linux.git/net/mac80211/debugfs_netdev.c, branch v5.15

mac80211: Switch to a virtual time-based airtime scheduler

2021-06-23T16:12:00+00:00

This switches the airtime scheduler in mac80211 to use a virtual
time-based scheduler instead of the round-robin scheduler used before.
This has a couple of advantages:

- No need to sync up the round-robin scheduler in firmware/hardware with
  the round-robin airtime scheduler.

- If several stations are eligible for transmission we can schedule both
  of them; no need to hard-block the scheduling rotation until the head
  of the queue has used up its quantum.

- The check of whether a station is eligible for transmission becomes
  simpler (in ieee80211_txq_may_transmit()).

The drawback is that scheduling becomes slightly more expensive, as we
need to maintain an rbtree of TXQs sorted by virtual time. This means
that ieee80211_register_airtime() becomes O(logN) in the number of
currently scheduled TXQs because it can change the order of the
scheduled stations. We mitigate this overhead by only resorting when a
station changes position in the tree, and hopefully N rarely grows too
big (it's only TXQs currently backlogged, not all associated stations),
so it shouldn't be too big of an issue.

To prevent divisions in the fast path, we maintain both station sums and
pre-computed reciprocals of the sums. This turns the fast-path operation
into a multiplication, with divisions only happening as the number of
active stations change (to re-compute the current sum of all active
station weights). To prevent this re-computation of the reciprocal from
happening too frequently, we use a time-based notion of station
activity, instead of updating the weight every time a station gets
scheduled or de-scheduled. As queues can oscillate between empty and
occupied quite frequently, this can significantly cut down on the number
of re-computations. It also has the added benefit of making the station
airtime calculation independent on whether the queue happened to have
drained at the time an airtime value was accounted.

Co-developed-by: Yibo Zhao 
Signed-off-by: Yibo Zhao 
Signed-off-by: Toke Høiland-Jørgensen 
Link: https://lore.kernel.org/r/20210623134755.235545-1-toke@redhat.com
Signed-off-by: Johannes Berg

mac80211: Remove redundant assignment to ret

2021-06-23T08:57:55+00:00

Variable 'ret' is set to -ENODEV but this value is never read as it
is overwritten with a new value later on, hence it is a redundant
assignment and can be removed.

Clean up the following clang-analyzer warning:

net/mac80211/debugfs_netdev.c:60:2: warning: Value stored to 'ret' is
never read [clang-analyzer-deadcode.DeadStores]

Reported-by: Abaci Robot 
Signed-off-by: Yang Li 
Link: https://lore.kernel.org/r/1619774483-116805-1-git-send-email-yang.lee@linux.alibaba.com
Signed-off-by: Johannes Berg

mac80211: remove trailing semicolon in macro definitions

2020-12-11T11:51:55+00:00

The macro uses should have (and already have) the semicolon.

Signed-off-by: Tom Rix 
Link: https://lore.kernel.org/r/20201127193842.2876355-1-trix@redhat.com
Signed-off-by: Johannes Berg

mac80211: remove WDS-related code

2020-11-11T07:39:13+00:00

Now that all the mac80211-based drivers have removed WDS code
and in particular the ability to advertise such devices, also
remove all the code related to WDS here.

Link: https://lore.kernel.org/r/20201109105103.38960c413d46.I3603c90a44562d847c39d15d5ff33d8c00df5834@changeid
Signed-off-by: Johannes Berg

cfg80211/mac80211: add connected to auth server to meshconf

2020-07-31T07:24:24+00:00

Besides information about num of peerings and gate connectivity,
the mesh formation byte also contains a flag for authentication
server connectivity, that currently cannot be set in the mesh conf.
This patch adds this capability, which is necessary to implement
802.1X authentication in mesh mode.

Signed-off-by: Markus Theil 
Link: https://lore.kernel.org/r/20200611140238.427461-1-markus.theil@tu-ilmenau.de
Signed-off-by: Johannes Berg

cfg80211/mac80211: add mesh_param "mesh_nolearn" to skip path discovery

2020-07-31T07:24:23+00:00

Currently, before being able to forward a packet between two 802.11s
nodes, both a PLINK handshake is performed upon receiving a beacon and
then later a PREQ/PREP exchange for path discovery is performed on
demand upon receiving a data frame to forward.

