Re: [PATCH v5 0/5] PCI: try "pci=use_crs" again

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Tue, 23 Feb 2010 10:24:15 -0700
Bjorn Helgaas <bjorn.helgaas@hp.com> wrote:

> Historically, Linux has assumed a single PCI host bridge, with that
> bridge claiming all the address space left after RAM and legacy
> devices are taken out.
> 
> If the system contains multiple host bridges, we can no longer
> operate under that assumption.  We have to know what parts of the
> address space are claimed by each bridge so that when we assign
> resources to a PCI device, we take them from a range claimed by the
> upstream host bridge.
> 
> On x86 and ia64, we use ACPI to enumerate all the PCI host bridges in
> the system, and part of the host bridge description is the
> "_CRS" (current resource settings" property, which lists the address
> space used by the bridge.  On x86, we currently ignore most of the
> _CRS information.  This patch series changes this, so we will use
> _CRS to learn about the host bridge windows.
> 
> Since most x86 machines with multiple host bridges are relatively
> new, this series only turns this on for machines with BIOS dates of
> 2008 or newer.
> 
> Changes from v4 to v5:
>     - Add EXPORT_SYMBOL_GPL(pci_bus_resource_n) for module builds.

Thanks, it built this time.  Pushed to my linux-next branch.

-- 
Jesse Barnes, Intel Open Source Technology Center