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
17/* scaled fraction values */
18#define MINSTREL_SCALE  16
19#define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
20#define MINSTREL_TRUNC(val) ((val) >> MINSTREL_SCALE)
21
22/* number of highest throughput rates to consider*/
23#define MAX_THR_RATES 4
24
25/*
26 * Perform EWMA (Exponentially Weighted Moving Average) calculation
27  */
28static inline int
29minstrel_ewma(int old, int new, int weight)
30{
31	return (new * (EWMA_DIV - weight) + old * weight) / EWMA_DIV;
32}
33
34struct minstrel_rate_stats {
35	/* current / last sampling period attempts/success counters */
36	unsigned int attempts, last_attempts;
37	unsigned int success, last_success;
38
39	/* total attempts/success counters */
40	u64 att_hist, succ_hist;
41
42	/* current throughput */
43	unsigned int cur_tp;
44
45	/* packet delivery probabilities */
46	unsigned int cur_prob, probability;
47
48	/* maximum retry counts */
49	unsigned int retry_count;
50	unsigned int retry_count_rtscts;
51
52	u8 sample_skipped;
53	bool retry_updated;
54};
55
56struct minstrel_rate {
57	int bitrate;
58	int rix;
59
60	unsigned int perfect_tx_time;
61	unsigned int ack_time;
62
63	int sample_limit;
64	unsigned int retry_count_cts;
65	unsigned int adjusted_retry_count;
66
67	struct minstrel_rate_stats stats;
68};
69
70struct minstrel_sta_info {
71	struct ieee80211_sta *sta;
72
73	unsigned long stats_update;
74	unsigned int sp_ack_dur;
75	unsigned int rate_avg;
76
77	unsigned int lowest_rix;
78
79	u8 max_tp_rate[MAX_THR_RATES];
80	u8 max_prob_rate;
81	unsigned int total_packets;
82	unsigned int sample_packets;
83	int sample_deferred;
84
85	unsigned int sample_row;
86	unsigned int sample_column;
87
88	int n_rates;
89	struct minstrel_rate *r;
90	bool prev_sample;
91
92	/* sampling table */
93	u8 *sample_table;
94
95#ifdef CONFIG_MAC80211_DEBUGFS
96	struct dentry *dbg_stats;
97#endif
98};
99
100struct minstrel_priv {
101	struct ieee80211_hw *hw;
102	bool has_mrr;
103	unsigned int cw_min;
104	unsigned int cw_max;
105	unsigned int max_retry;
106	unsigned int segment_size;
107	unsigned int update_interval;
108	unsigned int lookaround_rate;
109	unsigned int lookaround_rate_mrr;
110
111	u8 cck_rates[4];
112
113#ifdef CONFIG_MAC80211_DEBUGFS
114	/*
115	 * enable fixed rate processing per RC
116	 *   - write static index to debugfs:ieee80211/phyX/rc/fixed_rate_idx
117	 *   - write -1 to enable RC processing again
118	 *   - setting will be applied on next update
119	 */
120	u32 fixed_rate_idx;
121	struct dentry *dbg_fixed_rate;
122#endif
123
124};
125
126struct minstrel_debugfs_info {
127	size_t len;
128	char buf[];
129};
130
131extern const struct rate_control_ops mac80211_minstrel;
132void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
133void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
134
135/* debugfs */
136int minstrel_stats_open(struct inode *inode, struct file *file);
137ssize_t minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos);
138int minstrel_stats_release(struct inode *inode, struct file *file);
139
140#endif
141