Subject: Re: [net-next 3/6] net: marvell: prestera: Add basic devlink support

From: Ido Schimmel <[email-masked]>
Date: Wed, 3 Jun 2020 13:07:49 +0300

On Thu, May 28, 2020 at 06:12:42PM +0300, Vadym Kochan wrote:
> Add very basic support for devlink interface:
> 
>     - driver name
>     - fw version
>     - devlink ports

I suggest adding support for reload while the driver is still simple. I
use it all the time because I run with modules built-in. It's also used
in FIB offload tests to relocate the netdevs to a different namespace
where the test is performed

> 
> Signed-off-by: Vadym Kochan <[email-masked]>
> ---
>  drivers/net/ethernet/marvell/prestera/Kconfig |   1 +
>  .../net/ethernet/marvell/prestera/Makefile    |   2 +-
>  .../net/ethernet/marvell/prestera/prestera.h  |   4 +
>  .../marvell/prestera/prestera_devlink.c       | 111 ++++++++++++++++++
>  .../marvell/prestera/prestera_devlink.h       |  25 ++++
>  .../ethernet/marvell/prestera/prestera_main.c |  27 ++++-
>  6 files changed, 165 insertions(+), 5 deletions(-)
>  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_devlink.c
>  create mode 100644 drivers/net/ethernet/marvell/prestera/prestera_devlink.h
> 
> diff --git a/drivers/net/ethernet/marvell/prestera/Kconfig b/drivers/net/ethernet/marvell/prestera/Kconfig
> index 0848edb272a5..dfd5174d0568 100644
> --- a/drivers/net/ethernet/marvell/prestera/Kconfig
> +++ b/drivers/net/ethernet/marvell/prestera/Kconfig
> @@ -6,6 +6,7 @@
>  config PRESTERA
>  	tristate "Marvell Prestera Switch ASICs support"
>  	depends on NET_SWITCHDEV && VLAN_8021Q
> +	select NET_DEVLINK
>  	help
>  	  This driver supports Marvell Prestera Switch ASICs family.
>  
> diff --git a/drivers/net/ethernet/marvell/prestera/Makefile b/drivers/net/ethernet/marvell/prestera/Makefile
> index 2146714eab21..babd71fba809 100644
> --- a/drivers/net/ethernet/marvell/prestera/Makefile
> +++ b/drivers/net/ethernet/marvell/prestera/Makefile
> @@ -1,6 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  obj-$(CONFIG_PRESTERA)	+= prestera.o
>  prestera-objs		:= prestera_main.o prestera_hw.o prestera_dsa.o \
> -			   prestera_rxtx.o
> +			   prestera_rxtx.o prestera_devlink.o
>  
>  obj-$(CONFIG_PRESTERA_PCI)	+= prestera_pci.o
> diff --git a/drivers/net/ethernet/marvell/prestera/prestera.h b/drivers/net/ethernet/marvell/prestera/prestera.h
> index 5079d872e18a..f8abaaff5f21 100644
> --- a/drivers/net/ethernet/marvell/prestera/prestera.h
> +++ b/drivers/net/ethernet/marvell/prestera/prestera.h
> @@ -11,6 +11,9 @@
>  #include <linux/notifier.h>
>  #include <uapi/linux/if_ether.h>
>  #include <linux/workqueue.h>
> +#include <net/devlink.h>
> +
> +#define PRESTERA_DRV_NAME	"prestera"
>  
>  struct prestera_fw_rev {
>  	u16 maj;
> @@ -63,6 +66,7 @@ struct prestera_port_caps {
>  struct prestera_port {
>  	struct net_device *dev;
>  	struct prestera_switch *sw;
> +	struct devlink_port dl_port;
>  	u32 id;
>  	u32 hw_id;
>  	u32 dev_id;
> diff --git a/drivers/net/ethernet/marvell/prestera/prestera_devlink.c b/drivers/net/ethernet/marvell/prestera/prestera_devlink.c
> new file mode 100644
> index 000000000000..58021057981b
> --- /dev/null
> +++ b/drivers/net/ethernet/marvell/prestera/prestera_devlink.c
> @@ -0,0 +1,111 @@
> +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
> +/* Copyright (c) 2019-2020 Marvell International Ltd. All rights reserved */
> +
> +#include <net/devlink.h>
> +
> +#include "prestera.h"
> +#include "prestera_devlink.h"
> +
> +static int prestera_dl_info_get(struct devlink *dl,
> +				struct devlink_info_req *req,
> +				struct netlink_ext_ack *extack)
> +{
> +	struct prestera_switch *sw = devlink_priv(dl);
> +	char buf[16];
> +	int err = 0;
> +
> +	err = devlink_info_driver_name_put(req, PRESTERA_DRV_NAME);
> +	if (err)
> +		return err;
> +
> +	snprintf(buf, sizeof(buf), "%d.%d.%d",
> +		 sw->dev->fw_rev.maj,
> +		 sw->dev->fw_rev.min,
> +		 sw->dev->fw_rev.sub);
> +
> +	err = devlink_info_version_running_put(req,
> +					       DEVLINK_INFO_VERSION_GENERIC_FW,
> +					       buf);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +static const struct devlink_ops prestera_dl_ops = {
> +	.info_get = prestera_dl_info_get,
> +};
> +
> +struct prestera_switch *prestera_devlink_alloc(void)
> +{
> +	struct devlink *dl;
> +
> +	dl = devlink_alloc(&prestera_dl_ops, sizeof(struct prestera_switch));
> +
> +	return devlink_priv(dl);
> +}
> +
> +void prestera_devlink_free(struct prestera_switch *sw)
> +{
> +	struct devlink *dl = priv_to_devlink(sw);
> +
> +	devlink_free(dl);
> +}
> +
> +int prestera_devlink_register(struct prestera_switch *sw)
> +{
> +	struct devlink *dl = priv_to_devlink(sw);
> +	int err;
> +
> +	err = devlink_register(dl, sw->dev->dev);
> +	if (err) {
> +		dev_warn(sw->dev->dev, "devlink_register failed: %d\n", err);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +void prestera_devlink_unregister(struct prestera_switch *sw)
> +{
> +	struct devlink *dl = priv_to_devlink(sw);
> +
> +	devlink_unregister(dl);
> +}
> +
> +int prestera_devlink_port_register(struct prestera_port *port)
> +{
> +	struct devlink *dl = priv_to_devlink(port->sw);
> +	struct prestera_switch *sw;
> +	int err;
> +
> +	sw = port->sw;
> +	dl = priv_to_devlink(sw);
> +
> +	devlink_port_attrs_set(&port->dl_port, DEVLINK_PORT_FLAVOUR_PHYSICAL,
> +			       port->fp_id, false, 0,
> +			       &port->sw->id, sizeof(port->sw->id));
> +
> +	err = devlink_port_register(dl, &port->dl_port, port->fp_id);
> +	if (err)
> +		dev_err(sw->dev->dev, "devlink_port_register failed: %d\n", err);

