1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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__FBSDID("$FreeBSD: releng/12.0/sys/dev/ath/if_ath_tx_ht.c 326255 2017-11-27 14:52:40Z pfg $");
34
35#include "opt_inet.h"
36#include "opt_ath.h"
37#include "opt_wlan.h"
38
39#include <sys/param.h>
40#include <sys/systm.h>
41#include <sys/sysctl.h>
42#include <sys/mbuf.h>
43#include <sys/malloc.h>
44#include <sys/lock.h>
45#include <sys/mutex.h>
46#include <sys/kernel.h>
47#include <sys/socket.h>
48#include <sys/sockio.h>
49#include <sys/errno.h>
50#include <sys/callout.h>
51#include <sys/bus.h>
52#include <sys/endian.h>
53#include <sys/kthread.h>
54#include <sys/taskqueue.h>
55#include <sys/priv.h>
56
57#include <machine/bus.h>
58
59#include <net/if.h>
60#include <net/if_dl.h>
61#include <net/if_media.h>
62#include <net/if_types.h>
63#include <net/if_arp.h>
64#include <net/ethernet.h>
65#include <net/if_llc.h>
66
67#include <net80211/ieee80211_var.h>
68#include <net80211/ieee80211_regdomain.h>
69#ifdef IEEE80211_SUPPORT_SUPERG
70#include <net80211/ieee80211_superg.h>
71#endif
72#ifdef IEEE80211_SUPPORT_TDMA
73#include <net80211/ieee80211_tdma.h>
74#endif
75
76#include <net/bpf.h>
77
78#ifdef INET
79#include <netinet/in.h>
80#include <netinet/if_ether.h>
81#endif
82
83#include <dev/ath/if_athvar.h>
84#include <dev/ath/ath_hal/ah_devid.h>		/* XXX for softled */
85#include <dev/ath/ath_hal/ah_diagcodes.h>
86
87#ifdef ATH_TX99_DIAG
88#include <dev/ath/ath_tx99/ath_tx99.h>
89#endif
90
91#include <dev/ath/if_ath_tx.h>		/* XXX for some support functions */
92#include <dev/ath/if_ath_tx_ht.h>
93#include <dev/ath/if_athrate.h>
94#include <dev/ath/if_ath_debug.h>
95
96/*
97 * XXX net80211?
98 */
99#define	IEEE80211_AMPDU_SUBFRAME_DEFAULT		32
100
101#define	ATH_AGGR_DELIM_SZ	4	/* delimiter size */
102#define	ATH_AGGR_MINPLEN	256	/* in bytes, minimum packet length */
103/* number of delimiters for encryption padding */
104#define	ATH_AGGR_ENCRYPTDELIM	10
105
106/*
107 * returns delimiter padding required given the packet length
108 */
109#define	ATH_AGGR_GET_NDELIM(_len)					\
110	    (((((_len) + ATH_AGGR_DELIM_SZ) < ATH_AGGR_MINPLEN) ?	\
111	    (ATH_AGGR_MINPLEN - (_len) - ATH_AGGR_DELIM_SZ) : 0) >> 2)
112
113#define	PADBYTES(_len)		((4 - ((_len) % 4)) % 4)
114
115int ath_max_4ms_framelen[4][32] = {
116	[MCS_HT20] = {
117		3212,  6432,  9648,  12864,  19300,  25736,  28952,  32172,
118		6424,  12852, 19280, 25708,  38568,  51424,  57852,  64280,
119		9628,  19260, 28896, 38528,  57792,  65532,  65532,  65532,
120		12828, 25656, 38488, 51320,  65532,  65532,  65532,  65532,
121	},
122	[MCS_HT20_SGI] = {
123		3572,  7144,  10720,  14296,  21444,  28596,  32172,  35744,
124		7140,  14284, 21428,  28568,  42856,  57144,  64288,  65532,
125		10700, 21408, 32112,  42816,  64228,  65532,  65532,  65532,
126		14256, 28516, 42780,  57040,  65532,  65532,  65532,  65532,
127	},
128	[MCS_HT40] = {
129		6680,  13360,  20044,  26724,  40092,  53456,  60140,  65532,
130		13348, 26700,  40052,  53400,  65532,  65532,  65532,  65532,
131		20004, 40008,  60016,  65532,  65532,  65532,  65532,  65532,
132		26644, 53292,  65532,  65532,  65532,  65532,  65532,  65532,
133	},
134	[MCS_HT40_SGI] = {
135		7420,  14844,  22272,  29696,  44544,  59396,  65532,  65532,
136		14832, 29668,  44504,  59340,  65532,  65532,  65532,  65532,
137		22232, 44464,  65532,  65532,  65532,  65532,  65532,  65532,
138		29616, 59232,  65532,  65532,  65532,  65532,  65532,  65532,
139	}
140};
141
142/*
143 * XXX should be in net80211
144 */
145static int ieee80211_mpdudensity_map[] = {
146	0,		/* IEEE80211_HTCAP_MPDUDENSITY_NA */
147	25,		/* IEEE80211_HTCAP_MPDUDENSITY_025 */
148	50,		/* IEEE80211_HTCAP_MPDUDENSITY_05 */
149	100,		/* IEEE80211_HTCAP_MPDUDENSITY_1 */
150	200,		/* IEEE80211_HTCAP_MPDUDENSITY_2 */
151	400,		/* IEEE80211_HTCAP_MPDUDENSITY_4 */
152	800,		/* IEEE80211_HTCAP_MPDUDENSITY_8 */
153	1600,		/* IEEE80211_HTCAP_MPDUDENSITY_16 */
154};
155
156/*
157 * XXX should be in the HAL/net80211 ?
