From e7fd8b68404f3d8bc03f85bc3c078d67096be06f Mon Sep 17 00:00:00 2001 From: Kai-Heng Feng Date: Thu, 29 Sep 2022 15:05:23 +0800 Subject: [PATCH] kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE mode 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 --- include/linux/reboot.h | 8 ++++++++ kernel/reboot.c | 17 +++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/include/linux/reboot.h b/include/linux/reboot.h index e5d9ef886179..2b6bb593be5b 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -105,6 +105,14 @@ enum sys_off_mode { */ SYS_OFF_MODE_POWER_OFF, + /** + * @SYS_OFF_MODE_RESTART_PREPARE: + * + * Handlers prepare system to be restarted. Handlers are + * allowed to sleep. + */ + SYS_OFF_MODE_RESTART_PREPARE, + /** * @SYS_OFF_MODE_RESTART: * diff --git a/kernel/reboot.c b/kernel/reboot.c index 3c35445bf5ad..3bba88c7ffc6 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -243,6 +243,17 @@ void migrate_to_reboot_cpu(void) set_cpus_allowed_ptr(current, cpumask_of(cpu)); } +/* + * Notifier list for kernel code which wants to be called + * to prepare system for restart. + */ +static BLOCKING_NOTIFIER_HEAD(restart_prep_handler_list); + +static void do_kernel_restart_prepare(void) +{ + blocking_notifier_call_chain(&restart_prep_handler_list, 0, NULL); +} + /** * kernel_restart - reboot the system * @cmd: pointer to buffer containing command to execute for restart @@ -254,6 +265,7 @@ void migrate_to_reboot_cpu(void) void kernel_restart(char *cmd) { kernel_restart_prepare(cmd); + do_kernel_restart_prepare(); migrate_to_reboot_cpu(); syscore_shutdown(); if (!cmd) @@ -396,6 +408,11 @@ register_sys_off_handler(enum sys_off_mode mode, handler->list = &power_off_handler_list; break; + case SYS_OFF_MODE_RESTART_PREPARE: + handler->list = &restart_prep_handler_list; + handler->blocking = true; + break; + case SYS_OFF_MODE_RESTART: handler->list = &restart_handler_list; break;