drm/xe: Fix modifying exec_queue priority in xe_migrate_init

After exec_queue has been created, we cannot simply modify q->priority.
This needs to be done by the backend via q->ops.  However in this case,
it would be more efficient to simply pass a flag when creating the
exec_queue and set the desired priority upfront during queue creation.

To that end: new flag EXEC_QUEUE_FLAG_HIGH_PRIORITY is introduced.
The priority field is moved to be with other scheduling properties and
is now exec_queue.sched_props.priority. This is no longer set to initial
value by the backend, but is now set within __xe_exec_queue_create().

Fixes: b4eecedc ("drm/xe: Fix potential deadlock handling page faults")
Signed-off-by: Brian Welty <brian.welty@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>

drivers/gpu/drm/xe/xe_exec_queue.c

@@ -67,6 +67,11 @@ static struct xe_exec_queue *__xe_exec_queue_create(struct xe_device *xe,
 	q->sched_props.timeslice_us = hwe->eclass->sched_props.timeslice_us;
 	q->sched_props.preempt_timeout_us =
 				hwe->eclass->sched_props.preempt_timeout_us;
+	if (q->flags & EXEC_QUEUE_FLAG_KERNEL &&
+	    q->flags & EXEC_QUEUE_FLAG_HIGH_PRIORITY)
+		q->sched_props.priority = XE_EXEC_QUEUE_PRIORITY_KERNEL;
+	else
+		q->sched_props.priority = XE_EXEC_QUEUE_PRIORITY_NORMAL;
 
 	if (xe_exec_queue_is_parallel(q)) {
 		q->parallel.composite_fence_ctx = dma_fence_context_alloc(1);

drivers/gpu/drm/xe/xe_exec_queue_types.h

@@ -52,8 +52,6 @@ struct xe_exec_queue {
 	struct xe_vm *vm;
 	/** @class: class of this exec queue */
 	enum xe_engine_class class;
-	/** @priority: priority of this exec queue */
-	enum xe_exec_queue_priority priority;
 	/**
 	 * @logical_mask: logical mask of where job submitted to exec queue can run
 	 */
@@ -84,6 +82,8 @@ struct xe_exec_queue {
 #define EXEC_QUEUE_FLAG_VM			BIT(4)
 /* child of VM queue for multi-tile VM jobs */
 #define EXEC_QUEUE_FLAG_BIND_ENGINE_CHILD	BIT(5)
+/* kernel exec_queue only, set priority to highest level */
+#define EXEC_QUEUE_FLAG_HIGH_PRIORITY		BIT(6)
 
 	/**
 	 * @flags: flags for this exec queue, should statically setup aside from ban
@@ -142,6 +142,8 @@ struct xe_exec_queue {
 		u32 timeslice_us;
 		/** @preempt_timeout_us: preemption timeout in micro-seconds */
 		u32 preempt_timeout_us;
+		/** @priority: priority of this exec queue */
+		enum xe_exec_queue_priority priority;
 	} sched_props;
 
 	/** @compute: compute exec queue state */

drivers/gpu/drm/xe/xe_guc_submit.c

@@ -421,7 +421,7 @@ static void init_policies(struct xe_guc *guc, struct xe_exec_queue *q)
 {
 	struct exec_queue_policy policy;
 	struct xe_device *xe = guc_to_xe(guc);
-	enum xe_exec_queue_priority prio = q->priority;
+	enum xe_exec_queue_priority prio = q->sched_props.priority;
 	u32 timeslice_us = q->sched_props.timeslice_us;
 	u32 preempt_timeout_us = q->sched_props.preempt_timeout_us;
 
@@ -1231,7 +1231,6 @@ static int guc_exec_queue_init(struct xe_exec_queue *q)
 	err = xe_sched_entity_init(&ge->entity, sched);
 	if (err)
 		goto err_sched;
-	q->priority = XE_EXEC_QUEUE_PRIORITY_NORMAL;
 
 	if (xe_exec_queue_is_lr(q))
 		INIT_WORK(&q->guc->lr_tdr, xe_guc_exec_queue_lr_cleanup);
@@ -1301,14 +1300,14 @@ static int guc_exec_queue_set_priority(struct xe_exec_queue *q,
 {
 	struct xe_sched_msg *msg;
 
-	if (q->priority == priority || exec_queue_killed_or_banned(q))
+	if (q->sched_props.priority == priority || exec_queue_killed_or_banned(q))
 		return 0;
 
 	msg = kmalloc(sizeof(*msg), GFP_KERNEL);
 	if (!msg)
 		return -ENOMEM;
 
-	q->priority = priority;
+	q->sched_props.priority = priority;
 	guc_exec_queue_add_msg(q, msg, SET_SCHED_PROPS);
 
 	return 0;

drivers/gpu/drm/xe/xe_migrate.c

@@ -344,7 +344,8 @@ struct xe_migrate *xe_migrate_init(struct xe_tile *tile)
 
 		m->q = xe_exec_queue_create(xe, vm, logical_mask, 1, hwe,
 					    EXEC_QUEUE_FLAG_KERNEL |
-					    EXEC_QUEUE_FLAG_PERMANENT);
+					    EXEC_QUEUE_FLAG_PERMANENT |
+					    EXEC_QUEUE_FLAG_HIGH_PRIORITY);
 	} else {
 		m->q = xe_exec_queue_create_class(xe, primary_gt, vm,
 						  XE_ENGINE_CLASS_COPY,
@@ -355,8 +356,6 @@ struct xe_migrate *xe_migrate_init(struct xe_tile *tile)
 		xe_vm_close_and_put(vm);
 		return ERR_CAST(m->q);
 	}
-	if (xe->info.has_usm)
-		m->q->priority = XE_EXEC_QUEUE_PRIORITY_KERNEL;
 
 	mutex_init(&m->job_mutex);