From e016173f656b89f5f71b7d45dfc599ada8107eef Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Mon, 17 Feb 2025 21:39:47 +0100 Subject: reboot: add support for configuring emergency hardware protection action 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 --- Documentation/ABI/testing/sysfs-kernel-reboot | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'Documentation/ABI/testing/sysfs-kernel-reboot') diff --git a/Documentation/ABI/testing/sysfs-kernel-reboot b/Documentation/ABI/testing/sysfs-kernel-reboot index 837330fb2511..e117aba46be0 100644 --- a/Documentation/ABI/testing/sysfs-kernel-reboot +++ b/Documentation/ABI/testing/sysfs-kernel-reboot @@ -30,3 +30,11 @@ KernelVersion: 5.11 Contact: Matteo Croce Description: Don't wait for any other CPUs on reboot and avoid anything that could hang. + +What: /sys/kernel/reboot/hw_protection +Date: April 2025 +KernelVersion: 6.15 +Contact: Ahmad Fatoum +Description: Hardware protection action taken on critical events like + overtemperature or imminent voltage loss. + Valid values are: reboot shutdown -- cgit v1.2.3