projects/linux·blob v2.6.13 · refs

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1/*
2 * kernel/power/disk.c - Suspend-to-disk support.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2004 Pavel Machek <[email protected]>
7 *
8 * This file is released under the GPLv2.
9 *
10 */
11
12#include <linux/suspend.h>
13#include <linux/syscalls.h>
14#include <linux/reboot.h>
15#include <linux/string.h>
16#include <linux/device.h>
17#include <linux/delay.h>
18#include <linux/fs.h>
19#include <linux/mount.h>
20
21#include "power.h"
22
23
24extern suspend_disk_method_t pm_disk_mode;
25extern struct pm_ops * pm_ops;
26
27extern int swsusp_suspend(void);
28extern int swsusp_write(void);
29extern int swsusp_check(void);
30extern int swsusp_read(void);
31extern void swsusp_close(void);
32extern int swsusp_resume(void);
33extern int swsusp_free(void);
34
35
36static int noresume = 0;
37char resume_file[256] = CONFIG_PM_STD_PARTITION;
38dev_t swsusp_resume_device;
39
40/**
41 * power_down - Shut machine down for hibernate.
42 * @mode: Suspend-to-disk mode
43 *
44 * Use the platform driver, if configured so, and return gracefully if it
45 * fails.
46 * Otherwise, try to power off and reboot. If they fail, halt the machine,
47 * there ain't no turning back.
48 */
49
50static void power_down(suspend_disk_method_t mode)
51{
52 unsigned long flags;
53 int error = 0;
54
55 local_irq_save(flags);
56 switch(mode) {
57 case PM_DISK_PLATFORM:
58 device_shutdown();
59 error = pm_ops->enter(PM_SUSPEND_DISK);
60 break;
61 case PM_DISK_SHUTDOWN:
62 kernel_power_off();
63 break;
64 case PM_DISK_REBOOT:
65 kernel_restart(NULL);
66 break;
67 }
68 kernel_halt();
69 /* Valid image is on the disk, if we continue we risk serious data corruption
70 after resume. */
71 printk(KERN_CRIT "Please power me down manually\n");
72 while(1);
73}
74
75
76static int in_suspend __nosavedata = 0;
77
78
79/**
80 * free_some_memory - Try to free as much memory as possible
81 *
82 * ... but do not OOM-kill anyone
83 *
84 * Notice: all userland should be stopped at this point, or
85 * livelock is possible.
86 */
87
88static void free_some_memory(void)
89{
90 unsigned int i = 0;
91 unsigned int tmp;
92 unsigned long pages = 0;
93 char *p = "-\\|/";
94
95 printk("Freeing memory... ");
96 while ((tmp = shrink_all_memory(10000))) {
97 pages += tmp;
98 printk("\b%c", p[i]);
99 i++;
100 if (i > 3)
101 i = 0;
102 }
103 printk("\bdone (%li pages freed)\n", pages);
104}
105
106
107static inline void platform_finish(void)
108{
109 if (pm_disk_mode == PM_DISK_PLATFORM) {
110 if (pm_ops && pm_ops->finish)
111 pm_ops->finish(PM_SUSPEND_DISK);
112 }
113}
114
115static void finish(void)
116{
117 device_resume();
118 platform_finish();
119 thaw_processes();
120 enable_nonboot_cpus();
121 pm_restore_console();
122}
123
124
125static int prepare_processes(void)
126{
127 int error;
128
129 pm_prepare_console();
130
131 sys_sync();
132
133 disable_nonboot_cpus();
134
135 if (freeze_processes()) {
136 error = -EBUSY;
137 goto thaw;
138 }
139
140 if (pm_disk_mode == PM_DISK_PLATFORM) {
141 if (pm_ops && pm_ops->prepare) {
142 if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
143 goto thaw;
144 }
145 }
146
147 /* Free memory before shutting down devices. */
148 free_some_memory();
149 return 0;
150thaw:
151 thaw_processes();
152 enable_nonboot_cpus();
153 pm_restore_console();
154 return error;
155}
156
157static void unprepare_processes(void)
158{
159 platform_finish();
160 thaw_processes();
161 enable_nonboot_cpus();
162 pm_restore_console();
163}
164
165static int prepare_devices(void)
166{
167 int error;
168
169 if ((error = device_suspend(PMSG_FREEZE)))
170 printk("Some devices failed to suspend\n");
171 return error;
172}
173
174/**
175 * pm_suspend_disk - The granpappy of power management.
176 *
177 * If we're going through the firmware, then get it over with quickly.
178 *
179 * If not, then call swsusp to do its thing, then figure out how
180 * to power down the system.
181 */
182
183int pm_suspend_disk(void)
184{
185 int error;
186
187 error = prepare_processes();
188 if (error)
189 return error;
190 error = prepare_devices();
191
192 if (error) {
193 unprepare_processes();
194 return error;
195 }
196
197 pr_debug("PM: Attempting to suspend to disk.\n");
198 if (pm_disk_mode == PM_DISK_FIRMWARE)
199 return pm_ops->enter(PM_SUSPEND_DISK);
200
201 pr_debug("PM: snapshotting memory.\n");
202 in_suspend = 1;
203 if ((error = swsusp_suspend()))
204 goto Done;
205
206 if (in_suspend) {
207 pr_debug("PM: writing image.\n");
208 error = swsusp_write();
209 if (!error)
210 power_down(pm_disk_mode);
211 } else
212 pr_debug("PM: Image restored successfully.\n");
213 swsusp_free();
214 Done:
215 finish();
216 return error;
217}
218
219
220/**
221 * software_resume - Resume from a saved image.
