projects/linux·blob v2.6.21 · 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#include <linux/pm.h>
21#include <linux/console.h>
22#include <linux/cpu.h>
23#include <linux/freezer.h>
24
25#include "power.h"
26
27
28static int noresume = 0;
29char resume_file[256] = CONFIG_PM_STD_PARTITION;
30dev_t swsusp_resume_device;
31sector_t swsusp_resume_block;
32
33/**
34 * platform_prepare - prepare the machine for hibernation using the
35 * platform driver if so configured and return an error code if it fails
36 */
37
38static inline int platform_prepare(void)
39{
40 int error = 0;
41
42 if (pm_disk_mode == PM_DISK_PLATFORM) {
43 if (pm_ops && pm_ops->prepare)
44 error = pm_ops->prepare(PM_SUSPEND_DISK);
45 }
46 return error;
47}
48
49/**
50 * power_down - Shut machine down for hibernate.
51 * @mode: Suspend-to-disk mode
52 *
53 * Use the platform driver, if configured so, and return gracefully if it
54 * fails.
55 * Otherwise, try to power off and reboot. If they fail, halt the machine,
56 * there ain't no turning back.
57 */
58
59static void power_down(suspend_disk_method_t mode)
60{
61 switch(mode) {
62 case PM_DISK_PLATFORM:
63 if (pm_ops && pm_ops->enter) {
64 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
65 pm_ops->enter(PM_SUSPEND_DISK);
66 break;
67 }
68 case PM_DISK_SHUTDOWN:
69 kernel_power_off();
70 break;
71 case PM_DISK_REBOOT:
72 kernel_restart(NULL);
73 break;
74 }
75 kernel_halt();
76 /* Valid image is on the disk, if we continue we risk serious data corruption
77 after resume. */
78 printk(KERN_CRIT "Please power me down manually\n");
79 while(1);
80}
81
82static inline void platform_finish(void)
83{
84 if (pm_disk_mode == PM_DISK_PLATFORM) {
85 if (pm_ops && pm_ops->finish)
86 pm_ops->finish(PM_SUSPEND_DISK);
87 }
88}
89
90static void unprepare_processes(void)
91{
92 thaw_processes();
93 pm_restore_console();
94}
95
96static int prepare_processes(void)
97{
98 int error = 0;
99
100 pm_prepare_console();
101 if (freeze_processes()) {
102 error = -EBUSY;
103 unprepare_processes();
104 }
105 return error;
106}
107
108/**
109 * pm_suspend_disk - The granpappy of hibernation power management.
110 *
111 * If we're going through the firmware, then get it over with quickly.
112 *
113 * If not, then call swsusp to do its thing, then figure out how
114 * to power down the system.
115 */
116
117int pm_suspend_disk(void)
118{
119 int error;
120
121 error = prepare_processes();
122 if (error)
123 return error;
124
125 if (pm_disk_mode == PM_DISK_TESTPROC) {
126 printk("swsusp debug: Waiting for 5 seconds.\n");
127 mdelay(5000);
128 goto Thaw;
129 }
130 /* Free memory before shutting down devices. */
131 error = swsusp_shrink_memory();
132 if (error)
133 goto Thaw;
134
135 error = platform_prepare();
136 if (error)
137 goto Thaw;
138
139 suspend_console();
140 error = device_suspend(PMSG_FREEZE);
141 if (error) {
142 printk(KERN_ERR "PM: Some devices failed to suspend\n");
143 goto Resume_devices;
144 }
145 error = disable_nonboot_cpus();
146 if (error)
147 goto Enable_cpus;
148
149 if (pm_disk_mode == PM_DISK_TEST) {
150 printk("swsusp debug: Waiting for 5 seconds.\n");
151 mdelay(5000);
152 goto Enable_cpus;
153 }
154
155 pr_debug("PM: snapshotting memory.\n");
156 in_suspend = 1;
157 error = swsusp_suspend();
158 if (error)
159 goto Enable_cpus;
160
161 if (in_suspend) {
162 enable_nonboot_cpus();
163 platform_finish();
164 device_resume();
165 resume_console();
166 pr_debug("PM: writing image.\n");
167 error = swsusp_write();
168 if (!error)
169 power_down(pm_disk_mode);
170 else {
171 swsusp_free();
172 goto Thaw;
173 }
174 } else {
175 pr_debug("PM: Image restored successfully.\n");
176 }
177
178 swsusp_free();
179 Enable_cpus:
180 enable_nonboot_cpus();
181 Resume_devices:
182 platform_finish();
183 device_resume();
184 resume_console();
185 Thaw:
186 unprepare_processes();
187 return error;
188}
189
190
191/**
192 * software_resume - Resume from a saved image.
