Commit | Line | Data |
---|---|---|
eb50fd3a | 1 | // SPDX-License-Identifier: GPL-2.0 |
ed7279ae GKH |
2 | /* |
3 | * SVC Greybus "watchdog" driver. | |
4 | * | |
5 | * Copyright 2016 Google Inc. | |
ed7279ae GKH |
6 | */ |
7 | ||
8 | #include <linux/delay.h> | |
192c70dc | 9 | #include <linux/suspend.h> |
ed7279ae | 10 | #include <linux/workqueue.h> |
ec0ad868 | 11 | #include <linux/greybus.h> |
ed7279ae | 12 | |
28cf2035 | 13 | #define SVC_WATCHDOG_PERIOD (2 * HZ) |
ed7279ae GKH |
14 | |
15 | struct gb_svc_watchdog { | |
16 | struct delayed_work work; | |
17 | struct gb_svc *svc; | |
d562853d | 18 | bool enabled; |
192c70dc | 19 | struct notifier_block pm_notifier; |
ed7279ae GKH |
20 | }; |
21 | ||
22 | static struct delayed_work reset_work; | |
23 | ||
192c70dc DL |
24 | static int svc_watchdog_pm_notifier(struct notifier_block *notifier, |
25 | unsigned long pm_event, void *unused) | |
26 | { | |
27 | struct gb_svc_watchdog *watchdog = | |
28 | container_of(notifier, struct gb_svc_watchdog, pm_notifier); | |
29 | ||
30 | switch (pm_event) { | |
31 | case PM_SUSPEND_PREPARE: | |
32 | gb_svc_watchdog_disable(watchdog->svc); | |
33 | break; | |
34 | case PM_POST_SUSPEND: | |
35 | gb_svc_watchdog_enable(watchdog->svc); | |
36 | break; | |
37 | default: | |
38 | break; | |
39 | } | |
40 | ||
41 | return NOTIFY_DONE; | |
42 | } | |
43 | ||
ed7279ae GKH |
44 | static void greybus_reset(struct work_struct *work) |
45 | { | |
377e7a27 | 46 | static char const start_path[] = "/system/bin/start"; |
ed7279ae GKH |
47 | static char *envp[] = { |
48 | "HOME=/", | |
49 | "PATH=/sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin", | |
50 | NULL, | |
51 | }; | |
52 | static char *argv[] = { | |
377e7a27 | 53 | (char *)start_path, |
ed7279ae GKH |
54 | "unipro_reset", |
55 | NULL, | |
56 | }; | |
57 | ||
62730c95 | 58 | pr_err("svc_watchdog: calling \"%s %s\" to reset greybus network!\n", |
ed7279ae GKH |
59 | argv[0], argv[1]); |
60 | call_usermodehelper(start_path, argv, envp, UMH_WAIT_EXEC); | |
61 | } | |
62 | ||
63 | static void do_work(struct work_struct *work) | |
64 | { | |
65 | struct gb_svc_watchdog *watchdog; | |
66 | struct gb_svc *svc; | |
67 | int retval; | |
68 | ||
69 | watchdog = container_of(work, struct gb_svc_watchdog, work.work); | |
70 | svc = watchdog->svc; | |
71 | ||
72 | dev_dbg(&svc->dev, "%s: ping.\n", __func__); | |
73 | retval = gb_svc_ping(svc); | |
74 | if (retval) { | |
75 | /* | |
76 | * Something went really wrong, let's warn userspace and then | |
77 | * pull the plug and reset the whole greybus network. | |
78 | * We need to do this outside of this workqueue as we will be | |
79 | * tearing down the svc device itself. So queue up | |
80 | * yet-another-callback to do that. | |
81 | */ | |
82 | dev_err(&svc->dev, | |
83 | "SVC ping has returned %d, something is wrong!!!\n", | |
84 | retval); | |
ed7279ae | 85 | |
7c4a0edb DL |
86 | if (svc->action == GB_SVC_WATCHDOG_BITE_PANIC_KERNEL) { |
87 | panic("SVC is not responding\n"); | |
88 | } else if (svc->action == GB_SVC_WATCHDOG_BITE_RESET_UNIPRO) { | |
89 | dev_err(&svc->dev, "Resetting the greybus network, watch out!!!\n"); | |
d562853d | 90 | |
7c4a0edb | 91 | INIT_DELAYED_WORK(&reset_work, greybus_reset); |
