xref: /titanic_44/usr/src/uts/common/io/ath/ath_rate.c (revision b6917abefc343244b784f0cc34bc65b01469c3bf)
1 /*
2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 2002-2004 Sam Leffler, Errno Consulting
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  * notice, this list of conditions and the following disclaimer,
15  * without modification.
16  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
17  * similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
18  * redistribution must be conditioned upon including a substantially
19  * similar Disclaimer requirement for further binary redistribution.
20  * 3. Neither the names of the above-listed copyright holders nor the names
21  * of any contributors may be used to endorse or promote products derived
22  * from this software without specific prior written permission.
23  *
24  * NO WARRANTY
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
28  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
29  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
30  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
33  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
35  * THE POSSIBILITY OF SUCH DAMAGES.
36  */
37 
38 #pragma ident	"%Z%%M%	%I%	%E% SMI"
39 
40 #include <sys/param.h>
41 #include <sys/types.h>
42 #include <sys/signal.h>
43 #include <sys/stream.h>
44 #include <sys/termio.h>
45 #include <sys/errno.h>
46 #include <sys/file.h>
47 #include <sys/cmn_err.h>
48 #include <sys/stropts.h>
49 #include <sys/strsubr.h>
50 #include <sys/strtty.h>
51 #include <sys/kbio.h>
52 #include <sys/cred.h>
53 #include <sys/stat.h>
54 #include <sys/consdev.h>
55 #include <sys/kmem.h>
56 #include <sys/modctl.h>
57 #include <sys/ddi.h>
58 #include <sys/sunddi.h>
59 #include <sys/pci.h>
60 #include <sys/errno.h>
61 #include <sys/dlpi.h>
62 #include <sys/ethernet.h>
63 #include <sys/list.h>
64 #include <sys/byteorder.h>
65 #include <sys/strsun.h>
66 #include <inet/common.h>
67 #include <inet/nd.h>
68 #include <inet/mi.h>
69 #include <inet/wifi_ioctl.h>
70 #include "ath_hal.h"
71 #include "ath_impl.h"
72 #include "ath_rate.h"
73 
74 void
75 ath_rate_update(ath_t *asc, struct ieee80211_node *in, int32_t rate)
76 {
77 	struct ath_node *an = ATH_NODE(in);
78 	const HAL_RATE_TABLE *rt = asc->asc_currates;
79 	uint8_t rix;
80 
81 	in->in_txrate = rate;
82 	/* management/control frames always go at the lowest speed */
83 	an->an_tx_mgtrate = rt->info[0].rateCode;
84 	an->an_tx_mgtratesp = an->an_tx_mgtrate | rt->info[0].shortPreamble;
85 	ATH_DEBUG((ATH_DBG_RATE, "ath: ath_rate_update(): "
86 	    "mgtrate=%d mgtratesp=%d\n",
87 	    an->an_tx_mgtrate, an->an_tx_mgtratesp));
88 	/*
89 	 * Before associating a node has no rate set setup
90 	 * so we can't calculate any transmit codes to use.
91 	 * This is ok since we should never be sending anything
92 	 * but management frames and those always go at the
93 	 * lowest hardware rate.
94 	 */
95 	if (in->in_rates.ir_nrates == 0)
96 		goto done;
97 	an->an_tx_rix0 = asc->asc_rixmap[
98 	    in->in_rates.ir_rates[rate] & IEEE80211_RATE_VAL];
99 	an->an_tx_rate0 = rt->info[an->an_tx_rix0].rateCode;
100 	an->an_tx_rate0sp = an->an_tx_rate0 |
101 	    rt->info[an->an_tx_rix0].shortPreamble;
102 	if (asc->asc_mrretry) {
103 		/*
104 		 * Hardware supports multi-rate retry; setup two
105 		 * step-down retry rates and make the lowest rate
106 		 * be the ``last chance''.  We use 4, 2, 2, 2 tries
107 		 * respectively (4 is set here, the rest are fixed
108 		 * in the xmit routine).
