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

   1 /******************************************************************************
   2  *
   3  * Copyright(c) 2005 - 2011 Intel Corporation. All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called LICENSE.
  20  *
  21  * Contact Information:
  22  *  Intel Linux Wireless <ilw@linux.intel.com>
  23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  24  *
  25  *****************************************************************************/
  26
  27 #include <linux/kernel.h>
  28 #include <linux/init.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/slab.h>
  31 #include <net/mac80211.h>
  32
  33 #include <linux/netdevice.h>
  34 #include <linux/etherdevice.h>
  35 #include <linux/delay.h>
  36
  37 #include <linux/workqueue.h>
  38
  39 #include "iwl-commands.h"
  40 #include "iwl-3945.h"
  41 #include "iwl-sta.h"
  42
  43 #define RS_NAME "iwl-3945-rs"
  44
  45 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT_3945] = {
  46         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  47 };
  48
  49 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT_3945] = {
  50         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  51 };
  52
  53 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT_3945] = {
  54         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  55 };
  56
  57 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT_3945] = {
  58         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  59 };
  60
  61 struct iwl3945_tpt_entry {
  62         s8 min_rssi;
  63         u8 index;
  64 };
  65
  66 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  67         {-60, IWL_RATE_54M_INDEX},
  68         {-64, IWL_RATE_48M_INDEX},
  69         {-72, IWL_RATE_36M_INDEX},
  70         {-80, IWL_RATE_24M_INDEX},
  71         {-84, IWL_RATE_18M_INDEX},
  72         {-85, IWL_RATE_12M_INDEX},
  73         {-87, IWL_RATE_9M_INDEX},
  74         {-89, IWL_RATE_6M_INDEX}
  75 };
  76
  77 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
  78         {-60, IWL_RATE_54M_INDEX},
  79         {-64, IWL_RATE_48M_INDEX},
  80         {-68, IWL_RATE_36M_INDEX},
  81         {-80, IWL_RATE_24M_INDEX},
  82         {-84, IWL_RATE_18M_INDEX},
  83         {-85, IWL_RATE_12M_INDEX},
  84         {-86, IWL_RATE_11M_INDEX},
  85         {-88, IWL_RATE_5M_INDEX},
  86         {-90, IWL_RATE_2M_INDEX},
  87         {-92, IWL_RATE_1M_INDEX}
  88 };
  89
  90 #define IWL_RATE_MAX_WINDOW          62
  91 #define IWL_RATE_FLUSH          (3*HZ)
  92 #define IWL_RATE_WIN_FLUSH       (HZ/2)
  93 #define IWL39_RATE_HIGH_TH          11520
  94 #define IWL_SUCCESS_UP_TH          8960
  95 #define IWL_SUCCESS_DOWN_TH       10880
  96 #define IWL_RATE_MIN_FAILURE_TH       6
  97 #define IWL_RATE_MIN_SUCCESS_TH       8
  98 #define IWL_RATE_DECREASE_TH       1920
  99 #define IWL_RATE_RETRY_TH            15
 100
 101 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 102 {
 103         u32 index = 0;
 104         u32 table_size = 0;
 105         struct iwl3945_tpt_entry *tpt_table = NULL;
 106
 107         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 108                 rssi = IWL_MIN_RSSI_VAL;
 109
 110         switch (band) {
 111         case IEEE80211_BAND_2GHZ:
 112                 tpt_table = iwl3945_tpt_table_g;
 113                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 114                 break;
 115
 116         case IEEE80211_BAND_5GHZ:
 117                 tpt_table = iwl3945_tpt_table_a;
 118                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 119                 break;
 120
 121         default:
 122                 BUG();
 123                 break;
 124         }
 125
 126         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 127                 index++;
 128
 129         index = min(index, (table_size - 1));
 130
 131         return tpt_table[index].index;
 132 }
 133
 134 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 135 {
 136         window->data = 0;
 137         window->success_counter = 0;
 138         window->success_ratio = -1;
 139         window->counter = 0;
 140         window->average_tpt = IWL_INVALID_VALUE;
 141         window->stamp = 0;
 142 }
 143
 144 /**
 145  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 146  *
 147  * Returns the number of windows that have gathered data but were
 148  * not flushed.  If there were any that were not flushed, then
 149  * reschedule the rate flushing routine.
