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

   1 /******************************************************************************
   2  *
   3  * Copyright(c) 2005 - 2008 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  * James P. Ketrenos <ipw2100-admin@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-3945.h"
  40
  41 #define RS_NAME "iwl-3945-rs"
  42
  43 struct iwl3945_rate_scale_data {
  44         u64 data;
  45         s32 success_counter;
  46         s32 success_ratio;
  47         s32 counter;
  48         s32 average_tpt;
  49         unsigned long stamp;
  50 };
  51
  52 struct iwl3945_rs_sta {
  53         spinlock_t lock;
  54         s32 *expected_tpt;
  55         unsigned long last_partial_flush;
  56         unsigned long last_flush;
  57         u32 flush_time;
  58         u32 last_tx_packets;
  59         u32 tx_packets;
  60         u8 tgg;
  61         u8 flush_pending;
  62         u8 start_rate;
  63         u8 ibss_sta_added;
  64         struct timer_list rate_scale_flush;
  65         struct iwl3945_rate_scale_data win[IWL_RATE_COUNT];
  66 #ifdef CONFIG_MAC80211_DEBUGFS
  67         struct dentry *rs_sta_dbgfs_stats_table_file;
  68 #endif
  69
  70         /* used to be in sta_info */
  71         int last_txrate_idx;
  72 };
  73
  74 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT] = {
  75         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  76 };
  77
  78 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  79         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  80 };
  81
  82 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT] = {
  83         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  84 };
  85
  86 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT] = {
  87         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  88 };
  89
  90 struct iwl3945_tpt_entry {
  91         s8 min_rssi;
  92         u8 index;
  93 };
  94
  95 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  96         {-60, IWL_RATE_54M_INDEX},
  97         {-64, IWL_RATE_48M_INDEX},
  98         {-72, IWL_RATE_36M_INDEX},
  99         {-80, IWL_RATE_24M_INDEX},
 100         {-84, IWL_RATE_18M_INDEX},
 101         {-85, IWL_RATE_12M_INDEX},
 102         {-87, IWL_RATE_9M_INDEX},
 103         {-89, IWL_RATE_6M_INDEX}
 104 };
 105
 106 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 107         {-60, IWL_RATE_54M_INDEX},
 108         {-64, IWL_RATE_48M_INDEX},
 109         {-68, IWL_RATE_36M_INDEX},
 110         {-80, IWL_RATE_24M_INDEX},
 111         {-84, IWL_RATE_18M_INDEX},
 112         {-85, IWL_RATE_12M_INDEX},
 113         {-86, IWL_RATE_11M_INDEX},
 114         {-88, IWL_RATE_5M_INDEX},
 115         {-90, IWL_RATE_2M_INDEX},
 116         {-92, IWL_RATE_1M_INDEX}
 117 };
 118
 119 #define IWL_RATE_MAX_WINDOW          62
 120 #define IWL_RATE_FLUSH           (3*HZ)
 121 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 122 #define IWL_RATE_HIGH_TH          11520
 123 #define IWL_SUCCESS_UP_TH          8960
 124 #define IWL_SUCCESS_DOWN_TH       10880
 125 #define IWL_RATE_MIN_FAILURE_TH       8
 126 #define IWL_RATE_MIN_SUCCESS_TH       8
 127 #define IWL_RATE_DECREASE_TH       1920
 128
 129 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 130 {
 131         u32 index = 0;
 132         u32 table_size = 0;
 133         struct iwl3945_tpt_entry *tpt_table = NULL;
 134
 135         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 136                 rssi = IWL_MIN_RSSI_VAL;
 137
 138         switch (band) {
 139         case IEEE80211_BAND_2GHZ:
 140                 tpt_table = iwl3945_tpt_table_g;
 141                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 142                 break;
 143
 144         case IEEE80211_BAND_5GHZ:
 145                 tpt_table = iwl3945_tpt_table_a;
 146                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 147                 break;
 148
 149         default:
 150                 BUG();
 151                 break;
 152         }
 153
 154         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 155                 index++;
 156
 157         index = min(index, (table_size - 1));
 158
 159         return tpt_table[index].index;
 160 }
 161
 162 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 163 {
 164         window->data = 0;
 165         window->success_counter = 0;
 166         window->success_ratio = -1;
 167         window->counter = 0;
 168         window->average_tpt = IWL_INV_TPT;
 169         window->stamp = 0;
 170 }
 171
 172 /**
 173  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 174  *
 175  * Returns the number of windows that have gathered data but were
 176  * not flushed.  If there were any that were not flushed, then
 177  * reschedule the rate flushing routine.
