static int software_resume(void) { int error; unsigned int flags; /* * If the user said "noresume".. bail out early. */ if (noresume) return 0; /* * name_to_dev_t() below takes a sysfs buffer mutex when sysfs * is configured into the kernel. Since the regular hibernate * trigger path is via sysfs which takes a buffer mutex before * calling hibernate functions (which take pm_mutex) this can * cause lockdep to complain about a possible ABBA deadlock * which cannot happen since we're in the boot code here and * sysfs can't be invoked yet. Therefore, we use a subclass * here to avoid lockdep complaining. */ mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING); if (swsusp_resume_device) goto Check_image; if (!strlen(resume_file)) { error = -ENOENT; goto Unlock; } pr_debug("PM: Checking image partition %s\n", resume_file); /* Check if the device is there */ swsusp_resume_device = name_to_dev_t(resume_file); if (!swsusp_resume_device) { /* * Some device discovery might still be in progress; we need * to wait for this to finish. */ wait_for_device_probe(); /* * We can't depend on SCSI devices being available after loading * one of their modules until scsi_complete_async_scans() is * called and the resume device usually is a SCSI one. */ scsi_complete_async_scans(); swsusp_resume_device = name_to_dev_t(resume_file); if (!swsusp_resume_device) { error = -ENODEV; goto Unlock; } } Check_image: pr_debug("PM: Resume from partition %d:%d\n", MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); pr_debug("PM: Checking hibernation image.\n"); error = swsusp_check(); if (error) goto Unlock; /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { error = -EBUSY; swsusp_close(FMODE_READ); goto Unlock; } pm_prepare_console(); error = pm_notifier_call_chain(PM_RESTORE_PREPARE); if (error) goto close_finish; error = usermodehelper_disable(); if (error) goto close_finish; error = create_basic_memory_bitmaps(); if (error) goto close_finish; pr_debug("PM: Preparing processes for restore.\n"); error = prepare_processes(); if (error) { swsusp_close(FMODE_READ); goto Done; } pr_debug("PM: Reading hibernation image.\n"); error = swsusp_read(&flags); swsusp_close(FMODE_READ); if (!error) hibernation_restore(flags & SF_PLATFORM_MODE); printk(KERN_ERR "PM: Restore failed, recovering.\n"); swsusp_free(); thaw_processes(); Done: free_basic_memory_bitmaps(); usermodehelper_enable(); Finish: pm_notifier_call_chain(PM_POST_RESTORE); pm_restore_console(); atomic_inc(&snapshot_device_available); /* For success case, the suspend path will release the lock */ Unlock: mutex_unlock(&pm_mutex); pr_debug("PM: Resume from disk failed.\n"); return error; close_finish: swsusp_close(FMODE_READ); goto Finish; }
/** * software_resume - Resume from a saved hibernation image. * * This routine is called as a late initcall, when all devices have been * discovered and initialized already. * * The image reading code is called to see if there is a hibernation image * available for reading. If that is the case, devices are quiesced and the * contents of memory is restored from the saved image. * * If this is successful, control reappears in the restored target kernel in * hibernation_snaphot() which returns to hibernate(). Otherwise, the routine * attempts to recover gracefully and make the kernel return to the normal mode * of operation. */ static int software_resume(void) { int error; unsigned int flags; /* * If the user said "noresume".. bail out early. */ if (noresume || !hibernation_available()) return 0; /* * name_to_dev_t() below takes a sysfs buffer mutex when sysfs * is configured into the kernel. Since the regular hibernate * trigger path is via sysfs which takes a buffer mutex before * calling hibernate functions (which take pm_mutex) this can * cause lockdep to complain about a possible ABBA deadlock * which cannot happen since we're in the boot code here and * sysfs can't be invoked yet. Therefore, we use a subclass * here to avoid lockdep complaining. */ mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING); if (swsusp_resume_device) goto Check_image; if (!strlen(resume_file)) { error = -ENOENT; goto Unlock; } pr_debug("PM: Checking hibernation image partition %s\n", resume_file); if (resume_delay) { printk(KERN_INFO "Waiting %dsec before reading resume device...\n", resume_delay); ssleep(resume_delay); } /* Check if the device is there */ swsusp_resume_device = name_to_dev_t(resume_file); /* * name_to_dev_t is ineffective to verify parition if resume_file is in * integer format. (e.g. major:minor) */ if (isdigit(resume_file[0]) && resume_wait) { int partno; while (!get_gendisk(swsusp_resume_device, &partno)) msleep(10); } if (!swsusp_resume_device) { /* * Some device discovery might still be in progress; we need * to wait for this to finish. */ wait_for_device_probe(); if (resume_wait) { while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0) msleep(10); async_synchronize_full(); } swsusp_resume_device = name_to_dev_t(resume_file); if (!swsusp_resume_device) { error = -ENODEV; goto Unlock; } } Check_image: pr_debug("PM: Hibernation image partition %d:%d present\n", MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); pr_debug("PM: Looking for hibernation image.\n"); error = swsusp_check(); if (error) goto Unlock; /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { error = -EBUSY; swsusp_close(FMODE_READ); goto Unlock; } pm_prepare_console(); error = pm_notifier_call_chain(PM_RESTORE_PREPARE); if (error) goto Close_Finish; pr_debug("PM: Preparing processes for restore.\n"); error = freeze_processes(); if (error) goto Close_Finish; pr_debug("PM: Loading hibernation image.\n"); lock_device_hotplug(); error = create_basic_memory_bitmaps(); if (error) goto Thaw; error = swsusp_read(&flags); swsusp_close(FMODE_READ); if (!error) hibernation_restore(flags & SF_PLATFORM_MODE); printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n"); swsusp_free(); free_basic_memory_bitmaps(); Thaw: unlock_device_hotplug(); thaw_processes(); Finish: pm_notifier_call_chain(PM_POST_RESTORE); pm_restore_console(); atomic_inc(&snapshot_device_available); /* For success case, the suspend path will release the lock */ Unlock: mutex_unlock(&pm_mutex); pr_debug("PM: Hibernation image not present or could not be loaded.\n"); return error; Close_Finish: swsusp_close(FMODE_READ); goto Finish; }
