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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
*/
#ifndef __RC_MINSTREL_H
#define __RC_MINSTREL_H
#define EWMA_LEVEL 96 /* ewma weighting factor [/EWMA_DIV] */
#define EWMA_DIV 128
#define SAMPLE_COLUMNS 10 /* number of columns in sample table */
/* scaled fraction values */
#define MINSTREL_SCALE 12
#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
/* number of highest throughput rates to consider*/
#define MAX_THR_RATES 4
/*
* Coefficients for moving average with noise filter (period=16),
* scaled by 10 bits
*
* a1 = exp(-pi * sqrt(2) / period)
* coeff2 = 2 * a1 * cos(sqrt(2) * 2 * pi / period)
* coeff3 = -sqr(a1)
* coeff1 = 1 - coeff2 - coeff3
*/
#define MINSTREL_AVG_COEFF1 (MINSTREL_FRAC(1, 1) - \
MINSTREL_AVG_COEFF2 - \
MINSTREL_AVG_COEFF3)
#define MINSTREL_AVG_COEFF2 0x00001499
#define MINSTREL_AVG_COEFF3 -0x0000092e
/*
* Perform EWMA (Exponentially Weighted Moving Average) calculation
*/
static inline int
minstrel_ewma(int old, int new, int weight)
{
int diff, incr;
diff = new - old;
incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
return old + incr;
}
struct minstrel_avg_ctx {
s32 prev[2];
};
static inline int minstrel_filter_avg_add(struct minstrel_avg_ctx *ctx, s32 in)
{
s32 out_1 = ctx->prev[0];
s32 out_2 = ctx->prev[1];
s32 val;
if (!in)
in += 1;
if (!out_1) {
val = out_1 = in;
goto out;
}
val = MINSTREL_AVG_COEFF1 * in;
val += MINSTREL_AVG_COEFF2 * out_1;
val += MINSTREL_AVG_COEFF3 * out_2;
val >>= MINSTREL_SCALE;
if (val > 1 << MINSTREL_SCALE)
val = 1 << MINSTREL_SCALE;
if (val < 0)
val = 1;
out:
ctx->prev[1] = out_1;
ctx->prev[0] = val;
return val;
}
struct minstrel_rate_stats {
/* current / last sampling period attempts/success counters */
u16 attempts, last_attempts;
u16 success, last_success;
/* total attempts/success counters */
u32 att_hist, succ_hist;
struct minstrel_avg_ctx avg;
/* prob_ewma - exponential weighted moving average of prob */
u16 prob_ewma;
/* maximum retry counts */
u8 retry_count;
u8 retry_count_rtscts;
u8 sample_skipped;
bool retry_updated;
};
struct minstrel_rate {
int bitrate;
s8 rix;
u8 retry_count_cts;
u8 adjusted_retry_count;
unsigned int perfect_tx_time;
unsigned int ack_time;
int sample_limit;
struct minstrel_rate_stats stats;
};
struct minstrel_sta_info {
struct ieee80211_sta *sta;
unsigned long last_stats_update;
unsigned int sp_ack_dur;
unsigned int rate_avg;
unsigned int lowest_rix;
u8 max_tp_rate[MAX_THR_RATES];
u8 max_prob_rate;
unsigned int total_packets;
unsigned int sample_packets;
int sample_deferred;
unsigned int sample_row;
unsigned int sample_column;
int n_rates;
struct minstrel_rate *r;
bool prev_sample;
/* sampling table */
u8 *sample_table;
};
struct minstrel_priv {
struct ieee80211_hw *hw;
bool has_mrr;
bool new_avg;
u32 sample_switch;
unsigned int cw_min;
unsigned int cw_max;
unsigned int max_retry;
unsigned int segment_size;
unsigned int update_interval;
unsigned int lookaround_rate;
unsigned int lookaround_rate_mrr;
u8 cck_rates[4];
#ifdef CONFIG_MAC80211_DEBUGFS
/*
* enable fixed rate processing per RC
* - write static index to debugfs:ieee80211/phyX/rc/fixed_rate_idx
* - write -1 to enable RC processing again
* - setting will be applied on next update
*/
u32 fixed_rate_idx;
#endif
};
struct minstrel_debugfs_info {
size_t len;
char buf[];
};
extern const struct rate_control_ops mac80211_minstrel;
void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
/* Recalculate success probabilities and counters for a given rate using EWMA */
void minstrel_calc_rate_stats(struct minstrel_priv *mp,
struct minstrel_rate_stats *mrs);
int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
/* debugfs */
int minstrel_stats_open(struct inode *inode, struct file *file);
int minstrel_stats_csv_open(struct inode *inode, struct file *file);
#endif
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