 178  */
 179 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 180 {
 181         int unflushed = 0;
 182         int i;
 183         unsigned long flags;
 184
 185         /*
 186          * For each rate, if we have collected data on that rate
 187          * and it has been more than IWL_RATE_WIN_FLUSH
 188          * since we flushed, clear out the gathered statistics
 189          */
 190         for (i = 0; i < IWL_RATE_COUNT; i++) {
 191                 if (!rs_sta->win[i].counter)
 192                         continue;
 193
 194                 spin_lock_irqsave(&rs_sta->lock, flags);
 195                 if (time_after(jiffies, rs_sta->win[i].stamp +
 196                                IWL_RATE_WIN_FLUSH)) {
 197                         IWL_DEBUG_RATE("flushing %d samples of rate "
 198                                        "index %d\n",
 199                                        rs_sta->win[i].counter, i);
 200                         iwl3945_clear_window(&rs_sta->win[i]);
 201                 } else
 202                         unflushed++;
 203                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 204         }
 205
 206         return unflushed;
 207 }
 208
 209 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 210 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 211 #define IWL_AVERAGE_PACKETS             1500
 212
 213 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 214 {
 215         struct iwl3945_rs_sta *rs_sta = (void *)data;
 216         int unflushed = 0;
 217         unsigned long flags;
 218         u32 packet_count, duration, pps;
 219
 220         IWL_DEBUG_RATE("enter\n");
 221
 222         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 223
 224         spin_lock_irqsave(&rs_sta->lock, flags);
 225
 226         /* Number of packets Rx'd since last time this timer ran */
 227         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 228
 229         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 230
 231         if (unflushed) {
 232                 duration =
 233                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 234
 235                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 236                                packet_count, duration);
 237
 238                 /* Determine packets per second */
 239                 if (duration)
 240                         pps = (packet_count * 1000) / duration;
 241                 else
 242                         pps = 0;
 243
 244                 if (pps) {
 245                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
 246                         if (duration < IWL_RATE_FLUSH_MIN)
 247                                 duration = IWL_RATE_FLUSH_MIN;
 248                         else if (duration > IWL_RATE_FLUSH_MAX)
 249                                 duration = IWL_RATE_FLUSH_MAX;
 250                 } else
 251                         duration = IWL_RATE_FLUSH_MAX;
 252
 253                 rs_sta->flush_time = msecs_to_jiffies(duration);
 254
 255                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 256                                duration, packet_count);
 257
 258                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 259                           rs_sta->flush_time);
 260
 261                 rs_sta->last_partial_flush = jiffies;
 262         } else {
 263                 rs_sta->flush_time = IWL_RATE_FLUSH;
 264                 rs_sta->flush_pending = 0;
 265         }
 266         /* If there weren't any unflushed entries, we don't schedule the timer
 267          * to run again */
 268
 269         rs_sta->last_flush = jiffies;
 270
 271         spin_unlock_irqrestore(&rs_sta->lock, flags);
 272
 273         IWL_DEBUG_RATE("leave\n");
 274 }
 275
 276 /**
 277  * iwl3945_collect_tx_data - Update the success/failure sliding window
 278  *
 279  * We keep a sliding window of the last 64 packets transmitted
 280  * at this rate.  window->data contains the bitmask of successful
 281  * packets.
