2 * Copyright (c) 2011 Adrian Chadd, Xenion Pty Ltd.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer,
10 * without modification.
11 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12 * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13 * redistribution must be conditioned upon including a substantially
14 * similar Disclaimer requirement for further binary redistribution.
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27 * THE POSSIBILITY OF SUCH DAMAGES.
30 #include <sys/cdefs.h>
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/sysctl.h>
40 #include <sys/malloc.h>
42 #include <sys/mutex.h>
43 #include <sys/kernel.h>
44 #include <sys/socket.h>
45 #include <sys/sockio.h>
46 #include <sys/errno.h>
47 #include <sys/callout.h>
49 #include <sys/endian.h>
50 #include <sys/kthread.h>
51 #include <sys/taskqueue.h>
54 #include <machine/bus.h>
57 #include <net/if_dl.h>
58 #include <net/if_media.h>
59 #include <net/if_types.h>
60 #include <net/if_arp.h>
61 #include <net/ethernet.h>
62 #include <net/if_llc.h>
64 #include <net80211/ieee80211_var.h>
65 #include <net80211/ieee80211_regdomain.h>
66 #ifdef IEEE80211_SUPPORT_SUPERG
67 #include <net80211/ieee80211_superg.h>
69 #ifdef IEEE80211_SUPPORT_TDMA
70 #include <net80211/ieee80211_tdma.h>
76 #include <netinet/in.h>
77 #include <netinet/if_ether.h>
80 #include <dev/ath/if_athvar.h>
81 #include <dev/ath/ath_hal/ah_devid.h> /* XXX for softled */
82 #include <dev/ath/ath_hal/ah_diagcodes.h>
85 #include <dev/ath/ath_tx99/ath_tx99.h>
88 #include <dev/ath/if_ath_tx.h> /* XXX for some support functions */
89 #include <dev/ath/if_ath_tx_ht.h>
90 #include <dev/ath/if_athrate.h>
91 #include <dev/ath/if_ath_debug.h>
96 #define IEEE80211_AMPDU_SUBFRAME_DEFAULT 32
98 #define ATH_AGGR_DELIM_SZ 4 /* delimiter size */
99 #define ATH_AGGR_MINPLEN 256 /* in bytes, minimum packet length */
100 /* number of delimiters for encryption padding */
101 #define ATH_AGGR_ENCRYPTDELIM 10
104 * returns delimiter padding required given the packet length
106 #define ATH_AGGR_GET_NDELIM(_len) \
107 (((((_len) + ATH_AGGR_DELIM_SZ) < ATH_AGGR_MINPLEN) ? \
108 (ATH_AGGR_MINPLEN - (_len) - ATH_AGGR_DELIM_SZ) : 0) >> 2)
110 #define PADBYTES(_len) ((4 - ((_len) % 4)) % 4)
112 int ath_max_4ms_framelen[4][32] = {
114 3212, 6432, 9648, 12864, 19300, 25736, 28952, 32172,
115 6424, 12852, 19280, 25708, 38568, 51424, 57852, 64280,
116 9628, 19260, 28896, 38528, 57792, 65532, 65532, 65532,
117 12828, 25656, 38488, 51320, 65532, 65532, 65532, 65532,
120 3572, 7144, 10720, 14296, 21444, 28596, 32172, 35744,
121 7140, 14284, 21428, 28568, 42856, 57144, 64288, 65532,
122 10700, 21408, 32112, 42816, 64228, 65532, 65532, 65532,
123 14256, 28516, 42780, 57040, 65532, 65532, 65532, 65532,
126 6680, 13360, 20044, 26724, 40092, 53456, 60140, 65532,
127 13348, 26700, 40052, 53400, 65532, 65532, 65532, 65532,
128 20004, 40008, 60016, 65532, 65532, 65532, 65532, 65532,
129 26644, 53292, 65532, 65532, 65532, 65532, 65532, 65532,
132 7420, 14844, 22272, 29696, 44544, 59396, 65532, 65532,
133 14832, 29668, 44504, 59340, 65532, 65532, 65532, 65532,
134 22232, 44464, 65532, 65532, 65532, 65532, 65532, 65532,
135 29616, 59232, 65532, 65532, 65532, 65532, 65532, 65532,
140 * XXX should be in net80211
142 static int ieee80211_mpdudensity_map[] = {
143 0, /* IEEE80211_HTCAP_MPDUDENSITY_NA */
144 25, /* IEEE80211_HTCAP_MPDUDENSITY_025 */
145 50, /* IEEE80211_HTCAP_MPDUDENSITY_05 */
146 100, /* IEEE80211_HTCAP_MPDUDENSITY_1 */
147 200, /* IEEE80211_HTCAP_MPDUDENSITY_2 */
148 400, /* IEEE80211_HTCAP_MPDUDENSITY_4 */
149 800, /* IEEE80211_HTCAP_MPDUDENSITY_8 */
150 1600, /* IEEE80211_HTCAP_MPDUDENSITY_16 */
154 * XXX should be in the HAL/net80211 ?
