Re: [PATCH v14 1/8] drm/ttm: Balance ttm_resource_cursor_init() and ttm_resource_cursor_fini()

Christian König <christian.koenig@xxxxxxx> · Wed, 20 Nov 2024 11:51:21 +0100

Am 15.11.24 um 16:01 schrieb Thomas Hellström:
Make the interface more symmetric by providing and using a
ttm_resource_cursor_init().

v10:
- Fix a stray newline (Matthew Brost)
- Update kerneldoc (Matthew Brost)

Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Reviewed-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Reviewed-by: Christian König <christian.koenig@xxxxxxx>

Did you plan to merge this through drm-misc-next or the XE branch?

If through drm-misc-next then I would go ahead and push this patch since 
that is really a stand alone cleanup.

Regards,
Christian.

---
  drivers/gpu/drm/ttm/ttm_bo.c       |  3 ++-
  drivers/gpu/drm/ttm/ttm_bo_util.c  |  3 ++-
  drivers/gpu/drm/ttm/ttm_resource.c | 35 ++++++++++++++++++++----------
  include/drm/ttm/ttm_resource.h     | 11 +++++-----
  4 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 48c5365efca1..06d6a452c4f4 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -450,7 +450,8 @@ int ttm_bo_evict_first(struct ttm_device *bdev, struct ttm_resource_manager *man
  	int ret = 0;
  
  	spin_lock(&bdev->lru_lock);
-	res = ttm_resource_manager_first(man, &cursor);
+	ttm_resource_cursor_init(&cursor, man);
+	res = ttm_resource_manager_first(&cursor);
  	ttm_resource_cursor_fini(&cursor);
  	if (!res) {
  		ret = -ENOENT;
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index d939925efa81..917096bd5f68 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -865,7 +865,8 @@ s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev,
  	s64 lret;
  
  	spin_lock(&bdev->lru_lock);
-	ttm_resource_manager_for_each_res(man, &cursor, res) {
+	ttm_resource_cursor_init(&cursor, man);
+	ttm_resource_manager_for_each_res(&cursor, res) {
  		struct ttm_buffer_object *bo = res->bo;
  		bool bo_needs_unlock = false;
  		bool bo_locked = false;
diff --git a/drivers/gpu/drm/ttm/ttm_resource.c b/drivers/gpu/drm/ttm/ttm_resource.c
index a87665eb28a6..e19360cc7930 100644
--- a/drivers/gpu/drm/ttm/ttm_resource.c
+++ b/drivers/gpu/drm/ttm/ttm_resource.c
@@ -81,6 +81,23 @@ static void ttm_bulk_move_drop_cursors(struct ttm_lru_bulk_move *bulk)
  		ttm_resource_cursor_clear_bulk(cursor);
  }
  
+/**
+ * ttm_resource_cursor_init() - Initialize a struct ttm_resource_cursor
+ * @cursor: The cursor to initialize.
+ * @man: The resource manager.
+ *
+ * Initialize the cursor before using it for iteration.
+ */
+void ttm_resource_cursor_init(struct ttm_resource_cursor *cursor,
+			      struct ttm_resource_manager *man)
+{
+	cursor->priority = 0;
+	cursor->man = man;
+	ttm_lru_item_init(&cursor->hitch, TTM_LRU_HITCH);
+	INIT_LIST_HEAD(&cursor->bulk_link);
+	INIT_LIST_HEAD(&cursor->hitch.link);
+}
+
  /**
   * ttm_resource_cursor_fini() - Finalize the LRU list cursor usage
   * @cursor: The struct ttm_resource_cursor to finalize.
@@ -593,7 +610,6 @@ ttm_resource_cursor_check_bulk(struct ttm_resource_cursor *cursor,
  /**
   * ttm_resource_manager_first() - Start iterating over the resources
   * of a resource manager
- * @man: resource manager to iterate over
   * @cursor: cursor to record the position
   *
   * Initializes the cursor and starts iterating. When done iterating,
@@ -602,17 +618,16 @@ ttm_resource_cursor_check_bulk(struct ttm_resource_cursor *cursor,
   * Return: The first resource from the resource manager.
   */
  struct ttm_resource *
-ttm_resource_manager_first(struct ttm_resource_manager *man,
-			   struct ttm_resource_cursor *cursor)
+ttm_resource_manager_first(struct ttm_resource_cursor *cursor)
  {
-	lockdep_assert_held(&man->bdev->lru_lock);
+	struct ttm_resource_manager *man = cursor->man;
  
-	cursor->priority = 0;
-	cursor->man = man;
-	ttm_lru_item_init(&cursor->hitch, TTM_LRU_HITCH);
-	INIT_LIST_HEAD(&cursor->bulk_link);
-	list_add(&cursor->hitch.link, &man->lru[cursor->priority]);
+	if (WARN_ON_ONCE(!man))
+		return NULL;
+
+	lockdep_assert_held(&man->bdev->lru_lock);
  
+	list_move(&cursor->hitch.link, &man->lru[cursor->priority]);
  	return ttm_resource_manager_next(cursor);
  }
  
@@ -648,8 +663,6 @@ ttm_resource_manager_next(struct ttm_resource_cursor *cursor)
  		ttm_resource_cursor_clear_bulk(cursor);
  	}
  
-	ttm_resource_cursor_fini(cursor);
-
  	return NULL;
  }
  
diff --git a/include/drm/ttm/ttm_resource.h b/include/drm/ttm/ttm_resource.h
index be034be56ba1..e1f3b95d73b6 100644
--- a/include/drm/ttm/ttm_resource.h
+++ b/include/drm/ttm/ttm_resource.h
@@ -325,6 +325,9 @@ struct ttm_resource_cursor {
  	unsigned int priority;
  };
  
+void ttm_resource_cursor_init(struct ttm_resource_cursor *cursor,
+			      struct ttm_resource_manager *man);
+
  void ttm_resource_cursor_fini(struct ttm_resource_cursor *cursor);
  
  /**
@@ -456,8 +459,7 @@ void ttm_resource_manager_debug(struct ttm_resource_manager *man,
  				struct drm_printer *p);
  
  struct ttm_resource *
-ttm_resource_manager_first(struct ttm_resource_manager *man,
-			   struct ttm_resource_cursor *cursor);
+ttm_resource_manager_first(struct ttm_resource_cursor *cursor);
  struct ttm_resource *
  ttm_resource_manager_next(struct ttm_resource_cursor *cursor);
  
@@ -466,14 +468,13 @@ ttm_lru_first_res_or_null(struct list_head *head);
  
  /**
   * ttm_resource_manager_for_each_res - iterate over all resources
- * @man: the resource manager
   * @cursor: struct ttm_resource_cursor for the current position
   * @res: the current resource
   *
   * Iterate over all the evictable resources in a resource manager.
   */
-#define ttm_resource_manager_for_each_res(man, cursor, res)		\
-	for (res = ttm_resource_manager_first(man, cursor); res;	\
+#define ttm_resource_manager_for_each_res(cursor, res)	\
+	for (res = ttm_resource_manager_first(cursor); res;	\
  	     res = ttm_resource_manager_next(cursor))
  
  struct ttm_kmap_iter *







