[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 <cornelia.huck@de.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
index ac845c1ebf83..71fe380f86f6 100644
--- a/drivers/s390/cio/css.h
+++ b/drivers/s390/cio/css.h
@@ -160,6 +160,8 @@ struct channel_subsystem {
         int cm_enabled;
         void *cub_addr1;
         void *cub_addr2;
+        /* for orphaned ccw devices */
+        struct subchannel *pseudo_subchannel;
 };
 #define to_css(dev) container_of(dev, struct channel_subsystem, device)
 
@@ -187,6 +189,8 @@ void css_clear_subchannel_slow_list(void);
 int css_slow_subchannels_exist(void);
 extern int need_rescan;
 
+int sch_is_pseudo_sch(struct subchannel *);
+
 extern struct workqueue_struct *slow_path_wq;
 extern struct work_struct slow_path_work;