From: Rana Shahout <ra...@mellanox.com>
To avoid multiply/division operations on the data path,
we hold a {channel, tc}==>txq mapping table.
We held this mapping table inside the channel object that is
being destroyed upon some configuration operations (e.g MTU change).
So in case ndo_select_queue occurs during such a configuration operation,
it may access a NULL channel pointer, resulting in kernel panic.
To fix this issue we moved the {channel, tc}==>txq mapping table
outside the channel object so that it will be available also
during such configuration operations.
Signed-off-by: Rana Shahout <ra...@mellanox.com>
---
Hi Dave,
This patch fixes a bug in the mlx5 Ethernet driver that causes
a kernel panic due to a NULL pointer access upon the select_queue
callback, in cause it happens in congestion with certain configuration
operations.
The path was applied and tested over commit dc25b25 ("Merge
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net").
Thanks,
Achiad
drivers/net/ethernet/mellanox/mlx5/core/en.h | 2 +-
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 8 ++++----
drivers/net/ethernet/mellanox/mlx5/core/en_tx.c | 2 +-
3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h
b/drivers/net/ethernet/mellanox/mlx5/core/en.h
index 27ca459..0983a20 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
@@ -405,7 +405,6 @@ struct mlx5e_channel {
__be32 mkey_be;
u8 num_tc;
unsigned long flags;
- int tc_to_txq_map[MLX5E_MAX_NUM_TC];
/* control */
struct mlx5e_priv *priv;
@@ -475,6 +474,7 @@ struct mlx5e_priv {
/* priv data path fields - start */
int default_vlan_prio;
struct mlx5e_sq **txq_to_sq_map;
+ int channeltc_to_txq_map[MLX5E_MAX_NUM_CHANNELS][MLX5E_MAX_NUM_TC];
/* priv data path fields - end */
unsigned long state;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 55166dd..59874d6 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -949,13 +949,13 @@ static void mlx5e_close_sqs(struct mlx5e_channel *c)
mlx5e_close_sq(&c->sq[tc]);
}
-static void mlx5e_build_tc_to_txq_map(struct mlx5e_channel *c,
- int num_channels)
+static void mlx5e_build_channeltc_to_txq_map(struct mlx5e_priv *priv, int ix)
{
int i;
for (i = 0; i < MLX5E_MAX_NUM_TC; i++)
- c->tc_to_txq_map[i] = c->ix + i * num_channels;
+ priv->channeltc_to_txq_map[ix][i] =
+ ix + i * priv->params.num_channels;
}
static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix,
@@ -979,7 +979,7 @@ static int mlx5e_open_channel(struct mlx5e_priv *priv, int
ix,
c->mkey_be = cpu_to_be32(priv->mr.key);
c->num_tc = priv->params.num_tc;
- mlx5e_build_tc_to_txq_map(c, priv->params.num_channels);
+ mlx5e_build_channeltc_to_txq_map(priv, ix);
netif_napi_add(netdev, &c->napi, mlx5e_napi_poll, 64);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
index 64380bc..b73672f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
@@ -106,7 +106,7 @@ u16 mlx5e_select_queue(struct net_device *dev, struct
sk_buff *skb,
priv->default_vlan_prio;
int tc = netdev_get_prio_tc_map(dev, up);
- return priv->channel[channel_ix]->tc_to_txq_map[tc];
+ return priv->channeltc_to_txq_map[channel_ix][tc];
}
static inline u16 mlx5e_get_inline_hdr_size(struct mlx5e_sq *sq,
--
1.8.3.1
--
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