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 | ||
11 | #include <linux/suspend.h> | |
12 | #include <linux/kobject.h> | |
13 | #include <linux/string.h> | |
14 | #include <linux/delay.h> | |
15 | #include <linux/errno.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/pm.h> | |
18 | ||
19 | ||
20 | #include "power.h" | |
21 | ||
5ae947ec DSL |
22 | /*This is just an arbitrary number */ |
23 | #define FREE_PAGE_NUMBER (100) | |
24 | ||
1da177e4 LT |
25 | DECLARE_MUTEX(pm_sem); |
26 | ||
123d3c13 | 27 | struct pm_ops *pm_ops; |
1da177e4 LT |
28 | suspend_disk_method_t pm_disk_mode = PM_DISK_SHUTDOWN; |
29 | ||
30 | /** | |
31 | * pm_set_ops - Set the global power method table. | |
32 | * @ops: Pointer to ops structure. | |
33 | */ | |
34 | ||
35 | void pm_set_ops(struct pm_ops * ops) | |
36 | { | |
37 | down(&pm_sem); | |
38 | pm_ops = ops; | |
39 | up(&pm_sem); | |
40 | } | |
41 | ||
42 | ||
43 | /** | |
44 | * suspend_prepare - Do prep work before entering low-power state. | |
45 | * @state: State we're entering. | |
46 | * | |
47 | * This is common code that is called for each state that we're | |
48 | * entering. Allocate a console, stop all processes, then make sure | |
49 | * the platform can enter the requested state. | |
50 | */ | |
51 | ||
52 | static int suspend_prepare(suspend_state_t state) | |
53 | { | |
54 | int error = 0; | |
5ae947ec | 55 | unsigned int free_pages; |
1da177e4 LT |
56 | |
57 | if (!pm_ops || !pm_ops->enter) | |
58 | return -EPERM; | |
59 | ||
60 | pm_prepare_console(); | |
61 | ||
5a72e04d LS |
62 | disable_nonboot_cpus(); |
63 | ||
64 | if (num_online_cpus() != 1) { | |
65 | error = -EPERM; | |
66 | goto Enable_cpu; | |
67 | } | |
68 | ||
1da177e4 LT |
69 | if (freeze_processes()) { |
70 | error = -EAGAIN; | |
71 | goto Thaw; | |
72 | } | |
73 | ||
5ae947ec DSL |
74 | if ((free_pages = nr_free_pages()) < FREE_PAGE_NUMBER) { |
75 | pr_debug("PM: free some memory\n"); | |
76 | shrink_all_memory(FREE_PAGE_NUMBER - free_pages); | |
77 | if (nr_free_pages() < FREE_PAGE_NUMBER) { | |
78 | error = -ENOMEM; | |
79 | printk(KERN_ERR "PM: No enough memory\n"); | |
80 | goto Thaw; | |
81 | } | |
82 | } | |
83 | ||
1da177e4 LT |
84 | if (pm_ops->prepare) { |
85 | if ((error = pm_ops->prepare(state))) | |
86 | goto Thaw; | |
87 | } | |
88 | ||
557240b4 | 89 | suspend_console(); |
1da177e4 LT |
90 | if ((error = device_suspend(PMSG_SUSPEND))) { |
91 | printk(KERN_ERR "Some devices failed to suspend\n"); | |
92 | goto Finish; | |
93 | } | |
94 | return 0; | |
95 | Finish: | |
96 | if (pm_ops->finish) | |
97 | pm_ops->finish(state); | |
98 | Thaw: | |
99 | thaw_processes(); | |
5a72e04d LS |
100 | Enable_cpu: |
101 | enable_nonboot_cpus(); | |
1da177e4 LT |
102 | pm_restore_console(); |
103 | return error; | |
104 | } | |
105 | ||
106 | ||
9b238205 | 107 | int suspend_enter(suspend_state_t state) |
1da177e4 LT |
108 | { |
109 | int error = 0; | |
110 | unsigned long flags; | |
111 | ||
112 | local_irq_save(flags); | |
113 | ||
114 | if ((error = device_power_down(PMSG_SUSPEND))) { | |
115 | printk(KERN_ERR "Some devices failed to power down\n"); | |
116 | goto Done; | |
117 | } | |
118 | error = pm_ops->enter(state); | |
119 | device_power_up(); | |
120 | Done: | |
121 | local_irq_restore(flags); | |
122 | return error; | |
123 | } | |
124 | ||
125 | ||
126 | /** | |
127 | * suspend_finish - Do final work before exiting suspend sequence. | |
128 | * @state: State we're coming out of. | |
129 | * | |
130 | * Call platform code to clean up, restart processes, and free the | |
131 | * console that we've allocated. This is not called for suspend-to-disk. | |
132 | */ | |
133 | ||
134 | static void suspend_finish(suspend_state_t state) | |
135 | { | |
136 | device_resume(); | |
557240b4 | 137 | resume_console(); |
1da177e4 | 138 | thaw_processes(); |
5a72e04d | 139 | enable_nonboot_cpus(); |
1a38416c DSL |
140 | if (pm_ops && pm_ops->finish) |
141 | pm_ops->finish(state); | |
1da177e4 LT |
142 | pm_restore_console(); |
143 | } | |
144 | ||
145 | ||
146 | ||
147 | ||
57c4ce3c | 148 | static char *pm_states[PM_SUSPEND_MAX] = { |
1da177e4 LT |
149 | [PM_SUSPEND_STANDBY] = "standby", |
150 | [PM_SUSPEND_MEM] = "mem", | |
57c4ce3c | 151 | #ifdef CONFIG_SOFTWARE_SUSPEND |
1da177e4 | 152 | [PM_SUSPEND_DISK] = "disk", |
57c4ce3c | 153 | #endif |
1da177e4 LT |
154 | }; |
155 | ||
123d3c13 PM |
156 | static inline int valid_state(suspend_state_t state) |
157 | { | |
158 | /* Suspend-to-disk does not really need low-level support. | |
