Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Generic watchdog defines. Derived from.. |
| 3 | * |
| 4 | * Berkshire PC Watchdog Defines |
| 5 | * by Ken Hollis <khollis@bitgate.com> |
| 6 | * |
| 7 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 8 | #ifndef _LINUX_WATCHDOG_H |
| 9 | #define _LINUX_WATCHDOG_H |
| 10 | |
Andrey Panin | 4bfdf37 | 2005-07-27 11:43:58 -0700 | [diff] [blame] | 11 | |
Wim Van Sebroeck | ff0b3cd | 2011-11-29 16:24:16 +0100 | [diff] [blame] | 12 | #include <linux/bitops.h> |
Alan Cox | 45f5fed | 2012-05-10 21:48:59 +0200 | [diff] [blame] | 13 | #include <linux/cdev.h> |
Guenter Roeck | 664a392 | 2016-02-28 13:12:15 -0800 | [diff] [blame] | 14 | #include <linux/device.h> |
| 15 | #include <linux/kernel.h> |
Damien Riegel | 2165bf5 | 2015-11-16 12:27:59 -0500 | [diff] [blame] | 16 | #include <linux/notifier.h> |
David Howells | 607ca46 | 2012-10-13 10:46:48 +0100 | [diff] [blame] | 17 | #include <uapi/linux/watchdog.h> |
Andrey Panin | 4bfdf37 | 2005-07-27 11:43:58 -0700 | [diff] [blame] | 18 | |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 19 | struct watchdog_ops; |
| 20 | struct watchdog_device; |
Guenter Roeck | b4ffb19 | 2015-12-25 16:01:42 -0800 | [diff] [blame] | 21 | struct watchdog_core_data; |
Vladimir Zapolskiy | ff84136 | 2016-10-07 15:39:54 +0300 | [diff] [blame] | 22 | struct watchdog_governor; |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 23 | |
| 24 | /** struct watchdog_ops - The watchdog-devices operations |
| 25 | * |
| 26 | * @owner: The module owner. |
| 27 | * @start: The routine for starting the watchdog device. |
| 28 | * @stop: The routine for stopping the watchdog device. |
| 29 | * @ping: The routine that sends a keepalive ping to the watchdog device. |
Wim Van Sebroeck | 2fa0356 | 2011-07-22 18:56:38 +0000 | [diff] [blame] | 30 | * @status: The routine that shows the status of the watchdog device. |
Wolfram Sang | 760d280 | 2015-11-03 09:00:16 +0100 | [diff] [blame] | 31 | * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds). |
Wolfram Sang | df044e0 | 2016-08-31 14:52:41 +0300 | [diff] [blame] | 32 | * @set_pretimeout:The routine for setting the watchdog devices pretimeout. |
Wolfram Sang | 760d280 | 2015-11-03 09:00:16 +0100 | [diff] [blame] | 33 | * @get_timeleft:The routine that gets the time left before a reset (in seconds). |
Damien Riegel | 2165bf5 | 2015-11-16 12:27:59 -0500 | [diff] [blame] | 34 | * @restart: The routine for restarting the machine. |
Wim Van Sebroeck | 78d88fc | 2011-07-22 18:59:49 +0000 | [diff] [blame] | 35 | * @ioctl: The routines that handles extra ioctl calls. |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 36 | * |
| 37 | * The watchdog_ops structure contains a list of low-level operations |
| 38 | * that control a watchdog device. It also contains the module that owns |
| 39 | * these operations. The start and stop function are mandatory, all other |
Wolfram Sang | 80220fa | 2015-11-03 09:00:15 +0100 | [diff] [blame] | 40 | * functions are optional. |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 41 | */ |
| 42 | struct watchdog_ops { |
| 43 | struct module *owner; |
