platform/x86: wmi: Remove obsolete duplicate GUID allowlist

The whitelist-based approach for preventing older WMI drivers from
being instantiated multiple times has many drawbacks:

- uses cannot see all available WMI devices (if not whitelisted)
- whitelisting a WMI driver requires changes in the WMI driver core
- maintenance burden for driver and subsystem developers

Since the WMI driver core already takes care that older WMI drivers
are not being instantiated multiple times, remove the now redundant
whitelist.

Tested on a ASUS Prime B650-Plus.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240226193557.2888-3-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Do not instantiate older WMI drivers multiple times

Many older WMI drivers cannot be instantiated multiple times for
two reasons:

- they are using the legacy GUID-based WMI API
- they are singletons (with global state)

Prevent such WMI drivers from binding to WMI devices with a duplicated
GUID, as this would mean that the WMI driver will be instantiated at
least two times (one for the original GUID and one for the duplicated
GUID).
WMI drivers which can be instantiated multiple times can signal this
by setting a flag inside struct wmi_driver.

Tested on a ASUS Prime B650-Plus.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240226193557.2888-2-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Ignore duplicated GUIDs in legacy matches

When matching a WMI device to a GUID used by the legacy GUID-based
API, devices with a duplicated GUID should be ignored.

Add an additional WMI device flag signaling that the GUID used by
the WMI device is also used by another WMI device. Ignore such
devices inside the match functions used by the legacy GUID-based API.

Tested on a ASUS Prime B650-Plus.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240226193557.2888-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Always evaluate _WED when receiving an event

The ACPI WMI specification states:

"The _WED control method is evaluated by the mapper in
response to receiving a notification from a control
method."

This means that _WED should be evaluated unconditionally even
if no WMI event consumers are present.
Some firmware implementations actually depend on this behavior
by storing the event data inside a queue which will fill up if
the WMI core stops retrieving event data items due to no
consumers being present

Fix this by always evaluating _WED even if no WMI event consumers
are present.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240219115919.16526-4-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Check if event data is not NULL

WMI event drivers which do not have no_notify_data set expect
that each WMI event contains valid data. Evaluating _WED however
might return no data, which can cause issues with such drivers.

Fix this by validating that evaluating _WED did return data.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240219115919.16526-3-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Prevent incompatible event driver from probing

If a WMI event driver has no_notify_data set, then it indicates
support for WMI events which provide no notify data, otherwise
the notify() callback expects a valid ACPI object as notify data.

However if a WMI event driver which requires notify data is bound
to a WMI event device which cannot retrieve such data due to the
_WED ACPI method being absent, then the driver will be dysfunctional
since all WMI events will be dropped due to the missing notify data.

Fix this by not allowing such WMI event drivers to bind to WMI event
devices which do not support retrieving of notify data. Also reword
the description of no_notify_data a bit.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240219115919.16526-2-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Make input buffer mandatory when evaluating methods

The ACPI-WMI specification declares in the section "ACPI Control Method
Naming Conventions and Functionality for Windows 2000 Instrumentation"
that a WMxx control method takes 3 arguments: instance, method id and
argument buffer. This is also the case even when the underlying WMI
method does not have any input arguments.

So if a WMI driver evaluates a WMI method without passing an input
buffer, ACPICA will log a warning complaining that the third argument
is missing.

Prevent this by checking that a input buffer was passed, and return
an error if this was not the case.

Tested on a Asus PRIME B650-Plus.

Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240212185016.5494-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Replace pr_err() with dev_err()

Using dev_err() allows users to find out from which
device the error message came from.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240206220447.3102-4-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Remove unnecessary out-of-memory message

If kzalloc() fails, an out-of-memory message is already
printed. Remove the unnecessary second warning message.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240206220447.3102-3-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Use FW_BUG when warning about missing control methods

A missing WQxx control method is a firmware bug and should be
marked as such using FW_BUG so that users know that the issue
is not a kernel issue.
Since get_subobj_info() might fail even if the control method
is present, we need to print the warning only if acpi_get_handle()
fails.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240206220447.3102-2-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Check if WMxx control method exists

Some devices like the MSI GF63-12VF contain WMI method blocks
without providing the necessary WMxx ACPI control methods.
Avoid creating WMI devices for such WMI method blocks since
the resulting WMI device is going to be unusable.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240206220447.3102-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform: x86: wmi: make wmi_bus_type const

Now that the driver core can properly handle constant struct bus_type,
move the wmi_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Ricardo B. Marliere" <ricardo@marliere.net>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240204-bus_cleanup-platform-drivers-x86-v1-1-1f0839b385c6@marliere.net
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Stop using ACPI device class

When an ACPI netlink event is received by acpid, the ACPI device
class is passed as its first argument. But since the class string
is not initialized during probe, an empty string is being passed:

netlink: PNP0C14:01 000000d0 00000000

Fix this by passing a static string instead.

Tested on a Dell Inspiron 3505.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20240130221942.2770-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Use ACPI device name in netlink event

The device name inside the ACPI netlink event is limited to
15 characters, so the WMI device name will get truncated.

This can be observed with kacpimon when receiving an event
from WMI device "9DBB5994-A997-11DA-B012-B622A1EF5492":

netlink: 9DBB5994-A997- 000000d0 00000000

Fix this by using the shorter device name from the ACPI
bus device instead. This still allows users to uniquely
identify the WMI device by using the notify id (0xd0).

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240121200824.2778-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Fix wmi_dev_probe()

This has a reversed if statement so it accidentally disables the wmi
method before returning.

Fixes: 704af3a40747 ("platform/x86: wmi: Remove chardev interface")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/9c81251b-bc87-4ca3-bb86-843dc85e5145@moroto.mountain
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Fix notify callback locking

When an legacy WMI event handler is removed, an WMI event could
have called the handler just before it was removed, meaning the
handler could still be running after wmi_remove_notify_handler()
returns.
Something similar could also happens when using the WMI bus, as
the WMI core might still call the notify() callback from an WMI
driver even if its remove() callback was just called.

Fix this by introducing a rw semaphore which ensures that the
event state of a WMI device does not change while the WMI core
is handling an event for it.

Tested on a Dell Inspiron 3505 and a Acer Aspire E1-731.

Fixes: 1686f5444546 ("platform/x86: wmi: Incorporate acpi_install_notify_handler")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240103192707.115512-5-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Decouple legacy WMI notify handlers from wmi_block_list

Until now, legacy WMI notify handler functions where using the
wmi_block_list, which did no refcounting on the returned WMI device.
This meant that the WMI device could disappear at any moment,
potentially leading to various errors.
Fix this by using bus_find_device() which returns an actual
reference to the found WMI device.

