s2ram: add arch irq disable/enable hooks
[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/pm.h>
19 #include <linux/console.h>
20 #include <linux/cpu.h>
21 #include <linux/resume-trace.h>
22 #include <linux/freezer.h>
23 #include <linux/vmstat.h>
24
25 #include "power.h"
26
27 /*This is just an arbitrary number */
28 #define FREE_PAGE_NUMBER (100)
29
30 DEFINE_MUTEX(pm_mutex);
31
32 struct pm_ops *pm_ops;
33 suspend_disk_method_t pm_disk_mode = PM_DISK_PLATFORM;
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 static inline void pm_finish(suspend_state_t state)
48 {
49         if (pm_ops->finish)
50                 pm_ops->finish(state);
51 }
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 {
64         int error;
65         unsigned int free_pages;
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
77         if ((free_pages = global_page_state(NR_FREE_PAGES))
78                         < FREE_PAGE_NUMBER) {
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
88         if (pm_ops->prepare) {
89                 if ((error = pm_ops->prepare(state)))
90                         goto Thaw;
91         }
92
93         suspend_console();
94         error = device_suspend(PMSG_SUSPEND);
95         if (error) {
96                 printk(KERN_ERR "Some devices failed to suspend\n");
97                 goto Resume_devices;
98         }
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();
108  Thaw:
109         thaw_processes();
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 int suspend_enter(suspend_state_t state)
127 {
128         int error = 0;
129
130         arch_suspend_disable_irqs();
131         BUG_ON(!irqs_disabled());
132
133         if ((error = device_power_down(PMSG_SUSPEND))) {
134                 printk(KERN_ERR "Some devices failed to power down\n");
135                 goto Done;
136         }
137         error = pm_ops->enter(state);
138         device_power_up();
139  Done:
140         arch_suspend_enable_irqs();
141         BUG_ON(irqs_disabled());
142         return error;
143 }
144
145
146 /**
147  *      suspend_finish - Do final work before exiting suspend sequence.
148  *      @state:         State we're coming out of.
149  *
150  *      Call platform code to clean up, restart processes, and free the 
151  *      console that we've allocated. This is not called for suspend-to-disk.
152  */
153
154 static void suspend_finish(suspend_state_t state)
155 {
156         enable_nonboot_cpus();
157         pm_finish(state);
158         device_resume();
159         resume_console();
160         thaw_processes();
161         pm_restore_console();
162 }
163
164
165
166
167 static const char * const pm_states[PM_SUSPEND_MAX] = {
168         [PM_SUSPEND_STANDBY]    = "standby",
169         [PM_SUSPEND_MEM]        = "mem",
170 #ifdef CONFIG_SOFTWARE_SUSPEND
171         [PM_SUSPEND_DISK]       = "disk",
172 #endif
173 };
174
175 static inline int valid_state(suspend_state_t state)
176 {
177         /* Suspend-to-disk does not really need low-level support.
178          * It can work with reboot if needed. */
179         if (state == PM_SUSPEND_DISK)
180                 return 1;
181
182         /* all other states need lowlevel support and need to be
183          * valid to the lowlevel implementation, no valid callback
184          * implies that all are valid. */
185         if (!pm_ops || (pm_ops->valid && !pm_ops->valid(state)))
186                 return 0;
187         return 1;
188 }
189
190
191 /**
192  *      enter_state - Do common work of entering low-power state.
193  *      @state:         pm_state structure for state we're entering.
194  *
195  *      Make sure we're the only ones trying to enter a sleep state. Fail
196  *      if someone has beat us to it, since we don't want anything weird to
197  *      happen when we wake up.
198  *      Then, do the setup for suspend, enter the state, and cleaup (after
199  *      we've woken up).
