Subject: [PATCH rdma-next 2/8] RDMA/cma: Skip device which doesn't support CM

From: Leon Romanovsky <[email-masked]>
Date: Mon, 5 Apr 2021 08:49:54 +0300

From: Parav Pandit <[email-masked]>

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 <[email-masked]>
Signed-off-by: Leon Romanovsky <[email-masked]>
---
 drivers/infiniband/core/cma.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 42a1c8955c50..80156faf90de 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -157,11 +157,13 @@ EXPORT_SYMBOL(rdma_res_to_id);
 
 static int cma_add_one(struct ib_device *device);
 static void cma_remove_one(struct ib_device *device, void *client_data);
+static bool cma_supported(struct ib_device *device);
 
 static struct ib_client cma_client = {
 	.name   = "cma",
 	.add    = cma_add_one,
-	.remove = cma_remove_one
+	.remove = cma_remove_one,
+	.is_supported = cma_supported,
 };
 
 static struct ib_sa_client sa_client;
@@ -4870,6 +4872,17 @@ 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;
-- 
2.30.2