xref: /freebsd/sys/dev/ath/if_ath_tx_ht.c (revision 724b4bfdf1306e4f2c451b6d146fe0fe0353b2c8)
1 /*-
2  * Copyright (c) 2011 Adrian Chadd, Xenion Pty Ltd.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
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.
15  *
16  * NO WARRANTY
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.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_inet.h"
34 #include "opt_ath.h"
35 #include "opt_wlan.h"
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/sysctl.h>
40 #include <sys/mbuf.h>
41 #include <sys/malloc.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/kernel.h>
45 #include <sys/socket.h>
46 #include <sys/sockio.h>
47 #include <sys/errno.h>
48 #include <sys/callout.h>
49 #include <sys/bus.h>
50 #include <sys/endian.h>
51 #include <sys/kthread.h>
52 #include <sys/taskqueue.h>
53 #include <sys/priv.h>
54 
55 #include <machine/bus.h>
56 
57 #include <net/if.h>
58 #include <net/if_dl.h>
59 #include <net/if_media.h>
60 #include <net/if_types.h>
61 #include <net/if_arp.h>
62 #include <net/ethernet.h>
63 #include <net/if_llc.h>
64 
65 #include <net80211/ieee80211_var.h>
66 #include <net80211/ieee80211_regdomain.h>
67 #ifdef IEEE80211_SUPPORT_SUPERG
68 #include <net80211/ieee80211_superg.h>
69 #endif
70 #ifdef IEEE80211_SUPPORT_TDMA
71 #include <net80211/ieee80211_tdma.h>
72 #endif
73 
74 #include <net/bpf.h>
75 
76 #ifdef INET
77 #include <netinet/in.h>
78 #include <netinet/if_ether.h>
79 #endif
80 
81 #include <dev/ath/if_athvar.h>
82 #include <dev/ath/ath_hal/ah_devid.h>		/* XXX for softled */
83 #include <dev/ath/ath_hal/ah_diagcodes.h>
84 
85 #ifdef ATH_TX99_DIAG
86 #include <dev/ath/ath_tx99/ath_tx99.h>
87 #endif
88 
89 #include <dev/ath/if_ath_tx.h>		/* XXX for some support functions */
90 #include <dev/ath/if_ath_tx_ht.h>
91 #include <dev/ath/if_athrate.h>
92 #include <dev/ath/if_ath_debug.h>
93 
94 /*
95  * XXX net80211?
96  */
97 #define	IEEE80211_AMPDU_SUBFRAME_DEFAULT		32
98 
99 #define	ATH_AGGR_DELIM_SZ	4	/* delimiter size */
100 #define	ATH_AGGR_MINPLEN	256	/* in bytes, minimum packet length */
101 /* number of delimiters for encryption padding */
102 #define	ATH_AGGR_ENCRYPTDELIM	10
103 
104 /*
105  * returns delimiter padding required given the packet length
106  */
107 #define	ATH_AGGR_GET_NDELIM(_len)					\
108 	    (((((_len) + ATH_AGGR_DELIM_SZ) < ATH_AGGR_MINPLEN) ?	\
109 	    (ATH_AGGR_MINPLEN - (_len) - ATH_AGGR_DELIM_SZ) : 0) >> 2)
110 
111 #define	PADBYTES(_len)		((4 - ((_len) % 4)) % 4)
112 
113 int ath_max_4ms_framelen[4][32] = {
114 	[MCS_HT20] = {
115 		3212,  6432,  9648,  12864,  19300,  25736,  28952,  32172,
116 		6424,  12852, 19280, 25708,  38568,  51424,  57852,  64280,
117 		9628,  19260, 28896, 38528,  57792,  65532,  65532,  65532,
118 		12828, 25656, 38488, 51320,  65532,  65532,  65532,  65532,
119 	},
120 	[MCS_HT20_SGI] = {
121 		3572,  7144,  10720,  14296,  21444,  28596,  32172,  35744,
122 		7140,  14284, 21428,  28568,  42856,  57144,  64288,  65532,
123 		10700, 21408, 32112,  42816,  64228,  65532,  65532,  65532,
124 		14256, 28516, 42780,  57040,  65532,  65532,  65532,  65532,
125 	},
126 	[MCS_HT40] = {
127 		6680,  13360,  20044,  26724,  40092,  53456,  60140,  65532,
128 		13348, 26700,  40052,  53400,  65532,  65532,  65532,  65532,
