diff options
Diffstat (limited to 'drivers/s390/net/qeth_core_main.c')
-rw-r--r-- | drivers/s390/net/qeth_core_main.c | 81 |
1 files changed, 59 insertions, 22 deletions
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index d23ad6e3bb45..d057ead200b5 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -3367,7 +3367,6 @@ static void qeth_flush_buffers(struct qeth_qdio_out_q *queue, int index, qdio_flags = QDIO_FLAG_SYNC_OUTPUT; if (atomic_read(&queue->set_pci_flags_count)) qdio_flags |= QDIO_FLAG_PCI_OUT; - atomic_add(count, &queue->used_buffers); rc = do_QDIO(CARD_DDEV(queue->card), qdio_flags, queue->queue_no, index, count); if (rc) { @@ -3407,7 +3406,6 @@ static void qeth_check_outbound_queue(struct qeth_qdio_out_q *queue) * do_send_packet. So, we check if there is a * packing buffer to be flushed here. */ - netif_stop_subqueue(queue->card->dev, queue->queue_no); index = queue->next_buf_to_fill; q_was_packing = queue->do_pack; /* queue->do_pack may change */ @@ -3535,7 +3533,7 @@ static void qeth_qdio_output_handler(struct ccw_device *ccwdev, struct qeth_qdio_out_q *queue = card->qdio.out_qs[__queue]; struct qeth_qdio_out_buffer *buffer; struct net_device *dev = card->dev; - u16 txq; + struct netdev_queue *txq; int i; QETH_CARD_TEXT(card, 6, "qdouhdl"); @@ -3590,8 +3588,15 @@ static void qeth_qdio_output_handler(struct ccw_device *ccwdev, if (card->info.type != QETH_CARD_TYPE_IQD) qeth_check_outbound_queue(queue); - txq = IS_IQD(card) ? qeth_iqd_translate_txq(dev, __queue) : __queue; - netif_wake_subqueue(dev, txq); + if (IS_IQD(card)) + __queue = qeth_iqd_translate_txq(dev, __queue); + txq = netdev_get_tx_queue(dev, __queue); + /* xmit may have observed the full-condition, but not yet stopped the + * txq. In which case the code below won't trigger. So before returning, + * xmit will re-check the txq's fill level and wake it up if needed. + */ + if (netif_tx_queue_stopped(txq) && !qeth_out_queue_is_full(queue)) + netif_tx_wake_queue(txq); } /** @@ -3845,11 +3850,13 @@ static void __qeth_fill_buffer(struct sk_buff *skb, * from qeth_core_header_cache. * @offset: when mapping the skb, start at skb->data + offset * @hd_len: if > 0, build a dedicated header element of this size + * flush: Prepare the buffer to be flushed, regardless of its fill level. */ static int qeth_fill_buffer(struct qeth_qdio_out_q *queue, struct qeth_qdio_out_buffer *buf, struct sk_buff *skb, struct qeth_hdr *hdr, - unsigned int offset, unsigned int hd_len) + unsigned int offset, unsigned int hd_len, + bool flush) { struct qdio_buffer *buffer = buf->buffer; bool is_first_elem = true; @@ -3878,8 +3885,8 @@ static int qeth_fill_buffer(struct qeth_qdio_out_q *queue, QETH_TXQ_STAT_INC(queue, skbs_pack); /* If the buffer still has free elements, keep using it. */ - if (buf->next_element_to_fill < - QETH_MAX_BUFFER_ELEMENTS(queue->card)) + if (!flush && buf->next_element_to_fill < + QETH_MAX_BUFFER_ELEMENTS(queue->card)) return 0; } @@ -3896,15 +3903,31 @@ static int qeth_do_send_packet_fast(struct qeth_qdio_out_q *queue, { int index = queue->next_buf_to_fill; struct qeth_qdio_out_buffer *buffer = queue->bufs[index]; + struct netdev_queue *txq; + bool stopped = false; - /* - * check if buffer is empty to make sure that we do not 'overtake' - * ourselves and try to fill a buffer that is already primed + /* Just a sanity check, the wake/stop logic should ensure that we always + * get a free buffer. */ if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY) return -EBUSY; - qeth_fill_buffer(queue, buffer, skb, hdr, offset, hd_len); + + txq = netdev_get_tx_queue(queue->card->dev, skb_get_queue_mapping(skb)); + + if (atomic_inc_return(&queue->used_buffers) >= QDIO_MAX_BUFFERS_PER_Q) { + /* If a TX completion happens right _here_ and misses to wake + * the txq, then our re-check below will catch the race. + */ + QETH_TXQ_STAT_INC(queue, stopped); + netif_tx_stop_queue(txq); + stopped = true; + } + + qeth_fill_buffer(queue, buffer, skb, hdr, offset, hd_len, stopped); qeth_flush_buffers(queue, index, 1); + + if (stopped && !qeth_out_queue_is_full(queue)) + netif_tx_start_queue(txq); return 0; } @@ -3914,6 +3937,8 @@ int qeth_do_send_packet(struct qeth_card *card, struct qeth_qdio_out_q *queue, int elements_needed) { struct qeth_qdio_out_buffer *buffer; + struct netdev_queue *txq; + bool stopped = false; int start_index; int flush_count = 0; int do_pack = 0; @@ -3925,14 +3950,17 @@ int qeth_do_send_packet(struct qeth_card *card, struct qeth_qdio_out_q *queue, QETH_OUT_Q_LOCKED) != QETH_OUT_Q_UNLOCKED); start_index = queue->next_buf_to_fill; buffer = queue->bufs[queue->next_buf_to_fill]; - /* - * check if buffer is empty to make sure that we do not 'overtake' - * ourselves and try to fill a buffer that is already primed + + /* Just a sanity check, the wake/stop logic should ensure that we always + * get a free buffer. */ if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY) { atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED); return -EBUSY; } + + txq = netdev_get_tx_queue(card->dev, skb_get_queue_mapping(skb)); + /* check if we need to switch packing state of this queue */ qeth_switch_to_packing_if_needed(queue); if (queue->do_pack) { @@ -3947,8 +3975,8 @@ int qeth_do_send_packet(struct qeth_card *card, struct qeth_qdio_out_q *queue, (queue->next_buf_to_fill + 1) % QDIO_MAX_BUFFERS_PER_Q; buffer = queue->bufs[queue->next_buf_to_fill]; - /* we did a step forward, so check buffer state - * again */ + + /* We stepped forward, so sanity-check again: */ if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY) { qeth_flush_buffers(queue, start_index, @@ -3961,8 +3989,18 @@ int qeth_do_send_packet(struct qeth_card *card, struct qeth_qdio_out_q *queue, } } - flush_count += qeth_fill_buffer(queue, buffer, skb, hdr, offset, - hd_len); + if (buffer->next_element_to_fill == 0 && + atomic_inc_return(&queue->used_buffers) >= QDIO_MAX_BUFFERS_PER_Q) { + /* If a TX completion happens right _here_ and misses to wake + * the txq, then our re-check below will catch the race. + */ + QETH_TXQ_STAT_INC(queue, stopped); + netif_tx_stop_queue(txq); + stopped = true; + } + + flush_count += qeth_fill_buffer(queue, buffer, skb, hdr, offset, hd_len, + stopped); if (flush_count) qeth_flush_buffers(queue, start_index, flush_count); else if (!atomic_read(&queue->set_pci_flags_count)) @@ -3993,6 +4031,8 @@ out: if (do_pack) QETH_TXQ_STAT_ADD(queue, bufs_pack, flush_count); + if (stopped && !qeth_out_queue_is_full(queue)) + netif_tx_start_queue(txq); return rc; } EXPORT_SYMBOL_GPL(qeth_do_send_packet); @@ -4079,9 +4119,6 @@ int qeth_xmit(struct qeth_card *card, struct sk_buff *skb, } else { if (!push_len) kmem_cache_free(qeth_core_header_cache, hdr); - if (rc == -EBUSY) - /* roll back to ETH header */ - skb_pull(skb, push_len); } return rc; } |