This patch fixes two issues reported by Roland Dreier and Christoph Hellwig:

- Mismatched sync/locking between completion handler and destroy cq We
  introduced a counter nr_events per cq to track number of irq events
  seen. This counter is incremented when an event queue entry is seen
  and decremented after completion handler has been called regardless
  if scaling code is active or not. Note that nr_callbacks tracks
  number of events assigned to a cpu and both counters can potentially
  diverge.

  The sync between running completion handler and destroy cq is done
  by using the global spin lock ehca_cq_idr_lock.

- Replace yield by wait_event on the counter above to become zero.
Signed-off-by: NHoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Allow users to en/disable scaling code when loading ib_ehca module,
rather than requiring the module to be rebuilt to change the setting.
Signed-off-by: NHoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Rework ehca interrupt handling to avoid/reduce missed irq events.
Signed-off-by: NHoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Remove prototypes for functions that don't exist.
Signed-off-by: NHoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

This patch removes do_mmap() from ehca:
 - Call remap_pfn_range() for hardware register block
 - Use vm_insert_page() to register memory allocated for completion
   queues and queue pairs
 - The actual mmap() call/trigger is now controlled by user space,
   ie. libehca
Signed-off-by: NHoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>

Add a driver for IBM GX bus InfiniBand adapters, which are usable with
some pSeries/System p systems.

Signed-off-by: Heiko J Schick <schickhj.ibm.com>
Signed-off-by: NRoland Dreier <rolandd@cisco.com>