129 		20004, 40008,  60016,  65532,  65532,  65532,  65532,  65532,
130 		26644, 53292,  65532,  65532,  65532,  65532,  65532,  65532,
131 	},
132 	[MCS_HT40_SGI] = {
133 		7420,  14844,  22272,  29696,  44544,  59396,  65532,  65532,
134 		14832, 29668,  44504,  59340,  65532,  65532,  65532,  65532,
135 		22232, 44464,  65532,  65532,  65532,  65532,  65532,  65532,
136 		29616, 59232,  65532,  65532,  65532,  65532,  65532,  65532,
137 	}
138 };
139 
140 /*
141  * XXX should be in net80211
142  */
143 static int ieee80211_mpdudensity_map[] = {
144 	0,		/* IEEE80211_HTCAP_MPDUDENSITY_NA */
145 	25,		/* IEEE80211_HTCAP_MPDUDENSITY_025 */
146 	50,		/* IEEE80211_HTCAP_MPDUDENSITY_05 */
147 	100,		/* IEEE80211_HTCAP_MPDUDENSITY_1 */
148 	200,		/* IEEE80211_HTCAP_MPDUDENSITY_2 */
149 	400,		/* IEEE80211_HTCAP_MPDUDENSITY_4 */
150 	800,		/* IEEE80211_HTCAP_MPDUDENSITY_8 */
151 	1600,		/* IEEE80211_HTCAP_MPDUDENSITY_16 */
152 };
153 
154 /*
155  * XXX should be in the HAL/net80211 ?
156  */
157 #define	BITS_PER_BYTE		8
158 #define	OFDM_PLCP_BITS		22
159 #define	HT_RC_2_MCS(_rc)	((_rc) & 0x7f)
160 #define	HT_RC_2_STREAMS(_rc)	((((_rc) & 0x78) >> 3) + 1)
161 #define	L_STF			8
162 #define	L_LTF			8
163 #define	L_SIG			4
164 #define	HT_SIG			8
165 #define	HT_STF			4
166 #define	HT_LTF(_ns)		(4 * (_ns))
167 #define	SYMBOL_TIME(_ns)	((_ns) << 2)		// ns * 4 us
168 #define	SYMBOL_TIME_HALFGI(_ns)	(((_ns) * 18 + 4) / 5)	// ns * 3.6 us
169 #define	NUM_SYMBOLS_PER_USEC(_usec)	(_usec >> 2)
170 #define	NUM_SYMBOLS_PER_USEC_HALFGI(_usec)	(((_usec*5)-4)/18)
171 #define	IS_HT_RATE(_rate)	((_rate) & 0x80)
172 
173 const uint32_t bits_per_symbol[][2] = {
174     /* 20MHz 40MHz */
175     {    26,   54 },     //  0: BPSK
176     {    52,  108 },     //  1: QPSK 1/2
177     {    78,  162 },     //  2: QPSK 3/4
178     {   104,  216 },     //  3: 16-QAM 1/2
179     {   156,  324 },     //  4: 16-QAM 3/4
180     {   208,  432 },     //  5: 64-QAM 2/3
181     {   234,  486 },     //  6: 64-QAM 3/4
182     {   260,  540 },     //  7: 64-QAM 5/6
183     {    52,  108 },     //  8: BPSK
184     {   104,  216 },     //  9: QPSK 1/2
185     {   156,  324 },     // 10: QPSK 3/4
186     {   208,  432 },     // 11: 16-QAM 1/2
187     {   312,  648 },     // 12: 16-QAM 3/4
188     {   416,  864 },     // 13: 64-QAM 2/3
189     {   468,  972 },     // 14: 64-QAM 3/4
190     {   520, 1080 },     // 15: 64-QAM 5/6
191     {    78,  162 },     // 16: BPSK
192     {   156,  324 },     // 17: QPSK 1/2
193     {   234,  486 },     // 18: QPSK 3/4
194     {   312,  648 },     // 19: 16-QAM 1/2
195     {   468,  972 },     // 20: 16-QAM 3/4
196     {   624, 1296 },     // 21: 64-QAM 2/3
197     {   702, 1458 },     // 22: 64-QAM 3/4
198     {   780, 1620 },     // 23: 64-QAM 5/6
199     {   104,  216 },     // 24: BPSK
200     {   208,  432 },     // 25: QPSK 1/2
201     {   312,  648 },     // 26: QPSK 3/4
202     {   416,  864 },     // 27: 16-QAM 1/2
203     {   624, 1296 },     // 28: 16-QAM 3/4
204     {   832, 1728 },     // 29: 64-QAM 2/3
205     {   936, 1944 },     // 30: 64-QAM 3/4
206     {  1040, 2160 },     // 31: 64-QAM 5/6
207 };
208 
209 /*
210  * Fill in the rate array information based on the current
211  * node configuration and the choices made by the rate
212  * selection code and ath_buf setup code.
