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  *  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         s32 *expected_tpt;
  56         unsigned long last_partial_flush;
  57         unsigned long last_flush;
  58         u32 flush_time;
  59         u32 last_tx_packets;
  60         u32 tx_packets;
  61         u8 tgg;
  62         u8 flush_pending;
  63         u8 start_rate;
  64         u8 ibss_sta_added;
  65         struct timer_list rate_scale_flush;
  66         struct iwl3945_rate_scale_data win[IWL_RATE_COUNT];
  67 #ifdef CONFIG_MAC80211_DEBUGFS
  68         struct dentry *rs_sta_dbgfs_stats_table_file;
  69 #endif
  70
  71         /* used to be in sta_info */
  72         int last_txrate_idx;
  73 };
  74
  75 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT] = {
  76         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  77 };
  78
  79 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  80         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  81 };
  82
  83 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT] = {
  84         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  85 };
  86
  87 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT] = {
  88         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  89 };
  90
  91 struct iwl3945_tpt_entry {
  92         s8 min_rssi;
  93         u8 index;
  94 };
  95
  96 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  97         {-60, IWL_RATE_54M_INDEX},
  98         {-64, IWL_RATE_48M_INDEX},
  99         {-72, IWL_RATE_36M_INDEX},
 100         {-80, IWL_RATE_24M_INDEX},
 101         {-84, IWL_RATE_18M_INDEX},
 102         {-85, IWL_RATE_12M_INDEX},
 103         {-87, IWL_RATE_9M_INDEX},
 104         {-89, IWL_RATE_6M_INDEX}
 105 };
 106
 107 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 108         {-60, IWL_RATE_54M_INDEX},
 109         {-64, IWL_RATE_48M_INDEX},
 110         {-68, IWL_RATE_36M_INDEX},
 111         {-80, IWL_RATE_24M_INDEX},
 112         {-84, IWL_RATE_18M_INDEX},
 113         {-85, IWL_RATE_12M_INDEX},
 114         {-86, IWL_RATE_11M_INDEX},
 115         {-88, IWL_RATE_5M_INDEX},
 116         {-90, IWL_RATE_2M_INDEX},
 117         {-92, IWL_RATE_1M_INDEX}
 118 };
 119
 120 #define IWL_RATE_MAX_WINDOW          62
 121 #define IWL_RATE_FLUSH           (3*HZ)
 122 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 123 #define IWL_RATE_HIGH_TH          11520
 124 #define IWL_SUCCESS_UP_TH          8960
 125 #define IWL_SUCCESS_DOWN_TH       10880
 126 #define IWL_RATE_MIN_FAILURE_TH       8
 127 #define IWL_RATE_MIN_SUCCESS_TH       8
 128 #define IWL_RATE_DECREASE_TH       1920
 129
 130 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 131 {
 132         u32 index = 0;
 133         u32 table_size = 0;
 134         struct iwl3945_tpt_entry *tpt_table = NULL;
 135
 136         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 137                 rssi = IWL_MIN_RSSI_VAL;
 138
 139         switch (band) {
 140         case IEEE80211_BAND_2GHZ:
 141                 tpt_table = iwl3945_tpt_table_g;
 142                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 143                 break;
 144
 145         case IEEE80211_BAND_5GHZ:
 146                 tpt_table = iwl3945_tpt_table_a;
 147                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 148                 break;
 149
 150         default:
 151                 BUG();
 152                 break;
 153         }
 154
 155         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 156                 index++;
 157
 158         index = min(index, (table_size - 1));
 159
 160         return tpt_table[index].index;
 161 }
 162
 163 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 164 {
 165         window->data = 0;
 166         window->success_counter = 0;
 167         window->success_ratio = -1;
 168         window->counter = 0;
 169         window->average_tpt = IWL_INV_TPT;
 170         window->stamp = 0;
 171 }
 172
 173 /**
 174  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 175  *
 176  * Returns the number of windows that have gathered data but were
 177  * not flushed.  If there were any that were not flushed, then
 178  * reschedule the rate flushing routine.
