On Mon, Oct 10, 2011 at 09:40:17AM +0100, David Laight wrote:

Actually memory barriers shouldn't really be added to
any of these 'accessor' functions.
(Or, at least, ones without barriers should be provided.)

The driver may want to to a series of writes, then a
single barrier, before a final write of a command (etc).

in_le32() from io.h is specially horrid!

	David

The driver would like to control if and when we want to put a memory
barrier. We really don't want it to be done under the hood. In this
respect we prefer raw functions which are still available to all
platforms.