Use the host message loop for any unknown message types instead of performing
a reject message in the sequencer. Pass reject messages to the host
message loop too which frees up a sequencer interrupt type slot.
Default to issuing a bus reset if initiator mode is enabled. It seems
that the reset scsi bus bit is not defined in the same location for
all aic78xx BIOSes, so attempting to honor this setting will have to
wait until I get more information on how to detect it.
Nuke some unused variables.
in target mode, but we are not completing the command.
Use a template of allowed bus arbitration phases to selectively and
dynamically enable/disable initiator or target (re)selection.
Properly handle timeouts for target role transactions - just go to the
bus free state and report the error to the peripheral driver.
Checkpoint support for the XPT_ABORT_CCB function code. This currently
handles the accept tio and immediate notify ccb types, but does not
handle the continue target I/O or SCSI I/O ccb types. This is enough
to handle dynamic target enable/disable events.
Clean up the SCSI reset code so that we perform at most 1 SCSI bus
reset at initialization, the reset requested by the XPT layer.
is more robust and common code can be used for both the target and iniator
roles. The mechanism for tracking negotiation state has also been simplified.
Add support for sync/wide negotiation in target mode and fix many of
the target mode bugs running at higher speeds uncovered. Make a first
stab at getting all of the bus skew delays correct. Sync+Wide dataout
transfers still cause problems, but this may be an initiator problem.
Ensure that we exit BITBUCKET mode if the controller is restarted.
Add support for target mode only firmware downloads. This has been
tested on the aic7880, but should mean that we can perform target mode
on any aic7xxx controller. Mixed mode (initiator and target roles in
the same firmware load) is currently only supported on the aic7890, but
with optimization, may fit on chips with less instruction space.
use a 256 entry ring buffer of descriptersfor this purpose. This allows
the use of a simple 8bit counter in the sequencer code for tracking start
location.
Entries in the ring buffer now contain a "cmd_valid" byte at their tail.
As an entry is serviced, this byte is cleared by the kernel and set by
the sequencer during its dma of a new entry. Since this byte is the last
portion of the command touched during a dma, the kernel can use this
byte to ensure the command it processes is completely valid.
The new command format requires a fixed sized DMA from the controller
to deliver which allowed for additional simplification of the sequencer
code. The hack that required 1 SCB slot to be stolen for incoming
command delivery notification is also gone.
- Convert to CAM
- Use a new DMA based queuing and paging scheme
- Add preliminary target mode support
- Add support for the aic789X chips
- Take advantage of external SRAM on more controllers.
- Numerous bug fixes and performance improvements.
operands that are set during seqeuncer program download instead of at
assembly time.
Convert the sequencer code to use" downloaded constants" for four run time
constants that vary depending on the board type. This frees up 4 bytes
of sequencer scratch ram space where these constants used to be stored and
also removes the additional instructions required to load their values
into the accumulator prior to using them.
Remove the REJBYTE sram variable. The host driver can just as easly
read the accumulator to get this value.
The scratch ram savings is important as the old code used to clober the
SCSICONF register on 274X cards which sits near the top of scratch ram
space. The SCSICONF register controls bus termination, and clobbering
it is not a good thing. Now we have 4 bytes to spare.
This should fix the reported problems with cards that don't have devices
attached to them failing with a stream of "Somone reset bus X" messages.
Doug Ledford determined the cause of the problem, fixes by me.
entry to the QOUTFIFO when it is full. This should eliminate the
"Timed out while idle" problems that many have reported.
In truth, this is somewhat of a hack. Although are interrupt latency is
low enough that we should be able to always service the queue in time,
since each entry must be passed up to the higher SCSI layer for what can
be a large amount of processing (perhaps even resulting in a new command
being queued) with interrupts disabled, we need this mechanism to avoid
overflow. In the future, these additional tasks will be offloaded to a
software interrupt handler which should make this hack unnecessary.
if SCB Paging was enabled:
disconnect with more data to transfer
disconnected SCB gets paged out
target reconnects so we page SCB back in
target completes transfer so residual is 0
target disconnects
SCB gets reused but not paged out since the residual is 0 (optimization)
target reconnects so we page the SCB back in
we report a residual because of stale residual information.
The fix for this is to set a flag that forces the SCB to be paged back
up to the host if we page in an SCB with a residual
Pointed out by: Doug Ledford <dledford@dialnet.net>
New sequencer assembler for the aic7xxx adapters. This assembler
performs some amount of register type checking, allows bit
manipulation of symbolic constants, and generates "patch tables"
for conditionalized downloading of portions of the program.
This makes it easier to take full advantage of the different
features of the aic7xxx cards without imposing run time penalies
or being bound to the small memory footprints of the low end
cards for features like target mode.
aic7xxx.reg:
New, assembler parsed, register definitions fo the aic7xxx cards.
This was done primarily in anticipation of 7810 support which
will have a different register layout, but should be able to use
the same assembler. The kernel aic7xxx driver consumes a generated
file in the compile directory to get the definitions of the register
locations.
aic7xxx.seq:
Convert to the slighly different syntax of the new assembler.
Conditionalize SCB_PAGING, ultra, and twin features which shaves
quite a bit of space once the program is downloaded.
Add code to leave the selection hardware enabled during reconnects
that win bus arbitration. This ensures that we will rearbitrate
as soon as the bus goes free instead of delaying for a bit.
When we expect the bus to go free, perform all of the cleanup
associated with that event "up front" and enter a loop awaiting
bus free. If we see a REQ first, complain, but attempt to
continue. This will hopefully address, or at least help diagnose,
the "target didn't send identify" messages that have been reported.
Spelling corrections obtained from NetBSD.
