2 * kernel/power/main.c - PM subsystem core functionality.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
7 * This file is released under the GPLv2
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 #include <linux/syscalls.h>
27 DEFINE_MUTEX(pm_mutex
);
29 unsigned int pm_flags
;
30 EXPORT_SYMBOL(pm_flags
);
32 #ifdef CONFIG_PM_SLEEP
34 /* Routines for PM-transition notifications */
36 static BLOCKING_NOTIFIER_HEAD(pm_chain_head
);
38 int register_pm_notifier(struct notifier_block
*nb
)
40 return blocking_notifier_chain_register(&pm_chain_head
, nb
);
42 EXPORT_SYMBOL_GPL(register_pm_notifier
);
44 int unregister_pm_notifier(struct notifier_block
*nb
)
46 return blocking_notifier_chain_unregister(&pm_chain_head
, nb
);
48 EXPORT_SYMBOL_GPL(unregister_pm_notifier
);
50 int pm_notifier_call_chain(unsigned long val
)
52 return (blocking_notifier_call_chain(&pm_chain_head
, val
, NULL
)
53 == NOTIFY_BAD
) ? -EINVAL
: 0;
56 #ifdef CONFIG_PM_DEBUG
57 int pm_test_level
= TEST_NONE
;
59 static int suspend_test(int level
)
61 if (pm_test_level
== level
) {
62 printk(KERN_INFO
"suspend debug: Waiting for 5 seconds.\n");
69 static const char * const pm_tests
[__TEST_AFTER_LAST
] = {
72 [TEST_CPUS
] = "processors",
73 [TEST_PLATFORM
] = "platform",
74 [TEST_DEVICES
] = "devices",
75 [TEST_FREEZER
] = "freezer",
78 static ssize_t
pm_test_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
84 for (level
= TEST_FIRST
; level
<= TEST_MAX
; level
++)
85 if (pm_tests
[level
]) {
86 if (level
== pm_test_level
)
87 s
+= sprintf(s
, "[%s] ", pm_tests
[level
]);
89 s
+= sprintf(s
, "%s ", pm_tests
[level
]);
93 /* convert the last space to a newline */
99 static ssize_t
pm_test_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
100 const char *buf
, size_t n
)
102 const char * const *s
;
108 p
= memchr(buf
, '\n', n
);
109 len
= p
? p
- buf
: n
;
111 mutex_lock(&pm_mutex
);
114 for (s
= &pm_tests
[level
]; level
<= TEST_MAX
; s
++, level
++)
115 if (*s
&& len
== strlen(*s
) && !strncmp(buf
, *s
, len
)) {
116 pm_test_level
= level
;
121 mutex_unlock(&pm_mutex
);
123 return error
? error
: n
;
127 #else /* !CONFIG_PM_DEBUG */
128 static inline int suspend_test(int level
) { return 0; }
129 #endif /* !CONFIG_PM_DEBUG */
131 #endif /* CONFIG_PM_SLEEP */
133 #ifdef CONFIG_SUSPEND
135 /* This is just an arbitrary number */
136 #define FREE_PAGE_NUMBER (100)
138 static struct platform_suspend_ops
*suspend_ops
;
141 * suspend_set_ops - Set the global suspend method table.
142 * @ops: Pointer to ops structure.
145 void suspend_set_ops(struct platform_suspend_ops
*ops
)
147 mutex_lock(&pm_mutex
);
149 mutex_unlock(&pm_mutex
);
153 * suspend_valid_only_mem - generic memory-only valid callback
155 * Platform drivers that implement mem suspend only and only need
156 * to check for that in their .valid callback can use this instead
157 * of rolling their own .valid callback.
159 int suspend_valid_only_mem(suspend_state_t state
)
161 return state
== PM_SUSPEND_MEM
;
165 * suspend_prepare - Do prep work before entering low-power state.
167 * This is common code that is called for each state that we're entering.
168 * Run suspend notifiers, allocate a console and stop all processes.
