Commit | Line | Data |
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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 | /** | |
3b5fe852 MH |
129 | * suspend_enter - enter the desired system sleep state. |
130 | * @state: State to enter | |
131 | * @wakeup: Returns information that suspend should not be entered again. | |
a9d70523 | 132 | * |
3b5fe852 | 133 | * This function should be called after devices have been suspended. |
a9d70523 | 134 | */ |
3b5fe852 | 135 | static int suspend_enter(suspend_state_t state, bool *wakeup) |
a9d70523 RW |
136 | { |
137 | int error; | |
138 | ||
139 | if (suspend_ops->prepare) { | |
140 | error = suspend_ops->prepare(); | |
141 | if (error) | |
ce441011 | 142 | goto Platform_finish; |
a9d70523 RW |
143 | } |
144 | ||
145 | error = dpm_suspend_noirq(PMSG_SUSPEND); | |
146 | if (error) { | |
147 | printk(KERN_ERR "PM: Some devices failed to power down\n"); | |
ce441011 | 148 | goto Platform_finish; |
a9d70523 RW |
149 | } |
150 | ||
151 | if (suspend_ops->prepare_late) { | |
152 | error = suspend_ops->prepare_late(); | |
153 | if (error) | |
ce441011 | 154 | goto Platform_wake; |
a9d70523 RW |
155 | } |
156 | ||
157 | if (suspend_test(TEST_PLATFORM)) | |
158 | goto Platform_wake; | |
159 | ||
160 | error = disable_nonboot_cpus(); | |
161 | if (error || suspend_test(TEST_CPUS)) | |
162 | goto Enable_cpus; | |
163 | ||
164 | arch_suspend_disable_irqs(); | |
165 | BUG_ON(!irqs_disabled()); | |
166 | ||
2e711c04 | 167 | error = syscore_suspend(); |
a9d70523 | 168 | if (!error) { |
3b5fe852 MH |
169 | *wakeup = pm_wakeup_pending(); |
170 | if (!(suspend_test(TEST_CORE) || *wakeup)) { | |
a9d70523 | 171 | error = suspend_ops->enter(state); |
c125e96f RW |
172 | events_check_enabled = false; |
173 | } | |
40dc166c | 174 | syscore_resume(); |
a9d70523 RW |
175 | } |
176 | ||
177 | arch_suspend_enable_irqs(); | |
178 | BUG_ON(irqs_disabled()); | |
179 | ||
180 | Enable_cpus: | |
181 | enable_nonboot_cpus(); | |
182 | ||
183 | Platform_wake: | |
184 | if (suspend_ops->wake) | |
185 | suspend_ops->wake(); | |
186 | ||
a9d70523 RW |
187 | dpm_resume_noirq(PMSG_RESUME); |
188 | ||
ce441011 | 189 | Platform_finish: |
a9d70523 RW |
190 | if (suspend_ops->finish) |
191 | suspend_ops->finish(); | |
192 | ||
193 | return error; | |
194 | } | |
195 | ||
196 | /** | |
197 | * suspend_devices_and_enter - suspend devices and enter the desired system | |
198 | * sleep state. | |
199 | * @state: state to enter | |
200 | */ | |
201 | int suspend_devices_and_enter(suspend_state_t state) | |
202 | { | |
203 | int error; | |
3b5fe852 | 204 | bool wakeup = false; |
a9d70523 RW |
205 | |
206 | if (!suspend_ops) | |
207 | return -ENOSYS; | |
208 | ||
938cfed1 | 209 | trace_machine_suspend(state); |
a9d70523 RW |
210 | if (suspend_ops->begin) { |
211 | error = suspend_ops->begin(state); | |
212 | if (error) | |
213 | goto Close; | |
214 | } | |
215 | suspend_console(); | |
216 | suspend_test_start(); | |
217 | error = dpm_suspend_start(PMSG_SUSPEND); | |
218 | if (error) { | |
219 | printk(KERN_ERR "PM: Some devices failed to suspend\n"); | |
220 | goto Recover_platform; | |
221 | } | |
222 | suspend_test_finish("suspend devices"); | |
223 | if (suspend_test(TEST_DEVICES)) | |
224 | goto Recover_platform; | |
225 | ||
3b5fe852 MH |
226 | do { |
227 | error = suspend_enter(state, &wakeup); | |
228 | } while (!error && !wakeup | |
229 | && suspend_ops->suspend_again && suspend_ops->suspend_again()); | |
a9d70523 RW |
230 | |
231 | Resume_devices: | |
232 | suspend_test_start(); | |
233 | dpm_resume_end(PMSG_RESUME); | |
234 | suspend_test_finish("resume devices"); | |
235 | resume_console(); | |
236 | Close: | |
237 | if (suspend_ops->end) | |
238 | suspend_ops->end(); | |
938cfed1 | 239 | trace_machine_suspend(PWR_EVENT_EXIT); |
a9d70523 RW |
240 | return error; |
241 | ||
242 | Recover_platform: | |
243 | if (suspend_ops->recover) | |
244 | suspend_ops->recover(); | |
245 | goto Resume_devices; | |
246 | } | |
247 | ||
248 | /** | |
249 | * suspend_finish - Do final work before exiting suspend sequence. | |
250 | * | |
251 | * Call platform code to clean up, restart processes, and free the | |
252 | * console that we've allocated. This is not called for suspend-to-disk. | |
253 | */ | |
254 | static void suspend_finish(void) | |
255 | { | |
256 | suspend_thaw_processes(); | |
257 | usermodehelper_enable(); | |
258 | pm_notifier_call_chain(PM_POST_SUSPEND); | |
259 | pm_restore_console(); | |
260 | } | |
261 | ||
262 | /** | |
263 | * enter_state - Do common work of entering low-power state. | |
264 | * @state: pm_state structure for state we're entering. | |
265 | * | |
266 | * Make sure we're the only ones trying to enter a sleep state. Fail | |
267 | * if someone has beat us to it, since we don't want anything weird to | |
268 | * happen when we wake up. | |
269 | * Then, do the setup for suspend, enter the state, and cleaup (after | |
270 | * we've woken up). | |
271 | */ | |
272 | int enter_state(suspend_state_t state) | |
273 | { | |
274 | int error; | |
275 | ||
276 | if (!valid_state(state)) | |
277 | return -ENODEV; | |
278 | ||
279 | if (!mutex_trylock(&pm_mutex)) | |
280 | return -EBUSY; | |
281 | ||
282 | printk(KERN_INFO "PM: Syncing filesystems ... "); | |
283 | sys_sync(); | |
284 | printk("done.\n"); | |
285 | ||
286 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); | |
287 | error = suspend_prepare(); | |
288 | if (error) | |
289 | goto Unlock; | |
290 | ||
291 | if (suspend_test(TEST_FREEZER)) | |
292 | goto Finish; | |
293 | ||
294 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); | |
87186475 | 295 | pm_restrict_gfp_mask(); |
a9d70523 | 296 | error = suspend_devices_and_enter(state); |
87186475 | 297 | pm_restore_gfp_mask(); |
a9d70523 RW |
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); |