222 *
223 * Called as a late_initcall (so all devices are discovered and
224 * initialized), we call swsusp to see if we have a saved image or not.
225 * If so, we quiesce devices, the restore the saved image. We will
226 * return above (in pm_suspend_disk() ) if everything goes well.
227 * Otherwise, we fail gracefully and return to the normally
228 * scheduled program.
229 *
230 */
231
232static int software_resume(void)
233{
234 int error;
235
236 if (!swsusp_resume_device) {
237 if (!strlen(resume_file))
238 return -ENOENT;
239 swsusp_resume_device = name_to_dev_t(resume_file);
240 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
241 } else {
242 pr_debug("swsusp: Resume From Partition %d:%d\n",
243 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
244 }
245
246 if (noresume) {
247 /**
248 * FIXME: If noresume is specified, we need to find the partition
249 * and reset it back to normal swap space.
250 */
251 return 0;
252 }
253
254 pr_debug("PM: Checking swsusp image.\n");
255
256 if ((error = swsusp_check()))
257 goto Done;
258
259 pr_debug("PM: Preparing processes for restore.\n");
260
261 if ((error = prepare_processes())) {
262 swsusp_close();
263 goto Done;
264 }
265
266 pr_debug("PM: Reading swsusp image.\n");
267
268 if ((error = swsusp_read()))
269 goto Cleanup;
270
271 pr_debug("PM: Preparing devices for restore.\n");
272
273 if ((error = prepare_devices()))
274 goto Free;
275
276 mb();
277
278 pr_debug("PM: Restoring saved image.\n");
279 swsusp_resume();
280 pr_debug("PM: Restore failed, recovering.n");
281 finish();
282 Free:
283 swsusp_free();
284 Cleanup:
285 unprepare_processes();
286 Done:
287 pr_debug("PM: Resume from disk failed.\n");
288 return 0;
289}
290
291late_initcall(software_resume);
292
293
294static char * pm_disk_modes[] = {
295 [PM_DISK_FIRMWARE] = "firmware",
296 [PM_DISK_PLATFORM] = "platform",
297 [PM_DISK_SHUTDOWN] = "shutdown",
298 [PM_DISK_REBOOT] = "reboot",
299};
300
301/**
302 * disk - Control suspend-to-disk mode
303 *
304 * Suspend-to-disk can be handled in several ways. The greatest
305 * distinction is who writes memory to disk - the firmware or the OS.
306 * If the firmware does it, we assume that it also handles suspending
307 * the system.
308 * If the OS does it, then we have three options for putting the system
309 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
310 * powering off the system or rebooting the system (for testing).
311 *
312 * The system will support either 'firmware' or 'platform', and that is
313 * known a priori (and encoded in pm_ops). But, the user may choose
314 * 'shutdown' or 'reboot' as alternatives.
315 *
316 * show() will display what the mode is currently set to.
317 * store() will accept one of
318 *
319 * 'firmware'
320 * 'platform'
321 * 'shutdown'
322 * 'reboot'
323 *
324 * It will only change to 'firmware' or 'platform' if the system
325 * supports it (as determined from pm_ops->pm_disk_mode).
326 */
327
328static ssize_t disk_show(struct subsystem * subsys, char * buf)
329{
330 return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
331}
332
333
334static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
335{
336 int error = 0;
337 int i;
338 int len;
339 char *p;
340 suspend_disk_method_t mode = 0;
341
342 p = memchr(buf, '\n', n);
343 len = p ? p - buf : n;
344
345 down(&pm_sem);
346 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
347 if (!strncmp(buf, pm_disk_modes[i], len)) {
348 mode = i;
349 break;
350 }
351 }
352 if (mode) {
353 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT)
354 pm_disk_mode = mode;
355 else {
356 if (pm_ops && pm_ops->enter &&
357 (mode == pm_ops->pm_disk_mode))
358 pm_disk_mode = mode;
359 else
360 error = -EINVAL;
361 }
362 } else
363 error = -EINVAL;
364
365 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
366 pm_disk_modes[mode]);
367 up(&pm_sem);
368 return error ? error : n;
369}
370
371power_attr(disk);
372
373static ssize_t resume_show(struct subsystem * subsys, char *buf)
374{
375 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
376 MINOR(swsusp_resume_device));
377}
378
379static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n)
380{
381 int len;
382 char *p;
383 unsigned int maj, min;
384 int error = -EINVAL;
385 dev_t res;
386
387 p = memchr(buf, '\n', n);
388 len = p ? p - buf : n;
389
390 if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
391 res = MKDEV(maj,min);
392 if (maj == MAJOR(res) && min == MINOR(res)) {
393 swsusp_resume_device = res;
394 printk("Attempting manual resume\n");
395 noresume = 0;
396 software_resume();
397 }
398 }
399
400 return error >= 0 ? n : error;
401}
402
403power_attr(resume);
404
405static struct attribute * g[] = {
406 &disk_attr.attr,
407 &resume_attr.attr,
408 NULL,
409};
410
411
412static struct attribute_group attr_group = {
413 .attrs = g,
414};
415
416
417static int __init pm_disk_init(void)
418{
419 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
420}
421
422core_initcall(pm_disk_init);
423
424
425static int __init resume_setup(char *str)
426{
427 if (noresume)
428 return 1;
429
430 strncpy( resume_file, str, 255 );
431 return 1;
432}
433
434static int __init noresume_setup(char *str)
435{
436 noresume = 1;
437 return 1;
438}
439
440__setup("noresume", noresume_setup);
441__setup("resume=", resume_setup);