s390/qdio: add helpers to manage qdio buffers

Users of qdio buffers employ different strategies to manage these
buffers. The qeth driver uses huge contiguous buffers which leads
to high order allocations with all their downsides.

This patch provides helpers to allocate, free, and reset arrays of
qdio buffers using non contiguous pages.

Reviewed-by: Martin Peschke <mpeschke@linux.vnet.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/qdio.h b/arch/s390/include/asm/qdio.h
index d786c63..06f3034 100644
--- a/arch/s390/include/asm/qdio.h
+++ b/arch/s390/include/asm/qdio.h
@@ -415,6 +415,10 @@
 #define QDIO_FLAG_SYNC_OUTPUT		0x02
 #define QDIO_FLAG_PCI_OUT		0x10
 
+int qdio_alloc_buffers(struct qdio_buffer **buf, unsigned int count);
+void qdio_free_buffers(struct qdio_buffer **buf, unsigned int count);
+void qdio_reset_buffers(struct qdio_buffer **buf, unsigned int count);
+
 extern int qdio_allocate(struct qdio_initialize *);
 extern int qdio_establish(struct qdio_initialize *);
 extern int qdio_activate(struct ccw_device *);