drivers/net/wireless/iwlwifi/iwl-3945-rs.c

   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
  42 #define RS_NAME "iwl-3945-rs"
  43
  44 struct iwl3945_rate_scale_data {
  45         u64 data;
  46         s32 success_counter;
  47         s32 success_ratio;
  48         s32 counter;
  49         s32 average_tpt;
  50         unsigned long stamp;
  51 };
  52
  53 struct iwl3945_rs_sta {
  54         spinlock_t lock;
  55         struct iwl_priv *priv;
  56         s32 *expected_tpt;
  57         unsigned long last_partial_flush;
  58         unsigned long last_flush;
  59         u32 flush_time;
  60         u32 last_tx_packets;
  61         u32 tx_packets;
  62         u8 tgg;
  63         u8 flush_pending;
  64         u8 start_rate;
  65         u8 ibss_sta_added;
  66         struct timer_list rate_scale_flush;
  67         struct iwl3945_rate_scale_data win[IWL_RATE_COUNT_3945];
  68 #ifdef CONFIG_MAC80211_DEBUGFS
  69         struct dentry *rs_sta_dbgfs_stats_table_file;
  70 #endif
  71
  72         /* used to be in sta_info */
  73         int last_txrate_idx;
  74 };
  75
  76 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT_3945] = {
  77         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  78 };
  79
  80 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT_3945] = {
  81         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  82 };
  83
  84 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT_3945] = {
  85         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  86 };
  87
  88 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT_3945] = {
  89         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  90 };
  91
  92 struct iwl3945_tpt_entry {
  93         s8 min_rssi;
  94         u8 index;
  95 };
  96
  97 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  98         {-60, IWL_RATE_54M_INDEX},
  99         {-64, IWL_RATE_48M_INDEX},
 100         {-72, IWL_RATE_36M_INDEX},
 101         {-80, IWL_RATE_24M_INDEX},
 102         {-84, IWL_RATE_18M_INDEX},
 103         {-85, IWL_RATE_12M_INDEX},
 104         {-87, IWL_RATE_9M_INDEX},
 105         {-89, IWL_RATE_6M_INDEX}
 106 };
 107
 108 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 109         {-60, IWL_RATE_54M_INDEX},
 110         {-64, IWL_RATE_48M_INDEX},
 111         {-68, IWL_RATE_36M_INDEX},
 112         {-80, IWL_RATE_24M_INDEX},
 113         {-84, IWL_RATE_18M_INDEX},
 114         {-85, IWL_RATE_12M_INDEX},
 115         {-86, IWL_RATE_11M_INDEX},
 116         {-88, IWL_RATE_5M_INDEX},
 117         {-90, IWL_RATE_2M_INDEX},
 118         {-92, IWL_RATE_1M_INDEX}
 119 };
 120
 121 #define IWL_RATE_MAX_WINDOW          62
 122 #define IWL_RATE_FLUSH           (3*HZ)
 123 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 124 #define IWL39_RATE_HIGH_TH          11520
 125 #define IWL_SUCCESS_UP_TH          8960
 126 #define IWL_SUCCESS_DOWN_TH       10880
 127 #define IWL_RATE_MIN_FAILURE_TH       8
 128 #define IWL_RATE_MIN_SUCCESS_TH       8
 129 #define IWL_RATE_DECREASE_TH       1920
 130
 131 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 132 {
 133         u32 index = 0;
 134         u32 table_size = 0;
 135         struct iwl3945_tpt_entry *tpt_table = NULL;
 136
 137         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 138                 rssi = IWL_MIN_RSSI_VAL;
 139
 140         switch (band) {
 141         case IEEE80211_BAND_2GHZ:
 142                 tpt_table = iwl3945_tpt_table_g;
 143                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 144                 break;
 145
 146         case IEEE80211_BAND_5GHZ:
 147                 tpt_table = iwl3945_tpt_table_a;
 148                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 149                 break;
 150
 151         default:
 152                 BUG();
 153                 break;
 154         }
 155
 156         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 157                 index++;
 158
 159         index = min(index, (table_size - 1));
 160
 161         return tpt_table[index].index;
 162 }
 163
 164 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 165 {
 166         window->data = 0;
 167         window->success_counter = 0;
 168         window->success_ratio = -1;
 169         window->counter = 0;
 170         window->average_tpt = IWL_INVALID_VALUE;
 171         window->stamp = 0;
 172 }
 173
 174 /**
 175  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 176  *
 177  * Returns the number of windows that have gathered data but were
 178  * not flushed.  If there were any that were not flushed, then
 179  * reschedule the rate flushing routine.