Tested on a Dell Inspiron 3505 and a Acer Aspire E1-731.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240103192707.115512-4-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Return immediately if an suitable WMI event is found

Commit 58f6425eb92f ("WMI: Cater for multiple events with same GUID")
allowed legacy WMI notify handlers to be installed for multiple WMI
devices with the same GUID.
However this is useless since the legacy GUID-based interface is
blacklisted from seeing WMI devices with duplicated GUIDs.

Return immediately if a suitable WMI event is found in
wmi_install/remove_notify_handler() since searching for other suitable
events is pointless.

Tested on a Dell Inspiron 3505 and a Acer Aspire E1-731.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240103192707.115512-3-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Fix error handling in legacy WMI notify handler functions

When wmi_install_notify_handler()/wmi_remove_notify_handler() are
unable to enable/disable the WMI device, they unconditionally return
an error to the caller.
When registering legacy WMI notify handlers, this means that the
callback remains registered despite wmi_install_notify_handler()
having returned an error.
When removing legacy WMI notify handlers, this means that the
callback is removed despite wmi_remove_notify_handler() having
returned an error.

Fix this by only warning when the WMI device could not be enabled.
This behaviour matches the bus-based WMI interface.

Tested on a Dell Inspiron 3505 and a Acer Aspire E1-731.

Fixes: 58f6425eb92f ("WMI: Cater for multiple events with same GUID")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20240103192707.115512-2-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

hwmon: (dell-smm) Add support for WMI SMM interface

Some Dell machines like the Dell Optiplex 7000 do not support
the legacy SMM interface, but instead expect all SMM calls
to be issued over a special WMI interface.
Add support for this interface so users can control the fans
on those machines.

Tested-by: <serverror@serverror.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231123004820.50635-8-W_Armin@gmx.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

platform/x86: wmi: Simplify get_subobj_info()

All callers who call get_subobj_info() with **info being NULL
should better use acpi_has_method() instead.
Convert the only caller who does this to acpi_has_method()
to drop the dummy info handling.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231218192420.305411-7-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Decouple ACPI notify handler from wmi_block_list

Currently, the ACPI notify handler searches all WMI devices for
a matching WMI event device. This is inefficient since only WMI devices
associated with the notified ACPI device need to be searched.
Use the WMI bus device and device_for_each_child() to search for
a matching WMI event device instead.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231218192420.305411-6-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Create WMI bus device first

Create the WMI bus device first so that it can be used
by the ACPI handlers.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231218192420.305411-5-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Use devres for resource handling

Use devres for cleaning up the ACPI handlers and the
WMI bus device to simplify the error handling.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231218192420.305411-4-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Remove ACPI handlers after WMI devices

When removing the ACPI notify/address space handlers, the WMI devices
are still active and might still depend on ACPI EC access or
WMI events.
Fix this by removing the ACPI handlers after all WMI devices
associated with an ACPI device have been removed.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231218192420.305411-3-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Remove unused variable in address space handler

The variable "i" is always zero and only used in shift operations.
Remove it to make the code more readable.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231218192420.305411-2-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Remove chardev interface

The design of the WMI chardev interface is broken:
- it assumes that WMI drivers are not instantiated twice
- it offers next to no abstractions, the WMI driver gets
a raw byte buffer
- it is only used by a single driver, something which is
unlikely to change

Since the only user (dell-smbios-wmi) has been migrated
to his own ioctl interface, remove it.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231210202443.646427-6-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Remove debug_event module param

Users can already listen to ACPI WMI events through
the ACPI netlink interface. The old wmi_notify_debug()
interface also uses the deprecated GUID-based interface.
Remove it to make the event handling code more readable.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231210202443.646427-3-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Remove debug_dump_wdg module param

The functionality of dumping WDG entries is better provided by
userspace tools like "fwts wmi", which also does not suffer from
garbled printk output caused by pr_cont().

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231210202443.646427-2-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86/intel/wmi: thunderbolt: Use bus-based WMI interface

Currently, the driver still uses the legacy GUID-based interface
to invoke WMI methods. Use the modern bus-based interface instead.

Tested on a Lenovo E51-80.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231103182526.3524-4-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: intel-wmi-sbl-fw-update: Use bus-based WMI interface

Currently, the driver was still using the deprecated GUID-based
interface to query/set data blocks. Use the modern bus-based
interface for this.

Tested with a custom SSDT from the Intel Slim Bootloader project.

Reviewed-by: Jithu Joseph <jithu.joseph@intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231103182526.3524-3-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Add wmidev_block_set()

Currently, WMI drivers have to use the deprecated GUID-based
interface when setting data blocks. This prevents those
drivers from fully moving away from this interface.

Provide wmidev_block_set() so drivers using wmi_set_block() can
fully migrate to the modern bus-based interface.

Tested with a custom SSDT from the Intel Slim Bootloader project.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231103182526.3524-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Skip blocks with zero instances

Some machines like the HP Omen 17 ck2000nf contain WMI blocks
with zero instances, so any WMI driver which tries to handle the
associated WMI device will fail.
Skip such WMI blocks to avoid confusing any WMI drivers.

Reported-by: Alexis Belmonte <alexbelm48@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218188
Fixes: bff431e49ff5 ("ACPI: WMI: Add ACPI-WMI mapping driver")
Tested-by: Alexis Belmonte <alexbelm48@gmail.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231129181654.5800-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Decouple WMI device removal from wmi_block_list

Use device_for_each_child_reverse() to find and unregister WMI devices
belonging to a WMI bus device instead of iterating thru the entire
wmi_block_list.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-6-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Fix opening of char device

Since commit fa1f68db6ca7 ("drivers: misc: pass miscdevice pointer via
file private data"), the miscdevice stores a pointer to itself inside
filp->private_data, which means that private_data will not be NULL when
wmi_char_open() is called. This might cause memory corruption should
wmi_char_open() be unable to find its driver, something which can
happen when the associated WMI device is deleted in wmi_free_devices().

Fix the problem by using the miscdevice pointer to retrieve the WMI
device data associated with a char device using container_of(). This
also avoids wmi_char_open() picking a wrong WMI device bound to a
driver with the same name as the original driver.

Fixes: 44b6b7661132 ("platform/x86: wmi: create userspace interface for drivers")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-5-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Fix probe failure when failing to register WMI devices

When a WMI device besides the first one somehow fails to register,
retval is returned while still containing a negative error code. This
causes the ACPI device fail to probe, leaving behind zombie WMI devices
leading to various errors later.

Handle the single error path separately and return 0 unconditionally
after trying to register all WMI devices to solve the issue. Also
continue to register WMI devices even if some fail to allocate memory.

