Merge branch 'devlink-Support-get-set-mac-address-of-a-port-function'

Parav Pandit says:

====================
devlink: Support get,set mac address of a port function

Currently, ip link set dev <pfndev> vf <vf_num> <param> <value> has
below few limitations.

1. Command is limited to set VF parameters only.
It cannot set the default MAC address for the PCI PF.

2. It can be set only on system where PCI SR-IOV capability exists.
In smartnic based system, eswitch of a NIC resides on a different
embedded cpu which has the VF and PF representors for the SR-IOV
functions of a host system in which this smartnic is plugged-in.

3. It cannot setup the function attributes of sub-function described
in detail in comprehensive RFC [1] and [2].

This series covers the first small part to let user query and set MAC
address (hardware address) of a PCI PF/VF which is represented by
devlink port pcipf, pcivf port flavours respectively.

Whenever a devlink port manages a function connected to a devlink port,
it allows to query and set its hardware address.

Driver implements necessary get/set callback functions if it supports
port function for a given port type.

Patch summary:
Patch-1 Prepares devlink port fill routines for extack
Patch-2 and 3 extended devlink interface to get/set port function
attributes, mainly hardware address to start with.

Patch-2 Extended port dump command to query port function hardware
address
Patch-3 Introduces a command to set the hardware address of a port
function

Patch-4 to 9 refactors and implement devlink callbacks in mlx5_core
driver.
Patch-4 Constify the mac address pointer in set routines
Patch-5 Introduces eswich check helper to use in devlink facing
callbacks
Patch-6 Moves port index, port number conversion routine to eswitch
header file
Patch-7 Implements port function query devlink callback
Patch-8 Refactors mac address setting routine to uniformly use
state_lock
Patch-9 Implements port function set devlink callback

[1] https://lore.kernel.org/netdev/20200519092258.GF4655@nanopsycho/
[2] https://marc.info/?l=linux-netdev&m=158555928517777&w=2
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 129 insertions, 4 deletions

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 2cafbc808b09..baa45eca6b5a 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -85,6 +85,10 @@ EXPORT_SYMBOL(devlink_dpipe_header_ipv6);
 EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwmsg);
 EXPORT_TRACEPOINT_SYMBOL_GPL(devlink_hwerr);
 
+static const struct nla_policy devlink_function_nl_policy[DEVLINK_PORT_FUNCTION_ATTR_MAX + 1] = {
+	[DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR] = { .type = NLA_BINARY },
+};
+
 static LIST_HEAD(devlink_list);
 
 /* devlink_mutex
@@ -563,10 +567,54 @@ static int devlink_nl_port_attrs_put(struct sk_buff *msg,
 	return 0;
 }
 
+static int
+devlink_nl_port_function_attrs_put(struct sk_buff *msg, struct devlink_port *port,
+				   struct netlink_ext_ack *extack)
+{
+	struct devlink *devlink = port->devlink;
+	const struct devlink_ops *ops;
+	struct nlattr *function_attr;
+	bool empty_nest = true;
+	int err = 0;
+
+	function_attr = nla_nest_start_noflag(msg, DEVLINK_ATTR_PORT_FUNCTION);
+	if (!function_attr)
+		return -EMSGSIZE;
+
+	ops = devlink->ops;
+	if (ops->port_function_hw_addr_get) {
+		int uninitialized_var(hw_addr_len);
+		u8 hw_addr[MAX_ADDR_LEN];
+
+		err = ops->port_function_hw_addr_get(devlink, port, hw_addr, &hw_addr_len, extack);
+		if (err == -EOPNOTSUPP) {
+			/* Port function attributes are optional for a port. If port doesn't
+			 * support function attribute, returning -EOPNOTSUPP is not an error.
+			 */
+			err = 0;
+			goto out;
+		} else if (err) {
+			goto out;
+		}
+		err = nla_put(msg, DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR, hw_addr_len, hw_addr);
+		if (err)
+			goto out;
+		empty_nest = false;
+	}
+
+out:
+	if (err || empty_nest)
+		nla_nest_cancel(msg, function_attr);
+	else
+		nla_nest_end(msg, function_attr);
+	return err;
+}
+
 static int devlink_nl_port_fill(struct sk_buff *msg, struct devlink *devlink,
 				struct devlink_port *devlink_port,
 				enum devlink_command cmd, u32 portid,
-				u32 seq, int flags)
+				u32 seq, int flags,
+				struct netlink_ext_ack *extack)
 {
 	void *hdr;
 
@@ -607,6 +655,8 @@ static int devlink_nl_port_fill(struct sk_buff *msg, struct devlink *devlink,
 	spin_unlock_bh(&devlink_port->type_lock);
 	if (devlink_nl_port_attrs_put(msg, devlink_port))
 		goto nla_put_failure;
+	if (devlink_nl_port_function_attrs_put(msg, devlink_port, extack))
+		goto nla_put_failure;
 
 	genlmsg_end(msg, hdr);
 	return 0;
@@ -634,7 +684,8 @@ static void devlink_port_notify(struct devlink_port *devlink_port,
 	if (!msg)
 		return;
 
