ARM: mach-shmobile: r8a7740: reserve DMA memory for the frame buffer

The default 2MB size of DMA coherent memory isn't enough for allocate
frame buffer memory.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Simon Horman <horms@verge.net.au>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

arch/arm/mach-shmobile/setup-r8a7740.c

@@ -18,6 +18,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 #include <linux/delay.h>
+#include <linux/dma-mapping.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/io.h>
@@ -60,6 +61,12 @@ static struct map_desc r8a7740_io_desc[] __initdata = {
 void __init r8a7740_map_io(void)
 {
 	iotable_init(r8a7740_io_desc, ARRAY_SIZE(r8a7740_io_desc));
+
+	/*
+	 * DMA memory at 0xff200000 - 0xffdfffff. The default 2MB size isn't
+	 * enough to allocate the frame buffer memory.
+	 */
+	init_consistent_dma_size(12 << 20);
 }
 
 /* SCIFA0 */