devlink: Support get and set state of port function

devlink port function can be in active or inactive state.
Allow users to get and set port function's state.

When the port function it activated, its operational state may change
after a while when the device is created and driver binds to it.
Similarly on deactivation flow.

To clearly describe the state of the port function and its device's
operational state in the host system, define state and opstate
attributes.

Example of a PCI SF port which supports a port function:

$ devlink dev eswitch set pci/0000:06:00.0 mode switchdev

$ devlink port show
pci/0000:06:00.0/65535: type eth netdev ens2f0np0 flavour physical port 0 splittable false

$ devlink port add pci/0000:06:00.0 flavour pcisf pfnum 0 sfnum 88
pci/0000:08:00.0/32768: type eth netdev eth6 flavour pcisf controller 0 pfnum 0 sfnum 88 external false splittable false
  function:
    hw_addr 00:00:00:00:00:00 state inactive opstate detached

$ devlink port show pci/0000:06:00.0/32768
pci/0000:06:00.0/32768: type eth netdev ens2f0npf0sf88 flavour pcisf controller 0 pfnum 0 sfnum 88 external false splittable false
  function:
    hw_addr 00:00:00:00:88:88 state inactive opstate detached

$ devlink port function set pci/0000:06:00.0/32768 hw_addr 00:00:00:00:88:88 state active

$ devlink port show pci/0000:06:00.0/32768 -jp
{
    "port": {
        "pci/0000:06:00.0/32768": {
            "type": "eth",
            "netdev": "ens2f0npf0sf88",
            "flavour": "pcisf",
            "controller": 0,
            "pfnum": 0,
            "sfnum": 88,
            "external": false,
            "splittable": false,
            "function": {
                "hw_addr": "00:00:00:00:88:88",
                "state": "active",
                "opstate": "attached"
            }
        }
    }
}

Signed-off-by: Parav Pandit <parav@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Vu Pham <vuhuong@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

1 files changed, 89 insertions, 1 deletions

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 541b5f549274..9f1be69bd5f8 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -87,6 +87,9 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_trap_report);
 
 static const struct nla_policy devlink_function_nl_policy[DEVLINK_PORT_FUNCTION_ATTR_MAX + 1] = {
 	[DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR] = { .type = NLA_BINARY },
+	[DEVLINK_PORT_FN_ATTR_STATE] =
+		NLA_POLICY_RANGE(NLA_U8, DEVLINK_PORT_FN_STATE_INACTIVE,
+				 DEVLINK_PORT_FN_STATE_ACTIVE),
 };
 
 static LIST_HEAD(devlink_list);
@@ -746,6 +749,58 @@ devlink_port_fn_hw_addr_fill(struct devlink *devlink, const struct devlink_ops *
 	return 0;
 }
 
+static bool
+devlink_port_fn_state_valid(enum devlink_port_fn_state state)
+{
+	return state == DEVLINK_PORT_FN_STATE_INACTIVE ||
+	       state == DEVLINK_PORT_FN_STATE_ACTIVE;
+}
+
+static bool
+devlink_port_fn_opstate_valid(enum devlink_port_fn_opstate opstate)
+{
+	return opstate == DEVLINK_PORT_FN_OPSTATE_DETACHED ||
+	       opstate == DEVLINK_PORT_FN_OPSTATE_ATTACHED;
+}
+
+static int
+devlink_port_fn_state_fill(struct devlink *devlink,
+			   const struct devlink_ops *ops,
+			   struct devlink_port *port, struct sk_buff *msg,
+			   struct netlink_ext_ack *extack,
+			   bool *msg_updated)
+{
+	enum devlink_port_fn_opstate opstate;
+	enum devlink_port_fn_state state;
+	int err;
+
+	if (!ops->port_fn_state_get)
+		return 0;
+
+	err = ops->port_fn_state_get(devlink, port, &state, &opstate, extack);
+	if (err) {
+		if (err == -EOPNOTSUPP)
+			return 0;
+		return err;
+	}
+	if (!devlink_port_fn_state_valid(state)) {
+		WARN_ON_ONCE(1);
+		NL_SET_ERR_MSG_MOD(extack, "Invalid state read from driver");
+		return -EINVAL;
+	}
+	if (!devlink_port_fn_opstate_valid(opstate)) {
+		WARN_ON_ONCE(1);
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid operational state read from driver");
+		return -EINVAL;
+	}
+	if (nla_put_u8(msg, DEVLINK_PORT_FN_ATTR_STATE, state) ||
+	    nla_put_u8(msg, DEVLINK_PORT_FN_ATTR_OPSTATE, opstate))
+		return -EMSGSIZE;
+	*msg_updated = true;
+	return 0;
+}
+
 static int
 devlink_nl_port_function_attrs_put(struct sk_buff *msg, struct devlink_port *port,
 				   struct netlink_ext_ack *extack)
@@ -763,6 +818,11 @@ devlink_nl_port_function_attrs_put(struct sk_buff *msg, struct devlink_port *por
 	ops = devlink->ops;
 	err = devlink_port_fn_hw_addr_fill(devlink, ops, port, msg,
 					   extack, &msg_updated);
+	if (err)
+		goto out;
+	err = devlink_port_fn_state_fill(devlink, ops, port, msg, extack,
+					 &msg_updated);
+out:
 	if (err || !msg_updated)
 		nla_nest_cancel(msg, function_attr);
 	else
@@ -1028,6 +1088,24 @@ devlink_port_function_hw_addr_set(struct devlink *devlink, struct devlink_port *
 	return ops->port_function_hw_addr_set(devlink, port, hw_addr, hw_addr_len, extack);
 }
 
+static int devlink_port_fn_state_set(struct devlink *devlink,
+				     struct devlink_port *port,
+				     const struct nlattr *attr,
+				     struct netlink_ext_ack *extack)
+{
+	enum devlink_port_fn_state state;
+	const struct devlink_ops *ops;
+
+	state = nla_get_u8(attr);
+	ops = devlink->ops;
+	if (!ops->port_fn_state_set) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Function does not support state setting");
+		return -EOPNOTSUPP;
+	}
+	return ops->port_fn_state_set(devlink, port, state, extack);
+}
+
 static int
 devlink_port_function_set(struct devlink *devlink, struct devlink_port *port,
 			  const struct nlattr *attr, struct netlink_ext_ack *extack)
@@ -1043,8 +1121,18 @@ devlink_port_function_set(struct devlink *devlink, struct devlink_port *port,
 	}
 
 	attr = tb[DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR];
-	if (attr)
+	if (attr) {
 		err = devlink_port_function_hw_addr_set(devlink, port, attr, extack);
+		if (err)
+			return err;
+	}
+	/* Keep this as the last function attribute set, so that when
+	 * multiple port function attributes are set along with state,
+	 * Those can be applied first before activating the state.
+	 */
+	attr = tb[DEVLINK_PORT_FN_ATTR_STATE];
+	if (attr)
+		err = devlink_port_fn_state_set(devlink, port, attr, extack);
 
 	if (!err)
 		devlink_port_notify(port, DEVLINK_CMD_PORT_NEW);