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[ARM] pxa: Gumstix Verdex PCMCIA support
[linux-2.6/verdex.git] / drivers / net / wireless / iwlwifi / iwl-3945-rs.c
blobcbb0585083a9cbfbbf838889c4b74dea67f684c3
1 /******************************************************************************
2 *
3 * Copyright(c) 2005 - 2009 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/init.h>
29 #include <linux/skbuff.h>
30 #include <linux/wireless.h>
31 #include <net/mac80211.h>
32
33 #include <linux/netdevice.h>
34 #include <linux/etherdevice.h>
35 #include <linux/delay.h>
36
37 #include <linux/workqueue.h>
38
39 #include "iwl-commands.h"
40 #include "iwl-3945.h"
41 #include "iwl-sta.h"
42
43 #define RS_NAME "iwl-3945-rs"
44
45 struct iwl3945_rate_scale_data {
46 u64 data;
47 s32 success_counter;
48 s32 success_ratio;
49 s32 counter;
50 s32 average_tpt;
51 unsigned long stamp;
52 };
53
54 struct iwl3945_rs_sta {
55 spinlock_t lock;
56 struct iwl_priv *priv;
57 s32 *expected_tpt;
58 unsigned long last_partial_flush;
59 unsigned long last_flush;
60 u32 flush_time;
61 u32 last_tx_packets;
62 u32 tx_packets;
63 u8 tgg;
64 u8 flush_pending;
65 u8 start_rate;
66 u8 ibss_sta_added;
67 struct timer_list rate_scale_flush;
68 struct iwl3945_rate_scale_data win[IWL_RATE_COUNT_3945];
69 #ifdef CONFIG_MAC80211_DEBUGFS
70 struct dentry *rs_sta_dbgfs_stats_table_file;
71 #endif
72
73 /* used to be in sta_info */
74 int last_txrate_idx;
75 };
76
77 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT_3945] = {
78 7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
79 };
80
81 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT_3945] = {
82 7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
83 };
84
85 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT_3945] = {
86 0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
87 };
88
89 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT_3945] = {
90 7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
91 };
92
93 struct iwl3945_tpt_entry {
94 s8 min_rssi;
95 u8 index;
96 };
97
98 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
99 {-60, IWL_RATE_54M_INDEX},
100 {-64, IWL_RATE_48M_INDEX},
101 {-72, IWL_RATE_36M_INDEX},
102 {-80, IWL_RATE_24M_INDEX},
103 {-84, IWL_RATE_18M_INDEX},
104 {-85, IWL_RATE_12M_INDEX},
105 {-87, IWL_RATE_9M_INDEX},
106 {-89, IWL_RATE_6M_INDEX}
107 };
108
109 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
110 {-60, IWL_RATE_54M_INDEX},
111 {-64, IWL_RATE_48M_INDEX},
112 {-68, IWL_RATE_36M_INDEX},
113 {-80, IWL_RATE_24M_INDEX},
114 {-84, IWL_RATE_18M_INDEX},
115 {-85, IWL_RATE_12M_INDEX},
116 {-86, IWL_RATE_11M_INDEX},
117 {-88, IWL_RATE_5M_INDEX},
118 {-90, IWL_RATE_2M_INDEX},
119 {-92, IWL_RATE_1M_INDEX}
120 };
121
122 #define IWL_RATE_MAX_WINDOW 62
123 #define IWL_RATE_FLUSH (3*HZ)
124 #define IWL_RATE_WIN_FLUSH (HZ/2)
125 #define IWL39_RATE_HIGH_TH 11520
126 #define IWL_SUCCESS_UP_TH 8960
127 #define IWL_SUCCESS_DOWN_TH 10880
128 #define IWL_RATE_MIN_FAILURE_TH 6
129 #define IWL_RATE_MIN_SUCCESS_TH 8
130 #define IWL_RATE_DECREASE_TH 1920
131 #define IWL_RATE_RETRY_TH 15
132
133 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
134 {
135 u32 index = 0;
136 u32 table_size = 0;
137 struct iwl3945_tpt_entry *tpt_table = NULL;
138
139 if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
140 rssi = IWL_MIN_RSSI_VAL;
141
142 switch (band) {
143 case IEEE80211_BAND_2GHZ:
144 tpt_table = iwl3945_tpt_table_g;
145 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
146 break;
147
148 case IEEE80211_BAND_5GHZ:
149 tpt_table = iwl3945_tpt_table_a;
150 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
151 break;
152
153 default:
154 BUG();
155 break;
156 }
157
158 while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
159 index++;
160
161 index = min(index, (table_size - 1));
162
163 return tpt_table[index].index;
164 }
165
166 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
167 {
168 window->data = 0;
169 window->success_counter = 0;
170 window->success_ratio = -1;
171 window->counter = 0;
172 window->average_tpt = IWL_INVALID_VALUE;
173 window->stamp = 0;
174 }
175
176 /**
177 * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
178 *
179 * Returns the number of windows that have gathered data but were
180 * not flushed. If there were any that were not flushed, then
181 * reschedule the rate flushing routine.
