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>
diff --git a/drivers/infiniband/hw/mlx4/main.c b/drivers/infiniband/hw/mlx4/main.c
index 5266b49..4f230c2 100644
--- a/drivers/infiniband/hw/mlx4/main.c
+++ b/drivers/infiniband/hw/mlx4/main.c
@@ -898,7 +898,6 @@
 	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 @@
 		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_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 @@
 		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;
 	}