From: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Date: Wed, 13 Apr 2022 17:30:14 +0200
Subject: ice, xsk: Avoid refilling single Rx descriptors
Patch-mainline: v5.19-rc1
Git-commit: 4efad196163f4302c5cdc020899074b174eaf956
References: jsc#PED-376

Call alloc Rx routine for ZC driver only when the amount of unallocated
descriptors exceeds given threshold.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220413153015.453864-14-maciej.fijalkowski@intel.com
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/ice/ice_xsk.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/ice/ice_xsk.c
+++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
@@ -592,6 +592,7 @@ int ice_clean_rx_irq_zc(struct ice_rx_ri
 	unsigned int xdp_xmit = 0;
 	struct bpf_prog *xdp_prog;
 	bool failure = false;
+	int entries_to_alloc;
 
 	/* ZC patch is enabled only when XDP program is set,
 	 * so here it can not be NULL
@@ -683,7 +684,9 @@ construct_skb:
 		ice_receive_skb(rx_ring, skb, vlan_tag);
 	}
 
-	failure |= !ice_alloc_rx_bufs_zc(rx_ring, ICE_DESC_UNUSED(rx_ring));
+	entries_to_alloc = ICE_DESC_UNUSED(rx_ring);
+	if (entries_to_alloc > ICE_RING_QUARTER(rx_ring))
+		failure |= !ice_alloc_rx_bufs_zc(rx_ring, entries_to_alloc);
 
 	ice_finalize_xdp_rx(xdp_ring, xdp_xmit);
 	ice_update_rx_ring_stats(rx_ring, total_rx_packets, total_rx_bytes);