After suspend/resume cycle there is an error message and auto-mode
or CnQF stops working.
[ 5741.447511] amd-pmf AMDI0100:00: SMU cmd failed. err: 0xff
[ 5741.447523] amd-pmf AMDI0100:00: AMD_PMF_REGISTER_RESPONSE:ff
[ 5741.447527] amd-pmf AMDI0100:00: AMD_PMF_REGISTER_ARGUMENT:7
[ 5741.447531] amd-pmf AMDI0100:00: AMD_PMF_REGISTER_MESSAGE:16
[ 5741.447540] amd-pmf AMDI0100:00: [AUTO_MODE] avg power: 0 mW mode: QUIET
This is because the DRAM address used for accessing metrics table
needs to be refreshed after a suspend resume cycle. Add a resume
callback to reset this again.
Fixes: 1a409b35c9 ("platform/x86/amd/pmf: Get performance metrics from PMFW")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20230513011408.958-1-mario.limonciello@amd.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
On ASUS GU604V the key 0x7B is issued when the charger is connected or
disconnected, and key 0xC0 is issued when an external display is
connected or disconnected.
This commit maps them to KE_IGNORE to slience kernel messages about
unknown keys, such as:
kernel: asus_wmi: Unknown key code 0x7b
Signed-off-by: Alexandru Sorodoc <ealex95@gmail.com>
Link: https://lore.kernel.org/r/20230512101517.47416-1-ealex95@gmail.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
On the Android yb1-x90f/l models there is not ACPI method to control
the keyboard backlight brightness. Instead the second PWM controller
is exposed directly to the OS there.
Add support for controlling keyboard backlight brightness on the Android
model by using the PWM subsystem to directly control the PWM.
The Android model also requires explicitly turning the backlight off
on suspend, which on the Windows model was done automatically.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-19-hdegoede@redhat.com
The Lenovo Yoga Book 1 comes in 2 versions.
Version 1: The yb1-x91f/l currently supported by lenovo-yogabook-wmi, which
has a WMI interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
Version 2: The yb1-x90f/l which is the same hardware shipping with Android
as factory OS. This version has a very different BIOS and ACPI tables which
lack the WMI interface.
Instead the x86-android-tablets.ko code which does devices instantiation
for devices missing from ACPI on various x86 Android tablets will
instantiate a platform device for the keyboard half touch-kbd/digitizer
toggle functionality.
This patch adds a platform driver to the lenovo-yogabook code which binds
to the platform device instantiated by x86-android-tablets.ko offering
touch-kbd/digitizer toggle functionality on the Android model.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-18-hdegoede@redhat.com
Group WMI specific code together. Note this just moves a bunch of
code-blocks around, not a single line is changed.
This is a preparation patch for making lenovo-yogabook-wmi also work
on the Android version of the Yoga Book 1 which does not have a WMI
interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-16-hdegoede@redhat.com
Change the yogabook_wmi_ prefix of remaining generic (non WMI specific)
symbols to yogabook_ .
This is a preparation patch for making lenovo-yogabook-wmi also work
on the Android version of the Yoga Book 1 which does not have a WMI
interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-15-hdegoede@redhat.com
Add a yogabook_toggle_digitizer_mode() helper function.
This is a preparation patch for making lenovo-yogabook-wmi also work
on the Android version of the Yoga Book 1 which does not have a WMI
interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-14-hdegoede@redhat.com
Abstract kbd backlight setting.
This is a preparation patch for making lenovo-yogabook-wmi also work
on the Android version of the Yoga Book 1 which does not have a WMI
interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-13-hdegoede@redhat.com
lenovo-yogabook-wmi: controls the power-state itself and stores
this in data->flags so there is no need to poke inside ACPI device
internals.
This is a preparation patch for making lenovo-yogabook-wmi also work
on the Android version of the Yoga Book 1 which does not have a WMI
interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-12-hdegoede@redhat.com
Split probe() and remove() into generic and WMI specific parts.
