From 6cf5c8ee655ab80d897b7a86bfc4dbde6fb462d5 Mon Sep 17 00:00:00 2001 From: Mike Loptien Date: Thu, 18 Jul 2013 10:16:31 -0600 Subject: AMD Fam16: Add secondary bus number to CRES method Adding the 'WordBusNumber' macro to the PCI0 CRES ResourceTemplate in the AMD FCH ACPI code. This sets up the bus number for the PCI0 device and the secondary bus number in the CRS method. This change came in response to a 'dmesg' error which states: '[FIRMWARE BUG]: ACPI: no secondary bus range in _CRS' By adding the 'WordBusNumber' macro, ACPI can set up a valid range for the PCIe downstream busses, thereby relieving the Linux kernel from "guessing" the valid range based off _BBN or assuming [0-0xFF]. The Linux kernel code that checks this bus range is in `drivers/acpi/pci_root.c`. PCI busses can have up to 256 secondary busses connected to them via a PCI-PCI bridge. However, these busses do not have to be sequentially numbered, so leaving out a section of the range (eg. allowing [0-0x7F]) will unnecessarily restrict the downstream busses. Change-Id: Ib2d36f69a26b715798ef1ea17deb0905fa0cad87 Signed-off-by: Mike Loptien Reviewed-on: http://review.coreboot.org/3822 Tested-by: build bot (Jenkins) Reviewed-by: Paul Menzel --- src/southbridge/amd/agesa/hudson/acpi/fch.asl | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'src/southbridge/amd/agesa/hudson/acpi/fch.asl') diff --git a/src/southbridge/amd/agesa/hudson/acpi/fch.asl b/src/southbridge/amd/agesa/hudson/acpi/fch.asl index 4fbf853038..5d3a29ce5c 100755 --- a/src/southbridge/amd/agesa/hudson/acpi/fch.asl +++ b/src/southbridge/amd/agesa/hudson/acpi/fch.asl @@ -71,6 +71,22 @@ Device(ACMD) { #endif Name(CRES, ResourceTemplate() { + /* Set the Bus number and Secondary Bus number for the PCI0 device + * The Secondary bus range for PCI0 lets the system + * know what bus values are allowed on the downstream + * side of this PCI bus if there is a PCI-PCI bridge. + * PCI busses can have 256 secondary busses which + * range from [0-0xFF] but they do not need to be + * sequential. + */ + WordBusNumber (ResourceProducer, MinFixed, MaxFixed, PosDecode, + 0x0000, /* address granularity */ + 0x0000, /* range minimum */ + 0x00FF, /* range maximum */ + 0x0000, /* translation */ + 0x0100, /* length */ + ,, PSB0) /* ResourceSourceIndex, ResourceSource, DescriptorName */ + IO(Decode16, 0x0CF8, 0x0CF8, 1, 8) WORDIO(ResourceProducer, MinFixed, MaxFixed, PosDecode, EntireRange, -- cgit v1.2.3