 150  */
 151 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 152 {
 153         int unflushed = 0;
 154         int i;
 155         unsigned long flags;
 156         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 157
 158         /*
 159          * For each rate, if we have collected data on that rate
 160          * and it has been more than IWL_RATE_WIN_FLUSH
 161          * since we flushed, clear out the gathered statistics
 162          */
 163         for (i = 0; i < IWL_RATE_COUNT_3945; i++) {
 164                 if (!rs_sta->win[i].counter)
 165                         continue;
 166
 167                 spin_lock_irqsave(&rs_sta->lock, flags);
 168                 if (time_after(jiffies, rs_sta->win[i].stamp +
 169                                IWL_RATE_WIN_FLUSH)) {
 170                         IWL_DEBUG_RATE(priv, "flushing %d samples of rate "
 171                                        "index %d\n",
 172                                        rs_sta->win[i].counter, i);
 173                         iwl3945_clear_window(&rs_sta->win[i]);
 174                 } else
 175                         unflushed++;
 176                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 177         }
 178
 179         return unflushed;
 180 }
 181
 182 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 183 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 184 #define IWL_AVERAGE_PACKETS             1500
 185
 186 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 187 {
 188         struct iwl3945_rs_sta *rs_sta = (void *)data;
 189         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 190         int unflushed = 0;
 191         unsigned long flags;
 192         u32 packet_count, duration, pps;
 193
 194         IWL_DEBUG_RATE(priv, "enter\n");
 195
 196         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 197
 198         spin_lock_irqsave(&rs_sta->lock, flags);
 199
 200         /* Number of packets Rx'd since last time this timer ran */
 201         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 202
 203         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 204
 205         if (unflushed) {
 206                 duration =
 207                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 208
 209                 IWL_DEBUG_RATE(priv, "Tx'd %d packets in %dms\n",
 210                                packet_count, duration);
 211
 212                 /* Determine packets per second */
 213                 if (duration)
 214                         pps = (packet_count * 1000) / duration;
 215                 else
 216                         pps = 0;
 217
 218                 if (pps) {
 219                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
 220                         if (duration < IWL_RATE_FLUSH_MIN)
 221                                 duration = IWL_RATE_FLUSH_MIN;
 222                         else if (duration > IWL_RATE_FLUSH_MAX)
 223                                 duration = IWL_RATE_FLUSH_MAX;
 224                 } else
 225                         duration = IWL_RATE_FLUSH_MAX;
 226
 227                 rs_sta->flush_time = msecs_to_jiffies(duration);
 228
 229                 IWL_DEBUG_RATE(priv, "new flush period: %d msec ave %d\n",
 230                                duration, packet_count);
 231
 232                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 233                           rs_sta->flush_time);
 234
 235                 rs_sta->last_partial_flush = jiffies;
 236         } else {
 237                 rs_sta->flush_time = IWL_RATE_FLUSH;
 238                 rs_sta->flush_pending = 0;
 239         }
 240         /* If there weren't any unflushed entries, we don't schedule the timer
 241          * to run again */
 242
 243         rs_sta->last_flush = jiffies;
 244
 245         spin_unlock_irqrestore(&rs_sta->lock, flags);
 246
 247         IWL_DEBUG_RATE(priv, "leave\n");
 248 }
 249
 250 /**
 251  * iwl3945_collect_tx_data - Update the success/failure sliding window
 252  *
 253  * We keep a sliding window of the last 64 packets transmitted
 254  * at this rate.  window->data contains the bitmask of successful
 255  * packets.
 256  */
 257 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 258                                 struct iwl3945_rate_scale_data *window,
 259                                 int success, int retries, int index)
 260 {
 261         unsigned long flags;
 262         s32 fail_count;
 263         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 264
 265         if (!retries) {
 266                 IWL_DEBUG_RATE(priv, "leave: retries == 0 -- should be at least 1\n");
 267                 return;
 268         }
 269
 270         spin_lock_irqsave(&rs_sta->lock, flags);
 271
 272         /*
 273          * Keep track of only the latest 62 tx frame attempts in this rate's
 274          * history window; anything older isn't really relevant any more.
 275          * If we have filled up the sliding window, drop the oldest attempt;
 276          * if the oldest attempt (highest bit in bitmap) shows "success",
 277          * subtract "1" from the success counter (this is the main reason
 278          * we keep these bitmaps!).
