[PATCH net-next 1/2] ethtool: add SET for TCP_DATA_SPLIT ringparam

Alexander Lobakin
2023-12-12T14:29:55Z

Follow up commit 9690ae604290 ("ethtool: add header/data split
indication") and add the set part of Ethtool's header split, i.e.
ability to enable/disable header split via the Ethtool Netlink
interface. This might be helpful to optimize the setup for particular
workloads, for example, to avoid XDP frags, and so on.
A driver should advertise ``ETHTOOL_RING_USE_TCP_DATA_SPLIT`` in its
ops->supported_ring_params to allow doing that. "Unknown" passed from
the userspace when the header split is supported means the driver is
free to choose the preferred state.

Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
include/linux/ethtool.h | 2 ++
net/ethtool/rings.c | 12 ++++++++++++
2 files changed, 14 insertions(+)

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index deb683d3360f..67b30940234b 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -95,6 +95,7 @@ struct kernel_ethtool_ringparam {
* @ETHTOOL_RING_USE_TX_PUSH: capture for setting tx_push
* @ETHTOOL_RING_USE_RX_PUSH: capture for setting rx_push
* @ETHTOOL_RING_USE_TX_PUSH_BUF_LEN: capture for setting tx_push_buf_len
+ * @ETHTOOL_RING_USE_TCP_DATA_SPLIT: capture for setting tcp_data_split
*/
enum ethtool_supported_ring_param {
ETHTOOL_RING_USE_RX_BUF_LEN = BIT(0),
@@ -102,6 +103,7 @@ enum ethtool_supported_ring_param {
ETHTOOL_RING_USE_TX_PUSH = BIT(2),
ETHTOOL_RING_USE_RX_PUSH = BIT(3),
ETHTOOL_RING_USE_TX_PUSH_BUF_LEN = BIT(4),
+ ETHTOOL_RING_USE_TCP_DATA_SPLIT = BIT(5),
};

#define __ETH_RSS_HASH_BIT(bit) ((u32)1 << (bit))
diff --git a/net/ethtool/rings.c b/net/ethtool/rings.c
index fb09f774ea01..b7865a14fdf8 100644
--- a/net/ethtool/rings.c
+++ b/net/ethtool/rings.c
@@ -124,6 +124,8 @@ const struct nla_policy ethnl_rings_set_policy[] = {
[ETHTOOL_A_RINGS_RX_JUMBO] = { .type = NLA_U32 },
[ETHTOOL_A_RINGS_TX] = { .type = NLA_U32 },
[ETHTOOL_A_RINGS_RX_BUF_LEN] = NLA_POLICY_MIN(NLA_U32, 1),
+ [ETHTOOL_A_RINGS_TCP_DATA_SPLIT] =
+ NLA_POLICY_MAX(NLA_U8, ETHTOOL_TCP_DATA_SPLIT_ENABLED),
[ETHTOOL_A_RINGS_CQE_SIZE] = NLA_POLICY_MIN(NLA_U32, 1),
[ETHTOOL_A_RINGS_TX_PUSH] = NLA_POLICY_MAX(NLA_U8, 1),
[ETHTOOL_A_RINGS_RX_PUSH] = NLA_POLICY_MAX(NLA_U8, 1),
@@ -145,6 +147,14 @@ ethnl_set_rings_validate(struct ethnl_req_info *req_info,
return -EOPNOTSUPP;
}

+ if (tb[ETHTOOL_A_RINGS_TCP_DATA_SPLIT] &&
+ !(ops->supported_ring_params & ETHTOOL_RING_USE_TCP_DATA_SPLIT)) {
+ NL_SET_ERR_MSG_ATTR(info->extack,
+ tb[ETHTOOL_A_RINGS_TCP_DATA_SPLIT],
+ "setting TCP data split is not supported");
+ return -EOPNOTSUPP;
+ }
+
if (tb[ETHTOOL_A_RINGS_CQE_SIZE] &&
!(ops->supported_ring_params & ETHTOOL_RING_USE_CQE_SIZE)) {
NL_SET_ERR_MSG_ATTR(info->extack,
@@ -202,6 +212,8 @@ ethnl_set_rings(struct ethnl_req_info *req_info, struct genl_info *info)
ethnl_update_u32(&ringparam.tx_pending, tb[ETHTOOL_A_RINGS_TX], &mod);
ethnl_update_u32(&kernel_ringparam.rx_buf_len,
tb[ETHTOOL_A_RINGS_RX_BUF_LEN], &mod);
+ ethnl_update_u8(&kernel_ringparam.tcp_data_split,
+ tb[ETHTOOL_A_RINGS_TCP_DATA_SPLIT], &mod);
ethnl_update_u32(&kernel_ringparam.cqe_size,
tb[ETHTOOL_A_RINGS_CQE_SIZE], &mod);
ethnl_update_u8(&kernel_ringparam.tx_push,
--
2.43.0