 179  */
 180 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 181 {
 182         int unflushed = 0;
 183         int i;
 184         unsigned long flags;
 185
 186         /*
 187          * For each rate, if we have collected data on that rate
 188          * and it has been more than IWL_RATE_WIN_FLUSH
 189          * since we flushed, clear out the gathered statistics
 190          */
 191         for (i = 0; i < IWL_RATE_COUNT; i++) {
 192                 if (!rs_sta->win[i].counter)
 193                         continue;
 194
 195                 spin_lock_irqsave(&rs_sta->lock, flags);
 196                 if (time_after(jiffies, rs_sta->win[i].stamp +
 197                                IWL_RATE_WIN_FLUSH)) {
 198                         IWL_DEBUG_RATE("flushing %d samples of rate "
 199                                        "index %d\n",
 200                                        rs_sta->win[i].counter, i);
 201                         iwl3945_clear_window(&rs_sta->win[i]);
 202                 } else
 203                         unflushed++;
 204                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 205         }
 206
 207         return unflushed;
 208 }
 209
 210 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 211 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 212 #define IWL_AVERAGE_PACKETS             1500
 213
 214 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 215 {
 216         struct iwl3945_rs_sta *rs_sta = (void *)data;
 217         int unflushed = 0;
 218         unsigned long flags;
 219         u32 packet_count, duration, pps;
 220
 221         IWL_DEBUG_RATE("enter\n");
 222
 223         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 224
 225         spin_lock_irqsave(&rs_sta->lock, flags);
 226
 227         /* Number of packets Rx'd since last time this timer ran */
 228         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 229
 230         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 231
 232         if (unflushed) {
 233                 duration =
 234                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 235
 236                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 237                                packet_count, duration);
 238
 239                 /* Determine packets per second */
 240                 if (duration)
 241                         pps = (packet_count * 1000) / duration;
 242                 else
 243                         pps = 0;
 244
 245                 if (pps) {
 246                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
 247                         if (duration < IWL_RATE_FLUSH_MIN)
 248                                 duration = IWL_RATE_FLUSH_MIN;
 249                         else if (duration > IWL_RATE_FLUSH_MAX)
 250                                 duration = IWL_RATE_FLUSH_MAX;
 251                 } else
 252                         duration = IWL_RATE_FLUSH_MAX;
 253
 254                 rs_sta->flush_time = msecs_to_jiffies(duration);
 255
 256                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 257                                duration, packet_count);
 258
 259                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 260                           rs_sta->flush_time);
 261
 262                 rs_sta->last_partial_flush = jiffies;
 263         } else {
 264                 rs_sta->flush_time = IWL_RATE_FLUSH;
 265                 rs_sta->flush_pending = 0;
 266         }
 267         /* If there weren't any unflushed entries, we don't schedule the timer
 268          * to run again */
 269
 270         rs_sta->last_flush = jiffies;
 271
 272         spin_unlock_irqrestore(&rs_sta->lock, flags);
 273
 274         IWL_DEBUG_RATE("leave\n");
 275 }
 276
 277 /**
 278  * iwl3945_collect_tx_data - Update the success/failure sliding window
 279  *
 280  * We keep a sliding window of the last 64 packets transmitted
 281  * at this rate.  window->data contains the bitmask of successful
 282  * packets.
