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.
 
 endmenu