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-commands.h"
  41 #include "iwl-3945.h"
  42
  43 #define RS_NAME "iwl-3945-rs"
  44
  45 struct iwl3945_rate_scale_data {
  46         u64 data;
  47         s32 success_counter;
  48         s32 success_ratio;
  49         s32 counter;
  50         s32 average_tpt;
  51         unsigned long stamp;
  52 };
  53
  54 struct iwl3945_rs_sta {
  55         spinlock_t lock;
  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];
  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] = {
  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] = {
  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] = {
  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] = {
  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 IWL_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       8
 128 #define IWL_RATE_MIN_SUCCESS_TH       8
 129 #define IWL_RATE_DECREASE_TH       1920
 130
 131 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 132 {
 133         u32 index = 0;
 134         u32 table_size = 0;
 135         struct iwl3945_tpt_entry *tpt_table = NULL;
 136
 137         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 138                 rssi = IWL_MIN_RSSI_VAL;
 139
 140         switch (band) {
 141         case IEEE80211_BAND_2GHZ:
 142                 tpt_table = iwl3945_tpt_table_g;
 143                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 144                 break;
 145
 146         case IEEE80211_BAND_5GHZ:
 147                 tpt_table = iwl3945_tpt_table_a;
 148                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 149                 break;
 150
 151         default:
 152                 BUG();
 153                 break;
 154         }
 155
 156         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 157                 index++;
 158
 159         index = min(index, (table_size - 1));
 160
 161         return tpt_table[index].index;
 162 }
 163
 164 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 165 {
 166         window->data = 0;
 167         window->success_counter = 0;
 168         window->success_ratio = -1;
 169         window->counter = 0;
 170         window->average_tpt = IWL_INV_TPT;
 171         window->stamp = 0;
 172 }
 173
 174 /**
 175  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 176  *
 177  * Returns the number of windows that have gathered data but were
 178  * not flushed.  If there were any that were not flushed, then
 179  * reschedule the rate flushing routine.
 180  */
 181 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 182 {
 183         int unflushed = 0;
 184         int i;
 185         unsigned long flags;
 186
 187         /*
 188          * For each rate, if we have collected data on that rate
 189          * and it has been more than IWL_RATE_WIN_FLUSH
 190          * since we flushed, clear out the gathered statistics
 191          */
 192         for (i = 0; i < IWL_RATE_COUNT; i++) {
 193                 if (!rs_sta->win[i].counter)
 194                         continue;
 195
 196                 spin_lock_irqsave(&rs_sta->lock, flags);
 197                 if (time_after(jiffies, rs_sta->win[i].stamp +
 198                                IWL_RATE_WIN_FLUSH)) {
 199                         IWL_DEBUG_RATE("flushing %d samples of rate "
 200                                        "index %d\n",
 201                                        rs_sta->win[i].counter, i);
 202                         iwl3945_clear_window(&rs_sta->win[i]);
 203                 } else
 204                         unflushed++;
 205                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 206         }
 207
 208         return unflushed;
 209 }
 210
 211 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 212 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 213 #define IWL_AVERAGE_PACKETS             1500
 214
 215 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 216 {
 217         struct iwl3945_rs_sta *rs_sta = (void *)data;
 218         int unflushed = 0;
 219         unsigned long flags;
 220         u32 packet_count, duration, pps;
 221
 222         IWL_DEBUG_RATE("enter\n");
 223
 224         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 225
 226         spin_lock_irqsave(&rs_sta->lock, flags);
 227
 228         /* Number of packets Rx'd since last time this timer ran */
 229         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 230
 231         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 232
 233         if (unflushed) {
 234                 duration =
 235                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 236
 237                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 238                                packet_count, duration);
 239
 240                 /* Determine packets per second */
 241                 if (duration)
 242                         pps = (packet_count * 1000) / duration;
 243                 else
 244                         pps = 0;
 245
 246                 if (pps) {
 247                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
 248                         if (duration < IWL_RATE_FLUSH_MIN)
 249                                 duration = IWL_RATE_FLUSH_MIN;
 250                         else if (duration > IWL_RATE_FLUSH_MAX)
 251                                 duration = IWL_RATE_FLUSH_MAX;
 252                 } else
 253                         duration = IWL_RATE_FLUSH_MAX;
 254
 255                 rs_sta->flush_time = msecs_to_jiffies(duration);
 256
 257                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 258                                duration, packet_count);
 259
 260                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 261                           rs_sta->flush_time);
 262
 263                 rs_sta->last_partial_flush = jiffies;
 264         } else {
 265                 rs_sta->flush_time = IWL_RATE_FLUSH;
 266                 rs_sta->flush_pending = 0;
 267         }
 268         /* If there weren't any unflushed entries, we don't schedule the timer
 269          * to run again */
 270
 271         rs_sta->last_flush = jiffies;
 272
 273         spin_unlock_irqrestore(&rs_sta->lock, flags);
 274
 275         IWL_DEBUG_RATE("leave\n");
 276 }
 277
 278 /**
 279  * iwl3945_collect_tx_data - Update the success/failure sliding window
 280  *
 281  * We keep a sliding window of the last 64 packets transmitted
 282  * at this rate.  window->data contains the bitmask of successful
 283  * packets.
