According to documentation [0] the correct offset for the Upstream Peer
Decode Configuration Register (UPDCR) is 0x1014.  It was previously defined
as 0x1114.

d99321b6 ("PCI: Enable quirks for PCIe ACS on Intel PCH root ports")
intended to enforce isolation between PCI devices allowing them to be put
into separate IOMMU groups.  Due to the wrong register offset the intended
isolation was not fully enforced.  This is fixed with this patch.

Please note that I did not test this patch because I have no hardware that
implements this register.

[0] https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/4th-gen-core-family-mobile-i-o-datasheet.pdf (page 325)
Fixes: d99321b6 ("PCI: Enable quirks for PCIe ACS on Intel PCH root ports")
Link: https://lore.kernel.org/r/7a3505df-79ba-8a28-464c-88b83eefffa6@kernkonzept.comSigned-off-by: Steffen Liebergeld <steffen.liebergeld@kernkonzept.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
Acked-by: Ashok Raj <ashok.raj@intel.com>
Cc: stable@vger.kernel.org	# v3.15+