 180  */
 181 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 182 {
 183         int unflushed = 0;
 184         int i;
 185         unsigned long flags;
 186         struct iwl_priv *priv = rs_sta->priv;
 187
 188         /*
 189          * For each rate, if we have collected data on that rate
 190          * and it has been more than IWL_RATE_WIN_FLUSH
 191          * since we flushed, clear out the gathered statistics
 192          */
 193         for (i = 0; i < IWL_RATE_COUNT_3945; i++) {
 194                 if (!rs_sta->win[i].counter)
 195                         continue;
 196
 197                 spin_lock_irqsave(&rs_sta->lock, flags);
 198                 if (time_after(jiffies, rs_sta->win[i].stamp +
 199                                IWL_RATE_WIN_FLUSH)) {
 200                         IWL_DEBUG_RATE("flushing %d samples of rate "
 201                                        "index %d\n",
 202                                        rs_sta->win[i].counter, i);
 203                         iwl3945_clear_window(&rs_sta->win[i]);
 204                 } else
 205                         unflushed++;
 206                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 207         }
 208
 209         return unflushed;
 210 }
 211
 212 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 213 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 214 #define IWL_AVERAGE_PACKETS             1500
 215
 216 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 217 {
 218         struct iwl3945_rs_sta *rs_sta = (void *)data;
 219         struct iwl_priv *priv = rs_sta->priv;
 220         int unflushed = 0;
 221         unsigned long flags;
 222         u32 packet_count, duration, pps;
 223
 224         IWL_DEBUG_RATE("enter\n");
 225
 226         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 227
 228         spin_lock_irqsave(&rs_sta->lock, flags);
 229
 230         /* Number of packets Rx'd since last time this timer ran */
 231         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 232
 233         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 234
 235         if (unflushed) {
 236                 duration =
 237                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 238
 239                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 240                                packet_count, duration);
 241
 242                 /* Determine packets per second */
 243                 if (duration)
 244                         pps = (packet_count * 1000) / duration;
 245                 else
 246                         pps = 0;
 247
 248                 if (pps) {
 249                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
 250                         if (duration < IWL_RATE_FLUSH_MIN)
 251                                 duration = IWL_RATE_FLUSH_MIN;
 252                         else if (duration > IWL_RATE_FLUSH_MAX)
 253                                 duration = IWL_RATE_FLUSH_MAX;
 254                 } else
 255                         duration = IWL_RATE_FLUSH_MAX;
 256
 257                 rs_sta->flush_time = msecs_to_jiffies(duration);
 258
 259                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 260                                duration, packet_count);
 261
 262                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 263                           rs_sta->flush_time);
 264
 265                 rs_sta->last_partial_flush = jiffies;
 266         } else {
 267                 rs_sta->flush_time = IWL_RATE_FLUSH;
 268                 rs_sta->flush_pending = 0;
 269         }
 270         /* If there weren't any unflushed entries, we don't schedule the timer
 271          * to run again */
 272
 273         rs_sta->last_flush = jiffies;
 274
 275         spin_unlock_irqrestore(&rs_sta->lock, flags);
 276
 277         IWL_DEBUG_RATE("leave\n");
 278 }
 279
 280 /**
 281  * iwl3945_collect_tx_data - Update the success/failure sliding window
 282  *
 283  * We keep a sliding window of the last 64 packets transmitted
 284  * at this rate.  window->data contains the bitmask of successful
 285  * packets.