213  *
214  * Later on, this may end up also being made by the
215  * rate control code, but for now it can live here.
216  *
217  * This needs to be called just before the packet is
218  * queued to the software queue or hardware queue,
219  * so all of the needed fields in bf_state are setup.
220  */
221 void
222 ath_tx_rate_fill_rcflags(struct ath_softc *sc, struct ath_buf *bf)
223 {
224 	struct ieee80211_node *ni = bf->bf_node;
225 	struct ieee80211com *ic = ni->ni_ic;
226 	const HAL_RATE_TABLE *rt = sc->sc_currates;
227 	struct ath_rc_series *rc = bf->bf_state.bfs_rc;
228 	uint8_t rate;
229 	int i;
230 
231 	for (i = 0; i < ATH_RC_NUM; i++) {
232 		rc[i].flags = 0;
233 		if (rc[i].tries == 0)
234 			continue;
235 
236 		rate = rt->info[rc[i].rix].rateCode;
237 
238 		/*
239 		 * XXX only do this for legacy rates?
240 		 */
241 		if (bf->bf_state.bfs_shpream)
242 			rate |= rt->info[rc[i].rix].shortPreamble;
243 
244 		/*
245 		 * Save this, used by the TX and completion code
246 		 */
247 		rc[i].ratecode = rate;
248 
249 		if (bf->bf_state.bfs_txflags &
250 		    (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
251 			rc[i].flags |= ATH_RC_RTSCTS_FLAG;
252 
253 		/* Only enable shortgi, 2040, dual-stream if HT is set */
254 		if (IS_HT_RATE(rate)) {
255 			rc[i].flags |= ATH_RC_HT_FLAG;
256 
257 			if (ni->ni_chw == 40)
258 				rc[i].flags |= ATH_RC_CW40_FLAG;
259 
260 			if (ni->ni_chw == 40 &&
261 			    ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
262 			    ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40)
263 				rc[i].flags |= ATH_RC_SGI_FLAG;
264 
265 			if (ni->ni_chw == 20 &&
266 			    ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
267 			    ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20)
268 				rc[i].flags |= ATH_RC_SGI_FLAG;
269 
270 			/* XXX dual stream? and 3-stream? */
271 		}
272 
273 		/*
274 		 * Calculate the maximum 4ms frame length based
275 		 * on the MCS rate, SGI and channel width flags.
276 		 */
277 		if ((rc[i].flags & ATH_RC_HT_FLAG) &&
278 		    (HT_RC_2_MCS(rate) < 32)) {
279 			int j;
280 			if (rc[i].flags & ATH_RC_CW40_FLAG) {
281 				if (rc[i].flags & ATH_RC_SGI_FLAG)
282 					j = MCS_HT40_SGI;
283 				else
284 					j = MCS_HT40;
285 			} else {
286 				if (rc[i].flags & ATH_RC_SGI_FLAG)
287 					j = MCS_HT20_SGI;
288 				else
289 					j = MCS_HT20;
290 			}
291 			rc[i].max4msframelen =
292 			    ath_max_4ms_framelen[j][HT_RC_2_MCS(rate)];
293 		} else
294 			rc[i].max4msframelen = 0;
295 		DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
296 		    "%s: i=%d, rate=0x%x, flags=0x%x, max4ms=%d\n",
297 		    __func__, i, rate, rc[i].flags, rc[i].max4msframelen);
298 	}
299 }
300 
301 /*
302  * Return the number of delimiters to be added to
303  * meet the minimum required mpdudensity.
