Merge tag 'drm-misc-next-2022-10-20' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

drm-misc-next for 6.2:

UAPI Changes:
  - Documentation for page-flip flags

Cross-subsystem Changes:
  - dma-buf: Add unlocked variant of vmapping and attachment-mapping
    functions

Core Changes:
  - atomic-helpers: CRTC primary plane test fixes
  - connector: TV API consistency improvements, cmdline parsing
    improvements
  - crtc-helpers: Introduce drm_crtc_helper_atomic_check() helper
  - edid: Fixes for HFVSDB parsing,
  - fourcc: Addition of the Vivante tiled modifier
  - makefile: Sort and reorganize the objects files
  - mode_config: Remove fb_base from drm_mode_config_funcs
  - sched: Add a module parameter to change the scheduling policy,
    refcounting fix for fences
  - tests: Sort the Kunit tests in the Makefile, improvements to the
    DP-MST tests
  - ttm: Remove unnecessary drm_mm_clean() call

Driver Changes:
  - New driver: ofdrm
  - Move all drivers to a common dma-buf locking convention
  - bridge:
    - adv7533: Remove dynamic lane switching
    - it6505: Runtime PM support
    - ps8640: Handle AUX defer messages
    - tc358775: Drop soft-reset over I2C
  - ast: Atomic Gamma LUT Support, Convert to SHMEM, various
    improvements
  - lcdif: Support for YUV planes
  - mgag200: Fix PLL Setup on some revisions
  - udl: Modesetting improvements, hot-unplug support
  - vc4: Fix support for PAL-M

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20221020072405.g3o4hxuk75gmeumw@houat

2 files changed, 118 insertions, 4 deletions

diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
index 6137537aaea4..c97bc1149663 100644
--- a/drivers/gpu/drm/scheduler/sched_entity.c
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -73,6 +73,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
 	entity->priority = priority;
 	entity->sched_list = num_sched_list > 1 ? sched_list : NULL;
 	entity->last_scheduled = NULL;
+	RB_CLEAR_NODE(&entity->rb_tree_node);
 
 	if(num_sched_list)
 		entity->rq = &sched_list[0]->sched_rq[entity->priority];
@@ -207,6 +208,7 @@ static void drm_sched_entity_kill_jobs_cb(struct dma_fence *f,
 	struct drm_sched_job *job = container_of(cb, struct drm_sched_job,
 						 finish_cb);
 
+	dma_fence_put(f);
 	INIT_WORK(&job->work, drm_sched_entity_kill_jobs_work);
 	schedule_work(&job->work);
 }
@@ -234,8 +236,10 @@ static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
 		struct drm_sched_fence *s_fence = job->s_fence;
 
 		/* Wait for all dependencies to avoid data corruptions */
-		while ((f = drm_sched_job_dependency(job, entity)))
+		while ((f = drm_sched_job_dependency(job, entity))) {
 			dma_fence_wait(f, false);
+			dma_fence_put(f);
+		}
 
 		drm_sched_fence_scheduled(s_fence);
 		dma_fence_set_error(&s_fence->finished, -ESRCH);
@@ -250,6 +254,7 @@ static void drm_sched_entity_kill_jobs(struct drm_sched_entity *entity)
 			continue;
 		}
 
+		dma_fence_get(entity->last_scheduled);
 		r = dma_fence_add_callback(entity->last_scheduled,
 					   &job->finish_cb,
 					   drm_sched_entity_kill_jobs_cb);
@@ -444,6 +449,19 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
 	smp_wmb();
 
 	spsc_queue_pop(&entity->job_queue);
+
+	/*
+	 * Update the entity's location in the min heap according to
+	 * the timestamp of the next job, if any.
+	 */
+	if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) {
+		struct drm_sched_job *next;
+
+		next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
+		if (next)
+			drm_sched_rq_update_fifo(entity, next->submit_ts);
+	}
+
 	return sched_job;
 }
 
@@ -508,6 +526,7 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
 	atomic_inc(entity->rq->sched->score);
 	WRITE_ONCE(entity->last_user, current->group_leader);
 	first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
+	sched_job->submit_ts = ktime_get();
 
 	/* first job wakes up scheduler */
 	if (first) {
@@ -519,8 +538,13 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
 			DRM_ERROR("Trying to push to a killed entity\n");
 			return;
 		}
+
 		drm_sched_rq_add_entity(entity->rq, entity);
 		spin_unlock(&entity->rq_lock);
+
+		if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
+			drm_sched_rq_update_fifo(entity, sched_job->submit_ts);
+
 		drm_sched_wakeup(entity->rq->sched);
 	}
 }
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index e5a4ecde0063..2fab218d7082 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -62,6 +62,55 @@
 #define to_drm_sched_job(sched_job)		\
 		container_of((sched_job), struct drm_sched_job, queue_node)
 
