ice: xsk: drop power of 2 ring size restriction for AF_XDP

[ Upstream commit b3056ae ]

We had multiple customers in the past months that reported commit
296f13f ("ice: xsk: Force rings to be sized to power of 2")
makes them unable to use ring size of 8160 in conjunction with AF_XDP.
Remove this restriction.

Fixes: 296f13f ("ice: xsk: Force rings to be sized to power of 2")
CC: Alasdair McWilliam <alasdair.mcwilliam@outlook.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: George Kuruvinakunnel <george.kuruvinakunnel@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: mfijalko

drivers/net/ethernet/intel/ice/ice_xsk.c

@@ -392,13 +392,6 @@ int ice_xsk_pool_setup(struct ice_vsi *vsi, struct xsk_buff_pool *pool, u16 qid)
 		goto failure;
 	}
 
-	if (!is_power_of_2(vsi->rx_rings[qid]->count) ||
-	    !is_power_of_2(vsi->tx_rings[qid]->count)) {
-		netdev_err(vsi->netdev, "Please align ring sizes to power of 2\n");
-		pool_failure = -EINVAL;
-		goto failure;
-	}
-
 	if_running = netif_running(vsi->netdev) && ice_is_xdp_ena_vsi(vsi);
 
 	if (if_running) {
@@ -534,11 +527,10 @@ static bool __ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
 bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count)
 {
 	u16 rx_thresh = ICE_RING_QUARTER(rx_ring);
-	u16 batched, leftover, i, tail_bumps;
+	u16 leftover, i, tail_bumps;
 
-	batched = ALIGN_DOWN(count, rx_thresh);
-	tail_bumps = batched / rx_thresh;
-	leftover = count & (rx_thresh - 1);
+	tail_bumps = count / rx_thresh;
+	leftover = count - (tail_bumps * rx_thresh);
 
 	for (i = 0; i < tail_bumps; i++)
 		if (!__ice_alloc_rx_bufs_zc(rx_ring, rx_thresh))
@@ -1037,14 +1029,16 @@ bool ice_xsk_any_rx_ring_ena(struct ice_vsi *vsi)
  */
 void ice_xsk_clean_rx_ring(struct ice_rx_ring *rx_ring)
 {
-	u16 count_mask = rx_ring->count - 1;
 	u16 ntc = rx_ring->next_to_clean;
 	u16 ntu = rx_ring->next_to_use;
 
-	for ( ; ntc != ntu; ntc = (ntc + 1) & count_mask) {
+	while (ntc != ntu) {
 		struct xdp_buff *xdp = *ice_xdp_buf(rx_ring, ntc);
 
 		xsk_buff_free(xdp);
+		ntc++;
+		if (ntc >= rx_ring->count)
+			ntc = 0;
 	}
 }