the response queue. Instead of the ad hoc ISP_SWIZZLE_REQUEST, we now have
a complete set of inline functions in isp_inline.h. Each platform is
responsible for providing just one of a set of ISP_IOX_{GET,PUT}{8,16,32}
macros.
The reason this needs to be done is that we need to have a single set of
functions that will work correctly on multiple architectures for both little
and big endian machines. It also needs to work correctly in the case that
we have the request or response queues in memory that has to be treated
specially (e.g., have ddi_dma_sync called on it for Solaris after we update
it or before we read from it). It also has to handle the SBus cards (for
platforms that have them) which, while on a Big Endian machine, do *not*
require *most* of the request/response queue entry fields to be swizzled
or unswizzled.
One thing that falls out of this is that we no longer build requests in the
request queue itself. Instead, we build the request locally (e.g., on the
stack) and then as part of the swizzling operation, copy it to the request
queue entry we've allocated. I thought long and hard about whether this was
too expensive a change to make as it in a lot of cases requires an extra
copy. On balance, the flexbility is worth it. With any luck, the entry that
we build locally stays in a processor writeback cache (after all, it's only
64 bytes) so that the cost of actually flushing it to the memory area that is
the shared queue with the PCI device is not all that expensive. We may examine
this again and try to get clever in the future to try and avoid copies.
Another change that falls out of this is that MEMORYBARRIER should be taken
a lot more seriously. The macro ISP_ADD_REQUEST does a MEMORYBARRIER on the
entry being added. But there had been many other places this had been missing.
It's now very important that it be done.
Additional changes:
Fix a longstanding buglet of sorts. When we get an entry via isp_getrqentry,
the iptr value that gets returned is the value we intend to eventually plug
into the ISP registers as the entry *one past* the last one we've written-
*not* the current entry we're updating. All along we've been calling sync
functions on the wrong index value. Argh. The 'fix' here is to rename all
'iptr' variables as 'nxti' to remember that this is the 'next' pointer-
not the current pointer.
Devote a single bit to mboxbsy- and set aside bits for output mbox registers
that we need to pick up- we can have at least one command which does not
have any defined output registers (MBOX_EXECUTE_FIRMWARE).
MFC after: 2 weeks
----
Make a device for each ISP- really usable only with devfs and add an ioctl
entry point (this can be used to (re)set debug levels, reset the HBA,
rescan the fabric, issue lips, etc).
----
Add in a kernel thread for Fibre Channel cards. The purpose of this
thread is to be woken up to clean up after Fibre Channel events
block things. Basically, any FC event that casts doubt on the
location or identify of FC devices blocks the queues. When, and
if, we get the PORT DATABASE CHANGED or NAME SERVER DATABASE CHANGED
async event, we activate the kthread which will then, in full thread
context, re-evaluate the local loop and/or the fabric. When it's
satisfied that things are stable, it can then release the blocked
queues and let commands flow again.
The prior mechanism was a lazy evaluation. That is, the next command
to come down the pipe after change events would pay the full price
for re-evaluation. And if this was done off of a softcall, it really
could hang up the system.
These changes brings the FreeBSD port more in line with the Solaris,
Linux and NetBSD ports. It also, more importantly, gets us being
more proactive about topology changes which could then be reflected
upwards to CAM so that the periph driver can be informed sooner
rather than later when things arrive or depart.
---
Add in the (correct) usage of locking macros- we now have lock transition
macros which allow us to transition from holding the CAM lock (Giant)
and grabbing the softc lock and vice versa. Switch over to having this
HBA do real locking. Some folks claim this won't be a win. They're right.
But you have to start somewhere, and this will begin to teach us how
to DTRT for HBAs, etc.
--
Start putting in prototype 2300 support. Add back in LIP
and Loop Reset as async events that each platform will handle.
Add in another int_bogus instrumentation point.
Do some more substantial target mode cleanups.
MFC after: 8 weeks
tag is active for an ATIO, and say that you want to reconnect with
a tag value in a CTIO have *never* been exercised until now. This lossage
derived from Solaris code where this stuff originally came from that is
about 7 years old. Amazing.
We now bundle the incoming tag (legal values are 0..256) as the low
16 bits of the ccb_accept_tio's at_tagid while we put the firmware
handle for this ATIO in the top 16 bits- define some macros to make
this cleaner.
Complete some Ansification.
This is a pretty invasive change, but there are three good
reasons to do this:
1. We'll never have > 16 bits of handle.
2. We can (eventually) enable the RIO (Reduced Interrupt Operation)
bits which return multiple completing 16 bit handles in mailbox
registers.
3. The !)$*)$*~)@$*~)$* Qlogic target mode for parallel SCSI spec
changed such that at_reserved (which was 32 bits) was split into
two pieces- and one of which was a 16 bit handle id that functions
like the at_rxid for Fibre Channel (a tag for the f/w to correlate
CTIOs with a particular command). Since we had to muck with that
and this changed the whole handler architecture, we might as well...
Propagate new at_handle on through int ct_fwhandle. Follow
implications of changing to 16 bit handles.
These above changes at least get Qlogic 1040 cards working in target
mode again. 1080/12160 cards don't work yet.
In isp.c:
Prepare for doing all loop management in outer layers.
code gratefully borrowed from Patrick Stirling who did a lot of the
grunt work on this years ago. There are also some beginnings of
swizzle macros in case we go to a big endian machine. This is just
a first pass at this and is likely to change a bit over the next
