[PATCH net-next] net/mlx5e: advertise tcp-data-split support

[Dimitri Daskalakis <dimitri.daskalakis1@gmail.com>]

From: Dimitri Daskalakis <daskald@meta.com>

The ability to set tcp-data-split was introduced in
commit 46bcce5dfd33 ("net/mlx5e: Support ethtool tcp-data-split settings")
This commit dropped reporting from mlx5e_ethtool_get_ringparam()
without explaining why.

commit d347b28c492e ("net/mlx5e: Add hds-thresh query support via ethtool")
added support for ETHTOOL_RING_USE_HDS_THRS, and modified
mlx5e_ethtool_get_ringparam() to report an hds_thresh of 0.

Between these two commits, hds._defer_reset_hds would skip the reset because
neither hds-thresh or tcp-data-split was present in the ring config. After the
second commit this introduced a KeyError in the hds.set_hds_enable/disable
tests.

Re-adding the feature advertisement fixes the self test.

Signed-off-by: Dimitri Daskalakis <daskald@meta.com>
---
Before:
 # Interface: eth0, driver: mlx5_core
 TAP version 13
 1..13
 ok 1 hds.get_hds # SKIP tcp-data-split not supported by device
 ok 2 hds.get_hds_thresh
 # Exception while handling defer / cleanup (callback 1 of 1)!
 ...
 # Defer Exception| KeyError: 'tcp-data-split'
 # Defer Exception|
 not ok 3 hds.set_hds_disable
 # Exception while handling defer / cleanup (callback 1 of 1)!
 ...
 # Defer Exception| KeyError: 'tcp-data-split'
 # Defer Exception|
 not ok 4 hds.set_hds_enable
 ok 5 hds.set_hds_thresh_random # SKIP hds-thresh-max is too small
 ok 6 hds.set_hds_thresh_zero
 ok 7 hds.set_hds_thresh_max
 ok 8 hds.set_hds_thresh_gt
 ok 9 hds.set_xdp # SKIP tcp-data-split not supported by device
 ok 10 hds.enabled_set_xdp # SKIP tcp-data-split not supported by device
 ok 11 hds.ioctl # SKIP tcp-data-split not supported by device
 ok 12 hds.ioctl_set_xdp # SKIP tcp-data-split not supported by device
 ok 13 hds.ioctl_enabled_set_xdp # SKIP tcp-data-split not supported by device

After:
 # Interface: eth0, driver: mlx5_core
 TAP version 13
 1..13
 ok 1 hds.get_hds
 ok 2 hds.get_hds_thresh
 ok 3 hds.set_hds_disable
 ok 4 hds.set_hds_enable # SKIP disabling of HDS not supported by the device
 ok 5 hds.set_hds_thresh_random # SKIP hds-thresh-max is too small
 ok 6 hds.set_hds_thresh_zero
 ok 7 hds.set_hds_thresh_max
 ok 8 hds.set_hds_thresh_gt
 ok 9 hds.set_xdp
 ...
 # Exception| net.lib.ynl.pyynl.lib.ynl.NlError: Netlink error: mlx5_core: TCP-data-split is not supported when GRO HW is disabled: Invalid argument
 # Exception|
 not ok 10 hds.enabled_set_xdp
 ok 11 hds.ioctl
 ok 12 hds.ioctl_set_xdp
 ...
 # Exception| net.lib.ynl.pyynl.lib.ynl.NlError: Netlink error: mlx5_core: TCP-data-split is not supported when GRO HW is disabled: Invalid argument
 # Exception|
 not ok 13 hds.ioctl_enabled_set_xdp
 # Totals: pass:9 fail:2 xfail:0 xpass:0 skip:2 error:0

---
 drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
index 261c466a4d36..62060a6fa185 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c
@@ -378,6 +378,11 @@ void mlx5e_ethtool_get_ringparam(struct mlx5e_priv *priv,
 
 	kernel_param->hds_thresh = 0;
 	kernel_param->hds_thresh_max = 0;
+
+	kernel_param->tcp_data_split =
+		(priv->channels.params.packet_merge.type == MLX5E_PACKET_MERGE_SHAMPO) ?
+		ETHTOOL_TCP_DATA_SPLIT_ENABLED :
+		ETHTOOL_TCP_DATA_SPLIT_DISABLED;
 }
 
 static void mlx5e_get_ringparam(struct net_device *dev,
-- 
2.52.0