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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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Benjamin Herrenschmidt 2017-04-06 11:02:48 +10:00 committed by David S. Miller
parent eb50af2044
commit 01dd70b52a
1 changed files with 24 additions and 68 deletions
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92
drivers/net/ethernet/faraday/ftgmac100.c
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@ -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,