Fixes: 6ee50aaa9a20 ("platform/x86: wmi: Instantiate all devices before adding them")
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-4-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Fix refcounting of WMI devices in legacy functions

Until now, legacy GUID-based functions where using find_guid() when
searching for WMI devices, which did no refcounting on the returned
WMI device. This meant that the WMI device could disappear at any
moment, potentially leading to various errors. Fix this by using
bus_find_device() which returns an actual reference to the found
WMI device.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-3-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Decouple probe deferring from wmi_block_list

Many aggregate WMI drivers do not use -EPROBE_DEFER when they
cannot find a WMI device during probe, instead they require
all WMI devices associated with an platform device to become
available at once. This is currently achieved by adding those
WMI devices to the wmi_block_list before they are registered,
which is then used by the deprecated GUID-based functions to
search for WMI devices.

Replace this approach with a device link which defers probing
of the WMI device until the associated platform device has finished
probing (and has registered all WMI devices). New aggregate WMI
drivers should not rely on this behaviour.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20231020211005.38216-2-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

platform/x86: wmi: Replace open coded guid_parse_and_compare()

Even though we have no issues in the code, let's replace the open
coded guid_parse_and_compare().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230621151155.78279-2-andriy.shevchenko@linux.intel.com
Tested-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Break possible infinite loop when parsing GUID

The while-loop may break on one of the two conditions, either ID string
is empty or GUID matches. The second one, may never be reached if the
parsed string is not correct GUID. In such a case the loop will never
advance to check the next ID.

Break possible infinite loop by factoring out guid_parse_and_compare()
helper which may be moved to the generic header for everyone later on
and preventing from similar mistake in the future.

Interestingly that firstly it appeared when WMI was turned into a bus
driver, but later when duplicated GUIDs were checked, the while-loop
has been replaced by for-loop and hence no mistake made again.

Fixes: a48e23385fcf ("platform/x86: wmi: add context pointer field to struct wmi_device_id")
Fixes: 844af950da94 ("platform/x86: wmi: Turn WMI into a bus driver")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230621151155.78279-1-andriy.shevchenko@linux.intel.com
Tested-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Allow retrieving the number of WMI object instances

Currently, the WMI driver core knows how many instances of a given
WMI object exist, but WMI drivers cannot access this information.
At the same time, some current and upcoming WMI drivers want to
have access to this information. Add wmi_instance_count() and
wmidev_instance_count() to allow WMI drivers to get the number of
WMI object instances.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20230430203153.5587-2-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Mark GUID-based WMI interface as deprecated

The WMI driver core supports a more mordern bus-based interface for
interacting with WMI devices. The older GUID-based interface depends
on each WMI GUID and notification id being unique on a given system,
which turned out is not the case.
Mark the older interface as deprecated since new WMI drivers should
use the bus-based interface to avoid this issues.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20230424222939.208137-3-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Add kernel doc comments

Add kernel doc comments useful for documenting the functions/structs
used to interact with the WMI driver core.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20230424222939.208137-2-W_Armin@gmx.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230302144732.1903781-29-u.kleine-koenig@pengutronix.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

driver core: make struct bus_type.uevent() take a const *

The uevent() callback in struct bus_type should not be modifying the
device that is passed into it, so mark it as a const * and propagate the
function signature changes out into all relevant subsystems that use
this callback.

Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

platform/x86: wmi: move dev_to_wblock() and dev_to_wdev to use container_of_const()

The driver core is changing to pass some pointers as const, so move the
dev_to_wdev() and dev_to_wblock() functions to use container_of_const()
to handle this change.

Both of these functions now properly keep the const-ness of the pointer
passed into it, while as before it could be lost.

Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Mark Gross <markgross@kernel.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230111113018.459199-10-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

platform/x86: dell: Add new dell-wmi-ddv driver

The dell-wmi-ddv driver adds support for reading
the current temperature and ePPID of ACPI batteries
on supported Dell machines.

Since the WMI interface used by this driver does not
do any input validation and thus cannot be used for probing,
the driver depends on the ACPI battery extension machanism
to discover batteries.

The driver also supports a debugfs interface for retrieving
buffers containing fan and thermal sensor information.
Since the meaing of the content of those buffers is currently
unknown, the interface is meant for reverse-engineering and
will likely be replaced with an hwmon interface once the
meaning has been understood.

The driver was tested on a Dell Inspiron 3505.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220927204521.601887-3-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Drop forward declaration of static functions

Usually it's not necessary to declare static functions if the symbols are
in the right order. Moving the definition of acpi_wmi_driver down in the
compilation unit allows to drop two such declarations.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220919122213.852322-1-u.kleine-koenig@pengutronix.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Allow duplicate GUIDs for drivers that use struct wmi_driver

The WMI subsystem in the kernel currently tracks WMI devices by
a GUID string not by ACPI device. The GUID used by the `wmi-bmof`
module however is available from many devices on nearly every machine.

This originally was thought to be a bug, but as it happens on most
machines it is a design mistake. It has been fixed by tying an ACPI
device to the driver with struct wmi_driver. So drivers that have
moved over to struct wmi_driver can actually support multiple
instantiations of a GUID without any problem.

Add an allow list into wmi.c for GUIDs that the drivers that are known
to use struct wmi_driver. The list is populated with `wmi-bmof` right
now. The additional instances of that in sysfs with be suffixed with -%d

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20220829201500.6341-1-mario.limonciello@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: replace usage of found with dedicated list iterator variable

To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.

To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable instead of a
found boolean [1].

This removes the need to use a found variable and simply checking if
the variable was set, can determine if the break/goto was hit.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220324072015.62063-1-jakobkoschel@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Add no_notify_data flag to struct wmi_driver

Some WMI implementations do notifies on WMI objects without a _WED method
allow WMI drivers to indicate that _WED should not be called for notifies
on the WMI objects the driver is bound to.

Instead the driver's notify callback will simply be called with a NULL
data argument.

Reported-by: Yauhen Kharuzhy <jekhor@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211128190031.405620-3-hdegoede@redhat.com

platform/x86: wmi: Fix driver->notify() vs ->probe() race

The driver core sets struct device->driver before calling out
to the bus' probe() method, this leaves a window where an ACPI
notify may happen on the WMI object before the driver's
probe() method has completed running, causing e.g. the
driver's notify() callback to get called with drvdata
not yet being set leading to a NULL pointer deref.

At a check for this to the WMI core, ensuring that the notify()
callback is not called before the driver is ready.

Fixes: 1686f5444546 ("platform/x86: wmi: Incorporate acpi_install_notify_handler")
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211128190031.405620-2-hdegoede@redhat.com

platform/x86: wmi: Replace read_takes_no_args with a flags field

Replace the wmi_block.read_takes_no_args bool field with
an unsigned long flags field, used together with test_bit()
and friends.

