| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Generic watchdog defines. Derived from.. |
| * |
| * Berkshire PC Watchdog Defines |
| * by Ken Hollis <khollis@bitgate.com> |
| * |
| */ |
| #ifndef _LINUX_WATCHDOG_H |
| #define _LINUX_WATCHDOG_H |
| |
| |
| #include <linux/bitops.h> |
| #include <linux/cdev.h> |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/notifier.h> |
| #include <uapi/linux/watchdog.h> |
| |
| struct watchdog_ops; |
| struct watchdog_device; |
| struct watchdog_core_data; |
| struct watchdog_governor; |
| |
| /** struct watchdog_ops - The watchdog-devices operations |
| * |
| * @owner: The module owner. |
| * @start: The routine for starting the watchdog device. |
| * @stop: The routine for stopping the watchdog device. |
| * @ping: The routine that sends a keepalive ping to the watchdog device. |
| * @status: The routine that shows the status of the watchdog device. |
| * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds). |
| * @set_pretimeout:The routine for setting the watchdog devices pretimeout. |
| * @get_timeleft:The routine that gets the time left before a reset (in seconds). |
| * @restart: The routine for restarting the machine. |
| * @ioctl: The routines that handles extra ioctl calls. |
| * |
| * The watchdog_ops structure contains a list of low-level operations |
| * that control a watchdog device. It also contains the module that owns |
| * these operations. The start function is mandatory, all other |
| * functions are optional. |
| */ |
| struct watchdog_ops { |
| struct module *owner; |
| /* mandatory operations */ |
| int (*start)(struct watchdog_device *); |
| /* optional operations */ |
| int (*stop)(struct watchdog_device *); |
| int (*ping)(struct watchdog_device *); |
| unsigned int (*status)(struct watchdog_device *); |
| int (*set_timeout)(struct watchdog_device *, unsigned int); |
| int (*set_pretimeout)(struct watchdog_device *, unsigned int); |
| unsigned int (*get_timeleft)(struct watchdog_device *); |
| int (*restart)(struct watchdog_device *, unsigned long, void *); |
| long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long); |
| }; |
| |
| /** struct watchdog_device - The structure that defines a watchdog device |
| * |
| * @id: The watchdog's ID. (Allocated by watchdog_register_device) |
| * @parent: The parent bus device |
| * @groups: List of sysfs attribute groups to create when creating the |
| * watchdog device. |
| * @info: Pointer to a watchdog_info structure. |
| * @ops: Pointer to the list of watchdog operations. |
| * @gov: Pointer to watchdog pretimeout governor. |
| * @bootstatus: Status of the watchdog device at boot. |
| * @timeout: The watchdog devices timeout value (in seconds). |
| * @pretimeout: The watchdog devices pre_timeout value. |
| * @min_timeout:The watchdog devices minimum timeout value (in seconds). |
| * @max_timeout:The watchdog devices maximum timeout value (in seconds) |
| * as configurable from user space. Only relevant if |
| * max_hw_heartbeat_ms is not provided. |
| * @min_hw_heartbeat_ms: |
| * Hardware limit for minimum time between heartbeats, |
| * in milli-seconds. |
| * @max_hw_heartbeat_ms: |
| * Hardware limit for maximum timeout, in milli-seconds. |
| * Replaces max_timeout if specified. |
| * @reboot_nb: The notifier block to stop watchdog on reboot. |
| * @restart_nb: The notifier block to register a restart function. |
| * @driver_data:Pointer to the drivers private data. |
| * @wd_data: Pointer to watchdog core internal data. |
| * @status: Field that contains the devices internal status bits. |
| * @deferred: Entry in wtd_deferred_reg_list which is used to |
| * register early initialized watchdogs. |
| * |
| * The watchdog_device structure contains all information about a |
| * watchdog timer device. |
| * |
| * The driver-data field may not be accessed directly. It must be accessed |
| * via the watchdog_set_drvdata and watchdog_get_drvdata helpers. |
| */ |
| struct watchdog_device { |
| int id; |
| struct device *parent; |
| const struct attribute_group **groups; |
| const struct watchdog_info *info; |
| const struct watchdog_ops *ops; |
| const struct watchdog_governor *gov; |
| unsigned int bootstatus; |
| unsigned int timeout; |
| unsigned int pretimeout; |
