xref: /freebsd/sys/dev/ath/if_ath_tx_ht.c (revision 70e0bbedef95258a4dadc996d641a9bebd3f107d)
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 #define	ATH_AGGR_ENCRYPTDELIM	10	/* number of delimiters for encryption padding */
102 
103 /*
104  * returns delimiter padding required given the packet length
105  */
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)
109 
110 #define	PADBYTES(_len)		((4 - ((_len) % 4)) % 4)
111 
112 int ath_max_4ms_framelen[4][32] = {
113 	[MCS_HT20] = {
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,
118 	},
119 	[MCS_HT20_SGI] = {
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,
124 	},
125 	[MCS_HT40] = {
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,
130 	},
131 	[MCS_HT40_SGI] = {
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,
136 	}
137 };
138 
139 /*
140  * XXX should be in net80211
141  */
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 */
151 };
152 
153 /*
154  * XXX should be in the HAL/net80211 ?
155  */
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)
160 #define	L_STF			8
161 #define	L_LTF			8
162 #define	L_SIG			4
163 #define	HT_SIG			8
164 #define	HT_STF			4
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)
171 
172 const uint32_t bits_per_symbol[][2] = {
173     /* 20MHz 40MHz */
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
206 };
207 
208 /*
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.
212  *
213  * Later on, this may end up also being made by the
214  * rate control code, but for now it can live here.
215  *
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.
219  */
220 void
221 ath_tx_rate_fill_rcflags(struct ath_softc *sc, struct ath_buf *bf)
222 {
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;
227 	uint8_t rate;
228 	int i;
229 
230 	for (i = 0; i < ATH_RC_NUM; i++) {
231 		rc[i].flags = 0;
232 		if (rc[i].tries == 0)
233 			continue;
234 
235 		rate = rt->info[rc[i].rix].rateCode;
236 
237 		/*
238 		 * XXX only do this for legacy rates?
239 		 */
240 		if (bf->bf_state.bfs_shpream)
241 			rate |= rt->info[rc[i].rix].shortPreamble;
242 
243 		/*
244 		 * Save this, used by the TX and completion code
245 		 */
246 		rc[i].ratecode = rate;
247 
248 		if (bf->bf_state.bfs_flags &
249 		    (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
250 			rc[i].flags |= ATH_RC_RTSCTS_FLAG;
251 
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;
255 
256 			if (ni->ni_chw == 40)
257 				rc[i].flags |= ATH_RC_CW40_FLAG;
258 
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;
263 
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;
268 
269 			/* XXX dual stream? and 3-stream? */
270 		}
271 
272 		/*
273 		 * Calculate the maximum 4ms frame length based
274 		 * on the MCS rate, SGI and channel width flags.
275 		 */
276 		if ((rc[i].flags & ATH_RC_HT_FLAG) &&
277 		    (HT_RC_2_MCS(rate) < 32)) {
278 			int j;
279 			if (rc[i].flags & ATH_RC_CW40_FLAG) {
280 				if (rc[i].flags & ATH_RC_SGI_FLAG)
281 					j = MCS_HT40_SGI;
282 				else
283 					j = MCS_HT40;
284 			} else {
285 				if (rc[i].flags & ATH_RC_SGI_FLAG)
286 					j = MCS_HT20_SGI;
287 				else
288 					j = MCS_HT20;
289 			}
290 			rc[i].max4msframelen =
291 			    ath_max_4ms_framelen[j][HT_RC_2_MCS(rate)];
292 		} else
293 			rc[i].max4msframelen = 0;
294 		DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
295 		    "%s: i=%d, rate=0x%x, flags=0x%x, max4ms=%d\n",
296 		    __func__, i, rate, rc[i].flags, rc[i].max4msframelen);
297 	}
298 }
299 
300 /*
301  * Return the number of delimiters to be added to
302  * meet the minimum required mpdudensity.
303  *
304  * Caller should make sure that the rate is HT.
305  *
306  * TODO: is this delimiter calculation supposed to be the
307  * total frame length, the hdr length, the data length (including
308  * delimiters, padding, CRC, etc) or ?
309  *
310  * TODO: this should ensure that the rate control information
311  * HAS been setup for the first rate.
312  *
313  * TODO: ensure this is only called for MCS rates.
