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
configured, but after all adapters have been configured. When multiple
adapters are present, only the last configured adapter could be matched
to the boot device slot. The adapter attach routines now check if that
adapter slot matches the boot device slot and saves the softc pointer
for that controller. Then when the disks are configured, dk_establish()
matches the appropriate controller. Also change the rz boot device test
to include a check for the adapter so that it works when booting from a
disk on adapters other than the first one.
- Make local-only function and variables static.
- Move function prototypes and extern variable declarations to
header files.
- Delete unused variables.
There's still a handful of extern declaraions that should be fixed up.
* dec_5100.c: sysconf, interrupt, and motherboard (drain writebuffer)
support for 5100.
* support for hardware kludge in 5100: sii DMA buffer is hardware
padded to alternate 32-bit words, not alternating 16-bit halfwords.
* 5100 has no framebuffer, console is wired to serial port 0.
With ibus support, boots as far as exec'ing init, and hangs.
