Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6db74704 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by David S. Miller
Browse files

ftgmac100: Add support for fragmented tx 



Add NETIF_F_SG and create multiple TX ring entries for skb fragments.

On reclaim, the skb is only freed on the segment marked as "last".

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e9245539

drivers/net/ethernet/faraday/ftgmac100.c

+94 −25
Original line number Diff line number Diff line
@@ -47,7 +47,7 @@ 
#define RX_BUF_SIZE		MAX_PKT_SIZE	/* must be smaller than 0x3fff */



/* Min number of tx ring entries before stopping queue */

#define TX_THRESHOLD		(1)

#define TX_THRESHOLD		(MAX_SKB_FRAGS + 1)



struct ftgmac100_descs {

	struct ftgmac100_rxdes rxdes[RX_QUEUE_ENTRIES];
@@ -489,20 +489,30 @@ static void ftgmac100_txdes_set_first_segment(struct ftgmac100_txdes *txdes) 
	txdes->txdes0 |= cpu_to_le32(FTGMAC100_TXDES0_FTS);

}



static inline bool ftgmac100_txdes_get_first_segment(struct ftgmac100_txdes *txdes)

{

	return (txdes->txdes0 & cpu_to_le32(FTGMAC100_TXDES0_FTS)) != 0;

}



static void ftgmac100_txdes_set_last_segment(struct ftgmac100_txdes *txdes)

{

	txdes->txdes0 |= cpu_to_le32(FTGMAC100_TXDES0_LTS);

}



static inline bool ftgmac100_txdes_get_last_segment(struct ftgmac100_txdes *txdes)

{

	return (txdes->txdes0 & cpu_to_le32(FTGMAC100_TXDES0_LTS)) != 0;

}



static void ftgmac100_txdes_set_buffer_size(struct ftgmac100_txdes *txdes,

					    unsigned int len)

{

	txdes->txdes0 |= cpu_to_le32(FTGMAC100_TXDES0_TXBUF_SIZE(len));

}



static void ftgmac100_txdes_set_txint(struct ftgmac100_txdes *txdes)

static inline unsigned int ftgmac100_txdes_get_buffer_size(struct ftgmac100_txdes *txdes)

{

	txdes->txdes1 |= cpu_to_le32(FTGMAC100_TXDES1_TXIC);

	return FTGMAC100_TXDES0_TXBUF_SIZE(cpu_to_le32(txdes->txdes0));

}



static void ftgmac100_txdes_set_tcpcs(struct ftgmac100_txdes *txdes)
@@ -528,7 +538,7 @@ static void ftgmac100_txdes_set_dma_addr(struct ftgmac100_txdes *txdes, 


static dma_addr_t ftgmac100_txdes_get_dma_addr(struct ftgmac100_txdes *txdes)

{

	return le32_to_cpu(txdes->txdes3);

	return (dma_addr_t)le32_to_cpu(txdes->txdes3);

}



static int ftgmac100_next_tx_pointer(int pointer)
@@ -558,12 +568,18 @@ static void ftgmac100_free_tx_packet(struct ftgmac100 *priv, 
				     struct sk_buff *skb,

				     struct ftgmac100_txdes *txdes)

{

	dma_addr_t map;



	map = ftgmac100_txdes_get_dma_addr(txdes);

	dma_addr_t map = ftgmac100_txdes_get_dma_addr(txdes);



	dma_unmap_single(priv->dev, map, skb_headlen(skb), DMA_TO_DEVICE);

	if (ftgmac100_txdes_get_first_segment(txdes)) {

		dma_unmap_single(priv->dev, map, skb_headlen(skb),

				 DMA_TO_DEVICE);

	} else {

		dma_unmap_page(priv->dev, map,

			       ftgmac100_txdes_get_buffer_size(txdes),

			       DMA_TO_DEVICE);

	}



	if (ftgmac100_txdes_get_last_segment(txdes))

		dev_kfree_skb(skb);

	priv->tx_skbs[pointer] = NULL;
@@ -626,8 +642,8 @@ static int ftgmac100_hard_start_xmit(struct sk_buff *skb, 
				     struct net_device *netdev)

{

	struct ftgmac100 *priv = netdev_priv(netdev);

	struct ftgmac100_txdes *txdes;

	unsigned int pointer;

	struct ftgmac100_txdes *txdes, *first;

	unsigned int pointer, nfrags, len, i, j;

	dma_addr_t map;



	/* The HW doesn't pad small frames */
@@ -643,26 +659,33 @@ static int ftgmac100_hard_start_xmit(struct sk_buff *skb, 
		goto drop;

	}



	map = dma_map_single(priv->dev, skb->data, skb_headlen(skb), DMA_TO_DEVICE);

	if (unlikely(dma_mapping_error(priv->dev, map))) {

		/* drop packet */

	/* Do we have a limit on #fragments ? I yet have to get a reply

	 * from Aspeed. If there's one I haven't hit it.

