net: netsec: add xdp tx return bulking support

Convert netsec driver to xdp_return_frame_bulk APIs.
Rely on xdp_return_frame_rx_napi for XDP_TX in order to try to recycle
the page in the "in-irq" page_pool cache.
Co-developed-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/01487b8f5167d62649339469cdd0c6d8df885902.1605605531.git.lorenzo@kernel.orgSigned-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/socionext/netsec.c

@@ -631,6 +631,7 @@ static void netsec_set_rx_de(struct netsec_priv *priv,
 static bool netsec_clean_tx_dring(struct netsec_priv *priv)
 {
 	struct netsec_desc_ring *dring = &priv->desc_ring[NETSEC_RING_TX];
+	struct xdp_frame_bulk bq;
 	struct netsec_de *entry;
 	int tail = dring->tail;
 	unsigned int bytes;
@@ -639,8 +640,11 @@ static bool netsec_clean_tx_dring(struct netsec_priv *priv)
 	spin_lock(&dring->lock);
 
 	bytes = 0;
+	xdp_frame_bulk_init(&bq);
 	entry = dring->vaddr + DESC_SZ * tail;
 
+	rcu_read_lock(); /* need for xdp_return_frame_bulk */
+
 	while (!(entry->attr & (1U << NETSEC_TX_SHIFT_OWN_FIELD)) &&
 	       cnt < DESC_NUM) {
 		struct netsec_desc *desc;
@@ -665,7 +669,10 @@ static bool netsec_clean_tx_dring(struct netsec_priv *priv)
 			dev_kfree_skb(desc->skb);
 		} else {
 			bytes += desc->xdpf->len;
-			xdp_return_frame(desc->xdpf);
+			if (desc->buf_type == TYPE_NETSEC_XDP_TX)
+				xdp_return_frame_rx_napi(desc->xdpf);
+			else
+				xdp_return_frame_bulk(desc->xdpf, &bq);
 		}
 next:
 		/* clean up so netsec_uninit_pkt_dring() won't free the skb
@@ -684,6 +691,9 @@ static bool netsec_clean_tx_dring(struct netsec_priv *priv)
 		entry = dring->vaddr + DESC_SZ * tail;
 		cnt++;
 	}
+	xdp_flush_frame_bulk(&bq);
+
+	rcu_read_unlock();
 
 	spin_unlock(&dring->lock);