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 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
 334                          struct ieee80211_sta *sta, void *priv_sta)
 335 {
 336         struct iwl3945_rs_sta *rs_sta = priv_sta;
 337         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
 338         int i;
 339
 340         IWL_DEBUG_RATE(priv, "enter\n");
 341
 342         spin_lock_init(&rs_sta->lock);
 343
 344         rs_sta->priv = priv;
 345
 346         rs_sta->start_rate = IWL_RATE_INVALID;
 347
 348         /* default to just 802.11b */
 349         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 350
 351         rs_sta->last_partial_flush = jiffies;
 352         rs_sta->last_flush = jiffies;
 353         rs_sta->flush_time = IWL_RATE_FLUSH;
 354         rs_sta->last_tx_packets = 0;
 355         rs_sta->ibss_sta_added = 0;
 356
 357         init_timer(&rs_sta->rate_scale_flush);
 358         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 359         rs_sta->rate_scale_flush.function = iwl3945_bg_rate_scale_flush;
 360
 361         for (i = 0; i < IWL_RATE_COUNT_3945; i++)
 362                 iwl3945_clear_window(&rs_sta->win[i]);
 363
 364         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 365          * the lowest or the highest rate.. Could consider using RSSI from
 366          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 367          * after assoc.. */
 368
 369         for (i = sband->n_bitrates - 1; i >= 0; i--) {
 370                 if (sta->supp_rates[sband->band] & (1 << i)) {
 371                         rs_sta->last_txrate_idx = i;
 372                         break;
 373                 }
 374         }
 375
 376         priv->sta_supp_rates = sta->supp_rates[sband->band];
 377         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 378         if (sband->band == IEEE80211_BAND_5GHZ) {
 379                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 380                 priv->sta_supp_rates = priv->sta_supp_rates <<
 381                                                 IWL_FIRST_OFDM_RATE;
 382         }
 383
 384
 385         IWL_DEBUG_RATE(priv, "leave\n");
 386 }
 387
 388 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 389 {
 390         return hw->priv;
 391 }
 392
 393 /* rate scale requires free function to be implemented */
 394 static void rs_free(void *priv)
 395 {
 396         return;
 397 }
 398
 399 static void *rs_alloc_sta(void *iwl_priv, struct ieee80211_sta *sta, gfp_t gfp)
 400 {
 401         struct iwl3945_rs_sta *rs_sta;
 402         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 403         struct iwl_priv *priv __maybe_unused = iwl_priv;
 404
 405         IWL_DEBUG_RATE(priv, "enter\n");
 406
 407         rs_sta = &psta->rs_sta;
 408
 409         IWL_DEBUG_RATE(priv, "leave\n");
 410
 411         return rs_sta;
 412 }
 413
 414 static void rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
 415                         void *priv_sta)
 416 {
 417         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 418         struct iwl3945_rs_sta *rs_sta = &psta->rs_sta;
 419         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 420
 421         IWL_DEBUG_RATE(priv, "enter\n");
 422         del_timer_sync(&rs_sta->rate_scale_flush);
 423         IWL_DEBUG_RATE(priv, "leave\n");
 424 }
 425
 426
 427 /**
 428  * rs_tx_status - Update rate control values based on Tx results
 429  *
 430  * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
 431  * the hardware for each rate.
