1 /*
2 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
3 * Use is subject to license terms.
4 */
5
6 /*
7 * Copyright (c) 2003, 2004 David Young. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or
10 * without modification, are permitted provided that the following
11 * conditions are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer in the documentation and/or other materials provided
17 * with the distribution.
18 * 3. The name of David Young may not be used to endorse or promote
19 * products derived from this software without specific prior
20 * written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY David Young ``AS IS'' AND ANY
23 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
24 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
25 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL David
26 * Young BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
27 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
28 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
30 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
33 * OF SUCH DAMAGE.
34 */
35
36 #include <sys/types.h>
37 #include <sys/byteorder.h>
38 #include <sys/conf.h>
39 #include <sys/cmn_err.h>
40 #include <sys/ddi.h>
41 #include <sys/sunddi.h>
42 #include <sys/stream.h>
43 #include <sys/strsun.h>
44 #include <sys/modctl.h>
45 #include <sys/devops.h>
46 #include <sys/dlpi.h>
47 #include <sys/gld.h>
48 #include <sys/varargs.h>
49 #include <sys/pci.h>
50 #include <sys/net80211.h>
51
52 #include "ral_rate.h"
53
54 #define MAX(a, b) ((a) > (b) ? (a) : (b))
55
56 #ifdef interpolate
57 #undef interpolate
58 #endif
59 #define interpolate(parm, old, new) \
60 ((parm##_old * (old) + \
61 (parm##_denom - parm##_old) * (new)) / \
62 parm##_denom)
63
64 static struct ral_rssadapt_expavgctl master_expavgctl;
65
66 void
ral_rate_init(void)67 ral_rate_init(void)
68 {
69 master_expavgctl.rc_decay_denom = 16;
70 master_expavgctl.rc_decay_old = 15;
71 master_expavgctl.rc_thresh_denom = 8;
72 master_expavgctl.rc_thresh_old = 4;
73 master_expavgctl.rc_avgrssi_denom = 8;
74 master_expavgctl.rc_avgrssi_old = 4;
75 }
76
77 /* ARGSUSED */
78 int
ral_rssadapt_choose(struct ral_rssadapt * ra,struct ieee80211_rateset * rs,struct ieee80211_frame * wh,uint32_t len,const char * dvname,int do_not_adapt)79 ral_rssadapt_choose(struct ral_rssadapt *ra, struct ieee80211_rateset *rs,
80 struct ieee80211_frame *wh, uint32_t len,
81 const char *dvname, int do_not_adapt)
82 {
83 uint16_t (*thrs)[IEEE80211_RATE_SIZE];
84 int flags = 0, i, rateidx = 0, thridx, top;
85
86 if ((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
87 flags |= IEEE80211_RATE_BASIC;
88
89 for (i = 0, top = RAL_RSSADAPT_BKT0;
90 i < RAL_RSSADAPT_BKTS;
91 i++, top <<= RAL_RSSADAPT_BKTPOWER) {
92 thridx = i;
93 if (len <= top)
94 break;
95 }
96
97 thrs = &ra->ra_rate_thresh[thridx];
98
99 i = rs->ir_nrates;
100 while (--i >= 0) {
101 rateidx = i;
102 if ((rs->ir_rates[i] & flags) != flags)
103 continue;
104 if (do_not_adapt)
105 break;
106 if ((*thrs)[i] < ra->ra_avg_rssi)
107 break;
108 }
109
110 return (rateidx);
111 }
112
113 void
ral_rssadapt_updatestats(struct ral_rssadapt * ra)114 ral_rssadapt_updatestats(struct ral_rssadapt *ra)
115 {
116 long interval;
117
118 ra->ra_pktrate =
119 (ra->ra_pktrate + 10 * (ra->ra_nfail + ra->ra_nok)) / 2;
120 ra->ra_nfail = ra->ra_nok = 0;
121
122 /*
123 * a node is eligible for its rate to be raised every 1/10 to 10
124 * seconds, more eligible in proportion to recent packet rates.
