From 730b3ab54af4f816cdf541a23c879c9379a480db Mon Sep 17 00:00:00 2001
From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Mon, 15 May 2017 17:55:23 -0700
Subject: [PATCH] nfp: eliminate an if statement in calculation of completed
frames
Given that our rings are always a power of 2, we can simplify the
calculation of number of completed TX descriptors by using masking
instead of if statement based on whether the index have wrapped
or not.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index c64514f8ee65b..da83e17b8b206 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -940,10 +940,7 @@ static void nfp_net_tx_complete(struct nfp_net_tx_ring *tx_ring)
if (qcp_rd_p == tx_ring->qcp_rd_p)
return;
- if (qcp_rd_p > tx_ring->qcp_rd_p)
- todo = qcp_rd_p - tx_ring->qcp_rd_p;
- else
- todo = qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p;
+ todo = D_IDX(tx_ring, qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p);
while (todo--) {
idx = D_IDX(tx_ring, tx_ring->rd_p++);
@@ -1014,10 +1011,7 @@ static bool nfp_net_xdp_complete(struct nfp_net_tx_ring *tx_ring)
if (qcp_rd_p == tx_ring->qcp_rd_p)
return true;
- if (qcp_rd_p > tx_ring->qcp_rd_p)
- todo = qcp_rd_p - tx_ring->qcp_rd_p;
- else
- todo = qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p;
+ todo = D_IDX(tx_ring, qcp_rd_p + tx_ring->cnt - tx_ring->qcp_rd_p);
done_all = todo <= NFP_NET_XDP_MAX_COMPLETE;
todo = min(todo, NFP_NET_XDP_MAX_COMPLETE);
--
2.30.2