alpha: fix vmalloc breakage

On alpha, we have to map some stuff in the VMALLOC space very early in the
boot process (to make SRM console callbacks work and so on, see
arch/alpha/mm/init.c).  For old VM allocator, we just manually placed a
vm_struct onto the global vmlist and this worked for ages.

Unfortunately, the new allocator isn't aware of this, so it constantly
tries to allocate the VM space which is already in use, making vmalloc on
alpha defunct.

This patch forces KVA to import vmlist entries on init.

[akpm@linux-foundation.org: remove unneeded check (per Johannes)]
Signed-off-by: NIvan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/vmalloc.c

@@ -24,6 +24,7 @@
 #include <linux/rbtree.h>
 #include <linux/radix-tree.h>
 #include <linux/rcupdate.h>
+#include <linux/bootmem.h>
 
 #include <asm/atomic.h>
 #include <asm/uaccess.h>
@@ -984,6 +985,8 @@ EXPORT_SYMBOL(vm_map_ram);
 
 void __init vmalloc_init(void)
 {
+	struct vmap_area *va;
+	struct vm_struct *tmp;
 	int i;
 
 	for_each_possible_cpu(i) {
@@ -996,6 +999,14 @@ void __init vmalloc_init(void)
 		vbq->nr_dirty = 0;
 	}
 
+	/* Import existing vmlist entries. */
+	for (tmp = vmlist; tmp; tmp = tmp->next) {
+		va = alloc_bootmem(sizeof(struct vmap_area));
+		va->flags = tmp->flags | VM_VM_AREA;
+		va->va_start = (unsigned long)tmp->addr;
+		va->va_end = va->va_start + tmp->size;
+		__insert_vmap_area(va);
+	}
 	vmap_initialized = true;
 }