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1/******************************************************************************
2 *
3 * Copyright(c) 2005 - 2011 Intel Corporation. All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2 of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
17 *
18 * The full GNU General Public License is included in this distribution in the
19 * file called LICENSE.
20 *
21 * Contact Information:
22 * Intel Linux Wireless <ilw@linux.intel.com>
23 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
24 *
25 *****************************************************************************/
26
27#include <linux/kernel.h>
28#include <linux/skbuff.h>
29#include <linux/slab.h>
30#include <net/mac80211.h>
31
32#include <linux/netdevice.h>
33#include <linux/etherdevice.h>
34#include <linux/delay.h>
35
36#include <linux/workqueue.h>
37
38#include "commands.h"
39#include "3945.h"
40
41#define RS_NAME "iwl-3945-rs"
42
43static s32 il3945_expected_tpt_g[RATE_COUNT_3945] = {
44 7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
45};
46
47static s32 il3945_expected_tpt_g_prot[RATE_COUNT_3945] = {
48 7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
49};
50
51static s32 il3945_expected_tpt_a[RATE_COUNT_3945] = {
52 0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
53};
54
55static s32 il3945_expected_tpt_b[RATE_COUNT_3945] = {
56 7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
57};
58
59struct il3945_tpt_entry {
60 s8 min_rssi;
61 u8 idx;
62};
63
64static struct il3945_tpt_entry il3945_tpt_table_a[] = {
65 {-60, RATE_54M_IDX},
66 {-64, RATE_48M_IDX},
67 {-72, RATE_36M_IDX},
68 {-80, RATE_24M_IDX},
69 {-84, RATE_18M_IDX},
70 {-85, RATE_12M_IDX},
71 {-87, RATE_9M_IDX},
72 {-89, RATE_6M_IDX}
73};
74
75static struct il3945_tpt_entry il3945_tpt_table_g[] = {
76 {-60, RATE_54M_IDX},
77 {-64, RATE_48M_IDX},
78 {-68, RATE_36M_IDX},
79 {-80, RATE_24M_IDX},
80 {-84, RATE_18M_IDX},
81 {-85, RATE_12M_IDX},
82 {-86, RATE_11M_IDX},
83 {-88, RATE_5M_IDX},
84 {-90, RATE_2M_IDX},
85 {-92, RATE_1M_IDX}
86};
87
88#define RATE_MAX_WINDOW 62
89#define RATE_FLUSH (3*HZ)
90#define RATE_WIN_FLUSH (HZ/2)
91#define IL39_RATE_HIGH_TH 11520
92#define IL_SUCCESS_UP_TH 8960
93#define IL_SUCCESS_DOWN_TH 10880
94#define RATE_MIN_FAILURE_TH 6
95#define RATE_MIN_SUCCESS_TH 8
96#define RATE_DECREASE_TH 1920
97#define RATE_RETRY_TH 15
98
99static u8
100il3945_get_rate_idx_by_rssi(s32 rssi, enum nl80211_band band)
101{
102 u32 idx = 0;
103 u32 table_size = 0;
104 struct il3945_tpt_entry *tpt_table = NULL;
105
106 if (rssi < IL_MIN_RSSI_VAL || rssi > IL_MAX_RSSI_VAL)
107 rssi = IL_MIN_RSSI_VAL;
108
109 switch (band) {
110 case NL80211_BAND_2GHZ:
111 tpt_table = il3945_tpt_table_g;
112 table_size = ARRAY_SIZE(il3945_tpt_table_g);
113 break;
114 case NL80211_BAND_5GHZ:
115 tpt_table = il3945_tpt_table_a;
116 table_size = ARRAY_SIZE(il3945_tpt_table_a);
117 break;
118 default:
119 BUG();
120 break;
121 }
122
123 while (idx < table_size && rssi < tpt_table[idx].min_rssi)
124 idx++;
125
126 idx = min(idx, table_size - 1);
127
128 return tpt_table[idx].idx;
129}
130
131static void
132il3945_clear_win(struct il3945_rate_scale_data *win)
133{
134 win->data = 0;
135 win->success_counter = 0;
136 win->success_ratio = -1;
137 win->counter = 0;
138 win->average_tpt = IL_INVALID_VALUE;
139 win->stamp = 0;
140}
141
142/**
143 * il3945_rate_scale_flush_wins - flush out the rate scale wins
144 *
145 * Returns the number of wins that have gathered data but were
146 * not flushed. If there were any that were not flushed, then
147 * reschedule the rate flushing routine.
