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author | John Garry <john.garry@huawei.com> | 2018-03-15 02:15:57 +0800 |
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committer | Bjorn Helgaas <helgaas@kernel.org> | 2018-04-04 08:42:50 -0500 |
commit | dfda4492322ed0a1eb9c4d4715c4b90c9af57352 (patch) | |
tree | b4119c1d8752279a7f1e00e4c00cd386a5026077 /tools | |
parent | d87fb0917a073d71300b2b31b3773f6690bd1712 (diff) |
ACPI / scan: Do not enumerate Indirect IO host children
Through the logical PIO framework, systems which otherwise have no IO space
access to legacy ISA/LPC devices may access these devices through so-called
"indirect IO" method. In this, IO space accesses for non-PCI hosts are
redirected to a host LLDD to manually generate the IO space (bus) accesses.
Hosts are able to register a region in logical PIO space to map to its bus
address range.
Indirect IO child devices have an associated host-specific bus address.
Special translation is required to map between a logical PIO address for a
device and its host bus address.
Since in the ACPI tables the child device IO resources would be the
host-specific values, it is required the ACPI scan code should not
enumerate these devices, and that this should be the responsibility of the
host driver so that it can "fixup" the resources so that they map to the
appropriate logical PIO addresses.
To avoid enumerating these child devices, add a check from
acpi_device_enumeration_by_parent() as to whether the parent for a device
is a member of a known list of "indirect IO" hosts. For now, the HiSilicon
LPC host controller ID is added.
Tested-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'tools')
0 files changed, 0 insertions, 0 deletions