Commit Graph

15 Commits

Author SHA1 Message Date
Justin T. Gibbs
72df3c5621 Sync Perforce IDs, add tranceiver state change support, and correct
numerous error recovery buglets.

Many thanks to Tor Egge for his assistance in diagnosing problems with
the error recovery code.

aic7xxx.c:
	Report missed bus free events using their own sequencer interrupt
	code to avoid confusion with other "bad phase" interrupts.

	Remove a delay used in debugging.  This delay could only be hit
	in certain, very extreme, error recovery scenarios.

	Handle transceiver state changes correctly.  You can now
	plug an SE device into a hot-plug LVD bus without hanging
	the controller.

	When stepping through a critical section, panic if we step
	more than a reasonable number of times.

	After a bus reset, disable bus reset interupts until we either
	our first attempt to (re)select another device, or another device
	attemps to select us.  This removes the need to busy wait in
	kernel for the scsi reset line to fall yet still ensures we
	see any reset events that impact the state of either our initiator
	or target roles.  Before this change, we had the potential of
	servicing a "storm" of reset interrupts if the reset line was
	held for a significant amount of time.

	Indicate the current sequencer address whenever we dump the
	card's state.

aic7xxx.reg:
	Transceiver state change register definitions.

	Add the missed bussfree sequencer interrupt code.

	Re-enable the scsi reset interrupt if it has been
	disabled before every attempt to (re)select a device
	and when we have been selected as a target.

	When being (re)selected, check to see if the selection
	dissappeared just after we enabled our bus free interrupt.
	If the bus has gone free again, go back to the idle loop
	and wait for another selection.

	Note two locations where we should change our behavior
	if ATN is still raised.  If ATN is raised during the
	presentation of a command complete or disconnect message,
	we should ignore the message and expect the target to put
	us in msgout phase.  We don't currently do this as it
	requires some code re-arrangement so that critical sections
	can be properly placed around our handling of these two
	events.  Otherwise, we cannot guarantee that the check of
	ATN is atomic relative to our acking of the message in
	byte (the kernel could assert ATN).

	Only set the IDENTIFY_SEEN flag after we have settled
	on the SCB for this transaction.  The kernel looks at
	this flag before assuming that SCB_TAG is valid.  This
	avoids confusion during certain types of error recovery.

	Add a critical section around findSCB.  We cannot allow
	the kernel to remove an entry from the disconnected
	list while we are traversing it.  Ditto for get_free_or_disc_scb.

aic7xxx_freebsd.c:
	Only assume that SCB_TAG is accurate if IDENTIFY_SEEN is
	set in SEQ_FLAGS.

	Fix a typo that caused us to execute some code for the
	non-SCB paging case when paging SCBs.  This only occurred
	during error recovery.
2000-11-10 20:13:41 +00:00
Justin T. Gibbs
47c2d60f79 aic7xxx.c:
When restarting the sequencer, ensure that the SCBCNT register
	is 0.  A non-zero count will prevent the setting of the CCSCBDIR
	bit in any future dma operations.  The only time CCSCBCNT would
	be non-zero is if we happened to halt the dma during a reset,
	but even that should never happen.  Better safe than sorry.

	When a command completes before the target responds to an
	ATN for a recovery command, we now notify the kernel so that
	any recovery operation requeued in the qinfifo can be removed
	safely.  In the past, we did this in ahc_done(), but ahc_done()
	may be called without the card paused.  This also avoids a
	recursive call to ahc_search_qinifo() which could have occurred if
	ahc_search_qinififo() happened to be the routine to complete
	a recovery action.

	Fix 8bit math used for adjusting the qinfifo.  The index must
	be wrapped properly within the 256 entry array.  We rely on the
	fact that qinfifonext is a uint8_t in most cases to handle
	this wrap, but we missed a few spots where the resultant
	calculation was promoted to an int.

	Change the way that we deal with aborting the first or second
	entry from the qinfifo.  We now swap the first entry in the
	qinfifo with the "next queued scb" to force the sequencer
	to see an abort collision if we ever touch the qinififo while
	the sequencer is mid SCB dma.

aic7xxx.reg:
	Add new MKMSG_FAILED sequencer interrupt.  This displaced
	the BOGUS_TAG interrupt used in some previous sequencer code
	debugging.

aic7xxx.seq:
	Increment our position in the qinfifo only once the dma
	is complete and we have verified that the queue has not
	been changed during our DMA.  This simplifies code in the
	kernel.

	Protect against "instruction creep" when issuing a pausing
	sequencer interrupt.  On at least the 7890/91/96/97, the
	sequencer will coast after issuing the interrupt for up
	to two instructions.  In the past we delt with this by
	using carefully placed nops.  Now we call a routine to
	issue the interrupt followed by a nop and a ret.

