[RFC PATCH 2/4] drm/scheduler: implement a function to modify sched list

[Nirmoy Das]

implement drm_sched_entity_modify_sched() which can modify existing
sched_list with a different one. This is going to be helpful when
userspace changes priority of a ctx/entity then driver can switch to
corresponding hw shced list for that priority

Signed-off-by: Nirmoy Das <nirmoy.das at amd.com>
---
 drivers/gpu/drm/scheduler/sched_entity.c | 24 ++++++++++++++++++++++++
 include/drm/gpu_scheduler.h              |  4 ++++
 2 files changed, 28 insertions(+)

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
index 63bccd201b97..711e9d504bcb 100644
--- a/drivers/gpu/drm/scheduler/sched_entity.c
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -83,6 +83,30 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
 }
 EXPORT_SYMBOL(drm_sched_entity_init);
 
+/**
+ * drm_sched_entity_modify_sched - Modify sched of an entity
+ *
+ * @entity: scheduler entity to init
+ * @sched_list: the list of new drm scheds which will replace
+ *		existing entity->sched_list
+ * @num_sched_list: number of drm sched in sched_list
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
+				  struct drm_gpu_scheduler **sched_list,
+				  unsigned int num_sched_list)
+{
+	if (!(entity && sched_list && (num_sched_list == 0 || sched_list[0])))
+		return -EINVAL;
+
+	entity->sched_list = num_sched_list > 1 ? sched_list : NULL;
+	entity->num_sched_list = num_sched_list;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_sched_entity_modify_sched);
+
 /**
  * drm_sched_entity_is_idle - Check if entity is idle
  *
diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
index 589be851f8a1..0c164a96d51b 100644
--- a/include/drm/gpu_scheduler.h
+++ b/include/drm/gpu_scheduler.h
@@ -297,6 +297,10 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched);
 int drm_sched_job_init(struct drm_sched_job *job,
 		       struct drm_sched_entity *entity,
 		       void *owner);
+int drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
+				  struct drm_gpu_scheduler **sched_list,
+                                  unsigned int num_sched_list);
+
 void drm_sched_job_cleanup(struct drm_sched_job *job);
 void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
 void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad);
-- 
2.25.0