The 'local' variable in __ieee80211_vif_copy_chanctx_to_vlans()
is only used/needed when lockdep is compiled in, mark it as such
to avoid compile warnings in the other case.

While at it, fix some indentation where it's used.
Reviewed-by: NLuciano Coelho <luciano.coelho@intel.com>
Reviewed-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

It doesn't make much sense to store refcount in
the chanctx structure. One still needs to hold
chanctx_mtx to get the value safely. Besides,
refcount isn't on performance critical paths.

This will make implementing chanctx reservation
refcounting a little easier.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The function did a little too much. Split it up so
the code can be easily reused in the future.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The function did a little too much. Split it up so
the code can be easily reused in the future.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Use a separate function to look for reservation
chanctx. For multi-interface/channel reservation
search sematics differ slightly.

The new routine allows reservations to be merged
with chanctx that are already reserved by other
interface(s).
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This allows new vifs to be assigned to a chanctx
as long as chanctx's reservation chandefs (if any)
and chanctx's current chandef (implied by assigned
vifs at the time, if any) and the new vif chandef
are all compatible.

This implies it is impossible to assign a new vif
to an in-place reservation chanctx.

This gives no advantages for single-channel
hardware. It makes sense for multi-channel
hardware only.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This can be useful. Provides a more straghtforward
way to iterate over interfaces taking part in
chanctx reservation and allows tracking chanctx
usage explicitly.

The structure is protected by local->chanctx_mtx.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This can be useful. Provides a more straghtforward
way to iterate over interfaces bound to a given
chanctx and allows tracking chanctx usage
explicitly.

The structure is protected by local->chanctx_mtx.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Initial chanctx reservation code wasn't aware of
radar detection requirements. This is necessary
for chanctx reservations to be used for channel
switching in the future.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Do not allocate more channel contexts than a
driver is capable for currently matching interface
combination.

This allows the ieee80211_vif_reserve_chanctx() to
act as a guard against breaking interface
combinations.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

With single-channel drivers, we need to be able to change a running
chanctx if we want to use chanctx reservation.  Not all drivers may be
able to do this, so add a flag that indicates support for it.

Changing a running chanctx can also be used as an optimization in
multi-channel drivers when the context needs to be reserved for future
usage.

Introduce IEEE80211_CHANCTX_RESERVED chanctx mode to mark a channel as
reserved so nobody else can use it (since we know it's going to
change).  In the future, we may allow several vifs to use the same
reservation as long as they plan to use the chanctx on the same
future channel.
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

In order to support channel switch with multiple vifs and multiple
contexts, we implement a concept of channel context reservation.  This
allows us to reserve a channel context to be used later.

The reservation functionality is not tied directly to channel switch
and may be used in other situations (eg. reserving a channel context
during IBSS join).

We first check if an existing compatible context exists and if it
does, we reserve it.  If there is no compatible context we create a
new one and reserve it.

Additionally, split ieee80211_vif_copy_chanctx_to_vlans() so we can
call it while already holding the chanctx mutex.
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Combine the functions into one, so that we can switch from one context
to the other without having to unassign and assign separately.  This
is needed by the channel reservation functionality because otherwise
we have a small period of time when the chanctx is set to NULL, which
can cause problems if someone else is trying to dereference it.
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

ieee80211_vif_change_channel() locks chanctx_mtx.  When implementing
channel reservation for CS, we will need to call the function to
change channel when the lock is already held, so split the part that
requires the lock out and leave the locking in the original function.
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

It was impossible to change chanctx of master AP
for AP VLANs because the copy function requires
RTNL which can't be simply taken in mac80211 code
due to possible deadlocks.

This is required for future chanctx reservation
that re-bind vifs to new chanctx. This requires
safe AP VLAN iteration without RTNL.

Now VLANs can be iterated while holding either
RTNL or local->mtx because the list is modified
while holding both of these locks.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Move the counting part of the interface combination check from
cfg80211 to mac80211.