314  *
315  * TODO: enforce MCS < 31
316  */
317 static int
318 ath_compute_num_delims(struct ath_softc *sc, struct ath_buf *first_bf,
319     uint16_t pktlen)
320 {
321 	const HAL_RATE_TABLE *rt = sc->sc_currates;
322 	struct ieee80211_node *ni = first_bf->bf_node;
323 	struct ieee80211vap *vap = ni->ni_vap;
324 	int ndelim, mindelim = 0;
325 	int mpdudensity;	 /* in 1/100'th of a microsecond */
326 	uint8_t rc, rix, flags;
327 	int width, half_gi;
328 	uint32_t nsymbits, nsymbols;
329 	uint16_t minlen;
330 
331 	/*
332 	 * vap->iv_ampdu_density is a value, rather than the actual
333 	 * density.
334 	 */
335 	if (vap->iv_ampdu_density > IEEE80211_HTCAP_MPDUDENSITY_16)
336 		mpdudensity = 1600;		/* maximum density */
337 	else
338 		mpdudensity = ieee80211_mpdudensity_map[vap->iv_ampdu_density];
339 
340 	/* Select standard number of delimiters based on frame length */
341 	ndelim = ATH_AGGR_GET_NDELIM(pktlen);
342 
343 	/*
344 	 * If encryption is enabled, add extra delimiters to let the
345 	 * crypto hardware catch up. This could be tuned per-MAC and
346 	 * per-rate, but for now we'll simply assume encryption is
347 	 * always enabled.
348 	 */
349 	ndelim += ATH_AGGR_ENCRYPTDELIM;
350 
351 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
352 	    "%s: pktlen=%d, ndelim=%d, mpdudensity=%d\n",
353 	    __func__, pktlen, ndelim, mpdudensity);
354 
355 	/*
356 	 * If the MPDU density is 0, we can return here.
357 	 * Otherwise, we need to convert the desired mpdudensity
358 	 * into a byte length, based on the rate in the subframe.
359 	 */
360 	if (mpdudensity == 0)
361 		return ndelim;
362 
363 	/*
364 	 * Convert desired mpdu density from microeconds to bytes based
365 	 * on highest rate in rate series (i.e. first rate) to determine
366 	 * required minimum length for subframe. Take into account
367 	 * whether high rate is 20 or 40Mhz and half or full GI.
368 	 */
369 	rix = first_bf->bf_state.bfs_rc[0].rix;
370 	rc = rt->info[rix].rateCode;
371 	flags = first_bf->bf_state.bfs_rc[0].flags;
372 	width = !! (flags & ATH_RC_CW40_FLAG);
373 	half_gi = !! (flags & ATH_RC_SGI_FLAG);
374 
375 	/*
376 	 * mpdudensity is in 1/100th of a usec, so divide by 100
377 	 */
378 	if (half_gi)
379 		nsymbols = NUM_SYMBOLS_PER_USEC_HALFGI(mpdudensity);
380 	else
381 		nsymbols = NUM_SYMBOLS_PER_USEC(mpdudensity);
382 	nsymbols /= 100;
383 
384 	if (nsymbols == 0)
385 		nsymbols = 1;
386 
387 	nsymbits = bits_per_symbol[HT_RC_2_MCS(rc)][width];
388 	minlen = (nsymbols * nsymbits) / BITS_PER_BYTE;
389 
390 	/*
391 	 * Min length is the minimum frame length for the
392 	 * required MPDU density.
393 	 */
394 	if (pktlen < minlen) {
395 		mindelim = (minlen - pktlen) / ATH_AGGR_DELIM_SZ;
396 		ndelim = MAX(mindelim, ndelim);
397 	}
398 
399 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
400 	    "%s: pktlen=%d, minlen=%d, rix=%x, rc=%x, width=%d, hgi=%d, ndelim=%d\n",
401 	    __func__, pktlen, minlen, rix, rc, width, half_gi, ndelim);
402 
403 	return ndelim;
404 }
405 
406 /*
407  * Fetch the aggregation limit.
408  *
409  * It's the lowest of the four rate series 4ms frame length.
