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 struct minstrel_rate_stats {
  39         /* current / last sampling period attempts/success counters */
  40         u16 attempts, last_attempts;
  41         u16 success, last_success;
  42
  43         /* total attempts/success counters */
  44         u32 att_hist, succ_hist;
  45
  46         /* prob_ewma - exponential weighted moving average of prob */
  47         u16 prob_ewma;
  48
  49         /* maximum retry counts */
  50         u8 retry_count;
  51         u8 retry_count_rtscts;
  52
  53         u8 sample_skipped;
  54         bool retry_updated;
  55 };
  56
  57 struct minstrel_rate {
  58         int bitrate;
  59
  60         s8 rix;
  61         u8 retry_count_cts;
  62         u8 adjusted_retry_count;
  63
  64         unsigned int perfect_tx_time;
  65         unsigned int ack_time;
  66
  67         int sample_limit;
  68
  69         struct minstrel_rate_stats stats;
  70 };
  71
  72 struct minstrel_sta_info {
  73         struct ieee80211_sta *sta;
  74
  75         unsigned long last_stats_update;
  76         unsigned int sp_ack_dur;
  77         unsigned int rate_avg;
  78
  79         unsigned int lowest_rix;
  80
  81         u8 max_tp_rate[MAX_THR_RATES];
  82         u8 max_prob_rate;
  83         unsigned int total_packets;
  84         unsigned int sample_packets;
  85         int sample_deferred;
  86
  87         unsigned int sample_row;
  88         unsigned int sample_column;
  89
  90         int n_rates;
  91         struct minstrel_rate *r;
  92         bool prev_sample;
  93
  94         /* sampling table */
  95         u8 *sample_table;
  96 };
  97
  98 struct minstrel_priv {
  99         struct ieee80211_hw *hw;
 100         bool has_mrr;
 101         unsigned int cw_min;
 102         unsigned int cw_max;
 103         unsigned int max_retry;
 104         unsigned int segment_size;
 105         unsigned int update_interval;
 106         unsigned int lookaround_rate;
 107         unsigned int lookaround_rate_mrr;
 108
 109         u8 cck_rates[4];
 110
 111 #ifdef CONFIG_MAC80211_DEBUGFS
 112         /*
 113          * enable fixed rate processing per RC
 114          *   - write static index to debugfs:ieee80211/phyX/rc/fixed_rate_idx
 115          *   - write -1 to enable RC processing again
 116          *   - setting will be applied on next update
 117          */
 118         u32 fixed_rate_idx;
 119 #endif
 120 };
 121
 122 struct minstrel_debugfs_info {
 123         size_t len;
 124         char buf[];
 125 };
 126
 127 extern const struct rate_control_ops mac80211_minstrel;
 128 void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 129
 130 /* Recalculate success probabilities and counters for a given rate using EWMA */
 131 void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs);
 132 int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
 133
 134 /* debugfs */
 135 int minstrel_stats_open(struct inode *inode, struct file *file);
 136 int minstrel_stats_csv_open(struct inode *inode, struct file *file);
 137
 138 #endif