[PATCH for-next] RDMA/nldev: Add parent bdf to device information dump

[Gal Pressman <galpress@amazon.com>]

Add the ability to query the device's bdf through rdma tool netlink
command (in addition to the sysfs infra).

In case of virtual devices (rxe/siw), the netdev bdf will be shown.

Signed-off-by: Gal Pressman <galpress@amazon.com>
---
 drivers/infiniband/core/nldev.c  | 10 +++++++++-
 include/uapi/rdma/rdma_netlink.h |  5 +++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 12d29d54a081..9704b1449c01 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -291,7 +291,15 @@ static int fill_dev_info(struct sk_buff *msg, struct ib_device *device)
 	else if (rdma_protocol_usnic(device, port))
 		ret = nla_put_string(msg, RDMA_NLDEV_ATTR_DEV_PROTOCOL,
 				     "usnic");
-	return ret;
+	if (ret)
+		return ret;
+
+	if (device->dev.parent)
+		if (nla_put_string(msg, RDMA_NLDEV_PARENT_BDF,
+				   dev_name(device->dev.parent)))
+			return -EMSGSIZE;
+
+	return 0;
 }
 
 static int fill_port_info(struct sk_buff *msg,
diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
index d2f5b8396243..7495104668eb 100644
--- a/include/uapi/rdma/rdma_netlink.h
+++ b/include/uapi/rdma/rdma_netlink.h
@@ -533,6 +533,11 @@ enum rdma_nldev_attr {
 
 	RDMA_NLDEV_ATTR_RES_RAW,	/* binary */
 
+	/*
+	 * Parent device BDF (bus, device, function).
+	 */
+	RDMA_NLDEV_PARENT_BDF,			/* string */
+
 	/*
 	 * Always the end
 	 */
-- 
2.29.1