[S390] qdio: improve inbound buffer acknowledgement

- Use automatic acknowledgement of incoming buffers in QEBSM mode
- Move ACK for non-QEBSM mode always to the newest buffer to prevent
  a race with qdio_stop_polling
- Remove the polling spinlock, the upper layer drivers return new buffers
  in the same code path and could not run in parallel
- Don't flood the error log in case of no-target-buffer-empty
- In handle_inbound we check if we would overwrite an ACK'ed buffer, if so
  advance the pointer to the oldest ACK'ed buffer so we don't overwrite an
  empty buffer in qdio_stop_polling

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/s390/cio/qdio_debug.c b/drivers/s390/cio/qdio_debug.c
index 0add07c1b5d..f8a3b6967f6 100644
--- a/drivers/s390/cio/qdio_debug.c
+++ b/drivers/s390/cio/qdio_debug.c
@@ -60,16 +60,18 @@ static int qstat_show(struct seq_file *m, void *v)
         if (!q)
                 return 0;
 
-        seq_printf(m, "device state indicator: %d\n", *q->irq_ptr->dsci);
+        seq_printf(m, "device state indicator: %d\n", *(u32 *)q->irq_ptr->dsci);
         seq_printf(m, "nr_used: %d\n", atomic_read(&q->nr_buf_used));
         seq_printf(m, "ftc: %d\n", q->first_to_check);
         seq_printf(m, "last_move_ftc: %d\n", q->last_move_ftc);
         seq_printf(m, "polling: %d\n", q->u.in.polling);
+        seq_printf(m, "ack count: %d\n", q->u.in.ack_count);
         seq_printf(m, "slsb buffer states:\n");
+        seq_printf(m, "|0      |8      |16     |24     |32     |40     |48     |56  63|\n");
 
         qdio_siga_sync_q(q);
         for (i = 0; i < QDIO_MAX_BUFFERS_PER_Q; i++) {
-                get_buf_state(q, i, &state);
+                get_buf_state(q, i, &state, 0);
                 switch (state) {
                 case SLSB_P_INPUT_NOT_INIT:
                 case SLSB_P_OUTPUT_NOT_INIT:
@@ -101,6 +103,7 @@ static int qstat_show(struct seq_file *m, void *v)
                         seq_printf(m, "\n");
         }
         seq_printf(m, "\n");
+        seq_printf(m, "|64     |72     |80     |88     |96     |104    |112    |   127|\n");
         return 0;
 }