kernel/linux.git/include/net/mac80211.h, branch v5.5.10

mac80211: use more bits for ack_frame_id

2020-02-19T18:54:10+00:00

commit f2b18baca9539c6a3116d48b70972c7a2ba5d766 upstream. It turns out that this wasn't a good idea, I hit a test failure in hwsim due to this. That particular failure was easily worked around, but it raised questions: if an AP needs to, for example, send action frames to each connected station, the current limit is nowhere near enough (especially if those stations are sleeping and the frames are queued for a while.) Shuffle around some bits to make more room for ack_frame_id to allow up to 8192 queued up frames, that's enough for queueing 4 frames to each connected station, even at the maximum of 2007 stations on a single AP. We take the bits from band (which currently only 2 but I leave 3 in case we add another band) and from the hw_queue, which can only need 4 since it has a limit of 16 queues. Fixes: 6912daed05e1 ("mac80211: Shrink the size of ack_frame_id to make room for tx_time_est") Signed-off-by: Johannes Berg Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/20200115122549.b9a4ef9f4980.Ied52ed90150220b83a280009c590b65d125d087c@changeid Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman

mac80211: Use Airtime-based Queue Limits (AQL) on packet dequeue

2019-11-22T12:36:25+00:00

The previous commit added the ability to throttle stations when they queue too much airtime in the hardware. This commit enables the functionality by calculating the expected airtime usage of each packet that is dequeued from the TXQs in mac80211, and accounting that as pending airtime. The estimated airtime for each skb is stored in the tx_info, so we can subtract the same amount from the running total when the skb is freed or recycled. The throttling mechanism relies on this accounting to be accurate (i.e., that we are not freeing skbs without subtracting any airtime they were accounted for), so we put the subtraction into ieee80211_report_used_skb(). As an optimisation, we also subtract the airtime on regular TX completion, zeroing out the value stored in the packet afterwards, to avoid having to do an expensive lookup of the station from the packet data on every packet. This patch does *not* include any mechanism to wake a throttled TXQ again, on the assumption that this will happen anyway as a side effect of whatever freed the skb (most commonly a TX completion). Signed-off-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/20191119060610.76681-5-kyan@google.com Signed-off-by: Johannes Berg

mac80211: Implement Airtime-based Queue Limit (AQL)

2019-11-22T12:36:25+00:00

In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg

mac80211: Import airtime calculation code from mt76

2019-11-22T12:36:25+00:00

Felix recently added code to calculate airtime of packets to the mt76 driver. Import this into mac80211 so we can use it for airtime queue limit calculations. The airtime.c file is copied verbatim from the mt76 driver, and adjusted to be usable in mac80211. This involves: - Switching to mac80211 data structures. - Adding support for 160 MHz channels and HE mode. - Moving the symbol and duration calculations around a bit to avoid rounding with the higher rates and longer symbol times used for HE rates. The per-rate TX rate calculation is also split out to its own function so it can be used directly for the AQL calculations later. Signed-off-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/20191119060610.76681-3-kyan@google.com [fix HE_GROUP_IDX() to use 3 * bw, since there are 3 _gi values] Signed-off-by: Johannes Berg

mac80211: Shrink the size of ack_frame_id to make room for tx_time_est

2019-11-08T09:19:19+00:00

To implement airtime queue limiting, we need to keep a running account of the estimated airtime of all skbs queued into the device. Do to this correctly, we need to store the airtime estimate into the skb so we can decrease the outstanding balance when the skb is freed. This means that the time estimate must be stored somewhere that will survive for the lifetime of the skb. To get this, decrease the size of the ack_frame_id field to 6 bits, and lower the size of the ID space accordingly. This leaves 10 bits for use for tx_time_est, which is enough to store a maximum of 4096 us, if we shift the values so they become units of 4us. Signed-off-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/r/157182474063.150713.16132669599100802716.stgit@toke.dk Signed-off-by: Johannes Berg

mac80211: fix a typo of "function"

2019-10-28T12:14:37+00:00

Signed-off-by: Joe Perches Link: https://lore.kernel.org/r/4d53be6c963542878d370ff1a6dc7c3a89b28d23.camel@perches.com Signed-off-by: Johannes Berg

mac80211: typo fixes in kerneldoc comments

2019-10-28T12:13:35+00:00

Correct some trivial typos in kerneldoc comments. Signed-off-by: Chris Packham Link: https://lore.kernel.org/r/20191024213647.5507-1-chris.packham@alliedtelesis.co.nz Signed-off-by: Johannes Berg

mac80211: simplify TX aggregation start

2019-10-04T11:58:13+00:00

There really is no need to make drivers call the ieee80211_start_tx_ba_cb_irqsafe() function and then schedule the worker if all we want is to set a bit. Add a new return value (that was previously considered invalid) to indicate that the driver is immediately ready for the session, and make drivers use it. The only drivers that remain different are the Intel ones as they need to negotiate more with the firmware. Link: https://lore.kernel.org/r/1570007543-I152912660131cbab2e5d80b4218238c20f8a06e5@changeid Signed-off-by: Johannes Berg

mac80211: allow drivers to set max MTU

2019-09-11T07:33:29+00:00

Make it possibly for drivers to adjust the default max_mtu by storing it in the hardware struct and using that value for all interfaces. Signed-off-by: Wen Gong Link: https://lore.kernel.org/r/1567738137-31748-1-git-send-email-wgong@codeaurora.org Signed-off-by: Johannes Berg

mac80211: allow setting spatial reuse parameters from bss_conf

2019-07-31T09:00:52+00:00

Store the OBSS PD parameters inside bss_conf when bringing up an AP and/or when a station connects to an AP. This allows the driver to configure the HW accordingly. Signed-off-by: John Crispin Link: https://lore.kernel.org/r/20190730163701.18836-3-john@phrozen.org Signed-off-by: Johannes Berg