 286  */
 287 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 288                                 struct iwl3945_rate_scale_data *window,
 289                                 int success, int retries, int index)
 290 {
 291         unsigned long flags;
 292         s32 fail_count;
 293         struct iwl_priv *priv = rs_sta->priv;
 294
 295         if (!retries) {
 296                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 297                 return;
 298         }
 299
 300         spin_lock_irqsave(&rs_sta->lock, flags);
 301         while (retries--) {
 302
 303                 /* If we have filled up the window then subtract one from the
 304                  * success counter if the high-bit is counting toward
 305                  * success */
 306                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 307                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 308                                 window->success_counter--;
 309                 } else
 310                         window->counter++;
 311
 312                 /* Slide the window to the left one bit */
 313                 window->data = (window->data << 1);
 314
 315                 /* If this packet was a success then set the low bit high */
 316                 if (success) {
 317                         window->success_counter++;
 318                         window->data |= 1;
 319                 }
 320
 321                 /* window->counter can't be 0 -- it is either >0 or
 322                  * IWL_RATE_MAX_WINDOW */
 323                 window->success_ratio = 12800 * window->success_counter /
 324                     window->counter;
 325
 326                 /* Tag this window as having been updated */
 327                 window->stamp = jiffies;
 328
 329         }
 330
 331         fail_count = window->counter - window->success_counter;
 332         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
 333             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
 334                 window->average_tpt = ((window->success_ratio *
 335                                 rs_sta->expected_tpt[index] + 64) / 128);
 336         else
 337                 window->average_tpt = IWL_INVALID_VALUE;
 338
 339         spin_unlock_irqrestore(&rs_sta->lock, flags);
 340
 341 }
 342
 343 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
 344                          struct ieee80211_sta *sta, void *priv_sta)
 345 {
 346         struct iwl3945_rs_sta *rs_sta = priv_sta;
 347         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
 348         int i;
 349
 350         IWL_DEBUG_RATE("enter\n");
 351
 352         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 353          * the lowest or the highest rate.. Could consider using RSSI from
 354          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 355          * after assoc.. */
 356
 357         for (i = sband->n_bitrates - 1; i >= 0; i--) {
 358                 if (sta->supp_rates[sband->band] & (1 << i)) {
 359                         rs_sta->last_txrate_idx = i;
 360                         break;
 361                 }
 362         }
 363
 364         priv->sta_supp_rates = sta->supp_rates[sband->band];
 365         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 366         if (sband->band == IEEE80211_BAND_5GHZ) {
 367                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 368                 priv->sta_supp_rates = priv->sta_supp_rates <<
 369                                                 IWL_FIRST_OFDM_RATE;
 370         }
 371
 372
 373         IWL_DEBUG_RATE("leave\n");
 374 }
 375
 376 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 377 {
 378         return hw->priv;
 379 }
 380
 381 /* rate scale requires free function to be implemented */
 382 static void rs_free(void *priv)
 383 {
 384         return;
 385 }
 386
 387 static void *rs_alloc_sta(void *iwl_priv, struct ieee80211_sta *sta, gfp_t gfp)
 388 {
 389         struct iwl3945_rs_sta *rs_sta;
 390         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 391         struct iwl_priv *priv = iwl_priv;
 392         int i;
 393
 394         /*
 395          * XXX: If it's using sta->drv_priv anyway, it might
 396          *      as well just put all the information there.
 397          */
 398
 399         IWL_DEBUG_RATE("enter\n");
 400
 401         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 402         if (!rs_sta) {
 403                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 404                 return NULL;
 405         }
 406
 407         psta->rs_sta = rs_sta;
 408
 409         spin_lock_init(&rs_sta->lock);
 410
 411         rs_sta->priv = priv;
 412
 413         rs_sta->start_rate = IWL_RATE_INVALID;
 414
 415         /* default to just 802.11b */
 416         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 417
 418         rs_sta->last_partial_flush = jiffies;
 419         rs_sta->last_flush = jiffies;
 420         rs_sta->flush_time = IWL_RATE_FLUSH;
 421         rs_sta->last_tx_packets = 0;
 422         rs_sta->ibss_sta_added = 0;
 423
 424         init_timer(&rs_sta->rate_scale_flush);
 425         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 426         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 427
 428         for (i = 0; i < IWL_RATE_COUNT_3945; i++)
 429                 iwl3945_clear_window(&rs_sta->win[i]);
 430
 431         IWL_DEBUG_RATE("leave\n");
 432
 433         return rs_sta;
 434 }
 435
 436 static void rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
 437                         void *priv_sta)
 438 {
 439         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 440         struct iwl3945_rs_sta *rs_sta = priv_sta;
 441         struct iwl_priv *priv = rs_sta->priv;
 442
 443         psta->rs_sta = NULL;
 444
 445         IWL_DEBUG_RATE("enter\n");
 446         del_timer_sync(&rs_sta->rate_scale_flush);
 447         kfree(rs_sta);
 448         IWL_DEBUG_RATE("leave\n");
 449 }
 450
 451
 452 /**
 453  * rs_tx_status - Update rate control values based on Tx results
 454  *
 455  * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
 456  * the hardware for each rate.
