[PATCH rdma-next 1/3] RDMA/cma: Skip device which doesn't support CM

[Leon Romanovsky <leon@kernel.org>]

From: Parav Pandit <parav@nvidia.com>

A switchdev RDMA device do not support IB CM. When such device is added
to the RDMA CM's device list, when application invokes rdma_listen(),
cma attempts to listen to such device, however it has IB CM attribute
disabled
.
Due to this, rdma_listen() call fails to listen for other non
switchdev devices as well.

A below error message can be seen.

infiniband mlx5_0: RDMA CMA: cma_listen_on_dev, error -38

A failing call flow is below.

rdma_listen()
  cma_listen_on_all()
    cma_listen_on_dev()
      _cma_attach_to_dev()
      rdma_listen() <- fails on a specific switchdev device

Hence, when a IB device doesn't support IB CM or IW CM, avoid adding
such device to the cma list.

Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/infiniband/core/cma.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index bb7bd024f3bd..2dc302a83014 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -4900,6 +4900,17 @@ static void cma_process_remove(struct cma_device *cma_dev)
 	wait_for_completion(&cma_dev->comp);
 }
 
+static bool cma_supported(struct ib_device *device)
+{
+	u32 i;
+
+	rdma_for_each_port(device, i) {
+		if (rdma_cap_ib_cm(device, i) || rdma_cap_iw_cm(device, i))
+			return true;
+	}
+	return false;
+}
+
 static int cma_add_one(struct ib_device *device)
 {
 	struct rdma_id_private *to_destroy;
@@ -4909,6 +4920,9 @@ static int cma_add_one(struct ib_device *device)
 	int ret;
 	u32 i;
 
+	if (!cma_supported(device))
+		return -EOPNOTSUPP;
+
 	cma_dev = kmalloc(sizeof(*cma_dev), GFP_KERNEL);
 	if (!cma_dev)
 		return -ENOMEM;
-- 
2.30.2