 282  */
 283 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 284                                 struct iwl3945_rate_scale_data *window,
 285                                 int success, int retries, int index)
 286 {
 287         unsigned long flags;
 288         s32 fail_count;
 289
 290         if (!retries) {
 291                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 292                 return;
 293         }
 294
 295         spin_lock_irqsave(&rs_sta->lock, flags);
 296         while (retries--) {
 297
 298                 /* If we have filled up the window then subtract one from the
 299                  * success counter if the high-bit is counting toward
 300                  * success */
 301                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 302                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 303                                 window->success_counter--;
 304                 } else
 305                         window->counter++;
 306
 307                 /* Slide the window to the left one bit */
 308                 window->data = (window->data << 1);
 309
 310                 /* If this packet was a success then set the low bit high */
 311                 if (success) {
 312                         window->success_counter++;
 313                         window->data |= 1;
 314                 }
 315
 316                 /* window->counter can't be 0 -- it is either >0 or
 317                  * IWL_RATE_MAX_WINDOW */
 318                 window->success_ratio = 12800 * window->success_counter /
 319                     window->counter;
 320
 321                 /* Tag this window as having been updated */
 322                 window->stamp = jiffies;
 323
 324         }
 325
 326         fail_count = window->counter - window->success_counter;
 327         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
 328             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
 329                 window->average_tpt = ((window->success_ratio *
 330                                 rs_sta->expected_tpt[index] + 64) / 128);
 331         else
 332                 window->average_tpt = IWL_INV_TPT;
 333
 334         spin_unlock_irqrestore(&rs_sta->lock, flags);
 335
 336 }
 337
 338 static void rs_rate_init(void *priv, struct ieee80211_supported_band *sband,
 339                          struct ieee80211_sta *sta, void *priv_sta)
 340 {
 341         struct iwl3945_rs_sta *rs_sta = priv_sta;
 342         int i;
 343
 344         IWL_DEBUG_RATE("enter\n");
 345
 346         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 347          * the lowest or the highest rate.. Could consider using RSSI from
 348          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 349          * after assoc.. */
 350
 351         for (i = IWL_RATE_COUNT - 1; i >= 0; i--) {
 352                 if (sta->supp_rates[sband->band] & (1 << i)) {
 353                         rs_sta->last_txrate_idx = i;
 354                         break;
 355                 }
 356         }
 357
 358         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 359         if (sband->band == IEEE80211_BAND_5GHZ)
 360                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 361
 362         IWL_DEBUG_RATE("leave\n");
 363 }
 364
 365 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 366 {
 367         return hw->priv;
 368 }
 369
 370 /* rate scale requires free function to be implemented */
 371 static void rs_free(void *priv)
 372 {
 373         return;
 374 }
 375
 376 static void *rs_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 377 {
 378         struct iwl3945_rs_sta *rs_sta;
 379         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 380         int i;
 381
 382         /*
 383          * XXX: If it's using sta->drv_priv anyway, it might
 384          *      as well just put all the information there.
 385          */
 386
 387         IWL_DEBUG_RATE("enter\n");
 388
 389         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 390         if (!rs_sta) {
 391                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 392                 return NULL;
 393         }
 394
 395         psta->rs_sta = rs_sta;
 396
 397         spin_lock_init(&rs_sta->lock);
 398
 399         rs_sta->start_rate = IWL_RATE_INVALID;
 400
 401         /* default to just 802.11b */
 402         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 403
 404         rs_sta->last_partial_flush = jiffies;
 405         rs_sta->last_flush = jiffies;
 406         rs_sta->flush_time = IWL_RATE_FLUSH;
 407         rs_sta->last_tx_packets = 0;
 408         rs_sta->ibss_sta_added = 0;
 409
 410         init_timer(&rs_sta->rate_scale_flush);
 411         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 412         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 413
 414         for (i = 0; i < IWL_RATE_COUNT; i++)
 415                 iwl3945_clear_window(&rs_sta->win[i]);
 416
 417         IWL_DEBUG_RATE("leave\n");
 418
 419         return rs_sta;
 420 }
 421
 422 static void rs_free_sta(void *priv, struct ieee80211_sta *sta,
 423                         void *priv_sta)
 424 {
 425         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 426         struct iwl3945_rs_sta *rs_sta = priv_sta;
 427
 428         psta->rs_sta = NULL;
 429
 430         IWL_DEBUG_RATE("enter\n");
 431         del_timer_sync(&rs_sta->rate_scale_flush);
 432         kfree(rs_sta);
 433         IWL_DEBUG_RATE("leave\n");
 434 }
 435
 436
 437 /**
 438  * rs_tx_status - Update rate control values based on Tx results
 439  *
 440  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 441  * the hardware for each rate.
