[RFC v1 8/9] drm/xe/hw_engine_group: Resume LR exec queues suspended by dma fence jobs

[Francois Dugast]

Submission of a dma fence job leads to suspending the long running exec
queues of the hw engine group. Work is queued in the resume worker for
this group and execution is resumed on the attached exec queues in long
running mode.

This is another entry point for execution on the hw engine group so the
execution mode is updated.

Signed-off-by: Francois Dugast <francois.dugast at intel.com>
---
 drivers/gpu/drm/xe/xe_hw_engine.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
index e6c755a04fd8..dd8ef65cbf2d 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine.c
+++ b/drivers/gpu/drm/xe/xe_hw_engine.c
@@ -431,6 +431,26 @@ hw_engine_setup_default_state(struct xe_hw_engine *hwe)
 	xe_rtp_process_to_sr(&ctx, engine_entries, &hwe->reg_sr);
 }
 
+static void hw_engine_group_resume_work_func(struct work_struct *w)
+{
+	struct xe_exec_queue *q;
+	struct xe_hw_engine_group *group = container_of(w, struct xe_hw_engine_group, resume_work);
+	int err;
+
+	err = xe_hw_engine_group_get_mode(group, EXEC_MODE_LR);
+	if (err)
+		return;
+
+	list_for_each_entry(q, &group->exec_queue_list, hw_engine_group_link) {
+		if (!xe_vm_in_lr_mode(q->vm))
+			continue;
+
+		q->ops->resume(q);
+	}
+
+	xe_hw_engine_group_put(group);
+}
+
 static struct xe_hw_engine_group *
 hw_engine_group_alloc(struct xe_device *xe)
 {
@@ -438,6 +458,8 @@ hw_engine_group_alloc(struct xe_device *xe)
 
 	group = kzalloc(sizeof(*group), GFP_KERNEL);
 	init_rwsem(&group->mode_sem);
+	group->resume_wq = alloc_ordered_workqueue("xe-resume-lr-jobs-wq", 0);
+	INIT_WORK(&group->resume_work, hw_engine_group_resume_work_func);
 	INIT_LIST_HEAD(&group->exec_queue_list);
 
 	return group;
@@ -1235,6 +1257,7 @@ static int xe_hw_engine_group_suspend_lr_jobs(struct xe_hw_engine_group *group)
 {
 	int err;
 	struct xe_exec_queue *q;
+	bool suspended_queue = false;
 
 	lockdep_assert_held(&group->mode_sem);
 
@@ -1247,8 +1270,13 @@ static int xe_hw_engine_group_suspend_lr_jobs(struct xe_hw_engine_group *group)
 			return err;
 
 		q->ops->suspend_wait(q);
+
+		suspended_queue = true;
 	}
 
+	if (suspended_queue)
+		queue_work(group->resume_wq, &group->resume_work);
+
 	return 0;
 }
 
-- 
2.43.0