 279          * */
 280         while (retries > 0) {
 281                 if (window->counter >= IWL_RATE_MAX_WINDOW) {
 282
 283                         /* remove earliest */
 284                         window->counter = IWL_RATE_MAX_WINDOW - 1;
 285
 286                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1))) {
 287                                 window->data &= ~(1ULL << (IWL_RATE_MAX_WINDOW - 1));
 288                                 window->success_counter--;
 289                         }
 290                 }
 291
 292                 /* Increment frames-attempted counter */
 293                 window->counter++;
 294
 295                 /* Shift bitmap by one frame (throw away oldest history),
 296                  * OR in "1", and increment "success" if this
 297                  * frame was successful. */
 298                 window->data <<= 1;
 299                 if (success > 0) {
 300                         window->success_counter++;
 301                         window->data |= 0x1;
 302                         success--;
 303                 }
 304
 305                 retries--;
 306         }
 307
 308         /* Calculate current success ratio, avoid divide-by-0! */
 309         if (window->counter > 0)
 310                 window->success_ratio = 128 * (100 * window->success_counter)
 311                                         / window->counter;
 312         else
 313                 window->success_ratio = IWL_INVALID_VALUE;
 314
 315         fail_count = window->counter - window->success_counter;
 316
 317         /* Calculate average throughput, if we have enough history. */
 318         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
 319             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
 320                 window->average_tpt = ((window->success_ratio *
 321                                 rs_sta->expected_tpt[index] + 64) / 128);
 322         else
 323                 window->average_tpt = IWL_INVALID_VALUE;
 324
 325         /* Tag this window as having been updated */
 326         window->stamp = jiffies;
 327
 328         spin_unlock_irqrestore(&rs_sta->lock, flags);
 329
 330 }
 331
 332 /*
 333  * Called after adding a new station to initialize rate scaling
 334  */
 335 void iwl3945_rs_rate_init(struct iwl_priv *priv, struct ieee80211_sta *sta, u8 sta_id)
 336 {
 337         struct ieee80211_hw *hw = priv->hw;
 338         struct ieee80211_conf *conf = &priv->hw->conf;
 339         struct iwl3945_sta_priv *psta;
 340         struct iwl3945_rs_sta *rs_sta;
 341         struct ieee80211_supported_band *sband;
 342         int i;
 343
 344         IWL_DEBUG_INFO(priv, "enter\n");
 345         if (sta_id == priv->contexts[IWL_RXON_CTX_BSS].bcast_sta_id)
 346                 goto out;
 347
 348         psta = (struct iwl3945_sta_priv *) sta->drv_priv;
 349         rs_sta = &psta->rs_sta;
 350         sband = hw->wiphy->bands[conf->channel->band];
 351
 352         rs_sta->priv = priv;
 353
 354         rs_sta->start_rate = IWL_RATE_INVALID;
 355
 356         /* default to just 802.11b */
 357         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 358
 359         rs_sta->last_partial_flush = jiffies;
 360         rs_sta->last_flush = jiffies;
 361         rs_sta->flush_time = IWL_RATE_FLUSH;
 362         rs_sta->last_tx_packets = 0;
 363
 364         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 365         rs_sta->rate_scale_flush.function = iwl3945_bg_rate_scale_flush;
 366
 367         for (i = 0; i < IWL_RATE_COUNT_3945; i++)
 368                 iwl3945_clear_window(&rs_sta->win[i]);
 369
 370         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 371          * the lowest or the highest rate.. Could consider using RSSI from
 372          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 373          * after assoc.. */
 374
 375         for (i = sband->n_bitrates - 1; i >= 0; i--) {
 376                 if (sta->supp_rates[sband->band] & (1 << i)) {
 377                         rs_sta->last_txrate_idx = i;
 378                         break;
 379                 }
 380         }
 381
 382         priv->_3945.sta_supp_rates = sta->supp_rates[sband->band];
 383         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 384         if (sband->band == IEEE80211_BAND_5GHZ) {
 385                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 386                 priv->_3945.sta_supp_rates = priv->_3945.sta_supp_rates <<
 387                                                 IWL_FIRST_OFDM_RATE;
 388         }
 389
 390 out:
 391         priv->stations[sta_id].used &= ~IWL_STA_UCODE_INPROGRESS;
 392
 393         IWL_DEBUG_INFO(priv, "leave\n");
 394 }
 395
 396 static void *iwl3945_rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 397 {
 398         return hw->priv;
 399 }
 400
 401 /* rate scale requires free function to be implemented */
 402 static void iwl3945_rs_free(void *priv)
 403 {
 404         return;
 405 }
 406
 407 static void *iwl3945_rs_alloc_sta(void *iwl_priv, struct ieee80211_sta *sta, gfp_t gfp)
 408 {
 409         struct iwl3945_rs_sta *rs_sta;
 410         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 411         struct iwl_priv *priv __maybe_unused = iwl_priv;
 412
 413         IWL_DEBUG_RATE(priv, "enter\n");
 414
 415         rs_sta = &psta->rs_sta;
 416
 417         spin_lock_init(&rs_sta->lock);
 418         init_timer(&rs_sta->rate_scale_flush);
 419
 420         IWL_DEBUG_RATE(priv, "leave\n");
 421
 422         return rs_sta;
 423 }
 424
 425 static void iwl3945_rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
 426                         void *priv_sta)
 427 {
 428         struct iwl3945_rs_sta *rs_sta = priv_sta;
 429
 430         /*
 431          * Be careful not to use any members of iwl3945_rs_sta (like trying
 432          * to use iwl_priv to print out debugging) since it may not be fully
 433          * initialized at this point.
