[PATCH 5.11 074/306] s390/qeth: schedule TX NAPI on QAOB completion
From: gregkh@linuxfoundation.org
Date: 2021-03-15 14:11:42
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Julian Wiedmann <redacted>
commit 3e83d467a08e25b27c44c885f511624a71c84f7c upstream.
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 <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/s390/net/qeth_core_main.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c@@ -470,6 +470,7 @@ static void qeth_qdio_handle_aob(struct 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);
@@ -512,7 +513,9 @@ static void qeth_qdio_handle_aob(struct buffer->is_header[i] = 0; } + queue = buffer->q; atomic_set(&buffer->state, QETH_QDIO_BUF_EMPTY); + napi_schedule(&queue->napi); break; default: WARN_ON_ONCE(1);
@@ -7225,9 +7228,7 @@ 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;
@@ -7239,8 +7240,12 @@ 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);
@@ -7250,6 +7255,11 @@ 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;
@@ -7270,10 +7280,6 @@ 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);