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

   1 /******************************************************************************
   2  *
   3  * Copyright(c) 2005 - 2009 Intel Corporation. All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called LICENSE.
  20  *
  21  * Contact Information:
  22  *  Intel Linux Wireless <ilw@linux.intel.com>
  23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  24  *
  25  *****************************************************************************/
  26
  27 #include <linux/kernel.h>
  28 #include <linux/init.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/wireless.h>
  31 #include <net/mac80211.h>
  32
  33 #include <linux/netdevice.h>
  34 #include <linux/etherdevice.h>
  35 #include <linux/delay.h>
  36
  37 #include <linux/workqueue.h>
  38
  39 #include "iwl-commands.h"
  40 #include "iwl-3945.h"
  41 #include "iwl-sta.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         struct iwl_priv *priv;
  57         s32 *expected_tpt;
  58         unsigned long last_partial_flush;
  59         unsigned long last_flush;
  60         u32 flush_time;
  61         u32 last_tx_packets;
  62         u32 tx_packets;
  63         u8 tgg;
  64         u8 flush_pending;
  65         u8 start_rate;
  66         u8 ibss_sta_added;
  67         struct timer_list rate_scale_flush;
  68         struct iwl3945_rate_scale_data win[IWL_RATE_COUNT_3945];
  69 #ifdef CONFIG_MAC80211_DEBUGFS
  70         struct dentry *rs_sta_dbgfs_stats_table_file;
  71 #endif
  72
  73         /* used to be in sta_info */
  74         int last_txrate_idx;
  75 };
  76
  77 static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT_3945] = {
  78         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  79 };
  80
  81 static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT_3945] = {
  82         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  83 };
  84
  85 static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT_3945] = {
  86         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  87 };
  88
  89 static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT_3945] = {
  90         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  91 };
  92
  93 struct iwl3945_tpt_entry {
  94         s8 min_rssi;
  95         u8 index;
  96 };
  97
  98 static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
  99         {-60, IWL_RATE_54M_INDEX},
 100         {-64, IWL_RATE_48M_INDEX},
 101         {-72, IWL_RATE_36M_INDEX},
 102         {-80, IWL_RATE_24M_INDEX},
 103         {-84, IWL_RATE_18M_INDEX},
 104         {-85, IWL_RATE_12M_INDEX},
 105         {-87, IWL_RATE_9M_INDEX},
 106         {-89, IWL_RATE_6M_INDEX}
 107 };
 108
 109 static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
 110         {-60, IWL_RATE_54M_INDEX},
 111         {-64, IWL_RATE_48M_INDEX},
 112         {-68, IWL_RATE_36M_INDEX},
 113         {-80, IWL_RATE_24M_INDEX},
 114         {-84, IWL_RATE_18M_INDEX},
 115         {-85, IWL_RATE_12M_INDEX},
 116         {-86, IWL_RATE_11M_INDEX},
 117         {-88, IWL_RATE_5M_INDEX},
 118         {-90, IWL_RATE_2M_INDEX},
 119         {-92, IWL_RATE_1M_INDEX}
 120 };
 121
 122 #define IWL_RATE_MAX_WINDOW          62
 123 #define IWL_RATE_FLUSH           (3*HZ)
 124 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 125 #define IWL39_RATE_HIGH_TH          11520
 126 #define IWL_SUCCESS_UP_TH          8960
 127 #define IWL_SUCCESS_DOWN_TH       10880
 128 #define IWL_RATE_MIN_FAILURE_TH       6
 129 #define IWL_RATE_MIN_SUCCESS_TH       8
 130 #define IWL_RATE_DECREASE_TH       1920
 131 #define IWL_RATE_RETRY_TH            15
 132
 133 static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
 134 {
 135         u32 index = 0;
 136         u32 table_size = 0;
 137         struct iwl3945_tpt_entry *tpt_table = NULL;
 138
 139         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 140                 rssi = IWL_MIN_RSSI_VAL;
 141
 142         switch (band) {
 143         case IEEE80211_BAND_2GHZ:
 144                 tpt_table = iwl3945_tpt_table_g;
 145                 table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
 146                 break;
 147
 148         case IEEE80211_BAND_5GHZ:
 149                 tpt_table = iwl3945_tpt_table_a;
 150                 table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
 151                 break;
 152
 153         default:
 154                 BUG();
 155                 break;
 156         }
 157
 158         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 159                 index++;
 160
 161         index = min(index, (table_size - 1));
 162
 163         return tpt_table[index].index;
 164 }
 165
 166 static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
 167 {
 168         window->data = 0;
 169         window->success_counter = 0;
 170         window->success_ratio = -1;
 171         window->counter = 0;
 172         window->average_tpt = IWL_INVALID_VALUE;
 173         window->stamp = 0;
 174 }
 175
 176 /**
 177  * iwl3945_rate_scale_flush_windows - flush out the rate scale windows
 178  *
 179  * Returns the number of windows that have gathered data but were
 180  * not flushed.  If there were any that were not flushed, then
 181  * reschedule the rate flushing routine.
