net: ena: Advertise TX push support

LLQ is auto enabled by the device and disabling it isn't supported on
new ENA generations while on old ones causes sub-optimal performance.

This patch adds advertisement of push-mode when LLQ mode is used, but
rejects an attempt to modify it.

Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/amazon/ena/ena_ethtool.c b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
index de7ec02d8c09d775127cf5645934590ccf90608c..d671df4b76bc71b53035b7695d517c027c0e8980 100644 (file)
--- a/drivers/net/ethernet/amazon/ena/ena_ethtool.c
+++ b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
@@ -479,12 +479,14 @@ static void ena_get_ringparam(struct net_device *netdev,
        if (adapter->ena_dev->tx_mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_DEV) {
                bool large_llq_supported = adapter->large_llq_header_supported;
 
+               kernel_ring->tx_push = true;
                kernel_ring->tx_push_buf_len = adapter->ena_dev->tx_max_header_size;
                if (large_llq_supported)
                        kernel_ring->tx_push_buf_max_len = ENA_LLQ_LARGE_HEADER;
                else
                        kernel_ring->tx_push_buf_max_len = ENA_LLQ_HEADER;
        } else {
+               kernel_ring->tx_push = false;
                kernel_ring->tx_push_buf_max_len = 0;
                kernel_ring->tx_push_buf_len = 0;
        }
@@ -516,6 +518,12 @@ static int ena_set_ringparam(struct net_device *netdev,
        /* This value is ignored if LLQ is not supported */
        new_tx_push_buf_len = adapter->ena_dev->tx_max_header_size;
 
+       if ((adapter->ena_dev->tx_mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_DEV) !=
+           kernel_ring->tx_push) {
+               NL_SET_ERR_MSG_MOD(extack, "Push mode state cannot be modified");
+               return -EINVAL;
+       }
+
        /* Validate that the push buffer is supported on the underlying device */
        if (kernel_ring->tx_push_buf_len) {
                enum ena_admin_placement_policy_type placement;
@@ -957,7 +965,8 @@ static int ena_set_tunable(struct net_device *netdev,
 static const struct ethtool_ops ena_ethtool_ops = {
        .supported_coalesce_params = ETHTOOL_COALESCE_USECS |
                                     ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
-       .supported_ring_params  = ETHTOOL_RING_USE_TX_PUSH_BUF_LEN,
+       .supported_ring_params  = ETHTOOL_RING_USE_TX_PUSH_BUF_LEN |
+                                 ETHTOOL_RING_USE_TX_PUSH,
        .get_link_ksettings     = ena_get_link_ksettings,
        .get_drvinfo            = ena_get_drvinfo,
        .get_msglevel           = ena_get_msglevel,