[PATCH 5.0 041/117] net/mlx5e: Update xon formula

Greg Kroah-Hartman
2019-04-15T19:11:02Z

[ Upstream commit e28408e98bced123038857b6e3c81fa12a2e3e68 ]

Set xon = xoff - netdev's max_mtu.
netdev's max_mtu will give enough time for the pause frame to
arrive at the sender.

Fixes: 0696d60853d5 ("net/mlx5e: Receive buffer configuration")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../mellanox/mlx5/core/en/port_buffer.c | 28 +++++++++++--------
1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
index f00de0c987cd..4ab0d030b544 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/port_buffer.c
@@ -143,7 +143,7 @@ static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
}

static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
- u32 xoff, unsigned int mtu)
+ u32 xoff, unsigned int max_mtu)
{
int i;

@@ -155,11 +155,12 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
}

if (port_buffer->buffer[i].size <
- (xoff + mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))
+ (xoff + max_mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))
return -ENOMEM;

port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;
- port_buffer->buffer[i].xon = port_buffer->buffer[i].xoff - mtu;
+ port_buffer->buffer[i].xon =
+ port_buffer->buffer[i].xoff - max_mtu;
}

return 0;
@@ -167,7 +168,7 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,

/**
* update_buffer_lossy()
- * mtu: device's MTU
+ * max_mtu: netdev's max_mtu
* pfc_en: current pfc configuration
* buffer: current prio to buffer mapping
* xoff: xoff value
@@ -184,7 +185,7 @@ static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
* Return 0 if no error.
* Set change to true if buffer configuration is modified.
*/
-static int update_buffer_lossy(unsigned int mtu,
+static int update_buffer_lossy(unsigned int max_mtu,
u8 pfc_en, u8 *buffer, u32 xoff,
struct mlx5e_port_buffer *port_buffer,
bool *change)
@@ -221,7 +222,7 @@ static int update_buffer_lossy(unsigned int mtu,
}

if (changed) {
- err = update_xoff_threshold(port_buffer, xoff, mtu);
+ err = update_xoff_threshold(port_buffer, xoff, max_mtu);
if (err)
return err;

@@ -231,6 +232,7 @@ static int update_buffer_lossy(unsigned int mtu,
return 0;
}

+#define MINIMUM_MAX_MTU 9216
int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
u32 change, unsigned int mtu,
struct ieee_pfc *pfc,
@@ -242,12 +244,14 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
bool update_prio2buffer = false;
u8 buffer[MLX5E_MAX_PRIORITY];
bool update_buffer = false;
+ unsigned int max_mtu;
u32 total_used = 0;
u8 curr_pfc_en;
int err;
int i;

mlx5e_dbg(HW, priv, "%s: change=%x\n", __func__, change);
+ max_mtu = max_t(unsigned int, priv->netdev->max_mtu, MINIMUM_MAX_MTU);

err = mlx5e_port_query_buffer(priv, &port_buffer);
if (err)
@@ -255,7 +259,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,

if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
update_buffer = true;
- err = update_xoff_threshold(&port_buffer, xoff, mtu);
+ err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
if (err)
return err;
}
@@ -265,7 +269,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
if (err)
return err;

- err = update_buffer_lossy(mtu, pfc->pfc_en, buffer, xoff,
+ err = update_buffer_lossy(max_mtu, pfc->pfc_en, buffer, xoff,
&port_buffer, &update_buffer);
if (err)
return err;
@@ -277,8 +281,8 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
if (err)
return err;

- err = update_buffer_lossy(mtu, curr_pfc_en, prio2buffer, xoff,
- &port_buffer, &update_buffer);
+ err = update_buffer_lossy(max_mtu, curr_pfc_en, prio2buffer,
+ xoff, &port_buffer, &update_buffer);
if (err)
return err;
}
@@ -302,7 +306,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
return -EINVAL;

update_buffer = true;
- err = update_xoff_threshold(&port_buffer, xoff, mtu);
+ err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
if (err)
return err;
}
@@ -310,7 +314,7 @@ int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
/* Need to update buffer configuration if xoff value is changed */
if (!update_buffer && xoff != priv->dcbx.xoff) {
update_buffer = true;
- err = update_xoff_threshold(&port_buffer, xoff, mtu);
+ err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
if (err)
return err;
}
--
2.19.1