125 */
126 interval = MAX(100000, 10000000 / MAX(1, 10 * ra->ra_pktrate));
127 ra->ra_raise_interval.tv_sec = interval / (1000 * 1000);
128 ra->ra_raise_interval.tv_usec = interval % (1000 * 1000);
129 }
130
131 /* ARGSUSED */
132 void
ral_rssadapt_input(struct ieee80211com * ic,struct ieee80211_node * ni,struct ral_rssadapt * ra,int rssi)133 ral_rssadapt_input(struct ieee80211com *ic, struct ieee80211_node *ni,
134 struct ral_rssadapt *ra, int rssi)
135 {
136 ra->ra_avg_rssi = interpolate(master_expavgctl.rc_avgrssi,
137 ra->ra_avg_rssi, (rssi << 8));
138 }
139
140 /*
141 * Adapt the data rate to suit the conditions. When a transmitted
142 * packet is dropped after RAL_RSSADAPT_RETRY_LIMIT retransmissions,
143 * raise the RSS threshold for transmitting packets of similar length at
144 * the same data rate.
145 */
146 /* ARGSUSED */
147 void
ral_rssadapt_lower_rate(struct ieee80211com * ic,struct ieee80211_node * ni,struct ral_rssadapt * ra,struct ral_rssdesc * id)148 ral_rssadapt_lower_rate(struct ieee80211com *ic, struct ieee80211_node *ni,
149 struct ral_rssadapt *ra, struct ral_rssdesc *id)
150 {
151 struct ieee80211_rateset *rs = &ni->in_rates;
152 uint16_t last_thr;
153 uint32_t i, thridx, top;
154
155 ra->ra_nfail++;
156
157 if (id->id_rateidx >= rs->ir_nrates)
158 return;
159
160 for (i = 0, top = RAL_RSSADAPT_BKT0;
161 i < RAL_RSSADAPT_BKTS;
162 i++, top <<= RAL_RSSADAPT_BKTPOWER) {
163 thridx = i;
164 if (id->id_len <= top)
165 break;
166 }
167
168 last_thr = ra->ra_rate_thresh[thridx][id->id_rateidx];
169 ra->ra_rate_thresh[thridx][id->id_rateidx] =
170 interpolate(master_expavgctl.rc_thresh, last_thr,
171 (id->id_rssi << 8));
172 }
173
174 /* ARGSUSED */
175 void
ral_rssadapt_raise_rate(struct ieee80211com * ic,struct ral_rssadapt * ra,struct ral_rssdesc * id)176 ral_rssadapt_raise_rate(struct ieee80211com *ic, struct ral_rssadapt *ra,
177 struct ral_rssdesc *id)
178 {
179 uint16_t (*thrs)[IEEE80211_RATE_SIZE], newthr, oldthr;
180 struct ieee80211_node *ni = id->id_node;
181 struct ieee80211_rateset *rs = &ni->in_rates;
182 int i, top;
183
184 ra->ra_nok++;
185
186 for (i = 0, top = RAL_RSSADAPT_BKT0;
187 i < RAL_RSSADAPT_BKTS;
188 i++, top <<= RAL_RSSADAPT_BKTPOWER) {
189 thrs = &ra->ra_rate_thresh[i];
190 if (id->id_len <= top)
191 break;
192 }
193
194 if (id->id_rateidx + 1 < rs->ir_nrates &&
195 (*thrs)[id->id_rateidx + 1] > (*thrs)[id->id_rateidx]) {
196 oldthr = (*thrs)[id->id_rateidx + 1];
197 if ((*thrs)[id->id_rateidx] == 0)
198 newthr = ra->ra_avg_rssi;
199 else
200 newthr = (*thrs)[id->id_rateidx];
201 (*thrs)[id->id_rateidx + 1] =
202 interpolate(master_expavgctl.rc_decay, oldthr, newthr);
203 }
204 }
205