When running a mesh protocol on top of an 802.11s interface, like
batman-adv, we do not need the multi-hop mesh routing capabilities of
802.11s and usually set mesh_fwding=0. However, even with mesh_fwding=0
the PREQ/PREP path discovery is still performed on demand. Even though
in this scenario the next hop PREQ/PREP will determine is always the
direct 11s neighbor node.

The new mesh_nolearn parameter allows to skip the PREQ/PREP exchange in
this scenario, leading to a reduced delay, reduced packet buffering and
simplifies HWMP in general.

mesh_nolearn is still rather conservative in that if the packet destination
is not a direct 11s neighbor, it will fall back to PREQ/PREP path
discovery.

For normal, multi-hop 802.11s mesh routing it is usually not advisable
to enable mesh_nolearn as a transmission to a direct but distant neighbor
might be worse than reaching that same node via a more robust /
higher throughput etc. multi-hop path.

Cc: Sven Eckelmann 
Cc: Simon Wunderlich 
Signed-off-by: Linus Lüssing 
Link: https://lore.kernel.org/r/20200617073034.26149-1-linus.luessing@c0d3.blue
[fix nl80211 policy to range 0/1 only]
Signed-off-by: Johannes Berg

mac80211: mlme: remove duplicate AID bookkeeping

2020-04-24T09:46:11+00:00

Maintain the connection AID only in sdata->vif.bss_conf.aid, not
also in sdata->u.mgd.aid.

Keep setting that where we set ifmgd->aid before, which has the
side effect of exposing the AID to the driver before the station
entry (AP) is marked associated, in case it needs it then.

Requested-by: Felix Fietkau 
Signed-off-by: Johannes Berg 
Tested-by: Lorenzo Bianconi 
Link: https://lore.kernel.org/r/20200417123802.085d4a322b0c.I2e7a2ceceea8c6880219f9e9ee4d4ac985fd295a@changeid
Signed-off-by: Johannes Berg

mac80211: Remove support for changing AP SMPS mode

2020-02-07T11:48:29+00:00

The SMPS feature is defined in the specification only to be
used by non-AP stations and not by APs, so remove the support
for changing the AP's SMPS mode dynamically.

Signed-off-by: Ilan Peer 
Signed-off-by: Luca Coelho 
Link: https://lore.kernel.org/r/20200131111300.891737-20-luca@coelho.fi
Signed-off-by: Johannes Berg

mac80211: fix txq null pointer dereference

2019-10-01T15:56:19+00:00

If the interface type is P2P_DEVICE or NAN, read the file of
'/sys/kernel/debug/ieee80211/phyx/netdev:wlanx/aqm' will get a
NULL pointer dereference. As for those interface type, the
pointer sdata->vif.txq is NULL.

Unable to handle kernel NULL pointer dereference at virtual address 00000011
CPU: 1 PID: 30936 Comm: cat Not tainted 4.14.104 #1
task: ffffffc0337e4880 task.stack: ffffff800cd20000
PC is at ieee80211_if_fmt_aqm+0x34/0xa0 [mac80211]
LR is at ieee80211_if_fmt_aqm+0x34/0xa0 [mac80211]
[...]
Process cat (pid: 30936, stack limit = 0xffffff800cd20000)
[...]
[] ieee80211_if_fmt_aqm+0x34/0xa0 [mac80211]
[] ieee80211_if_read+0x60/0xbc [mac80211]
[] ieee80211_if_read_aqm+0x28/0x30 [mac80211]
[] full_proxy_read+0x2c/0x48
[] __vfs_read+0x2c/0xd4
[] vfs_read+0x8c/0x108
[] SyS_read+0x40/0x7c

Signed-off-by: Miaoqing Pan 
Acked-by: Toke Høiland-Jørgensen 
Link: https://lore.kernel.org/r/1569549796-8223-1-git-send-email-miaoqing@codeaurora.org
[trim useless data from commit message]
Signed-off-by: Johannes Berg

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-06-22T12:59:24+00:00

Minor SPDX change conflict.

Signed-off-by: David S. Miller