xref: /freebsd/sys/dev/ath/if_ath_tx_ht.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011 Adrian Chadd, Xenion Pty Ltd.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
14  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
15  *    redistribution must be conditioned upon including a substantially
16  *    similar Disclaimer requirement for further binary redistribution.
17  *
18  * NO WARRANTY
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
22  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
23  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
24  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
27  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
29  * THE POSSIBILITY OF SUCH DAMAGES.
30  */
31 
32 #include <sys/cdefs.h>
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 ieee80211vap *vap = ni->ni_vap;
226 	struct ieee80211com *ic = ni->ni_ic;
227 	const HAL_RATE_TABLE *rt = sc->sc_currates;
228 	struct ath_rc_series *rc = bf->bf_state.bfs_rc;
229 	uint8_t rate;
230 	int i;
231 	int do_ldpc;
232 	int do_stbc;
233 
234 	/*
235 	 * We only do LDPC if the rate is 11n, both we and the
236 	 * receiver support LDPC and it's enabled.
237 	 *
238 	 * It's a global flag, not a per-try flag, so we clear
239 	 * it if any of the rate entries aren't 11n.
240 	 */
241 	do_ldpc = 0;
242 	if ((ni->ni_vap->iv_flags_ht & IEEE80211_FHT_LDPC_TX) &&
243 	    (ni->ni_htcap & IEEE80211_HTCAP_LDPC))
244 		do_ldpc = 1;
245 
246 	/*
247 	 * The 11n duration calculation doesn't know about LDPC,
248 	 * so don't enable it for positioning.
249 	 */
250 	if (bf->bf_flags & ATH_BUF_TOA_PROBE)
251 		do_ldpc = 0;
252 
253 	do_stbc = 0;
254 
255 	for (i = 0; i < ATH_RC_NUM; i++) {
256 		rc[i].flags = 0;
257 		if (rc[i].tries == 0)
258 			continue;
259 
260 		rate = rt->info[rc[i].rix].rateCode;
261 
262 		/*
263 		 * Only enable short preamble for legacy rates
264 		 */
265 		if ((! IS_HT_RATE(rate)) && bf->bf_state.bfs_shpream)
266 			rate |= rt->info[rc[i].rix].shortPreamble;
267 
268 		/*
269 		 * Save this, used by the TX and completion code
270 		 */
271 		rc[i].ratecode = rate;
272 
273 		if (bf->bf_state.bfs_txflags &
274 		    (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
275 			rc[i].flags |= ATH_RC_RTSCTS_FLAG;
276 
277 		/*
278 		 * If we can't do LDPC, don't.
279 		 */
280 		if (! IS_HT_RATE(rate))
281 			do_ldpc = 0;
282 
283 		/* Only enable shortgi, 2040, dual-stream if HT is set */
284 		if (IS_HT_RATE(rate)) {
285 			rc[i].flags |= ATH_RC_HT_FLAG;
286 
287 			if (ni->ni_chw == 40)
288 				rc[i].flags |= ATH_RC_CW40_FLAG;
289 
290 			/*
291 			 * NOTE: Don't do short-gi for positioning frames.
292 			 *
293 			 * For now, the ath_hal and net80211 HT duration
294 			 * calculation rounds up the 11n data txtime
295 			 * to the nearest multiple of 3.6 microseconds
296 			 * and doesn't return the fractional part, so
297 			 * we are always "out" by some amount.
298 			 */
299 			if (ni->ni_chw == 40 &&
300 			    ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
301 			    ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40 &&
302 			    vap->iv_flags_ht & IEEE80211_FHT_SHORTGI40 &&
303 			    (bf->bf_flags & ATH_BUF_TOA_PROBE) == 0) {
304 				rc[i].flags |= ATH_RC_SGI_FLAG;
305 			}
306 
307 			if (ni->ni_chw == 20 &&
308 			    ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
309 			    ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20 &&
310 			    vap->iv_flags_ht & IEEE80211_FHT_SHORTGI20 &&
311 			    (bf->bf_flags & ATH_BUF_TOA_PROBE) == 0) {
312 				rc[i].flags |= ATH_RC_SGI_FLAG;
313 			}
314 
315 			/*
316 			 * If we have STBC TX enabled and the receiver
317 			 * can receive (at least) 1 stream STBC, AND it's
318 			 * MCS 0-7, AND we have at least two chains enabled,
319 			 * and we're not doing positioning, enable STBC.
