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freebsd-skq/sys/dev/ath/if_ath_tx_ht.c
adrian b9db55d70c 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

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/*-
* Copyright (c) 2011 Adrian Chadd, Xenion Pty Ltd.
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_ath.h"
#include "opt_wlan.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/errno.h>
#include <sys/callout.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/kthread.h>
#include <sys/taskqueue.h>
#include <sys/priv.h>
#include <machine/bus.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_llc.h>
#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_regdomain.h>
#ifdef IEEE80211_SUPPORT_SUPERG
#include <net80211/ieee80211_superg.h>
#endif
#ifdef IEEE80211_SUPPORT_TDMA
#include <net80211/ieee80211_tdma.h>
#endif
#include <net/bpf.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif
#include <dev/ath/if_athvar.h>
#include <dev/ath/ath_hal/ah_devid.h> /* XXX for softled */
#include <dev/ath/ath_hal/ah_diagcodes.h>
#ifdef ATH_TX99_DIAG
#include <dev/ath/ath_tx99/ath_tx99.h>
#endif
#include <dev/ath/if_ath_tx.h> /* XXX for some support functions */
#include <dev/ath/if_ath_tx_ht.h>
#include <dev/ath/if_athrate.h>
#include <dev/ath/if_ath_debug.h>
/*
* XXX net80211?
*/
#define IEEE80211_AMPDU_SUBFRAME_DEFAULT 32
#define ATH_AGGR_DELIM_SZ 4 /* delimiter size */
#define ATH_AGGR_MINPLEN 256 /* in bytes, minimum packet length */
#define ATH_AGGR_ENCRYPTDELIM 10 /* number of delimiters for encryption padding */
/*
* returns delimiter padding required given the packet length
*/
#define ATH_AGGR_GET_NDELIM(_len) \
(((((_len) + ATH_AGGR_DELIM_SZ) < ATH_AGGR_MINPLEN) ? \
(ATH_AGGR_MINPLEN - (_len) - ATH_AGGR_DELIM_SZ) : 0) >> 2)
#define PADBYTES(_len) ((4 - ((_len) % 4)) % 4)
int ath_max_4ms_framelen[4][32] = {
[MCS_HT20] = {
3212, 6432, 9648, 12864, 19300, 25736, 28952, 32172,
6424, 12852, 19280, 25708, 38568, 51424, 57852, 64280,
9628, 19260, 28896, 38528, 57792, 65532, 65532, 65532,
12828, 25656, 38488, 51320, 65532, 65532, 65532, 65532,
},
[MCS_HT20_SGI] = {
3572, 7144, 10720, 14296, 21444, 28596, 32172, 35744,
7140, 14284, 21428, 28568, 42856, 57144, 64288, 65532,
10700, 21408, 32112, 42816, 64228, 65532, 65532, 65532,
14256, 28516, 42780, 57040, 65532, 65532, 65532, 65532,
},
[MCS_HT40] = {
6680, 13360, 20044, 26724, 40092, 53456, 60140, 65532,
13348, 26700, 40052, 53400, 65532, 65532, 65532, 65532,
20004, 40008, 60016, 65532, 65532, 65532, 65532, 65532,
26644, 53292, 65532, 65532, 65532, 65532, 65532, 65532,
},
[MCS_HT40_SGI] = {
7420, 14844, 22272, 29696, 44544, 59396, 65532, 65532,
14832, 29668, 44504, 59340, 65532, 65532, 65532, 65532,
22232, 44464, 65532, 65532, 65532, 65532, 65532, 65532,
29616, 59232, 65532, 65532, 65532, 65532, 65532, 65532,
}
};
/*
* XXX should be in net80211
*/
static int ieee80211_mpdudensity_map[] = {
0, /* IEEE80211_HTCAP_MPDUDENSITY_NA */
25, /* IEEE80211_HTCAP_MPDUDENSITY_025 */
50, /* IEEE80211_HTCAP_MPDUDENSITY_05 */
100, /* IEEE80211_HTCAP_MPDUDENSITY_1 */
200, /* IEEE80211_HTCAP_MPDUDENSITY_2 */
400, /* IEEE80211_HTCAP_MPDUDENSITY_4 */
800, /* IEEE80211_HTCAP_MPDUDENSITY_8 */
1600, /* IEEE80211_HTCAP_MPDUDENSITY_16 */
};
/*
* XXX should be in the HAL/net80211 ?