+int drm_sched_policy = DRM_SCHED_POLICY_RR;
+
+/**
+ * DOC: sched_policy (int)
+ * Used to override default entities scheduling policy in a run queue.
+ */
+MODULE_PARM_DESC(sched_policy, "Specify schedule policy for entities on a runqueue, " __stringify(DRM_SCHED_POLICY_RR) " = Round Robin (default), " __stringify(DRM_SCHED_POLICY_FIFO) " = use FIFO.");
+module_param_named(sched_policy, drm_sched_policy, int, 0444);
+
+static __always_inline bool drm_sched_entity_compare_before(struct rb_node *a,
+							    const struct rb_node *b)
+{
+	struct drm_sched_entity *ent_a =  rb_entry((a), struct drm_sched_entity, rb_tree_node);
+	struct drm_sched_entity *ent_b =  rb_entry((b), struct drm_sched_entity, rb_tree_node);
+
+	return ktime_before(ent_a->oldest_job_waiting, ent_b->oldest_job_waiting);
+}
+
+static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *entity)
+{
+	struct drm_sched_rq *rq = entity->rq;
+
+	if (!RB_EMPTY_NODE(&entity->rb_tree_node)) {
+		rb_erase_cached(&entity->rb_tree_node, &rq->rb_tree_root);
+		RB_CLEAR_NODE(&entity->rb_tree_node);
+	}
+}
+
+void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts)
+{
+	/*
+	 * Both locks need to be grabbed, one to protect from entity->rq change
+	 * for entity from within concurrent drm_sched_entity_select_rq and the
+	 * other to update the rb tree structure.
+	 */
+	spin_lock(&entity->rq_lock);
+	spin_lock(&entity->rq->lock);
+
+	drm_sched_rq_remove_fifo_locked(entity);
+
+	entity->oldest_job_waiting = ts;
+
+	rb_add_cached(&entity->rb_tree_node, &entity->rq->rb_tree_root,
+		      drm_sched_entity_compare_before);
+
+	spin_unlock(&entity->rq->lock);
+	spin_unlock(&entity->rq_lock);
+}
+
 /**
  * drm_sched_rq_init - initialize a given run queue struct
  *
@@ -75,6 +124,7 @@ static void drm_sched_rq_init(struct drm_gpu_scheduler *sched,
 {
 	spin_lock_init(&rq->lock);
 	INIT_LIST_HEAD(&rq->entities);
+	rq->rb_tree_root = RB_ROOT_CACHED;
 	rq->current_entity = NULL;
 	rq->sched = sched;
 }
@@ -92,9 +142,12 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
 {
 	if (!list_empty(&entity->list))
 		return;
+
 	spin_lock(&rq->lock);
+
 	atomic_inc(rq->sched->score);
 	list_add_tail(&entity->list, &rq->entities);
+
 	spin_unlock(&rq->lock);
 }
 
@@ -111,23 +164,30 @@ void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
 {
 	if (list_empty(&entity->list))
 		return;
+
 	spin_lock(&rq->lock);
+
 	atomic_dec(rq->sched->score);
 	list_del_init(&entity->list);
+
 	if (rq->current_entity == entity)
 		rq->current_entity = NULL;
+
+	if (drm_sched_policy == DRM_SCHED_POLICY_FIFO)
+		drm_sched_rq_remove_fifo_locked(entity);
+
 	spin_unlock(&rq->lock);
 }
 
 /**
- * drm_sched_rq_select_entity - Select an entity which could provide a job to run
+ * drm_sched_rq_select_entity_rr - Select an entity which could provide a job to run
  *
  * @rq: scheduler run queue to check.
  *
  * Try to find a ready entity, returns NULL if none found.
  */
 static struct drm_sched_entity *
-drm_sched_rq_select_entity(struct drm_sched_rq *rq)
+drm_sched_rq_select_entity_rr(struct drm_sched_rq *rq)
 {
 	struct drm_sched_entity *entity;
 
@@ -164,6 +224,34 @@ drm_sched_rq_select_entity(struct drm_sched_rq *rq)
 }
 
 /**
+ * drm_sched_rq_select_entity_fifo - Select an entity which provides a job to run
+ *
+ * @rq: scheduler run queue to check.
+ *
+ * Find oldest waiting ready entity, returns NULL if none found.
+ */
+static struct drm_sched_entity *
+drm_sched_rq_select_entity_fifo(struct drm_sched_rq *rq)
+{
+	struct rb_node *rb;
+
+	spin_lock(&rq->lock);
+	for (rb = rb_first_cached(&rq->rb_tree_root); rb; rb = rb_next(rb)) {
+		struct drm_sched_entity *entity;
+
+		entity = rb_entry(rb, struct drm_sched_entity, rb_tree_node);
+		if (drm_sched_entity_is_ready(entity)) {
+			rq->current_entity = entity;
+			reinit_completion(&entity->entity_idle);
+			break;
+		}
+	}
+	spin_unlock(&rq->lock);
+
+	return rb ? rb_entry(rb, struct drm_sched_entity, rb_tree_node) : NULL;
+}
+
+/**
  * drm_sched_job_done - complete a job
  * @s_job: pointer to the job which is done
  *
@@ -803,7 +891,9 @@ drm_sched_select_entity(struct drm_gpu_scheduler *sched)
 
 	/* Kernel run queue has higher priority than normal run queue*/
 	for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
-		entity = drm_sched_rq_select_entity(&sched->sched_rq[i]);
+		entity = drm_sched_policy == DRM_SCHED_POLICY_FIFO ?
+			drm_sched_rq_select_entity_fifo(&sched->sched_rq[i]) :
+			drm_sched_rq_select_entity_rr(&sched->sched_rq[i]);
 		if (entity)
 			break;
 	}