320 			 */
321 			if (ic->ic_htcaps & IEEE80211_HTCAP_TXSTBC &&
322 			    (ni->ni_vap->iv_flags_ht & IEEE80211_FHT_STBC_TX) &&
323 			    (ni->ni_htcap & IEEE80211_HTCAP_RXSTBC) &&
324 			    (sc->sc_cur_txchainmask > 1) &&
325 			    (HT_RC_2_STREAMS(rate) == 1) &&
326 			    (bf->bf_flags & ATH_BUF_TOA_PROBE) == 0) {
327 				rc[i].flags |= ATH_RC_STBC_FLAG;
328 				do_stbc = 1;
329 			}
330 
331 			/*
332 			 * Dual / Triple stream rate?
333 			 */
334 			if (HT_RC_2_STREAMS(rate) == 2)
335 				rc[i].flags |= ATH_RC_DS_FLAG;
336 			else if (HT_RC_2_STREAMS(rate) == 3)
337 				rc[i].flags |= ATH_RC_TS_FLAG;
338 		}
339 
340 		/*
341 		 * Calculate the maximum TX power cap for the current
342 		 * node.
343 		 */
344 		rc[i].tx_power_cap = ieee80211_get_node_txpower(ni);
345 
346 		/*
347 		 * Calculate the maximum 4ms frame length based
348 		 * on the MCS rate, SGI and channel width flags.
349 		 */
350 		if ((rc[i].flags & ATH_RC_HT_FLAG) &&
351 		    (HT_RC_2_MCS(rate) < 32)) {
352 			int j;
353 			if (rc[i].flags & ATH_RC_CW40_FLAG) {
354 				if (rc[i].flags & ATH_RC_SGI_FLAG)
355 					j = MCS_HT40_SGI;
356 				else
357 					j = MCS_HT40;
358 			} else {
359 				if (rc[i].flags & ATH_RC_SGI_FLAG)
360 					j = MCS_HT20_SGI;
361 				else
362 					j = MCS_HT20;
363 			}
364 			rc[i].max4msframelen =
365 			    ath_max_4ms_framelen[j][HT_RC_2_MCS(rate)];
366 		} else
367 			rc[i].max4msframelen = 0;
368 		DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
369 		    "%s: i=%d, rate=0x%x, flags=0x%x, max4ms=%d\n",
370 		    __func__, i, rate, rc[i].flags, rc[i].max4msframelen);
371 	}
372 
373 	/*
374 	 * LDPC is a global flag, so ...
375 	 */
376 	if (do_ldpc) {
377 		bf->bf_state.bfs_txflags |= HAL_TXDESC_LDPC;
378 		sc->sc_stats.ast_tx_ldpc++;
379 	}
380 
381 	if (do_stbc) {
382 		sc->sc_stats.ast_tx_stbc++;
383 	}
384 }
385 
386 /*
387  * Return the number of delimiters to be added to
388  * meet the minimum required mpdudensity.
389  *
390  * Caller should make sure that the rate is HT.
391  *
392  * TODO: is this delimiter calculation supposed to be the
393  * total frame length, the hdr length, the data length (including
394  * delimiters, padding, CRC, etc) or ?
395  *
396  * TODO: this should ensure that the rate control information
397  * HAS been setup for the first rate.
398  *
399  * TODO: ensure this is only called for MCS rates.
400  *
401  * TODO: enforce MCS < 31
402  */
403 static int
404 ath_compute_num_delims(struct ath_softc *sc, struct ath_buf *first_bf,
405     uint16_t pktlen, int is_first)
406 {
407 	const HAL_RATE_TABLE *rt = sc->sc_currates;
408 	struct ieee80211_node *ni = first_bf->bf_node;
409 	struct ieee80211vap *vap = ni->ni_vap;
410 	int ndelim, mindelim = 0;
411 	int mpdudensity;	/* in 1/100'th of a microsecond */
412 	int peer_mpdudensity;	/* net80211 value */
413 	uint8_t rc, rix, flags;
414 	int width, half_gi;
415 	uint32_t nsymbits, nsymbols;
416 	uint16_t minlen;
417 
418 	/*
419 	 * Get the advertised density from the node.
