drm/vc4: bo: Add a managed action to cleanup the cache

The BO cache needs to be cleaned up using vc4_bo_cache_destroy, but it's
not used consistently (vc4_drv's bind calls it in its error path, but
doesn't in unbind), and we can make that automatic through a managed
action. Let's remove the requirement to call vc4_bo_cache_destroy.

Fixes: c826a6e106 ("drm/vc4: Add a BO cache.")
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20201029190104.2181730-1-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_bo.c

@@ -1005,6 +1005,7 @@ int vc4_get_tiling_ioctl(struct drm_device *dev, void *data,
 	return 0;
 }
 
+static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused);
 int vc4_bo_cache_init(struct drm_device *dev)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
@@ -1033,10 +1034,10 @@ int vc4_bo_cache_init(struct drm_device *dev)
 	INIT_WORK(&vc4->bo_cache.time_work, vc4_bo_cache_time_work);
 	timer_setup(&vc4->bo_cache.time_timer, vc4_bo_cache_time_timer, 0);
 
-	return 0;
+	return drmm_add_action_or_reset(dev, vc4_bo_cache_destroy, NULL);
 }
 
-void vc4_bo_cache_destroy(struct drm_device *dev)
+static void vc4_bo_cache_destroy(struct drm_device *dev, void *unused)
 {
 	struct vc4_dev *vc4 = to_vc4_dev(dev);
 	int i;

drivers/gpu/drm/vc4/vc4_drv.c

@@ -315,7 +315,6 @@ unbind_all:
 gem_destroy:
 	vc4_gem_destroy(drm);
 	drm_mode_config_cleanup(drm);
-	vc4_bo_cache_destroy(drm);
 dev_put:
 	drm_dev_put(drm);
 	return ret;

drivers/gpu/drm/vc4/vc4_drv.h

@@ -14,6 +14,7 @@
 #include <drm/drm_device.h>
 #include <drm/drm_encoder.h>
 #include <drm/drm_gem_cma_helper.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_mm.h>
 #include <drm/drm_modeset_lock.h>
 
@@ -809,7 +810,6 @@ struct drm_gem_object *vc4_prime_import_sg_table(struct drm_device *dev,
 						 struct sg_table *sgt);
 void *vc4_prime_vmap(struct drm_gem_object *obj);
 int vc4_bo_cache_init(struct drm_device *dev);
-void vc4_bo_cache_destroy(struct drm_device *dev);
 int vc4_bo_inc_usecnt(struct vc4_bo *bo);
 void vc4_bo_dec_usecnt(struct vc4_bo *bo);
 void vc4_bo_add_to_purgeable_pool(struct vc4_bo *bo);