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

Fix undefined behavior: (1 << 31) is not defined as 1 is an int and this
shifts into the sign bit. Instead use (1U << 31) which gets the
expected result.

This fix is not ideal as it assumes a 32 bit int, but does fix the issue
for most cases.

A similar change was made in OpenBSD.

Discussed with: -arch, rdivacky
Reviewed by: cperciva

Multi-bss (aka vap) support for 802.11 devices.

Note this includes changes to all drivers and moves some device firmware
loading to use firmware(9) and a separate module (e.g. ral). Also there
no longer are separate wlan_scan* modules; this functionality is now
bundled into the wlan module.

Supported by: Hobnob and Marvell
Reviewed by: many
Obtained from: Atheros (some bits)

Various bug fixes for 2560 parts of ral(4):
- Rename rt2560_read_eeprom to rt2560_read_config, we already have
rt2560_eeprom_read
- If hardware gives us wrong encryption done index, shout out loudly and
terminate the processing loop
- Process encryption done if RX done bit is set in interrupt status register
(according to Ralink Linux driver)
- Turn VALID/BUSY bits in TX descriptor only after TX descriptor is fully setup
- Fix BBP read: RT2560_BBPCSR can't be written until its RT2560_BBP_BUSY bit is
off (according to Ralink Linux driver)
- Skip invalid (0 of 0xffff) BBP register/value entries stored in EEPROM
- Fix channel TX power location in EEPROM, if channel TX power is above 31 set
it to 24 (TX power only has 5bits in RF register, "24" is according to Ralink
Linux driver)
- Configure BBP according to the BBP register/value stored in EEPROM, restore
BBP17 (RX sensitivity tuning) to default value after this.
- Set TX/RX antenna after BBP is initialized; these two operation will try to
set BBP registers
- Reconfigure ACK TX time registers according to 802.11g standard (TX @36Mb,
other side's ACK should be sent @24Mb).
- 2560 parts have two TX ring: one for management/control packets, one for data
packets. Add private OACTIVE flag for each of them. Turn on IFF_DRV_OACTIVE
if one of private OACTIVE is on; turn off IFF_DRV_OACTIVE iff all of them are
off.
- Rework watchdog to mimic old if_watchdog action. Process TX done/encryption
done in watchdog function (according to Ralink Linux driver)

Obtained from: DragonFly
Approved by: sam (mentor)
Tested by: sam
Related to PR: kern/117655

# Forcing long slot time setting is not included in this commit, comment and
# related code is in place, so if problem pops up, quick tests could be done.

Update 802.11 wireless support:
o major overhaul of the way channels are handled: channels are now
fully enumerated and uniquely identify the operating characteristics;
these changes are visible to user applications which require changes
o make scanning support independent of the state machine to enable
background scanning and roaming
o move scanning support into loadable modules based on the operating
mode to enable different policies and reduce the memory footprint
on systems w/ constrained resources
o add background scanning in station mode (no support for adhoc/ibss
mode yet)
o significantly speedup sta mode scanning with a variety of techniques
o add roaming support when background scanning is supported; for now
we use a simple algorithm to trigger a roam: we threshold the rssi
and tx rate, if either drops too low we try to roam to a new ap
o add tx fragmentation support
o add first cut at 802.11n support: this code works with forthcoming
drivers but is incomplete; it's included now to establish a baseline
for other drivers to be developed and for user applications
o adjust max_linkhdr et. al. to reflect 802.11 requirements; this eliminates
prepending mbufs for traffic generated locally
o add support for Atheros protocol extensions; mainly the fast frames
encapsulation (note this can be used with any card that can tx+rx
large frames correctly)
o add sta support for ap's that beacon both WPA1+2 support
o change all data types from bsd-style to posix-style
o propagate noise floor data from drivers to net80211 and on to user apps
o correct various issues in the sta mode state machine related to handling
authentication and association failures
o enable the addition of sta mode power save support for drivers that need
net80211 support (not in this commit)
o remove old WI compatibility ioctls (wicontrol is officially dead)
o change the data structures returned for get sta info and get scan
results so future additions will not break user apps
o fixed tx rate is now maintained internally as an ieee rate and not an
index into the rate set; this needs to be extended to deal with
multi-mode operation
o add extended channel specifications to radiotap to enable 11n sniffing

Drivers:
o ath: add support for bg scanning, tx fragmentation, fast frames,
dynamic turbo (lightly tested), 11n (sniffing only and needs
new hal)
o awi: compile tested only
o ndis: lightly tested
o ipw: lightly tested
o iwi: add support for bg scanning (well tested but may have some
rough edges)
o ral, ural, rum: add suppoort for bg scanning, calibrate rssi data
o wi: lightly tested

This work is based on contributions by Atheros, kmacy, sephe, thompsa,
mlaier, kevlo, and others. Much of the scanning work was supported by
Atheros. The 11n work was supported by Marvell.

Add support for the second (RT2561/RT2561S) and third (RT2661 MIMO XR)
generations of 802.11abg chipsets from Ralink Technology.
Get rid of the pccard front-end while I'm here since all adapters are
cardbus ones.

Obtained from: OpenBSD