freebsd-dev/sys/dev/ath/if_ath_misc.h

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/*-
* Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
* redistribution must be conditioned upon including a substantially
* similar Disclaimer requirement for further binary redistribution.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
* OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGES.
*
* $FreeBSD$
*/
#ifndef __IF_ATH_MISC_H__
#define __IF_ATH_MISC_H__
/*
* This is where definitions for "public things" in if_ath.c
* will go for the time being.
*
* Anything in here should eventually be moved out of if_ath.c
* and into something else.
*/
/* unaligned little endian access */
#define LE_READ_2(p) \
((u_int16_t) \
((((u_int8_t *)(p))[0] ) | (((u_int8_t *)(p))[1] << 8)))
#define LE_READ_4(p) \
((u_int32_t) \
((((u_int8_t *)(p))[0] ) | (((u_int8_t *)(p))[1] << 8) | \
(((u_int8_t *)(p))[2] << 16) | (((u_int8_t *)(p))[3] << 24)))
extern int ath_tx_findrix(const struct ath_softc *sc, uint8_t rate);
extern struct ath_buf * ath_getbuf(struct ath_softc *sc);
extern struct ath_buf * _ath_getbuf_locked(struct ath_softc *sc);
extern struct ath_buf * ath_buf_clone(struct ath_softc *sc,
const struct ath_buf *bf);
extern void ath_freebuf(struct ath_softc *sc, struct ath_buf *bf);
extern int ath_reset(struct ifnet *, ATH_RESET_TYPE);
extern void ath_tx_draintxq(struct ath_softc *sc, struct ath_txq *txq);
extern void ath_tx_default_comp(struct ath_softc *sc, struct ath_buf *bf,
int fail);
Introduce TX aggregation and software TX queue management for Atheros AR5416 and later wireless devices. This is a very large commit - the complete history can be found in the user/adrian/if_ath_tx branch. Legacy (ie, pre-AR5416) devices also use the per-software TXQ support and (in theory) can support non-aggregation ADDBA sessions. However, the net80211 stack doesn't currently support this. In summary: TX path: * queued frames normally go onto a per-TID, per-node queue * some special frames (eg ADDBA control frames) are thrown directly onto the relevant hardware queue so they can go out before any software queued frames are queued. * Add methods to create, suspend, resume and tear down an aggregation session. * Add in software retransmission of both normal and aggregate frames. * Add in completion handling of aggregate frames, including parsing the block ack bitmap provided by the hardware. * Write an aggregation function which can assemble frames into an aggregate based on the selected rate control and channel configuration. * The per-TID queues are locked based on their target hardware TX queue. This matches what ath9k/atheros does, and thus simplified porting over some of the aggregation logic. * When doing TX aggregation, stick the sequence number allocation in the TX path rather than net80211 TX path, and protect it by the TXQ lock. Rate control: * Delay rate control selection until the frame is about to be queued to the hardware, so retried frames can have their rate control choices changed. Frames with a static rate control selection have that applied before each TX, just to simplify the TX path (ie, not have "static" and "dynamic" rate control special cased.) * Teach ath_rate_sample about aggregates - both completion and errors. * Add an EWMA for tracking what the current "good" MCS rate is based on failure rates. Misc: * Introduce a bunch of dirty hacks and workarounds so TID mapping and net80211 frame inspection can be kept out of the net80211 layer. Because of the way this code works (and it's from Atheros and Linux ath9k), there is a consistent, 1:1 mapping between TID and AC. So we need to ensure that frames going to a specific TID will _always_ end up on the right AC, and vice versa, or the completion/locking will simply get very confused. I plan on addressing this mess in the future. Known issues: * There is no BAR frame transmission just yet. A whole lot of tidying up needs to occur before BAR frame TX can occur in the "correct" place - ie, once the TID TX queue has been drained. * Interface reset/purge/etc results in frames in the TX and RX queues being removed. This creates holes in the sequence numbers being assigned and the TX/RX AMPDU code (on either side) just hangs. * There's no filtered frame support at the present moment, so stations going into power saving mode will simply have a number of frames dropped - likely resulting in a traffic "hang". * Raw frame TX is going to just not function with 11n aggregation. Likely this needs