This is a preparation patch for fixing a driver->notify() vs ->probe()
race, which requires atomic flag handling.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211128190031.405620-1-hdegoede@redhat.com

platform/x86: wmi: change notification handler type

Since AML code on some Xiaomi laptops notifies the WMI hotkey with
0x20 event, we need ACPI_ALL_NOTIFY here to be able to handle it.

Signed-off-by: Mikalai Ramanovich <nikolay.romanovich.00@gmail.com>
Link: https://lore.kernel.org/r/20211015191322.73388-1-nikolay.romanovich.00@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: more detailed error reporting in find_guid()

Make `find_guid()` return an acpi_status, and make it handle NULL
pointer GUID strings; and adapt users accordingly.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-31-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: introduce helper to retrieve event data

Previously, `acpi_wmi_notify_handler()` and `wmi_get_event_data()`
shared more or less the exact same code to query the data for
a particular event.

Introduce a function to get rid of the duplication, and use it
from `acpi_wmi_notify_handler()` and `wmi_get_event_data()`.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-30-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: introduce helper to determine type

Introduce helper function to determine the appropriate
ACPI type for the input parameter.

This also fixes the following checkpatch warning:
"braces {} are not necessary for any arm of this statement".

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-29-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: introduce helper to generate method names

Instead of "manually" constructing the ACPI method name and
hard-coding sizes in WMI functions, introduce a helper method
which generates the method name for an arbitrary WMI block.

Furthermore, save the appropriate buffer size into a macro.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-28-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: introduce helper to convert driver to WMI driver

Introduce a helper function which wraps the appropriate
`container_of()` macro invocation to convert
a `struct device_driver` to `struct wmi_driver`.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-27-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: simplify error handling logic

The current code carries out the following ACPI status
mapping:

AE_NOT_FOUND -> AE_OK
AE_OK -> AE_OK
AE_$X -> AE_$X

That is, everything is mapped to itself, except AE_NOT_FOUND.
The current code does not do it in the most straighforward way.
Simplify the logic.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-26-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: do not fail if disabling fails

Previously, `__query_block()` would fail if the
second WCxx method call failed. However, the
WQxx method might have succeeded, and potentially
allocated memory for the result. Instead of
throwing away the result and potentially
leaking memory, ignore the result of
the second WCxx call.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-25-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: improve debug messages

Print the event identifier number in addition to
the already printed information, and use %u for
printing unsigned values in `wmi_notify_debug()`.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-24-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: align arguments of functions

Align the arguments of
* wmi_evaluate_method()
* wmi_install_notify_handler()
* wmidev_evaluate_method()
* find_guid_context()
* acpi_wmi_ec_space_handler()
* wmi_char_read()

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-23-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: move variables

Move some variables in order to keep them
in the narrowest possible scope.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-22-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove variable

The `block` variable is assigned and only used once, the code
shorter and probably clearer without it; so remove it.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-21-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: use sizeof(*p) in allocation

As per the coding style guide, the preferred way
to pass the size of objects to allocator functions
is `sizeof(*p)`. Use that.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-20-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: use !p to check for NULL

Other parts of the code use the `!p` idiom to check
for NULL pointers, convert `find_guid_context()` to
do the same.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-19-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: use sysfs_emit()

Instead of `sprintf()` use the new `sysfs_emit()` function.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-17-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: make GUID block packed

The `guid_block` struct is overlaid onto a buffer
coming from the _WDG ACPI object of the device.
For this reason mark the struct packed and add
assertions about sizes.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-16-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: use guid_t and guid_equal()

Instead of hard-coding a 16 long byte array,
use the available `guid_t` type and related methods.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-15-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: use bool instead of int

The `bool` type is more expressive for a yes/no
kind of value, so use that as the type of the
`enable` parameter of `wmi_method_enable()`.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-13-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: use BIT() macro

Instead of manually creating the bit masks,
use the `BIT()` macro to do it.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-12-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove unnecessary checks

The `find_guid_context()` is only called from one place,
and `wblock` and `wdriver` cannot be NULL there.
So remove the currently redundant checks.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-11-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove stray empty line

Remove an empty line after the last statement
in `acpi_wmi_notify_handler()` which serves
no purpose.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-10-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove unnecessary casts

Void pointers are implictly cast to arbitrary pointer types,
so remove superfluous casts.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-9-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove unnecessary argument

The GUID block is available for `wmi_create_device()`
through `wblock->gblock`. Use that consistently in
the function instead of using a mix of `gblock` and
`wblock->gblock`.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-8-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove unnecessary variable

The `status` variable was assigned at the end, and then
immediately returned. Remove it altogether, and return
the previously assigned value directly.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-7-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove unnecessary initializations

Some pointers are initialized when they are defined,
but they are almost immediately reassigned in the
following lines. Remove these superfluous assignments.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-6-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove unnecessary initialization

The empty initializer `{ }` is enough to properly initialize
the terminating acpi_device_id entry in the device table,
so use that.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-5-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: remove commas

Remove commas that are after terminating entries in arrays.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-4-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: fix checkpatch warnings

Fix the following two checkpatch warnings:

* "space required before the open parenthesis '('"
* "that open brace { should be on the previous line"

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-3-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: fix kernel doc

The kernel doc erroneously specified `wmi_uninstall_notify_handler()`
for the `wmi_remove_notify_handler()` function. Fix that.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-2-pobrn@protonmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

bus: Make remove callback return void

The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

platform/x86: wmi: Make remove callback return void

The driver core ignores the return value of struct bus_type::remove()
(and so wmi_dev_remove()) because there is only little that can be done.

To simplify the quest to make this function return void, let struct
wmi_driver::remove() return void, too. All implementers of this callback
return 0 already and this way it should be obvious to driver authors
that returning an error code is a bad idea.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Pali Rohár <pali@kernel.org>
Link: https://lore.kernel.org/r/20210301160404.1677064-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform: x86: ACPI: Get rid of ACPICA message printing

A few x86 platform drivers use ACPI_DEBUG_PRINT() or ACPI_EXCEPTION()
for printing messages, but that is questionable, because those macros
belong to ACPICA and they should not be used elsewhere. In addition,
ACPI_DEBUG_PRINT() requires special enabling to allow it to actually
print the message, which is a nuisance, and the _COMPONENT symbol
generally needed for that is not defined in any of the files in
question.

For this reason, replace the ACPI_DEBUG_PRINT() in lg-laptop.c with
pr_debug() and the one in xo15-ebook.c with acpi_handle_debug()
(with the additional benefit that the source object can be identified
more easily after this change).

Also drop the ACPI_MODULE_NAME() definitions that are only used by
the ACPICA message printing macros from those files and from wmi.c
and surfacepro3_button.c (while at it).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/2074665.VPHYfYaQb6@kreacher
[hdegoede@redhat.com: Drop acer-wmi.c chunk, a similar patch was already merged]
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: remove unneeded break

A break is not needed if it is preceded by a return

Signed-off-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20201019133212.12671-1-trix@redhat.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Revert "platform/x86: wmi: Destroy on cleanup rather than unregister"

This reverts commit 7b11e8989618581bc0226ad313264cdc05d48d86.