This is a preparation patch for making lenovo-yogabook-wmi also work
on the Android version of the Yoga Book 1 which does not have a WMI
interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-11-hdegoede@redhat.com
Use the (new) PMIC LED driver for pen icon LED control instead of using
custom WMI calls for this.
This will also work on the Android version of the Lenovo Yoga Book 1,
where there is no WMI interface for this.
The dev_id of the lookup is set using dev_name() so that it will also
work for both the Windows YB1 WMI-device as well as the Android YB1
platform-device. While at it also move the gpio_lookup to using dev_name()
for the dev_id.
Note this also removes the need to turn of the LED during suspend since
the PMIC LED driver now already does that.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-10-hdegoede@redhat.com
Add a "struct device *dev" local variable to probe().
This is a preparation patch for making lenovo-yogabook-wmi also work
on the Android version of the Yoga Book 1 which does not have a WMI
interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
While at it also move the dev_set_drvdata() call to the end of probe().
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-9-hdegoede@redhat.com
Store a "struct device *dev" instead of a "struct wmi_device *wdev;"
in the "struct yogabook_wmi" driver-data.
This is a preparation patch for making lenovo-yogabook-wmi also work
on the Android version of the Yoga Book 1 which does not have a WMI
interface to deal with toggling the keyboard half between
touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-8-hdegoede@redhat.com
Switch to DEFINE_SIMPLE_DEV_PM_OPS() so that the __maybe_unused can
be dropped from the suspend/resume callbacks.
While at it also drop the _wmi_ part from the callback names in preparation
for making lenovo-yogabook-wmi also work on the Android version of
the Yoga Book 1 which does not have a WMI interface to deal with toggling
the keyboard half between touch-keyboard and wacom-digitizer mode.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-7-hdegoede@redhat.com
Ensure that both the keyboard touchscreen and the digitizer have their
driver bound after remove(). Without this modprobing lenovo-yogabook-wmi
after a rmmod fails because lenovo-yogabook-wmi defers probing until
both devices have their driver bound.
Fixes: c0549b72d9 ("platform/x86: lenovo-yogabook-wmi: Add driver for Lenovo Yoga Book")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-4-hdegoede@redhat.com
When yogabook_wmi_remove() runs yogabook_wmi_work might still be running
and using the devices which yogabook_wmi_remove() puts.
To avoid this move to explicitly cancelling the work rather then using
devm_work_autocancel().
This requires also making the yogabook_backside_hall_irq handler non
devm managed, so that it cannot re-queue the work while
yogabook_wmi_remove() runs.
Fixes: c0549b72d9 ("platform/x86: lenovo-yogabook-wmi: Add driver for Lenovo Yoga Book")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230430165807.472798-3-hdegoede@redhat.com
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>
The Cyberbook T116 rugged tablet comes in both Windows and Android versions
and even on the Android version the DSDT is mostly sane. This tablet has
2 extra general purpose buttons in the row with the power + volume-buttons,
labeled P and F.
Use the x86-android-tablets infra to create a gpio-button device for these
2 extra buttons.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20230505205901.42649-2-hdegoede@redhat.com
Modify the gpio_keys support in x86_android_tablet_init() for
tablets which have more then 1 key/button which needs to be handled
by the gpio_keys driver.
This requires copying over the struct gpio_keys_button from
the x86_gpio_button struct array to a new gpio_keys_button struct array,
as an added benefit this allows marking the per model x86_gpio_button
arrays __initconst so that they all can be freed after module init().
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230505205901.42649-1-hdegoede@redhat.com
The Lenovo Yoga Book yb1-x90f/l has (another) bug in its DSDT where
the UART resource for the BTH0 ACPI device contains
"\\_SB.PCIO.URT1" as path to the UART.
Note that is with a letter 'O' instead of the number '0' which is wrong.
Add a x86_serdev_info entry to make the x86-android-tablets module
manually setup the /sys/bus/serial device for the Bluetooth UART
to fix Bluetooth not working due to this bug.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230429180230.97716-1-hdegoede@redhat.com
The Nextbook Ares 8A is a x86 ACPI tablet which ships with Android x86
as factory OS. Its DSDT contains a bunch of I2C devices which are not
actually there, causing various resource conflicts. Enumeration of these
is skipped through the acpi_quirk_skip_i2c_client_enumeration().