 432  */
 433 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 434                          struct ieee80211_sta *sta, void *priv_sta,
 435                          struct sk_buff *skb)
 436 {
 437         s8 retries = 0, current_count;
 438         int scale_rate_index, first_index, last_index;
 439         unsigned long flags;
 440         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 441         struct iwl3945_rs_sta *rs_sta = priv_sta;
 442         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 443
 444         IWL_DEBUG_RATE(priv, "enter\n");
 445
 446         retries = info->status.rates[0].count;
 447         /* Sanity Check for retries */
 448         if (retries > IWL_RATE_RETRY_TH)
 449                 retries = IWL_RATE_RETRY_TH;
 450
 451         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 452         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
 453                 IWL_DEBUG_RATE(priv, "leave: Rate out of bounds: %d\n", first_index);
 454                 return;
 455         }
 456
 457         if (!priv_sta) {
 458                 IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
 459                 return;
 460         }
 461
 462         rs_sta->tx_packets++;
 463
 464         scale_rate_index = first_index;
 465         last_index = first_index;
 466
 467         /*
 468          * Update the window for each rate.  We determine which rates
 469          * were Tx'd based on the total number of retries vs. the number
 470          * of retries configured for each rate -- currently set to the
 471          * priv value 'retry_rate' vs. rate specific
 472          *
 473          * On exit from this while loop last_index indicates the rate
 474          * at which the frame was finally transmitted (or failed if no
 475          * ACK)
 476          */
 477         while (retries > 1) {
 478                 if ((retries - 1) < priv->retry_rate) {
 479                         current_count = (retries - 1);
 480                         last_index = scale_rate_index;
 481                 } else {
 482                         current_count = priv->retry_rate;
 483                         last_index = iwl3945_rs_next_rate(priv,
 484                                                          scale_rate_index);
 485                 }
 486
 487                 /* Update this rate accounting for as many retries
 488                  * as was used for it (per current_count) */
 489                 iwl3945_collect_tx_data(rs_sta,
 490                                     &rs_sta->win[scale_rate_index],
 491                                     0, current_count, scale_rate_index);
 492                 IWL_DEBUG_RATE(priv, "Update rate %d for %d retries.\n",
 493                                scale_rate_index, current_count);
 494
 495                 retries -= current_count;
 496
 497                 scale_rate_index = last_index;
 498         }
 499
 500
 501         /* Update the last index window with success/failure based on ACK */
 502         IWL_DEBUG_RATE(priv, "Update rate %d with %s.\n",
 503                        last_index,
 504                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 505                        "success" : "failure");
 506         iwl3945_collect_tx_data(rs_sta,
 507                             &rs_sta->win[last_index],
 508                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 509
 510         /* We updated the rate scale window -- if its been more than
 511          * flush_time since the last run, schedule the flush
 512          * again */
 513         spin_lock_irqsave(&rs_sta->lock, flags);
 514
 515         if (!rs_sta->flush_pending &&
 516             time_after(jiffies, rs_sta->last_flush +
 517                        rs_sta->flush_time)) {
 518
 519                 rs_sta->last_partial_flush = jiffies;
 520                 rs_sta->flush_pending = 1;
 521                 mod_timer(&rs_sta->rate_scale_flush,
 522                           jiffies + rs_sta->flush_time);
 523         }
 524
 525         spin_unlock_irqrestore(&rs_sta->lock, flags);
 526
 527         IWL_DEBUG_RATE(priv, "leave\n");
 528
 529         return;
 530 }
 531
 532 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 533                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 534 {
 535         u8 high = IWL_RATE_INVALID;
 536         u8 low = IWL_RATE_INVALID;
 537         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 538
 539         /* 802.11A walks to the next literal adjacent rate in
 540          * the rate table */
 541         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 542                 int i;
 543                 u32 mask;
 544
 545                 /* Find the previous rate that is in the rate mask */
 546                 i = index - 1;
 547                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 548                         if (rate_mask & mask) {
 549                                 low = i;
 550                                 break;
 551                         }
 552                 }
 553
 554                 /* Find the next rate that is in the rate mask */
 555                 i = index + 1;
 556                 for (mask = (1 << i); i < IWL_RATE_COUNT_3945;
 557                      i++, mask <<= 1) {
 558                         if (rate_mask & mask) {
 559                                 high = i;
 560                                 break;
 561                         }
 562                 }
 563
 564                 return (high << 8) | low;
 565         }
 566
 567         low = index;
 568         while (low != IWL_RATE_INVALID) {
 569                 if (rs_sta->tgg)
 570                         low = iwl3945_rates[low].prev_rs_tgg;
 571                 else
 572                         low = iwl3945_rates[low].prev_rs;
 573                 if (low == IWL_RATE_INVALID)
 574                         break;
 575                 if (rate_mask & (1 << low))
 576                         break;
 577                 IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low);
 578         }
 579
 580         high = index;
 581         while (high != IWL_RATE_INVALID) {
 582                 if (rs_sta->tgg)
 583                         high = iwl3945_rates[high].next_rs_tgg;
 584                 else
 585                         high = iwl3945_rates[high].next_rs;
 586                 if (high == IWL_RATE_INVALID)
 587                         break;
 588                 if (rate_mask & (1 << high))
 589                         break;
 590                 IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high);
 591         }
 592
 593         return (high << 8) | low;
 594 }
 595
 596 /**
 597  * rs_get_rate - find the rate for the requested packet
 598  *
 599  * Returns the ieee80211_rate structure allocated by the driver.