 442  */
 443 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 444                          struct ieee80211_sta *sta, void *priv_sta,
 445                          struct sk_buff *skb)
 446 {
 447         s8 retries = 0, current_count;
 448         int scale_rate_index, first_index, last_index;
 449         unsigned long flags;
 450         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 451         struct iwl3945_rs_sta *rs_sta = priv_sta;
 452         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 453
 454         IWL_DEBUG_RATE("enter\n");
 455
 456         retries = info->status.rates[0].count;
 457
 458         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 459         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 460                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 461                 return;
 462         }
 463
 464         if (!priv_sta) {
 465                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 466                 return;
 467         }
 468
 469         rs_sta->tx_packets++;
 470
 471         scale_rate_index = first_index;
 472         last_index = first_index;
 473
 474         /*
 475          * Update the window for each rate.  We determine which rates
 476          * were Tx'd based on the total number of retries vs. the number
 477          * of retries configured for each rate -- currently set to the
 478          * priv value 'retry_rate' vs. rate specific
 479          *
 480          * On exit from this while loop last_index indicates the rate
 481          * at which the frame was finally transmitted (or failed if no
 482          * ACK)
 483          */
 484         while (retries > 1) {
 485                 if ((retries - 1) < priv->retry_rate) {
 486                         current_count = (retries - 1);
 487                         last_index = scale_rate_index;
 488                 } else {
 489                         current_count = priv->retry_rate;
 490                         last_index = iwl3945_rs_next_rate(priv,
 491                                                          scale_rate_index);
 492                 }
 493
 494                 /* Update this rate accounting for as many retries
 495                  * as was used for it (per current_count) */
 496                 iwl3945_collect_tx_data(rs_sta,
 497                                     &rs_sta->win[scale_rate_index],
 498                                     0, current_count, scale_rate_index);
 499                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 500                                scale_rate_index, current_count);
 501
 502                 retries -= current_count;
 503
 504                 scale_rate_index = last_index;
 505         }
 506
 507
 508         /* Update the last index window with success/failure based on ACK */
 509         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 510                        last_index,
 511                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 512                        "success" : "failure");
 513         iwl3945_collect_tx_data(rs_sta,
 514                             &rs_sta->win[last_index],
 515                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 516
 517         /* We updated the rate scale window -- if its been more than
 518          * flush_time since the last run, schedule the flush
 519          * again */
 520         spin_lock_irqsave(&rs_sta->lock, flags);
 521
 522         if (!rs_sta->flush_pending &&
 523             time_after(jiffies, rs_sta->last_flush +
 524                        rs_sta->flush_time)) {
 525
 526                 rs_sta->last_partial_flush = jiffies;
 527                 rs_sta->flush_pending = 1;
 528                 mod_timer(&rs_sta->rate_scale_flush,
 529                           jiffies + rs_sta->flush_time);
 530         }
 531
 532         spin_unlock_irqrestore(&rs_sta->lock, flags);
 533
 534         IWL_DEBUG_RATE("leave\n");
 535
 536         return;
 537 }
 538
 539 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 540                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 541 {
 542         u8 high = IWL_RATE_INVALID;
 543         u8 low = IWL_RATE_INVALID;
 544
 545         /* 802.11A walks to the next literal adjacent rate in
 546          * the rate table */
 547         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 548                 int i;
 549                 u32 mask;
 550
 551                 /* Find the previous rate that is in the rate mask */
 552                 i = index - 1;
 553                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 554                         if (rate_mask & mask) {
 555                                 low = i;
 556                                 break;
 557                         }