Add support for manually instantiating the I2C devices which are
actually present on this tablet by adding the necessary device info to
the x86-android-tablets module.
Note the Ares 8A is the Cherry Trail (CHT) model, the regular Ares 8
is Bay Trail (BYT) based and was already supported. This also updates
the comments for the BYT model to point out this is the BYT model.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230429105057.7697-3-hdegoede@redhat.com
Since commit 5adc409340 ("ACPI: x86: Introduce an
acpi_quirk_skip_gpio_event_handlers() helper") the ACPI GPIO code will
not register any GPIO event handlers at all for devices which have
the ACPI_QUIRK_SKIP_GPIO_EVENT_HANDLERS set in their DMI table entry
in drivers/acpi/x86/utils.c .
This includes the Nextbook Ares 8 and the Asus ME176C and TF103C models,
so x86-android-tablets no longer needs to disable the GPIO event handlers
on these, since they have never been registered at all.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230429105057.7697-2-hdegoede@redhat.com
Previously, some support for certain keys on the HP keyboard has been
added already in commit 3ee5447b20 ("platform/x86: hp-wmi: Handle Omen
Key event"), however this as tested did not allow even the fn+esc key on
my HP Envy which uses the same keycode on my HP Envy x360 laptop to work
--the keycode rather than being passed in as a separate int from WMI, was
being passed in as the event_data for the HPWMI_OMEN_KEY event.
This patch, as tested was able to properly get the keycode for fn+esc,
and for fn+f12 which is supposed to be a programmable key according to
HP's keyboard diagram and is thus mapped to KEY_PROG2. The fn+f8 key
combination (mute microphone) was a standard HPWMI_BEZEL_BUTTON key,
however it did not previously have an entry in the sparse keymap. This
patch preserves the original HPWMI_OMEN_KEY behavior for laptops that
use it by only taking the keycode from the event_data only when the
event_data is nonzero.
Signed-off-by: Jonathan Singer <jes965@nyu.edu>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20230426184852.2100-2-jes965@nyu.edu
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Previously, when the camera toggle switch was hit, the hp-wmi driver
would report an invalid event code. By adding a case for that in the
event handling switch statement we can eliminate that error code and
enable a framework for potential further kernel handling of that key.
This change was tested on my HP Envy x360 15-ey0023dx laptop, but it
would likely work for any HP laptop with a camera toggle button. Now
we emit an SW_CAMERA_LENS_COVER event, on a device that gets created
on the first such event so as to not report incorrectly the state of
the camera shutter before we can know its state.
Signed-off-by: Jonathan Singer <jes965@nyu.edu>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20230426184852.2100-1-jes965@nyu.edu
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
The new generation of CPUs have granular control at a cluster level.
Each package/die can have multiple power domains, which further can
have multiple fabric clusters. The TPMI interface allows control at
fabric cluster level.
Use the updated uncore sysfs feature to expose controls at cluster
level. At each cluster level there is a control for maximum and minimum
uncore frequency. Also present current uncore frequency at a cluster
level.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wendy Wang <wendy.wang@intel.com>
Link: https://lore.kernel.org/r/20230418171340.681662-4-srinivas.pandruvada@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
An SoC can contain multiple power domains with individual or collection
of mesh partitions. This partition is called fabric cluster.
Certain type of meshes will need to run at the same frequency, they will
be placed in the same fabric cluster. Benefit of fabric cluster is that
it offers a scalable mechanism to deal with partitioned fabrics in a SoC.
The current sysfs interface supports control at package and die level.
This interface is not enough to support more granular control at
fabric cluster level.
SoCs with the support of TPMI (Topology Aware Register and PM Capsule
Interface), can have multiple power domains. Each power domain can
contain one or more fabric clusters.
To support such granular controls, enhance uncore common to optionally
create new directories to provide controls at fabric cluster level. It
is also important to have flexibility to change granularity for future
version of SoCs. If the directory name contains scope like:
"package_*_die_*_power_domain_*_cluster_*", then this is not expandable.