 434          */
 435         del_timer_sync(&rs_sta->rate_scale_flush);
 436 }
 437
 438
 439 /**
 440  * iwl3945_rs_tx_status - Update rate control values based on Tx results
 441  *
 442  * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
 443  * the hardware for each rate.
 444  */
 445 static void iwl3945_rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 446                          struct ieee80211_sta *sta, void *priv_sta,
 447                          struct sk_buff *skb)
 448 {
 449         s8 retries = 0, current_count;
 450         int scale_rate_index, first_index, last_index;
 451         unsigned long flags;
 452         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 453         struct iwl3945_rs_sta *rs_sta = priv_sta;
 454         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 455
 456         IWL_DEBUG_RATE(priv, "enter\n");
 457
 458         retries = info->status.rates[0].count;
 459         /* Sanity Check for retries */
 460         if (retries > IWL_RATE_RETRY_TH)
 461                 retries = IWL_RATE_RETRY_TH;
 462
 463         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 464         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
 465                 IWL_DEBUG_RATE(priv, "leave: Rate out of bounds: %d\n", first_index);
 466                 return;
 467         }
 468
 469         if (!priv_sta) {
 470                 IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
 471                 return;
 472         }
 473
 474         /* Treat uninitialized rate scaling data same as non-existing. */
 475         if (!rs_sta->priv) {
 476                 IWL_DEBUG_RATE(priv, "leave: STA priv data uninitialized!\n");
 477                 return;
 478         }
 479
 480
 481         rs_sta->tx_packets++;
 482
 483         scale_rate_index = first_index;
 484         last_index = first_index;
 485
 486         /*
 487          * Update the window for each rate.  We determine which rates
 488          * were Tx'd based on the total number of retries vs. the number
 489          * of retries configured for each rate -- currently set to the
 490          * priv value 'retry_rate' vs. rate specific
 491          *
 492          * On exit from this while loop last_index indicates the rate
 493          * at which the frame was finally transmitted (or failed if no
 494          * ACK)
 495          */
 496         while (retries > 1) {
 497                 if ((retries - 1) < priv->retry_rate) {
 498                         current_count = (retries - 1);
 499                         last_index = scale_rate_index;
 500                 } else {
 501                         current_count = priv->retry_rate;
 502                         last_index = iwl3945_rs_next_rate(priv,
 503                                                          scale_rate_index);
 504                 }
 505
 506                 /* Update this rate accounting for as many retries
 507                  * as was used for it (per current_count) */
 508                 iwl3945_collect_tx_data(rs_sta,
 509                                     &rs_sta->win[scale_rate_index],
 510                                     0, current_count, scale_rate_index);
 511                 IWL_DEBUG_RATE(priv, "Update rate %d for %d retries.\n",
 512                                scale_rate_index, current_count);
 513
 514                 retries -= current_count;
 515
 516                 scale_rate_index = last_index;
 517         }
 518
 519
 520         /* Update the last index window with success/failure based on ACK */
 521         IWL_DEBUG_RATE(priv, "Update rate %d with %s.\n",
 522                        last_index,
 523                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 524                        "success" : "failure");
 525         iwl3945_collect_tx_data(rs_sta,
 526                             &rs_sta->win[last_index],