 284  */
 285 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 286                                 struct iwl3945_rate_scale_data *window,
 287                                 int success, int retries, int index)
 288 {
 289         unsigned long flags;
 290         s32 fail_count;
 291
 292         if (!retries) {
 293                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 294                 return;
 295         }
 296
 297         spin_lock_irqsave(&rs_sta->lock, flags);
 298         while (retries--) {
 299
 300                 /* If we have filled up the window then subtract one from the
 301                  * success counter if the high-bit is counting toward
 302                  * success */
 303                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 304                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 305                                 window->success_counter--;
 306                 } else
 307                         window->counter++;
 308
 309                 /* Slide the window to the left one bit */
 310                 window->data = (window->data << 1);
 311
 312                 /* If this packet was a success then set the low bit high */
 313                 if (success) {
 314                         window->success_counter++;
 315                         window->data |= 1;
 316                 }
 317
 318                 /* window->counter can't be 0 -- it is either >0 or
 319                  * IWL_RATE_MAX_WINDOW */
 320                 window->success_ratio = 12800 * window->success_counter /
 321                     window->counter;
 322
 323                 /* Tag this window as having been updated */
 324                 window->stamp = jiffies;
 325
 326         }
 327
 328         fail_count = window->counter - window->success_counter;
 329         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
 330             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
 331                 window->average_tpt = ((window->success_ratio *
 332                                 rs_sta->expected_tpt[index] + 64) / 128);
 333         else
 334                 window->average_tpt = IWL_INV_TPT;
 335
 336         spin_unlock_irqrestore(&rs_sta->lock, flags);
 337
 338 }
 339
 340 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
 341                          struct ieee80211_sta *sta, void *priv_sta)
 342 {
 343         struct iwl3945_rs_sta *rs_sta = priv_sta;
 344         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 345         int i;
 346
 347         IWL_DEBUG_RATE("enter\n");
 348
 349         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 350          * the lowest or the highest rate.. Could consider using RSSI from
 351          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 352          * after assoc.. */
 353
 354         for (i = sband->n_bitrates - 1; i >= 0; i--) {
 355                 if (sta->supp_rates[sband->band] & (1 << i)) {
 356                         rs_sta->last_txrate_idx = i;
 357                         break;
 358                 }
 359         }
 360
 361         priv->sta_supp_rates = sta->supp_rates[sband->band];
 362         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 363         if (sband->band == IEEE80211_BAND_5GHZ) {
 364                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 365                 priv->sta_supp_rates = priv->sta_supp_rates <<
 366                                                 IWL_FIRST_OFDM_RATE;
 367         }
 368
 369
 370         IWL_DEBUG_RATE("leave\n");
 371 }
 372
 373 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 374 {
 375         return hw->priv;
 376 }
 377
 378 /* rate scale requires free function to be implemented */
 379 static void rs_free(void *priv)
 380 {
 381         return;
 382 }
 383
 384 static void *rs_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 385 {
 386         struct iwl3945_rs_sta *rs_sta;
 387         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 388         int i;
 389
 390         /*
 391          * XXX: If it's using sta->drv_priv anyway, it might
 392          *      as well just put all the information there.
