WIP kernel: work: refactor to use scheduler API

This uses the cherry-picked scheduler API from zephyrproject-rtos#29668 to avoid certain
race conditions in SMP between unpending and readying threads.

Signed-off-by: Peter Bigot <[email protected]>

kernel/work.c

@@ -15,7 +15,7 @@
 #include <wait_q.h>
 #include <spinlock.h>
 #include <errno.h>
-#include <ksched.h>
+#include <sys/scheduler.h>
 #include <sys/printk.h>
 
 /* Lock to protect the internal state of all work items, and
@@ -182,15 +182,9 @@ static inline void queue_remove(struct k_work_q *queue,
 static inline bool _notify_queue(struct k_work_q *queue)
 {
  bool rv = false;
- struct k_thread *waiter;
 
  if (queue != NULL) {
- waiter = z_unpend_first_thread(&queue->notifyq);
- if (waiter) {
- rv = true;
- arch_thread_return_value_set(waiter, 0);
- z_ready_thread(waiter);
- }
+ rv = k_sched_wake(&queue->notifyq, 0, NULL);
  }
 
  return rv;
@@ -599,8 +593,6 @@ static void work_queue_main(void *workq_ptr, void *p2, void *p3)
  work = CONTAINER_OF(node, struct k_work, node);
  } else if (atomic_test_and_clear_bit(&queue->flags,
  K_WORK_QUEUE_DRAIN_BIT)) {
- struct k_thread *waiter;
-
  /* Not busy and draining: move threads waiting for
  * drain to ready state. The held spinlock inhibits
  * reschedule; released threads get their chance when
@@ -611,13 +603,7 @@ static void work_queue_main(void *workq_ptr, void *p2, void *p3)
  * here doesn't mean that the queue will allow new
  * submissions.
  */
- do {
- waiter = z_unpend_first_thread(&queue->drainq);
- if (waiter) {
- arch_thread_return_value_set(waiter, 1);
- z_ready_thread(waiter);
- }
- } while (waiter != NULL);
+ (void)k_sched_wake_all(&queue->drainq, 1, NULL);
  }
 
  if (work == NULL) {
@@ -628,7 +614,8 @@ static void work_queue_main(void *workq_ptr, void *p2, void *p3)
  * check again.
  */
 
- (void)z_pend_curr(&queue->lock, key, &queue->notifyq, K_FOREVER);
+ (void)k_sched_wait(&queue->lock, key, &queue->notifyq,
+ K_FOREVER, NULL);
  continue;
  }
 
@@ -706,7 +693,8 @@ int k_work_queue_drain(struct k_work_q *queue,
  }
 
  _notify_queue(queue);
- ret = z_pend_curr(&queue->lock, key, &queue->drainq, K_FOREVER);
+ ret = k_sched_wait(&queue->lock, key, &queue->drainq,
+ K_FOREVER, NULL);
  } else {
  k_spin_unlock(&queue->lock, key);
  }