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| author |   Julian Wiedmann <jwi@linux.vnet.ibm.com> | 2017-12-06 08:53:33 +0100 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2018-03-26 16:12:25 +0200 |
| commit | 152485bf76907ac7a2cc0a63b0822b23ef25da56 (patch) | |
| tree | e4ea6117a3466c3b0dd253be6a9b6d8796ab9a67 /drivers/s390 | |
| parent | Merge tag 'vfio-ccw-20180305' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features (diff) | |
| download | linux-dev-152485bf76907ac7a2cc0a63b0822b23ef25da56.tar.xz linux-dev-152485bf76907ac7a2cc0a63b0822b23ef25da56.zip | |
s390/qdio: simplify math in get_*_buffer_frontier()
When determining the buffer count that get_buf_states() should
be queried for, 'count' is capped at 127 buffers.
So the check
q->first_to_check == (q->first_to_check + count) % 128
can be reduced to
count == 0
This helps to emphasize that get_buf_states() is really only
called with count > 0.
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to '')
| -rw-r--r-- | drivers/s390/cio/qdio_main.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index d5b02de02a3a..6b340e6e29ac 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/drivers/s390/cio/qdio_main.c @@ -502,8 +502,8 @@ static inline void inbound_primed(struct qdio_q *q, int count) static int get_inbound_buffer_frontier(struct qdio_q *q) { - int count, stop; unsigned char state = 0; + int count; q->timestamp = get_tod_clock_fast(); @@ -512,9 +512,7 @@ static int get_inbound_buffer_frontier(struct qdio_q *q) * would return 0. */ count = min(atomic_read(&q->nr_buf_used), QDIO_MAX_BUFFERS_MASK); - stop = add_buf(q->first_to_check, count); - - if (q->first_to_check == stop) + if (!count) goto out; /* @@ -734,8 +732,8 @@ void qdio_inbound_processing(unsigned long data) static int get_outbound_buffer_frontier(struct qdio_q *q) { - int count, stop; unsigned char state = 0; + int count; q->timestamp = get_tod_clock_fast(); @@ -751,8 +749,7 @@ static int get_outbound_buffer_frontier(struct qdio_q *q) * would return 0. */ count = min(atomic_read(&q->nr_buf_used), QDIO_MAX_BUFFERS_MASK); - stop = add_buf(q->first_to_check, count); - if (q->first_to_check == stop) + if (!count) goto out; count = get_buf_states(q, q->first_to_check, &state, count, 0, 1); |