 182  */
 183 static int iwl3945_rate_scale_flush_windows(struct iwl3945_rs_sta *rs_sta)
 184 {
 185         int unflushed = 0;
 186         int i;
 187         unsigned long flags;
 188         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 189
 190         /*
 191          * For each rate, if we have collected data on that rate
 192          * and it has been more than IWL_RATE_WIN_FLUSH
 193          * since we flushed, clear out the gathered statistics
 194          */
 195         for (i = 0; i < IWL_RATE_COUNT_3945; i++) {
 196                 if (!rs_sta->win[i].counter)
 197                         continue;
 198
 199                 spin_lock_irqsave(&rs_sta->lock, flags);
 200                 if (time_after(jiffies, rs_sta->win[i].stamp +
 201                                IWL_RATE_WIN_FLUSH)) {
 202                         IWL_DEBUG_RATE(priv, "flushing %d samples of rate "
 203                                        "index %d\n",
 204                                        rs_sta->win[i].counter, i);
 205                         iwl3945_clear_window(&rs_sta->win[i]);
 206                 } else
 207                         unflushed++;
 208                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 209         }
 210
 211         return unflushed;
 212 }
 213
 214 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 215 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 216 #define IWL_AVERAGE_PACKETS             1500
 217
 218 static void iwl3945_bg_rate_scale_flush(unsigned long data)
 219 {
 220         struct iwl3945_rs_sta *rs_sta = (void *)data;
 221         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 222         int unflushed = 0;
 223         unsigned long flags;
 224         u32 packet_count, duration, pps;
 225
 226         IWL_DEBUG_RATE(priv, "enter\n");
 227
 228         unflushed = iwl3945_rate_scale_flush_windows(rs_sta);
 229
 230         spin_lock_irqsave(&rs_sta->lock, flags);
 231
 232         /* Number of packets Rx'd since last time this timer ran */
 233         packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
 234
 235         rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
 236
 237         if (unflushed) {
 238                 duration =
 239                     jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
 240
 241                 IWL_DEBUG_RATE(priv, "Tx'd %d packets in %dms\n",
 242                                packet_count, duration);
 243
 244                 /* Determine packets per second */
 245                 if (duration)
 246                         pps = (packet_count * 1000) / duration;
 247                 else
 248                         pps = 0;
 249
 250                 if (pps) {
 251                         duration = (IWL_AVERAGE_PACKETS * 1000) / pps;
 252                         if (duration < IWL_RATE_FLUSH_MIN)
 253                                 duration = IWL_RATE_FLUSH_MIN;
 254                         else if (duration > IWL_RATE_FLUSH_MAX)
 255                                 duration = IWL_RATE_FLUSH_MAX;
 256                 } else
 257                         duration = IWL_RATE_FLUSH_MAX;
 258
 259                 rs_sta->flush_time = msecs_to_jiffies(duration);
 260
 261                 IWL_DEBUG_RATE(priv, "new flush period: %d msec ave %d\n",
 262                                duration, packet_count);
 263
 264                 mod_timer(&rs_sta->rate_scale_flush, jiffies +
 265                           rs_sta->flush_time);
 266
 267                 rs_sta->last_partial_flush = jiffies;
 268         } else {
 269                 rs_sta->flush_time = IWL_RATE_FLUSH;
 270                 rs_sta->flush_pending = 0;
 271         }
 272         /* If there weren't any unflushed entries, we don't schedule the timer
 273          * to run again */
 274
 275         rs_sta->last_flush = jiffies;
 276
 277         spin_unlock_irqrestore(&rs_sta->lock, flags);
 278
 279         IWL_DEBUG_RATE(priv, "leave\n");
 280 }
 281
 282 /**
 283  * iwl3945_collect_tx_data - Update the success/failure sliding window
 284  *
 285  * We keep a sliding window of the last 64 packets transmitted
 286  * at this rate.  window->data contains the bitmask of successful
 287  * packets.
 288  */
 289 static void iwl3945_collect_tx_data(struct iwl3945_rs_sta *rs_sta,
 290                                 struct iwl3945_rate_scale_data *window,
 291                                 int success, int retries, int index)
 292 {
 293         unsigned long flags;
 294         s32 fail_count;
 295         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 296
 297         if (!retries) {
 298                 IWL_DEBUG_RATE(priv, "leave: retries == 0 -- should be at least 1\n");
 299                 return;
 300         }
 301
 302         spin_lock_irqsave(&rs_sta->lock, flags);
 303
 304         /*
 305          * Keep track of only the latest 62 tx frame attempts in this rate's
 306          * history window; anything older isn't really relevant any more.