156 #define BITS_PER_BYTE 8
157 #define OFDM_PLCP_BITS 22
158 #define HT_RC_2_MCS(_rc) ((_rc) & 0x7f)
159 #define HT_RC_2_STREAMS(_rc) ((((_rc) & 0x78) >> 3) + 1)
165 #define HT_LTF(_ns) (4 * (_ns))
166 #define SYMBOL_TIME(_ns) ((_ns) << 2) // ns * 4 us
167 #define SYMBOL_TIME_HALFGI(_ns) (((_ns) * 18 + 4) / 5) // ns * 3.6 us
168 #define NUM_SYMBOLS_PER_USEC(_usec) (_usec >> 2)
169 #define NUM_SYMBOLS_PER_USEC_HALFGI(_usec) (((_usec*5)-4)/18)
170 #define IS_HT_RATE(_rate) ((_rate) & 0x80)
172 const uint32_t bits_per_symbol[][2] = {
174 { 26, 54 }, // 0: BPSK
175 { 52, 108 }, // 1: QPSK 1/2
176 { 78, 162 }, // 2: QPSK 3/4
177 { 104, 216 }, // 3: 16-QAM 1/2
178 { 156, 324 }, // 4: 16-QAM 3/4
179 { 208, 432 }, // 5: 64-QAM 2/3
180 { 234, 486 }, // 6: 64-QAM 3/4
181 { 260, 540 }, // 7: 64-QAM 5/6
182 { 52, 108 }, // 8: BPSK
183 { 104, 216 }, // 9: QPSK 1/2
184 { 156, 324 }, // 10: QPSK 3/4
185 { 208, 432 }, // 11: 16-QAM 1/2
186 { 312, 648 }, // 12: 16-QAM 3/4
187 { 416, 864 }, // 13: 64-QAM 2/3
188 { 468, 972 }, // 14: 64-QAM 3/4
189 { 520, 1080 }, // 15: 64-QAM 5/6
190 { 78, 162 }, // 16: BPSK
191 { 156, 324 }, // 17: QPSK 1/2
192 { 234, 486 }, // 18: QPSK 3/4
193 { 312, 648 }, // 19: 16-QAM 1/2
194 { 468, 972 }, // 20: 16-QAM 3/4
195 { 624, 1296 }, // 21: 64-QAM 2/3
196 { 702, 1458 }, // 22: 64-QAM 3/4
197 { 780, 1620 }, // 23: 64-QAM 5/6
198 { 104, 216 }, // 24: BPSK
199 { 208, 432 }, // 25: QPSK 1/2
200 { 312, 648 }, // 26: QPSK 3/4
201 { 416, 864 }, // 27: 16-QAM 1/2
202 { 624, 1296 }, // 28: 16-QAM 3/4
203 { 832, 1728 }, // 29: 64-QAM 2/3
204 { 936, 1944 }, // 30: 64-QAM 3/4
205 { 1040, 2160 }, // 31: 64-QAM 5/6
209 * Fill in the rate array information based on the current
210 * node configuration and the choices made by the rate
211 * selection code and ath_buf setup code.
213 * Later on, this may end up also being made by the
214 * rate control code, but for now it can live here.