200  */
201
202 static int enter_state(suspend_state_t state)
203 {
204         int error;
205
206         if (!valid_state(state))
207                 return -ENODEV;
208         if (!mutex_trylock(&pm_mutex))
209                 return -EBUSY;
210
211         if (state == PM_SUSPEND_DISK) {
212                 error = pm_suspend_disk();
213                 goto Unlock;
214         }
215
216         pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
217         if ((error = suspend_prepare(state)))
218                 goto Unlock;
219
220         pr_debug("PM: Entering %s sleep\n", pm_states[state]);
221         error = suspend_enter(state);
222
223         pr_debug("PM: Finishing wakeup.\n");
224         suspend_finish(state);
225  Unlock:
226         mutex_unlock(&pm_mutex);
227         return error;
228 }
229
230 /*
231  * This is main interface to the outside world. It needs to be
232  * called from process context.
233  */
234 int software_suspend(void)
235 {
236         return enter_state(PM_SUSPEND_DISK);
237 }
238
239
240 /**
241  *      pm_suspend - Externally visible function for suspending system.
242  *      @state:         Enumarted value of state to enter.
243  *
244  *      Determine whether or not value is within range, get state 
245  *      structure, and enter (above).
246  */
247
248 int pm_suspend(suspend_state_t state)
249 {
250         if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
251                 return enter_state(state);
252         return -EINVAL;
253 }
254
255 EXPORT_SYMBOL(pm_suspend);
256
257 decl_subsys(power,NULL,NULL);
258
259
260 /**
261  *      state - control system power state.
262  *
263  *      show() returns what states are supported, which is hard-coded to
264  *      'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
265  *      'disk' (Suspend-to-Disk).
266  *
267  *      store() accepts one of those strings, translates it into the 
268  *      proper enumerated value, and initiates a suspend transition.
269  */
270
271 static ssize_t state_show(struct subsystem * subsys, char * buf)
272 {
273         int i;
274         char * s = buf;
275
276         for (i = 0; i < PM_SUSPEND_MAX; i++) {
277                 if (pm_states[i] && valid_state(i))
278                         s += sprintf(s,"%s ", pm_states[i]);
279         }
280         s += sprintf(s,"\n");
281         return (s - buf);
282 }
283
284 static ssize_t state_store(struct subsystem * subsys, const char * buf, size_t n)
285 {
286         suspend_state_t state = PM_SUSPEND_STANDBY;
287         const char * const *s;
288         char *p;
289         int error;
290         int len;
291
292         p = memchr(buf, '\n', n);
293         len = p ? p - buf : n;
294
295         for (s = &pm_states[state]; state < PM_SUSPEND_MAX; s++, state++) {
296                 if (*s && !strncmp(buf, *s, len))
297                         break;
298         }
299         if (state < PM_SUSPEND_MAX && *s)
300                 error = enter_state(state);
301         else
302                 error = -EINVAL;
303         return error ? error : n;
304 }
305
306 power_attr(state);
307
308 #ifdef CONFIG_PM_TRACE
309 int pm_trace_enabled;
310
311 static ssize_t pm_trace_show(struct subsystem * subsys, char * buf)
312 {
313         return sprintf(buf, "%d\n", pm_trace_enabled);
314 }
315
316 static ssize_t
317 pm_trace_store(struct subsystem * subsys, const char * buf, size_t n)
318 {
319         int val;
320
321         if (sscanf(buf, "%d", &val) == 1) {
322                 pm_trace_enabled = !!val;
323                 return n;
324         }
325         return -EINVAL;
326 }
327
328 power_attr(pm_trace);
329
330 static struct attribute * g[] = {
331         &state_attr.attr,
332         &pm_trace_attr.attr,
333         NULL,
334 };
335 #else
336 static struct attribute * g[] = {
337         &state_attr.attr,
338         NULL,
339 };
340 #endif /* CONFIG_PM_TRACE */
341
342 static struct attribute_group attr_group = {
343         .attrs = g,
344 };
345
346
347 static int __init pm_init(void)
348 {
349         int error = subsystem_register(&power_subsys);
350         if (!error)
351                 error = sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
352         return error;
353 }
354
355 core_initcall(pm_init);