The cpufreq policies also have different scopes. There the scope of the
policy (affected_cpus) specified by attributes inside each policy.
So, follow the same model for uncore frequency scaling sysfs as:
"sys/devices/system/cpu/cpufreq/policy*"
Allow client drivers to optionally support granular control for each
fabric cluster. Here, the directory name will be "uncore" suffixed with
an unique instance number. For example: uncore00, uncore01 etc.
Attributes in the directory identify package id, power domain and
fabric cluster id. This interface is expandable even if some new level
of granularity is introduced. A new sysfs attribute can identify new
level.
For compatibility with the existing sysfs and provide easy way to set
limits for each fabric cluster in the package/die, the existing control
at package/die levels are still provided. For majority of users, this is
an easy approach.
For example: On a single package/die system, with three power domains
and one fabric cluster per power domain:
$tree -L 2 /sys/devices/system/cpu/intel_uncore_frequency/
/sys/devices/system/cpu/intel_uncore_frequency/
├── package_00_die_00
│ ├── current_freq_khz
│ ├── initial_max_freq_khz
│ ├── initial_min_freq_khz
│ ├── max_freq_khz
│ └── min_freq_khz
├── uncore00
│ ├── current_freq_khz
│ ├── domain_id
│ ├── fabric_cluster_id
│ ├── initial_max_freq_khz
│ ├── initial_min_freq_khz
│ ├── max_freq_khz
│ ├── min_freq_khz
│ └── package_id
├── uncore01
│ ├── current_freq_khz
│ ├── domain_id
│ ├── fabric_cluster_id
│ ├── initial_max_freq_khz
│ ├── initial_min_freq_khz
│ ├── max_freq_khz
│ ├── min_freq_khz
│ └── package_id
└── uncore02
├── current_freq_khz
├── domain_id
├── fabric_cluster_id
├── initial_max_freq_khz
├── initial_min_freq_khz
├── max_freq_khz
├── min_freq_khz
└── package_id
The attribute for cluster id is "fabric_cluster_id" instead of just
"cluster_id" is to avoid confusion with usage of term clusters in
other part of the Linux kernel.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wendy Wang <wendy.wang@intel.com>
Link: https://lore.kernel.org/r/20230418171340.681662-3-srinivas.pandruvada@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Implement support of uncore frequency control via TPMI (Topology Aware
Register and PM Capsule Interface). This driver provides the similar
functionality as the current uncore frequency driver using MSRs.
The hardware interface to read/write is basically substitution of MSR
0x620 and 0x621. There are specific MMIO offset and bits to get/set
minimum and maximum uncore ratio, similar to MSRs.
The scope of the uncore MSRs is package/die. But new generation of CPUs
have more granular control at a cluster level. Each package/die can have
multiple power domains, which further can have multiple clusters. The
TPMI interface allows control at cluster level.
The primary use case for uncore sysfs is to set maximum and minimum
uncore frequency to reduce power consumption or latency. The current
uncore sysfs control is per package/die. This is enough for the majority
of users as workload will move to different power domains as it moves
between different CPUs.
The current uncore sysfs provides controls at package/die level. When
user sets maximum/minimum limits, the driver sets the same limits to
each cluster.
Here number of power domains = number of resources in this aux device.
There are offsets and bits to discover number of clusters and offset for
each cluster level controls.
The TPMI documentation can be downloaded from:
https://github.com/intel/tpmi_power_management
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Wendy Wang <wendy.wang@intel.com>
Link: https://lore.kernel.org/r/20230420220514.747573-1-srinivas.pandruvada@linux.intel.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
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>
There has been a lot of confusion around which platform profiles are
supported on various platforms and it would be useful to have a debug
method to be able to override the profile mode that is selected.
I don't expect this to be used in anything other than debugging in
conjunction with Lenovo engineers - but it does give a way to get a
system working whilst we wait for either FW fixes, or a driver fix
to land upstream, if something is wonky in the mode detection logic
Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://lore.kernel.org/r/20230505132523.214338-2-mpearson-lenovo@squebb.ca
Cc: stable@vger.kernel.org
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
I had incorrectly thought that PSC profiles were not usable on Intel
platforms so had blocked them in the driver initialistion. This broke
platform profiles on the T490.
