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s390/qeth: schedule TX NAPI on QAOB completion

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[ Upstream commit 3e83d467a08e25b27c44c885f511624a71c84f7c ]

When a QAOB notifies us that a pending TX buffer has been delivered, the
actual TX completion processing by qeth_tx_complete_pending_bufs()
is done within the context of a TX NAPI instance. We shouldn't rely on
this instance being scheduled by some other TX event, but just do it
ourselves.

qeth_qdio_handle_aob() is called from qeth_poll(), ie. our main NAPI
instance. To avoid touching the TX queue's NAPI instance
before/after it is (un-)registered, reorder the code in qeth_open()
and qeth_stop() accordingly.

Fixes: 0da9581ddb0f ("qeth: exploit asynchronous delivery of storage blocks")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Julian Wiedmann 2021-03-09 17:52:20 +01:00 committed by Greg Kroah-Hartman
parent f3f6765fd0
commit e8e99acd08
1 changed files with 12 additions and 6 deletions
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18
drivers/s390/net/qeth_core_main.c
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@ -470,6 +470,7 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
struct qaob *aob;
struct qeth_qdio_out_buffer *buffer;
enum iucv_tx_notify notification;
struct qeth_qdio_out_q *queue;
unsigned int i;
aob = (struct qaob *) phys_to_virt(phys_aob_addr);
@ -511,7 +512,9 @@ static void qeth_qdio_handle_aob(struct qeth_card *card,
kmem_cache_free(qeth_core_header_cache, data);
}
queue = buffer->q;
atomic_set(&buffer->state, QETH_QDIO_BUF_EMPTY);
napi_schedule(&queue->napi);
break;
default:
WARN_ON_ONCE(1);
@ -7013,9 +7016,7 @@ int qeth_open(struct net_device *dev)
card->data.state = CH_STATE_UP;
netif_tx_start_all_queues(dev);
napi_enable(&card->napi);
local_bh_disable();
napi_schedule(&card->napi);
if (IS_IQD(card)) {
struct qeth_qdio_out_q *queue;
unsigned int i;
@ -7027,8 +7028,12 @@ int qeth_open(struct net_device *dev)
napi_schedule(&queue->napi);
}
}
napi_enable(&card->napi);
napi_schedule(&card->napi);
/* kick-start the NAPI softirq: */
local_bh_enable();
return 0;
}
EXPORT_SYMBOL_GPL(qeth_open);
@ -7038,6 +7043,11 @@ int qeth_stop(struct net_device *dev)
struct qeth_card *card = dev->ml_priv;
QETH_CARD_TEXT(card, 4, "qethstop");
napi_disable(&card->napi);
cancel_delayed_work_sync(&card->buffer_reclaim_work);
qdio_stop_irq(CARD_DDEV(card));
if (IS_IQD(card)) {
struct qeth_qdio_out_q *queue;
unsigned int i;
@ -7058,10 +7068,6 @@ int qeth_stop(struct net_device *dev)
netif_tx_disable(dev);
}
napi_disable(&card->napi);
cancel_delayed_work_sync(&card->buffer_reclaim_work);
qdio_stop_irq(CARD_DDEV(card));
return 0;
}
EXPORT_SYMBOL_GPL(qeth_stop);