1 /*-
2 * Copyright (c) 2005 John Bicket
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 * 3. Neither the names of the above-listed copyright holders nor the names
16 * of any contributors may be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 *
19 * Alternatively, this software may be distributed under the terms of the
20 * GNU General Public License ("GPL") version 2 as published by the Free
21 * Software Foundation.
22 *
23 * NO WARRANTY
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTABILITY
27 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
28 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
29 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
32 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
34 * THE POSSIBILITY OF SUCH DAMAGES.
35 *
36 * $FreeBSD$
37 */
38
39 /*
40 * Defintions for the Atheros Wireless LAN controller driver.
41 */
42 #ifndef _DEV_ATH_RATE_SAMPLE_H
43 #define _DEV_ATH_RATE_SAMPLE_H
44
45 /* per-device state */
46 struct sample_softc {
47 struct ath_ratectrl arc; /* base class */
48 int smoothing_rate; /* ewma percentage [0..99] */
49 int smoothing_minpackets;
50 int sample_rate; /* %time to try different tx rates */
51 int max_successive_failures;
52 int stale_failure_timeout; /* how long to honor max_successive_failures */
53 int min_switch; /* min time between rate changes */
54 int min_good_pct; /* min good percentage for a rate to be considered */
55 };
56 #define ATH_SOFTC_SAMPLE(sc) ((struct sample_softc *)sc->sc_rc)
57
58 struct rate_stats {
59 unsigned average_tx_time;
60 int successive_failures;
61 uint64_t tries;
62 uint64_t total_packets; /* pkts total since assoc */
63 uint64_t packets_acked; /* pkts acked since assoc */
64 int ewma_pct; /* EWMA percentage */
65 unsigned perfect_tx_time; /* transmit time for 0 retries */
66 int last_tx;
67 };
68
69 struct txschedule {
70 uint8_t t0, r0; /* series 0: tries, rate code */
71 uint8_t t1, r1; /* series 1: tries, rate code */
72 uint8_t t2, r2; /* series 2: tries, rate code */
73 uint8_t t3, r3; /* series 3: tries, rate code */
74 };
75
76 /*
77 * for now, we track performance for three different packet
78 * size buckets
79 */
80 #define NUM_PACKET_SIZE_BINS 2
81
82 static const int packet_size_bins[NUM_PACKET_SIZE_BINS] = { 250, 1600 };
83
84 static inline int
bin_to_size(int index)85 bin_to_size(int index)
86 {
87 return packet_size_bins[index];
88 }
89
90 /* per-node state */
91 struct sample_node {
92 int static_rix; /* rate index of fixed tx rate */
93 #define SAMPLE_MAXRATES 64 /* NB: corresponds to hal info[32] */
94 uint64_t ratemask; /* bit mask of valid rate indices */
95 const struct txschedule *sched; /* tx schedule table */
96
97 const HAL_RATE_TABLE *currates;
98
99 struct rate_stats stats[NUM_PACKET_SIZE_BINS][SAMPLE_MAXRATES];
100 int last_sample_rix[NUM_PACKET_SIZE_BINS];
101
102 int current_sample_rix[NUM_PACKET_SIZE_BINS];
103 int packets_sent[NUM_PACKET_SIZE_BINS];
104
105 int current_rix[NUM_PACKET_SIZE_BINS];
106 int packets_since_switch[NUM_PACKET_SIZE_BINS];
107 unsigned ticks_since_switch[NUM_PACKET_SIZE_BINS];
108
109 int packets_since_sample[NUM_PACKET_SIZE_BINS];
110 unsigned sample_tt[NUM_PACKET_SIZE_BINS];
111 };
112
113 #ifdef _KERNEL
114
115 #define ATH_NODE_SAMPLE(an) ((struct sample_node *)&(an)[1])
116 #define IS_RATE_DEFINED(sn, rix) (((uint64_t)(sn)->ratemask & (1ULL<<((uint64_t) rix))) != 0)
117
118 #ifndef MIN
119 #define MIN(a,b) ((a) < (b) ? (a) : (b))
120 #endif
121 #ifndef MAX
122 #define MAX(a,b) ((a) > (b) ? (a) : (b))
123 #endif
124
125 #define WIFI_CW_MIN 31
126 #define WIFI_CW_MAX 1023
127
128 /*
129 * Calculate the transmit duration of a frame.