Consider the following hardware setting.

|-PNP0C14:00
| |-- device #1
|-PNP0C14:01
| |-- device #2

When unloading wmi driver module, device #2 will be first unregistered.
But device_destroy() using MKDEV(0, 0) will locate PNP0C14:00 first
and unregister it. This is incorrect. Should use device_unregister() to
unregister the real parent device.

Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>
Link: https://lore.kernel.org/r/20191115052710.46880-1-yongxin.liu@windriver.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

platform/x86: wmi: Describe function parameters

There are few parameters that are not described properly.
Fill the gap by describing them properly in kernel doc format.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: Fix indentation in some cases

There is no need to split lines as they perfectly fit 80 character limit.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: Replace UUID redefinitions by their originals

There are types and helpers that are redefined with old names.
Convert the WMI library to use those types and helpers directly.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

acpi: Remove header dependency

In order to avoid future header hell, remove the inclusion of
proc_fs.h from acpi_bus.h. All it needs is a forward declaration of a
struct.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lkml.kernel.org/r/20200321113241.246190285@linutronix.de

compat_ioctl: move more drivers to compat_ptr_ioctl

The .ioctl and .compat_ioctl file operations have the same prototype so
they can both point to the same function, which works great almost all
the time when all the commands are compatible.

One exception is the s390 architecture, where a compat pointer is only
31 bit wide, and converting it into a 64-bit pointer requires calling
compat_ptr(). Most drivers here will never run in s390, but since we now
have a generic helper for it, it's easy enough to use it consistently.

I double-checked all these drivers to ensure that all ioctl arguments
are used as pointers or are ignored, but are not interpreted as integer
values.

Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Darren Hart (VMware) <dvhart@infradead.org>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

platform/x86: wmi: Remove acpi_has_method() call

acpi_has_method() is unnecessary within __query_block() and should be
removed to avoid extra work.

wc_status is initialized to AE_ERROR before the acpi_has_method() call.
acpi_has_method() and acpi_execute_simple_method() failing due to the
method not existing will result in the same outcome from __query_block().

Signed-off-by: Kelsey Skunberg <skunberg.kelsey@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: add context argument to the probe function

The struct wmi_device_id has a context pointer field, forward this
pointer as an argument to the probe function in struct wmi_driver.

Update existing users of the same probe function to accept this new
context argument.

Signed-off-by: Mattias Jacobsson <2pi@mok.nu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: add context pointer field to struct wmi_device_id

When using wmi_install_notify_handler() to initialize a WMI handler a
data pointer can be supplied which will be passed on to the notification
handler. No similar feature exist when handling WMI events via struct
wmi_driver.

Add a context field pointer to struct wmi_device_id and add a function
find_guid_context() to retrieve that context pointer.

Signed-off-by: Mattias Jacobsson <2pi@mok.nu>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: Add function to get _UID of WMI device

Add a new function to acpi.h / wmi.c that returns _UID of the ACPI WMI
device. For example, it returns "ATK" for the following declaration in
DSDT:
Device (ATKD)
{
Name (_HID, "PNP0C14" /* Windows Management Instrumentation Device */)
// _HID: Hardware ID
Name (_UID, "ATK") // _UID: Unique ID
..

Generally, it is possible that multiple PNP0C14 ACPI devices are present in
the system as mentioned in the commit message of commit bff431e49ff5
("ACPI: WMI: Add ACPI-WMI mapping driver").

Therefore the _UID is returned for a specific ACPI device that declares the
given GUID, to which it is also mapped by other methods of wmi module.

Signed-off-by: Yurii Pavlovskyi <yurii.pavlovskyi@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version 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 you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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>

platform/x86: wmi: fix potential null pointer dereference

In the function wmi_dev_match() the variable id is dereferenced without
first performing a NULL check. The variable can for example be NULL if
a WMI driver is registered without specifying the id_table field in
struct wmi_driver.

Add a NULL check and return that the driver can't handle the device if
the variable is NULL.

Fixes: 844af950da94 ("platform/x86: wmi: Turn WMI into a bus driver")
Signed-off-by: Mattias Jacobsson <2pi@mok.nu>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: declare device_type structure as constant

The only usage of device_type structure is getting stored as
a reference in the type field of device structure. This type
field is declared const. Therefore, the device_type structure
can never be modified and can be declared as const.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: Do not mix pages and kmalloc

The probe handler_data was being allocated with __get_free_pages()
for no reason I could find. The error path was using kfree(). Since
other things are happily using kmalloc() in the probe path, switch to
kmalloc() entirely. This fixes the error path mismatch and will avoid
issues with CONFIG_HARDENED_USERCOPY_PAGESPAN=y.

Reported-by: Mihai Donțu <mihai.dontu@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Mario Limonciello <Mario.limonciello@dell.com>
Cc: stable@vger.kernel.org
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Fix misuse of vsprintf extension %pULL

%pULL doesn't officially exist but %pUL does.

Miscellanea:

o Add missing newlines to a couple logging messages

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Fix misuse of vsprintf extension %pULL

%pULL doesn't officially exist but %pUL does.

Miscellanea:

o Add missing newlines to a couple logging messages

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Replace list_for_each() by list_for_each_entry()

In all cases list_for_each() followed by list_entry(),
so, replace them by list_for_each_entry() macro.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Replace kmalloc + sprintf() with kasprintf()

kasprintf() does the job of two: kmalloc() and sprintf().
Replace two calls with one.

Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: fix off-by-one write in wmi_dev_probe()

wmi_dev_probe() allocates one byte less than necessary, thus
subsequent sprintf() call writes trailing zero past the end
of the 'buf':

BUG: KASAN: slab-out-of-bounds in vsnprintf+0xda4/0x1240
Write of size 1 at addr ffff880423529caf by task kworker/1:1/32

Call Trace:
dump_stack+0xb3/0x14d
print_address_description+0xd7/0x380
kasan_report+0x166/0x2b0
vsnprintf+0xda4/0x1240
sprintf+0x9b/0xd0
wmi_dev_probe+0x1c3/0x400
driver_probe_device+0x5d1/0x990
bus_for_each_drv+0x109/0x190
__device_attach+0x217/0x360
bus_probe_device+0x1ad/0x260
deferred_probe_work_func+0x10f/0x5d0
process_one_work+0xa8b/0x1dc0
worker_thread+0x20d/0x17d0
kthread+0x311/0x3d0
ret_from_fork+0x3a/0x50

Allocated by task 32:
kasan_kmalloc+0xa0/0xd0
__kmalloc+0x14f/0x3e0
wmi_dev_probe+0x182/0x400
driver_probe_device+0x5d1/0x990
bus_for_each_drv+0x109/0x190
__device_attach+0x217/0x360
bus_probe_device+0x1ad/0x260
deferred_probe_work_func+0x10f/0x5d0
process_one_work+0xa8b/0x1dc0
worker_thread+0x20d/0x17d0
kthread+0x311/0x3d0
ret_from_fork+0x3a/0x50

Increment allocation size to fix this.

