What is the reel purpose of in_beXX() and out_beXX() fonctions ?

[Benjamin Herrenschmidt]

On Mon, 2014-10-27 at 15:05 +0000, David Laight wrote:
> 
> Unfortunately the functions sometimes contain additional (often
> unneeded) 
> sequencing instructions - the driver may be able to perform multiple 
> operations between the sequencing instructions.

That's in part why some folks are working on proper relaxed accessors
(see Will Deacon's stuff)

Cheers,
Ben.