 307          * If we have filled up the sliding window, drop the oldest attempt;
 308          * if the oldest attempt (highest bit in bitmap) shows "success",
 309          * subtract "1" from the success counter (this is the main reason
 310          * we keep these bitmaps!).
 311          * */
 312         while (retries > 0) {
 313                 if (window->counter >= IWL_RATE_MAX_WINDOW) {
 314
 315                         /* remove earliest */
 316                         window->counter = IWL_RATE_MAX_WINDOW - 1;
 317
 318                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1))) {
 319                                 window->data &= ~(1ULL << (IWL_RATE_MAX_WINDOW - 1));
 320                                 window->success_counter--;
 321                         }
 322                 }
 323
 324                 /* Increment frames-attempted counter */
 325                 window->counter++;
 326
 327                 /* Shift bitmap by one frame (throw away oldest history),
 328                  * OR in "1", and increment "success" if this
 329                  * frame was successful. */
 330                 window->data <<= 1;
 331                 if (success > 0) {
 332                         window->success_counter++;
 333                         window->data |= 0x1;
 334                         success--;
 335                 }
 336
 337                 retries--;
 338         }
 339
 340         /* Calculate current success ratio, avoid divide-by-0! */
 341         if (window->counter > 0)
 342                 window->success_ratio = 128 * (100 * window->success_counter)
 343                                         / window->counter;
 344         else
 345                 window->success_ratio = IWL_INVALID_VALUE;
 346
 347         fail_count = window->counter - window->success_counter;
 348
 349         /* Calculate average throughput, if we have enough history. */
 350         if ((fail_count >= IWL_RATE_MIN_FAILURE_TH) ||
 351             (window->success_counter >= IWL_RATE_MIN_SUCCESS_TH))
 352                 window->average_tpt = ((window->success_ratio *
 353                                 rs_sta->expected_tpt[index] + 64) / 128);
 354         else
 355                 window->average_tpt = IWL_INVALID_VALUE;
 356
 357         /* Tag this window as having been updated */
 358         window->stamp = jiffies;
 359
 360         spin_unlock_irqrestore(&rs_sta->lock, flags);
 361
 362 }
 363
 364 static void rs_rate_init(void *priv_r, struct ieee80211_supported_band *sband,
 365                          struct ieee80211_sta *sta, void *priv_sta)
 366 {
 367         struct iwl3945_rs_sta *rs_sta = priv_sta;
 368         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
 369         int i;
 370
 371         IWL_DEBUG_RATE(priv, "enter\n");
 372
 373         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 374          * the lowest or the highest rate.. Could consider using RSSI from
 375          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 376          * after assoc.. */
 377
 378         for (i = sband->n_bitrates - 1; i >= 0; i--) {
 379                 if (sta->supp_rates[sband->band] & (1 << i)) {
 380                         rs_sta->last_txrate_idx = i;
 381                         break;
 382                 }
 383         }
 384
 385         priv->sta_supp_rates = sta->supp_rates[sband->band];
 386         /* For 5 GHz band it start at IWL_FIRST_OFDM_RATE */
 387         if (sband->band == IEEE80211_BAND_5GHZ) {
 388                 rs_sta->last_txrate_idx += IWL_FIRST_OFDM_RATE;
 389                 priv->sta_supp_rates = priv->sta_supp_rates <<
 390                                                 IWL_FIRST_OFDM_RATE;
 391         }
 392
 393
 394         IWL_DEBUG_RATE(priv, "leave\n");
 395 }
 396
 397 static void *rs_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
 398 {
 399         return hw->priv;
 400 }
 401
 402 /* rate scale requires free function to be implemented */
 403 static void rs_free(void *priv)
 404 {
 405         return;
 406 }
 407
 408 static void *rs_alloc_sta(void *iwl_priv, struct ieee80211_sta *sta, gfp_t gfp)
 409 {
 410         struct iwl3945_rs_sta *rs_sta;
 411         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 412         struct iwl_priv *priv = iwl_priv;
 413         int i;
 414
 415         /*
 416          * XXX: If it's using sta->drv_priv anyway, it might
 417          *      as well just put all the information there.
