commit 25eaa97fc74b225e13cf11ed8d770192ddc9355d
Author: Eric Anholt <eric@anholt.net>
Date:   Thu Aug 21 12:53:33 2008 -0700

    Export kmap_atomic_pfn for DRM-GEM.
    
    The driver would like to map IO space directly for copying data in when
    appropriate, to avoid CPU cache flushing for streaming writes.
    kmap_atomic_pfn lets us avoid IPIs associated with ioremap for this process.
    
    Signed-off-by: Eric Anholt <eric@anholt.net>

diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 165c871..d52e91d 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -137,6 +137,7 @@ void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
 
 	return (void*) vaddr;
 }
+EXPORT_SYMBOL(kmap_atomic_pfn);
 
 struct page *kmap_atomic_to_page(void *ptr)
 {