216 * This needs to be called just before the packet is
217 * queued to the software queue or hardware queue,
218 * so all of the needed fields in bf_state are setup.
221 ath_tx_rate_fill_rcflags(struct ath_softc *sc, struct ath_buf *bf)
223 struct ieee80211_node *ni = bf->bf_node;
224 struct ieee80211com *ic = ni->ni_ic;
225 const HAL_RATE_TABLE *rt = sc->sc_currates;
226 struct ath_rc_series *rc = bf->bf_state.bfs_rc;
230 for (i = 0; i < ATH_RC_NUM; i++) {
232 if (rc[i].tries == 0)
235 rate = rt->info[rc[i].rix].rateCode;
238 * Only enable short preamble for legacy rates
240 if ((! IS_HT_RATE(rate)) && bf->bf_state.bfs_shpream)
241 rate |= rt->info[rc[i].rix].shortPreamble;
244 * Save this, used by the TX and completion code
246 rc[i].ratecode = rate;
248 if (bf->bf_state.bfs_txflags &
249 (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
250 rc[i].flags |= ATH_RC_RTSCTS_FLAG;
252 /* Only enable shortgi, 2040, dual-stream if HT is set */
253 if (IS_HT_RATE(rate)) {
254 rc[i].flags |= ATH_RC_HT_FLAG;
256 if (ni->ni_chw == 40)
257 rc[i].flags |= ATH_RC_CW40_FLAG;
259 if (ni->ni_chw == 40 &&
260 ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
261 ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40)
262 rc[i].flags |= ATH_RC_SGI_FLAG;
264 if (ni->ni_chw == 20 &&
265 ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
266 ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20)
267 rc[i].flags |= ATH_RC_SGI_FLAG;
270 * If we have STBC TX enabled and the receiver
271 * can receive (at least) 1 stream STBC, AND it's
272 * MCS 0-7, AND we have at least two chains enabled,
275 if (ic->ic_htcaps & IEEE80211_HTCAP_TXSTBC &&
276 ni->ni_htcap & IEEE80211_HTCAP_RXSTBC_1STREAM &&
277 (sc->sc_cur_txchainmask > 1) &&
278 HT_RC_2_STREAMS(rate) == 1) {
279 rc[i].flags |= ATH_RC_STBC_FLAG;
287 * Dual / Triple stream rate?
289 if (HT_RC_2_STREAMS(rate) == 2)
290 rc[i].flags |= ATH_RC_DS_FLAG;
291 else if (HT_RC_2_STREAMS(rate) == 3)
292 rc[i].flags |= ATH_RC_TS_FLAG;
296 * Calculate the maximum TX power cap for the current
299 rc[i].tx_power_cap = ieee80211_get_node_txpower(ni);
302 * Calculate the maximum 4ms frame length based
303 * on the MCS rate, SGI and channel width flags.
305 if ((rc[i].flags & ATH_RC_HT_FLAG) &&
306 (HT_RC_2_MCS(rate) < 32)) {
308 if (rc[i].flags & ATH_RC_CW40_FLAG) {
309 if (rc[i].flags & ATH_RC_SGI_FLAG)
314 if (rc[i].flags & ATH_RC_SGI_FLAG)
319 rc[i].max4msframelen =
320 ath_max_4ms_framelen[j][HT_RC_2_MCS(rate)];
322 rc[i].max4msframelen = 0;
323 DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
324 "%s: i=%d, rate=0x%x, flags=0x%x, max4ms=%d\n",
325 __func__, i, rate, rc[i].flags, rc[i].max4msframelen);
330 * Return the number of delimiters to be added to
331 * meet the minimum required mpdudensity.
333 * Caller should make sure that the rate is HT.
335 * TODO: is this delimiter calculation supposed to be the
336 * total frame length, the hdr length, the data length (including
337 * delimiters, padding, CRC, etc) or ?
339 * TODO: this should ensure that the rate control information
340 * HAS been setup for the first rate.
342 * TODO: ensure this is only called for MCS rates.
