[POWERPC] Add arch-specific walk_memory_remove() for 64-bit powerpc

walk_memory_resource() verifies if there are holes in a given memory
range, by checking against /proc/iomem.  On x86/ia64 system memory is
represented in /proc/iomem.  On powerpc, we don't show system memory as
IO resource in /proc/iomem - instead it's maintained in
/proc/device-tree.

This provides a way for an architecture to provide its own
walk_memory_resource() function.  On powerpc, the memory region is
small (16MB), contiguous and non-overlapping.  So extra checking
against the device-tree is not needed.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@gate.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d55063c021d5..26b963c33c88 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -272,6 +272,9 @@ config HOTPLUG_CPU
 config ARCH_ENABLE_MEMORY_HOTPLUG
         def_bool y
 
+config ARCH_HAS_WALK_MEMORY
+        def_bool y
+
 config ARCH_ENABLE_MEMORY_HOTREMOVE
         def_bool y