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Mattias Nisslerad018372007-12-19 01:25:57 +01001/*
2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005, Devicescape Software, Inc.
4 * Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de>
Stefano Briviob7c50de92008-01-29 20:29:16 +01005 * Copyright 2007-2008, Stefano Brivio <stefano.brivio@polimi.it>
Mattias Nisslerad018372007-12-19 01:25:57 +01006 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#include <linux/netdevice.h>
13#include <linux/types.h>
14#include <linux/skbuff.h>
Johannes Berg4b475892008-01-02 15:17:03 +010015#include <linux/debugfs.h>
Mattias Nisslerad018372007-12-19 01:25:57 +010016#include <net/mac80211.h>
Johannes Berg2c8dccc2008-04-08 15:14:40 -040017#include "rate.h"
Luis Carlos Coboee385852008-02-23 15:17:11 +010018#include "mesh.h"
Mattias Nissler12446c62007-12-19 01:27:18 +010019#include "rc80211_pid.h"
20
Mattias Nisslerad018372007-12-19 01:25:57 +010021
22/* This is an implementation of a TX rate control algorithm that uses a PID
23 * controller. Given a target failed frames rate, the controller decides about
24 * TX rate changes to meet the target failed frames rate.
25 *
26 * The controller basically computes the following:
27 *
Stefano Brivio1dc4d1e2007-12-19 01:26:52 +010028 * adj = CP * err + CI * err_avg + CD * (err - last_err) * (1 + sharpening)
Mattias Nisslerad018372007-12-19 01:25:57 +010029 *
30 * where
31 * adj adjustment value that is used to switch TX rate (see below)
32 * err current error: target vs. current failed frames percentage
33 * last_err last error
34 * err_avg average (i.e. poor man's integral) of recent errors
Stefano Brivio1dc4d1e2007-12-19 01:26:52 +010035 * sharpening non-zero when fast response is needed (i.e. right after
36 * association or no frames sent for a long time), heading
37 * to zero over time
Mattias Nisslerad018372007-12-19 01:25:57 +010038 * CP Proportional coefficient
39 * CI Integral coefficient
40 * CD Derivative coefficient
41 *
42 * CP, CI, CD are subject to careful tuning.
43 *
44 * The integral component uses a exponential moving average approach instead of
45 * an actual sliding window. The advantage is that we don't need to keep an
46 * array of the last N error values and computation is easier.
47 *
Stefano Brivio90d501d2007-12-19 01:26:34 +010048 * Once we have the adj value, we map it to a rate by means of a learning
49 * algorithm. This algorithm keeps the state of the percentual failed frames
50 * difference between rates. The behaviour of the lowest available rate is kept
51 * as a reference value, and every time we switch between two rates, we compute
52 * the difference between the failed frames each rate exhibited. By doing so,
53 * we compare behaviours which different rates exhibited in adjacent timeslices,
54 * thus the comparison is minimally affected by external conditions. This
55 * difference gets propagated to the whole set of measurements, so that the
56 * reference is always the same. Periodically, we normalize this set so that
57 * recent events weigh the most. By comparing the adj value with this set, we
58 * avoid pejorative switches to lower rates and allow for switches to higher
59 * rates if they behaved well.
Mattias Nisslerad018372007-12-19 01:25:57 +010060 *
61 * Note that for the computations we use a fixed-point representation to avoid
62 * floating point arithmetic. Hence, all values are shifted left by
63 * RC_PID_ARITH_SHIFT.
