iwlwifi: enable 2-wire bt coex support for non-combo device
[linux-2.6.git] / drivers / net / wireless / iwlwifi / iwl-3945-rs.c
1 /******************************************************************************
2  *
3  * Copyright(c) 2005 - 2010 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/slab.h>
31 #include <linux/wireless.h>
32 #include <net/mac80211.h>
33
34 #include <linux/netdevice.h>
35 #include <linux/etherdevice.h>
36 #include <linux/delay.h>
37
38 #include <linux/workqueue.h>
39
40 #include "iwl-commands.h"
41 #include "iwl-3945.h"
42 #include "iwl-sta.h"
43
44 #define RS_NAME "iwl-3945-rs"
45
46 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT_3945] = {
47         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
48 };
49
50 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT_3945] = {
51         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
52 };
53
54 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT_3945] = {
55         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
56 };
57
58 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT_3945] = {
59         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
60 };
61
62 struct iwl3945_tpt_entry {
63         s8 min_rssi;
64         u8 index;
65 };
66
67 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
68         {-60, IWL_RATE_54M_INDEX},
69         {-64, IWL_RATE_48M_INDEX},
70         {-72, IWL_RATE_36M_INDEX},
71         {-80, IWL_RATE_24M_INDEX},
72         {-84, IWL_RATE_18M_INDEX},
73         {-85, IWL_RATE_12M_INDEX},
74         {-87, IWL_RATE_9M_INDEX},
75         {-89, IWL_RATE_6M_INDEX}
76 };
77
78 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
79         {-60, IWL_RATE_54M_INDEX},
80         {-64, IWL_RATE_48M_INDEX},
81         {-68, IWL_RATE_36M_INDEX},
82         {-80, IWL_RATE_24M_INDEX},
83         {-84, IWL_RATE_18M_INDEX},
84         {-85, IWL_RATE_12M_INDEX},
85         {-86, IWL_RATE_11M_INDEX},
86         {-88, IWL_RATE_5M_INDEX},
87         {-90, IWL_RATE_2M_INDEX},
88         {-92, IWL_RATE_1M_INDEX}
89 };
90
91 #define IWL_RATE_MAX_WINDOW          62
92 #define IWL_RATE_FLUSH           (3*HZ)
93 #define IWL_RATE_WIN_FLUSH       (HZ/2)
94 #define IWL39_RATE_HIGH_TH          11520
95 #define IWL_SUCCESS_UP_TH          8960
96 #define IWL_SUCCESS_DOWN_TH       10880
97 #define IWL_RATE_MIN_FAILURE_TH       6
98 #define IWL_RATE_MIN_SUCCESS_TH       8
99 #define IWL_RATE_DECREASE_TH       1920
100 #define IWL_RATE_RETRY_TH            15
101
102 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
103 {
104         u32 index = 0;
105         u32 table_size = 0;
106         struct iwl3945_tpt_entry *tpt_table = NULL;
107
108         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
109                 rssi = IWL_MIN_RSSI_VAL;
110
111         switch (band) {
112         case IEEE80211_BAND_2GHZ:
113                 tpt_table = iwl3945_tpt_table_g;
114                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
115                 break;
116
117         case IEEE80211_BAND_5GHZ:
118                 tpt_table = iwl3945_tpt_table_a;
119                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
120                 break;
121
122         default:
123                 BUG();
124                 break;
125         }
126
127         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
128                 index++;
129
130         index = min(index, (table_size - 1));
131
132         return tpt_table[index].index;
133 }
134
135 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
136 {
137         window->data = 0;
138         window->success_counter = 0;
139         window->success_ratio = -1;
140         window->counter = 0;
141         window->average_tpt = IWL_INVALID_VALUE;
142         window->stamp = 0;
143 }
144
145 /**
146  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
147  *
148  * Returns the number of windows that have gathered data but were
149  * not flushed.  If there were any that were not flushed, then
150  * reschedule the rate flushing routine.
