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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> |
a9d70523 RW |
19 | |
20 | #include "power.h" | |
21 | ||
22 | const char *const pm_states[PM_SUSPEND_MAX] = { | |
23 | [PM_SUSPEND_STANDBY] = "standby", | |
24 | [PM_SUSPEND_MEM] = "mem", | |
25 | }; | |
26 | ||
27 | static struct platform_suspend_ops *suspend_ops; | |
28 | ||
29 | /** | |
30 | * suspend_set_ops - Set the global suspend method table. | |
31 | * @ops: Pointer to ops structure. | |
32 | */ | |
33 | void suspend_set_ops(struct platform_suspend_ops *ops) | |
34 | { | |
35 | mutex_lock(&pm_mutex); | |
36 | suspend_ops = ops; | |
37 | mutex_unlock(&pm_mutex); | |
38 | } | |
39 | ||
40 | bool valid_state(suspend_state_t state) | |
41 | { | |
42 | /* | |
43 | * All states need lowlevel support and need to be valid to the lowlevel | |
44 | * implementation, no valid callback implies that none are valid. | |
45 | */ | |
46 | return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); | |
47 | } | |
48 | ||
49 | /** | |
50 | * suspend_valid_only_mem - generic memory-only valid callback | |
51 | * | |
52 | * Platform drivers that implement mem suspend only and only need | |
53 | * to check for that in their .valid callback can use this instead | |
54 | * of rolling their own .valid callback. | |
55 | */ | |
56 | int suspend_valid_only_mem(suspend_state_t state) | |
57 | { | |
58 | return state == PM_SUSPEND_MEM; | |
59 | } | |
60 | ||
61 | static int suspend_test(int level) | |
62 | { | |
63 | #ifdef CONFIG_PM_DEBUG | |
64 | if (pm_test_level == level) { | |
65 | printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); | |
66 | mdelay(5000); | |
67 | return 1; | |
68 | } | |
69 | #endif /* !CONFIG_PM_DEBUG */ | |
70 | return 0; | |
71 | } | |
72 | ||
73 | /** | |
74 | * suspend_prepare - Do prep work before entering low-power state. | |
75 | * | |
76 | * This is common code that is called for each state that we're entering. | |
77 | * Run suspend notifiers, allocate a console and stop all processes. | |
78 | */ | |
79 | static int suspend_prepare(void) | |
80 | { | |
81 | int error; | |
82 | ||
83 | if (!suspend_ops || !suspend_ops->enter) | |
84 | return -EPERM; | |
85 | ||
86 | pm_prepare_console(); | |
87 | ||
88 | error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); | |
89 | if (error) | |
90 | goto Finish; | |
91 | ||
92 | error = usermodehelper_disable(); | |
93 | if (error) | |
94 | goto Finish; | |
95 | ||
96 | error = suspend_freeze_processes(); | |
97 | if (!error) | |
98 | return 0; | |
99 | ||
100 | suspend_thaw_processes(); | |
101 | usermodehelper_enable(); | |
102 | Finish: | |
103 | pm_notifier_call_chain(PM_POST_SUSPEND); | |
104 | pm_restore_console(); | |
105 | return error; | |
106 | } | |
107 | ||
108 | /* default implementation */ | |
109 | void __attribute__ ((weak)) arch_suspend_disable_irqs(void) | |
110 | { | |
111 | local_irq_disable(); | |
112 | } | |
113 | ||
114 | /* default implementation */ | |
115 | void __attribute__ ((weak)) arch_suspend_enable_irqs(void) | |
116 | { | |
117 | local_irq_enable(); | |
118 | } | |
119 | ||
120 | /** | |
121 | * suspend_enter - enter the desired system sleep state. | |
122 | * @state: state to enter | |
123 | * | |
124 | * This function should be called after devices have been suspended. | |
125 | */ | |
126 | static int suspend_enter(suspend_state_t state) | |
127 | { | |
128 | int error; | |
129 | ||
130 | if (suspend_ops->prepare) { | |
131 | error = suspend_ops->prepare(); | |
132 | if (error) | |
133 | return error; | |
134 | } | |
135 | ||
136 | error = dpm_suspend_noirq(PMSG_SUSPEND); | |
137 | if (error) { | |
138 | printk(KERN_ERR "PM: Some devices failed to power down\n"); | |
139 | goto Platfrom_finish; | |
140 | } | |
141 | ||
142 | if (suspend_ops->prepare_late) { | |
143 | error = suspend_ops->prepare_late(); | |
144 | if (error) | |
145 | goto Power_up_devices; | |
146 | } | |
147 | ||
148 | if (suspend_test(TEST_PLATFORM)) | |
149 | goto Platform_wake; | |
150 | ||
151 | error = disable_nonboot_cpus(); | |
152 | if (error || suspend_test(TEST_CPUS)) | |
153 | goto Enable_cpus; | |
154 | ||
155 | arch_suspend_disable_irqs(); | |
156 | BUG_ON(!irqs_disabled()); | |
157 | ||
158 | error = sysdev_suspend(PMSG_SUSPEND); | |
159 | if (!error) { | |
160 | if (!suspend_test(TEST_CORE)) | |
161 | error = suspend_ops->enter(state); | |
162 | sysdev_resume(); | |
