[PATCH] drm/gem: fix mmap vma size calculations

[David Herrmann <dh.herrmann@gmail.com>]

The VMA manager is page-size based so drm_vma_node_size() returns the size
in pages. However, drm_gem_mmap_obj() requires the size in bytes. Apply
PAGE_SHIFT so we no longer get EINVAL during mmaps.

This bug was introduced with the recent intrduction of the unified VMA
manager. Fixes i915 gtt mmap failure reported by Sedat Dilek in:
  Re: linux-next: Tree for Jul 25 [ call-trace: drm | drm-intel related? ]

Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
---
 drivers/gpu/drm/drm_gem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 3613b50..1f76572 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -666,7 +666,7 @@ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 	}
 
 	obj = container_of(node, struct drm_gem_object, vma_node);
-	ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node), vma);
+	ret = drm_gem_mmap_obj(obj, drm_vma_node_size(node) << PAGE_SHIFT, vma);
 
 	mutex_unlock(&dev->struct_mutex);
 
-- 
1.8.3.4