151  */
152 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
153 {
154         int unflushed = 0;
155         int i;
156         unsigned long flags;
157         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
158
159         /*
160          * For each rate, if we have collected data on that rate
161          * and it has been more than IWL_RATE_WIN_FLUSH
162          * since we flushed, clear out the gathered statistics
163          */
164         for (i = 0; i < IWL_RATE_COUNT_3945; i++) {
165                 if (!rs_sta->win[i].counter)
166                         continue;
167
168                 spin_lock_irqsave(&rs_sta->lock, flags);
169                 if (time_after(jiffies, rs_sta->win[i].stamp +
170                                IWL_RATE_WIN_FLUSH)) {
171                         IWL_DEBUG_RATE(priv, "flushing %d samples of rate "
172                                        "index %d\n",
173                                        rs_sta->win[i].counter, i);
174                         iwl3945_clear_window(&rs_sta->win[i]);
175                 } else
176                         unflushed++;
177                 spin_unlock_irqrestore(&rs_sta->lock, flags);
178         }
179
180         return unflushed;
181 }
182
183 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
184 #define IWL_RATE_FLUSH_MIN              50      /* msec */
185 #define IWL_AVERAGE_PACKETS             1500
186
187 static void iwl3945_bg_rate_scale_flush(unsigned long data)
188 {
189         struct iwl3945_rs_sta *rs_sta = (void *)data;
190         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
191         int unflushed = 0;
192         unsigned long flags;
193         u32 packet_count, duration, pps;
194
195         IWL_DEBUG_RATE(priv, "enter\n");
196
197         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
198
199         spin_lock_irqsave(&rs_sta->lock, flags);
200
201         /* Number of packets Rx'd since last time this timer ran */
202         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
203
204         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
205
206         if (unflushed) {
207                 duration =
208                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
209
210                 IWL_DEBUG_RATE(priv, "Tx'd %d packets in %dms\n",
211                                packet_count, duration);
212
213                 /* Determine packets per second */
214                 if (duration)
215                         pps = (packet_count * 1000) / duration;
216                 else
217                         pps = 0;
218
219                 if (pps) {
220                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
221                         if (duration < IWL_RATE_FLUSH_MIN)
222                                 duration = IWL_RATE_FLUSH_MIN;
223                         else if (duration > IWL_RATE_FLUSH_MAX)
224                                 duration = IWL_RATE_FLUSH_MAX;
225                 } else
226                         duration = IWL_RATE_FLUSH_MAX;
227
228                 rs_sta->flush_time = msecs_to_jiffies(duration);
229
230                 IWL_DEBUG_RATE(priv, "new flush period: %d msec ave %d\n",
231                                duration, packet_count);
232
233                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
234                           rs_sta->flush_time);
235
236                 rs_sta->last_partial_flush = jiffies;
237         } else {
238                 rs_sta->flush_time = IWL_RATE_FLUSH;
239                 rs_sta->flush_pending = 0;
240         }
241         /* If there weren't any unflushed entries, we don't schedule the timer
242          * to run again */
243
244         rs_sta->last_flush = jiffies;
245
246         spin_unlock_irqrestore(&rs_sta->lock, flags);
247
248         IWL_DEBUG_RATE(priv, "leave\n");
249 }
250
251 /**
252  * iwl3945_collect_tx_data - Update the success/failure sliding window
253  *
254  * We keep a sliding window of the last 64 packets transmitted
255  * at this rate.  window->data contains the bitmask of successful
256  * packets.
257  */
258 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
259                                 struct iwl3945_rate_scale_data *window,
260                                 int success, int retries, int index)
261 {
262         unsigned long flags;
263         s32 fail_count;
264         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
265
266         if (!retries) {
267                 IWL_DEBUG_RATE(priv, "leave: retries == 0 -- should be at least 1\n");
268                 return;
269         }
270
271         spin_lock_irqsave(&rs_sta->lock, flags);
272
273         /*
274          * Keep track of only the latest 62 tx frame attempts in this rate's
275          * history window; anything older isn't really relevant any more.
