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>

diff --git a/arch/sparc/kernel/pci.c b/arch/sparc/kernel/pci.c
index da24fb6deb037836aad8b0c420587ef731ea6bfb..cc4c31e5185e57d8dc35b6748f3ecb712e4731d4 100644 (file)
--- 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) {