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[S390] qdio: EQBS retry after CCQ 96

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>
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1 parent a2b8601 commit 25f269f17316549e026c5dd0db7526411a504de6 Jan Glauber committed with Martin Schwidefsky
Showing with 41 additions and 40 deletions.
  1. +41 −40 drivers/s390/cio/qdio_main.c
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81 drivers/s390/cio/qdio_main.c
@@ -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 @@ static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
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);

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