276          * If we have filled up the sliding window, drop the oldest attempt;
277          * if the oldest attempt (highest bit in bitmap) shows "success",
278          * subtract "1" from the success counter (this is the main reason
279          * we keep these bitmaps!).
280          * */
281         while (retries > 0) {
282                 if (window->counter >= IWL_RATE_MAX_WINDOW) {
283
284                         /* remove earliest */
285                         window->counter = IWL_RATE_MAX_WINDOW - 1;
286
287                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1))) {
288                                 window->data &= ~(1ULL << (IWL_RATE_MAX_WINDOW - 1));
289                                 window->success_counter--;
290                         }
291                 }
292
293                 /* Increment frames-attempted counter */
294                 window->counter++;
295
296                 /* Shift bitmap by one frame (throw away oldest history),
297                  * OR in "1", and increment "success" if this
298                  * frame was successful. */
299                 window->data <<= 1;
300                 if (success > 0) {
301                         window->success_counter++;
302                         window->data |= 0x1;
303                         success--;
304                 }
305
306                 retries--;
307         }
308
309         /* Calculate current success ratio, avoid divide-by-0! */
310         if (window->counter > 0)
311                 window->success_ratio = 128 * (100 * window->success_counter)
312                                         / window->counter;
313         else
314                 window->success_ratio = IWL_INVALID_VALUE;
315
316         fail_count = window->counter - window->success_counter;
317
318         /* Calculate average throughput, if we have enough history. */
319         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
320             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
321                 window->average_tpt = ((window->success_ratio *
322                                 rs_sta->expected_tpt[index] + 64) / 128);
323         else
324                 window->average_tpt = IWL_INVALID_VALUE;
325
326         /* Tag this window as having been updated */
327         window->stamp = jiffies;
328
329         spin_unlock_irqrestore(&rs_sta->lock, flags);
330
331 }
332
333 /*
334  * Called after adding a new station to initialize rate scaling
335  */
336 void iwl3945_rs_rate_init(struct iwl_priv *priv, struct ieee80211_sta *sta, u8 sta_id)
337 {
338         struct ieee80211_hw *hw = priv->hw;
339         struct ieee80211_conf *conf = &priv->hw->conf;
340         struct iwl3945_sta_priv *psta;
341         struct iwl3945_rs_sta *rs_sta;
342         struct ieee80211_supported_band *sband;
343         int i;
344
345         IWL_DEBUG_INFO(priv, "enter\n");
346         if (sta_id == priv->contexts[IWL_RXON_CTX_BSS].bcast_sta_id)
347                 goto out;
348
349         psta = (struct iwl3945_sta_priv *) sta->drv_priv;
350         rs_sta = &psta->rs_sta;
351         sband = hw->wiphy->bands[conf->channel->band];
352
353         rs_sta->priv = priv;
354
355         rs_sta->start_rate = IWL_RATE_INVALID;
356
357         /* default to just 802.11b */
358         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
359
360         rs_sta->last_partial_flush = jiffies;
361         rs_sta->last_flush = jiffies;
362         rs_sta->flush_time = IWL_RATE_FLUSH;
363         rs_sta->last_tx_packets = 0;
364
365         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
366         rs_sta->rate_scale_flush.function = iwl3945_bg_rate_scale_flush;
367
368         for (i = 0; i < IWL_RATE_COUNT_3945; i++)
369                 iwl3945_clear_window(&rs_sta->win[i]);
370
371         /* TODO: what is a good starting rate for STA? About middle? Maybe not
372          * the lowest or the highest rate.. Could consider using RSSI from
373          * previous packets? Need to have IEEE 802.1X auth succeed immediately
374          * after assoc.. */
375
376         for (i = sband->n_bitrates - 1; i >= 0; i--) {
377                 if (sta->supp_rates[sband->band] & (1 << i)) {
378                         rs_sta->last_txrate_idx = i;
379                         break;
380                 }
381         }
382
383         priv->_3945.sta_supp_rates = sta->supp_rates[sband->band];
384         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
385         if (sband->band == IEEE80211_BAND_5GHZ) {
386                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