64 */
65
Mattias Nisslerad018372007-12-19 01:25:57 +010066
Stefano Briviob7c50de92008-01-29 20:29:16 +010067/* Adjust the rate while ensuring that we won't switch to a lower rate if it
68 * exhibited a worse failed frames behaviour and we'll choose the highest rate
69 * whose failed frames behaviour is not worse than the one of the original rate
70 * target. While at it, check that the new rate is valid. */
Johannes Berg4b7679a2008-09-18 18:14:18 +020071static void rate_control_pid_adjust_rate(struct ieee80211_supported_band *sband,
72 struct ieee80211_sta *sta,
73 struct rc_pid_sta_info *spinfo, int adj,
Stefano Brivio90d501d2007-12-19 01:26:34 +010074 struct rc_pid_rateinfo *rinfo)
Mattias Nisslerad018372007-12-19 01:25:57 +010075{
Stefano Briviob7c50de92008-01-29 20:29:16 +010076 int cur_sorted, new_sorted, probe, tmp, n_bitrates, band;
Johannes Bergae17e982008-09-11 03:04:36 +020077 int cur = spinfo->txrate_idx;
Mattias Nisslerad018372007-12-19 01:25:57 +010078
Stefano Briviob7c50de92008-01-29 20:29:16 +010079 band = sband->band;
80 n_bitrates = sband->n_bitrates;
Mattias Nisslerad018372007-12-19 01:25:57 +010081
Stefano Briviob7c50de92008-01-29 20:29:16 +010082 /* Map passed arguments to sorted values. */
83 cur_sorted = rinfo[cur].rev_index;
84 new_sorted = cur_sorted + adj;
Mattias Nisslerad018372007-12-19 01:25:57 +010085
Stefano Briviob7c50de92008-01-29 20:29:16 +010086 /* Check limits. */
87 if (new_sorted < 0)
88 new_sorted = rinfo[0].rev_index;
89 else if (new_sorted >= n_bitrates)
90 new_sorted = rinfo[n_bitrates - 1].rev_index;
91
92 tmp = new_sorted;
93
94 if (adj < 0) {
95 /* Ensure that the rate decrease isn't disadvantageous. */
96 for (probe = cur_sorted; probe >= new_sorted; probe--)
97 if (rinfo[probe].diff <= rinfo[cur_sorted].diff &&
98 rate_supported(sta, band, rinfo[probe].index))
99 tmp = probe;
100 } else {
101 /* Look for rate increase with zero (or below) cost. */
102 for (probe = new_sorted + 1; probe < n_bitrates; probe++)
103 if (rinfo[probe].diff <= rinfo[new_sorted].diff &&
104 rate_supported(sta, band, rinfo[probe].index))
105 tmp = probe;
106 }
107
108 /* Fit the rate found to the nearest supported rate. */
109 do {
110 if (rate_supported(sta, band, rinfo[tmp].index)) {
Johannes Bergae17e982008-09-11 03:04:36 +0200111 spinfo->txrate_idx = rinfo[tmp].index;
Mattias Nisslerad018372007-12-19 01:25:57 +0100112 break;
113 }
Stefano Briviob7c50de92008-01-29 20:29:16 +0100114 if (adj < 0)
115 tmp--;
116 else
117 tmp++;
118 } while (tmp < n_bitrates && tmp >= 0);
Mattias Nissler12446c62007-12-19 01:27:18 +0100119
120#ifdef CONFIG_MAC80211_DEBUGFS
Johannes Bergae17e982008-09-11 03:04:36 +0200121 rate_control_pid_event_rate_change(&spinfo->events,
122 spinfo->txrate_idx,
123 sband->bitrates[spinfo->txrate_idx].bitrate);
Mattias Nissler12446c62007-12-19 01:27:18 +0100124#endif
Mattias Nisslerad018372007-12-19 01:25:57 +0100125}
126
Stefano Brivio90d501d2007-12-19 01:26:34 +0100127/* Normalize the failed frames per-rate differences. */
Mattias Nissler1946b742007-12-20 13:27:26 +0100128static void rate_control_pid_normalize(struct rc_pid_info *pinfo, int l)
Stefano Brivio90d501d2007-12-19 01:26:34 +0100129{
Mattias Nissler1946b742007-12-20 13:27:26 +0100130 int i, norm_offset = pinfo->norm_offset;
131 struct rc_pid_rateinfo *r = pinfo->rinfo;
Stefano Brivio90d501d2007-12-19 01:26:34 +0100132
Mattias Nissler1946b742007-12-20 13:27:26 +0100133 if (r[0].diff > norm_offset)
134 r[0].diff -= norm_offset;
135 else if (r[0].diff < -norm_offset)
