[PATCH net-next v4 06/15] net: stmmac: add helper to set receive tail pointer

["Russell King (Oracle)" <rmk+kernel@armlinux.org.uk>]

Setting the queue receive tail pointer follows a common pattern:
calculate the DMA address, and then call stmmac_set_rx_tail_ptr().
The only difference between all the call sites is the index used.

Factor this out into a static function, and add a comment about why
it only uses the normal descriptor size.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 40 +++++++++----------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index dca62e7b259a..8823f8f5b053 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -380,6 +380,18 @@ static struct dma_desc *stmmac_get_rx_desc(struct stmmac_priv *priv,
 		return &rx_q->dma_rx[index];
 }
 
+static void stmmac_set_queue_rx_tail_ptr(struct stmmac_priv *priv,
+					 struct stmmac_rx_queue *rx_q,
+					 unsigned int chan, unsigned int index)
+{
+	/* This only needs to deal with normal descriptors as enhanced
+	 * descriptiors are only supported with dwmac1000 (<v4.0) which
+	 * does not implement .set_rx_tail_ptr
+	 */
+	rx_q->rx_tail_addr = rx_q->dma_rx_phy + index * sizeof(struct dma_desc);
+	stmmac_set_rx_tail_ptr(priv, priv->ioaddr, rx_q->rx_tail_addr, chan);
+}
+
 /**
  * stmmac_rx_dirty - Get RX queue dirty
  * @priv: driver private structure
@@ -3302,11 +3314,8 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 		stmmac_init_rx_chan(priv, priv->ioaddr, priv->plat->dma_cfg,
 				    rx_q->dma_rx_phy, chan);
 
-		rx_q->rx_tail_addr = rx_q->dma_rx_phy +
-				     (rx_q->buf_alloc_num *
-				      sizeof(struct dma_desc));
-		stmmac_set_rx_tail_ptr(priv, priv->ioaddr,
-				       rx_q->rx_tail_addr, chan);
+		stmmac_set_queue_rx_tail_ptr(priv, rx_q, chan,
+					     rx_q->buf_alloc_num);
 	}
 
 	/* DMA TX Channel Configuration */
@@ -4999,9 +5008,7 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv, u32 queue)
 		entry = STMMAC_GET_ENTRY(entry, priv->dma_conf.dma_rx_size);
 	}
 	rx_q->dirty_rx = entry;
-	rx_q->rx_tail_addr = rx_q->dma_rx_phy +
-			    (rx_q->dirty_rx * sizeof(struct dma_desc));
-	stmmac_set_rx_tail_ptr(priv, priv->ioaddr, rx_q->rx_tail_addr, queue);
+	stmmac_set_queue_rx_tail_ptr(priv, rx_q, queue, rx_q->dirty_rx);
 	/* Wake up Rx DMA from the suspend state if required */
 	stmmac_enable_dma_reception(priv, priv->ioaddr, queue);
 }
@@ -5381,9 +5388,7 @@ static bool stmmac_rx_refill_zc(struct stmmac_priv *priv, u32 queue, u32 budget)
 
 	if (rx_desc) {
 		rx_q->dirty_rx = entry;
-		rx_q->rx_tail_addr = rx_q->dma_rx_phy +
-				     (rx_q->dirty_rx * sizeof(struct dma_desc));
-		stmmac_set_rx_tail_ptr(priv, priv->ioaddr, rx_q->rx_tail_addr, queue);
+		stmmac_set_queue_rx_tail_ptr(priv, rx_q, queue, rx_q->dirty_rx);
 	}
 
 	return ret;
@@ -6951,10 +6956,8 @@ void stmmac_enable_rx_queue(struct stmmac_priv *priv, u32 queue)
 	stmmac_init_rx_chan(priv, priv->ioaddr, priv->plat->dma_cfg,
 			    rx_q->dma_rx_phy, rx_q->queue_index);
 
-	rx_q->rx_tail_addr = rx_q->dma_rx_phy + (rx_q->buf_alloc_num *
-			     sizeof(struct dma_desc));
-	stmmac_set_rx_tail_ptr(priv, priv->ioaddr,
-			       rx_q->rx_tail_addr, rx_q->queue_index);
+	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);
@@ -7105,11 +7108,8 @@ int stmmac_xdp_open(struct net_device *dev)
 		stmmac_init_rx_chan(priv, priv->ioaddr, priv->plat->dma_cfg,
 				    rx_q->dma_rx_phy, chan);
 
-		rx_q->rx_tail_addr = rx_q->dma_rx_phy +
-				     (rx_q->buf_alloc_num *
-				      sizeof(struct dma_desc));
-		stmmac_set_rx_tail_ptr(priv, priv->ioaddr,
-				       rx_q->rx_tail_addr, chan);
+		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);
-- 
2.47.3