NOMMU: Stub out vm_get_page_prot() if there's no MMU

Stub out vm_get_page_prot() if there's no MMU.

This was added by commit 804af2cf6e7a ("[AGPGART] remove private page
protection map") and is used in commit c07fbfd17e61 ("fbmem: VM_IO set,
but not propagated") in the fbmem video driver, but the function doesn't
exist on NOMMU, resulting in an undefined symbol at link time.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 831c693416b2..e6b1210772ce 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1363,7 +1363,15 @@ static inline unsigned long vma_pages(struct vm_area_struct *vma)
         return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 }
 
+#ifdef CONFIG_MMU
 pgprot_t vm_get_page_prot(unsigned long vm_flags);
+#else
+static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
+{
+        return __pgprot(0);
+}
+#endif
+
 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
                         unsigned long pfn, unsigned long size, pgprot_t);