*/
#define BITS_PER_BYTE 8
#define OFDM_PLCP_BITS 22
#define HT_RC_2_MCS(_rc) ((_rc) & 0x7f)
#define HT_RC_2_STREAMS(_rc) ((((_rc) & 0x78) >> 3) + 1)
#define L_STF 8
#define L_LTF 8
#define L_SIG 4
#define HT_SIG 8
#define HT_STF 4
#define HT_LTF(_ns) (4 * (_ns))
#define SYMBOL_TIME(_ns) ((_ns) << 2) // ns * 4 us
#define SYMBOL_TIME_HALFGI(_ns) (((_ns) * 18 + 4) / 5) // ns * 3.6 us
#define NUM_SYMBOLS_PER_USEC(_usec) (_usec >> 2)
#define NUM_SYMBOLS_PER_USEC_HALFGI(_usec) (((_usec*5)-4)/18)
#define IS_HT_RATE(_rate) ((_rate) & 0x80)
const uint32_t bits_per_symbol[][2] = {
/* 20MHz 40MHz */
{ 26, 54 }, // 0: BPSK
{ 52, 108 }, // 1: QPSK 1/2
{ 78, 162 }, // 2: QPSK 3/4
{ 104, 216 }, // 3: 16-QAM 1/2
{ 156, 324 }, // 4: 16-QAM 3/4
{ 208, 432 }, // 5: 64-QAM 2/3
{ 234, 486 }, // 6: 64-QAM 3/4
{ 260, 540 }, // 7: 64-QAM 5/6
{ 52, 108 }, // 8: BPSK
{ 104, 216 }, // 9: QPSK 1/2
{ 156, 324 }, // 10: QPSK 3/4
{ 208, 432 }, // 11: 16-QAM 1/2
{ 312, 648 }, // 12: 16-QAM 3/4
{ 416, 864 }, // 13: 64-QAM 2/3
{ 468, 972 }, // 14: 64-QAM 3/4
{ 520, 1080 }, // 15: 64-QAM 5/6
{ 78, 162 }, // 16: BPSK
{ 156, 324 }, // 17: QPSK 1/2
{ 234, 486 }, // 18: QPSK 3/4
{ 312, 648 }, // 19: 16-QAM 1/2
{ 468, 972 }, // 20: 16-QAM 3/4
{ 624, 1296 }, // 21: 64-QAM 2/3
{ 702, 1458 }, // 22: 64-QAM 3/4
{ 780, 1620 }, // 23: 64-QAM 5/6
{ 104, 216 }, // 24: BPSK
{ 208, 432 }, // 25: QPSK 1/2
{ 312, 648 }, // 26: QPSK 3/4
{ 416, 864 }, // 27: 16-QAM 1/2
{ 624, 1296 }, // 28: 16-QAM 3/4
{ 832, 1728 }, // 29: 64-QAM 2/3
{ 936, 1944 }, // 30: 64-QAM 3/4
{ 1040, 2160 }, // 31: 64-QAM 5/6
};
/*
* Fill in the rate array information based on the current
* node configuration and the choices made by the rate
* selection code and ath_buf setup code.
*
* Later on, this may end up also being made by the
* rate control code, but for now it can live here.
*
* This needs to be called just before the packet is
* queued to the software queue or hardware queue,
* so all of the needed fields in bf_state are setup.
*/
void
ath_tx_rate_fill_rcflags(struct ath_softc *sc, struct ath_buf *bf)
{
struct ieee80211_node *ni = bf->bf_node;
struct ieee80211com *ic = ni->ni_ic;
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct ath_rc_series *rc = bf->bf_state.bfs_rc;
uint8_t rate;
int i;
for (i = 0; i < ATH_RC_NUM; i++) {
rc[i].flags = 0;
if (rc[i].tries == 0)
continue;
rate = rt->info[rc[i].rix].rateCode;
/*
* XXX only do this for legacy rates?
*/
if (bf->bf_state.bfs_shpream)
rate |= rt->info[rc[i].rix].shortPreamble;
/*
* Save this, used by the TX and completion code
*/
rc[i].ratecode = rate;
if (bf->bf_state.bfs_flags &
(HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
rc[i].flags |= ATH_RC_RTSCTS_FLAG;
/* Only enable shortgi, 2040, dual-stream if HT is set */
if (IS_HT_RATE(rate)) {
rc[i].flags |= ATH_RC_HT_FLAG;
if (ni->ni_chw == 40)
rc[i].flags |= ATH_RC_CW40_FLAG;
if (ni->ni_chw == 40 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40)
rc[i].flags |= ATH_RC_SGI_FLAG;
if (ni->ni_chw == 20 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20)
rc[i].flags |= ATH_RC_SGI_FLAG;
/* XXX dual stream? and 3-stream? */
}
/*
* Calculate the maximum 4ms frame length based
* on the MCS rate, SGI and channel width flags.