 558                 }
 559
 560                 /* Find the next rate that is in the rate mask */
 561                 i = index + 1;
 562                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 563                         if (rate_mask & mask) {
 564                                 high = i;
 565                                 break;
 566                         }
 567                 }
 568
 569                 return (high << 8) | low;
 570         }
 571
 572         low = index;
 573         while (low != IWL_RATE_INVALID) {
 574                 if (rs_sta->tgg)
 575                         low = iwl3945_rates[low].prev_rs_tgg;
 576                 else
 577                         low = iwl3945_rates[low].prev_rs;
 578                 if (low == IWL_RATE_INVALID)
 579                         break;
 580                 if (rate_mask & (1 << low))
 581                         break;
 582                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 583         }
 584
 585         high = index;
 586         while (high != IWL_RATE_INVALID) {
 587                 if (rs_sta->tgg)
 588                         high = iwl3945_rates[high].next_rs_tgg;
 589                 else
 590                         high = iwl3945_rates[high].next_rs;
 591                 if (high == IWL_RATE_INVALID)
 592                         break;
 593                 if (rate_mask & (1 << high))
 594                         break;
 595                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 596         }
 597
 598         return (high << 8) | low;
 599 }
 600
 601 /**
 602  * rs_get_rate - find the rate for the requested packet
 603  *
 604  * Returns the ieee80211_rate structure allocated by the driver.
 605  *
 606  * The rate control algorithm has no internal mapping between hw_mode's
 607  * rate ordering and the rate ordering used by the rate control algorithm.
 608  *
 609  * The rate control algorithm uses a single table of rates that goes across
 610  * the entire A/B/G spectrum vs. being limited to just one particular
 611  * hw_mode.
 612  *
 613  * As such, we can't convert the index obtained below into the hw_mode's
 614  * rate table and must reference the driver allocated rate table
 615  *
 616  */
 617 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 618                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 619 {
 620         struct ieee80211_supported_band *sband = txrc->sband;
 621         struct sk_buff *skb = txrc->skb;
 622         u8 low = IWL_RATE_INVALID;
 623         u8 high = IWL_RATE_INVALID;
 624         u16 high_low;
 625         int index;
 626         struct iwl3945_rs_sta *rs_sta = priv_sta;
 627         struct iwl3945_rate_scale_data *window = NULL;
 628         int current_tpt = IWL_INV_TPT;
 629         int low_tpt = IWL_INV_TPT;
 630         int high_tpt = IWL_INV_TPT;
 631         u32 fail_count;
 632         s8 scale_action = 0;
 633         unsigned long flags;
 634         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 635         u16 fc, rate_mask;
 636         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 637         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 638
 639         IWL_DEBUG_RATE("enter\n");
 640
 641         /* Send management frames and broadcast/multicast data using lowest
 642          * rate. */
 643         fc = le16_to_cpu(hdr->frame_control);
 644         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 645             is_multicast_ether_addr(hdr->addr1) ||
 646             !sta || !priv_sta) {
 647                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 648                 info->control.rates[0].idx = rate_lowest_index(sband, sta);
 649                 return;
 650         }
 651
 652         rate_mask = sta->supp_rates[sband->band];
 653         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 654
 655         if (sband->band == IEEE80211_BAND_5GHZ)
 656                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 657
 658         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 659             !rs_sta->ibss_sta_added) {
 660                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 661
 662                 if (sta_id == IWL_INVALID_STATION) {
 663                         IWL_DEBUG_RATE("LQ: ADD station %pm\n",
 664                                        hdr->addr1);
 665                         sta_id = iwl3945_add_station(priv,
 666                                     hdr->addr1, 0, CMD_ASYNC);
 667                 }
 668                 if (sta_id != IWL_INVALID_STATION)
 669                         rs_sta->ibss_sta_added = 1;
 670         }
 671
 672         spin_lock_irqsave(&rs_sta->lock, flags);
 673
 674         /* for recent assoc, choose best rate regarding
 675          * to rssi value
 676          */