170 static int suspend_prepare(void)
173 unsigned int free_pages
;
175 if (!suspend_ops
|| !suspend_ops
->enter
)
178 pm_prepare_console();
180 error
= pm_notifier_call_chain(PM_SUSPEND_PREPARE
);
184 if (suspend_freeze_processes()) {
189 free_pages
= global_page_state(NR_FREE_PAGES
);
190 if (free_pages
< FREE_PAGE_NUMBER
) {
191 pr_debug("PM: free some memory\n");
192 shrink_all_memory(FREE_PAGE_NUMBER
- free_pages
);
193 if (nr_free_pages() < FREE_PAGE_NUMBER
) {
195 printk(KERN_ERR
"PM: No enough memory\n");
202 suspend_thaw_processes();
204 pm_notifier_call_chain(PM_POST_SUSPEND
);
205 pm_restore_console();
209 /* default implementation */
210 void __attribute__ ((weak
)) arch_suspend_disable_irqs(void)
215 /* default implementation */
216 void __attribute__ ((weak
)) arch_suspend_enable_irqs(void)
222 * suspend_enter - enter the desired system sleep state.
223 * @state: state to enter
225 * This function should be called after devices have been suspended.
227 static int suspend_enter(suspend_state_t state
)
232 arch_suspend_disable_irqs();
233 BUG_ON(!irqs_disabled());
235 if ((error
= device_power_down(PMSG_SUSPEND
))) {
236 printk(KERN_ERR
"PM: Some devices failed to power down\n");
240 if (!suspend_test(TEST_CORE
))
241 error
= suspend_ops
->enter(state
);
243 device_power_up(PMSG_RESUME
);
245 arch_suspend_enable_irqs();
246 BUG_ON(irqs_disabled());
252 * suspend_devices_and_enter - suspend devices and enter the desired system
254 * @state: state to enter
256 int suspend_devices_and_enter(suspend_state_t state
)
263 if (suspend_ops
->begin
) {
264 error
= suspend_ops
->begin(state
);
269 error
= device_suspend(PMSG_SUSPEND
);
271 printk(KERN_ERR
"PM: Some devices failed to suspend\n");
272 goto Recover_platform
;
275 if (suspend_test(TEST_DEVICES
))
276 goto Recover_platform
;
278 if (suspend_ops
->prepare
) {
279 error
= suspend_ops
->prepare();
284 if (suspend_test(TEST_PLATFORM
))
287 error
= disable_nonboot_cpus();
288 if (!error
&& !suspend_test(TEST_CPUS
))
289 suspend_enter(state
);
291 enable_nonboot_cpus();
293 if (suspend_ops
->finish
)
294 suspend_ops
->finish();
296 device_resume(PMSG_RESUME
);
299 if (suspend_ops
->end
)
304 if (suspend_ops
->recover
)
305 suspend_ops
->recover();
310 * suspend_finish - Do final work before exiting suspend sequence.
312 * Call platform code to clean up, restart processes, and free the
313 * console that we've allocated. This is not called for suspend-to-disk.
315 static void suspend_finish(void)
317 suspend_thaw_processes();
318 pm_notifier_call_chain(PM_POST_SUSPEND
);
319 pm_restore_console();
325 static const char * const pm_states
[PM_SUSPEND_MAX
] = {
326 [PM_SUSPEND_STANDBY
] = "standby",
327 [PM_SUSPEND_MEM
] = "mem",
330 static inline int valid_state(suspend_state_t state
)
332 /* All states need lowlevel support and need to be valid
333 * to the lowlevel implementation, no valid callback
334 * implies that none are valid. */
335 if (!suspend_ops
|| !suspend_ops
->valid
|| !suspend_ops
->valid(state
))
342 * enter_state - Do common work of entering low-power state.
343 * @state: pm_state structure for state we're entering.
345 * Make sure we're the only ones trying to enter a sleep state. Fail
346 * if someone has beat us to it, since we don't want anything weird to
347 * happen when we wake up.