 527                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 528
 529         /* We updated the rate scale window -- if its been more than
 530          * flush_time since the last run, schedule the flush
 531          * again */
 532         spin_lock_irqsave(&rs_sta->lock, flags);
 533
 534         if (!rs_sta->flush_pending &&
 535             time_after(jiffies, rs_sta->last_flush +
 536                        rs_sta->flush_time)) {
 537
 538                 rs_sta->last_partial_flush = jiffies;
 539                 rs_sta->flush_pending = 1;
 540                 mod_timer(&rs_sta->rate_scale_flush,
 541                           jiffies + rs_sta->flush_time);
 542         }
 543
 544         spin_unlock_irqrestore(&rs_sta->lock, flags);
 545
 546         IWL_DEBUG_RATE(priv, "leave\n");
 547 }
 548
 549 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 550                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 551 {
 552         u8 high = IWL_RATE_INVALID;
 553         u8 low = IWL_RATE_INVALID;
 554         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 555
 556         /* 802.11A walks to the next literal adjacent rate in
 557          * the rate table */
 558         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 559                 int i;
 560                 u32 mask;
 561
 562                 /* Find the previous rate that is in the rate mask */
 563                 i = index - 1;
 564                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 565                         if (rate_mask & mask) {
 566                                 low = i;
 567                                 break;
 568                         }
 569                 }
 570
 571                 /* Find the next rate that is in the rate mask */
 572                 i = index + 1;
 573                 for (mask = (1 << i); i < IWL_RATE_COUNT_3945;
 574                      i++, mask <<= 1) {
 575                         if (rate_mask & mask) {
 576                                 high = i;
 577                                 break;
 578                         }
 579                 }
 580
 581                 return (high << 8) | low;
 582         }
 583
 584         low = index;
 585         while (low != IWL_RATE_INVALID) {
 586                 if (rs_sta->tgg)
 587                         low = iwl3945_rates[low].prev_rs_tgg;
 588                 else
 589                         low = iwl3945_rates[low].prev_rs;
 590                 if (low == IWL_RATE_INVALID)
 591                         break;
 592                 if (rate_mask & (1 << low))
 593                         break;
 594                 IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low);
 595         }
 596
 597         high = index;
 598         while (high != IWL_RATE_INVALID) {
 599                 if (rs_sta->tgg)
 600                         high = iwl3945_rates[high].next_rs_tgg;
 601                 else
 602                         high = iwl3945_rates[high].next_rs;
 603                 if (high == IWL_RATE_INVALID)
 604                         break;
 605                 if (rate_mask & (1 << high))
 606                         break;
 607                 IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high);
 608         }
 609
 610         return (high << 8) | low;
 611 }
 612
 613 /**
 614  * iwl3945_rs_get_rate - find the rate for the requested packet
 615  *
 616  * Returns the ieee80211_rate structure allocated by the driver.
 617  *
 618  * The rate control algorithm has no internal mapping between hw_mode's
 619  * rate ordering and the rate ordering used by the rate control algorithm.
 620  *
 621  * The rate control algorithm uses a single table of rates that goes across
 622  * the entire A/B/G spectrum vs. being limited to just one particular
 623  * hw_mode.