387                 priv->_3945.sta_supp_rates = priv->_3945.sta_supp_rates <<
388                                                 IWL_FIRST_OFDM_RATE;
389         }
390
391 out:
392         priv->stations[sta_id].used &= ~IWL_STA_UCODE_INPROGRESS;
393
394         IWL_DEBUG_INFO(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 __maybe_unused = iwl_priv;
413
414         IWL_DEBUG_RATE(priv, "enter\n");
415
416         rs_sta = &psta->rs_sta;
417
418         spin_lock_init(&rs_sta->lock);
419         init_timer(&rs_sta->rate_scale_flush);
420
421         IWL_DEBUG_RATE(priv, "leave\n");
422
423         return rs_sta;
424 }
425
426 static void rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
427                         void *priv_sta)
428 {
429         struct iwl3945_rs_sta *rs_sta = priv_sta;
430
431         /*
432          * Be careful not to use any members of iwl3945_rs_sta (like trying
433          * to use iwl_priv to print out debugging) since it may not be fully
434          * initialized at this point.
435          */
436         del_timer_sync(&rs_sta->rate_scale_flush);
437 }
438
439
440 /**
441  * rs_tx_status - Update rate control values based on Tx results
442  *
443  * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
444  * the hardware for each rate.
445  */
446 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
447                          struct ieee80211_sta *sta, void *priv_sta,
448                          struct sk_buff *skb)
449 {
450         s8 retries = 0, current_count;
451         int scale_rate_index, first_index, last_index;
452         unsigned long flags;
453         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
454         struct iwl3945_rs_sta *rs_sta = priv_sta;
455         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
456
457         IWL_DEBUG_RATE(priv, "enter\n");
458
459         retries = info->status.rates[0].count;
460         /* Sanity Check for retries */
461         if (retries > IWL_RATE_RETRY_TH)
462                 retries = IWL_RATE_RETRY_TH;
463
464         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
465         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
466                 IWL_DEBUG_RATE(priv, "leave: Rate out of bounds: %d\n", first_index);
467                 return;
468         }
469
470         if (!priv_sta) {
471                 IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
472                 return;
473         }
474
475         /* Treat uninitialized rate scaling data same as non-existing. */
476         if (!rs_sta->priv) {
477                 IWL_DEBUG_RATE(priv, "leave: STA priv data uninitialized!\n");
478                 return;
479         }
480
481
482         rs_sta->tx_packets++;
483
484         scale_rate_index = first_index;
485         last_index = first_index;
486
487         /*
488          * Update the window for each rate.  We determine which rates
489          * were Tx'd based on the total number of retries vs. the number
490          * of retries configured for each rate -- currently set to the
491          * priv value 'retry_rate' vs. rate specific
492          *
493          * On exit from this while loop last_index indicates the rate
494          * at which the frame was finally transmitted (or failed if no
495          * ACK)
496          */
497         while (retries > 1) {
498                 if ((retries - 1) < priv->retry_rate) {
499                         current_count = (retries - 1);
500                         last_index = scale_rate_index;
501                 } else {
502                         current_count = priv->retry_rate;
503                         last_index = iwl3945_rs_next_rate(priv,
504                                                          scale_rate_index);
505                 }
506
507                 /* Update this rate accounting for as many retries
508                  * as was used for it (per current_count) */
509                 iwl3945_collect_tx_data(rs_sta,
510                                     &rs_sta->win[scale_rate_index],
511                                     0, current_count, scale_rate_index);
512                 IWL_DEBUG_RATE(priv, "Update rate %d for %d retries.\n",
513                                scale_rate_index, current_count);
514
515                 retries -= current_count;
516
517                 scale_rate_index = last_index;
518         }
519
520
521         /* Update the last index window with success/failure based on ACK */
522         IWL_DEBUG_RATE(priv, "Update rate %d with %s.\n",
523                        last_index,
524                        (info->flags & IEEE80211_TX_STAT_ACK) ?
