s390/qeth: don't take queue lock in send_packet_fast()

Locking the output queue prior to TX is needed on OSA devices,
to synchronize against a packing flush from the TX completion code
(via qeth_check_outbound_queue()).
But send_packet_fast() is only used for IQDs, which don't do packing.
So remove the locking, and apply some easy cleanups.

Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h
index e3d3609..b7e8531 100644 (file)
--- a/drivers/s390/net/qeth_core.h
+++ b/drivers/s390/net/qeth_core.h
@@ -962,8 +962,7 @@ int qeth_get_priority_queue(struct qeth_card *, struct sk_buff *, int, int);
 int qeth_get_elements_no(struct qeth_card *card, struct sk_buff *skb,
                         int extra_elems, int data_offset);
 int qeth_get_elements_for_frags(struct sk_buff *);
-int qeth_do_send_packet_fast(struct qeth_card *card,
-                            struct qeth_qdio_out_q *queue, struct sk_buff *skb,
+int qeth_do_send_packet_fast(struct qeth_qdio_out_q *queue, struct sk_buff *skb,
                             struct qeth_hdr *hdr, unsigned int offset,
                             unsigned int hd_len);
 int qeth_do_send_packet(struct qeth_card *card, struct qeth_qdio_out_q *queue,

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 7703280..68e118f 100644 (file)
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4040,35 +4040,23 @@ static int qeth_fill_buffer(struct qeth_qdio_out_q *queue,
        return flush_cnt;
 }
 
-int qeth_do_send_packet_fast(struct qeth_card *card,
-                            struct qeth_qdio_out_q *queue, struct sk_buff *skb,
+int qeth_do_send_packet_fast(struct qeth_qdio_out_q *queue, struct sk_buff *skb,
                             struct qeth_hdr *hdr, unsigned int offset,
                             unsigned int hd_len)
 {
-       struct qeth_qdio_out_buffer *buffer;
-       int index;
+       int index = queue->next_buf_to_fill;
+       struct qeth_qdio_out_buffer *buffer = queue->bufs[index];
 
-       /* spin until we get the queue ... */
-       while (atomic_cmpxchg(&queue->state, QETH_OUT_Q_UNLOCKED,
-                             QETH_OUT_Q_LOCKED) != QETH_OUT_Q_UNLOCKED);
-       /* ... now we've got the queue */
-       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
         */
        if (atomic_read(&buffer->state) != QETH_QDIO_BUF_EMPTY)
-               goto out;
-       queue->next_buf_to_fill = (queue->next_buf_to_fill + 1) %
-                                         QDIO_MAX_BUFFERS_PER_Q;
-       atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED);
+               return -EBUSY;
+       queue->next_buf_to_fill = (index + 1) % QDIO_MAX_BUFFERS_PER_Q;
        qeth_fill_buffer(queue, buffer, skb, hdr, offset, hd_len);
        qeth_flush_buffers(queue, index, 1);
        return 0;
-out:
-       atomic_set(&queue->state, QETH_OUT_Q_UNLOCKED);
-       return -EBUSY;
 }
 EXPORT_SYMBOL_GPL(qeth_do_send_packet_fast);
 

diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c
index 25a0f38..009de72 100644 (file)
--- a/drivers/s390/net/qeth_l2_main.c
+++ b/drivers/s390/net/qeth_l2_main.c
@@ -698,7 +698,7 @@ static int qeth_l2_xmit_iqd(struct qeth_card *card, struct sk_buff *skb,
                rc = -E2BIG;
                goto out;
        }
-       rc = qeth_do_send_packet_fast(card, queue, skb, hdr, data_offset,
+       rc = qeth_do_send_packet_fast(queue, skb, hdr, data_offset,
                                      sizeof(*hdr) + data_offset);
 out:
        if (rc)

diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c
index ab661a4..733f94c 100644 (file)
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -2771,8 +2771,8 @@ static netdev_tx_t qeth_l3_hard_start_xmit(struct sk_buff *skb,
                rc = qeth_do_send_packet(card, queue, new_skb, hdr, hd_len,
                                         hd_len, elements);
        } else
-               rc = qeth_do_send_packet_fast(card, queue, new_skb, hdr,
-                                             data_offset, hd_len);
+               rc = qeth_do_send_packet_fast(queue, new_skb, hdr, data_offset,
+                                             hd_len);
 
        if (!rc) {
                card->stats.tx_packets++;