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authorJack Morgenstein <jackm@dev.mellanox.co.il>2019-03-12 17:05:48 +0200
committerDavid S. Miller <davem@davemloft.net>2019-03-12 15:00:15 -0700
commitc07d27927f2f2e96fcd27bb9fb330c9ea65612d0 (patch)
tree2756f420fcafcfc2258e03f12ffba7fd5153cc01
parentnet/mlx4_core: Fix reset flow when in command polling mode (diff)
downloadlinux-dev-c07d27927f2f2e96fcd27bb9fb330c9ea65612d0.tar.xz
linux-dev-c07d27927f2f2e96fcd27bb9fb330c9ea65612d0.zip
net/mlx4_core: Fix locking in SRIOV mode when switching between events and polling
In procedures mlx4_cmd_use_events() and mlx4_cmd_use_polling(), we need to guarantee that there are no FW commands in progress on the comm channel (for VFs) or wrapped FW commands (on the PF) when SRIOV is active. We do this by also taking the slave_cmd_mutex when SRIOV is active. This is especially important when switching from event to polling, since we free the command-context array during the switch. If there are FW commands in progress (e.g., waiting for a completion event), the completion event handler will access freed memory. Since the decision to use comm_wait or comm_poll is taken before grabbing the event_sem/poll_sem in mlx4_comm_cmd_wait/poll, we must take the slave_cmd_mutex as well (to guarantee that the decision to use events or polling and the call to the appropriate cmd function are atomic). Fixes: a7e1f04905e5 ("net/mlx4_core: Fix deadlock when switching between polling and event fw commands") Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Tariq Toukan <tariqt@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/mellanox/mlx4/cmd.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/cmd.c b/drivers/net/ethernet/mellanox/mlx4/cmd.c
index 44081acd48fb..a5d5d6fc1da0 100644
--- a/drivers/net/ethernet/mellanox/mlx4/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx4/cmd.c
@@ -2645,6 +2645,8 @@ int mlx4_cmd_use_events(struct mlx4_dev *dev)
if (!priv->cmd.context)
return -ENOMEM;
+ if (mlx4_is_mfunc(dev))
+ mutex_lock(&priv->cmd.slave_cmd_mutex);
down_write(&priv->cmd.switch_sem);
for (i = 0; i < priv->cmd.max_cmds; ++i) {
priv->cmd.context[i].token = i;
@@ -2670,6 +2672,8 @@ int mlx4_cmd_use_events(struct mlx4_dev *dev)
down(&priv->cmd.poll_sem);
priv->cmd.use_events = 1;
up_write(&priv->cmd.switch_sem);
+ if (mlx4_is_mfunc(dev))
+ mutex_unlock(&priv->cmd.slave_cmd_mutex);
return err;
}
@@ -2682,6 +2686,8 @@ void mlx4_cmd_use_polling(struct mlx4_dev *dev)
struct mlx4_priv *priv = mlx4_priv(dev);
int i;
+ if (mlx4_is_mfunc(dev))
+ mutex_lock(&priv->cmd.slave_cmd_mutex);
down_write(&priv->cmd.switch_sem);
priv->cmd.use_events = 0;
@@ -2693,6 +2699,8 @@ void mlx4_cmd_use_polling(struct mlx4_dev *dev)
up(&priv->cmd.poll_sem);
up_write(&priv->cmd.switch_sem);
+ if (mlx4_is_mfunc(dev))
+ mutex_unlock(&priv->cmd.slave_cmd_mutex);
}
struct mlx4_cmd_mailbox *mlx4_alloc_cmd_mailbox(struct mlx4_dev *dev)