420 	 */
421 	peer_mpdudensity =
422 	    _IEEE80211_MASKSHIFT(ni->ni_htparam, IEEE80211_HTCAP_MPDUDENSITY);
423 
424 	/*
425 	 * vap->iv_ampdu_density is a net80211 value, rather than the actual
426 	 * density.  Larger values are longer A-MPDU density spacing values,
427 	 * and we want to obey larger configured / negotiated density values
428 	 * per station if we get it.
429 	 */
430 	if (vap->iv_ampdu_density > peer_mpdudensity)
431 		peer_mpdudensity = vap->iv_ampdu_density;
432 
433 	/*
434 	 * Convert the A-MPDU density net80211 value to a 1/100 microsecond
435 	 * value for subsequent calculations.
436 	 */
437 	if (peer_mpdudensity > IEEE80211_HTCAP_MPDUDENSITY_16)
438 		mpdudensity = 1600;		/* maximum density */
439 	else
440 		mpdudensity = ieee80211_mpdudensity_map[peer_mpdudensity];
441 
442 	/* Select standard number of delimiters based on frame length */
443 	ndelim = ATH_AGGR_GET_NDELIM(pktlen);
444 
445 	/*
446 	 * If encryption is enabled, add extra delimiters to let the
447 	 * crypto hardware catch up. This could be tuned per-MAC and
448 	 * per-rate, but for now we'll simply assume encryption is
449 	 * always enabled.
450 	 *
451 	 * Also note that the Atheros reference driver inserts two
452 	 * delimiters by default for pre-AR9380 peers.  This will
453 	 * include "that" required delimiter.
454 	 */
455 	ndelim += ATH_AGGR_ENCRYPTDELIM;
456 
457 	/*
458 	 * For AR9380, there's a minimum number of delimiters
459 	 * required when doing RTS.
460 	 *
461 	 * XXX TODO: this is only needed if (a) RTS/CTS is enabled for
462 	 * this exchange, and (b) (done) this is the first sub-frame
463 	 * in the aggregate.
464 	 */
465 	if (sc->sc_use_ent && (sc->sc_ent_cfg & AH_ENT_RTSCTS_DELIM_WAR)
466 	    && ndelim < AH_FIRST_DESC_NDELIMS && is_first)
467 		ndelim = AH_FIRST_DESC_NDELIMS;
468 
469 	/*
470 	 * If sc_delim_min_pad is non-zero, enforce it as the minimum
471 	 * pad delimiter count.
472 	 */
473 	if (sc->sc_delim_min_pad != 0)
474 		ndelim = MAX(ndelim, sc->sc_delim_min_pad);
475 
476 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
477 	    "%s: pktlen=%d, ndelim=%d, mpdudensity=%d\n",
478 	    __func__, pktlen, ndelim, mpdudensity);
479 
480 	/*
481 	 * If the MPDU density is 0, we can return here.
482 	 * Otherwise, we need to convert the desired mpdudensity
483 	 * into a byte length, based on the rate in the subframe.
484 	 */
485 	if (mpdudensity == 0)
486 		return ndelim;
487 
488 	/*
489 	 * Convert desired mpdu density from microeconds to bytes based
490 	 * on highest rate in rate series (i.e. first rate) to determine
491 	 * required minimum length for subframe. Take into account
492 	 * whether high rate is 20 or 40Mhz and half or full GI.
