qdio: extend API to allow polling

Extend the qdio API to allow polling in the upper-layer driver. This
is needed by qeth to use NAPI.

To use the new interface the upper-layer driver must specify the
queue_start_poll(). This callback is used to signal the upper-layer
driver that is has initiative and must process the inbound queue by
calling qdio_get_next_buffers(). If the upper-layer driver wants to
stop polling it calls qdio_start_irq().

Since adapter interrupts are not completely stoppable qdio implements
a software bit QDIO_QUEUE_IRQS_DISABLED to safely disable interrupts for an
input queue.

The old interface is preserved and will be used as is by zfcp.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/s390/cio/qdio_setup.c b/drivers/s390/cio/qdio_setup.c
index 34c7e4046df4..a13cf7ec64b2 100644
--- a/drivers/s390/cio/qdio_setup.c
+++ b/drivers/s390/cio/qdio_setup.c
@@ -161,6 +161,7 @@ static void setup_queues(struct qdio_irq *irq_ptr,
                 setup_queues_misc(q, irq_ptr, qdio_init->input_handler, i);
 
                 q->is_input_q = 1;
+                q->u.in.queue_start_poll = qdio_init->queue_start_poll;
                 setup_storage_lists(q, irq_ptr, input_sbal_array, i);
                 input_sbal_array += QDIO_MAX_BUFFERS_PER_Q;