344 * TODO: enforce MCS < 31
347 ath_compute_num_delims(struct ath_softc *sc, struct ath_buf *first_bf,
350 const HAL_RATE_TABLE *rt = sc->sc_currates;
351 struct ieee80211_node *ni = first_bf->bf_node;
352 struct ieee80211vap *vap = ni->ni_vap;
353 int ndelim, mindelim = 0;
354 int mpdudensity; /* in 1/100'th of a microsecond */
355 uint8_t rc, rix, flags;
357 uint32_t nsymbits, nsymbols;
361 * vap->iv_ampdu_density is a value, rather than the actual
364 if (vap->iv_ampdu_density > IEEE80211_HTCAP_MPDUDENSITY_16)
365 mpdudensity = 1600; /* maximum density */
367 mpdudensity = ieee80211_mpdudensity_map[vap->iv_ampdu_density];
369 /* Select standard number of delimiters based on frame length */
370 ndelim = ATH_AGGR_GET_NDELIM(pktlen);
373 * If encryption is enabled, add extra delimiters to let the
374 * crypto hardware catch up. This could be tuned per-MAC and
375 * per-rate, but for now we'll simply assume encryption is
378 * Also note that the Atheros reference driver inserts two
379 * delimiters by default for pre-AR9380 peers. This will
380 * include "that" required delimiter.
382 ndelim += ATH_AGGR_ENCRYPTDELIM;
385 * For AR9380, there's a minimum number of delimeters
386 * required when doing RTS.
388 * XXX TODO: this is only needed if (a) RTS/CTS is enabled, and
389 * XXX (b) this is the first sub-frame in the aggregate.
391 if (sc->sc_use_ent && (sc->sc_ent_cfg & AH_ENT_RTSCTS_DELIM_WAR)
392 && ndelim < AH_FIRST_DESC_NDELIMS)
393 ndelim = AH_FIRST_DESC_NDELIMS;
396 * If sc_delim_min_pad is non-zero, enforce it as the minimum
397 * pad delimiter count.
399 if (sc->sc_delim_min_pad != 0)
400 ndelim = MAX(ndelim, sc->sc_delim_min_pad);
402 DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
403 "%s: pktlen=%d, ndelim=%d, mpdudensity=%d\n",
404 __func__, pktlen, ndelim, mpdudensity);
407 * If the MPDU density is 0, we can return here.
408 * Otherwise, we need to convert the desired mpdudensity
409 * into a byte length, based on the rate in the subframe.
411 if (mpdudensity == 0)
415 * Convert desired mpdu density from microeconds to bytes based
416 * on highest rate in rate series (i.e. first rate) to determine
417 * required minimum length for subframe. Take into account
418 * whether high rate is 20 or 40Mhz and half or full GI.
420 rix = first_bf->bf_state.bfs_rc[0].rix;
421 rc = rt->info[rix].rateCode;
422 flags = first_bf->bf_state.bfs_rc[0].flags;
423 width = !! (flags & ATH_RC_CW40_FLAG);
424 half_gi = !! (flags & ATH_RC_SGI_FLAG);
427 * mpdudensity is in 1/100th of a usec, so divide by 100
430 nsymbols = NUM_SYMBOLS_PER_USEC_HALFGI(mpdudensity);
432 nsymbols = NUM_SYMBOLS_PER_USEC(mpdudensity);
438 nsymbits = bits_per_symbol[HT_RC_2_MCS(rc)][width];
439 minlen = (nsymbols * nsymbits) / BITS_PER_BYTE;
442 * Min length is the minimum frame length for the
443 * required MPDU density.
445 if (pktlen < minlen) {
446 mindelim = (minlen - pktlen) / ATH_AGGR_DELIM_SZ;
447 ndelim = MAX(mindelim, ndelim);
450 DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
451 "%s: pktlen=%d, minlen=%d, rix=%x, rc=%x, width=%d, hgi=%d, ndelim=%d\n",
452 __func__, pktlen, minlen, rix, rc, width, half_gi, ndelim);
458 * Fetch the aggregation limit.
460 * It's the lowest of the four rate series 4ms frame length.