 600  *
 601  * The rate control algorithm has no internal mapping between hw_mode's
 602  * rate ordering and the rate ordering used by the rate control algorithm.
 603  *
 604  * The rate control algorithm uses a single table of rates that goes across
 605  * the entire A/B/G spectrum vs. being limited to just one particular
 606  * hw_mode.
 607  *
 608  * As such, we can't convert the index obtained below into the hw_mode's
 609  * rate table and must reference the driver allocated rate table
 610  *
 611  */
 612 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 613                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 614 {
 615         struct ieee80211_supported_band *sband = txrc->sband;
 616         struct sk_buff *skb = txrc->skb;
 617         u8 low = IWL_RATE_INVALID;
 618         u8 high = IWL_RATE_INVALID;
 619         u16 high_low;
 620         int index;
 621         struct iwl3945_rs_sta *rs_sta = priv_sta;
 622         struct iwl3945_rate_scale_data *window = NULL;
 623         int current_tpt = IWL_INVALID_VALUE;
 624         int low_tpt = IWL_INVALID_VALUE;
 625         int high_tpt = IWL_INVALID_VALUE;
 626         u32 fail_count;
 627         s8 scale_action = 0;
 628         unsigned long flags;
 629         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 630         u16 rate_mask = sta ? sta->supp_rates[sband->band] : 0;
 631         s8 max_rate_idx = -1;
 632         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
 633         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 634
 635         IWL_DEBUG_RATE(priv, "enter\n");
 636
 637         if (rate_control_send_low(sta, priv_sta, txrc))
 638                 return;
 639
 640         rate_mask = sta->supp_rates[sband->band];
 641
 642         /* get user max rate if set */
 643         max_rate_idx = txrc->max_rate_idx;
 644         if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1))
 645                 max_rate_idx += IWL_FIRST_OFDM_RATE;
 646         if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT))
 647                 max_rate_idx = -1;
 648
 649         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
 650
 651         if (sband->band == IEEE80211_BAND_5GHZ)
 652                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 653
 654         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 655             !rs_sta->ibss_sta_added) {
 656                 u8 sta_id = iwl_find_station(priv, hdr->addr1);
 657
 658                 if (sta_id == IWL_INVALID_STATION) {
 659                         IWL_DEBUG_RATE(priv, "LQ: ADD station %pM\n",
 660                                        hdr->addr1);
 661                         sta_id = iwl_add_station(priv, hdr->addr1, false,
 662                                 CMD_ASYNC, NULL);
 663                 }
 664                 if (sta_id != IWL_INVALID_STATION)
 665                         rs_sta->ibss_sta_added = 1;
 666         }
 667
 668         spin_lock_irqsave(&rs_sta->lock, flags);
 669
 670         /* for recent assoc, choose best rate regarding
 671          * to rssi value
 672          */
 673         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 674                 if (rs_sta->start_rate < index &&
 675                    (rate_mask & (1 << rs_sta->start_rate)))
 676                         index = rs_sta->start_rate;
 677                 rs_sta->start_rate = IWL_RATE_INVALID;
 678         }
 679
 680         /* force user max rate if set by user */
 681         if ((max_rate_idx != -1) && (max_rate_idx < index)) {
 682                 if (rate_mask & (1 << max_rate_idx))
 683                         index = max_rate_idx;
 684         }
 685
 686         window = &(rs_sta->win[index]);
 687
 688         fail_count = window->counter - window->success_counter;
 689
 690         if (((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
 691              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 692                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 693
 694                 IWL_DEBUG_RATE(priv, "Invalid average_tpt on rate %d: "
 695                                "counter: %d, success_counter: %d, "
 696                                "expected_tpt is %sNULL\n",
 697                                index,
 698                                window->counter,
 699                                window->success_counter,
 700                                rs_sta->expected_tpt ? "not " : "");
 701
 702            /* Can't calculate this yet; not enough history */
 703                 window->average_tpt = IWL_INVALID_VALUE;
 704                 goto out;
 705
 706         }
 707
 708         current_tpt = window->average_tpt;
 709
 710         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 711                                              sband->band);
 712         low = high_low & 0xff;
 713         high = (high_low >> 8) & 0xff;
 714