525                        "success" : "failure");
526         iwl3945_collect_tx_data(rs_sta,
527                             &rs_sta->win[last_index],
528                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
529
530         /* We updated the rate scale window -- if its been more than
531          * flush_time since the last run, schedule the flush
532          * again */
533         spin_lock_irqsave(&rs_sta->lock, flags);
534
535         if (!rs_sta->flush_pending &&
536             time_after(jiffies, rs_sta->last_flush +
537                        rs_sta->flush_time)) {
538
539                 rs_sta->last_partial_flush = jiffies;
540                 rs_sta->flush_pending = 1;
541                 mod_timer(&rs_sta->rate_scale_flush,
542                           jiffies + rs_sta->flush_time);
543         }
544
545         spin_unlock_irqrestore(&rs_sta->lock, flags);
546
547         IWL_DEBUG_RATE(priv, "leave\n");
548 }
549
550 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
551                                  u8 index, u16 rate_mask, enum ieee80211_band band)
552 {
553         u8 high = IWL_RATE_INVALID;
554         u8 low = IWL_RATE_INVALID;
555         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
556
557         /* 802.11A walks to the next literal adjacent rate in
558          * the rate table */
559         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
560                 int i;
561                 u32 mask;
562
563                 /* Find the previous rate that is in the rate mask */
564                 i = index - 1;
565                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
566                         if (rate_mask & mask) {
567                                 low = i;
568                                 break;
569                         }
570                 }
571
572                 /* Find the next rate that is in the rate mask */
573                 i = index + 1;
574                 for (mask = (1 << i); i < IWL_RATE_COUNT_3945;
575                      i++, mask <<= 1) {
576                         if (rate_mask & mask) {
577                                 high = i;
578                                 break;
579                         }
580                 }
581
582                 return (high << 8) | low;
583         }
584
585         low = index;
586         while (low != IWL_RATE_INVALID) {
587                 if (rs_sta->tgg)
588                         low = iwl3945_rates[low].prev_rs_tgg;
589                 else
590                         low = iwl3945_rates[low].prev_rs;
591                 if (low == IWL_RATE_INVALID)
592                         break;
593                 if (rate_mask & (1 << low))
594                         break;
595                 IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low);
596         }
597
598         high = index;
599         while (high != IWL_RATE_INVALID) {
600                 if (rs_sta->tgg)
601                         high = iwl3945_rates[high].next_rs_tgg;
602                 else
603                         high = iwl3945_rates[high].next_rs;
604                 if (high == IWL_RATE_INVALID)
605                         break;
606                 if (rate_mask & (1 << high))
607                         break;
608                 IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high);
609         }
610
611         return (high << 8) | low;
612 }
613
614 /**
615  * rs_get_rate - find the rate for the requested packet
616  *
617  * Returns the ieee80211_rate structure allocated by the driver.
618  *
619  * The rate control algorithm has no internal mapping between hw_mode's
620  * rate ordering and the rate ordering used by the rate control algorithm.
621  *
622  * The rate control algorithm uses a single table of rates that goes across
623  * the entire A/B/G spectrum vs. being limited to just one particular
624  * hw_mode.
