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       6
 128 #define IWL_RATE_MIN_SUCCESS_TH       8
 129 #define IWL_RATE_DECREASE_TH       1920
 130 #define IWL_RATE_RETRY_TH            15
 131
 132 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 133 {
 134         u32 index = 0;
 135         u32 table_size = 0;
 136         struct iwl3945_tpt_entry *tpt_table = NULL;
 137
 138         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 139                 rssi = IWL_MIN_RSSI_VAL;
 140
 141         switch (band) {
 142         case IEEE80211_BAND_2GHZ:
 143                 tpt_table = iwl3945_tpt_table_g;
 144                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 145                 break;
 146
 147         case IEEE80211_BAND_5GHZ:
 148                 tpt_table = iwl3945_tpt_table_a;
 149                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 150                 break;
 151
 152         default:
 153                 BUG();
 154                 break;
 155         }
 156
 157         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 158                 index++;
 159
 160         index = min(index, (table_size - 1));
 161
 162         return tpt_table[index].index;
 163 }
 164
 165 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 166 {
 167         window->data = 0;
 168         window->success_counter = 0;
 169         window->success_ratio = -1;
 170         window->counter = 0;
 171         window->average_tpt = IWL_INVALID_VALUE;
 172         window->stamp = 0;
 173 }
 174
 175 /**
 176  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 177  *
 178  * Returns the number of windows that have gathered data but were
 179  * not flushed.  If there were any that were not flushed, then
 180  * reschedule the rate flushing routine.
 181  */
 182 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 183 {
 184         int unflushed = 0;
 185         int i;
 186         unsigned long flags;
 187         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 188
 189         /*
 190          * For each rate, if we have collected data on that rate
 191          * and it has been more than IWL_RATE_WIN_FLUSH
 192          * since we flushed, clear out the gathered statistics
 193          */
 194         for (i = 0; i < IWL_RATE_COUNT_3945; i++) {
 195                 if (!rs_sta->win[i].counter)
 196                         continue;
 197
 198                 spin_lock_irqsave(&rs_sta->lock, flags);
 199                 if (time_after(jiffies, rs_sta->win[i].stamp +
 200                                IWL_RATE_WIN_FLUSH)) {
 201                         IWL_DEBUG_RATE(priv, "flushing %d samples of rate "
 202                                        "index %d\n",
 203                                        rs_sta->win[i].counter, i);
 204                         iwl3945_clear_window(&rs_sta->win[i]);
 205                 } else
 206                         unflushed++;
 207                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 208         }
 209
 210         return unflushed;
 211 }
 212
 213 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 214 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 215 #define IWL_AVERAGE_PACKETS             1500
 216
 217 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 218 {
 219         struct iwl3945_rs_sta *rs_sta = (void *)data;
 220         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 221         int unflushed = 0;
 222         unsigned long flags;
 223         u32 packet_count, duration, pps;
 224
 225         IWL_DEBUG_RATE(priv, "enter\n");
 226
 227         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 228
 229         spin_lock_irqsave(&rs_sta->lock, flags);
 230
 231         /* Number of packets Rx'd since last time this timer ran */
 232         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 233
 234         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 235
 236         if (unflushed) {
 237                 duration =
 238                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 239
 240                 IWL_DEBUG_RATE(priv, "Tx'd %d packets in %dms\n",
 241                                packet_count, duration);
 242
 243                 /* Determine packets per second */
 244                 if (duration)
 245                         pps = (packet_count * 1000) / duration;
 246                 else
 247                         pps = 0;
 248
 249                 if (pps) {
 250                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
 251                         if (duration < IWL_RATE_FLUSH_MIN)
 252                                 duration = IWL_RATE_FLUSH_MIN;
 253                         else if (duration > IWL_RATE_FLUSH_MAX)
 254                                 duration = IWL_RATE_FLUSH_MAX;
 255                 } else
 256                         duration = IWL_RATE_FLUSH_MAX;
 257
 258                 rs_sta->flush_time = msecs_to_jiffies(duration);
 259
 260                 IWL_DEBUG_RATE(priv, "new flush period: %d msec ave %d\n",
 261                                duration, packet_count);
 262
 263                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 264                           rs_sta->flush_time);
 265
 266                 rs_sta->last_partial_flush = jiffies;
 267         } else {
 268                 rs_sta->flush_time = IWL_RATE_FLUSH;
 269                 rs_sta->flush_pending = 0;
 270         }
 271         /* If there weren't any unflushed entries, we don't schedule the timer
 272          * to run again */
 273
 274         rs_sta->last_flush = jiffies;
 275
 276         spin_unlock_irqrestore(&rs_sta->lock, flags);
 277
 278         IWL_DEBUG_RATE(priv, "leave\n");
 279 }
 280
 281 /**
 282  * iwl3945_collect_tx_data - Update the success/failure sliding window
 283  *
 284  * We keep a sliding window of the last 64 packets transmitted
 285  * at this rate.  window->data contains the bitmask of successful
 286  * packets.