 715         /* If user set max rate, dont allow higher than user constrain */
 716         if ((max_rate_idx != -1) && (max_rate_idx < high))
 717                 high = IWL_RATE_INVALID;
 718
 719         /* Collect Measured throughputs of adjacent rates */
 720         if (low != IWL_RATE_INVALID)
 721                 low_tpt = rs_sta->win[low].average_tpt;
 722
 723         if (high != IWL_RATE_INVALID)
 724                 high_tpt = rs_sta->win[high].average_tpt;
 725
 726         spin_unlock_irqrestore(&rs_sta->lock, flags);
 727
 728         scale_action = 0;
 729
 730         /* Low success ratio , need to drop the rate */
 731         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 732                 IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
 733                 scale_action = -1;
 734         /* No throughput measured yet for adjacent rates,
 735          * try increase */
 736         } else if ((low_tpt == IWL_INVALID_VALUE) &&
 737                    (high_tpt == IWL_INVALID_VALUE)) {
 738
 739                 if (high != IWL_RATE_INVALID && window->success_ratio >= IWL_RATE_INCREASE_TH)
 740                         scale_action = 1;
 741                 else if (low != IWL_RATE_INVALID)
 742                         scale_action = 0;
 743
 744         /* Both adjacent throughputs are measured, but neither one has
 745          * better throughput; we're using the best rate, don't change
 746          * it! */
 747         } else if ((low_tpt != IWL_INVALID_VALUE) &&
 748                  (high_tpt != IWL_INVALID_VALUE) &&
 749                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 750
 751                 IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < "
 752                                "current_tpt [%d]\n",
 753                                low_tpt, high_tpt, current_tpt);
 754                 scale_action = 0;
 755
 756         /* At least one of the rates has better throughput */
 757         } else {
 758                 if (high_tpt != IWL_INVALID_VALUE) {
 759
 760                         /* High rate has better throughput, Increase
 761                          * rate */
 762                         if (high_tpt > current_tpt &&
 763                                 window->success_ratio >= IWL_RATE_INCREASE_TH)
 764                                 scale_action = 1;
 765                         else {
 766                                 IWL_DEBUG_RATE(priv,
 767                                     "decrease rate because of high tpt\n");
 768                                 scale_action = 0;
 769                         }
 770                 } else if (low_tpt != IWL_INVALID_VALUE) {
 771                         if (low_tpt > current_tpt) {
 772                                 IWL_DEBUG_RATE(priv,
 773                                     "decrease rate because of low tpt\n");
 774                                 scale_action = -1;
 775                         } else if (window->success_ratio >= IWL_RATE_INCREASE_TH) {
 776                                 /* Lower rate has better
 777                                  * throughput,decrease rate */
 778                                 scale_action = 1;
 779                         }
 780                 }
 781         }
 782
 783         /* Sanity check; asked for decrease, but success rate or throughput
 784          * has been good at old rate.  Don't change it. */
 785         if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
 786                     ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 787                      (current_tpt > (100 * rs_sta->expected_tpt[low]))))
 788                 scale_action = 0;
 789
 790         switch (scale_action) {
 791         case -1:
 792
 793                 /* Decrese rate */
 794                 if (low != IWL_RATE_INVALID)
 795                         index = low;
 796                 break;
 797
 798         case 1:
 799                 /* Increase rate */
 800                 if (high != IWL_RATE_INVALID)
 801                         index = high;
 802
 803                 break;
 804
 805         case 0:
 806         default:
 807                 /* No change */
 808                 break;
 809         }
 810
 811         IWL_DEBUG_RATE(priv, "Selected %d (action %d) - low %d high %d\n",
 812                        index, scale_action, low, high);
 813
 814  out:
 815
 816         rs_sta->last_txrate_idx = index;
 817         if (sband->band == IEEE80211_BAND_5GHZ)
 818                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 819                                 IWL_FIRST_OFDM_RATE;
 820         else
 821                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 822
 823         IWL_DEBUG_RATE(priv, "leave: %d\n", index);
 824 }
 825
 826 #ifdef CONFIG_MAC80211_DEBUGFS
 827 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 828 {
 829         file->private_data = inode->i_private;
 830         return 0;
 831 }
 832
