UIO: add pgprot_noncached() to UIO mmap code

[Chris Wright]

-stable review patch.  If anyone has any objections, please let us know.
---------------------

From: Jean-Samuel Chenard <jsamch@xxxxxxxxx>

upstream commit: c9698d6b1a90929e427a165bd8283f803f57d9bd

Mapping of physical memory in UIO needs pgprot_noncached() to ensure
that IO memory is not cached. Without pgprot_noncached(), it (accidentally)
works on x86 and arm, but fails on PPC.

Signed-off-by: Jean-Samuel Chenard <jsamch@xxxxxxxxx>
Signed-off-by: Hans J Koch <hjk@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
---
 drivers/uio/uio.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c
@@ -447,6 +447,8 @@ static int uio_mmap_physical(struct vm_a
 
 	vma->vm_flags |= VM_IO | VM_RESERVED;
 
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
 	return remap_pfn_range(vma,
 			       vma->vm_start,
 			       idev->info->mem[mi].addr >> PAGE_SHIFT,

-- 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/