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a9d70523 RW |
1 | /* |
2 | * kernel/power/suspend.c - Suspend to RAM and standby functionality. | |
3 | * | |
4 | * Copyright (c) 2003 Patrick Mochel | |
5 | * Copyright (c) 2003 Open Source Development Lab | |
6 | * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | */ | |
10 | ||
11 | #include <linux/string.h> | |
12 | #include <linux/delay.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/console.h> | |
16 | #include <linux/cpu.h> | |
17 | #include <linux/syscalls.h> | |
5a0e3ad6 | 18 | #include <linux/gfp.h> |
dd4c4f17 MG |
19 | #include <linux/io.h> |
20 | #include <linux/kernel.h> | |
21 | #include <linux/list.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/suspend.h> | |
40dc166c | 25 | #include <linux/syscore_ops.h> |
938cfed1 | 26 | #include <trace/events/power.h> |
a9d70523 RW |
27 | |
28 | #include "power.h" | |
29 | ||
30 | const char *const pm_states[PM_SUSPEND_MAX] = { | |
31 | [PM_SUSPEND_STANDBY] = "standby", | |
32 | [PM_SUSPEND_MEM] = "mem", | |
33 | }; | |
34 | ||
2f55ac07 | 35 | static const struct platform_suspend_ops *suspend_ops; |
a9d70523 RW |
36 | |
37 | /** | |
38 | * suspend_set_ops - Set the global suspend method table. | |
39 | * @ops: Pointer to ops structure. | |
40 | */ | |
2f55ac07 | 41 | void suspend_set_ops(const struct platform_suspend_ops *ops) |
a9d70523 RW |
42 | { |
43 | mutex_lock(&pm_mutex); | |
44 | suspend_ops = ops; | |
45 | mutex_unlock(&pm_mutex); | |
46 | } | |
47 | ||
48 | bool valid_state(suspend_state_t state) | |
49 | { | |
50 | /* | |
51 | * All states need lowlevel support and need to be valid to the lowlevel | |
52 | * implementation, no valid callback implies that none are valid. | |
53 | */ | |
54 | return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); | |
55 | } | |
56 | ||
57 | /** | |
58 | * suspend_valid_only_mem - generic memory-only valid callback | |
59 | * | |
60 | * Platform drivers that implement mem suspend only and only need | |
61 | * to check for that in their .valid callback can use this instead | |
62 | * of rolling their own .valid callback. | |
63 | */ | |
64 | int suspend_valid_only_mem(suspend_state_t state) | |
65 | { | |
66 | return state == PM_SUSPEND_MEM; | |
67 | } | |
68 | ||
69 | static int suspend_test(int level) | |
70 | { | |
71 | #ifdef CONFIG_PM_DEBUG | |
72 | if (pm_test_level == level) { | |
73 | printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); | |
74 | mdelay(5000); | |
75 | return 1; | |
76 | } | |
77 | #endif /* !CONFIG_PM_DEBUG */ | |
78 | return 0; | |
79 | } | |
80 | ||
81 | /** | |
82 | * suspend_prepare - Do prep work before entering low-power state. | |
83 | * | |
84 | * This is common code that is called for each state that we're entering. | |
85 | * Run suspend notifiers, allocate a console and stop all processes. | |
86 | */ | |
87 | static int suspend_prepare(void) | |
88 | { | |
89 | int error; | |
90 | ||
91 | if (!suspend_ops || !suspend_ops->enter) | |
92 | return -EPERM; | |
93 | ||
94 | pm_prepare_console(); | |
95 | ||
96 | error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); | |
97 | if (error) | |
98 | goto Finish; | |
99 | ||
100 | error = usermodehelper_disable(); | |
101 | if (error) | |
102 | goto Finish; | |
103 | ||
104 | error = suspend_freeze_processes(); | |
105 | if (!error) | |
106 | return 0; | |
