net/devlink: Support querying hardware address of port function

PCI PF and VF devlink port can manage the function represented by
a devlink port.

Enable users to query port function's hardware address.

Example of a PCI VF port which supports a port function:
$ devlink port show pci/0000:06:00.0/2
pci/0000:06:00.0/2: type eth netdev enp6s0pf0vf1 flavour pcivf pfnum 0 vfnum 1
  function:
    hw_addr 00:11:22:33:44:66

$ devlink port show pci/0000:06:00.0/2 -jp
{
    "port": {
        "pci/0000:06:00.0/2": {
            "type": "eth",
            "netdev": "enp6s0pf0vf1",
            "flavour": "pcivf",
            "pfnum": 0,
            "vfnum": 1,
            "function": {
                "hw_addr": "00:11:22:33:44:66"
            }
        }
    }
}

Signed-off-by: Parav Pandit <parav@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 1df6dfe..56fc9cd 100644 (file)
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -1107,6 +1107,18 @@ struct devlink_ops {
        int (*trap_policer_counter_get)(struct devlink *devlink,
                                        const struct devlink_trap_policer *policer,
                                        u64 *p_drops);
+       /**
+        * @port_function_hw_addr_get: Port function's hardware address get function.
+        *
+        * Should be used by device drivers to report the hardware address of a function managed
+        * by the devlink port. Driver should return -EOPNOTSUPP if it doesn't support port
+        * function handling for a particular port.
+        *
+        * Note: @extack can be NULL when port notifier queries the port function.
+        */
+       int (*port_function_hw_addr_get)(struct devlink *devlink, struct devlink_port *port,
+                                        u8 *hw_addr, int *hw_addr_len,
+                                        struct netlink_ext_ack *extack);
 };
 
 static inline void *devlink_priv(struct devlink *devlink)

diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 08563e6..07d0af8 100644 (file)
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -451,6 +451,8 @@ enum devlink_attr {
        DEVLINK_ATTR_TRAP_POLICER_RATE,                 /* u64 */
        DEVLINK_ATTR_TRAP_POLICER_BURST,                /* u64 */
 
+       DEVLINK_ATTR_PORT_FUNCTION,                     /* nested */
+
        /* add new attributes above here, update the policy in devlink.c */
 
        __DEVLINK_ATTR_MAX,
@@ -497,4 +499,12 @@ enum devlink_resource_unit {
        DEVLINK_RESOURCE_UNIT_ENTRY,
 };
 
+enum devlink_port_function_attr {
+       DEVLINK_PORT_FUNCTION_ATTR_UNSPEC,
+       DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR,     /* binary */
+
+       __DEVLINK_PORT_FUNCTION_ATTR_MAX,
+       DEVLINK_PORT_FUNCTION_ATTR_MAX = __DEVLINK_PORT_FUNCTION_ATTR_MAX - 1
+};
+
 #endif /* _UAPI_LINUX_DEVLINK_H_ */

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 0519763..b6848b6 100644 (file)
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -563,6 +563,49 @@ 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,
@@ -608,6 +651,8 @@ 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;