vmalloc: add un/map_kernel_range_noflush()

Impact: two more public map/unmap functions

Implement map_kernel_range_noflush() and unmap_kernel_range_noflush().
These functions respectively map and unmap address range in kernel VM
area but doesn't do any vcache or tlb flushing.  These will be used by
new percpu allocator.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index bbc0513..599ba79 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -91,6 +91,9 @@
 
 extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
 			struct page ***pages);
+extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
+				    pgprot_t prot, struct page **pages);
+extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);
 extern void unmap_kernel_range(unsigned long addr, unsigned long size);
 
 /* Allocate/destroy a 'vmalloc' VM area. */