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[2001:14ba:16e2:8300::6]) by smtp.gmail.com with ESMTPSA id d25sm2146998ljg.96.2021.04.13.22.52.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Apr 2021 22:52:20 -0700 (PDT) Date: Wed, 14 Apr 2021 08:52:14 +0300 From: Matti Vaittinen To: Matti Vaittinen , Matti Vaittinen Cc: Mark Brown , Kees Cook , Andy Shevchenko , Zhang Rui , Guenter Roeck , "agross@kernel.org" , "devicetree@vger.kernel.org" , linux-power , "linux-kernel@vger.kernel.org" , "linux-renesas-soc@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , "bjorn.andersson@linaro.org" , "lgirdwood@gmail.com" , "robh+dt@kernel.org" , Daniel Lezcano , Amit Kucheria , Matteo Croce , Andrew Morton , Petr Mladek , "Rafael J. Wysocki" , Mike Rapoport , Josef Bacik , Kai-Heng Feng , linux-pm@vger.kernel.org Subject: [PATCH v7 2/9] reboot: thermal: Export hardware protection shutdown Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org 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 --- 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 =]