[S390] pm: ccw bus power management callbacks

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 237 insertions, 0 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 35441fa16be1..228a6c314d84 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1895,6 +1895,242 @@ static void ccw_device_shutdown(struct device *dev)
         disable_cmf(cdev);
 }
 
+static int ccw_device_pm_prepare(struct device *dev)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+
+        if (work_pending(&cdev->private->kick_work))
+                return -EAGAIN;
+        /* Fail while device is being set online/offline. */
+        if (atomic_read(&cdev->private->onoff))
+                return -EAGAIN;
+
+        if (cdev->online && cdev->drv && cdev->drv->prepare)
+                return cdev->drv->prepare(cdev);
+
+        return 0;
+}
+
+static void ccw_device_pm_complete(struct device *dev)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+
+        if (cdev->online && cdev->drv && cdev->drv->complete)
+                cdev->drv->complete(cdev);
+}
+
+static int ccw_device_pm_freeze(struct device *dev)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+        int ret, cm_enabled;
+
+        /* Fail suspend while device is in transistional state. */
+        if (!dev_fsm_final_state(cdev))
+                return -EAGAIN;
+        if (!cdev->online)
+                return 0;
+        if (cdev->drv && cdev->drv->freeze) {
+                ret = cdev->drv->freeze(cdev);
+                if (ret)
+                        return ret;
+        }
+
+        spin_lock_irq(sch->lock);
+        cm_enabled = cdev->private->cmb != NULL;
+        spin_unlock_irq(sch->lock);
+        if (cm_enabled) {
+                /* Don't have the css write on memory. */
+                ret = ccw_set_cmf(cdev, 0);
+                if (ret)
+                        return ret;
+        }
+        /* From here on, disallow device driver I/O. */
+        spin_lock_irq(sch->lock);
+        ret = cio_disable_subchannel(sch);
+        spin_unlock_irq(sch->lock);
+
+        return ret;
+}
+
+static int ccw_device_pm_thaw(struct device *dev)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+        int ret, cm_enabled;
+
+        if (!cdev->online)
+                return 0;
+
+        spin_lock_irq(sch->lock);
+        /* Allow device driver I/O again. */
+        ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
+        cm_enabled = cdev->private->cmb != NULL;
+        spin_unlock_irq(sch->lock);
+        if (ret)
+                return ret;
+
+        if (cm_enabled) {
+                ret = ccw_set_cmf(cdev, 1);
+                if (ret)
+                        return ret;
+        }
+
+        if (cdev->drv && cdev->drv->thaw)
+                ret = cdev->drv->thaw(cdev);
+
+        return ret;
+}
+
+static void __ccw_device_pm_restore(struct ccw_device *cdev)
+{
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+        int ret;
+
+        if (cio_is_console(sch->schid))
+                goto out;
+        /*
+         * While we were sleeping, devices may have gone or become
+         * available again. Kick re-detection.
+         */
+        spin_lock_irq(sch->lock);
+        cdev->private->flags.resuming = 1;
+        ret = ccw_device_recognition(cdev);
+        spin_unlock_irq(sch->lock);
+        if (ret) {
+                CIO_MSG_EVENT(0, "Couldn't start recognition for device "
+                              "%s (ret=%d)\n", dev_name(&cdev->dev), ret);
+                spin_lock_irq(sch->lock);
+                cdev->private->state = DEV_STATE_DISCONNECTED;
+                spin_unlock_irq(sch->lock);
+                /* notify driver after the resume cb */
+                goto out;
+        }
+        wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
+                   cdev->private->state == DEV_STATE_DISCONNECTED);
+
+out:
+        cdev->private->flags.resuming = 0;
+}
+
+static int resume_handle_boxed(struct ccw_device *cdev)
+{
+        cdev->private->state = DEV_STATE_BOXED;
+        if (ccw_device_notify(cdev, CIO_BOXED))
+                return 0;