| 44 | /* mandatory operations */ |
| 45 | int (*start)(struct watchdog_device *); |
| 46 | int (*stop)(struct watchdog_device *); |
| 47 | /* optional operations */ |
| 48 | int (*ping)(struct watchdog_device *); |
Wim Van Sebroeck | 2fa0356 | 2011-07-22 18:56:38 +0000 | [diff] [blame] | 49 | unsigned int (*status)(struct watchdog_device *); |
Wim Van Sebroeck | 014d694 | 2011-07-22 18:58:21 +0000 | [diff] [blame] | 50 | int (*set_timeout)(struct watchdog_device *, unsigned int); |
Wolfram Sang | df044e0 | 2016-08-31 14:52:41 +0300 | [diff] [blame] | 51 | int (*set_pretimeout)(struct watchdog_device *, unsigned int); |
Viresh Kumar | fd7b673 | 2012-03-16 09:14:00 +0100 | [diff] [blame] | 52 | unsigned int (*get_timeleft)(struct watchdog_device *); |
Guenter Roeck | 4d8b229 | 2016-02-26 17:32:49 -0800 | [diff] [blame] | 53 | int (*restart)(struct watchdog_device *, unsigned long, void *); |
Wim Van Sebroeck | 78d88fc | 2011-07-22 18:59:49 +0000 | [diff] [blame] | 54 | long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long); |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 55 | }; |
| 56 | |
| 57 | /** struct watchdog_device - The structure that defines a watchdog device |
| 58 | * |
Alan Cox | 45f5fed | 2012-05-10 21:48:59 +0200 | [diff] [blame] | 59 | * @id: The watchdog's ID. (Allocated by watchdog_register_device) |
Alan Cox | d6b469d | 2012-05-11 12:00:20 +0200 | [diff] [blame] | 60 | * @parent: The parent bus device |
Guenter Roeck | faa5847 | 2016-01-03 15:11:56 -0800 | [diff] [blame] | 61 | * @groups: List of sysfs attribute groups to create when creating the |
| 62 | * watchdog device. |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 63 | * @info: Pointer to a watchdog_info structure. |
| 64 | * @ops: Pointer to the list of watchdog operations. |
Vladimir Zapolskiy | ff84136 | 2016-10-07 15:39:54 +0300 | [diff] [blame] | 65 | * @gov: Pointer to watchdog pretimeout governor. |
Wim Van Sebroeck | 2fa0356 | 2011-07-22 18:56:38 +0000 | [diff] [blame] | 66 | * @bootstatus: Status of the watchdog device at boot. |
Wolfram Sang | 760d280 | 2015-11-03 09:00:16 +0100 | [diff] [blame] | 67 | * @timeout: The watchdog devices timeout value (in seconds). |
Wolfram Sang | df044e0 | 2016-08-31 14:52:41 +0300 | [diff] [blame] | 68 | * @pretimeout: The watchdog devices pre_timeout value. |
Wolfram Sang | 760d280 | 2015-11-03 09:00:16 +0100 | [diff] [blame] | 69 | * @min_timeout:The watchdog devices minimum timeout value (in seconds). |
Guenter Roeck | 664a392 | 2016-02-28 13:12:15 -0800 | [diff] [blame] | 70 | * @max_timeout:The watchdog devices maximum timeout value (in seconds) |
| 71 | * as configurable from user space. Only relevant if |
| 72 | * max_hw_heartbeat_ms is not provided. |
Guenter Roeck | 15013ad | 2016-02-28 13:12:18 -0800 | [diff] [blame] | 73 | * @min_hw_heartbeat_ms: |
Guenter Roeck | f9f535c | 2016-05-27 14:19:06 -0700 | [diff] [blame] | 74 | * Hardware limit for minimum time between heartbeats, |
| 75 | * in milli-seconds. |
Guenter Roeck | 664a392 | 2016-02-28 13:12:15 -0800 | [diff] [blame] | 76 | * @max_hw_heartbeat_ms: |
| 77 | * Hardware limit for maximum timeout, in milli-seconds. |