Return the error?

> +
> +	return 0;
> +}
> +
> +void prestera_devlink_port_unregister(struct prestera_port *port)
> +{
> +	devlink_port_unregister(&port->dl_port);
> +}
> +
> +void prestera_devlink_port_type_set(struct prestera_port *port)
> +{
> +	devlink_port_type_eth_set(&port->dl_port, port->dev);
> +}
> +
> +struct devlink_port *prestera_devlink_get_port(struct net_device *dev)
> +{
> +	struct prestera_port *port = netdev_priv(dev);
> +
> +	return &port->dl_port;
> +}
> diff --git a/drivers/net/ethernet/marvell/prestera/prestera_devlink.h b/drivers/net/ethernet/marvell/prestera/prestera_devlink.h
> new file mode 100644
> index 000000000000..b46441d1e758
> --- /dev/null
> +++ b/drivers/net/ethernet/marvell/prestera/prestera_devlink.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
> + *
> + * Copyright (c) 2019-2020 Marvell International Ltd. All rights reserved.
> + *
> + */
> +
> +#ifndef _PRESTERA_DEVLINK_H_
> +#define _PRESTERA_DEVLINK_H_
> +
> +#include "prestera.h"
> +
> +struct prestera_switch *prestera_devlink_alloc(void);
> +void prestera_devlink_free(struct prestera_switch *sw);
> +
> +int prestera_devlink_register(struct prestera_switch *sw);
> +void prestera_devlink_unregister(struct prestera_switch *sw);
> +
> +int prestera_devlink_port_register(struct prestera_port *port);
> +void prestera_devlink_port_unregister(struct prestera_port *port);
> +
> +void prestera_devlink_port_type_set(struct prestera_port *port);
> +
> +struct devlink_port *prestera_devlink_get_port(struct net_device *dev);
> +
> +#endif /* _PRESTERA_DEVLINK_H_ */
> diff --git a/drivers/net/ethernet/marvell/prestera/prestera_main.c b/drivers/net/ethernet/marvell/prestera/prestera_main.c
> index b5241e9b784a..ddab9422fe5e 100644
> --- a/drivers/net/ethernet/marvell/prestera/prestera_main.c
> +++ b/drivers/net/ethernet/marvell/prestera/prestera_main.c
> @@ -14,6 +14,7 @@
>  #include "prestera.h"
>  #include "prestera_hw.h"
>  #include "prestera_rxtx.h"
> +#include "prestera_devlink.h"
>  
>  #define PRESTERA_MTU_DEFAULT 1536
>  
> @@ -185,6 +186,7 @@ static const struct net_device_ops netdev_ops = {
>  	.ndo_change_mtu = prestera_port_change_mtu,
>  	.ndo_get_stats64 = prestera_port_get_stats64,
>  	.ndo_set_mac_address = prestera_port_set_mac_address,
> +	.ndo_get_devlink_port = prestera_devlink_get_port,
>  };
>  
>  static int prestera_port_autoneg_set(struct prestera_port *port, bool enable,
> @@ -234,9 +236,13 @@ static int prestera_port_create(struct prestera_switch *sw, u32 id)
>  					&port->hw_id, &port->dev_id);
>  	if (err) {
>  		dev_err(prestera_dev(sw), "Failed to get port(%u) info\n", id);
> -		goto err_port_init;
> +		goto err_port_info_get;