 418          */
 419
 420         IWL_DEBUG_RATE(priv, "enter\n");
 421
 422         rs_sta = kzalloc(sizeof(struct iwl3945_rs_sta), gfp);
 423         if (!rs_sta) {
 424                 IWL_DEBUG_RATE(priv, "leave: ENOMEM\n");
 425                 return NULL;
 426         }
 427
 428         psta->rs_sta = rs_sta;
 429
 430         spin_lock_init(&rs_sta->lock);
 431
 432         rs_sta->priv = priv;
 433
 434         rs_sta->start_rate = IWL_RATE_INVALID;
 435
 436         /* default to just 802.11b */
 437         rs_sta->expected_tpt = iwl3945_expected_tpt_b;
 438
 439         rs_sta->last_partial_flush = jiffies;
 440         rs_sta->last_flush = jiffies;
 441         rs_sta->flush_time = IWL_RATE_FLUSH;
 442         rs_sta->last_tx_packets = 0;
 443         rs_sta->ibss_sta_added = 0;
 444
 445         init_timer(&rs_sta->rate_scale_flush);
 446         rs_sta->rate_scale_flush.data = (unsigned long)rs_sta;
 447         rs_sta->rate_scale_flush.function = &iwl3945_bg_rate_scale_flush;
 448
 449         for (i = 0; i < IWL_RATE_COUNT_3945; i++)
 450                 iwl3945_clear_window(&rs_sta->win[i]);
 451
 452         IWL_DEBUG_RATE(priv, "leave\n");
 453
 454         return rs_sta;
 455 }
 456
 457 static void rs_free_sta(void *iwl_priv, struct ieee80211_sta *sta,
 458                         void *priv_sta)
 459 {
 460         struct iwl3945_sta_priv *psta = (void *) sta->drv_priv;
 461         struct iwl3945_rs_sta *rs_sta = priv_sta;
 462         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 463
 464         psta->rs_sta = NULL;
 465
 466         IWL_DEBUG_RATE(priv, "enter\n");
 467         del_timer_sync(&rs_sta->rate_scale_flush);
 468         kfree(rs_sta);
 469         IWL_DEBUG_RATE(priv, "leave\n");
 470 }
 471
 472
 473 /**
 474  * rs_tx_status - Update rate control values based on Tx results
 475  *
 476  * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
 477  * the hardware for each rate.
 478  */
 479 static void rs_tx_status(void *priv_rate, struct ieee80211_supported_band *sband,
 480                          struct ieee80211_sta *sta, void *priv_sta,
 481                          struct sk_buff *skb)
 482 {
 483         s8 retries = 0, current_count;
 484         int scale_rate_index, first_index, last_index;
 485         unsigned long flags;
 486         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 487         struct iwl3945_rs_sta *rs_sta = priv_sta;
 488         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 489
 490         IWL_DEBUG_RATE(priv, "enter\n");
 491
 492         retries = info->status.rates[0].count;
 493         /* Sanity Check for retries */
 494         if (retries > IWL_RATE_RETRY_TH)
 495                 retries = IWL_RATE_RETRY_TH;
 496
 497         first_index = sband->bitrates[info->status.rates[0].idx].hw_value;
 498         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT_3945)) {
 499                 IWL_DEBUG_RATE(priv, "leave: Rate out of bounds: %d\n", first_index);
 500                 return;
 501         }
 502
 503         if (!priv_sta) {
 504                 IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
 505                 return;
 506         }
 507
 508         rs_sta->tx_packets++;
 509
 510         scale_rate_index = first_index;
 511         last_index = first_index;
 512
 513         /*
 514          * Update the window for each rate.  We determine which rates
 515          * were Tx'd based on the total number of retries vs. the number
 516          * of retries configured for each rate -- currently set to the
 517          * priv value 'retry_rate' vs. rate specific
 518          *
 519          * On exit from this while loop last_index indicates the rate
 520          * at which the frame was finally transmitted (or failed if no
 521          * ACK)
 522          */
 523         while (retries > 1) {
 524                 if ((retries - 1) < priv->retry_rate) {
 525                         current_count = (retries - 1);
 526                         last_index = scale_rate_index;
 527                 } else {
 528                         current_count = priv->retry_rate;
 529                         last_index = iwl3945_rs_next_rate(priv,
 530                                                          scale_rate_index);
 531                 }
 532
 533                 /* Update this rate accounting for as many retries
 534                  * as was used for it (per current_count) */
 535                 iwl3945_collect_tx_data(rs_sta,
 536                                     &rs_sta->win[scale_rate_index],
 537                                     0, current_count, scale_rate_index);
 538                 IWL_DEBUG_RATE(priv, "Update rate %d for %d retries.\n",
 539                                scale_rate_index, current_count);
 540
 541                 retries -= current_count;
 542
 543                 scale_rate_index = last_index;
 544         }
 545
 546
 547         /* Update the last index window with success/failure based on ACK */
 548         IWL_DEBUG_RATE(priv, "Update rate %d with %s.\n",
 549                        last_index,
 550                        (info->flags & IEEE80211_TX_STAT_ACK) ?