159 | * It can work with reboot if needed. */ | |
160 | if (state == PM_SUSPEND_DISK) | |
161 | return 1; | |
162 | ||
163 | if (pm_ops && pm_ops->valid && !pm_ops->valid(state)) | |
164 | return 0; | |
165 | return 1; | |
166 | } | |
167 | ||
1da177e4 LT |
168 | |
169 | /** | |
170 | * enter_state - Do common work of entering low-power state. | |
171 | * @state: pm_state structure for state we're entering. | |
172 | * | |
173 | * Make sure we're the only ones trying to enter a sleep state. Fail | |
174 | * if someone has beat us to it, since we don't want anything weird to | |
175 | * happen when we wake up. | |
176 | * Then, do the setup for suspend, enter the state, and cleaup (after | |
177 | * we've woken up). | |
178 | */ | |
179 | ||
180 | static int enter_state(suspend_state_t state) | |
181 | { | |
182 | int error; | |
183 | ||
123d3c13 | 184 | if (!valid_state(state)) |
eb9289eb | 185 | return -ENODEV; |
1da177e4 LT |
186 | if (down_trylock(&pm_sem)) |
187 | return -EBUSY; | |
188 | ||
189 | if (state == PM_SUSPEND_DISK) { | |
190 | error = pm_suspend_disk(); | |
191 | goto Unlock; | |
192 | } | |
193 | ||
82428b62 | 194 | pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]); |
1da177e4 LT |
195 | if ((error = suspend_prepare(state))) |
196 | goto Unlock; | |
197 | ||
82428b62 | 198 | pr_debug("PM: Entering %s sleep\n", pm_states[state]); |
1da177e4 LT |
199 | error = suspend_enter(state); |
200 | ||
82428b62 | 201 | pr_debug("PM: Finishing wakeup.\n"); |
1da177e4 LT |
202 | suspend_finish(state); |
203 | Unlock: | |
204 | up(&pm_sem); | |
205 | return error; | |
206 | } | |
207 | ||
208 | /* | |
209 | * This is main interface to the outside world. It needs to be | |
210 | * called from process context. | |
211 | */ | |
212 | int software_suspend(void) | |
213 | { | |
214 | return enter_state(PM_SUSPEND_DISK); | |
215 | } | |
216 | ||
217 | ||
218 | /** | |
219 | * pm_suspend - Externally visible function for suspending system. | |
220 | * @state: Enumarted value of state to enter. | |
221 | * | |
222 | * Determine whether or not value is within range, get state | |
223 | * structure, and enter (above). | |
224 | */ | |
225 | ||
226 | int pm_suspend(suspend_state_t state) | |
227 | { | |
e2a5b420 | 228 | if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX) |
1da177e4 LT |
229 | return enter_state(state); |
230 | return -EINVAL; | |
231 | } | |
232 | ||
233 | ||
234 | ||
235 | decl_subsys(power,NULL,NULL); | |
236 | ||
237 | ||
238 | /** | |
239 | * state - control system power state. | |
240 | * | |
241 | * show() returns what states are supported, which is hard-coded to | |
242 | * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and | |
243 | * 'disk' (Suspend-to-Disk). | |
244 | * | |
245 | * store() accepts one of those strings, translates it into the | |
246 | * proper enumerated value, and initiates a suspend transition. | |
247 | */ | |
248 | ||
249 | static ssize_t state_show(struct subsystem * subsys, char * buf) | |
250 | { | |
251 | int i; | |
252 | char * s = buf; | |
253 | ||
254 | for (i = 0; i < PM_SUSPEND_MAX; i++) { | |
123d3c13 PM |
255 | if (pm_states[i] && valid_state(i)) |
256 | s += sprintf(s,"%s ", pm_states[i]); | |
1da177e4 LT |
257 | } |
258 | s += sprintf(s,"\n"); | |
259 | return (s - buf); | |
260 | } | |
261 | ||
262 | static ssize_t state_store(struct subsystem * subsys, const char * buf, size_t n) | |
263 | { | |
264 | suspend_state_t state = PM_SUSPEND_STANDBY; | |
265 | char ** s; | |
266 | char *p; | |
267 | int error; | |
268 | int len; | |
269 | ||
270 | p = memchr(buf, '\n', n); | |
271 | len = p ? p - buf : n; | |
272 | ||
273 | for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) { | |
274 | if (*s && !strncmp(buf, *s, len)) | |
275 | break; | |
276 | } | |
47bb7899 | 277 | if (state < PM_SUSPEND_MAX && *s) |
1da177e4 LT |
278 | error = enter_state(state); |
279 | else | |
280 | error = -EINVAL; | |
281 | return error ? error : n; | |
282 | } | |
283 | ||
284 | power_attr(state); | |
285 | ||
286 | static struct attribute * g[] = { | |
287 | &state_attr.attr, | |
288 | NULL, | |
289 | }; | |
290 | ||
291 | static struct attribute_group attr_group = { | |
292 | .attrs = g, | |
293 | }; | |
294 | ||
295 | ||
296 | static int __init pm_init(void) | |
297 | { | |
298 | int error = subsystem_register(&power_subsys); | |
299 | if (!error) | |
300 | error = sysfs_create_group(&power_subsys.kset.kobj,&attr_group); | |
301 | return error; | |
302 | } | |
303 | ||
304 | core_initcall(pm_init); |