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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * kernel/power/main.c - PM subsystem core functionality. | |
3 | * | |
4 | * Copyright (c) 2003 Patrick Mochel | |
5 | * Copyright (c) 2003 Open Source Development Lab | |
6 | * | |
7 | * This file is released under the GPLv2 | |
8 | * | |
9 | */ | |
10 | ||
4cf30348 | 11 | #include <linux/module.h> |
1da177e4 LT |
12 | #include <linux/suspend.h> |
13 | #include <linux/kobject.h> | |
14 | #include <linux/string.h> | |
15 | #include <linux/delay.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/pm.h> | |
6cc07191 | 19 | #include <linux/console.h> |
e3920fb4 | 20 | #include <linux/cpu.h> |
c5c6ba4e | 21 | #include <linux/resume-trace.h> |
7dfb7103 | 22 | #include <linux/freezer.h> |
96177299 | 23 | #include <linux/vmstat.h> |
1da177e4 LT |
24 | |
25 | #include "power.h" | |
26 | ||
5ae947ec DSL |
27 | /*This is just an arbitrary number */ |
28 | #define FREE_PAGE_NUMBER (100) | |
29 | ||
a6d70980 | 30 | DEFINE_MUTEX(pm_mutex); |
1da177e4 | 31 | |
123d3c13 | 32 | struct pm_ops *pm_ops; |
9185cfa9 | 33 | suspend_disk_method_t pm_disk_mode = PM_DISK_PLATFORM; |
1da177e4 LT |
34 | |
35 | /** | |
36 | * pm_set_ops - Set the global power method table. | |
37 | * @ops: Pointer to ops structure. | |
38 | */ | |
39 | ||
40 | void pm_set_ops(struct pm_ops * ops) | |
41 | { | |
a6d70980 | 42 | mutex_lock(&pm_mutex); |
1da177e4 | 43 | pm_ops = ops; |
a6d70980 | 44 | mutex_unlock(&pm_mutex); |
1da177e4 LT |
45 | } |
46 | ||
e3c7db62 RW |
47 | static inline void pm_finish(suspend_state_t state) |
48 | { | |
49 | if (pm_ops->finish) | |
50 | pm_ops->finish(state); | |
51 | } | |
1da177e4 LT |
52 | |
53 | /** | |
54 | * suspend_prepare - Do prep work before entering low-power state. | |
55 | * @state: State we're entering. | |
56 | * | |
57 | * This is common code that is called for each state that we're | |
58 | * entering. Allocate a console, stop all processes, then make sure | |
59 | * the platform can enter the requested state. | |
60 | */ | |
61 | ||
62 | static int suspend_prepare(suspend_state_t state) | |
63 | { | |
e3920fb4 | 64 | int error; |
5ae947ec | 65 | unsigned int free_pages; |
1da177e4 LT |
66 | |
67 | if (!pm_ops || !pm_ops->enter) | |
68 | return -EPERM; | |
69 | ||
70 | pm_prepare_console(); | |
71 | ||
72 | if (freeze_processes()) { | |
73 | error = -EAGAIN; | |
74 | goto Thaw; | |
75 | } | |
76 | ||
96177299 CL |
77 | if ((free_pages = global_page_state(NR_FREE_PAGES)) |
78 | < FREE_PAGE_NUMBER) { | |
5ae947ec DSL |
79 | pr_debug("PM: free some memory\n"); |
80 | shrink_all_memory(FREE_PAGE_NUMBER - free_pages); | |
81 | if (nr_free_pages() < FREE_PAGE_NUMBER) { | |
82 | error = -ENOMEM; | |
83 | printk(KERN_ERR "PM: No enough memory\n"); | |
84 | goto Thaw; | |
85 | } | |
86 | } | |
87 | ||
1da177e4 LT |
88 | if (pm_ops->prepare) { |
89 | if ((error = pm_ops->prepare(state))) | |
90 | goto Thaw; | |
91 | } | |
92 | ||
557240b4 | 93 | suspend_console(); |
e3c7db62 RW |
94 | error = device_suspend(PMSG_SUSPEND); |
95 | if (error) { | |
1da177e4 | 96 | printk(KERN_ERR "Some devices failed to suspend\n"); |
e3c7db62 | 97 | goto Resume_devices; |
1da177e4 | 98 | } |
e3c7db62 RW |
99 | error = disable_nonboot_cpus(); |
100 | if (!error) | |
101 | return 0; | |
102 | ||
103 | enable_nonboot_cpus(); | |
104 | Resume_devices: | |
105 | pm_finish(state); | |
106 | device_resume(); | |
107 | resume_console(); | |
1da177e4 LT |
108 | Thaw: |
109 | thaw_processes(); | |
110 | pm_restore_console(); | |
111 | return error; | |
112 | } | |
113 | ||
114 | ||
9b238205 | 115 | int suspend_enter(suspend_state_t state) |