 287  */
 288 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 289                                 struct iwl3945_rate_scale_data *window,
 290                                 int success, int retries, int index)
 291 {
 292         unsigned long flags;
 293         s32 fail_count;
 294         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 295
 296         if (!retries) {
 297                 IWL_DEBUG_RATE(priv, "leave: retries == 0 -- should be at least 1\n");
 298                 return;
 299         }
 300
 301         spin_lock_irqsave(&rs_sta->lock, flags);
 302
 303         /*
 304          * Keep track of only the latest 62 tx frame attempts in this rate's
 305          * history window; anything older isn't really relevant any more.
 306          * If we have filled up the sliding window, drop the oldest attempt;
 307          * if the oldest attempt (highest bit in bitmap) shows "success",
 308          * subtract "1" from the success counter (this is the main reason
 309          * we keep these bitmaps!).
 310          * */
 311         while (retries > 0) {
 312                 if (window->counter >= IWL_RATE_MAX_WINDOW) {
 313
 314                         /* remove earliest */
 315                         window->counter = IWL_RATE_MAX_WINDOW - 1;
 316
 317                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1))) {
 318                                 window->data &= ~(1ULL << (IWL_RATE_MAX_WINDOW - 1));
 319                                 window->success_counter--;
 320                         }
 321                 }
 322
 323                 /* Increment frames-attempted counter */
 324                 window->counter++;
 325
 326                 /* Shift bitmap by one frame (throw away oldest history),
 327                  * OR in "1", and increment "success" if this
 328                  * frame was successful. */
 329                 window->data <<= 1;
 330                 if (success > 0) {
 331                         window->success_counter++;
 332                         window->data |= 0x1;
 333                         success--;
 334                 }
 335
 336                 retries--;
 337         }
 338
 339         /* Calculate current success ratio, avoid divide-by-0! */
 340         if (window->counter > 0)
 341                 window->success_ratio = 128 * (100 * window->success_counter)
 342                                         / window->counter;
 343         else
 344                 window->success_ratio = IWL_INVALID_VALUE;
 345
 346         fail_count = window->counter - window->success_counter;
 347
 348         /* Calculate average throughput, if we have enough history. */
 349         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
 350             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
 351                 window->average_tpt = ((window->success_ratio *
 352                                 rs_sta->expected_tpt[index] + 64) / 128);
 353         else
 354                 window->average_tpt = IWL_INVALID_VALUE;
 355
 356         /* Tag this window as having been updated */
 357         window->stamp = jiffies;
 358
 359         spin_unlock_irqrestore(&rs_sta->lock, flags);
 360
 361 }
 362
 363 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
 364                          struct ieee80211_sta *sta, void *priv_sta)
 365 {
 366         struct iwl3945_rs_sta *rs_sta = priv_sta;
 367         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
 368         int i;
 369
 370         IWL_DEBUG_RATE(priv, "enter\n");
 371
 372         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 373          * the lowest or the highest rate.. Could consider using RSSI from
 374          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 375          * after assoc.. */
 376
 377         for (i = sband->n_bitrates - 1; i >= 0; i--) {
 378                 if (sta->supp_rates[sband->band] & (1 << i)) {
 379                         rs_sta->last_txrate_idx = i;
 380                         break;
 381                 }
 382         }
 383
 384         priv->sta_supp_rates = sta->supp_rates[sband->band];
 385         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 386         if (sband->band == IEEE80211_BAND_5GHZ) {
 387                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 388                 priv->sta_supp_rates = priv->sta_supp_rates <<
 389                                                 IWL_FIRST_OFDM_RATE;
 390         }
 391
 392
 393         IWL_DEBUG_RATE(priv, "leave\n");
 394 }
 395
 396 static void *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 rs_free(void *priv)
 403 {
 404         return;
 405 }
 406
 407 static void *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 = iwl_priv;
 412         int i;
 413
 414         /*
 415          * XXX: If it's using sta->drv_priv anyway, it might
 416          *      as well just put all the information there.
