Re: [PATCH net-next 2/3] ethtool: add compat for flash update

[Jiri Pirko <jiri@resnulli.us>]

Fri, Feb 15, 2019 at 09:53:15AM CET, mkubecek@suse.cz wrote:
>On Thu, Feb 14, 2019 at 01:40:45PM -0800, Jakub Kicinski wrote:
>> If driver does not support ethtool flash update operation
>> call into devlink.
>> 
>> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
>> ---
>...
>> diff --git a/net/core/devlink.c b/net/core/devlink.c
>> index bd507e13bb7b..d169b5426d3d 100644
>> --- a/net/core/devlink.c
>> +++ b/net/core/devlink.c
>> @@ -6435,6 +6435,36 @@ void devlink_compat_running_version(struct net_device *dev,
>>  	mutex_unlock(&devlink_mutex);
>>  }
>>  
>> +int devlink_compat_flash_update(struct net_device *dev, const char *file_name)
>> +{
>> +	struct devlink_port *devlink_port;
>> +	struct devlink *devlink;
>> +
>> +	mutex_lock(&devlink_mutex);
>> +	list_for_each_entry(devlink, &devlink_list, list) {
>> +		mutex_lock(&devlink->lock);
>> +		list_for_each_entry(devlink_port, &devlink->port_list, list) {
>> +			int ret = -EOPNOTSUPP;
>> +
>> +			if (devlink_port->type != DEVLINK_PORT_TYPE_ETH ||
>> +			    devlink_port->type_dev != dev)
>> +				continue;
>> +
>> +			mutex_unlock(&devlink_mutex);
>> +			if (devlink->ops->flash_update)
>> +				ret = devlink->ops->flash_update(devlink,
>> +								 file_name,
>> +								 NULL, NULL);
>> +			mutex_unlock(&devlink->lock);
>> +			return ret;
>> +		}
>> +		mutex_unlock(&devlink->lock);
>> +	}
>> +	mutex_unlock(&devlink_mutex);
>> +
>> +	return -EOPNOTSUPP;
>> +}
>> +
>>  static int __init devlink_module_init(void)
>>  {
>>  	return genl_register_family(&devlink_nl_family);
>
>We already have similar lookup in devlink_compat_running_version() (the
>only difference seems to be that we keep holding devlink_mutex until the
>end there) and it's likely the net_device -> devlink lookup will be
>needed in more places in the future. How about having a helper for it?
>
>I also wonder how does the lookup scale. But I don't have clear idea
>how long the lists can become in real life and the ethtool operations
>are not really time critical.

Another thing is, that you don't really have to do the lookup. If you
have struct net_device *dev inside the driver, you can get the devlink
instance according to that. So it is just a matter of another ndo I
guess.


>
>Michal Kubecek