xref: /freebsd/sys/dev/ath/ath_rate/sample/sample.h (revision a7623790fb345e6dc986dfd31df0ace115e6f2e4)
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  * $FreeBSD$
39  */
40 
41 /*
42  * Defintions for the Atheros Wireless LAN controller driver.
43  */
44 #ifndef _DEV_ATH_RATE_SAMPLE_H
45 #define _DEV_ATH_RATE_SAMPLE_H
46 
47 /* per-device state */
48 struct sample_softc {
49 	struct ath_ratectrl arc;	/* base class */
50 	int	smoothing_rate;		/* ewma percentage [0..99] */
51 	int	smoothing_minpackets;
52 	int	sample_rate;		/* %time to try different tx rates */
53 	int	max_successive_failures;
54 	int	stale_failure_timeout;	/* how long to honor max_successive_failures */
55 	int	min_switch;		/* min time between rate changes */
56 	int	min_good_pct;		/* min good percentage for a rate to be considered */
57 };
58 #define	ATH_SOFTC_SAMPLE(sc)	((struct sample_softc *)sc->sc_rc)
59 
60 struct rate_stats {
61 	unsigned average_tx_time;
62 	int successive_failures;
63 	uint64_t tries;
64 	uint64_t total_packets;	/* pkts total since assoc */
65 	uint64_t packets_acked;	/* pkts acked since assoc */
66 	int ewma_pct;	/* EWMA percentage */
67 	unsigned perfect_tx_time; /* transmit time for 0 retries */
68 	int last_tx;
69 };
70 
71 struct txschedule {
72 	uint8_t	t0, r0;		/* series 0: tries, rate code */
73 	uint8_t	t1, r1;		/* series 1: tries, rate code */
74 	uint8_t	t2, r2;		/* series 2: tries, rate code */
75 	uint8_t	t3, r3;		/* series 3: tries, rate code */
76 };
77 
78 /*
79  * We track performance for eight different packet size buckets.
80  */
81 #define NUM_PACKET_SIZE_BINS 7
82 
83 static const int packet_size_bins[NUM_PACKET_SIZE_BINS]  = { 250, 1600, 4096, 8192, 16384, 32768, 65536 };
84 
85 static inline int
86 bin_to_size(int index)
87 {
88 	return packet_size_bins[index];
89 }
90 
91 /* per-node state */
92 struct sample_node {
93 	int static_rix;			/* rate index of fixed tx rate */
94 #define	SAMPLE_MAXRATES	64		/* NB: corresponds to hal info[32] */
95 	uint64_t ratemask;		/* bit mask of valid rate indices */
96 	const struct txschedule *sched;	/* tx schedule table */
97 
98 	const HAL_RATE_TABLE *currates;
99 
100 	struct rate_stats stats[NUM_PACKET_SIZE_BINS][SAMPLE_MAXRATES];
101 	int last_sample_rix[NUM_PACKET_SIZE_BINS];
102 
103 	int current_sample_rix[NUM_PACKET_SIZE_BINS];
104 	int packets_sent[NUM_PACKET_SIZE_BINS];
105 
106 	int current_rix[NUM_PACKET_SIZE_BINS];
107 	int packets_since_switch[NUM_PACKET_SIZE_BINS];
108 	int ticks_since_switch[NUM_PACKET_SIZE_BINS];
109 
110 	int packets_since_sample[NUM_PACKET_SIZE_BINS];
111 	unsigned sample_tt[NUM_PACKET_SIZE_BINS];
112 };
113 
114 #ifdef	_KERNEL
115 
116 #define	ATH_NODE_SAMPLE(an)	((struct sample_node *)&(an)[1])
117 #define	IS_RATE_DEFINED(sn, rix)	(((uint64_t) (sn)->ratemask & (1ULL<<((uint64_t) rix))) != 0)
118 
119 #ifndef MIN
120 #define	MIN(a,b)	((a) < (b) ? (a) : (b))
121 #endif
122 #ifndef MAX
123 #define	MAX(a,b)	((a) > (b) ? (a) : (b))
124 #endif
125 
126 #define WIFI_CW_MIN 31
127 #define WIFI_CW_MAX 1023
128 
129 /*
130  * Calculate the transmit duration of a frame.
