This is a completely rewritten scsipi_xfer execution engine, and the
associated changes to HBA drivers. Overview of changes & features:
- All xfers are queued in the mid-layer, rather than doing so in an
ad-hoc fashion in individual adapter drivers.
- Adapter/channel resource management in the mid-layer, avoids even trying
to start running an xfer if the adapter/channel doesn't have the resources.
- Better communication between the mid-layer and the adapters.
- Asynchronous event notification mechanism from adapter to mid-layer and
peripherals.
- Better peripheral queue management: freeze/thaw, sorted requeueing during
recovery, etc.
- Clean separation of peripherals, adapters, and adapter channels (no more
scsipi_link).
- Kernel thread for each scsipi_channel makes error recovery much easier
(no more dealing with interrupt context when recovering from an error).
- Mid-layer support for tagged queueing: commands can have the tag type
set explicitly, tag IDs are allocated in the mid-layer (thus eliminating
the need to use buggy tag ID allocation schemes in many adapter drivers).
- support for QUEUE FULL and CHECK CONDITION status in mid-layer; the command
will be requeued, or a REQUEST SENSE will be sent as appropriate.
Just before the merge syssrc has been tagged with thorpej_scsipi_beforemerge
Also, if the so-called DMA operation is a write and ends without target-
complete set, count the data in the FIFO as residual and add that to the
amount in the counters. Hauke Fath reports that this passes early testing
on his Quantum Viking.
if it is 64k. TCL and TCM will be set properly if we just leave it alone.
Not only that, the ncr53c9x driver issues TRPAD or TRANS based on this
value. We do not want TRPAD in this case!
an ugly bit where we record the value of a2 while handling a "nofault" bus
error in locore.s in order to know how far the transaction got before a
disconnect (see esp.c comments for more details on this).
Also get rid of a loop (and delay()!) in the interrupt routine--hinted at
and researched by Chas Williams <chas@cmf.nrl.navy.mil>.
and scsipi_device respectively, with size reduction of ncr53c9x_softc.
Specifying NULL instructs the driver to use default adapter and default
device codes. Every target port has ncr53c9x_attach(sc, NULL, NULL) anyway.
anything that might cause an interrupt (e.g. the SCSI bus reset in
ncr53c9x_attach()). If we don't do this, the initial interrupt is
lost, thus causing the state machine to never enter IDLE state, thus
causing SCSI commands to never be executed.
Fixes kern/8544, reported by Erik Bertelsen <erik@mediator.uni-c.dk>.
at levels 5 (sound) and 6 (via1) on the Q700.
Raise splhigh when reading and writing registers. It's ugly, but it's
possible that we could get an interrupt from a higher-level source,
causing a re-read of a memory location.
This is not good when, e.g., we are reading the interrupt register.
Ideally, we would just raise splhigh() in ncr53c9x_readregs(), but
that's m.i. code, and it may be expensive on other architectures.
struct scsipi_adapter; they were not used.
Add a scsipi_ioctl entry point to struct scsipi_adapter. This will be
used to issue ioctl commands to the host adapters.
Inspired by PR #6090, from Matt Jacob.
deal with cheap CD-ROMs and other devices that do not appear to have
any way to enable parity generation. In the future, it might be nice
to have this configurable on a per-device basis with back-to-back
parity errors automatically disabling parity for the device. That
would require some MI changes.
* Handle unaligned and odd-length transfers.
This could probably be handled better in the future.
but is a marked improvement. This takes advantage of a pseudo-DMA hardware
hack of Apple's that exposes a 16-bit register that the Apple-designed
memory controller acts like a DMA controller and handshakes into or out
of the FIFO. Wierd.
(currently only CD-ROM drives on i386). The sys/dev/scsipi system provides 2
busses to which devices can attach (scsibus and atapibus). This needed to
change some include files and structure names in the low level scsi drivers.
second argument. The NuBus autoconfig code had to be reorganized as a
result of this, and looks much more like a directly-attached bus now.
These changes eliminate __BROKEN_INDIRECT_CONFIG.
instead of 0x400.
- Restructure interrupt handling for more performance--continue to
read/write data as long as the device keeps us in a data xfer phase.
There is still a lot of room for speed improvement here. Perhaps it
lies is speeding up the interrupt path in general?
some guesses for the machines that have two of these buggers (I don't have
such a machine). This driver is a copy of the sparc/alpha esp with a
minimum of changes--after we get it performing a bit more respectably,
we should see about re-normalizing the sources.