 393          */
 394
 395         IWL_DEBUG_RATE("enter\n");
 396
 397         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 398         if (!rs_sta) {
 399                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 400                 return NULL;
 401         }
 402
 403         psta->rs_sta = rs_sta;
 404
 405         spin_lock_init(&rs_sta->lock);
 406
 407         rs_sta->start_rate = IWL_RATE_INVALID;
 408
 409         /* default to just 802.11b */
 410         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 411
 412         rs_sta->last_partial_flush = jiffies;
 413         rs_sta->last_flush = jiffies;
 414         rs_sta->flush_time = IWL_RATE_FLUSH;
 415         rs_sta->last_tx_packets = 0;
 416         rs_sta->ibss_sta_added = 0;
 417
 418         init_timer(&rs_sta->rate_scale_flush);
 419         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 420         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 421
 422         for (i = 0; i < IWL_RATE_COUNT; i++)
 423                 iwl3945_clear_window(&rs_sta->win[i]);
 424
 425         IWL_DEBUG_RATE("leave\n");
 426
 427         return rs_sta;
 428 }
 429
 430 static void rs_free_sta(void *priv, struct ieee80211_sta *sta,
 431                         void *priv_sta)
 432 {
 433         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 434         struct iwl3945_rs_sta *rs_sta = priv_sta;
 435
 436         psta->rs_sta = NULL;
 437
 438         IWL_DEBUG_RATE("enter\n");
 439         del_timer_sync(&rs_sta->rate_scale_flush);
 440         kfree(rs_sta);
 441         IWL_DEBUG_RATE("leave\n");
 442 }
 443
 444
 445 /**
 446  * rs_tx_status - Update rate control values based on Tx results
 447  *
 448  * NOTE: Uses iwl3945_priv->retry_rate for the # of retries attempted by
 449  * the hardware for each rate.
 450  */
 451 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 452                          struct ieee80211_sta *sta, void *priv_sta,
 453                          struct sk_buff *skb)
 454 {
 455         s8 retries = 0, current_count;
 456         int scale_rate_index, first_index, last_index;
 457         unsigned long flags;
 458         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_rate;
 459         struct iwl3945_rs_sta *rs_sta = priv_sta;
 460         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 461
 462         IWL_DEBUG_RATE("enter\n");
 463
 464         retries = info->status.rates[0].count;
 465
 466         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 467         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 468                 IWL_DEBUG_RATE("leave: Rate out of bounds: %d\n", first_index);
 469                 return;
 470         }
 471
 472         if (!priv_sta) {
 473                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 474                 return;
 475         }
 476
 477         rs_sta->tx_packets++;
 478
 479         scale_rate_index = first_index;
 480         last_index = first_index;
 481
 482         /*
 483          * Update the window for each rate.  We determine which rates
 484          * were Tx'd based on the total number of retries vs. the number
 485          * of retries configured for each rate -- currently set to the
 486          * priv value 'retry_rate' vs. rate specific
 487          *
 488          * On exit from this while loop last_index indicates the rate
 489          * at which the frame was finally transmitted (or failed if no
 490          * ACK)
 491          */
 492         while (retries > 1) {
 493                 if ((retries - 1) < priv->retry_rate) {
 494                         current_count = (retries - 1);
 495                         last_index = scale_rate_index;
 496                 } else {
 497                         current_count = priv->retry_rate;
 498                         last_index = iwl3945_rs_next_rate(priv,
 499                                                          scale_rate_index);
 500                 }
 501
 502                 /* Update this rate accounting for as many retries
 503                  * as was used for it (per current_count) */
 504                 iwl3945_collect_tx_data(rs_sta,
 505                                     &rs_sta->win[scale_rate_index],
 506                                     0, current_count, scale_rate_index);
 507                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 508                                scale_rate_index, current_count);
 509
 510                 retries -= current_count;
 511
 512                 scale_rate_index = last_index;
 513         }
 514
 515
 516         /* Update the last index window with success/failure based on ACK */
 517         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 518                        last_index,
 519                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 520                        "success" : "failure");
 521         iwl3945_collect_tx_data(rs_sta,
 522                             &rs_sta->win[last_index],
 523                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 524
 525         /* We updated the rate scale window -- if its been more than
 526          * flush_time since the last run, schedule the flush
 527          * again */
 528         spin_lock_irqsave(&rs_sta->lock, flags);
 529
 530         if (!rs_sta->flush_pending &&
