[PATCH net-next 1/2] devlink: add device capability reporting to devlink info API

[Kalesh A P <kalesh-anakkur.purayil@broadcom.com>]

From: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>

It may be useful if we expose the device capabilities
to the user through devlink info API.
Add a new devlink API to allow retrieving device capabilities.

Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
---
 Documentation/networking/devlink/devlink-info.rst |  3 +++
 include/net/devlink.h                             |  2 ++
 include/uapi/linux/devlink.h                      |  3 +++
 net/core/devlink.c                                | 25 +++++++++++++++++++++++
 4 files changed, 33 insertions(+)

diff --git a/Documentation/networking/devlink/devlink-info.rst b/Documentation/networking/devlink/devlink-info.rst
index 7572bf6..b9b32dc 100644
--- a/Documentation/networking/devlink/devlink-info.rst
+++ b/Documentation/networking/devlink/devlink-info.rst
@@ -78,6 +78,9 @@ versions is generally discouraged - here, and via any other Linux API.
        ``stored`` versions when new software is flashed, it must not report
        them.
 
+   * - ``capabilities``
+     - Group for device capabilities.
+
 Each version can be reported at most once in each version group. Firmware
 components stored on the flash should feature in both the ``running`` and
 ``stored`` sections, if device is capable of reporting ``stored`` versions
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 08f4c61..e06d781 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1687,6 +1687,8 @@ int devlink_info_version_stored_put(struct devlink_info_req *req,
 int devlink_info_version_running_put(struct devlink_info_req *req,
 				     const char *version_name,
 				     const char *version_value);
+int devlink_info_device_capability_put(struct devlink_info_req *req,
+				       const char *capability_name);
 
 int devlink_fmsg_obj_nest_start(struct devlink_fmsg *fmsg);
 int devlink_fmsg_obj_nest_end(struct devlink_fmsg *fmsg);
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 32f53a00..f61a59ae 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -551,6 +551,9 @@ enum devlink_attr {
 	DEVLINK_ATTR_RATE_NODE_NAME,		/* string */
 	DEVLINK_ATTR_RATE_PARENT_NODE_NAME,	/* string */
 
+	DEVLINK_ATTR_INFO_DEVICE_CAPABILITY_LIST,	/* nested */
+	DEVLINK_ATTR_INFO_DEVICE_CAPABILITY_NAME,	/* string */
+
 	/* add new attributes above here, update the policy in devlink.c */
 
 	__DEVLINK_ATTR_MAX,
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 8fa0153..4f1ce03 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -5850,6 +5850,31 @@ int devlink_info_version_running_put(struct devlink_info_req *req,
 }
 EXPORT_SYMBOL_GPL(devlink_info_version_running_put);
 
+int devlink_info_device_capability_put(struct devlink_info_req *req,
+				       const char *capability_name)
+{
+	struct nlattr *nest;
+	int err;
+
+	nest = nla_nest_start(req->msg, DEVLINK_ATTR_INFO_DEVICE_CAPABILITY_LIST);
+	if (!nest)
+		return -EMSGSIZE;
+
+	err = nla_put_string(req->msg, DEVLINK_ATTR_INFO_DEVICE_CAPABILITY_NAME,
+			     capability_name);
+	if (err)
+		goto nla_put_failure;
+
+	nla_nest_end(req->msg, nest);
+
+	return 0;
+
+nla_put_failure:
+	nla_nest_cancel(req->msg, nest);
+	return err;
+}
+EXPORT_SYMBOL_GPL(devlink_info_device_capability_put);
+
 static int
 devlink_nl_info_fill(struct sk_buff *msg, struct devlink *devlink,
 		     enum devlink_command cmd, u32 portid,
-- 
2.10.1