182 */
183 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
184 {
185 int unflushed = 0;
186 int i;
187 unsigned long flags;
188 struct iwl_priv *priv __maybe_unused = rs_sta->priv;
189
190 /*
191 * For each rate, if we have collected data on that rate
192 * and it has been more than IWL_RATE_WIN_FLUSH
193 * since we flushed, clear out the gathered statistics
194 */
195 for (i = 0; i < IWL_RATE_COUNT_3945; i++) {
196 if (!rs_sta->win[i].counter)
197 continue;
198
199 spin_lock_irqsave(&rs_sta->lock, flags);
200 if (time_after(jiffies, rs_sta->win[i].stamp +
201 IWL_RATE_WIN_FLUSH)) {
202 IWL_DEBUG_RATE(priv, "flushing %d samples of rate "
203 "index %d\n",
204 rs_sta->win[i].counter, i);
205 iwl3945_clear_window(&rs_sta->win[i]);
206 } else
207 unflushed++;
208 spin_unlock_irqrestore(&rs_sta->lock, flags);
209 }
210
211 return unflushed;
212 }
213
214 #define IWL_RATE_FLUSH_MAX 5000 /* msec */
215 #define IWL_RATE_FLUSH_MIN 50 /* msec */
216 #define IWL_AVERAGE_PACKETS 1500
217
218 static void iwl3945_bg_rate_scale_flush(unsigned long data)
219 {
220 struct iwl3945_rs_sta *rs_sta = (void *)data;
221 struct iwl_priv *priv __maybe_unused = rs_sta->priv;
222 int unflushed = 0;
223 unsigned long flags;
224 u32 packet_count, duration, pps;
225
226 IWL_DEBUG_RATE(priv, "enter\n");
227
228 unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
229
230 spin_lock_irqsave(&rs_sta->lock, flags);
231
232 /* Number of packets Rx'd since last time this timer ran */
233 packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
234
235 rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
236
237 if (unflushed) {
238 duration =
239 jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
240
241 IWL_DEBUG_RATE(priv, "Tx'd %d packets in %dms\n",
242 packet_count, duration);
243
244 /* Determine packets per second */
245 if (duration)
246 pps = (packet_count * 1000) / duration;
247 else
248 pps = 0;
249
250 if (pps) {
251 duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
252 if (duration < IWL_RATE_FLUSH_MIN)
253 duration = IWL_RATE_FLUSH_MIN;
254 else if (duration > IWL_RATE_FLUSH_MAX)
255 duration = IWL_RATE_FLUSH_MAX;
256 } else
257 duration = IWL_RATE_FLUSH_MAX;
258
259 rs_sta->flush_time = msecs_to_jiffies(duration);
260
261 IWL_DEBUG_RATE(priv, "new flush period: %d msec ave %d\n",
262 duration, packet_count);
263
264 mod_timer(&rs_sta->rate_scale_flush, jiffies +
265 rs_sta->flush_time);
266
267 rs_sta->last_partial_flush = jiffies;
268 } else {
269 rs_sta->flush_time = IWL_RATE_FLUSH;
270 rs_sta->flush_pending = 0;
271 }
272 /* If there weren't any unflushed entries, we don't schedule the timer
273 * to run again */
274
275 rs_sta->last_flush = jiffies;
276
277 spin_unlock_irqrestore(&rs_sta->lock, flags);
278
279 IWL_DEBUG_RATE(priv, "leave\n");
280 }
281
282 /**
283 * iwl3945_collect_tx_data - Update the success/failure sliding window
284 *
285 * We keep a sliding window of the last 64 packets transmitted
286 * at this rate. window->data contains the bitmask of successful
287 * packets.
