1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2005 John Bicket
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 * 3. Neither the names of the above-listed copyright holders nor the names
18 * of any contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * Alternatively, this software may be distributed under the terms of the
22 * GNU General Public License ("GPL") version 2 as published by the Free
23 * Software Foundation.
24 *
25 * NO WARRANTY
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
29 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
30 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
31 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
34 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
36 * THE POSSIBILITY OF SUCH DAMAGES.
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 * We track performance for eight different packet size buckets.
78 */
79 #define NUM_PACKET_SIZE_BINS 7
80
81 static const int packet_size_bins[NUM_PACKET_SIZE_BINS] = { 250, 1600, 4096, 8192, 16384, 32768, 65536 };
82
83 static inline int
bin_to_size(int index)84 bin_to_size(int index)
85 {
86 return packet_size_bins[index];
87 }
88
89 /* per-node state */
90 struct sample_node {
91 int static_rix; /* rate index of fixed tx rate */
92 #define SAMPLE_MAXRATES 64 /* NB: corresponds to hal info[32] */
93 uint64_t ratemask; /* bit mask of valid rate indices */
94 const struct txschedule *sched; /* tx schedule table */
95
96 const HAL_RATE_TABLE *currates;
97
98 struct rate_stats stats[NUM_PACKET_SIZE_BINS][SAMPLE_MAXRATES];
99 int last_sample_rix[NUM_PACKET_SIZE_BINS];
100
101 int current_sample_rix[NUM_PACKET_SIZE_BINS];
102 int packets_sent[NUM_PACKET_SIZE_BINS];
103
104 int current_rix[NUM_PACKET_SIZE_BINS];
105 int packets_since_switch[NUM_PACKET_SIZE_BINS];
106 int ticks_since_switch[NUM_PACKET_SIZE_BINS];
107
108 int packets_since_sample[NUM_PACKET_SIZE_BINS];
109 unsigned sample_tt[NUM_PACKET_SIZE_BINS];
110 };
111
112 #ifdef _KERNEL
113
114 #define ATH_NODE_SAMPLE(an) ((struct sample_node *)&(an)[1])
115 #define IS_RATE_DEFINED(sn, rix) (((uint64_t) (sn)->ratemask & (1ULL<<((uint64_t) rix))) != 0)
116
117 #ifndef MIN
118 #define MIN(a,b) ((a) < (b) ? (a) : (b))
119 #endif
120 #ifndef MAX
121 #define MAX(a,b) ((a) > (b) ? (a) : (b))
122 #endif
123
124 #define WIFI_CW_MIN 31
125 #define WIFI_CW_MAX 1023
126
127 /*
128 * Calculate the transmit duration of a frame.
129 */
calc_usecs_unicast_packet(struct ath_softc * sc,int length,int rix,int short_retries,int long_retries,int is_ht40)130 static unsigned calc_usecs_unicast_packet(struct ath_softc *sc,
131 int length,
132 int rix, int short_retries,
133 int long_retries, int is_ht40)
134 {
135 const HAL_RATE_TABLE *rt = sc->sc_currates;
136 struct ieee80211com *ic = &sc->sc_ic;
137 int rts, cts;
138
139 unsigned t_slot = 20;
140 unsigned t_difs = 50;
141 unsigned t_sifs = 10;
142 int tt = 0;
143 int x = 0;
144 int cw = WIFI_CW_MIN;
145 int cix;
146
147 KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
148
149 if (rix >= rt->rateCount) {
150 printf("bogus rix %d, max %u, mode %u\n",
151 rix, rt->rateCount, sc->sc_curmode);
152 return 0;
153 }
154 cix = rt->info[rix].controlRate;
155 /*
156 * XXX getting mac/phy level timings should be fixed for turbo
157 * rates, and there is probably a way to get this from the
158 * hal...
159 */
160 switch (rt->info[rix].phy) {
161 case IEEE80211_T_OFDM:
162 t_slot = 9;
163 t_sifs = 16;
164 t_difs = 28;
165 /* fall through */
166 case IEEE80211_T_TURBO:
167 t_slot = 9;
168 t_sifs = 8;
169 t_difs = 28;
170 break;
171 case IEEE80211_T_HT:
172 t_slot = 9;
173 t_sifs = 8;
174 t_difs = 28;
175 break;
176 case IEEE80211_T_DS:
177 /* fall through to default */
178 default:
179 /* pg 205 ieee.802.11.pdf */
180 t_slot = 20;
181 t_difs = 50;
182 t_sifs = 10;
183 }
184
185 rts = cts = 0;
186
187 if ((ic->ic_flags & IEEE80211_F_USEPROT) &&
188 rt->info[rix].phy == IEEE80211_T_OFDM) {
189 if (ic->ic_protmode == IEEE80211_PROT_RTSCTS)
190 rts = 1;
191 else if (ic->ic_protmode == IEEE80211_PROT_CTSONLY)
192 cts = 1;
193
194 cix = rt->info[sc->sc_protrix].controlRate;
195 }
196
197 if (0 /*length > ic->ic_rtsthreshold */) {
198 rts = 1;
199 }
200
201 if (rts || cts) {
202 int ctsrate;
203 int ctsduration = 0;
204
205 /* NB: this is intentionally not a runtime check */
206 KASSERT(cix < rt->rateCount,
207 ("bogus cix %d, max %u, mode %u\n", cix, rt->rateCount,
208 sc->sc_curmode));
209
210 ctsrate = rt->info[cix].rateCode | rt->info[cix].shortPreamble;
211 if (rts) /* SIFS + CTS */
212 ctsduration += rt->info[cix].spAckDuration;
213
214 /* XXX assumes short preamble, include SIFS */
215 ctsduration += ath_hal_pkt_txtime(sc->sc_ah, rt, length, rix,
216 is_ht40, 0, 1);
217
218 if (cts) /* SIFS + ACK */
219 ctsduration += rt->info[cix].spAckDuration;
220
221 tt += (short_retries + 1) * ctsduration;
222 }
223 tt += t_difs;
224
225 /* XXX assumes short preamble, include SIFS */
226 tt += (long_retries+1)*ath_hal_pkt_txtime(sc->sc_ah, rt, length, rix,
227 is_ht40, 0, 1);
228
229 tt += (long_retries+1)*(t_sifs + rt->info[rix].spAckDuration);
230
231 for (x = 0; x <= short_retries + long_retries; x++) {
232 cw = MIN(WIFI_CW_MAX, (cw + 1) * 2);
233 tt += (t_slot * cw/2);
234 }
235 return tt;
236 }
237
238 #endif /* _KERNEL */
239
240 #endif /* _DEV_ATH_RATE_SAMPLE_H */
241