410  */
411 static int
412 ath_get_aggr_limit(struct ath_softc *sc, struct ath_buf *bf)
413 {
414 	int amin = 65530;
415 	int i;
416 
417 	for (i = 0; i < 4; i++) {
418 		if (bf->bf_state.bfs_rc[i].tries == 0)
419 			continue;
420 		amin = MIN(amin, bf->bf_state.bfs_rc[i].max4msframelen);
421 	}
422 
423 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR, "%s: max frame len= %d\n",
424 	    __func__, amin);
425 
426 	return amin;
427 }
428 
429 /*
430  * Setup a 11n rate series structure
431  *
432  * This should be called for both legacy and MCS rates.
433  *
434  * It, along with ath_buf_set_rate, must be called -after- a burst
435  * or aggregate is setup.
436  */
437 static void
438 ath_rateseries_setup(struct ath_softc *sc, struct ieee80211_node *ni,
439     struct ath_buf *bf, HAL_11N_RATE_SERIES *series)
440 {
441 #define	HT_RC_2_STREAMS(_rc)	((((_rc) & 0x78) >> 3) + 1)
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_flags;
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 < 4;  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 
515 		/* PktDuration doesn't include slot, ACK, RTS, etc timing - it's just the packet duration */
516 		if (series[i].Rate & IEEE80211_RATE_MCS) {
517 			series[i].PktDuration =
518 			    ath_computedur_ht(pktlen
519 				, series[i].Rate
520 				, HT_RC_2_STREAMS(series[i].Rate)
521 				, series[i].RateFlags & HAL_RATESERIES_2040
522 				, series[i].RateFlags & HAL_RATESERIES_HALFGI);
523 		} else {
524 			if (shortPreamble)
525 				series[i].Rate |=
526 				    rt->info[rc[i].rix].shortPreamble;
527 			series[i].PktDuration = ath_hal_computetxtime(ah,
528 			    rt, pktlen, rc[i].rix, shortPreamble);
529 		}
530 	}
531 #undef	HT_RC_2_STREAMS
532 }
533 
534 #if 0
535 static void
536 ath_rateseries_print(HAL_11N_RATE_SERIES *series)
537 {
538 	int i;
539 	for (i = 0; i < 4; i++) {
540 		printf("series %d: rate %x; tries %d; pktDuration %d; chSel %d; rateFlags %x\n",
541 		    i,
542 		    series[i].Rate,
543 		    series[i].Tries,
544 		    series[i].PktDuration,
545 		    series[i].ChSel,
546 		    series[i].RateFlags);
547 	}
548 }
549 #endif
550 
551 /*
552  * Setup the 11n rate scenario and burst duration for the given TX descriptor
553  * list.
554  *
555  * This isn't useful for sending beacon frames, which has different needs
556  * wrt what's passed into the rate scenario function.
557  */
558 
559 void
560 ath_buf_set_rate(struct ath_softc *sc, struct ieee80211_node *ni,
561     struct ath_buf *bf)
562 {
563 	HAL_11N_RATE_SERIES series[4];
564 	struct ath_desc *ds = bf->bf_desc;
565 	struct ath_desc *lastds = NULL;
566 	struct ath_hal *ah = sc->sc_ah;
567 	int is_pspoll = (bf->bf_state.bfs_atype == HAL_PKT_TYPE_PSPOLL);
568 	int ctsrate = bf->bf_state.bfs_ctsrate;
569 	int flags = bf->bf_state.bfs_flags;
570 
571 	/* Setup rate scenario */
572 	memset(&series, 0, sizeof(series));
573 
574 	ath_rateseries_setup(sc, ni, bf, series);
575 
576 	/* Enforce AR5416 aggregate limit - can't do RTS w/ an agg frame > 8k */
577 
578 	/* Enforce RTS and CTS are mutually exclusive */
579 
580 	/* Get a pointer to the last tx descriptor in the list */
581 	lastds = bf->bf_lastds;
582 
583 #if 0
584 	printf("pktlen: %d; flags 0x%x\n", pktlen, flags);
585 	ath_rateseries_print(series);
586 #endif
587 
588 	/* Set rate scenario */
589 	ath_hal_set11nratescenario(ah, ds,
590 	    !is_pspoll,	/* whether to override the duration or not */
591 			/* don't allow hardware to override the duration on ps-poll packets */
592 	    ctsrate,	/* rts/cts rate */
593 	    series,	/* 11n rate series */
594 	    4,		/* number of series */
595 	    flags);
596 
597 	/* Setup the last descriptor in the chain */
598 	ath_hal_setuplasttxdesc(ah, lastds, ds);
599 
600 	/* Set burst duration */
601 	/*
602 	 * This is only required when doing 11n burst, not aggregation
603 	 * ie, if there's a second frame in a RIFS or A-MPDU burst
604 	 * w/ >1 A-MPDU frame bursting back to back.
