[PATCH net-next 5/5] net/mlx5e: RX, Remove unnecessary RQT redirects

[Tariq Toukan <tariqt@nvidia.com>]

RQTs (Receive Queue Table) should redirect traffic to the channels' RQs
when they're active.  Otherwise, redirect to the designated "drop RQ".

RQTs are created in "inactive" state, pointing to the "drop RQ".
In activate and de-activate flows, do not "deactivate" the rest of RQTs
(beyond the num of channels), as they are already inactive.

This cuts down unnecessary execution of FW commands (MODIFY_RQT), and
improves the latency of open/close channels or configuration change.

Perf:
NIC: Connect-X7.
Configuration: 1 combined channel, max num channels 248.
Measure time for "interface up + interface down".

Before: 0.313 sec
After:  0.057 sec (5.5x faster)

247 MODIFY_RQT commands saved in interface up.
247 MODIFY_RQT commands saved in interface down.

Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c b/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c
index 5fcbe47337b0..b3fdb1afa1e6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c
@@ -579,8 +579,6 @@ void mlx5e_rx_res_channels_activate(struct mlx5e_rx_res *res, struct mlx5e_chann
 
 	for (ix = 0; ix < nch; ix++)
 		mlx5e_rx_res_channel_activate_direct(res, chs, ix);
-	for (ix = nch; ix < res->max_nch; ix++)
-		mlx5e_rx_res_channel_deactivate_direct(res, ix);
 
 	if (res->features & MLX5E_RX_RES_FEATURE_PTP) {
 		u32 rqn;
@@ -603,7 +601,7 @@ void mlx5e_rx_res_channels_deactivate(struct mlx5e_rx_res *res)
 
 	mlx5e_rx_res_rss_disable(res);
 
-	for (ix = 0; ix < res->max_nch; ix++)
+	for (ix = 0; ix < res->rss_nch; ix++)
 		mlx5e_rx_res_channel_deactivate_direct(res, ix);
 
 	if (res->features & MLX5E_RX_RES_FEATURE_PTP) {
-- 
2.31.1