[PATCH] swsusp: add resume_offset command line parameter
[linux-2.6-block.git] / kernel / power / disk.c
CommitLineData
1da177e4
LT
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 <pavel@suse.cz>
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>
d53d9f16 19#include <linux/mount.h>
88d10bba 20#include <linux/pm.h>
97c7801c 21#include <linux/console.h>
e3920fb4 22#include <linux/cpu.h>
d53d9f16 23
1da177e4
LT
24#include "power.h"
25
26
1da177e4
LT
27static int noresume = 0;
28char resume_file[256] = CONFIG_PM_STD_PARTITION;
29dev_t swsusp_resume_device;
9a154d9d 30sector_t swsusp_resume_block;
1da177e4
LT
31
32/**
33 * power_down - Shut machine down for hibernate.
34 * @mode: Suspend-to-disk mode
35 *
36 * Use the platform driver, if configured so, and return gracefully if it
37 * fails.
38 * Otherwise, try to power off and reboot. If they fail, halt the machine,
39 * there ain't no turning back.
40 */
41
42static void power_down(suspend_disk_method_t mode)
43{
1da177e4
LT
44 int error = 0;
45
1da177e4
LT
46 switch(mode) {
47 case PM_DISK_PLATFORM:
729b4d4c 48 kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
1da177e4
LT
49 error = pm_ops->enter(PM_SUSPEND_DISK);
50 break;
51 case PM_DISK_SHUTDOWN:
fdde86ac 52 kernel_power_off();
1da177e4
LT
53 break;
54 case PM_DISK_REBOOT:
fdde86ac 55 kernel_restart(NULL);
1da177e4
LT
56 break;
57 }
fdde86ac 58 kernel_halt();
1da177e4
LT
59 /* Valid image is on the disk, if we continue we risk serious data corruption
60 after resume. */
61 printk(KERN_CRIT "Please power me down manually\n");
62 while(1);
63}
64
1da177e4
LT
65static inline void platform_finish(void)
66{
67 if (pm_disk_mode == PM_DISK_PLATFORM) {
68 if (pm_ops && pm_ops->finish)
69 pm_ops->finish(PM_SUSPEND_DISK);
70 }
71}
72
1da177e4
LT
73static int prepare_processes(void)
74{
b918f6e6 75 int error = 0;
1da177e4
LT
76
77 pm_prepare_console();
e3920fb4
RW
78
79 error = disable_nonboot_cpus();
80 if (error)
81 goto enable_cpus;
5a72e04d 82
1da177e4
LT
83 if (freeze_processes()) {
84 error = -EBUSY;
5a72e04d 85 goto thaw;
1da177e4
LT
86 }
87
b918f6e6
RW
88 if (pm_disk_mode == PM_DISK_TESTPROC) {
89 printk("swsusp debug: Waiting for 5 seconds.\n");
90 mdelay(5000);
91 goto thaw;
92 }
93
1da177e4 94 /* Free memory before shutting down devices. */
72a97e08
RW
95 if (!(error = swsusp_shrink_memory()))
96 return 0;
5a72e04d
LS
97thaw:
98 thaw_processes();
e3920fb4 99enable_cpus:
5a72e04d
LS
100 enable_nonboot_cpus();
101 pm_restore_console();
102 return error;
1da177e4
LT
103}
104
105static void unprepare_processes(void)
106{
5a72e04d 107 platform_finish();
1da177e4 108 thaw_processes();
5a72e04d 109 enable_nonboot_cpus();
1da177e4
LT
110 pm_restore_console();
111}
112
1da177e4 113/**
f1cc0a89 114 * pm_suspend_disk - The granpappy of hibernation power management.
1da177e4
LT
115 *
116 * If we're going through the firmware, then get it over with quickly.
117 *
118 * If not, then call swsusp to do its thing, then figure out how
119 * to power down the system.