 457  */
 458 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 459                          struct ieee80211_sta *sta, void *priv_sta,
 460                          struct sk_buff *skb)
 461 {
 462         s8 retries = 0, current_count;
 463         int scale_rate_index, first_index, last_index;
 464         unsigned long flags;
 465         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 466         struct iwl3945_rs_sta *rs_sta = priv_sta;
 467         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 468
 469         IWL_DEBUG_RATE("enter\n");
 470
 471         retries = info->status.rates[0].count;
 472
 473         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 474         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
 475                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 476                 return;
 477         }
 478
 479         if (!priv_sta) {
 480                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 481                 return;
 482         }
 483
 484         rs_sta->tx_packets++;
 485
 486         scale_rate_index = first_index;
 487         last_index = first_index;
 488
 489         /*
 490          * Update the window for each rate.  We determine which rates
 491          * were Tx'd based on the total number of retries vs. the number
 492          * of retries configured for each rate -- currently set to the
 493          * priv value 'retry_rate' vs. rate specific
 494          *
 495          * On exit from this while loop last_index indicates the rate
 496          * at which the frame was finally transmitted (or failed if no
 497          * ACK)
 498          */
 499         while (retries > 1) {
 500                 if ((retries - 1) < priv->retry_rate) {
 501                         current_count = (retries - 1);
 502                         last_index = scale_rate_index;
 503                 } else {
 504                         current_count = priv->retry_rate;
 505                         last_index = iwl3945_rs_next_rate(priv,
 506                                                          scale_rate_index);
 507                 }
 508
 509                 /* Update this rate accounting for as many retries
 510                  * as was used for it (per current_count) */
 511                 iwl3945_collect_tx_data(rs_sta,
 512                                     &rs_sta->win[scale_rate_index],
 513                                     0, current_count, scale_rate_index);
 514                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 515                                scale_rate_index, current_count);
 516
 517                 retries -= current_count;
 518
 519                 scale_rate_index = last_index;
 520         }
 521
 522
 523         /* Update the last index window with success/failure based on ACK */
 524         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 525                        last_index,
 526                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 527                        "success" : "failure");
 528         iwl3945_collect_tx_data(rs_sta,
 529                             &rs_sta->win[last_index],
 530                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 531
 532         /* We updated the rate scale window -- if its been more than
 533          * flush_time since the last run, schedule the flush
 534          * again */
 535         spin_lock_irqsave(&rs_sta->lock, flags);
 536
 537         if (!rs_sta->flush_pending &&
 538             time_after(jiffies, rs_sta->last_flush +
 539                        rs_sta->flush_time)) {
 540
 541                 rs_sta->last_partial_flush = jiffies;
 542                 rs_sta->flush_pending = 1;
 543                 mod_timer(&rs_sta->rate_scale_flush,
 544                           jiffies + rs_sta->flush_time);
 545         }
 546
 547         spin_unlock_irqrestore(&rs_sta->lock, flags);
 548
 549         IWL_DEBUG_RATE("leave\n");
 550
 551         return;
 552 }
 553
 554 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 555                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 556 {
 557         u8 high = IWL_RATE_INVALID;
 558         u8 low = IWL_RATE_INVALID;
 559         struct iwl_priv *priv = rs_sta->priv;
 560
 561         /* 802.11A walks to the next literal adjacent rate in
 562          * the rate table */
 563         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 564                 int i;
 565                 u32 mask;
 566
 567                 /* Find the previous rate that is in the rate mask */
 568                 i = index - 1;
 569                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 570                         if (rate_mask & mask) {
 571                                 low = i;
 572                                 break;
 573                         }
 574                 }
 575
