Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION
[linux-2.6.git] / kernel / power / main.c
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/module.h>
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/console.h>
19 #include <linux/cpu.h>
20 #include <linux/resume-trace.h>
21 #include <linux/freezer.h>
22 #include <linux/vmstat.h>
23
24 #include "power.h"
25
26 BLOCKING_NOTIFIER_HEAD(pm_chain_head);
27
28 /*This is just an arbitrary number */
29 #define FREE_PAGE_NUMBER (100)
30
31 DEFINE_MUTEX(pm_mutex);
32
33 struct pm_ops *pm_ops;
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 {
42         mutex_lock(&pm_mutex);
43         pm_ops = ops;
44         mutex_unlock(&pm_mutex);
45 }
46
47 /**
48  * pm_valid_only_mem - generic memory-only valid callback
49  *
50  * pm_ops drivers that implement mem suspend only and only need
51  * to check for that in their .valid callback can use this instead
52  * of rolling their own .valid callback.
53  */
54 int pm_valid_only_mem(suspend_state_t state)
55 {
56         return state == PM_SUSPEND_MEM;
57 }
58
59
60 static inline void pm_finish(suspend_state_t state)
61 {
62         if (pm_ops->finish)
63                 pm_ops->finish(state);
64 }
65
66 /**
67  *      suspend_prepare - Do prep work before entering low-power state.
68  *
69  *      This is common code that is called for each state that we're entering.
70  *      Run suspend notifiers, allocate a console and stop all processes.
71  */
72 static int suspend_prepare(void)
73 {
74         int error;
75         unsigned int free_pages;
76
77         if (!pm_ops || !pm_ops->enter)
78                 return -EPERM;
79
80         error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
81         if (error)
82                 goto Finish;
83
84         pm_prepare_console();
85
86         if (freeze_processes()) {
87                 error = -EAGAIN;
88                 goto Thaw;
89         }
90
91         free_pages = global_page_state(NR_FREE_PAGES);
92         if (free_pages < FREE_PAGE_NUMBER) {
93                 pr_debug("PM: free some memory\n");
94                 shrink_all_memory(FREE_PAGE_NUMBER - free_pages);
95                 if (nr_free_pages() < FREE_PAGE_NUMBER) {
96                         error = -ENOMEM;
97                         printk(KERN_ERR "PM: No enough memory\n");
98                 }
99         }
100         if (!error)
101                 return 0;
102
103  Thaw:
104         thaw_processes();
105         pm_restore_console();
106  Finish:
107         pm_notifier_call_chain(PM_POST_SUSPEND);
108         return error;
109 }
110
111 /* default implementation */
112 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
113 {
114         local_irq_disable();
115 }
116
117 /* default implementation */
118 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
119 {
120         local_irq_enable();
121 }
122
123 /**
124  *      suspend_enter - enter the desired system sleep state.
125  *      @state:         state to enter
126  *
127  *      This function should be called after devices have been suspended.
128  */
129 int suspend_enter(suspend_state_t state)
130 {
131         int error = 0;
132
133         arch_suspend_disable_irqs();
134         BUG_ON(!irqs_disabled());
135
136         if ((error = device_power_down(PMSG_SUSPEND))) {
137                 printk(KERN_ERR "Some devices failed to power down\n");
138                 goto Done;
139         }
140         error = pm_ops->enter(state);
141         device_power_up();
142  Done:
143         arch_suspend_enable_irqs();
144         BUG_ON(irqs_disabled());
145         return error;
146 }
147
148 /**
149  *      suspend_devices_and_enter - suspend devices and enter the desired system sleep
150  *                        state.
151  *      @state:           state to enter
152  */
153 int suspend_devices_and_enter(suspend_state_t state)
154 {
155         int error;
156
157         if (!pm_ops)
158                 return -ENOSYS;
159
160         if (pm_ops->set_target) {
161                 error = pm_ops->set_target(state);
162                 if (error)
163                         return error;
164         }
165         suspend_console();
166         error = device_suspend(PMSG_SUSPEND);
167         if (error) {
168                 printk(KERN_ERR "Some devices failed to suspend\n");
169                 goto Resume_console;
170         }
171         if (pm_ops->prepare) {
172                 error = pm_ops->prepare(state);
173                 if (error)
174                         goto Resume_devices;
175         }
176         error = disable_nonboot_cpus();
177         if (!error)
178                 suspend_enter(state);
179
180         enable_nonboot_cpus();
181         pm_finish(state);
182  Resume_devices:
183         device_resume();
184  Resume_console:
185         resume_console();
186         return error;
187 }
188
189 /**
190  *      suspend_finish - Do final work before exiting suspend sequence.
191  *
192  *      Call platform code to clean up, restart processes, and free the 
193  *      console that we've allocated. This is not called for suspend-to-disk.
