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[2001:14ba:16e2:8300::1]) by smtp.gmail.com with ESMTPSA id 6sm2257942lfz.189.2021.05.18.04.26.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 May 2021 04:26:11 -0700 (PDT) Date: Tue, 18 May 2021 14:26:04 +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 v10 03/11] thermal: Use generic HW-protection shutdown API Message-ID: <2cf331403a881c523c3dda463f66c9ab7a080755.1621333893.git.matti.vaittinen@fi.rohmeurope.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The hardware shutdown function was exported from kernel/reboot for other subsystems to use. Logic is copied from the thermal_core. The protection mutex is replaced by an atomic_t to allow calls also from an IRQ context. Also the WARN() was replaced by pr_emerg() based on discussions here: https://lore.kernel.org/lkml/YJuPwAZroVZ%2Fw633@alley/ and here: https://lore.kernel.org/linux-iommu/20210331093104.383705-4-geert+renesas@glider.be/ Use the exported API instead of implementing own just for the thermal_core. Signed-off-by: Matti Vaittinen --- Changelog: v10: - update commit message to mention changing WARN() to pr_emerg() v9: - Update the thermal documentation v8: - new patch (change added in v7, splitted in own patch at v8) Use the exported API instead --- .../driver-api/thermal/sysfs-api.rst | 24 +++---- drivers/thermal/thermal_core.c | 63 ++----------------- 2 files changed, 13 insertions(+), 74 deletions(-) diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst index 4b638c14bc16..c93fa5e961a0 100644 --- a/Documentation/driver-api/thermal/sysfs-api.rst +++ b/Documentation/driver-api/thermal/sysfs-api.rst @@ -740,21 +740,15 @@ possible. 5. thermal_emergency_poweroff ============================= -On an event of critical trip temperature crossing. Thermal framework -allows the system to shutdown gracefully by calling orderly_poweroff(). -In the event of a failure of orderly_poweroff() to shut down the system -we are in danger of keeping the system alive at undesirably high -temperatures. To mitigate this high risk scenario we program a work -queue to fire after a pre-determined number of seconds to start -an emergency shutdown of the device using the kernel_power_off() -function. In case kernel_power_off() fails then finally -emergency_restart() is called in the worst case. +On an event of critical trip temperature crossing the thermal framework +shuts down the system by calling hw_protection_shutdown(). The +hw_protection_shutdown() first attempts to perform an orderly shutdown +but accepts a delay after which it proceeds doing a forced power-off +or as last resort an emergency_restart. The delay should be carefully profiled so as to give adequate time for -orderly_poweroff(). In case of failure of an orderly_poweroff() the -emergency poweroff kicks in after the delay has elapsed and shuts down -the system. +orderly poweroff. -If set to 0 emergency poweroff will not be supported. So a carefully -profiled non-zero positive value is a must for emergency poweroff to be -triggered. +If the delay is set to 0 emergency poweroff will not be supported. So a +carefully profiled non-zero positive value is a must for emergency +poweroff to be triggered. diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index d20b25f40d19..10a2d8e1cacf 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); @@ -1538,7 +1484,6 @@ 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);