 283  */
 284 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 285                                 struct iwl3945_rate_scale_data *window,
 286                                 int success, int retries, int index)
 287 {
 288         unsigned long flags;
 289         s32 fail_count;
 290
 291         if (!retries) {
 292                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 293                 return;
 294         }
 295
 296         spin_lock_irqsave(&rs_sta->lock, flags);
 297         while (retries--) {
 298
 299                 /* If we have filled up the window then subtract one from the
 300                  * success counter if the high-bit is counting toward
 301                  * success */
 302                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 303                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 304                                 window->success_counter--;
 305                 } else
 306                         window->counter++;
 307
 308                 /* Slide the window to the left one bit */
 309                 window->data = (window->data << 1);
 310
 311                 /* If this packet was a success then set the low bit high */
 312                 if (success) {
 313                         window->success_counter++;
 314                         window->data |= 1;
 315                 }
 316
 317                 /* window->counter can't be 0 -- it is either >0 or
 318                  * IWL_RATE_MAX_WINDOW */
 319                 window->success_ratio = 12800 * window->success_counter /
 320                     window->counter;
 321
 322                 /* Tag this window as having been updated */
 323                 window->stamp = jiffies;
 324
 325         }
 326
 327         fail_count = window->counter - window->success_counter;
 328         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
 329             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
 330                 window->average_tpt = ((window->success_ratio *
 331                                 rs_sta->expected_tpt[index] + 64) / 128);
 332         else
 333                 window->average_tpt = IWL_INV_TPT;
 334
 335         spin_unlock_irqrestore(&rs_sta->lock, flags);
 336
 337 }
 338
 339 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
 340                          struct ieee80211_sta *sta, void *priv_sta)
 341 {
 342         struct iwl3945_rs_sta *rs_sta = priv_sta;
 343         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 344         int i;
 345
 346         IWL_DEBUG_RATE("enter\n");
 347
 348         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 349          * the lowest or the highest rate.. Could consider using RSSI from
 350          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 351          * after assoc.. */
 352
 353         for (i = sband->n_bitrates - 1; i >= 0; i--) {
 354                 if (sta->supp_rates[sband->band] & (1 << i)) {
 355                         rs_sta->last_txrate_idx = i;
 356                         break;
 357                 }
 358         }
 359
 360         priv->sta_supp_rates = sta->supp_rates[sband->band];
 361         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 362         if (sband->band == IEEE80211_BAND_5GHZ) {
 363                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 364                 priv->sta_supp_rates = priv->sta_supp_rates <<
 365                                                 IWL_FIRST_OFDM_RATE;
 366         }
 367
 368
 369         IWL_DEBUG_RATE("leave\n");
 370 }
 371
 372 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 373 {
 374         return hw->priv;
 375 }
 376
 377 /* rate scale requires free function to be implemented */
 378 static void rs_free(void *priv)
 379 {
 380         return;
 381 }
 382
 383 static void *rs_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 384 {
 385         struct iwl3945_rs_sta *rs_sta;
 386         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 387         int i;
 388
 389         /*
 390          * XXX: If it's using sta->drv_priv anyway, it might
 391          *      as well just put all the information there.
 392          */
 393
 394         IWL_DEBUG_RATE("enter\n");
 395
 396         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 397         if (!rs_sta) {
 398                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 399                 return NULL;
 400         }
 401
 402         psta->rs_sta = rs_sta;
 403
 404         spin_lock_init(&rs_sta->lock);
 405
 406         rs_sta->start_rate = IWL_RATE_INVALID;
 407
 408         /* default to just 802.11b */
 409         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 410
 411         rs_sta->last_partial_flush = jiffies;
 412         rs_sta->last_flush = jiffies;
 413         rs_sta->flush_time = IWL_RATE_FLUSH;
 414         rs_sta->last_tx_packets = 0;
 415         rs_sta->ibss_sta_added = 0;
 416
 417         init_timer(&rs_sta->rate_scale_flush);
 418         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 419         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 420
 421         for (i = 0; i < IWL_RATE_COUNT; i++)
 422                 iwl3945_clear_window(&rs_sta->win[i]);
 423
 424         IWL_DEBUG_RATE("leave\n");
 425
 426         return rs_sta;
 427 }
 428
 429 static void rs_free_sta(void *priv, struct ieee80211_sta *sta,
 430                         void *priv_sta)
 431 {
 432         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 433         struct iwl3945_rs_sta *rs_sta = priv_sta;
 434
 435         psta->rs_sta = NULL;
 436
 437         IWL_DEBUG_RATE("enter\n");
 438         del_timer_sync(&rs_sta->rate_scale_flush);
 439         kfree(rs_sta);
 440         IWL_DEBUG_RATE("leave\n");
 441 }
 442
 443
 444 /**
 445  * rs_tx_status - Update rate control values based on Tx results
 446  *
 447  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 448  * the hardware for each rate.
