[CI] drm/ttm: Introduce TTM lru list links of different types

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

These will come in handy when LRU list iterators attach themselves
to the current list position with a LRU hitch.

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
---
 drivers/gpu/drm/ttm/ttm_device.c   | 13 ++++--
 drivers/gpu/drm/ttm/ttm_resource.c | 68 +++++++++++++++++++++---------
 include/drm/ttm/ttm_resource.h     | 31 +++++++++++++-
 3 files changed, 88 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
index 76027960054f..f27406e851e5 100644
--- a/drivers/gpu/drm/ttm/ttm_device.c
+++ b/drivers/gpu/drm/ttm/ttm_device.c
@@ -270,17 +270,22 @@ EXPORT_SYMBOL(ttm_device_fini);
 static void ttm_device_clear_lru_dma_mappings(struct ttm_device *bdev,
 					      struct list_head *list)
 {
-	struct ttm_resource *res;
+	struct ttm_lru_item *lru;
 
 	spin_lock(&bdev->lru_lock);
-	while ((res = list_first_entry_or_null(list, typeof(*res), lru))) {
-		struct ttm_buffer_object *bo = res->bo;
+	while ((lru = list_first_entry_or_null(list, typeof(*lru), link))) {
+		struct ttm_buffer_object *bo;
+
+		if (!ttm_lru_item_is_res(lru))
+			continue;
+
+		bo = ttm_lru_item_to_res(lru)->bo;
 
 		/* Take ref against racing releases once lru_lock is unlocked */
 		if (!ttm_bo_get_unless_zero(bo))
 			continue;
 
-		list_del_init(&res->lru);
+		list_del_init(&bo->resource->lru.link);
 		spin_unlock(&bdev->lru_lock);
 
 		if (bo->ttm)
diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index fb14f7716cf8..a347130570ee 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -69,8 +69,8 @@ void ttm_lru_bulk_move_tail(struct ttm_lru_bulk_move *bulk)
 			dma_resv_assert_held(pos->last->bo->base.resv);
 
 			man = ttm_manager_type(pos->first->bo->bdev, i);
-			list_bulk_move_tail(&man->lru[j], &pos->first->lru,
-					    &pos->last->lru);
+			list_bulk_move_tail(&man->lru[j], &pos->first->lru.link,
+					    &pos->last->lru.link);
 		}
 	}
 }
@@ -83,14 +83,36 @@ ttm_lru_bulk_move_pos(struct ttm_lru_bulk_move *bulk, struct ttm_resource *res)
 	return &bulk->pos[res->mem_type][res->bo->priority];
 }
 
+static struct ttm_resource *ttm_lru_prev_res(struct ttm_resource *cur)
+{
+	struct ttm_lru_item *lru = &cur->lru;
+
+	do {
+		lru = list_prev_entry(lru, link);
+	} while (!ttm_lru_item_is_res(lru));
+
+	return ttm_lru_item_to_res(lru);
+}
+
+static struct ttm_resource *ttm_lru_next_res(struct ttm_resource *cur)
+{
+	struct ttm_lru_item *lru = &cur->lru;
+
+	do {
+		lru = list_next_entry(lru, link);
+	} while (!ttm_lru_item_is_res(lru));
+
+	return ttm_lru_item_to_res(lru);
+}
+
 /* Move the resource to the tail of the bulk move range */
 static void ttm_lru_bulk_move_pos_tail(struct ttm_lru_bulk_move_pos *pos,
 				       struct ttm_resource *res)
 {
 	if (pos->last != res) {
 		if (pos->first == res)
-			pos->first = list_next_entry(res, lru);
-		list_move(&res->lru, &pos->last->lru);
+			pos->first = ttm_lru_next_res(res);
+		list_move(&res->lru.link, &pos->last->lru.link);
 		pos->last = res;
 	}
 }
@@ -120,11 +142,11 @@ static void ttm_lru_bulk_move_del(struct ttm_lru_bulk_move *bulk,
 		pos->first = NULL;
 		pos->last = NULL;
 	} else if (pos->first == res) {
-		pos->first = list_next_entry(res, lru);
+		pos->first = ttm_lru_next_res(res);
 	} else if (pos->last == res) {
-		pos->last = list_prev_entry(res, lru);
+		pos->last = ttm_lru_prev_res(res);
 	} else {
-		list_move(&res->lru, &pos->last->lru);
+		list_move(&res->lru.link, &pos->last->lru.link);
 	}
 }
 
@@ -153,7 +175,7 @@ void ttm_resource_move_to_lru_tail(struct ttm_resource *res)
 	lockdep_assert_held(&bo->bdev->lru_lock);
 
 	if (bo->pin_count) {
-		list_move_tail(&res->lru, &bdev->pinned);
+		list_move_tail(&res->lru.link, &bdev->pinned);
 