304  *
305  * Caller should make sure that the rate is HT.
306  *
307  * TODO: is this delimiter calculation supposed to be the
308  * total frame length, the hdr length, the data length (including
309  * delimiters, padding, CRC, etc) or ?
310  *
311  * TODO: this should ensure that the rate control information
312  * HAS been setup for the first rate.
313  *
314  * TODO: ensure this is only called for MCS rates.
315  *
316  * TODO: enforce MCS < 31
317  */
318 static int
319 ath_compute_num_delims(struct ath_softc *sc, struct ath_buf *first_bf,
320     uint16_t pktlen)
321 {
322 	const HAL_RATE_TABLE *rt = sc->sc_currates;
323 	struct ieee80211_node *ni = first_bf->bf_node;
324 	struct ieee80211vap *vap = ni->ni_vap;
325 	int ndelim, mindelim = 0;
326 	int mpdudensity;	 /* in 1/100'th of a microsecond */
327 	uint8_t rc, rix, flags;
328 	int width, half_gi;
329 	uint32_t nsymbits, nsymbols;
330 	uint16_t minlen;
331 
332 	/*
333 	 * vap->iv_ampdu_density is a value, rather than the actual
334 	 * density.
335 	 */
336 	if (vap->iv_ampdu_density > IEEE80211_HTCAP_MPDUDENSITY_16)
337 		mpdudensity = 1600;		/* maximum density */
338 	else
339 		mpdudensity = ieee80211_mpdudensity_map[vap->iv_ampdu_density];
340 
341 	/* Select standard number of delimiters based on frame length */
342 	ndelim = ATH_AGGR_GET_NDELIM(pktlen);
343 
344 	/*
345 	 * If encryption is enabled, add extra delimiters to let the
346 	 * crypto hardware catch up. This could be tuned per-MAC and
347 	 * per-rate, but for now we'll simply assume encryption is
348 	 * always enabled.
349 	 */
350 	ndelim += ATH_AGGR_ENCRYPTDELIM;
351 
352 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
353 	    "%s: pktlen=%d, ndelim=%d, mpdudensity=%d\n",
354 	    __func__, pktlen, ndelim, mpdudensity);
355 
356 	/*
357 	 * If the MPDU density is 0, we can return here.
358 	 * Otherwise, we need to convert the desired mpdudensity
359 	 * into a byte length, based on the rate in the subframe.
360 	 */
361 	if (mpdudensity == 0)
362 		return ndelim;
363 
364 	/*
365 	 * Convert desired mpdu density from microeconds to bytes based
366 	 * on highest rate in rate series (i.e. first rate) to determine
367 	 * required minimum length for subframe. Take into account
368 	 * whether high rate is 20 or 40Mhz and half or full GI.
369 	 */
370 	rix = first_bf->bf_state.bfs_rc[0].rix;
371 	rc = rt->info[rix].rateCode;
372 	flags = first_bf->bf_state.bfs_rc[0].flags;
373 	width = !! (flags & ATH_RC_CW40_FLAG);
374 	half_gi = !! (flags & ATH_RC_SGI_FLAG);
375 
376 	/*
377 	 * mpdudensity is in 1/100th of a usec, so divide by 100
378 	 */
379 	if (half_gi)
380 		nsymbols = NUM_SYMBOLS_PER_USEC_HALFGI(mpdudensity);
381 	else
382 		nsymbols = NUM_SYMBOLS_PER_USEC(mpdudensity);
383 	nsymbols /= 100;
384 
385 	if (nsymbols == 0)
386 		nsymbols = 1;
387 
388 	nsymbits = bits_per_symbol[HT_RC_2_MCS(rc)][width];
389 	minlen = (nsymbols * nsymbits) / BITS_PER_BYTE;
390 
391 	/*
392 	 * Min length is the minimum frame length for the
393 	 * required MPDU density.