193 *
194 * Called as a late_initcall (so all devices are discovered and
195 * initialized), we call swsusp to see if we have a saved image or not.
196 * If so, we quiesce devices, the restore the saved image. We will
197 * return above (in pm_suspend_disk() ) if everything goes well.
198 * Otherwise, we fail gracefully and return to the normally
199 * scheduled program.
200 *
201 */
202
203static int software_resume(void)
204{
205 int error;
206
207 mutex_lock(&pm_mutex);
208 if (!swsusp_resume_device) {
209 if (!strlen(resume_file)) {
210 mutex_unlock(&pm_mutex);
211 return -ENOENT;
212 }
213 swsusp_resume_device = name_to_dev_t(resume_file);
214 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
215 } else {
216 pr_debug("swsusp: Resume From Partition %d:%d\n",
217 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
218 }
219
220 if (noresume) {
221 /**
222 * FIXME: If noresume is specified, we need to find the partition
223 * and reset it back to normal swap space.
224 */
225 mutex_unlock(&pm_mutex);
226 return 0;
227 }
228
229 pr_debug("PM: Checking swsusp image.\n");
230
231 error = swsusp_check();
232 if (error)
233 goto Done;
234
235 pr_debug("PM: Preparing processes for restore.\n");
236
237 error = prepare_processes();
238 if (error) {
239 swsusp_close();
240 goto Done;
241 }
242
243 pr_debug("PM: Reading swsusp image.\n");
244
245 error = swsusp_read();
246 if (error) {
247 swsusp_free();
248 goto Thaw;
249 }
250
251 pr_debug("PM: Preparing devices for restore.\n");
252
253 suspend_console();
254 error = device_suspend(PMSG_PRETHAW);
255 if (error)
256 goto Free;
257
258 error = disable_nonboot_cpus();
259 if (!error)
260 swsusp_resume();
261
262 enable_nonboot_cpus();
263 Free:
264 swsusp_free();
265 device_resume();
266 resume_console();
267 Thaw:
268 printk(KERN_ERR "PM: Restore failed, recovering.\n");
269 unprepare_processes();
270 Done:
271 /* For success case, the suspend path will release the lock */
272 mutex_unlock(&pm_mutex);
273 pr_debug("PM: Resume from disk failed.\n");
274 return 0;
275}
276
277late_initcall(software_resume);
278
279
280static const char * const pm_disk_modes[] = {
281 [PM_DISK_FIRMWARE] = "firmware",
282 [PM_DISK_PLATFORM] = "platform",
283 [PM_DISK_SHUTDOWN] = "shutdown",
284 [PM_DISK_REBOOT] = "reboot",
285 [PM_DISK_TEST] = "test",
286 [PM_DISK_TESTPROC] = "testproc",
287};
288
289/**
290 * disk - Control suspend-to-disk mode
291 *
292 * Suspend-to-disk can be handled in several ways. The greatest
293 * distinction is who writes memory to disk - the firmware or the OS.
294 * If the firmware does it, we assume that it also handles suspending
295 * the system.
296 * If the OS does it, then we have three options for putting the system
297 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
298 * powering off the system or rebooting the system (for testing).