 531             time_after(jiffies, rs_sta->last_flush +
 532                        rs_sta->flush_time)) {
 533
 534                 rs_sta->last_partial_flush = jiffies;
 535                 rs_sta->flush_pending = 1;
 536                 mod_timer(&rs_sta->rate_scale_flush,
 537                           jiffies + rs_sta->flush_time);
 538         }
 539
 540         spin_unlock_irqrestore(&rs_sta->lock, flags);
 541
 542         IWL_DEBUG_RATE("leave\n");
 543
 544         return;
 545 }
 546
 547 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 548                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 549 {
 550         u8 high = IWL_RATE_INVALID;
 551         u8 low = IWL_RATE_INVALID;
 552
 553         /* 802.11A walks to the next literal adjacent rate in
 554          * the rate table */
 555         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 556                 int i;
 557                 u32 mask;
 558
 559                 /* Find the previous rate that is in the rate mask */
 560                 i = index - 1;
 561                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 562                         if (rate_mask & mask) {
 563                                 low = i;
 564                                 break;
 565                         }
 566                 }
 567
 568                 /* Find the next rate that is in the rate mask */
 569                 i = index + 1;
 570                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 571                         if (rate_mask & mask) {
 572                                 high = i;
 573                                 break;
 574                         }
 575                 }
 576
 577                 return (high << 8) | low;
 578         }
 579
 580         low = index;
 581         while (low != IWL_RATE_INVALID) {
 582                 if (rs_sta->tgg)
 583                         low = iwl3945_rates[low].prev_rs_tgg;
 584                 else
 585                         low = iwl3945_rates[low].prev_rs;
 586                 if (low == IWL_RATE_INVALID)
 587                         break;
 588                 if (rate_mask & (1 << low))
 589                         break;
 590                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 591         }
 592
 593         high = index;
 594         while (high != IWL_RATE_INVALID) {
 595                 if (rs_sta->tgg)
 596                         high = iwl3945_rates[high].next_rs_tgg;
 597                 else
 598                         high = iwl3945_rates[high].next_rs;
 599                 if (high == IWL_RATE_INVALID)
 600                         break;
 601                 if (rate_mask & (1 << high))
 602                         break;
 603                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 604         }
 605
 606         return (high << 8) | low;
 607 }
 608
 609 /**
 610  * rs_get_rate - find the rate for the requested packet
 611  *
 612  * Returns the ieee80211_rate structure allocated by the driver.
 613  *
 614  * The rate control algorithm has no internal mapping between hw_mode's
 615  * rate ordering and the rate ordering used by the rate control algorithm.
 616  *
 617  * The rate control algorithm uses a single table of rates that goes across
 618  * the entire A/B/G spectrum vs. being limited to just one particular
 619  * hw_mode.
 620  *
 621  * As such, we can't convert the index obtained below into the hw_mode's
 622  * rate table and must reference the driver allocated rate table
 623  *
 624  */
 625 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 626                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 627 {
 628         struct ieee80211_supported_band *sband = txrc->sband;
 629         struct sk_buff *skb = txrc->skb;
 630         u8 low = IWL_RATE_INVALID;
 631         u8 high = IWL_RATE_INVALID;
 632         u16 high_low;
 633         int index;
 634         struct iwl3945_rs_sta *rs_sta = priv_sta;
 635         struct iwl3945_rate_scale_data *window = NULL;
 636         int current_tpt = IWL_INV_TPT;
 637         int low_tpt = IWL_INV_TPT;
 638         int high_tpt = IWL_INV_TPT;
 639         u32 fail_count;
 640         s8 scale_action = 0;
 641         unsigned long flags;
 642         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 643         u16 fc;
 644         u16 rate_mask = 0;
 645         struct iwl3945_priv *priv = (struct iwl3945_priv *)priv_r;
 646         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 647
 648         IWL_DEBUG_RATE("enter\n");
 649
 650         if (sta)
 651                 rate_mask = sta->supp_rates[sband->band];
 652
 653         /* Send management frames and broadcast/multicast data using lowest
 654          * rate. */
 655         fc = le16_to_cpu(hdr->frame_control);
 656         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 657             is_multicast_ether_addr(hdr->addr1) ||
 658             !sta || !priv_sta) {
 659                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 660                 if (!rate_mask)
 661                         info->control.rates[0].idx =
 662                                         rate_lowest_index(sband, NULL);
 663                 else
 664                         info->control.rates[0].idx =
 665                                         rate_lowest_index(sband, sta);
 666                 return;
