Re: [PATCH net-next RFC v1 4/4] net: dsa: mv88e6xxx: Add per port devlink regions

[Vladimir Oltean <vladimir.oltean@nxp.com>]

On Sat, Sep 19, 2020 at 04:43:32PM +0200, Andrew Lunn wrote:
> Add a devlink region to return the per port registers.
> 
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
> ---
>  drivers/net/dsa/mv88e6xxx/chip.c    |  8 ++++
>  drivers/net/dsa/mv88e6xxx/devlink.c | 61 +++++++++++++++++++++++++++++
>  drivers/net/dsa/mv88e6xxx/devlink.h |  6 ++-
>  3 files changed, 74 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/dsa/mv88e6xxx/chip.c b/drivers/net/dsa/mv88e6xxx/chip.c
> index 9417412e5fce..3d2d813f7a79 100644
> --- a/drivers/net/dsa/mv88e6xxx/chip.c
> +++ b/drivers/net/dsa/mv88e6xxx/chip.c
> @@ -2741,10 +2741,16 @@ static int mv88e6xxx_port_enable(struct dsa_switch *ds, int port,
>  	struct mv88e6xxx_chip *chip = ds->priv;
>  	int err;
>  
> +	err = mv88e6xxx_setup_devlink_regions_port(ds, chip, port);
> +	if (err)
> +		return err;
> +
>  	mv88e6xxx_reg_lock(chip);
>  	err = mv88e6xxx_serdes_power(chip, port, true);
>  	mv88e6xxx_reg_unlock(chip);
>  
> +	if (err)
> +		mv88e6xxx_teardown_devlink_regions_port(chip, port);
>  	return err;
>  }
>  
> @@ -2752,6 +2758,8 @@ static void mv88e6xxx_port_disable(struct dsa_switch *ds, int port)
>  {
>  	struct mv88e6xxx_chip *chip = ds->priv;
>  
> +	mv88e6xxx_teardown_devlink_regions_port(chip, port);
> +
>  	mv88e6xxx_reg_lock(chip);
>  	if (mv88e6xxx_serdes_power(chip, port, false))
>  		dev_err(chip->dev, "failed to power off SERDES\n");
> diff --git a/drivers/net/dsa/mv88e6xxx/devlink.c b/drivers/net/dsa/mv88e6xxx/devlink.c
> index 81e1560db206..dc8a244aa154 100644
> --- a/drivers/net/dsa/mv88e6xxx/devlink.c
> +++ b/drivers/net/dsa/mv88e6xxx/devlink.c
> @@ -415,6 +415,36 @@ static int mv88e6xxx_region_atu_snapshot(struct devlink *dl,
>  	return err;
>  }
>  
> +static int mv88e6xxx_region_port_snapshot(struct devlink_port *devlink_port,
> +					  const struct devlink_port_region_ops *ops,
> +					  struct netlink_ext_ack *extack,
> +					  u8 **data)
> +{
> +	struct dsa_switch *ds = dsa_devlink_port_to_ds(devlink_port);
> +	int port = dsa_devlink_port_to_port(devlink_port);
> +	struct mv88e6xxx_chip *chip = ds->priv;
> +	u16 *registers;
> +	int i, err;
> +
> +	registers = kmalloc_array(32, sizeof(u16), GFP_KERNEL);
> +	if (!registers)
> +		return -ENOMEM;
> +
> +	mv88e6xxx_reg_lock(chip);
> +	for (i = 0; i < 32; i++) {
> +		err = mv88e6xxx_port_read(chip, port, i, &registers[i]);
> +		if (err) {
> +			kfree(registers);
> +			goto out;
> +		}
> +	}
> +	*data = (u8 *)registers;
> +out:
> +	mv88e6xxx_reg_unlock(chip);
> +
> +	return err;
> +}
> +
>  static struct mv88e6xxx_region_priv mv88e6xxx_region_global1_priv = {
>  	.id = MV88E6XXX_REGION_GLOBAL1,
>  };
> @@ -443,6 +473,12 @@ static struct devlink_region_ops mv88e6xxx_region_atu_ops = {
>  	.destructor = kfree,
>  };
>  
> +static const struct devlink_port_region_ops mv88e6xxx_region_port_ops = {
> +	.name = "port",
> +	.snapshot = mv88e6xxx_region_port_snapshot,
> +	.destructor = kfree,
> +};
> +
>  struct mv88e6xxx_region {
>  	struct devlink_region_ops *ops;
>  	u64 size;
> @@ -478,6 +514,31 @@ void mv88e6xxx_teardown_devlink_regions(struct dsa_switch *ds)
>  	mv88e6xxx_teardown_devlink_regions_global(chip);
>  }
>  
> +int mv88e6xxx_setup_devlink_regions_port(struct dsa_switch *ds,
> +					 struct mv88e6xxx_chip *chip,
> +					 int port)

You probably don't need to pass both *ds and *chip here, since you can
derive one from the other.

> +{
> +	struct devlink_region *region;
> +
> +	region = dsa_devlink_port_region_create(ds,
> +						port,
> +						&mv88e6xxx_region_port_ops, 1,
> +						32 * sizeof(u16));
> +	if (IS_ERR(region))
> +		return PTR_ERR(region);
> +
> +	chip->ports[port].region = region;
> +
> +	return 0;
> +}
> +
> +void mv88e6xxx_teardown_devlink_regions_port(struct mv88e6xxx_chip *chip,
> +					     int port)
> +{
> +	if (chip->ports[port].region)
> +		dsa_devlink_region_destroy(chip->ports[port].region);
> +}
> +
>  static int mv88e6xxx_setup_devlink_regions_global(struct dsa_switch *ds,
>  						  struct mv88e6xxx_chip *chip)
>  {
> diff --git a/drivers/net/dsa/mv88e6xxx/devlink.h b/drivers/net/dsa/mv88e6xxx/devlink.h
> index 3d72db3dcf95..9302f0ee550d 100644
> --- a/drivers/net/dsa/mv88e6xxx/devlink.h
> +++ b/drivers/net/dsa/mv88e6xxx/devlink.h
> @@ -14,7 +14,11 @@ int mv88e6xxx_devlink_param_set(struct dsa_switch *ds, u32 id,
>  				struct devlink_param_gset_ctx *ctx);
>  int mv88e6xxx_setup_devlink_regions(struct dsa_switch *ds);
>  void mv88e6xxx_teardown_devlink_regions(struct dsa_switch *ds);
> -
> +int mv88e6xxx_setup_devlink_regions_port(struct dsa_switch *ds,
> +					 struct mv88e6xxx_chip *chip,
> +					 int port);
> +void mv88e6xxx_teardown_devlink_regions_port(struct mv88e6xxx_chip *chip,
> +					     int port);
>  int mv88e6xxx_devlink_info_get(struct dsa_switch *ds,
>  			       struct devlink_info_req *req,
>  			       struct netlink_ext_ack *extack);
> -- 
> 2.28.0
> 

Thanks,
-Vladimir