394 	 */
395 	if (pktlen < minlen) {
396 		mindelim = (minlen - pktlen) / ATH_AGGR_DELIM_SZ;
397 		ndelim = MAX(mindelim, ndelim);
398 	}
399 
400 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
401 	    "%s: pktlen=%d, minlen=%d, rix=%x, rc=%x, width=%d, hgi=%d, ndelim=%d\n",
402 	    __func__, pktlen, minlen, rix, rc, width, half_gi, ndelim);
403 
404 	return ndelim;
405 }
406 
407 /*
408  * Fetch the aggregation limit.
409  *
410  * It's the lowest of the four rate series 4ms frame length.
411  */
412 static int
413 ath_get_aggr_limit(struct ath_softc *sc, struct ath_buf *bf)
414 {
415 	int amin = 65530;
416 	int i;
417 
418 	for (i = 0; i < ATH_RC_NUM; i++) {
419 		if (bf->bf_state.bfs_rc[i].tries == 0)
420 			continue;
421 		amin = MIN(amin, bf->bf_state.bfs_rc[i].max4msframelen);
422 	}
423 
424 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR, "%s: max frame len= %d\n",
425 	    __func__, amin);
426 
427 	return amin;
428 }
429 
430 /*
431  * Setup a 11n rate series structure
432  *
433  * This should be called for both legacy and MCS rates.
434  *
435  * It, along with ath_buf_set_rate, must be called -after- a burst
436  * or aggregate is setup.
437  */
438 static void
439 ath_rateseries_setup(struct ath_softc *sc, struct ieee80211_node *ni,
440     struct ath_buf *bf, HAL_11N_RATE_SERIES *series)
441 {
442 	struct ieee80211com *ic = ni->ni_ic;
443 	struct ath_hal *ah = sc->sc_ah;
444 	HAL_BOOL shortPreamble = AH_FALSE;
445 	const HAL_RATE_TABLE *rt = sc->sc_currates;
446 	int i;
447 	int pktlen;
448 	int flags = bf->bf_state.bfs_txflags;
449 	struct ath_rc_series *rc = bf->bf_state.bfs_rc;
450 
451 	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
452 	    (ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE))
453 		shortPreamble = AH_TRUE;
454 
455 	/*
456 	 * If this is the first frame in an aggregate series,
457 	 * use the aggregate length.
458 	 */
459 	if (bf->bf_state.bfs_aggr)
460 		pktlen = bf->bf_state.bfs_al;
461 	else
462 		pktlen = bf->bf_state.bfs_pktlen;
463 
464 	/*
465 	 * XXX TODO: modify this routine to use the bfs_rc[x].flags
466 	 * XXX fields.
467 	 */
468 	memset(series, 0, sizeof(HAL_11N_RATE_SERIES) * 4);
469 	for (i = 0; i < ATH_RC_NUM;  i++) {
470 		/* Only set flags for actual TX attempts */
471 		if (rc[i].tries == 0)
472 			continue;
473 
474 		series[i].Tries = rc[i].tries;
475 
476 		/*
477 		 * XXX this isn't strictly correct - sc_txchainmask
478 		 * XXX isn't the currently active chainmask;
479 		 * XXX it's the interface chainmask at startup.
480 		 * XXX It's overridden in the HAL rate scenario function
481 		 * XXX for now.
482 		 */
483 		series[i].ChSel = sc->sc_txchainmask;
484 
485 		if (flags & (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
486 			series[i].RateFlags |= HAL_RATESERIES_RTS_CTS;
487 
488 		/*
489 		 * Transmit 40MHz frames only if the node has negotiated
490 		 * it rather than whether the node is capable of it or not.
491 	 	 * It's subtly different in the hostap case.
492 	 	 */
493 		if (ni->ni_chw == 40)
494 			series[i].RateFlags |= HAL_RATESERIES_2040;
495 
496 		/*
497 		 * Set short-GI only if the node has advertised it
498 		 * the channel width is suitable, and we support it.
499 		 * We don't currently have a "negotiated" set of bits -
500 		 * ni_htcap is what the remote end sends, not what this
501 		 * node is capable of.
