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
timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
that the adapter is disabled even if it wasn't enabled/disabled during
configuring its children. This fixes the bug that if an aic pcmcia card
is inserted in a slot during boot, further attaching of any card on the
slot fails once the card is removed.
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.
(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.
multi-channel driver), or to SCSI_CHANNEL_ONLY_ONE if a
single-channel driver.
(2) use scsiprint() rather than a locally-defined autoconfig print
function, and kill any locally-defined print function.
a char *, because that's what was really intended, and because
if the print function modifies the string, various things could become
unhappy (so the string should _not_ be modified).
* Add an ACB_RESET flag, so that a BUS DEVICE RESET can be queued within the
driver.
* If ACB_ABORT or ACB_RESET is set during reselection, schedule a message and
assert ATN.
* Optimize aic_datain_pio(), aic_dataout_pio() and aicintr() somewhat.
* Schedule a timeout only when we select the target, so that commands can't
time out prematurely.
1) If we get an unexpected disconnect, issue a REQUEST SENSE, as recommended
by the SCSI-2 spec. If the target created a contingent allegiance condition,
this will clear it. Also, if it happened while sending a SDTR or WDTR message,
disable negotiation for that target.
2) Since some lame devices still don't deal correctly, make sure we deassert
ATN if our last message out is interrupted. If we get a MESSAGE PARITY ERROR,
we'll reassert ATN anyway. This should ensure that we never have to send a
MESSAGE NO OPERATION.
3) Set AIC_ABORTING only when actually sending a BUS DEVICE RESET or ABORT,
so we get better error detection.
4) Other internal reorganization of no consequence.
- split softc size and match/attach out from cfdriver into
a new struct cfattach.
- new "attach" directive for files.*. May specify the name of
the cfattach structure, so that devices may be easily attached
to parents with different autoconfiguration semantics.
mycroft