enforcing the TXOP and TBTT limits:
* Frames which will overlap with TBTT will not TX;
* Frames which will exceed TXOP will be filtered.
This is not enabled by default; it's intended to be enabled by the
TDMA code on 802.11n capable chipsets.
the revamped sysctl code did not work, and needed a change. This
makes the limit get set at the time that all sysctl stats are
created and is actually more elegant imho anyway.
TX hot path by getting rid of index calculations and simply
managing pointers. Much of the creative code is due to my
coworker here at Intel, Alex Duyck, thanks Alex!
Also, this whole series of patches was given the critical
eye of Gleb Smirnoff and is all the better for it, thanks
Gleb!
- add a limit for both RX and TX, change the default to 256
- change the sysctl usage to be common, and now to be called
during init for each ring.
- the TX limit is not yet used, but the changes in the last
patch in this series uses the value.
- the motivation behind these changes is to improve data
locality in the final code.
- rxeof interface changes since it now gets limit from the
ring struct
defines (at Gleb's request). Also, change the defines around
the old transmit code to IXGBE_LEGACY_TX, I do this to make
it possible to define this regardless of the OS level (it is
not defined by default). There are also a couple changed
comments for clarity.
these are FCOE stats (fiber channel over ethernet), something that
FreeBSD does not yet have, they were mistaken for flow control by
the implementor I believe. Secondly, the real flow control stats
are oddly named with a 'link' tag on the front, it was requested
by my validation engineer to make these stats have the same name as
the igb driver for clarity and that seemed reasonable to me.
multiqueue code, this functionality has proven to be more
trouble than it was worth. Thanks to Gleb for a second
critical look over my code and help in the patches!
It returns memory regions restricted from being used by kernel. These
regions are dfined in "memreserve" property of root node in the same
format as "reg" property of /memory node
embryonic connection has been setup and never attempt to abort a tid
before this is done. This fixes a bad race where a listening socket is
closed when the driver is in the middle of step (b) here. The symptom
of this were "ARP miss" errors from the driver followed by tid leaks.
A hardware-offloaded passive open works this way:
a) A SYN "hits" the TCAM entry for a server tid and the chip delivers it
to the queue associated with the server tid (say, queue A). It waits
for a response from the driver telling it what to do.
b) The driver decides it is ok to proceed. It adds the new tid to the
list of embryonic connections associated with the server tid and then
hands off the SYN to the kernel's syncache to make sure that the kernel
okays it too. If it does then the driver provides an L2 table entry,
queue id (say, queue B), etc. and instructs the chip to send the SYN/ACK
response.
c) The chip delivers a status to queue B depending on how the third step
of the 3-way handshake goes. The driver removes the tid from its list
of embryonic connections and either expands the syncache entry or
destroys the tid. In any case all subsequent messages for the new tid
will be delivered to queue B, not queue A. Anything running in queue B
knows that the L2 entry has long been setup and the new flag is of no
interest from here on. If the listener is closed it will deal with
so_comp as normal.
MFC after: 1 week
now this works for non-debug and debug builds.
* Add a comment reminding me (or someone) to audit all of the relevant
math to ensure there's no weird wrapping issues still lurking about.
But yes, this does seem to be mostly working.
Pointy-hat-to: adrian, yet again
* add some further debugging prints, which are quite nice to have
* add in ALQ hooks (optional!) to allow for the TDMA information to be
logged in-line with the TX and RX descriptor information.
The existing logic wrapped programming nexttbtt at 65535 TU.
This is not good enough for the 11n chips, whose nexttbtt register
(GENERIC_TIMER_0) has an initial value from 0..2^31-1 TSF.
So converting the TU to TSF had the counter wrap at (65535 << 10) TSF.
Once this wrap occured, the nexttbtt value was very very low, much
lower than the current TSF value. At this point, the nexttbtt timer
would constantly fire, leading to the TX queue being constantly gated
open.. and when this occured, the sender was not correctly transmitting
in its slot but just able to continuously transmit. The master would
then delay transmitting its beacon until after the air became free
(which I guess would be after the burst interval, before the next burst
interval would quickly follow) and that big delta in master beacon TX
would start causing big swings in the slot timing adjustment.
