Commit Graph

10 Commits

Author SHA1 Message Date
Mattias Jacobsson
eacc95eae6 platform/x86: wmi: move struct wmi_device_id to mod_devicetable.h
In preparation for adding WMI support to MODULE_DEVICE_TABLE() move the
definition of struct wmi_device_id to mod_devicetable.h and inline
guid_string in the struct.

Changing guid_string to an inline char array changes the loop conditions
when looping over an array of struct wmi_device_id. Therefore update
wmi_dev_match()'s loop to check for an empty guid_string instead of a
NULL pointer.

Signed-off-by: Mattias Jacobsson <2pi@mok.nu>
[dvhart: Move UUID_STRING_LEN define to this patch]
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2019-03-07 08:46:07 -08:00
Mario Limonciello
44b6b76611 platform/x86: wmi: create userspace interface for drivers
For WMI operations that are only Set or Query readable and writable sysfs
attributes created by WMI vendor drivers or the bus driver makes sense.

For other WMI operations that are run on Method, there needs to be a
way to guarantee to userspace that the results from the method call
belong to the data request to the method call.  Sysfs attributes don't
work well in this scenario because two userspace processes may be
competing at reading/writing an attribute and step on each other's
data.

When a WMI vendor driver declares a callback method in the wmi_driver
the WMI bus driver will create a character device that maps to that
function.  This callback method will be responsible for filtering
invalid requests and performing the actual call.

That character device will correspond to this path:
/dev/wmi/$driver

Performing read() on this character device will provide the size
of the buffer that the character device needs to perform calls.
This buffer size can be set by vendor drivers through a new symbol
or when MOF parsing is available by the MOF.

Performing ioctl() on this character device will be interpretd
by the WMI bus driver. It will perform sanity tests for size of
data, test them for a valid instance, copy the data from userspace
and pass iton to the vendor driver to further process and run.

This creates an implicit policy that each driver will only be allowed
a single character device.  If a module matches multiple GUID's,
the wmi_devices will need to be all handled by the same wmi_driver.

The WMI vendor drivers will be responsible for managing inappropriate
access to this character device and proper locking on data used by
it.

When a WMI vendor driver is unloaded the WMI bus driver will clean
up the character device and any memory allocated for the call.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-11-03 16:34:00 -07:00
Mario Limonciello
f97e058cfe platform/x86: wmi: Don't allow drivers to get each other's GUIDs
The only driver using this was dell-wmi, and it really was a hack.
The driver was getting a data attribute from another driver and this
type of action should not be encouraged.

Rather drivers that need to interact with one another should pass
data back and forth via exported functions.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-11-03 16:33:58 -07:00
Mario Limonciello
722c856d46 platform/x86: wmi: Add new method wmidev_evaluate_method
Drivers properly using the wmibus can pass their wmi_device
pointer rather than the GUID back to the WMI bus to evaluate
the proper methods.

Any "new" drivers added that use the WMI bus should use this
rather than the old wmi_evaluate_method that would take the
GUID.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reviewed-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-11-03 16:33:57 -07:00
Darren Hart (VMware)
fd70da6a62 platform/x86: wmi: Require query for data blocks, rename writable to setable
The Microsoft WMI documentation requires all data blocks to implement
the Query Control Method (WQxx). If we encounter a data block not
implementing this control method, issue a warning, and ignore the data
block. Remove the "readable" attribute as all data blocks must be
readable (query-able).

Be consistent with the language in the documentation, replace the
"writable" attribute with "setable".

Simplify (flatten) the control flow of wmi_create_device a bit while
we are updating it for the above changes.

Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-06 10:15:20 -07:00
Andy Lutomirski
f63019861c platform/x86: wmi: Add an interface for subdrivers to access sibling devices
Some subdrivers need to access sibling devices. This gives them a
clean way to do so.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06 10:15:19 -07:00
Andy Lutomirski
56a370259d platform/x86: wmi: Add a new interface to read block data
wmi_query_block is unnecessarily indirect. Add a straightforward
method for wmi bus drivers to use to read block data.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06 10:15:19 -07:00
Andy Lutomirski
1686f54445 platform/x86: wmi: Incorporate acpi_install_notify_handler
As a platform driver, acpi_driver.notify will not be available,
so use acpi_install_notify_handler as we will be converting to a
platform driver.

This gives event drivers a simple way to handle events. It
also seems closer to what the Windows docs suggest that Windows
does: it sounds like, in Windows, the mapper is responsible for
called _WED before dispatching to the subdriver.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
[dvhart: merge two development commits and update commit message]
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06 10:15:19 -07:00
Andy Lutomirski
d4fc91adfd platform/x86: wmi: Probe data objects for read and write capabilities
The Dell XPS 13 9350 has one RW data object, one RO data object, and one
totally inaccessible data object. Check for the existence of the
accessor methods and report in sysfs.

The docs also permit WQxx getters for single-instance objects to
take no parameters. Probe for that as well to avoid ACPICA warnings
about mismatched signatures.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06 10:15:18 -07:00
Andy Lutomirski
844af950da platform/x86: wmi: Turn WMI into a bus driver
WMI is logically a bus: the WMI driver binds to an ACPI node (or
more than one), and each instance of the WMI driver enumerates its
children and hopes that drivers will attach to the children that are
useful.

This patch gives WMI a driver model bus type and the ability to
match to drivers. The bus itself is a device in the new "wmi_bus"
class, and all of the individual WMI devices are slotted into the
device hierarchy correctly.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Mario Limonciello <mario_limonciello@dell.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-06-06 10:15:18 -07:00