From 25f269f17316549e026c5dd0db7526411a504de6 Mon Sep 17 00:00:00 2001 From: Jan Glauber Date: Sun, 30 Oct 2011 15:17:06 +0100 Subject: [PATCH] [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 Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/qdio_main.c | 81 ++++++++++++++++++------------------ 1 file changed, 41 insertions(+), 40 deletions(-) diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c index a76d6764ce6..7c567b2268a 100644 --- a/drivers/s390/cio/qdio_main.c +++ b/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 @@ 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); -- 2.20.1