From 8b664cd127a1e3777e23c8aaa96ba52ef741bb55 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Thu, 31 Oct 2019 13:42:15 +0100 Subject: [PATCH] s390/qeth: use IQD Multi-Write For IQD devices with Multi-Write support, we can defer the queue-flush further and transmit multiple IO buffers with a single TX doorbell. The same-target restriction still applies. Signed-off-by: Julian Wiedmann Reviewed-by: Alexandra Winter Signed-off-by: David S. Miller --- drivers/s390/net/qeth_core.h | 9 +++++++ drivers/s390/net/qeth_core_main.c | 54 +++++++++++++++++++++++++++++++-------- 2 files changed, 53 insertions(+), 10 deletions(-) diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index e4b55f9..d081545 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -532,6 +532,8 @@ struct qeth_qdio_out_q { struct timer_list timer; struct qeth_hdr *prev_hdr; u8 bulk_start; + u8 bulk_count; + u8 bulk_max; }; #define qeth_for_each_output_queue(card, q, i) \ @@ -878,6 +880,13 @@ static inline u16 qeth_iqd_translate_txq(struct net_device *dev, u16 txq) return txq; } +static inline bool qeth_iqd_is_mcast_queue(struct qeth_card *card, + struct qeth_qdio_out_q *queue) +{ + return qeth_iqd_translate_txq(card->dev, queue->queue_no) == + QETH_IQD_MCAST_TXQ; +} + static inline void qeth_scrub_qdio_buffer(struct qdio_buffer *buf, unsigned int elements) { diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index dda2743..62054af 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -2634,6 +2634,18 @@ static int qeth_init_input_buffer(struct qeth_card *card, return 0; } +static unsigned int qeth_tx_select_bulk_max(struct qeth_card *card, + struct qeth_qdio_out_q *queue) +{ + if (!IS_IQD(card) || + qeth_iqd_is_mcast_queue(card, queue) || + card->options.cq == QETH_CQ_ENABLED || + qdio_get_ssqd_desc(CARD_DDEV(card), &card->ssqd)) + return 1; + + return card->ssqd.mmwc ? card->ssqd.mmwc : 1; +} + int qeth_init_qdio_queues(struct qeth_card *card) { unsigned int i; @@ -2673,6 +2685,8 @@ int qeth_init_qdio_queues(struct qeth_card *card) queue->do_pack = 0; queue->prev_hdr = NULL; queue->bulk_start = 0; + queue->bulk_count = 0; + queue->bulk_max = qeth_tx_select_bulk_max(card, queue); atomic_set(&queue->used_buffers, 0); atomic_set(&queue->set_pci_flags_count, 0); atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED); @@ -3318,10 +3332,11 @@ static void qeth_flush_buffers(struct qeth_qdio_out_q *queue, int index, static void qeth_flush_queue(struct qeth_qdio_out_q *queue) { - qeth_flush_buffers(queue, queue->bulk_start, 1); + qeth_flush_buffers(queue, queue->bulk_start, queue->bulk_count); - queue->bulk_start = QDIO_BUFNR(queue->bulk_start + 1); + queue->bulk_start = QDIO_BUFNR(queue->bulk_start + queue->bulk_count); queue->prev_hdr = NULL; + queue->bulk_count = 0; } static void qeth_check_outbound_queue(struct qeth_qdio_out_q *queue) @@ -3680,10 +3695,10 @@ check_layout: } static bool qeth_iqd_may_bulk(struct qeth_qdio_out_q *queue, - struct qeth_qdio_out_buffer *buffer, struct sk_buff *curr_skb, struct qeth_hdr *curr_hdr) { + struct qeth_qdio_out_buffer *buffer = queue->bufs[queue->bulk_start]; struct qeth_hdr *prev_hdr = queue->prev_hdr; if (!prev_hdr) @@ -3803,13 +3818,14 @@ static int __qeth_xmit(struct qeth_card *card, struct qeth_qdio_out_q *queue, struct qeth_hdr *hdr, unsigned int offset, unsigned int hd_len) { - struct qeth_qdio_out_buffer *buffer = queue->bufs[queue->bulk_start]; unsigned int bytes = qdisc_pkt_len(skb); + struct qeth_qdio_out_buffer *buffer; unsigned int next_element; struct netdev_queue *txq; bool stopped = false; bool flush; + buffer = queue->bufs[QDIO_BUFNR(queue->bulk_start + queue->bulk_count)]; txq = netdev_get_tx_queue(card->dev, skb_get_queue_mapping(skb)); /* Just a sanity check, the wake/stop logic should ensure that we always @@ -3818,11 +3834,23 @@ static int __qeth_xmit(struct qeth_card *card, struct qeth_qdio_out_q *queue, if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY) return -EBUSY; - if ((buffer->next_element_to_fill + elements > queue->max_elements) || - !qeth_iqd_may_bulk(queue, buffer, skb, hdr)) { - atomic_set(&buffer->state, QETH_QDIO_BUF_PRIMED); - qeth_flush_queue(queue); - buffer = queue->bufs[queue->bulk_start]; + flush = !qeth_iqd_may_bulk(queue, skb, hdr); + + if (flush || + (buffer->next_element_to_fill + elements > queue->max_elements)) { + if (buffer->next_element_to_fill > 0) { + atomic_set(&buffer->state, QETH_QDIO_BUF_PRIMED); + queue->bulk_count++; + } + + if (queue->bulk_count >= queue->bulk_max) + flush = true; + + if (flush) + qeth_flush_queue(queue); + + buffer = queue->bufs[QDIO_BUFNR(queue->bulk_start + + queue->bulk_count)]; /* Sanity-check again: */ if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY) @@ -3848,7 +3876,13 @@ static int __qeth_xmit(struct qeth_card *card, struct qeth_qdio_out_q *queue, if (flush || next_element >= queue->max_elements) { atomic_set(&buffer->state, QETH_QDIO_BUF_PRIMED); - qeth_flush_queue(queue); + queue->bulk_count++; + + if (queue->bulk_count >= queue->bulk_max) + flush = true; + + if (flush) + qeth_flush_queue(queue); } if (stopped && !qeth_out_queue_is_full(queue)) -- 2.7.4