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  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  */
  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 EWMSD (Exponentially Weighted Moving Standard Deviation) calculation
  40  */
  41 static inline int
  42 minstrel_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
  56 struct 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
  80 struct 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
  95 struct 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
 126 struct 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
 151 struct minstrel_debugfs_info {
 152         size_t len;
 153         char buf[];
 154 };
 155
 156 extern const struct rate_control_ops mac80211_minstrel;
 157 void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 158 void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
 159
 160 /* Recalculate success probabilities and counters for a given rate using EWMA */
 161 void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs);
 162 int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
 163
 164 /* debugfs */
 165 int minstrel_stats_open(struct inode *inode, struct file *file);
 166 int minstrel_stats_csv_open(struct inode *inode, struct file *file);
 167 ssize_t minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos);
 168 int minstrel_stats_release(struct inode *inode, struct file *file);
 169
 170 #endif