wifi: mt76: use atomic iface iteration for pre-TBTT work

In addition to the previous series I posted, over time I'd
also like to get rid of the iflist_mtx in mac80211. That
isn't easy now since lots of places use iteration and would
have to be audited, but even a cursory look suggests that
mt76 might be more problematic than most since holding the
wiphy lock for the latency-sensitive pre-TBTT work could be
an issue.

Convert the pre-TBTT work to use atomic iteration and then
sending the device commands outside of it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: mt76x02: improve reliability of the beacon hang check

Increment the counter only when writing beacons to the hardware in order
to avoid triggering restarts if beacons are disabled.
Additionally, avoid resetting the MAC if stopping it failed

Signed-off-by: Felix Fietkau <nbd@nbd.name>

wifi: mac80211: return a beacon for a specific link

Pass the link id through to the get_beacon and return
the beacon for a specific link id.

Signed-off-by: Shaul Triebitz <shaul.triebitz@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

mt76: mt76x02: minor mt76x02_mac_set_beacon optimization

We do not call mt76x02_mac_set_beacon() with NULL skb any longer and
we do not need to return error value.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: mt76x02: remove a copy call for usb speedup

This patch removes a mt76_wr_copy call from the beacon path to hw.
The skb which is used in this place gets therefore build with txwi
inside its data. For mt76 usb drivers, this saves one synchronuous
copy call over usb, which lets the beacon work complete faster.

In mmio case, there is not enough headroom to put the txwi into the
skb, it is therefore using an additional mt76_wr_copy, which is fast
over mmio. Thanks Stanislaw for pointing this out.

Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: mt76x02: split beaconing

Sending beacons to the hardware always happens in batches. In order to
speed up beacon processing on usb devices, this patch splits out common
code an calls it only once.

Beacons are sequentially written into the beacon memory area, by
tracking its usage with the dev->beacon_data_count. For MBSS support
and buffered traffic dev->beacon_data_count is used to create the bypass
mask.

The code is also adapted for the mmio part of the driver, but should not
have any performance implication there.

MBSS tests were performed with AVM AC860 USB NIC with temporary support
for 5 BSS'. Different combinations of active vifs were created and
brought up. Afterwards connection and data transfer was tested for the
announced BSS'.

Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: mt76x02: omit beacon slot clearing

mt76 hw does not send beacons from beacon slots, if the corresponding
bitmask is set accordingly. Therefore we can omit clearing the beacon
memory. Clearing uses many usb calls, if usb drivers are used. These
calls unnecessarily slow down the beacon tasklet. Thanks to Stanislaw
Gruzska for pointing this out.

Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

net/wireless: Delete unnecessary checks before the macro call “dev_kfree_skb”

The dev_kfree_skb() function performs also input parameter validation.
Thus the test around the shown calls is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

mt76: mt76x02: do not copy beacon skb in mt76x02_mac_set_beacon_enable

Do not copy beacon skb in mt76x02_mac_set_beacon_enable for usb devices
since it will be done in mt76x02_update_beacon_iter. Moreover squash
mt76x02_mac_set_beacon_enable and __mt76x02_mac_set_beacon_enable since
the latter is run just by mt76x02_mac_set_beacon_enable

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: mt76x02: introduce mt76x02_pre_tbtt_enable and mt76x02_beacon_enable macros

Improve code readability introducing mt76x02_pre_tbtt_enable and
mt76x02_beacon_enable utility macros

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: switch to SPDX tag instead of verbose boilerplate text

No functional change intended.

Add SPDX identifiers to all remaining files in /mt76.

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: mt76x02: fix some checkpatch warnings

This fixes the following checkpatch warnings:

ERROR: code indent should use tabs where possible
CHECK: Alignment should match open parenthesis
CHECK: No space is necessary after a cast
CHECK: Please don't use multiple blank lines
CHECK: Avoid precedence issues in macro
WARNING: Statements should start on a tabstop
WARNING: Unnecessary space before function pointer arguments

Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: mt76x02: remove useless return in mt76x02_resync_beacon_timer

Remove useless return statment in mt76x02_resync_beacon_timer routine

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: move beacon_mask in mt76_dev

Move beacon_mask in mt76_dev data structure since it is used by
all drivers

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76: move beacon_int in mt76_dev

Move beacon_int in mt76_dev data structure since it is used by
all drivers

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76x02: make beacon slots bigger for USB

Since we sent PS buffered frames via beacon memory we need to make
beacon slots bigger. That imply we will also need to decrease number
of slots as beacon SRAM memory is limited to 8kB.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76x02u: implement pre TBTT work for USB

Program beacons data and PS buffered frames on TBTT work for USB.
We do not have MT_TXQ_PSD queue available via USB endpoints. The way
we can send PS broadcast frames in timely manner before PS stations go
sleep again is program them in beacon data area. Hardware do not modify
those frames since TXWI is properly configured. mt76x02_mac_set_beacon()
already handle this and free no longer used frames.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76x02: generalize some mmio beaconing functions

Move some TBTT mmio functions to mt76x02_beacon.c and create new ones
in order to be reused by USB pre-TBTT.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76x02: introduce beacon_ops

Enabling/disableing TBTT and beacon will be diffrent for USB. Introduce
beacon_ops to encapsulate that and implement it for MMIO. USB
implementation is noop for now.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

mt76x02: introduce mt76x02_beacon.c

Move most of beaconing code into separate file and separate beacon
initialization for USB and MMIO as pre TBTT implementation for USB
will be different.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>