120 */
121
122int pm_suspend_disk(void)
123{
124 int error;
125
126 error = prepare_processes();
5a72e04d
LS
127 if (error)
128 return error;
1da177e4 129
b918f6e6
RW
130 if (pm_disk_mode == PM_DISK_TESTPROC)
131 goto Thaw;
132
97c7801c 133 suspend_console();
99dc7d63 134 error = device_suspend(PMSG_FREEZE);
1da177e4 135 if (error) {
97c7801c 136 resume_console();
99dc7d63 137 printk("Some devices failed to suspend\n");
b918f6e6
RW
138 goto Thaw;
139 }
140
141 if (pm_disk_mode == PM_DISK_TEST) {
142 printk("swsusp debug: Waiting for 5 seconds.\n");
143 mdelay(5000);
144 goto Done;
1da177e4
LT
145 }
146
1da177e4
LT
147 pr_debug("PM: snapshotting memory.\n");
148 in_suspend = 1;
149 if ((error = swsusp_suspend()))
150 goto Done;
151
152 if (in_suspend) {
0245b3e7 153 device_resume();
97c7801c 154 resume_console();
1da177e4 155 pr_debug("PM: writing image.\n");
f577eb30 156 error = swsusp_write();
1da177e4
LT
157 if (!error)
158 power_down(pm_disk_mode);
99dc7d63 159 else {
99dc7d63 160 swsusp_free();
b918f6e6 161 goto Thaw;
99dc7d63 162 }
b918f6e6 163 } else {
1da177e4 164 pr_debug("PM: Image restored successfully.\n");
b918f6e6 165 }
99dc7d63 166
1da177e4
LT
167 swsusp_free();
168 Done:
99dc7d63 169 device_resume();
97c7801c 170 resume_console();
b918f6e6 171 Thaw:
99dc7d63 172 unprepare_processes();
1da177e4
LT
173 return error;
174}
175
176
177/**
178 * software_resume - Resume from a saved image.
179 *
180 * Called as a late_initcall (so all devices are discovered and
181 * initialized), we call swsusp to see if we have a saved image or not.
182 * If so, we quiesce devices, the restore the saved image. We will
183 * return above (in pm_suspend_disk() ) if everything goes well.
184 * Otherwise, we fail gracefully and return to the normally
185 * scheduled program.
186 *
187 */
188
189static int software_resume(void)
190{
191 int error;
192
dd5d666b 193 down(&pm_sem);
3efa147a 194 if (!swsusp_resume_device) {
dd5d666b
SL
195 if (!strlen(resume_file)) {
196 up(&pm_sem);
3efa147a 197 return -ENOENT;
dd5d666b 198 }
3efa147a
PM
199 swsusp_resume_device = name_to_dev_t(resume_file);
200 pr_debug("swsusp: Resume From Partition %s\n", resume_file);
201 } else {
202 pr_debug("swsusp: Resume From Partition %d:%d\n",
203 MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
204 }
205
1da177e4
LT
206 if (noresume) {
207 /**
208 * FIXME: If noresume is specified, we need to find the partition
209 * and reset it back to normal swap space.
210 */
dd5d666b 211 up(&pm_sem);
1da177e4
LT
212 return 0;
213 }
214
215 pr_debug("PM: Checking swsusp image.\n");
216
217 if ((error = swsusp_check()))
218 goto Done;
219
220 pr_debug("PM: Preparing processes for restore.\n");
221
222 if ((error = prepare_processes())) {
223 swsusp_close();
5a72e04d 224 goto Done;
1da177e4
LT
225 }
226
227 pr_debug("PM: Reading swsusp image.\n");
228
f577eb30 229 if ((error = swsusp_read())) {
2c1b4a5c
RW
230 swsusp_free();
231 goto Thaw;
232 }
1da177e4
LT
233
234 pr_debug("PM: Preparing devices for restore.\n");
235
97c7801c 236 suspend_console();
f1cc0a89 237 if ((error = device_suspend(PMSG_PRETHAW))) {
97c7801c 238 resume_console();
99dc7d63 239 printk("Some devices failed to suspend\n");
2c1b4a5c
RW
240 swsusp_free();
241 goto Thaw;
99dc7d63 242 }
1da177e4
LT
243
244 mb();
245
246 pr_debug("PM: Restoring saved image.\n");
247 swsusp_resume();
248 pr_debug("PM: Restore failed, recovering.n");
99dc7d63 249 device_resume();
97c7801c 250 resume_console();
2c1b4a5c 251 Thaw:
1da177e4
LT
252 unprepare_processes();
253 Done:
dd5d666b
SL
254 /* For success case, the suspend path will release the lock */
255 up(&pm_sem);
1da177e4
LT
256 pr_debug("PM: Resume from disk failed.\n");
257 return 0;
258}
259
260late_initcall(software_resume);
261
262
3b364b8d 263static const char * const pm_disk_modes[] = {
1da177e4
LT
264 [PM_DISK_FIRMWARE] = "firmware",
265 [PM_DISK_PLATFORM] = "platform",
266 [PM_DISK_SHUTDOWN] = "shutdown",
267 [PM_DISK_REBOOT] = "reboot",
b918f6e6
RW
268 [PM_DISK_TEST] = "test",
269 [PM_DISK_TESTPROC] = "testproc",
1da177e4
LT
270};
271
272/**
273 * disk - Control suspend-to-disk mode
274 *
275 * Suspend-to-disk can be handled in several ways. The greatest
276 * distinction is who writes memory to disk - the firmware or the OS.
277 * If the firmware does it, we assume that it also handles suspending
278 * the system.
279 * If the OS does it, then we have three options for putting the system
280 * to sleep - using the platform driver (e.g. ACPI or other PM registers),
281 * powering off the system or rebooting the system (for testing).
