ixgbe: get rid of custom busy polling code

In linux-4.5, busy polling was implemented in core
NAPI stack, meaning that all custom implementation can
be removed from drivers.

Not only we remove lot's of code, we also remove one lock
operation in fast path, and allow GRO to do its job.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 54 deletions

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 3b3b52b62a5fe..86135c00d4b12 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1720,11 +1720,7 @@ static void ixgbe_process_skb_fields(struct ixgbe_ring *rx_ring,
 static void ixgbe_rx_skb(struct ixgbe_q_vector *q_vector,
 			 struct sk_buff *skb)
 {
-	skb_mark_napi_id(skb, &q_vector->napi);
-	if (ixgbe_qv_busy_polling(q_vector))
-		netif_receive_skb(skb);
-	else
-		napi_gro_receive(&q_vector->napi, skb);
+	napi_gro_receive(&q_vector->napi, skb);
 }
 
 /**
@@ -2201,40 +2197,6 @@ static int ixgbe_clean_rx_irq(struct ixgbe_q_vector *q_vector,
 	return total_rx_packets;
 }
 
-#ifdef CONFIG_NET_RX_BUSY_POLL
-/* must be called with local_bh_disable()d */
-static int ixgbe_low_latency_recv(struct napi_struct *napi)
-{
-	struct ixgbe_q_vector *q_vector =
-			container_of(napi, struct ixgbe_q_vector, napi);
-	struct ixgbe_adapter *adapter = q_vector->adapter;
-	struct ixgbe_ring  *ring;
-	int found = 0;
-
-	if (test_bit(__IXGBE_DOWN, &adapter->state))
-		return LL_FLUSH_FAILED;
-
-	if (!ixgbe_qv_lock_poll(q_vector))
-		return LL_FLUSH_BUSY;
-
-	ixgbe_for_each_ring(ring, q_vector->rx) {
-		found = ixgbe_clean_rx_irq(q_vector, ring, 4);
-#ifdef BP_EXTENDED_STATS
-		if (found)
-			ring->stats.cleaned += found;
-		else
-			ring->stats.misses++;
-#endif
-		if (found)
-			break;
-	}
-
-	ixgbe_qv_unlock_poll(q_vector);
-
-	return found;
-}
-#endif	/* CONFIG_NET_RX_BUSY_POLL */
-
 /**
  * ixgbe_configure_msix - Configure MSI-X hardware
  * @adapter: board private structure
@@ -2878,8 +2840,8 @@ int ixgbe_poll(struct napi_struct *napi, int budget)
 			clean_complete = false;
 	}
 
-	/* Exit if we are called by netpoll or busy polling is active */
-	if ((budget <= 0) || !ixgbe_qv_lock_napi(q_vector))
+	/* Exit if we are called by netpoll */
+	if (budget <= 0)
 		return budget;
 
 	/* attempt to distribute budget to each queue fairly, but don't allow
@@ -2898,7 +2860,6 @@ int ixgbe_poll(struct napi_struct *napi, int budget)
 			clean_complete = false;
 	}
 
-	ixgbe_qv_unlock_napi(q_vector);
 	/* If all work not completed, return budget and keep polling */
 	if (!clean_complete)
 		return budget;
@@ -4581,23 +4542,16 @@ static void ixgbe_napi_enable_all(struct ixgbe_adapter *adapter)
 {
 	int q_idx;
 
-	for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++) {
-		ixgbe_qv_init_lock(adapter->q_vector[q_idx]);
+	for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++)
 		napi_enable(&adapter->q_vector[q_idx]->napi);
-	}
 }
 
 static void ixgbe_napi_disable_all(struct ixgbe_adapter *adapter)
 {
 	int q_idx;
 
-	for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++) {
+	for (q_idx = 0; q_idx < adapter->num_q_vectors; q_idx++)
 		napi_disable(&adapter->q_vector[q_idx]->napi);
-		while (!ixgbe_qv_disable(adapter->q_vector[q_idx])) {
-			pr_info("QV %d locked\n", q_idx);
-			usleep_range(1000, 20000);
-		}
-	}
 }
 
 static void ixgbe_clear_udp_tunnel_port(struct ixgbe_adapter *adapter, u32 mask)
@@ -9352,9 +9306,6 @@ static const struct net_device_ops ixgbe_netdev_ops = {
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	.ndo_poll_controller	= ixgbe_netpoll,
 #endif
-#ifdef CONFIG_NET_RX_BUSY_POLL
-	.ndo_busy_poll		= ixgbe_low_latency_recv,
-#endif
 #ifdef IXGBE_FCOE
 	.ndo_fcoe_ddp_setup = ixgbe_fcoe_ddp_get,
 	.ndo_fcoe_ddp_target = ixgbe_fcoe_ddp_target,