net/mlx5: Avoid using pending command interface slots
Currently when firmware command gets stuck or it takes long time to
complete, the driver command will get timeout and the command slot is
freed and can be used for new commands, and if the firmware receive new
command on the old busy slot its behavior is unexpected and this could
be harmful.
To fix this when the driver command gets timeout we return failure,
but we don't free the command slot and we wait for the firmware to
explicitly respond to that command.
Once all the entries are busy we will stop processing new firmware
commands.
Fixes: 9cba4ebcf374 ('net/mlx5: Fix potential deadlock in command mode change')
Signed-off-by: Mohamad Haj Yahia <mohamad@mellanox.com>
Cc: kernel-team@fb.com
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
index 5bdaf3d..10d2828 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/cmd.c
@@ -774,7 +774,7 @@
mlx5_core_warn(dev, "%s(0x%x) timeout. Will cause a leak of a command resource\n",
mlx5_command_str(msg_to_opcode(ent->in)),
msg_to_opcode(ent->in));
- mlx5_cmd_comp_handler(dev, 1UL << ent->idx);
+ mlx5_cmd_comp_handler(dev, 1UL << ent->idx, true);
}
static void cmd_work_handler(struct work_struct *work)
@@ -804,6 +804,7 @@
}
cmd->ent_arr[ent->idx] = ent;
+ set_bit(MLX5_CMD_ENT_STATE_PENDING_COMP, &ent->state);
lay = get_inst(cmd, ent->idx);
ent->lay = lay;
memset(lay, 0, sizeof(*lay));
@@ -825,6 +826,20 @@
if (ent->callback)
schedule_delayed_work(&ent->cb_timeout_work, cb_timeout);
+ /* Skip sending command to fw if internal error */
+ if (pci_channel_offline(dev->pdev) ||
+ dev->state == MLX5_DEVICE_STATE_INTERNAL_ERROR) {
+ u8 status = 0;
+ u32 drv_synd;
+
+ ent->ret = mlx5_internal_err_ret_value(dev, msg_to_opcode(ent->in), &drv_synd, &status);
+ MLX5_SET(mbox_out, ent->out, status, status);
+ MLX5_SET(mbox_out, ent->out, syndrome, drv_synd);
+
+ mlx5_cmd_comp_handler(dev, 1UL << ent->idx, true);
+ return;
+ }
+
/* ring doorbell after the descriptor is valid */
mlx5_core_dbg(dev, "writing 0x%x to command doorbell\n", 1 << ent->idx);
wmb();
@@ -835,7 +850,7 @@
poll_timeout(ent);
/* make sure we read the descriptor after ownership is SW */
rmb();
- mlx5_cmd_comp_handler(dev, 1UL << ent->idx);
+ mlx5_cmd_comp_handler(dev, 1UL << ent->idx, (ent->ret == -ETIMEDOUT));
}
}
@@ -879,7 +894,7 @@
wait_for_completion(&ent->done);
} else if (!wait_for_completion_timeout(&ent->done, timeout)) {
ent->ret = -ETIMEDOUT;
- mlx5_cmd_comp_handler(dev, 1UL << ent->idx);
+ mlx5_cmd_comp_handler(dev, 1UL << ent->idx, true);
}
err = ent->ret;
@@ -1375,7 +1390,7 @@
}
}
-void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec)
+void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec, bool forced)
{
struct mlx5_cmd *cmd = &dev->cmd;
struct mlx5_cmd_work_ent *ent;
@@ -1395,6 +1410,19 @@
struct semaphore *sem;
ent = cmd->ent_arr[i];
+
+ /* if we already completed the command, ignore it */
+ if (!test_and_clear_bit(MLX5_CMD_ENT_STATE_PENDING_COMP,
+ &ent->state)) {
+ /* only real completion can free the cmd slot */
+ if (!forced) {
+ mlx5_core_err(dev, "Command completion arrived after timeout (entry idx = %d).\n",
+ ent->idx);
+ free_ent(cmd, ent->idx);
+ }
+ continue;
+ }
+
if (ent->callback)
cancel_delayed_work(&ent->cb_timeout_work);
if (ent->page_queue)
@@ -1417,7 +1445,10 @@
mlx5_core_dbg(dev, "command completed. ret 0x%x, delivery status %s(0x%x)\n",
ent->ret, deliv_status_to_str(ent->status), ent->status);
}
- free_ent(cmd, ent->idx);
+
+ /* only real completion will free the entry slot */
+ if (!forced)
+ free_ent(cmd, ent->idx);
if (ent->callback) {
ds = ent->ts2 - ent->ts1;
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
index ea5d8d3..33eae5a 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
@@ -422,7 +422,7 @@
break;
case MLX5_EVENT_TYPE_CMD:
- mlx5_cmd_comp_handler(dev, be32_to_cpu(eqe->data.cmd.vector));
+ mlx5_cmd_comp_handler(dev, be32_to_cpu(eqe->data.cmd.vector), false);
break;
case MLX5_EVENT_TYPE_PORT_CHANGE:
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/health.c b/drivers/net/ethernet/mellanox/mlx5/core/health.c
index d051539..44f59b1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/health.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/health.c
@@ -90,7 +90,7 @@
spin_unlock_irqrestore(&dev->cmd.alloc_lock, flags);
mlx5_core_dbg(dev, "vector 0x%llx\n", vector);
- mlx5_cmd_comp_handler(dev, vector);
+ mlx5_cmd_comp_handler(dev, vector, true);
return;
no_trig:
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index bcdf739..93273d9 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -787,7 +787,12 @@
typedef void (*mlx5_cmd_cbk_t)(int status, void *context);
+enum {
+ MLX5_CMD_ENT_STATE_PENDING_COMP,
+};
+
struct mlx5_cmd_work_ent {
+ unsigned long state;
struct mlx5_cmd_msg *in;
struct mlx5_cmd_msg *out;
void *uout;
@@ -976,7 +981,7 @@
void mlx5_rsc_event(struct mlx5_core_dev *dev, u32 rsn, int event_type);
void mlx5_srq_event(struct mlx5_core_dev *dev, u32 srqn, int event_type);
struct mlx5_core_srq *mlx5_core_get_srq(struct mlx5_core_dev *dev, u32 srqn);
-void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec);
+void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, u64 vec, bool forced);
void mlx5_cq_event(struct mlx5_core_dev *dev, u32 cqn, int event_type);
int mlx5_create_map_eq(struct mlx5_core_dev *dev, struct mlx5_eq *eq, u8 vecidx,
int nent, u64 mask, const char *name,