1 // SPDX-License-Identifier: GPL-2.0-only
3  * kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
62 #define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
75 	return atomic_add_unless(&hibernate_atomic, -1, 0);  in hibernate_acquire()
91  * hibernation_set_ops - Set the global hibernate operations.
98 	if (ops && !(ops->begin && ops->end &&  ops->pre_snapshot  in hibernation_set_ops()
99 	    && ops->prepare && ops->finish && ops->enter && ops->pre_restore  in hibernation_set_ops()
100 	    && ops->restore_cleanup && ops->leave)) {  in hibernation_set_ops()
145  * platform_begin - Call platform to start hibernation.
151 		hibernation_ops->begin(PMSG_FREEZE) : 0;  in platform_begin()
155  * platform_end - Call platform to finish transition to the working state.
161 		hibernation_ops->end();  in platform_end()
165  * platform_pre_snapshot - Call platform to prepare the machine for hibernation.
175 		hibernation_ops->pre_snapshot() : 0;  in platform_pre_snapshot()
179  * platform_leave - Call platform to prepare a transition to the working state.
190 		hibernation_ops->leave();  in platform_leave()
194  * platform_finish - Call platform to switch the system to the working state.
205 		hibernation_ops->finish();  in platform_finish()
209  * platform_pre_restore - Prepare for hibernate image restoration.
212  * Use the platform driver to prepare the system for resume from a hibernation
221 		hibernation_ops->pre_restore() : 0;  in platform_pre_restore()
225  * platform_restore_cleanup - Switch to the working state after failing restore.
238 		hibernation_ops->restore_cleanup();  in platform_restore_cleanup()
242  * platform_recover - Recover from a failure to suspend devices.
247 	if (platform_mode && hibernation_ops && hibernation_ops->recover)  in platform_recover()
248 		hibernation_ops->recover();  in platform_recover()
252  * swsusp_show_speed - Print time elapsed between two events during hibernation.
271 		centisecs = 1;	/* avoid div-by-zero */  in swsusp_show_speed()
285  * create_image - Create a hibernation image.
351 	/* Allow architectures to do nosmt-specific post-resume dances */  in create_image()
365  * hibernation_snapshot - Quiesce devices and create a hibernation image.
451  * resume_target_kernel - Restore system state from a hibernation image.
456  * the low-level code that will restore the remaining contents of memory and
465 		pr_err("Some devices failed to power down, aborting resume\n");  in resume_target_kernel()
529  * hibernation_restore - Quiesce devices and restore from a hibernation image.
561  * hibernation_platform_enter - Power off the system using the platform driver.
568 		return -ENOSYS;  in hibernation_platform_enter()
572 	 * hibernation_ops->finish() before saving the image, so we should let  in hibernation_platform_enter()
575 	error = hibernation_ops->begin(PMSG_HIBERNATE);  in hibernation_platform_enter()
583 		if (hibernation_ops->recover)  in hibernation_platform_enter()
584 			hibernation_ops->recover();  in hibernation_platform_enter()
592 	error = hibernation_ops->prepare();  in hibernation_platform_enter()
604 		error = -EAGAIN;  in hibernation_platform_enter()
608 	hibernation_ops->enter();  in hibernation_platform_enter()
621 	hibernation_ops->finish();  in hibernation_platform_enter()
631 	hibernation_ops->end();  in hibernation_platform_enter()
637  * power_down - Shut the machine down for hibernation.
658 				pr_err("Swap will be unusable! Try swapon -a.\n");  in power_down()
671 		if (error == -EAGAIN || error == -EBUSY) {  in power_down()
686 	 * corruption after resume.  in power_down()
722  * hibernate - Carry out system hibernation, including saving the image.
732 		return -EPERM;  in hibernate()
738 		error = -EBUSY;  in hibernate()
816  * hibernate_quiet_exec - Execute a function with all devices frozen.
830 		error = -EBUSY;  in hibernate_quiet_exec()
916 		return -ENOENT;  in find_resume_device()
921 		pr_info("Waiting %dsec before reading resume device ...\n",  in find_resume_device()
960 		error = -EBUSY;  in software_resume()
965 	pr_info("resume from hibernation\n");  in software_resume()
988 	pr_info("resume failed (%d)\n", error);  in software_resume()
1001  * software_resume_initcall - Resume from a saved hibernation image.
1046  * /sys/power/disk - Control hibernation mode.
1103 	return buf-start;  in disk_show()
1117 		return -EPERM;  in disk_store()
1120 	len = p ? p - buf : n;  in disk_store()
1144 				error = -EINVAL;  in disk_store()
1147 		error = -EINVAL;  in disk_store()
1177 	if (len && buf[len-1] == '\n')  in resume_store()
1178 		len--;  in resume_store()
1181 		return -ENOMEM;  in resume_store()
1185 		unsigned maj, min, offset;  in resume_store()  local
1190 		    sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,  in resume_store()
1194 				error = -EINVAL;  in resume_store()
1198 				error = -EINVAL;  in resume_store()
1209 	pm_pr_dbg("Configured hibernation resume from disk to %u\n",  in resume_store()
1216 power_attr(resume);
1228 	unsigned long long offset;  in resume_offset_store()  local
1231 	rc = kstrtoull(buf, 0, &offset);  in resume_offset_store()
1234 	swsusp_resume_block = offset;  in resume_offset_store()
1257 	return -EINVAL;  in image_size_store()
1279 	return -EINVAL;  in reserved_size_store()
1318 	unsigned long long offset;  in resume_offset_setup()  local
1323 	if (sscanf(str, "%llu", &offset) == 1)  in resume_offset_setup()
1324 		swsusp_resume_block = offset;  in resume_offset_setup()
1375 __setup("resume=", resume_setup);