From b5a824250e4aac4fb76c5076b6a5e460e52c831a Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 25 May 2017 21:48:18 +0100 Subject: [PATCH] drm/i915: Add kerneldoc to describe i915_gem_object.vma_list Add kerneldoc for the vma_list stored on the i915_gem_object, in particular, documenting the expected ordering of elements -- i.e. that we do expect GGTT VMA first followed by the ppGTT VMA. Signed-off-by: Chris Wilson Cc: Joonas Lahtinen Link: http://patchwork.freedesktop.org/patch/msgid/20170525204818.12044-1-chris@chris-wilson.co.uk Reviewed-by: Joonas Lahtinen --- drivers/gpu/drm/i915/i915_gem_object.h | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem_object.h b/drivers/gpu/drm/i915/i915_gem_object.h index 35e1a27729dc..915057824284 100644 --- a/drivers/gpu/drm/i915/i915_gem_object.h +++ b/drivers/gpu/drm/i915/i915_gem_object.h @@ -68,8 +68,23 @@ struct drm_i915_gem_object { const struct drm_i915_gem_object_ops *ops; - /** List of VMAs backed by this object */ + /** + * @vma_list: List of VMAs backed by this object + * + * The VMA on this list are ordered by type, all GGTT vma are placed + * at the head and all ppGTT vma are placed at the tail. The different + * types of GGTT vma are unordered between themselves, use the + * @vma_tree (which has a defined order between all VMA) to find an + * exact match. + */ struct list_head vma_list; + /** + * @vma_tree: Ordered tree of VMAs backed by this object + * + * All VMA created for this object are placed in the @vma_tree for + * fast retrieval via a binary search in i915_vma_instance(). + * They are also added to @vma_list for easy iteration. + */ struct rb_root vma_tree; /** Stolen memory for this object, instead of being backed by shmem. */