136 r[0].diff += norm_offset;
Stefano Brivio90d501d2007-12-19 01:26:34 +0100137 for (i = 0; i < l - 1; i++)
Mattias Nissler1946b742007-12-20 13:27:26 +0100138 if (r[i + 1].diff > r[i].diff + norm_offset)
139 r[i + 1].diff -= norm_offset;
Stefano Brivio90d501d2007-12-19 01:26:34 +0100140 else if (r[i + 1].diff <= r[i].diff)
Mattias Nissler1946b742007-12-20 13:27:26 +0100141 r[i + 1].diff += norm_offset;
Stefano Brivio90d501d2007-12-19 01:26:34 +0100142}
143
Mattias Nisslerad018372007-12-19 01:25:57 +0100144static void rate_control_pid_sample(struct rc_pid_info *pinfo,
Johannes Berg4b7679a2008-09-18 18:14:18 +0200145 struct ieee80211_supported_band *sband,
146 struct ieee80211_sta *sta,
147 struct rc_pid_sta_info *spinfo)
Mattias Nisslerad018372007-12-19 01:25:57 +0100148{
Stefano Brivio90d501d2007-12-19 01:26:34 +0100149 struct rc_pid_rateinfo *rinfo = pinfo->rinfo;
Mattias Nisslerad018372007-12-19 01:25:57 +0100150 u32 pf;
151 s32 err_avg;
Mattias Nissler1946b742007-12-20 13:27:26 +0100152 u32 err_prop;
153 u32 err_int;
154 u32 err_der;
Stefano Brivio90d501d2007-12-19 01:26:34 +0100155 int adj, i, j, tmp;
Mattias Nissler1946b742007-12-20 13:27:26 +0100156 unsigned long period;
Mattias Nisslerad018372007-12-19 01:25:57 +0100157
Stefano Brivio1dc4d1e2007-12-19 01:26:52 +0100158 /* In case nothing happened during the previous control interval, turn
159 * the sharpening factor on. */
Mattias Nissler1946b742007-12-20 13:27:26 +0100160 period = (HZ * pinfo->sampling_period + 500) / 1000;
161 if (!period)
162 period = 1;
163 if (jiffies - spinfo->last_sample > 2 * period)
164 spinfo->sharp_cnt = pinfo->sharpen_duration;
Stefano Brivio1dc4d1e2007-12-19 01:26:52 +0100165
Mattias Nisslerad018372007-12-19 01:25:57 +0100166 spinfo->last_sample = jiffies;
167
Stefano Brivio1dc4d1e2007-12-19 01:26:52 +0100168 /* This should never happen, but in case, we assume the old sample is
Mattias Nisslerad018372007-12-19 01:25:57 +0100169 * still a good measurement and copy it. */
Stefano Brivio1dc4d1e2007-12-19 01:26:52 +0100170 if (unlikely(spinfo->tx_num_xmit == 0))
Mattias Nisslerad018372007-12-19 01:25:57 +0100171 pf = spinfo->last_pf;
Javier Cardonabfc32e62009-08-17 17:15:55 -0700172 else
Mattias Nisslerad018372007-12-19 01:25:57 +0100173 pf = spinfo->tx_num_failed * 100 / spinfo->tx_num_xmit;
Johannes Berg4b7679a2008-09-18 18:14:18 +0200174
Stefano Brivio1dc4d1e2007-12-19 01:26:52 +0100175 spinfo->tx_num_xmit = 0;
176 spinfo->tx_num_failed = 0;
177
Stefano Brivio90d501d2007-12-19 01:26:34 +0100178 /* If we just switched rate, update the rate behaviour info. */
Johannes Bergae17e982008-09-11 03:04:36 +0200179 if (pinfo->oldrate != spinfo->txrate_idx) {
Stefano Brivio90d501d2007-12-19 01:26:34 +0100180
181 i = rinfo[pinfo->oldrate].rev_index;
Johannes Bergae17e982008-09-11 03:04:36 +0200182 j = rinfo[spinfo->txrate_idx].rev_index;
Stefano Brivio90d501d2007-12-19 01:26:34 +0100183
184 tmp = (pf - spinfo->last_pf);
185 tmp = RC_PID_DO_ARITH_RIGHT_SHIFT(tmp, RC_PID_ARITH_SHIFT);
186
187 rinfo[j].diff = rinfo[i].diff + tmp;
Johannes Bergae17e982008-09-11 03:04:36 +0200188 pinfo->oldrate = spinfo->txrate_idx;
Stefano Brivio90d501d2007-12-19 01:26:34 +0100189 }
Johannes Berg8318d782008-01-24 19:38:38 +0100190 rate_control_pid_normalize(pinfo, sband->n_bitrates);
Stefano Brivio90d501d2007-12-19 01:26:34 +0100191
Mattias Nisslerad018372007-12-19 01:25:57 +0100192 /* Compute the proportional, integral and derivative errors. */