148 */
149static int
150il3945_rate_scale_flush_wins(struct il3945_rs_sta *rs_sta)
151{
152 int unflushed = 0;
153 int i;
154 unsigned long flags;
155 struct il_priv *il __maybe_unused = rs_sta->il;
156
157 /*
158 * For each rate, if we have collected data on that rate
159 * and it has been more than RATE_WIN_FLUSH
160 * since we flushed, clear out the gathered stats
161 */
162 for (i = 0; i < RATE_COUNT_3945; i++) {
163 if (!rs_sta->win[i].counter)
164 continue;
165
166 spin_lock_irqsave(&rs_sta->lock, flags);
167 if (time_after(jiffies, rs_sta->win[i].stamp + RATE_WIN_FLUSH)) {
168 D_RATE("flushing %d samples of rate " "idx %d\n",
169 rs_sta->win[i].counter, i);
170 il3945_clear_win(&rs_sta->win[i]);
171 } else
172 unflushed++;
173 spin_unlock_irqrestore(&rs_sta->lock, flags);
174 }
175
176 return unflushed;
177}
178
179#define RATE_FLUSH_MAX 5000 /* msec */
180#define RATE_FLUSH_MIN 50 /* msec */
181#define IL_AVERAGE_PACKETS 1500
182
183static void
184il3945_bg_rate_scale_flush(struct timer_list *t)
185{
186 struct il3945_rs_sta *rs_sta = from_timer(rs_sta, t, rate_scale_flush);
187 struct il_priv *il __maybe_unused = rs_sta->il;
188 int unflushed = 0;
189 unsigned long flags;
190 u32 packet_count, duration, pps;
191
192 D_RATE("enter\n");
193
194 unflushed = il3945_rate_scale_flush_wins(rs_sta);
195
196 spin_lock_irqsave(&rs_sta->lock, flags);
197
198 /* Number of packets Rx'd since last time this timer ran */
199 packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
200
201 rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
202
203 if (unflushed) {
204 duration =
205 jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
206
207 D_RATE("Tx'd %d packets in %dms\n", packet_count, duration);
208
209 /* Determine packets per second */
210 if (duration)
211 pps = (packet_count * 1000) / duration;
212 else
213 pps = 0;
214
215 if (pps) {
216 duration = (IL_AVERAGE_PACKETS * 1000) / pps;
217 if (duration < RATE_FLUSH_MIN)
218 duration = RATE_FLUSH_MIN;
219 else if (duration > RATE_FLUSH_MAX)
220 duration = RATE_FLUSH_MAX;
221 } else
222 duration = RATE_FLUSH_MAX;
223
224 rs_sta->flush_time = msecs_to_jiffies(duration);
225
226 D_RATE("new flush period: %d msec ave %d\n", duration,
227 packet_count);
228
229 mod_timer(&rs_sta->rate_scale_flush,
230 jiffies + rs_sta->flush_time);
231
232 rs_sta->last_partial_flush = jiffies;
233 } else {
234 rs_sta->flush_time = RATE_FLUSH;
235 rs_sta->flush_pending = 0;
236 }
237 /* If there weren't any unflushed entries, we don't schedule the timer
238 * to run again */
239
240 rs_sta->last_flush = jiffies;
241
242 spin_unlock_irqrestore(&rs_sta->lock, flags);
243
244 D_RATE("leave\n");
245}
246
247/**
248 * il3945_collect_tx_data - Update the success/failure sliding win
249 *
250 * We keep a sliding win of the last 64 packets transmitted
251 * at this rate. win->data contains the bitmask of successful
252 * packets.
253 */
254static void
255il3945_collect_tx_data(struct il3945_rs_sta *rs_sta,
256 struct il3945_rate_scale_data *win, int success,
257 int retries, int idx)
258{
259 unsigned long flags;
260 s32 fail_count;
261 struct il_priv *il __maybe_unused = rs_sta->il;
262
263 if (!retries) {
264 D_RATE("leave: retries == 0 -- should be at least 1\n");
265 return;
266 }
267
268 spin_lock_irqsave(&rs_sta->lock, flags);
269
270 /*
271 * Keep track of only the latest 62 tx frame attempts in this rate's
272 * history win; anything older isn't really relevant any more.