1da177e4 LT |
116 | { |
117 | int error = 0; | |
118 | unsigned long flags; | |
119 | ||
120 | local_irq_save(flags); | |
121 | ||
122 | if ((error = device_power_down(PMSG_SUSPEND))) { | |
123 | printk(KERN_ERR "Some devices failed to power down\n"); | |
124 | goto Done; | |
125 | } | |
126 | error = pm_ops->enter(state); | |
127 | device_power_up(); | |
128 | Done: | |
129 | local_irq_restore(flags); | |
130 | return error; | |
131 | } | |
132 | ||
133 | ||
134 | /** | |
135 | * suspend_finish - Do final work before exiting suspend sequence. | |
136 | * @state: State we're coming out of. | |
137 | * | |
138 | * Call platform code to clean up, restart processes, and free the | |
139 | * console that we've allocated. This is not called for suspend-to-disk. | |
140 | */ | |
141 | ||
142 | static void suspend_finish(suspend_state_t state) | |
143 | { | |
e3c7db62 RW |
144 | enable_nonboot_cpus(); |
145 | pm_finish(state); | |
1da177e4 | 146 | device_resume(); |
557240b4 | 147 | resume_console(); |
1da177e4 LT |
148 | thaw_processes(); |
149 | pm_restore_console(); | |
150 | } | |
151 | ||
152 | ||
153 | ||
154 | ||
3b364b8d | 155 | static const char * const pm_states[PM_SUSPEND_MAX] = { |
1da177e4 LT |
156 | [PM_SUSPEND_STANDBY] = "standby", |
157 | [PM_SUSPEND_MEM] = "mem", | |
57c4ce3c | 158 | #ifdef CONFIG_SOFTWARE_SUSPEND |
1da177e4 | 159 | [PM_SUSPEND_DISK] = "disk", |
57c4ce3c | 160 | #endif |
1da177e4 LT |
161 | }; |
162 | ||
123d3c13 PM |
163 | static inline int valid_state(suspend_state_t state) |
164 | { | |
165 | /* Suspend-to-disk does not really need low-level support. | |
166 | * It can work with reboot if needed. */ | |
167 | if (state == PM_SUSPEND_DISK) | |
168 | return 1; | |
169 | ||
9c372d06 JB |
170 | /* all other states need lowlevel support and need to be |
171 | * valid to the lowlevel implementation, no valid callback | |
172 | * implies that all are valid. */ | |
173 | if (!pm_ops || (pm_ops->valid && !pm_ops->valid(state))) | |
123d3c13 PM |
174 | return 0; |
175 | return 1; | |
176 | } | |
177 | ||
1da177e4 LT |
178 | |
179 | /** | |
180 | * enter_state - Do common work of entering low-power state. | |
181 | * @state: pm_state structure for state we're entering. | |
182 | * | |
183 | * Make sure we're the only ones trying to enter a sleep state. Fail | |
184 | * if someone has beat us to it, since we don't want anything weird to | |
185 | * happen when we wake up. | |
186 | * Then, do the setup for suspend, enter the state, and cleaup (after | |
187 | * we've woken up). | |
188 | */ | |
189 | ||
190 | static int enter_state(suspend_state_t state) | |
191 | { | |
192 | int error; | |
193 | ||
123d3c13 | 194 | if (!valid_state(state)) |
eb9289eb | 195 | return -ENODEV; |
a6d70980 | 196 | if (!mutex_trylock(&pm_mutex)) |
1da177e4 LT |
197 | return -EBUSY; |
198 | ||
199 | if (state == PM_SUSPEND_DISK) { | |
200 | error = pm_suspend_disk(); | |
201 | goto Unlock; | |
202 | } | |
203 | ||
82428b62 | 204 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); |
1da177e4 LT |
205 | if ((error = suspend_prepare(state))) |
206 | goto Unlock; | |
207 | ||
82428b62 | 208 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); |
1da177e4 LT |
209 | error = suspend_enter(state); |
210 | ||
82428b62 | 211 | pr_debug("PM: Finishing wakeup.\n"); |
1da177e4 LT |
212 | suspend_finish(state); |
213 | Unlock: | |
a6d70980 | 214 | mutex_unlock(&pm_mutex); |
1da177e4 LT |
215 | return error; |
216 | } | |
217 | ||
218 | /* | |
219 | * This is main interface to the outside world. It needs to be | |
220 | * called from process context. | |
221 | */ | |