 677         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 678                 if (rs_sta->start_rate < index &&
 679                    (rate_mask & (1 << rs_sta->start_rate)))
 680                         index = rs_sta->start_rate;
 681                 rs_sta->start_rate = IWL_RATE_INVALID;
 682         }
 683
 684         window = &(rs_sta->win[index]);
 685
 686         fail_count = window->counter - window->success_counter;
 687
 688         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 689              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 690                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 691
 692                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 693                                "counter: %d, success_counter: %d, "
 694                                "expected_tpt is %sNULL\n",
 695                                index,
 696                                window->counter,
 697                                window->success_counter,
 698                                rs_sta->expected_tpt ? "not " : "");
 699                 goto out;
 700
 701         }
 702
 703         current_tpt = window->average_tpt;
 704
 705         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 706                                              sband->band);
 707         low = high_low & 0xff;
 708         high = (high_low >> 8) & 0xff;
 709
 710         if (low != IWL_RATE_INVALID)
 711                 low_tpt = rs_sta->win[low].average_tpt;
 712
 713         if (high != IWL_RATE_INVALID)
 714                 high_tpt = rs_sta->win[high].average_tpt;
 715
 716         spin_unlock_irqrestore(&rs_sta->lock, flags);
 717
 718         scale_action = 1;
 719
 720         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 721                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 722                 scale_action = -1;
 723         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 724                 scale_action = 1;
 725         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 726                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 727                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 728                                "current_tpt [%d]\n",
 729                                low_tpt, high_tpt, current_tpt);
 730                 scale_action = 0;
 731         } else {
 732                 if (high_tpt != IWL_INV_TPT) {
 733                         if (high_tpt > current_tpt)
 734                                 scale_action = 1;
 735                         else {
 736                                 IWL_DEBUG_RATE
 737                                     ("decrease rate because of high tpt\n");
 738                                 scale_action = -1;
 739                         }
 740                 } else if (low_tpt != IWL_INV_TPT) {
 741                         if (low_tpt > current_tpt) {
 742                                 IWL_DEBUG_RATE
 743                                     ("decrease rate because of low tpt\n");
 744                                 scale_action = -1;
 745                         } else
 746                                 scale_action = 1;
 747                 }
 748         }
 749
 750         if (scale_action == -1) {
 751                 if (window->success_ratio > IWL_SUCCESS_DOWN_TH)
 752                         scale_action = 0;
 753         } else if (scale_action == 1) {
 754                 if (window->success_ratio < IWL_SUCCESS_UP_TH) {
 755                         IWL_DEBUG_RATE("No action -- success_ratio [%d] < "
 756                                "SUCCESS UP\n", window->success_ratio);
 757                         scale_action = 0;
 758                 }
 759         }
 760
 761         switch (scale_action) {
 762         case -1:
 763                 if (low != IWL_RATE_INVALID)
 764                         index = low;
 765                 break;
 766
 767         case 1:
 768                 if (high != IWL_RATE_INVALID)
 769                         index = high;
 770
 771                 break;
 772
 773         case 0:
 774         default:
 775                 break;
 776         }
 777
 778         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 779                        index, scale_action, low, high);
 780
 781  out:
 782
 783         rs_sta->last_txrate_idx = index;
 784         if (sband->band == IEEE80211_BAND_5GHZ)
 785                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 786                                 IWL_FIRST_OFDM_RATE;
 787         else
 788                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 789
 790         IWL_DEBUG_RATE("leave: %d\n", index);
 791 }
 792
 793 #ifdef CONFIG_MAC80211_DEBUGFS
 794 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 795 {
