- Allocate interrupt handles dynamically from a pool(9) to reduce the
number of TLB misses during interrupt dispatch.
- Fully support evcnt(9) in all interrupt dispatchers.
useful should one occur.
- Manually poke some config values into the sh5pci host bridge's
config registers since it doesn't appear in config. space.
- Reserve the first 256 bytes of i/o space to avoid assigning i/o
address 0 to any cards.
- Slight tweak to the initialisation code after consultation with
SuperH and the linux driver.
