1 files changed, 358 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_pm.c b/drivers/scsi/scsi_pm.c
new file mode 100644
index 000000000..ebc193f7f
--- /dev/null
+++ b/drivers/scsi/scsi_pm.c
@@ -0,0 +1,358 @@
+/*
+ *	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);
+		err = pm_runtime_set_active(dev);
+		pm_runtime_enable(dev);
+
+		/*
+		 * 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 (!err && scsi_is_sdev_device(dev)) {
+			struct scsi_device *sdev = to_scsi_device(dev);
+
+			if (sdev->request_queue->dev)
+				blk_set_runtime_active(sdev->request_queue);
+		}
+	}
+
+	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;
+
+	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,
+};