From 9690ae60429020f38e4aa2540c306f27eb021bc0 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Thu, 27 Jan 2022 10:42:59 -0800 Subject: ethtool: add header/data split indication For applications running on a mix of platforms it's useful to have a clear indication whether host's NIC supports the geometry requirements of TCP zero-copy. TCP zero-copy Rx requires data to be neatly placed into memory pages. Most NICs can't do that. This patch is adding GET support only, since the NICs I work with either always have the feature enabled or enable it whenever MTU is set to jumbo. In other words I don't need SET. But adding set should be trivial. (The only note on SET is that we will likely want the setting to be "sticky" and use 0 / `unknown` to reset it back to driver default.) Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller --- net/ethtool/rings.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'net/ethtool') diff --git a/net/ethtool/rings.c b/net/ethtool/rings.c index c1d5f5e0fdc9..18a5035d3bee 100644 --- a/net/ethtool/rings.c +++ b/net/ethtool/rings.c @@ -53,7 +53,8 @@ static int rings_reply_size(const struct ethnl_req_info *req_base, nla_total_size(sizeof(u32)) + /* _RINGS_RX_MINI */ nla_total_size(sizeof(u32)) + /* _RINGS_RX_JUMBO */ nla_total_size(sizeof(u32)) + /* _RINGS_TX */ - nla_total_size(sizeof(u32)); /* _RINGS_RX_BUF_LEN */ + nla_total_size(sizeof(u32)) + /* _RINGS_RX_BUF_LEN */ + nla_total_size(sizeof(u8)); /* _RINGS_TCP_DATA_SPLIT */ } static int rings_fill_reply(struct sk_buff *skb, @@ -61,9 +62,11 @@ static int rings_fill_reply(struct sk_buff *skb, const struct ethnl_reply_data *reply_base) { const struct rings_reply_data *data = RINGS_REPDATA(reply_base); - const struct kernel_ethtool_ringparam *kernel_ringparam = &data->kernel_ringparam; + const struct kernel_ethtool_ringparam *kr = &data->kernel_ringparam; const struct ethtool_ringparam *ringparam = &data->ringparam; + WARN_ON(kr->tcp_data_split > ETHTOOL_TCP_DATA_SPLIT_ENABLED); + if ((ringparam->rx_max_pending && (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_MAX, ringparam->rx_max_pending) || @@ -84,9 +87,11 @@ static int rings_fill_reply(struct sk_buff *skb, ringparam->tx_max_pending) || nla_put_u32(skb, ETHTOOL_A_RINGS_TX, ringparam->tx_pending))) || - (kernel_ringparam->rx_buf_len && - (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_BUF_LEN, - kernel_ringparam->rx_buf_len)))) + (kr->rx_buf_len && + (nla_put_u32(skb, ETHTOOL_A_RINGS_RX_BUF_LEN, kr->rx_buf_len))) || + (kr->tcp_data_split && + (nla_put_u8(skb, ETHTOOL_A_RINGS_TCP_DATA_SPLIT, + kr->tcp_data_split)))) return -EMSGSIZE; return 0; -- cgit v1.2.3