273 * If we have filled up the sliding win, drop the oldest attempt;
274 * if the oldest attempt (highest bit in bitmap) shows "success",
275 * subtract "1" from the success counter (this is the main reason
276 * we keep these bitmaps!).
277 * */
278 while (retries > 0) {
279 if (win->counter >= RATE_MAX_WINDOW) {
280
281 /* remove earliest */
282 win->counter = RATE_MAX_WINDOW - 1;
283
284 if (win->data & (1ULL << (RATE_MAX_WINDOW - 1))) {
285 win->data &= ~(1ULL << (RATE_MAX_WINDOW - 1));
286 win->success_counter--;
287 }
288 }
289
290 /* Increment frames-attempted counter */
291 win->counter++;
292
293 /* Shift bitmap by one frame (throw away oldest history),
294 * OR in "1", and increment "success" if this
295 * frame was successful. */
296 win->data <<= 1;
297 if (success > 0) {
298 win->success_counter++;
299 win->data |= 0x1;
300 success--;
301 }
302
303 retries--;
304 }
305
306 /* Calculate current success ratio, avoid divide-by-0! */
307 if (win->counter > 0)
308 win->success_ratio =
309 128 * (100 * win->success_counter) / win->counter;
310 else
311 win->success_ratio = IL_INVALID_VALUE;
312
313 fail_count = win->counter - win->success_counter;
314
315 /* Calculate average throughput, if we have enough history. */
316 if (fail_count >= RATE_MIN_FAILURE_TH ||
317 win->success_counter >= RATE_MIN_SUCCESS_TH)
318 win->average_tpt =
319 ((win->success_ratio * rs_sta->expected_tpt[idx] +
320 64) / 128);
321 else
322 win->average_tpt = IL_INVALID_VALUE;
323
324 /* Tag this win as having been updated */
325 win->stamp = jiffies;
326
327 spin_unlock_irqrestore(&rs_sta->lock, flags);
328}
329
330/*
331 * Called after adding a new station to initialize rate scaling
332 */
333void
334il3945_rs_rate_init(struct il_priv *il, struct ieee80211_sta *sta, u8 sta_id)
335{
336 struct ieee80211_hw *hw = il->hw;
337 struct ieee80211_conf *conf = &il->hw->conf;
338 struct il3945_sta_priv *psta;
339 struct il3945_rs_sta *rs_sta;
340 struct ieee80211_supported_band *sband;
341 int i;
342
343 D_INFO("enter\n");
344 if (sta_id == il->hw_params.bcast_id)
345 goto out;
346
347 psta = (struct il3945_sta_priv *)sta->drv_priv;
348 rs_sta = &psta->rs_sta;
349 sband = hw->wiphy->bands[conf->chandef.chan->band];
350
351 rs_sta->il = il;
352
353 rs_sta->start_rate = RATE_INVALID;
354
355 /* default to just 802.11b */
356 rs_sta->expected_tpt = il3945_expected_tpt_b;
357
358 rs_sta->last_partial_flush = jiffies;
359 rs_sta->last_flush = jiffies;
360 rs_sta->flush_time = RATE_FLUSH;
361 rs_sta->last_tx_packets = 0;
362
363 for (i = 0; i < RATE_COUNT_3945; i++)
364 il3945_clear_win(&rs_sta->win[i]);
365
366 /* TODO: what is a good starting rate for STA? About middle? Maybe not
367 * the lowest or the highest rate.. Could consider using RSSI from
368 * previous packets? Need to have IEEE 802.1X auth succeed immediately
369 * after assoc.. */
370
371 for (i = sband->n_bitrates - 1; i >= 0; i--) {
372 if (sta->supp_rates[sband->band] & (1 << i)) {
373 rs_sta->last_txrate_idx = i;
374 break;
375 }
376 }
377
378 il->_3945.sta_supp_rates = sta->supp_rates[sband->band];
379 /* For 5 GHz band it start at IL_FIRST_OFDM_RATE */
380 if (sband->band == NL80211_BAND_5GHZ) {
381 rs_sta->last_txrate_idx += IL_FIRST_OFDM_RATE;
