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1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
4 */
5
6#ifndef __RC_MINSTREL_H
7#define __RC_MINSTREL_H
8
9#define EWMA_LEVEL 96 /* ewma weighting factor [/EWMA_DIV] */
10#define EWMA_DIV 128
11#define SAMPLE_COLUMNS 10 /* number of columns in sample table */
12
13/* scaled fraction values */
14#define MINSTREL_SCALE 12
15#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
16#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
17
18/* number of highest throughput rates to consider*/
19#define MAX_THR_RATES 4
20
21/*
22 * Coefficients for moving average with noise filter (period=16),
23 * scaled by 10 bits
24 *
25 * a1 = exp(-pi * sqrt(2) / period)
26 * coeff2 = 2 * a1 * cos(sqrt(2) * 2 * pi / period)
27 * coeff3 = -sqr(a1)
28 * coeff1 = 1 - coeff2 - coeff3
29 */
30#define MINSTREL_AVG_COEFF1 (MINSTREL_FRAC(1, 1) - \
31 MINSTREL_AVG_COEFF2 - \
32 MINSTREL_AVG_COEFF3)
33#define MINSTREL_AVG_COEFF2 0x00001499
34#define MINSTREL_AVG_COEFF3 -0x0000092e
35
36/*
37 * Perform EWMA (Exponentially Weighted Moving Average) calculation
38 */
39static inline int
40minstrel_ewma(int old, int new, int weight)
41{
42 int diff, incr;
43
44 diff = new - old;
45 incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
46
47 return old + incr;
48}
49
50static inline int minstrel_filter_avg_add(u16 *prev_1, u16 *prev_2, s32 in)
51{
52 s32 out_1 = *prev_1;
53 s32 out_2 = *prev_2;
54 s32 val;
55
56 if (!in)
57 in += 1;
58
59 if (!out_1) {
60 val = out_1 = in;
61 goto out;
62 }
63
64 val = MINSTREL_AVG_COEFF1 * in;
65 val += MINSTREL_AVG_COEFF2 * out_1;
66 val += MINSTREL_AVG_COEFF3 * out_2;
67 val >>= MINSTREL_SCALE;
68
69 if (val > 1 << MINSTREL_SCALE)
70 val = 1 << MINSTREL_SCALE;
71 if (val < 0)
72 val = 1;
73
74out:
75 *prev_2 = out_1;
76 *prev_1 = val;
77
78 return val;
79}
80
81struct minstrel_rate_stats {
82 /* current / last sampling period attempts/success counters */
83 u16 attempts, last_attempts;
84 u16 success, last_success;
85
86 /* total attempts/success counters */
87 u32 att_hist, succ_hist;
88
89 /* prob_avg - moving average of prob */
90 u16 prob_avg;
91 u16 prob_avg_1;
92
93 /* maximum retry counts */
94 u8 retry_count;
95 u8 retry_count_rtscts;
96
97 u8 sample_skipped;
98 bool retry_updated;
99};
100
101struct minstrel_rate {
102 int bitrate;
103
104 s8 rix;
105 u8 retry_count_cts;
106 u8 adjusted_retry_count;
107
108 unsigned int perfect_tx_time;
109 unsigned int ack_time;
110
111 int sample_limit;
112
113 struct minstrel_rate_stats stats;
114};
115
116struct minstrel_sta_info {
117 struct ieee80211_sta *sta;
118
119 unsigned long last_stats_update;
120 unsigned int sp_ack_dur;
121 unsigned int rate_avg;
122
123 unsigned int lowest_rix;
124
125 u8 max_tp_rate[MAX_THR_RATES];
126 u8 max_prob_rate;
127 unsigned int total_packets;
128 unsigned int sample_packets;
129 int sample_deferred;
130
131 unsigned int sample_row;
132 unsigned int sample_column;
133
134 int n_rates;
135 struct minstrel_rate *r;
136 bool prev_sample;
137
138 /* sampling table */
139 u8 *sample_table;
140};
141
142struct minstrel_priv {
143 struct ieee80211_hw *hw;
144 bool has_mrr;
145 bool new_avg;
146 u32 sample_switch;
147 unsigned int cw_min;
148 unsigned int cw_max;
149 unsigned int max_retry;
150 unsigned int segment_size;
151 unsigned int update_interval;
152 unsigned int lookaround_rate;
153 unsigned int lookaround_rate_mrr;
154
155 u8 cck_rates[4];
156
157#ifdef CONFIG_MAC80211_DEBUGFS
158 /*
159 * enable fixed rate processing per RC
160 * - write static index to debugfs:ieee80211/phyX/rc/fixed_rate_idx
161 * - write -1 to enable RC processing again
162 * - setting will be applied on next update
163 */
164 u32 fixed_rate_idx;
165#endif
166};
167
168struct minstrel_debugfs_info {
169 size_t len;
170 char buf[];
171};
172
173extern const struct rate_control_ops mac80211_minstrel;
174void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
175
176/* Recalculate success probabilities and counters for a given rate using EWMA */
177void minstrel_calc_rate_stats(struct minstrel_priv *mp,
178 struct minstrel_rate_stats *mrs);
179int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_avg);
180
181/* debugfs */
182int minstrel_stats_open(struct inode *inode, struct file *file);
183int minstrel_stats_csv_open(struct inode *inode, struct file *file);
184
185#endif
1/*
