From d7b5a4c94f49131811112526f7d404a50f0b5ca7 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Fri, 8 Dec 2006 15:54:28 +0100 Subject: [S390] Support for disconnected devices reappearing on another subchannel. - create a 'pseudo_subchannel' per channel subsystem (the 'orphanage') - use the orphanage as a shelter for ccw_devices that can't remain on the same subchannel Signed-off-by: Cornelia Huck Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/device.c | 287 ++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 237 insertions(+), 50 deletions(-) (limited to 'drivers/s390/cio/device.c') diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c index 9a31239fe02..7fe1ccdc781 100644 --- a/drivers/s390/cio/device.c +++ b/drivers/s390/cio/device.c @@ -23,6 +23,7 @@ #include /* HZ */ #include "cio.h" +#include "cio_debug.h" #include "css.h" #include "device.h" #include "ioasm.h" @@ -294,6 +295,11 @@ online_show (struct device *dev, struct device_attribute *attr, char *buf) return sprintf(buf, cdev->online ? "1\n" : "0\n"); } +int ccw_device_is_orphan(struct ccw_device *cdev) +{ + return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent)); +} + static void ccw_device_unregister(struct work_struct *work) { struct ccw_device_private *priv; @@ -310,10 +316,23 @@ static void ccw_device_remove_disconnected(struct ccw_device *cdev) { struct subchannel *sch; + unsigned long flags; /* * Forced offline in disconnected state means * 'throw away device'. */ + if (ccw_device_is_orphan(cdev)) { + /* Deregister ccw device. */ + spin_lock_irqsave(cdev->ccwlock, flags); + cdev->private->state = DEV_STATE_NOT_OPER; + spin_unlock_irqrestore(cdev->ccwlock, flags); + if (get_device(&cdev->dev)) { + PREPARE_WORK(&cdev->private->kick_work, + ccw_device_unregister); + queue_work(ccw_device_work, &cdev->private->kick_work); + } + return ; + } sch = to_subchannel(cdev->dev.parent); css_sch_device_unregister(sch); /* Reset intparm to zeroes. */ @@ -474,6 +493,8 @@ available_show (struct device *dev, struct device_attribute *attr, char *buf) struct ccw_device *cdev = to_ccwdev(dev); struct subchannel *sch; + if (ccw_device_is_orphan(cdev)) + return sprintf(buf, "no device\n"); switch (cdev->private->state) { case DEV_STATE_BOXED: return sprintf(buf, "boxed\n"); @@ -574,11 +595,10 @@ match_devno(struct device * dev, void * data) cdev = to_ccwdev(dev); if ((cdev->private->state == DEV_STATE_DISCONNECTED) && + !ccw_device_is_orphan(cdev) && ccw_dev_id_is_equal(&cdev->private->dev_id, &d->dev_id) && - (cdev != d->sibling)) { - cdev->private->state = DEV_STATE_NOT_OPER; + (cdev != d->sibling)) return 1; - } return 0; } @@ -595,6 +615,28 @@ static struct ccw_device * get_disc_ccwdev_by_dev_id(struct ccw_dev_id *dev_id, return dev ? to_ccwdev(dev) : NULL; } +static int match_orphan(struct device *dev, void *data) +{ + struct ccw_dev_id *dev_id; + struct ccw_device *cdev; + + dev_id = data; + cdev = to_ccwdev(dev); + return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id); +} + +static struct ccw_device * +get_orphaned_ccwdev_by_dev_id(struct channel_subsystem *css, + struct ccw_dev_id *dev_id) +{ + struct device *dev; + + dev = device_find_child(&css->pseudo_subchannel->dev, dev_id, + match_orphan); + + return dev ? to_ccwdev(dev) : NULL; +} + static void ccw_device_add_changed(struct work_struct *work) { @@ -614,64 +656,19 @@ ccw_device_add_changed(struct work_struct *work) } } -extern int css_get_ssd_info(struct subchannel *sch); - -void -ccw_device_do_unreg_rereg(struct work_struct *work) +void ccw_device_do_unreg_rereg(struct work_struct *work) { struct ccw_device_private *priv; struct ccw_device *cdev; struct subchannel *sch; - int need_rename; priv = container_of(work, struct ccw_device_private, kick_work); cdev = priv->cdev; sch = to_subchannel(cdev->dev.parent); - if (cdev->private->dev_id.devno != sch->schib.pmcw.dev) { - /* - * The device number has changed. This is usually only when - * a device has been detached under VM and then re-appeared - * on another subchannel because of a different attachment - * order than before. Ideally, we should should just switch - * subchannels, but unfortunately, this is not possible with - * the current implementation. - * Instead, we search for the old subchannel for this device - * number and deregister so there are no collisions with the - * newly registered ccw_device. - * FIXME: Find another solution so the block layer doesn't - * get possibly sick... - */ - struct ccw_device *other_cdev; - struct ccw_dev_id dev_id; - - need_rename = 1; - dev_id.devno = sch->schib.pmcw.dev; - dev_id.ssid = sch->schid.ssid; - other_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev); - if (other_cdev) { - struct subchannel *other_sch; - - other_sch = to_subchannel(other_cdev->dev.parent); - if (get_device(&other_sch->dev)) { - stsch(other_sch->schid, &other_sch->schib); - if (other_sch->schib.pmcw.dnv) { - other_sch->schib.pmcw.intparm = 0; - cio_modify(other_sch); - } - css_sch_device_unregister(other_sch); - } - } - /* Update ssd info here. */ - css_get_ssd_info(sch); - cdev->private->dev_id.devno = sch->schib.pmcw.dev; - } else - need_rename = 0; + device_remove_files(&cdev->dev); if (test_and_clear_bit(1, &cdev->private->registered)) device_del(&cdev->dev); - if (need_rename) - snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.%x.%04x", - sch->schid.ssid, sch->schib.pmcw.dev); PREPARE_WORK(&cdev->private->kick_work, ccw_device_add_changed); queue_work(ccw_device_work, &cdev->private->kick_work); @@ -736,6 +733,131 @@ static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch) return cdev; } +static int io_subchannel_recog(struct ccw_device *, struct subchannel *); + +static void sch_attach_device(struct subchannel *sch, + struct ccw_device *cdev) +{ + spin_lock_irq(sch->lock); + sch->dev.driver_data = cdev; + cdev->private->schid = sch->schid; + cdev->ccwlock = sch->lock; + device_trigger_reprobe(sch); + spin_unlock_irq(sch->lock); +} + +static void sch_attach_disconnected_device(struct subchannel *sch, + struct ccw_device *cdev) +{ + struct subchannel *other_sch; + int ret; + + other_sch = to_subchannel(get_device(cdev->dev.parent)); + ret = device_move(&cdev->dev, &sch->dev); + if (ret) { + CIO_MSG_EVENT(2, "Moving disconnected device 0.%x.%04x failed " + "(ret=%d)!\n", cdev->private->dev_id.ssid, + cdev->private->dev_id.devno, ret); + put_device(&other_sch->dev); + return; + } + other_sch->dev.driver_data = NULL; + /* No need to keep a subchannel without ccw device around. */ + css_sch_device_unregister(other_sch); + put_device(&other_sch->dev); + sch_attach_device(sch, cdev); +} + +static void sch_attach_orphaned_device(struct subchannel *sch, + struct ccw_device *cdev) +{ + int ret; + + /* Try to move the ccw device to its new subchannel. */ + ret = device_move(&cdev->dev, &sch->dev); + if (ret) { + CIO_MSG_EVENT(0, "Moving device 0.%x.%04x from orphanage " + "failed (ret=%d)!\n", + cdev->private->dev_id.ssid, + cdev->private->dev_id.devno, ret); + return; + } + sch_attach_device(sch, cdev); +} + +static void sch_create_and_recog_new_device(struct subchannel *sch) +{ + struct ccw_device *cdev; + + /* Need to allocate a new ccw device. */ + cdev = io_subchannel_create_ccwdev(sch); + if (IS_ERR(cdev)) { + /* OK, we did everything we could... */ + css_sch_device_unregister(sch); + return; + } + spin_lock_irq(sch->lock); + sch->dev.driver_data = cdev; + spin_unlock_irq(sch->lock); + /* Start recognition for the new ccw device. */ + if (io_subchannel_recog(cdev, sch)) { + spin_lock_irq(sch->lock); + sch->dev.driver_data = NULL; + spin_unlock_irq(sch->lock); + if (cdev->dev.release) + cdev->dev.release(&cdev->dev); + css_sch_device_unregister(sch); + } +} + + +void