158 */
159#define	BITS_PER_BYTE		8
160#define	OFDM_PLCP_BITS		22
161#define	HT_RC_2_MCS(_rc)	((_rc) & 0x7f)
162#define	HT_RC_2_STREAMS(_rc)	((((_rc) & 0x78) >> 3) + 1)
163#define	L_STF			8
164#define	L_LTF			8
165#define	L_SIG			4
166#define	HT_SIG			8
167#define	HT_STF			4
168#define	HT_LTF(_ns)		(4 * (_ns))
169#define	SYMBOL_TIME(_ns)	((_ns) << 2)		// ns * 4 us
170#define	SYMBOL_TIME_HALFGI(_ns)	(((_ns) * 18 + 4) / 5)	// ns * 3.6 us
171#define	NUM_SYMBOLS_PER_USEC(_usec)	(_usec >> 2)
172#define	NUM_SYMBOLS_PER_USEC_HALFGI(_usec)	(((_usec*5)-4)/18)
173#define	IS_HT_RATE(_rate)	((_rate) & 0x80)
174
175const uint32_t bits_per_symbol[][2] = {
176    /* 20MHz 40MHz */
177    {    26,   54 },     //  0: BPSK
178    {    52,  108 },     //  1: QPSK 1/2
179    {    78,  162 },     //  2: QPSK 3/4
180    {   104,  216 },     //  3: 16-QAM 1/2
181    {   156,  324 },     //  4: 16-QAM 3/4
182    {   208,  432 },     //  5: 64-QAM 2/3
183    {   234,  486 },     //  6: 64-QAM 3/4
184    {   260,  540 },     //  7: 64-QAM 5/6
185    {    52,  108 },     //  8: BPSK
186    {   104,  216 },     //  9: QPSK 1/2
187    {   156,  324 },     // 10: QPSK 3/4
188    {   208,  432 },     // 11: 16-QAM 1/2
189    {   312,  648 },     // 12: 16-QAM 3/4
190    {   416,  864 },     // 13: 64-QAM 2/3
191    {   468,  972 },     // 14: 64-QAM 3/4
192    {   520, 1080 },     // 15: 64-QAM 5/6
193    {    78,  162 },     // 16: BPSK
194    {   156,  324 },     // 17: QPSK 1/2
195    {   234,  486 },     // 18: QPSK 3/4
196    {   312,  648 },     // 19: 16-QAM 1/2
197    {   468,  972 },     // 20: 16-QAM 3/4
198    {   624, 1296 },     // 21: 64-QAM 2/3
199    {   702, 1458 },     // 22: 64-QAM 3/4
200    {   780, 1620 },     // 23: 64-QAM 5/6
201    {   104,  216 },     // 24: BPSK
202    {   208,  432 },     // 25: QPSK 1/2
203    {   312,  648 },     // 26: QPSK 3/4
204    {   416,  864 },     // 27: 16-QAM 1/2
205    {   624, 1296 },     // 28: 16-QAM 3/4
206    {   832, 1728 },     // 29: 64-QAM 2/3
207    {   936, 1944 },     // 30: 64-QAM 3/4
208    {  1040, 2160 },     // 31: 64-QAM 5/6
209};
210
211/*
212 * Fill in the rate array information based on the current
213 * node configuration and the choices made by the rate
214 * selection code and ath_buf setup code.
215 *
216 * Later on, this may end up also being made by the
217 * rate control code, but for now it can live here.
218 *
219 * This needs to be called just before the packet is
220 * queued to the software queue or hardware queue,
221 * so all of the needed fields in bf_state are setup.
222 */
223void
224ath_tx_rate_fill_rcflags(struct ath_softc *sc, struct ath_buf *bf)
225{
226	struct ieee80211_node *ni = bf->bf_node;
227	struct ieee80211vap *vap = ni->ni_vap;
228	struct ieee80211com *ic = ni->ni_ic;
229	const HAL_RATE_TABLE *rt = sc->sc_currates;
230	struct ath_rc_series *rc = bf->bf_state.bfs_rc;
231	uint8_t rate;
232	int i;
233	int do_ldpc;
234	int do_stbc;
235
236	/*
237	 * We only do LDPC if the rate is 11n, both we and the
238	 * receiver support LDPC and it's enabled.
239	 *
240	 * It's a global flag, not a per-try flag, so we clear
241	 * it if any of the rate entries aren't 11n.