| 78 | * Replaces max_timeout if specified. |
Damien Riegel | e131319 | 2015-11-20 16:54:51 -0500 | [diff] [blame] | 79 | * @reboot_nb: The notifier block to stop watchdog on reboot. |
Damien Riegel | 2165bf5 | 2015-11-16 12:27:59 -0500 | [diff] [blame] | 80 | * @restart_nb: The notifier block to register a restart function. |
Guenter Roeck | b4ffb19 | 2015-12-25 16:01:42 -0800 | [diff] [blame] | 81 | * @driver_data:Pointer to the drivers private data. |
| 82 | * @wd_data: Pointer to watchdog core internal data. |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 83 | * @status: Field that contains the devices internal status bits. |
Guenter Roeck | 664a392 | 2016-02-28 13:12:15 -0800 | [diff] [blame] | 84 | * @deferred: Entry in wtd_deferred_reg_list which is used to |
| 85 | * register early initialized watchdogs. |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 86 | * |
| 87 | * The watchdog_device structure contains all information about a |
| 88 | * watchdog timer device. |
| 89 | * |
| 90 | * The driver-data field may not be accessed directly. It must be accessed |
| 91 | * via the watchdog_set_drvdata and watchdog_get_drvdata helpers. |
Hans de Goede | f4e9c82 | 2012-05-22 11:40:26 +0200 | [diff] [blame] | 92 | * |
| 93 | * The lock field is for watchdog core internal use only and should not be |
| 94 | * touched. |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 95 | */ |
| 96 | struct watchdog_device { |
Alan Cox | 45f5fed | 2012-05-10 21:48:59 +0200 | [diff] [blame] | 97 | int id; |
Alan Cox | d6b469d | 2012-05-11 12:00:20 +0200 | [diff] [blame] | 98 | struct device *parent; |
Guenter Roeck | faa5847 | 2016-01-03 15:11:56 -0800 | [diff] [blame] | 99 | const struct attribute_group **groups; |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 100 | const struct watchdog_info *info; |
| 101 | const struct watchdog_ops *ops; |
Vladimir Zapolskiy | ff84136 | 2016-10-07 15:39:54 +0300 | [diff] [blame] | 102 | const struct watchdog_governor *gov; |
Wim Van Sebroeck | 2fa0356 | 2011-07-22 18:56:38 +0000 | [diff] [blame] | 103 | unsigned int bootstatus; |
Wim Van Sebroeck | 014d694 | 2011-07-22 18:58:21 +0000 | [diff] [blame] | 104 | unsigned int timeout; |
Wolfram Sang | df044e0 | 2016-08-31 14:52:41 +0300 | [diff] [blame] | 105 | unsigned int pretimeout; |
Wim Van Sebroeck | 3f43f68 | 2011-07-22 19:00:16 +0000 | [diff] [blame] | 106 | unsigned int min_timeout; |
| 107 | unsigned int max_timeout; |
Guenter Roeck | 15013ad | 2016-02-28 13:12:18 -0800 | [diff] [blame] | 108 | unsigned int min_hw_heartbeat_ms; |
Guenter Roeck | 664a392 | 2016-02-28 13:12:15 -0800 | [diff] [blame] | 109 | unsigned int max_hw_heartbeat_ms; |
Damien Riegel | e131319 | 2015-11-20 16:54:51 -0500 | [diff] [blame] | 110 | struct notifier_block reboot_nb; |
Damien Riegel | 2165bf5 | 2015-11-16 12:27:59 -0500 | [diff] [blame] | 111 | struct notifier_block restart_nb; |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 112 | void *driver_data; |
Guenter Roeck | b4ffb19 | 2015-12-25 16:01:42 -0800 | [diff] [blame] | 113 | struct watchdog_core_data *wd_data; |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 114 | unsigned long status; |