493 	 */
494 	rix = first_bf->bf_state.bfs_rc[0].rix;
495 	rc = rt->info[rix].rateCode;
496 	flags = first_bf->bf_state.bfs_rc[0].flags;
497 	width = !! (flags & ATH_RC_CW40_FLAG);
498 	half_gi = !! (flags & ATH_RC_SGI_FLAG);
499 
500 	/*
501 	 * mpdudensity is in 1/100th of a usec, so divide by 100
502 	 */
503 	if (half_gi)
504 		nsymbols = NUM_SYMBOLS_PER_USEC_HALFGI(mpdudensity);
505 	else
506 		nsymbols = NUM_SYMBOLS_PER_USEC(mpdudensity);
507 	nsymbols /= 100;
508 
509 	if (nsymbols == 0)
510 		nsymbols = 1;
511 
512 	nsymbits = bits_per_symbol[HT_RC_2_MCS(rc)][width];
513 	minlen = (nsymbols * nsymbits) / BITS_PER_BYTE;
514 
515 	/*
516 	 * Min length is the minimum frame length for the
517 	 * required MPDU density.
518 	 */
519 	if (pktlen < minlen) {
520 		mindelim = (minlen - pktlen) / ATH_AGGR_DELIM_SZ;
521 		ndelim = MAX(mindelim, ndelim);
522 	}
523 
524 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
525 	    "%s: pktlen=%d, minlen=%d, rix=%x, rc=%x, width=%d, hgi=%d, ndelim=%d\n",
526 	    __func__, pktlen, minlen, rix, rc, width, half_gi, ndelim);
527 
528 	return ndelim;
529 }
530 
531 /*
532  * XXX TODO: put into net80211
533  */
534 static int
535 ath_rx_ampdu_to_byte(char a)
536 {
537 	switch (a) {
538 	case IEEE80211_HTCAP_MAXRXAMPDU_16K:
539 		return 16384;
540 		break;
541 	case IEEE80211_HTCAP_MAXRXAMPDU_32K:
542 		return 32768;
543 		break;
544 	case IEEE80211_HTCAP_MAXRXAMPDU_64K:
545 		return 65536;
546 		break;
547 	case IEEE80211_HTCAP_MAXRXAMPDU_8K:
548 	default:
549 		return 8192;
550 		break;
551 	}
552 }
553 
554 /*
555  * Fetch the aggregation limit.
556  *
557  * It's the lowest of the four rate series 4ms frame length.
558  *
559  * Also take into account the hardware specific limits (8KiB on AR5416)
560  * and per-peer limits in non-STA mode.
561  */
562 static int
563 ath_get_aggr_limit(struct ath_softc *sc, struct ieee80211_node *ni,
564     struct ath_buf *bf)
565 {
566 	struct ieee80211vap *vap = ni->ni_vap;
567 
568 	int amin = ATH_AGGR_MAXSIZE;
569 	int i;
570 
571 	/* Extract out the maximum configured driver A-MPDU limit */
572 	if (sc->sc_aggr_limit > 0 && sc->sc_aggr_limit < ATH_AGGR_MAXSIZE)
573 		amin = sc->sc_aggr_limit;
574 
575 	/* Check the vap configured transmit limit */
576 	amin = MIN(amin, ath_rx_ampdu_to_byte(vap->iv_ampdu_limit));
577 
578 	/*
579 	 * Check the HTCAP field for the maximum size the node has
580 	 * negotiated.  If it's smaller than what we have, cap it there.
581 	 */
582 	amin = MIN(amin, ath_rx_ampdu_to_byte(
583 	    _IEEE80211_MASKSHIFT(ni->ni_htparam, IEEE80211_HTCAP_MAXRXAMPDU)));
584 
585 	for (i = 0; i < ATH_RC_NUM; i++) {
586 		if (bf->bf_state.bfs_rc[i].tries == 0)
587 			continue;
588 		amin = MIN(amin, bf->bf_state.bfs_rc[i].max4msframelen);
589 	}
590 
591 	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
592 	    "%s: aggr_limit=%d, iv_ampdu_limit=%d, "
593 	    "peer maxrxampdu=%d, max frame len=%d\n",
594 	    __func__,
595 	    sc->sc_aggr_limit,
596 	    vap->iv_ampdu_limit,
597 	    _IEEE80211_MASKSHIFT(ni->ni_htparam, IEEE80211_HTCAP_MAXRXAMPDU),
598 	    amin);
599 
600 	return amin;
601 }
602 
603 /*
604  * Setup a 11n rate series structure
605  *
606  * This should be called for both legacy and MCS rates.
607  *
608  * This uses the rate series stuf from ath_tx_rate_fill_rcflags().
