static void iso_resource_work()

in core-cdev.c [1252:1349]

• 72 lines of code
• 25 McCabe index (conditional complexity)

static void iso_resource_work(struct work_struct *work)
{
	struct iso_resource_event *e;
	struct iso_resource *r =
			container_of(work, struct iso_resource, work.work);
	struct client *client = r->client;
	int generation, channel, bandwidth, todo;
	bool skip, free, success;

	spin_lock_irq(&client->lock);
	generation = client->device->generation;
	todo = r->todo;
	/* Allow 1000ms grace period for other reallocations. */
	if (todo == ISO_RES_ALLOC &&
	    time_before64(get_jiffies_64(),
			  client->device->card->reset_jiffies + HZ)) {
		schedule_iso_resource(r, DIV_ROUND_UP(HZ, 3));
		skip = true;
	} else {
		/* We could be called twice within the same generation. */
		skip = todo == ISO_RES_REALLOC &&
		       r->generation == generation;
	}
	free = todo == ISO_RES_DEALLOC ||
	       todo == ISO_RES_ALLOC_ONCE ||
	       todo == ISO_RES_DEALLOC_ONCE;
	r->generation = generation;
	spin_unlock_irq(&client->lock);

	if (skip)
		goto out;

	bandwidth = r->bandwidth;

	fw_iso_resource_manage(client->device->card, generation,
			r->channels, &channel, &bandwidth,
			todo == ISO_RES_ALLOC ||
			todo == ISO_RES_REALLOC ||
			todo == ISO_RES_ALLOC_ONCE);
	/*
	 * Is this generation outdated already?  As long as this resource sticks
	 * in the idr, it will be scheduled again for a newer generation or at
	 * shutdown.
	 */
	if (channel == -EAGAIN &&
	    (todo == ISO_RES_ALLOC || todo == ISO_RES_REALLOC))
		goto out;

	success = channel >= 0 || bandwidth > 0;

	spin_lock_irq(&client->lock);
	/*
	 * Transit from allocation to reallocation, except if the client
	 * requested deallocation in the meantime.
	 */
	if (r->todo == ISO_RES_ALLOC)
		r->todo = ISO_RES_REALLOC;
	/*
	 * Allocation or reallocation failure?  Pull this resource out of the
	 * idr and prepare for deletion, unless the client is shutting down.
	 */
	if (r->todo == ISO_RES_REALLOC && !success &&
	    !client->in_shutdown &&
	    idr_remove(&client->resource_idr, r->resource.handle)) {
		client_put(client);
		free = true;
	}
	spin_unlock_irq(&client->lock);

	if (todo == ISO_RES_ALLOC && channel >= 0)
		r->channels = 1ULL << channel;

	if (todo == ISO_RES_REALLOC && success)
		goto out;

	if (todo == ISO_RES_ALLOC || todo == ISO_RES_ALLOC_ONCE) {
		e = r->e_alloc;
		r->e_alloc = NULL;
	} else {
		e = r->e_dealloc;
		r->e_dealloc = NULL;
	}
	e->iso_resource.handle    = r->resource.handle;
	e->iso_resource.channel   = channel;
	e->iso_resource.bandwidth = bandwidth;

	queue_event(client, &e->event,
		    &e->iso_resource, sizeof(e->iso_resource), NULL, 0);

	if (free) {
		cancel_delayed_work(&r->work);
		kfree(r->e_alloc);
		kfree(r->e_dealloc);
		kfree(r);
	}
 out:
	client_put(client);
}