 576                 /* Find the next rate that is in the rate mask */
 577                 i = index + 1;
 578                 for (mask = (1 << i); i < IWL_RATE_COUNT_3945;
 579                      i++, mask <<= 1) {
 580                         if (rate_mask & mask) {
 581                                 high = i;
 582                                 break;
 583                         }
 584                 }
 585
 586                 return (high << 8) | low;
 587         }
 588
 589         low = index;
 590         while (low != IWL_RATE_INVALID) {
 591                 if (rs_sta->tgg)
 592                         low = iwl3945_rates[low].prev_rs_tgg;
 593                 else
 594                         low = iwl3945_rates[low].prev_rs;
 595                 if (low == IWL_RATE_INVALID)
 596                         break;
 597                 if (rate_mask & (1 << low))
 598                         break;
 599                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 600         }
 601
 602         high = index;
 603         while (high != IWL_RATE_INVALID) {
 604                 if (rs_sta->tgg)
 605                         high = iwl3945_rates[high].next_rs_tgg;
 606                 else
 607                         high = iwl3945_rates[high].next_rs;
 608                 if (high == IWL_RATE_INVALID)
 609                         break;
 610                 if (rate_mask & (1 << high))
 611                         break;
 612                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 613         }
 614
 615         return (high << 8) | low;
 616 }
 617
 618 /**
 619  * rs_get_rate - find the rate for the requested packet
 620  *
 621  * Returns the ieee80211_rate structure allocated by the driver.
 622  *
 623  * The rate control algorithm has no internal mapping between hw_mode's
 624  * rate ordering and the rate ordering used by the rate control algorithm.
 625  *
 626  * The rate control algorithm uses a single table of rates that goes across
 627  * the entire A/B/G spectrum vs. being limited to just one particular
 628  * hw_mode.
 629  *
 630  * As such, we can't convert the index obtained below into the hw_mode's
 631  * rate table and must reference the driver allocated rate table
 632  *
 633  */
 634 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 635                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 636 {
 637         struct ieee80211_supported_band *sband = txrc->sband;
 638         struct sk_buff *skb = txrc->skb;
 639         u8 low = IWL_RATE_INVALID;
 640         u8 high = IWL_RATE_INVALID;
 641         u16 high_low;
 642         int index;
 643         struct iwl3945_rs_sta *rs_sta = priv_sta;
 644         struct iwl3945_rate_scale_data *window = NULL;
 645         int current_tpt = IWL_INVALID_VALUE;
 646         int low_tpt = IWL_INVALID_VALUE;
 647         int high_tpt = IWL_INVALID_VALUE;
 648         u32 fail_count;
 649         s8 scale_action = 0;
 650         unsigned long flags;
 651         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 652         u16 fc;
 653         u16 rate_mask = 0;
 654         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
 655         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 656
 657         IWL_DEBUG_RATE("enter\n");
 658
 659         if (sta)
 660                 rate_mask = sta->supp_rates[sband->band];
 661
 662         /* Send management frames and broadcast/multicast data using lowest
 663          * rate. */
 664         fc = le16_to_cpu(hdr->frame_control);
 665         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 666             is_multicast_ether_addr(hdr->addr1) ||
 667             !sta || !priv_sta) {
 668                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 669                 if (!rate_mask)
 670                         info->control.rates[0].idx =
 671                                         rate_lowest_index(sband, NULL);
 672                 else
 673                         info->control.rates[0].idx =
 674                                         rate_lowest_index(sband, sta);
 675                 return;
 676         }
 677
 678         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
 679
 680         if (sband->band == IEEE80211_BAND_5GHZ)
 681                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 682
 683         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 684             !rs_sta->ibss_sta_added) {
 685                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 686
 687                 if (sta_id == IWL_INVALID_STATION) {
 688                         IWL_DEBUG_RATE("LQ: ADD station %pm\n",
 689                                        hdr->addr1);
 690                         sta_id = iwl3945_add_station(priv,
 691                                     hdr->addr1, 0, CMD_ASYNC);
 692                 }
 693                 if (sta_id != IWL_INVALID_STATION)