609  *
610  * It, along with ath_buf_set_rate, must be called -after- a burst
611  * or aggregate is setup.
612  */
613 static void
614 ath_rateseries_setup(struct ath_softc *sc, struct ieee80211_node *ni,
615     struct ath_buf *bf, HAL_11N_RATE_SERIES *series)
616 {
617 	struct ieee80211com *ic = ni->ni_ic;
618 	struct ath_hal *ah = sc->sc_ah;
619 	HAL_BOOL shortPreamble = AH_FALSE;
620 	const HAL_RATE_TABLE *rt = sc->sc_currates;
621 	int i;
622 	int pktlen;
623 	struct ath_rc_series *rc = bf->bf_state.bfs_rc;
624 
625 	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
626 	    (ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE))
627 		shortPreamble = AH_TRUE;
628 
629 	/*
630 	 * If this is the first frame in an aggregate series,
631 	 * use the aggregate length.
632 	 */
633 	if (bf->bf_state.bfs_aggr)
634 		pktlen = bf->bf_state.bfs_al;
635 	else
636 		pktlen = bf->bf_state.bfs_pktlen;
637 
638 	/*
639 	 * XXX TODO: modify this routine to use the bfs_rc[x].flags
640 	 * XXX fields.
641 	 */
642 	memset(series, 0, sizeof(HAL_11N_RATE_SERIES) * 4);
643 	for (i = 0; i < ATH_RC_NUM;  i++) {
644 		/* Only set flags for actual TX attempts */
645 		if (rc[i].tries == 0)
646 			continue;
647 
648 		series[i].Tries = rc[i].tries;
649 
650 		/*
651 		 * XXX TODO: When the NIC is capable of three stream TX,
652 		 * transmit 1/2 stream rates on two streams.
653 		 *
654 		 * This reduces the power consumption of the NIC and
655 		 * keeps it within the PCIe slot power limits.
656 		 */
657 		series[i].ChSel = sc->sc_cur_txchainmask;
658 
659 		/*
660 		 * Setup rate and TX power cap for this series.
661 		 */
662 		series[i].Rate = rt->info[rc[i].rix].rateCode;
663 		series[i].RateIndex = rc[i].rix;
664 		series[i].tx_power_cap = rc[i].tx_power_cap;
665 
666 		/*
667 		 * Enable RTS/CTS as appropriate.
668 		 */
669 		if (rc[i].flags & ATH_RC_RTSCTS_FLAG)
670 			series[i].RateFlags |= HAL_RATESERIES_RTS_CTS;
671 
672 		/*
673 		 * 11n rate? Update 11n flags.
674 		 */
675 		if (rc[i].flags & ATH_RC_HT_FLAG) {
676 			if (rc[i].flags & ATH_RC_CW40_FLAG)
677 				series[i].RateFlags |= HAL_RATESERIES_2040;
678 
679 			if (rc[i].flags & ATH_RC_SGI_FLAG)
680 				series[i].RateFlags |= HAL_RATESERIES_HALFGI;
681 
682 			if (rc[i].flags & ATH_RC_STBC_FLAG)
683 				series[i].RateFlags |= HAL_RATESERIES_STBC;
684 		}
685 
686 		/*
687 		 * TODO: If we're all doing 11n rates then we can set LDPC.
688 		 * If we've been asked to /do/ LDPC but we are handed a
689 		 * legacy rate, then we should complain.  Loudly.
