Subject: [PATCH net-next V3 11/15] devlink: Add 'keep_link_up' generic devlink device param

From: Saeed Mahameed <[email-masked]>
Date: Fri, 25 Apr 2025 14:48:04 -0700

From: Saeed Mahameed <[email-masked]>

Devices that support this in permanent mode will be requested to keep the
port link up even when driver is not loaded, netdev carrier state won't
affect the physical port link state.

This is useful for when the link is needed to access onboard management
such as BMC, even if the host driver isn't loaded.

Reviewed-by: Jiri Pirko <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 Documentation/networking/devlink/devlink-params.rst | 4 ++++
 include/net/devlink.h                               | 4 ++++
 net/devlink/param.c                                 | 4 ++++
 3 files changed, 12 insertions(+)

diff --git a/Documentation/networking/devlink/devlink-params.rst b/Documentation/networking/devlink/devlink-params.rst
index f266da05ab0d..2fbfab78030f 100644
--- a/Documentation/networking/devlink/devlink-params.rst
+++ b/Documentation/networking/devlink/devlink-params.rst
@@ -140,3 +140,7 @@ own name.
    * - ``total_vfs``
      - u32
      - The total number of Virtual Functions (VFs) supported by the PF.
+   * - ``keep_link_up``
+     - Boolean
+     - When enabled, the device will keep the port link up even if the driver is
+       not loaded.
diff --git a/include/net/devlink.h b/include/net/devlink.h
index b409ccbcfd12..ca32c61583cf 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -523,6 +523,7 @@ enum devlink_param_generic_id {
 	DEVLINK_PARAM_GENERIC_ID_IO_EQ_SIZE,
 	DEVLINK_PARAM_GENERIC_ID_EVENT_EQ_SIZE,
 	DEVLINK_PARAM_GENERIC_ID_TOTAL_VFS,
+	DEVLINK_PARAM_GENERIC_ID_KEEP_LINK_UP,
 
 	/* add new param generic ids above here*/
 	__DEVLINK_PARAM_GENERIC_ID_MAX,
@@ -584,6 +585,9 @@ enum devlink_param_generic_id {
 #define DEVLINK_PARAM_GENERIC_TOTAL_VFS_NAME "total_vfs"
 #define DEVLINK_PARAM_GENERIC_TOTAL_VFS_TYPE DEVLINK_PARAM_TYPE_U32
 
+#define DEVLINK_PARAM_GENERIC_KEEP_LINK_UP_NAME "keep_link_up"
+#define DEVLINK_PARAM_GENERIC_KEEP_LINK_UP_TYPE DEVLINK_PARAM_TYPE_BOOL
+
 #define DEVLINK_PARAM_GENERIC(_id, _cmodes, _get, _set, _validate)	\
 {									\
 	.id = DEVLINK_PARAM_GENERIC_ID_##_id,				\
diff --git a/net/devlink/param.c b/net/devlink/param.c
index 7f36bb8d970c..2fc3bd2650ab 100644
--- a/net/devlink/param.c
+++ b/net/devlink/param.c
@@ -97,6 +97,10 @@ static const struct devlink_param devlink_param_generic[] = {
 		.name = DEVLINK_PARAM_GENERIC_TOTAL_VFS_NAME,
 		.type = DEVLINK_PARAM_GENERIC_TOTAL_VFS_TYPE,
 	},
+	{	.id = DEVLINK_PARAM_GENERIC_ID_KEEP_LINK_UP,
+		.name = DEVLINK_PARAM_GENERIC_KEEP_LINK_UP_NAME,
+		.type = DEVLINK_PARAM_GENERIC_KEEP_LINK_UP_TYPE,
+	},
 };
 
 static int devlink_param_generic_verify(const struct devlink_param *param)
-- 
2.49.0