past we stored this data in the CCB and attained the CCB via a pointer
in the SCB. In ahc_timeout(), however, the timedout SCB may have already
been completed (inherent race), meaning that the CCB could have been recycled,
and the ahc pointer reset.
Clean up the logic in ahc_search_qinfifo that deals with the busy device
table. For some reason it assumed that the only valid time to search
to see if additional lun entries should be checked was if lun 0 matched.
Now we properly itterate through the necessary luns. The busy device
table is used to detect invalid reselections, so a device would have had
to perform an unexpected reselection for this to cause problems. Further,
all luns are collapsed to a single entry unless we have external ram
with large SCBs (3940AU models) so the chance of this happening was
rather remote.
Clean up the logic for dealing with the untagged queues. We now set a
flag in the SCB that indicates that it is on the untagged queue instead
of inferring this from the type and setup of the CCB pased into us by
CAM.
In ahc_timeout(), don't print the path of the SCB until the controller
is paused and we are sure that it has not completed yet. This, in
conjunction with referencing the ahc pointer in the SCB rather than
the CCB in the SCB avoids panics in the case of a timedout scb completing
just before the timeout handler runs. This turns out to be guaranteed
if interrupt delivery is failing, as we run our interrupt handler to
flush any "just missed events" when a timeout occurs. Mention the
likelyhood of broken interrupts if a timedout SCB is completed by
our call to ahc_intr().
aic7xxx.c:
In target mode, reset the TQINPOS on every restart of the sequencer.
In the past we did this only during a bus reset, but there are other
reasons the sequencer might be reset.
In ahc_clear_critical_section(), disable pausing chip interrupts while
we step the sequencer out of a critical section. This avoids the
possibility of getting a pausing interrupt (unexpected bus free,
bus reset, etc.) that would prevent the sequencer from stepping.
Send the correct async notifications in the case of a BDR or bus reset.
In ahc_loadseq(), correct the calculation of our critical sections.
In some cases, the sections would be larger than needed.
aic7xxx.h:
Remove an unused SCB flag.
aic7xxx.seq:
MK_MESSAGE is cleared by the kernel, there is no need to waste
a sequencer instruction clearing it.
aic7xxx_freebsd.c:
Go through the host message loop instead of issuing a single
byte message directly in the ahc_timeout() case where we
are currently on the bus to the device. The effect is the same,
but this way we get a nice printf saying that an expected BDR
was delivered instead of an unexpected bus free.
If we are requeuing an SCB for an error recovery action, be sure
to set the DISCONNECTED flag in the in-core version of the SCB.
This ensures that, in the SCB-paging case, the sequencer will
still recognize the reselection as valid even if the version
of the SCB with this flag set was never previously paged out
to system memory. In the non-paging case, set the MK_MESSAGE
flag in SCB_CONTROL directly.
aic7xxx_pci.c:
Enable the Memeory Write and Invalidate bug workaround for
all aic7880 chips with revs < 1. This bug is rarely triggered
in FreeBSD as most transfers end on cache-aligned boundaries,
but a recheck of my references indicates that these chips
are affected.
non-LVD controllers. We only need to take special action on the qinfifo
if we have dectected the case of an SCB that has been removed from the
qinfifo but has not been fully DMAed to the controller. A missing
conditional caused this code to be executed every time an SCB was
aborted from the queue
Don't attempt to print the path of an SCB that has been freed.
Clean up the traversal of the pending scb list in
ahc_update_pending_syncrates(). This has no functional change.
Correct ahc_timeout()'s requeing of a timedout SCB to effect a
recovery action. We now use ahc_qinfifo_requeue() and a
new function ahc_qinfifo_count() instead of performing the
requeue inline. The old code did not conform to the new qinfifo
method.
Clear the timedout SCB from the disconnected list. This ensures
that the SCB_NEXT field is free to be used for queuing us to
the qinfifo.
In ahc_search_qinfifo, the SEARCH_REMOVE case must also handle
an SCB that has been removed from the QINFIFO but not yet been
fully dmaed to the card.
Correct locking for ahc_get_scb() calls.