 551                        "success" : "failure");
 552         iwl3945_collect_tx_data(rs_sta,
 553                             &rs_sta->win[last_index],
 554                             info->flags & IEEE80211_TX_STAT_ACK, 1, last_index);
 555
 556         /* We updated the rate scale window -- if its been more than
 557          * flush_time since the last run, schedule the flush
 558          * again */
 559         spin_lock_irqsave(&rs_sta->lock, flags);
 560
 561         if (!rs_sta->flush_pending &&
 562             time_after(jiffies, rs_sta->last_flush +
 563                        rs_sta->flush_time)) {
 564
 565                 rs_sta->last_partial_flush = jiffies;
 566                 rs_sta->flush_pending = 1;
 567                 mod_timer(&rs_sta->rate_scale_flush,
 568                           jiffies + rs_sta->flush_time);
 569         }
 570
 571         spin_unlock_irqrestore(&rs_sta->lock, flags);
 572
 573         IWL_DEBUG_RATE(priv, "leave\n");
 574
 575         return;
 576 }
 577
 578 static u16 iwl3945_get_adjacent_rate(struct iwl3945_rs_sta *rs_sta,
 579                                  u8 index, u16 rate_mask, enum ieee80211_band band)
 580 {
 581         u8 high = IWL_RATE_INVALID;
 582         u8 low = IWL_RATE_INVALID;
 583         struct iwl_priv *priv __maybe_unused = rs_sta->priv;
 584
 585         /* 802.11A walks to the next literal adjacent rate in
 586          * the rate table */
 587         if (unlikely(band == IEEE80211_BAND_5GHZ)) {
 588                 int i;
 589                 u32 mask;
 590
 591                 /* Find the previous rate that is in the rate mask */
 592                 i = index - 1;
 593                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 594                         if (rate_mask & mask) {
 595                                 low = i;
 596                                 break;
 597                         }
 598                 }
 599
 600                 /* Find the next rate that is in the rate mask */
 601                 i = index + 1;
 602                 for (mask = (1 << i); i < IWL_RATE_COUNT_3945;
 603                      i++, mask <<= 1) {
 604                         if (rate_mask & mask) {
 605                                 high = i;
 606                                 break;
 607                         }
 608                 }
 609
 610                 return (high << 8) | low;
 611         }
 612
 613         low = index;
 614         while (low != IWL_RATE_INVALID) {
 615                 if (rs_sta->tgg)
 616                         low = iwl3945_rates[low].prev_rs_tgg;
 617                 else
 618                         low = iwl3945_rates[low].prev_rs;
 619                 if (low == IWL_RATE_INVALID)
 620                         break;
 621                 if (rate_mask & (1 << low))
 622                         break;
 623                 IWL_DEBUG_RATE(priv, "Skipping masked lower rate: %d\n", low);
 624         }
 625
 626         high = index;
 627         while (high != IWL_RATE_INVALID) {
 628                 if (rs_sta->tgg)
 629                         high = iwl3945_rates[high].next_rs_tgg;
 630                 else
 631                         high = iwl3945_rates[high].next_rs;
 632                 if (high == IWL_RATE_INVALID)
 633                         break;
 634                 if (rate_mask & (1 << high))
 635                         break;
 636                 IWL_DEBUG_RATE(priv, "Skipping masked higher rate: %d\n", high);
 637         }
 638
 639         return (high << 8) | low;
 640 }
 641
 642 /**
 643  * rs_get_rate - find the rate for the requested packet
 644  *
 645  * Returns the ieee80211_rate structure allocated by the driver.
 646  *
 647  * The rate control algorithm has no internal mapping between hw_mode's
 648  * rate ordering and the rate ordering used by the rate control algorithm.
 649  *
 650  * The rate control algorithm uses a single table of rates that goes across
 651  * the entire A/B/G spectrum vs. being limited to just one particular
 652  * hw_mode.