*/
if ((rc[i].flags & ATH_RC_HT_FLAG) &&
(HT_RC_2_MCS(rate) < 32)) {
int j;
if (rc[i].flags & ATH_RC_CW40_FLAG) {
if (rc[i].flags & ATH_RC_SGI_FLAG)
j = MCS_HT40_SGI;
else
j = MCS_HT40;
} else {
if (rc[i].flags & ATH_RC_SGI_FLAG)
j = MCS_HT20_SGI;
else
j = MCS_HT20;
}
rc[i].max4msframelen =
ath_max_4ms_framelen[j][HT_RC_2_MCS(rate)];
} else
rc[i].max4msframelen = 0;
DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
"%s: i=%d, rate=0x%x, flags=0x%x, max4ms=%d\n",
__func__, i, rate, rc[i].flags, rc[i].max4msframelen);
}
}
/*
* Return the number of delimiters to be added to
* meet the minimum required mpdudensity.
*
* Caller should make sure that the rate is HT.
*
* TODO: is this delimiter calculation supposed to be the
* total frame length, the hdr length, the data length (including
* delimiters, padding, CRC, etc) or ?
*
* TODO: this should ensure that the rate control information
* HAS been setup for the first rate.
*
* TODO: ensure this is only called for MCS rates.
*
* TODO: enforce MCS < 31
*/
static int
ath_compute_num_delims(struct ath_softc *sc, struct ath_buf *first_bf,
uint16_t pktlen)
{
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct ieee80211_node *ni = first_bf->bf_node;
struct ieee80211vap *vap = ni->ni_vap;
int ndelim, mindelim = 0;
int mpdudensity; /* in 1/100'th of a microsecond */
uint8_t rc, rix, flags;
int width, half_gi;
uint32_t nsymbits, nsymbols;
uint16_t minlen;
/*
* vap->iv_ampdu_density is a value, rather than the actual
* density.
*/
if (vap->iv_ampdu_density > IEEE80211_HTCAP_MPDUDENSITY_16)
mpdudensity = 1600; /* maximum density */
else
mpdudensity = ieee80211_mpdudensity_map[vap->iv_ampdu_density];
/* Select standard number of delimiters based on frame length */
ndelim = ATH_AGGR_GET_NDELIM(pktlen);
/*
* If encryption is enabled, add extra delimiters to let the
* crypto hardware catch up. This could be tuned per-MAC and
* per-rate, but for now we'll simply assume encryption is
* always enabled.
*/
ndelim += ATH_AGGR_ENCRYPTDELIM;
DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
"%s: pktlen=%d, ndelim=%d, mpdudensity=%d\n",
__func__, pktlen, ndelim, mpdudensity);
/*
* If the MPDU density is 0, we can return here.
* Otherwise, we need to convert the desired mpdudensity
* into a byte length, based on the rate in the subframe.
*/
if (mpdudensity == 0)
return ndelim;
/*
* Convert desired mpdu density from microeconds to bytes based
* on highest rate in rate series (i.e. first rate) to determine
* required minimum length for subframe. Take into account
* whether high rate is 20 or 40Mhz and half or full GI.
*/
rix = first_bf->bf_state.bfs_rc[0].rix;
rc = rt->info[rix].rateCode;
flags = first_bf->bf_state.bfs_rc[0].flags;
width = !! (flags & ATH_RC_CW40_FLAG);
half_gi = !! (flags & ATH_RC_SGI_FLAG);
/*
* mpdudensity is in 1/100th of a usec, so divide by 100
*/
if (half_gi)
nsymbols = NUM_SYMBOLS_PER_USEC_HALFGI(mpdudensity);
else
nsymbols = NUM_SYMBOLS_PER_USEC(mpdudensity);
nsymbols /= 100;
if (nsymbols == 0)
nsymbols = 1;
nsymbits = bits_per_symbol[HT_RC_2_MCS(rc)][width];
minlen = (nsymbols * nsymbits) / BITS_PER_BYTE;
/*
* Min length is the minimum frame length for the
* required MPDU density.
