after the selection timeout is posted but the number executed isn't
reliable. So wait for MSG_OUT rigth after the select so that the state of
the script when the interruption is handled is known.
For this add another indirecton: the DSA in the LUN table points to
a table of DSA indexed by the tag number when tagged command is in use.
For non tagged command, the LUN DSA still points to the tables describing the
xfer directly.
yet.
If is restricted to SIOP which implement the load/store instruction, and
has 10 scratch registers (basically, 825 and newer, possibly 770).
It implements a different interface between host and script, using a real
ring for command starts, and improved support for reconnect which will allow
256 tag per device. It uses interrupt on the fly to signal complete command,
which allows several commands to be serviced per interrupt and doesn't require
the script to stop to signal command completion.
This chip is very similar to the 53c710, except that it's
missing a few registers, doesn't do relative jumps and
doesn't have the table-indirect addressing mode.
I have checked that this still generates the same output
on the existing scripts for the other chips.
This is based on amiga's siop driver, but converted to use
bus_space(9) functions and modified to fit bus_dma(9) framework.
Currently tested on NetBSD/arc with jazzio 53c710 SCSI,
which really requires bus_dma(9) functions :-)
Sync transfers and disconnect/reconnect are also working.
TODO:
- Test under more heavy load
- Clean up osiop_checkintr() hander
- Reorganize command queue and sync negotiation handling more suitable
for thorpej-scsipi mid-layer
- Re-think defered interrupt handling for amiga
Install the core of the scheduler in main script (so it's in RAM when there is
one), and avoid jump in the common case. The command part of the scheduler now
lives in host memory, with tables.
Add template for a tag switch.
- After reselect, don't clear ack after the IDENTIFY message, this breaks
when the reselecting target has different sync parameters than the previous
one.
'command slots' in which the host can put command and wait for the script
to start them
- Change siop.c to do full disconnect/reslelect, allowing as much as one
command per target/lun to run in parallel.
- Fix bug in registers init where a board without BIOS would end at
ID 0 (now the driver works on alpha too).
- better handling of messages, sending back a MSG_EXT_SDTR in response to an
incoming MSG_EXT_SDTR, and MSG_MESSAGE_REJECT for unhandled messages.
- fix use of bus_dmamap_sync() and htole32().
- supports shared interrups
- change some int8 and int16 to int, for alpha and mips benefits ( suggested by
Toru Nishimura)
(the name 'siop' is still being discussed, may change).
Only basic disconnect/reselect for now, no sync/wide negotiation.
Tested with 810A, 875 and 895 on i386 only.
The bus-independant part should also be able to handle the 53c720 and 53c770.
A new driver with enhanced script should appear for the 825/875/895 'soon'.
bouyer