ARM: shmobile: Add shared R-Car Gen2 CMA reservation code

Add R-Car Gen2 CMA memory reservation code that can be
shared between multiple SoCs and boards. At this point
r8a7790 and r8a7791 are supported.

The top 256MiB of the legacy 32-bit physical memory space
is assigned to a separate CMA area that may be assigned
to various devices later on.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
[horms+renesas@verge.net.au: rebased]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/mach-shmobile/rcar-gen2.h

@@ -4,5 +4,6 @@
 void rcar_gen2_timer_init(void);
 #define MD(nr) BIT(nr)
 u32 rcar_gen2_read_mode_pins(void);
+void rcar_gen2_reserve(void);
 
 #endif /* __ASM_RCAR_GEN2_H__ */

arch/arm/mach-shmobile/setup-r8a7790.c

@@ -327,6 +327,7 @@ DT_MACHINE_START(R8A7790_DT, "Generic R8A7790 (Flattened Device Tree)")
 	.init_early	= r8a7790_init_early,
 	.init_time	= rcar_gen2_timer_init,
 	.init_late	= shmobile_init_late,
+	.reserve	= rcar_gen2_reserve,
 	.dt_compat	= r8a7790_boards_compat_dt,
 MACHINE_END
 #endif /* CONFIG_USE_OF */

arch/arm/mach-shmobile/setup-r8a7791.c

@@ -218,6 +218,7 @@ DT_MACHINE_START(R8A7791_DT, "Generic R8A7791 (Flattened Device Tree)")
 	.init_early	= shmobile_init_delay,
 	.init_time	= rcar_gen2_timer_init,
 	.init_late	= shmobile_init_late,
+	.reserve	= rcar_gen2_reserve,
 	.dt_compat	= r8a7791_boards_compat_dt,
 MACHINE_END
 #endif /* CONFIG_USE_OF */

arch/arm/mach-shmobile/setup-rcar-gen2.c

@@ -20,8 +20,11 @@
 
 #include <linux/clk/shmobile.h>
 #include <linux/clocksource.h>
+#include <linux/device.h>
+#include <linux/dma-contiguous.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/of_fdt.h>
 #include <asm/mach/arch.h>
 #include "common.h"
 #include "rcar-gen2.h"