static int software_resume(void) { int error; down(&pm_sem); if (!swsusp_resume_device) { if (!strlen(resume_file)) { up(&pm_sem); return -ENOENT; } swsusp_resume_device = name_to_dev_t(resume_file); pr_debug("swsusp: Resume From Partition %s\n", resume_file); } else { pr_debug("swsusp: Resume From Partition %d:%d\n", MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); } if (noresume) { /** * FIXME: If noresume is specified, we need to find the partition * and reset it back to normal swap space. */ up(&pm_sem); return 0; } pr_debug("PM: Checking swsusp image.\n"); if ((error = swsusp_check())) goto Done; pr_debug("PM: Preparing processes for restore.\n"); if ((error = prepare_processes())) { swsusp_close(); goto Done; } pr_debug("PM: Reading swsusp image.\n"); if ((error = swsusp_read())) goto Cleanup; pr_debug("PM: Preparing devices for restore.\n"); if ((error = device_suspend(PMSG_FREEZE))) { printk("Some devices failed to suspend\n"); goto Free; } mb(); pr_debug("PM: Restoring saved image.\n"); swsusp_resume(); pr_debug("PM: Restore failed, recovering.n"); device_resume(); Free: swsusp_free(); Cleanup: unprepare_processes(); Done: /* For success case, the suspend path will release the lock */ up(&pm_sem); pr_debug("PM: Resume from disk failed.\n"); return 0; }
static int software_resume(void) { int error; unsigned int flags; /* * name_to_dev_t() below takes a sysfs buffer mutex when sysfs * is configured into the kernel. Since the regular hibernate * trigger path is via sysfs which takes a buffer mutex before * calling hibernate functions (which take pm_mutex) this can * cause lockdep to complain about a possible ABBA deadlock * which cannot happen since we're in the boot code here and * sysfs can't be invoked yet. Therefore, we use a subclass * here to avoid lockdep complaining. */ mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING); if (!swsusp_resume_device) { if (!strlen(resume_file)) { mutex_unlock(&pm_mutex); return -ENOENT; } swsusp_resume_device = name_to_dev_t(resume_file); pr_debug("PM: Resume from partition %s\n", resume_file); } else { pr_debug("PM: Resume from partition %d:%d\n", MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); } if (noresume) { /** * FIXME: If noresume is specified, we need to find the * partition and reset it back to normal swap space. */ mutex_unlock(&pm_mutex); return 0; } pr_debug("PM: Checking hibernation image.\n"); error = swsusp_check(); if (error) goto Unlock; /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { error = -EBUSY; goto Unlock; } pm_prepare_console(); error = pm_notifier_call_chain(PM_RESTORE_PREPARE); if (error) goto Finish; error = create_basic_memory_bitmaps(); if (error) goto Finish; pr_debug("PM: Preparing processes for restore.\n"); error = prepare_processes(); if (error) { swsusp_close(); goto Done; } pr_debug("PM: Reading hibernation image.\n"); error = swsusp_read(&flags); if (!error) hibernation_restore(flags & SF_PLATFORM_MODE); printk(KERN_ERR "PM: Restore failed, recovering.\n"); swsusp_free(); thaw_processes(); Done: free_basic_memory_bitmaps(); Finish: pm_notifier_call_chain(PM_POST_RESTORE); pm_restore_console(); atomic_inc(&snapshot_device_available); /* For success case, the suspend path will release the lock */ Unlock: mutex_unlock(&pm_mutex); pr_debug("PM: Resume from disk failed.\n"); return error; }
static int software_resume(void) { int error; mutex_lock(&pm_mutex); if (!swsusp_resume_device) { if (!strlen(resume_file)) { mutex_unlock(&pm_mutex); return -ENOENT; } swsusp_resume_device = name_to_dev_t(resume_file); pr_debug("swsusp: Resume From Partition %s\n", resume_file); } else { pr_debug("swsusp: Resume From Partition %d:%d\n", MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device)); } if (noresume) { /** * FIXME: If noresume is specified, we need to find the partition * and reset it back to normal swap space. */ mutex_unlock(&pm_mutex); return 0; } pr_debug("PM: Checking swsusp image.\n"); error = swsusp_check(); if (error) goto Unlock; error = create_basic_memory_bitmaps(); if (error) goto Unlock; pr_debug("PM: Preparing processes for restore.\n"); error = prepare_processes(); if (error) { swsusp_close(); goto Done; } pr_debug("PM: Reading swsusp image.\n"); error = swsusp_read(); if (error) { swsusp_free(); goto Thaw; } pr_debug("PM: Preparing devices for restore.\n"); suspend_console(); error = device_suspend(PMSG_PRETHAW); if (error) goto Free; error = disable_nonboot_cpus(); if (!error) swsusp_resume(); enable_nonboot_cpus(); Free: swsusp_free(); device_resume(); resume_console(); Thaw: printk(KERN_ERR "PM: Restore failed, recovering.\n"); unprepare_processes(); Done: free_basic_memory_bitmaps(); /* For success case, the suspend path will release the lock */ Unlock: mutex_unlock(&pm_mutex); pr_debug("PM: Resume from disk failed.\n"); return 0; }