net: macb: make macb_tx_skb generic

The macb_tx_skb structure is renamed to macb_tx_buff with
no functional changes.

This is a preparatory step for adding xdp xmit support.

Signed-off-by: Paolo Valerio <pvalerio@redhat.com>

Author: vlrpl

drivers/net/ethernet/cadence/macb.h

@@ -988,15 +988,15 @@ struct macb_dma_desc_ptp {
 /* Scaled PPM fraction */
 #define PPM_FRACTION	16
 
-/* struct macb_tx_skb - data about an skb which is being transmitted
+/* struct macb_tx_buff - data about an skb which is being transmitted
  * @skb: skb currently being transmitted, only set for the last buffer
  *       of the frame
  * @mapping: DMA address of the skb's fragment buffer
  * @size: size of the DMA mapped buffer
  * @mapped_as_page: true when buffer was mapped with skb_frag_dma_map(),
  *                  false when buffer was mapped with dma_map_single()
  */
-struct macb_tx_skb {
+struct macb_tx_buff {
 	struct sk_buff		*skb;
 	dma_addr_t		mapping;
 	size_t			size;
@@ -1290,7 +1290,7 @@ struct macb_queue {
 	spinlock_t		tx_ptr_lock;
 	unsigned int		tx_head, tx_tail;
 	struct macb_dma_desc	*tx_ring;
-	struct macb_tx_skb	*tx_skb;
+	struct macb_tx_buff	*tx_buff;
 	dma_addr_t		tx_ring_dma;
 	struct work_struct	tx_error_task;
 	bool			txubr_pending;
@@ -1376,7 +1376,7 @@ struct macb {
 	int			phy_reset_ms;
 
 	/* AT91RM9200 transmit queue (1 on wire + 1 queued) */
-	struct macb_tx_skb	rm9200_txq[2];
+	struct macb_tx_buff	rm9200_txq[2];
 	unsigned int		max_tx_length;
 
 	u64			ethtool_stats[GEM_STATS_LEN + QUEUE_STATS_LEN * MACB_MAX_QUEUES];

drivers/net/ethernet/cadence/macb_main.c

@@ -191,10 +191,10 @@ static struct macb_dma_desc *macb_tx_desc(struct macb_queue *queue,
 	return &queue->tx_ring[index];
 }
 
-static struct macb_tx_skb *macb_tx_skb(struct macb_queue *queue,
-				       unsigned int index)
+static struct macb_tx_buff *macb_tx_buff(struct macb_queue *queue,
+					 unsigned int index)
 {
-	return &queue->tx_skb[macb_tx_ring_wrap(queue->bp, index)];
+	return &queue->tx_buff[macb_tx_ring_wrap(queue->bp, index)];
 }
 
 static dma_addr_t macb_tx_dma(struct macb_queue *queue, unsigned int index)
@@ -1136,21 +1136,21 @@ static int macb_halt_tx(struct macb *bp)
 					bp, TSR);
 }
 
-static void macb_tx_unmap(struct macb *bp, struct macb_tx_skb *tx_skb, int budget)
+static void macb_tx_unmap(struct macb *bp, struct macb_tx_buff *tx_buff, int budget)
 {
-	if (tx_skb->mapping) {
-		if (tx_skb->mapped_as_page)
-			dma_unmap_page(&bp->pdev->dev, tx_skb->mapping,
-				       tx_skb->size, DMA_TO_DEVICE);
+	if (tx_buff->mapping) {
+		if (tx_buff->mapped_as_page)
+			dma_unmap_page(&bp->pdev->dev, tx_buff->mapping,
+				       tx_buff->size, DMA_TO_DEVICE);
 		else
-			dma_unmap_single(&bp->pdev->dev, tx_skb->mapping,
-					 tx_skb->size, DMA_TO_DEVICE);
-		tx_skb->mapping = 0;
+			dma_unmap_single(&bp->pdev->dev, tx_buff->mapping,
+					 tx_buff->size, DMA_TO_DEVICE);
+		tx_buff->mapping = 0;
 	}
 
-	if (tx_skb->skb) {
-		napi_consume_skb(tx_skb->skb, budget);
-		tx_skb->skb = NULL;
+	if (tx_buff->skb) {
+		napi_consume_skb(tx_buff->skb, budget);
+		tx_buff->skb = NULL;
 	}
 }
 