690 		 */
691 
692 		/*
693 		 * PktDuration doesn't include slot, ACK, RTS, etc timing -
694 		 * it's just the packet duration
695 		 */
696 		if (rc[i].flags & ATH_RC_HT_FLAG) {
697 			series[i].PktDuration =
698 			    ath_computedur_ht(pktlen
699 				, series[i].Rate
700 				, HT_RC_2_STREAMS(series[i].Rate)
701 				, series[i].RateFlags & HAL_RATESERIES_2040
702 				, series[i].RateFlags & HAL_RATESERIES_HALFGI);
703 		} else {
704 			if (shortPreamble)
705 				series[i].Rate |=
706 				    rt->info[rc[i].rix].shortPreamble;
707 			/* XXX TODO: don't include SIFS */
708 			series[i].PktDuration = ath_hal_computetxtime(ah,
709 			    rt, pktlen, rc[i].rix, shortPreamble, AH_TRUE);
710 		}
711 	}
712 }
713 
714 #ifdef	ATH_DEBUG
715 static void
716 ath_rateseries_print(struct ath_softc *sc, HAL_11N_RATE_SERIES *series)
717 {
718 	int i;
719 	for (i = 0; i < ATH_RC_NUM; i++) {
720 		device_printf(sc->sc_dev ,"series %d: rate %x; tries %d; "
721 		    "pktDuration %d; chSel %d; txpowcap %d, rateFlags %x\n",
722 		    i,
723 		    series[i].Rate,
724 		    series[i].Tries,
725 		    series[i].PktDuration,
726 		    series[i].ChSel,
727 		    series[i].tx_power_cap,
728 		    series[i].RateFlags);
729 	}
730 }
731 #endif
732 
733 /*
734  * Setup the 11n rate scenario and burst duration for the given TX descriptor
735  * list.
736  *
737  * This isn't useful for sending beacon frames, which has different needs
738  * wrt what's passed into the rate scenario function.
739  */
740 void
741 ath_buf_set_rate(struct ath_softc *sc, struct ieee80211_node *ni,
742     struct ath_buf *bf)
743 {
744 	HAL_11N_RATE_SERIES series[4];
745 	struct ath_desc *ds = bf->bf_desc;
746 	struct ath_hal *ah = sc->sc_ah;
747 	int is_pspoll = (bf->bf_state.bfs_atype == HAL_PKT_TYPE_PSPOLL);
748 	int ctsrate = bf->bf_state.bfs_ctsrate;
749 	int flags = bf->bf_state.bfs_txflags;
750 
751 	/* Setup rate scenario */
752 	memset(&series, 0, sizeof(series));
753 
754 	ath_rateseries_setup(sc, ni, bf, series);
755 
756 #ifdef	ATH_DEBUG
757 	if (sc->sc_debug & ATH_DEBUG_XMIT)
758 		ath_rateseries_print(sc, series);
759 #endif
760 
761 	/* Set rate scenario */
762 	/*
763 	 * Note: Don't allow hardware to override the duration on
764 	 * ps-poll packets.
765 	 */
766 	ath_hal_set11nratescenario(ah, ds,
767 	    !is_pspoll,	/* whether to override the duration or not */
768 	    ctsrate,	/* rts/cts rate */
769 	    series,	/* 11n rate series */
770 	    4,		/* number of series */
771 	    flags);
772 
773 	/* Set burst duration */
774 	/*
775 	 * This is only required when doing 11n burst, not aggregation
776 	 * ie, if there's a second frame in a RIFS or A-MPDU burst
777 	 * w/ >1 A-MPDU frame bursting back to back.
778 	 * Normal A-MPDU doesn't do bursting -between- aggregates.
779 	 *
780 	 * .. and it's highly likely this won't ever be implemented
781 	 */
782 	//ath_hal_set11nburstduration(ah, ds, 8192);
783 }
784 
785 /*
786  * Form an aggregate packet list.
787  *
788  * This function enforces the aggregate restrictions/requirements.
789  *
790  * These are:
791  *
792  * + The aggregate size maximum (64k for AR9160 and later, 8K for
793  *   AR5416 when doing RTS frame protection.)
794  * + Maximum number of sub-frames for an aggregate
795  * + The aggregate delimiter size, giving MACs time to do whatever is
796  *   needed before each frame
797  * + Enforce the BAW limit
798  *
799  * Each descriptor queued should have the DMA setup.
800  * The rate series, descriptor setup, linking, etc is all done
801  * externally. This routine simply chains them together.
802  * ath_tx_setds_11n() will take care of configuring the per-
803  * descriptor setup, and ath_buf_set_rate() will configure the
804  * rate control.
805  *
806  * The TID lock is required for the entirety of this function.
807  *
808  * If some code in another thread adds to the head of this
809  * list, very strange behaviour will occur. Since retransmission is the
810  * only reason this will occur, and this routine is designed to be called
811  * from within the scheduler task, it won't ever clash with the completion
812  * task.