 417          */
 418
 419         IWL_DEBUG_RATE(priv, "enter\n");
 420
 421         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 422         if (!rs_sta) {
 423                 IWL_DEBUG_RATE(priv, "leave: ENOMEM\n");
 424                 return NULL;
 425         }
 426
 427         psta->rs_sta = rs_sta;
 428
 429         spin_lock_init(&rs_sta->lock);
 430
 431         rs_sta->priv = priv;
 432
 433         rs_sta->start_rate = IWL_RATE_INVALID;
 434
 435         /* default to just 802.11b */
 436         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 437
 438         rs_sta->last_partial_flush = jiffies;
 439         rs_sta->last_flush = jiffies;
 440         rs_sta->flush_time = IWL_RATE_FLUSH;
 441         rs_sta->last_tx_packets = 0;
 442         rs_sta->ibss_sta_added = 0;
 443
 444         init_timer(&rs_sta->rate_scale_flush);
 445         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 446         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 447
 448         for (i = 0; i < IWL_RATE_COUNT_3945; i++)
 449                 iwl3945_clear_window(&rs_sta->win[i]);
 450
 451         IWL_DEBUG_RATE(priv, "leave\n");
 452
 453         return rs_sta;
 454 }
 455
 456 static void rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
 457                         void *priv_sta)
 458 {
 459         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 460         struct iwl3945_rs_sta *rs_sta = priv_sta;
 461         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 462
 463         psta->rs_sta = NULL;
 464
 465         IWL_DEBUG_RATE(priv, "enter\n");
 466         del_timer_sync(&rs_sta->rate_scale_flush);
 467         kfree(rs_sta);
 468         IWL_DEBUG_RATE(priv, "leave\n");
 469 }
 470
 471
 472 /**
 473  * rs_tx_status - Update rate control values based on Tx results
 474  *
 475  * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
 476  * the hardware for each rate.
 477  */
 478 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 479                          struct ieee80211_sta *sta, void *priv_sta,
 480                          struct sk_buff *skb)
 481 {
 482         s8 retries = 0, current_count;
 483         int scale_rate_index, first_index, last_index;
 484         unsigned long flags;
 485         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 486         struct iwl3945_rs_sta *rs_sta = priv_sta;
 487         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 488
 489         IWL_DEBUG_RATE(priv, "enter\n");
 490
 491         retries = info->status.rates[0].count;
 492         /* Sanity Check for retries */
 493         if (retries > IWL_RATE_RETRY_TH)
 494                 retries = IWL_RATE_RETRY_TH;
 495
 496         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 497         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
 498                 IWL_DEBUG_RATE(priv, "leave: Rate out of bounds: %d\n", first_index);
 499                 return;
 500         }
 501
 502         if (!priv_sta) {
 503                 IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
 504                 return;
 505         }
 506
 507         rs_sta->tx_packets++;
 508
 509         scale_rate_index = first_index;
 510         last_index = first_index;
 511
 512         /*
 513          * Update the window for each rate.  We determine which rates
 514          * were Tx'd based on the total number of retries vs. the number
 515          * of retries configured for each rate -- currently set to the
 516          * priv value 'retry_rate' vs. rate specific
 517          *
 518          * On exit from this while loop last_index indicates the rate
 519          * at which the frame was finally transmitted (or failed if no
 520          * ACK)
 521          */
 522         while (retries > 1) {
 523                 if ((retries - 1) < priv->retry_rate) {
 524                         current_count = (retries - 1);
 525                         last_index = scale_rate_index;
 526                 } else {
 527                         current_count = priv->retry_rate;
 528                         last_index = iwl3945_rs_next_rate(priv,
 529                                                          scale_rate_index);
 530                 }
 531
 532                 /* Update this rate accounting for as many retries
 533                  * as was used for it (per current_count) */
 534                 iwl3945_collect_tx_data(rs_sta,
 535                                     &rs_sta->win[scale_rate_index],
 536                                     0, current_count, scale_rate_index);
