RFC: ATA to CAM integration patch

[Scott Long]

Alexander Motin wrote:
> Pieter de Goeje wrote:
>> However there is a problem with camcontrol:
>>
>> nox# camcontrol devlist
>> cam_periph_mapmem: attempt to map 79200 bytes, which is greater than 
>> DFLTPHYS(65536)
>> camcontrol: error sending CAMIOCOMMAND ioctl: Argument list too long
> 
> Thank you for report. I have missed this due to increased DFLTPHYS value 
> in my kernel. Attached trivial patch fixes that.
> 

This should be addressed via multi-part transfers at some point.
Probably ok to leave for now.

>> nox# camcontrol inquiry ada0
>> ahcich1: ahci_ch_intr ERROR is 48000000 cs 00000100 ss 00000000 rs 
>> 00000100 tfd 451 serr 00000000
>>
>> nox# camcontrol inquiry ada1
>> ahcich7: ahci_ch_intr ERROR is 40000001 cs 00002000 ss 00000000 rs 
>> 00002000 tfd 451 serr 00000000
> 
> This is not a problem. ATA disks does not have SCSI INQUIRY command. 
> They use own IDENTIFY instead. inquiry should work for ATAPI devices, as 
> they are SCSI deep inside.
> 

This is really the big missing piece in camcontrol; we need to add
support for getting the IDENT info and getting/setting various
attributes, as well as sending ATA commands over passthrough.

Scott