, u16 lid, u8 sl)
 }
 
 /*
- * Snoop SM MADs for port info and P_Key table sets, so we can
- * synthesize LID change and P_Key change events.
+ * Snoop SM MADs for port info, GUID info, and  P_Key table sets, so we can
+ * synthesize LID change, Client-Rereg, GID change, and P_Key change events.
  */
 static void smp_snoop(struct ib_device *ibdev, u8 port_num, struct ib_mad *mad,
-				u16 prev_lid)
+		      u16 prev_lid)
 {
-	struct ib_event event;
+	struct ib_port_info *pinfo;
+	u16 lid;
 
+	struct mlx4_ib_dev *dev = to_mdev(ibdev);
 	if ((mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_LID_ROUTED ||
 	     mad->mad_hdr.mgmt_class == IB_MGMT_CLASS_SUBN_DIRECTED_ROUTE) &&
-	    mad->mad_hdr.method == IB_MGMT_METHOD_SET) {
-		if (mad->mad_hdr.attr_id == IB_SMP_ATTR_PORT_INFO) {
-			struct ib_port_info *pinfo =
-				(struct ib_port_info *) ((struct ib_smp *) mad)->data;
-			u16 lid = be16_to_cpu(pinfo->lid);
+	    mad->mad_hdr.method == IB_MGMT_METHOD_SET)
+		switch (mad->mad_hdr.attr_id) {
+		case IB_SMP_ATTR_PORT_INFO:
+			pinfo = (struct ib_port_info *) ((struct ib_smp *) mad)->data;
+			lid = be16_to_cpu(pinfo->lid);
 
-			update_sm_ah(to_mdev(ibdev), port_num,
+			update_sm_ah(dev, port_num,
 				     be16_to_cpu(pinfo->sm_lid),
 				     pinfo->neighbormtu_mastersmsl & 0xf);
 
-			event.device	       = ibdev;
-			event.element.port_num = port_num;
+			if (pinfo->clientrereg_resv_subnetto & 0x80)
+				mlx4_ib_dispatch_event(dev, port_num,
+						       IB_EVENT_CLIENT_REREGISTER);
 
-			if (pinfo->clientrereg_resv_subnetto & 0x80) {
-				event.event    = IB_EVENT_CLIENT_REREGISTER;
-				ib_dispatch_event(&event);
-			}
+			if (prev_lid != lid)
+				mlx4_ib_dispatch_event(dev, port_num,
+						       IB_EVENT_LID_CHANGE);
+			break;
 
-			if (prev_lid != lid) {
-				event.event    = IB_EVENT_LID_CHANGE;
-				ib_dispatch_event(&event);
-			}
-		}
+		case IB_SMP_ATTR_PKEY_TABLE:
+			mlx4_ib_dispatch_event(dev, port_num,
+					       IB_EVENT_PKEY_CHANGE);
+			break;
 
-		if (mad->mad_hdr.attr_id == IB_SMP_ATTR_PKEY_TABLE) {
-			event.device	       = ibdev;
-			event.event	       = IB_EVENT_PKEY_CHANGE;
-			event.element.port_num = port_num;
-			ib_dispatch_event(&event);
+		case IB_SMP_ATTR_GUID_INFO:
+			mlx4_ib_dispatch_event(dev, port_num,
+					       IB_EVENT_GID_CHANGE);
+			break;
+		default:
+			break;
 		}
-	}
 }
 
 static void node_desc_override(struct ib_device *dev,
@@ -305,7 +307,8 @@ static int ib_process_mad(struct ib_device *ibdev, int mad_flags, u8 port_num,
 		return IB_MAD_RESULT_FAILURE;
 
 	if (!out_mad->mad_hdr.status) {
-		smp_snoop(ibdev, port_num, in_mad, prev_lid);
+		if (!(to_mdev(ibdev)->dev->caps.flags & MLX4_DEV_CAP_FLAG_PORT_MNG_CHG_EV))
+			smp_snoop(ibdev, port_num, in_mad, prev_lid);
 		node_desc_override(ibdev, out_mad);
 	}
 
