ice: Determine descriptor count and ring size based on PAGE_SIZE

Currently we set the default number of Tx and Rx descriptors to 128 by
default. For Rx this amounts to a full page (assuming 4K pages) because
each Rx descriptor is 32 Bytes, but for Tx it only amounts to a half
page because each Tx descriptor is 16 Bytes (assuming 4K pages).
Instead of assuming 4K pages, determine the ring size and the number of
descriptors for Tx and Rx based on a calculation using the PAGE_SIZE,
ICE_MAX_NUM_DESC, and ICE_REQ_DESC_MULTIPLE. This change is being made
to improve the performance of the driver when using the default
settings.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 24 insertions, 4 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index c6572f6fb488..d3061f243877 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -276,7 +276,26 @@ err_txrings:
 }
 
 /**
- * ice_vsi_set_num_qs - Set num queues, descriptors and vectors for a VSI
+ * ice_vsi_set_num_desc - Set number of descriptors for queues on this VSI
+ * @vsi: the VSI being configured
+ */
+static void ice_vsi_set_num_desc(struct ice_vsi *vsi)
+{
+        switch (vsi->type) {
+        case ICE_VSI_PF:
+                vsi->num_rx_desc = ICE_DFLT_NUM_RX_DESC;
+                vsi->num_tx_desc = ICE_DFLT_NUM_TX_DESC;
+                break;
+        default:
+                dev_dbg(&vsi->back->pdev->dev,
+                        "Not setting number of Tx/Rx descriptors for VSI type %d\n",
+                        vsi->type);
+                break;
+        }
+}
+
+/**
+ * ice_vsi_set_num_qs - Set number of queues, descriptors and vectors for a VSI
  * @vsi: the VSI being configured
  *
  * Return 0 on success and a negative value on error
@@ -289,7 +308,6 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi)
         case ICE_VSI_PF:
                 vsi->alloc_txq = pf->num_lan_tx;
                 vsi->alloc_rxq = pf->num_lan_rx;
-                vsi->num_desc = ALIGN(ICE_DFLT_NUM_DESC, ICE_REQ_DESC_MULTIPLE);
                 vsi->num_q_vectors = max_t(int, pf->num_lan_rx, pf->num_lan_tx);
                 break;
         case ICE_VSI_VF:
@@ -307,6 +325,8 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi)
                          vsi->type);
                 break;
         }
+
+        ice_vsi_set_num_desc(vsi);
 }
 
 /**
@@ -1212,7 +1232,7 @@ static int ice_vsi_alloc_rings(struct ice_vsi *vsi)
                 ring->ring_active = false;
                 ring->vsi = vsi;
                 ring->dev = &pf->pdev->dev;
-                ring->count = vsi->num_desc;
+                ring->count = vsi->num_tx_desc;
                 vsi->tx_rings[i] = ring;
         }
 
@@ -1231,7 +1251,7 @@ static int ice_vsi_alloc_rings(struct ice_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;
                 vsi->rx_rings[i] = ring;
         }