From: Fabio Estevam <festevam@xxxxxxx>
Introduce hw_protection_reboot() to trigger an emergency reboot.
It is a counterpart of hw_protection_shutdown() with the difference
that it will force a reboot instead of shutdown.
The motivation for doing this is to allow the thermal subystem
to trigger a reboot when the temperature reaches the critical
temperature.
Signed-off-by: Fabio Estevam <festevam@xxxxxxx>
---
Changes since v4:
- None
include/linux/reboot.h | 1 +
kernel/reboot.c | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/include/linux/reboot.h b/include/linux/reboot.h
index 2b6bb593be5b..4a319bc24f6a 100644
--- a/include/linux/reboot.h
+++ b/include/linux/reboot.h
@@ -174,6 +174,7 @@ void ctrl_alt_del(void);
extern void orderly_poweroff(bool force);
extern void orderly_reboot(void);
+void hw_protection_reboot(const char *reason, int ms_until_forced);
void hw_protection_shutdown(const char *reason, int ms_until_forced);
/*
diff --git a/kernel/reboot.c b/kernel/reboot.c
index 3bba88c7ffc6..05333ae8bc6b 100644
--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -952,6 +952,40 @@ static void hw_failure_emergency_poweroff(int poweroff_delay_ms)
msecs_to_jiffies(poweroff_delay_ms));
}
+/**
+ * hw_protection_reboot - Trigger an emergency system reboot
+ *
+ * @reason: Reason of emergency reboot to be printed.
+ * @ms_until_forced: Time to wait for orderly reboot before tiggering a
+ * forced reboot. Negative value disables the forced
+ * reboot.
+ *
+ * Initiate an emergency system reboot in order to protect hardware from
+ * further damage. Usage examples include a thermal protection.
+ *
+ * NOTE: The request is ignored if protection reboot is already pending even
+ * if the previous request has given a large timeout for forced reboot.
+ * Can be called from any context.
+ */
+void hw_protection_reboot(const char *reason, int ms_until_forced)
+{
+ static atomic_t allow_proceed = ATOMIC_INIT(1);
+
+ pr_emerg("HARDWARE PROTECTION reboot (%s)\n", reason);
+
+ /* Reboot should be initiated only once. */
+ if (!atomic_dec_and_test(&allow_proceed))
+ return;
+
+ /*
+ * Queue a backup emergency reboot in the event of
+ * orderly_reboot failure
+ */
+ hw_failure_emergency_poweroff(ms_until_forced);
+ orderly_reboot();
+}
+EXPORT_SYMBOL_GPL(hw_protection_reboot);
+
/**
* hw_protection_shutdown - Trigger an emergency system poweroff
*
--
2.34.1
