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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>
This commit is contained in:
Jakub Kicinski 2017-05-15 17:55:23 -07:00 committed by David S. Miller
parent 4aa3b7660a
commit 730b3ab54a
1 changed files with 2 additions and 8 deletions
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10
drivers/net/ethernet/netronome/nfp/nfp_net_common.c
View File

@ -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);