[PATCH] s390: common i/o layer

[PATCH] s390: common i/o layer

From: Martin Schwidefsky <schwidefsky@de.ibm.com>

 - Make blacklist busid-aware. Add "all" keyword and ! operator to cio_ignore
   kernel parameter.
 - Add state change notify function for ccw devices (not mandatory) and
   introduce the "device disconnected" state.
 - Remove auto offline from remove function for ccw devices to be able to
   distinguish between user initiated offline and implicit offline due to
   device removal.
 - Store pointer to subchannel structure in the (hardware) subchannel intparm
   and remove the ioinfo array (hurray...). Remove intparm parameter of
   cio_start.
 - Use busid instead of subchannel number for debug output.
 - Use an opm mask to track which paths are logically online for a subchannel.
 - Pathgroup every device it was requested for, even single path devices.
 - Give i/o on a logically switched off path a grace period to complete, then
   kill the i/o to get the path offline.
 - Correctly initialize all spin_locks with spin_lock_init.
 - Handle status pending/busy while disabling subchannel.
 - Set busid already in cio_validate_subchannel.
 - Add s390_root_dev_{register,unregister} functions.
 - Do stcrw() inside a kernel thread. Add crw overflow handling.
 - Use subchannel lock directly instead of ccw device lock pointer in
   ccw_device_recognition to avoid accessing an already free structure.
 - Take/release ccw device lock in ccw_device_console_enable.
 - Don't wipe out the busid field in ccw_device_console_enable.
 - Call ccw_device_unregister() directly on a notoper event - delaying it via
   queue_work is harmful (subchannel may be removed before ccw_device).
 - Handle not opertional condition in ccw_device_cancel_halt_clear.
 - Correct status pending handling: don't collect pending status directly
   but wait for the interrupt to show up.
 - Enable subchannel when trying a steal lock operation.
 - Introduce doverify bit for delayed path verification.
 - Fix locking in __ccw_device_retry_loop/read_conf_data/read_dev/chars.
 - Make SPID retry mechanism more obvious.
 - qdio: check return code of ccw_device_{halt,clear} in qdio_cleanup. Don't
   try to wait for an interrupt we won't get.
 - qdio: fix shared indicators.
 - qdio: add code to handle i/o killed by cio with active queues.
 - qdio: don't do a shutdown on timeout in interrupt context.
 - Update cio documentation.