b6fc2876 | 92 | schedule_delayed_work(&reset_work, HZ / 2); |
7c4a0edb DL |
93 | |
94 | /* | |
95 | * Disable ourselves, we don't want to trip again unless | |
96 | * userspace wants us to. | |
97 | */ | |
98 | watchdog->enabled = false; | |
99 | } | |
ed7279ae GKH |
100 | } |
101 | ||
102 | /* resubmit our work to happen again, if we are still "alive" */ | |
d562853d | 103 | if (watchdog->enabled) |
b6fc2876 | 104 | schedule_delayed_work(&watchdog->work, SVC_WATCHDOG_PERIOD); |
ed7279ae GKH |
105 | } |
106 | ||
107 | int gb_svc_watchdog_create(struct gb_svc *svc) | |
108 | { | |
109 | struct gb_svc_watchdog *watchdog; | |
192c70dc | 110 | int retval; |
ed7279ae GKH |
111 | |
112 | if (svc->watchdog) | |
113 | return 0; | |
114 | ||
115 | watchdog = kmalloc(sizeof(*watchdog), GFP_KERNEL); | |
116 | if (!watchdog) | |
117 | return -ENOMEM; | |
118 | ||
d562853d | 119 | watchdog->enabled = false; |
ed7279ae GKH |
120 | watchdog->svc = svc; |
121 | INIT_DELAYED_WORK(&watchdog->work, do_work); | |
122 | svc->watchdog = watchdog; | |
123 | ||
192c70dc DL |
124 | watchdog->pm_notifier.notifier_call = svc_watchdog_pm_notifier; |
125 | retval = register_pm_notifier(&watchdog->pm_notifier); | |
126 | if (retval) { | |
127 | dev_err(&svc->dev, "error registering pm notifier(%d)\n", | |
128 | retval); | |
129 | goto svc_watchdog_create_err; | |
130 | } | |
131 | ||
132 | retval = gb_svc_watchdog_enable(svc); | |
133 | if (retval) { | |
134 | dev_err(&svc->dev, "error enabling watchdog (%d)\n", retval); | |
135 | unregister_pm_notifier(&watchdog->pm_notifier); | |
136 | goto svc_watchdog_create_err; | |
137 | } | |
138 | return retval; | |
139 | ||
140 | svc_watchdog_create_err: | |
141 | svc->watchdog = NULL; | |
142 | kfree(watchdog); | |
143 | ||
144 | return retval; | |
ed7279ae GKH |
145 | } |
146 | ||
147 | void gb_svc_watchdog_destroy(struct gb_svc *svc) | |
148 | { | |
149 | struct gb_svc_watchdog *watchdog = svc->watchdog; | |
150 | ||
151 | if (!watchdog) | |
152 | return; | |
153 | ||
192c70dc | 154 | unregister_pm_notifier(&watchdog->pm_notifier); |
d562853d | 155 | gb_svc_watchdog_disable(svc); |
ed7279ae GKH |
156 | svc->watchdog = NULL; |
157 | kfree(watchdog); | |
158 | } | |
d562853d GKH |
159 | |
160 | bool gb_svc_watchdog_enabled(struct gb_svc *svc) | |
161 | { | |
162 | if (!svc || !svc->watchdog) | |
163 | return false; | |
164 | return svc->watchdog->enabled; | |
165 | } | |
166 | ||
167 | int gb_svc_watchdog_enable(struct gb_svc *svc) | |
168 | { | |
169 | struct gb_svc_watchdog *watchdog; | |
170 | ||
171 | if (!svc->watchdog) | |
172 | return -ENODEV; | |
173 | ||
174 | watchdog = svc->watchdog; | |
175 | if (watchdog->enabled) | |
176 | return 0; | |
177 | ||
178 | watchdog->enabled = true; | |
b6fc2876 | 179 | schedule_delayed_work(&watchdog->work, SVC_WATCHDOG_PERIOD); |
d562853d GKH |
180 | return 0; |
181 | } | |
182 | ||
183 | int gb_svc_watchdog_disable(struct gb_svc *svc) | |
184 | { | |
185 | struct gb_svc_watchdog *watchdog; | |
186 | ||
187 | if (!svc->watchdog) | |
188 | return -ENODEV; | |
189 | ||
190 | watchdog = svc->watchdog; | |
191 | if (!watchdog->enabled) | |
192 | return 0; | |
193 | ||
194 | watchdog->enabled = false; | |
195 | cancel_delayed_work_sync(&watchdog->work); | |
196 | return 0; | |
197 | } |