/* * scsi_pm.c Copyright (C) 2010 Alan Stern * * SCSI dynamic Power Management * Initial version: Alan Stern <stern@rowland.harvard.edu> */ #include <linux/pm_runtime.h> #include <linux/export.h> #include <linux/async.h> #include <scsi/scsi.h> #include <scsi/scsi_device.h> #include <scsi/scsi_driver.h> #include <scsi/scsi_host.h> #include "scsi_priv.h" #ifdef CONFIG_PM_SLEEP static int do_scsi_suspend(struct device *dev, const struct dev_pm_ops *pm) { return pm && pm->suspend ? pm->suspend(dev) : 0; } static int do_scsi_freeze(struct device *dev, const struct dev_pm_ops *pm) { return pm && pm->freeze ? pm->freeze(dev) : 0; } static int do_scsi_poweroff(struct device *dev, const struct dev_pm_ops *pm) { return pm && pm->poweroff ? pm->poweroff(dev) : 0; } static int do_scsi_resume(struct device *dev, const struct dev_pm_ops *pm) { return pm && pm->resume ? pm->resume(dev) : 0; } static int do_scsi_thaw(struct device *dev, const struct dev_pm_ops *pm) { return pm && pm->thaw ? pm->thaw(dev) : 0; } static int do_scsi_restore(struct device *dev, const struct dev_pm_ops *pm) { return pm && pm->restore ? pm->restore(dev) : 0; } static int scsi_dev_type_suspend(struct device *dev, int (*cb)(struct device *, const struct dev_pm_ops *)) { const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; int err; /* flush pending in-flight resume operations, suspend is synchronous */ async_synchronize_full_domain(&scsi_sd_pm_domain); err = scsi_device_quiesce(to_scsi_device(dev)); if (err == 0) { err = cb(dev, pm); if (err) scsi_device_resume(to_scsi_device(dev)); } dev_dbg(dev, "scsi suspend: %d\n", err); return err; } static int scsi_dev_type_resume(struct device *dev, int (*cb)(struct device *, const struct dev_pm_ops *)) { const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; int err = 0; err = cb(dev, pm); scsi_device_resume(to_scsi_device(dev)); dev_dbg(dev, "scsi resume: %d\n", err); if (err == 0) { pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); } return err; } static int scsi_bus_suspend_common(struct device *dev, int (*cb)(struct device *, const struct dev_pm_ops *)) { int err = 0; if (scsi_is_sdev_device(dev)) { /* * All the high-level SCSI drivers that implement runtime * PM treat runtime suspend, system suspend, and system * hibernate nearly identically. In all cases the requirements * for runtime suspension are stricter. */ if (pm_runtime_suspended(dev)) return 0; err = scsi_dev_type_suspend(dev, cb); } return err; } static void async_sdev_resume(void *dev, async_cookie_t cookie) { scsi_dev_type_resume(dev, do_scsi_resume); } static void async_sdev_thaw(void *dev, async_cookie_t cookie) { scsi_dev_type_resume(dev, do_scsi_thaw); } static void async_sdev_restore(void *dev, async_cookie_t cookie) { scsi_dev_type_resume(dev, do_scsi_restore); } static int scsi_bus_resume_common(struct device *dev, int (*cb)(struct device *, const struct dev_pm_ops *)) { async_func_t fn; if (!scsi_is_sdev_device(dev)) fn = NULL; else if (cb == do_scsi_resume) fn = async_sdev_resume; else if (cb == do_scsi_thaw) fn = async_sdev_thaw; else if (cb == do_scsi_restore) fn = async_sdev_restore; else fn = NULL; /* * Forcibly set runtime PM status of request queue to "active" to * make sure we can again get requests from the queue (see also * blk_pm_peek_request()). * * The resume hook will correct runtime PM status of the disk. */ if (scsi_is_sdev_device(dev) && pm_runtime_suspended(dev)) blk_set_runtime_active(to_scsi_device(dev)->request_queue); if (fn) { async_schedule_domain(fn, dev, &scsi_sd_pm_domain); /* * If a user has disabled async probing a likely reason * is due to a storage enclosure that does not inject * staggered spin-ups. For safety, make resume * synchronous as well in that case. */ if (strncmp(scsi_scan_type, "async", 5) != 0) async_synchronize_full_domain(&scsi_sd_pm_domain); } else { pm_runtime_disable(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); } return 0; } static