2 * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9#ifndef __RC_MINSTREL_H
10#define __RC_MINSTREL_H
11
12#define EWMA_LEVEL 96 /* ewma weighting factor [/EWMA_DIV] */
13#define EWMA_DIV 128
14#define SAMPLE_COLUMNS 10 /* number of columns in sample table */
15
16/* scaled fraction values */
17#define MINSTREL_SCALE 16
18#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
19#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
20
21/* number of highest throughput rates to consider*/
22#define MAX_THR_RATES 4
23
24/*
25 * Perform EWMA (Exponentially Weighted Moving Average) calculation
26 */
27static inline int
28minstrel_ewma(int old, int new, int weight)
29{
30 int diff, incr;
31
32 diff = new - old;
33 incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
34
35 return old + incr;
36}
37
38/*
39 * Perform EWMSD (Exponentially Weighted Moving Standard Deviation) calculation
40 */
41static inline int
42minstrel_ewmsd(int old_ewmsd, int cur_prob, int prob_ewma, int weight)
43{
44 int diff, incr, tmp_var;
45
46 /* calculate exponential weighted moving variance */
47 diff = MINSTREL_TRUNC((cur_prob - prob_ewma) * 1000000);
48 incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
49 tmp_var = old_ewmsd * old_ewmsd;
50 tmp_var = weight * (tmp_var + diff * incr / 1000000) / EWMA_DIV;
51
52 /* return standard deviation */
53 return (u16) int_sqrt(tmp_var);
54}
55
56struct minstrel_rate_stats {
57 /* current / last sampling period attempts/success counters */
58 u16 attempts, last_attempts;
59 u16 success, last_success;
60
61 /* total attempts/success counters */
62 u64 att_hist, succ_hist;
63
64 /* statistis of packet delivery probability
65 * cur_prob - current prob within last update intervall
66 * prob_ewma - exponential weighted moving average of prob
67 * prob_ewmsd - exp. weighted moving standard deviation of prob */
68 unsigned int cur_prob;
69 unsigned int prob_ewma;
70 u16 prob_ewmsd;
71
72 /* maximum retry counts */
73 u8 retry_count;
74 u8 retry_count_rtscts;
75
76 u8 sample_skipped;
77 bool retry_updated;
78};
79
80struct minstrel_rate {
81 int bitrate;
82
83 s8 rix;
84 u8 retry_count_cts;
85 u8 adjusted_retry_count;
86
87 unsigned int perfect_tx_time;
88 unsigned int ack_time;
89
90 int sample_limit;
91
92 struct minstrel_rate_stats stats;
93};
94
95struct minstrel_sta_info {
96 struct ieee80211_sta *sta;
97
98 unsigned long last_stats_update;
99 unsigned int sp_ack_dur;
100 unsigned int rate_avg;
101
102 unsigned int lowest_rix;
103
104 u8 max_tp_rate[MAX_THR_RATES];
105 u8 max_prob_rate;
106 unsigned int total_packets;
107 unsigned int sample_packets;
108 int sample_deferred;
109
110 unsigned int sample_row;
111 unsigned int sample_column;
112
113 int n_rates;
114 struct minstrel_rate *r;
115 bool prev_sample;
116
117 /* sampling table */
118 u8 *sample_table;
119
120#ifdef CONFIG_MAC80211_DEBUGFS
121 struct dentry *dbg_stats;
122 struct dentry *dbg_stats_csv;
123#endif
124};
125
126struct minstrel_priv {
127 struct ieee80211_hw *hw;
128 bool has_mrr;
129 unsigned int cw_min;
130 unsigned int cw_max;
131 unsigned int max_retry;
132 unsigned int segment_size;
133 unsigned int update_interval;
134 unsigned int lookaround_rate;
135 unsigned int lookaround_rate_mrr;
136
137 u8 cck_rates[4];
138
139#ifdef CONFIG_MAC80211_DEBUGFS
140 /*
141 * enable fixed rate processing per RC
142 * - write static index to debugfs:ieee80211/phyX/rc/fixed_rate_idx
143 * - write -1 to enable RC processing again
144 * - setting will be applied on next update
145 */
146 u32 fixed_rate_idx;
147 struct dentry *dbg_fixed_rate;
148#endif
149};
150
151struct minstrel_debugfs_info {
152 size_t len;
153 char buf[];
154};
155
156extern const struct rate_control_ops mac80211_minstrel;
157void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
158void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
159
160/* Recalculate success probabilities and counters for a given rate using EWMA */
161void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs);
162int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
163
164/* debugfs */
165int minstrel_stats_open(struct inode *inode, struct file *file);
166int minstrel_stats_csv_open(struct inode *inode, struct file *file);
167ssize_t minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos);
168int minstrel_stats_release(struct inode *inode, struct file *file);
169
170#endif