109 		 */
110 		an->an_tx_try0 = 1 + 3;		/* 4 tries at rate 0 */
111 		if (--rate >= 0) {
112 			rix = asc->asc_rixmap[
113 			    in->in_rates.ir_rates[rate]&IEEE80211_RATE_VAL];
114 			an->an_tx_rate1 = rt->info[rix].rateCode;
115 			an->an_tx_rate1sp = an->an_tx_rate1 |
116 			    rt->info[rix].shortPreamble;
117 		} else {
118 			an->an_tx_rate1 = an->an_tx_rate1sp = 0;
119 		}
120 		if (--rate >= 0) {
121 			rix = asc->asc_rixmap[
122 			    in->in_rates.ir_rates[rate]&IEEE80211_RATE_VAL];
123 			an->an_tx_rate2 = rt->info[rix].rateCode;
124 			an->an_tx_rate2sp = an->an_tx_rate2 |
125 			    rt->info[rix].shortPreamble;
126 		} else {
127 			an->an_tx_rate2 = an->an_tx_rate2sp = 0;
128 		}
129 		if (rate > 0) {
130 			an->an_tx_rate3 = rt->info[0].rateCode;
131 			an->an_tx_rate3sp =
132 			    an->an_tx_mgtrate | rt->info[0].shortPreamble;
133 		} else {
134 			an->an_tx_rate3 = an->an_tx_rate3sp = 0;
135 		}
136 	} else {
137 		an->an_tx_try0 = ATH_TXMAXTRY;  /* max tries at rate 0 */
138 		an->an_tx_rate1 = an->an_tx_rate1sp = 0;
139 		an->an_tx_rate2 = an->an_tx_rate2sp = 0;
140 		an->an_tx_rate3 = an->an_tx_rate3sp = 0;
141 	}
142 done:
143 	an->an_tx_ok = an->an_tx_err = an->an_tx_retr = an->an_tx_upper = 0;
144 }
145 
146 
147 /*
148  * Set the starting transmit rate for a node.
149  */
150 void
151 ath_rate_ctl_start(ath_t *asc, struct ieee80211_node *in)
152 {
153 	ieee80211com_t *ic = (ieee80211com_t *)asc;
154 	int32_t srate;
155 
156 	if (ic->ic_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
157 		/*
158 		 * No fixed rate is requested. For 11b start with
159 		 * the highest negotiated rate; otherwise, for 11g
160 		 * and 11a, we start "in the middle" at 24Mb or 36Mb.
161 		 */
162 		srate = in->in_rates.ir_nrates - 1;
163 		if (asc->asc_curmode != IEEE80211_MODE_11B) {
164 			/*
165 			 * Scan the negotiated rate set to find the
166 			 * closest rate.
167 			 */
168 			/* NB: the rate set is assumed sorted */
169 			for (; srate >= 0 && IEEE80211_RATE(srate) > 72;
170 			    srate--) {}
171 		}
172 	} else {
173 		/*
174 		 * A fixed rate is to be used; We know the rate is
175 		 * there because the rate set is checked when the
176 		 * station associates.
177 		 */
178 		/* NB: the rate set is assumed sorted */
179 		srate = in->in_rates.ir_nrates - 1;
180 		for (; srate >= 0 && IEEE80211_RATE(srate) != ic->ic_fixed_rate;
181 		    srate--) {}
182 	}
183 	ATH_DEBUG((ATH_DBG_RATE, "ath: ath_rate_ctl_start(): "
184 	    "srate=%d rate=%d\n", srate, IEEE80211_RATE(srate)));
185 	ath_rate_update(asc, in, srate);
186 }
187 
188 void
189 ath_rate_cb(void *arg, struct ieee80211_node *in)
190 {
191 	ath_rate_update((ath_t *)arg, in, 0);
192 }
193 
194 /*
195  * Reset the rate control state for each 802.11 state transition.
196  */
197 void
198 ath_rate_ctl_reset(ath_t *asc, enum ieee80211_state state)
199 {
200 	ieee80211com_t *ic = (ieee80211com_t *)asc;
201 	struct ieee80211_node *in;
202 
203 	if (ic->ic_opmode == IEEE80211_M_STA) {
204 		/*
205 		 * Reset local xmit state; this is really only
206 		 * meaningful when operating in station mode.
207 		 */
208 		in = (struct ieee80211_node *)ic->ic_bss;
209 		if (state == IEEE80211_S_RUN) {
210 			ath_rate_ctl_start(asc, in);
211 		} else {
212 			ath_rate_update(asc, in, 0);
213 		}
214 	} else {
215 		/*
216 		 * When operating as a station the node table holds
217 		 * the AP's that were discovered during scanning.
218 		 * For any other operating mode we want to reset the
219 		 * tx rate state of each node.
220 		 */
221 		ieee80211_iterate_nodes(&ic->ic_sta, ath_rate_cb, asc);
222 		ath_rate_update(asc, ic->ic_bss, 0);
223 	}
224 }
225 
226 
227 /*
228  * Examine and potentially adjust the transmit rate.
229  */
230 void
231 ath_rate_ctl(ieee80211com_t *isc, struct ieee80211_node *in)
232 {
233 	ath_t *asc = (ath_t *)isc;
234 	struct ath_node *an = ATH_NODE(in);
235 	struct ieee80211_rateset *rs = &in->in_rates;
236 	int32_t mod = 0, nrate, enough;
237 
238 	/*
239 	 * Rate control(very primitive version).