502 		 */
503 		if (ni->ni_chw == 40 &&
504 		    ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
505 		    ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40)
506 			series[i].RateFlags |= HAL_RATESERIES_HALFGI;
507 
508 		if (ni->ni_chw == 20 &&
509 		    ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
510 		    ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20)
511 			series[i].RateFlags |= HAL_RATESERIES_HALFGI;
512 
513 		series[i].Rate = rt->info[rc[i].rix].rateCode;
514 		series[i].RateIndex = rc[i].rix;
515 		series[i].tx_power_cap = 0x3f;	/* XXX for now */
516 
517 		/*
518 		 * PktDuration doesn't include slot, ACK, RTS, etc timing -
519 		 * it's just the packet duration
520 		 */
521 		if (series[i].Rate & IEEE80211_RATE_MCS) {
522 			series[i].PktDuration =
523 			    ath_computedur_ht(pktlen
524 				, series[i].Rate
525 				, HT_RC_2_STREAMS(series[i].Rate)
526 				, series[i].RateFlags & HAL_RATESERIES_2040
527 				, series[i].RateFlags & HAL_RATESERIES_HALFGI);
528 		} else {
529 			if (shortPreamble)
530 				series[i].Rate |=
531 				    rt->info[rc[i].rix].shortPreamble;
532 			series[i].PktDuration = ath_hal_computetxtime(ah,
533 			    rt, pktlen, rc[i].rix, shortPreamble);
534 		}
535 	}
536 }
537 
538 #if 0
539 static void
540 ath_rateseries_print(struct ath_softc *sc, HAL_11N_RATE_SERIES *series)
541 {
542 	int i;
543 	for (i = 0; i < ATH_RC_NUM; i++) {
544 		device_printf(sc->sc_dev ,"series %d: rate %x; tries %d; "
545 		    "pktDuration %d; chSel %d; rateFlags %x\n",
546 		    i,
547 		    series[i].Rate,
548 		    series[i].Tries,
549 		    series[i].PktDuration,
550 		    series[i].ChSel,
551 		    series[i].RateFlags);
552 	}
553 }
554 #endif
555 
556 /*
557  * Setup the 11n rate scenario and burst duration for the given TX descriptor
558  * list.
559  *
560  * This isn't useful for sending beacon frames, which has different needs
561  * wrt what's passed into the rate scenario function.
562  */
563 void
564 ath_buf_set_rate(struct ath_softc *sc, struct ieee80211_node *ni,
565     struct ath_buf *bf)
566 {
567 	HAL_11N_RATE_SERIES series[4];
568 	struct ath_desc *ds = bf->bf_desc;
569 	struct ath_hal *ah = sc->sc_ah;
570 	int is_pspoll = (bf->bf_state.bfs_atype == HAL_PKT_TYPE_PSPOLL);
571 	int ctsrate = bf->bf_state.bfs_ctsrate;
572 	int flags = bf->bf_state.bfs_txflags;
573 
574 	/* Setup rate scenario */
575 	memset(&series, 0, sizeof(series));
576 
577 	ath_rateseries_setup(sc, ni, bf, series);
578 
579 #if 0
580 	printf("pktlen: %d; flags 0x%x\n", pktlen, flags);
581 	ath_rateseries_print(sc, series);
582 #endif
583 
584 	/* Set rate scenario */
585 	/*
586 	 * Note: Don't allow hardware to override the duration on
587 	 * ps-poll packets.
588 	 */
589 	ath_hal_set11nratescenario(ah, ds,
590 	    !is_pspoll,	/* whether to override the duration or not */
591 	    ctsrate,	/* rts/cts rate */
592 	    series,	/* 11n rate series */
593 	    4,		/* number of series */
594 	    flags);
595 
596 	/* Set burst duration */
597 	/*
598 	 * This is only required when doing 11n burst, not aggregation
599 	 * ie, if there's a second frame in a RIFS or A-MPDU burst
600 	 * w/ >1 A-MPDU frame bursting back to back.
601 	 * Normal A-MPDU doesn't do bursting -between- aggregates.
602 	 *
603 	 * .. and it's highly likely this won't ever be implemented
604 	 */
605 	//ath_hal_set11nburstduration(ah, ds, 8192);
606 }
607 
608 /*
609  * Form an aggregate packet list.
