static int devm_of_pci_get_host_bridge_resources()

in of.c [274:410]

• 104 lines of code
• 24 McCabe index (conditional complexity)

static int devm_of_pci_get_host_bridge_resources(struct device *dev,
			unsigned char busno, unsigned char bus_max,
			struct list_head *resources,
			struct list_head *ib_resources,
			resource_size_t *io_base)
{
	struct device_node *dev_node = dev->of_node;
	struct resource *res, tmp_res;
	struct resource *bus_range;
	struct of_pci_range range;
	struct of_pci_range_parser parser;
	const char *range_type;
	int err;

	if (io_base)
		*io_base = (resource_size_t)OF_BAD_ADDR;

	bus_range = devm_kzalloc(dev, sizeof(*bus_range), GFP_KERNEL);
	if (!bus_range)
		return -ENOMEM;

	dev_info(dev, "host bridge %pOF ranges:\n", dev_node);

	err = of_pci_parse_bus_range(dev_node, bus_range);
	if (err) {
		bus_range->start = busno;
		bus_range->end = bus_max;
		bus_range->flags = IORESOURCE_BUS;
		dev_info(dev, "  No bus range found for %pOF, using %pR\n",
			 dev_node, bus_range);
	} else {
		if (bus_range->end > bus_range->start + bus_max)
			bus_range->end = bus_range->start + bus_max;
	}
	pci_add_resource(resources, bus_range);

	/* Check for ranges property */
	err = of_pci_range_parser_init(&parser, dev_node);
	if (err)
		return 0;

	dev_dbg(dev, "Parsing ranges property...\n");
	for_each_of_pci_range(&parser, &range) {
		/* Read next ranges element */
		if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
			range_type = "IO";
		else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
			range_type = "MEM";
		else
			range_type = "err";
		dev_info(dev, "  %6s %#012llx..%#012llx -> %#012llx\n",
			 range_type, range.cpu_addr,
			 range.cpu_addr + range.size - 1, range.pci_addr);

		/*
		 * If we failed translation or got a zero-sized region
		 * then skip this range
		 */
		if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
			continue;

		err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
		if (err)
			continue;

		res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
		if (!res) {
			err = -ENOMEM;
			goto failed;
		}

		if (resource_type(res) == IORESOURCE_IO) {
			if (!io_base) {
				dev_err(dev, "I/O range found for %pOF. Please provide an io_base pointer to save CPU base address\n",
					dev_node);
				err = -EINVAL;
				goto failed;
			}
			if (*io_base != (resource_size_t)OF_BAD_ADDR)
				dev_warn(dev, "More than one I/O resource converted for %pOF. CPU base address for old range lost!\n",
					 dev_node);
			*io_base = range.cpu_addr;
		} else if (resource_type(res) == IORESOURCE_MEM) {
			res->flags &= ~IORESOURCE_MEM_64;
		}

		pci_add_resource_offset(resources, res,	res->start - range.pci_addr);
	}

	/* Check for dma-ranges property */
	if (!ib_resources)
		return 0;
	err = of_pci_dma_range_parser_init(&parser, dev_node);
	if (err)
		return 0;

	dev_dbg(dev, "Parsing dma-ranges property...\n");
	for_each_of_pci_range(&parser, &range) {
		struct resource_entry *entry;
		/*
		 * If we failed translation or got a zero-sized region
		 * then skip this range
		 */
		if (((range.flags & IORESOURCE_TYPE_BITS) != IORESOURCE_MEM) ||
		    range.cpu_addr == OF_BAD_ADDR || range.size == 0)
			continue;

		dev_info(dev, "  %6s %#012llx..%#012llx -> %#012llx\n",
			 "IB MEM", range.cpu_addr,
			 range.cpu_addr + range.size - 1, range.pci_addr);


		err = of_pci_range_to_resource(&range, dev_node, &tmp_res);
		if (err)
			continue;

		res = devm_kmemdup(dev, &tmp_res, sizeof(tmp_res), GFP_KERNEL);
		if (!res) {
			err = -ENOMEM;
			goto failed;
		}

		/* Keep the resource list sorted */
		resource_list_for_each_entry(entry, ib_resources)
			if (entry->res->start > res->start)
				break;

		pci_add_resource_offset(&entry->node, res,
					res->start - range.pci_addr);
	}

	return 0;

failed:
	pci_free_resource_list(resources);
	return err;
}