Set SCB syncrate settings in ahc_execute_scb() to avoid a race
condition that could allow a newly queued SCB to be missed
by ahc_update_pending_syncrates().
When notifying the system of transfer negotiation updates, only
set the valid bits for tagged queuing and disconnection if the
path is fully qualified. Sync/Wide settins apply to all luns
of a target, but tagged queuing and disconnection may change
on a per-lun basis.
Add missing ahc_unlock() calls in ahc_timeout() for the target
mode case.
of two (one to access the circular input fifo, the other to get the SCB).
This costs us a command slot so the driver can now only queue 254
simultaneous commands.
Have the kernel driver honor critical sections in sequencer code.
When prefetching S/G segments only pull a cacheline's worth but
never less than two elements. This reduces the impact of the
prefetch on the main data transfer when compared to the 128
byte fetches the driver used to do.
Add "bootverbose" logging for transfer negotiations.
Correct a bug in ahc_set_syncrate() that would prevent an update
of the sync parameters if only the ppr_options had changed.
Correct locking for calls to ahc_free_scb(). ahc_free_scb() is no
longer protected internally to simplify ports to other platforms.
Make sure we unfreeze our SIMQ if a resource shortage has occurred
and an SCB is been freed.
ahc_pci.c:
Turn on cacheline streaming for all controllers that support it.
Clarify diagnostic messages about PCI interrupts.
ahc_pci.c:
Bring back the AHC_ALLOW_MEMIO option at least until the
memory mapped I/O problem on the SuperMicro 370DR3 is
better understood.
aic7xxx.c:
If we see a spurious SCSI interrupt, attempt to clear it and
continue by unpausing the sequencer.
Change the interface to ahc_send_async(). Some async messages
need to be broadcast to all the luns of a target or all the
targets of a bus. This is easier to achieve by passing explicit
channel, target, and lun parameters instead of attempting to
construct a device info struct to match.
Filter the sync parameters for the PPR message in exactly the
same way we do for an old fashioned SDTR message.
Correct some typos and correct a panic message.
Handle rejected PPR messages.
In ahc_handle_msg_reject(), let ahc_build_transfer_msg() build
any additional transfer messages instead of doing this inline.
aic7xxx.h:
Increase the size of both msgout_buf and msgin_buf to
better accomodate PPR messages.
aic7xxx_freebsd.c:
Update for change in ahc_send_async() parameters.
aic7xxx_freebsd.h
Update for change in ahc_send_async() parameters.
Honor AHC_ALLOW_MEMIO.
aic7xxx_pci.c:
Check the error register before going into full blown PCI
interrupt handling. This avoids a few costly PCI configuration
space reads when we run our PCI interrupt handler because another
device sharing our interrupt line is more active than we are.
Also unpause the sequencer after processing a PCI interrupt.
Separate our platform independent hooks from core driver functionality
shared between platforms (FreeBSD and Linux at this time).
Add sequencer workarounds for several chip->chipset interactions.
Correct external SCB corruption problem on aic7895 based cards (3940AUW).
Lots of cleanups resulting from the port to another OS.
the drivers.
* Remove legacy inx/outx support from chipset and replace with macros
which call busspace.
* Rework pci config accesses to route through the pcib device instead of
calling a MD function directly.
With these changes it is possible to cleanly support machines which have
more than one independantly numbered PCI busses. As a bonus, the new
busspace implementation should be measurably faster than the old one.
didn't bother to send a saved data pointers after the last transfer,
is not recorded in sgptr. This was only a problem if the target
reported non-zero status as we always check the residual in that case.
Correct the BUILD_TCL macro. It was placing the target id
in the wrong bits. This was only an issue for adapters that
do not perform SCB paging (aha-3940AUW for instance).
Don't bother inlining ahc_index_busy_tcl. It is never
used in a performance critical path and is a bit chunky.
Correct ahc_index_busy_tcl to deal with "busy target tables"
embedded in the latter half of 64byte SCBs.
Don't initialize the busy target table to its empty state
until after we have finished extracting configuration
information from chip SRAM. In the common case of using
16 bytes of chip SRAM to do untagged target lookups,
we were trashing the last 8 targets configuration data.
