The later firmware devices (including iwn!) support multiple configuration
contexts for a lot of things, leaving it up to the firmware to decide
which channel and vap is active. This allows for things like off-channel
p2p sta/ap operation and other weird things.
However, net80211 is still focused on a "net80211 drives all" when it comes to driving
the NIC, and as part of this history a lot of these options are global and not per-VAP.
This is fine when net80211 drives things and all VAPs share a single channel - these
parameters importantly really reflect the state of the channel! - but it will increasingly
be not fine when we start supporting more weird configurations and more recent NICs.
Yeah, recent like iwn/iwm.
Anyway - so, migrate all of the HT protection, legacy protection and preamble
stuff to be per-VAP. The global flags are still there; they're now calculated
in a deferred taskqueue that mirrors the old behaviour. Firmware based drivers
which have per-VAP configuration of these parameters can now just listen to the
per-VAP options.
What do I mean by per-channel? Well, the above configuration parameters really
are about interoperation with other devices on the same channel. Eg, HT protection
mode will flip to legacy/mixed if it hears ANY BSS that supports non-HT stations or
indicates it has non-HT stations associated. So, these flags really should be
per-channel rather than per-VAP, and then for things like "do i need short preamble
or long preamble?" turn into a "do I need it for this current operating channel".
Then any VAP using it can query the channel that it's on, reflecting the real
required state.
This patch does none of the above paragraph just yet.
I'm also cheating a bit - I'm currently not using separate taskqueues for
the beacon updates and the per-VAP configuration updates. I can always further
split it later if I need to but I didn't think it was SUPER important here.
So:
* Create vap taskqueue entries for ERP/protection, HT protection and short/long
preamble;
* Migrate the HT station count, short/long slot station count, etc - into per-VAP
variables rather than global;
* Fix a bug with my WME work from a while ago which made it per-VAP - do the WME
beacon update /after/ the WME update taskqueue runs, not before;
* Any time the HT protmode configuration changes or the ERP protection mode
config changes - schedule the task, which will call the driver without the
net80211 lock held and all correctly serialised;
* Use the global flags for beacon IEs and VAP flags for probe responses and
other IE situations.
The primary consumer of this is ath10k. iwn could use it when sending RXON,
but we don't support IBSS or AP modes on it yet, and I'm not yet sure whether
it's required in STA mode (ie whether the firmware parses beacons to change
protection mode or whether we need to.)
Tested:
* AR9280, STA/AP
* AR9380, DWDS STA+STA/AP
* ath10k work, STA/AP
* Intel 6235, STA
* Various rtwn / run NICs, DWDS STA and STA configurations
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