282 *
283 * The system will support either 'firmware' or 'platform', and that is
284 * known a priori (and encoded in pm_ops). But, the user may choose
285 * 'shutdown' or 'reboot' as alternatives.
286 *
287 * show() will display what the mode is currently set to.
288 * store() will accept one of
289 *
290 * 'firmware'
291 * 'platform'
292 * 'shutdown'
293 * 'reboot'
294 *
295 * It will only change to 'firmware' or 'platform' if the system
296 * supports it (as determined from pm_ops->pm_disk_mode).
297 */
298
299static ssize_t disk_show(struct subsystem * subsys, char * buf)
300{
301 return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
302}
303
304
305static ssize_t disk_store(struct subsystem * s, const char * buf, size_t n)
306{
307 int error = 0;
308 int i;
309 int len;
310 char *p;
311 suspend_disk_method_t mode = 0;
312
313 p = memchr(buf, '\n', n);
314 len = p ? p - buf : n;
315
316 down(&pm_sem);
317 for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
318 if (!strncmp(buf, pm_disk_modes[i], len)) {
319 mode = i;
320 break;
321 }
322 }
323 if (mode) {
b918f6e6
RW
324 if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
325 mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
1da177e4 326 pm_disk_mode = mode;
b918f6e6 327 } else {
1da177e4
LT
328 if (pm_ops && pm_ops->enter &&
329 (mode == pm_ops->pm_disk_mode))
330 pm_disk_mode = mode;
331 else
332 error = -EINVAL;
333 }
b918f6e6 334 } else {
1da177e4 335 error = -EINVAL;
b918f6e6 336 }
1da177e4
LT
337
338 pr_debug("PM: suspend-to-disk mode set to '%s'\n",
339 pm_disk_modes[mode]);
340 up(&pm_sem);
341 return error ? error : n;
342}
343
344power_attr(disk);
345
346static ssize_t resume_show(struct subsystem * subsys, char *buf)
347{
348 return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
349 MINOR(swsusp_resume_device));
350}
351
a576219a 352static ssize_t resume_store(struct subsystem *subsys, const char *buf, size_t n)
1da177e4 353{
1da177e4 354 unsigned int maj, min;
1da177e4 355 dev_t res;
a576219a 356 int ret = -EINVAL;
1da177e4 357
a576219a
AM
358 if (sscanf(buf, "%u:%u", &maj, &min) != 2)
359 goto out;
1da177e4 360
a576219a
AM
361 res = MKDEV(maj,min);
362 if (maj != MAJOR(res) || min != MINOR(res))
363 goto out;
1da177e4 364
a576219a
AM
365 down(&pm_sem);
366 swsusp_resume_device = res;
367 up(&pm_sem);
368 printk("Attempting manual resume\n");
369 noresume = 0;
370 software_resume();
371 ret = n;
372out:
373 return ret;
1da177e4
LT
374}
375
376power_attr(resume);
377
ca0aec0f
RW
378static ssize_t image_size_show(struct subsystem * subsys, char *buf)
379{
853609b6 380 return sprintf(buf, "%lu\n", image_size);
ca0aec0f
RW
381}
382
383static ssize_t image_size_store(struct subsystem * subsys, const char * buf, size_t n)
384{
853609b6 385 unsigned long size;
ca0aec0f 386
853609b6 387 if (sscanf(buf, "%lu", &size) == 1) {
ca0aec0f
RW
388 image_size = size;
389 return n;
390 }
391
392 return -EINVAL;
393}
394
395power_attr(image_size);
396
1da177e4
LT
397static struct attribute * g[] = {
398 &disk_attr.attr,
399 &resume_attr.attr,
ca0aec0f 400 &image_size_attr.attr,
1da177e4
LT
401 NULL,
402};
403
404
405static struct attribute_group attr_group = {
406 .attrs = g,
407};
408
409
410static int __init pm_disk_init(void)
411{
412 return sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
413}
414
415core_initcall(pm_disk_init);
416
417
418static int __init resume_setup(char *str)
419{
420 if (noresume)
421 return 1;
422
423 strncpy( resume_file, str, 255 );
424 return 1;
425}
426
9a154d9d
RW
427static int __init resume_offset_setup(char *str)
428{
429 unsigned long long offset;
430
431 if (noresume)
432 return 1;
433
434 if (sscanf(str, "%llu", &offset) == 1)
435 swsusp_resume_block = offset;
436
437 return 1;
438}
439
1da177e4
LT
440static int __init noresume_setup(char *str)
441{
442 noresume = 1;
443 return 1;
444}
445
446__setup("noresume", noresume_setup);
9a154d9d 447__setup("resume_offset=", resume_offset_setup);
1da177e4 448__setup("resume=", resume_setup);