MFC r344990:
Fix ieee80211_radiotap(9) usage in wireless drivers:

- Alignment issues:
* Add missing __packed attributes + padding across all drivers; in
most places there was an assumption that padding will be always
minimally suitable; in few places - e.g., in urtw(4) / rtwn(4) -
padding was just missing.
* Add __aligned(8) attribute for all Rx radiotap headers since they can
contain 64-bit TSF timestamp; it cannot appear in Tx radiotap headers, so
just drop the attribute here. Refresh ieee80211_radiotap(9) man page
accordingly.

- Since net80211 automatically updates channel frequency / flags in
ieee80211_radiotap_chan_change() drop duplicate setup for these fields
in drivers.

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

net80211 drivers: eliminate any references to sc_rxtap_len/sc_txtap_len (never used here)

Submitted by: <s3erios@gmail.com>
Differential Revision: https://reviews.freebsd.org/D3776

modify the rssi logic a bit to actually return a useful rssi.

The fullmac firmware doesn't seem to populate a useful rssi indicator
in the RX descriptor, so if one plotted said values, they'd basically
look like garbage.

The reference driver implements a "get current rssi" firmware command
which I guess is really meant for station operation only (as hostap
operation would need rssi per station, not a single firmware read.)

So:

* populate sc_currssi during each calibration run;
* use this in the RX path instead of trying to reconstruct the RSSI
value and passing it around as a pointer;
* do up a quick hack to map the rssi hardware value to some useful
signal level;
* the survey results provide an RSSI value between 0..100, so just
do another quick hack to map it into some usefulish signal level;
* supply a faked noise floor - I haven't yet found how to pull it
out of the firmware.

The scan results and the station RSSI information is now more useful
for indicating signal strength / distance.

rsu(4): Add support for 1T2R and 2T2R NICs.

This logic is mostly crimed from the reference driver and the linux
r92su driver.

I verified that it (a) worked on the rsu hardware I have, and (b)
did traffic testing whilst watching what ath(4) sent as a hostap.
It successfully sent MCS8..15 rates (which requires 2-stream reception)
as well as MCS0..7 (which is 1-stream.)

Tested:

* RTL8712, 1T1R NIC, MCS rates 0..7.
* RTL8712, 1T2R NIC, MCS rates 0..15

TODO:

* Find a 2T2R NIC!

net80211: include one copy of struct ieee80211_beacon_offsets into ieee80211vap

Submitted by: Andriy Voskoboinyk <s3erios@gmail.com>
Differential Revision: https://reviews.freebsd.org/D3658

Send a power command to the firmware to shut down the radio as well
during rsu_stop().

Begin fleshing out basic power-on / power-off and A-MPDU TX support.

* Add a new method to control NIC poweron / network-sleep / power off;
* Add in A-MPDU TX negotiation support, but comment it out because it
does break TX traffic;
* blank out the tx buffer before sending a firmware message, just in case;
* go into network-sleep once associated;

TODO:

* figure out why ampdu negotiation isn't working and breaking TX traffic,
then enable it.

Convert if_rsu to use a deferred transmit task rather than using rsu_start()
to do it directly.

Ensure that we re-queue starting transmit upon TX completion.

This solves two issues:

* It stops tx stalls - before this, if the transmit path filled the
mbuf queue then it'd never start another transmit.

* It enforces ordering - this is very required for 802.11n which
requires frames to be transmitted in the order they're queued.
Since everything remotely involved in USB has an unlock/thing/relock
pattern with that mutex, the only way to guarantee TX ordering is
to 100% defer it into a separate thread.

This now survives an iperf test and gets a reliable 30mbit/sec.

Add in a temporary (hah!) workaround for net80211 scanning versus NIC
requirements.

Don't start the opmode and join path until a pending survey is finished.
This seems to reliably fix things.

Ideally I'd just finish off the net80211 pluggable scan stuff and implement
the methods here so if_rsu can just drive the scan machinery.
However, that's a .. later thing.

Whilst here, remove the getbuf debugging; it's okay to run out of transmit
buffers under load; it however isn't okay to not be able to send commands.
I'll fix that later.

Add a very hacked up station only A-MPDU negotiation path.

This is enough to set things up; there are still lots of retransmits
seen but it's enough to get things working.

Use the H2C endpoint for sending firmware commands, rather than the voice
data queues.

This is similar to the openbsd and rtlwifi/r92su drivers.

Note: this driver still assumes it's a 4-endpoint device; I'll enforce
that in a follow-up commit.

Prepare for 11n - get the number of endpoints and whether 11n is available.

Bump RX_LIST_COUNT so we don't fall behind during active traffic.

Replay r286410. Change KPI of how device drivers that provide wireless
connectivity interact with the net80211 stack.

Historical background: originally wireless devices created an interface,
just like Ethernet devices do. Name of an interface matched the name of
the driver that created. Later, wlan(4) layer was introduced, and the
wlanX interfaces become the actual interface, leaving original ones as
"a parent interface" of wlanX. Kernelwise, the KPI between net80211 layer
and a driver became a mix of methods that pass a pointer to struct ifnet
as identifier and methods that pass pointer to struct ieee80211com. From
user point of view, the parent interface just hangs on in the ifconfig
list, and user can't do anything useful with it.

