- No more distinction between i/o-mapped and memory-mapped
devices. It's all "bus space" now, and space tags
differentiate the space with finer grain than the
bus chipset tag.
- Add memory barrier methods.
- Implement space alloc/free methods.
- Implement region read/write methods (like memcpy to/from
bus space).
This interface provides a better abstraction for dealing with
machine-independent chipset drivers.
In elink_reset(), since some machines may have more than one ISA bus,
implement a way of keeping track of which ISA bus has received an
elink_reset(); The static variable which was used previously didn't
scale.
