drm/i915: VM eviction only targets address space not physical pages

During eviction, we are only considering how to free up space within the
current address space and not concerned with freeing up physical memory.
As such we need only skip nodes that pinned in the current VM and not
globally.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem_evict.c

@@ -36,8 +36,7 @@
 static bool
 mark_free(struct i915_vma *vma, struct list_head *unwind)
 {
-	/* Freeing up memory requires no VMAs are pinned */
-	if (i915_gem_obj_is_pinned(vma->obj))
+	if (vma->pin_count)
 		return false;
 
 	if (WARN_ON(!list_empty(&vma->exec_list)))