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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> | |
a9d70523 RW |
25 | |
26 | #include "power.h" | |
27 | ||
28 | const char *const pm_states[PM_SUSPEND_MAX] = { | |
29 | [PM_SUSPEND_STANDBY] = "standby", | |
30 | [PM_SUSPEND_MEM] = "mem", | |
31 | }; | |
32 | ||
33 | static struct platform_suspend_ops *suspend_ops; | |
34 | ||
35 | /** | |
36 | * suspend_set_ops - Set the global suspend method table. | |
37 | * @ops: Pointer to ops structure. | |
38 | */ | |
39 | void suspend_set_ops(struct platform_suspend_ops *ops) | |
40 | { | |
41 | mutex_lock(&pm_mutex); | |
42 | suspend_ops = ops; | |
43 | mutex_unlock(&pm_mutex); | |
44 | } | |
45 | ||
46 | bool valid_state(suspend_state_t state) | |
47 | { | |
48 | /* | |
49 | * All states need lowlevel support and need to be valid to the lowlevel | |
50 | * implementation, no valid callback implies that none are valid. | |
51 | */ | |
52 | return suspend_ops && suspend_ops->valid && suspend_ops->valid(state); | |
53 | } | |
54 | ||
55 | /** | |
56 | * suspend_valid_only_mem - generic memory-only valid callback | |
57 | * | |
58 | * Platform drivers that implement mem suspend only and only need | |
59 | * to check for that in their .valid callback can use this instead | |
60 | * of rolling their own .valid callback. | |
61 | */ | |
62 | int suspend_valid_only_mem(suspend_state_t state) | |
63 | { | |
64 | return state == PM_SUSPEND_MEM; | |
65 | } | |
66 | ||
67 | static int suspend_test(int level) | |
68 | { | |
69 | #ifdef CONFIG_PM_DEBUG | |
70 | if (pm_test_level == level) { | |
71 | printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); | |
72 | mdelay(5000); | |
73 | return 1; | |
74 | } | |
75 | #endif /* !CONFIG_PM_DEBUG */ | |
76 | return 0; | |
77 | } | |
78 | ||
79 | /** | |
80 | * suspend_prepare - Do prep work before entering low-power state. | |
81 | * | |
82 | * This is common code that is called for each state that we're entering. | |
83 | * Run suspend notifiers, allocate a console and stop all processes. | |
84 | */ | |
85 | static int suspend_prepare(void) | |
86 | { | |
87 | int error; | |
88 | ||
89 | if (!suspend_ops || !suspend_ops->enter) | |
90 | return -EPERM; | |
91 | ||
92 | pm_prepare_console(); | |
93 | ||
94 | error = pm_notifier_call_chain(PM_SUSPEND_PREPARE); | |
95 | if (error) | |
96 | goto Finish; | |
97 | ||
98 | error = usermodehelper_disable(); | |
99 | if (error) | |
100 | goto Finish; | |
101 | ||
102 | error = suspend_freeze_processes(); | |
103 | if (!error) | |
104 | return 0; | |
105 | ||
106 | suspend_thaw_processes(); | |
107 | usermodehelper_enable(); | |
108 | Finish: | |
109 | pm_notifier_call_chain(PM_POST_SUSPEND); | |
110 | pm_restore_console(); | |
111 | return error; | |
112 | } | |
113 | ||
114 | /* default implementation */ | |
115 | void __attribute__ ((weak)) arch_suspend_disable_irqs(void) | |
116 | { | |
117 | local_irq_disable(); | |
118 | } | |
119 | ||
120 | /* default implementation */ | |
121 | void __attribute__ ((weak)) arch_suspend_enable_irqs(void) | |
122 | { | |
123 | local_irq_enable(); | |
124 | } | |
125 | ||
126 | /** | |
127 | * suspend_enter - enter the desired system sleep state. | |
128 | * @state: state to enter | |
129 | * | |
130 | * This function should be called after devices have been suspended. | |
131 | */ | |
132 | static int suspend_enter(suspend_state_t state) | |
133 | { | |
134 | int error; | |
135 | ||
136 | if (suspend_ops->prepare) { | |
137 | error = suspend_ops->prepare(); | |
138 | if (error) | |
139 | return error; | |
140 | } | |
141 | ||
142 | error = dpm_suspend_noirq(PMSG_SUSPEND); | |
143 | if (error) { | |
144 | printk(KERN_ERR "PM: Some devices failed to power down\n"); | |
145 | goto Platfrom_finish; | |
146 | } | |
147 | ||
148 | if (suspend_ops->prepare_late) { | |
149 | error = suspend_ops->prepare_late(); | |
150 | if (error) | |
151 | goto Power_up_devices; | |
152 | } | |
153 | ||
154 | if (suspend_test(TEST_PLATFORM)) | |
155 | goto Platform_wake; | |
156 | ||
157 | error = disable_nonboot_cpus(); | |
158 | if (error || suspend_test(TEST_CPUS)) | |
159 | goto Enable_cpus; | |
160 | ||
161 | arch_suspend_disable_irqs(); | |
162 | BUG_ON(!irqs_disabled()); | |
163 | ||
164 | error = sysdev_suspend(PMSG_SUSPEND); | |
165 | if (!error) { | |
166 | if (!suspend_test(TEST_CORE)) | |
167 | error = suspend_ops->enter(state); | |
