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Commit 01dd70b5 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by David S. Miller
Browse files

ftgmac100: Simplify rx pointer handling in the rx path 



We don't handle fragmented RX packets, so the "looping"
helpers to locate the first segment of a packet or to
drop a packet aren't actually helping.

Take them out and simplify ftgmac100_rx_packet() further
as a result.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent eb50af20

drivers/net/ethernet/faraday/ftgmac100.c

+24 −68
Original line number Diff line number Diff line
@@ -431,34 +431,6 @@ static int ftgmac100_next_rx_pointer(int pointer) 
	return (pointer + 1) & (RX_QUEUE_ENTRIES - 1);

}



static void ftgmac100_rx_pointer_advance(struct ftgmac100 *priv)

{

	priv->rx_pointer = ftgmac100_next_rx_pointer(priv->rx_pointer);

}



static struct ftgmac100_rxdes *ftgmac100_current_rxdes(struct ftgmac100 *priv)

{

	return &priv->descs->rxdes[priv->rx_pointer];

}



static struct ftgmac100_rxdes *

ftgmac100_rx_locate_first_segment(struct ftgmac100 *priv)

{

	struct ftgmac100_rxdes *rxdes = ftgmac100_current_rxdes(priv);



	while (ftgmac100_rxdes_packet_ready(rxdes)) {

		if (ftgmac100_rxdes_first_segment(rxdes))

			return rxdes;



		ftgmac100_rxdes_set_dma_own(priv, rxdes);

		ftgmac100_rx_pointer_advance(priv);

		rxdes = ftgmac100_current_rxdes(priv);

	}



	return NULL;

}





static void ftgmac100_rx_packet_error(struct ftgmac100 *priv,

				      struct ftgmac100_rxdes *rxdes)

{
@@ -476,51 +448,32 @@ static void ftgmac100_rx_packet_error(struct ftgmac100 *priv, 
		netdev->stats.rx_length_errors++;

}



static void ftgmac100_rx_drop_packet(struct ftgmac100 *priv)

{

	struct net_device *netdev = priv->netdev;

	struct ftgmac100_rxdes *rxdes = ftgmac100_current_rxdes(priv);

	bool done = false;



	if (net_ratelimit())

		netdev_dbg(netdev, "drop packet %p\n", rxdes);



	do {

		if (ftgmac100_rxdes_last_segment(rxdes))

			done = true;



		ftgmac100_rxdes_set_dma_own(priv, rxdes);

		ftgmac100_rx_pointer_advance(priv);

		rxdes = ftgmac100_current_rxdes(priv);

	} while (!done && ftgmac100_rxdes_packet_ready(rxdes));



	netdev->stats.rx_dropped++;

}



static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed)

{

	struct net_device *netdev = priv->netdev;

	struct ftgmac100_rxdes *rxdes;

	struct sk_buff *skb;

	struct page *page;

	unsigned int size;

	unsigned int pointer, size;

	dma_addr_t map;



	rxdes = ftgmac100_rx_locate_first_segment(priv);

	if (!rxdes)

	/* Grab next RX descriptor */

	pointer = priv->rx_pointer;

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



	/* Do we have a packet ? */

	if (!ftgmac100_rxdes_packet_ready(rxdes))

		return false;



	/* We don't support segmented rx frames, so drop these

	 * along with packets with errors.

	 */

	if (unlikely(!ftgmac100_rxdes_last_segment(rxdes))) {

		ftgmac100_rx_drop_packet(priv);

		return true;

	}

	/* We don't cope with fragmented RX packets */

	if (unlikely(!ftgmac100_rxdes_first_segment(rxdes) ||

		     !ftgmac100_rxdes_last_segment(rxdes)))

		goto drop;



	/* Any error (other than csum offload) flagged ? */

	if (unlikely(ftgmac100_rxdes_any_error(rxdes))) {

		ftgmac100_rx_packet_error(priv, rxdes);

		ftgmac100_rx_drop_packet(priv);

		return true;

		goto drop;

	}



	/* If the packet had no buffer (failed to allocate earlier)
@@ -529,8 +482,7 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed) 
	page = ftgmac100_rxdes_get_page(priv, rxdes);

	if (!page) {

		ftgmac100_alloc_rx_page(priv, rxdes, GFP_ATOMIC);

		ftgmac100_rx_pointer_advance(priv);

		return true;

		goto drop;

	}



	/* start processing */
@@ -538,9 +490,7 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed) 
	if (unlikely(!skb)) {

		if (net_ratelimit())

			netdev_err(netdev, "rx skb alloc failed\n");



		ftgmac100_rx_drop_packet(priv);

		return true;

		goto drop;

	}



	if (unlikely(ftgmac100_rxdes_multicast(rxdes)))
@@ -577,8 +527,7 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed) 


	ftgmac100_alloc_rx_page(priv, rxdes, GFP_ATOMIC);



	ftgmac100_rx_pointer_advance(priv);

	rxdes = ftgmac100_current_rxdes(priv);

	priv->rx_pointer = ftgmac100_next_rx_pointer(pointer);



	/* Small frames are copied into linear part of skb to free one page */

	if (skb->len <= 128) {
@@ -601,6 +550,13 @@ static bool ftgmac100_rx_packet(struct ftgmac100 *priv, int *processed) 


	(*processed)++;

	return true;



 drop:

	/* Clean rxdes0 (which resets own bit) */

	rxdes->rxdes0 &= cpu_to_le32(priv->rxdes0_edorr_mask);

	priv->rx_pointer = ftgmac100_next_rx_pointer(pointer);

	netdev->stats.rx_dropped++;

	return true;

}



static void ftgmac100_txdes_reset(const struct ftgmac100 *priv,