[PATCH net-next 4/7] netdevsim: Simulate set hardware address of a PCI port

[Parav Pandit <parav@nvidia.com>]

Allow users to get/set hardware address for the PCI port.

Below example creates one devlink port, queries a port, sets a
hardware address.

Example of a PCI SF port which supports a port function hw_addr set:
Create a device with ID=10 and one physical port.
$ echo "10 1" > /sys/bus/netdevsim/new_device

Add PCI PF port:
$ devlink port add netdevsim/netdevsim10 flavour pcipf pfnum 2
netdevsim/netdevsim10/1: type eth netdev eth1 flavour pcipf controller 0 pfnum 2 external false splittable false
  function:
    hw_addr 00:00:00:00:00:00

$ devlink port add netdevsim/netdevsim10 flavour pcisf pfnum 2
netdevsim/netdevsim10/2: type eth netdev eth2 flavour pcisf controller 0 pfnum 2 sfnum 0 splittable false
  function:
    hw_addr 00:00:00:00:00:00

Set the MAC address:
$ devlink port function set netdevsim/netdevsim10/2 hw_addr 00:11:22:33:44:55

Show devlink ports:
$ devlink port show
netdevsim/netdevsim10/0: type eth netdev eth0 flavour physical port 1 splittable false
netdevsim/netdevsim10/1: type eth netdev eth1 flavour pcipf controller 0 pfnum 2 external false splittable false
  function:
    hw_addr 00:00:00:00:00:00
netdevsim/netdevsim10/2: type eth netdev eth2 flavour pcisf controller 0 pfnum 2 sfnum 0 splittable false
  function:
    hw_addr 00:11:22:33:44:55

Show the port and function attributes in JSON format:
$ devlink port show netdevsim/netdevsim10/2 -jp
{
    "port": {
        "netdevsim/netdevsim10/2": {
            "type": "eth",
            "netdev": "eth2",
            "flavour": "pcisf",
            "controller": 0,
            "pfnum": 2,
            "sfnum": 0,
            "splittable": false,
            "function": {
                "hw_addr": "00:11:22:33:44:55"
            }
        }
    }
}

Signed-off-by: Parav Pandit <parav@nvidia.com>
---
 drivers/net/netdevsim/dev.c           |  1 +
 drivers/net/netdevsim/netdevsim.h     |  4 ++++
 drivers/net/netdevsim/port_function.c | 21 +++++++++++++++++++++
 3 files changed, 26 insertions(+)

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 6046906d6b85..ab15b5f7e955 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -908,6 +908,7 @@ static const struct devlink_ops nsim_dev_devlink_ops = {
 	.port_new = nsim_dev_devlink_port_new,
 	.port_del = nsim_dev_devlink_port_del,
 	.port_function_hw_addr_get = nsim_dev_port_fn_hw_addr_get,
+	.port_function_hw_addr_set = nsim_dev_port_fn_hw_addr_set,
 };
 
 #define NSIM_DEV_MAX_MACS_DEFAULT 32
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index e910c3cf480d..aafe2027a112 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -324,3 +324,7 @@ int nsim_dev_port_fn_hw_addr_get(struct devlink *devlink,
 				 struct devlink_port *port,
 				 u8 *hw_addr, int *hw_addr_len,
 				 struct netlink_ext_ack *extack);
+int nsim_dev_port_fn_hw_addr_set(struct devlink *devlink,
+				 struct devlink_port *port,
+				 const u8 *hw_addr, int hw_addr_len,
+				 struct netlink_ext_ack *extack);
diff --git a/drivers/net/netdevsim/port_function.c b/drivers/net/netdevsim/port_function.c
index 4031598e2076..d47cdf44770a 100644
--- a/drivers/net/netdevsim/port_function.c
+++ b/drivers/net/netdevsim/port_function.c
@@ -461,3 +461,24 @@ int nsim_dev_port_fn_hw_addr_get(struct devlink *devlink,
 	*hw_addr_len = ETH_ALEN;
 	return 0;
 }
+
+int nsim_dev_port_fn_hw_addr_set(struct devlink *devlink,
+				 struct devlink_port *dl_port,
+				 const u8 *hw_addr, int hw_addr_len,
+				 struct netlink_ext_ack *extack)
+{
+	struct nsim_dev *nsim_dev = devlink_priv(devlink);
+	struct nsim_port_fn *port;
+
+	if (hw_addr_len != ETH_ALEN) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Hardware address must be 6 bytes long");
+		return -EOPNOTSUPP;
+	}
+	port = nsim_dev_to_port_fn(nsim_dev, dl_port, extack);
+	if (IS_ERR(port))
+		return PTR_ERR(port);
+
+	memcpy(port->hw_addr, hw_addr, ETH_ALEN);
+	return 0;
+}
-- 
2.26.2