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author | Julian Wiedmann <jwi@linux.ibm.com> | 2019-08-23 11:48:47 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2019-08-24 16:39:18 -0700 |
commit | 7c47f5afdeef763599f1ae22d29b8c3904c58315 (patch) | |
tree | 0aa9265576bf9f2fb6fc67307a6200b0fd2809d0 /drivers/s390 | |
parent | fbbdbc6473070dcb3ee1d69cf1c49ff78677d716 (diff) | |
download | linux-stable-7c47f5afdeef763599f1ae22d29b8c3904c58315.tar.gz linux-stable-7c47f5afdeef763599f1ae22d29b8c3904c58315.tar.bz2 linux-stable-7c47f5afdeef763599f1ae22d29b8c3904c58315.zip |
s390/qdio: enable drivers to poll for Output completions
While commit d36deae75011 ("qdio: extend API to allow polling") enhanced
the qdio layer so that drivers can poll their Input Queues, we don't
have the corresponding infrastructure for Output Queues yet.
Factor out a helper that scans a single QDIO Queue, so that qeth can
implement TX NAPI on top of it.
While doing so, remove the duplicated tracking of the next-to-scan index
(q->first_to_check vs q->first_to_kick) in this code path.
qdio_handle_aobs() needs to move slightly upwards in the code hierarchy,
so that it's still called from the polling path.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Acked-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/s390')
-rw-r--r-- | drivers/s390/cio/qdio_main.c | 64 |
1 files changed, 43 insertions, 21 deletions
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index 4142c85e77d8..5efba0d29190 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -647,8 +647,6 @@ static void qdio_kick_handler(struct qdio_q *q, unsigned int count) qperf_inc(q, outbound_handler); DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "koh: s:%02x c:%02x", start, count); - if (q->u.out.use_cq) - qdio_handle_aobs(q, start, count); } q->handler(q->irq_ptr->cdev, q->qdio_error, q->nr, start, count, @@ -774,8 +772,11 @@ static inline int qdio_outbound_q_moved(struct qdio_q *q, unsigned int start) count = get_outbound_buffer_frontier(q, start); - if (count) + if (count) { DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "out moved:%1d", q->nr); + if (q->u.out.use_cq) + qdio_handle_aobs(q, start, count); + } return count; } @@ -1655,6 +1656,44 @@ rescan: } EXPORT_SYMBOL(qdio_start_irq); +static int __qdio_inspect_queue(struct qdio_q *q, unsigned int *bufnr, + unsigned int *error) +{ + unsigned int start = q->first_to_check; + int count; + + count = q->is_input_q ? qdio_inbound_q_moved(q, start) : + qdio_outbound_q_moved(q, start); + if (count == 0) + return 0; + + *bufnr = start; + *error = q->qdio_error; + + /* for the next time */ + q->first_to_check = add_buf(start, count); + q->qdio_error = 0; + + return count; +} + +int qdio_inspect_queue(struct ccw_device *cdev, unsigned int nr, bool is_input, + unsigned int *bufnr, unsigned int *error) +{ + struct qdio_irq *irq_ptr = cdev->private->qdio_data; + struct qdio_q *q; + + if (!irq_ptr) + return -ENODEV; + q = is_input ? irq_ptr->input_qs[nr] : irq_ptr->output_qs[nr]; + + if (need_siga_sync(q)) + qdio_siga_sync_q(q); + + return __qdio_inspect_queue(q, bufnr, error); +} +EXPORT_SYMBOL_GPL(qdio_inspect_queue); + /** * qdio_get_next_buffers - process input buffers * @cdev: associated ccw_device for the qdio subchannel @@ -1672,13 +1711,10 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, { struct qdio_q *q; struct qdio_irq *irq_ptr = cdev->private->qdio_data; - unsigned int start; - int count; if (!irq_ptr) return -ENODEV; q = irq_ptr->input_qs[nr]; - start = q->first_to_check; /* * Cannot rely on automatic sync after interrupt since queues may @@ -1689,25 +1725,11 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr, qdio_check_outbound_pci_queues(irq_ptr); - count = qdio_inbound_q_moved(q, start); - if (count == 0) - return 0; - - start = add_buf(start, count); - q->first_to_check = start; - /* Note: upper-layer MUST stop processing immediately here ... */ if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE)) return -EIO; - *bufnr = q->first_to_kick; - *error = q->qdio_error; - - /* for the next time */ - q->first_to_kick = add_buf(q->first_to_kick, count); - q->qdio_error = 0; - - return count; + return __qdio_inspect_queue(q, bufnr, error); } EXPORT_SYMBOL(qdio_get_next_buffers); |