drm/ttm: Create pinned list

This list will be used to capture all non VRAM BOs not
on LRU so when device is hot unplugged we can iterate
the list and unmap DMA mappings before device is removed.

v2: Reanme function to ttm_bo_move_to_pinned
v3: Move the pinned list to ttm device
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/451614/?series=93971

drivers/gpu/drm/ttm/ttm_bo.c

@@ -69,7 +69,17 @@ static void ttm_bo_mem_space_debug(struct ttm_buffer_object *bo,
 	}
 }
 
-static void ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
+static inline void ttm_bo_move_to_pinned(struct ttm_buffer_object *bo)
+{
+	struct ttm_device *bdev = bo->bdev;
+
+	list_move_tail(&bo->lru, &bdev->pinned);
+
+	if (bdev->funcs->del_from_lru_notify)
+		bdev->funcs->del_from_lru_notify(bo);
+}
+
+static inline void ttm_bo_del_from_lru(struct ttm_buffer_object *bo)
 {
 	struct ttm_device *bdev = bo->bdev;
 
@@ -98,7 +108,7 @@ void ttm_bo_move_to_lru_tail(struct ttm_buffer_object *bo,
 		dma_resv_assert_held(bo->base.resv);
 
 	if (bo->pin_count) {
-		ttm_bo_del_from_lru(bo);
+		ttm_bo_move_to_pinned(bo);
 		return;
 	}
 
@@ -342,7 +352,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
 		return ret;
 	}
 
-	ttm_bo_del_from_lru(bo);
+	ttm_bo_move_to_pinned(bo);
 	list_del_init(&bo->ddestroy);
 	spin_unlock(&bo->bdev->lru_lock);
 	ttm_bo_cleanup_memtype_use(bo);
@@ -1165,7 +1175,7 @@ int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
 		return 0;
 	}
 
-	ttm_bo_del_from_lru(bo);
+	ttm_bo_move_to_pinned(bo);
 	/* TODO: Cleanup the locking */
 	spin_unlock(&bo->bdev->lru_lock);
 

drivers/gpu/drm/ttm/ttm_device.c

@@ -210,6 +210,7 @@ int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs,
 	INIT_DELAYED_WORK(&bdev->wq, ttm_device_delayed_workqueue);
 	spin_lock_init(&bdev->lru_lock);
 	INIT_LIST_HEAD(&bdev->ddestroy);
+	INIT_LIST_HEAD(&bdev->pinned);
 	bdev->dev_mapping = mapping;
 	mutex_lock(&ttm_global_mutex);
 	list_add_tail(&bdev->device_list, &glob->device_list);

include/drm/ttm/ttm_device.h

@@ -265,6 +265,7 @@ struct ttm_device {
 	 */
 	spinlock_t lru_lock;
 	struct list_head ddestroy;
+	struct list_head pinned;
 
 	/*
 	 * Protected by load / firstopen / lastclose /unload sync.