From: Alexey Kardashevskiy aik@ozlabs.ru
commit dead1c845dbe97e0061dae2017eaf3bd8f8f06ee upstream.
The pseries platform uses the PCI_PROBE_DEVTREE method of PCI probing which reads "assigned-addresses" of every PCI device and initializes the device resources. However if the property is missing or zero sized, then there is no fallback of any kind and the PCI resources remain undiscovered, i.e. pdev->resource[] array remains empty.
This adds a fallback which parses the "reg" property in pretty much same way except it marks resources as "unset" which later make Linux assign those resources proper addresses.
This has an effect when: 1. a hypervisor failed to assign any resource for a device; 2. /chosen/linux,pci-probe-only=0 is in the DT so the system may try assigning a resource. Neither is likely to happen under PowerVM.
Signed-off-by: Alexey Kardashevskiy aik@ozlabs.ru Signed-off-by: Michael Ellerman mpe@ellerman.id.au Cc: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/kernel/pci_of_scan.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/arch/powerpc/kernel/pci_of_scan.c +++ b/arch/powerpc/kernel/pci_of_scan.c @@ -82,10 +82,16 @@ static void of_pci_parse_addrs(struct de const __be32 *addrs; u32 i; int proplen; + bool mark_unset = false;
addrs = of_get_property(node, "assigned-addresses", &proplen); - if (!addrs) - return; + if (!addrs || !proplen) { + addrs = of_get_property(node, "reg", &proplen); + if (!addrs || !proplen) + return; + mark_unset = true; + } + pr_debug(" parse addresses (%d bytes) @ %p\n", proplen, addrs); for (; proplen >= 20; proplen -= 20, addrs += 5) { flags = pci_parse_of_flags(of_read_number(addrs, 1), 0); @@ -110,6 +116,8 @@ static void of_pci_parse_addrs(struct de continue; } res->flags = flags; + if (mark_unset) + res->flags |= IORESOURCE_UNSET; res->name = pci_name(dev); region.start = base; region.end = base + size - 1;