	Tell the kernel should an SCB complete with the MK_MESSAGE
	flag still set.  This means the target ignored our ATN request.

	Clear the channel twice as we exit the data phase.  On the
	aic7890/91, the S/G preload logic may require the second
	clearing to get the last S/G out of the FIFO.

aic7xxx_freebsd.c:
	Don't bother searching the qinfifo for a doubly queued
	recovery scb in ahc_done.  This case is handled by the
	core driver now.

	Free the path used to issue async callbacks after the callback
	is complete.

aic7xxx_inline.h:
	Split the SCB queue routine into a routine that swaps
	the SCB with the "next queued SCB" and a routine that
	calls the swapping routine and notifies the card of
	the new SCB.  The swapping routine is now also used by
	ahc_search_qinfifo.
2000-11-06 20:05:38 +00:00
Justin T. Gibbs
dd1290f033 aic7xxx.c:
Filter incoming transfer negotiation requests to ensure they
	never exceed the settings specified by the user.

	In restart sequencer attempt to deal with a bug in the aic7895.
	If a third party reset occurs at just the right time, the
	stack register can lock up.  When restarting the sequencer
	after handling the SCSI reset, poke SEQADDR1 before resting
	the sequencers program counter.

	When something strange happens, dump the card's transaction
	state via ahc_dump_card_state().  This should aid in debugging.

	Handle request sense transactions via the QINFIFO instead of
	attaching them to the waiting queue directly.  The waiting
	queue consumes card SCB resources and, in the pathological case
	of every target on the bus beating our selection attemps and
	issuing a check condition, could have caused us to run out
	of SCBs.  I have never seen this happen, and only early
	cards with 3 or 4 SCBs had any real chance of ever getting
	into this state.

	Add additional sequencer interrupt codes to support firmware
	diagnostics.  The diagnostic code is enabled with the
	AHC_DEBUG_SEQUENCER kernel option.

	Make it possible to switch into and out of target mode on
	the fly.  The card comes up by default as an initiator but
	will switch into target mode as soon as an enable lun operation
	is performed.  As always, target mode behavior is gated
	by the AHC_TMODE_ENABLE kernel option so most users will
	not be affected by this change.

	In ahc_update_target_msg_request(), also issue a new
	request if the ppr_options have changed.

	Never issue a PPR as a target.  It is forbidden by the spec.

	Correct a bug in ahc_parse_msg() that prevented us from
	responding to PPR messages as a target.

	Mark SCBs that are on the untagged queue with a flag instead
	of checking several fields in the SCB to see if the SCB should
	be on the queue.  This makes it easier for things like automatic
	request sense requests to be queued without touching the
	untagged queues even though they are untagged requests.

	When dealing with ignore wide residue messages that occur
	in the middle of a transfer, reset HADDR, not SHADDR for
	non-ultra2 chips.  Although SHADDR is where the firmware
	fetches the ending transfer address for a save data pointers
	request, it is readonly. Setting HADDR has the side effect
	of also updating SHADDR.

	Cleanup the output of ahc_dump_card_state() by nulling out the
	free scb list in the non-paging case.  The free list is only
	used if we must page SCBs.

	Correct the transmission of cdbs > 12 bytes in length.  When
	swapping HSCBs prior to notifing the sequencer of the new
	transaction, the bus address pointer for the cdb must also
	be recalculated to reflect its new location.  We now defer
	the calculation of the cdb address until just before queing
	it to the card.

	When pulling transfer negotiation settings out of scratch
	ram, convert 5MHz/clock doubled settings to 10MHz.

	Add a new function ahc_qinfifo_requeue_tail() for use by
	error recovery actions and auto-request sense operations.
	These operations always occur when the sequencer is paused,
	so we can avoid the extra expense incurred in the normal
	SCB queue method.

	Use the BMOV instruction for all single byte moves on
	controllers that support it.  The bmov instruction is
	twice as fast as an AND with an immediate of 0xFF as
	is used on older controllers.

	Correct a few bugs in ahc_dump_card_state().  If we have
	hardware assisted queue registers, use them to get the
	sequencer's idea of the head of the queue.  When enumerating
	the untagged queue, it helps to use the correct index for
	the queue.

aic7xxx.h:

	Indicate via a feature flag, which controllers can take
	on both the target and the initiator role at the same time.

	Add the AHC_SEQUENCER_DEBUG flag.

	Add the SCB_CDB32_PTR flag used for dealing with cdbs
	with lengths between 13 and 32 bytes.

	Add new prototypes.

aic7xxx.reg:
	Allow the SCSIBUSL register to be written to.  This is
	required to fix a selection timeout problem on the 7892/99.

	Cleanup the sequencer interrupt codes so that all debugging
	codes are grouped at the end of the list.