288 */
289 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
290 struct iwl3945_rate_scale_data *window,
291 int success, int retries, int index)
292 {
293 unsigned long flags;
294 s32 fail_count;
295 struct iwl_priv *priv __maybe_unused = rs_sta->priv;
296
297 if (!retries) {
298 IWL_DEBUG_RATE(priv, "leave: retries == 0 -- should be at least 1\n");
299 return;
300 }
301
302 spin_lock_irqsave(&rs_sta->lock, flags);
303
304 /*
305 * Keep track of only the latest 62 tx frame attempts in this rate's
306 * history window; anything older isn't really relevant any more.
307 * If we have filled up the sliding window, drop the oldest attempt;
308 * if the oldest attempt (highest bit in bitmap) shows "success",
309 * subtract "1" from the success counter (this is the main reason
310 * we keep these bitmaps!).
311 * */
312 while (retries > 0) {
313 if (window->counter >= IWL_RATE_MAX_WINDOW) {
314
315 /* remove earliest */
316 window->counter = IWL_RATE_MAX_WINDOW - 1;
317
318 if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1))) {
319 window->data &= ~(1ULL << (IWL_RATE_MAX_WINDOW - 1));
320 window->success_counter--;
321 }
322 }
323
324 /* Increment frames-attempted counter */
325 window->counter++;
326
327 /* Shift bitmap by one frame (throw away oldest history),
328 * OR in "1", and increment "success" if this
329 * frame was successful. */
330 window->data <<= 1;
331 if (success > 0) {
332 window->success_counter++;
333 window->data |= 0x1;
334 success--;
335 }
336
337 retries--;
338 }
339
340 /* Calculate current success ratio, avoid divide-by-0! */
341 if (window->counter > 0)
342 window->success_ratio = 128 * (100 * window->success_counter)
343 / window->counter;
344 else
345 window->success_ratio = IWL_INVALID_VALUE;
346
347 fail_count = window->counter - window->success_counter;
348
349 /* Calculate average throughput, if we have enough history. */
350 if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
351 (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
352 window->average_tpt = ((window->success_ratio *
353 rs_sta->expected_tpt[index] + 64) / 128);
354 else
355 window->average_tpt = IWL_INVALID_VALUE;
356
357 /* Tag this window as having been updated */
358 window->stamp = jiffies;
359
360 spin_unlock_irqrestore(&rs_sta->lock, flags);
361
362 }
363
364 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
365 struct ieee80211_sta *sta, void *priv_sta)
366 {
367 struct iwl3945_rs_sta *rs_sta = priv_sta;
368 struct iwl_priv *priv = (struct iwl_priv *)priv_r;
369 int i;
370
371 IWL_DEBUG_RATE(priv, "enter\n");
372
373 /* TODO: what is a good starting rate for STA? About middle? Maybe not
374 * the lowest or the highest rate.. Could consider using RSSI from
375 * previous packets? Need to have IEEE 802.1X auth succeed immediately
376 * after assoc.. */
377
378 for (i = sband->n_bitrates - 1; i >= 0; i--) {
379 if (sta->supp_rates[sband->band] & (1 << i)) {
380 rs_sta->last_txrate_idx = i;
381 break;
382 }
383 }
384
385 priv->sta_supp_rates = sta->supp_rates[sband->band];
386 /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
387 if (sband->band == IEEE80211_BAND_5GHZ) {
388 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
389 priv->sta_supp_rates = priv->sta_supp_rates <<
390 IWL_FIRST_OFDM_RATE;
391 }
392
393
394 IWL_DEBUG_RATE(priv, "leave\n");
395 }
396
397 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
398 {
399 return hw->priv;
400 }
401
402 /* rate scale requires free function to be implemented */
403 static void rs_free(void *priv)
404 {
405 return;
406 }
407
408 static void *rs_alloc_sta(void *iwl_priv, struct ieee80211_sta *sta, gfp_t gfp)
409 {
410 struct iwl3945_rs_sta *rs_sta;
411 struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
412 struct iwl_priv *priv = iwl_priv;
413 int i;
414
415 /*
416 * XXX: If it's using sta->drv_priv anyway, it might
417 * as well just put all the information there.
