linux-stable.git/include/linux/reboot.h, branch v6.14.8

reboot: replace __hw_protection_shutdown bool action parameter with an enum

2025-04-10T12:44:32+00:00

[ Upstream commit 318f05a057157c400a92f17c5f2fa3dd96f57c7e ]

Patch series "reboot: support runtime configuration of emergency
hw_protection action", v3.

We currently leave the decision of whether to shutdown or reboot to
protect hardware in an emergency situation to the individual drivers.

This works out in some cases, where the driver detecting the critical
failure has inside knowledge: It binds to the system management controller
for example or is guided by hardware description that defines what to do.

This is inadequate in the general case though as a driver reporting e.g.
an imminent power failure can't know whether a shutdown or a reboot would
be more appropriate for a given hardware platform.

To address this, this series adds a hw_protection kernel parameter and
sysfs toggle that can be used to change the action from the shutdown
default to reboot.  A new hw_protection_trigger API then makes use of this
default action.

My particular use case is unattended embedded systems that don't have
support for shutdown and that power on automatically when power is
supplied:

  - A brief power cycle gets detected by the driver
  - The kernel powers down the system and SoC goes into shutdown mode
  - Power is restored
  - The system remains oblivious to the restored power
  - System needs to be manually power cycled for a duration long enough
    to drain the capacitors

With this series, such systems can configure the kernel with
hw_protection=reboot to have the boot firmware worry about critical
conditions.

This patch (of 12):

Currently __hw_protection_shutdown() either reboots or shuts down the
system according to its shutdown argument.

To make the logic easier to follow, both inside __hw_protection_shutdown
and at caller sites, lets replace the bool parameter with an enum.

This will be extra useful, when in a later commit, a third action is added
to the enumeration.

No functional change.

Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-0-e1c09b090c0c@pengutronix.de
Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-1-e1c09b090c0c@pengutronix.de
Signed-off-by: Ahmad Fatoum 
Reviewed-by: Tzung-Bi Shih 
Cc: Benson Leung 
Cc: Mark Brown 
Cc: Daniel Lezcano 
Cc: Fabio Estevam 
Cc: Guenter Roeck 
Cc: Jonathan Corbet 
Cc: Liam Girdwood 
Cc: Lukasz Luba 
Cc: Matteo Croce 
Cc: Matti Vaittinen 
Cc: "Rafael J. Wysocki" 
Cc: Rob Herring 
Cc: Rui Zhang 
Cc: Sascha Hauer 
Cc: "Serge E. Hallyn" 
Signed-off-by: Andrew Morton 
Stable-dep-of: bbf0ec4f57e0 ("reboot: reboot, not shutdown, on hw_protection_reboot timeout")
Signed-off-by: Sasha Levin

reboot: Introduce thermal_zone_device_critical_reboot()

2024-01-02T08:33:18+00:00

Introduce thermal_zone_device_critical_reboot() to trigger an
emergency reboot.

It is a counterpart of thermal_zone_device_critical() with the
difference that it will force a reboot instead of shutdown.

The motivation for doing this is to allow the thermal subystem
to trigger a reboot when the temperature reaches the critical
temperature.

Signed-off-by: Fabio Estevam 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20231129124330.519423-3-festevam@gmail.com

thermal/core: Prepare for introduction of thermal reboot

2024-01-02T08:33:18+00:00

Add some helper functions to make it easier introducing the support
for thermal reboot.

No functional change.

Signed-off-by: Fabio Estevam 
Signed-off-by: Daniel Lezcano 
Link: https://lore.kernel.org/r/20231129124330.519423-2-festevam@gmail.com

kernel/reboot: Add device to sys_off_handler

2023-07-28T10:33:09+00:00

If the dev is known (e.g. a devm-based sys_off_handler is used), it can
be passed to the handler's callback to have it available there.
Otherwise, cb_data might be set to the dev in most of the cases.

Reviewed-by: Dmitry Osipenko 
Signed-off-by: Benjamin Bara 
Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-3-18699d5dcd76@skidata.com
Signed-off-by: Lee Jones

kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode

2022-10-04T13:59:36+00:00

Add SYS_OFF_MODE_RESTART_PREPARE callbacks to be invoked before
a system restart.

