schedule: zephyr_ll: add zephyr_ll_grant_access()

Add function zephyr_ll_grant_access() to allow other threads
to access the scheduler mutex. This is needed if work is submitted
from other threads to the scheduler.

Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>

Author: kv2019i

src/include/sof/schedule/ll_schedule_domain.h

@@ -102,6 +102,7 @@ struct task *zephyr_ll_task_alloc(void);
 void zephyr_ll_task_free(struct task *task);
 struct k_heap *zephyr_ll_user_heap(void);
 void zephyr_ll_user_resources_init(void);
+void zephyr_ll_grant_access(struct k_thread *thread);
 #endif /* CONFIG_SOF_USERSPACE_LL */
 
 static inline struct ll_schedule_domain *domain_init

src/schedule/zephyr_ll.c

@@ -539,6 +539,13 @@ void zephyr_ll_task_free(struct task *task)
 	sof_heap_free(zephyr_ll_user_heap(), task);
 }
 
+void zephyr_ll_grant_access(struct k_thread *thread)
+{
+	struct zephyr_ll *ll_sch = (struct zephyr_ll *)scheduler_get_data(SOF_SCHEDULE_LL_TIMER);
+
+	k_thread_access_grant(thread, ll_sch->lock);
+}
+
 #endif /* CONFIG_SOF_USERSPACE_LL */
 
 int zephyr_ll_task_init(struct task *task,