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authorMike Marciniszyn <mike.marciniszyn@intel.com>2020-06-23 16:43:22 -0400
committerJason Gunthorpe <jgg@nvidia.com>2020-06-24 16:13:38 -0300
commit82172b765530f84b4b9da929f2dcf46f2b7b232b (patch)
tree0cad4abea1e1cf9a132ab10dbe2457e42207fdb2 /drivers/infiniband
parent822fbd37410639acdae368ea55477ddd3498651d (diff)
IB/hfi1: Correct -EBUSY handling in tx code
The current code mishandles -EBUSY in two ways: - The flow change doesn't test the return from the flush and runs on to process the current packet racing with the wakeup processing - The -EBUSY handling for a single packet inserts the tx into the txlist after the submit call, racing with the same wakeup processing Fix the first by dropping the skb and returning NETDEV_TX_OK. Fix the second by insuring the the list entry within the txreq is inited when allocated. This enables the sleep routine to detect that the txreq has used the non-list api and queue the packet to the txlist. Both flaws can lead to having the flushing thread executing in causing two threads to manipulate the txlist. Fixes: d99dc602e2a5 ("IB/hfi1: Add functions to transmit datagram ipoib packets") Link: https://lore.kernel.org/r/20200623204321.108092.83898.stgit@awfm-01.aw.intel.com Reviewed-by: Kaike Wan <kaike.wan@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/hw/hfi1/ipoib_tx.c35
1 files changed, 18 insertions, 17 deletions
diff --git a/drivers/infiniband/hw/hfi1/ipoib_tx.c b/drivers/infiniband/hw/hfi1/ipoib_tx.c
index 175290c56db9..76dcb5624aa6 100644
--- a/drivers/infiniband/hw/hfi1/ipoib_tx.c
+++ b/drivers/infiniband/hw/hfi1/ipoib_tx.c
@@ -369,6 +369,7 @@ static struct ipoib_txreq *hfi1_ipoib_send_dma_common(struct net_device *dev,
tx->priv = priv;
tx->txq = txp->txq;
tx->skb = skb;
+ INIT_LIST_HEAD(&tx->txreq.list);
hfi1_ipoib_build_ib_tx_headers(tx, txp);
@@ -469,6 +470,7 @@ static int hfi1_ipoib_send_dma_single(struct net_device *dev,
ret = hfi1_ipoib_submit_tx(txq, tx);
if (likely(!ret)) {
+tx_ok:
trace_sdma_output_ibhdr(tx->priv->dd,
&tx->sdma_hdr.hdr,
ib_is_sc5(txp->flow.sc5));
@@ -478,20 +480,8 @@ static int hfi1_ipoib_send_dma_single(struct net_device *dev,
txq->pkts_sent = false;
- if (ret == -EBUSY) {
- list_add_tail(&tx->txreq.list, &txq->tx_list);
-
- trace_sdma_output_ibhdr(tx->priv->dd,
- &tx->sdma_hdr.hdr,
- ib_is_sc5(txp->flow.sc5));
- hfi1_ipoib_check_queue_depth(txq);
- return NETDEV_TX_OK;
- }
-
- if (ret == -ECOMM) {
- hfi1_ipoib_check_queue_depth(txq);
- return NETDEV_TX_OK;
- }
+ if (ret == -EBUSY || ret == -ECOMM)
+ goto tx_ok;
sdma_txclean(priv->dd, &tx->txreq);
dev_kfree_skb_any(skb);
@@ -509,9 +499,17 @@ static int hfi1_ipoib_send_dma_list(struct net_device *dev,
struct ipoib_txreq *tx;
/* Has the flow change ? */
- if (txq->flow.as_int != txp->flow.as_int)
- (void)hfi1_ipoib_flush_tx_list(dev, txq);
-
+ if (txq->flow.as_int != txp->flow.as_int) {
+ int ret;
+
+ ret = hfi1_ipoib_flush_tx_list(dev, txq);
+ if (unlikely(ret)) {
+ if (ret == -EBUSY)
+ ++dev->stats.tx_dropped;
+ dev_kfree_skb_any(skb);
+ return NETDEV_TX_OK;
+ }
+ }
tx = hfi1_ipoib_send_dma_common(dev, skb, txp);
if (IS_ERR(tx)) {
int ret = PTR_ERR(tx);
@@ -612,6 +610,9 @@ static int hfi1_ipoib_sdma_sleep(struct sdma_engine *sde,
netif_stop_subqueue(txq->priv->netdev, txq->q_idx);
+ if (list_empty(&txreq->list))
+ /* came from non-list submit */
+ list_add_tail(&txreq->list, &txq->tx_list);
if (list_empty(&txq->wait.list))
iowait_queue(pkts_sent, wait->iow, &sde->dmawait);