 667         }
 668
 669         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT - 1);
 670
 671         if (sband->band == IEEE80211_BAND_5GHZ)
 672                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 673
 674         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 675             !rs_sta->ibss_sta_added) {
 676                 u8 sta_id = iwl3945_hw_find_station(priv, hdr->addr1);
 677
 678                 if (sta_id == IWL_INVALID_STATION) {
 679                         IWL_DEBUG_RATE("LQ: ADD station %pm\n",
 680                                        hdr->addr1);
 681                         sta_id = iwl3945_add_station(priv,
 682                                     hdr->addr1, 0, CMD_ASYNC);
 683                 }
 684                 if (sta_id != IWL_INVALID_STATION)
 685                         rs_sta->ibss_sta_added = 1;
 686         }
 687
 688         spin_lock_irqsave(&rs_sta->lock, flags);
 689
 690         /* for recent assoc, choose best rate regarding
 691          * to rssi value
 692          */
 693         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 694                 if (rs_sta->start_rate < index &&
 695                    (rate_mask & (1 << rs_sta->start_rate)))
 696                         index = rs_sta->start_rate;
 697                 rs_sta->start_rate = IWL_RATE_INVALID;
 698         }
 699
 700         window = &(rs_sta->win[index]);
 701
 702         fail_count = window->counter - window->success_counter;
 703
 704         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 705              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 706                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 707
 708                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 709                                "counter: %d, success_counter: %d, "
 710                                "expected_tpt is %sNULL\n",
 711                                index,
 712                                window->counter,
 713                                window->success_counter,
 714                                rs_sta->expected_tpt ? "not " : "");
 715                 goto out;
 716
 717         }
 718
 719         current_tpt = window->average_tpt;
 720
 721         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 722                                              sband->band);
 723         low = high_low & 0xff;
 724         high = (high_low >> 8) & 0xff;
 725
 726         if (low != IWL_RATE_INVALID)
 727                 low_tpt = rs_sta->win[low].average_tpt;
 728
 729         if (high != IWL_RATE_INVALID)
 730                 high_tpt = rs_sta->win[high].average_tpt;
 731
 732         spin_unlock_irqrestore(&rs_sta->lock, flags);
 733
 734         scale_action = 1;
 735
 736         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 737                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 738                 scale_action = -1;
 739         } else if ((low_tpt == IWL_INV_TPT) && (high_tpt == IWL_INV_TPT))
 740                 scale_action = 1;
 741         else if ((low_tpt != IWL_INV_TPT) && (high_tpt != IWL_INV_TPT) &&
 742                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 743                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 744                                "current_tpt [%d]\n",
 745                                low_tpt, high_tpt, current_tpt);
 746                 scale_action = 0;
 747         } else {
 748                 if (high_tpt != IWL_INV_TPT) {
 749                         if (high_tpt > current_tpt)
 750                                 scale_action = 1;
 751                         else {
 752                                 IWL_DEBUG_RATE
 753                                     ("decrease rate because of high tpt\n");
 754                                 scale_action = -1;
 755                         }
 756                 } else if (low_tpt != IWL_INV_TPT) {
 757                         if (low_tpt > current_tpt) {
 758                                 IWL_DEBUG_RATE
 759                                     ("decrease rate because of low tpt\n");
 760                                 scale_action = -1;
 761                         } else
 762                                 scale_action = 1;
 763                 }
 764         }
 765
 766         if (scale_action == -1) {
 767                 if (window->success_ratio > IWL_SUCCESS_DOWN_TH)
 768                         scale_action = 0;
 769         } else if (scale_action == 1) {
 770                 if (window->success_ratio < IWL_SUCCESS_UP_TH) {
 771                         IWL_DEBUG_RATE("No action -- success_ratio [%d] < "
 772                                "SUCCESS UP\n", window->success_ratio);
 773                         scale_action = 0;
 774                 }
 775         }
 776
 777         switch (scale_action) {
 778         case -1:
 779                 if (low != IWL_RATE_INVALID)
 780                         index = low;
 781                 break;
 782
 783         case 1:
 784                 if (high != IWL_RATE_INVALID)
 785                         index = high;
 786
 787                 break;
 788
 789         case 0:
 790         default:
 791                 break;
 792         }
 793
 794         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 795                        index, scale_action, low, high);
