From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH v17 08/10] ACPI / scan: do not enumerate Indirect IO host children Date: Mon, 19 Mar 2018 11:30:11 +0100 Message-ID: <2309217.pWfZsU88YQ@aspire.rjw.lan> References: <1521051359-34473-1-git-send-email-john.garry@huawei.com> <1521051359-34473-9-git-send-email-john.garry@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <1521051359-34473-9-git-send-email-john.garry@huawei.com> Sender: linux-kernel-owner@vger.kernel.org To: John Garry Cc: mika.westerberg@linux.intel.com, rafael@kernel.org, lorenzo.pieralisi@arm.com, hanjun.guo@linaro.org, robh+dt@kernel.org, bhelgaas@google.com, arnd@arndb.de, mark.rutland@arm.com, olof@lixom.net, dann.frazier@canonical.com, andy.shevchenko@gmail.com, robh@kernel.org, andriy.shevchenko@linux.intel.com, joe@perches.com, benh@kernel.crashing.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linuxarm@huawei.com, minyard@acm.org, devicetree@vger.kernel.org, linux-arch@vger.kernel.org, rdunlap@infradead.org, gregkh@linuxfoundation.org, akpm@linux-foundation.org, frowand.list@gmail.com, agraf@suse.de List-Id: linux-acpi@vger.kernel.org On Wednesday, March 14, 2018 7:15:57 PM CET John Garry wrote: > 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 it's 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, we 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. > > Signed-off-by: John Garry > Acked-by: Rafael J. Wysocki You have my ACK here already. Since I've ACKed the [7/10] too, I don't think there's anything more I can do about this series and I'm assuming that it will be routed through other trees. Thanks! > Reviewed-by: Andy Shevchenko > Tested-by: dann frazier > --- > drivers/acpi/scan.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > index f9e7904..a4cbf3e 100644 > --- a/drivers/acpi/scan.c > +++ b/drivers/acpi/scan.c > @@ -1524,11 +1524,25 @@ static int acpi_check_serial_bus_slave(struct acpi_resource *ares, void *data) > return -1; > } > > +static bool acpi_is_indirect_io_slave(struct acpi_device *device) > +{ > + struct acpi_device *parent = device->parent; > + const struct acpi_device_id indirect_io_hosts[] = { > + {"HISI0191", 0}, > + {} > + }; > + > + return parent && !acpi_match_device_ids(parent, indirect_io_hosts); > +} > + > static bool acpi_device_enumeration_by_parent(struct acpi_device *device) > { > struct list_head resource_list; > bool is_serial_bus_slave = false; > > + if (acpi_is_indirect_io_slave(device)) > + return true; > + > /* Macs use device properties in lieu of _CRS resources */ > if (x86_apple_machine && > (fwnode_property_present(&device->fwnode, "spiSclkPeriod") || >