+        ccw_device_schedule_sch_unregister(cdev);
+        return -ENODEV;
+}
+
+static int resume_handle_disc(struct ccw_device *cdev)
+{
+        cdev->private->state = DEV_STATE_DISCONNECTED;
+        if (ccw_device_notify(cdev, CIO_GONE))
+                return 0;
+        ccw_device_schedule_sch_unregister(cdev);
+        return -ENODEV;
+}
+
+static int ccw_device_pm_restore(struct device *dev)
+{
+        struct ccw_device *cdev = to_ccwdev(dev);
+        struct subchannel *sch = to_subchannel(cdev->dev.parent);
+        int ret = 0, cm_enabled;
+
+        __ccw_device_pm_restore(cdev);
+        spin_lock_irq(sch->lock);
+        if (cio_is_console(sch->schid)) {
+                cio_enable_subchannel(sch, (u32)(addr_t)sch);
+                spin_unlock_irq(sch->lock);
+                goto out_restore;
+        }
+        cdev->private->flags.donotify = 0;
+        /* check recognition results */
+        switch (cdev->private->state) {
+        case DEV_STATE_OFFLINE:
+                break;
+        case DEV_STATE_BOXED:
+                ret = resume_handle_boxed(cdev);
+                spin_unlock_irq(sch->lock);
+                if (ret)
+                        goto out;
+                goto out_restore;
+        case DEV_STATE_DISCONNECTED:
+                goto out_disc_unlock;
+        default:
+                goto out_unreg_unlock;
+        }
+        /* check if the device id has changed */
+        if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
+                CIO_MSG_EVENT(0, "resume: sch %s: failed (devno changed from "
+                              "%04x to %04x)\n", dev_name(&sch->dev),
+                              cdev->private->dev_id.devno,
+                              sch->schib.pmcw.dev);
+                goto out_unreg_unlock;
+        }
+        /* check if the device type has changed */
+        if (!ccw_device_test_sense_data(cdev)) {
+                ccw_device_update_sense_data(cdev);
+                PREPARE_WORK(&cdev->private->kick_work,
+                             ccw_device_do_unbind_bind);
+                queue_work(ccw_device_work, &cdev->private->kick_work);
+                ret = -ENODEV;
+                goto out_unlock;
+        }
+        if (!cdev->online) {
+                ret = 0;
+                goto out_unlock;
+        }
+        ret = ccw_device_online(cdev);
+        if (ret)
+                goto out_disc_unlock;
+
+        cm_enabled = cdev->private->cmb != NULL;
+        spin_unlock_irq(sch->lock);
+
+        wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
+        if (cdev->private->state != DEV_STATE_ONLINE) {
+                spin_lock_irq(sch->lock);
+                goto out_disc_unlock;
+        }
+        if (cm_enabled) {
+                ret = ccw_set_cmf(cdev, 1);
+                if (ret) {
+                        CIO_MSG_EVENT(2, "resume: cdev %s: cmf failed "
+                                      "(rc=%d)\n", dev_name(&cdev->dev), ret);
+                        ret = 0;
+                }
+        }
+
+out_restore:
+        if (cdev->online && cdev->drv && cdev->drv->restore)
+                ret = cdev->drv->restore(cdev);
+out:
+        return ret;
+
+out_disc_unlock:
+        ret = resume_handle_disc(cdev);
+        spin_unlock_irq(sch->lock);
+        if (ret)
+                return ret;
+        goto out_restore;
+
+out_unreg_unlock:
+        ccw_device_schedule_sch_unregister(cdev);
+        ret = -ENODEV;
+out_unlock:
+        spin_unlock_irq(sch->lock);
+        return ret;
+}
+
+static struct dev_pm_ops ccw_pm_ops = {
+        .prepare = ccw_device_pm_prepare,
+        .complete = ccw_device_pm_complete,
+        .freeze = ccw_device_pm_freeze,
+        .thaw = ccw_device_pm_thaw,
+        .restore = ccw_device_pm_restore,
+};
+
 struct bus_type ccw_bus_type = {
         .name   = "ccw",
         .match  = ccw_bus_match,
@@ -1902,6 +2138,7 @@ struct bus_type ccw_bus_type = {
         .probe  = ccw_device_probe,
         .remove = ccw_device_remove,
         .shutdown = ccw_device_shutdown,
+        .pm = &ccw_pm_ops,
 };
 
 /**