@@ -446,3 +449,62 @@ void mlx4_ib_mad_cleanup(struct mlx4_ib_dev *dev)
 			ib_destroy_ah(dev->sm_ah[p]);
 	}
 }
+
+void handle_port_mgmt_change_event(struct work_struct *work)
+{
+	struct ib_event_work *ew = container_of(work, struct ib_event_work, work);
+	struct mlx4_ib_dev *dev = ew->ib_dev;
+	struct mlx4_eqe *eqe = &(ew->ib_eqe);
+	u8 port = eqe->event.port_mgmt_change.port;
+	u32 changed_attr;
+
+	switch (eqe->subtype) {
+	case MLX4_DEV_PMC_SUBTYPE_PORT_INFO:
+		changed_attr = be32_to_cpu(eqe->event.port_mgmt_change.params.port_info.changed_attr);
+
+		/* Update the SM ah - This should be done before handling
+		   the other changed attributes so that MADs can be sent to the SM */
+		if (changed_attr & MSTR_SM_CHANGE_MASK) {
+			u16 lid = be16_to_cpu(eqe->event.port_mgmt_change.params.port_info.mstr_sm_lid);
+			u8 sl = eqe->event.port_mgmt_change.params.port_info.mstr_sm_sl & 0xf;
+			update_sm_ah(dev, port, lid, sl);
+		}
+
+		/* Check if it is a lid change event */
+		if (changed_attr & MLX4_EQ_PORT_INFO_LID_CHANGE_MASK)
+			mlx4_ib_dispatch_event(dev, port, IB_EVENT_LID_CHANGE);
+
+		/* Generate GUID changed event */
+		if (changed_attr & MLX4_EQ_PORT_INFO_GID_PFX_CHANGE_MASK)
+			mlx4_ib_dispatch_event(dev, port, IB_EVENT_GID_CHANGE);
+
+		if (changed_attr & MLX4_EQ_PORT_INFO_CLIENT_REREG_MASK)
+			mlx4_ib_dispatch_event(dev, port,
+					       IB_EVENT_CLIENT_REREGISTER);
+		break;
+
+	case MLX4_DEV_PMC_SUBTYPE_PKEY_TABLE:
+		mlx4_ib_dispatch_event(dev, port, IB_EVENT_PKEY_CHANGE);
+		break;
+	case MLX4_DEV_PMC_SUBTYPE_GUID_INFO:
+		mlx4_ib_dispatch_event(dev, port, IB_EVENT_GID_CHANGE);
+		break;
+	default:
+		pr_warn("Unsupported subtype 0x%x for "
+			"Port Management Change event\n", eqe->subtype);
+	}
+
+	kfree(ew);
+}
+
+void mlx4_ib_dispatch_event(struct mlx4_ib_dev *dev, u8 port_num,
+			    enum ib_event_type type)
+{
+	struct ib_event event;
+
+	event.device		= &dev->ib_dev;
+	event.element.port_num	= port_num;
+	event.event		= type;
+
+	ib_dispatch_event(&event);
+}
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 5266b49c46e..4f230c26622 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -898,7 +898,6 @@ static void update_gids_task(struct work_struct *work)
 	union ib_gid *gids;
 	int err;
 	struct mlx4_dev	*dev = gw->dev->dev;
-	struct ib_event event;
 
 	mailbox = mlx4_alloc_cmd_mailbox(dev);
 	if (IS_ERR(mailbox)) {
@@ -916,10 +915,7 @@ static void update_gids_task(struct work_struct *work)
 		pr_warn("set port command failed\n");
 	else {
 		memcpy(gw->dev->iboe.gid_table[gw->port - 1], gw->gids, sizeof gw->gids);
-		event.device = &gw->dev->ib_dev;
-		event.element.port_num = gw->port;
-		event.event    = IB_EVENT_GID_CHANGE;
-		ib_dispatch_event(&event);
+		mlx4_ib_dispatch_event(gw->dev, gw->port, IB_EVENT_GID_CHANGE);
 	}
 
 	mlx4_free_cmd_mailbox(dev, mailbox);
@@ -1383,10 +1379,18 @@ static void mlx4_ib_remove(struct mlx4_dev *dev, void *ibdev_ptr)
 }
 
 static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
-			  enum mlx4_dev_event event, int port)
+			  enum mlx4_dev_event event, unsigned long param)
 {
 	struct ib_event ibev;
 	struct mlx4_ib_dev *ibdev = to_mdev((struct ib_device *) ibdev_ptr);
+	struct mlx4_eqe *eqe = NULL;
+	struct ib_event_work *ew;
+	int port = 0;
+
+	if (event == MLX4_DEV_EVENT_PORT_MGMT_CHANGE)
+		eqe = (struct mlx4_eqe *)param;
+	else
+		port = (u8)param;
 
 	if (port > ibdev->num_ports)
 		return;
@@ -1405,6 +1409,19 @@ static void mlx4_ib_event(struct mlx4_dev *dev, void *ibdev_ptr,
 		ibev.event = IB_EVENT_DEVICE_FATAL;
 		break;
 
+	case MLX4_DEV_EVENT_PORT_MGMT_CHANGE:
+		ew = kmalloc(sizeof *ew, GFP_ATOMIC);
+		if (!ew) {
+			pr_err("failed to allocate memory for events work\n");
+			break;
+		}
+
+		INIT_WORK(&ew->work, handle_port_mgmt_change_event);
+		memcpy(&ew->ib_eqe, eqe, sizeof *eqe);
+		ew->ib_dev = ibdev;
+		handle_port_mgmt_change_event(&ew->work);
+		return;
+
 	default:
 		return;
 	}
diff --git a/drivers/infiniband/hw/mlx4/mlx4_ib.h b/drivers/infiniband/hw/mlx4/mlx4_ib.h
index 5f298afaa81..23bfbf9ee0e 100644
--- a/drivers/infiniband/hw/mlx4/mlx4_ib.h
+++ b/drivers/infiniband/hw/mlx4/mlx4_ib.h
@@ -224,6 +224,12 @@ struct mlx4_ib_dev {
 	int			eq_added;
 };
 
+struct ib_event_work {
+	struct work_struct	work;
+	struct mlx4_ib_dev	*ib_dev;
+	struct mlx4_eqe		ib_eqe;
+};
+
 static inline struct mlx4_ib_dev *to_mdev(struct ib_device *ibdev)
 {
 	return container_of(ibdev, struct mlx4_ib_dev, ib_dev);
@@ -381,4 +387,7 @@ static inline int mlx4_ib_ah_grh_present(struct mlx4_ib_ah *ah)
 int mlx4_ib_add_mc(struct mlx4_ib_dev *mdev, struct mlx4_ib_qp *mqp,
 		   union ib_gid *gid);
 
+void mlx4_ib_dispatch_event(struct mlx4_ib_dev *dev, u8 port_num,
+			    enum ib_event_type type);
+
 #endif /* MLX4_IB_H */