813  *
814  * So if you want to call this from an upper layer context (eg, to direct-
815  * dispatch aggregate frames to the hardware), please keep this in mind.
816  */
817 ATH_AGGR_STATUS
818 ath_tx_form_aggr(struct ath_softc *sc, struct ath_node *an,
819     struct ath_tid *tid, ath_bufhead *bf_q)
820 {
821 	//struct ieee80211_node *ni = &an->an_node;
822 	struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
823 	int nframes = 0;
824 	uint16_t aggr_limit = 0, al = 0, bpad = 0, al_delta, h_baw;
825 	struct ieee80211_tx_ampdu *tap;
826 	int status = ATH_AGGR_DONE;
827 	int prev_frames = 0;	/* XXX for AR5416 burst, not done here */
828 	int prev_al = 0;	/* XXX also for AR5416 burst */
829 
830 	ATH_TX_LOCK_ASSERT(sc);
831 
832 	tap = ath_tx_get_tx_tid(an, tid->tid);
833 	if (tap == NULL) {
834 		status = ATH_AGGR_ERROR;
835 		goto finish;
836 	}
837 
838 	/*
839 	 * Limit the maximum number of frames in this A-MPDU
840 	 * to half of the window size.  This is done to prevent
841 	 * sending a LOT of frames that may fail in one batch
842 	 * when operating in higher MCS rates.  If there are more
843 	 * frames available to send then up to two A-MPDUs will
844 	 * be queued per hardware queue, so we'll "just" get
845 	 * a second A-MPDU.
846 	 */
847 	h_baw = tap->txa_wnd / 2;
848 
849 	for (;;) {
850 		bf = ATH_TID_FIRST(tid);
851 		if (bf == NULL) {
852 			status = ATH_AGGR_DONE;
853 			break;
854 		}
855 		if (bf_first == NULL) {
856 			bf_first = bf;
857 			/*
858 			 * It's the first frame;
859 			 * set the aggregation limit based on the
860 			 * rate control decision that has been made.
861 			 */
862 			aggr_limit = ath_get_aggr_limit(sc, &an->an_node,
863 			    bf_first);
864 			if (bf_first->bf_state.bfs_rc_maxpktlen > 0) {
865 				aggr_limit = MIN(aggr_limit,
866 				    bf_first->bf_state.bfs_rc_maxpktlen);
867 			}
868 		}
869 
870 		/* Set this early just so things don't get confused */
871 		bf->bf_next = NULL;
872 
873 		/*
874 		 * If the frame doesn't have a sequence number that we're
875 		 * tracking in the BAW (eg NULL QOS data frame), we can't
876 		 * aggregate it. Stop the aggregation process; the sender
877 		 * can then TX what's in the list thus far and then
878 		 * TX the frame individually.
879 		 */
880 		if (! bf->bf_state.bfs_dobaw) {
881 			status = ATH_AGGR_NONAGGR;
882 			break;
883 		}
884 
885 		/*
886 		 * If any of the rates are non-HT, this packet
887 		 * can't be aggregated.
888 		 * XXX TODO: add a bf_state flag which gets marked
889 		 * if any active rate is non-HT.
890 		 */
891 
892 		/*
893 		 * do not exceed aggregation limit
894 		 */
895 		al_delta = ATH_AGGR_DELIM_SZ + bf->bf_state.bfs_pktlen;
896 		if (nframes &&
897 		    (aggr_limit < (al + bpad + al_delta + prev_al))) {
898 			status = ATH_AGGR_LIMITED;
899 			break;
900 		}
901 
902 		/*
903 		 * If RTS/CTS is set on the first frame, enforce
904 		 * the RTS aggregate limit.
905 		 */
906 		if (bf_first->bf_state.bfs_txflags &
907 		    (HAL_TXDESC_CTSENA | HAL_TXDESC_RTSENA)) {
908 			if (nframes &&
909 			   (sc->sc_rts_aggr_limit <
910 			     (al + bpad + al_delta + prev_al))) {
911 				status = ATH_AGGR_8K_LIMITED;
912 				break;
913 			}
914 		}
915 
916 		/*
917 		 * Do not exceed subframe limit.
