int optee_notif_wait()

in optee/notif.c [32:83]

• 31 lines of code
• 5 McCabe index (conditional complexity)

int optee_notif_wait(struct optee *optee, u_int key)
{
	unsigned long flags;
	struct notif_entry *entry;
	int rc = 0;

	if (key > optee->notif.max_key)
		return -EINVAL;

	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
	if (!entry)
		return -ENOMEM;
	init_completion(&entry->c);
	entry->key = key;

	spin_lock_irqsave(&optee->notif.lock, flags);

	/*
	 * If the bit is already set it means that the key has already
	 * been posted and we must not wait.
	 */
	if (test_bit(key, optee->notif.bitmap)) {
		clear_bit(key, optee->notif.bitmap);
		goto out;
	}

	/*
	 * Check if someone is already waiting for this key. If there is
	 * it's a programming error.
	 */
	if (have_key(optee, key)) {
		rc = -EBUSY;
		goto out;
	}

	list_add_tail(&entry->link, &optee->notif.db);

	/*
	 * Unlock temporarily and wait for completion.
	 */
	spin_unlock_irqrestore(&optee->notif.lock, flags);
	wait_for_completion(&entry->c);
	spin_lock_irqsave(&optee->notif.lock, flags);

	list_del(&entry->link);
out:
	spin_unlock_irqrestore(&optee->notif.lock, flags);

	kfree(entry);

	return rc;
}