625  *
626  * As such, we can't convert the index obtained below into the hw_mode's
627  * rate table and must reference the driver allocated rate table
628  *
629  */
630 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
631                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
632 {
633         struct ieee80211_supported_band *sband = txrc->sband;
634         struct sk_buff *skb = txrc->skb;
635         u8 low = IWL_RATE_INVALID;
636         u8 high = IWL_RATE_INVALID;
637         u16 high_low;
638         int index;
639         struct iwl3945_rs_sta *rs_sta = priv_sta;
640         struct iwl3945_rate_scale_data *window = NULL;
641         int current_tpt = IWL_INVALID_VALUE;
642         int low_tpt = IWL_INVALID_VALUE;
643         int high_tpt = IWL_INVALID_VALUE;
644         u32 fail_count;
645         s8 scale_action = 0;
646         unsigned long flags;
647         u16 rate_mask = sta ? sta->supp_rates[sband->band] : 0;
648         s8 max_rate_idx = -1;
649         struct iwl_priv *priv __maybe_unused = (struct iwl_priv *)priv_r;
650         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
651
652         IWL_DEBUG_RATE(priv, "enter\n");
653
654         /* Treat uninitialized rate scaling data same as non-existing. */
655         if (rs_sta && !rs_sta->priv) {
656                 IWL_DEBUG_RATE(priv, "Rate scaling information not initialized yet.\n");
657                 priv_sta = NULL;
658         }
659
660         if (rate_control_send_low(sta, priv_sta, txrc))
661                 return;
662
663         rate_mask = sta->supp_rates[sband->band];
664
665         /* get user max rate if set */
666         max_rate_idx = txrc->max_rate_idx;
667         if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1))
668                 max_rate_idx += IWL_FIRST_OFDM_RATE;
669         if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT))
670                 max_rate_idx = -1;
671
672         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
673
674         if (sband->band == IEEE80211_BAND_5GHZ)
675                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
676
677         spin_lock_irqsave(&rs_sta->lock, flags);
678
679         /* for recent assoc, choose best rate regarding
680          * to rssi value
681          */
682         if (rs_sta->start_rate != IWL_RATE_INVALID) {
683                 if (rs_sta->start_rate < index &&
684                    (rate_mask & (1 << rs_sta->start_rate)))
685                         index = rs_sta->start_rate;
686                 rs_sta->start_rate = IWL_RATE_INVALID;
687         }
688
689         /* force user max rate if set by user */
690         if ((max_rate_idx != -1) && (max_rate_idx < index)) {
691                 if (rate_mask & (1 << max_rate_idx))
692                         index = max_rate_idx;
693         }
694
695         window = &(rs_sta->win[index]);
696
697         fail_count = window->counter - window->success_counter;
698
699         if (((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
700              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
701                 spin_unlock_irqrestore(&rs_sta->lock, flags);
702
703                 IWL_DEBUG_RATE(priv, "Invalid average_tpt on rate %d: "
704                                "counter: %d, success_counter: %d, "
705                                "expected_tpt is %sNULL\n",
706                                index,
707                                window->counter,
708                                window->success_counter,
709                                rs_sta->expected_tpt ? "not " : "");
710
711            /* Can't calculate this yet; not enough history */
712                 window->average_tpt = IWL_INVALID_VALUE;
713                 goto out;
714
715         }
716
717         current_tpt = window->average_tpt;
718
719         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
720                                              sband->band);
721         low = high_low & 0xff;
722         high = (high_low >> 8) & 0xff;
723
724         /* If user set max rate, dont allow higher than user constrain */
725         if ((max_rate_idx != -1) && (max_rate_idx < high))
726                 high = IWL_RATE_INVALID;
727
728         /* Collect Measured throughputs of adjacent rates */
729         if (low != IWL_RATE_INVALID)
730                 low_tpt = rs_sta->win[low].average_tpt;
731
732         if (high != IWL_RATE_INVALID)
733                 high_tpt = rs_sta->win[high].average_tpt;
734
735         spin_unlock_irqrestore(&rs_sta->lock, flags);
736
737         scale_action = 0;
738
739         /* Low success ratio , need to drop the rate */
740         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
741                 IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
742                 scale_action = -1;
743         /* No throughput measured yet for adjacent rates,
744          * try increase */
745         } else if ((low_tpt == IWL_INVALID_VALUE) &&
746                    (high_tpt == IWL_INVALID_VALUE)) {
747
748                 if (high != IWL_RATE_INVALID && window->success_ratio >= IWL_RATE_INCREASE_TH)
749                         scale_action = 1;
750                 else if (low != IWL_RATE_INVALID)
751                         scale_action = 0;
752
753         /* Both adjacent throughputs are measured, but neither one has
754          * better throughput; we're using the best rate, don't change
755          * it! */
756         } else if ((low_tpt != IWL_INVALID_VALUE) &&
757                  (high_tpt != IWL_INVALID_VALUE) &&