This is needed to simplify locking when the driver has to perform a
combination check by itself (eg. with channel-switch).
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

rcu_assign_pointer() ensures that the initialization of a structure is
carried out before storing a pointer to that structure. However, in the
case that NULL is assigned there's no structure to initialize so using
RCU_INIT_POINTER instead is safe and more efficient.
Signed-off-by: NMonam Agarwal <monamagarwal123@gmail.com>
[squash eight tiny patches, rewrite commit log]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If chandef had non-HT width it was possible for
radar_enabled update to not be propagated properly
through drv_config(). This happened because
ieee80211_hw_conf_chan() would never see different
local->hw.conf.chandef and local->_oper_chandef.

This wasn't a problem with HT chandefs because
_oper_chandef width is reset to non-HT in
ieee80211_free_chanctx() making
ieee80211_hw_conf_chan() to kick in.

This problem led (at least) ath10k to not start
CAC if prior CAC was cancelled and both CACs were
requested for identical non-HT chandefs.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

All antennas should be operational when monitoring to maximize
reception.
Signed-off-by: NIdo Yariv <idox.yariv@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When calculating the current max bw required for
a channel context, we didn't consider the virtual
monitor interface, resulting in its channel context
being narrower than configured.

This broke monitor mode with iwlmvm, which uses the
minimal width.
Reported-by: NIdo Yariv <idox.yariv@intel.com>
Signed-off-by: NEliad Peller <eliadx.peller@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

radar_required setting wasn't protected by
local->mtx in some places. This should prevent
from scanning/radar detection/roc colliding.
Signed-off-by: NMichal Kazior <michal.kazior@tieto.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The scan code creates an iflist_mtx -> mtx locking dependency,
and a few other places, notably radar detection, were creating
the opposite dependency, causing lockdep to complain. As scan
and radar detection are mutually exclusive, the deadlock can't
really happen in practice, but it's still bad form.

A similar issue exists in the monitor mode code, but this is
only used by channel-context drivers right now and those have
to have hardware scan, so that also can't happen.

Still, fix these issues by making some of the channel context
code require the mtx to be held rather than acquiring it, thus
allowing the monitor/radar callers to keep the iflist_mtx->mtx
lock ordering.

While at it, also fix access to the local->scanning variable
in the radar code, and document that radar_detect_enabled is
now properly protected by the mtx.

All this would now introduce an ABBA deadlock between the DFS
work cancelling and local->mtx, so change the locking there a
bit to not need to use cancel_delayed_work_sync() but be able
to just use cancel_delayed_work(). The work is also safely
stopped/removed when the interface is stopped, so no extra
changes are needed.
Reported-by: NKalle Valo <kvalo@qca.qualcomm.com>
Tested-by: NSimon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The function is only used in one file, so move it up a
bit to avoid forward declarations and make it static.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add a new field to ieee80211_chanctx_conf to indicate
the min required channel configuration.

Tuning to a narrower channel might help reducing
the noise level and saving some power.

The min required channel definition is the max of
all min required channel definitions of the interfaces
bound to this channel context.

In AP mode, use 20MHz when there are no connected station.
When a new station is added/removed, calculate the new max
bandwidth supported by any of the stations (e.g. 80MHz when
80MHz and 40MHz stations are connected).

In other cases, simply use bss_conf.chandef as the
min required chandef.

Notify drivers about changes to this field by calling
drv_change_chanctx with a new CHANGE_MIN_WIDTH notification.
Signed-off-by: NEliad Peller <eliad@wizery.com>
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

There is no reason why we should have only one channel switch
announcement at a time for a single phy.  When support for channel
switch with multiple contexts and multiple vifs per context is
implemented, we will need the chandef data for each vif.  Move the
csa_chandef structure to sdata to prepare for this.
Reviewed-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NLuciano Coelho <luciano.coelho@intel.com>
[Fixed compilation with mesh]
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Limit the current implementation to a single channel context used by
a single vif, thereby avoiding multi-vif/channel complexities.

Reuse the main function from AP CSA code, but move a portion out in
order to fit the STA scenario.

Add a new mac80211 HW flag so we don't break devices that don't support
channel switch with channel-contexts. The new behavior will be opt-in.
Signed-off-by: NArik Nemtsov <arik@wizery.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The count field in CSA must be decremented with each beacon
transmitted. This patch implements the functionality for drivers
using ieee80211_beacon_get(). Other drivers must call back manually
after reaching count == 0.