 537                 IWL_DEBUG_RATE(priv, "Update rate %d for %d retries.\n",
 538                                scale_rate_index, current_count);
 539
 540                 retries -= current_count;
 541
 542                 scale_rate_index = last_index;
 543         }
 544
 545
 546         /* Update the last index window with success/failure based on ACK */
 547         IWL_DEBUG_RATE(priv, "Update rate %d with %s.\n",
 548                        last_index,
 549                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 550                        "success" : "failure");
 551         iwl3945_collect_tx_data(rs_sta,
 552                             &rs_sta->win[last_index],
 553                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 554
 555         /* We updated the rate scale window -- if its been more than
 556          * flush_time since the last run, schedule the flush
 557          * again */
 558         spin_lock_irqsave(&rs_sta->lock, flags);
 559
 560         if (!rs_sta->flush_pending &&
 561             time_after(jiffies, rs_sta->last_flush +
 562                        rs_sta->flush_time)) {
 563
 564                 rs_sta->last_partial_flush = jiffies;
 565                 rs_sta->flush_pending = 1;
 566                 mod_timer(&rs_sta->rate_scale_flush,
 567                           jiffies + rs_sta->flush_time);
 568         }
 569
 570         spin_unlock_irqrestore(&rs_sta->lock, flags);
 571
 572         IWL_DEBUG_RATE(priv, "leave\n");
 573
 574         return;
 575 }
 576
 577 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 578                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 579 {
 580         u8 high = IWL_RATE_INVALID;
 581         u8 low = IWL_RATE_INVALID;
 582         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 583
 584         /* 802.11A walks to the next literal adjacent rate in
 585          * the rate table */
 586         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 587                 int i;
 588                 u32 mask;
 589
 590                 /* Find the previous rate that is in the rate mask */
 591                 i = index - 1;
 592                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 593                         if (rate_mask & mask) {
 594                                 low = i;
 595                                 break;
 596                         }
 597                 }
 598
 599                 /* Find the next rate that is in the rate mask */
 600                 i = index + 1;
 601                 for (mask = (1 << i); i < IWL_RATE_COUNT_3945;
 602                      i++, mask <<= 1) {
 603                         if (rate_mask & mask) {
 604                                 high = i;
 605                                 break;
 606                         }
 607                 }
 608
 609                 return (high << 8) | low;
 610         }
 611
 612         low = index;
 613         while (low != IWL_RATE_INVALID) {
 614                 if (rs_sta->tgg)
 615                         low = iwl3945_rates[low].prev_rs_tgg;
 616                 else
 617                         low = iwl3945_rates[low].prev_rs;
 618                 if (low == IWL_RATE_INVALID)
 619                         break;
 620                 if (rate_mask & (1 << low))
 621                         break;
 622                 IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low);
 623         }
 624
 625         high = index;
 626         while (high != IWL_RATE_INVALID) {
 627                 if (rs_sta->tgg)
 628                         high = iwl3945_rates[high].next_rs_tgg;
 629                 else
 630                         high = iwl3945_rates[high].next_rs;
 631                 if (high == IWL_RATE_INVALID)
 632                         break;
 633                 if (rate_mask & (1 << high))
 634                         break;
 635                 IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high);
 636         }
 637
 638         return (high << 8) | low;
 639 }
 640
 641 /**
 642  * rs_get_rate - find the rate for the requested packet
 643  *
 644  * Returns the ieee80211_rate structure allocated by the driver.
 645  *
 646  * The rate control algorithm has no internal mapping between hw_mode's
 647  * rate ordering and the rate ordering used by the rate control algorithm.
 648  *
 649  * The rate control algorithm uses a single table of rates that goes across
 650  * the entire A/B/G spectrum vs. being limited to just one particular
 651  * hw_mode.