	Correct the definition of the ULTRA_ENB and DISC_DSB locations
	in scratch ram.  This prevented the driver from properly honoring
	these settings when no serial eeprom was available.

	Remove an unused sequencer flag.

aic7xxx.seq:
	Just before a potential select-out, clear the SCSIBUSL
	register.  Occasionally, during a selection timeout, the
	contents of the register may be presented on the bus,
	causing much confusion.

	Add sequencer diagnostic code to detect software and or
	hardware bugs.  The code attempts to verify most list
	operations so any corruption is caught before it occurs.
	We also track information about why a particular reconnection
	request was rejected.

	Don't clobber the digital REQ/ACK filter setting in SXFRCTL0
	when clearing the channel.

	Fix a target mode bug that would cause us to return busy
	status instead of queue full in respnse to a tagged transaction.

	Cleanup the overrun case.  It turns out that by simply
	butting the chip in bitbucket mode, it will ack any
	bytes until the phase changes.  This drasticaly simplifies
	things.

	Prior to leaving the data phase, make sure that the S/G
	preload queue is empty.

	Remove code to place a request sense request on the waiting
	queue.  This is all handled by the kernel now.

	Change the semantics of "findSCB".  In the past, findSCB
	ensured that a freshly paged in SCB appeared on the disconnected
	list.  The problem with this is that there is no guarantee that
	the paged in SCB is for a disconnected transation.  We now
	defer any list manipulation to the caller who usually discards
	the SCB via the free list.

	Inline some busy target table operations.

	Add a critical section to protect adding an SCB to
	the disconnected list.

aic7xxx_freebsd.c:
	Handle changes in the transfer negotiation setting API
	to filter incoming requests.  No filtering is necessary
	for "goal" requests from the XPT.

	Set the SCB_CDB32_PTR flag when queing a transaction with
	a large cdb.

	In ahc_timeout, only take action if the active SCB is
	the timedout SCB.  This deals with the case of two
	transactions to the same device with different timeout
	values.

	Use ahc_qinfifo_requeu_tail() instead of home grown
	version.

aic7xxx_inline.h:
	Honor SCB_CDB32_PTR when queuing a new request.

aic7xxx_pci.c:
	Use the maximum data fifo threshold for all chips.
2000-10-31 18:43:29 +00:00
David Malone
5417ec4db1 Add the use of M_ZERO to some malloc calls.
Submitted by:	josh@zipperup.org
Submitted by:	Robert Drehmel <robd@gmx.net>
Approved by:	gibbs
2000-10-29 15:47:16 +00:00
Justin T. Gibbs
70351c9a14 Store a pointer to our softc in the kernel's SCB structure. In the
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().
2000-10-11 23:46:34 +00:00
Justin T. Gibbs
b00aeda6f0 Close a race condition that doesn't really exist in -current. When
a resource shortage occurs, freeze our queue and then set the resource
shortage flag while the controller data structure is locked.  The old
code did these in the wrong order potentially allowing our interrupt
handler to release the queue and clear the flag before the freeze
ever occurred.
2000-10-09 19:54:54 +00:00
Justin T. Gibbs
73f1c25915 Clean up error recovery code:
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.
2000-10-09 01:46:01 +00:00
Justin T. Gibbs
039c6f3637 Correct corruption of the qinfifo in ahc_search_qinififo() for all
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.
2000-10-08 03:37:52 +00:00
Justin T. Gibbs
580bfdfb00 Fix single character typo in legacy transfer settings function
thereby re-enable tagged queuing.
2000-10-06 19:34:40 +00:00
Justin T. Gibbs
ff0c1daf6b Bring in a slew of fixes that were supposed to be in the last commit.
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.
2000-10-06 04:01:06 +00:00
Justin T. Gibbs
a49630ac82 Convert the driver to use a single DMA for fetching new commands instead
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.
2000-10-05 04:24:14 +00:00
Justin T. Gibbs
155c0683c7 ahc_set_transaction_status() takes an SCB. This makes it difficult to
use this helper function to report an error when SCB allocation fails.
2000-10-01 20:56:44 +00:00
Justin T. Gibbs
c498406d58 Add Perforce RCSIDs for easy revision correlation to my local tree.
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.
2000-09-22 22:18:05 +00:00
Justin T. Gibbs
dfd86f14c0 Remove the last two uses of ahc->unit in the FreeBSD version of the driver.
ahc->unit is depricated and will be going away as soon as the Linux
driver catches up.  In the FreeBSD case, it is always initialized to 0
and this caused some strangeness in registering multiple ahc controllers
with CAM.

Noticed by:	Tor.Egge@fast.no
2000-09-20 04:46:15 +00:00
Justin T. Gibbs
717d424718 Move aicasm to its own subdirectory.
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.
2000-09-16 20:02:28 +00:00