Stefano Brivio426706c2007-12-23 04:39:17 +0100193 err_prop = (pinfo->target << RC_PID_ARITH_SHIFT) - pf;
Mattias Nisslerad018372007-12-19 01:25:57 +0100194
Mattias Nissler1946b742007-12-20 13:27:26 +0100195 err_avg = spinfo->err_avg_sc >> pinfo->smoothing_shift;
Mattias Nisslerad018372007-12-19 01:25:57 +0100196 spinfo->err_avg_sc = spinfo->err_avg_sc - err_avg + err_prop;
Mattias Nissler1946b742007-12-20 13:27:26 +0100197 err_int = spinfo->err_avg_sc >> pinfo->smoothing_shift;
Mattias Nisslerad018372007-12-19 01:25:57 +0100198
Mattias Nissler1946b742007-12-20 13:27:26 +0100199 err_der = (pf - spinfo->last_pf) *
200 (1 + pinfo->sharpen_factor * spinfo->sharp_cnt);
Mattias Nisslerad018372007-12-19 01:25:57 +0100201 spinfo->last_pf = pf;
Stefano Brivio1dc4d1e2007-12-19 01:26:52 +0100202 if (spinfo->sharp_cnt)
203 spinfo->sharp_cnt--;
Mattias Nisslerad018372007-12-19 01:25:57 +0100204
Mattias Nissler12446c62007-12-19 01:27:18 +0100205#ifdef CONFIG_MAC80211_DEBUGFS
206 rate_control_pid_event_pf_sample(&spinfo->events, pf, err_prop, err_int,
207 err_der);
208#endif
209
Mattias Nisslerad018372007-12-19 01:25:57 +0100210 /* Compute the controller output. */
211 adj = (err_prop * pinfo->coeff_p + err_int * pinfo->coeff_i
212 + err_der * pinfo->coeff_d);
Stefano Brivio90d501d2007-12-19 01:26:34 +0100213 adj = RC_PID_DO_ARITH_RIGHT_SHIFT(adj, 2 * RC_PID_ARITH_SHIFT);
Mattias Nisslerad018372007-12-19 01:25:57 +0100214
215 /* Change rate. */
216 if (adj)
Johannes Berg4b7679a2008-09-18 18:14:18 +0200217 rate_control_pid_adjust_rate(sband, sta, spinfo, adj, rinfo);
Mattias Nisslerad018372007-12-19 01:25:57 +0100218}
219
Johannes Berg4b7679a2008-09-18 18:14:18 +0200220static void rate_control_pid_tx_status(void *priv, struct ieee80211_supported_band *sband,
221 struct ieee80211_sta *sta, void *priv_sta,
Johannes Berge039fa42008-05-15 12:55:29 +0200222 struct sk_buff *skb)
Mattias Nisslerad018372007-12-19 01:25:57 +0100223{
Mattias Nisslerad018372007-12-19 01:25:57 +0100224 struct rc_pid_info *pinfo = priv;
Johannes Berg4b7679a2008-09-18 18:14:18 +0200225 struct rc_pid_sta_info *spinfo = priv_sta;
Mattias Nissler1946b742007-12-20 13:27:26 +0100226 unsigned long period;
Johannes Berge039fa42008-05-15 12:55:29 +0200227 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
Mattias Nisslerad018372007-12-19 01:25:57 +0100228
Johannes Berg4b7679a2008-09-18 18:14:18 +0200229 if (!spinfo)
230 return;
Andrew Lutomirskidf26e7e2008-01-03 21:05:37 -0800231
Mattias Nisslerad018372007-12-19 01:25:57 +0100232 /* Ignore all frames that were sent with a different rate than the rate
233 * we currently advise mac80211 to use. */
Johannes Berge6a98542008-10-21 12:40:02 +0200234 if (info->status.rates[0].idx != spinfo->txrate_idx)
Johannes Berg4b7679a2008-09-18 18:14:18 +0200235 return;
Mattias Nisslerad018372007-12-19 01:25:57 +0100236
Mattias Nisslerad018372007-12-19 01:25:57 +0100237 spinfo->tx_num_xmit++;
238
Mattias Nissler12446c62007-12-19 01:27:18 +0100239#ifdef CONFIG_MAC80211_DEBUGFS
Johannes Berge039fa42008-05-15 12:55:29 +0200240 rate_control_pid_event_tx_status(&spinfo->events, info);
Mattias Nissler12446c62007-12-19 01:27:18 +0100241#endif
242
Mattias Nisslerad018372007-12-19 01:25:57 +0100243 /* We count frames that totally failed to be transmitted as two bad
244 * frames, those that made it out but had some retries as one good and
245 * one bad frame. */
Johannes Berge6a98542008-10-21 12:40:02 +0200246 if (!(info->flags & IEEE80211_TX_STAT_ACK)) {
Mattias Nisslerad018372007-12-19 01:25:57 +0100247 spinfo->tx_num_failed += 2;