242	 */
243	do_ldpc = 0;
244	if ((ni->ni_vap->iv_flags_ht & IEEE80211_FHT_LDPC_TX) &&
245	    (ni->ni_htcap & IEEE80211_HTCAP_LDPC))
246		do_ldpc = 1;
247
248	/*
249	 * The 11n duration calculation doesn't know about LDPC,
250	 * so don't enable it for positioning.
251	 */
252	if (bf->bf_flags & ATH_BUF_TOA_PROBE)
253		do_ldpc = 0;
254
255	do_stbc = 0;
256
257	for (i = 0; i < ATH_RC_NUM; i++) {
258		rc[i].flags = 0;
259		if (rc[i].tries == 0)
260			continue;
261
262		rate = rt->info[rc[i].rix].rateCode;
263
264		/*
265		 * Only enable short preamble for legacy rates
266		 */
267		if ((! IS_HT_RATE(rate)) && bf->bf_state.bfs_shpream)
268			rate |= rt->info[rc[i].rix].shortPreamble;
269
270		/*
271		 * Save this, used by the TX and completion code
272		 */
273		rc[i].ratecode = rate;
274
275		if (bf->bf_state.bfs_txflags &
276		    (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
277			rc[i].flags |= ATH_RC_RTSCTS_FLAG;
278
279		/*
280		 * If we can't do LDPC, don't.
281		 */
282		if (! IS_HT_RATE(rate))
283			do_ldpc = 0;
284
285		/* Only enable shortgi, 2040, dual-stream if HT is set */
286		if (IS_HT_RATE(rate)) {
287			rc[i].flags |= ATH_RC_HT_FLAG;
288
289			if (ni->ni_chw == 40)
290				rc[i].flags |= ATH_RC_CW40_FLAG;
291
292			/*
293			 * NOTE: Don't do short-gi for positioning frames.
294			 *
295			 * For now, the ath_hal and net80211 HT duration
296			 * calculation rounds up the 11n data txtime
297			 * to the nearest multiple of 3.6 microseconds
298			 * and doesn't return the fractional part, so
299			 * we are always "out" by some amount.
300			 */
301			if (ni->ni_chw == 40 &&
302			    ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
303			    ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40 &&
304			    vap->iv_flags_ht & IEEE80211_FHT_SHORTGI40 &&
305			    (bf->bf_flags & ATH_BUF_TOA_PROBE) == 0) {
306				rc[i].flags |= ATH_RC_SGI_FLAG;
307			}
308
309			if (ni->ni_chw == 20 &&
310			    ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
311			    ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20 &&
312			    vap->iv_flags_ht & IEEE80211_FHT_SHORTGI20 &&
313			    (bf->bf_flags & ATH_BUF_TOA_PROBE) == 0) {
314				rc[i].flags |= ATH_RC_SGI_FLAG;
315			}
316
317			/*
318			 * If we have STBC TX enabled and the receiver
319			 * can receive (at least) 1 stream STBC, AND it's
320			 * MCS 0-7, AND we have at least two chains enabled,
321			 * and we're not doing positioning, enable STBC.
322			 */
323			if (ic->ic_htcaps & IEEE80211_HTCAP_TXSTBC &&
324			    (ni->ni_vap->iv_flags_ht & IEEE80211_FHT_STBC_TX) &&
325			    (ni->ni_htcap & IEEE80211_HTCAP_RXSTBC) &&
326			    (sc->sc_cur_txchainmask > 1) &&
327			    (HT_RC_2_STREAMS(rate) == 1) &&
328			    (bf->bf_flags & ATH_BUF_TOA_PROBE) == 0) {
329				rc[i].flags |= ATH_RC_STBC_FLAG;
330				do_stbc = 1;
331			}
332
333			/*
334			 * Dual / Triple stream rate?
335			 */
336			if (HT_RC_2_STREAMS(rate) == 2)
337				rc[i].flags |= ATH_RC_DS_FLAG;
338			else if (HT_RC_2_STREAMS(rate) == 3)
339				rc[i].flags |= ATH_RC_TS_FLAG;
340		}
341
342		/*
343		 * Calculate the maximum TX power cap for the current
344		 * node.
345		 */
346		rc[i].tx_power_cap = ieee80211_get_node_txpower(ni);
347
348		/*
349		 * Calculate the maximum 4ms frame length based
350		 * on the MCS rate, SGI and channel width flags.
351		 */
352		if ((rc[i].flags & ATH_RC_HT_FLAG) &&
353		    (HT_RC_2_MCS(rate) < 32)) {
354			int j;
355			if (rc[i].flags & ATH_RC_CW40_FLAG) {
356				if (rc[i].flags & ATH_RC_SGI_FLAG)
357					j = MCS_HT40_SGI;
358				else
359					j = MCS_HT40;
360			} else {
361				if (rc[i].flags & ATH_RC_SGI_FLAG)
362					j = MCS_HT20_SGI;
363				else
364					j = MCS_HT20;
365			}
366			rc[i].max4msframelen =
367			    ath_max_4ms_framelen[j][HT_RC_2_MCS(rate)];
368		} else
369			rc[i].max4msframelen = 0;
370		DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
371		    "%s: i=%d, rate=0x%x, flags=0x%x, max4ms=%d\n",
372		    __func__, i, rate, rc[i].flags, rc[i].max4msframelen);
373	}
374
375	/*
376	 * LDPC is a global flag, so ...