Fixes: 44b6b7661132 ("platform/x86: wmi: create userspace interface for drivers")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: Call acpi_wmi_init() later

Calling acpi_wmi_init() at the subsys_initcall() level causes ordering
issues to appear on some systems and they are difficult to reproduce,
because there is no guaranteed ordering between subsys_initcall()
calls, so they may occur in different orders on different systems.

In particular, commit 86d9f48534e8 (mm/slab: fix kmemcg cache
creation delayed issue) exposed one of these issues where genl_init()
and acpi_wmi_init() are both called at the same initcall level, but
the former must run before the latter so as to avoid a NULL pointer
dereference.

For this reason, move the acpi_wmi_init() invocation to the
initcall_sync level which should still be early enough for things
to work correctly in the WMI land.

Link: https://marc.info/?t=151274596700002&r=1&w=2
Reported-by: Jonathan McDowell <noodles@earth.li>
Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Call acpi_wmi_init() later

Calling acpi_wmi_init() at the subsys_initcall() level causes ordering
issues to appear on some systems and they are difficult to reproduce,
because there is no guaranteed ordering between subsys_initcall()
calls, so they may occur in different orders on different systems.

In particular, commit 86d9f48534e8 (mm/slab: fix kmemcg cache
creation delayed issue) exposed one of these issues where genl_init()
and acpi_wmi_init() are both called at the same initcall level, but
the former must run before the latter so as to avoid a NULL pointer
dereference.

For this reason, move the acpi_wmi_init() invocation to the
initcall_sync level which should still be early enough for things
to work correctly in the WMI land.

Link: https://marc.info/?t=151274596700002&r=1&w=2
Reported-by: Jonathan McDowell <noodles@earth.li>
Reported-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: release mutex on module acquistion failure

This failure mode should have also released the mutex.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

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>

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>

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>

platform/x86: wmi: Destroy on cleanup rather than unregister

device_create documentation says to cleanup using device_destroy

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Cleanup exit routine in reverse order of init

The initialize routine is:
* class -> bus -> platform

The exit routine is:
* platform -> class -> bus

Fix the exit routine to be:
* platform -> bus -> class

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Sort include list

The include list is randomly assembled right now. Sort in alphabetical
order.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Fix check for method instance number

instance_count defines number of instances of data block and instance
itself is indexed from zero, which means first instance has number 0.
Therefore check for invalid instance should be non-strict inequality.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Darren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

platform/x86: wmi: Fix error handling in acpi_wmi_init()

The order of resource deallocations is messed up in acpi_wmi_init().
It should be vice versa.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi: Fix printing info about WDG structure

object_id and notify_id are in one union structure and their meaning is
defined by flags. Therefore do not print notify_id for non-event block and
do not print object_id for event block. Remove also reserved member as it
does not have any defined meaning or type yet.

As object_id and notify_id union members overlaps and have different types,
it caused that kernel print to dmesg binary data. This patch eliminates it.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

platform/x86: wmi*: Add recent copyright statements

Add copyright statements for Andy Lutomirski and Darren Hart (VMware)
for their contributions to the WMI bus infrastructure and the creation
of the wmi-bmof driver.

Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>

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>

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>

platform/x86: wmi: Bind the platform device, not the ACPI node

We already have the PNP glue to instantiate platform devices for the
ACPI devices that WMI drives. WMI should therefore attach to the
platform device, not the ACPI node.

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>

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>

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>

platform/x86: wmi: Instantiate all devices before adding them

At some point, we will want sub-drivers to get references to other
devices on the same WMI bus. This change is needed to avoid races.

This ends up simplifying the setup code and fixing some leaks, too.

This is based on the original work of Andy Lutomirski <luto@kernel.org>,
but includes several modifications, many in response to review from
Michał Kępień <kernel@kempniu.pl>:

https://www.spinics.net/lists/platform-driver-x86/msg08201.html

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>

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>

platform/x86: wmi: Split devices into types and add basic sysfs attributes

Divide the "data", "method" and "event" types. All devices get
"instance_count" and "expensive" attributes, data and method devices get
"object_id" attributes, and event devices get "notify_id" attributes.

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>

platform/x86: wmi: Fix error handling when creating devices

We have two memory leaks. If guid_already_parsed returned true, we leak
the wmi_block. If wmi_create_device failed, we leak the device.

Simplify the logic and fix both of them.

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>

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>

platform/x86: wmi: Track wmi devices per ACPI device

Currently we free all devices when we detach from any ACPI node.
Instead, keep track of which node WMI devices are attached to and
free them only as needed. While we are at it, match up notifications
with the device they came from correctly.

This will make our behavior more straightforward on systems with
more than one WMI node in the ACPI tables (e.g. the Dell XPS 13
9350).

This also adds a warning when GUIDs are not unique.

NB: The guid_string parameter in guid_already_parsed was a
little-endian binary GUID, not a string.

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>

platform/x86: wmi: Clean up acpi_wmi_add

Rearrange acpi_wmi_add to use Linux's error handling conventions.

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>

platform/x86: wmi: Pass the acpi_device through to parse_wdg

We will need the device to convert to a bus architecture and bind WMI to
the platform device.

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>

platform/x86: wmi: Drop "Mapper (un)loaded" messages

WMI is just a driver. There is no need to announce when it is loaded.

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>

drivers/platform/x86/wmi.c: use generic UUID library

Instead of opencoding let's use generic UUID library functions here.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

wmi: Remove private %pUL implementation

The work performed by wmi_gtoa is equivalent to simply sprintf(out,
"%pUL", in), so one could replace its body by this. However, most
users feed the result directly as a %s argument to some other function
which also understands the %p extensions (they all ultimately use
vsnprintf), so we can eliminate some stack buffers and quite a bit of
code by just using %pUL directly.

