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
be attached with this flag.
Some CF Card (for ex. IBM MicroDrive and SanDisk) doesn't seem to implement
drive select command. In this case, you can't eliminate ghost drive properly.
So you should use this flag to ignore the ghost by force.
wdc drivers (like macppc's obio IDE interface) can use it. Also add
support to both wd attach line and to wdc_print_modes() to print
Ultra/{33,66,100} for respective UDMA modes (From Manuel Bouyer).
if an IRQ was not detected, unless the force flag was given. Use this to
detect if the IRQ was for us (closer to shared IRQ for controllers which
don't have their own IRQ handler in pciide.c) and to poll for DMA xfer.
Also makes the timeout recovery code simpler.
- ATAPI cleanup: don't call controller-specific functions from atapiconf.c
(wdc_*), so that it's possible to attach an atapibus to something else
than a wdc/pciide (Hi Lennart :).
Overload struct scsi_adapter with struct atapi_adapter, defined
as struct scsi_adapter + atapi-specific callbacks. scsipi_link still points
to an scsi_adapter, atapi code casts it to atapi_adapter if needed.
Move atapi_softc to atapiconf.h so that it can be used by the underlying
controller code (e.g. atapi_wdc.c).
Add an atapi-specific callback *atapi_probedev(), which probe a drive
in a controller-specific way, allocate the sc_link and fills in the
ataparams if needed. It then calls atapi_probedev() (from atapiconf.c)
to do the generic initialisations and attach the device.
- While I'm there merge and centralise the state definitions in atavar.h.
It should now be possible to use a common ata/atapi routine to set the
drive's modes (will do later).
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.
- Don't rely on ATA signature: some ide controllers seems to not transmit it
properly (SIMIDE on arm32 machines). Instead, when we guess a drive is here
after reset, just mark it as ATA and OLD is it's not ATAPI.
- at attach time, use IDENTIFY to eliminate ghost from the probe. If the
drive had the old flag and IDENTIFY failed, issue a WDCC_RECAL command
to detect a pre-ATA disk. If IDENTIFY succeded, remove the OLD flag,
it's obviously not a pre-ATA disk.
- add a new controller flag, WDC_CAPABILITY_PREATA, used to shorcut parts
of the probe (not necessary, but makes the probe/attach faster). This is
only set by the ISA front-end, all other controllers supported can't have
pre-ATA drives attached.
The mechanism used are more or less the same as before, they have just been
reordered. Should solve port-arm32/7324 (waiting for feedback).
are called from the interrupt or timeout handler, 0 otherwise.
- use this to know if we can busy-wait for wait_for_unbusy or wait_for_ready
This fixes a bug where CDs withot the DRQ_INTR capability would not busy-wait
for the CMDOUT phase.
While I'm there change 2 delay() to DELAY() for consistency, and
garbage-collect some old code from wdcintr() which has been ifdef'd out
for some time now.
the disk is ready to transfer data, and in ATA-5 the DSC has been obsoleted.
So only wait for DRQ to transfer data. This can be made conditional on the
ATA version if it's proven to break with some drives (worked with all the
drives I have access to).
While I'm there correct a few typos.
an array of fixed-sized channel_softc elements. This way IDE controllers
which more than 1 channel (pciide) can extend the channel data easily
for private needs.
To avoid the double dereference at runtime, change the argument of
wdcstart() to the channel data pointer instead of the array index.
This bus space tag and handle is used for 32 bit data transfers i.e.
when WDC_CAPABILITY_DATA32 is enabled as the 32 bit data register may
not be part of the standard drive registers.
* Fix bug in wdc that would overflow ATAPI transfer length.
* Improve wdc probe code so that 'wdc' is probed in if present
even if there are no drives attached, and so that it works
properly even if the only device is an ATAPI slave.
* bus_space-ify.
* split the ISA attachment from the wdc driver, and remove
ISA dependencies from non-ISA files.
* claim that wd and wdc are now machine-independent (probably not
completely true, but mostly so; they at least work on arm32 and
i386).
* Various other minor fixups and cleanups, some of which were pointed
out by Kazuki Sakamoto.
bjh21