We only support legacy (i.e. PCI IDE compatible) mode, for now. Also
note that DMA is disabled for rev 0 chips unless explicitly enabled
with PCIIDE_I31244_ENABLEDMA.
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.
IDE controllers, which are more-or-less compatible with the
AMD controllers.
XXX Need to determine the correct timing value for the nForce2
XXX at Ultra133, so we cap it at Ultra100, for now.
pdc202xx_setup_channel, pdc20268_setup_channel:
Properly compute the address of the DMA control register for channel 1.
I think the controllers ignore these bits, I suspect it's only there so that
the BIOS can tell the OS is has configured DMA, but better be correct.
Thanks to Alexander Yurchenko for pointing this out.
on current-users, with cross-check and some improvement from linux-2.4.19
and FreeBSD-current.
Also don't set the APO_UDMA_CLK66 bit for Ultra/100 capable chipset, and
support Ultra/133 for the VT8233A.
Using pdc202xx_setup_channel() for PDC20268 and newer is wrong, and will
cause trap trying to read from a non-existent register on some arches
(e.g. macppc).
pointed out by Makoto Fujiwara on port-macppc.
Note: The code is written a little more cruftily than it should be. It's also
only tested on the OSB4. I'm not sure it even makes sense to have support for
`native' mode, but I put it in just in case.