168 | sysdev_resume(); | |
169 | } | |
170 | ||
171 | arch_suspend_enable_irqs(); | |
172 | BUG_ON(irqs_disabled()); | |
173 | ||
174 | Enable_cpus: | |
175 | enable_nonboot_cpus(); | |
176 | ||
177 | Platform_wake: | |
178 | if (suspend_ops->wake) | |
179 | suspend_ops->wake(); | |
180 | ||
181 | Power_up_devices: | |
182 | dpm_resume_noirq(PMSG_RESUME); | |
183 | ||
184 | Platfrom_finish: | |
185 | if (suspend_ops->finish) | |
186 | suspend_ops->finish(); | |
187 | ||
188 | return error; | |
189 | } | |
190 | ||
191 | /** | |
192 | * suspend_devices_and_enter - suspend devices and enter the desired system | |
193 | * sleep state. | |
194 | * @state: state to enter | |
195 | */ | |
196 | int suspend_devices_and_enter(suspend_state_t state) | |
197 | { | |
198 | int error; | |
452aa699 | 199 | gfp_t saved_mask; |
a9d70523 RW |
200 | |
201 | if (!suspend_ops) | |
202 | return -ENOSYS; | |
203 | ||
204 | if (suspend_ops->begin) { | |
205 | error = suspend_ops->begin(state); | |
206 | if (error) | |
207 | goto Close; | |
208 | } | |
209 | suspend_console(); | |
452aa699 | 210 | saved_mask = clear_gfp_allowed_mask(GFP_IOFS); |
a9d70523 RW |
211 | suspend_test_start(); |
212 | error = dpm_suspend_start(PMSG_SUSPEND); | |
213 | if (error) { | |
214 | printk(KERN_ERR "PM: Some devices failed to suspend\n"); | |
215 | goto Recover_platform; | |
216 | } | |
217 | suspend_test_finish("suspend devices"); | |
218 | if (suspend_test(TEST_DEVICES)) | |
219 | goto Recover_platform; | |
220 | ||
221 | suspend_enter(state); | |
222 | ||
223 | Resume_devices: | |
224 | suspend_test_start(); | |
225 | dpm_resume_end(PMSG_RESUME); | |
226 | suspend_test_finish("resume devices"); | |
452aa699 | 227 | set_gfp_allowed_mask(saved_mask); |
a9d70523 RW |
228 | resume_console(); |
229 | Close: | |
230 | if (suspend_ops->end) | |
231 | suspend_ops->end(); | |
232 | return error; | |
233 | ||
234 | Recover_platform: | |
235 | if (suspend_ops->recover) | |
236 | suspend_ops->recover(); | |
237 | goto Resume_devices; | |
238 | } | |
239 | ||
240 | /** | |
241 | * suspend_finish - Do final work before exiting suspend sequence. | |
242 | * | |
243 | * Call platform code to clean up, restart processes, and free the | |
244 | * console that we've allocated. This is not called for suspend-to-disk. | |
245 | */ | |
246 | static void suspend_finish(void) | |
247 | { | |
248 | suspend_thaw_processes(); | |
249 | usermodehelper_enable(); | |
250 | pm_notifier_call_chain(PM_POST_SUSPEND); | |
251 | pm_restore_console(); | |
252 | } | |
253 | ||
254 | /** | |
255 | * enter_state - Do common work of entering low-power state. | |
256 | * @state: pm_state structure for state we're entering. | |
257 | * | |
258 | * Make sure we're the only ones trying to enter a sleep state. Fail | |
259 | * if someone has beat us to it, since we don't want anything weird to | |
260 | * happen when we wake up. | |
261 | * Then, do the setup for suspend, enter the state, and cleaup (after | |
262 | * we've woken up). | |
263 | */ | |
264 | int enter_state(suspend_state_t state) | |
265 | { | |
266 | int error; | |
267 | ||
268 | if (!valid_state(state)) | |
269 | return -ENODEV; | |
270 | ||
271 | if (!mutex_trylock(&pm_mutex)) | |
272 | return -EBUSY; | |
273 | ||
274 | printk(KERN_INFO "PM: Syncing filesystems ... "); | |
275 | sys_sync(); | |
276 | printk("done.\n"); | |
277 | ||
278 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); | |
279 | error = suspend_prepare(); | |
280 | if (error) | |
281 | goto Unlock; | |
282 | ||
283 | if (suspend_test(TEST_FREEZER)) | |
284 | goto Finish; | |
285 | ||
286 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); | |
287 | error = suspend_devices_and_enter(state); | |
288 | ||
289 | Finish: | |
290 | pr_debug("PM: Finishing wakeup.\n"); | |
291 | suspend_finish(); | |
292 | Unlock: | |
293 | mutex_unlock(&pm_mutex); | |
294 | return error; | |
295 | } | |
296 | ||
297 | /** | |
298 | * pm_suspend - Externally visible function for suspending system. | |
299 | * @state: Enumerated value of state to enter. | |
300 | * | |
301 | * Determine whether or not value is within range, get state | |
302 | * structure, and enter (above). | |
303 | */ | |
304 | int pm_suspend(suspend_state_t state) | |
305 | { | |
306 | if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) | |
307 | return enter_state(state); | |
308 | return -EINVAL; | |
309 | } | |
310 | EXPORT_SYMBOL(pm_suspend); |