248 spinfo->tx_num_xmit++;
Larry Finger1dc5a842008-11-16 17:09:25 -0600249 } else if (info->status.rates[0].count > 1) {
Mattias Nisslerad018372007-12-19 01:25:57 +0100250 spinfo->tx_num_failed++;
251 spinfo->tx_num_xmit++;
252 }
253
Mattias Nisslerad018372007-12-19 01:25:57 +0100254 /* Update PID controller state. */
Mattias Nissler1946b742007-12-20 13:27:26 +0100255 period = (HZ * pinfo->sampling_period + 500) / 1000;
256 if (!period)
257 period = 1;
258 if (time_after(jiffies, spinfo->last_sample + period))
Johannes Berg4b7679a2008-09-18 18:14:18 +0200259 rate_control_pid_sample(pinfo, sband, sta, spinfo);
Mattias Nisslerad018372007-12-19 01:25:57 +0100260}
261
Johannes Berg4b7679a2008-09-18 18:14:18 +0200262static void
Johannes Berge6a98542008-10-21 12:40:02 +0200263rate_control_pid_get_rate(void *priv, struct ieee80211_sta *sta,
264 void *priv_sta,
265 struct ieee80211_tx_rate_control *txrc)
Mattias Nisslerad018372007-12-19 01:25:57 +0100266{
Johannes Berge6a98542008-10-21 12:40:02 +0200267 struct sk_buff *skb = txrc->skb;
268 struct ieee80211_supported_band *sband = txrc->sband;
Johannes Berge6a98542008-10-21 12:40:02 +0200269 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
Johannes Berg4b7679a2008-09-18 18:14:18 +0200270 struct rc_pid_sta_info *spinfo = priv_sta;
Mattias Nisslerad018372007-12-19 01:25:57 +0100271 int rateidx;
272
Johannes Berge6a98542008-10-21 12:40:02 +0200273 if (txrc->rts)
274 info->control.rates[0].count =
275 txrc->hw->conf.long_frame_max_tx_count;
276 else
277 info->control.rates[0].count =
278 txrc->hw->conf.short_frame_max_tx_count;
279
Gábor Stefanik92236842009-04-23 20:06:06 +0200280 /* Send management frames and NO_ACK data using lowest rate. */
Luis R. Rodriguez4c6d4f52009-07-16 10:05:41 -0700281 if (rate_control_send_low(sta, priv_sta, txrc))
Mattias Nisslerad018372007-12-19 01:25:57 +0100282 return;
Mattias Nisslerad018372007-12-19 01:25:57 +0100283
Johannes Bergae17e982008-09-11 03:04:36 +0200284 rateidx = spinfo->txrate_idx;
Mattias Nisslerad018372007-12-19 01:25:57 +0100285
Johannes Berg8318d782008-01-24 19:38:38 +0100286 if (rateidx >= sband->n_bitrates)
287 rateidx = sband->n_bitrates - 1;
Mattias Nisslerad018372007-12-19 01:25:57 +0100288
Johannes Berge6a98542008-10-21 12:40:02 +0200289 info->control.rates[0].idx = rateidx;
Mattias Nissler12446c62007-12-19 01:27:18 +0100290
291#ifdef CONFIG_MAC80211_DEBUGFS
Johannes Berg4b7679a2008-09-18 18:14:18 +0200292 rate_control_pid_event_tx_rate(&spinfo->events,
Johannes Berg8318d782008-01-24 19:38:38 +0100293 rateidx, sband->bitrates[rateidx].bitrate);
Mattias Nissler12446c62007-12-19 01:27:18 +0100294#endif
Mattias Nisslerad018372007-12-19 01:25:57 +0100295}
296
Johannes Berg4b7679a2008-09-18 18:14:18 +0200297static void
298rate_control_pid_rate_init(void *priv, struct ieee80211_supported_band *sband,
299 struct ieee80211_sta *sta, void *priv_sta)
Mattias Nisslerad018372007-12-19 01:25:57 +0100300{
Johannes Berg4b7679a2008-09-18 18:14:18 +0200301 struct rc_pid_sta_info *spinfo = priv_sta;
Jiri Slaby69092682009-05-04 18:10:28 +0200302 struct rc_pid_info *pinfo = priv;
303 struct rc_pid_rateinfo *rinfo = pinfo->rinfo;
Jiri Slaby69092682009-05-04 18:10:28 +0200304 int i, j, tmp;
305 bool s;
Johannes Berg4b7679a2008-09-18 18:14:18 +0200306
Mattias Nisslerad018372007-12-19 01:25:57 +0100307 /* TODO: This routine should consider using RSSI from previous packets
308 * as we need to have IEEE 802.1X auth succeed immediately after assoc..
