MFC: r247165

Fix command timeout caused by data underrun during fetching ATAPI sense
data, introduced by r246713 (MFC'ed to stable/9 in r251874). There are two
places where ata_request is filled in ATA_CAM: ata_cam_begin_transaction()
and ata_cam_request_sense(). In the first case DMA should be done for
addresses from the CCB. In second case, DMA should be done to the different
address, the address of the sense buffer inside the CCB structure itself.
MFC: r251116

Allow unmapped I/O via aacd(4). It shouldn't be too hard to add the
same support for aacp(4), I'm lacking the necessary hardware for
testing, though.
MFC r248712:

Do not pass unmapped buffers to drivers that cannot handle them

Submitted by:	kan, mav
Obtained from:	Netflix
MFC: r251373

Flag isp(4) as supporting unmapped I/O; all necessary conversion actually
already has been done as part of r246713 (MFC'ed to stable/9 in r251874).
MFC: r242823

Give panic format string to pacify clang warning.
MFC: r247264

Turn off fast posting for the ISP2100- I'd forgotten that it actually
might have been enabled for them- now that we use all 32 bits of handle.
Fast Posting doesn't pass the full 32 bits.
MFC: r251403 (partial)

Flag sym(4) as supporting unmapped I/O; all necessary conversion actually
already has been done as part of r246713 (MFC'ed to stable/9 in r251874).
MFC: r245263

Clang complains about the comparision of fak < 0 always being
false. It is right. Delete it because on the next line we catch all
'negative' cases with the test > 2, since 'negative' numbers are just
really big unsigned numbers and we do an identical action.