758                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
759
760                 IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < "
761                                "current_tpt [%d]\n",
762                                low_tpt, high_tpt, current_tpt);
763                 scale_action = 0;
764
765         /* At least one of the rates has better throughput */
766         } else {
767                 if (high_tpt != IWL_INVALID_VALUE) {
768
769                         /* High rate has better throughput, Increase
770                          * rate */
771                         if (high_tpt > current_tpt &&
772                                 window->success_ratio >= IWL_RATE_INCREASE_TH)
773                                 scale_action = 1;
774                         else {
775                                 IWL_DEBUG_RATE(priv,
776                                     "decrease rate because of high tpt\n");
777                                 scale_action = 0;
778                         }
779                 } else if (low_tpt != IWL_INVALID_VALUE) {
780                         if (low_tpt > current_tpt) {
781                                 IWL_DEBUG_RATE(priv,
782                                     "decrease rate because of low tpt\n");
783                                 scale_action = -1;
784                         } else if (window->success_ratio >= IWL_RATE_INCREASE_TH) {
785                                 /* Lower rate has better
786                                  * throughput,decrease rate */
787                                 scale_action = 1;
788                         }
789                 }
790         }
791
792         /* Sanity check; asked for decrease, but success rate or throughput
793          * has been good at old rate.  Don't change it. */
794         if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
795                     ((window->success_ratio > IWL_RATE_HIGH_TH) ||
796                      (current_tpt > (100 * rs_sta->expected_tpt[low]))))
797                 scale_action = 0;
798
799         switch (scale_action) {
800         case -1:
801
802                 /* Decrese rate */
803                 if (low != IWL_RATE_INVALID)
804                         index = low;
805                 break;
806
807         case 1:
808                 /* Increase rate */
809                 if (high != IWL_RATE_INVALID)
810                         index = high;
811
812                 break;
813
814         case 0:
815         default:
816                 /* No change */
817                 break;
818         }
819
820         IWL_DEBUG_RATE(priv, "Selected %d (action %d) - low %d high %d\n",
821                        index, scale_action, low, high);
822
823  out:
824
825         rs_sta->last_txrate_idx = index;
826         if (sband->band == IEEE80211_BAND_5GHZ)
827                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
828                                 IWL_FIRST_OFDM_RATE;
829         else
830                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
831
832         IWL_DEBUG_RATE(priv, "leave: %d\n", index);
833 }
834
835 #ifdef CONFIG_MAC80211_DEBUGFS
836 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
837 {
838         file->private_data = inode->i_private;
839         return 0;
840 }
841
842 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
843                                                   char __user *user_buf,
844                                                   size_t count, loff_t *ppos)
845 {
846         char *buff;
847         int desc = 0;
848         int j;
849         ssize_t ret;
850         struct iwl3945_rs_sta *lq_sta = file->private_data;
851
852         buff = kmalloc(1024, GFP_KERNEL);
853         if (!buff)
854                 return -ENOMEM;
855
856         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
857                         "rate=0x%X flush time %d\n",
858                         lq_sta->tx_packets,
859                         lq_sta->last_txrate_idx,
860                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
861         for (j = 0; j < IWL_RATE_COUNT_3945; j++) {
862                 desc += sprintf(buff+desc,
863                                 "counter=%d success=%d %%=%d\n",
864                                 lq_sta->win[j].counter,
865                                 lq_sta->win[j].success_counter,
866                                 lq_sta->win[j].success_ratio);
867         }
868         ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
869         kfree(buff);
870         return ret;
871 }
872
873 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
874         .read = iwl3945_sta_dbgfs_stats_table_read,
875         .open = iwl3945_open_file_generic,
876         .llseek = default_llseek,
877 };
878
879 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
880                                 struct dentry *dir)
881 {
882         struct iwl3945_rs_sta *lq_sta = priv_sta;
883
884         lq_sta->rs_sta_dbgfs_stats_table_file =
885                 debugfs_create_file("rate_stats_table", 0600, dir,
886                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
887
888 }
889
890 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
891 {
892         struct iwl3945_rs_sta *lq_sta = priv_sta;
893         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
894 }
895 #endif
896
897 /*
898  * Initialization of rate scaling information is done by driver after
899  * the station is added. Since mac80211 calls this function before a
900  * station is added we ignore it.
