[PATCH v7 2/9] drm/sched: Add pending job list iterator

[Matthew Brost <matthew.brost@intel.com>]

Stop open coding pending job list in drivers. Add pending job list
iterator which safely walks DRM scheduler list asserting DRM scheduler
is stopped.

v2:
 - Fix checkpatch (CI)
v3:
 - Drop locked version (Christian)
v4:
 - Reorder patch (Niranjana)

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
---
 include/drm/gpu_scheduler.h | 50 +++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index 385bf34e76fe..9d228513d06c 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -730,4 +730,54 @@ static inline bool drm_sched_job_is_signaled(struct drm_sched_job *job)
 		dma_fence_is_signaled(&s_fence->finished);
 }
 
+/**
+ * struct drm_sched_pending_job_iter - DRM scheduler pending job iterator state
+ * @sched: DRM scheduler associated with pending job iterator
+ */
+struct drm_sched_pending_job_iter {
+	struct drm_gpu_scheduler *sched;
+};
+
+/* Drivers should never call this directly */
+static inline struct drm_sched_pending_job_iter
+__drm_sched_pending_job_iter_begin(struct drm_gpu_scheduler *sched)
+{
+	struct drm_sched_pending_job_iter iter = {
+		.sched = sched,
+	};
+
+	WARN_ON(!drm_sched_is_stopped(sched));
+	return iter;
+}
+
+/* Drivers should never call this directly */
+static inline void
+__drm_sched_pending_job_iter_end(const struct drm_sched_pending_job_iter iter)
+{
+	WARN_ON(!drm_sched_is_stopped(iter.sched));
+}
+
+DEFINE_CLASS(drm_sched_pending_job_iter, struct drm_sched_pending_job_iter,
+	     __drm_sched_pending_job_iter_end(_T),
+	     __drm_sched_pending_job_iter_begin(__sched),
+	     struct drm_gpu_scheduler *__sched);
+static inline void *
+class_drm_sched_pending_job_iter_lock_ptr(class_drm_sched_pending_job_iter_t *_T)
+{ return _T; }
+#define class_drm_sched_pending_job_iter_is_conditional false
+
+/**
+ * drm_sched_for_each_pending_job() - Iterator for each pending job in scheduler
+ * @__job: Current pending job being iterated over
+ * @__sched: DRM scheduler to iterate over pending jobs
+ * @__entity: DRM scheduler entity to filter jobs, NULL indicates no filter
+ *
+ * Iterator for each pending job in scheduler, filtering on an entity, and
+ * enforcing scheduler is fully stopped
+ */
+#define drm_sched_for_each_pending_job(__job, __sched, __entity)		\
+	scoped_guard(drm_sched_pending_job_iter, (__sched))			\
+		list_for_each_entry((__job), &(__sched)->pending_list, list)	\
+			for_each_if(!(__entity) || (__job)->entity == (__entity))
+
 #endif
-- 
2.34.1