i40e: consolidate handling of XDP program actions

Consolidate the actions performed on the packet based on the XDP
program result into a separate function that is easier to read and
maintain. Simplify the i40e_construct_skb_zc function, so that the
input xdp buffer is always freed, regardless of whether the output
skb is successfully created or not. Simplify the behavior of the
i40e_clean_rx_irq_zc function, so that the current packet descriptor
is dropped when function i40_construct_skb_zc returns an error as
opposed to re-processing the same description on the next invocation.

Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 1167496..470b860 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -250,17 +250,70 @@ static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
                               xdp->data_end - xdp->data_hard_start,
                               GFP_ATOMIC | __GFP_NOWARN);
        if (unlikely(!skb))
-               return NULL;
+               goto out;
 
        skb_reserve(skb, xdp->data - xdp->data_hard_start);
        memcpy(__skb_put(skb, datasize), xdp->data, datasize);
        if (metasize)
                skb_metadata_set(skb, metasize);
 
+out:
        xsk_buff_free(xdp);
        return skb;
 }
 
+static void i40e_handle_xdp_result_zc(struct i40e_ring *rx_ring,
+                                     struct xdp_buff *xdp_buff,
+                                     union i40e_rx_desc *rx_desc,
+                                     unsigned int *rx_packets,
+                                     unsigned int *rx_bytes,
+                                     unsigned int size,
+                                     unsigned int xdp_res)
+{
+       struct sk_buff *skb;
+
+       *rx_packets = 1;
+       *rx_bytes = size;
+
+       if (likely(xdp_res == I40E_XDP_REDIR) || xdp_res == I40E_XDP_TX)
+               return;
+
+       if (xdp_res == I40E_XDP_CONSUMED) {
+               xsk_buff_free(xdp_buff);
+               return;
+       }
+
+       if (xdp_res == I40E_XDP_PASS) {
+               /* NB! We are not checking for errors using
+                * i40e_test_staterr with
+                * BIT(I40E_RXD_QW1_ERROR_SHIFT). This is due to that
+                * SBP is *not* set in PRT_SBPVSI (default not set).
+                */
+               skb = i40e_construct_skb_zc(rx_ring, xdp_buff);
+               if (!skb) {
+                       rx_ring->rx_stats.alloc_buff_failed++;
+                       *rx_packets = 0;
+                       *rx_bytes = 0;
+                       return;
+               }
+
+               if (eth_skb_pad(skb)) {
+                       *rx_packets = 0;
+                       *rx_bytes = 0;
+                       return;
+               }
+
+               *rx_bytes = skb->len;
+               i40e_process_skb_fields(rx_ring, rx_desc, skb);
+               napi_gro_receive(&rx_ring->q_vector->napi, skb);
+               return;
+       }
+
+       /* Should never get here, as all valid cases have been handled already.
+        */
+       WARN_ON_ONCE(1);
+}
+
 /**
  * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring
  * @rx_ring: Rx ring
@@ -276,10 +329,11 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
        u16 count_mask = rx_ring->count - 1;
        unsigned int xdp_res, xdp_xmit = 0;
        bool failure = false;
-       struct sk_buff *skb;
 
        while (likely(total_rx_packets < (unsigned int)budget)) {
                union i40e_rx_desc *rx_desc;
+               unsigned int rx_packets;
+               unsigned int rx_bytes;
                struct xdp_buff *bi;
                unsigned int size;
                u64 qword;
@@ -313,42 +367,12 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
                xsk_buff_dma_sync_for_cpu(bi, rx_ring->xsk_pool);
 
                xdp_res = i40e_run_xdp_zc(rx_ring, bi);
-               if (xdp_res) {
-                       if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR))
-                               xdp_xmit |= xdp_res;
-                       else
-                               xsk_buff_free(bi);
-
-                       total_rx_bytes += size;
-                       total_rx_packets++;
-
-                       next_to_clean = (next_to_clean + 1) & count_mask;
-                       continue;
-               }
-
-               /* XDP_PASS path */
-
-               /* NB! We are not checking for errors using
-                * i40e_test_staterr with
-                * BIT(I40E_RXD_QW1_ERROR_SHIFT). This is due to that
-                * SBP is *not* set in PRT_SBPVSI (default not set).
-                */
-               skb = i40e_construct_skb_zc(rx_ring, bi);
-               if (!skb) {
-                       rx_ring->rx_stats.alloc_buff_failed++;
-                       break;
-               }
-
+               i40e_handle_xdp_result_zc(rx_ring, bi, rx_desc, &rx_packets,
+                                         &rx_bytes, size, xdp_res);
+               total_rx_packets += rx_packets;
+               total_rx_bytes += rx_bytes;
+               xdp_xmit |= xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR);
                next_to_clean = (next_to_clean + 1) & count_mask;
-
-               if (eth_skb_pad(skb))
-                       continue;
-
-               total_rx_bytes += skb->len;
-               total_rx_packets++;
-
-               i40e_process_skb_fields(rx_ring, rx_desc, skb);
-               napi_gro_receive(&rx_ring->q_vector->napi, skb);
        }
 
        rx_ring->next_to_clean = next_to_clean;