net/mac80211/rc80211_minstrel.h

   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  12
  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  */
  27 static inline int
  28 minstrel_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 EWMV (Exponentially Weighted Moving Variance) calculation
  40  */
  41 static inline int
  42 minstrel_ewmv(int old_ewmv, int cur_prob, int prob_ewma, int weight)
  43 {
  44         int diff, incr;
  45
  46         diff = cur_prob - prob_ewma;
  47         incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
  48         return weight * (old_ewmv + MINSTREL_TRUNC(diff * incr)) / EWMA_DIV;
  49 }
  50
  51 struct minstrel_rate_stats {
  52         /* current / last sampling period attempts/success counters */
  53         u16 attempts, last_attempts;
  54         u16 success, last_success;
  55
  56         /* total attempts/success counters */
  57         u32 att_hist, succ_hist;
  58
  59         /* statistis of packet delivery probability
  60          *  prob_ewma - exponential weighted moving average of prob
  61          *  prob_ewmsd - exp. weighted moving standard deviation of prob */
  62         u16 prob_ewma;
  63         u16 prob_ewmv;
  64
  65         /* maximum retry counts */
  66         u8 retry_count;
  67         u8 retry_count_rtscts;
  68
  69         u8 sample_skipped;
  70         bool retry_updated;
  71 };
  72
  73 struct minstrel_rate {
  74         int bitrate;
  75
  76         s8 rix;
  77         u8 retry_count_cts;
  78         u8 adjusted_retry_count;
  79
  80         unsigned int perfect_tx_time;
  81         unsigned int ack_time;
  82
  83         int sample_limit;
  84
  85         struct minstrel_rate_stats stats;
  86 };
  87
  88 struct minstrel_sta_info {
  89         struct ieee80211_sta *sta;
  90
  91         unsigned long last_stats_update;
  92         unsigned int sp_ack_dur;
  93         unsigned int rate_avg;
  94
  95         unsigned int lowest_rix;
  96
  97         u8 max_tp_rate[MAX_THR_RATES];
  98         u8 max_prob_rate;
  99         unsigned int total_packets;
 100         unsigned int sample_packets;
 101         int sample_deferred;
 102
 103         unsigned int sample_row;
 104         unsigned int sample_column;
 105
 106         int n_rates;
 107         struct minstrel_rate *r;
 108         bool prev_sample;
 109
 110         /* sampling table */
 111         u8 *sample_table;
 112
 113 #ifdef CONFIG_MAC80211_DEBUGFS
 114         struct dentry *dbg_stats;
 115         struct dentry *dbg_stats_csv;
 116 #endif
 117 };
 118
 119 struct minstrel_priv {
 120         struct ieee80211_hw *hw;
 121         bool has_mrr;
 122         unsigned int cw_min;
 123         unsigned int cw_max;
 124         unsigned int max_retry;
 125         unsigned int segment_size;
 126         unsigned int update_interval;
 127         unsigned int lookaround_rate;
 128         unsigned int lookaround_rate_mrr;
 129
 130         u8 cck_rates[4];
 131
 132 #ifdef CONFIG_MAC80211_DEBUGFS
 133         /*
 134          * enable fixed rate processing per RC
 135          *   - write static index to debugfs:ieee80211/phyX/rc/fixed_rate_idx
 136          *   - write -1 to enable RC processing again
 137          *   - setting will be applied on next update
 138          */
 139         u32 fixed_rate_idx;
 140         struct dentry *dbg_fixed_rate;
 141 #endif
 142 };
 143
 144 struct minstrel_debugfs_info {
 145         size_t len;
 146         char buf[];
 147 };
 148
 149 /* Get EWMSD (Exponentially Weighted Moving Standard Deviation) * 10 */
 150 static inline int
 151 minstrel_get_ewmsd10(struct minstrel_rate_stats *mrs)
 152 {
 153         unsigned int ewmv = mrs->prob_ewmv;
 154         return int_sqrt(MINSTREL_TRUNC(ewmv * 1000 * 1000));
 155 }
 156
 157 extern const struct rate_control_ops mac80211_minstrel;
 158 void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 159 void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
 160
 161 /* Recalculate success probabilities and counters for a given rate using EWMA */
 162 void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs);
 163 int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
 164
 165 /* debugfs */
 166 int minstrel_stats_open(struct inode *inode, struct file *file);
 167 int minstrel_stats_csv_open(struct inode *inode, struct file *file);
 168 ssize_t minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos);
 169 int minstrel_stats_release(struct inode *inode, struct file *file);
 170
 171 #endif