-	err = devlink_nl_port_fill(msg, devlink, devlink_port, cmd, 0, 0, 0);
+	err = devlink_nl_port_fill(msg, devlink, devlink_port, cmd, 0, 0, 0,
+				   NULL);
 	if (err) {
 		nlmsg_free(msg);
 		return;
@@ -708,7 +759,8 @@ static int devlink_nl_cmd_port_get_doit(struct sk_buff *skb,
 
 	err = devlink_nl_port_fill(msg, devlink, devlink_port,
 				   DEVLINK_CMD_PORT_NEW,
-				   info->snd_portid, info->snd_seq, 0);
+				   info->snd_portid, info->snd_seq, 0,
+				   info->extack);
 	if (err) {
 		nlmsg_free(msg);
 		return err;
@@ -740,7 +792,8 @@ static int devlink_nl_cmd_port_get_dumpit(struct sk_buff *msg,
 						   DEVLINK_CMD_NEW,
 						   NETLINK_CB(cb->skb).portid,
 						   cb->nlh->nlmsg_seq,
-						   NLM_F_MULTI);
+						   NLM_F_MULTI,
+						   cb->extack);
 			if (err) {
 				mutex_unlock(&devlink->lock);
 				goto out;
@@ -778,6 +831,67 @@ static int devlink_port_type_set(struct devlink *devlink,
 	return -EOPNOTSUPP;
 }
 
+static int
+devlink_port_function_hw_addr_set(struct devlink *devlink, struct devlink_port *port,
+				  const struct nlattr *attr, struct netlink_ext_ack *extack)
+{
+	const struct devlink_ops *ops;
+	const u8 *hw_addr;
+	int hw_addr_len;
+	int err;
+
+	hw_addr = nla_data(attr);
+	hw_addr_len = nla_len(attr);
+	if (hw_addr_len > MAX_ADDR_LEN) {
+		NL_SET_ERR_MSG_MOD(extack, "Port function hardware address too long");
+		return -EINVAL;
+	}
+	if (port->type == DEVLINK_PORT_TYPE_ETH) {
+		if (hw_addr_len != ETH_ALEN) {
+			NL_SET_ERR_MSG_MOD(extack, "Address must be 6 bytes for Ethernet device");
+			return -EINVAL;
+		}
+		if (!is_unicast_ether_addr(hw_addr)) {
+			NL_SET_ERR_MSG_MOD(extack, "Non-unicast hardware address unsupported");
+			return -EINVAL;
+		}
+	}
+
+	ops = devlink->ops;
+	if (!ops->port_function_hw_addr_set) {
+		NL_SET_ERR_MSG_MOD(extack, "Port doesn't support function attributes");
+		return -EOPNOTSUPP;
+	}
+
+	err = ops->port_function_hw_addr_set(devlink, port, hw_addr, hw_addr_len, extack);
+	if (err)
+		return err;
+
+	devlink_port_notify(port, DEVLINK_CMD_PORT_NEW);
+	return 0;
+}
+
+static int
+devlink_port_function_set(struct devlink *devlink, struct devlink_port *port,
+			  const struct nlattr *attr, struct netlink_ext_ack *extack)
+{
+	struct nlattr *tb[DEVLINK_PORT_FUNCTION_ATTR_MAX + 1];
+	int err;
+
+	err = nla_parse_nested(tb, DEVLINK_PORT_FUNCTION_ATTR_MAX, attr,
+			       devlink_function_nl_policy, extack);
+	if (err < 0) {
+		NL_SET_ERR_MSG_MOD(extack, "Fail to parse port function attributes");
+		return err;
+	}
+
+	attr = tb[DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR];
+	if (attr)
+		err = devlink_port_function_hw_addr_set(devlink, port, attr, extack);
+
+	return err;
+}
+
 static int devlink_nl_cmd_port_set_doit(struct sk_buff *skb,
 					struct genl_info *info)
 {
@@ -793,6 +907,16 @@ static int devlink_nl_cmd_port_set_doit(struct sk_buff *skb,
 		if (err)
 			return err;
 	}
+
+	if (info->attrs[DEVLINK_ATTR_PORT_FUNCTION]) {
+		struct nlattr *attr = info->attrs[DEVLINK_ATTR_PORT_FUNCTION];
+		struct netlink_ext_ack *extack = info->extack;
+
+		err = devlink_port_function_set(devlink, devlink_port, attr, extack);
+		if (err)
+			return err;
+	}
+
 	return 0;
 }
 
@@ -6709,6 +6833,7 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
 	[DEVLINK_ATTR_TRAP_POLICER_ID] = { .type = NLA_U32 },
 	[DEVLINK_ATTR_TRAP_POLICER_RATE] = { .type = NLA_U64 },
 	[DEVLINK_ATTR_TRAP_POLICER_BURST] = { .type = NLA_U64 },
+	[DEVLINK_ATTR_PORT_FUNCTION] = { .type = NLA_NESTED },
 };
 
 static const struct genl_ops devlink_nl_ops[] = {