linux/arch/x86/pci
Gary Hade 62f420f828 PCI: use _CRS for PCI resource allocation
Use _CRS for PCI resource allocation

This patch resolves an issue where incorrect PCI memory and i/o ranges
are being assigned to hotplugged PCI devices on some IBM systems.  The
resource mis-allocation not only makes the PCI device unuseable but
often makes the entire system unuseable due to resulting machine checks.

The hotplug capable PCI slots on the affected systems are not located
under a standard P2P bridge but are instead located under PCI root
bridges or subtractive decode P2P bridges.  For example, the IBM x3850
contains 2 hotplug capable PCI-X slots and 4 hotplug capable PCIe slots
with the PCI-X slots each located under a PCI root bridge and the PCIe
slots each located under a subtractive decode P2P bridge.

The current i386/x86_64 PCI resource allocation code does not use _CRS
returned resource information.  No other resource information source is
available for slots that are not below a standard P2P bridge so
incorrect ranges are being allocated from e820 hole causing the bad
result.

This patch causes the kernel to use _CRS returned resource info.  It is
roughly based on a change provided by Matthew Wilcox for the ia64 kernel
in 2005.  Due to possible buggy BIOS factor and possible yet to be
discovered kernel issues the function is disabled by default and can be
enabled with pci=use_crs.

Signed-off-by: Gary Hade <gary.hade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-10-12 15:03:18 -07:00
..
acpi.c PCI: use _CRS for PCI resource allocation 2007-10-12 15:03:18 -07:00
common.c PCI: use _CRS for PCI resource allocation 2007-10-12 15:03:18 -07:00
direct.c i386: move pci 2007-10-11 11:16:36 +02:00
early.c i386: move pci 2007-10-11 11:16:36 +02:00
fixup.c PCI: re-enable onboard sound on "MSI K8T Neo2-FIR" 2007-10-12 15:03:16 -07:00
i386.c PCI: skip ISA ioresource alignment on some systems 2007-10-12 15:03:18 -07:00
init.c i386: move pci 2007-10-11 11:16:36 +02:00
irq.c i386: add support for picopower irq router 2007-10-12 15:03:15 -07:00
k8-bus_64.c x86_64: move pci 2007-10-11 11:17:12 +02:00
legacy.c i386: move pci 2007-10-11 11:16:36 +02:00
Makefile x86_64: move pci 2007-10-11 11:17:12 +02:00
Makefile_32 i386: move pci 2007-10-11 11:16:36 +02:00
Makefile_64 x86_64: move pci 2007-10-11 11:17:12 +02:00
mmconfig_32.c i386: move pci 2007-10-11 11:16:36 +02:00
mmconfig_64.c x86_64: move pci 2007-10-11 11:17:12 +02:00
mmconfig-shared.c i386: move pci 2007-10-11 11:16:36 +02:00
numa.c i386: move pci 2007-10-11 11:16:36 +02:00
pcbios.c i386: move pci 2007-10-11 11:16:36 +02:00
pci.h PCI: use _CRS for PCI resource allocation 2007-10-12 15:03:18 -07:00
visws.c i386: move pci 2007-10-11 11:16:36 +02:00