 694                         rs_sta->ibss_sta_added = 1;
 695         }
 696
 697         spin_lock_irqsave(&rs_sta->lock, flags);
 698
 699         /* for recent assoc, choose best rate regarding
 700          * to rssi value
 701          */
 702         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 703                 if (rs_sta->start_rate < index &&
 704                    (rate_mask & (1 << rs_sta->start_rate)))
 705                         index = rs_sta->start_rate;
 706                 rs_sta->start_rate = IWL_RATE_INVALID;
 707         }
 708
 709         window = &(rs_sta->win[index]);
 710
 711         fail_count = window->counter - window->success_counter;
 712
 713         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 714              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 715                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 716
 717                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 718                                "counter: %d, success_counter: %d, "
 719                                "expected_tpt is %sNULL\n",
 720                                index,
 721                                window->counter,
 722                                window->success_counter,
 723                                rs_sta->expected_tpt ? "not " : "");
 724                 goto out;
 725
 726         }
 727
 728         current_tpt = window->average_tpt;
 729
 730         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 731                                              sband->band);
 732         low = high_low & 0xff;
 733         high = (high_low >> 8) & 0xff;
 734
 735         if (low != IWL_RATE_INVALID)
 736                 low_tpt = rs_sta->win[low].average_tpt;
 737
 738         if (high != IWL_RATE_INVALID)
 739                 high_tpt = rs_sta->win[high].average_tpt;
 740
 741         spin_unlock_irqrestore(&rs_sta->lock, flags);
 742
 743         scale_action = 1;
 744
 745         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 746                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 747                 scale_action = -1;
 748         } else if ((low_tpt == IWL_INVALID_VALUE) &&
 749                    (high_tpt == IWL_INVALID_VALUE))
 750                 scale_action = 1;
 751         else if ((low_tpt != IWL_INVALID_VALUE) &&
 752                  (high_tpt != IWL_INVALID_VALUE) &&
 753                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 754                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 755                                "current_tpt [%d]\n",
 756                                low_tpt, high_tpt, current_tpt);
 757                 scale_action = 0;
 758         } else {
 759                 if (high_tpt != IWL_INVALID_VALUE) {
 760                         if (high_tpt > current_tpt)
 761                                 scale_action = 1;
 762                         else {
 763                                 IWL_DEBUG_RATE
 764                                     ("decrease rate because of high tpt\n");
 765                                 scale_action = -1;
 766                         }
 767                 } else if (low_tpt != IWL_INVALID_VALUE) {
 768                         if (low_tpt > current_tpt) {
 769                                 IWL_DEBUG_RATE
 770                                     ("decrease rate because of low tpt\n");
 771                                 scale_action = -1;
 772                         } else
 773                                 scale_action = 1;
 774                 }
 775         }
 776
 777         if (scale_action == -1) {
 778                 if (window->success_ratio > IWL_SUCCESS_DOWN_TH)
 779                         scale_action = 0;
 780         } else if (scale_action == 1) {
 781                 if (window->success_ratio < IWL_SUCCESS_UP_TH) {
 782                         IWL_DEBUG_RATE("No action -- success_ratio [%d] < "
 783                                "SUCCESS UP\n", window->success_ratio);
 784                         scale_action = 0;
 785                 }
 786         }
 787
 788         switch (scale_action) {
 789         case -1:
 790                 if (low != IWL_RATE_INVALID)
 791                         index = low;
 792                 break;
 793
 794         case 1:
 795                 if (high != IWL_RATE_INVALID)
 796                         index = high;
 797
 798                 break;
 799
 800         case 0:
 801         default:
 802                 break;
 803         }
 804
 805         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 806                        index, scale_action, low, high);
 807
 808  out:
 809
 810         rs_sta->last_txrate_idx = index;
 811         if (sband->band == IEEE80211_BAND_5GHZ)
 812                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 813                                 IWL_FIRST_OFDM_RATE;
