IB/isert: Adjust CQ size to HW limits

isert has an issue of trying to create a CQ with more CQEs than are
supported by the hardware, that currently results in failures during
isert_device creation during first session login.

This is the isert version of the patch that Minh Tran submitted for
iser, and is simple a workaround required to function with existing
ocrdma hardware.

Signed-off-by: Chris Moore <chris.moore@emulex.com>
Reviewied-by: Sagi Grimberg <sagig@mellanox.com>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/infiniband/ulp/isert/ib_isert.c

@@ -228,12 +228,16 @@ isert_create_device_ib_res(struct isert_device *device)
 	struct isert_cq_desc *cq_desc;
 	struct ib_device_attr *dev_attr;
 	int ret = 0, i, j;
+	int max_rx_cqe, max_tx_cqe;
 
 	dev_attr = &device->dev_attr;
 	ret = isert_query_device(ib_dev, dev_attr);
 	if (ret)
 		return ret;
 
+	max_rx_cqe = min(ISER_MAX_RX_CQ_LEN, dev_attr->max_cqe);
+	max_tx_cqe = min(ISER_MAX_TX_CQ_LEN, dev_attr->max_cqe);
+
 	/* asign function handlers */
 	if (dev_attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS &&
 	    dev_attr->device_cap_flags & IB_DEVICE_SIGNATURE_HANDOVER) {
@@ -275,7 +279,7 @@ isert_create_device_ib_res(struct isert_device *device)
 						isert_cq_rx_callback,
 						isert_cq_event_callback,
 						(void *)&cq_desc[i],
-						ISER_MAX_RX_CQ_LEN, i);
+						max_rx_cqe, i);
 		if (IS_ERR(device->dev_rx_cq[i])) {
 			ret = PTR_ERR(device->dev_rx_cq[i]);
 			device->dev_rx_cq[i] = NULL;
@@ -287,7 +291,7 @@ isert_create_device_ib_res(struct isert_device *device)
 						isert_cq_tx_callback,
 						isert_cq_event_callback,
 						(void *)&cq_desc[i],
-						ISER_MAX_TX_CQ_LEN, i);
+						max_tx_cqe, i);
 		if (IS_ERR(device->dev_tx_cq[i])) {
 			ret = PTR_ERR(device->dev_tx_cq[i]);
 			device->dev_tx_cq[i] = NULL;