s390/qdio: split up CCQ handling for EQBS / SQBS

Get rid of the confusing two-stage translation in a hot path, and only
handle CCQs that we anticipate for the respective command. Any
unexpected value (such as CCQ 97 (rc == 1) for SQBS) should be
considered a severe HW/driver bug, and traced as such.

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>

diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
index de647b7..a337281 100644 (file)
--- a/drivers/s390/cio/qdio_main.c
+++ b/drivers/s390/cio/qdio_main.c
@@ -98,22 +98,6 @@ static inline int do_siga_output(unsigned long schid, unsigned long mask,
        return cc;
 }
 
-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;
-       /* 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;
-}
-
 /**
  * qdio_do_eqbs - extract buffer states for QEBSM
  * @q: queue to manipulate
@@ -128,7 +112,7 @@ 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;
+       int tmp_count = count, tmp_start = start, nr = q->nr;
        unsigned int ccq = 0;
 
        qperf_inc(q, eqbs);
@@ -138,27 +122,30 @@ static int qdio_do_eqbs(struct qdio_q *q, unsigned char *state,
 again:
        ccq = do_eqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count,
                      auto_ack);
-       rc = qdio_check_ccq(q, ccq);
-       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 == 2) {
+       switch (ccq) {
+       case 0:
+       case 32:
+               /* all done, or next buffer state different */
+               return count - tmp_count;
+       case 96:
+               /* not all buffers processed */
                qperf_inc(q, eqbs_partial);
                DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS part:%02x",
                        tmp_count);
                return count - tmp_count;
+       case 97:
+               /* no buffer processed */
+               DBF_DEV_EVENT(DBF_WARN, q->irq_ptr, "EQBS again:%2d", ccq);
+               goto again;
+       default:
+               DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);
+               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_GET_BUF_STATE, q->nr,
+                          q->first_to_kick, count, q->irq_ptr->int_parm);
+               return 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_GET_BUF_STATE,
-                  q->nr, q->first_to_kick, count, q->irq_ptr->int_parm);
-       return 0;
 }
 
 /**
@@ -178,7 +165,6 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
        unsigned int ccq = 0;
        int tmp_count = count, tmp_start = start;
        int nr = q->nr;
-       int rc;
 
        if (!count)
                return 0;
@@ -188,23 +174,26 @@ static int qdio_do_sqbs(struct qdio_q *q, unsigned char state, int start,
                nr += q->irq_ptr->nr_input_qs;
 again:
        ccq = do_sqbs(q->irq_ptr->sch_token, state, nr, &tmp_start, &tmp_count);
-       rc = qdio_check_ccq(q, ccq);
-       if (!rc) {
+
+       switch (ccq) {
+       case 0:
+       case 32:
+               /* all done, or active buffer adapter-owned */
                WARN_ON_ONCE(tmp_count);
                return count - tmp_count;
-       }
-
-       if (rc == 1 || rc == 2) {
+       case 96:
+               /* not all buffers processed */
                DBF_DEV_EVENT(DBF_INFO, q->irq_ptr, "SQBS again:%2d", ccq);
                qperf_inc(q, sqbs_partial);
                goto again;
+       default:
+               DBF_ERROR("%4x ccq:%3d", SCH_NO(q), ccq);
+               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_SET_BUF_STATE, q->nr,
+                          q->first_to_kick, count, q->irq_ptr->int_parm);
+               return 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_SET_BUF_STATE,
-                  q->nr, q->first_to_kick, count, q->irq_ptr->int_parm);
-       return 0;
 }
 
 /*