610  *
611  * This function enforces the aggregate restrictions/requirements.
612  *
613  * These are:
614  *
615  * + The aggregate size maximum (64k for AR9160 and later, 8K for
616  *   AR5416 when doing RTS frame protection.)
617  * + Maximum number of sub-frames for an aggregate
618  * + The aggregate delimiter size, giving MACs time to do whatever is
619  *   needed before each frame
620  * + Enforce the BAW limit
621  *
622  * Each descriptor queued should have the DMA setup.
623  * The rate series, descriptor setup, linking, etc is all done
624  * externally. This routine simply chains them together.
625  * ath_tx_setds_11n() will take care of configuring the per-
626  * descriptor setup, and ath_buf_set_rate() will configure the
627  * rate control.
628  *
629  * The TID lock is required for the entirety of this function.
630  *
631  * If some code in another thread adds to the head of this
632  * list, very strange behaviour will occur. Since retransmission is the
633  * only reason this will occur, and this routine is designed to be called
634  * from within the scheduler task, it won't ever clash with the completion
635  * task.
636  *
637  * So if you want to call this from an upper layer context (eg, to direct-
638  * dispatch aggregate frames to the hardware), please keep this in mind.
639  */
640 ATH_AGGR_STATUS
641 ath_tx_form_aggr(struct ath_softc *sc, struct ath_node *an,
642     struct ath_tid *tid, ath_bufhead *bf_q)
643 {
644 	//struct ieee80211_node *ni = &an->an_node;
645 	struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
646 	int nframes = 0;
647 	uint16_t aggr_limit = 0, al = 0, bpad = 0, al_delta, h_baw;
648 	struct ieee80211_tx_ampdu *tap;
649 	int status = ATH_AGGR_DONE;
650 	int prev_frames = 0;	/* XXX for AR5416 burst, not done here */
651 	int prev_al = 0;	/* XXX also for AR5416 burst */
652 
653 	ATH_TXQ_LOCK_ASSERT(sc->sc_ac2q[tid->ac]);
654 
655 	tap = ath_tx_get_tx_tid(an, tid->tid);
656 	if (tap == NULL) {
657 		status = ATH_AGGR_ERROR;
658 		goto finish;
659 	}
660 
661 	h_baw = tap->txa_wnd / 2;
662 
663 	for (;;) {
664 		bf = ATH_TID_FIRST(tid);
665 		if (bf_first == NULL)
666 			bf_first = bf;
667 		if (bf == NULL) {
668 			status = ATH_AGGR_DONE;
669 			break;
670 		} else {
671 			/*
672 			 * It's the first frame;
673 			 * set the aggregation limit based on the
674 			 * rate control decision that has been made.
675 			 */
676 			aggr_limit = ath_get_aggr_limit(sc, bf_first);
677 		}
678 
679 		/* Set this early just so things don't get confused */
680 		bf->bf_next = NULL;
681 
682 		/*
683 		 * Don't unlock the tid lock until we're sure we are going
684 		 * to queue this frame.
685 		 */
686 
687 		/*
688 		 * If the frame doesn't have a sequence number that we're
689 		 * tracking in the BAW (eg NULL QOS data frame), we can't
690 		 * aggregate it. Stop the aggregation process; the sender
691 		 * can then TX what's in the list thus far and then
692 		 * TX the frame individually.
693 		 */
694 		if (! bf->bf_state.bfs_dobaw) {
695 			status = ATH_AGGR_NONAGGR;
696 			break;
697 		}
698 
699 		/*
700 		 * If any of the rates are non-HT, this packet
701 		 * can't be aggregated.
702 		 * XXX TODO: add a bf_state flag which gets marked
703 		 * if any active rate is non-HT.
704 		 */
705 
706 		/*
707 		 * do not exceed aggregation limit
708 		 */
709 		al_delta = ATH_AGGR_DELIM_SZ + bf->bf_state.bfs_pktlen;
710 		if (nframes &&
711 		    (aggr_limit < (al + bpad + al_delta + prev_al))) {
712 			status = ATH_AGGR_LIMITED;
713 			break;
714 		}
715 
716 		/*
717 		 * If RTS/CTS is set on the first frame, enforce
718 		 * the RTS aggregate limit.
