There are three sites that configure the hardware for the receive
buffer size using the same logic to determine the buffer size.
Add a helper so there is only one copy of this code.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 54 ++++++++-----------
 1 file changed, 21 insertions(+), 33 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 787b02c2607a..47b536c15c0e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -393,6 +393,24 @@ static void stmmac_set_queue_rx_tail_ptr(struct stmmac_priv *priv,
 	stmmac_set_rx_tail_ptr(priv, priv->ioaddr, rx_tail_addr, chan);
 }
 
+static void stmmac_set_queue_rx_buf_size(struct stmmac_priv *priv,
+					 struct stmmac_rx_queue *rx_q,
+					 unsigned int chan)
+{
+	u32 buf_size;
+
+	if (rx_q->xsk_pool && rx_q->buf_alloc_num) {
+		buf_size = xsk_pool_get_rx_frame_size(rx_q->xsk_pool);
+		stmmac_set_dma_bfsize(priv, priv->ioaddr,
+				      buf_size,
+				      rx_q->queue_index);
+	} else {
+		stmmac_set_dma_bfsize(priv, priv->ioaddr,
+				      priv->dma_conf.dma_buf_sz,
+				      rx_q->queue_index);
+	}
+}
+
 /**
  * stmmac_rx_dirty - Get RX queue dirty
  * @priv: driver private structure
@@ -2605,23 +2623,13 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
 	/* configure all channels */
 	for (chan = 0; chan < rx_channels_count; chan++) {
 		struct stmmac_rx_queue *rx_q = &priv->dma_conf.rx_queue[chan];
-		u32 buf_size;
 
 		qmode = priv->plat->rx_queues_cfg[chan].mode_to_use;
 
 		stmmac_dma_rx_mode(priv, priv->ioaddr, rxmode, chan,
 				rxfifosz, qmode);
 
-		if (rx_q->xsk_pool && rx_q->buf_alloc_num) {
-			buf_size = xsk_pool_get_rx_frame_size(rx_q->xsk_pool);
-			stmmac_set_dma_bfsize(priv, priv->ioaddr,
-					      buf_size,
-					      chan);
-		} else {
-			stmmac_set_dma_bfsize(priv, priv->ioaddr,
-					      priv->dma_conf.dma_buf_sz,
-					      chan);
-		}
+		stmmac_set_queue_rx_buf_size(priv, rx_q, chan);
 	}
 
 	for (chan = 0; chan < tx_channels_count; chan++) {
@@ -6935,7 +6943,6 @@ void stmmac_enable_rx_queue(struct stmmac_priv *priv, u32 queue)
 	struct stmmac_rx_queue *rx_q = &priv->dma_conf.rx_queue[queue];
 	struct stmmac_channel *ch = &priv->channel[queue];
 	unsigned long flags;
-	u32 buf_size;
 	int ret;
 
 	ret = __alloc_dma_rx_desc_resources(priv, &priv->dma_conf, queue);
@@ -6960,16 +6967,7 @@ void stmmac_enable_rx_queue(struct stmmac_priv *priv, u32 queue)
 	stmmac_set_queue_rx_tail_ptr(priv, rx_q, rx_q->queue_index,
 				     rx_q->buf_alloc_num);
 
-	if (rx_q->xsk_pool && rx_q->buf_alloc_num) {
-		buf_size = xsk_pool_get_rx_frame_size(rx_q->xsk_pool);
-		stmmac_set_dma_bfsize(priv, priv->ioaddr,
-				      buf_size,
-				      rx_q->queue_index);
-	} else {
-		stmmac_set_dma_bfsize(priv, priv->ioaddr,
-				      priv->dma_conf.dma_buf_sz,
-				      rx_q->queue_index);
-	}
+	stmmac_set_queue_rx_buf_size(priv, rx_q, rx_q->queue_index);
 
 	stmmac_start_rx_dma(priv, queue);
 
@@ -7072,7 +7070,6 @@ int stmmac_xdp_open(struct net_device *dev)
 	u8 dma_csr_ch = max(rx_cnt, tx_cnt);
 	struct stmmac_rx_queue *rx_q;
 	struct stmmac_tx_queue *tx_q;
-	u32 buf_size;
 	bool sph_en;
 	u8 chan;
 	int ret;
@@ -7112,16 +7109,7 @@ int stmmac_xdp_open(struct net_device *dev)
 		stmmac_set_queue_rx_tail_ptr(priv, rx_q, chan,
 					     rx_q->buf_alloc_num);
 
-		if (rx_q->xsk_pool && rx_q->buf_alloc_num) {
-			buf_size = xsk_pool_get_rx_frame_size(rx_q->xsk_pool);
-			stmmac_set_dma_bfsize(priv, priv->ioaddr,
-					      buf_size,
-					      rx_q->queue_index);
-		} else {
-			stmmac_set_dma_bfsize(priv, priv->ioaddr,
-					      priv->dma_conf.dma_buf_sz,
-					      rx_q->queue_index);
-		}
+		stmmac_set_queue_rx_buf_size(priv, rx_q, chan);
 
 		stmmac_enable_sph(priv, priv->ioaddr, sph_en, chan);
 	}
-- 
2.47.3