From: Paolo Abeni Date: Tue, 3 Sep 2024 09:38:00 +0000 (+0200) Subject: Merge branch 'netdev_features-start-cleaning-netdev_features_t-up' X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c55f34a7a1c347afc4c7adc5639c9f7b3749a922;p=users%2Fjedix%2Flinux-maple.git Merge branch 'netdev_features-start-cleaning-netdev_features_t-up' Alexander Lobakin says: ==================== netdev_features: start cleaning netdev_features_t up NETDEV_FEATURE_COUNT is currently 64, which means we can't add any new features as netdev_features_t is u64. As per several discussions, instead of converting netdev_features_t to a bitmap, which would mean A LOT of changes, we can try cleaning up netdev feature bits. There's a bunch of bits which don't really mean features, rather device attributes/properties that can't be changed via Ethtool in any of the drivers. Such attributes can be moved to netdev private flags without losing any functionality. Start converting some read-only netdev features to private flags from the ones that are most obvious, like lockless Tx, inability to change network namespace etc. I was able to reduce NETDEV_FEATURE_COUNT from 64 to 60, which mean 4 free slots for new features. There are obviously more read-only features to convert, such as highDMA, "challenged VLAN", HSR (4 bits) - this will be done in subsequent series. Please note that currently netdev features are not uAPI/ABI by any means. Ethtool passes their names and bits to the userspace separately and there are no hardcoded names/bits in the userspace, so that new Ethtool could work on older kernels and vice versa. This, however, isn't true for Ethtools < 3.4. I haven't changed the bit positions of the already existing features and instead replaced the freed bits with stubs. But it's anyway theoretically possible that Ethtools older than 2011 will break. I hope no currently supported distros supply such an ancient version. Shell scripts also most likely won't break since the removed bits were always read-only, meaning nobody would try touching them from a script. ==================== Link: https://patch.msgid.link/20240829123340.789395-1-aleksander.lobakin@intel.com Signed-off-by: Paolo Abeni --- c55f34a7a1c347afc4c7adc5639c9f7b3749a922