[PATCH v6 6/6] pci: Add support for creating a generic host_bridge from device tree

Arnd Bergmann
2014-03-08T17:15:08Z

On Wednesday 05 March 2014, Liviu Dudau wrote:
> +
> + pr_debug("Parsing ranges property...\n");
> + for_each_of_pci_range(&parser, &range) {
> + /* Read next ranges element */
> + pr_debug("pci_space: 0x%08x pci_addr:0x%016llx ",
> + range.pci_space, range.pci_addr);
> + pr_debug("cpu_addr:0x%016llx size:0x%016llx\n",
> + range.cpu_addr, range.size);
> +
> + /*
> + * 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;
> +
> + res = kzalloc(sizeof(struct resource), GFP_KERNEL);
> + if (!res)
> + return -ENOMEM;
> +
> + of_pci_range_to_resource(&range, dev, res);
> +
> + if (resource_type(res) == IORESOURCE_IO)
> + *io_base = range.cpu_addr;
> +
> + pci_add_resource_offset(resources, res,
> + res->start - range.pci_addr);
> + }

As mentioned regarding the pci_register_io_range() helper, x86
would not enter the 'resource_type(res) == IORESOURCE_IO' code path,
which on the one hand is fine so we can return an error from
pci_register_io_range() there, but I think it will lead to
io_base getting an uninitialized content.

There could also be other reasons why pci_register_io_range() fails,
e.g. because the space is exhausted, and I think we should try to
catch that here and skip the pci_add_resource_offset() and io_base
assignment then.

Arnd