This code was originally implemented 7 years ago, but never really worked
due to trivial error. I think this functionality may be not required.
Initiators supporting optional periodic command status checks detected
those terminated commands and retried them 3 seconds later. But thinking
about less featured initiators and the fact that it is our race makes
virtual ports "unknown" it may be good to have this feature.
It is normal for ZOMBIE ports to be logged out. This status is not really
an error until Gone Device Timeout expires, so make CAM retry after delay.
MFC after: 1 week
Firmware automatically logs in only to local loop ports, and those ports
can be easily identified without extra flag by zero domain and area IDs.
MFC after: 1 week
Since we no longer need additional buffers for request and response IOCBs,
we can increase receive space by 192 bytes, that is enough for fetching 48
more ports. The new limit is 1020 fabric ports per virtual port.
MFC after: 1 month
This should close the race between request arriving on new target mode
virtual port and its scanner thread finally fetch its address for request
routing.
For some reason firmware sends Port Database Changed notifications in case
of explicit login requests from the driver when target port is unavailabe.
Those notifications don't give driver any new information, but only cause
infinite scan loop.
Previously we had to do it synchronously because we could not drop the lock
due to potential scratch memory use conflicts. Previous commits fixed that
collision, so here it goes -- slower and less reliable external requests
are executed asynchronously without spinning in tight loop and with more
safe timeout handling.
Usually IOCBs should be put on queue for asynchronous processing and should
not require additional DMA memory. But there are some cases like aborts and
resets that for external reasons has to be synchronous. Give those cases
separate 2*64 byte DMA area to decouple them from other DMA scratch area
users, using it for asynchronous requests.
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
This space does not require DMA syncing. It reduces lock scope of the DMA
scratch space. It allows whole DMA scratch space to be used to I/O, so now
we can fetch up to ~1000 ports from SNS.
Due to the last fact, increase maximal number of ports from 256 to 1024.
Before this change virtual ports control IOCBs were executed synchronously
via Execute IOCB mailbox command. It required exclusive use of scratch
space of driver and mailbox registers of the hardware. Because of that
shared resources use this code could not really sleep, having to spin for
completion, blocking any other operation.
This change introduces new asynchronous design, sending the IOCBs directly
on request queue and gracefully waiting for their return on response queue.
Returned IOCBs are identified with unified handle space from r292725.
I am not sure why this was split long ago, but I see no reason for it.
At this point this unification just slightly reduces memory usage, but
as next step I plan to reuse shared handle space for other IOCB types.
- Make scan aborted by event restart immediately and infinitely.
- Improve handling of some loop events from firmware.
- Remove loop down timer, adding its functionality to scanner thread.
- Some more unification and simplification.
Hacks to enable target mode there complicated code, while didn't really
work. And for outdated hardware fixing it is not really interesting.
Initiator mode tested with Qlogic 1080 adapter is still working fine.
While later firmware always registers for RSCN requests, older one does
it only in initiator mode. But in target mode there RSCN can be the only
way to detect gone intiator.
For those chips we are not receiving login events, adding initiators
based on ATIO requests. But there is no port ID in that structure, so
in fabric mode we have to explicitly fetch it from firmware to be able
to do normal scan after that.
This change simplifies and unifies port adding/updating for loop and
fabric scanners. It also fixes problems with scanning restarts due to
concurrent port databases changes. It also fixes many cosmetic issues.
Modern cards in most cases operate abstract port handles, that have no
any relation to real loop IDs. Leave loopid used only where it really
goes about local loop IDs.
While there, fix few more cases where LUNs were still printed in decimal.