 796         file->private_data = inode->i_private;
 797         return 0;
 798 }
 799
 800 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 801                                                   char __user *user_buf,
 802                                                   size_t count, loff_t *ppos)
 803 {
 804         char buff[1024];
 805         int desc = 0;
 806         int j;
 807         struct iwl3945_rs_sta *lq_sta = file->private_data;
 808
 809         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 810                         "rate=0x%X flush time %d\n",
 811                         lq_sta->tx_packets,
 812                         lq_sta->last_txrate_idx,
 813                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 814         for (j = 0; j < IWL_RATE_COUNT; j++) {
 815                 desc += sprintf(buff+desc,
 816                                 "counter=%d success=%d %%=%d\n",
 817                                 lq_sta->win[j].counter,
 818                                 lq_sta->win[j].success_counter,
 819                                 lq_sta->win[j].success_ratio);
 820         }
 821         return simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 822 }
 823
 824 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 825         .read = iwl3945_sta_dbgfs_stats_table_read,
 826         .open = iwl3945_open_file_generic,
 827 };
 828
 829 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 830                                 struct dentry *dir)
 831 {
 832         struct iwl3945_rs_sta *lq_sta = priv_sta;
 833
 834         lq_sta->rs_sta_dbgfs_stats_table_file =
 835                 debugfs_create_file("rate_stats_table", 0600, dir,
 836                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 837
 838 }
 839
 840 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 841 {
 842         struct iwl3945_rs_sta *lq_sta = priv_sta;
 843         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 844 }
 845 #endif
 846
 847 static struct rate_control_ops rs_ops = {
 848         .module = NULL,
 849         .name = RS_NAME,
 850         .tx_status = rs_tx_status,
 851         .get_rate = rs_get_rate,
 852         .rate_init = rs_rate_init,
 853         .alloc = rs_alloc,
 854         .free = rs_free,
 855         .alloc_sta = rs_alloc_sta,
 856         .free_sta = rs_free_sta,
 857 #ifdef CONFIG_MAC80211_DEBUGFS
 858         .add_sta_debugfs = iwl3945_add_debugfs,
 859         .remove_sta_debugfs = iwl3945_remove_debugfs,
 860 #endif
 861
 862 };
 863
 864 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 865 {
 866         struct iwl3945_priv *priv = hw->priv;
 867         s32 rssi = 0;
 868         unsigned long flags;
 869         struct iwl3945_rs_sta *rs_sta;
 870         struct ieee80211_sta *sta;
 871         struct iwl3945_sta_priv *psta;
 872
 873         IWL_DEBUG_RATE("enter\n");
 874
 875         rcu_read_lock();
 876
 877         sta = ieee80211_find_sta(hw, priv->stations[sta_id].sta.sta.addr);
 878         if (!sta) {
 879                 rcu_read_unlock();
 880                 return;
 881         }
 882
 883         psta = (void *) sta->drv_priv;
 884         rs_sta = psta->rs_sta;
 885
 886         spin_lock_irqsave(&rs_sta->lock, flags);
 887
 888         rs_sta->tgg = 0;
 889         switch (priv->band) {
 890         case IEEE80211_BAND_2GHZ:
 891                 /* TODO: this always does G, not a regression */
 892                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 893                         rs_sta->tgg = 1;
 894                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 895                 } else
 896                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 897                 break;
 898
 899         case IEEE80211_BAND_5GHZ:
 900                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 901                 break;
 902         case IEEE80211_NUM_BANDS:
 903                 BUG();
 904                 break;
 905         }
 906
 907         spin_unlock_irqrestore(&rs_sta->lock, flags);
 908
 909         rssi = priv->last_rx_rssi;
 910         if (rssi == 0)
 911                 rssi = IWL_MIN_RSSI_VAL;
 912
 913         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 914
 915         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 916
 917         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 918                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 919                        iwl3945_rates[rs_sta->start_rate].plcp);
 920         rcu_read_unlock();
 921 }
 922
 923 int iwl3945_rate_control_register(void)
 924 {
 925         return ieee80211_rate_control_register(&rs_ops);
 926 }
 927
 928 void iwl3945_rate_control_unregister(void)
 929 {
 930         ieee80211_rate_control_unregister(&rs_ops);
 931 }
 932
 933