348 * Then, do the setup for suspend, enter the state, and cleaup (after
351 static int enter_state(suspend_state_t state
)
355 if (!valid_state(state
))
358 if (!mutex_trylock(&pm_mutex
))
361 printk(KERN_INFO
"PM: Syncing filesystems ... ");
365 pr_debug("PM: Preparing system for %s sleep\n", pm_states
[state
]);
366 error
= suspend_prepare();
370 if (suspend_test(TEST_FREEZER
))
373 pr_debug("PM: Entering %s sleep\n", pm_states
[state
]);
374 error
= suspend_devices_and_enter(state
);
377 pr_debug("PM: Finishing wakeup.\n");
380 mutex_unlock(&pm_mutex
);
386 * pm_suspend - Externally visible function for suspending system.
387 * @state: Enumerated value of state to enter.
389 * Determine whether or not value is within range, get state
390 * structure, and enter (above).
393 int pm_suspend(suspend_state_t state
)
395 if (state
> PM_SUSPEND_ON
&& state
<= PM_SUSPEND_MAX
)
396 return enter_state(state
);
400 EXPORT_SYMBOL(pm_suspend
);
402 #endif /* CONFIG_SUSPEND */
404 struct kobject
*power_kobj
;
407 * state - control system power state.
409 * show() returns what states are supported, which is hard-coded to
410 * 'standby' (Power-On Suspend), 'mem' (Suspend-to-RAM), and
411 * 'disk' (Suspend-to-Disk).
413 * store() accepts one of those strings, translates it into the
414 * proper enumerated value, and initiates a suspend transition.
417 static ssize_t
state_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
421 #ifdef CONFIG_SUSPEND
424 for (i
= 0; i
< PM_SUSPEND_MAX
; i
++) {
425 if (pm_states
[i
] && valid_state(i
))
426 s
+= sprintf(s
,"%s ", pm_states
[i
]);
429 #ifdef CONFIG_HIBERNATION
430 s
+= sprintf(s
, "%s\n", "disk");
433 /* convert the last space to a newline */
439 static ssize_t
state_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
440 const char *buf
, size_t n
)
442 #ifdef CONFIG_SUSPEND
443 suspend_state_t state
= PM_SUSPEND_STANDBY
;
444 const char * const *s
;
450 p
= memchr(buf
, '\n', n
);
451 len
= p
? p
- buf
: n
;
453 /* First, check if we are requested to hibernate */
454 if (len
== 4 && !strncmp(buf
, "disk", len
)) {
459 #ifdef CONFIG_SUSPEND
460 for (s
= &pm_states
[state
]; state
< PM_SUSPEND_MAX
; s
++, state
++) {
461 if (*s
&& len
== strlen(*s
) && !strncmp(buf
, *s
, len
))
464 if (state
< PM_SUSPEND_MAX
&& *s
)
465 error
= enter_state(state
);
469 return error
? error
: n
;
474 #ifdef CONFIG_PM_TRACE
475 int pm_trace_enabled
;
477 static ssize_t
pm_trace_show(struct kobject
*kobj
, struct kobj_attribute
*attr
,
480 return sprintf(buf
, "%d\n", pm_trace_enabled
);
484 pm_trace_store(struct kobject
*kobj
, struct kobj_attribute
*attr
,
485 const char *buf
, size_t n
)
489 if (sscanf(buf
, "%d", &val
) == 1) {
490 pm_trace_enabled
= !!val
;
496 power_attr(pm_trace
);
497 #endif /* CONFIG_PM_TRACE */
499 static struct attribute
* g
[] = {
501 #ifdef CONFIG_PM_TRACE
504 #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_PM_DEBUG)
510 static struct attribute_group attr_group
= {
515 static int __init
pm_init(void)
517 power_kobj
= kobject_create_and_add("power", NULL
);
520 return sysfs_create_group(power_kobj
, &attr_group
);
523 core_initcall(pm_init
);