static int vm_cmdline_set()

in virtio_mmio.c [654:708]

• 39 lines of code
• 6 McCabe index (conditional complexity)

static int vm_cmdline_set(const char *device,
		const struct kernel_param *kp)
{
	int err;
	struct resource resources[2] = {};
	char *str;
	long long int base, size;
	unsigned int irq;
	int processed, consumed = 0;
	struct platform_device *pdev;

	/* Consume "size" part of the command line parameter */
	size = memparse(device, &str);

	/* Get "@<base>:<irq>[:<id>]" chunks */
	processed = sscanf(str, "@%lli:%u%n:%d%n",
			&base, &irq, &consumed,
			&vm_cmdline_id, &consumed);

	/*
	 * sscanf() must process at least 2 chunks; also there
	 * must be no extra characters after the last chunk, so
	 * str[consumed] must be '\0'
	 */
	if (processed < 2 || str[consumed] || irq == 0)
		return -EINVAL;

	resources[0].flags = IORESOURCE_MEM;
	resources[0].start = base;
	resources[0].end = base + size - 1;

	resources[1].flags = IORESOURCE_IRQ;
	resources[1].start = resources[1].end = irq;

	if (!vm_cmdline_parent_registered) {
		err = device_register(&vm_cmdline_parent);
		if (err) {
			pr_err("Failed to register parent device!\n");
			return err;
		}
		vm_cmdline_parent_registered = 1;
	}

	pr_info("Registering device virtio-mmio.%d at 0x%llx-0x%llx, IRQ %d.\n",
		       vm_cmdline_id,
		       (unsigned long long)resources[0].start,
		       (unsigned long long)resources[0].end,
		       (int)resources[1].start);

	pdev = platform_device_register_resndata(&vm_cmdline_parent,
			"virtio-mmio", vm_cmdline_id++,
			resources, ARRAY_SIZE(resources), NULL, 0);

	return PTR_ERR_OR_ZERO(pdev);
}