qede: Linearize SKBs when needed

There's a corner-case in HW where an SKB queued for transmission that
contains too many frags will cause FW to assert.
This patch solves this by linearizing the SKB if necessary.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yuval Mintz 2016-02-24 16:52:46 +02:00 committed by David S. Miller
parent 0e7441d73d
commit b1199b100e
1 changed files with 33 additions and 5 deletions

View File

@ -380,6 +380,28 @@ static int map_frag_to_bd(struct qede_dev *edev,
return 0;
}
/* +2 for 1st BD for headers and 2nd BD for headlen (if required) */
#if ((MAX_SKB_FRAGS + 2) > ETH_TX_MAX_BDS_PER_NON_LSO_PACKET)
static bool qede_pkt_req_lin(struct qede_dev *edev, struct sk_buff *skb,
u8 xmit_type)
{
int allowed_frags = ETH_TX_MAX_BDS_PER_NON_LSO_PACKET - 1;
if (xmit_type & XMIT_LSO) {
int hlen;
hlen = skb_transport_header(skb) +
tcp_hdrlen(skb) - skb->data;
/* linear payload would require its own BD */
if (skb_headlen(skb) > hlen)
allowed_frags--;
}
return (skb_shinfo(skb)->nr_frags > allowed_frags);
}
#endif
/* Main transmit function */
static
netdev_tx_t qede_start_xmit(struct sk_buff *skb,
@ -407,16 +429,22 @@ netdev_tx_t qede_start_xmit(struct sk_buff *skb,
txq = QEDE_TX_QUEUE(edev, txq_index);
netdev_txq = netdev_get_tx_queue(ndev, txq_index);
/* Current code doesn't support SKB linearization, since the max number
* of skb frags can be passed in the FW HSI.
*/
BUILD_BUG_ON(MAX_SKB_FRAGS > ETH_TX_MAX_BDS_PER_NON_LSO_PACKET);
WARN_ON(qed_chain_get_elem_left(&txq->tx_pbl) <
(MAX_SKB_FRAGS + 1));
xmit_type = qede_xmit_type(edev, skb, &ipv6_ext);
#if ((MAX_SKB_FRAGS + 2) > ETH_TX_MAX_BDS_PER_NON_LSO_PACKET)
if (qede_pkt_req_lin(edev, skb, xmit_type)) {
if (skb_linearize(skb)) {
DP_NOTICE(edev,
"SKB linearization failed - silently dropping this SKB\n");
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
}
#endif
/* Fill the entry in the SW ring and the BDs in the FW ring */
idx = txq->sw_tx_prod & NUM_TX_BDS_MAX;
txq->sw_tx_ring[idx].skb = skb;