463 ath_get_aggr_limit(struct ath_softc *sc, struct ath_buf *bf)
465 int amin = ATH_AGGR_MAXSIZE;
468 if (sc->sc_aggr_limit > 0 && sc->sc_aggr_limit < ATH_AGGR_MAXSIZE)
469 amin = sc->sc_aggr_limit;
471 for (i = 0; i < ATH_RC_NUM; i++) {
472 if (bf->bf_state.bfs_rc[i].tries == 0)
474 amin = MIN(amin, bf->bf_state.bfs_rc[i].max4msframelen);
477 DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR, "%s: max frame len= %d\n",
484 * Setup a 11n rate series structure
486 * This should be called for both legacy and MCS rates.
488 * This uses the rate series stuf from ath_tx_rate_fill_rcflags().
490 * It, along with ath_buf_set_rate, must be called -after- a burst
491 * or aggregate is setup.
494 ath_rateseries_setup(struct ath_softc *sc, struct ieee80211_node *ni,
495 struct ath_buf *bf, HAL_11N_RATE_SERIES *series)
497 struct ieee80211com *ic = ni->ni_ic;
498 struct ath_hal *ah = sc->sc_ah;
499 HAL_BOOL shortPreamble = AH_FALSE;
500 const HAL_RATE_TABLE *rt = sc->sc_currates;
503 struct ath_rc_series *rc = bf->bf_state.bfs_rc;
505 if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
506 (ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE))
507 shortPreamble = AH_TRUE;
510 * If this is the first frame in an aggregate series,
511 * use the aggregate length.
513 if (bf->bf_state.bfs_aggr)
514 pktlen = bf->bf_state.bfs_al;
516 pktlen = bf->bf_state.bfs_pktlen;
519 * XXX TODO: modify this routine to use the bfs_rc[x].flags
522 memset(series, 0, sizeof(HAL_11N_RATE_SERIES) * 4);
523 for (i = 0; i < ATH_RC_NUM; i++) {
524 /* Only set flags for actual TX attempts */
525 if (rc[i].tries == 0)
528 series[i].Tries = rc[i].tries;
531 * XXX TODO: When the NIC is capable of three stream TX,
532 * transmit 1/2 stream rates on two streams.
534 * This reduces the power consumption of the NIC and
535 * keeps it within the PCIe slot power limits.
537 series[i].ChSel = sc->sc_cur_txchainmask;
540 * Setup rate and TX power cap for this series.
542 series[i].Rate = rt->info[rc[i].rix].rateCode;
543 series[i].RateIndex = rc[i].rix;
544 series[i].tx_power_cap = rc[i].tx_power_cap;
547 * Enable RTS/CTS as appropriate.
549 if (rc[i].flags & ATH_RC_RTSCTS_FLAG)
550 series[i].RateFlags |= HAL_RATESERIES_RTS_CTS;
553 * 11n rate? Update 11n flags.
555 if (rc[i].flags & ATH_RC_HT_FLAG) {
556 if (rc[i].flags & ATH_RC_CW40_FLAG)
557 series[i].RateFlags |= HAL_RATESERIES_2040;
559 if (rc[i].flags & ATH_RC_SGI_FLAG)
560 series[i].RateFlags |= HAL_RATESERIES_HALFGI;
562 if (rc[i].flags & ATH_RC_STBC_FLAG)
563 series[i].RateFlags |= HAL_RATESERIES_STBC;
567 * PktDuration doesn't include slot, ACK, RTS, etc timing -
568 * it's just the packet duration
570 if (rc[i].flags & ATH_RC_HT_FLAG) {
571 series[i].PktDuration =
572 ath_computedur_ht(pktlen
574 , HT_RC_2_STREAMS(series[i].Rate)
575 , series[i].RateFlags & HAL_RATESERIES_2040
576 , series[i].RateFlags & HAL_RATESERIES_HALFGI);
580 rt->info[rc[i].rix].shortPreamble;
581 series[i].PktDuration = ath_hal_computetxtime(ah,
582 rt, pktlen, rc[i].rix, shortPreamble);
589 ath_rateseries_print(struct ath_softc *sc, HAL_11N_RATE_SERIES *series)
592 for (i = 0; i < ATH_RC_NUM; i++) {
593 device_printf(sc->sc_dev ,"series %d: rate %x; tries %d; "
594 "pktDuration %d; chSel %d; txpowcap %d, rateFlags %x\n",
598 series[i].PktDuration,
600 series[i].tx_power_cap,
601 series[i].RateFlags);
607 * Setup the 11n rate scenario and burst duration for the given TX descriptor
610 * This isn't useful for sending beacon frames, which has different needs
611 * wrt what's passed into the rate scenario function.