(actually only target 8 because of the bug in the
BUILD_TCL macro).
Cram the "bus reset delivered" message back under bootverbose.
Fix the cleanup of the SCB busy target table when aborting
commands. If the lun is wildcarded, we must loop through
all possible luns.
aic7xxx.h:
Only bother supporting 64 luns right now. It doesn't seem
like either this driver or any peripherals will be doing
information unit transfers (where the lun number is a
32 bit integer) any time soon.
aic7xxx.seq:
Fix support for the aic7895. We must flush the data
FIFO if performing a manual transfer that is not
a multiple of 8 bytes. We were doing this quite
regularly for embedded cdbs.
Manaually flush the fifo on earlier adapters when
dealing with embedded cdbs too. We were stuffing
the FIFO with 16 bytes instead, but triggering
the flush is more efficient and allows us to
remove two instructions from the "copy_to_fifo"
routine.
other systems.
o Normalize copyright text.
o Clean up probe code function interfaces by passing around a single
structure of common arguments instead of passing "too many" args
in each function call.
o Add support for the AAA-131 as a SCSI adapter.
o Add support for the AHA-4944 courtesy of "Matthew N. Dodd" <winter@jurai.net
o Correct manual termination support for PCI cards. The bit definitions
for manual termination control in the SEEPROM were incorrect.
o Add support for extracting NVRAM information from SCB 2 for BIOSen
that use this mechanism to pass this data to OS drivers.
o Properly set the STPWLEVEL bit in PCI config space based on the
setting in an SEEPROM.
o Go back to useing 32byte SCBs for all controllers. The current
firmware allows us to embed 12byte cdbs on all controllers in
a 32byte SCB, and larger cdbs are rarely used, so it is a
better use of this space to offer more SCBs (32).
o Add support for U160 transfers.
o Add an idle loop executed during data transfers that prefetches
S/G segments on controllers that have a secondary DMA engine
(aic789X).
o Improve the performance of reselections by avoiding an extra
one byte DMA in the case of an SCB lookup miss for the reselecting
target. We now keep a 16byte "untagged target" array on the card
for dealing with untagged reselections. If the controller has
external SCB ram and can support 64byte SCBs, then we use an
"untagged target/lun" array to maximize concurrency. Without
external SCB ram, the controller is limited to one untagged
transaction per target, auto-request sense operations excluded.
o Correct the setup of the STPWEN bit in SXFRCTL1. This control
line is tri-stated until set to one, so set it to one and then
set it to the desired value.
o Add tagged queuing support to our target role implementation.
o Handle the common cases of the ignore wide residue message
in firmware.
o Add preliminary support for 39bit addressing.
o Add support for assembling on big-endian machines. Big-endian
support is not complete in the driver.
o Correctly remove SCBs in the waiting for selection queue when
freezing a device queue.
o Now that we understand more about the autoflush bug on the
aic7890, only use the workaround on devices that need it.
o Add a workaround for the "aic7890 hangs the system when you
attempt to pause it" problem. We can now pause the aic7890
safely regardless of what instruction it is executing.
negotiation features (DT, ULTRA2, ULTRA, FAST). The offsets
where not properly updated when the DT entry was added and so
the driver could attempt to negotiate a speed faster than that
supported by the target device or even requested by the user
via SCSI-Select settings. *
o Update the target mode incoming command queue kernel index value
ever 128 commands instead of 32. This means that the kernel will
always try to keep its index (as seen on the card - the kernel may
actually have cleared more space) 128 commands ahead of where the
sequencer is adding entries.
o Use the HS_MAILBOX register instead of the KERNEL_TQINPOS location
in SRAM to indicate the kernel's target queue possition on Ultra2
cards. This avoids the "pause bug" on these cards and also turns
out to be much more efficient.
o When enabling or disabling a particular target id for target mode,
make sure that the taret id in the SCSIID register does not
reference an ID that is not to receive target selections. This
is only an issue on chips that support the multiple target id
feature where the value in SCSIID will still affect selection
behavior regardless of the values in the target id bit field
registers.
o Remove some target mode debugging printfs.
o Make sure that the sense length reported in ATIO commands is
always zero. This driver does not, yet, report HBA generated
sense information for accepted commands.
o Honor the CAM_TIME_INFINITY and CAM_TIME_DEFAULT values for
the CCB timeout field.
o Make the driver compile with AHC_DEBUG again.
