i40evf: add new write-back mode

Add write-back on interrupt throttle rate timer expiration support
for the i40evf driver, when running on X722 devices.

Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 86aacb9..659d782 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -1222,6 +1222,12 @@ static int i40e_vc_get_vf_resources_msg(struct i40e_vf *vf, u8 *msg)
        if (vf->driver_caps & I40E_VIRTCHNL_VF_OFFLOAD_RX_POLLING)
                vfres->vf_offload_flags |= I40E_VIRTCHNL_VF_OFFLOAD_RX_POLLING;
 
+       if (pf->flags & I40E_FLAG_WB_ON_ITR_CAPABLE) {
+               if (vf->driver_caps & I40E_VIRTCHNL_VF_OFFLOAD_WB_ON_ITR)
+                       vfres->vf_offload_flags |=
+                                       I40E_VIRTCHNL_VF_OFFLOAD_WB_ON_ITR;
+       }
+
        vfres->num_vsis = num_vsis;
        vfres->num_queue_pairs = vf->num_queue_pairs;
        vfres->max_vectors = pf->hw.func_caps.num_msix_vectors_vf;

diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
index 7a00657..7d663fb 100644 (file)
--- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c
@@ -252,6 +252,22 @@ static bool i40e_clean_tx_irq(struct i40e_ring *tx_ring, int budget)
        tx_ring->q_vector->tx.total_bytes += total_bytes;
        tx_ring->q_vector->tx.total_packets += total_packets;
 
+       if (tx_ring->flags & I40E_TXR_FLAGS_WB_ON_ITR) {
+               unsigned int j = 0;
+               /* check to see if there are < 4 descriptors
+                * waiting to be written back, then kick the hardware to force
+                * them to be written back in case we stay in NAPI.
+                * In this mode on X722 we do not enable Interrupt.
+                */
+               j = i40evf_get_tx_pending(tx_ring);
+
+               if (budget &&
+                   ((j / (WB_STRIDE + 1)) == 0) && (j > 0) &&
+                   !test_bit(__I40E_DOWN, &tx_ring->vsi->state) &&
+                   (I40E_DESC_UNUSED(tx_ring) != tx_ring->count))
+                       tx_ring->arm_wb = true;
+       }
+
        netdev_tx_completed_queue(netdev_get_tx_queue(tx_ring->netdev,
                                                      tx_ring->queue_index),
                                  total_packets, total_bytes);

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
index 798f0de..615ad0f 100644 (file)
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -2511,6 +2511,11 @@ static void i40evf_init_task(struct work_struct *work)
        if (adapter->vf_res->vf_offload_flags &
                    I40E_VIRTCHNL_VF_OFFLOAD_WB_ON_ITR)
                adapter->flags |= I40EVF_FLAG_WB_ON_ITR_CAPABLE;
+
+       if (adapter->vf_res->vf_offload_flags &
+           I40E_VIRTCHNL_VF_OFFLOAD_WB_ON_ITR)
+               adapter->flags |= I40EVF_FLAG_WB_ON_ITR_CAPABLE;
+
        err = i40evf_request_misc_irq(adapter);
        if (err)
                goto err_sw_init;