 653  *
 654  * As such, we can't convert the index obtained below into the hw_mode's
 655  * rate table and must reference the driver allocated rate table
 656  *
 657  */
 658 static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
 659                         void *priv_sta, struct ieee80211_tx_rate_control *txrc)
 660 {
 661         struct ieee80211_supported_band *sband = txrc->sband;
 662         struct sk_buff *skb = txrc->skb;
 663         u8 low = IWL_RATE_INVALID;
 664         u8 high = IWL_RATE_INVALID;
 665         u16 high_low;
 666         int index;
 667         struct iwl3945_rs_sta *rs_sta = priv_sta;
 668         struct iwl3945_rate_scale_data *window = NULL;
 669         int current_tpt = IWL_INVALID_VALUE;
 670         int low_tpt = IWL_INVALID_VALUE;
 671         int high_tpt = IWL_INVALID_VALUE;
 672         u32 fail_count;
 673         s8 scale_action = 0;
 674         unsigned long flags;
 675         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 676         u16 fc;
 677         u16 rate_mask = sta ? sta->supp_rates[sband->band] : 0;
 678         s8 max_rate_idx = -1;
 679         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
 680         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 681
 682         IWL_DEBUG_RATE(priv, "enter\n");
 683
 684         /* Send management frames and NO_ACK data using lowest rate. */
 685         fc = le16_to_cpu(hdr->frame_control);
 686         if ((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA ||
 687             info->flags & IEEE80211_TX_CTL_NO_ACK ||
 688             !sta || !priv_sta) {
 689                 IWL_DEBUG_RATE(priv, "leave: No STA priv data to update!\n");
 690                 info->control.rates[0].idx = rate_lowest_index(sband, sta);
 691                 if (info->flags & IEEE80211_TX_CTL_NO_ACK)
 692                         info->control.rates[0].count = 1;
 693                 return;
 694         }
 695
 696         /* get user max rate if set */
 697         max_rate_idx = txrc->max_rate_idx;
 698         if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1))
 699                 max_rate_idx += IWL_FIRST_OFDM_RATE;
 700         if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT))
 701                 max_rate_idx = -1;
 702
 703         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
 704
 705         if (sband->band == IEEE80211_BAND_5GHZ)
 706                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 707
 708         if ((priv->iw_mode == NL80211_IFTYPE_ADHOC) &&
 709             !rs_sta->ibss_sta_added) {
 710                 u8 sta_id = iwl_find_station(priv, hdr->addr1);
 711
 712                 if (sta_id == IWL_INVALID_STATION) {
 713                         IWL_DEBUG_RATE(priv, "LQ: ADD station %pm\n",
 714                                        hdr->addr1);
 715                         sta_id = iwl_add_station(priv, hdr->addr1, false,
 716                                 CMD_ASYNC, NULL);
 717                 }
 718                 if (sta_id != IWL_INVALID_STATION)
 719                         rs_sta->ibss_sta_added = 1;
 720         }
 721
 722         spin_lock_irqsave(&rs_sta->lock, flags);
 723
 724         /* for recent assoc, choose best rate regarding
 725          * to rssi value
 726          */
 727         if (rs_sta->start_rate != IWL_RATE_INVALID) {
 728                 if (rs_sta->start_rate < index &&
 729                    (rate_mask & (1 << rs_sta->start_rate)))
 730                         index = rs_sta->start_rate;
 731                 rs_sta->start_rate = IWL_RATE_INVALID;
 732         }
 733
 734         /* force user max rate if set by user */
 735         if ((max_rate_idx != -1) && (max_rate_idx < index)) {
 736                 if (rate_mask & (1 << max_rate_idx))
 737                         index = max_rate_idx;
 738         }
 739
 740         window = &(rs_sta->win[index]);
 741
 742         fail_count = window->counter - window->success_counter;
 743
 744         if (((fail_count < IWL_RATE_MIN_FAILURE_TH) &&
 745              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 746                 spin_unlock_irqrestore(&rs_sta->lock, flags);
 747
 748                 IWL_DEBUG_RATE(priv, "Invalid average_tpt on rate %d: "
 749                                "counter: %d, success_counter: %d, "
 750                                "expected_tpt is %sNULL\n",
 751                                index,
 752                                window->counter,
 753                                window->success_counter,
 754                                rs_sta->expected_tpt ? "not " : "");
 755
 756            /* Can't calculate this yet; not enough history */
 757                 window->average_tpt = IWL_INVALID_VALUE;
 758                 goto out;
 759
 760         }
 761
 762         current_tpt = window->average_tpt;
 763
 764         high_low = iwl3945_get_adjacent_rate(rs_sta, index, rate_mask,
 765                                              sband->band);
 766         low = high_low & 0xff;