* Noticed by: Andrew Gallatin<gallatin@cs.duke.edu>
for optimizing the unpause operation no-longer exist, and this is much
safer.
When restarting the sequencer, reconstitute the free SCB list on the card.
This deals with a single instruction gap between marking the SCB as free
and actually getting it onto the free list.
Reduce the number of transfer negotiations that occur. In the past, we
renegotiated after every reported check condition status. This ensures
that we catch devices that have unexpectidly reset. In this situation,
the target will always report the check condition before performing a
data-phase. The new behavior is to renegotiate for any check-condition where
the residual matches the orginal data-length of the command (including
0 length transffers). This avoids renegotiations during things like
variable tape block reads, where the check condition is reported only
to indicate the residual of the read.
Revamp the parity error detection logic. We now properly report and
handle injected parity errors in all phases. The old code used to hang
on message-in parity errors.
Correct the reporting of selection timeout errors to the XPT. When
a selection timeout occurs, only the currently selecting command
is flagged with SELTO status instead of aborting all currently active
commands to that target.
Fix flipped arguments in ahc_match_scb and in some of the callers of this
routine. I wish that gcc allowed you to request warnings for enums passed
as ints.
Make ahc_find_msg generically handle all message types.
Work around the target mode data-in wideodd bug in all non-U2 chips.
We can now do sync-wide target mode transfers in target mode across the
hole product line.
Use lastphase exclusively for handling timeouts. The current phase
doesn't take the bus free state into account.
Fix a bug in the timeout handler that could cause corruption of the
disconnected list.
When sending an embedded cdb to a target, ensure that we start on a
quad word boundary in the data-fifo. It seems that unaligned stores
do not work correctly.
93cx6.c:
Make the SRAM dump output a little prettier.
aic7xxx.c:
Store all SG entries into our SG array in kernel space.
This makes data-overrun and other error reporting more
useful as we can dump all SG entries. In the past,
we only stored the SG entries that the sequencer might
need to access, which meant we skipped the first element
that is embedded into the SCB.
Add a table of chip strings and replace ugly switch
statements with table lookups.
Add a table with bus phase strings and message reponses
to parity errors in those phases. Use the table to
pretty print bus phase messages as well as collapse
another switch statement.
Fix a bug in target mode that could cause us to unpause
the sequencer early in bus reset processing.
Add the 80MHz/DT mode into our syncrate table. This
rate is not yet used or enabled.
Correct some comments, clean up some code...
aic7xxx.h:
Add U160 controller feature information.
Add some more bit fields for various SEEPROM formats.
aic7xxx.reg:
Add U160 register and register bit definitions.
aic7xxx.seq:
Make phasemis state tracking more straight forward. This
avoids the consumption of SINDEX which is a very useful register.
For the U160 chips, you must use the 'mov' instruction to
update DFCNTRL. Using 'or' to set the PRELOADED bit is
completely ineffective.
At the end of the command phase, wair for our ACK signal
to de-assert before disabling the SCSI dma engine. For
slow devices, this avoids clearing the ACK before the
other end has had a chance to see it and lower REQ.
the input fifo to be returned as successful and frozen. Most, if not
all, peripheral drivers do not check the qfrozen bit for successfully
completed commands, so the result would not only be lost commands, but
devices locked out from receiving commands. This was a bad bug that
crept in two or three months ago during some target mode work.
aic7xxx.c:
Add a function for sucking firmware out of the controller
prior to reset.
Remove some inline bloat from functions that should not have
been inlined.
During initialization, wait 1ms after the chip reset before
touching any registers. You can get machine checks on certain
architectures (Atari I think?) without the delay.
Return CAM_REQ_CMP for external BDR requests instead
of CAM_BDR_SENT.
Bump some messages to bootverbose levels above 1.
Don't clear any negotiated sync rate if the target rejects
a WDTR message. The sync rate is only cleared if the target
accepts a WDTR message.