After discussion with the FW team PSC does work on Intel platforms and
should be allowed.
Note - it's possible this may impact other platforms where it is advertised
but special driver support that only Windows has is needed. But if it does
then they will need fixing via quirks. Please report any issues to me so I
can get them addressed - but I haven't found any problems in testing...yet
Fixes: bce6243f76 ("platform/x86: thinkpad_acpi: do not use PSC mode on Intel platforms")
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2177962
Cc: stable@vger.kernel.org
Signed-off-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Link: https://lore.kernel.org/r/20230505132523.214338-1-mpearson-lenovo@squebb.ca
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Pull module updates from Luis Chamberlain:
"The summary of the changes for this pull requests is:
- Song Liu's new struct module_memory replacement
- Nick Alcock's MODULE_LICENSE() removal for non-modules
- My cleanups and enhancements to reduce the areas where we vmalloc
module memory for duplicates, and the respective debug code which
proves the remaining vmalloc pressure comes from userspace.
Most of the changes have been in linux-next for quite some time except
the minor fixes I made to check if a module was already loaded prior
to allocating the final module memory with vmalloc and the respective
debug code it introduces to help clarify the issue. Although the
functional change is small it is rather safe as it can only *help*
reduce vmalloc space for duplicates and is confirmed to fix a bootup
issue with over 400 CPUs with KASAN enabled. I don't expect stable
kernels to pick up that fix as the cleanups would have also had to
have been picked up. Folks on larger CPU systems with modules will
want to just upgrade if vmalloc space has been an issue on bootup.
Given the size of this request, here's some more elaborate details:
The functional change change in this pull request is the very first
patch from Song Liu which replaces the 'struct module_layout' with a
new 'struct module_memory'. The old data structure tried to put
together all types of supported module memory types in one data
structure, the new one abstracts the differences in memory types in a
module to allow each one to provide their own set of details. This
paves the way in the future so we can deal with them in a cleaner way.
If you look at changes they also provide a nice cleanup of how we
handle these different memory areas in a module. This change has been
in linux-next since before the merge window opened for v6.3 so to
provide more than a full kernel cycle of testing. It's a good thing as
quite a bit of fixes have been found for it.
Jason Baron then made dynamic debug a first class citizen module user
by using module notifier callbacks to allocate / remove module
specific dynamic debug information.
Nick Alcock has done quite a bit of work cross-tree to remove module
license tags from things which cannot possibly be module at my request
so to:
a) help him with his longer term tooling goals which require a
deterministic evaluation if a piece a symbol code could ever be
part of a module or not. But quite recently it is has been made
clear that tooling is not the only one that would benefit.
Disambiguating symbols also helps efforts such as live patching,
kprobes and BPF, but for other reasons and R&D on this area is
active with no clear solution in sight.
b) help us inch closer to the now generally accepted long term goal
of automating all the MODULE_LICENSE() tags from SPDX license tags
In so far as a) is concerned, although module license tags are a no-op
for non-modules, tools which would want create a mapping of possible
modules can only rely on the module license tag after the commit
8b41fc4454 ("kbuild: create modules.builtin without
Makefile.modbuiltin or tristate.conf").
Nick has been working on this *for years* and AFAICT I was the only
one to suggest two alternatives to this approach for tooling. The
complexity in one of my suggested approaches lies in that we'd need a
possible-obj-m and a could-be-module which would check if the object
being built is part of any kconfig build which could ever lead to it
being part of a module, and if so define a new define
-DPOSSIBLE_MODULE [0].
A more obvious yet theoretical approach I've suggested would be to
have a tristate in kconfig imply the same new -DPOSSIBLE_MODULE as
well but that means getting kconfig symbol names mapping to modules
always, and I don't think that's the case today. I am not aware of
Nick or anyone exploring either of these options. Quite recently Josh
Poimboeuf has pointed out that live patching, kprobes and BPF would
benefit from resolving some part of the disambiguation as well but for
other reasons. The function granularity KASLR (fgkaslr) patches were
mentioned but Joe Lawrence has clarified this effort has been dropped
with no clear solution in sight [1].
