Subject: [PATCH 47/53] i40e: split XDP_TX tail and XDP_REDIRECT map flushing

From: Jesper Dangaard Brouer <[email-masked]>
Date: Tue, 26 Jun 2018 17:39:53 +0200

[ Upstream commit 2e6893123830d04edc366e0ce59d46e622e140c1 ]

The driver was combining the XDP_TX tail flush and XDP_REDIRECT
map flushing (xdp_do_flush_map).  This is suboptimal, these two
flush operations should be kept separate.

It looks like the mistake was copy-pasted from ixgbe.

Fixes: d9314c474d4f ("i40e: add support for XDP_REDIRECT")
Signed-off-by: Jesper Dangaard Brouer <[email-masked]>
Acked-by: Björn Töpel <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/ethernet/intel/i40e/i40e_txrx.c | 24 +++++++++++++--------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index f174c72480ab..8d3522c94c3f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
@@ -2199,9 +2199,10 @@ static bool i40e_is_non_eop(struct i40e_ring *rx_ring,
 	return true;
 }
 
-#define I40E_XDP_PASS 0
-#define I40E_XDP_CONSUMED 1
-#define I40E_XDP_TX 2
+#define I40E_XDP_PASS		0
+#define I40E_XDP_CONSUMED	BIT(0)
+#define I40E_XDP_TX		BIT(1)
+#define I40E_XDP_REDIR		BIT(2)
 
 static int i40e_xmit_xdp_ring(struct xdp_buff *xdp,
 			      struct i40e_ring *xdp_ring);
@@ -2235,7 +2236,7 @@ static struct sk_buff *i40e_run_xdp(struct i40e_ring *rx_ring,
 		break;
 	case XDP_REDIRECT:
 		err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
-		result = !err ? I40E_XDP_TX : I40E_XDP_CONSUMED;
+		result = !err ? I40E_XDP_REDIR : I40E_XDP_CONSUMED;
 		break;
 	default:
 		bpf_warn_invalid_xdp_action(act);
@@ -2298,7 +2299,8 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 	unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 	struct sk_buff *skb = rx_ring->skb;
 	u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
-	bool failure = false, xdp_xmit = false;
+	unsigned int xdp_xmit = 0;
+	bool failure = false;
 	struct xdp_buff xdp;
 
 	xdp.rxq = &rx_ring->xdp_rxq;
@@ -2359,8 +2361,10 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		}
 
 		if (IS_ERR(skb)) {
-			if (PTR_ERR(skb) == -I40E_XDP_TX) {
-				xdp_xmit = true;
+			unsigned int xdp_res = -PTR_ERR(skb);
+
+			if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR)) {
+				xdp_xmit |= xdp_res;
 				i40e_rx_buffer_flip(rx_ring, rx_buffer, size);
 			} else {
 				rx_buffer->pagecnt_bias++;
@@ -2414,12 +2418,14 @@ static int i40e_clean_rx_irq(struct i40e_ring *rx_ring, int budget)
 		total_rx_packets++;
 	}
 
-	if (xdp_xmit) {
+	if (xdp_xmit & I40E_XDP_REDIR)
+		xdp_do_flush_map();
+
+	if (xdp_xmit & I40E_XDP_TX) {
 		struct i40e_ring *xdp_ring =
 			rx_ring->vsi->xdp_rings[rx_ring->queue_index];
 
 		i40e_xdp_ring_update_tail(xdp_ring);
-		xdp_do_flush_map();
 	}
 
 	rx_ring->skb = skb;
-- 
2.17.1