418 */
419
420 IWL_DEBUG_RATE(priv, "enter\n");
421
422 rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
423 if (!rs_sta) {
424 IWL_DEBUG_RATE(priv, "leave: ENOMEM\n");
425 return NULL;
426 }
427
428 psta->rs_sta = rs_sta;
429
430 spin_lock_init(&rs_sta->lock);
431
432 rs_sta->priv = priv;
433
434 rs_sta->start_rate = IWL_RATE_INVALID;
435
436 /* default to just 802.11b */
437 rs_sta->expected_tpt = iwl3945_expected_tpt_b;
438
439 rs_sta->last_partial_flush = jiffies;
440 rs_sta->last_flush = jiffies;
441 rs_sta->flush_time = IWL_RATE_FLUSH;
442 rs_sta->last_tx_packets = 0;
443 rs_sta->ibss_sta_added = 0;
444
445 init_timer(&rs_sta->rate_scale_flush);
446 rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
447 rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
448
449 for (i = 0; i < IWL_RATE_COUNT_3945; i++)
450 iwl3945_clear_window(&rs_sta->win[i]);
451
452 IWL_DEBUG_RATE(priv, "leave\n");
453
454 return rs_sta;
455 }
456
457 static void rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
458 void *priv_sta)
459 {
460 struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
461 struct iwl3945_rs_sta *rs_sta = priv_sta;
462 struct iwl_priv *priv __maybe_unused = rs_sta->priv;
463
464 psta->rs_sta = NULL;
465
466 IWL_DEBUG_RATE(priv, "enter\n");
467 del_timer_sync(&rs_sta->rate_scale_flush);
468 kfree(rs_sta);
469 IWL_DEBUG_RATE(priv, "leave\n");
470 }
471
472
473 /**
474 * rs_tx_status - Update rate control values based on Tx results
475 *
476 * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
477 * the hardware for each rate.
478 */
479 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
480 struct ieee80211_sta *sta, void *priv_sta,
481 struct sk_buff *skb)
482 {
483 s8 retries = 0, current_count;
484 int scale_rate_index, first_index, last_index;
485 unsigned long flags;
486 struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
487 struct iwl3945_rs_sta *rs_sta = priv_sta;
488 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
489
490 IWL_DEBUG_RATE(priv, "enter\n");
491
492 retries = info->status.rates[0].count;
493 /* Sanity Check for retries */
494 if (retries > IWL_RATE_RETRY_TH)
495 retries = IWL_RATE_RETRY_TH;
496
497 first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
498 if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
499 IWL_DEBUG_RATE(priv, "leave: Rate out of bounds: %d\n", first_index);
500 return;
501 }
502
503 if (!priv_sta) {
504 IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
505 return;
506 }
507
508 rs_sta->tx_packets++;
509
510 scale_rate_index = first_index;
511 last_index = first_index;
512
513 /*
514 * Update the window for each rate. We determine which rates
515 * were Tx'd based on the total number of retries vs. the number
516 * of retries configured for each rate -- currently set to the
517 * priv value 'retry_rate' vs. rate specific
518 *
519 * On exit from this while loop last_index indicates the rate
520 * at which the frame was finally transmitted (or failed if no
521 * ACK)
522 */
523 while (retries > 1) {
524 if ((retries - 1) < priv->retry_rate) {
525 current_count = (retries - 1);
526 last_index = scale_rate_index;
527 } else {
528 current_count = priv->retry_rate;
529 last_index = iwl3945_rs_next_rate(priv,
530 scale_rate_index);
531 }
532
533 /* Update this rate accounting for as many retries
534 * as was used for it (per current_count) */
535 iwl3945_collect_tx_data(rs_sta,
536 &rs_sta->win[scale_rate_index],
537 0, current_count, scale_rate_index);
538 IWL_DEBUG_RATE(priv, "Update rate %d for %d retries.\n",
539 scale_rate_index, current_count);
540
541 retries -= current_count;
542
543 scale_rate_index = last_index;
544 }
545
546
547 /* Update the last index window with success/failure based on ACK */
548 IWL_DEBUG_RATE(priv, "Update rate %d with %s.\n",
549 last_index,
550 (info->flags & IEEE80211_TX_STAT_ACK) ?