382 il->_3945.sta_supp_rates <<= IL_FIRST_OFDM_RATE;
383 }
384
385out:
386 il->stations[sta_id].used &= ~IL_STA_UCODE_INPROGRESS;
387
388 D_INFO("leave\n");
389}
390
391static void *
392il3945_rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
393{
394 return hw->priv;
395}
396
397/* rate scale requires free function to be implemented */
398static void
399il3945_rs_free(void *il)
400{
401}
402
403static void *
404il3945_rs_alloc_sta(void *il_priv, struct ieee80211_sta *sta, gfp_t gfp)
405{
406 struct il3945_rs_sta *rs_sta;
407 struct il3945_sta_priv *psta = (void *)sta->drv_priv;
408 struct il_priv *il __maybe_unused = il_priv;
409
410 D_RATE("enter\n");
411
412 rs_sta = &psta->rs_sta;
413
414 spin_lock_init(&rs_sta->lock);
415 timer_setup(&rs_sta->rate_scale_flush, il3945_bg_rate_scale_flush, 0);
416 D_RATE("leave\n");
417
418 return rs_sta;
419}
420
421static void
422il3945_rs_free_sta(void *il_priv, struct ieee80211_sta *sta, void *il_sta)
423{
424 struct il3945_rs_sta *rs_sta = il_sta;
425
426 /*
427 * Be careful not to use any members of il3945_rs_sta (like trying
428 * to use il_priv to print out debugging) since it may not be fully
429 * initialized at this point.
430 */
431 del_timer_sync(&rs_sta->rate_scale_flush);
432}
433
434/**
435 * il3945_rs_tx_status - Update rate control values based on Tx results
436 *
437 * NOTE: Uses il_priv->retry_rate for the # of retries attempted by
438 * the hardware for each rate.
439 */
440static void
441il3945_rs_tx_status(void *il_rate, struct ieee80211_supported_band *sband,
442 struct ieee80211_sta *sta, void *il_sta,
443 struct sk_buff *skb)
444{
445 s8 retries = 0, current_count;
446 int scale_rate_idx, first_idx, last_idx;
447 unsigned long flags;
448 struct il_priv *il = (struct il_priv *)il_rate;
449 struct il3945_rs_sta *rs_sta = il_sta;
450 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
451
452 D_RATE("enter\n");
453
454 retries = info->status.rates[0].count;
455 /* Sanity Check for retries */
456 if (retries > RATE_RETRY_TH)
457 retries = RATE_RETRY_TH;
458
459 first_idx = sband->bitrates[info->status.rates[0].idx].hw_value;
460 if (first_idx < 0 || first_idx >= RATE_COUNT_3945) {
461 D_RATE("leave: Rate out of bounds: %d\n", first_idx);
462 return;
463 }
464
465 if (!il_sta) {
466 D_RATE("leave: No STA il data to update!\n");
467 return;
468 }
469
470 /* Treat uninitialized rate scaling data same as non-existing. */
471 if (!rs_sta->il) {
472 D_RATE("leave: STA il data uninitialized!\n");
473 return;
474 }
475
476 rs_sta->tx_packets++;
477
478 scale_rate_idx = first_idx;
479 last_idx = first_idx;
480
481 /*
482 * Update the win for each rate. We determine which rates
483 * were Tx'd based on the total number of retries vs. the number
484 * of retries configured for each rate -- currently set to the
485 * il value 'retry_rate' vs. rate specific
486 *
487 * On exit from this while loop last_idx indicates the rate
488 * at which the frame was finally transmitted (or failed if no
489 * ACK)
490 */
491 while (retries > 1) {
492 if ((retries - 1) < il->retry_rate) {
493 current_count = (retries - 1);
494 last_idx = scale_rate_idx;
495 } else {
496 current_count = il->retry_rate;