 652  *
 653  * As such, we can't convert the index obtained below into the hw_mode's
 654  * rate table and must reference the driver allocated rate table
 655  *
 656  */
 657 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 658                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 659 {
 660         struct ieee80211_supported_band *sband = txrc->sband;
 661         struct sk_buff *skb = txrc->skb;
 662         u8 low = IWL_RATE_INVALID;
 663         u8 high = IWL_RATE_INVALID;
 664         u16 high_low;
 665         int index;
 666         struct iwl3945_rs_sta *rs_sta = priv_sta;
 667         struct iwl3945_rate_scale_data *window = NULL;
 668         int current_tpt = IWL_INVALID_VALUE;
 669         int low_tpt = IWL_INVALID_VALUE;
 670         int high_tpt = IWL_INVALID_VALUE;
 671         u32 fail_count;
 672         s8 scale_action = 0;
 673         unsigned long flags;
 674         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 675         u16 fc;
 676         u16 rate_mask = 0;
 677         s8 max_rate_idx = -1;
 678         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
 679         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 680
 681         IWL_DEBUG_RATE(priv, "enter\n");
 682
 683         if (sta)
 684                 rate_mask = sta->supp_rates[sband->band];
 685
 686         /* Send management frames and broadcast/multicast data using lowest
 687          * rate. */
 688         fc = le16_to_cpu(hdr->frame_control);
 689         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 690             is_multicast_ether_addr(hdr->addr1) ||
 691             !sta || !priv_sta) {
 692                 IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
 693                 if (!rate_mask)
 694                         info->control.rates[0].idx =
 695                                         rate_lowest_index(sband, NULL);
 696                 else
 697                         info->control.rates[0].idx =
 698                                         rate_lowest_index(sband, sta);
 699                 return;
 700         }
 701
 702         /* get user max rate if set */
 703         max_rate_idx = txrc->max_rate_idx;
 704         if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1))
 705                 max_rate_idx += IWL_FIRST_OFDM_RATE;
 706         if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT))
 707                 max_rate_idx = -1;
 708
 709         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
 710
 711         if (sband->band == IEEE80211_BAND_5GHZ)
 712                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 713
 714         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 715             !rs_sta->ibss_sta_added) {
 716                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 717
 718                 if (sta_id == IWL_INVALID_STATION) {
 719                         IWL_DEBUG_RATE(priv, "LQ: ADD station %pm\n",
 720                                        hdr->addr1);
 721                         sta_id = iwl3945_add_station(priv,
 722                                     hdr->addr1, 0, CMD_ASYNC, NULL);
 723                 }
 724                 if (sta_id != IWL_INVALID_STATION)
 725                         rs_sta->ibss_sta_added = 1;
 726         }
 727
 728         spin_lock_irqsave(&rs_sta->lock, flags);
 729
 730         /* for recent assoc, choose best rate regarding
 731          * to rssi value
 732          */
 733         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 734                 if (rs_sta->start_rate < index &&
 735                    (rate_mask & (1 << rs_sta->start_rate)))
 736                         index = rs_sta->start_rate;
 737                 rs_sta->start_rate = IWL_RATE_INVALID;
 738         }
 739
 740         /* force user max rate if set by user */
 741         if ((max_rate_idx != -1) && (max_rate_idx < index)) {
 742                 if (rate_mask & (1 << max_rate_idx))
 743                         index = max_rate_idx;
 744         }
 745
 746         window = &(rs_sta->win[index]);
 747
 748         fail_count = window->counter - window->success_counter;
 749
 750         if (((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
 751              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 752                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 753
 754                 IWL_DEBUG_RATE(priv, "Invalid average_tpt on rate %d: "
 755                                "counter: %d, success_counter: %d, "
 756                                "expected_tpt is %sNULL\n",
 757                                index,
 758                                window->counter,
 759                                window->success_counter,
 760                                rs_sta->expected_tpt ? "not " : "");
 761
 762            /* Can't calculate this yet; not enough history */
 763                 window->average_tpt = IWL_INVALID_VALUE;
 764                 goto out;
 765
 766         }
 767
 768         current_tpt = window->average_tpt;