In the meantime removing module license tags from code which could
never be modules is welcomed for both objectives mentioned above. Some
developers have also welcomed these changes as it has helped clarify
when a module was never possible and they forgot to clean this up, and
so you'll see quite a bit of Nick's patches in other pull requests for
this merge window. I just picked up the stragglers after rc3. LWN has
good coverage on the motivation behind this work [2] and the typical
cross-tree issues he ran into along the way. The only concrete blocker
issue he ran into was that we should not remove the MODULE_LICENSE()
tags from files which have no SPDX tags yet, even if they can never be
modules. Nick ended up giving up on his efforts due to having to do
this vetting and backlash he ran into from folks who really did *not
understand* the core of the issue nor were providing any alternative /
guidance. I've gone through his changes and dropped the patches which
dropped the module license tags where an SPDX license tag was missing,
it only consisted of 11 drivers. To see if a pull request deals with a
file which lacks SPDX tags you can just use:
./scripts/spdxcheck.py -f \
$(git diff --name-only commid-id | xargs echo)
You'll see a core module file in this pull request for the above, but
that's not related to his changes. WE just need to add the SPDX
license tag for the kernel/module/kmod.c file in the future but it
demonstrates the effectiveness of the script.
Most of Nick's changes were spread out through different trees, and I
just picked up the slack after rc3 for the last kernel was out. Those
changes have been in linux-next for over two weeks.
The cleanups, debug code I added and final fix I added for modules
were motivated by David Hildenbrand's report of boot failing on a
systems with over 400 CPUs when KASAN was enabled due to running out
of virtual memory space. Although the functional change only consists
of 3 lines in the patch "module: avoid allocation if module is already
present and ready", proving that this was the best we can do on the
modules side took quite a bit of effort and new debug code.
The initial cleanups I did on the modules side of things has been in
linux-next since around rc3 of the last kernel, the actual final fix
for and debug code however have only been in linux-next for about a
week or so but I think it is worth getting that code in for this merge
window as it does help fix / prove / evaluate the issues reported with
larger number of CPUs. Userspace is not yet fixed as it is taking a
bit of time for folks to understand the crux of the issue and find a
proper resolution. Worst come to worst, I have a kludge-of-concept [3]
of how to make kernel_read*() calls for modules unique / converge
them, but I'm currently inclined to just see if userspace can fix this
instead"
Link: https://lore.kernel.org/all/Y/kXDqW+7d71C4wz@bombadil.infradead.org/ [0]
Link: https://lkml.kernel.org/r/025f2151-ce7c-5630-9b90-98742c97ac65@redhat.com [1]
Link: https://lwn.net/Articles/927569/ [2]
Link: https://lkml.kernel.org/r/20230414052840.1994456-3-mcgrof@kernel.org [3]
* tag 'modules-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (121 commits)
module: add debugging auto-load duplicate module support
module: stats: fix invalid_mod_bytes typo
module: remove use of uninitialized variable len
module: fix building stats for 32-bit targets
module: stats: include uapi/linux/module.h
module: avoid allocation if module is already present and ready
module: add debug stats to help identify memory pressure
module: extract patient module check into helper
modules/kmod: replace implementation with a semaphore
Change DEFINE_SEMAPHORE() to take a number argument
module: fix kmemleak annotations for non init ELF sections
module: Ignore L0 and rename is_arm_mapping_symbol()
module: Move is_arm_mapping_symbol() to module_symbol.h
module: Sync code of is_arm_mapping_symbol()
scripts/gdb: use mem instead of core_layout to get the module address
interconnect: remove module-related code
interconnect: remove MODULE_LICENSE in non-modules
zswap: remove MODULE_LICENSE in non-modules
zpool: remove MODULE_LICENSE in non-modules
x86/mm/dump_pagetables: remove MODULE_LICENSE in non-modules
...