719 		 */
720 		if (bf_first->bf_state.bfs_txflags &
721 		    (HAL_TXDESC_CTSENA | HAL_TXDESC_RTSENA)) {
722 			if (nframes &&
723 			   (sc->sc_rts_aggr_limit <
724 			     (al + bpad + al_delta + prev_al))) {
725 				status = ATH_AGGR_8K_LIMITED;
726 				break;
727 			}
728 		}
729 
730 		/*
731 		 * Do not exceed subframe limit.
732 		 */
733 		if ((nframes + prev_frames) >= MIN((h_baw),
734 		    IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
735 			status = ATH_AGGR_LIMITED;
736 			break;
737 		}
738 
739 		/*
740 		 * If the current frame has an RTS/CTS configuration
741 		 * that differs from the first frame, override the
742 		 * subsequent frame with this config.
743 		 */
744 		bf->bf_state.bfs_txflags &=
745 		    ~ (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
746 		bf->bf_state.bfs_txflags |=
747 		    bf_first->bf_state.bfs_txflags &
748 		    (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
749 
750 		/*
751 		 * If the packet has a sequence number, do not
752 		 * step outside of the block-ack window.
753 		 */
754 		if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
755 		    SEQNO(bf->bf_state.bfs_seqno))) {
756 			status = ATH_AGGR_BAW_CLOSED;
757 			break;
758 		}
759 
760 		/*
761 		 * this packet is part of an aggregate.
762 		 */
763 		ATH_TID_REMOVE(tid, bf, bf_list);
764 
765 		/* The TID lock is required for the BAW update */
766 		ath_tx_addto_baw(sc, an, tid, bf);
767 		bf->bf_state.bfs_addedbaw = 1;
768 
769 		/*
770 		 * XXX enforce ACK for aggregate frames (this needs to be
771 		 * XXX handled more gracefully?
772 		 */
773 		if (bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) {
774 			device_printf(sc->sc_dev,
775 			    "%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
776 			    __func__);
777 			bf->bf_state.bfs_txflags &= (~HAL_TXDESC_NOACK);
778 		}
779 
780 		/*
781 		 * Add the now owned buffer (which isn't
782 		 * on the software TXQ any longer) to our
783 		 * aggregate frame list.
784 		 */
785 		TAILQ_INSERT_TAIL(bf_q, bf, bf_list);
786 		nframes ++;
787 
788 		/* Completion handler */
789 		bf->bf_comp = ath_tx_aggr_comp;
790 
791 		/*
792 		 * add padding for previous frame to aggregation length
793 		 */
794 		al += bpad + al_delta;
795 
796 		/*
797 		 * Calculate delimiters needed for the current frame
798 		 */
799 		bf->bf_state.bfs_ndelim =
800 		    ath_compute_num_delims(sc, bf_first,
801 		    bf->bf_state.bfs_pktlen);
802 
803 		/*
804 		 * Calculate the padding needed from this set of delimiters,
805 		 * used when calculating if the next frame will fit in
806 		 * the aggregate.
807 		 */
808 		bpad = PADBYTES(al_delta) + (bf->bf_state.bfs_ndelim << 2);
809 
810 		/*
811 		 * Chain the buffers together
812 		 */
813 		if (bf_prev)
814 			bf_prev->bf_next = bf;
815 		bf_prev = bf;
816 
817 		/*
818 		 * XXX TODO: if any sub-frames have RTS/CTS enabled;
819 		 * enable it for the entire aggregate.
820 		 */
821 
822 #if 0
823 		/*
824 		 * terminate aggregation on a small packet boundary
825 		 */
826 		if (bf->bf_state.bfs_pktlen < ATH_AGGR_MINPLEN) {
827 			status = ATH_AGGR_SHORTPKT;
828 			break;
829 		}
830 #endif
831 
832 	}
833 
834 finish:
835 	/*
836 	 * Just in case the list was empty when we tried to
837 	 * dequeue a packet ..
838 	 */
839 	if (bf_first) {
840 		bf_first->bf_state.bfs_al = al;
841 		bf_first->bf_state.bfs_nframes = nframes;
842 	}
843 	return status;
844 }
845