In wmi_dev_uevent I'm not sure whether there's room for a
nul-terminator in env->buf, so I've just replaced wmi_gtoa with the
equivalent sprintf call.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

wmi: Use bool function return values of true/false not 1/0

Use the normal return values for bool functions

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

x86/wmi: delete unused wmi_data_lock mutex causing gcc warning

In commit bff431e49ff531a343fbb2b4426e313000844f32 ("ACPI: WMI: Add
ACPI-WMI mapping driver") this mutex was added, but the rest of the
final commit never actually made use of it, resulting in:

In file included from include/linux/mutex.h:29:0,
from include/linux/kernfs.h:13,
from include/linux/sysfs.h:15,
from include/linux/kobject.h:21,
from include/linux/device.h:17,
from drivers/platform/x86/wmi.c:35:
drivers/platform/x86/wmi.c:48:21: warning: ‘wmi_data_lock’ defined but not used [-Wunused-variable]
static DEFINE_MUTEX(wmi_data_lock);
^

A git grep shows no other instances/references to the wmi_data_lock.
Delete it, assuming that the mutex addition was just a leftover from
an earlier work in progress version of the change, since the original
dates from 2008.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>

WMI: Remove unnecessary null test

This patch removes the null test on block. block is initialized at the
beginning of the function to &wblock->gblock. Since wblock is
dereferenced prior to the null test, wblock must be a valid pointer,
and &wblock->gblock cannot be null.

The following Coccinelle script is used for detecting the change:

@r@
expression e,f;
identifier g,y;
statement S1,S2;
@@

*e = &f->g
<+...
f->y
...+>
*if (e != NULL || ...)
S1 else S2

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

ACPI: Clean up inclusions of ACPI header files

Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and
<acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h>
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds. For CONFIG_ACPI set,
<linux/acpi.h> includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met. Namely, it is required that <acpi/acpi_bus.h> be included
prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the
latter depends on are always there. And <acpi/acpi.h> which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds. That also is taken care of including
<linux/acpi.h> as appropriate.

Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86, wmi fix modalias_show return values

I just fixed this same bug in arch/powerpc/kernel/vio.c and took a quick
look for other similar errors in the kernel.

modalias_show() should return an empty string on error, not errno.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

wmi: convert acpi_get_handle() to acpi_has_method()

acpi_has_method() is a new ACPI API introduced to check
the existence of an ACPI control method.

It can be used to replace acpi_get_handle() in the case that
1. the calling function doesn't need the ACPI handle of the control method.
and
2. the calling function doesn't care the reason why the method is unavailable.

Convert acpi_get_handle() to acpi_has_method()
in drivers/platform/x86/wmi.c in this patch.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
CC: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

wmi: convert acpi_evaluate_object() to acpi_execute_simple_method()

acpi_execute_simple_method() is a new ACPI API introduced to invoke
an ACPI control method that has single integer parameter and no return value.

Convert acpi_evaluate_object() to acpi_execute_simple_method()
in drivers/platform/x86/wmi.c

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
CC: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

wmi: parse_wdg() should return kernel error codes

The current code returns a mix of acpi_status and kernel error codes.
It should just return kernel error codes. There are already error paths
in this function which return -ENOMEM and that's what the caller
expects.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

x86: wmi: convert class code to use dev_groups

The dev_attrs field of struct class is going away soon, dev_groups
should be used instead. This converts the wmi class code to use the
correct field.

Cc: Matthew Garrett <matthew.garrett@nebula.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers: avoid format string in dev_set_name

Calling dev_set_name with a single paramter causes it to be handled as a
format string. Many callers are passing potentially dynamic string
content, so use "%s" in those cases to avoid any potential accidents,
including wrappers like device_create*() and bdi_register().

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI: Remove useless type argument of driver .remove() operation

The second argument of ACPI driver .remove() operation is only used
by the ACPI processor driver and the value passed to that driver
through it is always available from the given struct acpi_device
object's removal_type field. For this reason, the second ACPI driver
.remove() argument is in fact useless, so drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Jiang Liu <jiang.liu@huawei.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>

module_param: make bool parameters really bool (drivers & misc)

module_param(bool) used to counter-intuitively take an int. In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

It's time to remove the int/unsigned int option. For this version
it'll simply give a warning, but it'll break next kernel version.

Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

x86: fix up files really needing to include module.h

These files aren't just exporting symbols -- they are also defining
a MODULE_LICENSE etc. so give them the full module.h file.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

WMI: properly cleanup devices to avoid crashes

We need to remove devices that we destroy from the list, otherwise
we'll crash if there are more than one "_WDG" methods in DSDT.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=32052

Tested-by: Ilya Tumaykin <librarian_rus@yahoo.com>
Cc: stable@kernel.org
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

wmi: Removed trailing whitespace from logging message.

Just neatening.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: return error if wmi_create_device() fails

The break resets the retval to 0 but we want to return an error code.
This was introduced in c64eefd48c4 "WMI: embed struct device directly
into wmi_block"

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>

WMI: Cater for multiple events with same GUID

WMI data blocks can contain WMI events with the same GUID but with
different notifiy_ids, for example volume up/down hotkeys.
This patch enables a single event handler to be registered and
unregistered against all events with same GUID but different
notify_ids. Since an event handler is passed the notify_id of
an event it can can differentiate between the different events.

The patch also ensures we only register and unregister a device per
unique GUID.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

wmi: use memcmp instead of strncmp to compare GUIDs

While looking for the duplicates in /sys/class/wmi/, I couldn't find
them. The code that looks for duplicates uses strncmp in a binary GUID,
which may contain zero bytes. The right function is memcmp, which is
also used in another section of wmi code.

It was finding 49142400-C6A3-40FA-BADB-8A2652834100 as a duplicate of
39142400-C6A3-40FA-BADB-8A2652834100. Since the first byte is the fourth
printed, they were found as equal by strncmp.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@kernel.org

WMI: embed struct device directly into wmi_block

Instead of creating wmi_blocks and then register corresponding devices
on a separate pass do it all in one shot, since lifetime rules for both
objects are the same. This also takes care of leaking devices when
device_create fails for one of them.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: make use of class device's attributres

Instead of adding modalias attribute manually set it up as class's
device attribute so driver core will create and remove it for us.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: use pr_err() and friends

This makes source more concise and easier to read.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: use separate list head for storing wmi blocks

Do not abuse wmi_block structure to hold the head of list
of blocks, use separate list_head for that.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: simplify handling of returned WMI blocks in parse_wdg()

There is no reason why we allocate memory and copy data into an
intermediate buffer, it is not like we are working with data coming
from userspace.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: fix potential NULL pointer dereference

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: do not leak memory in parse_wdg()

If we _WDG returned object that is not buffer we were forgetting
to free memory allocated for that object.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: fix wmi_gtoa() to actully terminate the string

Courtesy of sparse...

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: free wmi blocks when parse_wdg() fails

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

WMI: remove EC region handler when _WDG parsing fails

Driver initialization was forgetting to remove EC address space handler
in cases when parse_wdg() method failed.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

platform: x86: throw away custom methods

In 2.6.35 the hex_to_bin() was introduced.