901  */
902 static void rs_rate_init_stub(void *priv_r, struct ieee80211_supported_band *sband,
903                               struct ieee80211_sta *sta, void *priv_sta)
904 {
905 }
906
907 static struct rate_control_ops rs_ops = {
908         .module = NULL,
909         .name = RS_NAME,
910         .tx_status = rs_tx_status,
911         .get_rate = rs_get_rate,
912         .rate_init = rs_rate_init_stub,
913         .alloc = rs_alloc,
914         .free = rs_free,
915         .alloc_sta = rs_alloc_sta,
916         .free_sta = rs_free_sta,
917 #ifdef CONFIG_MAC80211_DEBUGFS
918         .add_sta_debugfs = iwl3945_add_debugfs,
919         .remove_sta_debugfs = iwl3945_remove_debugfs,
920 #endif
921
922 };
923 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
924 {
925         struct iwl_priv *priv = hw->priv;
926         s32 rssi = 0;
927         unsigned long flags;
928         struct iwl3945_rs_sta *rs_sta;
929         struct ieee80211_sta *sta;
930         struct iwl3945_sta_priv *psta;
931
932         IWL_DEBUG_RATE(priv, "enter\n");
933
934         rcu_read_lock();
935
936         sta = ieee80211_find_sta(priv->contexts[IWL_RXON_CTX_BSS].vif,
937                                  priv->stations[sta_id].sta.sta.addr);
938         if (!sta) {
939                 IWL_DEBUG_RATE(priv, "Unable to find station to initialize rate scaling.\n");
940                 rcu_read_unlock();
941                 return;
942         }
943
944         psta = (void *) sta->drv_priv;
945         rs_sta = &psta->rs_sta;
946
947         spin_lock_irqsave(&rs_sta->lock, flags);
948
949         rs_sta->tgg = 0;
950         switch (priv->band) {
951         case IEEE80211_BAND_2GHZ:
952                 /* TODO: this always does G, not a regression */
953                 if (priv->contexts[IWL_RXON_CTX_BSS].active.flags &
954                                                 RXON_FLG_TGG_PROTECT_MSK) {
955                         rs_sta->tgg = 1;
956                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
957                 } else
958                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
959                 break;
960
961         case IEEE80211_BAND_5GHZ:
962                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
963                 break;
964         case IEEE80211_NUM_BANDS:
965                 BUG();
966                 break;
967         }
968
969         spin_unlock_irqrestore(&rs_sta->lock, flags);
970
971         rssi = priv->_3945.last_rx_rssi;
972         if (rssi == 0)
973                 rssi = IWL_MIN_RSSI_VAL;
974
975         IWL_DEBUG_RATE(priv, "Network RSSI: %d\n", rssi);
976
977         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
978
979         IWL_DEBUG_RATE(priv, "leave: rssi %d assign rate index: "
980                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
981                        iwl3945_rates[rs_sta->start_rate].plcp);
982         rcu_read_unlock();
983 }
984
985 int iwl3945_rate_control_register(void)
986 {
987         return ieee80211_rate_control_register(&rs_ops);
988 }
989
990 void iwl3945_rate_control_unregister(void)
991 {
992         ieee80211_rate_control_unregister(&rs_ops);
993 }
994
995