551 "success" : "failure");
552 iwl3945_collect_tx_data(rs_sta,
553 &rs_sta->win[last_index],
554 info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
555
556 /* We updated the rate scale window -- if its been more than
557 * flush_time since the last run, schedule the flush
558 * again */
559 spin_lock_irqsave(&rs_sta->lock, flags);
560
561 if (!rs_sta->flush_pending &&
562 time_after(jiffies, rs_sta->last_flush +
563 rs_sta->flush_time)) {
564
565 rs_sta->last_partial_flush = jiffies;
566 rs_sta->flush_pending = 1;
567 mod_timer(&rs_sta->rate_scale_flush,
568 jiffies + rs_sta->flush_time);
569 }
570
571 spin_unlock_irqrestore(&rs_sta->lock, flags);
572
573 IWL_DEBUG_RATE(priv, "leave\n");
574
575 return;
576 }
577
578 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
579 u8 index, u16 rate_mask, enum ieee80211_band band)
580 {
581 u8 high = IWL_RATE_INVALID;
582 u8 low = IWL_RATE_INVALID;
583 struct iwl_priv *priv __maybe_unused = rs_sta->priv;
584
585 /* 802.11A walks to the next literal adjacent rate in
586 * the rate table */
587 if (unlikely(band == IEEE80211_BAND_5GHZ)) {
588 int i;
589 u32 mask;
590
591 /* Find the previous rate that is in the rate mask */
592 i = index - 1;
593 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
594 if (rate_mask & mask) {
595 low = i;
596 break;
597 }
598 }
599
600 /* Find the next rate that is in the rate mask */
601 i = index + 1;
602 for (mask = (1 << i); i < IWL_RATE_COUNT_3945;
603 i++, mask <<= 1) {
604 if (rate_mask & mask) {
605 high = i;
606 break;
607 }
608 }
609
610 return (high << 8) | low;
611 }
612
613 low = index;
614 while (low != IWL_RATE_INVALID) {
615 if (rs_sta->tgg)
616 low = iwl3945_rates[low].prev_rs_tgg;
617 else
618 low = iwl3945_rates[low].prev_rs;
619 if (low == IWL_RATE_INVALID)
620 break;
621 if (rate_mask & (1 << low))
622 break;
623 IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low);
624 }
625
626 high = index;
627 while (high != IWL_RATE_INVALID) {
628 if (rs_sta->tgg)
629 high = iwl3945_rates[high].next_rs_tgg;
630 else
631 high = iwl3945_rates[high].next_rs;
632 if (high == IWL_RATE_INVALID)
633 break;
634 if (rate_mask & (1 << high))
635 break;
636 IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high);
637 }
638
639 return (high << 8) | low;
640 }
641
642 /**
643 * rs_get_rate - find the rate for the requested packet
644 *
645 * Returns the ieee80211_rate structure allocated by the driver.
646 *
647 * The rate control algorithm has no internal mapping between hw_mode's
648 * rate ordering and the rate ordering used by the rate control algorithm.
649 *
650 * The rate control algorithm uses a single table of rates that goes across
651 * the entire A/B/G spectrum vs. being limited to just one particular
652 * hw_mode.
