i40e: Fix descriptor count manipulation

Changing descriptor count via 'ethtool -G' is not persistent across resets.
When PF reset occurs, we roll back to the default value of vsi->num_desc,
which is used then in i40e_alloc_rings to set descriptor count. XDP does a
PF reset so when user has changed the descriptor count and load XDP
program, the default count will be back there.

To fix this:
  * introduce new VSI members - num_tx_desc and num_rx_desc in favour of
    num_desc
  * set them in i40e_set_ringparam to user's values
  * set them to default values in i40e_set_num_rings_in_vsi only when they
    don't have previous values
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -775,7 +775,8 @@ struct i40e_vsi {
 	u16 alloc_queue_pairs;	/* Allocated Tx/Rx queues */
 	u16 req_queue_pairs;	/* User requested queue pairs */
 	u16 num_queue_pairs;	/* Used tx and rx pairs */
-	u16 num_desc;
+	u16 num_tx_desc;
+	u16 num_rx_desc;
 	enum i40e_vsi_type type;  /* VSI type, e.g., LAN, FCoE, etc */
 	s16 vf_id;		/* Virtual function ID for SRIOV VSIs */
 

drivers/net/ethernet/intel/i40e/i40e_debugfs.c

@@ -333,8 +333,9 @@ static void i40e_dbg_dump_vsi_seid(struct i40e_pf *pf, int seid)
 		 "    seid = %d, id = %d, uplink_seid = %d\n",
 		 vsi->seid, vsi->id, vsi->uplink_seid);
 	dev_info(&pf->pdev->dev,
-		 "    base_queue = %d, num_queue_pairs = %d, num_desc = %d\n",
-		 vsi->base_queue, vsi->num_queue_pairs, vsi->num_desc);
+		 "    base_queue = %d, num_queue_pairs = %d, num_tx_desc = %d, num_rx_desc = %d\n",
+		 vsi->base_queue, vsi->num_queue_pairs, vsi->num_tx_desc,
+		 vsi->num_rx_desc);
 	dev_info(&pf->pdev->dev, "    type = %i\n", vsi->type);
 	if (vsi->type == I40E_VSI_SRIOV)
 		dev_info(&pf->pdev->dev, "    VF ID = %i\n", vsi->vf_id);

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -1982,6 +1982,8 @@ static int i40e_set_ringparam(struct net_device *netdev,
 			if (i40e_enabled_xdp_vsi(vsi))
 				vsi->xdp_rings[i]->count = new_tx_count;
 		}
+		vsi->num_tx_desc = new_tx_count;
+		vsi->num_rx_desc = new_rx_count;
 		goto done;
 	}
 
@@ -2118,6 +2120,8 @@ static int i40e_set_ringparam(struct net_device *netdev,
 		rx_rings = NULL;
 	}
 
+	vsi->num_tx_desc = new_tx_count;
+	vsi->num_rx_desc = new_rx_count;
 	i40e_up(vsi);
 
 free_tx:

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -10078,7 +10078,11 @@ static int i40e_set_num_rings_in_vsi(struct i40e_vsi *vsi)
 	switch (vsi->type) {
 	case I40E_VSI_MAIN:
 		vsi->alloc_queue_pairs = pf->num_lan_qps;
-		vsi->num_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
+		if (!vsi->num_tx_desc)
+			vsi->num_tx_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
+						 I40E_REQ_DESCRIPTOR_MULTIPLE);
+		if (!vsi->num_rx_desc)
+			vsi->num_rx_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
 						 I40E_REQ_DESCRIPTOR_MULTIPLE);
 		if (pf->flags & I40E_FLAG_MSIX_ENABLED)
 			vsi->num_q_vectors = pf->num_lan_msix;
@@ -10089,21 +10093,31 @@ static int i40e_set_num_rings_in_vsi(struct i40e_vsi *vsi)
 
 	case I40E_VSI_FDIR:
 		vsi->alloc_queue_pairs = 1;
-		vsi->num_desc = ALIGN(I40E_FDIR_RING_COUNT,
+		vsi->num_tx_desc = ALIGN(I40E_FDIR_RING_COUNT,
+					 I40E_REQ_DESCRIPTOR_MULTIPLE);
+		vsi->num_rx_desc = ALIGN(I40E_FDIR_RING_COUNT,
 					 I40E_REQ_DESCRIPTOR_MULTIPLE);
 		vsi->num_q_vectors = pf->num_fdsb_msix;
 		break;
 
 	case I40E_VSI_VMDQ2:
 		vsi->alloc_queue_pairs = pf->num_vmdq_qps;
-		vsi->num_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
+		if (!vsi->num_tx_desc)
+			vsi->num_tx_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
+						 I40E_REQ_DESCRIPTOR_MULTIPLE);
+		if (!vsi->num_rx_desc)
+			vsi->num_rx_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
 						 I40E_REQ_DESCRIPTOR_MULTIPLE);
 		vsi->num_q_vectors = pf->num_vmdq_msix;
 		break;
 
 	case I40E_VSI_SRIOV:
 		vsi->alloc_queue_pairs = pf->num_vf_qps;
-		vsi->num_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
+		if (!vsi->num_tx_desc)
+			vsi->num_tx_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
+						 I40E_REQ_DESCRIPTOR_MULTIPLE);
+		if (!vsi->num_rx_desc)
+			vsi->num_rx_desc = ALIGN(I40E_DEFAULT_NUM_DESCRIPTORS,
 						 I40E_REQ_DESCRIPTOR_MULTIPLE);
 		break;
 
@@ -10380,7 +10394,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
 		ring->vsi = vsi;
 		ring->netdev = vsi->netdev;
 		ring->dev = &pf->pdev->dev;
-		ring->count = vsi->num_desc;
+		ring->count = vsi->num_tx_desc;
 		ring->size = 0;
 		ring->dcb_tc = 0;
 		if (vsi->back->hw_features & I40E_HW_WB_ON_ITR_CAPABLE)
@@ -10397,7 +10411,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
 		ring->vsi = vsi;
 		ring->netdev = NULL;
 		ring->dev = &pf->pdev->dev;
-		ring->count = vsi->num_desc;
+		ring->count = vsi->num_tx_desc;
 		ring->size = 0;
 		ring->dcb_tc = 0;
 		if (vsi->back->hw_features & I40E_HW_WB_ON_ITR_CAPABLE)
@@ -10413,7 +10427,7 @@ static int i40e_alloc_rings(struct i40e_vsi *vsi)
 		ring->vsi = vsi;
 		ring->netdev = vsi->netdev;
 		ring->dev = &pf->pdev->dev;
-		ring->count = vsi->num_desc;
+		ring->count = vsi->num_rx_desc;
 		ring->size = 0;
 		ring->dcb_tc = 0;
 		ring->itr_setting = pf->rx_itr_default;