377	 */
378	if (do_ldpc) {
379		bf->bf_state.bfs_txflags |= HAL_TXDESC_LDPC;
380		sc->sc_stats.ast_tx_ldpc++;
381	}
382
383	if (do_stbc) {
384		sc->sc_stats.ast_tx_stbc++;
385	}
386}
387
388/*
389 * Return the number of delimiters to be added to
390 * meet the minimum required mpdudensity.
391 *
392 * Caller should make sure that the rate is HT.
393 *
394 * TODO: is this delimiter calculation supposed to be the
395 * total frame length, the hdr length, the data length (including
396 * delimiters, padding, CRC, etc) or ?
397 *
398 * TODO: this should ensure that the rate control information
399 * HAS been setup for the first rate.
400 *
401 * TODO: ensure this is only called for MCS rates.
402 *
403 * TODO: enforce MCS < 31
404 */
405static int
406ath_compute_num_delims(struct ath_softc *sc, struct ath_buf *first_bf,
407    uint16_t pktlen, int is_first)
408{
409	const HAL_RATE_TABLE *rt = sc->sc_currates;
410	struct ieee80211_node *ni = first_bf->bf_node;
411	struct ieee80211vap *vap = ni->ni_vap;
412	int ndelim, mindelim = 0;
413	int mpdudensity;	/* in 1/100'th of a microsecond */
414	int peer_mpdudensity;	/* net80211 value */
415	uint8_t rc, rix, flags;
416	int width, half_gi;
417	uint32_t nsymbits, nsymbols;
418	uint16_t minlen;
419
420	/*
421	 * Get the advertised density from the node.
422	 */
423	peer_mpdudensity =
424	    _IEEE80211_MASKSHIFT(ni->ni_htparam, IEEE80211_HTCAP_MPDUDENSITY);
425
426	/*
427	 * vap->iv_ampdu_density is a net80211 value, rather than the actual
428	 * density.  Larger values are longer A-MPDU density spacing values,
429	 * and we want to obey larger configured / negotiated density values
430	 * per station if we get it.
431	 */
432	if (vap->iv_ampdu_density > peer_mpdudensity)
433		peer_mpdudensity = vap->iv_ampdu_density;
434
435	/*
436	 * Convert the A-MPDU density net80211 value to a 1/100 microsecond
437	 * value for subsequent calculations.
438	 */
439	if (peer_mpdudensity > IEEE80211_HTCAP_MPDUDENSITY_16)
440		mpdudensity = 1600;		/* maximum density */
441	else
442		mpdudensity = ieee80211_mpdudensity_map[peer_mpdudensity];
443
444	/* Select standard number of delimiters based on frame length */
445	ndelim = ATH_AGGR_GET_NDELIM(pktlen);
446
447	/*
448	 * If encryption is enabled, add extra delimiters to let the
449	 * crypto hardware catch up. This could be tuned per-MAC and
450	 * per-rate, but for now we'll simply assume encryption is
451	 * always enabled.
452	 *
453	 * Also note that the Atheros reference driver inserts two
454	 * delimiters by default for pre-AR9380 peers.  This will
455	 * include "that" required delimiter.
456	 */
457	ndelim += ATH_AGGR_ENCRYPTDELIM;
458
459	/*
460	 * For AR9380, there's a minimum number of delimeters
461	 * required when doing RTS.
462	 *
463	 * XXX TODO: this is only needed if (a) RTS/CTS is enabled for
464	 * this exchange, and (b) (done) this is the first sub-frame
465	 * in the aggregate.
466	 */
467	if (sc->sc_use_ent && (sc->sc_ent_cfg & AH_ENT_RTSCTS_DELIM_WAR)
468	    && ndelim < AH_FIRST_DESC_NDELIMS && is_first)
469		ndelim = AH_FIRST_DESC_NDELIMS;
470
471	/*
472	 * If sc_delim_min_pad is non-zero, enforce it as the minimum
473	 * pad delimiter count.
474	 */
475	if (sc->sc_delim_min_pad != 0)
476		ndelim = MAX(ndelim, sc->sc_delim_min_pad);
477
478	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
479	    "%s: pktlen=%d, ndelim=%d, mpdudensity=%d\n",
480	    __func__, pktlen, ndelim, mpdudensity);
481
482	/*
483	 * If the MPDU density is 0, we can return here.
484	 * Otherwise, we need to convert the desired mpdudensity
485	 * into a byte length, based on the rate in the subframe.
486	 */
487	if (mpdudensity == 0)
488		return ndelim;
489
490	/*
491	 * Convert desired mpdu density from microeconds to bytes based
492	 * on highest rate in rate series (i.e. first rate) to determine
493	 * required minimum length for subframe. Take into account
494	 * whether high rate is 20 or 40Mhz and half or full GI.
