Re: [RFC net-next 1/3] net: marvell: prestera: Add Switchdev driver for Prestera family ASIC device 98DX325x (AC3x)

[Florian Fainelli <f.fainelli@gmail.com>]

On 2/25/2020 8:30 AM, Vadym Kochan wrote:
> Marvell Prestera 98DX326x integrates up to 24 ports of 1GbE with 8
> ports of 10GbE uplinks or 2 ports of 40Gbps stacking for a largely
> wireless SMB deployment.
> 
> This driver implementation includes only L1 & basic L2 support.
> 
> The core Prestera switching logic is implemented in prestera.c, there is
> an intermediate hw layer between core logic and firmware. It is
> implemented in prestera_hw.c, the purpose of it is to encapsulate hw
> related logic, in future there is a plan to support more devices with
> different HW related configurations.
> 
> The following Switchdev features are supported:
> 
>     - VLAN-aware bridge offloading
>     - VLAN-unaware bridge offloading
>     - FDB offloading (learning, ageing)
>     - Switchport configuration
> 
> Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
> Signed-off-by: Andrii Savka <andrii.savka@plvision.eu>
> Signed-off-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
> Signed-off-by: Serhiy Boiko <serhiy.boiko@plvision.eu>
> Signed-off-by: Serhiy Pshyk <serhiy.pshyk@plvision.eu>
> Signed-off-by: Taras Chornyi <taras.chornyi@plvision.eu>
> Signed-off-by: Volodymyr Mytnyk <volodymyr.mytnyk@plvision.eu>

Very little to pick on, the driver is nice and clean, great job!

> ---

[snip]

> +#define PORT_STATS_CACHE_TIMEOUT_MS	(msecs_to_jiffies(1000))
> +#define PORT_STATS_CNT	(sizeof(struct mvsw_pr_port_stats) / sizeof(u64))

All entries in mvsw_pr_port_stats are u64 so you can use ARRAY_SIZE() here.

[snip]

> +
> +	err = register_netdev(net_dev);
> +	if (err)
> +		goto err_register_netdev;
> +
> +	list_add(&port->list, &sw->port_list);

As soon as you publish the network device it can be used by notifiers,
user-space etc, better do this as the last operation.

[snip]

> +int mvsw_pr_hw_port_stats_get(const struct mvsw_pr_port *port,
> +			      struct mvsw_pr_port_stats *stats)
> +{
> +	struct mvsw_msg_port_stats_ret resp;
> +	struct mvsw_msg_port_attr_cmd req = {
> +		.attr = MVSW_MSG_PORT_ATTR_STATS,
> +		.port = port->hw_id,
> +		.dev = port->dev_id
> +	};
> +	u64 *hw_val = resp.stats;
> +	int err;
> +
> +	err = fw_send_req_resp(port->sw, MVSW_MSG_TYPE_PORT_ATTR_GET,
> +			       &req, &resp);
> +	if (err)
> +		return err;
> +
> +	stats->good_octets_received = hw_val[MVSW_PORT_GOOD_OCTETS_RCV_CNT];

This seems error prone and not scaling really well, since all stats
member are u64 and they are ordered in the same way as the response, is
not a memcpy() sufficient here?
-- 
Florian