in preparation for future mvmeppc and mvme88k ports.
This needs a bit if tidying up to make it trully shareable, which will
happen as the new mvme ports are added.
Basically, bus_dmamap_sync() `PREREAD' needs to flush the cache
for the start and end of the region if it is not aligned to
a cacheline boundary, otherwise a subsequent POSTREAD can *purge*
valid data which was in the cacheline but *outside* the region
passed to bus_dmamap_sync().
Bus snooping doesn't always help here because osiop(4) calls
bus_dmamap_sync() with POSTREAD even if no data was actually
transferred! (And we can't rely on snooping on the 68060 models anyway).
. use a structure for the tag instead of an integer constant,
. add bus_space_{peek,poke}_N() (and G/C `badaddr()'),
. fix a few drivers which have dependencies on the implementation.
vme_dmamem*.
This is still a work in progress, but seems to DTRT on mvme167 so far.
TODO:
. Get VMEbus slave mode going on mvme147. This should be easy.
. Fix up the A16 slave mappings.
. Bounce buffer support. (Messy, but pretty much a `must have'.)
. Figure out how to deal with `location monitor' interrupts
within the framework. (Useful for Busnet, among other things.)
. It would be nice to make use of the VMEchip2's DMA facilities...
"off_t" and the return value is a "paddr_t" to allow mappings
at offsets past 2^31 bytes. Somewhat inspired by FreeBSD, which
only changed the offset to a "vm_offset_t".
Includes updates for the i386, pc532 and sh3 mmmmap from Jason Thorpe.
These changes add support for:
o The MI VMEbus framework on both MVME147 and MVME167.
o Enhancements to the existing MD bus_space(9) implementation.
o Most of the bus_dma(9) API.
scw