IB/isert: Adjust CQ size to HW limits

commit b1a5ad00 upstream.

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>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/infiniband/ulp/isert/ib_isert.c

@@ -212,6 +212,13 @@ isert_create_device_ib_res(struct isert_device *device)
 	struct ib_device *ib_dev = device->ib_device;
 	struct isert_cq_desc *cq_desc;
 	int ret = 0, i, j;
+	int max_rx_cqe, max_tx_cqe;
+	struct ib_device_attr dev_attr;
+
+	memset(&dev_attr, 0, sizeof(struct ib_device_attr));
+	ret = isert_query_device(device->ib_device, &dev_attr);
+	if (ret)
+		return ret;
 
 	device->cqs_used = min_t(int, num_online_cpus(),
 				 device->ib_device->num_comp_vectors);
@@ -234,6 +241,9 @@ isert_create_device_ib_res(struct isert_device *device)
 		goto out_cq_desc;
 	}
 
+	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);
+
 	for (i = 0; i < device->cqs_used; i++) {
 		cq_desc[i].device = device;
 		cq_desc[i].cq_index = i;
@@ -242,7 +252,7 @@ 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;
@@ -253,7 +263,7 @@ 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;