131  */
132 static unsigned calc_usecs_unicast_packet(struct ath_softc *sc,
133 				int length,
134 				int rix, int short_retries,
135 				int long_retries, int is_ht40)
136 {
137 	const HAL_RATE_TABLE *rt = sc->sc_currates;
138 	struct ieee80211com *ic = &sc->sc_ic;
139 	int rts, cts;
140 
141 	unsigned t_slot = 20;
142 	unsigned t_difs = 50;
143 	unsigned t_sifs = 10;
144 	int tt = 0;
145 	int x = 0;
146 	int cw = WIFI_CW_MIN;
147 	int cix;
148 
149 	KASSERT(rt != NULL, ("no rate table, mode %u", sc->sc_curmode));
150 
151 	if (rix >= rt->rateCount) {
152 		printf("bogus rix %d, max %u, mode %u\n",
153 		       rix, rt->rateCount, sc->sc_curmode);
154 		return 0;
155 	}
156 	cix = rt->info[rix].controlRate;
157 	/*
158 	 * XXX getting mac/phy level timings should be fixed for turbo
159 	 * rates, and there is probably a way to get this from the
160 	 * hal...
161 	 */
162 	switch (rt->info[rix].phy) {
163 	case IEEE80211_T_OFDM:
164 		t_slot = 9;
165 		t_sifs = 16;
166 		t_difs = 28;
167 		/* fall through */
168 	case IEEE80211_T_TURBO:
169 		t_slot = 9;
170 		t_sifs = 8;
171 		t_difs = 28;
172 		break;
173 	case IEEE80211_T_HT:
174 		t_slot = 9;
175 		t_sifs = 8;
176 		t_difs = 28;
177 		break;
178 	case IEEE80211_T_DS:
179 		/* fall through to default */
180 	default:
181 		/* pg 205 ieee.802.11.pdf */
182 		t_slot = 20;
183 		t_difs = 50;
184 		t_sifs = 10;
185 	}
186 
187 	rts = cts = 0;
188 
189 	if ((ic->ic_flags & IEEE80211_F_USEPROT) &&
190 	    rt->info[rix].phy == IEEE80211_T_OFDM) {
191 		if (ic->ic_protmode == IEEE80211_PROT_RTSCTS)
192 			rts = 1;
193 		else if (ic->ic_protmode == IEEE80211_PROT_CTSONLY)
194 			cts = 1;
195 
196 		cix = rt->info[sc->sc_protrix].controlRate;
197 	}
198 
199 	if (0 /*length > ic->ic_rtsthreshold */) {
200 		rts = 1;
201 	}
202 
203 	if (rts || cts) {
204 		int ctsrate;
205 		int ctsduration = 0;
206 
207 		/* NB: this is intentionally not a runtime check */
208 		KASSERT(cix < rt->rateCount,
209 		    ("bogus cix %d, max %u, mode %u\n", cix, rt->rateCount,
210 		     sc->sc_curmode));
211 
212 		ctsrate = rt->info[cix].rateCode | rt->info[cix].shortPreamble;
213 		if (rts)		/* SIFS + CTS */
214 			ctsduration += rt->info[cix].spAckDuration;
215 
216 		/* XXX assumes short preamble, include SIFS */
217 		ctsduration += ath_hal_pkt_txtime(sc->sc_ah, rt, length, rix,
218 		    is_ht40, 0, 1);
219 
220 		if (cts)	/* SIFS + ACK */
221 			ctsduration += rt->info[cix].spAckDuration;
222 
223 		tt += (short_retries + 1) * ctsduration;
224 	}
225 	tt += t_difs;
226 
227 	/* XXX assumes short preamble, include SIFS */
228 	tt += (long_retries+1)*ath_hal_pkt_txtime(sc->sc_ah, rt, length, rix,
229 	    is_ht40, 0, 1);
230 
231 	tt += (long_retries+1)*(t_sifs + rt->info[rix].spAckDuration);
232 
233 	for (x = 0; x <= short_retries + long_retries; x++) {
234 		cw = MIN(WIFI_CW_MAX, (cw + 1) * 2);
235 		tt += (t_slot * cw/2);
236 	}
237 	return tt;
238 }
239 
240 #endif	/* _KERNEL */
241 
242 #endif /* _DEV_ATH_RATE_SAMPLE_H */
243