240 	 */
241 	asc->asc_stats.ast_rate_calls++;
242 
243 	enough = (an->an_tx_ok + an->an_tx_err >= 10);
244 
245 	/* no packet reached -> down */
246 	if (an->an_tx_err > 0 && an->an_tx_ok == 0)
247 		mod = -1;
248 
249 	/* all packets needs retry in average -> down */
250 	if (enough && an->an_tx_ok < an->an_tx_retr)
251 		mod = -1;
252 
253 	/* no error and less than 10% of packets needs retry -> up */
254 	if (enough && an->an_tx_err == 0 && an->an_tx_ok > an->an_tx_retr * 10)
255 		mod = 1;
256 
257 	nrate = in->in_txrate;
258 	switch (mod) {
259 	case 0:
260 		if (enough && an->an_tx_upper > 0)
261 			an->an_tx_upper--;
262 		break;
263 	case -1:
264 		if (nrate > 0) {
265 			nrate--;
266 			asc->asc_stats.ast_rate_drop++;
267 		}
268 		an->an_tx_upper = 0;
269 		break;
270 	case 1:
271 		if (++an->an_tx_upper < 10)
272 			break;
273 		an->an_tx_upper = 0;
274 		if (nrate + 1 < rs->ir_nrates) {
275 			nrate++;
276 			asc->asc_stats.ast_rate_raise++;
277 		}
278 		break;
279 	}
280 
281 	if (nrate != in->in_txrate) {
282 		ATH_DEBUG((ATH_DBG_RATE, "ath: ath_rate_ctl(): %dM -> %dM "
283 		    "(%d ok, %d err, %d retr)\n",
284 		    (rs->ir_rates[in->in_txrate] & IEEE80211_RATE_VAL) / 2,
285 		    (rs->ir_rates[nrate] & IEEE80211_RATE_VAL) / 2,
286 		    an->an_tx_ok, an->an_tx_err, an->an_tx_retr));
287 		ath_rate_update(asc, in, nrate);
288 	} else if (enough)
289 		an->an_tx_ok = an->an_tx_err = an->an_tx_retr = 0;
290 }
291 
292 
293 /*
294  * Read rate table from the HAL, and then
295  * copy the table to the driver's data structure.
296  */
297 void
298 ath_rate_setup(ath_t *asc, uint32_t mode)
299 {
300 	int32_t i;
301 	uint8_t maxrates;
302 	struct ieee80211_rateset *rs;
303 	struct ath_hal *ah = asc->asc_ah;
304 	ieee80211com_t *ic = (ieee80211com_t *)asc;
305 	const HAL_RATE_TABLE *rt;
306 
307 	switch (mode) {
308 	case IEEE80211_MODE_11A:
309 		asc->asc_rates[mode] = ATH_HAL_GETRATETABLE(ah, HAL_MODE_11A);
310 		break;
311 	case IEEE80211_MODE_11B:
312 		asc->asc_rates[mode] = ATH_HAL_GETRATETABLE(ah, HAL_MODE_11B);
313 		break;
314 	case IEEE80211_MODE_11G:
315 		asc->asc_rates[mode] = ATH_HAL_GETRATETABLE(ah, HAL_MODE_11G);
316 		break;
317 	case IEEE80211_MODE_TURBO_A:
318 		asc->asc_rates[mode] = ATH_HAL_GETRATETABLE(ah, HAL_MODE_TURBO);
319 		break;
320 	case IEEE80211_MODE_TURBO_G:
321 		asc->asc_rates[mode] = ATH_HAL_GETRATETABLE(ah, HAL_MODE_108G);
322 		break;
323 	default:
324 		ATH_DEBUG((ATH_DBG_RATE, "ath: ath_rate_setup(): "
325 		    "invalid mode %u\n", mode));
326 		return;
327 	}
328 
329 	rt = asc->asc_rates[mode];
330 	if (rt == NULL)
331 		return;
332 	if (rt->rateCount > IEEE80211_RATE_MAXSIZE) {
333 		ATH_DEBUG((ATH_DBG_RATE, "ath: ath_rate_setup(): "
334 		    "rate table too small (%u > %u)\n",
335 		    rt->rateCount, IEEE80211_RATE_MAXSIZE));
336 		maxrates = IEEE80211_RATE_MAXSIZE;
337 	} else
338 		maxrates = rt->rateCount;
339 	rs = &ic->ic_sup_rates[mode];
340 	for (i = 0; i < maxrates; i++)
341 		rs->ir_rates[i] = rt->info[i].dot11Rate;
342 	rs->ir_nrates = maxrates;
343 }
344