107 | ||
108 | suspend_thaw_processes(); | |
109 | usermodehelper_enable(); | |
110 | Finish: | |
111 | pm_notifier_call_chain(PM_POST_SUSPEND); | |
112 | pm_restore_console(); | |
113 | return error; | |
114 | } | |
115 | ||
116 | /* default implementation */ | |
117 | void __attribute__ ((weak)) arch_suspend_disable_irqs(void) | |
118 | { | |
119 | local_irq_disable(); | |
120 | } | |
121 | ||
122 | /* default implementation */ | |
123 | void __attribute__ ((weak)) arch_suspend_enable_irqs(void) | |
124 | { | |
125 | local_irq_enable(); | |
126 | } | |
127 | ||
128 | /** | |
129 | * suspend_enter - enter the desired system sleep state. | |
130 | * @state: state to enter | |
131 | * | |
132 | * This function should be called after devices have been suspended. | |
133 | */ | |
134 | static int suspend_enter(suspend_state_t state) | |
135 | { | |
136 | int error; | |
137 | ||
138 | if (suspend_ops->prepare) { | |
139 | error = suspend_ops->prepare(); | |
140 | if (error) | |
ce441011 | 141 | goto Platform_finish; |
a9d70523 RW |
142 | } |
143 | ||
144 | error = dpm_suspend_noirq(PMSG_SUSPEND); | |
145 | if (error) { | |
146 | printk(KERN_ERR "PM: Some devices failed to power down\n"); | |
ce441011 | 147 | goto Platform_finish; |
a9d70523 RW |
148 | } |
149 | ||
150 | if (suspend_ops->prepare_late) { | |
151 | error = suspend_ops->prepare_late(); | |
152 | if (error) | |
ce441011 | 153 | goto Platform_wake; |
a9d70523 RW |
154 | } |
155 | ||
156 | if (suspend_test(TEST_PLATFORM)) | |
157 | goto Platform_wake; | |
158 | ||
159 | error = disable_nonboot_cpus(); | |
160 | if (error || suspend_test(TEST_CPUS)) | |
161 | goto Enable_cpus; | |
162 | ||
163 | arch_suspend_disable_irqs(); | |
164 | BUG_ON(!irqs_disabled()); | |
165 | ||
166 | error = sysdev_suspend(PMSG_SUSPEND); | |
2ca6f62f | 167 | if (!error) { |
40dc166c | 168 | error = syscore_suspend(); |
2ca6f62f RW |
169 | if (error) |
170 | sysdev_resume(); | |
171 | } | |
a9d70523 | 172 | if (!error) { |
a2867e08 | 173 | if (!(suspend_test(TEST_CORE) || pm_wakeup_pending())) { |
a9d70523 | 174 | error = suspend_ops->enter(state); |
c125e96f RW |
175 | events_check_enabled = false; |
176 | } | |
40dc166c | 177 | syscore_resume(); |
a9d70523 RW |
178 | sysdev_resume(); |
179 | } | |
180 | ||
181 | arch_suspend_enable_irqs(); | |
182 | BUG_ON(irqs_disabled()); | |
183 | ||
184 | Enable_cpus: | |
185 | enable_nonboot_cpus(); | |
186 | ||
187 | Platform_wake: | |
188 | if (suspend_ops->wake) | |
189 | suspend_ops->wake(); | |
190 | ||
a9d70523 RW |
191 | dpm_resume_noirq(PMSG_RESUME); |
192 | ||
ce441011 | 193 | Platform_finish: |
a9d70523 RW |
194 | if (suspend_ops->finish) |
195 | suspend_ops->finish(); | |
196 | ||
197 | return error; | |
198 | } | |
199 | ||
200 | /** | |
201 | * suspend_devices_and_enter - suspend devices and enter the desired system | |
202 | * sleep state. | |
203 | * @state: state to enter | |
204 | */ | |
205 | int suspend_devices_and_enter(suspend_state_t state) | |
206 | { | |
207 | int error; | |
208 | ||
209 | if (!suspend_ops) | |
210 | return -ENOSYS; | |
211 | ||
938cfed1 | 212 | trace_machine_suspend(state); |
a9d70523 RW |
213 | if (suspend_ops->begin) { |
214 | error = suspend_ops->begin(state); | |
215 | if (error) | |
216 | goto Close; | |
217 | } | |
218 | suspend_console(); | |
c9e664f1 | 219 | pm_restrict_gfp_mask(); |