*/
if (pktlen < minlen) {
mindelim = (minlen - pktlen) / ATH_AGGR_DELIM_SZ;
ndelim = MAX(mindelim, ndelim);
}
DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
"%s: pktlen=%d, minlen=%d, rix=%x, rc=%x, width=%d, hgi=%d, ndelim=%d\n",
__func__, pktlen, minlen, rix, rc, width, half_gi, ndelim);
return ndelim;
}
/*
* Fetch the aggregation limit.
*
* It's the lowest of the four rate series 4ms frame length.
*/
static int
ath_get_aggr_limit(struct ath_softc *sc, struct ath_buf *bf)
{
int amin = 65530;
int i;
for (i = 0; i < 4; i++) {
if (bf->bf_state.bfs_rc[i].tries == 0)
continue;
amin = MIN(amin, bf->bf_state.bfs_rc[i].max4msframelen);
}
DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR, "%s: max frame len= %d\n",
__func__, amin);
return amin;
}
/*
* Setup a 11n rate series structure
*
* This should be called for both legacy and MCS rates.
*
* It, along with ath_buf_set_rate, must be called -after- a burst
* or aggregate is setup.
*/
static void
ath_rateseries_setup(struct ath_softc *sc, struct ieee80211_node *ni,
struct ath_buf *bf, HAL_11N_RATE_SERIES *series)
{
#define HT_RC_2_STREAMS(_rc) ((((_rc) & 0x78) >> 3) + 1)
struct ieee80211com *ic = ni->ni_ic;
struct ath_hal *ah = sc->sc_ah;
HAL_BOOL shortPreamble = AH_FALSE;
const HAL_RATE_TABLE *rt = sc->sc_currates;
int i;
int pktlen;
int flags = bf->bf_state.bfs_flags;
struct ath_rc_series *rc = bf->bf_state.bfs_rc;
if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE))
shortPreamble = AH_TRUE;
/*
* If this is the first frame in an aggregate series,
* use the aggregate length.
*/
if (bf->bf_state.bfs_aggr)
pktlen = bf->bf_state.bfs_al;
else
pktlen = bf->bf_state.bfs_pktlen;
/*
* XXX TODO: modify this routine to use the bfs_rc[x].flags
* XXX fields.
*/
memset(series, 0, sizeof(HAL_11N_RATE_SERIES) * 4);
for (i = 0; i < 4; i++) {
/* Only set flags for actual TX attempts */
if (rc[i].tries == 0)
continue;
series[i].Tries = rc[i].tries;
/*
* XXX this isn't strictly correct - sc_txchainmask
* XXX isn't the currently active chainmask;
* XXX it's the interface chainmask at startup.
* XXX It's overridden in the HAL rate scenario function
* XXX for now.
*/
series[i].ChSel = sc->sc_txchainmask;
if (flags & (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
series[i].RateFlags |= HAL_RATESERIES_RTS_CTS;
/*
* Transmit 40MHz frames only if the node has negotiated
* it rather than whether the node is capable of it or not.
* It's subtly different in the hostap case.
*/
if (ni->ni_chw == 40)
series[i].RateFlags |= HAL_RATESERIES_2040;
/*
* Set short-GI only if the node has advertised it
* the channel width is suitable, and we support it.
* We don't currently have a "negotiated" set of bits -
* ni_htcap is what the remote end sends, not what this
* node is capable of.
*/
if (ni->ni_chw == 40 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40)
series[i].RateFlags |= HAL_RATESERIES_HALFGI;
if (ni->ni_chw == 20 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20)
series[i].RateFlags |= HAL_RATESERIES_HALFGI;
series[i].Rate = rt->info[rc[i].rix].rateCode;
/* PktDuration doesn't include slot, ACK, RTS, etc timing - it's just the packet duration */
if (series[i].Rate & IEEE80211_RATE_MCS) {
series[i].PktDuration =
ath_computedur_ht(pktlen
, series[i].Rate
, HT_RC_2_STREAMS(series[i].Rate)
, series[i].RateFlags & HAL_RATESERIES_2040
, series[i].RateFlags & HAL_RATESERIES_HALFGI);
} else {
if (shortPreamble)
series[i].Rate |=
rt->info[rc[i].rix].shortPreamble;
series[i].PktDuration = ath_hal_computetxtime(ah,
rt, pktlen, rc[i].rix, shortPreamble);
}
}
#undef HT_RC_2_STREAMS
}
#if 0
static void
ath_rateseries_print(HAL_11N_RATE_SERIES *series)
{
int i;
for (i = 0; i < 4; i++) {
printf("series %d: rate %x; tries %d; pktDuration %d; chSel %d; rateFlags %x\n",
i,
series[i].Rate,
series[i].Tries,
series[i].PktDuration,
series[i].ChSel,
series[i].RateFlags);
}
}
#endif
/*
* Setup the 11n rate scenario and burst duration for the given TX descriptor
* list.
