[ 075/175] gma500: Fix mmap frambuffer

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

------------------

From: Yoichi Yuasa <redacted>

commit 1278f7de7fa5606ed513a5271f7fb63910ef1b8b upstream.

It cannot map correctly if page fault begins from a intermediate address.

[The driver prefaults the mapping, so we need to work from the correct
 base address not the faulting address otherwise the map appears offset by
 the fault offset]

Signed-off-by: Yoichi Yuasa <redacted>
Signed-off-by: Alan Cox <redacted>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/gma500/framebuffer.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/gma500/framebuffer.c
+++ b/drivers/gpu/drm/gma500/framebuffer.c

@@ -158,7 +158,7 @@ static int psbfb_vm_fault(struct vm_area
 	unsigned long phys_addr = (unsigned long)dev_priv->stolen_base;
 
 	page_num = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
-	address = (unsigned long)vmf->virtual_address;
+	address = (unsigned long)vmf->virtual_address - (vmf->pgoff << PAGE_SHIFT);
 
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);