Re: [PATCH net-next 2/4] net: dsa: Add wrappers for overloaded ndo_ops

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

On 7/19/2020 8:40 AM, Andrew Lunn wrote:
>> +#if IS_ENABLED(CONFIG_NET_DSA)
>> +#define dsa_build_ndo_op(name, arg1_type, arg1_name, arg2_type, arg2_name) \
>> +static int inline dsa_##name(struct net_device *dev, arg1_type arg1_name, \
>> +			     arg2_type arg2_name)	\
>> +{							\
>> +	const struct dsa_netdevice_ops *ops;		\
>> +	int err = -EOPNOTSUPP;				\
>> +							\
>> +	if (!dev->dsa_ptr)				\
>> +		return err;				\
>> +							\
>> +	ops = dev->dsa_ptr->netdev_ops;			\
>> +	if (!ops || !ops->name)				\
>> +		return err;				\
>> +							\
>> +	return ops->name(dev, arg1_name, arg2_name);	\
>> +}
>> +#else
>> +#define dsa_build_ndo_op(name, ...)			\
>> +static inline int dsa_##name(struct net_device *dev, ...) \
>> +{							\
>> +	return -EOPNOTSUPP;				\
>> +}
>> +#endif
>> +
>> +dsa_build_ndo_op(ndo_do_ioctl, struct ifreq *, ifr, int, cmd);
>> +dsa_build_ndo_op(ndo_get_phys_port_name, char *, name, size_t, len);
> 
> Hi Florian
> 
> I tend to avoid this sort of macro magic. Tools like
> https://elixir.bootlin.com/ and other cross references have trouble
> following it. The current macros only handle calls with two
> parameters. And i doubt it is actually saving many lines of code, if
> there are only two invocations.

It saves about 20 lines of code for each new function that is added.
Since the boilerplate logic is always the same, if you prefer I could
provide it as a separate helper function and avoid the macro to generate
the function body, yes let's do that.
-- 
Florian