Re: [PATCH net-next v4 05/10] net: phylink: Add some helpers for working with mac caps

[Sean Anderson <sean.anderson@seco.com>]

On 8/18/22 12:46 PM, Sean Anderson wrote:
> This adds a table for converting between speed/duplex and mac
> capabilities. It also adds a helper for getting the max speed/duplex
> from some caps. It is intended to be used by Russell King's DSA phylink
> series. The table will be used directly later in this series.
> 
> Co-developed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> [ adapted to live in phylink.c ]
> Signed-off-by: Sean Anderson <sean.anderson@seco.com>
> ---
> This is adapted from [1].
> 
> [1] https://lore.kernel.org/netdev/E1oCNlE-006e3z-3T@rmk-PC.armlinux.org.uk/
> 
> Changes in v4:
> - Wrap docstring to 80 columns
> 
> Changes in v3:
> - New
> 
>  drivers/net/phy/phylink.c | 57 +++++++++++++++++++++++++++++++++++++++
>  include/linux/phylink.h   |  2 ++
>  2 files changed, 59 insertions(+)
> 
> diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
> index 68a58ab6a8ed..8a9da7449c73 100644
> --- a/drivers/net/phy/phylink.c
> +++ b/drivers/net/phy/phylink.c
> @@ -304,6 +304,63 @@ void phylink_caps_to_linkmodes(unsigned long *linkmodes, unsigned long caps)
>  }
>  EXPORT_SYMBOL_GPL(phylink_caps_to_linkmodes);
>  
> +static struct {
> +	unsigned long mask;
> +	int speed;
> +	unsigned int duplex;
> +} phylink_caps_params[] = {
> +	{ MAC_400000FD, SPEED_400000, DUPLEX_FULL },
> +	{ MAC_200000FD, SPEED_200000, DUPLEX_FULL },
> +	{ MAC_100000FD, SPEED_100000, DUPLEX_FULL },
> +	{ MAC_56000FD,  SPEED_56000,  DUPLEX_FULL },
> +	{ MAC_50000FD,  SPEED_50000,  DUPLEX_FULL },
> +	{ MAC_40000FD,  SPEED_40000,  DUPLEX_FULL },
> +	{ MAC_25000FD,  SPEED_25000,  DUPLEX_FULL },
> +	{ MAC_20000FD,  SPEED_20000,  DUPLEX_FULL },
> +	{ MAC_10000FD,  SPEED_10000,  DUPLEX_FULL },
> +	{ MAC_5000FD,   SPEED_5000,   DUPLEX_FULL },
> +	{ MAC_2500FD,   SPEED_2500,   DUPLEX_FULL },
> +	{ MAC_1000FD,   SPEED_1000,   DUPLEX_FULL },
> +	{ MAC_1000HD,   SPEED_1000,   DUPLEX_HALF },
> +	{ MAC_100FD,    SPEED_100,    DUPLEX_FULL },
> +	{ MAC_100HD,    SPEED_100,    DUPLEX_HALF },
> +	{ MAC_10FD,     SPEED_10,     DUPLEX_FULL },
> +	{ MAC_10HD,     SPEED_10,     DUPLEX_HALF },
> +};
> +
> +/**
> + * phylink_caps_find_max_speed() - Find the max speed/duplex of mac capabilities
> + * @caps: A mask of mac capabilities
> + * @speed: Variable to store the maximum speed
> + * @duplex: Variable to store the maximum duplex
> + *
> + * Find the maximum speed (and associated duplex) supported by a mask of mac
> + * capabilities. @speed and @duplex are always set, even if no matching mac
> + * capability was found.
> + *
> + * Return: 0 on success, or %-EINVAL if the maximum speed/duplex could not be
> + *         determined.
> + */
> +int phylink_caps_find_max_speed(unsigned long caps, int *speed,
> +				unsigned int *duplex)
> +{
> +	int i;
> +
> +	*speed = SPEED_UNKNOWN;
> +	*duplex = DUPLEX_UNKNOWN;
> +
> +	for (i = 0; i < ARRAY_SIZE(phylink_caps_params); i++) {
> +		if (caps & phylink_caps_params[i].mask) {
> +			*speed = phylink_caps_params[i].speed;
> +			*duplex = phylink_caps_params[i].duplex;
> +			return 0;
> +		}
> +	}
> +
> +	return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(phylink_caps_find_max_speed);
> +
>  /**
>   * phylink_get_capabilities() - get capabilities for a given MAC
>   * @interface: phy interface mode defined by &typedef phy_interface_t
> diff --git a/include/linux/phylink.h b/include/linux/phylink.h
> index 661d1d4fdbec..a5a236cfacb6 100644
> --- a/include/linux/phylink.h
> +++ b/include/linux/phylink.h
> @@ -535,6 +535,8 @@ void pcs_link_up(struct phylink_pcs *pcs, unsigned int mode,
>  #endif
>  
>  void phylink_caps_to_linkmodes(unsigned long *linkmodes, unsigned long caps);
> +int phylink_caps_find_max_speed(unsigned long caps, int *speed,
> +				unsigned int *duplex);
>  unsigned long phylink_get_capabilities(phy_interface_t interface,
>  				       unsigned long mac_capabilities);
>  void phylink_generic_validate(struct phylink_config *config,
> 

...and it looks like I removed the wrong helper function

(that is, phylink_cap_from_speed_duplex was removed instead of
 phylink_caps_find_max_speed)

Will be fixed in v5

--Sean