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[S390] qdio: EQBS retry after CCQ 96

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Running under z/VM with QIOASSIST enabled, qdio queues could stall if EQBS
did not extract all SBAL states. Add an instant retry for EQBS and, if the
retry fails, set up a timer to ensure outstanding SBALs are processed later.

While at it, optimize qdio_do_eqbs and qdio_do_sqbs to eliminate 3 jumps on
the hot path.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Jan Glauber 2011-10-30 15:17:06 +01:00 • committed by Martin Schwidefsky
commit 25f269f173
1 changed files with 41 additions and 40 deletions
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81
drivers/s390/cio/qdio_main.c
View file

@ -104,9 +104,12 @@ static inline int qdio_check_ccq(struct qdio_q *q, unsigned int ccq)
/* all done or next buffer state different */
if (ccq == 0 || ccq == 32)
return 0;
/* not all buffers processed */
if (ccq == 96 || ccq == 97)
/* no buffer processed */
if (ccq == 97)
return 1;
/* not all buffers processed */
if (ccq == 96)
return 2;
/* notify devices immediately */
DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);
return -EIO;
@ -126,10 +129,8 @@ static inline int qdio_check_ccq(struct qdio_q *q, unsigned int ccq)
static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
int start, int count, int auto_ack)
{
int rc, tmp_count = count, tmp_start = start, nr = q->nr, retried = 0;
unsigned int ccq = 0;
int tmp_count = count, tmp_start = start;
int nr = q->nr;
int rc;
BUG_ON(!q->irq_ptr->sch_token);
qperf_inc(q, eqbs);
@ -140,30 +141,34 @@ again:
ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count,
auto_ack);
rc = qdio_check_ccq(q, ccq);
/* At least one buffer was processed, return and extract the remaining
* buffers later.
*/
if ((ccq == 96) && (count != tmp_count)) {
qperf_inc(q, eqbs_partial);
return (count - tmp_count);
}
if (!rc)
return count - tmp_count;
if (rc == 1) {
DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS again:%2d", ccq);
goto again;
}
if (rc < 0) {
DBF_ERROR("%4x EQBS ERROR", SCH_NO(q));
DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
q->handler(q->irq_ptr->cdev,
QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
q->nr, q->first_to_kick, count,
q->irq_ptr->int_parm);
return 0;
if (rc == 2) {
BUG_ON(tmp_count == count);
qperf_inc(q, eqbs_partial);
DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS part:%02x",
tmp_count);
/*
* Retry once, if that fails bail out and process the
* extracted buffers before trying again.
*/
if (!retried++)
goto again;
else
return count - tmp_count;
}
return count - tmp_count;
DBF_ERROR("%4x EQBS ERROR", SCH_NO(q));
DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
q->handler(q->irq_ptr->cdev, QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
0, -1, -1, q->irq_ptr->int_parm);
return 0;
}
/**
@ -196,22 +201,22 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
again:
ccq = do_sqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);
rc = qdio_check_ccq(q, ccq);
if (rc == 1) {
if (!rc) {
WARN_ON(tmp_count);
return count - tmp_count;
}
if (rc == 1 || rc == 2) {
DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "SQBS again:%2d", ccq);
qperf_inc(q, sqbs_partial);
goto again;
}
if (rc < 0) {
DBF_ERROR("%4x SQBS ERROR", SCH_NO(q));
DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
q->handler(q->irq_ptr->cdev,
QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
q->nr, q->first_to_kick, count,
q->irq_ptr->int_parm);
return 0;
}
WARN_ON(tmp_count);
return count - tmp_count;
DBF_ERROR("%4x SQBS ERROR", SCH_NO(q));
DBF_ERROR("%3d%3d%2d", count, tmp_count, nr);
q->handler(q->irq_ptr->cdev, QDIO_ERROR_ACTIVATE_CHECK_CONDITION,
0, -1, -1, q->irq_ptr->int_parm);
return 0;
}
/* returns number of examined buffers and their common state in *state */
@ -915,10 +920,6 @@ static void __qdio_outbound_processing(struct qdio_q *q)
if (!pci_out_supported(q) && !qdio_outbound_q_done(q))
goto sched;
/* bail out for HiperSockets unicast queues */
if (queue_type(q) == QDIO_IQDIO_QFMT && !multicast_outbound(q))
return;
if ((queue_type(q) == QDIO_IQDIO_QFMT) &&
(atomic_read(&q->nr_buf_used)) > QDIO_IQDIO_POLL_LVL)
goto sched;
@ -928,8 +929,8 @@ static void __qdio_outbound_processing(struct qdio_q *q)
/*
* Now we know that queue type is either qeth without pci enabled
* or HiperSockets multicast. Make sure buffer switch from PRIMED to
* EMPTY is noticed and outbound_handler is called after some time.
* or HiperSockets. Make sure buffer switch from PRIMED to EMPTY
* is noticed and outbound_handler is called after some time.
*/
if (qdio_outbound_q_done(q))
del_timer(&q->u.out.timer);