LXR linux/net/mac80211/rc80211

   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 */
  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 EWMV (Exponentially Weighted Moving Variance) calculation
  40 */
  41static inline int
  42minstrel_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
  51struct 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
  73struct 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
  88struct 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
 119struct 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
 144struct minstrel_debugfs_info {
 145        size_t len;
 146        char buf[];
 147};
 148
 149/* Get EWMSD (Exponentially Weighted Moving Standard Deviation) * 10 */
 150static inline int
 151minstrel_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
 157extern const struct rate_control_ops mac80211_minstrel;
 158void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 159void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
 160
 161/* Recalculate success probabilities and counters for a given rate using EWMA */
 162void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs);
 163int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
 164
 165/* debugfs */
 166int minstrel_stats_open(struct inode *inode, struct file *file);
 167int minstrel_stats_csv_open(struct inode *inode, struct file *file);
 168ssize_t minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos);
 169int minstrel_stats_release(struct inode *inode, struct file *file);
 170
 171#endif
 172