Heiko Carstens wrote:

> This looks wrong: "b" is a u64 and you write it to something that is an
> unsigned long. We're going to miss a few bits on 31 bit platforms...

Indeed. Here's another version protecting the quad macros with __s390x__.
to be applied on rc6-mm1.

For the moment, __raw_writeq() is needed by __iowrite64_copy() which is
protected by CONFIG_64BIT. Some drivers also use it.

Thanks for reviewing,

C.