Signed-off-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: platform-driver-x86@vger.kernel.org
Signed-off-by: Matthew Garrett <mjg@redhat.com>

X86 platform driver: Fix section mismatch in wmi.c

The .add function must not be declared __init.

Signed-off-by: Thomas Renninger <trenn@suse.de>

CC: Alexey Starikovskiy <astarikovskiy@suse.de>
CC: Len Brown <lenb@kernel.org>
CC: linux-kernel@vger.kernel.org
CC: linux-acpi@vger.kernel.org
CC: platform-driver-x86@vger.kernel.org
Signed-off-by: Matthew Garrett <mjg@redhat.com>

wmi: fix a memory leak in wmi_notify_debug

When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER,
the caller must kfree the returned buffer if AE_OK is returned.

The callers of wmi_get_event_data() pass ACPI_ALLOCATE_BUFFER,
and thus must check its return value before accessing
or kfree() on the buffer.

This patch adds return value checking for wmi_get_event_data()
and adds a missing kfree(obj) in the end of wmi_notify_debug

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

wmi: fix memory leak in parse_wdg

This patch properly kfree out.pointer and gblock in error path.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

X86 platfrom wmi: Add debug facility to dump WMI data in a readable way

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: platform-driver-x86@vger.kernel.org
CC: mjg59@srcf.ucam.org
CC: corentin.chary@gmail.com
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

X86 platform wmi: Also log GUID string when an event happens and debug is set

Output in log with debug=1:
ACPI: WMI: DEBUG Event INTEGER_TYPE - 65535
ACPI: WMI: DEBUG Event GUID: CC1A61AC-4256-41A3-B9E0-05A445ADE2F5

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: platform-driver-x86@vger.kernel.org
CC: mjg59@srcf.ucam.org
CC: corentin.chary@gmail.com
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

X86 platform wmi: Introduce debug param to log all WMI events

To give people easily an idea what could be WMI driven on their system.
Introduces:
wmi.debug=[01]

Tested on an acer:
ACPI: WMI: DEBUG Event INTEGER_TYPE - 65535

Situation where a driver registers for specific event and debug
handler gets overridden and set again if the registering driver gets
unloaded again is untested, but should work.

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: platform-driver-x86@vger.kernel.org
CC: mjg59@srcf.ucam.org
CC: corentin.chary@gmail.com
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86: Use kmemdup

Use kmemdup when some other buffer is immediately copied into the
allocated region.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to,size,flag;
statement S;
@@

- to = \(kmalloc\|kzalloc\)(size,flag);
+ to = kmemdup(from,size,flag);
if (to==NULL || ...) S
- memcpy(to, from, size);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

ACPI: replace acpi_integer by u64

acpi_integer is now obsolete and removed from the ACPICA code base,
replaced by u64.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

wmi: check find_guid() return value to prevent oops

Signed-off-by: rol@as2917.net <Paul Rolland>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI: WMI: Survive BIOS with duplicate GUIDs

It would appear that in BIOS's with nVidia hooks, the GUID
05901221-D566-11D1-B2F0-00A0C9062910 is duplicated. For now, the simplest
solution is to just ignore any duplicate GUIDs. These particular hooks are not
currently supported/ used in the kernel, so whoever does that can figure out
what the 'right' solution should be (if there's a better one).

http://bugzilla.kernel.org/show_bug.cgi?id=14846

Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: Oldřich Jedlička <oldium.pro@seznam.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

wmi: check find_guid() return value to prevent oops

Signed-off-by: Paul Rolland <rol@as2917.net>
Signed-off-by: Len Brown <len.brown@intel.com>

wmi: Free the allocated acpi objects through wmi_get_event_data

These function allocate an acpi object by calling wmi_get_event_data, which
then calls acpi_evaluate_object, and it is not freed afterwards.

And kernel doc is fixed for parameters of wmi_get_event_data.

Signed-off-by: Anisse Astier <anisse@astier.eu>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>

wmi: Add support for module autoloading

WMI provides interface-specific GUIDs that are exported from modules as
modalises, but the core currently generates no events to trigger module
loading. This patch adds support for registering devices for each WMI GUID
and generating the appropriate uevent.

Based heavily on a patch by Carlos Corbacho (<carlos@strangeworlds.co.uk>).

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Tested-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Acked-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: Move definition of PREFIX from acpi_bus.h to internal..h

Linux/ACPI core files using internal.h all PREFIX "ACPI: ",
however, not all ACPI drivers use/want it -- and they
should not have to #undef PREFIX to define their own.

Add GPL commment to internal.h while we are there.

This does not change any actual console output,
asside from a whitespace fix.

Signed-off-by: Len Brown <len.brown@intel.com>

wmi: fix kernel panic when stack protection enabled.

Summary:
Kernel panic arise when stack protection is enabled, since strncat will
add a null terminating byte '\0'; So in functions
like this one (wmi_query_block):
char wc[4]="WC";
....
strncat(method, block->object_id, 2);
...
the length of wc should be n+1 (wc[5]) or stack protection
fault will arise. This is not noticeable when stack protection is
disabled,but , isn't good either.
Config used: [CONFIG_CC_STACKPROTECTOR_ALL=y,
CONFIG_CC_STACKPROTECTOR=y]

Panic Trace
------------
.... stack-protector: kernel stack corrupted in : fa7b182c
2.6.30-rc8-obelisco-generic
call_trace:
[<c04a6c40>] ? panic+0x45/0xd9
[<c012925d>] ? __stack_chk_fail+0x1c/0x40
[<fa7b182c>] ? wmi_query_block+0x15a/0x162 [wmi]
[<fa7b182c>] ? wmi_query_block+0x15a/0x162 [wmi]
[<fa7e7000>] ? acer_wmi_init+0x00/0x61a [acer_wmi]
[<fa7e7135>] ? acer_wmi_init+0x135/0x61a [acer_wmi]
[<c0101159>] ? do_one_initcall+0x50+0x126

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=13514

Signed-off-by: Costantino Leandro <lcostantino@gmail.com>
Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Cc: Len Brown <len.brown@intel.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI: WMI: use .notify method instead of installing handler directly

This patch adds a .notify() method. The presence of .notify() causes
Linux/ACPI to manage event handlers and notify handlers on our behalf,
so we don't have to install and remove them ourselves.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
CC: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>

acpi-wmi: unsigned cannot be less than 0

include/linux/pci-acpi.h:74:

typedef u32 acpi_status;

result is unsigned, so an error returned by acpi_bus_register_driver()
will not be noticed.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>

ACPI: move wmi, asus_acpi, toshiba_acpi to drivers/platform/x86

These are platform specific drivers that happen to use ACPI,
while drivers/acpi/ is for code that implements ACPI itself.

Signed-off-by: Len Brown <len.brown@intel.com>