RealView: Add sparsemem support for the RealView PBX platform

The RealView PBX board has two 512MB blocks of memory - one at
0x70000000 (with 256MB mirror at 0) and another at 0x20000000. Only the
block at 0x70000000 (or the mirror at 0) may be used for DMA (e.g.
framebuffer). This patch adds the sparsemem definitions to allow the use
of all the memory split as follows:

  256MB @ 0x00000000 (ZONE_DMA)
  512MB @ 0x20000000 (ZONE_NORMAL)
  256MB @ 0x80000000 (ZONE_NORMAL)

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/arch/arm/mach-realview/Kconfig b/arch/arm/mach-realview/Kconfig
index dfc9b0bc6eb2..c48e1f2c3349 100644
--- a/arch/arm/mach-realview/Kconfig
+++ b/arch/arm/mach-realview/Kconfig
@@ -70,6 +70,8 @@ config MACH_REALVIEW_PBX
         bool "Support RealView/PBX platform"
         select ARM_GIC
         select HAVE_PATA_PLATFORM
+        select ARCH_SPARSEMEM_ENABLE if CPU_V7 && !HIGH_PHYS_OFFSET
+        select ZONE_DMA if SPARSEMEM
         help
           Include support for the ARM(R) RealView PBX platform.
 
@@ -82,6 +84,7 @@ config REALVIEW_HIGH_PHYS_OFFSET
           0x70000000, 256MB of which being mirrored at 0x00000000. If
           the board supports 512MB of RAM, this option allows the
           memory to be accessed contiguously at the high physical
-          offset.
+          offset. On the PBX board, disabling this option allows 1GB of
+          RAM to be used with SPARSEMEM.
 
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