495	 */
496	rix = first_bf->bf_state.bfs_rc[0].rix;
497	rc = rt->info[rix].rateCode;
498	flags = first_bf->bf_state.bfs_rc[0].flags;
499	width = !! (flags & ATH_RC_CW40_FLAG);
500	half_gi = !! (flags & ATH_RC_SGI_FLAG);
501
502	/*
503	 * mpdudensity is in 1/100th of a usec, so divide by 100
504	 */
505	if (half_gi)
506		nsymbols = NUM_SYMBOLS_PER_USEC_HALFGI(mpdudensity);
507	else
508		nsymbols = NUM_SYMBOLS_PER_USEC(mpdudensity);
509	nsymbols /= 100;
510
511	if (nsymbols == 0)
512		nsymbols = 1;
513
514	nsymbits = bits_per_symbol[HT_RC_2_MCS(rc)][width];
515	minlen = (nsymbols * nsymbits) / BITS_PER_BYTE;
516
517	/*
518	 * Min length is the minimum frame length for the
519	 * required MPDU density.
520	 */
521	if (pktlen < minlen) {
522		mindelim = (minlen - pktlen) / ATH_AGGR_DELIM_SZ;
523		ndelim = MAX(mindelim, ndelim);
524	}
525
526	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
527	    "%s: pktlen=%d, minlen=%d, rix=%x, rc=%x, width=%d, hgi=%d, ndelim=%d\n",
528	    __func__, pktlen, minlen, rix, rc, width, half_gi, ndelim);
529
530	return ndelim;
531}
532
533/*
534 * XXX TODO: put into net80211
535 */
536static int
537ath_rx_ampdu_to_byte(char a)
538{
539	switch (a) {
540	case IEEE80211_HTCAP_MAXRXAMPDU_16K:
541		return 16384;
542		break;
543	case IEEE80211_HTCAP_MAXRXAMPDU_32K:
544		return 32768;
545		break;
546	case IEEE80211_HTCAP_MAXRXAMPDU_64K:
547		return 65536;
548		break;
549	case IEEE80211_HTCAP_MAXRXAMPDU_8K:
550	default:
551		return 8192;
552		break;
553	}
554}
555
556/*
557 * Fetch the aggregation limit.
558 *
559 * It's the lowest of the four rate series 4ms frame length.
560 *
561 * Also take into account the hardware specific limits (8KiB on AR5416)
562 * and per-peer limits in non-STA mode.
563 */
564static int
565ath_get_aggr_limit(struct ath_softc *sc, struct ieee80211_node *ni,
566    struct ath_buf *bf)
567{
568	struct ieee80211vap *vap = ni->ni_vap;
569
570	int amin = ATH_AGGR_MAXSIZE;
571	int i;
572
573	/* Extract out the maximum configured driver A-MPDU limit */
574	if (sc->sc_aggr_limit > 0 && sc->sc_aggr_limit < ATH_AGGR_MAXSIZE)
575		amin = sc->sc_aggr_limit;
576
577	/* Check the vap configured transmit limit */
578	amin = MIN(amin, ath_rx_ampdu_to_byte(vap->iv_ampdu_limit));
579
580	/*
581	 * Check the HTCAP field for the maximum size the node has
582	 * negotiated.  If it's smaller than what we have, cap it there.
583	 */
584	amin = MIN(amin, ath_rx_ampdu_to_byte(
585	    _IEEE80211_MASKSHIFT(ni->ni_htparam, IEEE80211_HTCAP_MAXRXAMPDU)));
586
587	for (i = 0; i < ATH_RC_NUM; i++) {
588		if (bf->bf_state.bfs_rc[i].tries == 0)
589			continue;
590		amin = MIN(amin, bf->bf_state.bfs_rc[i].max4msframelen);
591	}
592
593	DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
594	    "%s: aggr_limit=%d, iv_ampdu_limit=%d, "
595	    "peer maxrxampdu=%d, max frame len=%d\n",
596	    __func__,
597	    sc->sc_aggr_limit,
598	    vap->iv_ampdu_limit,
599	    _IEEE80211_MASKSHIFT(ni->ni_htparam, IEEE80211_HTCAP_MAXRXAMPDU),
600	    amin);
601
602	return amin;
603}
604
605/*
606 * Setup a 11n rate series structure
607 *
608 * This should be called for both legacy and MCS rates.
609 *
610 * This uses the rate series stuf from ath_tx_rate_fill_rcflags().
611 *
612 * It, along with ath_buf_set_rate, must be called -after- a burst
613 * or aggregate is setup.
614 */
615static void
616ath_rateseries_setup(struct ath_softc *sc, struct ieee80211_node *ni,
617    struct ath_buf *bf, HAL_11N_RATE_SERIES *series)
618{
619	struct ieee80211com *ic = ni->ni_ic;
620	struct ath_hal *ah = sc->sc_ah;
621	HAL_BOOL shortPreamble = AH_FALSE;
622	const HAL_RATE_TABLE *rt = sc->sc_currates;
623	int i;
624	int pktlen;
625	struct ath_rc_series *rc = bf->bf_state.bfs_rc;
626
627	if ((ic->ic_flags & IEEE80211_F_SHPREAMBLE) &&
628	    (ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE))
629		shortPreamble = AH_TRUE;
630
631	/*
632	 * If this is the first frame in an aggregate series,
633	 * use the aggregate length.
