drm/i915: handle walking compact dma scatter lists
So far the assumption was that each dma scatter list entry contains only
a single page. This might not hold in the future, when we'll introduce
compact scatter lists, so prepare for this everywhere in the i915 code
where we walk such a list.
We'll fix the place _creating_ these lists separately in the next patch
to help the reviewing/bisectability.
Reference: http://www.spinics.net/lists/dri-devel/msg33917.html
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 71f285c..1246a31 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1528,17 +1528,12 @@
int __must_check i915_gem_object_get_pages(struct drm_i915_gem_object *obj);
static inline struct page *i915_gem_object_get_page(struct drm_i915_gem_object *obj, int n)
{
- struct scatterlist *sg = obj->pages->sgl;
- int nents = obj->pages->nents;
- while (nents > SG_MAX_SINGLE_ALLOC) {
- if (n < SG_MAX_SINGLE_ALLOC - 1)
- break;
+ struct sg_page_iter sg_iter;
- sg = sg_chain_ptr(sg + SG_MAX_SINGLE_ALLOC - 1);
- n -= SG_MAX_SINGLE_ALLOC - 1;
- nents -= SG_MAX_SINGLE_ALLOC - 1;
- }
- return sg_page(sg+n);
+ for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, n)
+ return sg_iter.page;
+
+ return NULL;
}
static inline void i915_gem_object_pin_pages(struct drm_i915_gem_object *obj)
{