• Yinghai Lu's avatar
    PCI : Calculate right add_size · a4ac9fea
    Yinghai Lu authored
    During debug of one SRIOV enabled hotplug device, we found found that
    add_size is not passed properly.
    
    The device has devices under two level bridges:
    
     +-[0000:80]-+-00.0-[81-8f]--
     |           +-01.0-[90-9f]--
     |           +-02.0-[a0-af]----00.0-[a1-a3]--+-02.0-[a2]--+-00.0  Oracle Corporation Device
     |           |                               \-03.0-[a3]--+-00.0  Oracle Corporation Device
    
    Which means later the parent bridge will not try to add a big enough range:
    
    [  557.455077] pci 0000:a0:00.0: BAR 14: assigned [mem 0xf9000000-0xf93fffff]
    [  557.461974] pci 0000:a0:00.0: BAR 15: assigned [mem 0xf6000000-0xf61fffff pref]
    [  557.469340] pci 0000:a1:02.0: BAR 14: assigned [mem 0xf9000000-0xf91fffff]
    [  557.476231] pci 0000:a1:02.0: BAR 15: assigned [mem 0xf6000000-0xf60fffff pref]
    [  557.483582] pci 0000:a1:03.0: BAR 14: assigned [mem 0xf9200000-0xf93fffff]
    [  557.490468] pci 0000:a1:03.0: BAR 15: assigned [mem 0xf6100000-0xf61fffff pref]
    [  557.497833] pci 0000:a1:03.0: BAR 14: can't assign mem (size 0x200000)
    [  557.504378] pci 0000:a1:03.0: failed to add optional resources res=[mem 0xf9200000-0xf93fffff]
    [  557.513026] pci 0000:a1:02.0: BAR 14: can't assign mem (size 0x200000)
    [  557.519578] pci 0000:a1:02.0: failed to add optional resources res=[mem 0xf9000000-0xf91fffff]
    
    It turns out we did not calculate size1 properly.
    
    static resource_size_t calculate_memsize(resource_size_t size,
                    resource_size_t min_size,
                    resource_size_t size1,
                    resource_size_t old_size,
                    resource_size_t align)
    {
            if (size < min_size)
                    size = min_size;
            if (old_size == 1 )
                    old_size = 0;
            if (size < old_size)
                    size = old_size;
            size = ALIGN(size + size1, align);
            return size;
    }
    
    We should not pass add_size with min_size in calculate_memsize since
    that will make add_size not contribute final add_size.
    
    So just pass add_size with size1 to calculate_memsize().
    
    With this change, we should have chance to remove extra addon in
    pci_reassign_resource.
    Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
    Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
    a4ac9fea
setup-res.c 9.35 KB