 814         else
 815                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 816
 817         IWL_DEBUG_RATE("leave: %d\n", index);
 818 }
 819
 820 #ifdef CONFIG_MAC80211_DEBUGFS
 821 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 822 {
 823         file->private_data = inode->i_private;
 824         return 0;
 825 }
 826
 827 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 828                                                   char __user *user_buf,
 829                                                   size_t count, loff_t *ppos)
 830 {
 831         char buff[1024];
 832         int desc = 0;
 833         int j;
 834         struct iwl3945_rs_sta *lq_sta = file->private_data;
 835
 836         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 837                         "rate=0x%X flush time %d\n",
 838                         lq_sta->tx_packets,
 839                         lq_sta->last_txrate_idx,
 840                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 841         for (j = 0; j < IWL_RATE_COUNT_3945; j++) {
 842                 desc += sprintf(buff+desc,
 843                                 "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         return simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 849 }
 850
 851 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 852         .read = iwl3945_sta_dbgfs_stats_table_read,
 853         .open = iwl3945_open_file_generic,
 854 };
 855
 856 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 857                                 struct dentry *dir)
 858 {
 859         struct iwl3945_rs_sta *lq_sta = priv_sta;
 860
 861         lq_sta->rs_sta_dbgfs_stats_table_file =
 862                 debugfs_create_file("rate_stats_table", 0600, dir,
 863                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 864
 865 }
 866
 867 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 868 {
 869         struct iwl3945_rs_sta *lq_sta = priv_sta;
 870         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 871 }
 872 #endif
 873
 874 static struct rate_control_ops rs_ops = {
 875         .module = NULL,
 876         .name = RS_NAME,
 877         .tx_status = rs_tx_status,
 878         .get_rate = rs_get_rate,
 879         .rate_init = rs_rate_init,
 880         .alloc = rs_alloc,
 881         .free = rs_free,
 882         .alloc_sta = rs_alloc_sta,
 883         .free_sta = rs_free_sta,
 884 #ifdef CONFIG_MAC80211_DEBUGFS
 885         .add_sta_debugfs = iwl3945_add_debugfs,
 886         .remove_sta_debugfs = iwl3945_remove_debugfs,
 887 #endif
 888
 889 };
 890
 891 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 892 {
 893         struct iwl_priv *priv = hw->priv;
 894         s32 rssi = 0;
 895         unsigned long flags;
 896         struct iwl3945_rs_sta *rs_sta;
 897         struct ieee80211_sta *sta;
 898         struct iwl3945_sta_priv *psta;
 899
 900         IWL_DEBUG_RATE("enter\n");
 901
 902         rcu_read_lock();
 903
 904         sta = ieee80211_find_sta(hw, priv->stations_39[sta_id].sta.sta.addr);
 905         if (!sta) {
 906                 rcu_read_unlock();
 907                 return;
 908         }
 909
 910         psta = (void *) sta->drv_priv;
 911         rs_sta = psta->rs_sta;
 912
 913         spin_lock_irqsave(&rs_sta->lock, flags);
 914
 915         rs_sta->tgg = 0;
 916         switch (priv->band) {
 917         case IEEE80211_BAND_2GHZ:
 918                 /* TODO: this always does G, not a regression */
 919                 if (priv->active39_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 920                         rs_sta->tgg = 1;
 921                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 922                 } else
 923                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 924                 break;
 925
 926         case IEEE80211_BAND_5GHZ:
 927                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 928                 break;
 929         case IEEE80211_NUM_BANDS:
 930                 BUG();
 931                 break;
 932         }
 933
 934         spin_unlock_irqrestore(&rs_sta->lock, flags);
 935
 936         rssi = priv->last_rx_rssi;
 937         if (rssi == 0)
 938                 rssi = IWL_MIN_RSSI_VAL;
 939
 940         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 941
 942         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 943
 944         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 945                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 946                        iwl3945_rates[rs_sta->start_rate].plcp);
 947         rcu_read_unlock();
 948 }
 949
 950 int iwl3945_rate_control_register(void)
 951 {
 952         return ieee80211_rate_control_register(&rs_ops);
 953 }
 954
 955 void iwl3945_rate_control_unregister(void)
 956 {
 957         ieee80211_rate_control_unregister(&rs_ops);
 958 }
 959
 960