static int __init pcistub_init()

in xen-pciback/pci_stub.c [1509:1612]

• 89 lines of code
• 20 McCabe index (conditional complexity)

static int __init pcistub_init(void)
{
	int pos = 0;
	int err = 0;
	int domain, bus, slot, func;
	int parsed;

	if (pci_devs_to_hide && *pci_devs_to_hide) {
		do {
			parsed = 0;

			err = sscanf(pci_devs_to_hide + pos,
				     " (%x:%x:%x.%x) %n",
				     &domain, &bus, &slot, &func, &parsed);
			switch (err) {
			case 3:
				func = -1;
				sscanf(pci_devs_to_hide + pos,
				       " (%x:%x:%x.*) %n",
				       &domain, &bus, &slot, &parsed);
				break;
			case 2:
				slot = func = -1;
				sscanf(pci_devs_to_hide + pos,
				       " (%x:%x:*.*) %n",
				       &domain, &bus, &parsed);
				break;
			}

			if (!parsed) {
				domain = 0;
				err = sscanf(pci_devs_to_hide + pos,
					     " (%x:%x.%x) %n",
					     &bus, &slot, &func, &parsed);
				switch (err) {
				case 2:
					func = -1;
					sscanf(pci_devs_to_hide + pos,
					       " (%x:%x.*) %n",
					       &bus, &slot, &parsed);
					break;
				case 1:
					slot = func = -1;
					sscanf(pci_devs_to_hide + pos,
					       " (%x:*.*) %n",
					       &bus, &parsed);
					break;
				}
			}

			if (parsed <= 0)
				goto parse_error;

			err = pcistub_device_id_add(domain, bus, slot, func);
			if (err)
				goto out;

			pos += parsed;
		} while (pci_devs_to_hide[pos]);
	}

	/* If we're the first PCI Device Driver to register, we're the
	 * first one to get offered PCI devices as they become
	 * available (and thus we can be the first to grab them)
	 */
	err = pci_register_driver(&xen_pcibk_pci_driver);
	if (err < 0)
		goto out;

	err = driver_create_file(&xen_pcibk_pci_driver.driver,
				 &driver_attr_new_slot);
	if (!err)
		err = driver_create_file(&xen_pcibk_pci_driver.driver,
					 &driver_attr_remove_slot);
	if (!err)
		err = driver_create_file(&xen_pcibk_pci_driver.driver,
					 &driver_attr_slots);
	if (!err)
		err = driver_create_file(&xen_pcibk_pci_driver.driver,
					 &driver_attr_quirks);
	if (!err)
		err = driver_create_file(&xen_pcibk_pci_driver.driver,
					 &driver_attr_permissive);
	if (!err)
		err = driver_create_file(&xen_pcibk_pci_driver.driver,
					 &driver_attr_allow_interrupt_control);

	if (!err)
		err = driver_create_file(&xen_pcibk_pci_driver.driver,
					 &driver_attr_irq_handlers);
	if (!err)
		err = driver_create_file(&xen_pcibk_pci_driver.driver,
					&driver_attr_irq_handler_state);
	if (err)
		pcistub_exit();

out:
	return err;

parse_error:
	pr_err("Error parsing pci_devs_to_hide at \"%s\"\n",
	       pci_devs_to_hide + pos);
	return -EINVAL;
}