653 *
654 * As such, we can't convert the index obtained below into the hw_mode's
655 * rate table and must reference the driver allocated rate table
656 *
657 */
658 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
659 void *priv_sta, struct ieee80211_tx_rate_control *txrc)
660 {
661 struct ieee80211_supported_band *sband = txrc->sband;
662 struct sk_buff *skb = txrc->skb;
663 u8 low = IWL_RATE_INVALID;
664 u8 high = IWL_RATE_INVALID;
665 u16 high_low;
666 int index;
667 struct iwl3945_rs_sta *rs_sta = priv_sta;
668 struct iwl3945_rate_scale_data *window = NULL;
669 int current_tpt = IWL_INVALID_VALUE;
670 int low_tpt = IWL_INVALID_VALUE;
671 int high_tpt = IWL_INVALID_VALUE;
672 u32 fail_count;
673 s8 scale_action = 0;
674 unsigned long flags;
675 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
676 u16 rate_mask = sta ? sta->supp_rates[sband->band] : 0;
677 s8 max_rate_idx = -1;
678 struct iwl_priv *priv = (struct iwl_priv *)priv_r;
679 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
680
681 IWL_DEBUG_RATE(priv, "enter\n");
682
683 if (rate_control_send_low(sta, priv_sta, txrc))
684 return;
685
686 rate_mask = sta->supp_rates[sband->band];
687
688 /* get user max rate if set */
689 max_rate_idx = txrc->max_rate_idx;
690 if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1))
691 max_rate_idx += IWL_FIRST_OFDM_RATE;
692 if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT))
693 max_rate_idx = -1;
694
695 index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
696
697 if (sband->band == IEEE80211_BAND_5GHZ)
698 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
699
700 if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
701 !rs_sta->ibss_sta_added) {
702 u8 sta_id = iwl_find_station(priv, hdr->addr1);
703
704 if (sta_id == IWL_INVALID_STATION) {
705 IWL_DEBUG_RATE(priv, "LQ: ADD station %pM\n",
706 hdr->addr1);
707 sta_id = iwl_add_station(priv, hdr->addr1, false,
708 CMD_ASYNC, NULL);
709 }
710 if (sta_id != IWL_INVALID_STATION)
711 rs_sta->ibss_sta_added = 1;
712 }
713
714 spin_lock_irqsave(&rs_sta->lock, flags);
715
716 /* for recent assoc, choose best rate regarding
717 * to rssi value
718 */
719 if (rs_sta->start_rate != IWL_RATE_INVALID) {
720 if (rs_sta->start_rate < index &&
721 (rate_mask & (1 << rs_sta->start_rate)))
722 index = rs_sta->start_rate;
723 rs_sta->start_rate = IWL_RATE_INVALID;
724 }
725
726 /* force user max rate if set by user */
727 if ((max_rate_idx != -1) && (max_rate_idx < index)) {
728 if (rate_mask & (1 << max_rate_idx))
729 index = max_rate_idx;
730 }
731
732 window = &(rs_sta->win[index]);
733
734 fail_count = window->counter - window->success_counter;
735
736 if (((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
737 (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
738 spin_unlock_irqrestore(&rs_sta->lock, flags);
739
740 IWL_DEBUG_RATE(priv, "Invalid average_tpt on rate %d: "
741 "counter: %d, success_counter: %d, "
742 "expected_tpt is %sNULL\n",
743 index,
744 window->counter,
745 window->success_counter,
746 rs_sta->expected_tpt ? "not " : "");
747
748 /* Can't calculate this yet; not enough history */
749 window->average_tpt = IWL_INVALID_VALUE;
750 goto out;
751
752 }
753
754 current_tpt = window->average_tpt;
755
756 high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
757 sband->band);
758 low = high_low & 0xff;
759 high = (high_low >> 8) & 0xff;
760
761 /* If user set max rate, dont allow higher than user constrain */
762 if ((max_rate_idx != -1) && (max_rate_idx < high))