| 115 | /* Bit numbers for status flags */ |
Wim Van Sebroeck | 234445b | 2011-07-22 18:57:55 +0000 | [diff] [blame] | 116 | #define WDOG_ACTIVE 0 /* Is the watchdog running/active */ |
Guenter Roeck | b4ffb19 | 2015-12-25 16:01:42 -0800 | [diff] [blame] | 117 | #define WDOG_NO_WAY_OUT 1 /* Is 'nowayout' feature set ? */ |
| 118 | #define WDOG_STOP_ON_REBOOT 2 /* Should be stopped on reboot */ |
Guenter Roeck | ee14288 | 2016-02-28 13:12:16 -0800 | [diff] [blame] | 119 | #define WDOG_HW_RUNNING 3 /* True if HW watchdog running */ |
Jean-Baptiste Theou | ef90174 | 2015-06-09 09:55:02 -0700 | [diff] [blame] | 120 | struct list_head deferred; |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 121 | }; |
| 122 | |
Uwe Kleine-König | 4846e37 | 2014-09-09 22:18:31 +0200 | [diff] [blame] | 123 | #define WATCHDOG_NOWAYOUT IS_BUILTIN(CONFIG_WATCHDOG_NOWAYOUT) |
| 124 | #define WATCHDOG_NOWAYOUT_INIT_STATUS (WATCHDOG_NOWAYOUT << WDOG_NO_WAY_OUT) |
Wim Van Sebroeck | ff0b3cd | 2011-11-29 16:24:16 +0100 | [diff] [blame] | 125 | |
Adam Buchbinder | 48fc7f7 | 2012-09-19 21:48:00 -0400 | [diff] [blame] | 126 | /* Use the following function to check whether or not the watchdog is active */ |
Viresh Kumar | 257f8c4 | 2012-03-12 09:51:56 +0530 | [diff] [blame] | 127 | static inline bool watchdog_active(struct watchdog_device *wdd) |
| 128 | { |
| 129 | return test_bit(WDOG_ACTIVE, &wdd->status); |
| 130 | } |
| 131 | |
Guenter Roeck | ee14288 | 2016-02-28 13:12:16 -0800 | [diff] [blame] | 132 | /* |
| 133 | * Use the following function to check whether or not the hardware watchdog |
| 134 | * is running |
| 135 | */ |
| 136 | static inline bool watchdog_hw_running(struct watchdog_device *wdd) |
| 137 | { |
| 138 | return test_bit(WDOG_HW_RUNNING, &wdd->status); |
| 139 | } |
| 140 | |
Wim Van Sebroeck | ff0b3cd | 2011-11-29 16:24:16 +0100 | [diff] [blame] | 141 | /* Use the following function to set the nowayout feature */ |
Wim Van Sebroeck | 86a1e18 | 2012-03-05 16:51:11 +0100 | [diff] [blame] | 142 | static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout) |
Wim Van Sebroeck | ff0b3cd | 2011-11-29 16:24:16 +0100 | [diff] [blame] | 143 | { |
| 144 | if (nowayout) |
| 145 | set_bit(WDOG_NO_WAY_OUT, &wdd->status); |
| 146 | } |
| 147 | |
Damien Riegel | e131319 | 2015-11-20 16:54:51 -0500 | [diff] [blame] | 148 | /* Use the following function to stop the watchdog on reboot */ |
| 149 | static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd) |
| 150 | { |
| 151 | set_bit(WDOG_STOP_ON_REBOOT, &wdd->status); |
| 152 | } |
| 153 | |
Fabio Porcedda | 3048253 | 2013-01-08 11:04:10 +0100 | [diff] [blame] | 154 | /* Use the following function to check if a timeout value is invalid */ |
| 155 | static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t) |
| 156 | { |
Guenter Roeck | 1e93594 | 2015-09-29 01:27:24 -0700 | [diff] [blame] | 157 | /* |
| 158 | * The timeout is invalid if |
Guenter Roeck | 664a392 | 2016-02-28 13:12:15 -0800 | [diff] [blame] | 159 | * - the requested value is larger than UINT_MAX / 1000 |
