/* SPDX-License-Identifier: GPL-2.0 OR MIT */ #ifndef __DRM_EXEC_H__ #define __DRM_EXEC_H__ #include <linux/compiler.h> #include <linux/ww_mutex.h> #define DRM_EXEC_INTERRUPTIBLE_WAIT BIT(0) #define DRM_EXEC_IGNORE_DUPLICATES BIT(1) /* * Dummy value used to initially enter the retry loop. * internal use only. */ #define DRM_EXEC_DUMMY ((void *)~0) struct drm_gem_object; /** * struct drm_exec - Execution context */ struct drm_exec { /** * @flags: Flags to control locking behavior */ u32 flags; /** * @ticket: WW ticket used for acquiring locks */ struct ww_acquire_ctx ticket; /** * @num_objects: number of objects locked */ unsigned int num_objects; /** * @max_objects: maximum objects in array */ unsigned int max_objects; /** * @objects: array of the locked objects */ struct drm_gem_object **objects; /** * @contended: contended GEM object we backed off for */ struct drm_gem_object *contended; /** * @prelocked: already locked GEM object due to contention */ struct drm_gem_object *prelocked; }; /** * drm_exec_obj() - Return the object for a give drm_exec index * @exec: Pointer to the drm_exec context * @index: The index. * * Return: Pointer to the locked object corresponding to @index if * index is within the number of locked objects. NULL otherwise. */ static inline struct drm_gem_object * drm_exec_obj(struct drm_exec *exec, unsigned long index) { return index < exec->num_objects ? exec->objects[index] : NULL; } /* Helper for drm_exec_for_each_locked_object(). Internal use only. */ #define __drm_exec_for_each_locked_object(exec, obj, __index) \ for (unsigned long __index = 0; ((obj) = drm_exec_obj(exec, __index)); ++__index) /** * drm_exec_for_each_locked_object - iterate over all the locked objects * @exec: drm_exec object * @obj: the current GEM object * * Iterate over all the locked GEM objects inside the drm_exec object. */ #define drm_exec_for_each_locked_object(exec, obj) \ __drm_exec_for_each_locked_object(exec, obj, __UNIQUE_ID(drm_exec)) /* Helper for drm_exec_for_each_locked_object_reverse(). Internal use only. */ #define __drm_exec_for_each_locked_object_reverse(exec, obj, __index) \ for (unsigned long __index = (exec)->num_objects - 1; \ ((obj) = drm_exec_obj(exec, __index)); --__index) /** * drm_exec_for_each_locked_object_reverse - iterate over all the locked * objects in reverse locking order * @exec: drm_exec object * @obj: the current GEM object * * Iterate over all the locked GEM objects inside the drm_exec object in * reverse locking order. Note that the internal index may wrap around, * but that will be caught by drm_exec_obj(), returning a NULL object. */ #define drm_exec_for_each_locked_object_reverse(exec, obj) \ __drm_exec_for_each_locked_object_reverse(exec, obj, __UNIQUE_ID(drm_exec)) /** * drm_exec_until_all_locked - loop until all GEM objects are locked * @exec: drm_exec object * * Core functionality of the drm_exec object. Loops until all GEM objects are * locked and no more contention exists. At the beginning of the loop it is * guaranteed that no GEM object is locked. * * A global label name drm_exec_retry is used, if you need to use more than one * instance of this macro in the same function the label needs to be made local * to the block with the __label__ keyword. */ #define drm_exec_until_all_locked(exec) \ for (bool const __maybe_unused __drm_exec_loop = false; \ drm_exec_cleanup(exec);) \ if (false) { \ drm_exec_retry: __maybe_unused; \ continue; \ } else /** * drm_exec_retry_on_contention - restart the loop to grap all locks * @exec: drm_exec object * * Control flow helper to continue when a contention was detected and we need to * clean up and re-start the loop to prepare all GEM objects. * The __drm_exec_loop check exists to prevent usage outside of an * drm_exec_until_all_locked() loop. */ #define drm_exec_retry_on_contention(exec) \ do { \ if (unlikely(drm_exec_is_contended(exec))) \ goto drm_exec_retry; \ } while (__drm_exec_loop) /** * drm_exec_is_contended - check for contention * @exec: drm_exec object * * Returns true if the drm_exec object has run into some contention while * locking a GEM object and needs to clean up. */ static inline bool drm_exec_is_contended(struct drm_exec *exec) { return !!exec->contended; } /** * drm_exec_retry() - Unconditionally restart the loop to grab all locks. * @exec: drm_exec object * * Unconditionally retry the loop to lock all objects. For consistency, * the exec object needs to be newly initialized. * The __drm_exec_loop check exists to prevent usage outside of an * drm_exec_until_all_locked() loop. */ #define drm_exec_retry(_exec) \ do { \ WARN_ON((_exec)->contended != DRM_EXEC_DUMMY); \ goto drm_exec_retry; \ } while (__drm_exec_loop) /** * drm_exec_ticket - return the ww_acquire_ctx for this exec context * @exec: drm_exec object * * Return: Pointer to the ww_acquire_ctx embedded in @exec. */ static inline struct ww_acquire_ctx *drm_exec_ticket(struct drm_exec *exec) { return &exec->ticket; } void drm_exec_init(struct drm_exec *exec, u32 flags, unsigned nr); void drm_exec_fini(struct drm_exec *exec); bool drm_exec_cleanup(struct drm_exec *exec); int drm_exec_lock_obj(struct drm_exec *exec, struct drm_gem_object *obj); void drm_exec_unlock_obj(struct drm_exec *exec, struct drm_gem_object *obj); int drm_exec_prepare_obj(struct drm_exec *exec, struct drm_gem_object *obj, unsigned int num_fences); int drm_exec_prepare_array(struct drm_exec *exec, struct drm_gem_object **objects, unsigned int num_objects, unsigned int num_fences); #endif
