static int acrn_ioeventfd_handler()

in acrn/ioeventfd.c [189:230]

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

static int acrn_ioeventfd_handler(struct acrn_ioreq_client *client,
				  struct acrn_io_request *req)
{
	struct hsm_ioeventfd *p;
	u64 addr, val;
	int size;

	if (req->type == ACRN_IOREQ_TYPE_MMIO) {
		/*
		 * I/O requests are dispatched by range check only, so a
		 * acrn_ioreq_client need process both READ and WRITE accesses
		 * of same range. READ accesses are safe to be ignored here
		 * because virtio PCI devices write the notify registers for
		 * notification.
		 */
		if (req->reqs.mmio_request.direction == ACRN_IOREQ_DIR_READ) {
			/* reading does nothing and return 0 */
			req->reqs.mmio_request.value = 0;
			return 0;
		}
		addr = req->reqs.mmio_request.address;
		size = req->reqs.mmio_request.size;
		val = req->reqs.mmio_request.value;
	} else {
		if (req->reqs.pio_request.direction == ACRN_IOREQ_DIR_READ) {
			/* reading does nothing and return 0 */
			req->reqs.pio_request.value = 0;
			return 0;
		}
		addr = req->reqs.pio_request.address;
		size = req->reqs.pio_request.size;
		val = req->reqs.pio_request.value;
	}

	mutex_lock(&client->vm->ioeventfds_lock);
	p = hsm_ioeventfd_match(client->vm, addr, val, size, req->type);
	if (p)
		eventfd_signal(p->eventfd, 1);
	mutex_unlock(&client->vm->ioeventfds_lock);

	return 0;
}