Fix a small bug in the mesgin handling code that could cause
us to believe that we had recieved a message that was actually
received by another target. This could only confuse us in
some very rare transmission negotiation scenarios.
Remove some unecessary cleanup of residual information after
a residual is reported. The sequencer does this when the
command is queued now.
usually cleared by a successful selection, but there is no guarantee
that a future successful selection will ever occur (e.g. empty bus).
The driver never looks at SELINGO, but the busy LED does, so this
change has the cosmetic effect of fixing the rare instance where the
busy LED was left on, confusing the user.
events, in order to pave the way for removing a number of the ad-hoc
implementations currently in use.
Retire the at_shutdown family of functions and replace them with
new event handler lists.
Rework kern_shutdown.c to take greater advantage of the use of event
handlers.
Reviewed by: green
messages, abort messages, and abort tag messages.
Fix a bug in how default transfer negotiations are handled if the
user had disabled initial bus resets.
Support multi-targetid on the aic7895C.
Honor the 'bus reset at startup' option now that the XPT properly
handles transfer negotiation in this scenario.
Honor the sync rate settings on Ultra2 controllers. We would
always negotiate at the fastest speed. Oops.
aic7xxx.h:
Whitespace.
aic7xxx.seq:
Fix a minor nit that would cause the controller to miss the update
of the negotiation required bitmask causing the negotiation to
be delayed by a command.
tell the sequencer to pause itself for a target msg variable update. This
avoids the pause race entirely as HS_MAILBOX can be accessed without
pausing the chip.
3.2 Merge candidate.
NOTE: These changes will require recompilation of any userland
applications, like cdrecord, xmcd, etc., that use the CAM passthrough
interface. A make world is recommended.
camcontrol.[c8]:
- We now support two new commands, "tags" and "negotiate".
- The tags commands allows users to view the number of tagged
openings for a device as well as a number of other related
parameters, and it allows users to set tagged openings for
a device.
- The negotiate command allows users to enable and disable
disconnection and tagged queueing, set sync rates, offsets
and bus width. Note that not all of those features are
available for all controllers. Only the adv, ahc, and ncr
drivers fully support all of the features at this point.
Some cards do not allow the setting of sync rates, offsets and
the like, and some of the drivers don't have any facilities to
do so. Some drivers, like the adw driver, only support enabling
or disabling sync negotiation, but do not support setting sync
rates.
- new description in the camcontrol man page of how to format a disk
- cleanup of the camcontrol inquiry command
- add support in the 'devlist' command for skipping unconfigured devices if
-v was not specified on the command line.
- make use of the new base_transfer_speed in the path inquiry CCB.
- fix CCB bzero cases
cam_xpt.c, cam_sim.[ch], cam_ccb.h:
- new flags on many CCB function codes to designate whether they're
non-immediate, use a user-supplied CCB, and can only be passed from
userland programs via the xpt device. Use these flags in the transport
layer and pass driver to categorize CCBs.
- new flag in the transport layer device matching code for device nodes
that indicates whether a device is unconfigured
- bump the CAM version from 0x10 to 0x11
- Change the CAM ioctls to use the version as their group code, so we can
force users to recompile code even when the CCB size doesn't change.
- add + fill in a new value in the path inquiry CCB, base_transfer_speed.
Remove a corresponding field from the cam_sim structure, and add code to
every SIM to set this field to the proper value.
- Fix the set transfer settings code in the transport layer.
scsi_cd.c:
- make some variables volatile instead of just casting them in various
places
- fix a race condition in the changer code
- attach unless we get a "logical unit not supported" error. This should
fix all of the cases where people have devices that return weird errors
when they don't have media in the drive.
scsi_da.c:
- attach unless we get a "logical unit not supported" error
scsi_pass.c:
- for immediate CCBs, just malloc a CCB to send the user request in. This
gets rid of the 'held' count problem in camcontrol tags.
scsi_pass.h:
- change the CAM ioctls to use the CAM version as their group code.
adv driver:
- Allow changing the sync rate and offset separately.
adw driver
- Allow changing the sync rate and offset separately.
aha driver:
- Don't return CAM_REQ_CMP for SET_TRAN_SETTINGS CCBs.
ahc driver:
- Allow setting offset and sync rate separately
bt driver:
- Don't return CAM_REQ_CMP for SET_TRAN_SETTINGS CCBs.