614 ath_buf_set_rate(struct ath_softc *sc, struct ieee80211_node *ni,
617 HAL_11N_RATE_SERIES series[4];
618 struct ath_desc *ds = bf->bf_desc;
619 struct ath_hal *ah = sc->sc_ah;
620 int is_pspoll = (bf->bf_state.bfs_atype == HAL_PKT_TYPE_PSPOLL);
621 int ctsrate = bf->bf_state.bfs_ctsrate;
622 int flags = bf->bf_state.bfs_txflags;
624 /* Setup rate scenario */
625 memset(&series, 0, sizeof(series));
627 ath_rateseries_setup(sc, ni, bf, series);
630 ath_rateseries_print(sc, series);
633 /* Set rate scenario */
635 * Note: Don't allow hardware to override the duration on
638 ath_hal_set11nratescenario(ah, ds,
639 !is_pspoll, /* whether to override the duration or not */
640 ctsrate, /* rts/cts rate */
641 series, /* 11n rate series */
642 4, /* number of series */
645 /* Set burst duration */
647 * This is only required when doing 11n burst, not aggregation
648 * ie, if there's a second frame in a RIFS or A-MPDU burst
649 * w/ >1 A-MPDU frame bursting back to back.
650 * Normal A-MPDU doesn't do bursting -between- aggregates.
652 * .. and it's highly likely this won't ever be implemented
654 //ath_hal_set11nburstduration(ah, ds, 8192);
658 * Form an aggregate packet list.
660 * This function enforces the aggregate restrictions/requirements.
664 * + The aggregate size maximum (64k for AR9160 and later, 8K for
665 * AR5416 when doing RTS frame protection.)
666 * + Maximum number of sub-frames for an aggregate
667 * + The aggregate delimiter size, giving MACs time to do whatever is
668 * needed before each frame
669 * + Enforce the BAW limit
671 * Each descriptor queued should have the DMA setup.
672 * The rate series, descriptor setup, linking, etc is all done
673 * externally. This routine simply chains them together.
674 * ath_tx_setds_11n() will take care of configuring the per-
675 * descriptor setup, and ath_buf_set_rate() will configure the
678 * The TID lock is required for the entirety of this function.
680 * If some code in another thread adds to the head of this
681 * list, very strange behaviour will occur. Since retransmission is the
682 * only reason this will occur, and this routine is designed to be called
683 * from within the scheduler task, it won't ever clash with the completion
686 * So if you want to call this from an upper layer context (eg, to direct-
687 * dispatch aggregate frames to the hardware), please keep this in mind.
690 ath_tx_form_aggr(struct ath_softc *sc, struct ath_node *an,
691 struct ath_tid *tid, ath_bufhead *bf_q)
693 //struct ieee80211_node *ni = &an->an_node;
694 struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
696 uint16_t aggr_limit = 0, al = 0, bpad = 0, al_delta, h_baw;
697 struct ieee80211_tx_ampdu *tap;
698 int status = ATH_AGGR_DONE;
699 int prev_frames = 0; /* XXX for AR5416 burst, not done here */
700 int prev_al = 0; /* XXX also for AR5416 burst */
702 ATH_TX_LOCK_ASSERT(sc);
704 tap = ath_tx_get_tx_tid(an, tid->tid);
706 status = ATH_AGGR_ERROR;
710 h_baw = tap->txa_wnd / 2;
713 bf = ATH_TID_FIRST(tid);
714 if (bf_first == NULL)
717 status = ATH_AGGR_DONE;
721 * It's the first frame;
722 * set the aggregation limit based on the
723 * rate control decision that has been made.
