K 10
svn:author
V 8
jhibbits
K 8
svn:date
V 27
2019-03-01T02:49:47.263000Z
K 7
svn:log
V 515
powerpc/powernv: Add asynchronous token management for powernv

The OPAL firmware only supports a finite number of in-flight asynchronous
operations.  Rather than have each subsystem try to manage its own, use a
central management service to hand out tokens.

More work can be done to improve asynchronous behavior, such as funneling
things through a future OPAL heartbeat handler, but capabilities will be
added as needed.

Augment the existing consumers (i2c and sensors) to use this new API.

MFC after:	4 weeks

END