1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * Generic watchdog defines. Derived from.. |
4 | * |
5 | * Berkshire PC Watchdog Defines |
6 | * by Ken Hollis <khollis@bitgate.com> |
7 | * |
8 | */ |
9 | #ifndef _LINUX_WATCHDOG_H |
10 | #define _LINUX_WATCHDOG_H |
11 | |
12 | |
13 | #include <linux/bitops.h> |
14 | #include <linux/cdev.h> |
15 | #include <linux/device.h> |
16 | #include <linux/kernel.h> |
17 | #include <linux/notifier.h> |
18 | #include <uapi/linux/watchdog.h> |
19 | |
20 | struct watchdog_ops; |
21 | struct watchdog_device; |
22 | struct watchdog_core_data; |
23 | struct watchdog_governor; |
24 | |
25 | /** struct watchdog_ops - The watchdog-devices operations |
26 | * |
27 | * @owner: The module owner. |
28 | * @start: The routine for starting the watchdog device. |
29 | * @stop: The routine for stopping the watchdog device. |
30 | * @ping: The routine that sends a keepalive ping to the watchdog device. |
31 | * @status: The routine that shows the status of the watchdog device. |
32 | * @set_timeout:The routine for setting the watchdog devices timeout value (in seconds). |
33 | * @set_pretimeout:The routine for setting the watchdog devices pretimeout. |
34 | * @get_timeleft:The routine that gets the time left before a reset (in seconds). |
35 | * @restart: The routine for restarting the machine. |
36 | * @ioctl: The routines that handles extra ioctl calls. |
37 | * |
38 | * The watchdog_ops structure contains a list of low-level operations |
39 | * that control a watchdog device. It also contains the module that owns |
40 | * these operations. The start function is mandatory, all other |
41 | * functions are optional. |
42 | */ |
43 | struct watchdog_ops { |
44 | struct module *owner; |
45 | /* mandatory operations */ |
46 | int (*start)(struct watchdog_device *); |
47 | /* optional operations */ |
48 | int (*stop)(struct watchdog_device *); |
49 | int (*ping)(struct watchdog_device *); |
50 | unsigned int (*status)(struct watchdog_device *); |
51 | int (*set_timeout)(struct watchdog_device *, unsigned int); |
52 | int (*set_pretimeout)(struct watchdog_device *, unsigned int); |
53 | unsigned int (*get_timeleft)(struct watchdog_device *); |
54 | int (*restart)(struct watchdog_device *, unsigned long, void *); |
55 | long (*ioctl)(struct watchdog_device *, unsigned int, unsigned long); |
56 | }; |
57 | |
58 | /** struct watchdog_device - The structure that defines a watchdog device |
59 | * |
60 | * @id: The watchdog's ID. (Allocated by watchdog_register_device) |
61 | * @parent: The parent bus device |
62 | * @groups: List of sysfs attribute groups to create when creating the |
63 | * watchdog device. |
64 | * @info: Pointer to a watchdog_info structure. |
65 | * @ops: Pointer to the list of watchdog operations. |
66 | * @gov: Pointer to watchdog pretimeout governor. |
67 | * @bootstatus: Status of the watchdog device at boot. |
68 | * @timeout: The watchdog devices timeout value (in seconds). |
69 | * @pretimeout: The watchdog devices pre_timeout value. |
70 | * @min_timeout:The watchdog devices minimum timeout value (in seconds). |
71 | * @max_timeout:The watchdog devices maximum timeout value (in seconds) |
72 | * as configurable from user space. Only relevant if |
73 | * max_hw_heartbeat_ms is not provided. |
74 | * @min_hw_heartbeat_ms: |
75 | * Hardware limit for minimum time between heartbeats, |
76 | * in milli-seconds. |
77 | * @max_hw_heartbeat_ms: |
78 | * Hardware limit for maximum timeout, in milli-seconds. |
79 | * Replaces max_timeout if specified. |
80 | * @reboot_nb: The notifier block to stop watchdog on reboot. |
81 | * @restart_nb: The notifier block to register a restart function. |
82 | * @driver_data:Pointer to the drivers private data. |
83 | * @wd_data: Pointer to watchdog core internal data. |
84 | * @status: Field that contains the devices internal status bits. |
85 | * @deferred: Entry in wtd_deferred_reg_list which is used to |
86 | * register early initialized watchdogs. |
87 | * |
88 | * The watchdog_device structure contains all information about a |
89 | * watchdog timer device. |
90 | * |
91 | * The driver-data field may not be accessed directly. It must be accessed |
92 | * via the watchdog_set_drvdata and watchdog_get_drvdata helpers. |
93 | */ |
94 | struct watchdog_device { |
95 | int id; |
96 | struct device *parent; |
97 | const struct attribute_group **groups; |
98 | const struct watchdog_info *info; |
99 | const struct watchdog_ops *ops; |
100 | const struct watchdog_governor *gov; |
101 | unsigned int bootstatus; |
102 | unsigned int timeout; |
103 | unsigned int pretimeout; |
104 | unsigned int min_timeout; |
105 | unsigned int max_timeout; |
106 | unsigned int min_hw_heartbeat_ms; |
107 | unsigned int max_hw_heartbeat_ms; |
108 | struct notifier_block reboot_nb; |
109 | struct notifier_block restart_nb; |
110 | struct notifier_block pm_nb; |
111 | void *driver_data; |
112 | struct watchdog_core_data *wd_data; |
