Re: [PATCH net-next 03/15] ethtool: provide netdev features with FEATURES_GET request

From: Michal Kubecek
Date: Thu Mar 12 2020 - 05:19:51 EST


On Wed, Mar 11, 2020 at 03:49:08PM -0700, Jakub Kicinski wrote:
> On Wed, 11 Mar 2020 22:40:18 +0100 (CET) Michal Kubecek wrote:
> >
> > +#define ETHTOOL_DEV_FEATURE_WORDS ((NETDEV_FEATURE_COUNT + 31) / 32)
>
> nit: since this line is touched perhaps worth converting to
> DIV_ROUND_UP()?

Yes.

> > + for (i = 0; i < ETHTOOL_DEV_FEATURE_WORDS; i++)
> > + dest[i] = (u32)(src >> (32 * i));
>
> nit: cast unnecessary

OK.

> > + all_features = ~(netdev_features_t)0 >>
> > + (8 * sizeof(all_features) - NETDEV_FEATURE_COUNT);
>
> nit: GENMASK_ULL(NETDEV_FEATURE_COUNT % 32 - 1, 0) ?

Nice, I wasn't aware of this macro. But unless I want to fill data->all
directly, it would be without the "% 32" part.

> > +static int features_fill_reply(struct sk_buff *skb,
> > + const struct ethnl_req_info *req_base,
> > + const struct ethnl_reply_data *reply_base)
> > +{
> > + const struct features_reply_data *data = FEATURES_REPDATA(reply_base);
> > + bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
> > + int ret;
> > +
> > + ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_HW, data->hw,
> > + data->all, NETDEV_FEATURE_COUNT,
> > + netdev_features_strings, compact);
> > + if (ret < 0)
> > + return ret;
> > + ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_WANTED, data->wanted,
> > + NULL, NETDEV_FEATURE_COUNT,
> > + netdev_features_strings, compact);
> > + if (ret < 0)
> > + return ret;
> > + ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_ACTIVE, data->active,
> > + NULL, NETDEV_FEATURE_COUNT,
> > + netdev_features_strings, compact);
> > + if (ret < 0)
> > + return ret;
> > + ret = ethnl_put_bitset32(skb, ETHTOOL_A_FEATURES_NOCHANGE,
> > + data->nochange, NULL, NETDEV_FEATURE_COUNT,
> > + netdev_features_strings, compact);
> > +
> > + return ret;
>
> nit: return directly?

Ah, right. I eliminated "if (ret < 0)" but did not check again.

Michal