 449  */
 450 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 451                          struct ieee80211_sta *sta, void *priv_sta,
 452                          struct sk_buff *skb)
 453 {
 454         s8 retries = 0, current_count;
 455         int scale_rate_index, first_index, last_index;
 456         unsigned long flags;
 457         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 458         struct iwl3945_rs_sta *rs_sta = priv_sta;
 459         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 460
 461         IWL_DEBUG_RATE("enter\n");
 462
 463         retries = info->status.rates[0].count;
 464
 465         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 466         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 467                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 468                 return;
 469         }
 470
 471         if (!priv_sta) {
 472                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 473                 return;
 474         }
 475
 476         rs_sta->tx_packets++;
 477
 478         scale_rate_index = first_index;
 479         last_index = first_index;
 480
 481         /*
 482          * Update the window for each rate.  We determine which rates
 483          * were Tx'd based on the total number of retries vs. the number
 484          * of retries configured for each rate -- currently set to the
 485          * priv value 'retry_rate' vs. rate specific
 486          *
 487          * On exit from this while loop last_index indicates the rate
 488          * at which the frame was finally transmitted (or failed if no
 489          * ACK)
 490          */
 491         while (retries > 1) {
 492                 if ((retries - 1) < priv->retry_rate) {
 493                         current_count = (retries - 1);
 494                         last_index = scale_rate_index;
 495                 } else {
 496                         current_count = priv->retry_rate;
 497                         last_index = iwl3945_rs_next_rate(priv,
 498                                                          scale_rate_index);
 499                 }
 500
 501                 /* Update this rate accounting for as many retries
 502                  * as was used for it (per current_count) */
 503                 iwl3945_collect_tx_data(rs_sta,
 504                                     &rs_sta->win[scale_rate_index],
 505                                     0, current_count, scale_rate_index);
 506                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 507                                scale_rate_index, current_count);
 508
 509                 retries -= current_count;
 510
 511                 scale_rate_index = last_index;
 512         }
 513
 514
 515         /* Update the last index window with success/failure based on ACK */
 516         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 517                        last_index,
 518                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 519                        "success" : "failure");
 520         iwl3945_collect_tx_data(rs_sta,
 521                             &rs_sta->win[last_index],
 522                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 523
 524         /* We updated the rate scale window -- if its been more than
 525          * flush_time since the last run, schedule the flush
 526          * again */
 527         spin_lock_irqsave(&rs_sta->lock, flags);
 528
 529         if (!rs_sta->flush_pending &&
 530             time_after(jiffies, rs_sta->last_flush +
 531                        rs_sta->flush_time)) {
 532
 533                 rs_sta->last_partial_flush = jiffies;
 534                 rs_sta->flush_pending = 1;
 535                 mod_timer(&rs_sta->rate_scale_flush,
 536                           jiffies + rs_sta->flush_time);
 537         }
 538
 539         spin_unlock_irqrestore(&rs_sta->lock, flags);
 540
 541         IWL_DEBUG_RATE("leave\n");
 542
 543         return;
 544 }
 545
 546 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 547                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 548 {
 549         u8 high = IWL_RATE_INVALID;
 550         u8 low = IWL_RATE_INVALID;
 551
 552         /* 802.11A walks to the next literal adjacent rate in
 553          * the rate table */
 554         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 555                 int i;
 556                 u32 mask;
 557
 558                 /* Find the previous rate that is in the rate mask */
 559                 i = index - 1;
 560                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 561                         if (rate_mask & mask) {
 562                                 low = i;
 563                                 break;
 564                         }
 565                 }
 566
 567                 /* Find the next rate that is in the rate mask */
