MFC r345008:
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r345008 | ken | 2019-03-11 10:21:14 -0400 (Mon, 11 Mar 2019) | 59 lines

Fix CRN resets in the isp(4) driver in certain situations.

The Command Reference Number (CRN) is part of the FC-Tape features
that we enable when talking to tape drives. It starts at 1, and
goes to 255 and wraps around to 1. There are a number of reset
type conditions that result in the CRN getting reset to 1. These
are detailed in section 4.10 (table 8) of the FCP-4r02b specification.

One of the conditions is when a PRLI (Process Login) is sent by
the initiator, and the Establish Image Pair bit is set in Word 0
of the PRLI.

Previously, the isp(4) driver core sent a notification via
isp_async() that the target had changed or stayed in place, but
there was no indication of whether a PRLI was sent and whether the
Establish Image Pair bit was set.

The result of this was that in some situations, notably
switching back and forth between a direct connection and a switch
connection to a tape drive, the isp(4) driver would fail to reset
the CRN in situations that require it according to the spec. When
the CRN isn't reset in a situation that requires it, the tape drive
then rejects every subsequent command that is sent to the drive.
It is assuming that the commands are being sent out of order.

So, modify the isp(4) driver to include Word 0 of the PRLI command
when it sends isp_async() notifications of target changes. Look at
the Establish Image Pair bit, and reset the CRN if that bit is set.

With this change, I am able to switch a tape drive back and forth
between a direct connection and a switch connection, and the isp(4)
driver resets the CRN when it should.

sys/dev/isp_stds.h:
Add bit definitions for PRLI Word 0.

sys/dev/ispmbox.h:
Add PRLI Word 0 to the port database type, isp_pdb_t.

sys/dev/ispvar.h
Add PRLI Word 0 to fcportdb_t.

sys/dev/isp.c:
Populate the new prli_word0 parameter in the port database.

In isp_pdb_add_update(), add a check to see if the
Establish Image Pair bit is set in PRLI Word 0. If it is,
then that is an additional reason to create a change
notification.

sys/dev/isp_freebsd.c:
In isp_async(), if the device changed or stayed, look at
PRLI Word 0 to see if the Establish Image Pair bit is set.
If it is, reset the CRN if we haven't already.

Sponsored by: Spectra Logic
Differential Revision: https://reviews.freebsd.org/D19472

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Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Register symbolic port/node names in FC name server.

This is cosmetics that simplifies identification of new ports on FC switch.

It would be good to use target name from CTL here instead of hostname, but
it is not passed here through CAM now.

MFC after: 2 weeks

Register our FC4 Features in SNS.

Add partial support for QUERY TMF to CAM and isp(4).

This change allows to decode respective functions in isp(4) in target mode
and pass them through CAM to CTL. Unfortunately neither CAM nor isp(4)
support returning response info for those task management functions now.

On the other side I just have no initiator to test this functionality.

-----------
MISC CHANGES

Add a new async event- ISP_TARGET_NOTIFY_ACK, that will guarantee
eventual delivery of a NOTIFY ACK. This is tons better than just
ignoring the return from isp_notify_ack and hoping for the best.

Clean up the lower level lun enable code to be a bit more sensible.

Fix a botch in isp_endcmd which was messing up the sense data.

Fix notify ack for SRR to use a sensible error code in the case
of a reject.

Clean up and make clear what kind of firmware we've loaded and
what capabilities it has.
-----------
FULL (252 byte) SENSE DATA

In CTIOs for the ISP, there's only a limimted amount of space
to load SENSE DATA for associated CHECK CONDITIONS (24 or 26
bytes). This makes it difficult to send full SENSE DATA that can
be up to 252 bytes.

Implement MODE 2 responses which have us build the FCP Response
in system memory which the ISP will put onto the wire directly.

On the initiator side, the same problem occurs in that a command
status response only has a limited amount of space for SENSE DATA.
This data is supplemented by status continuation responses that
the ISP pushes onto the response queue after the status response.
We now pull them all together so that full sense data can be
returned to the periph driver.