634	 */
635	if (bf->bf_state.bfs_aggr)
636		pktlen = bf->bf_state.bfs_al;
637	else
638		pktlen = bf->bf_state.bfs_pktlen;
639
640	/*
641	 * XXX TODO: modify this routine to use the bfs_rc[x].flags
642	 * XXX fields.
643	 */
644	memset(series, 0, sizeof(HAL_11N_RATE_SERIES) * 4);
645	for (i = 0; i < ATH_RC_NUM;  i++) {
646		/* Only set flags for actual TX attempts */
647		if (rc[i].tries == 0)
648			continue;
649
650		series[i].Tries = rc[i].tries;
651
652		/*
653		 * XXX TODO: When the NIC is capable of three stream TX,
654		 * transmit 1/2 stream rates on two streams.
655		 *
656		 * This reduces the power consumption of the NIC and
657		 * keeps it within the PCIe slot power limits.
658		 */
659		series[i].ChSel = sc->sc_cur_txchainmask;
660
661		/*
662		 * Setup rate and TX power cap for this series.
663		 */
664		series[i].Rate = rt->info[rc[i].rix].rateCode;
665		series[i].RateIndex = rc[i].rix;
666		series[i].tx_power_cap = rc[i].tx_power_cap;
667
668		/*
669		 * Enable RTS/CTS as appropriate.
670		 */
671		if (rc[i].flags & ATH_RC_RTSCTS_FLAG)
672			series[i].RateFlags |= HAL_RATESERIES_RTS_CTS;
673
674		/*
675		 * 11n rate? Update 11n flags.
676		 */
677		if (rc[i].flags & ATH_RC_HT_FLAG) {
678			if (rc[i].flags & ATH_RC_CW40_FLAG)
679				series[i].RateFlags |= HAL_RATESERIES_2040;
680
681			if (rc[i].flags & ATH_RC_SGI_FLAG)
682				series[i].RateFlags |= HAL_RATESERIES_HALFGI;
683
684			if (rc[i].flags & ATH_RC_STBC_FLAG)
685				series[i].RateFlags |= HAL_RATESERIES_STBC;
686		}
687
688		/*
689		 * TODO: If we're all doing 11n rates then we can set LDPC.
690		 * If we've been asked to /do/ LDPC but we are handed a
691		 * legacy rate, then we should complain.  Loudly.
692		 */
693
694		/*
695		 * PktDuration doesn't include slot, ACK, RTS, etc timing -
696		 * it's just the packet duration
697		 */
698		if (rc[i].flags & ATH_RC_HT_FLAG) {
699			series[i].PktDuration =
700			    ath_computedur_ht(pktlen
701				, series[i].Rate
702				, HT_RC_2_STREAMS(series[i].Rate)
703				, series[i].RateFlags & HAL_RATESERIES_2040
704				, series[i].RateFlags & HAL_RATESERIES_HALFGI);
705		} else {
706			if (shortPreamble)
707				series[i].Rate |=
708				    rt->info[rc[i].rix].shortPreamble;
709			/* XXX TODO: don't include SIFS */
710			series[i].PktDuration = ath_hal_computetxtime(ah,
711			    rt, pktlen, rc[i].rix, shortPreamble, AH_TRUE);
712		}
713	}
714}
715
716#ifdef	ATH_DEBUG
717static void
718ath_rateseries_print(struct ath_softc *sc, HAL_11N_RATE_SERIES *series)
719{
720	int i;
721	for (i = 0; i < ATH_RC_NUM; i++) {
722		device_printf(sc->sc_dev ,"series %d: rate %x; tries %d; "
723		    "pktDuration %d; chSel %d; txpowcap %d, rateFlags %x\n",
724		    i,
725		    series[i].Rate,
726		    series[i].Tries,
727		    series[i].PktDuration,
728		    series[i].ChSel,
729		    series[i].tx_power_cap,
730		    series[i].RateFlags);
731	}
732}
733#endif
734
735/*
736 * Setup the 11n rate scenario and burst duration for the given TX descriptor
737 * list.
738 *
739 * This isn't useful for sending beacon frames, which has different needs
740 * wrt what's passed into the rate scenario function.
741 */
742void
743ath_buf_set_rate(struct ath_softc *sc, struct ieee80211_node *ni,
744    struct ath_buf *bf)
745{
746	HAL_11N_RATE_SERIES series[4];
747	struct ath_desc *ds = bf->bf_desc;
748	struct ath_hal *ah = sc->sc_ah;
749	int is_pspoll = (bf->bf_state.bfs_atype == HAL_PKT_TYPE_PSPOLL);
750	int ctsrate = bf->bf_state.bfs_ctsrate;
751	int flags = bf->bf_state.bfs_txflags;
752
753	/* Setup rate scenario */
754	memset(&series, 0, sizeof(series));
755
756	ath_rateseries_setup(sc, ni, bf, series);
757
758#ifdef	ATH_DEBUG
759	if (sc->sc_debug & ATH_DEBUG_XMIT)
760		ath_rateseries_print(sc, series);
761#endif
762
763	/* Set rate scenario */
764	/*
765	 * Note: Don't allow hardware to override the duration on
766	 * ps-poll packets.
