utilizing David Jones' new MI NCR 5380 code. Ported from the sun3 ncr_si.c
and "sw" DMA code written by me.
This driver contains user-configurable "options", which can be set via the
"flags" directive in the kernel configuration file. By default, only
DMA is enabled. DMA completion interrupts and reselection may be enabled
by setting the appropriate bits with "flags". See si.c for details.
Note that DMA completion interrupts and reselection don't yet work on the
4/100 controller. I don't know why, and it's unlikely that I'll have
the opportunity to find out any time soon. DMA does work, and results
in a considerable performance increase.
DMA, DMA completion interrupts, and reslection all work on my 4/260 (VME)
system with modern SCSI-II disks.
Remove dvma_malloc/dvma_free; drivers should allocate kernel memory and
use dvma_mapin/dvma_mapout to double map it in DVMA space.
Make the resource map `dvmamap' responsible for all DVMA allocation.
The VM map `physmap' only serves the role of placeholder in the VM system.
of FIFO overflows on high baud rates.
However, doing so on all 4 ports would cost a whopping 64KB (at 4096 entries
per FIFO) of kernel memory. So, the FIFOs are now allocated at attach time
allowing the size for the keyboard and mouse ports to be reduced (to 128)
which should be adequate for the 1200 baud they use.
- properly do MSG_IN handshaking, so we can actually receive multi-byte msgs.
- do synch negotiation (now that the above works).
- handle disconnects.
There are a few trial-and-error bits at points where the docs I have are
particularly ambiguous about the state of chip and/or SCSI bus.
Things to do:
- more cleanup
- deal with MSG_OUT phase better
- keep some "config reg 3" bits per target (ie. FASTCLK and FASTSCSI).
Since uname currently does not allow to discriminate different sparc
models, we use `sysctl.hw.cpumodel' to do this somewhat heuristicly:
if the returned strings starts with "SUN4-" a sun4 architecture is
assumed. This information is used to determine whether or not to strip
the a.out header off the 1st-stage bootblocks.
christos