918 		 */
919 		if ((nframes + prev_frames) >= MIN((h_baw),
920 		    IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
921 			status = ATH_AGGR_LIMITED;
922 			break;
923 		}
924 
925 		/*
926 		 * If the current frame has an RTS/CTS configuration
927 		 * that differs from the first frame, override the
928 		 * subsequent frame with this config.
929 		 */
930 		if (bf != bf_first) {
931 			bf->bf_state.bfs_txflags &=
932 			    ~ (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
933 			bf->bf_state.bfs_txflags |=
934 			    bf_first->bf_state.bfs_txflags &
935 			    (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
936 		}
937 
938 		/*
939 		 * If the packet has a sequence number, do not
940 		 * step outside of the block-ack window.
941 		 */
942 		if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
943 		    SEQNO(bf->bf_state.bfs_seqno))) {
944 			status = ATH_AGGR_BAW_CLOSED;
945 			break;
946 		}
947 
948 		/*
949 		 * this packet is part of an aggregate.
950 		 */
951 		ATH_TID_REMOVE(tid, bf, bf_list);
952 
953 		/* The TID lock is required for the BAW update */
954 		ath_tx_addto_baw(sc, an, tid, bf);
955 		bf->bf_state.bfs_addedbaw = 1;
956 
957 		/*
958 		 * XXX enforce ACK for aggregate frames (this needs to be
959 		 * XXX handled more gracefully?
960 		 */
961 		if (bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) {
962 			device_printf(sc->sc_dev,
963 			    "%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
964 			    __func__);
965 			bf->bf_state.bfs_txflags &= (~HAL_TXDESC_NOACK);
966 		}
967 
968 		/*
969 		 * Add the now owned buffer (which isn't
970 		 * on the software TXQ any longer) to our
971 		 * aggregate frame list.
972 		 */
973 		TAILQ_INSERT_TAIL(bf_q, bf, bf_list);
974 		nframes ++;
975 
976 		/* Completion handler */
977 		bf->bf_comp = ath_tx_aggr_comp;
978 
979 		/*
980 		 * add padding for previous frame to aggregation length
981 		 */
982 		al += bpad + al_delta;
983 
984 		/*
985 		 * Calculate delimiters needed for the current frame
986 		 */
987 		bf->bf_state.bfs_ndelim =
988 		    ath_compute_num_delims(sc, bf_first,
989 		    bf->bf_state.bfs_pktlen, (bf_first == bf));
990 
991 		/*
992 		 * Calculate the padding needed from this set of delimiters,
993 		 * used when calculating if the next frame will fit in
994 		 * the aggregate.
995 		 */
996 		bpad = PADBYTES(al_delta) + (bf->bf_state.bfs_ndelim << 2);
997 
998 		/*
999 		 * Chain the buffers together
1000 		 */
1001 		if (bf_prev)
1002 			bf_prev->bf_next = bf;
1003 		bf_prev = bf;
1004 
1005 		/*
1006 		 * If we're leaking frames, just return at this point;
1007 		 * we've queued a single frame and we don't want to add
1008 		 * any more.
1009 		 */
1010 		if (tid->an->an_leak_count) {
1011 			status = ATH_AGGR_LEAK_CLOSED;
1012 			break;
1013 		}
1014 
1015 #if 0
1016 		/*
1017 		 * terminate aggregation on a small packet boundary
1018 		 */
1019 		if (bf->bf_state.bfs_pktlen < ATH_AGGR_MINPLEN) {
1020 			status = ATH_AGGR_SHORTPKT;
1021 			break;
1022 		}
1023 #endif
1024 	}
1025 
1026 finish:
1027 	/*
1028 	 * Just in case the list was empty when we tried to
1029 	 * dequeue a packet ..
1030 	 */
1031 	if (bf_first) {
1032 		DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
1033 		"%s: al=%d bytes; requested %d bytes\n",
1034 		__func__, al, bf_first->bf_state.bfs_rc_maxpktlen);
1035 
1036 		bf_first->bf_state.bfs_al = al;
1037 		bf_first->bf_state.bfs_nframes = nframes;
1038 	}
1039 	return status;
1040 }
1041