Work around BIOSes that don't report the entire Intel MCH area.
MCHBAR is not an architected PCI BAR, so MCH space is usually reported as a
PNP0C02 resource. The MCH space was once 16KB, but is 32KB in newer parts.
Some BIOSes still report a PNP0C02 resource that is only 16KB, which means
the rest of the MCH space is consumed but unreported.
This can cause resource map sanity check warnings or (theoretically) a
device conflict if we assigned the unreported space to another device.
The Intel perf event uncore driver tripped over this when it claimed the
MCH region:
resource map sanity check conflict: 0xfed10000 0xfed15fff 0xfed10000 0xfed13fff pnp 00:01
Info: mapping multiple BARs. Your kernel is fine.
To prevent this, if we find a PNP0C02 resource that covers part of the MCH
space, extend it to cover the entire space.
References: http://lkml.kernel.org/r/20140224162400.GE16457@pd.tnic
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cb171f7abb