| 160 | * (since internal calculations are done in milli-seconds), |
| 161 | * or |
Guenter Roeck | 1e93594 | 2015-09-29 01:27:24 -0700 | [diff] [blame] | 162 | * - the requested value is smaller than the configured minimum timeout, |
| 163 | * or |
Guenter Roeck | 664a392 | 2016-02-28 13:12:15 -0800 | [diff] [blame] | 164 | * - a maximum hardware timeout is not configured, a maximum timeout |
| 165 | * is configured, and the requested value is larger than the |
| 166 | * configured maximum timeout. |
Guenter Roeck | 1e93594 | 2015-09-29 01:27:24 -0700 | [diff] [blame] | 167 | */ |
Guenter Roeck | 664a392 | 2016-02-28 13:12:15 -0800 | [diff] [blame] | 168 | return t > UINT_MAX / 1000 || t < wdd->min_timeout || |
| 169 | (!wdd->max_hw_heartbeat_ms && wdd->max_timeout && |
| 170 | t > wdd->max_timeout); |
Fabio Porcedda | 3048253 | 2013-01-08 11:04:10 +0100 | [diff] [blame] | 171 | } |
| 172 | |
Wolfram Sang | df044e0 | 2016-08-31 14:52:41 +0300 | [diff] [blame] | 173 | /* Use the following function to check if a pretimeout value is invalid */ |
| 174 | static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd, |
| 175 | unsigned int t) |
| 176 | { |
| 177 | return t && wdd->timeout && t >= wdd->timeout; |
| 178 | } |
| 179 | |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 180 | /* Use the following functions to manipulate watchdog driver specific data */ |
| 181 | static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data) |
| 182 | { |
| 183 | wdd->driver_data = data; |
| 184 | } |
| 185 | |
| 186 | static inline void *watchdog_get_drvdata(struct watchdog_device *wdd) |
| 187 | { |
| 188 | return wdd->driver_data; |
| 189 | } |
| 190 | |
Vladimir Zapolskiy | ff84136 | 2016-10-07 15:39:54 +0300 | [diff] [blame] | 191 | /* Use the following functions to report watchdog pretimeout event */ |
| 192 | #if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV) |
| 193 | void watchdog_notify_pretimeout(struct watchdog_device *wdd); |
| 194 | #else |
| 195 | static inline void watchdog_notify_pretimeout(struct watchdog_device *wdd) |
| 196 | { |
| 197 | pr_alert("watchdog%d: pretimeout event\n", wdd->id); |
| 198 | } |
| 199 | #endif |
| 200 | |
Fabio Porcedda | cf13a84 | 2012-10-05 12:16:09 +0200 | [diff] [blame] | 201 | /* drivers/watchdog/watchdog_core.c */ |
Damien Riegel | 2165bf5 | 2015-11-16 12:27:59 -0500 | [diff] [blame] | 202 | void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority); |
Fabio Porcedda | 3048253 | 2013-01-08 11:04:10 +0100 | [diff] [blame] | 203 | extern int watchdog_init_timeout(struct watchdog_device *wdd, |
| 204 | unsigned int timeout_parm, struct device *dev); |
Wim Van Sebroeck | 4331604 | 2011-07-22 18:55:18 +0000 | [diff] [blame] | 205 | extern int watchdog_register_device(struct watchdog_device *); |
| 206 | extern void watchdog_unregister_device(struct watchdog_device *); |
| 207 | |
Neil Armstrong | 83fbae5 | 2016-05-27 17:33:54 +0200 | [diff] [blame] | 208 | /* devres register variant */ |
| 209 | int devm_watchdog_register_device(struct device *dev, struct watchdog_device *); |
| 210 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | #endif /* ifndef _LINUX_WATCHDOG_H */ |