releases/4.19.35/net-mlx5e-update-xon-formula.patch

   1 From f3f8c009a5f039371341bc22e98b6b74490a7c6d Mon Sep 17 00:00:00 2001
   2 From: Huy Nguyen <huyn@mellanox.com>
   3 Date: Thu, 7 Mar 2019 14:07:32 -0600
   4 Subject: net/mlx5e: Update xon formula
   5
   6 [ Upstream commit e28408e98bced123038857b6e3c81fa12a2e3e68 ]
   7
   8 Set xon = xoff - netdev's max_mtu.
   9 netdev's max_mtu will give enough time for the pause frame to
  10 arrive at the sender.
  11
  12 Fixes: 0696d60853d5 ("net/mlx5e: Receive buffer configuration")
  13 Signed-off-by: Huy Nguyen <huyn@mellanox.com>
  14 Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
  15 Signed-off-by: Sasha Levin <sashal@kernel.org>
  16 ---
  17  .../mellanox/mlx5/core/en/port_buffer.c       | 28 +++++++++++--------
  18  1 file changed, 16 insertions(+), 12 deletions(-)
  19
  20 diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
  21 index f00de0c987cd..4ab0d030b544 100644
  22 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
  23 +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
  24 @@ -143,7 +143,7 @@ static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
  25  }
  26
  27  static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
  28 -                                u32 xoff, unsigned int mtu)
  29 +                                u32 xoff, unsigned int max_mtu)
  30  {
  31         int i;
  32
  33 @@ -155,11 +155,12 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
  34                 }
  35
  36                 if (port_buffer->buffer[i].size <
  37 -                   (xoff + mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))
  38 +                   (xoff + max_mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))
  39                         return -ENOMEM;
  40
  41                 port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;
  42 -               port_buffer->buffer[i].xon  = port_buffer->buffer[i].xoff - mtu;
  43 +               port_buffer->buffer[i].xon  =
  44 +                       port_buffer->buffer[i].xoff - max_mtu;
  45         }
  46
  47         return 0;
  48 @@ -167,7 +168,7 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
  49
  50  /**
  51   * update_buffer_lossy()
  52 - *   mtu: device's MTU
  53 + *   max_mtu: netdev's max_mtu
  54   *   pfc_en: <input> current pfc configuration
  55   *   buffer: <input> current prio to buffer mapping
  56   *   xoff:   <input> xoff value
  57 @@ -184,7 +185,7 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
  58   *     Return 0 if no error.
  59   *     Set change to true if buffer configuration is modified.
  60   */
  61 -static int update_buffer_lossy(unsigned int mtu,
  62 +static int update_buffer_lossy(unsigned int max_mtu,
  63                                u8 pfc_en, u8 *buffer, u32 xoff,
  64                                struct mlx5e_port_buffer *port_buffer,
  65                                bool *change)
  66 @@ -221,7 +222,7 @@ static int update_buffer_lossy(unsigned int mtu,
  67         }
  68
  69         if (changed) {
  70 -               err = update_xoff_threshold(port_buffer, xoff, mtu);
  71 +               err = update_xoff_threshold(port_buffer, xoff, max_mtu);
  72                 if (err)
  73                         return err;
  74
  75 @@ -231,6 +232,7 @@ static int update_buffer_lossy(unsigned int mtu,
  76         return 0;
  77  }
  78
  79 +#define MINIMUM_MAX_MTU 9216
  80  int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
  81                                     u32 change, unsigned int mtu,
  82                                     struct ieee_pfc *pfc,
  83 @@ -242,12 +244,14 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
  84         bool update_prio2buffer = false;
  85         u8 buffer[MLX5E_MAX_PRIORITY];
  86         bool update_buffer = false;
  87 +       unsigned int max_mtu;
  88         u32 total_used = 0;
  89         u8 curr_pfc_en;
  90         int err;
  91         int i;
  92
  93         mlx5e_dbg(HW, priv, "%s: change=%x\n", __func__, change);
  94 +       max_mtu = max_t(unsigned int, priv->netdev->max_mtu, MINIMUM_MAX_MTU);
  95
  96         err = mlx5e_port_query_buffer(priv, &port_buffer);
  97         if (err)
  98 @@ -255,7 +259,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
  99
 100         if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
 101                 update_buffer = true;
 102 -               err = update_xoff_threshold(&port_buffer, xoff, mtu);
 103 +               err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
 104                 if (err)
 105                         return err;
 106         }
 107 @@ -265,7 +269,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 108                 if (err)
 109                         return err;
 110
 111 -               err = update_buffer_lossy(mtu, pfc->pfc_en, buffer, xoff,
 112 +               err = update_buffer_lossy(max_mtu, pfc->pfc_en, buffer, xoff,
 113                                           &port_buffer, &update_buffer);
 114                 if (err)
 115                         return err;
 116 @@ -277,8 +281,8 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 117                 if (err)
 118                         return err;
 119
 120 -               err = update_buffer_lossy(mtu, curr_pfc_en, prio2buffer, xoff,
 121 -                                         &port_buffer, &update_buffer);
 122 +               err = update_buffer_lossy(max_mtu, curr_pfc_en, prio2buffer,
 123 +                                         xoff, &port_buffer, &update_buffer);
 124                 if (err)
 125                         return err;
 126         }
 127 @@ -302,7 +306,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 128                         return -EINVAL;
 129
 130                 update_buffer = true;
 131 -               err = update_xoff_threshold(&port_buffer, xoff, mtu);
 132 +               err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
 133                 if (err)
 134                         return err;
 135         }
 136 @@ -310,7 +314,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
 137         /* Need to update buffer configuration if xoff value is changed */
 138         if (!update_buffer && xoff != priv->dcbx.xoff) {
 139                 update_buffer = true;
 140 -               err = update_xoff_threshold(&port_buffer, xoff, mtu);
 141 +               err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
 142                 if (err)
 143                         return err;
 144         }
 145 --
 146 2.19.1
 147