target/linux/layerscape/patches-5.4/701-net-0197-dpaa2-eth-Add-congestion-group-taildrop.patch

   1 From fa204fc76c3936c55315ba9423fa7c920af2f9a9 Mon Sep 17 00:00:00 2001
   2 From: Ioana Radulescu <ruxandra.radulescu@nxp.com>
   3 Date: Wed, 4 Sep 2019 20:32:56 +0300
   4 Subject: [PATCH] dpaa2-eth: Add congestion group taildrop
   5
   6 The increase in number of ingress frame queues means we now risk
   7 depleting the buffer pool before the FQ taildrop kicks in.
   8
   9 Congestion group taildrop allows us to control the number of frames
  10 that can accumulate on a group of Rx frame queues belonging to the
  11 same traffic class.
  12
  13 This setting coexists with the frame queue based taildrop: whichever
  14 limit gets hit first triggers the frame drop.
  15
  16 Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
  17 ---
  18  drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 16 ++++++++++++++++
  19  drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h |  9 +++++++++
  20  2 files changed, 25 insertions(+)
  21
  22 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
  23 +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
  24 @@ -1257,6 +1257,22 @@ static void dpaa2_eth_set_rx_taildrop(st
  25                 }
  26         }
  27
  28 +       /* Congestion group taildrop: threshold is in frames, per group
  29 +        * of FQs belonging to the same traffic class
  30 +        */
  31 +       td.threshold = DPAA2_ETH_CG_TAILDROP_THRESH(priv);
  32 +       td.units = DPNI_CONGESTION_UNIT_FRAMES;
  33 +       for (i = 0; i < dpaa2_eth_tc_count(priv); i++) {
  34 +               err = dpni_set_taildrop(priv->mc_io, 0, priv->mc_token,
  35 +                                       DPNI_CP_GROUP, DPNI_QUEUE_RX,
  36 +                                       i, 0, &td);
  37 +               if (err) {
  38 +                       netdev_err(priv->net_dev,
  39 +                                  "dpni_set_taildrop(CG) failed\n");
  40 +                       return;
  41 +               }
  42 +       }
  43 +
  44         priv->rx_td_enabled = td.enable;
  45  }
  46
  47 --- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
  48 +++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
  49 @@ -56,6 +56,15 @@
  50  #define DPAA2_ETH_REFILL_THRESH \
  51         (DPAA2_ETH_NUM_BUFS - DPAA2_ETH_BUFS_PER_CMD)
  52
  53 +/* Congestion group taildrop threshold: number of frames allowed to accumulate
  54 + * at any moment in a group of Rx queues belonging to the same traffic class.
  55 + * Choose value such that we don't risk depleting the buffer pool before the
  56 + * taildrop kicks in
  57 + */
  58 +#define DPAA2_ETH_CG_TAILDROP_THRESH(priv)                             \
  59 +       (DPAA2_ETH_MAX_FRAMES_PER_QUEUE * dpaa2_eth_queue_count(priv) / \
  60 +        dpaa2_eth_tc_count(priv))
  61 +
  62  /* Maximum number of buffers that can be acquired/released through a single
  63   * QBMan command
  64   */