[PATCH] ppc64: bump IOMMU_MAX_ORDER

Signed-off-by: Anton Blanchard <anton@samba.org>

We have cards that want over 2MB of PCI consistent memory.  The
IOMAP_MAX_ORDER limit is just to catch bad drivers early, so we can bump
this a bit.

We want some room to grow but our maximum get_free_pages allocation on
ppc64 is currently 16MB, so it doesnt make sense to go above that.

include/asm-ppc64/iommu.h

@@ -29,10 +29,10 @@
 
 /*
  * IOMAP_MAX_ORDER defines the largest contiguous block
- * of dma (tce) space we can get.  IOMAP_MAX_ORDER = 10 
- * allows up to 2**9 pages (512 * 4096) = 2 MB
+ * of dma (tce) space we can get.  IOMAP_MAX_ORDER = 13
+ * allows up to 2**12 pages (4096 * 4096) = 16 MB
  */
-#define IOMAP_MAX_ORDER 10
+#define IOMAP_MAX_ORDER 13
 
 /*
  * Tces come in two formats, one for the virtual bus and a different