 624  *
 625  * As such, we can't convert the index obtained below into the hw_mode's
 626  * rate table and must reference the driver allocated rate table
 627  *
 628  */
 629 static void iwl3945_rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 630                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 631 {
 632         struct ieee80211_supported_band *sband = txrc->sband;
 633         struct sk_buff *skb = txrc->skb;
 634         u8 low = IWL_RATE_INVALID;
 635         u8 high = IWL_RATE_INVALID;
 636         u16 high_low;
 637         int index;
 638         struct iwl3945_rs_sta *rs_sta = priv_sta;
 639         struct iwl3945_rate_scale_data *window = NULL;
 640         int current_tpt = IWL_INVALID_VALUE;
 641         int low_tpt = IWL_INVALID_VALUE;
 642         int high_tpt = IWL_INVALID_VALUE;
 643         u32 fail_count;
 644         s8 scale_action = 0;
 645         unsigned long flags;
 646         u16 rate_mask;
 647         s8 max_rate_idx = -1;
 648         struct iwl_priv *priv __maybe_unused = (struct iwl_priv *)priv_r;
 649         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 650
 651         IWL_DEBUG_RATE(priv, "enter\n");
 652
 653         /* Treat uninitialized rate scaling data same as non-existing. */
 654         if (rs_sta && !rs_sta->priv) {
 655                 IWL_DEBUG_RATE(priv, "Rate scaling information not initialized yet.\n");
 656                 priv_sta = NULL;
 657         }
 658
 659         if (rate_control_send_low(sta, priv_sta, txrc))
 660                 return;
 661
 662         rate_mask = sta->supp_rates[sband->band];
 663
 664         /* get user max rate if set */
 665         max_rate_idx = txrc->max_rate_idx;
 666         if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1))
 667                 max_rate_idx += IWL_FIRST_OFDM_RATE;
 668         if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT))
 669                 max_rate_idx = -1;
 670
 671         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
 672
 673         if (sband->band == IEEE80211_BAND_5GHZ)
 674                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 675
 676         spin_lock_irqsave(&rs_sta->lock, flags);
 677
 678         /* for recent assoc, choose best rate regarding
 679          * to rssi value
 680          */
 681         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 682                 if (rs_sta->start_rate < index &&
 683                    (rate_mask & (1 << rs_sta->start_rate)))
 684                         index = rs_sta->start_rate;
 685                 rs_sta->start_rate = IWL_RATE_INVALID;
 686         }
 687
 688         /* force user max rate if set by user */
 689         if ((max_rate_idx != -1) && (max_rate_idx < index)) {
 690                 if (rate_mask & (1 << max_rate_idx))
 691                         index = max_rate_idx;
 692         }
 693
 694         window = &(rs_sta->win[index]);
 695
 696         fail_count = window->counter - window->success_counter;
 697
 698         if (((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
 699              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 700                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 701
 702                 IWL_DEBUG_RATE(priv, "Invalid average_tpt on rate %d: "
 703                                "counter: %d, success_counter: %d, "
 704                                "expected_tpt is %sNULL\n",
 705                                index,
 706                                window->counter,
 707                                window->success_counter,
 708                                rs_sta->expected_tpt ? "not " : "");
 709
 710            /* Can't calculate this yet; not enough history */
 711                 window->average_tpt = IWL_INVALID_VALUE;
 712                 goto out;
 713
 714         }
 715
 716         current_tpt = window->average_tpt;
 717
 718         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 719                                              sband->band);
 720         low = high_low & 0xff;
 721         high = (high_low >> 8) & 0xff;
 722
 723         /* If user set max rate, dont allow higher than user constrain */
 724         if ((max_rate_idx != -1) && (max_rate_idx < high))
 725                 high = IWL_RATE_INVALID;
 726
 727         /* Collect Measured throughputs of adjacent rates */
 728         if (low != IWL_RATE_INVALID)
 729                 low_tpt = rs_sta->win[low].average_tpt;
 730
 731         if (high != IWL_RATE_INVALID)
 732                 high_tpt = rs_sta->win[high].average_tpt;
 733
 734         spin_unlock_irqrestore(&rs_sta->lock, flags);
 735
 736         scale_action = 0;
 737
 738         /* Low success ratio , need to drop the rate */
 739         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 740                 IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
 741                 scale_action = -1;
 742         /* No throughput measured yet for adjacent rates,
 743          * try increase */
 744         } else if ((low_tpt == IWL_INVALID_VALUE) &&
 745                    (high_tpt == IWL_INVALID_VALUE)) {
 746
 747                 if (high != IWL_RATE_INVALID && window->success_ratio >= IWL_RATE_INCREASE_TH)
 748                         scale_action = 1;
 749                 else if (low != IWL_RATE_INVALID)
 750                         scale_action = 0;
 751
 752         /* Both adjacent throughputs are measured, but neither one has
 753          * better throughput; we're using the best rate, don't change
 754          * it! */
 755         } else if ((low_tpt != IWL_INVALID_VALUE) &&
 756                  (high_tpt != IWL_INVALID_VALUE) &&
 757                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 758
 759                 IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < "
 760                                "current_tpt [%d]\n",
 761                                low_tpt, high_tpt, current_tpt);
