http://mail-index.netbsd.org/tech-kern/2003/09/25/0006.html
This adds a device (atabus) between IDE controllers and wd or atapibus, to
have each ATA channel show up in the device tree. Later there will be atabus
devices in /dev, so that we can do IOCTL on them.
Each atabus has its own kernel thread, to handle operations that needs polling,
e.g. reset and others.
Device probing on each bus it defered to the atabus thread creation.
This allows to do the reset and basic device probes in parallel, which reduce
boot time on systems with several pciide controllers.
1) Don't wait for DRQ on an IDENTIFY command -- if it's not set when we see
BSY clear, abort the command and ignore the drive. (Do this by testing
for DRQ in the read/write cases in __wdccommand_intr().)
2) Don't wait for DRQ to deassert when we finish an IDENTIFY (or any other
non-block command that reads data) -- we don't do this for block I/O, and
empirically it doesn't clear on my CF cards at all, causing a pointless 1s
delay.
3) Add comments to some of the delay()s, and add missing ones in wdcreset()
and the WDCC_RECAL in the so-called "pre-ATA" probe.
4) Slightly simplify the reset sequence -- we were doing an extra I/O.
5) Modify the register writability test to make sure that registers are not
overlapped -- this can happen in some weird cases with a missing device 1.
6) Check the error register value after the reset -- if it's not 01h or 81h,
as appropriate (see ATA spec), punt.
Tested with a number of ATA-only, ATAPI-only, mixed ATA-ATAPI, CF, and IDE
disk configurations.
Also remove the SINGLE_DRIVE nonsense again.
most polling.
2) Clean up some goofiness in pciide -- get rid of the whole "candisable" path
(it's gratuitous) and simplify the code by calling pciide_map_compat_intr(),
*_set_modes() and wdc_print_modes() from central locations.
3) Add a register writability and register ghost test to eliminate phantom
drives more quickly.
in the default disklabel and the boot message, instead of using the
value reported by the drive (which is 16383 if the drive is larger than 8G).
Should fix PR 9864
be inserted into ktrace records. The general change has been to replace
"struct proc *" with "struct lwp *" in various function prototypes, pass
the lwp through and use l_proc to get the process pointer when needed.
Bump the kernel rev up to 1.6V
sector information in the kernel. Doing this uncovered some shortcomings
that should have been pretty obvious with the code committed prior, addressing
the major kludge with a new struct - disk_bacsecinfo to be passed into
DIOCBSLIST.
prempt read operations on matching regions with a failure rather than waiting
for the device to return a failure. The I/O operation must have already failed
MAXRETRIES times before being added to the list - this can generally take up
to 12 seconds.
List is made accessible to userspace via DIOCBSLIST and DIOCBSFLUSH.
Such RAID controllers are actually just IDE controllers with a BIOS that
can create RAID volumes and write the configuration info to config blocks
on the disks. The BIOS can do I/O to these volumes, and the OS must
understand the config blocks and implement RAID in software in order to be
able to use these volumes.
Only SPAN (simple concatenation) and RAID0 are supported at this time,
and writing back config blocks is also not supported at this time. Currently,
only the Promise configuration scheme is supported, although supporting
the Highpoint scheme should not be too difficult.
In any case, this is sufficient to use the Promise RAID0 volume (thus
preserving the win2k AS installation) on this new Intel server I have.
Thanks to Soren Schmidt for doing the work in FreeBSD; it made this
task much easier. The config block parsing code is adapted from his
work.
wiz