NCR driver:
- Fix the ultra/ultra 2 negotiation bug
- allow setting both the sync rate and offset separately
Other HBA drivers:
- Put code in to set the base_transfer_speed field for
XPT_GET_TRAN_SETTINGS CCBs.
Reviewed by: gibbs, mjacob (isp), imp (aha)
Don't mess with the IRQMS bit in the host control register unless
we are an aic7770 chip.
Use calling context to determine if the card is already paused when
we update the target message request bit field in controller scratch
ram. Looking at the paused bit in the HCNTRL register opened up a
race condition.
Insert delays in the target message request update routine as a temporary
work around for what looks like a chip bug. I'm still investigating this
one.
Fix the Abort/Abort Tag/BDR handler to pull its message from the message
buffer in our softc instead of attempting to get it from a register on
the controller. The message is never recorded by the controller in the
new message scheme.
Don't rely on having an SCB when a BDR occurs. We can issue these during
invalid reconnects to.
Fix a few cases where we were restarting the sequencer but then still
falling out of a switch statement to unpause the sequencer again.
This could cause us to mess up sequencer state if it generated another
pausing interrupt between the time of the restart and unpause.
Kill the 'transceiver settle' loop during card initialization. I
failed to realize that a controller that is not connected to any
cables will never settle or enable the SCSI transceivers at all.
The correct solution is to monitor the IOERR interrupt which indicates
that the transceiver state has changed (UW<->LVD).
Modify the aic7xxx assembler to properly echo input when stdin is not
a tty.
connection.
Clean up support for devices featuring the multiple target SCSI ID feature.
On aic7890/91/96/97 chips, we can now assume the target role on multiple
target ids simultaneously. Although these chips also have sufficient
instruction space to hold to support the initiator and target role at the
same time, the initiator role is currently disabled as it will conflict
(chip design restriction) with the multi-tid feature. I'll probably add
a nob to enable the initiator (there-by disabling multi-tid) some time
in the future.
Return queue full or busy, depending on the tagged nature of the incoming
request, if our command input queue fills up in host memeory.
Deal with accept target I/O resource shortages.
If we get an underrun on a transaction that wasn't supposed to transmit
any data, don't attempt to print out the S/G list. The code would
run until hitting a non-present page. (oops)
black hole device. The controller will now only accept selections if
the black hole device is present and some other target/lun is enabled
for target mode.
Handle the IGNORE WIDE RESIDUE message. This support has not been tested.
Checkpoint work on handling ABORT, BUS DEVICE RESET, TERMINATE I/O PROCESS,
and CLEAR QUEUE messages as a target.
Fix a few problems with tagged command handling in target mode.
Wait until the sync offset counter falls to 0 before changing phase
after a data-in transfer completes as the DMA logic seems to indicate
transfer complete as soon as our last REQ is issued.
Simplify some of the target mode message handling code in the sequencer.
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.
for possible buffer overflow problems. Replaced most sprintf()'s
with snprintf(); for others cases, added terminating NUL bytes where
appropriate, replaced constants like "16" with sizeof(), etc.
These changes include several bug fixes, but most changes are for
maintainability's sake. Any instance where it wasn't "immediately
obvious" that a buffer overflow could not occur was made safer.
Reviewed by: Bruce Evans <bde@zeta.org.au>
Reviewed by: Matthew Dillon <dillon@apollo.backplane.com>
Reviewed by: Mike Spengler <mks@networkcs.com>
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.
Correct a problem where an external bus reset on the 'background' channel of
a Twin Channel EISA controller could put the driver into an infinite loop.
Noticed by: Twin Channel bug, Joerg Wunsch <joerg@FreeBSD.org>
Submitted by: -Wunused, Poul-Henning Kamp <phk@freebsd.org>
a timeout, we must remove the pending SCB from the disconnected list
or risk list corruption when our BDR request using the same SCB is placed
on the waiting list.
Eradicate some silly uses of u_int8_t that just serve to slow the code down.
- 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.