763 high = IWL_RATE_INVALID;
764
765 /* Collect Measured throughputs of adjacent rates */
766 if (low != IWL_RATE_INVALID)
767 low_tpt = rs_sta->win[low].average_tpt;
768
769 if (high != IWL_RATE_INVALID)
770 high_tpt = rs_sta->win[high].average_tpt;
771
772 spin_unlock_irqrestore(&rs_sta->lock, flags);
773
774 scale_action = 0;
775
776 /* Low success ratio , need to drop the rate */
777 if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
778 IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
779 scale_action = -1;
780 /* No throughput measured yet for adjacent rates,
781 * try increase */
782 } else if ((low_tpt == IWL_INVALID_VALUE) &&
783 (high_tpt == IWL_INVALID_VALUE)) {
784
785 if (high != IWL_RATE_INVALID && window->success_ratio >= IWL_RATE_INCREASE_TH)
786 scale_action = 1;
787 else if (low != IWL_RATE_INVALID)
788 scale_action = 0;
789
790 /* Both adjacent throughputs are measured, but neither one has
791 * better throughput; we're using the best rate, don't change
792 * it! */
793 } else if ((low_tpt != IWL_INVALID_VALUE) &&
794 (high_tpt != IWL_INVALID_VALUE) &&
795 (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
796
797 IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < "
798 "current_tpt [%d]\n",
799 low_tpt, high_tpt, current_tpt);
800 scale_action = 0;
801
802 /* At least one of the rates has better throughput */
803 } else {
804 if (high_tpt != IWL_INVALID_VALUE) {
805
806 /* High rate has better throughput, Increase
807 * rate */
808 if (high_tpt > current_tpt &&
809 window->success_ratio >= IWL_RATE_INCREASE_TH)
810 scale_action = 1;
811 else {
812 IWL_DEBUG_RATE(priv,
813 "decrease rate because of high tpt\n");
814 scale_action = 0;
815 }
816 } else if (low_tpt != IWL_INVALID_VALUE) {
817 if (low_tpt > current_tpt) {
818 IWL_DEBUG_RATE(priv,
819 "decrease rate because of low tpt\n");
820 scale_action = -1;
821 } else if (window->success_ratio >= IWL_RATE_INCREASE_TH) {
822 /* Lower rate has better
823 * throughput,decrease rate */
824 scale_action = 1;
825 }
826 }
827 }
828
829 /* Sanity check; asked for decrease, but success rate or throughput
830 * has been good at old rate. Don't change it. */
831 if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
832 ((window->success_ratio > IWL_RATE_HIGH_TH) ||
833 (current_tpt > (100 * rs_sta->expected_tpt[low]))))
834 scale_action = 0;
835
836 switch (scale_action) {
837 case -1:
838
839 /* Decrese rate */
840 if (low != IWL_RATE_INVALID)
841 index = low;
842 break;
843
844 case 1:
845 /* Increase rate */
846 if (high != IWL_RATE_INVALID)
847 index = high;
848
849 break;
850
851 case 0:
852 default:
853 /* No change */
854 break;
855 }
856
857 IWL_DEBUG_RATE(priv, "Selected %d (action %d) - low %d high %d\n",
858 index, scale_action, low, high);
859
860 out:
861
862 rs_sta->last_txrate_idx = index;
863 if (sband->band == IEEE80211_BAND_5GHZ)
864 info->control.rates[0].idx = rs_sta->last_txrate_idx -
865 IWL_FIRST_OFDM_RATE;
866 else
867 info->control.rates[0].idx = rs_sta->last_txrate_idx;
868
869 IWL_DEBUG_RATE(priv, "leave: %d\n", index);
870 }
871
872 #ifdef CONFIG_MAC80211_DEBUGFS
873 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
874 {
875 file->private_data = inode->i_private;
876 return 0;
877 }
878
879 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
880 char __user *user_buf,
881 size_t count, loff_t *ppos)
882 {
883 char *buff;
884 int desc = 0;
885 int j;
886 ssize_t ret;
887 struct iwl3945_rs_sta *lq_sta = file->private_data;