222 | int software_suspend(void) | |
223 | { | |
224 | return enter_state(PM_SUSPEND_DISK); | |
225 | } | |
226 | ||
227 | ||
228 | /** | |
229 | * pm_suspend - Externally visible function for suspending system. | |
230 | * @state: Enumarted value of state to enter. | |
231 | * | |
232 | * Determine whether or not value is within range, get state | |
233 | * structure, and enter (above). | |
234 | */ | |
235 | ||
236 | int pm_suspend(suspend_state_t state) | |
237 | { | |
e2a5b420 | 238 | if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) |
1da177e4 LT |
239 | return enter_state(state); |
240 | return -EINVAL; | |
241 | } | |
242 | ||
4cf30348 | 243 | EXPORT_SYMBOL(pm_suspend); |
1da177e4 LT |
244 | |
245 | decl_subsys(power,NULL,NULL); | |
246 | ||
247 | ||
248 | /** | |
249 | * state - control system power state. | |
250 | * | |
251 | * show() returns what states are supported, which is hard-coded to | |
252 | * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and | |
253 | * 'disk' (Suspend-to-Disk). | |
254 | * | |
255 | * store() accepts one of those strings, translates it into the | |
256 | * proper enumerated value, and initiates a suspend transition. | |
257 | */ | |
258 | ||
259 | static ssize_t state_show(struct subsystem * subsys, char * buf) | |
260 | { | |
261 | int i; | |
262 | char * s = buf; | |
263 | ||
264 | for (i = 0; i < PM_SUSPEND_MAX; i++) { | |
123d3c13 PM |
265 | if (pm_states[i] && valid_state(i)) |
266 | s += sprintf(s,"%s ", pm_states[i]); | |
1da177e4 LT |
267 | } |
268 | s += sprintf(s,"\n"); | |
269 | return (s - buf); | |
270 | } | |
271 | ||
272 | static ssize_t state_store(struct subsystem * subsys, const char * buf, size_t n) | |
273 | { | |
274 | suspend_state_t state = PM_SUSPEND_STANDBY; | |
3b364b8d | 275 | const char * const *s; |
1da177e4 LT |
276 | char *p; |
277 | int error; | |
278 | int len; | |
279 | ||
280 | p = memchr(buf, '\n', n); | |
281 | len = p ? p - buf : n; | |
282 | ||
283 | for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) { | |
284 | if (*s && !strncmp(buf, *s, len)) | |
285 | break; | |
286 | } | |
47bb7899 | 287 | if (state < PM_SUSPEND_MAX && *s) |
1da177e4 LT |
288 | error = enter_state(state); |
289 | else | |
290 | error = -EINVAL; | |
291 | return error ? error : n; | |
292 | } | |
293 | ||
294 | power_attr(state); | |
295 | ||
c5c6ba4e RW |
296 | #ifdef CONFIG_PM_TRACE |
297 | int pm_trace_enabled; | |
298 | ||
299 | static ssize_t pm_trace_show(struct subsystem * subsys, char * buf) | |
300 | { | |
301 | return sprintf(buf, "%d\n", pm_trace_enabled); | |
302 | } | |
303 | ||
304 | static ssize_t | |
305 | pm_trace_store(struct subsystem * subsys, const char * buf, size_t n) | |
306 | { | |
307 | int val; | |
308 | ||
309 | if (sscanf(buf, "%d", &val) == 1) { | |
310 | pm_trace_enabled = !!val; | |
311 | return n; | |
312 | } | |
313 | return -EINVAL; | |
314 | } | |
315 | ||
316 | power_attr(pm_trace); | |
317 | ||
318 | static struct attribute * g[] = { | |
319 | &state_attr.attr, | |
320 | &pm_trace_attr.attr, | |
321 | NULL, | |
322 | }; | |
323 | #else | |
1da177e4 LT |
324 | static struct attribute * g[] = { |
325 | &state_attr.attr, | |
326 | NULL, | |
327 | }; | |
c5c6ba4e | 328 | #endif /* CONFIG_PM_TRACE */ |
1da177e4 LT |
329 | |
330 | static struct attribute_group attr_group = { | |
331 | .attrs = g, | |
332 | }; | |
333 | ||
334 | ||
335 | static int __init pm_init(void) | |
336 | { | |
337 | int error = subsystem_register(&power_subsys); | |
338 | if (!error) | |
339 | error = sysfs_create_group(&power_subsys.kset.kobj,&attr_group); | |
340 | return error; | |
341 | } | |
342 | ||
343 | core_initcall(pm_init); |