| unsigned int min_timeout; |
| unsigned int max_timeout; |
| unsigned int min_hw_heartbeat_ms; |
| unsigned int max_hw_heartbeat_ms; |
| struct notifier_block reboot_nb; |
| struct notifier_block restart_nb; |
| void *driver_data; |
| struct watchdog_core_data *wd_data; |
| unsigned long status; |
| /* Bit numbers for status flags */ |
| #define WDOG_ACTIVE 0 /* Is the watchdog running/active */ |
| #define WDOG_NO_WAY_OUT 1 /* Is 'nowayout' feature set ? */ |
| #define WDOG_STOP_ON_REBOOT 2 /* Should be stopped on reboot */ |
| #define WDOG_HW_RUNNING 3 /* True if HW watchdog running */ |
| #define WDOG_STOP_ON_UNREGISTER 4 /* Should be stopped on unregister */ |
| struct list_head deferred; |
| }; |
| |
| #define WATCHDOG_NOWAYOUT IS_BUILTIN(CONFIG_WATCHDOG_NOWAYOUT) |
| #define WATCHDOG_NOWAYOUT_INIT_STATUS (WATCHDOG_NOWAYOUT << WDOG_NO_WAY_OUT) |
| |
| /* Use the following function to check whether or not the watchdog is active */ |
| static inline bool watchdog_active(struct watchdog_device *wdd) |
| { |
| return test_bit(WDOG_ACTIVE, &wdd->status); |
| } |
| |
| /* |
| * Use the following function to check whether or not the hardware watchdog |
| * is running |
| */ |
| static inline bool watchdog_hw_running(struct watchdog_device *wdd) |
| { |
| return test_bit(WDOG_HW_RUNNING, &wdd->status); |
| } |
| |
| /* Use the following function to set the nowayout feature */ |
| static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout) |
| { |
| if (nowayout) |
| set_bit(WDOG_NO_WAY_OUT, &wdd->status); |
| } |
| |
| /* Use the following function to stop the watchdog on reboot */ |
| static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd) |
| { |
| set_bit(WDOG_STOP_ON_REBOOT, &wdd->status); |
| } |
| |
| /* Use the following function to stop the watchdog when unregistering it */ |
| static inline void watchdog_stop_on_unregister(struct watchdog_device *wdd) |
| { |
| set_bit(WDOG_STOP_ON_UNREGISTER, &wdd->status); |
| } |
| |
| /* Use the following function to check if a timeout value is invalid */ |
| static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t) |
| { |
| /* |
| * The timeout is invalid if |
| * - the requested value is larger than UINT_MAX / 1000 |
| * (since internal calculations are done in milli-seconds), |
| * or |
| * - the requested value is smaller than the configured minimum timeout, |
| * or |
| * - a maximum hardware timeout is not configured, a maximum timeout |
| * is configured, and the requested value is larger than the |
| * configured maximum timeout. |
| */ |
| return t > UINT_MAX / 1000 || t < wdd->min_timeout || |
| (!wdd->max_hw_heartbeat_ms && wdd->max_timeout && |
| t > wdd->max_timeout); |
| } |
| |
| /* Use the following function to check if a pretimeout value is invalid */ |
| static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd, |
| unsigned int t) |
| { |
| return t && wdd->timeout && t >= wdd->timeout; |
| } |
| |
| /* Use the following functions to manipulate watchdog driver specific data */ |
| static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data) |
| { |
| wdd->driver_data = data; |
| } |
| |
| static inline void *watchdog_get_drvdata(struct watchdog_device *wdd) |
| { |
| return wdd->driver_data; |
| } |
| |
| /* Use the following functions to report watchdog pretimeout event */ |
| #if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV) |
| void watchdog_notify_pretimeout(struct watchdog_device *wdd); |
| #else |
| static inline void watchdog_notify_pretimeout(struct watchdog_device *wdd) |
| { |
| pr_alert("watchdog%d: pretimeout event\n", wdd->id); |
| } |
| #endif |
| |
| /* drivers/watchdog/watchdog_core.c */ |
| void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority); |
| extern int watchdog_init_timeout(struct watchdog_device *wdd, |
| unsigned int timeout_parm, struct device *dev); |
| extern int watchdog_register_device(struct watchdog_device *); |
| extern void watchdog_unregister_device(struct watchdog_device *); |
| |
| int watchdog_set_last_hw_keepalive(struct watchdog_device *, unsigned int); |
| |
| /* devres register variant */ |
| int devm_watchdog_register_device(struct device *dev, struct watchdog_device *); |
| |
| #endif /* ifndef _LINUX_WATCHDOG_H */ |