130 */
calc_usecs_unicast_packet(struct ath_softc * sc,int length,int rix,int short_retries,int long_retries,int is_ht40)131 static unsigned calc_usecs_unicast_packet(struct ath_softc *sc,
132 int length,
133 int rix, int short_retries,
134 int long_retries, int is_ht40)
135 {
136 const HAL_RATE_TABLE *rt = sc->sc_currates;
137 struct ieee80211com *ic = &sc->sc_ic;
138 int rts, cts;
139
140 unsigned t_slot = 20;
141 unsigned t_difs = 50;
142 unsigned t_sifs = 10;
143 int tt = 0;
144 int x = 0;
145 int cw = WIFI_CW_MIN;
146 int cix;
147
148 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
149
150 if (rix >= rt->rateCount) {
151 kprintf("bogus rix %d, max %u, mode %u\n",
152 rix, rt->rateCount, sc->sc_curmode);
153 return 0;
154 }
155 cix = rt->info[rix].controlRate;
156 /*
157 * XXX getting mac/phy level timings should be fixed for turbo
158 * rates, and there is probably a way to get this from the
159 * hal...
160 */
161 switch (rt->info[rix].phy) {
162 case IEEE80211_T_OFDM:
163 t_slot = 9;
164 t_sifs = 16;
165 t_difs = 28;
166 /* fall through */
167 case IEEE80211_T_TURBO:
168 t_slot = 9;
169 t_sifs = 8;
170 t_difs = 28;
171 break;
172 case IEEE80211_T_HT:
173 t_slot = 9;
174 t_sifs = 8;
175 t_difs = 28;
176 break;
177 case IEEE80211_T_DS:
178 /* fall through to default */
179 default:
180 /* pg 205 ieee.802.11.pdf */
181 t_slot = 20;
182 t_difs = 50;
183 t_sifs = 10;
184 }
185
186 rts = cts = 0;
187
188 if ((ic->ic_flags & IEEE80211_F_USEPROT) &&
189 rt->info[rix].phy == IEEE80211_T_OFDM) {
190 if (ic->ic_protmode == IEEE80211_PROT_RTSCTS)
191 rts = 1;
192 else if (ic->ic_protmode == IEEE80211_PROT_CTSONLY)
193 cts = 1;
194
195 cix = rt->info[sc->sc_protrix].controlRate;
196 }
197
198 if (0 /*length > ic->ic_rtsthreshold */) {
199 rts = 1;
200 }
201
202 if (rts || cts) {
203 int ctsrate;
204 int ctsduration = 0;
205
206 /* NB: this is intentionally not a runtime check */
207 KASSERT(cix < rt->rateCount,
208 ("bogus cix %d, max %u, mode %u\n", cix, rt->rateCount,
209 sc->sc_curmode));
210
211 ctsrate = rt->info[cix].rateCode | rt->info[cix].shortPreamble;
212 if (rts) /* SIFS + CTS */
213 ctsduration += rt->info[cix].spAckDuration;
214
215 /* XXX assumes short preamble */
216 ctsduration += ath_hal_pkt_txtime(sc->sc_ah, rt, length, rix,
217 is_ht40, 0);
218
219 if (cts) /* SIFS + ACK */
220 ctsduration += rt->info[cix].spAckDuration;
221
222 tt += (short_retries + 1) * ctsduration;
223 }
224 tt += t_difs;
225
226 /* XXX assumes short preamble */
227 tt += (long_retries+1)*ath_hal_pkt_txtime(sc->sc_ah, rt, length, rix,
228 is_ht40, 0);
229
230 tt += (long_retries+1)*(t_sifs + rt->info[rix].spAckDuration);
231
232 for (x = 0; x <= short_retries + long_retries; x++) {
233 cw = MIN(WIFI_CW_MAX, (cw + 1) * 2);
234 tt += (t_slot * cw/2);
235 }
236 return tt;
237 }
238
239 #endif /* _KERNEL */
240
241 #endif /* _DEV_ATH_RATE_SAMPLE_H */
242