Merge branch 'implement-devlink-rate-api-and-extend-it'

Michal Wilczynski says:

====================
Implement devlink-rate API and extend it

This patch series implements devlink-rate for ice driver. Unfortunately
current API isn't flexible enough for our use case, so there is a need to
extend it. Some functions have been introduced to enable the driver to
export current Tx scheduling configuration.

Pasting justification for this series from commit implementing devlink-rate
in ice driver(that is a part of this series):

There is a need to support modification of Tx scheduler tree, in the
ice driver. This will allow user to control Tx settings of each node in
the internal hierarchy of nodes. As a result user will be able to use
Hierarchy QoS implemented entirely in the hardware.

This patch implemenents devlink-rate API. It also exports initial
default hierarchy. It's mostly dictated by the fact that the tree
can't be removed entirely, all we can do is enable the user to modify
it. For example root node shouldn't ever be removed, also nodes that
have children are off-limits.

Example initial tree with 2 VF's:

[root@fedora ~]# devlink port function rate show
pci/0000:4b:00.0/node_27: type node parent node_26
pci/0000:4b:00.0/node_26: type node parent node_0
pci/0000:4b:00.0/node_34: type node parent node_33
pci/0000:4b:00.0/node_33: type node parent node_32
pci/0000:4b:00.0/node_32: type node parent node_16
pci/0000:4b:00.0/node_19: type node parent node_18
pci/0000:4b:00.0/node_18: type node parent node_17
pci/0000:4b:00.0/node_17: type node parent node_16
pci/0000:4b:00.0/node_21: type node parent node_20
pci/0000:4b:00.0/node_20: type node parent node_3
pci/0000:4b:00.0/node_14: type node parent node_5
pci/0000:4b:00.0/node_5: type node parent node_3
pci/0000:4b:00.0/node_13: type node parent node_4
pci/0000:4b:00.0/node_12: type node parent node_4
pci/0000:4b:00.0/node_11: type node parent node_4
pci/0000:4b:00.0/node_10: type node parent node_4
pci/0000:4b:00.0/node_9: type node parent node_4
pci/0000:4b:00.0/node_8: type node parent node_4
pci/0000:4b:00.0/node_7: type node parent node_4
pci/0000:4b:00.0/node_6: type node parent node_4
pci/0000:4b:00.0/node_4: type node parent node_3
pci/0000:4b:00.0/node_3: type node parent node_16
pci/0000:4b:00.0/node_16: type node parent node_15
pci/0000:4b:00.0/node_15: type node parent node_0
pci/0000:4b:00.0/node_2: type node parent node_1
pci/0000:4b:00.0/node_1: type node parent node_0
pci/0000:4b:00.0/node_0: type node
pci/0000:4b:00.0/1: type leaf parent node_27
pci/0000:4b:00.0/2: type leaf parent node_27

Let me visualize part of the tree:

                        +---------+
                        |  node_0 |
                        +---------+
                             |
                        +----v----+
                        | node_26 |
                        +----+----+
                             |
                        +----v----+
                        | node_27 |
                        +----+----+
                             |
                    |-----------------|
               +----v----+       +----v----+
               |   VF 1  |       |   VF 2  |
               +----+----+       +----+----+

So at this point there is a couple things that can be done.
For example we could only assign parameters to VF's.

[root@fedora ~]# devlink port function rate set pci/0000:4b:00.0/1 \
                 tx_max 5Gbps

This would cap the VF 1 BW to 5Gbps.

But let's say you would like to create a completely new branch.
This can be done like this:

[root@fedora ~]# devlink port function rate add \
                 pci/0000:4b:00.0/node_custom parent node_0
[root@fedora ~]# devlink port function rate add \
                 pci/0000:4b:00.0/node_custom_1 parent node_custom
[root@fedora ~]# devlink port function rate set \
                 pci/0000:4b:00.0/1 parent node_custom_1

This creates a completely new branch and reassigns VF 1 to it.

A number of parameters is supported per each node: tx_max, tx_share,
tx_priority and tx_weight.
====================

Link: https://lore.kernel.org/r/20221115104825.172668-1-michal.wilczynski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

2 files changed, 20 insertions, 1 deletions

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 611a23a3deb2..074a79b8933f 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -114,6 +114,9 @@ struct devlink_rate {
 			refcount_t refcnt;
 		};
 	};
+
+	u32 tx_priority;
+	u32 tx_weight;
 };
 
 struct devlink_port {
@@ -1511,10 +1514,18 @@ struct devlink_ops {
 				      u64 tx_share, struct netlink_ext_ack *extack);
 	int (*rate_leaf_tx_max_set)(struct devlink_rate *devlink_rate, void *priv,
 				    u64 tx_max, struct netlink_ext_ack *extack);
+	int (*rate_leaf_tx_priority_set)(struct devlink_rate *devlink_rate, void *priv,
+					 u32 tx_priority, struct netlink_ext_ack *extack);
+	int (*rate_leaf_tx_weight_set)(struct devlink_rate *devlink_rate, void *priv,
+				       u32 tx_weight, struct netlink_ext_ack *extack);
 	int (*rate_node_tx_share_set)(struct devlink_rate *devlink_rate, void *priv,
 				      u64 tx_share, struct netlink_ext_ack *extack);
 	int (*rate_node_tx_max_set)(struct devlink_rate *devlink_rate, void *priv,
 				    u64 tx_max, struct netlink_ext_ack *extack);
+	int (*rate_node_tx_priority_set)(struct devlink_rate *devlink_rate, void *priv,
+					 u32 tx_priority, struct netlink_ext_ack *extack);
+	int (*rate_node_tx_weight_set)(struct devlink_rate *devlink_rate, void *priv,
+				       u32 tx_weight, struct netlink_ext_ack *extack);
 	int (*rate_node_new)(struct devlink_rate *rate_node, void **priv,
 			     struct netlink_ext_ack *extack);
 	int (*rate_node_del)(struct devlink_rate *rate_node, void *priv,
@@ -1606,7 +1617,12 @@ void devlink_port_attrs_pci_vf_set(struct devlink_port *devlink_port, u32 contro
 void devlink_port_attrs_pci_sf_set(struct devlink_port *devlink_port,
 				   u32 controller, u16 pf, u32 sf,
 				   bool external);
-int devl_rate_leaf_create(struct devlink_port *port, void *priv);
+struct devlink_rate *
+devl_rate_node_create(struct devlink *devlink, void *priv, char *node_name,
+		      struct devlink_rate *parent);
+int
+devl_rate_leaf_create(struct devlink_port *devlink_port, void *priv,
+		      struct devlink_rate *parent);
 void devl_rate_leaf_destroy(struct devlink_port *devlink_port);
 void devl_rate_nodes_destroy(struct devlink *devlink);
 void devlink_port_linecard_set(struct devlink_port *devlink_port,
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 2f24b53a87a5..498d0d5d0957 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -607,6 +607,9 @@ enum devlink_attr {
 
 	DEVLINK_ATTR_SELFTESTS,			/* nested */
 
+	DEVLINK_ATTR_RATE_TX_PRIORITY,		/* u32 */
+	DEVLINK_ATTR_RATE_TX_WEIGHT,		/* u32 */
+
 	/* add new attributes above here, update the policy in devlink.c */
 
 	__DEVLINK_ATTR_MAX,