 769
 770         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 771                                              sband->band);
 772         low = high_low & 0xff;
 773         high = (high_low >> 8) & 0xff;
 774
 775         /* If user set max rate, dont allow higher than user constrain */
 776         if ((max_rate_idx != -1) && (max_rate_idx < high))
 777                 high = IWL_RATE_INVALID;
 778
 779         /* Collect Measured throughputs of adjacent rates */
 780         if (low != IWL_RATE_INVALID)
 781                 low_tpt = rs_sta->win[low].average_tpt;
 782
 783         if (high != IWL_RATE_INVALID)
 784                 high_tpt = rs_sta->win[high].average_tpt;
 785
 786         spin_unlock_irqrestore(&rs_sta->lock, flags);
 787
 788         scale_action = 0;
 789
 790         /* Low success ratio , need to drop the rate */
 791         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 792                 IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
 793                 scale_action = -1;
 794         /* No throughput measured yet for adjacent rates,
 795          * try increase */
 796         } else if ((low_tpt == IWL_INVALID_VALUE) &&
 797                    (high_tpt == IWL_INVALID_VALUE)) {
 798
 799                 if (high != IWL_RATE_INVALID && window->success_ratio >= IWL_RATE_INCREASE_TH)
 800                         scale_action = 1;
 801                 else if (low != IWL_RATE_INVALID)
 802                         scale_action = 0;
 803
 804         /* Both adjacent throughputs are measured, but neither one has
 805          * better throughput; we're using the best rate, don't change
 806          * it! */
 807         } else if ((low_tpt != IWL_INVALID_VALUE) &&
 808                  (high_tpt != IWL_INVALID_VALUE) &&
 809                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 810
 811                 IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < "
 812                                "current_tpt [%d]\n",
 813                                low_tpt, high_tpt, current_tpt);
 814                 scale_action = 0;
 815
 816         /* At least one of the rates has better throughput */
 817         } else {
 818                 if (high_tpt != IWL_INVALID_VALUE) {
 819
 820                         /* High rate has better throughput, Increase
 821                          * rate */
 822                         if (high_tpt > current_tpt &&
 823                                 window->success_ratio >= IWL_RATE_INCREASE_TH)
 824                                 scale_action = 1;
 825                         else {
 826                                 IWL_DEBUG_RATE(priv,
 827                                     "decrease rate because of high tpt\n");
 828                                 scale_action = 0;
 829                         }
 830                 } else if (low_tpt != IWL_INVALID_VALUE) {
 831                         if (low_tpt > current_tpt) {
 832                                 IWL_DEBUG_RATE(priv,
 833                                     "decrease rate because of low tpt\n");
 834                                 scale_action = -1;
 835                         } else if (window->success_ratio >= IWL_RATE_INCREASE_TH) {
 836                                 /* Lower rate has better
 837                                  * throughput,decrease rate */
 838                                 scale_action = 1;
 839                         }
 840                 }
 841         }
 842
 843         /* Sanity check; asked for decrease, but success rate or throughput
 844          * has been good at old rate.  Don't change it. */
 845         if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
 846                     ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 847                      (current_tpt > (100 * rs_sta->expected_tpt[low]))))
 848                 scale_action = 0;
 849
 850         switch (scale_action) {
 851         case -1:
 852
 853                 /* Decrese rate */
 854                 if (low != IWL_RATE_INVALID)
 855                         index = low;
 856                 break;
 857
 858         case 1:
 859                 /* Increase rate */
 860                 if (high != IWL_RATE_INVALID)
 861                         index = high;
 862
 863                 break;
 864
 865         case 0:
 866         default:
 867                 /* No change */
 868                 break;
 869         }
 870
 871         IWL_DEBUG_RATE(priv, "Selected %d (action %d) - low %d high %d\n",
 872                        index, scale_action, low, high);
 873
 874  out:
 875
 876         rs_sta->last_txrate_idx = index;
 877         if (sband->band == IEEE80211_BAND_5GHZ)
 878                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 879                                 IWL_FIRST_OFDM_RATE;
 880         else
 881                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 882
 883         IWL_DEBUG_RATE(priv, "leave: %d\n", index);
 884 }
 885
 886 #ifdef CONFIG_MAC80211_DEBUGFS