 767         high = (high_low >> 8) & 0xff;
 768
 769         /* If user set max rate, dont allow higher than user constrain */
 770         if ((max_rate_idx != -1) && (max_rate_idx < high))
 771                 high = IWL_RATE_INVALID;
 772
 773         /* Collect Measured throughputs of adjacent rates */
 774         if (low != IWL_RATE_INVALID)
 775                 low_tpt = rs_sta->win[low].average_tpt;
 776
 777         if (high != IWL_RATE_INVALID)
 778                 high_tpt = rs_sta->win[high].average_tpt;
 779
 780         spin_unlock_irqrestore(&rs_sta->lock, flags);
 781
 782         scale_action = 0;
 783
 784         /* Low success ratio , need to drop the rate */
 785         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 786                 IWL_DEBUG_RATE(priv, "decrease rate because of low success_ratio\n");
 787                 scale_action = -1;
 788         /* No throughput measured yet for adjacent rates,
 789          * try increase */
 790         } else if ((low_tpt == IWL_INVALID_VALUE) &&
 791                    (high_tpt == IWL_INVALID_VALUE)) {
 792
 793                 if (high != IWL_RATE_INVALID && window->success_ratio >= IWL_RATE_INCREASE_TH)
 794                         scale_action = 1;
 795                 else if (low != IWL_RATE_INVALID)
 796                         scale_action = 0;
 797
 798         /* Both adjacent throughputs are measured, but neither one has
 799          * better throughput; we're using the best rate, don't change
 800          * it! */
 801         } else if ((low_tpt != IWL_INVALID_VALUE) &&
 802                  (high_tpt != IWL_INVALID_VALUE) &&
 803                  (low_tpt < current_tpt) && (high_tpt < current_tpt)) {
 804
 805                 IWL_DEBUG_RATE(priv, "No action -- low [%d] & high [%d] < "
 806                                "current_tpt [%d]\n",
 807                                low_tpt, high_tpt, current_tpt);
 808                 scale_action = 0;
 809
 810         /* At least one of the rates has better throughput */
 811         } else {
 812                 if (high_tpt != IWL_INVALID_VALUE) {
 813
 814                         /* High rate has better throughput, Increase
 815                          * rate */
 816                         if (high_tpt > current_tpt &&
 817                                 window->success_ratio >= IWL_RATE_INCREASE_TH)
 818                                 scale_action = 1;
 819                         else {
 820                                 IWL_DEBUG_RATE(priv,
 821                                     "decrease rate because of high tpt\n");
 822                                 scale_action = 0;
 823                         }
 824                 } else if (low_tpt != IWL_INVALID_VALUE) {
 825                         if (low_tpt > current_tpt) {
 826                                 IWL_DEBUG_RATE(priv,
 827                                     "decrease rate because of low tpt\n");
 828                                 scale_action = -1;
 829                         } else if (window->success_ratio >= IWL_RATE_INCREASE_TH) {
 830                                 /* Lower rate has better
 831                                  * throughput,decrease rate */
 832                                 scale_action = 1;
 833                         }
 834                 }
 835         }
 836
 837         /* Sanity check; asked for decrease, but success rate or throughput
 838          * has been good at old rate.  Don't change it. */
 839         if ((scale_action == -1) && (low != IWL_RATE_INVALID) &&
 840                     ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 841                      (current_tpt > (100 * rs_sta->expected_tpt[low]))))
 842                 scale_action = 0;
 843
 844         switch (scale_action) {
 845         case -1:
 846
 847                 /* Decrese rate */
 848                 if (low != IWL_RATE_INVALID)
 849                         index = low;
 850                 break;
 851
 852         case 1:
 853                 /* Increase rate */
 854                 if (high != IWL_RATE_INVALID)
 855                         index = high;
 856
 857                 break;
 858
 859         case 0:
 860         default:
 861                 /* No change */
 862                 break;
 863         }
 864
 865         IWL_DEBUG_RATE(priv, "Selected %d (action %d) - low %d high %d\n",
 866                        index, scale_action, low, high);
 867
 868  out:
 869
 870         rs_sta->last_txrate_idx = index;
 871         if (sband->band == IEEE80211_BAND_5GHZ)
 872                 info->control.rates[0].idx = rs_sta->last_txrate_idx -
 873                                 IWL_FIRST_OFDM_RATE;
 874         else
 875                 info->control.rates[0].idx = rs_sta->last_txrate_idx;
 876
 877         IWL_DEBUG_RATE(priv, "leave: %d\n", index);
 878 }
 879
 880 #ifdef CONFIG_MAC80211_DEBUGFS
 881 static int iwl3945_open_file_generic(struct inode *inode, struct file *file)
 882 {
 883         file->private_data = inode->i_private;
 884         return 0;
 885 }