 568                 i = index + 1;
 569                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 570                         if (rate_mask & mask) {
 571                                 high = i;
 572                                 break;
 573                         }
 574                 }
 575
 576                 return (high << 8) | low;
 577         }
 578
 579         low = index;
 580         while (low != IWL_RATE_INVALID) {
 581                 if (rs_sta->tgg)
 582                         low = iwl3945_rates[low].prev_rs_tgg;
 583                 else
 584                         low = iwl3945_rates[low].prev_rs;
 585                 if (low == IWL_RATE_INVALID)
 586                         break;
 587                 if (rate_mask & (1 << low))
 588                         break;
 589                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 590         }
 591
 592         high = index;
 593         while (high != IWL_RATE_INVALID) {
 594                 if (rs_sta->tgg)
 595                         high = iwl3945_rates[high].next_rs_tgg;
 596                 else
 597                         high = iwl3945_rates[high].next_rs;
 598                 if (high == IWL_RATE_INVALID)
 599                         break;
 600                 if (rate_mask & (1 << high))
 601                         break;
 602                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 603         }
 604
 605         return (high << 8) | low;
 606 }
 607
 608 /**
 609  * rs_get_rate - find the rate for the requested packet
 610  *
 611  * Returns the ieee80211_rate structure allocated by the driver.
 612  *
 613  * The rate control algorithm has no internal mapping between hw_mode's
 614  * rate ordering and the rate ordering used by the rate control algorithm.
 615  *
 616  * The rate control algorithm uses a single table of rates that goes across
 617  * the entire A/B/G spectrum vs. being limited to just one particular
 618  * hw_mode.
 619  *
 620  * As such, we can't convert the index obtained below into the hw_mode's
 621  * rate table and must reference the driver allocated rate table
 622  *
 623  */
 624 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 625                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 626 {
 627         struct ieee80211_supported_band *sband = txrc->sband;
 628         struct sk_buff *skb = txrc->skb;
 629         u8 low = IWL_RATE_INVALID;
 630         u8 high = IWL_RATE_INVALID;
 631         u16 high_low;
 632         int index;
 633         struct iwl3945_rs_sta *rs_sta = priv_sta;
 634         struct iwl3945_rate_scale_data *window = NULL;
 635         int current_tpt = IWL_INV_TPT;
 636         int low_tpt = IWL_INV_TPT;
 637         int high_tpt = IWL_INV_TPT;
 638         u32 fail_count;
 639         s8 scale_action = 0;
 640         unsigned long flags;
 641         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 642         u16 fc;
 643         u16 rate_mask = 0;
 644         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 645         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 646
 647         IWL_DEBUG_RATE("enter\n");
 648
 649         if (sta)
 650                 rate_mask = sta->supp_rates[sband->band];
 651
 652         /* Send management frames and broadcast/multicast data using lowest
 653          * rate. */
 654         fc = le16_to_cpu(hdr->frame_control);
 655         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 656             is_multicast_ether_addr(hdr->addr1) ||
 657             !sta || !priv_sta) {
 658                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 659                 if (!rate_mask)
 660                         info->control.rates[0].idx =
 661                                         rate_lowest_index(sband, NULL);
 662                 else
 663                         info->control.rates[0].idx =
 664                                         rate_lowest_index(sband, sta);
 665                 return;
 666         }
 667
 668         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 669
 670         if (sband->band == IEEE80211_BAND_5GHZ)
 671                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 672
 673         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 674             !rs_sta->ibss_sta_added) {
 675                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 676
 677                 if (sta_id == IWL_INVALID_STATION) {
 678                         IWL_DEBUG_RATE("LQ: ADD station %pm\n",
 679                                        hdr->addr1);
 680                         sta_id = iwl3945_add_station(priv,
 681                                     hdr->addr1, 0, CMD_ASYNC);
 682                 }
 683                 if (sta_id != IWL_INVALID_STATION)
 684                         rs_sta->ibss_sta_added = 1;
 685         }
 686