@@ -1200,7 +1200,7 @@ static void macb_tx_error_task(struct work_struct *work)
 	u32			queue_index;
 	u32			packets = 0;
 	u32			bytes = 0;
-	struct macb_tx_skb	*tx_skb;
+	struct macb_tx_buff	*tx_buff;
 	struct macb_dma_desc	*desc;
 	struct sk_buff		*skb;
 	unsigned int		tail;
@@ -1240,16 +1240,16 @@ static void macb_tx_error_task(struct work_struct *work)
 
 		desc = macb_tx_desc(queue, tail);
 		ctrl = desc->ctrl;
-		tx_skb = macb_tx_skb(queue, tail);
-		skb = tx_skb->skb;
+		tx_buff = macb_tx_buff(queue, tail);
+		skb = tx_buff->skb;
 
 		if (ctrl & MACB_BIT(TX_USED)) {
 			/* skb is set for the last buffer of the frame */
 			while (!skb) {
-				macb_tx_unmap(bp, tx_skb, 0);
+				macb_tx_unmap(bp, tx_buff, 0);
 				tail++;
-				tx_skb = macb_tx_skb(queue, tail);
-				skb = tx_skb->skb;
+				tx_buff = macb_tx_buff(queue, tail);
+				skb = tx_buff->skb;
 			}
 
 			/* ctrl still refers to the first buffer descriptor
@@ -1278,7 +1278,7 @@ static void macb_tx_error_task(struct work_struct *work)
 			desc->ctrl = ctrl | MACB_BIT(TX_USED);
 		}
 
-		macb_tx_unmap(bp, tx_skb, 0);
+		macb_tx_unmap(bp, tx_buff, 0);
 	}
 
 	netdev_tx_completed_queue(netdev_get_tx_queue(bp->dev, queue_index),
@@ -1356,7 +1356,7 @@ static int macb_tx_complete(struct macb_queue *queue, int budget)
 	spin_lock_irqsave(&queue->tx_ptr_lock, flags);
 	head = queue->tx_head;
 	for (tail = queue->tx_tail; tail != head && packets < budget; tail++) {
-		struct macb_tx_skb	*tx_skb;
+		struct macb_tx_buff	*tx_buff;
 		struct sk_buff		*skb;
 		struct macb_dma_desc	*desc;
 		u32			ctrl;
@@ -1376,8 +1376,8 @@ static int macb_tx_complete(struct macb_queue *queue, int budget)
 
 		/* Process all buffers of the current transmitted frame */
 		for (;; tail++) {
-			tx_skb = macb_tx_skb(queue, tail);
-			skb = tx_skb->skb;
+			tx_buff = macb_tx_buff(queue, tail);
+			skb = tx_buff->skb;
 
 			/* First, update TX stats if needed */
 			if (skb) {
@@ -1397,7 +1397,7 @@ static int macb_tx_complete(struct macb_queue *queue, int budget)
 			}
 
 			/* Now we can safely release resources */
-			macb_tx_unmap(bp, tx_skb, budget);
+			macb_tx_unmap(bp, tx_buff, budget);
 
 			/* skb is set only for the last buffer of the frame.
 			 * WARNING: at this point skb has been freed by
@@ -2279,13 +2279,13 @@ static unsigned int macb_tx_map(struct macb *bp,
 				unsigned int hdrlen)
 {
 	dma_addr_t mapping;
+	unsigned int f, nr_frags = skb_shinfo(skb)->nr_frags;
 	unsigned int len, entry, i, tx_head = queue->tx_head;
-	struct macb_tx_skb *tx_skb = NULL;
+	u32 ctrl, lso_ctrl = 0, seq_ctrl = 0;
+	struct macb_tx_buff *tx_buff = NULL;
+	unsigned int eof = 1, mss_mfs = 0;
 	struct macb_dma_desc *desc;
 	unsigned int offset, size, count = 0;
-	unsigned int f, nr_frags = skb_shinfo(skb)->nr_frags;
-	unsigned int eof = 1, mss_mfs = 0;
-	u32 ctrl, lso_ctrl = 0, seq_ctrl = 0;
 
 	/* LSO */
 	if (skb_shinfo(skb)->gso_size != 0) {
@@ -2305,8 +2305,7 @@ static unsigned int macb_tx_map(struct macb *bp,
 
 	offset = 0;
 	while (len) {
-		entry = macb_tx_ring_wrap(bp, tx_head);
-		tx_skb = &queue->tx_skb[entry];
+		tx_buff = macb_tx_buff(queue, tx_head);
 
 		mapping = dma_map_single(&bp->pdev->dev,
 					 skb->data + offset,
@@ -2315,10 +2314,10 @@ static unsigned int macb_tx_map(struct macb *bp,
 			goto dma_error;
 
