From 730b3ab54af4f816cdf541a23c879c9379a480db Mon Sep 17 00:00:00 2001 From: Jakub Kicinski 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 Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- 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 c64514f..da83e17 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); -- 2.7.4