Merge branch 'xsk: another round of fixes'

Maciej Fijalkowski says:

====================

Hello,

yet another fixes for XSK from Magnus and me.

Magnus addresses the fact that xp_alloc() can return NULL, so this needs
to be handled to avoid clearing entries in the SW ring on driver side.
Then he addresses the off-by-one problem in Tx desc cleaning routine for
ice ZC driver.

From my side, I am adding protection to ZC Rx processing loop so that
cleaning of descriptors wouldn't go over already processed entries.
Then I also fix an issue with assigning XSK pool to Tx queues.

This is directed to bpf tree.

Thanks!

Maciej Fijalkowski (2):
  ice: xsk: stop Rx processing when ntc catches ntu
  ice: xsk: fix indexing in ice_tx_xsk_pool()
====================

Acked-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Author: Alexei Starovoitov

drivers/net/ethernet/intel/ice/ice.h

@@ -710,7 +710,7 @@ static inline struct xsk_buff_pool *ice_tx_xsk_pool(struct ice_tx_ring *ring)
 	struct ice_vsi *vsi = ring->vsi;
 	u16 qid;
 
-	qid = ring->q_index - vsi->num_xdp_txq;
+	qid = ring->q_index - vsi->alloc_txq;
 
 	if (!ice_is_xdp_ena_vsi(vsi) || !test_bit(qid, vsi->af_xdp_zc_qps))
 		return NULL;

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

@@ -608,6 +608,9 @@ int ice_clean_rx_irq_zc(struct ice_rx_ring *rx_ring, int budget)
 		 */
 		dma_rmb();
 
+		if (unlikely(rx_ring->next_to_clean == rx_ring->next_to_use))
+			break;
+
 		xdp = *ice_xdp_buf(rx_ring, rx_ring->next_to_clean);
 
 		size = le16_to_cpu(rx_desc->wb.pkt_len) &
@@ -754,7 +757,7 @@ static u16 ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring, int napi_budget)
 		next_dd = next_dd + tx_thresh;
 		if (next_dd >= desc_cnt)
 			next_dd = tx_thresh - 1;
-	} while (budget--);
+	} while (--budget);
 
 	xdp_ring->next_dd = next_dd;
 

net/xdp/xsk_buff_pool.c

@@ -591,9 +591,13 @@ u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 	u32 nb_entries1 = 0, nb_entries2;
 
 	if (unlikely(pool->dma_need_sync)) {
+		struct xdp_buff *buff;
+
 		/* Slow path */
-		*xdp = xp_alloc(pool);
-		return !!*xdp;
+		buff = xp_alloc(pool);
+		if (buff)
+			*xdp = buff;
+		return !!buff;
 	}
 
 	if (unlikely(pool->free_list_cnt)) {