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s390/qdio: simplify SBAL range calculation

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When passing a range of ready-to-process SBALs to the upper-layer
driver, use the available 'count' instead of calculating the distance
between the first_to_check and first_to_kick cursors.

This simplifies the logic of the queue-scan path, and opens up the
possibility of scanning all 128 SBALs in one go (as determining the
reported count no longer requires wrap-around safe arithmetic on the
queue's cursors).

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Julian Wiedmann 2019-03-28 10:43:46 +01:00 committed by Martin Schwidefsky
parent b39544c6e0
commit 65e4f77638
1 changed files with 9 additions and 15 deletions

24
drivers/s390/cio/qdio_main.c
View File

@ -636,17 +636,13 @@ static inline unsigned long qdio_aob_for_buffer(struct qdio_output_q *q,
return phys_aob;
}
static void qdio_kick_handler(struct qdio_q *q)
static void qdio_kick_handler(struct qdio_q *q, unsigned int count)
{
int start = q->first_to_kick;
int end = q->first_to_check;
int count;
if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
return;
count = sub_buf(end, start);
if (q->is_input_q) {
qperf_inc(q, inbound_handler);
DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "kih s:%02x c:%02x", start, count);
@ -662,7 +658,7 @@ static void qdio_kick_handler(struct qdio_q *q)
q->irq_ptr->int_parm);
/* for the next time */
q->first_to_kick = end;
q->first_to_kick = add_buf(start, count);
q->qdio_error = 0;
}
@ -685,7 +681,7 @@ static void __qdio_inbound_processing(struct qdio_q *q)
if (count == 0)
return;
qdio_kick_handler(q);
qdio_kick_handler(q, count);
if (!qdio_inbound_q_done(q)) {
/* means poll time is not yet over */
@ -843,7 +839,7 @@ static void __qdio_outbound_processing(struct qdio_q *q)
count = qdio_outbound_q_moved(q);
if (count)
qdio_kick_handler(q);
qdio_kick_handler(q, count);
if (queue_type(q) == QDIO_ZFCP_QFMT && !pci_out_supported(q->irq_ptr) &&
!qdio_outbound_q_done(q))
@ -911,7 +907,7 @@ static void __tiqdio_inbound_processing(struct qdio_q *q)
if (count == 0)
return;
qdio_kick_handler(q);
qdio_kick_handler(q, count);
if (!qdio_inbound_q_done(q)) {
qperf_inc(q, tasklet_inbound_resched);
@ -1674,7 +1670,6 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr,
int *error)
{
struct qdio_q *q;
int start, end;
struct qdio_irq *irq_ptr = cdev->private->qdio_data;
int count;
@ -1699,15 +1694,14 @@ int qdio_get_next_buffers(struct ccw_device *cdev, int nr, int *bufnr,
if (unlikely(q->irq_ptr->state != QDIO_IRQ_STATE_ACTIVE))
return -EIO;
start = q->first_to_kick;
end = q->first_to_check;
*bufnr = start;
*bufnr = q->first_to_kick;
*error = q->qdio_error;
/* for the next time */
q->first_to_kick = end;
q->first_to_kick = add_buf(q->first_to_kick, count);
q->qdio_error = 0;
return sub_buf(end, start);
return count;
}
EXPORT_SYMBOL(qdio_get_next_buffers);