to be modified to always override the sequence number if the frame is going into an aggregation session. However, general raw frame injection currently doesn't work in general in net80211, so let's just ignore this for now until this is sorted out. * HT protection is just not implemented and won't be until the above is sorted out. In addition, the AR5416 has issues RTS protecting large aggregates (anything >8k), so the work around needs to be ported and tested. Thus, this will be put on hold until the above work is complete. * The rate control module 'sample' is the only currently supported module; onoe/amrr haven't been tested and have likely bit rotted a little. I'll follow up with some commits to make them work again for non-11n rates, but they won't be updated to handle 11n and aggregation. If someone wishes to do so then they're welcome to send along patches. * .. and "sample" doesn't really do a good job of 11n TX. Specifically, the metrics used (packet TX time and failure/success rates) isn't as useful for 11n. It's likely that it should be extended to take into account the aggregate throughput possible and then choose a rate which maximises that. Ie, it may be acceptable for a higher MCS rate with a higher failure to be used if it gives a more acceptable throughput/latency then a lower MCS rate @ a lower error rate. Again, patches will be gratefully accepted. Because of this, ATH_ENABLE_11N is still not enabled by default. Sponsored by: Hobnob, Inc. Obtained from: Linux, Atheros
2011-11-08 22:43:13 +00:00
extern void ath_tx_update_ratectrl(struct ath_softc *sc,
struct ieee80211_node *ni, struct ath_rc_series *rc,
struct ath_tx_status *ts, int frmlen, int nframes, int nbad);
extern void ath_tx_freebuf(struct ath_softc *sc, struct ath_buf *bf,
int status);
extern void ath_txqmove(struct ath_txq *dst, struct ath_txq *src);
extern void ath_mode_init(struct ath_softc *sc);
extern void ath_setdefantenna(struct ath_softc *sc, u_int antenna);
extern void ath_setslottime(struct ath_softc *sc);
/*
* This is only here so that the RX proc function can call it.
* It's very likely that the "start TX after RX" call should be
* done via something in if_ath.c, moving "rx tasklet" into
* if_ath.c and do the ath_start() call there. Once that's done,
* we can kill this.
*/
extern void ath_start(struct ifnet *ifp);
Migrate the TX path to a taskqueue for now, until a better way of implementing parallel TX and TX/RX completion can be done without simply abusing long-held locks. Right now, multiple concurrent ath_start() entries can result in frames being dequeued out of order. Well, they're dequeued in order fine, but if there's any preemption or race between CPUs between: * removing the frame from the ifnet, and * calling and runningath_tx_start(), until the frame is placed on a software or hardware TXQ Then although dequeueing the frame is in-order, queueing it to the hardware may be out of order. This is solved in a lot of other drivers by just holding a TX lock over a rather long period of time. This lets them continue to direct dispatch without races between dequeue and hardware queue. Note to observers: if_transmit() doesn't necessarily solve this. It removes the ifnet from the main path, but the same issue exists if there's some intermediary queue (eg a bufring, which as an aside also may pull in ifnet when you're using ALTQ.) So, until I can sit down and code up a much better way of doing parallel TX, I'm going to leave the TX path using a deferred taskqueue task. What I will likely head towards is doing a direct dispatch to hardware or software via if_transmit(), but it'll require some driver changes to allow queues to be made without using the really large ath_buf / ath_desc entries. TODO: * Look at how feasible it'll be to just do direct dispatch to ath_tx_start() from if_transmit(), avoiding doing _any_ intermediary serialisation into a global queue. This may break ALTQ for example, so I have to be delicate. * It's quite likely that I should break up ath_tx_start() so it deposits frames onto the software queues first, and then only fill in the 802.11 fields when it's being queued to the hardware. That will make the if_transmit() -> software queue path very quick and lightweight. * This has some very bad behaviour when using ACPI and Cx states. I'll do some subsequent analysis using KTR and schedgraph and file a follow-up PR or two. PR: kern/168649
2012-06-04 22:01:12 +00:00
extern void ath_tx_tasklet(void *arg, int npending);
#endif