[PATCH iwl-next v4 04/13] idpf: link NAPIs to queues

[Alexander Lobakin <aleksander.lobakin@intel.com>]

Add the missing linking of NAPIs to netdev queues when enabling
interrupt vectors in order to support NAPI configuration and
interfaces requiring get_rx_queue()->napi to be set (like XSk
busy polling).

As currently, idpf_vport_{start,stop}() is called from several flows
with inconsistent RTNL locking, we need to synchronize them to avoid
runtime assertions. Notably:

* idpf_{open,stop}() -- regular NDOs, RTNL is always taken;
* idpf_initiate_soft_reset() -- usually called under RTNL;
* idpf_init_task -- called from the init work, needs RTNL;
* idpf_vport_dealloc -- called without RTNL taken, needs it.

Expand common idpf_vport_{start,stop}() to take an additional bool
telling whether we need to manually take the RTNL lock.

Suggested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> # helper
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
---
 drivers/net/ethernet/intel/idpf/idpf_lib.c  | 38 +++++++++++++++------
 drivers/net/ethernet/intel/idpf/idpf_txrx.c | 17 +++++++++
 2 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_lib.c b/drivers/net/ethernet/intel/idpf/idpf_lib.c
index 228991ac4271..8c4114473f29 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_lib.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_lib.c
@@ -883,14 +883,18 @@ static void idpf_remove_features(struct idpf_vport *vport)
 /**
  * idpf_vport_stop - Disable a vport
  * @vport: vport to disable
+ * @rtnl: whether to take RTNL lock
  */
-static void idpf_vport_stop(struct idpf_vport *vport)
+static void idpf_vport_stop(struct idpf_vport *vport, bool rtnl)
 {
 	struct idpf_netdev_priv *np = netdev_priv(vport->netdev);
 
 	if (np->state <= __IDPF_VPORT_DOWN)
 		return;
 
+	if (rtnl)
+		rtnl_lock();
+
 	netif_carrier_off(vport->netdev);
 	netif_tx_disable(vport->netdev);
 
@@ -912,6 +916,9 @@ static void idpf_vport_stop(struct idpf_vport *vport)
 	idpf_vport_queues_rel(vport);
 	idpf_vport_intr_rel(vport);
 	np->state = __IDPF_VPORT_DOWN;
+
+	if (rtnl)
+		rtnl_unlock();
 }
 
 /**
@@ -935,7 +942,7 @@ static int idpf_stop(struct net_device *netdev)
 	idpf_vport_ctrl_lock(netdev);
 	vport = idpf_netdev_to_vport(netdev);
 
-	idpf_vport_stop(vport);
+	idpf_vport_stop(vport, false);
 
 	idpf_vport_ctrl_unlock(netdev);
 
@@ -1028,7 +1035,7 @@ static void idpf_vport_dealloc(struct idpf_vport *vport)
 	idpf_idc_deinit_vport_aux_device(vport->vdev_info);
 
 	idpf_deinit_mac_addr(vport);
-	idpf_vport_stop(vport);
+	idpf_vport_stop(vport, true);
 
 	if (!test_bit(IDPF_HR_RESET_IN_PROG, adapter->flags))
 		idpf_decfg_netdev(vport);
@@ -1369,8 +1376,9 @@ static void idpf_rx_init_buf_tail(struct idpf_vport *vport)
 /**
  * idpf_vport_open - Bring up a vport
  * @vport: vport to bring up
+ * @rtnl: whether to take RTNL lock
  */
-static int idpf_vport_open(struct idpf_vport *vport)
+static int idpf_vport_open(struct idpf_vport *vport, bool rtnl)
 {
 	struct idpf_netdev_priv *np = netdev_priv(vport->netdev);
 	struct idpf_adapter *adapter = vport->adapter;
@@ -1380,6 +1388,9 @@ static int idpf_vport_open(struct idpf_vport *vport)
 	if (np->state != __IDPF_VPORT_DOWN)
 		return -EBUSY;
 
+	if (rtnl)
+		rtnl_lock();
+
 	/* we do not allow interface up just yet */
 	netif_carrier_off(vport->netdev);
 
