kernel/linux.git/include/linux/reboot.h, branch v6.19.11

reboot: retire hw_protection_reboot and hw_protection_shutdown helpers

2025-03-17T06:24:14+00:00

The hw_protection_reboot and hw_protection_shutdown functions mix mechanism with policy: They let the driver requesting an emergency action for hardware protection also decide how to deal with it. This is inadequate in the general case 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. With the addition of the hw_protection parameter, it's now possible to configure at runtime the default emergency action and drivers are expected to use hw_protection_trigger to have this parameter dictate policy. As no current users of either hw_protection_shutdown or hw_protection_shutdown helpers remain, remove them, as not to tempt driver authors to call them. Existing users now either defer to hw_protection_trigger or call __hw_protection_trigger with a suitable argument directly when they have inside knowledge on whether a reboot or shutdown would be more appropriate. Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-12-e1c09b090c0c@pengutronix.de Signed-off-by: Ahmad Fatoum Reviewed-by: Tzung-Bi Shih Cc: Benson Leung Cc: Daniel Lezcano Cc: Fabio Estevam Cc: Guenter Roeck Cc: Jonathan Corbet Cc: Liam Girdwood Cc: Lukasz Luba Cc: Mark Brown Cc: Matteo Croce Cc: Matti Vaittinen Cc: "Rafael J. Wysocki" Cc: Rob Herring (Arm) Cc: Rui Zhang Cc: Sascha Hauer Cc: "Serge E. Hallyn" Signed-off-by: Andrew Morton

reboot: add support for configuring emergency hardware protection action

2025-03-17T06:24:14+00:00

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. In the general case, however, the driver detecting the issue can't know what the appropriate course of action is and shouldn't be dictating the policy of dealing with it. Therefore, add a global hw_protection toggle that allows the user to specify whether shutdown or reboot should be the default action when the driver doesn't set policy. This introduces no functional change yet as hw_protection_trigger() has no callers, but these will be added in subsequent commits. [arnd@arndb.de: hide unused hw_protection_attr] Link: https://lkml.kernel.org/r/20250224141849.1546019-1-arnd@kernel.org Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-7-e1c09b090c0c@pengutronix.de Signed-off-by: Ahmad Fatoum Reviewed-by: Tzung-Bi Shih Cc: Benson Leung Cc: Daniel Lezcano Cc: Fabio Estevam Cc: Guenter Roeck Cc: Jonathan Corbet Cc: Liam Girdwood Cc: Lukasz Luba Cc: Mark Brown Cc: Matteo Croce Cc: Matti Vaittinen Cc: "Rafael J. Wysocki" Cc: Rob Herring (Arm) Cc: Rui Zhang Cc: Sascha Hauer Cc: "Serge E. Hallyn" Signed-off-by: Andrew Morton

reboot: rename now misleading __hw_protection_shutdown symbols

2025-03-17T06:24:13+00:00

The __hw_protection_shutdown function name has become misleading since it can cause either a shutdown (poweroff) or a reboot depending on its argument. To avoid further confusion, let's rename it, so it doesn't suggest that a poweroff is all it can do. Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-5-e1c09b090c0c@pengutronix.de Signed-off-by: Ahmad Fatoum Reviewed-by: Tzung-Bi Shih Cc: Benson Leung Cc: Daniel Lezcano Cc: Fabio Estevam Cc: Guenter Roeck Cc: Jonathan Corbet Cc: Liam Girdwood Cc: Lukasz Luba Cc: Mark Brown Cc: Matteo Croce Cc: Matti Vaittinen Cc: "Rafael J. Wysocki" Cc: Rob Herring (Arm) Cc: Rui Zhang Cc: Sascha Hauer Cc: "Serge E. Hallyn" Signed-off-by: Andrew Morton

reboot: replace __hw_protection_shutdown bool action parameter with an enum

2025-03-17T06:24:13+00:00

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

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