int scsi_bus_prepare(struct device *dev) { if (scsi_is_sdev_device(dev)) { /* sd probing uses async_schedule. Wait until it finishes. */ async_synchronize_full_domain(&scsi_sd_probe_domain); } else if (scsi_is_host_device(dev)) { /* Wait until async scanning is finished */ scsi_complete_async_scans(); } return 0; } static int scsi_bus_suspend(struct device *dev) { return scsi_bus_suspend_common(dev, do_scsi_suspend); } static int scsi_bus_resume(struct device *dev) { return scsi_bus_resume_common(dev, do_scsi_resume); } static int scsi_bus_freeze(struct device *dev) { return scsi_bus_suspend_common(dev, do_scsi_freeze); } static int scsi_bus_thaw(struct device *dev) { return scsi_bus_resume_common(dev, do_scsi_thaw); } static int scsi_bus_poweroff(struct device *dev) { return scsi_bus_suspend_common(dev, do_scsi_poweroff); } static int scsi_bus_restore(struct device *dev) { return scsi_bus_resume_common(dev, do_scsi_restore); } #else /* CONFIG_PM_SLEEP */ #define scsi_bus_prepare NULL #define scsi_bus_suspend NULL #define scsi_bus_resume NULL #define scsi_bus_freeze NULL #define scsi_bus_thaw NULL #define scsi_bus_poweroff NULL #define scsi_bus_restore NULL #endif /* CONFIG_PM_SLEEP */ static int sdev_runtime_suspend(struct device *dev) { const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; struct scsi_device *sdev = to_scsi_device(dev); int err = 0; err = blk_pre_runtime_suspend(sdev->request_queue); if (err) return err; if (pm && pm->runtime_suspend) err = pm->runtime_suspend(dev); blk_post_runtime_suspend(sdev->request_queue, err); return err; } static int scsi_runtime_suspend(struct device *dev) { int err = 0; dev_dbg(dev, "scsi_runtime_suspend\n"); if (scsi_is_sdev_device(dev)) err = sdev_runtime_suspend(dev); /* Insert hooks here for targets, hosts, and transport classes */ return err; } static int sdev_runtime_resume(struct device *dev) { struct scsi_device *sdev = to_scsi_device(dev); const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; int err = 0; blk_pre_runtime_resume(sdev->request_queue); if (pm && pm->runtime_resume) err = pm->runtime_resume(dev); blk_post_runtime_resume(sdev->request_queue, err); return err; } static int scsi_runtime_resume(struct device *dev) { int err = 0; dev_dbg(dev, "scsi_runtime_resume\n"); if (scsi_is_sdev_device(dev)) err = sdev_runtime_resume(dev); /* Insert hooks here for targets, hosts, and transport classes */ return err; } static int scsi_runtime_idle(struct device *dev) { dev_dbg(dev, "scsi_runtime_idle\n"); /* Insert hooks here for targets, hosts, and transport classes */ if (scsi_is_sdev_device(dev)) { pm_runtime_mark_last_busy(dev); pm_runtime_autosuspend(dev); return -EBUSY; } return 0; } int scsi_autopm_get_device(struct scsi_device *sdev) { int err; err = pm_runtime_get_sync(&sdev->sdev_gendev); if (err < 0 && err !=-EACCES) pm_runtime_put_sync(&sdev->sdev_gendev); else err = 0; return err; } EXPORT_SYMBOL_GPL(scsi_autopm_get_device); void scsi_autopm_put_device(struct scsi_device *sdev) { pm_runtime_put_sync(&sdev->sdev_gendev); } EXPORT_SYMBOL_GPL(scsi_autopm_put_device); void scsi_autopm_get_target(struct scsi_target *starget) { pm_runtime_get_sync(&starget->dev); } void scsi_autopm_put_target(struct scsi_target *starget) { pm_runtime_put_sync(&starget->dev); } int scsi_autopm_get_host(struct Scsi_Host *shost) { int err; err = pm_runtime_get_sync(&shost->shost_gendev); if (err < 0 && err !=-EACCES) pm_runtime_put_sync(&shost->shost_gendev); else err = 0; return err; } void scsi_autopm_put_host(struct Scsi_Host *shost) { pm_runtime_put_sync(&shost->shost_gendev); } const struct dev_pm_ops scsi_bus_pm_ops = { .prepare = scsi_bus_prepare, .suspend = scsi_bus_suspend, .resume = scsi_bus_resume, .freeze = scsi_bus_freeze, .thaw = scsi_bus_thaw, .poweroff = scsi_bus_poweroff, .restore = scsi_bus_restore, .runtime_suspend = scsi_runtime_suspend, .runtime_resume = scsi_runtime_resume, .runtime_idle = scsi_runtime_idle, };