[PATCH v3] powerpc/mm: fix undefined reference to `.__kernel_map_pages' on FSL PPC64

[Kim Phillips]

arch/powerpc has __kernel_map_pages implementations in mm/pgtable_32.c, and
mm/hash_utils_64.c, of which the former is built for PPC32, and the latter
for PPC64 machines with PPC_STD_MMU.  Fix arch/powerpc/Kconfig to not select
ARCH_SUPPORTS_DEBUG_PAGEALLOC when CONFIG_PPC_STD_MMU_64 isn't defined,
i.e., for 64-bit book3e builds to use the generic __kernel_map_pages()
in mm/debug-pagealloc.c.

  LD      init/built-in.o
mm/built-in.o: In function `kernel_map_pages':
include/linux/mm.h:2076: undefined reference to `.__kernel_map_pages'
include/linux/mm.h:2076: undefined reference to `.__kernel_map_pages'
include/linux/mm.h:2076: undefined reference to `.__kernel_map_pages'
Makefile:925: recipe for target 'vmlinux' failed
make: *** [vmlinux] Error 1

Signed-off-by: Kim Phillips <kim.phillips at freescale.com>
---
v3:
- fix wording for hash_utils_64.c implementation pointed out by
Michael Ellerman
- changed designation from 'mm:' to 'powerpc/mm:', as I think this
now belongs in ppc-land

v2:
- corrected SUPPORTS_DEBUG_PAGEALLOC selection to enable
non-STD_MMU_64 builds to use the generic __kernel_map_pages().

depends on:
From: Joonsoo Kim <iamjoonsoo.kim at lge.com>
Date: Thu, 22 Jan 2015 10:28:58 +0900
Subject: [PATCH] mm/debug_pagealloc: fix build failure on ppc and some other archs

 arch/powerpc/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a2a168e..22b0940 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -256,6 +256,7 @@ config PPC_OF_PLATFORM_PCI
 	default n
 
 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
+	depends on PPC32 || PPC_STD_MMU_64
 	def_bool y
 
 config ARCH_SUPPORTS_UPROBES
-- 
2.2.2