sparc64: Skip bogus PCI bridge ranges.

It seems that when a PCI Express bridge is not in use and has no devices
behind it, the ranges property is bogus.  Specifically the size property
is of the form [0xffffffff:...], and if you add this size to the resource
start address the 64-bit calculation will overflow.

Just check specifically for this size value signature and skip them.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index da24fb6deb03..cc4c31e5185e 100644
--- a/arch/sparc/kernel/pci.c
+++ b/arch/sparc/kernel/pci.c
@@ -489,6 +489,17 @@ static void of_scan_pci_bridge(struct pci_pbm_info *pbm,
                 size = GET_64BIT(ranges, 6);
                 if (flags == 0 || size == 0)
                         continue;
+
+                /* On PCI-Express systems, PCI bridges that have no devices downstream
+                 * have a bogus size value where the first 32-bit cell is 0xffffffff.
+                 * This results in a bogus range where start + size overflows.
+                 *
+                 * Just skip these otherwise the kernel will complain when the resource
+                 * tries to be claimed.
+                 */
+                if (size >> 32 == 0xffffffff)
+                        continue;
+
                 if (flags & IORESOURCE_IO) {
                         res = bus->resource[0];
                         if (res->flags) {