net: ena: Refactor napi functions

This patch focuses on changes to the XDP part of the napi
polling routine.

1. Update the `napi_comp` stat only when napi is actually
   complete.
2. Simplify the code by using a function pointer to the right
   napi routine (XDP vs non-XDP path)
3. Remove unnecessary local variables.
4. Adjust a debug print to show the processed XDP frame index
   rather than the pointer.
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://lore.kernel.org/r/20240101190855.18739-8-darinzon@amazon.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/amazon/ena/ena_netdev.c

@@ -1754,18 +1754,28 @@ static void ena_del_napi_in_range(struct ena_adapter *adapter,
 static void ena_init_napi_in_range(struct ena_adapter *adapter,
 				   int first_index, int count)
 {
+	int (*napi_handler)(struct napi_struct *napi, int budget);
 	int i;
 
 	for (i = first_index; i < first_index + count; i++) {
 		struct ena_napi *napi = &adapter->ena_napi[i];
+		struct ena_ring *rx_ring, *tx_ring;
 
-		netif_napi_add(adapter->netdev, &napi->napi,
-			       ENA_IS_XDP_INDEX(adapter, i) ? ena_xdp_io_poll : ena_io_poll);
+		memset(napi, 0, sizeof(*napi));
+
+		rx_ring = &adapter->rx_ring[i];
+		tx_ring = &adapter->tx_ring[i];
+
+		napi_handler = ena_io_poll;
+		if (ENA_IS_XDP_INDEX(adapter, i))
+			napi_handler = ena_xdp_io_poll;
+
+		netif_napi_add(adapter->netdev, &napi->napi, napi_handler);
 
 		if (!ENA_IS_XDP_INDEX(adapter, i))
-			napi->rx_ring = &adapter->rx_ring[i];
+			napi->rx_ring = rx_ring;
 
-		napi->tx_ring = &adapter->tx_ring[i];
+		napi->tx_ring = tx_ring;
 		napi->qid = i;
 	}
 }

drivers/net/ethernet/amazon/ena/ena_xdp.c

@@ -385,23 +385,22 @@ static int ena_clean_xdp_irq(struct ena_ring *tx_ring, u32 budget)
 			break;
 
 		tx_info = &tx_ring->tx_buffer_info[req_id];
-		xdpf = tx_info->xdpf;
 
-		tx_info->xdpf = NULL;
 		tx_info->last_jiffies = 0;
-		ena_unmap_tx_buff(tx_ring, tx_info);
 
-		netif_dbg(tx_ring->adapter, tx_done, tx_ring->netdev,
-			  "tx_poll: q %d skb %p completed\n", tx_ring->qid,
-			  xdpf);
+		xdpf = tx_info->xdpf;
+		tx_info->xdpf = NULL;
+		ena_unmap_tx_buff(tx_ring, tx_info);
+		xdp_return_frame(xdpf);
 
 		tx_pkts++;
 		total_done += tx_info->tx_descs;
-
-		xdp_return_frame(xdpf);
 		tx_ring->free_ids[next_to_clean] = req_id;
 		next_to_clean = ENA_TX_RING_IDX_NEXT(next_to_clean,
 						     tx_ring->ring_size);
+
+		netif_dbg(tx_ring->adapter, tx_done, tx_ring->netdev,
+			  "tx_poll: q %d pkt #%d req_id %d\n", tx_ring->qid, tx_pkts, req_id);
 	}
 
 	tx_ring->next_to_clean = next_to_clean;
@@ -421,22 +420,19 @@ static int ena_clean_xdp_irq(struct ena_ring *tx_ring, u32 budget)
 int ena_xdp_io_poll(struct napi_struct *napi, int budget)
 {
 	struct ena_napi *ena_napi = container_of(napi, struct ena_napi, napi);
-	u32 xdp_work_done, xdp_budget;
 	struct ena_ring *tx_ring;
-	int napi_comp_call = 0;
+	u32 work_done;
 	int ret;
 
 	tx_ring = ena_napi->tx_ring;
 
-	xdp_budget = budget;
-
 	if (!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags) ||
 	    test_bit(ENA_FLAG_TRIGGER_RESET, &tx_ring->adapter->flags)) {
 		napi_complete_done(napi, 0);
 		return 0;
 	}
 
-	xdp_work_done = ena_clean_xdp_irq(tx_ring, xdp_budget);
+	work_done = ena_clean_xdp_irq(tx_ring, budget);
 
 	/* If the device is about to reset or down, avoid unmask
 	 * the interrupt and return 0 so NAPI won't reschedule
@@ -444,18 +440,19 @@ int ena_xdp_io_poll(struct napi_struct *napi, int budget)
 	if (unlikely(!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags))) {
 		napi_complete_done(napi, 0);
 		ret = 0;
-	} else if (xdp_budget > xdp_work_done) {
-		napi_comp_call = 1;
-		if (napi_complete_done(napi, xdp_work_done))
+	} else if (budget > work_done) {
+		ena_increase_stat(&tx_ring->tx_stats.napi_comp, 1,
+				  &tx_ring->syncp);
+		if (napi_complete_done(napi, work_done))
 			ena_unmask_interrupt(tx_ring, NULL);
+
 		ena_update_ring_numa_node(tx_ring, NULL);
-		ret = xdp_work_done;
+		ret = work_done;
 	} else {
-		ret = xdp_budget;
+		ret = budget;
 	}
 
 	u64_stats_update_begin(&tx_ring->syncp);
-	tx_ring->tx_stats.napi_comp += napi_comp_call;
 	tx_ring->tx_stats.tx_poll++;
 	u64_stats_update_end(&tx_ring->syncp);
 	tx_ring->tx_stats.last_napi_jiffies = jiffies;