ccw_device_move_to_orphanage(struct work_struct *work) +{ + struct ccw_device_private *priv; + struct ccw_device *cdev; + struct ccw_device *replacing_cdev; + struct subchannel *sch; + int ret; + struct channel_subsystem *css; + struct ccw_dev_id dev_id; + + priv = container_of(work, struct ccw_device_private, kick_work); + cdev = priv->cdev; + sch = to_subchannel(cdev->dev.parent); + css = to_css(sch->dev.parent); + dev_id.devno = sch->schib.pmcw.dev; + dev_id.ssid = sch->schid.ssid; + + /* + * Move the orphaned ccw device to the orphanage so the replacing + * ccw device can take its place on the subchannel. + */ + ret = device_move(&cdev->dev, &css->pseudo_subchannel->dev); + if (ret) { + CIO_MSG_EVENT(0, "Moving device 0.%x.%04x to orphanage failed " + "(ret=%d)!\n", cdev->private->dev_id.ssid, + cdev->private->dev_id.devno, ret); + return; + } + cdev->ccwlock = css->pseudo_subchannel->lock; + /* + * Search for the replacing ccw device + * - among the disconnected devices + * - in the orphanage + */ + replacing_cdev = get_disc_ccwdev_by_dev_id(&dev_id, cdev); + if (replacing_cdev) { + sch_attach_disconnected_device(sch, replacing_cdev); + return; + } + replacing_cdev = get_orphaned_ccwdev_by_dev_id(css, &dev_id); + if (replacing_cdev) { + sch_attach_orphaned_device(sch, replacing_cdev); + return; + } + sch_create_and_recog_new_device(sch); +} + /* * Register recognized device. */ @@ -890,12 +1012,55 @@ io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch) return rc; } +static void ccw_device_move_to_sch(struct work_struct *work) +{ + struct ccw_device_private *priv; + int rc; + struct subchannel *sch; + struct ccw_device *cdev; + struct subchannel *former_parent; + + priv = container_of(work, struct ccw_device_private, kick_work); + sch = priv->sch; + cdev = priv->cdev; + former_parent = ccw_device_is_orphan(cdev) ? + NULL : to_subchannel(get_device(cdev->dev.parent)); + mutex_lock(&sch->reg_mutex); + /* Try to move the ccw device to its new subchannel. */ + rc = device_move(&cdev->dev, &sch->dev); + mutex_unlock(&sch->reg_mutex); + if (rc) { + CIO_MSG_EVENT(2, "Moving device 0.%x.%04x to subchannel " + "0.%x.%04x failed (ret=%d)!\n", + cdev->private->dev_id.ssid, + cdev->private->dev_id.devno, sch->schid.ssid, + sch->schid.sch_no, rc); + css_sch_device_unregister(sch); + goto out; + } + if (former_parent) { + spin_lock_irq(former_parent->lock); + former_parent->dev.driver_data = NULL; + spin_unlock_irq(former_parent->lock); + css_sch_device_unregister(former_parent); + /* Reset intparm to zeroes. */ + former_parent->schib.pmcw.intparm = 0; + cio_modify(former_parent); + } + sch_attach_device(sch, cdev); +out: + if (former_parent) + put_device(&former_parent->dev); + put_device(&cdev->dev); +} + static int io_subchannel_probe (struct subchannel *sch) { struct ccw_device *cdev; int rc; unsigned long flags; + struct ccw_dev_id dev_id; if (sch->dev.driver_data) { /* @@ -918,6 +1083,28 @@ io_subchannel_probe (struct subchannel *sch) get_device(&cdev->dev); return 0; } + /* + * First check if a fitting device may be found amongst the + * disconnected devices or in the orphanage. + */ + dev_id.devno = sch->schib.pmcw.dev; + dev_id.ssid = sch->schid.ssid; + cdev = get_disc_ccwdev_by_dev_id(&dev_id, NULL); + if (!cdev) + cdev = get_orphaned_ccwdev_by_dev_id(to_css(sch->dev.parent), + &dev_id); + if (cdev) { + /* + * Schedule moving the device until when we have a registered + * subchannel to move to and succeed the probe. We can + * unregister later again, when the probe is through. + */ + cdev->private->sch = sch; + PREPARE_WORK(&cdev->private->kick_work, + ccw_device_move_to_sch); + queue_work(slow_path_wq, &cdev->private->kick_work); + return 0; + } cdev = io_subchannel_create_ccwdev(sch); if (IS_ERR(cdev)) return PTR_ERR(cdev); -- cgit v1.2.3