163 | } | |
164 | ||
165 | arch_suspend_enable_irqs(); | |
166 | BUG_ON(irqs_disabled()); | |
167 | ||
168 | Enable_cpus: | |
169 | enable_nonboot_cpus(); | |
170 | ||
171 | Platform_wake: | |
172 | if (suspend_ops->wake) | |
173 | suspend_ops->wake(); | |
174 | ||
175 | Power_up_devices: | |
176 | dpm_resume_noirq(PMSG_RESUME); | |
177 | ||
178 | Platfrom_finish: | |
179 | if (suspend_ops->finish) | |
180 | suspend_ops->finish(); | |
181 | ||
182 | return error; | |
183 | } | |
184 | ||
185 | /** | |
186 | * suspend_devices_and_enter - suspend devices and enter the desired system | |
187 | * sleep state. | |
188 | * @state: state to enter | |
189 | */ | |
190 | int suspend_devices_and_enter(suspend_state_t state) | |
191 | { | |
192 | int error; | |
452aa699 | 193 | gfp_t saved_mask; |
a9d70523 RW |
194 | |
195 | if (!suspend_ops) | |
196 | return -ENOSYS; | |
197 | ||
198 | if (suspend_ops->begin) { | |
199 | error = suspend_ops->begin(state); | |
200 | if (error) | |
201 | goto Close; | |
202 | } | |
203 | suspend_console(); | |
452aa699 | 204 | saved_mask = clear_gfp_allowed_mask(GFP_IOFS); |
a9d70523 RW |
205 | suspend_test_start(); |
206 | error = dpm_suspend_start(PMSG_SUSPEND); | |
207 | if (error) { | |
208 | printk(KERN_ERR "PM: Some devices failed to suspend\n"); | |
209 | goto Recover_platform; | |
210 | } | |
211 | suspend_test_finish("suspend devices"); | |
212 | if (suspend_test(TEST_DEVICES)) | |
213 | goto Recover_platform; | |
214 | ||
215 | suspend_enter(state); | |
216 | ||
217 | Resume_devices: | |
218 | suspend_test_start(); | |
219 | dpm_resume_end(PMSG_RESUME); | |
220 | suspend_test_finish("resume devices"); | |
452aa699 | 221 | set_gfp_allowed_mask(saved_mask); |
a9d70523 RW |
222 | resume_console(); |
223 | Close: | |
224 | if (suspend_ops->end) | |
225 | suspend_ops->end(); | |
226 | return error; | |
227 | ||
228 | Recover_platform: | |
229 | if (suspend_ops->recover) | |
230 | suspend_ops->recover(); | |
231 | goto Resume_devices; | |
232 | } | |
233 | ||
234 | /** | |
235 | * suspend_finish - Do final work before exiting suspend sequence. | |
236 | * | |
237 | * Call platform code to clean up, restart processes, and free the | |
238 | * console that we've allocated. This is not called for suspend-to-disk. | |
239 | */ | |
240 | static void suspend_finish(void) | |
241 | { | |
242 | suspend_thaw_processes(); | |
243 | usermodehelper_enable(); | |
244 | pm_notifier_call_chain(PM_POST_SUSPEND); | |
245 | pm_restore_console(); | |
246 | } | |
247 | ||
248 | /** | |
249 | * enter_state - Do common work of entering low-power state. | |
250 | * @state: pm_state structure for state we're entering. | |
251 | * | |
252 | * Make sure we're the only ones trying to enter a sleep state. Fail | |
253 | * if someone has beat us to it, since we don't want anything weird to | |
254 | * happen when we wake up. | |
255 | * Then, do the setup for suspend, enter the state, and cleaup (after | |
256 | * we've woken up). | |
257 | */ | |
258 | int enter_state(suspend_state_t state) | |
259 | { | |
260 | int error; | |
261 | ||
262 | if (!valid_state(state)) | |
263 | return -ENODEV; | |
264 | ||
265 | if (!mutex_trylock(&pm_mutex)) | |
266 | return -EBUSY; | |
267 | ||
268 | printk(KERN_INFO "PM: Syncing filesystems ... "); | |
269 | sys_sync(); | |
270 | printk("done.\n"); | |
271 | ||
272 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); | |
273 | error = suspend_prepare(); | |
274 | if (error) | |
275 | goto Unlock; | |
276 | ||
277 | if (suspend_test(TEST_FREEZER)) | |
278 | goto Finish; | |
279 | ||
280 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); | |
281 | error = suspend_devices_and_enter(state); | |
282 | ||
283 | Finish: | |
284 | pr_debug("PM: Finishing wakeup.\n"); | |
285 | suspend_finish(); | |
286 | Unlock: | |
287 | mutex_unlock(&pm_mutex); | |
288 | return error; | |
289 | } | |
290 | ||
291 | /** | |
292 | * pm_suspend - Externally visible function for suspending system. | |
293 | * @state: Enumerated value of state to enter. | |
294 | * | |
295 | * Determine whether or not value is within range, get state | |
296 | * structure, and enter (above). | |
297 | */ | |
298 | int pm_suspend(suspend_state_t state) | |
299 | { | |
300 | if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) | |
301 | return enter_state(state); | |
302 | return -EINVAL; | |
303 | } | |
304 | EXPORT_SYMBOL(pm_suspend); |