	 */

	nfrags = skb_shinfo(skb)->nr_frags;



	/* Get header len */

	len = skb_headlen(skb);



	/* Map the packet head */

	map = dma_map_single(priv->dev, skb->data, len, DMA_TO_DEVICE);

	if (dma_mapping_error(priv->dev, map)) {

		if (net_ratelimit())

			netdev_err(netdev, "map socket buffer failed\n");

			netdev_err(netdev, "map tx packet head failed\n");

		goto drop;

	}



	/* Grab the next free tx descriptor */

	pointer = priv->tx_pointer;

	txdes = &priv->descs->txdes[pointer];

	txdes = first = &priv->descs->txdes[pointer];



	/* setup TX descriptor */

	/* Setup it up with the packet head. We don't set the OWN bit yet. */

	priv->tx_skbs[pointer] = skb;

	ftgmac100_txdes_set_dma_addr(txdes, map);

	ftgmac100_txdes_set_buffer_size(txdes, skb->len);



	ftgmac100_txdes_set_buffer_size(txdes, len);

	ftgmac100_txdes_set_first_segment(txdes);

	ftgmac100_txdes_set_last_segment(txdes);

	ftgmac100_txdes_set_txint(txdes);



	/* Setup HW checksumming */

	if (skb->ip_summed == CHECKSUM_PARTIAL) {

		__be16 protocol = skb->protocol;
@@ -677,14 +700,41 @@ static int ftgmac100_hard_start_xmit(struct sk_buff *skb, 
		}

	}



	/* Next descriptor */

	pointer = ftgmac100_next_tx_pointer(pointer);



	/* Add the fragments */

	for (i = 0; i < nfrags; i++) {

		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];



		len = frag->size;



		/* Map it */

		map = skb_frag_dma_map(priv->dev, frag, 0, len,

				       DMA_TO_DEVICE);

		if (dma_mapping_error(priv->dev, map))

			goto dma_err;



		/* Setup descriptor */

		priv->tx_skbs[pointer] = skb;

		txdes = &priv->descs->txdes[pointer];

		ftgmac100_txdes_set_dma_addr(txdes, map);

		ftgmac100_txdes_set_buffer_size(txdes, len);

		ftgmac100_txdes_set_dma_own(txdes);

		pointer = ftgmac100_next_tx_pointer(pointer);

	}



	/* Tag last fragment */

	ftgmac100_txdes_set_last_segment(txdes);



	/* Order the previous packet and descriptor udpates

	 * before setting the OWN bit.

	 */

	dma_wmb();

	ftgmac100_txdes_set_dma_own(txdes);

	ftgmac100_txdes_set_dma_own(first);



	/* Update next TX pointer */

	priv->tx_pointer = ftgmac100_next_tx_pointer(pointer);

	priv->tx_pointer = pointer;



	/* If there isn't enough room for all the fragments of a new packet

	 * in the TX ring, stop the queue. The sequence below is race free
@@ -702,6 +752,25 @@ static int ftgmac100_hard_start_xmit(struct sk_buff *skb, 


	return NETDEV_TX_OK;



 dma_err:

	if (net_ratelimit())

		netdev_err(netdev, "map tx fragment failed\n");



	/* Free head */

	pointer = priv->tx_pointer;

	ftgmac100_free_tx_packet(priv, pointer, skb, first);



	/* Then all fragments */

	for (j = 0; j < i; j++) {

		pointer = ftgmac100_next_tx_pointer(pointer);

		txdes = &priv->descs->txdes[pointer];

		ftgmac100_free_tx_packet(priv, pointer, skb, txdes);

	}



	/* This cannot be reached if we successfully mapped the

	 * last fragment, so we know ftgmac100_free_tx_packet()

	 * hasn't freed the skb yet.

	 */

 drop:

	/* Drop the packet */

	dev_kfree_skb_any(skb);
@@ -1441,12 +1510,12 @@ static int ftgmac100_probe(struct platform_device *pdev) 
	 * when NCSI is enabled on the interface. It doesn't work

	 * in that case.

	 */

	netdev->features = NETIF_F_RXCSUM | NETIF_F_IP_CSUM | NETIF_F_GRO;

	netdev->features = NETIF_F_RXCSUM | NETIF_F_IP_CSUM |

		NETIF_F_GRO | NETIF_F_SG;

	if (priv->use_ncsi &&

	    of_get_property(pdev->dev.of_node, "no-hw-checksum", NULL))

		netdev->features &= ~NETIF_F_IP_CSUM;





	/* register network device */

	err = register_netdev(netdev);

	if (err) {