 687         spin_lock_irqsave(&rs_sta->lock, flags);
 688
 689         /* for recent assoc, choose best rate regarding
 690          * to rssi value
 691          */
 692         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 693                 if (rs_sta->start_rate < index &&
 694                    (rate_mask & (1 << rs_sta->start_rate)))
 695                         index = rs_sta->start_rate;
 696                 rs_sta->start_rate = IWL_RATE_INVALID;
 697         }
 698
 699         window = &(rs_sta->win[index]);
 700
 701         fail_count = window->counter - window->success_counter;
 702
 703         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 704              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 705                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 706
 707                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 708                                "counter: %d, success_counter: %d, "
 709                                "expected_tpt is %sNULL\n",
 710                                index,
 711                                window->counter,
 712                                window->success_counter,
 713                                rs_sta->expected_tpt ? "not " : "");
 714                 goto out;
 715
 716         }
 717
 718         current_tpt = window->average_tpt;
 719
 720         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 721                                              sband->band);
 722         low = high_low & 0xff;
 723         high = (high_low >> 8) & 0xff;
 724
 725         if (low != IWL_RATE_INVALID)
 726                 low_tpt = rs_sta->win[low].average_tpt;
 727
 728         if (high != IWL_RATE_INVALID)
 729                 high_tpt = rs_sta->win[high].average_tpt;
 730
 731         spin_unlock_irqrestore(&rs_sta->lock, flags);
 732
 733         scale_action = 1;
 734
 735         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 736                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 737                 scale_action = -1;
 738         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 739                 scale_action = 1;
 740         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 741                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 742                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 743                                "current_tpt [%d]\n",
 744                                low_tpt, high_tpt, current_tpt);
 745                 scale_action = 0;
 746         } else {
 747                 if (high_tpt != IWL_INV_TPT) {
 748                         if (high_tpt > current_tpt)
 749                                 scale_action = 1;
 750                         else {
 751                                 IWL_DEBUG_RATE
 752                                     ("decrease rate because of high tpt\n");
 753                                 scale_action = -1;
 754                         }
 755                 } else if (low_tpt != IWL_INV_TPT) {
 756                         if (low_tpt > current_tpt) {
 757                                 IWL_DEBUG_RATE
 758                                     ("decrease rate because of low tpt\n");
 759                                 scale_action = -1;
 760                         } else
 761                                 scale_action = 1;
 762                 }
 763         }
 764
 765         if (scale_action == -1) {
 766                 if (window->success_ratio > IWL_SUCCESS_DOWN_TH)
 767                         scale_action = 0;
 768         } else if (scale_action == 1) {
 769                 if (window->success_ratio < IWL_SUCCESS_UP_TH) {
 770                         IWL_DEBUG_RATE("No action -- success_ratio [%d] < "
 771                                "SUCCESS UP\n", window->success_ratio);
 772                         scale_action = 0;
 773                 }
 774         }
 775
 776         switch (scale_action) {
 777         case -1:
 778                 if (low != IWL_RATE_INVALID)
 779                         index = low;
 780                 break;
 781
 782         case 1:
 783                 if (high != IWL_RATE_INVALID)
 784                         index = high;
 785
 786                 break;
 787
 788         case 0:
 789         default:
 790                 break;
 791         }
 792
 793         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 794                        index, scale_action, low, high);
 795
 796  out:
 797
 798         rs_sta->last_txrate_idx = index;
 799         if (sband->band == IEEE80211_BAND_5GHZ)
 800                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 801                                 IWL_FIRST_OFDM_RATE;
 802         else
 803                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 804
 805         IWL_DEBUG_RATE("leave: %d\n", index);
 806 }
 807
 808 #ifdef CONFIG_MAC80211_DEBUGFS