888
889 buff = kmalloc(1024, GFP_KERNEL);
890 if (!buff)
891 return -ENOMEM;
892
893 desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
894 "rate=0x%X flush time %d\n",
895 lq_sta->tx_packets,
896 lq_sta->last_txrate_idx,
897 lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
898 for (j = 0; j < IWL_RATE_COUNT_3945; j++) {
899 desc += sprintf(buff+desc,
900 "counter=%d success=%d %%=%d\n",
901 lq_sta->win[j].counter,
902 lq_sta->win[j].success_counter,
903 lq_sta->win[j].success_ratio);
904 }
905 ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
906 kfree(buff);
907 return ret;
908 }
909
910 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
911 .read = iwl3945_sta_dbgfs_stats_table_read,
912 .open = iwl3945_open_file_generic,
913 };
914
915 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
916 struct dentry *dir)
917 {
918 struct iwl3945_rs_sta *lq_sta = priv_sta;
919
920 lq_sta->rs_sta_dbgfs_stats_table_file =
921 debugfs_create_file("rate_stats_table", 0600, dir,
922 lq_sta, &rs_sta_dbgfs_stats_table_ops);
923
924 }
925
926 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
927 {
928 struct iwl3945_rs_sta *lq_sta = priv_sta;
929 debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
930 }
931 #endif
932
933 static struct rate_control_ops rs_ops = {
934 .module = NULL,
935 .name = RS_NAME,
936 .tx_status = rs_tx_status,
937 .get_rate = rs_get_rate,
938 .rate_init = rs_rate_init,
939 .alloc = rs_alloc,
940 .free = rs_free,
941 .alloc_sta = rs_alloc_sta,
942 .free_sta = rs_free_sta,
943 #ifdef CONFIG_MAC80211_DEBUGFS
944 .add_sta_debugfs = iwl3945_add_debugfs,
945 .remove_sta_debugfs = iwl3945_remove_debugfs,
946 #endif
947
948 };
949
950 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
951 {
952 struct iwl_priv *priv = hw->priv;
953 s32 rssi = 0;
954 unsigned long flags;
955 struct iwl3945_rs_sta *rs_sta;
956 struct ieee80211_sta *sta;
957 struct iwl3945_sta_priv *psta;
958
959 IWL_DEBUG_RATE(priv, "enter\n");
960
961 rcu_read_lock();
962
963 sta = ieee80211_find_sta(hw, priv->stations[sta_id].sta.sta.addr);
964 if (!sta) {
965 rcu_read_unlock();
966 return;
967 }
968
969 psta = (void *) sta->drv_priv;
970 rs_sta = psta->rs_sta;
971
972 spin_lock_irqsave(&rs_sta->lock, flags);
973
974 rs_sta->tgg = 0;
975 switch (priv->band) {
976 case IEEE80211_BAND_2GHZ:
977 /* TODO: this always does G, not a regression */
978 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
979 rs_sta->tgg = 1;
980 rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
981 } else
982 rs_sta->expected_tpt = iwl3945_expected_tpt_g;
983 break;
984
985 case IEEE80211_BAND_5GHZ:
986 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
987 break;
988 case IEEE80211_NUM_BANDS:
989 BUG();
990 break;
991 }
992
993 spin_unlock_irqrestore(&rs_sta->lock, flags);
994
995 rssi = priv->last_rx_rssi;
996 if (rssi == 0)
997 rssi = IWL_MIN_RSSI_VAL;
998
999 IWL_DEBUG_RATE(priv, "Network RSSI: %d\n", rssi);
1000
1001 rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
1002
1003 IWL_DEBUG_RATE(priv, "leave: rssi %d assign rate index: "
1004 "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
1005 iwl3945_rates[rs_sta->start_rate].plcp);
1006 rcu_read_unlock();
1007 }
1008
1009 int iwl3945_rate_control_register(void)
1010 {
1011 return ieee80211_rate_control_register(&rs_ops);
1012 }
1013
1014 void iwl3945_rate_control_unregister(void)
1015 {
1016 ieee80211_rate_control_unregister(&rs_ops);
1017 }
1018
1019
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