Suggested-by: Dmitry Osipenko 
Reviewed-by: Dmitry Osipenko 
Signed-off-by: Kai-Heng Feng 
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki

Merge tag 'pm-5.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2022-05-30T18:37:26+00:00

Pull more power management updates from Rafael Wysocki:
 "These update the ARM cpufreq drivers and fix up the CPPC cpufreq
  driver after recent changes, update the OPP code and PM documentation
  and add power sequences support to the system reboot and power off
  code.

  Specifics:

   - Add Tegra234 cpufreq support (Sumit Gupta)

   - Clean up and enhance the Mediatek cpufreq driver (Wan Jiabing,
     Rex-BC Chen, and Jia-Wei Chang)

   - Fix up the CPPC cpufreq driver after recent changes (Zheng Bin,
     Pierre Gondois)

   - Minor update to dt-binding for Qcom's opp-v2-kryo-cpu (Yassine
     Oudjana)

   - Use list iterator only inside the list_for_each_entry loop
     (Xiaomeng Tong, and Jakob Koschel)

   - New APIs related to finding OPP based on interconnect bandwidth
     (Krzysztof Kozlowski)

   - Fix the missing of_node_put() in _bandwidth_supported() (Dan
     Carpenter)

   - Cleanups (Krzysztof Kozlowski, and Viresh Kumar)

   - Add Out of Band mode description to the intel-speed-select utility
     documentation (Srinivas Pandruvada)

   - Add power sequences support to the system reboot and power off code
     and make related platform-specific changes for multiple platforms
     (Dmitry Osipenko, Geert Uytterhoeven)"

* tag 'pm-5.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (60 commits)
  cpufreq: CPPC: Fix unused-function warning
  cpufreq: CPPC: Fix build error without CONFIG_ACPI_CPPC_CPUFREQ_FIE
  Documentation: admin-guide: PM: Add Out of Band mode
  kernel/reboot: Change registration order of legacy power-off handler
  m68k: virt: Switch to new sys-off handler API
  kernel/reboot: Add devm_register_restart_handler()
  kernel/reboot: Add devm_register_power_off_handler()
  soc/tegra: pmc: Use sys-off handler API to power off Nexus 7 properly
  reboot: Remove pm_power_off_prepare()
  regulator: pfuze100: Use devm_register_sys_off_handler()
  ACPI: power: Switch to sys-off handler API
  memory: emif: Use kernel_can_power_off()
  mips: Use do_kernel_power_off()
  ia64: Use do_kernel_power_off()
  x86: Use do_kernel_power_off()
  sh: Use do_kernel_power_off()
  m68k: Switch to new sys-off handler API
  powerpc: Use do_kernel_power_off()
  xen/x86: Use do_kernel_power_off()
  parisc: Use do_kernel_power_off()
  ...

kernel/reboot: Add devm_register_restart_handler()

2022-05-19T17:30:31+00:00

Add devm_register_restart_handler() helper that registers sys-off
handler using restart mode and with a default priority. Most drivers
will want to register restart handler with a default priority, so this
helper will reduce the boilerplate code and make code easier to read and
follow.

Signed-off-by: Dmitry Osipenko 
Signed-off-by: Rafael J. Wysocki

kernel/reboot: Add devm_register_power_off_handler()

2022-05-19T17:30:31+00:00

Add devm_register_power_off_handler() helper that registers sys-off
handler using power-off mode and with a default priority. Most drivers
will want to register power-off handler with a default priority, so this
helper will reduce the boilerplate code and make code easier to read and
follow.

Signed-off-by: Dmitry Osipenko 
Signed-off-by: Rafael J. Wysocki

kernel/reboot: Add register_platform_power_off()

2022-05-19T17:30:30+00:00

Add platform-level registration helpers that will ease transition of the
arch/platform power-off callbacks to the new sys-off based API, allowing
us to remove the global pm_power_off variable in the future.

Signed-off-by: Dmitry Osipenko 
Signed-off-by: Rafael J. Wysocki

kernel/reboot: Add kernel_can_power_off()

2022-05-19T17:30:30+00:00

Add kernel_can_power_off() helper that replaces open-coded checks of
the global pm_power_off variable. This is a necessary step towards
supporting chained power-off handlers.

Signed-off-by: Dmitry Osipenko 
Signed-off-by: Rafael J. Wysocki