[ARM] Add initial sparsemem support

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig

@@ -422,6 +422,8 @@ config ARCH_SA1100
 	bool "SA1100-based"
 	select ISA
 	select ARCH_DISCONTIGMEM_ENABLE
+	select ARCH_SPARSEMEM_ENABLE
+	select ARCH_SELECT_MEMORY_MODEL
 	select ARCH_MTD_XIP
 	select GENERIC_GPIO
 	select GENERIC_TIME
@@ -774,6 +776,12 @@ config ARCH_DISCONTIGMEM_ENABLE
 	  or have huge holes in the physical address space for other reasons.
 	  See <file:Documentation/vm/numa> for more.
 
+config ARCH_SPARSEMEM_ENABLE
+	bool
+
+config ARCH_SELECT_MEMORY_MODEL
+	bool
+
 config NODES_SHIFT
 	int
 	default "4" if ARCH_LH7A40X

arch/arm/mach-clps711x/Kconfig

@@ -31,6 +31,8 @@ config ARCH_EDB7211
 	bool "EDB7211"
 	select ISA
 	select ARCH_DISCONTIGMEM_ENABLE
+	select ARCH_SPARSEMEM_ENABLE
+	select ARCH_SELECT_MEMORY_MODEL
 	help
 	  Say Y here if you intend to run this kernel on a Cirrus Logic EDB-7211
 	  evaluation board.

include/asm-arm/memory.h

@@ -217,7 +217,10 @@ static inline __deprecated void *bus_to_virt(unsigned long x)
 #ifndef CONFIG_DISCONTIGMEM
 
 #define ARCH_PFN_OFFSET		PHYS_PFN_OFFSET
+
+#ifndef CONFIG_SPARSEMEM
 #define pfn_valid(pfn)		((pfn) >= PHYS_PFN_OFFSET && (pfn) < (PHYS_PFN_OFFSET + max_mapnr))
+#endif
 
 #define virt_to_page(kaddr)	pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
 #define virt_addr_valid(kaddr)	((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory)

include/asm-arm/sparsemem.h

@@ -0,0 +1,10 @@
+#ifndef ASMARM_SPARSEMEM_H
+#define ASMARM_SPARSEMEM_H
+
+#include <asm/memory.h>
+
+#define MAX_PHYSADDR_BITS	32
+#define MAX_PHYSMEM_BITS	32
+#define SECTION_SIZE_BITS	NODE_MEM_SIZE_BITS
+
+#endif