*
* This isn't useful for sending beacon frames, which has different needs
* wrt what's passed into the rate scenario function.
*/
void
ath_buf_set_rate(struct ath_softc *sc, struct ieee80211_node *ni,
struct ath_buf *bf)
{
HAL_11N_RATE_SERIES series[4];
struct ath_desc *ds = bf->bf_desc;
struct ath_desc *lastds = NULL;
struct ath_hal *ah = sc->sc_ah;
int is_pspoll = (bf->bf_state.bfs_atype == HAL_PKT_TYPE_PSPOLL);
int ctsrate = bf->bf_state.bfs_ctsrate;
int flags = bf->bf_state.bfs_flags;
/* Setup rate scenario */
memset(&series, 0, sizeof(series));
ath_rateseries_setup(sc, ni, bf, series);
/* Enforce AR5416 aggregate limit - can't do RTS w/ an agg frame > 8k */
/* Enforce RTS and CTS are mutually exclusive */
/* Get a pointer to the last tx descriptor in the list */
lastds = bf->bf_lastds;
#if 0
printf("pktlen: %d; flags 0x%x\n", pktlen, flags);
ath_rateseries_print(series);
#endif
/* Set rate scenario */
ath_hal_set11nratescenario(ah, ds,
!is_pspoll, /* whether to override the duration or not */
/* don't allow hardware to override the duration on ps-poll packets */
ctsrate, /* rts/cts rate */
series, /* 11n rate series */
4, /* number of series */
flags);
/* Setup the last descriptor in the chain */
ath_hal_setuplasttxdesc(ah, lastds, ds);
/* Set burst duration */
/*
* This is only required when doing 11n burst, not aggregation
* ie, if there's a second frame in a RIFS or A-MPDU burst
* w/ >1 A-MPDU frame bursting back to back.
* Normal A-MPDU doesn't do bursting -between- aggregates.
*
* .. and it's highly likely this won't ever be implemented
*/
//ath_hal_set11nburstduration(ah, ds, 8192);
}
/*
* Form an aggregate packet list.
*
* This function enforces the aggregate restrictions/requirements.
*
* These are:
*
* + The aggregate size maximum (64k for AR9160 and later, 8K for
* AR5416 when doing RTS frame protection.)
* + Maximum number of sub-frames for an aggregate
* + The aggregate delimiter size, giving MACs time to do whatever is
* needed before each frame
* + Enforce the BAW limit
*
* Each descriptor queued should have the DMA setup.
* The rate series, descriptor setup, linking, etc is all done
* externally. This routine simply chains them together.
* ath_tx_setds_11n() will take care of configuring the per-
* descriptor setup, and ath_buf_set_rate() will configure the
* rate control.
*
* Note that the TID lock is only grabbed when dequeuing packets from
* the TID queue. If some code in another thread adds to the head of this
* list, very strange behaviour will occur. Since retransmission is the
* only reason this will occur, and this routine is designed to be called
* from within the scheduler task, it won't ever clash with the completion
* task.
*
* So if you want to call this from an upper layer context (eg, to direct-
* dispatch aggregate frames to the hardware), please keep this in mind.
*/
ATH_AGGR_STATUS
ath_tx_form_aggr(struct ath_softc *sc, struct ath_node *an, struct ath_tid *tid,
ath_bufhead *bf_q)
{
//struct ieee80211_node *ni = &an->an_node;
struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
int nframes = 0;
uint16_t aggr_limit = 0, al = 0, bpad = 0, al_delta, h_baw;
struct ieee80211_tx_ampdu *tap;
int status = ATH_AGGR_DONE;
int prev_frames = 0; /* XXX for AR5416 burst, not done here */
int prev_al = 0; /* XXX also for AR5416 burst */
ATH_TXQ_LOCK_ASSERT(sc->sc_ac2q[tid->ac]);
tap = ath_tx_get_tx_tid(an, tid->tid);
if (tap == NULL) {
status = ATH_AGGR_ERROR;
goto finish;
}
h_baw = tap->txa_wnd / 2;
for (;;) {
bf = TAILQ_FIRST(&tid->axq_q);
if (bf_first == NULL)
bf_first = bf;
if (bf == NULL) {
status = ATH_AGGR_DONE;
break;
} else {
/*
* It's the first frame;
* set the aggregation limit based on the
* rate control decision that has been made.
