[PATCH 3.16 11/17] tg3: Modify tg3_tso_bug() to handle multiple TX rings

From: Greg Kroah-Hartman
Date: Fri Aug 08 2014 - 17:37:51 EST


3.16-stable review patch. If anyone has any objections, please let me know.

------------------

From: Prashant Sreedharan <prashant@xxxxxxxxxxxx>

[ Upstream commit 4d8fdc95c60e90d84c8257a0067ff4b1729a3757 ]

tg3_tso_bug() was originally designed to handle only HW TX ring 0, Commit
d3f6f3a1d818410c17445bce4f4caab52eb102f1 ("tg3: Prevent page allocation failure
during TSO workaround") changed the driver logic to use tg3_tso_bug() for all
HW TX rings that are enabled. This patch fixes the regression by modifying
tg3_tso_bug() to handle multiple HW TX rings.

Signed-off-by: Prashant Sreedharan <prashant@xxxxxxxxxxxx>
Signed-off-by: Michael Chan <mchan@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/broadcom/tg3.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -7830,17 +7830,18 @@ static int tigon3_dma_hwbug_workaround(s

static netdev_tx_t tg3_start_xmit(struct sk_buff *, struct net_device *);

-/* Use GSO to workaround a rare TSO bug that may be triggered when the
- * TSO header is greater than 80 bytes.
+/* Use GSO to workaround all TSO packets that meet HW bug conditions
+ * indicated in tg3_tx_frag_set()
*/
-static int tg3_tso_bug(struct tg3 *tp, struct sk_buff *skb)
+static int tg3_tso_bug(struct tg3 *tp, struct tg3_napi *tnapi,
+ struct netdev_queue *txq, struct sk_buff *skb)
{
struct sk_buff *segs, *nskb;
u32 frag_cnt_est = skb_shinfo(skb)->gso_segs * 3;

/* Estimate the number of fragments in the worst case */
- if (unlikely(tg3_tx_avail(&tp->napi[0]) <= frag_cnt_est)) {
- netif_stop_queue(tp->dev);
+ if (unlikely(tg3_tx_avail(tnapi) <= frag_cnt_est)) {
+ netif_tx_stop_queue(txq);

/* netif_tx_stop_queue() must be done before checking
* checking tx index in tg3_tx_avail() below, because in
@@ -7848,13 +7849,14 @@ static int tg3_tso_bug(struct tg3 *tp, s
* netif_tx_queue_stopped().
*/
smp_mb();
- if (tg3_tx_avail(&tp->napi[0]) <= frag_cnt_est)
+ if (tg3_tx_avail(tnapi) <= frag_cnt_est)
return NETDEV_TX_BUSY;

- netif_wake_queue(tp->dev);
+ netif_tx_wake_queue(txq);
}

- segs = skb_gso_segment(skb, tp->dev->features & ~(NETIF_F_TSO | NETIF_F_TSO6));
+ segs = skb_gso_segment(skb, tp->dev->features &
+ ~(NETIF_F_TSO | NETIF_F_TSO6));
if (IS_ERR(segs) || !segs)
goto tg3_tso_bug_end;

@@ -7930,7 +7932,7 @@ static netdev_tx_t tg3_start_xmit(struct
if (!skb_is_gso_v6(skb)) {
if (unlikely((ETH_HLEN + hdr_len) > 80) &&
tg3_flag(tp, TSO_BUG))
- return tg3_tso_bug(tp, skb);
+ return tg3_tso_bug(tp, tnapi, txq, skb);

ip_csum = iph->check;
ip_tot_len = iph->tot_len;
@@ -8061,7 +8063,7 @@ static netdev_tx_t tg3_start_xmit(struct
iph->tot_len = ip_tot_len;
}
tcph->check = tcp_csum;
- return tg3_tso_bug(tp, skb);
+ return tg3_tso_bug(tp, tnapi, txq, skb);
}

/* If the workaround fails due to memory/mapping


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