 886
 887 static ssize_t iwl3945_sta_dbgfs_stats_table_read(struct file *file,
 888                                                   char __user *user_buf,
 889                                                   size_t count, loff_t *ppos)
 890 {
 891         char *buff;
 892         int desc = 0;
 893         int j;
 894         ssize_t ret;
 895         struct iwl3945_rs_sta *lq_sta = file->private_data;
 896
 897         buff = kmalloc(1024, GFP_KERNEL);
 898         if (!buff)
 899                 return -ENOMEM;
 900
 901         desc += sprintf(buff + desc, "tx packets=%d last rate index=%d\n"
 902                         "rate=0x%X flush time %d\n",
 903                         lq_sta->tx_packets,
 904                         lq_sta->last_txrate_idx,
 905                         lq_sta->start_rate, jiffies_to_msecs(lq_sta->flush_time));
 906         for (j = 0; j < IWL_RATE_COUNT_3945; j++) {
 907                 desc += sprintf(buff+desc,
 908                                 "counter=%d success=%d %%=%d\n",
 909                                 lq_sta->win[j].counter,
 910                                 lq_sta->win[j].success_counter,
 911                                 lq_sta->win[j].success_ratio);
 912         }
 913         ret = simple_read_from_buffer(user_buf, count, ppos, buff, desc);
 914         kfree(buff);
 915         return ret;
 916 }
 917
 918 static const struct file_operations rs_sta_dbgfs_stats_table_ops = {
 919         .read = iwl3945_sta_dbgfs_stats_table_read,
 920         .open = iwl3945_open_file_generic,
 921 };
 922
 923 static void iwl3945_add_debugfs(void *priv, void *priv_sta,
 924                                 struct dentry *dir)
 925 {
 926         struct iwl3945_rs_sta *lq_sta = priv_sta;
 927
 928         lq_sta->rs_sta_dbgfs_stats_table_file =
 929                 debugfs_create_file("rate_stats_table", 0600, dir,
 930                 lq_sta, &rs_sta_dbgfs_stats_table_ops);
 931
 932 }
 933
 934 static void iwl3945_remove_debugfs(void *priv, void *priv_sta)
 935 {
 936         struct iwl3945_rs_sta *lq_sta = priv_sta;
 937         debugfs_remove(lq_sta->rs_sta_dbgfs_stats_table_file);
 938 }
 939 #endif
 940
 941 static struct rate_control_ops rs_ops = {
 942         .module = NULL,
 943         .name = RS_NAME,
 944         .tx_status = rs_tx_status,
 945         .get_rate = rs_get_rate,
 946         .rate_init = rs_rate_init,
 947         .alloc = rs_alloc,
 948         .free = rs_free,
 949         .alloc_sta = rs_alloc_sta,
 950         .free_sta = rs_free_sta,
 951 #ifdef CONFIG_MAC80211_DEBUGFS
 952         .add_sta_debugfs = iwl3945_add_debugfs,
 953         .remove_sta_debugfs = iwl3945_remove_debugfs,
 954 #endif
 955
 956 };
 957
 958 void iwl3945_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 959 {
 960         struct iwl_priv *priv = hw->priv;
 961         s32 rssi = 0;
 962         unsigned long flags;
 963         struct iwl3945_rs_sta *rs_sta;
 964         struct ieee80211_sta *sta;
 965         struct iwl3945_sta_priv *psta;
 966
 967         IWL_DEBUG_RATE(priv, "enter\n");
 968
 969         rcu_read_lock();
 970
 971         sta = ieee80211_find_sta(hw, priv->stations[sta_id].sta.sta.addr);
 972         if (!sta) {
 973                 rcu_read_unlock();
 974                 return;
 975         }
 976
 977         psta = (void *) sta->drv_priv;
 978         rs_sta = psta->rs_sta;
 979
 980         spin_lock_irqsave(&rs_sta->lock, flags);
 981
 982         rs_sta->tgg = 0;
 983         switch (priv->band) {
 984         case IEEE80211_BAND_2GHZ:
 985                 /* TODO: this always does G, not a regression */
 986                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 987                         rs_sta->tgg = 1;
 988                         rs_sta->expected_tpt = iwl3945_expected_tpt_g_prot;
 989                 } else
 990                         rs_sta->expected_tpt = iwl3945_expected_tpt_g;
 991                 break;
 992
 993         case IEEE80211_BAND_5GHZ:
 994                 rs_sta->expected_tpt = iwl3945_expected_tpt_a;
 995                 break;
 996         case IEEE80211_NUM_BANDS:
 997                 BUG();
 998                 break;
 999         }
1000
1001         spin_unlock_irqrestore(&rs_sta->lock, flags);
1002
1003         rssi = priv->last_rx_rssi;
1004         if (rssi == 0)
1005                 rssi = IWL_MIN_RSSI_VAL;
1006
1007         IWL_DEBUG_RATE(priv, "Network RSSI: %d\n", rssi);
1008
1009         rs_sta->start_rate = iwl3945_get_rate_index_by_rssi(rssi, priv->band);
1010
1011         IWL_DEBUG_RATE(priv, "leave: rssi %d assign rate index: "
1012                        "%d (plcp 0x%x)\n", rssi, rs_sta->start_rate,
1013                        iwl3945_rates[rs_sta->start_rate].plcp);
1014         rcu_read_unlock();
1015 }
1016
1017 int iwl3945_rate_control_register(void)
1018 {
1019         return ieee80211_rate_control_register(&rs_ops);
1020 }
1021
1022 void iwl3945_rate_control_unregister(void)
1023 {
1024         ieee80211_rate_control_unregister(&rs_ops);
1025 }
1026
1027