i40evf: Enable VF to request an alternate queue allocation

Currently the VF gets a default number of allocated queues from HW on
init and it could choose to enable or disable those allocated queues.
This makes it such that the VF can request more or less underlying
allocated queues from the PF.

First the VF negotiates the number of queues it wants that can be
supported by the PF and if successful asks for a reset.  During reset
the PF will reallocate the HW queues for the VF and will then remap the
new queues.

Signed-off-by: Alan Brady <alan.brady@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 89 insertions, 5 deletions

diff --git a/drivers/net/ethernet/intel/i40evf/i40evf_main.c b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
index 69ef6c1d5364..8c513ce84345 100644
--- a/drivers/net/ethernet/intel/i40evf/i40evf_main.c
+++ b/drivers/net/ethernet/intel/i40evf/i40evf_main.c
@@ -1189,9 +1189,18 @@ static int i40evf_alloc_queues(struct i40evf_adapter *adapter)
 {
 	int i, num_active_queues;
 
-	num_active_queues = min_t(int,
-				  adapter->vsi_res->num_queue_pairs,
-				  (int)(num_online_cpus()));
+	/* If we're in reset reallocating queues we don't actually know yet for
+	 * certain the PF gave us the number of queues we asked for but we'll
+	 * assume it did.  Once basic reset is finished we'll confirm once we
+	 * start negotiating config with PF.
+	 */
+	if (adapter->num_req_queues)
+		num_active_queues = adapter->num_req_queues;
+	else
+		num_active_queues = min_t(int,
+					  adapter->vsi_res->num_queue_pairs,
+					  (int)(num_online_cpus()));
+
 
 	adapter->tx_rings = kcalloc(num_active_queues,
 				    sizeof(struct i40e_ring), GFP_KERNEL);
@@ -1540,6 +1549,48 @@ static void i40evf_free_rss(struct i40evf_adapter *adapter)
 }
 
 /**
+ * i40evf_reinit_interrupt_scheme - Reallocate queues and vectors
+ * @adapter: board private structure
+ *
+ * Returns 0 on success, negative on failure
+ **/
+static int i40evf_reinit_interrupt_scheme(struct i40evf_adapter *adapter)
+{
+	struct net_device *netdev = adapter->netdev;
+	int err;
+
+	if (netif_running(netdev))
+		i40evf_free_traffic_irqs(adapter);
+	i40evf_free_misc_irq(adapter);
+	i40evf_reset_interrupt_capability(adapter);
+	i40evf_free_q_vectors(adapter);
+	i40evf_free_queues(adapter);
+
+	err =  i40evf_init_interrupt_scheme(adapter);
+	if (err)
+		goto err;
+
+	netif_tx_stop_all_queues(netdev);
+
+	err = i40evf_request_misc_irq(adapter);
+	if (err)
+		goto err;
+
+	set_bit(__I40E_VSI_DOWN, adapter->vsi.state);
+
+	err = i40evf_map_rings_to_vectors(adapter);
+	if (err)
+		goto err;
+
+	if (RSS_AQ(adapter))
+		adapter->aq_required |= I40EVF_FLAG_AQ_CONFIGURE_RSS;
+	else
+		err = i40evf_init_rss(adapter);
+err:
+	return err;
+}
+
+/**
  * i40evf_watchdog_timer - Periodic call-back timer
  * @data: pointer to adapter disguised as unsigned long
  **/
@@ -1885,8 +1936,15 @@ continue_reset:
 	if (err)
 		dev_info(&adapter->pdev->dev, "Failed to init adminq: %d\n",
 			 err);
+	adapter->aq_required = 0;
 
-	adapter->aq_required = I40EVF_FLAG_AQ_GET_CONFIG;
+	if (adapter->flags & I40EVF_FLAG_REINIT_ITR_NEEDED) {
+		err = i40evf_reinit_interrupt_scheme(adapter);
+		if (err)
+			goto reset_err;
+	}
+
+	adapter->aq_required |= I40EVF_FLAG_AQ_GET_CONFIG;
 	adapter->aq_required |= I40EVF_FLAG_AQ_MAP_VECTORS;
 
 	/* re-add all MAC filters */
@@ -1916,6 +1974,15 @@ continue_reset:
 		if (err)
 			goto reset_err;
 
+		if (adapter->flags & I40EVF_FLAG_REINIT_ITR_NEEDED) {
+			err = i40evf_request_traffic_irqs(adapter,
+							  netdev->name);
+			if (err)
+				goto reset_err;
+
+			adapter->flags &= ~I40EVF_FLAG_REINIT_ITR_NEEDED;
+		}
+
 		i40evf_configure(adapter);
 
 		i40evf_up_complete(adapter);
@@ -2431,9 +2498,9 @@ static int i40evf_check_reset_complete(struct i40e_hw *hw)
 int i40evf_process_config(struct i40evf_adapter *adapter)
 {
 	struct virtchnl_vf_resource *vfres = adapter->vf_res;
+	int i, num_req_queues = adapter->num_req_queues;
 	struct net_device *netdev = adapter->netdev;
 	struct i40e_vsi *vsi = &adapter->vsi;
-	int i;
 	netdev_features_t hw_enc_features;
 	netdev_features_t hw_features;
 
@@ -2447,6 +2514,23 @@ int i40evf_process_config(struct i40evf_adapter *adapter)
 		return -ENODEV;
 	}
 
+	if (num_req_queues &&
+	    num_req_queues != adapter->vsi_res->num_queue_pairs) {
+		/* Problem.  The PF gave us fewer queues than what we had
+		 * negotiated in our request.  Need a reset to see if we can't
+		 * get back to a working state.
+		 */
+		dev_err(&adapter->pdev->dev,
+			"Requested %d queues, but PF only gave us %d.\n",
+			num_req_queues,
+			adapter->vsi_res->num_queue_pairs);
+		adapter->flags |= I40EVF_FLAG_REINIT_ITR_NEEDED;
+		adapter->num_req_queues = adapter->vsi_res->num_queue_pairs;
+		i40evf_schedule_reset(adapter);
+		return -ENODEV;
+	}
+	adapter->num_req_queues = 0;
+
 	hw_enc_features = NETIF_F_SG			|
 			  NETIF_F_IP_CSUM		|
 			  NETIF_F_IPV6_CSUM		|