a9d70523 RW |
220 | suspend_test_start(); |
221 | error = dpm_suspend_start(PMSG_SUSPEND); | |
222 | if (error) { | |
223 | printk(KERN_ERR "PM: Some devices failed to suspend\n"); | |
224 | goto Recover_platform; | |
225 | } | |
226 | suspend_test_finish("suspend devices"); | |
227 | if (suspend_test(TEST_DEVICES)) | |
228 | goto Recover_platform; | |
229 | ||
230 | suspend_enter(state); | |
231 | ||
232 | Resume_devices: | |
233 | suspend_test_start(); | |
234 | dpm_resume_end(PMSG_RESUME); | |
235 | suspend_test_finish("resume devices"); | |
c9e664f1 | 236 | pm_restore_gfp_mask(); |
a9d70523 RW |
237 | resume_console(); |
238 | Close: | |
239 | if (suspend_ops->end) | |
240 | suspend_ops->end(); | |
938cfed1 | 241 | trace_machine_suspend(PWR_EVENT_EXIT); |
a9d70523 RW |
242 | return error; |
243 | ||
244 | Recover_platform: | |
245 | if (suspend_ops->recover) | |
246 | suspend_ops->recover(); | |
247 | goto Resume_devices; | |
248 | } | |
249 | ||
250 | /** | |
251 | * suspend_finish - Do final work before exiting suspend sequence. | |
252 | * | |
253 | * Call platform code to clean up, restart processes, and free the | |
254 | * console that we've allocated. This is not called for suspend-to-disk. | |
255 | */ | |
256 | static void suspend_finish(void) | |
257 | { | |
258 | suspend_thaw_processes(); | |
259 | usermodehelper_enable(); | |
260 | pm_notifier_call_chain(PM_POST_SUSPEND); | |
261 | pm_restore_console(); | |
262 | } | |
263 | ||
264 | /** | |
265 | * enter_state - Do common work of entering low-power state. | |
266 | * @state: pm_state structure for state we're entering. | |
267 | * | |
268 | * Make sure we're the only ones trying to enter a sleep state. Fail | |
269 | * if someone has beat us to it, since we don't want anything weird to | |
270 | * happen when we wake up. | |
271 | * Then, do the setup for suspend, enter the state, and cleaup (after | |
272 | * we've woken up). | |
273 | */ | |
274 | int enter_state(suspend_state_t state) | |
275 | { | |
276 | int error; | |
277 | ||
278 | if (!valid_state(state)) | |
279 | return -ENODEV; | |
280 | ||
281 | if (!mutex_trylock(&pm_mutex)) | |
282 | return -EBUSY; | |
283 | ||
284 | printk(KERN_INFO "PM: Syncing filesystems ... "); | |
285 | sys_sync(); | |
286 | printk("done.\n"); | |
287 | ||
288 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); | |
289 | error = suspend_prepare(); | |
290 | if (error) | |
291 | goto Unlock; | |
292 | ||
293 | if (suspend_test(TEST_FREEZER)) | |
294 | goto Finish; | |
295 | ||
296 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); | |
297 | error = suspend_devices_and_enter(state); | |
298 | ||
299 | Finish: | |
300 | pr_debug("PM: Finishing wakeup.\n"); | |
301 | suspend_finish(); | |
302 | Unlock: | |
303 | mutex_unlock(&pm_mutex); | |
304 | return error; | |
305 | } | |
306 | ||
307 | /** | |
308 | * pm_suspend - Externally visible function for suspending system. | |
309 | * @state: Enumerated value of state to enter. | |
310 | * | |
311 | * Determine whether or not value is within range, get state | |
312 | * structure, and enter (above). | |
313 | */ | |
314 | int pm_suspend(suspend_state_t state) | |
315 | { | |
316 | if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) | |
317 | return enter_state(state); | |
318 | return -EINVAL; | |
319 | } | |
320 | EXPORT_SYMBOL(pm_suspend); |