| /* |
| * Copyright (C) 2014 Red Hat |
| * Author: Rob Clark <robdclark@gmail.com> |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR |
| * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
| * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| * OTHER DEALINGS IN THE SOFTWARE. |
| */ |
| |
| #ifndef DRM_MODESET_LOCK_H_ |
| #define DRM_MODESET_LOCK_H_ |
| |
| #include <linux/ww_mutex.h> |
| |
| struct drm_modeset_lock; |
| |
| /** |
| * struct drm_modeset_acquire_ctx - locking context (see ww_acquire_ctx) |
| * @ww_ctx: base acquire ctx |
| * @contended: used internally for -EDEADLK handling |
| * @locked: list of held locks |
| * @trylock_only: trylock mode used in atomic contexts/panic notifiers |
| * |
| * Each thread competing for a set of locks must use one acquire |
| * ctx. And if any lock fxn returns -EDEADLK, it must backoff and |
| * retry. |
| */ |
| struct drm_modeset_acquire_ctx { |
| |
| struct ww_acquire_ctx ww_ctx; |
| |
| /** |
| * Contended lock: if a lock is contended you should only call |
| * drm_modeset_backoff() which drops locks and slow-locks the |
| * contended lock. |
| */ |
| struct drm_modeset_lock *contended; |
| |
| /** |
| * list of held locks (drm_modeset_lock) |
| */ |
| struct list_head locked; |
| |
| /** |
| * Trylock mode, use only for panic handlers! |
| */ |
| bool trylock_only; |
| }; |
| |
| /** |
| * struct drm_modeset_lock - used for locking modeset resources. |
| * @mutex: resource locking |
| * @head: used to hold it's place on state->locked list when |
| * part of an atomic update |
| * |
| * Used for locking CRTCs and other modeset resources. |
| */ |
| struct drm_modeset_lock { |
| /** |
| * modeset lock |
| */ |
| struct ww_mutex mutex; |
| |
| /** |
| * Resources that are locked as part of an atomic update are added |
| * to a list (so we know what to unlock at the end). |
| */ |
| struct list_head head; |
| }; |
| |
| extern struct ww_class crtc_ww_class; |
| |
| void drm_modeset_acquire_init(struct drm_modeset_acquire_ctx *ctx, |
| uint32_t flags); |
| void drm_modeset_acquire_fini(struct drm_modeset_acquire_ctx *ctx); |
| void drm_modeset_drop_locks(struct drm_modeset_acquire_ctx *ctx); |
| void drm_modeset_backoff(struct drm_modeset_acquire_ctx *ctx); |
| int drm_modeset_backoff_interruptible(struct drm_modeset_acquire_ctx *ctx); |
| |
| /** |
| * drm_modeset_lock_init - initialize lock |
| * @lock: lock to init |
| */ |
| static inline void drm_modeset_lock_init(struct drm_modeset_lock *lock) |
| { |
| ww_mutex_init(&lock->mutex, &crtc_ww_class); |
| INIT_LIST_HEAD(&lock->head); |
| } |
| |
| /** |
| * drm_modeset_lock_fini - cleanup lock |
| * @lock: lock to cleanup |
| */ |
| static inline void drm_modeset_lock_fini(struct drm_modeset_lock *lock) |
| { |
| WARN_ON(!list_empty(&lock->head)); |
| } |
| |
| /** |
| * drm_modeset_is_locked - equivalent to mutex_is_locked() |
| * @lock: lock to check |
| */ |
| static inline bool drm_modeset_is_locked(struct drm_modeset_lock *lock) |
| { |
| return ww_mutex_is_locked(&lock->mutex); |
| } |
| |
| int drm_modeset_lock(struct drm_modeset_lock *lock, |
| struct drm_modeset_acquire_ctx *ctx); |
| int drm_modeset_lock_interruptible(struct drm_modeset_lock *lock, |
| struct drm_modeset_acquire_ctx *ctx); |
| void drm_modeset_unlock(struct drm_modeset_lock *lock); |
| |
| struct drm_device; |
| struct drm_crtc; |
| |
| void drm_modeset_lock_all(struct drm_device *dev); |
| int __drm_modeset_lock_all(struct drm_device *dev, bool trylock); |
| void drm_modeset_unlock_all(struct drm_device *dev); |
| void drm_modeset_lock_crtc(struct drm_crtc *crtc); |
| void drm_modeset_unlock_crtc(struct drm_crtc *crtc); |
| void drm_warn_on_modeset_not_all_locked(struct drm_device *dev); |
| struct drm_modeset_acquire_ctx * |
| drm_modeset_legacy_acquire_ctx(struct drm_crtc *crtc); |
| |
| int drm_modeset_lock_all_crtcs(struct drm_device *dev, |
| struct drm_modeset_acquire_ctx *ctx); |
| |
| #endif /* DRM_MODESET_LOCK_H_ */ |