linux/include
Ahmad Fatoum 318f05a057 reboot: replace __hw_protection_shutdown bool action parameter with an enum
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 <a.fatoum@pengutronix.de>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Cc: Benson Leung <bleung@chromium.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Fabio Estevam <festevam@denx.de>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Cc: Matteo Croce <teknoraver@meta.com>
Cc: Matti Vaittinen <mazziesaccount@gmail.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 23:24:13 -07:00
..
acpi LoongArch changes for v6.14 2025-01-28 08:52:01 -08:00
asm-generic arm64 fixes for -rc5 2025-03-01 13:44:51 -08:00
clocksource KVM/arm64 updates for 6.14 2025-01-28 09:01:36 -08:00
crypto
cxl
drm drm: Fix DSC BPP increment decoding 2025-02-13 10:20:30 +02:00
dt-bindings dt-bindings: clock: qcom: Add CAMCC clocks for QCS8300 2025-02-02 20:59:04 -06:00
hyperv
keys
kunit linux_kselftest-kunit-6.14-rc1 2025-01-22 12:32:39 -08:00
kvm
linux reboot: replace __hw_protection_shutdown bool action parameter with an enum 2025-03-16 23:24:13 -07:00
math-emu
media
memory
misc
net Including fixes from bluetooth. We didn't get netfilter or wireless PRs 2025-02-27 09:32:42 -08:00
pcmcia
ras
rdma
rv rv: Reset per-task monitors also for idle tasks 2025-01-23 12:16:04 -05:00
scsi Driver core and debugfs updates 2025-01-28 12:25:12 -08:00
soc soc: driver updates for 6.14 2025-01-24 14:56:59 -08:00
sound ASoC: cs35l56: Prevent races when soft-resetting using SPI control 2025-02-25 15:06:58 +00:00
target
trace Including fixes from bluetooth. We didn't get netfilter or wireless PRs 2025-02-27 09:32:42 -08:00
uapi Landlock fix for v6.14-rc5 2025-02-26 11:55:44 -08:00
ufs scsi: ufs: core: Fix use-after free in init error and remove paths 2025-02-03 17:20:01 -05:00
vdso
video
xen