767	 */
768	ath_hal_set11nratescenario(ah, ds,
769	    !is_pspoll,	/* whether to override the duration or not */
770	    ctsrate,	/* rts/cts rate */
771	    series,	/* 11n rate series */
772	    4,		/* number of series */
773	    flags);
774
775	/* Set burst duration */
776	/*
777	 * This is only required when doing 11n burst, not aggregation
778	 * ie, if there's a second frame in a RIFS or A-MPDU burst
779	 * w/ >1 A-MPDU frame bursting back to back.
780	 * Normal A-MPDU doesn't do bursting -between- aggregates.
781	 *
782	 * .. and it's highly likely this won't ever be implemented
783	 */
784	//ath_hal_set11nburstduration(ah, ds, 8192);
785}
786
787/*
788 * Form an aggregate packet list.
789 *
790 * This function enforces the aggregate restrictions/requirements.
791 *
792 * These are:
793 *
794 * + The aggregate size maximum (64k for AR9160 and later, 8K for
795 *   AR5416 when doing RTS frame protection.)
796 * + Maximum number of sub-frames for an aggregate
797 * + The aggregate delimiter size, giving MACs time to do whatever is
798 *   needed before each frame
799 * + Enforce the BAW limit
800 *
801 * Each descriptor queued should have the DMA setup.
802 * The rate series, descriptor setup, linking, etc is all done
803 * externally. This routine simply chains them together.
804 * ath_tx_setds_11n() will take care of configuring the per-
805 * descriptor setup, and ath_buf_set_rate() will configure the
806 * rate control.
807 *
808 * The TID lock is required for the entirety of this function.
809 *
810 * If some code in another thread adds to the head of this
811 * list, very strange behaviour will occur. Since retransmission is the
812 * only reason this will occur, and this routine is designed to be called
813 * from within the scheduler task, it won't ever clash with the completion
814 * task.
815 *
816 * So if you want to call this from an upper layer context (eg, to direct-
817 * dispatch aggregate frames to the hardware), please keep this in mind.
818 */
819ATH_AGGR_STATUS
820ath_tx_form_aggr(struct ath_softc *sc, struct ath_node *an,
821    struct ath_tid *tid, ath_bufhead *bf_q)
822{
823	//struct ieee80211_node *ni = &an->an_node;
824	struct ath_buf *bf, *bf_first = NULL, *bf_prev = NULL;
825	int nframes = 0;
826	uint16_t aggr_limit = 0, al = 0, bpad = 0, al_delta, h_baw;
827	struct ieee80211_tx_ampdu *tap;
828	int status = ATH_AGGR_DONE;
829	int prev_frames = 0;	/* XXX for AR5416 burst, not done here */
830	int prev_al = 0;	/* XXX also for AR5416 burst */
831
832	ATH_TX_LOCK_ASSERT(sc);
833
834	tap = ath_tx_get_tx_tid(an, tid->tid);
835	if (tap == NULL) {
836		status = ATH_AGGR_ERROR;
837		goto finish;
838	}
839
840	/*
841	 * Limit the maximum number of frames in this A-MPDU
842	 * to half of the window size.  This is done to prevent
843	 * sending a LOT of frames that may fail in one batch
844	 * when operating in higher MCS rates.  If there are more
845	 * frames available to send then up to two A-MPDUs will
846	 * be queued per hardware queue, so we'll "just" get
847	 * a second A-MPDU.
848	 */
849	h_baw = tap->txa_wnd / 2;
850
851	for (;;) {
852		bf = ATH_TID_FIRST(tid);
853		if (bf == NULL) {
854			status = ATH_AGGR_DONE;
855			break;
856		}
857		if (bf_first == NULL) {
858			bf_first = bf;
859			/*
860			 * It's the first frame;
861			 * set the aggregation limit based on the
862			 * rate control decision that has been made.
863			 */
864			aggr_limit = ath_get_aggr_limit(sc, &an->an_node,
865			    bf_first);
866			if (bf_first->bf_state.bfs_rc_maxpktlen > 0) {
867				aggr_limit = MIN(aggr_limit,
868				    bf_first->bf_state.bfs_rc_maxpktlen);
869			}
870		}
871
872		/* Set this early just so things don't get confused */
873		bf->bf_next = NULL;
874
875		/*
876		 * If the frame doesn't have a sequence number that we're
877		 * tracking in the BAW (eg NULL QOS data frame), we can't
878		 * aggregate it. Stop the aggregation process; the sender
879		 * can then TX what's in the list thus far and then
880		 * TX the frame individually.
881		 */
882		if (! bf->bf_state.bfs_dobaw) {
883			status = ATH_AGGR_NONAGGR;
884			break;
885		}
886
887		/*
888		 * If any of the rates are non-HT, this packet
889		 * can't be aggregated.
890		 * XXX TODO: add a bf_state flag which gets marked
891		 * if any active rate is non-HT.