 762                 scale_action = 0;
 763
 764         /* At least one of the rates has better throughput */
 765         } else {
 766                 if (high_tpt != IWL_INVALID_VALUE) {
 767
 768                         /* High rate has better throughput, Increase
 769                          * rate */
 770                         if (high_tpt > current_tpt &&
 771                                 window->success_ratio >= IWL_RATE_INCREASE_TH)
 772                                 scale_action = 1;
 773                         else {
 774                                 IWL_DEBUG_RATE(priv,
 775                                     "decrease rate because of high tpt\n");
 776                                 scale_action = 0;
 777                         }
 778                 } else if (low_tpt != IWL_INVALID_VALUE) {
 779                         if (low_tpt > current_tpt) {
 780                                 IWL_DEBUG_RATE(priv,
 781                                     "decrease rate because of low tpt\n");
 782                                 scale_action = -1;
 783                         } else if (window->success_ratio >= IWL_RATE_INCREASE_TH) {
 784                                 /* Lower rate has better
 785                                  * throughput,decrease rate */
 786                                 scale_action = 1;
 787                         }
 788                 }
 789         }
 790
 791         /* Sanity check; asked for decrease, but success rate or throughput
 792          * has been good at old rate.  Don't change it. */
 793         if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
 794                     ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 795                      (current_tpt > (100 * rs_sta->expected_tpt[low]))))
 796                 scale_action = 0;
 797
 798         switch (scale_action) {
 799         case -1:
 800
 801                 /* Decrese rate */
 802                 if (low != IWL_RATE_INVALID)
 803                         index = low;
 804                 break;
 805
 806         case 1:
 807                 /* Increase rate */
 808                 if (high != IWL_RATE_INVALID)
 809                         index = high;
 810
 811                 break;
 812
 813         case 0:
 814         default:
 815                 /* No change */
 816                 break;
 817         }
 818
 819         IWL_DEBUG_RATE(priv, "Selected %d (action %d) - low %d high %d\n",
 820                        index, scale_action, low, high);
 821
 822  out:
 823
 824         rs_sta->last_txrate_idx = index;
 825         if (sband->band == IEEE80211_BAND_5GHZ)
 826                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 827                                 IWL_FIRST_OFDM_RATE;
 828         else
 829                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 830
 831         IWL_DEBUG_RATE(priv, "leave: %d\n", index);
 832 }
 833
 834 #ifdef CONFIG_MAC80211_DEBUGFS
 835 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 836 {
 837         file->private_data = inode->i_private;
 838         return 0;
 839 }
 840
 841 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 842                                                   char __user *user_buf,
 843                                                   size_t count, loff_t *ppos)
 844 {
 845         char *buff;
 846         int desc = 0;
 847         int j;
 848         ssize_t ret;
 849         struct iwl3945_rs_sta *lq_sta = file->private_data;
 850
 851         buff = kmalloc(1024, GFP_KERNEL);
 852         if (!buff)
 853                 return -ENOMEM;
 854
 855         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 856                         "rate=0x%X flush time %d\n",
 857                         lq_sta->tx_packets,
 858                         lq_sta->last_txrate_idx,
 859                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 860         for (j = 0; j < IWL_RATE_COUNT_3945; j++) {
 861                 desc += sprintf(buff+desc,
 862                                 "counter=%d success=%d %%=%d\n",
 863                                 lq_sta->win[j].counter,
 864                                 lq_sta->win[j].success_counter,
 865                                 lq_sta->win[j].success_ratio);
 866         }
 867         ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 868         kfree(buff);
 869         return ret;
 870 }
 871
 872 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 873         .read = iwl3945_sta_dbgfs_stats_table_read,
 874         .open = iwl3945_open_file_generic,
 875         .llseek = default_llseek,
 876 };
 877
 878 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 879                                 struct dentry *dir)
 880 {
 881         struct iwl3945_rs_sta *lq_sta = priv_sta;
 882
 883         lq_sta->rs_sta_dbgfs_stats_table_file =
 884                 debugfs_create_file("rate_stats_table", 0600, dir,
 885                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 886
 887 }
 888
 889 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 890 {
 891         struct iwl3945_rs_sta *lq_sta = priv_sta;
 892         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 893 }
 894 #endif
 895
 896 /*
 897  * Initialization of rate scaling information is done by driver after
 898  * the station is added. Since mac80211 calls this function before a
 899  * station is added we ignore it.
 900  */
 901 static void iwl3945_rs_rate_init_stub(void *priv_r,
 902                                 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 = iwl3945_rs_tx_status,
 911         .get_rate = iwl3945_rs_get_rate,
 912         .rate_init = iwl3945_rs_rate_init_stub,
 913         .alloc = iwl3945_rs_alloc,
 914         .free = iwl3945_rs_free,
 915         .alloc_sta = iwl3945_rs_alloc_sta,
 916         .free_sta = iwl3945_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 }