With this change, the nexttbtt value is allowed to go all the way up
to the maximum value permissable by the 32 bit representation.
I haven't yet tested it to that point; I really should. The AR5212
HAL now filters out values above 65535 TU for the beacon configuration
(and the relevant legal values for SWBA, DBA and NEXTATIM) and the
AR5416 HAL just dutifully programs in what it should.
With this, TDMA is now useful on the 802.11n chips.
Tested:
* AR5416, AR9280 TDMA slave
* AR5413 TDMA slave
what the maximum legal values are.
The current beacon timer configuration from TDMA wraps things at
HAL_BEACON_PERIOD-1 TU. For the 11a chips this is fine, but for
the 11n chips it's not enough resolution. Since the 11a chips have a
limit on what's "valid", just enforce this so when I do write larger
values in, they get suitably wrapped before programming.
Tested:
* AR5413, TDMA slave
Todo:
* Run it for a (lot) longer on a clear channel, ensure that no strange
slippages occur.
* Re-validate this on STA configurations, just to be sure.
fail or not. The mbuf pointer is no longer valid, so
can't be reused after.
Fix igb_mq_start() where mbuf pointer was used after
drbr_enqueue().
This eventually leads us to all invocations of
igb_mq_start_locked() called with third argument as NULL.
This allows us to simplify this function.
Submitted by: Karim Fodil-Lemelin <fodillemlinkarim gmail.com>
Reviewed by: jfv
detailed information under the sound debug. To make it easier accessible,
export that information through the set of sysctls like dev.hdaa.X.nidY.
Also tune some output to make it both more compact and informative.
After chatting with the MAC team, the TSF writes (at least on the 11n
MACs, I don't know about pre-11n MACs) are done as 64 bit writes that
can take some time. So, doing a 32 bit TSF write is definitely not
supported. Leave a comment here which explains that.
Whilst here, add a comment which outlines that after a reset or TSF
write, the TSF write may take a while (up to 50uS) to update.
A write or reset shouldn't be done whilst the previous one is in
flight. Also (and this isn't currently done) a read shouldn't
occur until the SLEEP32_TSF_WRITE_STAT is clear. Right now we're
not doing that, mostly because we haven't been doing lots of TSF
resets/writes until recently.
TSF write.
The TSF_L32 update is fine for the AR5413 (and later, I guess) 11abg NICs
however on the 11n NICs this didn't work. The TSF writes were causing
a much larger time to be skipped, leading to the timing to never
converge.
I've tested this 64 bit TSF read, adjust and write on both the
11n NICs and the AR5413 NIC I've been using for testing. It works
fine on each.
This patch allows the AR5416/AR9280 to be used as a TDMA member.
I don't yet know why the AR9280 is ~7uS accurate rather than ~3uS;
I'll look into it soon.
Tested:
* AR5413, TDMA slave (~ 3us accuracy)
* AR5416, TDMA slave (~ 3us accuracy)
* AR9280, TDMA slave (~ 7us accuracy)
on the 802.11n NICs.
The 802.11n NICs return a TBTT value that continues far past the 16 bit
HAL_BEACON_PERIOD time (in TU.) The code would constrain nextslot to
HAL_BEACON_PERIOD, but it wasn't constraining nexttbtt - the pre-11n
NICs would only return TU values from 0 -> HAL_BEACON_PERIOD. Thus,
when nexttbtt exceeded 64 milliseconds, it would not wrap (but nextslot
did) which lead to a huge tsfdelta.
So until the slot calculation is converted to work in TSF rather than
a mix of TSF and TU, "make" the nexttbtt values match the TU assumptions
for pre-11n NICs.
This fixes the crazy deltatsf calculations but it doesn't fix the
non-convergent tsfdelta issue. That'll be fixed in a subsequent commit.
... instead of the ever increasing ones.
Also, do free old resources when allocating new ones when cx states
change.
Tested by: Tom Lislegaard <Tom.Lislegaard@proact.no>
Obtained from: jkim
MFC after: 1 week
