[PATCH net-next 1/2] devlink: add generic device max_sfs parameter

[Tariq Toukan <tariqt@nvidia.com>]

From: Nikolay Aleksandrov <nikolay@nvidia.com>

Add a new generic devlink device parameter (max_sfs) to control if and
how many light-weight NIC subfunctions can be created. Subfunctions are
a light-weight network functions backed by an underlying PCI function.
Their lifecycle can already be managed by devlink, but currently users
cannot enable them in the device. They can be enabled/disabled only via
external vendor tools. This parameter allows subfunctions to be enabled
(>0) or disabled (0) via devlink. A subsequent patch will add support
for max_sfs to the mlx5 driver.

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 Documentation/networking/devlink/devlink-params.rst | 6 ++++++
 include/net/devlink.h                               | 4 ++++
 net/devlink/param.c                                 | 5 +++++
 3 files changed, 15 insertions(+)

diff --git a/Documentation/networking/devlink/devlink-params.rst b/Documentation/networking/devlink/devlink-params.rst
index ea17756dcda6..29b8a9246fb6 100644
--- a/Documentation/networking/devlink/devlink-params.rst
+++ b/Documentation/networking/devlink/devlink-params.rst
@@ -165,3 +165,9 @@ own name.
      - u32
      - Controls the maximum number of MAC address filters that can be assigned
        to a Virtual Function (VF).
+   * - ``max_sfs``
+     - u32
+     - The maximum number of subfunctions which can be created on the device.
+       Modifying this parameter may require a device restart and PCI bus
+       rescanning because the BAR layout may change. A value of 0 disables
+       subfunction creation.
diff --git a/include/net/devlink.h b/include/net/devlink.h
index bcd31de1f890..4ec455cfe7a4 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -546,6 +546,7 @@ enum devlink_param_generic_id {
 	DEVLINK_PARAM_GENERIC_ID_TOTAL_VFS,
 	DEVLINK_PARAM_GENERIC_ID_NUM_DOORBELLS,
 	DEVLINK_PARAM_GENERIC_ID_MAX_MAC_PER_VF,
+	DEVLINK_PARAM_GENERIC_ID_MAX_SFS,
 
 	/* add new param generic ids above here*/
 	__DEVLINK_PARAM_GENERIC_ID_MAX,
@@ -619,6 +620,9 @@ enum devlink_param_generic_id {
 #define DEVLINK_PARAM_GENERIC_MAX_MAC_PER_VF_NAME "max_mac_per_vf"
 #define DEVLINK_PARAM_GENERIC_MAX_MAC_PER_VF_TYPE DEVLINK_PARAM_TYPE_U32
 
+#define DEVLINK_PARAM_GENERIC_MAX_SFS_NAME "max_sfs"
+#define DEVLINK_PARAM_GENERIC_MAX_SFS_TYPE DEVLINK_PARAM_TYPE_U32
+
 #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 cf95268da5b0..523243e49d88 100644
--- a/net/devlink/param.c
+++ b/net/devlink/param.c
@@ -117,6 +117,11 @@ static const struct devlink_param devlink_param_generic[] = {
 		.name = DEVLINK_PARAM_GENERIC_MAX_MAC_PER_VF_NAME,
 		.type = DEVLINK_PARAM_GENERIC_MAX_MAC_PER_VF_TYPE,
 	},
+	{
+		.id = DEVLINK_PARAM_GENERIC_ID_MAX_SFS,
+		.name = DEVLINK_PARAM_GENERIC_MAX_SFS_NAME,
+		.type = DEVLINK_PARAM_GENERIC_MAX_SFS_TYPE,
+	},
 };
 
 static int devlink_param_generic_verify(const struct devlink_param *param)
-- 
2.44.0