From b5a824250e4aac4fb76c5076b6a5e460e52c831a Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 25 May 2017 21:48:18 +0100
Subject: [PATCH] drm/i915: Add kerneldoc to describe i915_gem_object.vma_list
Git-commit: b5a824250e4aac4fb76c5076b6a5e460e52c831a
Patch-mainline: v4.13-rc1
References: FATE#322643 bsc#1055900
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 <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170525204818.12044-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/i915/i915_gem_object.h | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
--- 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. */