IB/cma: Add configfs for rdma_cm

Users would like to control the behaviour of rdma_cm.
For example, old applications which don't set the
required RoCE gid type could be executed on RoCE V2
network types. In order to support this configuration,
we implement a configfs for rdma_cm.

In order to use the configfs, one needs to mount it and
mkdir <IB device name> inside rdma_cm directory.

The patch adds support for a single configuration file,
default_roce_mode. The mode can either be "IB/RoCE v1" or
"RoCE v2".

Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/Documentation/ABI/testing/configfs-rdma_cm b/Documentation/ABI/testing/configfs-rdma_cm
new file mode 100644
index 000000000000..5c389aaf5291
--- /dev/null
+++ b/Documentation/ABI/testing/configfs-rdma_cm
@@ -0,0 +1,22 @@
+What:           /config/rdma_cm
+Date:           November 29, 2015
+KernelVersion:  4.4.0
+Description:    Interface is used to configure RDMA-cable HCAs in respect to
+                RDMA-CM attributes.
+
+                Attributes are visible only when configfs is mounted. To mount
+                configfs in /config directory use:
+                # mount -t configfs none /config/
+
+                In order to set parameters related to a specific HCA, a directory
+                for this HCA has to be created:
+                mkdir -p /config/rdma_cm/<hca>
+
+
+What:           /config/rdma_cm/<hca>/ports/<port-num>/default_roce_mode
+Date:           November 29, 2015
+KernelVersion:  4.4.0
+Description:    RDMA-CM based connections from HCA <hca> at port <port-num>
+                will be initiated with this RoCE type as default.
+                The possible RoCE types are either "IB/RoCE v1" or "RoCE v2".
+                This parameter has RW access.