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alistair23-linux/include/linux/wmi.h

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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>
2015-11-24 20:49:23 -07:00
/*
* wmi.h - ACPI WMI interface
*
* Copyright (c) 2015 Andrew Lutomirski
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#ifndef _LINUX_WMI_H
#define _LINUX_WMI_H
#include <linux/device.h>
#include <linux/acpi.h>
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>
2017-11-01 13:25:35 -06:00
#include <uapi/linux/wmi.h>
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>
2015-11-24 20:49:23 -07:00
struct wmi_device {
struct device dev;
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>
2015-11-25 15:03:43 -07:00
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>
2017-05-19 20:28:36 -06:00
/* True for data blocks implementing the Set Control Method */
bool setable;
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>
2015-11-24 20:49:23 -07:00
};
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>
2017-11-01 13:25:23 -06:00
/* evaluate the ACPI method associated with this device */
extern acpi_status wmidev_evaluate_method(struct wmi_device *wdev,
u8 instance, u32 method_id,
const struct acpi_buffer *in,
struct acpi_buffer *out);
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>
2015-11-25 19:19:26 -07:00
/* Caller must kfree the result. */
extern union acpi_object *wmidev_block_query(struct wmi_device *wdev,
u8 instance);
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>
2017-11-01 13:25:35 -06:00
extern int set_required_buffer_size(struct wmi_device *wdev, u64 length);
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>
2015-11-24 20:49:23 -07:00
struct wmi_device_id {
const char *guid_string;
};
struct wmi_driver {
struct device_driver driver;
const struct wmi_device_id *id_table;
int (*probe)(struct wmi_device *wdev);
int (*remove)(struct wmi_device *wdev);
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>
2015-11-25 18:33:25 -07:00
void (*notify)(struct wmi_device *device, union acpi_object *data);
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>
2017-11-01 13:25:35 -06:00
long (*filter_callback)(struct wmi_device *wdev, unsigned int cmd,
struct wmi_ioctl_buffer *arg);
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>
2015-11-24 20:49:23 -07:00
};
extern int __must_check __wmi_driver_register(struct wmi_driver *driver,
struct module *owner);
extern void wmi_driver_unregister(struct wmi_driver *driver);
#define wmi_driver_register(driver) __wmi_driver_register((driver), THIS_MODULE)
#define module_wmi_driver(__wmi_driver) \
module_driver(__wmi_driver, wmi_driver_register, \
wmi_driver_unregister)
#endif