freebsd-skq/sys/dev/ath/if_ath_tx_ht.c
Adrian Chadd b25c1f2af0 A few nitpicks:
* Use ATH_RC_NUM instead of '4' when iterating over the ratecontrol series
  array.

* A few style(9) fixes, hopefully no regressions here.

* Add some comments that better describe what's going on.
2012-06-16 21:37:15 +00:00

867 lines
24 KiB
C

/*-
* 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 */
/* number of delimiters for encryption padding */
#define ATH_AGGR_ENCRYPTDELIM 10
/*
* 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_txflags &
(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 < ATH_RC_NUM; 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)
{
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_txflags;
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 < ATH_RC_NUM; 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);
}
}
}
#if 0
static void
ath_rateseries_print(struct ath_softc *sc, HAL_11N_RATE_SERIES *series)
{
int i;
for (i = 0; i < ATH_RC_NUM; i++) {
device_printf(sc->sc_dev ,"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_txflags;
/* 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(sc, series);
#endif
/* Set rate scenario */
/*
* Note: Don't allow hardware to override the duration on
* ps-poll packets.
*/
ath_hal_set11nratescenario(ah, ds,
!is_pspoll, /* whether to override the duration or not */
ctsrate, /* rts/cts rate */
series, /* 11n rate series */
4, /* number of series */
flags);
/* Setup the last descriptor in the chain */
/*
* XXX Why is this done here, and not in the upper layer?
* The rate control code stores a copy of the RC info in
* the last descriptor as well as the first, then uses
* the shadow copy in the last descriptor to see what the RC
* decisions were. I'm not sure why; perhaps earlier hardware
* overwrote the first descriptor contents.
*
* In the 802.11n case, it also clears the moreaggr/delim
* fields. Again, this should be done by the caller of
* ath_buf_set_rate().
*/
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.
*
* The TID lock is required for the entirety of this function.
*
* 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.
*/
/*
* 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;
}
/*
* If RTS/CTS is set on the first frame, enforce
* the RTS aggregate limit.
*/
if (bf_first->bf_state.bfs_txflags &
(HAL_TXDESC_CTSENA | HAL_TXDESC_RTSENA)) {
if (nframes &&
(sc->sc_rts_aggr_limit <
(al + bpad + al_delta + prev_al))) {
status = ATH_AGGR_8K_LIMITED;
break;
}
}
/*
* Do not exceed subframe limit.
*/
if ((nframes + prev_frames) >= MIN((h_baw),
IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
status = ATH_AGGR_LIMITED;
break;
}
/*
* If the current frame has an RTS/CTS configuration
* that differs from the first frame, override the
* subsequent frame with this config.
*/
bf->bf_state.bfs_txflags &=
(HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
bf->bf_state.bfs_txflags |=
bf_first->bf_state.bfs_txflags &
(HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
/*
* 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;
}
/*
* 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 enforce ACK for aggregate frames (this needs to be
* XXX handled more gracefully?
*/
if (bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) {
device_printf(sc->sc_dev,
"%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
__func__);
bf->bf_state.bfs_txflags &= (~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;
}