497 last_idx = il3945_rs_next_rate(il, scale_rate_idx);
498 }
499
500 /* Update this rate accounting for as many retries
501 * as was used for it (per current_count) */
502 il3945_collect_tx_data(rs_sta, &rs_sta->win[scale_rate_idx], 0,
503 current_count, scale_rate_idx);
504 D_RATE("Update rate %d for %d retries.\n", scale_rate_idx,
505 current_count);
506
507 retries -= current_count;
508
509 scale_rate_idx = last_idx;
510 }
511
512 /* Update the last idx win with success/failure based on ACK */
513 D_RATE("Update rate %d with %s.\n", last_idx,
514 (info->flags & IEEE80211_TX_STAT_ACK) ? "success" : "failure");
515 il3945_collect_tx_data(rs_sta, &rs_sta->win[last_idx],
516 info->flags & IEEE80211_TX_STAT_ACK, 1,
517 last_idx);
518
519 /* We updated the rate scale win -- if its been more than
520 * flush_time since the last run, schedule the flush
521 * again */
522 spin_lock_irqsave(&rs_sta->lock, flags);
523
524 if (!rs_sta->flush_pending &&
525 time_after(jiffies, rs_sta->last_flush + rs_sta->flush_time)) {
526
527 rs_sta->last_partial_flush = jiffies;
528 rs_sta->flush_pending = 1;
529 mod_timer(&rs_sta->rate_scale_flush,
530 jiffies + rs_sta->flush_time);
531 }
532
533 spin_unlock_irqrestore(&rs_sta->lock, flags);
534
535 D_RATE("leave\n");
536}
537
538static u16
539il3945_get_adjacent_rate(struct il3945_rs_sta *rs_sta, u8 idx, u16 rate_mask,
540 enum nl80211_band band)
541{
542 u8 high = RATE_INVALID;
543 u8 low = RATE_INVALID;
544 struct il_priv *il __maybe_unused = rs_sta->il;
545
546 /* 802.11A walks to the next literal adjacent rate in
547 * the rate table */
548 if (unlikely(band == NL80211_BAND_5GHZ)) {
549 int i;
550 u32 mask;
551
552 /* Find the previous rate that is in the rate mask */
553 i = idx - 1;
554 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
555 if (rate_mask & mask) {
556 low = i;
557 break;
558 }
559 }
560
561 /* Find the next rate that is in the rate mask */
562 i = idx + 1;
563 for (mask = (1 << i); i < RATE_COUNT_3945; i++, mask <<= 1) {
564 if (rate_mask & mask) {
565 high = i;
566 break;
567 }
568 }
569
570 return (high << 8) | low;
571 }
572
573 low = idx;
574 while (low != RATE_INVALID) {
575 if (rs_sta->tgg)
576 low = il3945_rates[low].prev_rs_tgg;
577 else
578 low = il3945_rates[low].prev_rs;
579 if (low == RATE_INVALID)
580 break;
581 if (rate_mask & (1 << low))
582 break;
583 D_RATE("Skipping masked lower rate: %d\n", low);
584 }
585
586 high = idx;
587 while (high != RATE_INVALID) {
588 if (rs_sta->tgg)
589 high = il3945_rates[high].next_rs_tgg;
590 else
591 high = il3945_rates[high].next_rs;
592 if (high == RATE_INVALID)
593 break;
594 if (rate_mask & (1 << high))
595 break;
596 D_RATE("Skipping masked higher rate: %d\n", high);
597 }
598
599 return (high << 8) | low;
600}
601
602/**
603 * il3945_rs_get_rate - find the rate for the requested packet
604 *
605 * Returns the ieee80211_rate structure allocated by the driver.
606 *
607 * The rate control algorithm has no internal mapping between hw_mode's
608 * rate ordering and the rate ordering used by the rate control algorithm.
609 *
610 * The rate control algorithm uses a single table of rates that goes across
611 * the entire A/B/G spectrum vs. being limited to just one particular
612 * hw_mode.