309 * Until that method is implemented, we will use the lowest supported
310 * rate as a workaround. */
Johannes Berg8318d782008-01-24 19:38:38 +0100311
Stefano Brivio90d501d2007-12-19 01:26:34 +0100312 /* Sort the rates. This is optimized for the most common case (i.e.
313 * almost-sorted CCK+OFDM rates). Kind of bubble-sort with reversed
314 * mapping too. */
Johannes Berg8318d782008-01-24 19:38:38 +0100315 for (i = 0; i < sband->n_bitrates; i++) {
Stefano Brivio90d501d2007-12-19 01:26:34 +0100316 rinfo[i].index = i;
317 rinfo[i].rev_index = i;
Mattias Nissleradeed482008-07-07 23:08:19 +0200318 if (RC_PID_FAST_START)
Stefano Brivio90d501d2007-12-19 01:26:34 +0100319 rinfo[i].diff = 0;
320 else
Mattias Nissler1946b742007-12-20 13:27:26 +0100321 rinfo[i].diff = i * pinfo->norm_offset;
Stefano Brivio90d501d2007-12-19 01:26:34 +0100322 }
Johannes Berg8318d782008-01-24 19:38:38 +0100323 for (i = 1; i < sband->n_bitrates; i++) {
Stefano Brivio90d501d2007-12-19 01:26:34 +0100324 s = 0;
Johannes Berg8318d782008-01-24 19:38:38 +0100325 for (j = 0; j < sband->n_bitrates - i; j++)
326 if (unlikely(sband->bitrates[rinfo[j].index].bitrate >
327 sband->bitrates[rinfo[j + 1].index].bitrate)) {
Stefano Brivio90d501d2007-12-19 01:26:34 +0100328 tmp = rinfo[j].index;
329 rinfo[j].index = rinfo[j + 1].index;
330 rinfo[j + 1].index = tmp;
331 rinfo[rinfo[j].index].rev_index = j;
332 rinfo[rinfo[j + 1].index].rev_index = j + 1;
333 s = 1;
334 }
335 if (!s)
336 break;
337 }
Mattias Nisslerad018372007-12-19 01:25:57 +0100338
Jiri Slaby69092682009-05-04 18:10:28 +0200339 spinfo->txrate_idx = rate_lowest_index(sband, sta);
Jiri Slaby69092682009-05-04 18:10:28 +0200340}
341
342static void *rate_control_pid_alloc(struct ieee80211_hw *hw,
343 struct dentry *debugfsdir)
344{
345 struct rc_pid_info *pinfo;
346 struct rc_pid_rateinfo *rinfo;
347 struct ieee80211_supported_band *sband;
348 int i, max_rates = 0;
349#ifdef CONFIG_MAC80211_DEBUGFS
350 struct rc_pid_debugfs_entries *de;
351#endif
352
353 pinfo = kmalloc(sizeof(*pinfo), GFP_ATOMIC);
354 if (!pinfo)
355 return NULL;
356
357 for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
358 sband = hw->wiphy->bands[i];
John W. Linville621ad7c2009-05-05 15:18:26 -0400359 if (sband && sband->n_bitrates > max_rates)
Jiri Slaby69092682009-05-04 18:10:28 +0200360 max_rates = sband->n_bitrates;
361 }
362
363 rinfo = kmalloc(sizeof(*rinfo) * max_rates, GFP_ATOMIC);
364 if (!rinfo) {
365 kfree(pinfo);
366 return NULL;
367 }
368
369 pinfo->target = RC_PID_TARGET_PF;
370 pinfo->sampling_period = RC_PID_INTERVAL;
371 pinfo->coeff_p = RC_PID_COEFF_P;
372 pinfo->coeff_i = RC_PID_COEFF_I;
373 pinfo->coeff_d = RC_PID_COEFF_D;
374 pinfo->smoothing_shift = RC_PID_SMOOTHING_SHIFT;