This is supported on 23XX, 24XX and 25XX cards.

This is also preparation for doing >16 byte CDBs.

-----------
FC TAPE

Implement full FC-TAPE on both initiator and target mode side. This
capability is driven by firmware loaded, board type, board NVRAM
settings, or hint configuration options to enable or disable. This
is supported for 23XX, 24XX and 25XX cards.

On the initiator side, we pretty much just have to generate a command
reference number for each command we send out. This is FCP-4 compliant
in that we do this per ITL nexus to generate the allowed 1 thru 255
CRN.

In order to support the target side of FC-TAPE, we now pay attention
to more of the PRLI word 3 parameters which will tell us whether
an initiator wants confirmed responses. While we're at it, we'll
pay attention to the initiator view too and report it.

On sending back CTIOs, we will notice whether the initiator wants
confirmed responses and we'll set up flags to do so.

If a response or data frame is lost the initiator sends us an SRR
(Sequence Retransmit Request) ELS which shows up as an SRR notify
and all outstanding CTIOs are nuked with SRR Received status. The
SRR notify contains the offset that the initiator wants us to restart
the data transfer from or to retransmit the response frame.

If the ISP driver still has the CCB around for which the data segment
or response applies, it will retransmit.

However, we typically don't know about a lost data frame until we
send the FCP Response and the initiator totes up counters for data
moved and notices missing segments. In this case we've already
completed the data CCBs already and sent themn back up to the periph
driver. Because there's no really clean mechanism yet in CAM to
handle this, a hack has been put into place to complete the CTIO
CCB with the CAM_MESSAGE_RECV status which will have a MODIFY DATA
POINTER extended message in it. The internal ISP target groks this
and ctl(8) will be modified to deal with this as well.

At any rate, the data is retransmitted and an an FCP response is
sent. The whole point here is to successfully complete a command
so that you don't have to depend on ULP (SCSI) to have to recover,
which in the case of tape is not really possible (hence the name
FC-TAPE).

Sponsored by: Spectralogic
MFC after: 1 month

(semiforced commit to add comment missed in last delta)
Add a maximum response length for FCP RSPNS IUs.

Clarify some of the FC option words for setting parameters
and try and disable automatic PRLI when in target mode- this
should correct some cases of N-port topologies with 23XX cards
where we put out an illegal PRLI (in target mode only we're
not supposed to put out a PRLI).

Remove file unused in freebsd.

Add 8Gb support (isp_2500). Fix a fair number of configuration and
firmware loading bugs.

Target mode support has received some serious attention to make it
more usable and stable.

Some backward compatible additions to CAM have been made that make
target mode async events easier to deal with have also been put
into place.

Further refinement and better support for NP-IV (N-port Virtualization)
is now in place.

Code for release prior to RELENG_7 has been stripped away for code clarity.

Sponsored by: Copan Systems

Reviewed by: scottl, ken, jung-uk kim
Approved by: re

Fix some stupid copyright mistakes that have been there for quite some time.

Make the SAN login/logout stuff more common between different chipsets
and provied an isp_control entry point so that the outer layers can
do PLOGI/LOGO explicitly. Add MS IOCB support. This completes the cycle
for base support for SMI-S.

Push things closer to path failover by implementing loop down and
gone device timers and zombie state entries. There are tunables
that can be used to select a number of parameters.

loop_down_limit - how long to wait for loop to come back up before
declaring
all devices dead (default 300 seconds)

gone_device_time- how long to wait for a device that has appeared
to leave the loop or fabric to reappear (default 30 seconds)

Internal tunables include (which should be externalized):

quick_boot_time- how long to wait when booting for loop to come up

change_is_bad- whether or not to accept devices with the same
WWNN/WWPN that reappear at a different PortID as being the 'same'
device.

Keen students of some of the subtle issues here will ask how
one can keep devices from being re-accepted at all (the answer
is to set a gone_device_time to zero- that effectively would
be the same thing).

Add 4Gb (24XX) support and lay the foundation for a lot of new stuff.