This patch also contains the handling and finish worker for the channel
switch command, and mac80211/chanctx code to allow to change a channel
definition of an active channel context.
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NMathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
[small cleanups, catch identical chandef]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

local->hw.conf maybe not be synced when recalcing whether radar is
enabled, sometimes leaving radar enabled even if it's not neccesary
anymore.

Fix this by:
 * setting radar_enabled when creating the chanctx
 * turning radar_enabled off before destroying the last channel context
Reported-by: NZefir Kurtisi <zefir.kurtisi@neratec.com>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Drivers that don't use chanctxes cannot perform VHT association because
they still use a "backward compatibility" pair of {ieee80211_channel,
nl80211_channel_type} in ieee80211_conf and ieee80211_local.
Signed-off-by: NKarl Beldan <karl.beldan@rivierawaves.com>
[fix kernel-doc]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Corey Richardson reported that my idle handling cleanup
(commit fd0f979a, "mac80211: simplify idle handling")
broke ath9k_htc. The reason appears to be that it wants
to go out of idle before switching channels. To fix it,
reimplement that sequence.
Reported-by: NCorey Richardson <corey@octayn.net>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

For HT and VHT the current bandwidth can change,
add the function ieee80211_vif_change_bandwidth()
to take care of this. It returns a failure if the
new bandwidth isn't compatible with the existing
channel context, the caller has to handle that.
When it happens, also inform the driver that the
bandwidth changed for this virtual interface (no
drivers would actually care today though.)

Changing to/from HT/VHT isn't allowed though.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This should be called ieee80211_change_chanctx() since
it changes the channel context, not a chandef.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Since the idle decision rework, mac80211 started calling
bss_info_changed() for the driver's monitor interface,
which causes a crash for iwlwifi, but drivers generally
don't expect this to happen. Therefore, avoid it.

While at it, also prevent calling it in such cases and
only print a warning. For the P2P Device interface the
idle will no longer be called (no channel context), so
also prevent that and warn on it.
Reported-by: NChaitanya <chaitanya.mgit@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Add command to trigger radar detection in the driver/FW.
Once radar detection is started it should continuously
monitor for radars as long as the channel active.
If radar is detected usermode notified with 'radar
detected' event.

Scanning and remain on channel functionality must be disabled
while doing radar detection/scanning, and vice versa.

Based on original patch by Victor Goldenshtein <victorg@ti.com>
Signed-off-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Now that we have channel contexts, idle is (pretty
much) equivalent to not having a channel context.
Change the code to use this relation so that there
no longer is a need for a lot of idle recalculate
calls everywhere.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Currently the code assigns channel contexts to VLANs
(for use by the TX/RX code) when the AP master gets
its channel context assigned. This works fine, but
in the upcoming radar detection work the VLANs don't
require a channel context (during radar detection)
and assigning one to them anyway causes issues with
locking and also inconsistencies -- a VLAN interface
that is added before radar detection would get the
channel context, while one added during it wouldn't.

Fix these issues moving the channel context copying
to a new explicit operation that will not be used
in the radar detection code.
Acked-by: NSimon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

During suspend/resume channel contexts might be
iterated even if they haven't been re-added to
the driver, keep track of this and skip them in
iteration. Also use the new status for sanity
checks.

Also clarify the fact that during HW restart all
contexts are iterated over (thanks Eliad.)
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Make AP_VLAN type interfaces track the AP master channel
context so they have one assigned for the various lookups.
Don't give them their own refcount etc. since they're just
slaves to the AP master.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Convert mac80211 (and where necessary, some drivers a
little bit) to the new channel definition struct.

This will allow extending mac80211 for VHT, which is
currently restricted to channel contexts since there
are no drivers using that which makes it easier. As
I also don't care about VHT for drivers not using the
channel context API, I won't convert the previous API
to VHT support.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Even before channel contexts/multi-channel, having a
single global TX power limit was already problematic,
in particular if two managed interfaces connected to
two APs with different power constraints. The channel
context introduction completely broke this though and
in fact I had disabled TX power configuration there
for drivers using channel contexts.

Change everything to track TX power per interface so
that different user settings and different channel
maxima are treated correctly. Also continue tracking
the global TX power though for compatibility with
applications that attempt to configure the wiphy's
TX power globally.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>