From ab4f75eb1cc261263ac51814fed14fde08b6716f Mon Sep 17 00:00:00 2001 From: Ben Skeggs Date: Wed, 1 Jun 2022 20:46:51 +1000 Subject: [PATCH] drm/nouveau/nvkm: give each nvkm_event its own lockdep class The vblank and nonstall events have some annoying interactions with DRM locking, and aren't able to do certain things as a result. However, other uses of event notifications don't have such requirements, and upcoming patches take advantage of this for various improvements. Having separate classes for each nvkm_event's spinlocks allows lockdep to distinguish between them and avoid false-positives. v2: __always_inline + comment Signed-off-by: Ben Skeggs Reviewed-by: Lyude Paul --- .../gpu/drm/nouveau/include/nvkm/core/event.h | 19 +++++++++++++++++-- drivers/gpu/drm/nouveau/nvkm/core/event.c | 6 ++---- 2 files changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/nouveau/include/nvkm/core/event.h b/drivers/gpu/drm/nouveau/include/nvkm/core/event.h index 8e8fb4b6bca4..82b267c11147 100644 --- a/drivers/gpu/drm/nouveau/include/nvkm/core/event.h +++ b/drivers/gpu/drm/nouveau/include/nvkm/core/event.h @@ -25,8 +25,23 @@ struct nvkm_event_func { void (*fini)(struct nvkm_event *, int type, int index); }; -int nvkm_event_init(const struct nvkm_event_func *func, struct nvkm_subdev *, int types_nr, - int index_nr, struct nvkm_event *); +int __nvkm_event_init(const struct nvkm_event_func *func, struct nvkm_subdev *, int types_nr, + int index_nr, struct nvkm_event *); + +/* Each nvkm_event needs its own lockdep class due to inter-dependencies, to + * prevent lockdep false-positives. + * + * Inlining the spinlock initialisation ensures each is unique. + */ +static __always_inline int +nvkm_event_init(const struct nvkm_event_func *func, struct nvkm_subdev *subdev, + int types_nr, int index_nr, struct nvkm_event *event) +{ + spin_lock_init(&event->refs_lock); + spin_lock_init(&event->list_lock); + return __nvkm_event_init(func, subdev, types_nr, index_nr, event); +} + void nvkm_event_fini(struct nvkm_event *); #define NVKM_EVENT_KEEP 0 diff --git a/drivers/gpu/drm/nouveau/nvkm/core/event.c b/drivers/gpu/drm/nouveau/nvkm/core/event.c index 622df36391be..a6c877135598 100644 --- a/drivers/gpu/drm/nouveau/nvkm/core/event.c +++ b/drivers/gpu/drm/nouveau/nvkm/core/event.c @@ -198,8 +198,8 @@ nvkm_event_fini(struct nvkm_event *event) } int -nvkm_event_init(const struct nvkm_event_func *func, struct nvkm_subdev *subdev, - int types_nr, int index_nr, struct nvkm_event *event) +__nvkm_event_init(const struct nvkm_event_func *func, struct nvkm_subdev *subdev, + int types_nr, int index_nr, struct nvkm_event *event) { event->refs = kzalloc(array3_size(index_nr, types_nr, sizeof(*event->refs)), GFP_KERNEL); if (!event->refs) @@ -209,8 +209,6 @@ nvkm_event_init(const struct nvkm_event_func *func, struct nvkm_subdev *subdev, event->subdev = subdev; event->types_nr = types_nr; event->index_nr = index_nr; - spin_lock_init(&event->refs_lock); - spin_lock_init(&event->list_lock); INIT_LIST_HEAD(&event->ntfy); return 0; }