net: stmmac: Re-work the queue selection for TSO packets

Ben Hutchings says:
	"This is the wrong place to change the queue mapping.
	stmmac_xmit() is called with a specific TX queue locked,
	and accessing a different TX queue results in a data race
	for all of that queue's state.

	I think this commit should be reverted upstream and in all
	stable branches.  Instead, the driver should implement the
	ndo_select_queue operation and override the queue mapping there."

Fixes: c5acdbee22 ("net: stmmac: Send TSO packets always from Queue 0")
Suggested-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jose Abreu 2019-07-08 14:26:28 +02:00 committed by David S. Miller
parent 36c4357c63
commit 4993e5b37e
1 changed files with 18 additions and 10 deletions

View File

@ -3045,17 +3045,8 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
/* Manage oversized TCP frames for GMAC4 device */
if (skb_is_gso(skb) && priv->tso) {
if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) {
/*
* There is no way to determine the number of TSO
* capable Queues. Let's use always the Queue 0
* because if TSO is supported then at least this
* one will be capable.
*/
skb_set_queue_mapping(skb, 0);
if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))
return stmmac_tso_xmit(skb, dev);
}
}
if (unlikely(stmmac_tx_avail(priv, queue) < nfrags + 1)) {
@ -3872,6 +3863,22 @@ static int stmmac_setup_tc(struct net_device *ndev, enum tc_setup_type type,
}
}
static u16 stmmac_select_queue(struct net_device *dev, struct sk_buff *skb,
struct net_device *sb_dev)
{
if (skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6)) {
/*
* There is no way to determine the number of TSO
* capable Queues. Let's use always the Queue 0
* because if TSO is supported then at least this
* one will be capable.
*/
return 0;
}
return netdev_pick_tx(dev, skb, NULL) % dev->real_num_tx_queues;
}
static int stmmac_set_mac_address(struct net_device *ndev, void *addr)
{
struct stmmac_priv *priv = netdev_priv(ndev);
@ -4088,6 +4095,7 @@ static const struct net_device_ops stmmac_netdev_ops = {
.ndo_tx_timeout = stmmac_tx_timeout,
.ndo_do_ioctl = stmmac_ioctl,
.ndo_setup_tc = stmmac_setup_tc,
.ndo_select_queue = stmmac_select_queue,
#ifdef CONFIG_NET_POLL_CONTROLLER
.ndo_poll_controller = stmmac_poll_controller,
#endif