613 *
614 * As such, we can't convert the idx obtained below into the hw_mode's
615 * rate table and must reference the driver allocated rate table
616 *
617 */
618static void
619il3945_rs_get_rate(void *il_r, struct ieee80211_sta *sta, void *il_sta,
620 struct ieee80211_tx_rate_control *txrc)
621{
622 struct ieee80211_supported_band *sband = txrc->sband;
623 struct sk_buff *skb = txrc->skb;
624 u8 low = RATE_INVALID;
625 u8 high = RATE_INVALID;
626 u16 high_low;
627 int idx;
628 struct il3945_rs_sta *rs_sta = il_sta;
629 struct il3945_rate_scale_data *win = NULL;
630 int current_tpt = IL_INVALID_VALUE;
631 int low_tpt = IL_INVALID_VALUE;
632 int high_tpt = IL_INVALID_VALUE;
633 u32 fail_count;
634 s8 scale_action = 0;
635 unsigned long flags;
636 u16 rate_mask;
637 s8 max_rate_idx = -1;
638 struct il_priv *il __maybe_unused = (struct il_priv *)il_r;
639 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
640
641 D_RATE("enter\n");
642
643 /* Treat uninitialized rate scaling data same as non-existing. */
644 if (rs_sta && !rs_sta->il) {
645 D_RATE("Rate scaling information not initialized yet.\n");
646 il_sta = NULL;
647 }
648
649 if (rate_control_send_low(sta, il_sta, txrc))
650 return;
651
652 rate_mask = sta->supp_rates[sband->band];
653
654 /* get user max rate if set */
655 max_rate_idx = fls(txrc->rate_idx_mask) - 1;
656 if (sband->band == NL80211_BAND_5GHZ && max_rate_idx != -1)
657 max_rate_idx += IL_FIRST_OFDM_RATE;
658 if (max_rate_idx < 0 || max_rate_idx >= RATE_COUNT)
659 max_rate_idx = -1;
660
661 idx = min(rs_sta->last_txrate_idx & 0xffff, RATE_COUNT_3945 - 1);
662
663 if (sband->band == NL80211_BAND_5GHZ)
664 rate_mask = rate_mask << IL_FIRST_OFDM_RATE;
665
666 spin_lock_irqsave(&rs_sta->lock, flags);
667
668 /* for recent assoc, choose best rate regarding
669 * to rssi value
670 */
671 if (rs_sta->start_rate != RATE_INVALID) {
672 if (rs_sta->start_rate < idx &&
673 (rate_mask & (1 << rs_sta->start_rate)))
674 idx = rs_sta->start_rate;
675 rs_sta->start_rate = RATE_INVALID;
676 }
677
678 /* force user max rate if set by user */
679 if (max_rate_idx != -1 && max_rate_idx < idx) {
680 if (rate_mask & (1 << max_rate_idx))
681 idx = max_rate_idx;
682 }
683
684 win = &(rs_sta->win[idx]);
685
686 fail_count = win->counter - win->success_counter;
687
688 if (fail_count < RATE_MIN_FAILURE_TH &&
689 win->success_counter < RATE_MIN_SUCCESS_TH) {
690 spin_unlock_irqrestore(&rs_sta->lock, flags);
691
692 D_RATE("Invalid average_tpt on rate %d: "
693 "counter: %d, success_counter: %d, "
694 "expected_tpt is %sNULL\n", idx, win->counter,
695 win->success_counter,
696 rs_sta->expected_tpt ? "not " : "");
697
698 /* Can't calculate this yet; not enough history */
699 win->average_tpt = IL_INVALID_VALUE;
700 goto out;
701
702 }
703
704 current_tpt = win->average_tpt;
705
706 high_low =
707 il3945_get_adjacent_rate(rs_sta, idx, rate_mask, sband->band);
708 low = high_low & 0xff;
709 high = (high_low >> 8) & 0xff;
710
711 /* If user set max rate, dont allow higher than user constrain */
712 if (max_rate_idx != -1 && max_rate_idx < high)
713 high = RATE_INVALID;
714
715 /* Collect Measured throughputs of adjacent rates */
716 if (low != RATE_INVALID)
717 low_tpt = rs_sta->win[low].average_tpt;
718
719 if (high != RATE_INVALID)
720 high_tpt = rs_sta->win[high].average_tpt;
721
722 spin_unlock_irqrestore(&rs_sta->lock, flags);
723
724 scale_action = 0;
725
726 /* Low success ratio , need to drop the rate */
727 if (win->success_ratio < RATE_DECREASE_TH || !current_tpt) {
728 D_RATE("decrease rate because of low success_ratio\n");
729 scale_action = -1;
730 /* No throughput measured yet for adjacent rates,
731 * try increase */
732 } else if (low_tpt == IL_INVALID_VALUE && high_tpt == IL_INVALID_VALUE) {
733
734 if (high != RATE_INVALID &&
735 win->success_ratio >= RATE_INCREASE_TH)
736 scale_action = 1;
737 else if (low != RATE_INVALID)
738 scale_action = 0;
739