Seems like an unrelated change

>  	}
>  
> +	err = prestera_devlink_port_register(port);
> +	if (err)
> +		goto err_dl_port_register;
> +
>  	dev->features |= NETIF_F_NETNS_LOCAL;
>  	dev->netdev_ops = &netdev_ops;
>  
> @@ -295,11 +301,16 @@ static int prestera_port_create(struct prestera_switch *sw, u32 id)
>  	if (err)
>  		goto err_register_netdev;
>  
> +	prestera_devlink_port_type_set(port);
> +
>  	return 0;
>  
>  err_register_netdev:
>  	list_del_rcu(&port->list);
>  err_port_init:
> +	prestera_devlink_port_unregister(port);
> +err_dl_port_register:
> +err_port_info_get:
>  	free_netdev(dev);
>  	return err;
>  }
> @@ -313,6 +324,7 @@ static void prestera_port_destroy(struct prestera_port *port)

Shouldn't you call devlink_port_type_clear() here?

>  
>  	list_del_rcu(&port->list);
>  
> +	prestera_devlink_port_unregister(port);
>  	free_netdev(dev);
>  }
>  
> @@ -435,6 +447,10 @@ static int prestera_switch_init(struct prestera_switch *sw)
>  	if (err)
>  		return err;
>  
> +	err = prestera_devlink_register(sw);
> +	if (err)
> +		goto err_dl_register;
> +
>  	err = prestera_create_ports(sw);
>  	if (err)
>  		goto err_ports_create;
> @@ -442,6 +458,8 @@ static int prestera_switch_init(struct prestera_switch *sw)
>  	return 0;
>  
>  err_ports_create:
> +	prestera_devlink_unregister(sw);
> +err_dl_register:
>  	prestera_event_handlers_unregister(sw);
>  
>  	return err;
> @@ -450,6 +468,7 @@ static int prestera_switch_init(struct prestera_switch *sw)
>  static void prestera_switch_fini(struct prestera_switch *sw)
>  {
>  	prestera_destroy_ports(sw);
> +	prestera_devlink_unregister(sw);
>  	prestera_event_handlers_unregister(sw);
>  	prestera_rxtx_switch_fini(sw);
>  }
> @@ -459,7 +478,7 @@ int prestera_device_register(struct prestera_device *dev)
>  	struct prestera_switch *sw;
>  	int err;
>  
> -	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
> +	sw = prestera_devlink_alloc();
>  	if (!sw)
>  		return -ENOMEM;
>  
> @@ -468,7 +487,7 @@ int prestera_device_register(struct prestera_device *dev)
>  
>  	err = prestera_switch_init(sw);
>  	if (err) {
> -		kfree(sw);
> +		prestera_devlink_free(sw);
>  		return err;
>  	}
>  
> @@ -481,7 +500,7 @@ void prestera_device_unregister(struct prestera_device *dev)
>  	struct prestera_switch *sw = dev->priv;
>  
>  	prestera_switch_fini(sw);
> -	kfree(sw);
> +	prestera_devlink_free(sw);
>  }
>  EXPORT_SYMBOL(prestera_device_unregister);
>  
> -- 
> 2.17.1
>