605 	 * Normal A-MPDU doesn't do bursting -between- aggregates.
606 	 *
607 	 * .. and it's highly likely this won't ever be implemented
608 	 */
609 	//ath_hal_set11nburstduration(ah, ds, 8192);
610 }
611 
612 /*
613  * Form an aggregate packet list.
614  *
615  * This function enforces the aggregate restrictions/requirements.
616  *
617  * These are:
618  *
619  * + The aggregate size maximum (64k for AR9160 and later, 8K for
620  *   AR5416 when doing RTS frame protection.)
621  * + Maximum number of sub-frames for an aggregate
622  * + The aggregate delimiter size, giving MACs time to do whatever is
623  *   needed before each frame
624  * + Enforce the BAW limit
625  *
626  * Each descriptor queued should have the DMA setup.
627  * The rate series, descriptor setup, linking, etc is all done
628  * externally. This routine simply chains them together.
629  * ath_tx_setds_11n() will take care of configuring the per-
630  * descriptor setup, and ath_buf_set_rate() will configure the
631  * rate control.
632  *
633  * Note that the TID lock is only grabbed when dequeuing packets from
634  * the TID queue. If some code in another thread adds to the head of this
635  * list, very strange behaviour will occur. Since retransmission is the
636  * only reason this will occur, and this routine is designed to be called
637  * from within the scheduler task, it won't ever clash with the completion
638  * task.
639  *
640  * So if you want to call this from an upper layer context (eg, to direct-
641  * dispatch aggregate frames to the hardware), please keep this in mind.
642  */
643 ATH_AGGR_STATUS
644 ath_tx_form_aggr(struct ath_softc *sc, struct ath_node *an, struct ath_tid *tid,
645     ath_bufhead *bf_q)
646 {
647 	//struct ieee80211_node *ni = &an->an_node;
648 	struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
649 	int nframes = 0;
650 	uint16_t aggr_limit = 0, al = 0, bpad = 0, al_delta, h_baw;
651 	struct ieee80211_tx_ampdu *tap;
652 	int status = ATH_AGGR_DONE;
653 	int prev_frames = 0;	/* XXX for AR5416 burst, not done here */
654 	int prev_al = 0;	/* XXX also for AR5416 burst */
655 
656 	ATH_TXQ_LOCK_ASSERT(sc->sc_ac2q[tid->ac]);
657 
658 	tap = ath_tx_get_tx_tid(an, tid->tid);
659 	if (tap == NULL) {
660 		status = ATH_AGGR_ERROR;
661 		goto finish;
662 	}
663 
664 	h_baw = tap->txa_wnd / 2;
665 
666 	for (;;) {
667 		bf = TAILQ_FIRST(&tid->axq_q);
668 		if (bf_first == NULL)
669 			bf_first = bf;
670 		if (bf == NULL) {
671 			status = ATH_AGGR_DONE;
672 			break;
673 		} else {
674 			/*
675 			 * It's the first frame;
676 			 * set the aggregation limit based on the
677 			 * rate control decision that has been made.
678 			 */
679 			aggr_limit = ath_get_aggr_limit(sc, bf_first);
680 		}
681 
682 		/* Set this early just so things don't get confused */
683 		bf->bf_next = NULL;
684 
685 		/*
686 		 * Don't unlock the tid lock until we're sure we are going
687 		 * to queue this frame.
688 		 */
689 
690 		/*
691 		 * If the frame doesn't have a sequence number that we're
692 		 * tracking in the BAW (eg NULL QOS data frame), we can't
693 		 * aggregate it. Stop the aggregation process; the sender
694 		 * can then TX what's in the list thus far and then
695 		 * TX the frame individually.
696 		 */
697 		if (! bf->bf_state.bfs_dobaw) {
698 			status = ATH_AGGR_NONAGGR;
699 			break;
700 		}
701 
702 		/*
703 		 * If any of the rates are non-HT, this packet
704 		 * can't be aggregated.
705 		 * XXX TODO: add a bf_state flag which gets marked
706 		 * if any active rate is non-HT.
