This is a request from Cisco to update pci address space for 64-bit mips
Cavium Octeon.

The size returned by a 4GB or greater sized BAR register returns zero
which made the algorithm in pci_read_bases() hit a continue instead of
continuing to read the upper 32-bits of the address space. I needed to
add the code to check if it was a 64-bit memory space by checking the
relevant lower bits, in which case the lower 32-bits of the size are
0xffffffff by the way they calculate size. As far as I can tell this has
still not been fixed in the latest release of Linux which is 2.6.18. I
guess no one has
encountered such a large BAR register yet.