net: fec: add fec_alloc_rxq_buffers_pp() to allocate buffers from page pool

Currently, the buffers of RX queue are allocated from the page pool. In
the subsequent patches to support XDP zero copy, the RX buffers will be
allocated from the UMEM. Therefore, extract fec_alloc_rxq_buffers_pp()
from fec_enet_alloc_rxq_buffers() and we will add another helper to
allocate RX buffers from UMEM for the XDP zero copy mode. In addition,
fec_alloc_rxq_buffers_pp() only initializes bdp->bufaddr and does not
initialize other fields of bdp, because these will be initialized in
fec_enet_bd_init().

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-14-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: WeiFang-NXP

drivers/net/ethernet/freescale/fec_main.c

@@ -990,6 +990,13 @@ static void fec_enet_bd_init(struct net_device *dev)
 				bdp->cbd_sc = cpu_to_fec16(BD_ENET_RX_EMPTY);
 			else
 				bdp->cbd_sc = cpu_to_fec16(0);
+
+			if (fep->bufdesc_ex) {
+				struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
+
+				ebdp->cbd_esc = cpu_to_fec32(BD_ENET_RX_INT);
+			}
+
 			bdp = fec_enet_get_nextdesc(bdp, &rxq->bd);
 		}
 
@@ -3436,6 +3443,24 @@ static void fec_xdp_rxq_info_unreg(struct fec_enet_priv_rx_q *rxq)
 	}
 }
 
+static void fec_free_rxq_buffers(struct fec_enet_priv_rx_q *rxq)
+{
+	int i;
+
+	for (i = 0; i < rxq->bd.ring_size; i++) {
+		struct page *page = rxq->rx_buf[i];
+
+		if (!page)
+			continue;
+
+		page_pool_put_full_page(rxq->page_pool, page, false);
+		rxq->rx_buf[i] = NULL;
+	}
+
+	page_pool_destroy(rxq->page_pool);
+	rxq->page_pool = NULL;
+}
+
 static void fec_enet_free_buffers(struct net_device *ndev)
 {
 	struct fec_enet_private *fep = netdev_priv(ndev);
@@ -3449,16 +3474,10 @@ static void fec_enet_free_buffers(struct net_device *ndev)
 		rxq = fep->rx_queue[q];
 
 		fec_xdp_rxq_info_unreg(rxq);
-
-		for (i = 0; i < rxq->bd.ring_size; i++)
-			page_pool_put_full_page(rxq->page_pool, rxq->rx_buf[i],
-						false);
+		fec_free_rxq_buffers(rxq);
 
 		for (i = 0; i < XDP_STATS_TOTAL; i++)
 			rxq->stats[i] = 0;
-
-		page_pool_destroy(rxq->page_pool);
-		rxq->page_pool = NULL;
 	}
 
 	for (q = 0; q < fep->num_tx_queues; q++) {
@@ -3557,22 +3576,18 @@ static int fec_enet_alloc_queue(struct net_device *ndev)
 	return ret;
 }
 
-static int
-fec_enet_alloc_rxq_buffers(struct net_device *ndev, unsigned int queue)
+static int fec_alloc_rxq_buffers_pp(struct fec_enet_private *fep,
+				    struct fec_enet_priv_rx_q *rxq)
 {
-	struct fec_enet_private *fep = netdev_priv(ndev);
-	struct fec_enet_priv_rx_q *rxq;
+	struct bufdesc *bdp = rxq->bd.base;
 	dma_addr_t phys_addr;
-	struct bufdesc	*bdp;
 	struct page *page;
 	int i, err;
 
-	rxq = fep->rx_queue[queue];
-	bdp = rxq->bd.base;
-
 	err = fec_enet_create_page_pool(fep, rxq);
 	if (err < 0) {
-		netdev_err(ndev, "%s failed queue %d (%d)\n", __func__, queue, err);
+		netdev_err(fep->netdev, "%s failed queue %d (%d)\n",
+			   __func__, rxq->bd.qid, err);
 		return err;
 	}
 
@@ -3591,36 +3606,47 @@ fec_enet_alloc_rxq_buffers(struct net_device *ndev, unsigned int queue)
 
 	for (i = 0; i < rxq->bd.ring_size; i++) {
 		page = page_pool_dev_alloc_pages(rxq->page_pool);
-		if (!page)
-			goto err_alloc;
+		if (!page) {
+			err = -ENOMEM;
+			goto free_rx_buffers;
+		}
 
 		phys_addr = page_pool_get_dma_addr(page) + FEC_ENET_XDP_HEADROOM;
 		bdp->cbd_bufaddr = cpu_to_fec32(phys_addr);
-
 		rxq->rx_buf[i] = page;
-		bdp->cbd_sc = cpu_to_fec16(BD_ENET_RX_EMPTY);
-
-		if (fep->bufdesc_ex) {
-			struct bufdesc_ex *ebdp = (struct bufdesc_ex *)bdp;
-			ebdp->cbd_esc = cpu_to_fec32(BD_ENET_RX_INT);
-		}
-
 		bdp = fec_enet_get_nextdesc(bdp, &rxq->bd);
 	}
 
-	/* Set the last buffer to wrap. */
-	bdp = fec_enet_get_prevdesc(bdp, &rxq->bd);
-	bdp->cbd_sc |= cpu_to_fec16(BD_ENET_RX_WRAP);
+	return 0;
+
+free_rx_buffers:
+	fec_free_rxq_buffers(rxq);
+
+	return err;
+}
+
+static int
+fec_enet_alloc_rxq_buffers(struct net_device *ndev, unsigned int queue)
+{
+	struct fec_enet_private *fep = netdev_priv(ndev);
+	struct fec_enet_priv_rx_q *rxq;
+	int err;
+
+	rxq = fep->rx_queue[queue];
+	err = fec_alloc_rxq_buffers_pp(fep, rxq);
+	if (err)
+		goto free_buffers;
 
 	err = fec_xdp_rxq_info_reg(fep, rxq);
 	if (err)
-		goto err_alloc;
+		goto free_buffers;
 
 	return 0;
 
- err_alloc:
+free_buffers:
 	fec_enet_free_buffers(ndev);
-	return -ENOMEM;
+
+	return err;
 }
 
 static int