113 | unsigned long status; |
114 | /* Bit numbers for status flags */ |
115 | #define WDOG_ACTIVE 0 /* Is the watchdog running/active */ |
116 | #define WDOG_NO_WAY_OUT 1 /* Is 'nowayout' feature set ? */ |
117 | #define WDOG_STOP_ON_REBOOT 2 /* Should be stopped on reboot */ |
118 | #define WDOG_HW_RUNNING 3 /* True if HW watchdog running */ |
119 | #define WDOG_STOP_ON_UNREGISTER 4 /* Should be stopped on unregister */ |
120 | #define WDOG_NO_PING_ON_SUSPEND 5 /* Ping worker should be stopped on suspend */ |
121 | struct list_head deferred; |
122 | }; |
123 | |
124 | #define WATCHDOG_NOWAYOUT IS_BUILTIN(CONFIG_WATCHDOG_NOWAYOUT) |
125 | #define WATCHDOG_NOWAYOUT_INIT_STATUS (WATCHDOG_NOWAYOUT << WDOG_NO_WAY_OUT) |
126 | |
127 | /* Use the following function to check whether or not the watchdog is active */ |
128 | static inline bool watchdog_active(struct watchdog_device *wdd) |
129 | { |
130 | return test_bit(WDOG_ACTIVE, &wdd->status); |
131 | } |
132 | |
133 | /* |
134 | * Use the following function to check whether or not the hardware watchdog |
135 | * is running |
136 | */ |
137 | static inline bool watchdog_hw_running(struct watchdog_device *wdd) |
138 | { |
139 | return test_bit(WDOG_HW_RUNNING, &wdd->status); |
140 | } |
141 | |
142 | /* Use the following function to set the nowayout feature */ |
143 | static inline void watchdog_set_nowayout(struct watchdog_device *wdd, bool nowayout) |
144 | { |
145 | if (nowayout) |
146 | set_bit(WDOG_NO_WAY_OUT, addr: &wdd->status); |
147 | } |
148 | |
149 | /* Use the following function to stop the watchdog on reboot */ |
150 | static inline void watchdog_stop_on_reboot(struct watchdog_device *wdd) |
151 | { |
152 | set_bit(WDOG_STOP_ON_REBOOT, addr: &wdd->status); |
153 | } |
154 | |
155 | /* Use the following function to stop the watchdog when unregistering it */ |
156 | static inline void watchdog_stop_on_unregister(struct watchdog_device *wdd) |
157 | { |
158 | set_bit(WDOG_STOP_ON_UNREGISTER, addr: &wdd->status); |
159 | } |
160 | |
161 | /* Use the following function to stop the wdog ping worker when suspending */ |
162 | static inline void watchdog_stop_ping_on_suspend(struct watchdog_device *wdd) |
163 | { |
164 | set_bit(WDOG_NO_PING_ON_SUSPEND, addr: &wdd->status); |
165 | } |
166 | |
167 | /* Use the following function to check if a timeout value is invalid */ |
168 | static inline bool watchdog_timeout_invalid(struct watchdog_device *wdd, unsigned int t) |
169 | { |
170 | /* |
171 | * The timeout is invalid if |
172 | * - the requested value is larger than UINT_MAX / 1000 |
173 | * (since internal calculations are done in milli-seconds), |
174 | * or |
175 | * - the requested value is smaller than the configured minimum timeout, |
176 | * or |
177 | * - a maximum hardware timeout is not configured, a maximum timeout |
178 | * is configured, and the requested value is larger than the |
179 | * configured maximum timeout. |
180 | */ |
181 | return t > UINT_MAX / 1000 || t < wdd->min_timeout || |
182 | (!wdd->max_hw_heartbeat_ms && wdd->max_timeout && |
183 | t > wdd->max_timeout); |
184 | } |
185 | |
186 | /* Use the following function to check if a pretimeout value is invalid */ |
187 | static inline bool watchdog_pretimeout_invalid(struct watchdog_device *wdd, |
188 | unsigned int t) |
189 | { |
190 | return t && wdd->timeout && t >= wdd->timeout; |
191 | } |
192 | |
193 | /* Use the following functions to manipulate watchdog driver specific data */ |
194 | static inline void watchdog_set_drvdata(struct watchdog_device *wdd, void *data) |
195 | { |
196 | wdd->driver_data = data; |
197 | } |
198 | |
199 | static inline void *watchdog_get_drvdata(struct watchdog_device *wdd) |
200 | { |
201 | return wdd->driver_data; |
202 | } |
203 | |
204 | /* Use the following functions to report watchdog pretimeout event */ |
205 | #if IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV) |
206 | void watchdog_notify_pretimeout(struct watchdog_device *wdd); |
207 | #else |
208 | static inline void watchdog_notify_pretimeout(struct watchdog_device *wdd) |
209 | { |
210 | pr_alert("watchdog%d: pretimeout event\n" , wdd->id); |
211 | } |
212 | #endif |
213 | |
214 | /* drivers/watchdog/watchdog_core.c */ |
215 | void watchdog_set_restart_priority(struct watchdog_device *wdd, int priority); |
216 | extern int watchdog_init_timeout(struct watchdog_device *wdd, |
217 | unsigned int timeout_parm, struct device *dev); |
218 | extern int watchdog_register_device(struct watchdog_device *); |
219 | extern void watchdog_unregister_device(struct watchdog_device *); |
220 | int watchdog_dev_suspend(struct watchdog_device *wdd); |
221 | int watchdog_dev_resume(struct watchdog_device *wdd); |
222 | |
223 | int watchdog_set_last_hw_keepalive(struct watchdog_device *, unsigned int); |
224 | |
225 | /* devres register variant */ |
226 | int devm_watchdog_register_device(struct device *dev, struct watchdog_device *); |
227 | |
228 | #endif /* ifndef _LINUX_WATCHDOG_H */ |
229 | |