194  */
195 static void suspend_finish(void)
196 {
197         thaw_processes();
198         pm_restore_console();
199         pm_notifier_call_chain(PM_POST_SUSPEND);
200 }
201
202
203
204
205 static const char * const pm_states[PM_SUSPEND_MAX] = {
206         [PM_SUSPEND_STANDBY]    = "standby",
207         [PM_SUSPEND_MEM]        = "mem",
208 };
209
210 static inline int valid_state(suspend_state_t state)
211 {
212         /* All states need lowlevel support and need to be valid
213          * to the lowlevel implementation, no valid callback
214          * implies that none are valid. */
215         if (!pm_ops || !pm_ops->valid || !pm_ops->valid(state))
216                 return 0;
217         return 1;
218 }
219
220
221 /**
222  *      enter_state - Do common work of entering low-power state.
223  *      @state:         pm_state structure for state we're entering.
224  *
225  *      Make sure we're the only ones trying to enter a sleep state. Fail
226  *      if someone has beat us to it, since we don't want anything weird to
227  *      happen when we wake up.
228  *      Then, do the setup for suspend, enter the state, and cleaup (after
229  *      we've woken up).
230  */
231 static int enter_state(suspend_state_t state)
232 {
233         int error;
234
235         if (!valid_state(state))
236                 return -ENODEV;
237         if (!mutex_trylock(&pm_mutex))
238                 return -EBUSY;
239
240         pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
241         if ((error = suspend_prepare()))
242                 goto Unlock;
243
244         pr_debug("PM: Entering %s sleep\n", pm_states[state]);
245         error = suspend_devices_and_enter(state);
246
247         pr_debug("PM: Finishing wakeup.\n");
248         suspend_finish();
249  Unlock:
250         mutex_unlock(&pm_mutex);
251         return error;
252 }
253
254
255 /**
256  *      pm_suspend - Externally visible function for suspending system.
257  *      @state:         Enumerated value of state to enter.
258  *
259  *      Determine whether or not value is within range, get state 
260  *      structure, and enter (above).
261  */
262
263 int pm_suspend(suspend_state_t state)
264 {
265         if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
266                 return enter_state(state);
267         return -EINVAL;
268 }
269
270 EXPORT_SYMBOL(pm_suspend);
271
272 decl_subsys(power,NULL,NULL);
273
274
275 /**
276  *      state - control system power state.
277  *
278  *      show() returns what states are supported, which is hard-coded to
279  *      'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
280  *      'disk' (Suspend-to-Disk).
281  *
282  *      store() accepts one of those strings, translates it into the 
283  *      proper enumerated value, and initiates a suspend transition.
284  */
285
286 static ssize_t state_show(struct kset *kset, char *buf)
287 {
288         int i;
289         char * s = buf;
290
291         for (i = 0; i < PM_SUSPEND_MAX; i++) {
292                 if (pm_states[i] && valid_state(i))
293                         s += sprintf(s,"%s ", pm_states[i]);
294         }
295 #ifdef CONFIG_HIBERNATION
296         s += sprintf(s, "%s\n", "disk");
297 #else
298         if (s != buf)
299                 /* convert the last space to a newline */
300                 *(s-1) = '\n';
301 #endif
302         return (s - buf);
303 }
304
305 static ssize_t state_store(struct kset *kset, const char *buf, size_t n)
306 {
307         suspend_state_t state = PM_SUSPEND_STANDBY;
308         const char * const *s;
309         char *p;
310         int error;
311         int len;
312
313         p = memchr(buf, '\n', n);
314         len = p ? p - buf : n;
315
316         /* First, check if we are requested to hibernate */
317         if (len == 4 && !strncmp(buf, "disk", len)) {
318                 error = hibernate();
319                 return error ? error : n;
320         }
321
322         for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
323                 if (*s && len == strlen(*s) && !strncmp(buf, *s, len))
324                         break;
325         }
326         if (state < PM_SUSPEND_MAX && *s)
327                 error = enter_state(state);
328         else
329                 error = -EINVAL;
330         return error ? error : n;
331 }
332
333 power_attr(state);
334
335 #ifdef CONFIG_PM_TRACE
336 int pm_trace_enabled;
337
338 static ssize_t pm_trace_show(struct kset *kset, char *buf)
339 {
340         return sprintf(buf, "%d\n", pm_trace_enabled);
341 }
342
343 static ssize_t
344 pm_trace_store(struct kset *kset, const char *buf, size_t n)
345 {
346         int val;
347
348         if (sscanf(buf, "%d", &val) == 1) {
349                 pm_trace_enabled = !!val;
350                 return n;
351         }
352         return -EINVAL;
353 }
354
355 power_attr(pm_trace);
356
357 static struct attribute * g[] = {
358         &state_attr.attr,
359         &pm_trace_attr.attr,
360         NULL,
361 };
362 #else
363 static struct attribute * g[] = {
364         &state_attr.attr,
365         NULL,
366 };
367 #endif /* CONFIG_PM_TRACE */
368
369 static struct attribute_group attr_group = {
370         .attrs = g,
371 };
372
373
374 static int __init pm_init(void)
375 {
376         int error = subsystem_register(&power_subsys);
377         if (!error)
378                 error = sysfs_create_group(&power_subsys.kobj,&attr_group);
379         return error;
380 }
381
382 core_initcall(pm_init);