 		/* Save info to properly release resources */
-		tx_skb->skb = NULL;
-		tx_skb->mapping = mapping;
-		tx_skb->size = size;
-		tx_skb->mapped_as_page = false;
+		tx_buff->skb = NULL;
+		tx_buff->mapping = mapping;
+		tx_buff->size = size;
+		tx_buff->mapped_as_page = false;
 
 		len -= size;
 		offset += size;
@@ -2336,19 +2335,18 @@ static unsigned int macb_tx_map(struct macb *bp,
 		offset = 0;
 		while (len) {
 			size = min(len, bp->max_tx_length);
-			entry = macb_tx_ring_wrap(bp, tx_head);
-			tx_skb = &queue->tx_skb[entry];
+			tx_buff = macb_tx_buff(queue, tx_head);
 
 			mapping = skb_frag_dma_map(&bp->pdev->dev, frag,
 						   offset, size, DMA_TO_DEVICE);
 			if (dma_mapping_error(&bp->pdev->dev, mapping))
 				goto dma_error;
 
 			/* Save info to properly release resources */
-			tx_skb->skb = NULL;
-			tx_skb->mapping = mapping;
-			tx_skb->size = size;
-			tx_skb->mapped_as_page = true;
+			tx_buff->skb = NULL;
+			tx_buff->mapping = mapping;
+			tx_buff->size = size;
+			tx_buff->mapped_as_page = true;
 
 			len -= size;
 			offset += size;
@@ -2358,13 +2356,13 @@ static unsigned int macb_tx_map(struct macb *bp,
 	}
 
 	/* Should never happen */
-	if (unlikely(!tx_skb)) {
+	if (unlikely(!tx_buff)) {
 		netdev_err(bp->dev, "BUG! empty skb!\n");
 		return 0;
 	}
 
 	/* This is the last buffer of the frame: save socket buffer */
-	tx_skb->skb = skb;
+	tx_buff->skb = skb;
 
 	/* Update TX ring: update buffer descriptors in reverse order
 	 * to avoid race condition
@@ -2396,11 +2394,10 @@ static unsigned int macb_tx_map(struct macb *bp,
 
 	do {
 		i--;
-		entry = macb_tx_ring_wrap(bp, i);
-		tx_skb = &queue->tx_skb[entry];
-		desc = macb_tx_desc(queue, entry);
+		tx_buff = macb_tx_buff(queue, i);
+		desc = macb_tx_desc(queue, i);
 
-		ctrl = (u32)tx_skb->size;
+		ctrl = (u32)tx_buff->size;
 		if (eof) {
 			ctrl |= MACB_BIT(TX_LAST);
 			eof = 0;
@@ -2423,7 +2420,7 @@ static unsigned int macb_tx_map(struct macb *bp,
 			ctrl |= MACB_BF(MSS_MFS, mss_mfs);
 
 		/* Set TX buffer descriptor */
-		macb_set_addr(bp, desc, tx_skb->mapping);
+		macb_set_addr(bp, desc, tx_buff->mapping);
 		/* desc->addr must be visible to hardware before clearing
 		 * 'TX_USED' bit in desc->ctrl.
 		 */
@@ -2439,9 +2436,9 @@ static unsigned int macb_tx_map(struct macb *bp,
 	netdev_err(bp->dev, "TX DMA map failed\n");
 
 	for (i = queue->tx_head; i != tx_head; i++) {
-		tx_skb = macb_tx_skb(queue, i);
+		tx_buff = macb_tx_buff(queue, i);
 
-		macb_tx_unmap(bp, tx_skb, 0);
+		macb_tx_unmap(bp, tx_buff, 0);
 	}
 
 	return 0;
@@ -2771,8 +2768,8 @@ static void macb_free_consistent(struct macb *bp)
 	dma_free_coherent(dev, size, bp->queues[0].rx_ring, bp->queues[0].rx_ring_dma);
 
 	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
-		kfree(queue->tx_skb);
-		queue->tx_skb = NULL;
+		kfree(queue->tx_buff);
+		queue->tx_buff = NULL;
 		queue->tx_ring = NULL;
 		queue->rx_ring = NULL;
 	}
@@ -2850,9 +2847,9 @@ static int macb_alloc_consistent(struct macb *bp)
 		queue->rx_ring = rx + macb_rx_ring_size_per_queue(bp) * q;
 		queue->rx_ring_dma = rx_dma + macb_rx_ring_size_per_queue(bp) * q;
 
-		size = bp->tx_ring_size * sizeof(struct macb_tx_skb);
-		queue->tx_skb = kmalloc(size, GFP_KERNEL);
-		if (!queue->tx_skb)
+		size = bp->tx_ring_size * sizeof(struct macb_tx_buff);
+		queue->tx_buff = kmalloc(size, GFP_KERNEL);
+		if (!queue->tx_buff)
 			goto out_err;
 	}