 796
 797  out:
 798
 799         rs_sta->last_txrate_idx = index;
 800         if (sband->band == IEEE80211_BAND_5GHZ)
 801                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 802                                 IWL_FIRST_OFDM_RATE;
 803         else
 804                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 805
 806         IWL_DEBUG_RATE("leave: %d\n", index);
 807 }
 808
 809 #ifdef CONFIG_MAC80211_DEBUGFS
 810 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 811 {
 812         file->private_data = inode->i_private;
 813         return 0;
 814 }
 815
 816 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 817                                                   char __user *user_buf,
 818                                                   size_t count, loff_t *ppos)
 819 {
 820         char buff[1024];
 821         int desc = 0;
 822         int j;
 823         struct iwl3945_rs_sta *lq_sta = file->private_data;
 824
 825         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 826                         "rate=0x%X flush time %d\n",
 827                         lq_sta->tx_packets,
 828                         lq_sta->last_txrate_idx,
 829                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 830         for (j = 0; j < IWL_RATE_COUNT; j++) {
 831                 desc += sprintf(buff+desc,
 832                                 "counter=%d success=%d %%=%d\n",
 833                                 lq_sta->win[j].counter,
 834                                 lq_sta->win[j].success_counter,
 835                                 lq_sta->win[j].success_ratio);
 836         }
 837         return simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 838 }
 839
 840 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 841         .read = iwl3945_sta_dbgfs_stats_table_read,
 842         .open = iwl3945_open_file_generic,
 843 };
 844
 845 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 846                                 struct dentry *dir)
 847 {
 848         struct iwl3945_rs_sta *lq_sta = priv_sta;
 849
 850         lq_sta->rs_sta_dbgfs_stats_table_file =
 851                 debugfs_create_file("rate_stats_table", 0600, dir,
 852                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 853
 854 }
 855
 856 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 857 {
 858         struct iwl3945_rs_sta *lq_sta = priv_sta;
 859         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 860 }
 861 #endif
 862
 863 static struct rate_control_ops rs_ops = {
 864         .module = NULL,
 865         .name = RS_NAME,
 866         .tx_status = rs_tx_status,
 867         .get_rate = rs_get_rate,
 868         .rate_init = rs_rate_init,
 869         .alloc = rs_alloc,
 870         .free = rs_free,
 871         .alloc_sta = rs_alloc_sta,
 872         .free_sta = rs_free_sta,
 873 #ifdef CONFIG_MAC80211_DEBUGFS
 874         .add_sta_debugfs = iwl3945_add_debugfs,
 875         .remove_sta_debugfs = iwl3945_remove_debugfs,
 876 #endif
 877
 878 };
 879
 880 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 881 {
 882         struct iwl3945_priv *priv = hw->priv;
 883         s32 rssi = 0;
 884         unsigned long flags;
 885         struct iwl3945_rs_sta *rs_sta;
 886         struct ieee80211_sta *sta;
 887         struct iwl3945_sta_priv *psta;
 888
 889         IWL_DEBUG_RATE("enter\n");
 890
 891         rcu_read_lock();
 892
 893         sta = ieee80211_find_sta(hw, priv->stations[sta_id].sta.sta.addr);
 894         if (!sta) {
 895                 rcu_read_unlock();
 896                 return;
 897         }
 898
 899         psta = (void *) sta->drv_priv;
 900         rs_sta = psta->rs_sta;
 901
 902         spin_lock_irqsave(&rs_sta->lock, flags);
 903
 904         rs_sta->tgg = 0;
 905         switch (priv->band) {
 906         case IEEE80211_BAND_2GHZ:
 907                 /* TODO: this always does G, not a regression */
 908                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 909                         rs_sta->tgg = 1;
 910                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 911                 } else
 912                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 913                 break;
 914
 915         case IEEE80211_BAND_5GHZ:
 916                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 917                 break;
 918         case IEEE80211_NUM_BANDS:
 919                 BUG();
 920                 break;
 921         }
 922
 923         spin_unlock_irqrestore(&rs_sta->lock, flags);
 924
 925         rssi = priv->last_rx_rssi;
 926         if (rssi == 0)
 927                 rssi = IWL_MIN_RSSI_VAL;
 928
 929         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
 930
 931         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
 932
 933         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
 934                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
 935                        iwl3945_rates[rs_sta->start_rate].plcp);
 936         rcu_read_unlock();
 937 }
 938
 939 int iwl3945_rate_control_register(void)
 940 {
 941         return ieee80211_rate_control_register(&rs_ops);
 942 }
 943
 944 void iwl3945_rate_control_unregister(void)
 945 {
 946         ieee80211_rate_control_unregister(&rs_ops);
 947 }
 948
 949