707 		 */
708 
709 		/*
710 		 * If the packet has a sequence number, do not
711 		 * step outside of the block-ack window.
712 		 */
713 		if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
714 		    SEQNO(bf->bf_state.bfs_seqno))) {
715 		    status = ATH_AGGR_BAW_CLOSED;
716 		    break;
717 		}
718 
719 		/*
720 		 * XXX TODO: AR5416 has an 8K aggregation size limit
721 		 * when RTS is enabled, and RTS is required for dual-stream
722 		 * rates.
723 		 *
724 		 * For now, limit all aggregates for the AR5416 to be 8K.
725 		 */
726 
727 		/*
728 		 * do not exceed aggregation limit
729 		 */
730 		al_delta = ATH_AGGR_DELIM_SZ + bf->bf_state.bfs_pktlen;
731 		if (nframes &&
732 		    (aggr_limit < (al + bpad + al_delta + prev_al))) {
733 			status = ATH_AGGR_LIMITED;
734 			break;
735 		}
736 
737 		/*
738 		 * Do not exceed subframe limit.
739 		 */
740 		if ((nframes + prev_frames) >= MIN((h_baw),
741 		    IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
742 			status = ATH_AGGR_LIMITED;
743 			break;
744 		}
745 
746 		/*
747 		 * this packet is part of an aggregate.
748 		 */
749 		ATH_TXQ_REMOVE(tid, bf, bf_list);
750 
751 		/* The TID lock is required for the BAW update */
752 		ath_tx_addto_baw(sc, an, tid, bf);
753 		bf->bf_state.bfs_addedbaw = 1;
754 
755 		/*
756 		 * XXX TODO: If any frame in the aggregate requires RTS/CTS,
757 		 * set the first frame.
758 		 */
759 
760 		/*
761 		 * XXX enforce ACK for aggregate frames (this needs to be
762 		 * XXX handled more gracefully?
763 		 */
764 		if (bf->bf_state.bfs_flags & HAL_TXDESC_NOACK) {
765 			device_printf(sc->sc_dev,
766 			    "%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
767 			    __func__);
768 			bf->bf_state.bfs_flags &= (~HAL_TXDESC_NOACK);
769 		}
770 
771 		/*
772 		 * Add the now owned buffer (which isn't
773 		 * on the software TXQ any longer) to our
774 		 * aggregate frame list.
775 		 */
776 		TAILQ_INSERT_TAIL(bf_q, bf, bf_list);
777 		nframes ++;
778 
779 		/* Completion handler */
780 		bf->bf_comp = ath_tx_aggr_comp;
781 
782 		/*
783 		 * add padding for previous frame to aggregation length
784 		 */
785 		al += bpad + al_delta;
786 
787 		/*
788 		 * Calculate delimiters needed for the current frame
789 		 */
790 		bf->bf_state.bfs_ndelim =
791 		    ath_compute_num_delims(sc, bf_first,
792 		    bf->bf_state.bfs_pktlen);
793 
794 		/*
795 		 * Calculate the padding needed from this set of delimiters,
796 		 * used when calculating if the next frame will fit in
797 		 * the aggregate.
798 		 */
799 		bpad = PADBYTES(al_delta) + (bf->bf_state.bfs_ndelim << 2);
800 
801 		/*
802 		 * Chain the buffers together
803 		 */
804 		if (bf_prev)
805 			bf_prev->bf_next = bf;
806 		bf_prev = bf;
807 
808 		/*
809 		 * XXX TODO: if any sub-frames have RTS/CTS enabled;
810 		 * enable it for the entire aggregate.
811 		 */
812 
813 #if 0
814 		/*
815 		 * terminate aggregation on a small packet boundary
816 		 */
817 		if (bf->bf_state.bfs_pktlen < ATH_AGGR_MINPLEN) {
818 			status = ATH_AGGR_SHORTPKT;
819 			break;
820 		}
821 #endif
822 
823 	}
824 
825 finish:
826 	/*
827 	 * Just in case the list was empty when we tried to
828 	 * dequeue a packet ..
829 	 */
830 	if (bf_first) {
831 		bf_first->bf_state.bfs_al = al;
832 		bf_first->bf_state.bfs_nframes = nframes;
833 	}
834 	return status;
835 }
836