ACPI: pci_root: save downstream bus range
authorBjorn Helgaas <bjorn.helgaas@hp.com>
Thu, 11 Mar 2010 19:20:06 +0000 (12:20 -0700)
committerLen Brown <len.brown@intel.com>
Sun, 4 Apr 2010 04:29:41 +0000 (00:29 -0400)
commit6ad95513d60096b569e4e4bd721420f03b57e4d4
tree1029d5804adc51eb3f5c0aed56ef0fd00ae2042f
parent2eaa9cfdf33b8d7fb7aff27792192e0019ae8fc6
ACPI: pci_root: save downstream bus range

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: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Len Brown <len.brown@intel.com>
drivers/acpi/pci_root.c
include/acpi/acpi_bus.h