mm: consolidate init_mm definition

* create mm/init-mm.c, move init_mm there
* remove INIT_MM, initialize init_mm with C99 initializer
* unexport init_mm on all arches:

  init_mm is already unexported on x86.

  One strange place is some OMAP driver (drivers/video/omap/) which
  won't build modular, but it's already wants get_vm_area() export.
  Somebody should look there.

[akpm@linux-foundation.org: add missing #includes]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Americo Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/init-mm.c b/mm/init-mm.c
new file mode 100644
index 0000000..57aba0d
--- /dev/null
+++ b/mm/init-mm.c
@@ -0,0 +1,20 @@
+#include <linux/mm_types.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/cpumask.h>
+
+#include <asm/atomic.h>
+#include <asm/pgtable.h>
+
+struct mm_struct init_mm = {
+	.mm_rb		= RB_ROOT,
+	.pgd		= swapper_pg_dir,
+	.mm_users	= ATOMIC_INIT(2),
+	.mm_count	= ATOMIC_INIT(1),
+	.mmap_sem	= __RWSEM_INITIALIZER(init_mm.mmap_sem),
+	.page_table_lock =  __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock),
+	.mmlist		= LIST_HEAD_INIT(init_mm.mmlist),
+	.cpu_vm_mask	= CPU_MASK_ALL,
+};