patch-2_6_7-vs1_9_1_12

[linux-2.6.git] / drivers / s390 / cio / device.c

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 31d561b..a921b1f 100644 (file)
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1,7 +1,7 @@
 /*
  *  drivers/s390/cio/device.c
  *  bus driver for ccw devices
- *   $Revision: 1.115 $
+ *   $Revision: 1.120 $
  *
  *    Copyright (C) 2002 IBM Deutschland Entwicklung GmbH,
  *                      IBM Corporation
@@ -26,6 +26,7 @@
 #include "cio.h"
 #include "css.h"
 #include "device.h"
+#include "ioasm.h"
 
 /******************* bus type handling ***********************/
 
@@ -158,6 +159,11 @@ init_ccw_bus_type (void)
                ret = -ENOMEM; /* FIXME: better errno ? */
                goto out_err;
        }
+       slow_path_wq = create_singlethread_workqueue("kslowcrw");
+       if (!slow_path_wq) {
+               ret = -ENOMEM; /* FIXME: better errno ? */
+               goto out_err;
+       }
        if ((ret = bus_register (&ccw_bus_type)))
                goto out_err;
 
@@ -173,6 +179,8 @@ out_err:
                destroy_workqueue(ccw_device_work);
        if (ccw_device_notify_work)
                destroy_workqueue(ccw_device_notify_work);
+       if (slow_path_wq)
+               destroy_workqueue(slow_path_wq);
        return ret;
 }
 
@@ -499,20 +507,94 @@ ccw_device_register(struct ccw_device *cdev)
        return ret;
 }
 
-void
-ccw_device_do_unreg_rereg(void *data)
+static struct ccw_device *
+get_disc_ccwdev_by_devno(unsigned int devno, struct ccw_device *sibling)
 {
+       struct ccw_device *cdev;
+       struct list_head *entry;
        struct device *dev;
 
-       dev = (struct device *)data;
-       device_remove_files(dev);
-       device_del(dev);
-       if (device_add(dev)) {
+       if (!get_bus(&ccw_bus_type))
+               return NULL;
+       down_read(&ccw_bus_type.subsys.rwsem);
+       cdev = NULL;
+       list_for_each(entry, &ccw_bus_type.devices.list) {
+               dev = get_device(container_of(entry,
+                                             struct device, bus_list));
+               if (!dev)
+                       continue;
+               cdev = to_ccwdev(dev);
+               if ((cdev->private->state == DEV_STATE_DISCONNECTED) &&
+                   (cdev->private->devno == devno) &&
+                   (!strncmp(cdev->dev.bus_id, sibling->dev.bus_id,
+                             BUS_ID_SIZE))) {
+                       cdev->private->state = DEV_STATE_NOT_OPER;
+                       break;
+               }
                put_device(dev);
+               cdev = NULL;
+       }
+       up_read(&ccw_bus_type.subsys.rwsem);
+       put_bus(&ccw_bus_type);
+
+       return cdev;
+}
+
+void
+ccw_device_do_unreg_rereg(void *data)
+{
+       struct ccw_device *cdev;
+       struct subchannel *sch;
+       int need_rename;
+
+       cdev = (struct ccw_device *)data;
+       sch = to_subchannel(cdev->dev.parent);
+       if (cdev->private->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;
+
+               need_rename = 1;
+               other_cdev = get_disc_ccwdev_by_devno(sch->schib.pmcw.dev,
+                                                     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->irq, &other_sch->schib);
+                               if (other_sch->schib.pmcw.dnv) {
+                                       other_sch->schib.pmcw.intparm = 0;
+                                       cio_modify(other_sch);
+                               }
+                               device_unregister(&other_sch->dev);
+                       }
+               }
+               cdev->private->devno = sch->schib.pmcw.dev;
+       } else
+               need_rename = 0;
+       device_remove_files(&cdev->dev);
+       device_del(&cdev->dev);
+       if (need_rename)
+               snprintf (cdev->dev.bus_id, BUS_ID_SIZE, "0.0.%04x",
+                         sch->schib.pmcw.dev);
+       if (device_add(&cdev->dev)) {
+               put_device(&cdev->dev);
                return;
        }
-       if (device_add_files(dev))
-               device_unregister(dev);
+       if (device_add_files(&cdev->dev))
+               device_unregister(&cdev->dev);
 }
 
 static void
@@ -572,9 +654,7 @@ ccw_device_call_sch_unregister(void *data)
        struct subchannel *sch;
 
        sch = to_subchannel(cdev->dev.parent);
-       /* Check if device is registered. */
-       if (!list_empty(&sch->dev.node))
-               device_unregister(&sch->dev);
+       device_unregister(&sch->dev);
        /* Reset intparm to zeroes. */
        sch->schib.pmcw.intparm = 0;
        cio_modify(sch);
@@ -603,7 +683,7 @@ io_subchannel_recog_done(struct ccw_device *cdev)
                sch = to_subchannel(cdev->dev.parent);
                INIT_WORK(&cdev->private->kick_work,
                          ccw_device_call_sch_unregister, (void *) cdev);
-               queue_work(ccw_device_work, &cdev->private->kick_work);
+               queue_work(slow_path_wq, &cdev->private->kick_work);
                break;
        case DEV_STATE_BOXED:
                /* Device did not respond in time. */