375 pinfo->sharpen_factor = RC_PID_SHARPENING_FACTOR;
376 pinfo->sharpen_duration = RC_PID_SHARPENING_DURATION;
377 pinfo->norm_offset = RC_PID_NORM_OFFSET;
378 pinfo->rinfo = rinfo;
379 pinfo->oldrate = 0;
380
Mattias Nissler1946b742007-12-20 13:27:26 +0100381#ifdef CONFIG_MAC80211_DEBUGFS
382 de = &pinfo->dentries;
Mattias Nissler1946b742007-12-20 13:27:26 +0100383 de->target = debugfs_create_u32("target_pf", S_IRUSR | S_IWUSR,
Johannes Berg4b7679a2008-09-18 18:14:18 +0200384 debugfsdir, &pinfo->target);
Mattias Nissler1946b742007-12-20 13:27:26 +0100385 de->sampling_period = debugfs_create_u32("sampling_period",
Johannes Berg4b7679a2008-09-18 18:14:18 +0200386 S_IRUSR | S_IWUSR, debugfsdir,
Mattias Nissler1946b742007-12-20 13:27:26 +0100387 &pinfo->sampling_period);
388 de->coeff_p = debugfs_create_u32("coeff_p", S_IRUSR | S_IWUSR,
Tomas Winkler9902b182008-11-08 23:50:55 +0200389 debugfsdir, (u32 *)&pinfo->coeff_p);
Mattias Nissler1946b742007-12-20 13:27:26 +0100390 de->coeff_i = debugfs_create_u32("coeff_i", S_IRUSR | S_IWUSR,
Tomas Winkler9902b182008-11-08 23:50:55 +0200391 debugfsdir, (u32 *)&pinfo->coeff_i);
Mattias Nissler1946b742007-12-20 13:27:26 +0100392 de->coeff_d = debugfs_create_u32("coeff_d", S_IRUSR | S_IWUSR,
Tomas Winkler9902b182008-11-08 23:50:55 +0200393 debugfsdir, (u32 *)&pinfo->coeff_d);
Mattias Nissler1946b742007-12-20 13:27:26 +0100394 de->smoothing_shift = debugfs_create_u32("smoothing_shift",
Johannes Berg4b7679a2008-09-18 18:14:18 +0200395 S_IRUSR | S_IWUSR, debugfsdir,
Mattias Nissler1946b742007-12-20 13:27:26 +0100396 &pinfo->smoothing_shift);
397 de->sharpen_factor = debugfs_create_u32("sharpen_factor",
Johannes Berg4b7679a2008-09-18 18:14:18 +0200398 S_IRUSR | S_IWUSR, debugfsdir,
Mattias Nissler1946b742007-12-20 13:27:26 +0100399 &pinfo->sharpen_factor);
400 de->sharpen_duration = debugfs_create_u32("sharpen_duration",
Johannes Berg4b7679a2008-09-18 18:14:18 +0200401 S_IRUSR | S_IWUSR, debugfsdir,
Mattias Nissler1946b742007-12-20 13:27:26 +0100402 &pinfo->sharpen_duration);
403 de->norm_offset = debugfs_create_u32("norm_offset",
Johannes Berg4b7679a2008-09-18 18:14:18 +0200404 S_IRUSR | S_IWUSR, debugfsdir,
Mattias Nissler1946b742007-12-20 13:27:26 +0100405 &pinfo->norm_offset);
Mattias Nissler1946b742007-12-20 13:27:26 +0100406#endif
407
Mattias Nisslerad018372007-12-19 01:25:57 +0100408 return pinfo;
409}
410
411static void rate_control_pid_free(void *priv)
412{
413 struct rc_pid_info *pinfo = priv;
Mattias Nissler1946b742007-12-20 13:27:26 +0100414#ifdef CONFIG_MAC80211_DEBUGFS
415 struct rc_pid_debugfs_entries *de = &pinfo->dentries;
416
Mattias Nissler1946b742007-12-20 13:27:26 +0100417 debugfs_remove(de->norm_offset);