 	} else	if (bo->bulk_move) {
 		struct ttm_lru_bulk_move_pos *pos =
@@ -164,7 +186,7 @@ void ttm_resource_move_to_lru_tail(struct ttm_resource *res)
 		struct ttm_resource_manager *man;
 
 		man = ttm_manager_type(bdev, res->mem_type);
-		list_move_tail(&res->lru, &man->lru[bo->priority]);
+		list_move_tail(&res->lru.link, &man->lru[bo->priority]);
 	}
 }
 
@@ -195,9 +217,9 @@ void ttm_resource_init(struct ttm_buffer_object *bo,
 	man = ttm_manager_type(bo->bdev, place->mem_type);
 	spin_lock(&bo->bdev->lru_lock);
 	if (bo->pin_count)
-		list_add_tail(&res->lru, &bo->bdev->pinned);
+		list_add_tail(&res->lru.link, &bo->bdev->pinned);
 	else
-		list_add_tail(&res->lru, &man->lru[bo->priority]);
+		list_add_tail(&res->lru.link, &man->lru[bo->priority]);
 	man->usage += res->size;
 	spin_unlock(&bo->bdev->lru_lock);
 }
@@ -219,7 +241,7 @@ void ttm_resource_fini(struct ttm_resource_manager *man,
 	struct ttm_device *bdev = man->bdev;
 
 	spin_lock(&bdev->lru_lock);
-	list_del_init(&res->lru);
+	list_del_init(&res->lru.link);
 	man->usage -= res->size;
 	spin_unlock(&bdev->lru_lock);
 }
@@ -462,14 +484,16 @@ struct ttm_resource *
 ttm_resource_manager_first(struct ttm_resource_manager *man,
 			   struct ttm_resource_cursor *cursor)
 {
-	struct ttm_resource *res;
+	struct ttm_lru_item *lru;
 
 	lockdep_assert_held(&man->bdev->lru_lock);
 
 	for (cursor->priority = 0; cursor->priority < TTM_MAX_BO_PRIORITY;
 	     ++cursor->priority)
-		list_for_each_entry(res, &man->lru[cursor->priority], lru)
-			return res;
+		list_for_each_entry(lru, &man->lru[cursor->priority], link) {
+			if (ttm_lru_item_is_res(lru))
+				return ttm_lru_item_to_res(lru);
+		}
 
 	return NULL;
 }
@@ -488,15 +512,21 @@ ttm_resource_manager_next(struct ttm_resource_manager *man,
 			  struct ttm_resource_cursor *cursor,
 			  struct ttm_resource *res)
 {
+	struct ttm_lru_item *lru = &res->lru;
+
 	lockdep_assert_held(&man->bdev->lru_lock);
 
-	list_for_each_entry_continue(res, &man->lru[cursor->priority], lru)
-		return res;
+	list_for_each_entry_continue(lru, &man->lru[cursor->priority], link) {
+		if (ttm_lru_item_is_res(lru))
+			return ttm_lru_item_to_res(lru);
+	}
 
 	for (++cursor->priority; cursor->priority < TTM_MAX_BO_PRIORITY;
 	     ++cursor->priority)
-		list_for_each_entry(res, &man->lru[cursor->priority], lru)
-			return res;
+		list_for_each_entry(lru, &man->lru[cursor->priority], link) {
+			if (ttm_lru_item_is_res(lru))
+				ttm_lru_item_to_res(lru);
+		}
 
 	return NULL;
 }
diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
index 1afa13f0c22b..1446cfa726cb 100644
--- a/include/drm/ttm/ttm_resource.h
+++ b/include/drm/ttm/ttm_resource.h
@@ -49,6 +49,29 @@ struct io_mapping;
 struct sg_table;
 struct scatterlist;
 
+
+enum ttm_lru_item_type {
+	TTM_LRU_RESOURCE,
+	TTM_LRU_HITCH
+};
+
+struct ttm_lru_item {
+	struct list_head link;
+	enum ttm_lru_item_type type;
+};
+
+static inline void ttm_lru_item_init(struct ttm_lru_item *item,
+				     enum ttm_lru_item_type type)
+{
+	item->type = type;
+	INIT_LIST_HEAD(&item->link);
+}
+
+static inline bool ttm_lru_item_is_res(const struct ttm_lru_item *item)
+{
+	return item->type == TTM_LRU_RESOURCE;
+}
+
 struct ttm_resource_manager_func {
 	/**
 	 * struct ttm_resource_manager_func member alloc
@@ -217,9 +240,15 @@ struct ttm_resource {
 	/**
 	 * @lru: Least recently used list, see &ttm_resource_manager.lru
 	 */
-	struct list_head lru;
+	struct ttm_lru_item lru;
 };
 
+static inline struct ttm_resource *
+ttm_lru_item_to_res(struct ttm_lru_item *item)
+{
+	return container_of(item, struct ttm_resource, lru);
+}
+
 /**
  * struct ttm_resource_cursor
  *
-- 
2.43.0