 887 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 888 {
 889         file->private_data = inode->i_private;
 890         return 0;
 891 }
 892
 893 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 894                                                   char __user *user_buf,
 895                                                   size_t count, loff_t *ppos)
 896 {
 897         char *buff;
 898         int desc = 0;
 899         int j;
 900         ssize_t ret;
 901         struct iwl3945_rs_sta *lq_sta = file->private_data;
 902
 903         buff = kmalloc(1024, GFP_KERNEL);
 904         if (!buff)
 905                 return -ENOMEM;
 906
 907         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 908                         "rate=0x%X flush time %d\n",
 909                         lq_sta->tx_packets,
 910                         lq_sta->last_txrate_idx,
 911                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 912         for (j = 0; j < IWL_RATE_COUNT_3945; j++) {
 913                 desc += sprintf(buff+desc,
 914                                 "counter=%d success=%d %%=%d\n",
 915                                 lq_sta->win[j].counter,
 916                                 lq_sta->win[j].success_counter,
 917                                 lq_sta->win[j].success_ratio);
 918         }
 919         ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 920         kfree(buff);
 921         return ret;
 922 }
 923
 924 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 925         .read = iwl3945_sta_dbgfs_stats_table_read,
 926         .open = iwl3945_open_file_generic,
 927 };
 928
 929 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 930                                 struct dentry *dir)
 931 {
 932         struct iwl3945_rs_sta *lq_sta = priv_sta;
 933
 934         lq_sta->rs_sta_dbgfs_stats_table_file =
 935                 debugfs_create_file("rate_stats_table", 0600, dir,
 936                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 937
 938 }
 939
 940 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 941 {
 942         struct iwl3945_rs_sta *lq_sta = priv_sta;
 943         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 944 }
 945 #endif
 946
 947 static struct rate_control_ops rs_ops = {
 948         .module = NULL,
 949         .name = RS_NAME,
 950         .tx_status = rs_tx_status,
 951         .get_rate = rs_get_rate,
 952         .rate_init = rs_rate_init,
 953         .alloc = rs_alloc,
 954         .free = rs_free,
 955         .alloc_sta = rs_alloc_sta,
 956         .free_sta = rs_free_sta,
 957 #ifdef CONFIG_MAC80211_DEBUGFS
 958         .add_sta_debugfs = iwl3945_add_debugfs,
 959         .remove_sta_debugfs = iwl3945_remove_debugfs,
 960 #endif
 961
 962 };
 963
 964 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 965 {
 966         struct iwl_priv *priv = hw->priv;
 967         s32 rssi = 0;
 968         unsigned long flags;
 969         struct iwl3945_rs_sta *rs_sta;
 970         struct ieee80211_sta *sta;
 971         struct iwl3945_sta_priv *psta;
 972
 973         IWL_DEBUG_RATE(priv, "enter\n");
 974
 975         rcu_read_lock();
 976
 977         sta = ieee80211_find_sta(hw, priv->stations_39[sta_id].sta.sta.addr);
 978         if (!sta) {
 979                 rcu_read_unlock();
 980                 return;
 981         }
 982
 983         psta = (void *) sta->drv_priv;
 984         rs_sta = psta->rs_sta;
 985
 986         spin_lock_irqsave(&rs_sta->lock, flags);
 987
 988         rs_sta->tgg = 0;
 989         switch (priv->band) {
 990         case IEEE80211_BAND_2GHZ:
 991                 /* TODO: this always does G, not a regression */
 992                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 993                         rs_sta->tgg = 1;
 994                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 995                 } else
 996                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 997                 break;
 998
 999         case IEEE80211_BAND_5GHZ:
1000                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
1001                 break;
1002         case IEEE80211_NUM_BANDS:
1003                 BUG();
1004                 break;
1005         }
1006
1007         spin_unlock_irqrestore(&rs_sta->lock, flags);
1008
1009         rssi = priv->last_rx_rssi;
1010         if (rssi == 0)
1011                 rssi = IWL_MIN_RSSI_VAL;
1012
1013         IWL_DEBUG_RATE(priv, "Network RSSI: %d\n", rssi);
1014
1015         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
1016
1017         IWL_DEBUG_RATE(priv, "leave: rssi %d assign rate index: "
1018                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
1019                        iwl3945_rates[rs_sta->start_rate].plcp);
1020         rcu_read_unlock();
1021 }
1022
1023 int iwl3945_rate_control_register(void)
1024 {
1025         return ieee80211_rate_control_register(&rs_ops);
1026 }
1027
1028 void iwl3945_rate_control_unregister(void)
1029 {
1030         ieee80211_rate_control_unregister(&rs_ops);
1031 }
1032
1033