 809 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 810 {
 811         file->private_data = inode->i_private;
 812         return 0;
 813 }
 814
 815 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 816                                                   char __user *user_buf,
 817                                                   size_t count, loff_t *ppos)
 818 {
 819         char buff[1024];
 820         int desc = 0;
 821         int j;
 822         struct iwl3945_rs_sta *lq_sta = file->private_data;
 823
 824         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 825                         "rate=0x%X flush time %d\n",
 826                         lq_sta->tx_packets,
 827                         lq_sta->last_txrate_idx,
 828                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 829         for (j = 0; j < IWL_RATE_COUNT; j++) {
 830                 desc += sprintf(buff+desc,
 831                                 "counter=%d success=%d %%=%d\n",
 832                                 lq_sta->win[j].counter,
 833                                 lq_sta->win[j].success_counter,
 834                                 lq_sta->win[j].success_ratio);
 835         }
 836         return simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 837 }
 838
 839 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 840         .read = iwl3945_sta_dbgfs_stats_table_read,
 841         .open = iwl3945_open_file_generic,
 842 };
 843
 844 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 845                                 struct dentry *dir)
 846 {
 847         struct iwl3945_rs_sta *lq_sta = priv_sta;
 848
 849         lq_sta->rs_sta_dbgfs_stats_table_file =
 850                 debugfs_create_file("rate_stats_table", 0600, dir,
 851                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 852
 853 }
 854
 855 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 856 {
 857         struct iwl3945_rs_sta *lq_sta = priv_sta;
 858         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 859 }
 860 #endif
 861
 862 static struct rate_control_ops rs_ops = {
 863         .module = NULL,
 864         .name = RS_NAME,
 865         .tx_status = rs_tx_status,
 866         .get_rate = rs_get_rate,
 867         .rate_init = rs_rate_init,
 868         .alloc = rs_alloc,
 869         .free = rs_free,
 870         .alloc_sta = rs_alloc_sta,
 871         .free_sta = rs_free_sta,
 872 #ifdef CONFIG_MAC80211_DEBUGFS
 873         .add_sta_debugfs = iwl3945_add_debugfs,
 874         .remove_sta_debugfs = iwl3945_remove_debugfs,
 875 #endif
 876
 877 };
 878
 879 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 880 {
 881         struct iwl3945_priv *priv = hw->priv;
 882         s32 rssi = 0;
 883         unsigned long flags;
 884         struct iwl3945_rs_sta *rs_sta;
 885         struct ieee80211_sta *sta;
 886         struct iwl3945_sta_priv *psta;
 887
 888         IWL_DEBUG_RATE("enter\n");
 889
 890         rcu_read_lock();
 891
 892         sta = ieee80211_find_sta(hw, priv->stations[sta_id].sta.sta.addr);
 893         if (!sta) {
 894                 rcu_read_unlock();
 895                 return;
 896         }
 897
 898         psta = (void *) sta->drv_priv;
 899         rs_sta = psta->rs_sta;
 900
 901         spin_lock_irqsave(&rs_sta->lock, flags);
 902
 903         rs_sta->tgg = 0;
 904         switch (priv->band) {
 905         case IEEE80211_BAND_2GHZ:
 906                 /* TODO: this always does G, not a regression */
 907                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 908                         rs_sta->tgg = 1;
 909                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 910                 } else
 911                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 912                 break;
 913
 914         case IEEE80211_BAND_5GHZ:
 915                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 916                 break;
 917         case IEEE80211_NUM_BANDS:
 918                 BUG();
 919                 break;
 920         }
 921
 922         spin_unlock_irqrestore(&rs_sta->lock, flags);
 923
 924         rssi = priv->last_rx_rssi;
 925         if (rssi == 0)
 926                 rssi = IWL_MIN_RSSI_VAL;
 927
 928         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 929
 930         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 931
 932         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 933                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 934                        iwl3945_rates[rs_sta->start_rate].plcp);
 935         rcu_read_unlock();
 936 }
 937
 938 int iwl3945_rate_control_register(void)
 939 {
 940         return ieee80211_rate_control_register(&rs_ops);
 941 }
 942
 943 void iwl3945_rate_control_unregister(void)
 944 {
 945         ieee80211_rate_control_unregister(&rs_ops);
 946 }
 947
 948