418 debugfs_remove(de->sharpen_duration);
419 debugfs_remove(de->sharpen_factor);
420 debugfs_remove(de->smoothing_shift);
421 debugfs_remove(de->coeff_d);
422 debugfs_remove(de->coeff_i);
423 debugfs_remove(de->coeff_p);
424 debugfs_remove(de->sampling_period);
425 debugfs_remove(de->target);
Mattias Nissler1946b742007-12-20 13:27:26 +0100426#endif
427
Stefano Brivio90d501d2007-12-19 01:26:34 +0100428 kfree(pinfo->rinfo);
Mattias Nisslerad018372007-12-19 01:25:57 +0100429 kfree(pinfo);
430}
431
Johannes Berg4b7679a2008-09-18 18:14:18 +0200432static void *rate_control_pid_alloc_sta(void *priv, struct ieee80211_sta *sta,
433 gfp_t gfp)
Mattias Nisslerad018372007-12-19 01:25:57 +0100434{
435 struct rc_pid_sta_info *spinfo;
436
437 spinfo = kzalloc(sizeof(*spinfo), gfp);
Mattias Nissler12446c62007-12-19 01:27:18 +0100438 if (spinfo == NULL)
439 return NULL;
440
Stefano Brivioc09c7232008-01-17 00:38:29 +0100441 spinfo->last_sample = jiffies;
442
Mattias Nissler12446c62007-12-19 01:27:18 +0100443#ifdef CONFIG_MAC80211_DEBUGFS
444 spin_lock_init(&spinfo->events.lock);
445 init_waitqueue_head(&spinfo->events.waitqueue);
446#endif
Mattias Nisslerad018372007-12-19 01:25:57 +0100447
448 return spinfo;
449}
450
Johannes Berg4b7679a2008-09-18 18:14:18 +0200451static void rate_control_pid_free_sta(void *priv, struct ieee80211_sta *sta,
452 void *priv_sta)
Mattias Nisslerad018372007-12-19 01:25:57 +0100453{
Johannes Berg4b7679a2008-09-18 18:14:18 +0200454 kfree(priv_sta);
Mattias Nisslerad018372007-12-19 01:25:57 +0100455}
456
Johannes Berg4b475892008-01-02 15:17:03 +0100457static struct rate_control_ops mac80211_rcpid = {
Mattias Nisslerad018372007-12-19 01:25:57 +0100458 .name = "pid",
459 .tx_status = rate_control_pid_tx_status,
460 .get_rate = rate_control_pid_get_rate,
461 .rate_init = rate_control_pid_rate_init,
Mattias Nisslerad018372007-12-19 01:25:57 +0100462 .alloc = rate_control_pid_alloc,
463 .free = rate_control_pid_free,
464 .alloc_sta = rate_control_pid_alloc_sta,
465 .free_sta = rate_control_pid_free_sta,
Mattias Nissler12446c62007-12-19 01:27:18 +0100466#ifdef CONFIG_MAC80211_DEBUGFS
467 .add_sta_debugfs = rate_control_pid_add_sta_debugfs,
468 .remove_sta_debugfs = rate_control_pid_remove_sta_debugfs,
469#endif
Mattias Nisslerad018372007-12-19 01:25:57 +0100470};
Johannes Berg4b475892008-01-02 15:17:03 +0100471
Johannes Berg4b475892008-01-02 15:17:03 +0100472int __init rc80211_pid_init(void)
473{
474 return ieee80211_rate_control_register(&mac80211_rcpid);
475}
476
Johannes Bergf0b92052008-01-31 19:31:57 +0100477void rc80211_pid_exit(void)
Johannes Berg4b475892008-01-02 15:17:03 +0100478{
479 ieee80211_rate_control_unregister(&mac80211_rcpid);
480}