892		 */
893
894		/*
895		 * do not exceed aggregation limit
896		 */
897		al_delta = ATH_AGGR_DELIM_SZ + bf->bf_state.bfs_pktlen;
898		if (nframes &&
899		    (aggr_limit < (al + bpad + al_delta + prev_al))) {
900			status = ATH_AGGR_LIMITED;
901			break;
902		}
903
904		/*
905		 * If RTS/CTS is set on the first frame, enforce
906		 * the RTS aggregate limit.
907		 */
908		if (bf_first->bf_state.bfs_txflags &
909		    (HAL_TXDESC_CTSENA | HAL_TXDESC_RTSENA)) {
910			if (nframes &&
911			   (sc->sc_rts_aggr_limit <
912			     (al + bpad + al_delta + prev_al))) {
913				status = ATH_AGGR_8K_LIMITED;
914				break;
915			}
916		}
917
918		/*
919		 * Do not exceed subframe limit.
920		 */
921		if ((nframes + prev_frames) >= MIN((h_baw),
922		    IEEE80211_AMPDU_SUBFRAME_DEFAULT)) {
923			status = ATH_AGGR_LIMITED;
924			break;
925		}
926
927		/*
928		 * If the current frame has an RTS/CTS configuration
929		 * that differs from the first frame, override the
930		 * subsequent frame with this config.
931		 */
932		if (bf != bf_first) {
933			bf->bf_state.bfs_txflags &=
934			    ~ (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
935			bf->bf_state.bfs_txflags |=
936			    bf_first->bf_state.bfs_txflags &
937			    (HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA);
938		}
939
940		/*
941		 * If the packet has a sequence number, do not
942		 * step outside of the block-ack window.
943		 */
944		if (! BAW_WITHIN(tap->txa_start, tap->txa_wnd,
945		    SEQNO(bf->bf_state.bfs_seqno))) {
946			status = ATH_AGGR_BAW_CLOSED;
947			break;
948		}
949
950		/*
951		 * this packet is part of an aggregate.
952		 */
953		ATH_TID_REMOVE(tid, bf, bf_list);
954
955		/* The TID lock is required for the BAW update */
956		ath_tx_addto_baw(sc, an, tid, bf);
957		bf->bf_state.bfs_addedbaw = 1;
958
959		/*
960		 * XXX enforce ACK for aggregate frames (this needs to be
961		 * XXX handled more gracefully?
962		 */
963		if (bf->bf_state.bfs_txflags & HAL_TXDESC_NOACK) {
964			device_printf(sc->sc_dev,
965			    "%s: HAL_TXDESC_NOACK set for an aggregate frame?\n",
966			    __func__);
967			bf->bf_state.bfs_txflags &= (~HAL_TXDESC_NOACK);
968		}
969
970		/*
971		 * Add the now owned buffer (which isn't
972		 * on the software TXQ any longer) to our
973		 * aggregate frame list.
974		 */
975		TAILQ_INSERT_TAIL(bf_q, bf, bf_list);
976		nframes ++;
977
978		/* Completion handler */
979		bf->bf_comp = ath_tx_aggr_comp;
980
981		/*
982		 * add padding for previous frame to aggregation length
983		 */
984		al += bpad + al_delta;
985
986		/*
987		 * Calculate delimiters needed for the current frame
988		 */
989		bf->bf_state.bfs_ndelim =
990		    ath_compute_num_delims(sc, bf_first,
991		    bf->bf_state.bfs_pktlen, (bf_first == bf));
992
993		/*
994		 * Calculate the padding needed from this set of delimiters,
995		 * used when calculating if the next frame will fit in
996		 * the aggregate.
997		 */
998		bpad = PADBYTES(al_delta) + (bf->bf_state.bfs_ndelim << 2);
999
1000		/*
1001		 * Chain the buffers together
1002		 */
1003		if (bf_prev)
1004			bf_prev->bf_next = bf;
1005		bf_prev = bf;
1006
1007		/*
1008		 * If we're leaking frames, just return at this point;
1009		 * we've queued a single frame and we don't want to add
1010		 * any more.
1011		 */
1012		if (tid->an->an_leak_count) {
1013			status = ATH_AGGR_LEAK_CLOSED;
1014			break;
1015		}
1016
1017#if 0
1018		/*
1019		 * terminate aggregation on a small packet boundary
1020		 */
1021		if (bf->bf_state.bfs_pktlen < ATH_AGGR_MINPLEN) {
1022			status = ATH_AGGR_SHORTPKT;
1023			break;
1024		}
1025#endif
1026	}
1027
1028finish:
1029	/*
1030	 * Just in case the list was empty when we tried to
1031	 * dequeue a packet ..
1032	 */
1033	if (bf_first) {
1034		DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
1035		"%s: al=%d bytes; requested %d bytes\n",
1036		__func__, al, bf_first->bf_state.bfs_rc_maxpktlen);
1037
1038		bf_first->bf_state.bfs_al = al;
1039		bf_first->bf_state.bfs_nframes = nframes;
1040	}
1041	return status;
1042}
1043