725 aggr_limit = ath_get_aggr_limit(sc, bf_first);
728 /* Set this early just so things don't get confused */
732 * If the frame doesn't have a sequence number that we're
733 * tracking in the BAW (eg NULL QOS data frame), we can't
734 * aggregate it. Stop the aggregation process; the sender
735 * can then TX what's in the list thus far and then
736 * TX the frame individually.
738 if (! bf->bf_state.bfs_dobaw) {
739 status = ATH_AGGR_NONAGGR;
744 * If any of the rates are non-HT, this packet
745 * can't be aggregated.
746 * XXX TODO: add a bf_state flag which gets marked
747 * if any active rate is non-HT.
751 * do not exceed aggregation limit
753 al_delta = ATH_AGGR_DELIM_SZ + bf->bf_state.bfs_pktlen;
755 (aggr_limit < (al + bpad + al_delta + prev_al))) {
756 status = ATH_AGGR_LIMITED;
761 * If RTS/CTS is set on the first frame, enforce
762 * the RTS aggregate limit.
764 if (bf_first->bf_state.bfs_txflags &
765 (HAL_TXDESC_CTSENA | HAL_TXDESC_RTSENA)) {
767 (sc->sc_rts_aggr_limit <
768 (al + bpad + al_delta + prev_al))) {
769 status = ATH_AGGR_8K_LIMITED;
775 * Do not exceed subframe limit.
777 if ((nframes + prev_frames) >= MIN((h_baw),
778 IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
779 status = ATH_AGGR_LIMITED;
784 * If the current frame has an RTS/CTS configuration
785 * that differs from the first frame, override the
786 * subsequent frame with this config.
788 if (bf != bf_first) {
789 bf->bf_state.bfs_txflags &=
790 ~ (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
791 bf->bf_state.bfs_txflags |=
792 bf_first->bf_state.bfs_txflags &
793 (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
797 * If the packet has a sequence number, do not
798 * step outside of the block-ack window.
800 if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
801 SEQNO(bf->bf_state.bfs_seqno))) {
802 status = ATH_AGGR_BAW_CLOSED;
807 * this packet is part of an aggregate.
809 ATH_TID_REMOVE(tid, bf, bf_list);
811 /* The TID lock is required for the BAW update */
812 ath_tx_addto_baw(sc, an, tid, bf);
813 bf->bf_state.bfs_addedbaw = 1;
816 * XXX enforce ACK for aggregate frames (this needs to be
817 * XXX handled more gracefully?
819 if (bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) {
820 device_printf(sc->sc_dev,
821 "%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
823 bf->bf_state.bfs_txflags &= (~HAL_TXDESC_NOACK);
827 * Add the now owned buffer (which isn't
828 * on the software TXQ any longer) to our
829 * aggregate frame list.
831 TAILQ_INSERT_TAIL(bf_q, bf, bf_list);
834 /* Completion handler */
835 bf->bf_comp = ath_tx_aggr_comp;
838 * add padding for previous frame to aggregation length
840 al += bpad + al_delta;
843 * Calculate delimiters needed for the current frame
845 bf->bf_state.bfs_ndelim =
846 ath_compute_num_delims(sc, bf_first,
847 bf->bf_state.bfs_pktlen);
850 * Calculate the padding needed from this set of delimiters,
851 * used when calculating if the next frame will fit in
854 bpad = PADBYTES(al_delta) + (bf->bf_state.bfs_ndelim << 2);
857 * Chain the buffers together
860 bf_prev->bf_next = bf;
864 * If we're leaking frames, just return at this point;
865 * we've queued a single frame and we don't want to add
868 if (tid->an->an_leak_count) {
869 status = ATH_AGGR_LEAK_CLOSED;
875 * terminate aggregation on a small packet boundary
877 if (bf->bf_state.bfs_pktlen < ATH_AGGR_MINPLEN) {
878 status = ATH_AGGR_SHORTPKT;
887 * Just in case the list was empty when we tried to
888 * dequeue a packet ..
891 bf_first->bf_state.bfs_al = al;
892 bf_first->bf_state.bfs_nframes = nframes;