[S390] qdio: fix kernel panic for zfcp 31-bit

The queue_start_poll function pointer field in struct qdio_initialize
had to change its type and become a vector of function pointers to
support asynchronous delivery of storage blocks so rename the field to
make the type change explicit and ensure no other user of qdio tries
to use the field the old way. During setting up the qdio queues, only
dereference vector elements if the vector is actually allocated.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Einar Lueck <elelueck@de.ibm.com>
Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/qdio.h

@@ -352,7 +352,7 @@ typedef void qdio_handler_t(struct ccw_device *, unsigned int, int,
  * @no_output_qs: number of output queues
  * @input_handler: handler to be called for input queues
  * @output_handler: handler to be called for output queues
- * @queue_start_poll: polling handlers (one per input queue or NULL)
+ * @queue_start_poll_array: polling handlers (one per input queue or NULL)
  * @int_parm: interruption parameter
  * @input_sbal_addr_array:  address of no_input_qs * 128 pointers
  * @output_sbal_addr_array: address of no_output_qs * 128 pointers
@@ -372,7 +372,8 @@ struct qdio_initialize {
 	unsigned int no_output_qs;
 	qdio_handler_t *input_handler;
 	qdio_handler_t *output_handler;
-	void (**queue_start_poll) (struct ccw_device *, int, unsigned long);
+	void (**queue_start_poll_array) (struct ccw_device *, int,
+					  unsigned long);
 	int scan_threshold;
 	unsigned long int_parm;
 	void **input_sbal_addr_array;

drivers/s390/cio/qdio_setup.c

@@ -177,7 +177,8 @@ 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[i];
+		q->u.in.queue_start_poll = qdio_init->queue_start_poll_array ?
+				qdio_init->queue_start_poll_array[i] : NULL;
 
 		setup_storage_lists(q, irq_ptr, input_sbal_array, i);
 		input_sbal_array += QDIO_MAX_BUFFERS_PER_Q;

drivers/s390/net/qeth_core_main.c

@@ -4521,7 +4521,7 @@ static int qeth_qdio_establish(struct qeth_card *card)
 	init_data.no_output_qs           = card->qdio.no_out_queues;
 	init_data.input_handler          = card->discipline.input_handler;
 	init_data.output_handler         = card->discipline.output_handler;
-	init_data.queue_start_poll       = queue_start_poll;
+	init_data.queue_start_poll_array = queue_start_poll;
 	init_data.int_parm               = (unsigned long) card;
 	init_data.input_sbal_addr_array  = (void **) in_sbal_ptrs;
 	init_data.output_sbal_addr_array = (void **) out_sbal_ptrs;