[IA64] initialize /proc/iomem_machine properly when discontig mem.

With CONFIG_DISCONTIGMEM enabled /proc/iomem_machine isn't
initialized properly so that kexec failes because kexec-tools wrongly
tries to use ia64 boot mem (or efi memmap area).
This patch fixes /proc/iomem_machine.

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>

diff -r 75235538851a arch/ia64/mm/discontig.c
--- a/arch/ia64/mm/discontig.c	Thu Jul 24 14:31:08 2008 +0900
+++ b/arch/ia64/mm/discontig.c	Thu Jul 24 14:31:27 2008 +0900
@@ -21,6 +21,9 @@
 #include <linux/acpi.h>
 #include <linux/efi.h>
 #include <linux/nodemask.h>
+#if defined(CONFIG_XEN) && defined(CONFIG_KEXEC)
+#include <linux/kexec.h>
+#endif
 #include <asm/pgalloc.h>
 #include <asm/tlb.h>
 #include <asm/meminit.h>
@@ -502,10 +505,18 @@
 	reserve_pernode_space();
 	memory_less_nodes();
 	initialize_pernode_data();
+#if defined(CONFIG_XEN) && defined(CONFIG_KEXEC)
+	xen_machine_kexec_setup_resources();
+#endif
 
 	max_pfn = max_low_pfn;
 
 	find_initrd();
+#ifdef CONFIG_CRASH_DUMP
+	/* If we are doing a crash dump, we still need to know the real mem
+	 * size before original memory map is * reset. */
+	saved_max_pfn = max_pfn;
+#endif
 }
 
 #ifdef CONFIG_SMP