740 /* Both adjacent throughputs are measured, but neither one has
741 * better throughput; we're using the best rate, don't change
742 * it! */
743 } else if (low_tpt != IL_INVALID_VALUE && high_tpt != IL_INVALID_VALUE
744 && low_tpt < current_tpt && high_tpt < current_tpt) {
745
746 D_RATE("No action -- low [%d] & high [%d] < "
747 "current_tpt [%d]\n", low_tpt, high_tpt, current_tpt);
748 scale_action = 0;
749
750 /* At least one of the rates has better throughput */
751 } else {
752 if (high_tpt != IL_INVALID_VALUE) {
753
754 /* High rate has better throughput, Increase
755 * rate */
756 if (high_tpt > current_tpt &&
757 win->success_ratio >= RATE_INCREASE_TH)
758 scale_action = 1;
759 else {
760 D_RATE("decrease rate because of high tpt\n");
761 scale_action = 0;
762 }
763 } else if (low_tpt != IL_INVALID_VALUE) {
764 if (low_tpt > current_tpt) {
765 D_RATE("decrease rate because of low tpt\n");
766 scale_action = -1;
767 } else if (win->success_ratio >= RATE_INCREASE_TH) {
768 /* Lower rate has better
769 * throughput,decrease rate */
770 scale_action = 1;
771 }
772 }
773 }
774
775 /* Sanity check; asked for decrease, but success rate or throughput
776 * has been good at old rate. Don't change it. */
777 if (scale_action == -1 && low != RATE_INVALID &&
778 (win->success_ratio > RATE_HIGH_TH ||
779 current_tpt > 100 * rs_sta->expected_tpt[low]))
780 scale_action = 0;
781
782 switch (scale_action) {
783 case -1:
784 /* Decrese rate */
785 if (low != RATE_INVALID)
786 idx = low;
787 break;
788 case 1:
789 /* Increase rate */
790 if (high != RATE_INVALID)
791 idx = high;
792
793 break;
794 case 0:
795 default:
796 /* No change */
797 break;
798 }
799
800 D_RATE("Selected %d (action %d) - low %d high %d\n", idx, scale_action,
801 low, high);
802
803out:
804
805 if (sband->band == NL80211_BAND_5GHZ) {
806 if (WARN_ON_ONCE(idx < IL_FIRST_OFDM_RATE))
807 idx = IL_FIRST_OFDM_RATE;
808 rs_sta->last_txrate_idx = idx;
809 info->control.rates[0].idx = idx - IL_FIRST_OFDM_RATE;
810 } else {
811 rs_sta->last_txrate_idx = idx;
812 info->control.rates[0].idx = rs_sta->last_txrate_idx;
813 }
814 info->control.rates[0].count = 1;
815
816 D_RATE("leave: %d\n", idx);
817}
818
819#ifdef CONFIG_MAC80211_DEBUGFS
820
821static ssize_t
822il3945_sta_dbgfs_stats_table_read(struct file *file, char __user *user_buf,
823 size_t count, loff_t *ppos)
824{
825 char *buff;
826 int desc = 0;
827 int j;
828 ssize_t ret;
829 struct il3945_rs_sta *lq_sta = file->private_data;
830
831 buff = kmalloc(1024, GFP_KERNEL);
832 if (!buff)
833 return -ENOMEM;
834
835 desc +=
836 sprintf(buff + desc,
837 "tx packets=%d last rate idx=%d\n"
838 "rate=0x%X flush time %d\n", lq_sta->tx_packets,
839 lq_sta->last_txrate_idx, lq_sta->start_rate,
840 jiffies_to_msecs(lq_sta->flush_time));
841 for (j = 0; j < RATE_COUNT_3945; j++) {
842 desc +=
843 sprintf(buff + desc, "counter=%d success=%d %%=%d\n",
844 lq_sta->win[j].counter,
845 lq_sta->win[j].success_counter,
846 lq_sta->win[j].success_ratio);
847 }
848 ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
849 kfree(buff);
850 return ret;
851}
852
853static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
854 .read = il3945_sta_dbgfs_stats_table_read,
855 .open = simple_open,
856 .llseek = default_llseek,
857};
858
859static void
860il3945_add_debugfs(void *il, void *il_sta, struct dentry *dir)
861{
862 struct il3945_rs_sta *lq_sta = il_sta;
863
864 lq_sta->rs_sta_dbgfs_stats_table_file =
865 debugfs_create_file("rate_stats_table", 0600, dir, lq_sta,
866 &rs_sta_dbgfs_stats_table_ops);
867
868}
869
870static void
871il3945_remove_debugfs(void *il, void *il_sta)
872{
873 struct il3945_rs_sta *lq_sta = il_sta;
874 debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
875}
876#endif
877
878/*
879 * Initialization of rate scaling information is done by driver after
880 * the station is added. Since mac80211 calls this function before a
881 * station is added we ignore it.
