From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- include/drm/drm_syncobj.h | 136 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 include/drm/drm_syncobj.h (limited to 'include/drm/drm_syncobj.h') diff --git a/include/drm/drm_syncobj.h b/include/drm/drm_syncobj.h new file mode 100644 index 000000000..b40052132 --- /dev/null +++ b/include/drm/drm_syncobj.h @@ -0,0 +1,136 @@ +/* + * Copyright © 2017 Red Hat + * + * 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 (including the next + * paragraph) 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 AUTHORS OR COPYRIGHT HOLDERS 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. + * + * Authors: + * + */ +#ifndef __DRM_SYNCOBJ_H__ +#define __DRM_SYNCOBJ_H__ + +#include +#include + +struct drm_file; + +/** + * struct drm_syncobj - sync object. + * + * This structure defines a generic sync object which wraps a &dma_fence. + */ +struct drm_syncobj { + /** + * @refcount: Reference count of this object. + */ + struct kref refcount; + /** + * @fence: + * NULL or a pointer to the fence bound to this object. + * + * This field should not be used directly. Use drm_syncobj_fence_get() + * and drm_syncobj_replace_fence() instead. + */ + struct dma_fence __rcu *fence; + /** + * @cb_list: List of callbacks to call when the &fence gets replaced. + */ + struct list_head cb_list; + /** + * @ev_fd_list: List of registered eventfd. + */ + struct list_head ev_fd_list; + /** + * @lock: Protects &cb_list and &ev_fd_list, and write-locks &fence. + */ + spinlock_t lock; + /** + * @file: A file backing for this syncobj. + */ + struct file *file; +}; + +void drm_syncobj_free(struct kref *kref); + +/** + * drm_syncobj_get - acquire a syncobj reference + * @obj: sync object + * + * This acquires an additional reference to @obj. It is illegal to call this + * without already holding a reference. No locks required. + */ +static inline void +drm_syncobj_get(struct drm_syncobj *obj) +{ + kref_get(&obj->refcount); +} + +/** + * drm_syncobj_put - release a reference to a sync object. + * @obj: sync object. + */ +static inline void +drm_syncobj_put(struct drm_syncobj *obj) +{ + kref_put(&obj->refcount, drm_syncobj_free); +} + +/** + * drm_syncobj_fence_get - get a reference to a fence in a sync object + * @syncobj: sync object. + * + * This acquires additional reference to &drm_syncobj.fence contained in @obj, + * if not NULL. It is illegal to call this without already holding a reference. + * No locks required. + * + * Returns: + * Either the fence of @obj or NULL if there's none. + */ +static inline struct dma_fence * +drm_syncobj_fence_get(struct drm_syncobj *syncobj) +{ + struct dma_fence *fence; + + rcu_read_lock(); + fence = dma_fence_get_rcu_safe(&syncobj->fence); + rcu_read_unlock(); + + return fence; +} + +struct drm_syncobj *drm_syncobj_find(struct drm_file *file_private, + u32 handle); +void drm_syncobj_add_point(struct drm_syncobj *syncobj, + struct dma_fence_chain *chain, + struct dma_fence *fence, + uint64_t point); +void drm_syncobj_replace_fence(struct drm_syncobj *syncobj, + struct dma_fence *fence); +int drm_syncobj_find_fence(struct drm_file *file_private, + u32 handle, u64 point, u64 flags, + struct dma_fence **fence); +void drm_syncobj_free(struct kref *kref); +int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags, + struct dma_fence *fence); +int drm_syncobj_get_handle(struct drm_file *file_private, + struct drm_syncobj *syncobj, u32 *handle); +int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd); + +#endif -- cgit v1.3.1