@@ -1387,7 +1398,7 @@ static int idpf_vport_open(struct idpf_vport *vport)
 	if (err) {
 		dev_err(&adapter->pdev->dev, "Failed to allocate interrupts for vport %u: %d\n",
 			vport->vport_id, err);
-		return err;
+		goto err_rtnl_unlock;
 	}
 
 	err = idpf_vport_queues_alloc(vport);
@@ -1474,6 +1485,9 @@ static int idpf_vport_open(struct idpf_vport *vport)
 		goto deinit_rss;
 	}
 
+	if (rtnl)
+		rtnl_unlock();
+
 	return 0;
 
 deinit_rss:
@@ -1491,6 +1505,10 @@ static int idpf_vport_open(struct idpf_vport *vport)
 intr_rel:
 	idpf_vport_intr_rel(vport);
 
+err_rtnl_unlock:
+	if (rtnl)
+		rtnl_unlock();
+
 	return err;
 }
 
@@ -1571,7 +1589,7 @@ void idpf_init_task(struct work_struct *work)
 	np = netdev_priv(vport->netdev);
 	np->state = __IDPF_VPORT_DOWN;
 	if (test_and_clear_bit(IDPF_VPORT_UP_REQUESTED, vport_config->flags))
-		idpf_vport_open(vport);
+		idpf_vport_open(vport, true);
 
 	/* Spawn and return 'idpf_init_task' work queue until all the
 	 * default vports are created
@@ -1961,7 +1979,7 @@ int idpf_initiate_soft_reset(struct idpf_vport *vport,
 		idpf_send_delete_queues_msg(vport);
 	} else {
 		set_bit(IDPF_VPORT_DEL_QUEUES, vport->flags);
-		idpf_vport_stop(vport);
+		idpf_vport_stop(vport, false);
 	}
 
 	idpf_deinit_rss(vport);
@@ -1991,7 +2009,7 @@ int idpf_initiate_soft_reset(struct idpf_vport *vport,
 		goto err_open;
 
 	if (current_state == __IDPF_VPORT_UP)
-		err = idpf_vport_open(vport);
+		err = idpf_vport_open(vport, false);
 
 	goto free_vport;
 
@@ -2001,7 +2019,7 @@ int idpf_initiate_soft_reset(struct idpf_vport *vport,
 
 err_open:
 	if (current_state == __IDPF_VPORT_UP)
-		idpf_vport_open(vport);
+		idpf_vport_open(vport, false);
 
 free_vport:
 	kfree(new_vport);
@@ -2239,7 +2257,7 @@ static int idpf_open(struct net_device *netdev)
 	if (err)
 		goto unlock;
 
-	err = idpf_vport_open(vport);
+	err = idpf_vport_open(vport, false);
 
 unlock:
 	idpf_vport_ctrl_unlock(netdev);
diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
index 26dde653587d..834ff436d852 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
@@ -3508,6 +3508,20 @@ void idpf_vport_intr_rel(struct idpf_vport *vport)
 	vport->q_vectors = NULL;
 }
 
+static void idpf_q_vector_set_napi(struct idpf_q_vector *q_vector, bool link)
+{
+	struct napi_struct *napi = link ? &q_vector->napi : NULL;
+	struct net_device *dev = q_vector->vport->netdev;
+
+	for (u32 i = 0; i < q_vector->num_rxq; i++)
+		netif_queue_set_napi(dev, q_vector->rx[i]->idx,
+				     NETDEV_QUEUE_TYPE_RX, napi);
+
+	for (u32 i = 0; i < q_vector->num_txq; i++)
+		netif_queue_set_napi(dev, q_vector->tx[i]->idx,
+				     NETDEV_QUEUE_TYPE_TX, napi);
+}
+
 /**
  * idpf_vport_intr_rel_irq - Free the IRQ association with the OS
  * @vport: main vport structure
@@ -3528,6 +3542,7 @@ static void idpf_vport_intr_rel_irq(struct idpf_vport *vport)
 		vidx = vport->q_vector_idxs[vector];
 		irq_num = adapter->msix_entries[vidx].vector;
 
+		idpf_q_vector_set_napi(q_vector, false);
 		kfree(free_irq(irq_num, q_vector));
 	}
 }
@@ -3715,6 +3730,8 @@ static int idpf_vport_intr_req_irq(struct idpf_vport *vport)
 				   "Request_irq failed, error: %d\n", err);
 			goto free_q_irqs;
 		}
+
+		idpf_q_vector_set_napi(q_vector, true);
 	}
 
 	return 0;
-- 
2.50.1