882 */
883static void
884il3945_rs_rate_init_stub(void *il_r, struct ieee80211_supported_band *sband,
885 struct cfg80211_chan_def *chandef,
886 struct ieee80211_sta *sta, void *il_sta)
887{
888}
889
890static const struct rate_control_ops rs_ops = {
891 .name = RS_NAME,
892 .tx_status = il3945_rs_tx_status,
893 .get_rate = il3945_rs_get_rate,
894 .rate_init = il3945_rs_rate_init_stub,
895 .alloc = il3945_rs_alloc,
896 .free = il3945_rs_free,
897 .alloc_sta = il3945_rs_alloc_sta,
898 .free_sta = il3945_rs_free_sta,
899#ifdef CONFIG_MAC80211_DEBUGFS
900 .add_sta_debugfs = il3945_add_debugfs,
901 .remove_sta_debugfs = il3945_remove_debugfs,
902#endif
903
904};
905
906void
907il3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
908{
909 struct il_priv *il = hw->priv;
910 s32 rssi = 0;
911 unsigned long flags;
912 struct il3945_rs_sta *rs_sta;
913 struct ieee80211_sta *sta;
914 struct il3945_sta_priv *psta;
915
916 D_RATE("enter\n");
917
918 rcu_read_lock();
919
920 sta = ieee80211_find_sta(il->vif, il->stations[sta_id].sta.sta.addr);
921 if (!sta) {
922 D_RATE("Unable to find station to initialize rate scaling.\n");
923 rcu_read_unlock();
924 return;
925 }
926
927 psta = (void *)sta->drv_priv;
928 rs_sta = &psta->rs_sta;
929
930 spin_lock_irqsave(&rs_sta->lock, flags);
931
932 rs_sta->tgg = 0;
933 switch (il->band) {
934 case NL80211_BAND_2GHZ:
935 /* TODO: this always does G, not a regression */
936 if (il->active.flags & RXON_FLG_TGG_PROTECT_MSK) {
937 rs_sta->tgg = 1;
938 rs_sta->expected_tpt = il3945_expected_tpt_g_prot;
939 } else
940 rs_sta->expected_tpt = il3945_expected_tpt_g;
941 break;
942 case NL80211_BAND_5GHZ:
943 rs_sta->expected_tpt = il3945_expected_tpt_a;
944 break;
945 default:
946 BUG();
947 break;
948 }
949
950 spin_unlock_irqrestore(&rs_sta->lock, flags);
951
952 rssi = il->_3945.last_rx_rssi;
953 if (rssi == 0)
954 rssi = IL_MIN_RSSI_VAL;
955
956 D_RATE("Network RSSI: %d\n", rssi);
957
958 rs_sta->start_rate = il3945_get_rate_idx_by_rssi(rssi, il->band);
959
960 D_RATE("leave: rssi %d assign rate idx: " "%d (plcp 0x%x)\n", rssi,
961 rs_sta->start_rate, il3945_rates[rs_sta->start_rate].plcp);
962 rcu_read_unlock();
963}
964
965int
966il3945_rate_control_register(void)
967{
968 return ieee80211_rate_control_register(&rs_ops);
969}
970
971void
972il3945_rate_control_unregister(void)
973{
974 ieee80211_rate_control_unregister(&rs_ops);
975}