Now, the struct ifnet goes away. The struct ieee80211com is the only
KPI between a device driver and net80211. Details:

- The struct ieee80211com is embedded into drivers softc.
- Packets are sent via new ic_transmit method, which is very much like
the previous if_transmit.
- Bringing parent up/down is done via new ic_parent method, which notifies
driver about any changes: number of wlan(4) interfaces, number of them
in promisc or allmulti state.
- Device specific ioctls (if any) are received on new ic_ioctl method.
- Packets/errors accounting are done by the stack. In certain cases, when
driver experiences errors and can not attribute them to any specific
interface, driver updates ic_oerrors or ic_ierrors counters.

Details on interface configuration with new world order:
- A sequence of commands needed to bring up wireless DOESN"T change.
- /etc/rc.conf parameters DON'T change.
- List of devices that can be used to create wlan(4) interfaces is
now provided by net.wlan.devices sysctl.

Most drivers in this change were converted by me, except of wpi(4),
that was done by Andriy Voskoboinyk. Big thanks to Kevin Lo for testing
changes to at least 8 drivers. Thanks to pluknet@, Oliver Hartmann,
Olivier Cochard, gjb@, mmoll@, op@ and lev@, who also participated in
testing.

Reviewed by: adrian
Sponsored by: Netflix
Sponsored by: Nginx, Inc.

Revert the wifi ifnet changes until things are more baked and tested.

* 286410
* 286413
* 286416

The initial commit broke a variety of debug and features that aren't
in the GENERIC kernels but are enabled in other platforms.

Change KPI of how device drivers that provide wireless connectivity interact
with the net80211 stack.

Historical background: originally wireless devices created an interface,
just like Ethernet devices do. Name of an interface matched the name of
the driver that created. Later, wlan(4) layer was introduced, and the
wlanX interfaces become the actual interface, leaving original ones as
"a parent interface" of wlanX. Kernelwise, the KPI between net80211 layer
and a driver became a mix of methods that pass a pointer to struct ifnet
as identifier and methods that pass pointer to struct ieee80211com. From
user point of view, the parent interface just hangs on in the ifconfig
list, and user can't do anything useful with it.

Now, the struct ifnet goes away. The struct ieee80211com is the only
KPI between a device driver and net80211. Details:

- The struct ieee80211com is embedded into drivers softc.
- Packets are sent via new ic_transmit method, which is very much like
the previous if_transmit.
- Bringing parent up/down is done via new ic_parent method, which notifies
driver about any changes: number of wlan(4) interfaces, number of them
in promisc or allmulti state.
- Device specific ioctls (if any) are received on new ic_ioctl method.
- Packets/errors accounting are done by the stack. In certain cases, when
driver experiences errors and can not attribute them to any specific
interface, driver updates ic_oerrors or ic_ierrors counters.

Details on interface configuration with new world order:
- A sequence of commands needed to bring up wireless DOESN"T change.
- /etc/rc.conf parameters DON'T change.
- List of devices that can be used to create wlan(4) interfaces is
now provided by net.wlan.devices sysctl.

Most drivers in this change were converted by me, except of wpi(4),
that was done by Andriy Voskoboinyk. Big thanks to Kevin Lo for testing
changes to at least 8 drivers. Thanks to Olivier Cochard, gjb@, mmoll@,
op@ and lev@, who also participated in testing. Details here:

https://wiki.freebsd.org/projects/ifnet/net80211

Still, drivers: ndis, wtap, mwl, ipw, bwn, wi, upgt, uath were not
tested. Changes to mwl, ipw, bwn, wi, upgt are trivial and chances
of problems are low. The wtap wasn't compilable even before this change.
But the ndis driver is complex, and it is likely to be broken with this
commit. Help with testing and debugging it is appreciated.

Differential Revision: D2655, D2740
Sponsored by: Nginx, Inc.
Sponsored by: Netflix

Fixes for the RSU driver:
- The R92S_TCR register is an 8-bit register. Don't access it like a
16-bit register.
- Disable parsing the delete station event, due to many false events.
- Ensure that there is only one transfer queue for each endpoint, so
that packets transmitted don't get out of order.

MFC after: 1 week

- Split transmit queue into one for each type. Apparently there will
be a race when using a single active queue for all transmit types.
- Last argument of usb_pause_mtx() is ticks and not milliseconds.
- Remove unused watchdog.
- Remove some unused fields from the RSU softc structure.
- Workaround usbd_transfer_start() recursion from inside of completion
callback.

MFC after: 3 days

Import OpenBSD's rsu(4) WLAN driver.
Support chipsets are the Realtek RTL8188SU, RTL8191SU, and RTL8192SU.

Many thanks to Idwer Vollering for porting/writing the man page and for
testing.

Reviewed by: adrian, hselasky
Obtained from: OpenBSD
Tested by: kevlo, Idwer Vollering <vidwer at gmail.com>