 833 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 834                                                   char __user *user_buf,
 835                                                   size_t count, loff_t *ppos)
 836 {
 837         char *buff;
 838         int desc = 0;
 839         int j;
 840         ssize_t ret;
 841         struct iwl3945_rs_sta *lq_sta = file->private_data;
 842
 843         buff = kmalloc(1024, GFP_KERNEL);
 844         if (!buff)
 845                 return -ENOMEM;
 846
 847         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 848                         "rate=0x%X flush time %d\n",
 849                         lq_sta->tx_packets,
 850                         lq_sta->last_txrate_idx,
 851                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 852         for (j = 0; j < IWL_RATE_COUNT_3945; j++) {
 853                 desc += sprintf(buff+desc,
 854                                 "counter=%d success=%d %%=%d\n",
 855                                 lq_sta->win[j].counter,
 856                                 lq_sta->win[j].success_counter,
 857                                 lq_sta->win[j].success_ratio);
 858         }
 859         ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 860         kfree(buff);
 861         return ret;
 862 }
 863
 864 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 865         .read = iwl3945_sta_dbgfs_stats_table_read,
 866         .open = iwl3945_open_file_generic,
 867 };
 868
 869 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 870                                 struct dentry *dir)
 871 {
 872         struct iwl3945_rs_sta *lq_sta = priv_sta;
 873
 874         lq_sta->rs_sta_dbgfs_stats_table_file =
 875                 debugfs_create_file("rate_stats_table", 0600, dir,
 876                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 877
 878 }
 879
 880 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 881 {
 882         struct iwl3945_rs_sta *lq_sta = priv_sta;
 883         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 884 }
 885 #endif
 886
 887 static struct rate_control_ops rs_ops = {
 888         .module = NULL,
 889         .name = RS_NAME,
 890         .tx_status = rs_tx_status,
 891         .get_rate = rs_get_rate,
 892         .rate_init = rs_rate_init,
 893         .alloc = rs_alloc,
 894         .free = rs_free,
 895         .alloc_sta = rs_alloc_sta,
 896         .free_sta = rs_free_sta,
 897 #ifdef CONFIG_MAC80211_DEBUGFS
 898         .add_sta_debugfs = iwl3945_add_debugfs,
 899         .remove_sta_debugfs = iwl3945_remove_debugfs,
 900 #endif
 901
 902 };
 903
 904 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 905 {
 906         struct iwl_priv *priv = hw->priv;
 907         s32 rssi = 0;
 908         unsigned long flags;
 909         struct iwl3945_rs_sta *rs_sta;
 910         struct ieee80211_sta *sta;
 911         struct iwl3945_sta_priv *psta;
 912
 913         IWL_DEBUG_RATE(priv, "enter\n");
 914
 915         rcu_read_lock();
 916
 917         sta = ieee80211_find_sta(priv->vif,
 918                                  priv->stations[sta_id].sta.sta.addr);
 919         if (!sta) {
 920                 rcu_read_unlock();
 921                 return;
 922         }
 923
 924         psta = (void *) sta->drv_priv;
 925         rs_sta = &psta->rs_sta;
 926
 927         spin_lock_irqsave(&rs_sta->lock, flags);
 928
 929         rs_sta->tgg = 0;
 930         switch (priv->band) {
 931         case IEEE80211_BAND_2GHZ:
 932                 /* TODO: this always does G, not a regression */
 933                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 934                         rs_sta->tgg = 1;
 935                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 936                 } else
 937                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 938                 break;
 939
 940         case IEEE80211_BAND_5GHZ:
 941                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 942                 break;
 943         case IEEE80211_NUM_BANDS:
 944                 BUG();
 945                 break;
 946         }
 947
 948         spin_unlock_irqrestore(&rs_sta->lock, flags);
 949
 950         rssi = priv->last_rx_rssi;
 951         if (rssi == 0)
 952                 rssi = IWL_MIN_RSSI_VAL;
 953
 954         IWL_DEBUG_RATE(priv, "Network RSSI: %d\n", rssi);
 955
 956         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 957
 958         IWL_DEBUG_RATE(priv, "leave: rssi %d assign rate index: "
 959                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 960                        iwl3945_rates[rs_sta->start_rate].plcp);
 961         rcu_read_unlock();
 962 }
 963
 964 int iwl3945_rate_control_register(void)
 965 {
 966         return ieee80211_rate_control_register(&rs_ops);
 967 }
 968
 969 void iwl3945_rate_control_unregister(void)
 970 {
 971         ieee80211_rate_control_unregister(&rs_ops);
 972 }
 973
 974