• Bjorn Helgaas's avatar
    ACPI: pci_root: save downstream bus range · 6ad95513
    Bjorn Helgaas authored
    Previously, we only saved the root bus number, i.e., the beginning of the
    downstream bus range.  We now support IORESOURCE_BUS resources, so this
    patch uses that to keep track of both the beginning and the end of the
    downstream bus range.
    
    It's important to know both the beginning and the end for supporting _CBA
    (see PCI Firmware spec, rev 3.0, sec 4.1.3) and so we know the limits for
    any possible PCI bus renumbering (we can't renumber downstream buses to be
    outside the bus number range claimed by the host bridge).
    
    It's clear from the spec that the bus range is supposed to be in _CRS, but
    if we don't find it there, we'll assume [_BBN - 0xFF] or [0 - 0xFF].
    Signed-off-by: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
    Reviewed-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    6ad95513
pci_root.c 15.1 KB