Thermal core contains a logic for safety shutdown. System is attempted to
be powered off if temperature exceeds safety limits.
Currently this can be also utilized by regulator subsystem as a final
protection measure if PMICs report dangerous over-voltage, over-current or
over-temperature and if per regulator counter measures fail or do not
exist.
Move this logic to kernel/reboot.c and export the functionality for other
subsystems to use. Also replace the mutex with a spinlock to allow using
the function from any context.
Also the EMIF bus code has implemented a safety shut-down. EMIF does not
attempt orderly_poweroff at all. Thus the EMIF code is not converted to use
this new function.
Signed-off-by: Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx>
---
Changelog
v7:
- new patch
Please note - this patch has received only a minimal amount of testing.
(The new API call was tested to shut-down my system at driver probe but
no odd corner-cases have been tested).
Any testing for thermal shutdown is appreciated.
---
drivers/thermal/thermal_core.c | 63 ++-----------------------
include/linux/reboot.h | 1 +
kernel/reboot.c | 86 ++++++++++++++++++++++++++++++++++
3 files changed, 91 insertions(+), 59 deletions(-)
diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
index 996c038f83a4..b1444845af38 100644
--- a/drivers/thermal/thermal_core.c
+++ b/drivers/thermal/thermal_core.c
@@ -36,10 +36,8 @@ static LIST_HEAD(thermal_governor_list);
static DEFINE_MUTEX(thermal_list_lock);
static DEFINE_MUTEX(thermal_governor_lock);
-static DEFINE_MUTEX(poweroff_lock);
static atomic_t in_suspend;
-static bool power_off_triggered;
static struct thermal_governor *def_governor;
@@ -327,70 +325,18 @@ static void handle_non_critical_trips(struct thermal_zone_device *tz, int trip)
def_governor->throttle(tz, trip);
}
-/**
- * thermal_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 thermal_emergency_poweroff_func(struct work_struct *work)
-{
- /*
- * We have reached here after the emergency thermal 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
- */
- WARN(1, "Attempting kernel_power_off: Temperature too high\n");
- kernel_power_off();
-
- /*
- * Worst of the worst case trigger emergency restart
- */
- WARN(1, "Attempting emergency_restart: Temperature too high\n");
- emergency_restart();
-}
-
-static DECLARE_DELAYED_WORK(thermal_emergency_poweroff_work,
- thermal_emergency_poweroff_func);
-
-/**
- * thermal_emergency_poweroff - Trigger an emergency system poweroff
- *
- * This may be called from any critical situation to trigger a system shutdown
- * after a known period of time. By default this is not scheduled.
- */
-static void thermal_emergency_poweroff(void)
+void thermal_zone_device_critical(struct thermal_zone_device *tz)
{
- int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
/*
* poweroff_delay_ms must be a carefully profiled positive value.
- * Its a must for thermal_emergency_poweroff_work to be scheduled
+ * Its a must for forced_emergency_poweroff_work to be scheduled.
*/
- if (poweroff_delay_ms <= 0)
- return;
- schedule_delayed_work(&thermal_emergency_poweroff_work,
- msecs_to_jiffies(poweroff_delay_ms));
-}
+ int poweroff_delay_ms = CONFIG_THERMAL_EMERGENCY_POWEROFF_DELAY_MS;
-void thermal_zone_device_critical(struct thermal_zone_device *tz)
-{
dev_emerg(&tz->device, "%s: critical temperature reached, "
"shutting down\n", tz->type);
- mutex_lock(&poweroff_lock);
- if (!power_off_triggered) {
- /*
- * Queue a backup emergency shutdown in the event of
- * orderly_poweroff failure
- */
- thermal_emergency_poweroff();
- orderly_poweroff(true);
- power_off_triggered = true;
- }
- mutex_unlock(&poweroff_lock);
+ hw_protection_shutdown("Temperature too high", poweroff_delay_ms);
}
EXPORT_SYMBOL(thermal_zone_device_critical);
@@ -1549,7 +1495,6 @@ static int __init thermal_init(void)
ida_destroy(&thermal_cdev_ida);
mutex_destroy(&thermal_list_lock);
mutex_destroy(&thermal_governor_lock);
- mutex_destroy(&poweroff_lock);
return result;
}
postcore_initcall(thermal_init);
diff --git a/include/linux/reboot.h b/include/linux/reboot.h
index 3734cd8f38a8..af907a3d68d1 100644
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -79,6 +79,7 @@ extern char poweroff_cmd[POWEROFF_CMD_PATH_LEN];
extern void orderly_poweroff(bool force);
extern void orderly_reboot(void);
+void hw_protection_shutdown(const char *reason, int ms_until_forced);
/*
* Emergency restart, callable from an interrupt handler.
diff --git a/kernel/reboot.c b/kernel/reboot.c
index a6ad5eb2fa73..1b5fa6d213d4 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -518,6 +518,92 @@ 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
+ */
+ WARN(1, "Hardware protection timed-out. Trying forced poweroff\n");
+ kernel_power_off();
+
+ /*
+ * Worst of the worst case trigger emergency restart
+ */
+ WARN(1,
+ "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));
+}
+
+static bool prot_power_off_triggered;
+static DEFINE_SPINLOCK(poweroff_lock);
+
+/**
+ * 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)
+{
+ unsigned long flags;
+
+ pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason);
+
+ spin_lock_irqsave(&poweroff_lock, flags);
+ if (prot_power_off_triggered) {
+ spin_unlock(&poweroff_lock);
+ return;
+ }
+ prot_power_off_triggered = true;
+ spin_unlock_irqrestore(&poweroff_lock, flags);
+
+ /*
+ * 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 (;;) {
--
2.25.4
--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND
~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]