299 *
300 * The system will support either 'firmware' or 'platform', and that is
301 * known a priori (and encoded in pm_ops). But, the user may choose
302 * 'shutdown' or 'reboot' as alternatives.
303 *
304 * show() will display what the mode is currently set to.
305 * store() will accept one of
306 *
307 * 'firmware'
308 * 'platform'
309 * 'shutdown'
310 * 'reboot'
311 *
312 * It will only change to 'firmware' or 'platform' if the system
313 * supports it (as determined from pm_ops->pm_disk_mode).
314 */
315
316static ssize_t disk_show(struct subsystem * subsys, char * buf)
317{
318 return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
319}
320
321
322static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
323{
324 int error = 0;
325 int i;
326 int len;
327 char *p;
328 suspend_disk_method_t mode = 0;
329
330 p = memchr(buf, '\n', n);
331 len = p ? p - buf : n;
332
333 mutex_lock(&pm_mutex);
334 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
335 if (!strncmp(buf, pm_disk_modes[i], len)) {
336 mode = i;
337 break;
338 }
339 }
340 if (mode) {
341 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
342 mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
343 pm_disk_mode = mode;
344 } else {
345 if (pm_ops && pm_ops->enter &&
346 (mode == pm_ops->pm_disk_mode))
347 pm_disk_mode = mode;
348 else
349 error = -EINVAL;
350 }
351 } else {
352 error = -EINVAL;
353 }
354
355 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
356 pm_disk_modes[mode]);
357 mutex_unlock(&pm_mutex);
358 return error ? error : n;
359}
360
361power_attr(disk);
362
363static ssize_t resume_show(struct subsystem * subsys, char *buf)
364{
365 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
366 MINOR(swsusp_resume_device));
367}
368
369static ssize_t resume_store(struct subsystem *subsys, const char *buf, size_t n)
370{
371 unsigned int maj, min;
372 dev_t res;
373 int ret = -EINVAL;
374
375 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
376 goto out;
377
378 res = MKDEV(maj,min);
379 if (maj != MAJOR(res) || min != MINOR(res))
380 goto out;
381
382 mutex_lock(&pm_mutex);
383 swsusp_resume_device = res;
384 mutex_unlock(&pm_mutex);
385 printk("Attempting manual resume\n");
386 noresume = 0;
387 software_resume();
388 ret = n;
389 out:
390 return ret;
391}
392
393power_attr(resume);
394
395static ssize_t image_size_show(struct subsystem * subsys, char *buf)
396{
397 return sprintf(buf, "%lu\n", image_size);
398}
399
400static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n)
401{
402 unsigned long size;
403
404 if (sscanf(buf, "%lu", &size) == 1) {
405 image_size = size;
406 return n;
407 }
408
409 return -EINVAL;
410}
411
412power_attr(image_size);
413
414static struct attribute * g[] = {
415 &disk_attr.attr,
416 &resume_attr.attr,
417 &image_size_attr.attr,
418 NULL,
419};
420
421
422static struct attribute_group attr_group = {
423 .attrs = g,
424};
425
426
427static int __init pm_disk_init(void)
428{
429 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
430}
431
432core_initcall(pm_disk_init);
433
434
435static int __init resume_setup(char *str)
436{
437 if (noresume)
438 return 1;
439
440 strncpy( resume_file, str, 255 );
441 return 1;
442}
443
444static int __init resume_offset_setup(char *str)
445{
446 unsigned long long offset;
447
448 if (noresume)
449 return 1;
450
451 if (sscanf(str, "%llu", &offset) == 1)
452 swsusp_resume_block = offset;
453
454 return 1;
455}
456
457static int __init noresume_setup(char *str)
458{
459 noresume = 1;
460 return 1;
461}
462
463__setup("noresume", noresume_setup);
464__setup("resume_offset=", resume_offset_setup);
465__setup("resume=", resume_setup);