*/
aggr_limit = ath_get_aggr_limit(sc, bf_first);
}
/* Set this early just so things don't get confused */
bf->bf_next = NULL;
/*
* Don't unlock the tid lock until we're sure we are going
* to queue this frame.
*/
/*
* If the frame doesn't have a sequence number that we're
* tracking in the BAW (eg NULL QOS data frame), we can't
* aggregate it. Stop the aggregation process; the sender
* can then TX what's in the list thus far and then
* TX the frame individually.
*/
if (! bf->bf_state.bfs_dobaw) {
status = ATH_AGGR_NONAGGR;
break;
}
/*
* If any of the rates are non-HT, this packet
* can't be aggregated.
* XXX TODO: add a bf_state flag which gets marked
* if any active rate is non-HT.
*/
/*
* If the packet has a sequence number, do not
* step outside of the block-ack window.
*/
if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
SEQNO(bf->bf_state.bfs_seqno))) {
status = ATH_AGGR_BAW_CLOSED;
break;
}
/*
* XXX TODO: AR5416 has an 8K aggregation size limit
* when RTS is enabled, and RTS is required for dual-stream
* rates.
*
* For now, limit all aggregates for the AR5416 to be 8K.
*/
/*
* do not exceed aggregation limit
*/
al_delta = ATH_AGGR_DELIM_SZ + bf->bf_state.bfs_pktlen;
if (nframes &&
(aggr_limit < (al + bpad + al_delta + prev_al))) {
status = ATH_AGGR_LIMITED;
break;
}
/*
* Do not exceed subframe limit.
*/
if ((nframes + prev_frames) >= MIN((h_baw),
IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
status = ATH_AGGR_LIMITED;
break;
}
/*
* this packet is part of an aggregate.
*/
ATH_TXQ_REMOVE(tid, bf, bf_list);
/* The TID lock is required for the BAW update */
ath_tx_addto_baw(sc, an, tid, bf);
bf->bf_state.bfs_addedbaw = 1;
/*
* XXX TODO: If any frame in the aggregate requires RTS/CTS,
* set the first frame.
*/
/*
* XXX enforce ACK for aggregate frames (this needs to be
* XXX handled more gracefully?
*/
if (bf->bf_state.bfs_flags & HAL_TXDESC_NOACK) {
device_printf(sc->sc_dev,
"%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
__func__);
bf->bf_state.bfs_flags &= (~HAL_TXDESC_NOACK);
}
/*
* Add the now owned buffer (which isn't
* on the software TXQ any longer) to our
* aggregate frame list.
*/
TAILQ_INSERT_TAIL(bf_q, bf, bf_list);
nframes ++;
/* Completion handler */
bf->bf_comp = ath_tx_aggr_comp;
/*
* add padding for previous frame to aggregation length
*/
al += bpad + al_delta;
/*
* Calculate delimiters needed for the current frame
*/
bf->bf_state.bfs_ndelim =
ath_compute_num_delims(sc, bf_first,
bf->bf_state.bfs_pktlen);
/*
* Calculate the padding needed from this set of delimiters,
* used when calculating if the next frame will fit in
* the aggregate.
*/
bpad = PADBYTES(al_delta) + (bf->bf_state.bfs_ndelim << 2);
/*
* Chain the buffers together
*/
if (bf_prev)
bf_prev->bf_next = bf;
bf_prev = bf;
/*
* XXX TODO: if any sub-frames have RTS/CTS enabled;
* enable it for the entire aggregate.
*/
#if 0
/*
* terminate aggregation on a small packet boundary
*/
if (bf->bf_state.bfs_pktlen < ATH_AGGR_MINPLEN) {
status = ATH_AGGR_SHORTPKT;
break;
}
#endif
}
finish:
/*
* Just in case the list was empty when we tried to
* dequeue a packet ..
*/
if (bf_first) {
bf_first->bf_state.bfs_al = al;
bf_first->bf_state.bfs_nframes = nframes;
}
return status;
}
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