static int add_io_space()

in pci/pci.c [151:212]

• 49 lines of code
• 8 McCabe index (conditional complexity)

static int add_io_space(struct device *dev, struct pci_root_info *info,
			struct resource_entry *entry)
{
	struct resource_entry *iospace;
	struct resource *resource, *res = entry->res;
	char *name;
	unsigned long base, min, max, base_port;
	unsigned int sparse = 0, space_nr, len;

	len = strlen(info->common.name) + 32;
	iospace = resource_list_create_entry(NULL, len);
	if (!iospace) {
		dev_err(dev, "PCI: No memory for %s I/O port space\n",
			info->common.name);
		return -ENOMEM;
	}

	if (res->flags & IORESOURCE_IO_SPARSE)
		sparse = 1;
	space_nr = new_space(entry->offset, sparse);
	if (space_nr == ~0)
		goto free_resource;

	name = (char *)(iospace + 1);
	min = res->start - entry->offset;
	max = res->end - entry->offset;
	base = __pa(io_space[space_nr].mmio_base);
	base_port = IO_SPACE_BASE(space_nr);
	snprintf(name, len, "%s I/O Ports %08lx-%08lx", info->common.name,
		 base_port + min, base_port + max);

	/*
	 * The SDM guarantees the legacy 0-64K space is sparse, but if the
	 * mapping is done by the processor (not the bridge), ACPI may not
	 * mark it as sparse.
	 */
	if (space_nr == 0)
		sparse = 1;

	resource = iospace->res;
	resource->name  = name;
	resource->flags = IORESOURCE_MEM;
	resource->start = base + (sparse ? IO_SPACE_SPARSE_ENCODING(min) : min);
	resource->end   = base + (sparse ? IO_SPACE_SPARSE_ENCODING(max) : max);
	if (insert_resource(&iomem_resource, resource)) {
		dev_err(dev,
			"can't allocate host bridge io space resource  %pR\n",
			resource);
		goto free_resource;
	}

	entry->offset = base_port;
	res->start = min + base_port;
	res->end = max + base_port;
	resource_list_add_tail(iospace, &info->io_resources);

	return 0;

free_resource:
	resource_list_free_entry(iospace);
	return -ENOSPC;
}