diff options
Diffstat (limited to 'kernel/reboot.c')
| -rw-r--r-- | kernel/reboot.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/kernel/reboot.c b/kernel/reboot.c index a6ad5eb2fa73..f7440c0c7e43 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -7,6 +7,7 @@ #define pr_fmt(fmt) "reboot: " fmt +#include <linux/atomic.h> #include <linux/ctype.h> #include <linux/export.h> #include <linux/kexec.h> @@ -518,6 +519,84 @@ void orderly_reboot(void) } EXPORT_SYMBOL_GPL(orderly_reboot); +/** + * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay + * @work: work_struct associated with the emergency poweroff function + * + * This function is called in very critical situations to force + * a kernel poweroff after a configurable timeout value. + */ +static void hw_failure_emergency_poweroff_func(struct work_struct *work) +{ + /* + * We have reached here after the emergency shutdown waiting period has + * expired. This means orderly_poweroff has not been able to shut off + * the system for some reason. + * + * Try to shut down the system immediately using kernel_power_off + * if populated + */ + pr_emerg("Hardware protection timed-out. Trying forced poweroff\n"); + kernel_power_off(); + + /* + * Worst of the worst case trigger emergency restart + */ + pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n"); + emergency_restart(); +} + +static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, + hw_failure_emergency_poweroff_func); + +/** + * hw_failure_emergency_poweroff - Trigger an emergency system poweroff + * + * This may be called from any critical situation to trigger a system shutdown + * after a given period of time. If time is negative this is not scheduled. + */ +static void hw_failure_emergency_poweroff(int poweroff_delay_ms) +{ + if (poweroff_delay_ms <= 0) + return; + schedule_delayed_work(&hw_failure_emergency_poweroff_work, + msecs_to_jiffies(poweroff_delay_ms)); +} + +/** + * hw_protection_shutdown - Trigger an emergency system poweroff + * + * @reason: Reason of emergency shutdown to be printed. + * @ms_until_forced: Time to wait for orderly shutdown before tiggering a + * forced shudown. Negative value disables the forced + * shutdown. + * + * Initiate an emergency system shutdown in order to protect hardware from + * further damage. Usage examples include a thermal protection or a voltage or + * current regulator failures. + * NOTE: The request is ignored if protection shutdown is already pending even + * if the previous request has given a large timeout for forced shutdown. + * Can be called from any context. + */ +void hw_protection_shutdown(const char *reason, int ms_until_forced) +{ + static atomic_t allow_proceed = ATOMIC_INIT(1); + + pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason); + + /* Shutdown should be initiated only once. */ + if (!atomic_dec_and_test(&allow_proceed)) + return; + + /* + * Queue a backup emergency shutdown in the event of + * orderly_poweroff failure + */ + hw_failure_emergency_poweroff(ms_until_forced); + orderly_poweroff(true); +} +EXPORT_SYMBOL_GPL(hw_protection_shutdown); + static int __init reboot_setup(char *str) { for (;;) { |