git.oblomov.eu Git - linux-2.6/blob - drivers/net/wireless/iwlwifi/iwl-3945-rs.c

   1 /******************************************************************************
   2  *
   3  * Copyright(c) 2005 - 2007 Intel Corporation. All rights reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
  17  *
  18  * The full GNU General Public License is included in this distribution in the
  19  * file called LICENSE.
  20  *
  21  * Contact Information:
  22  * James P. Ketrenos <ipw2100-admin@linux.intel.com>
  23  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
  24  *
  25  *****************************************************************************/
  26
  27 #include <linux/kernel.h>
  28 #include <linux/init.h>
  29 #include <linux/skbuff.h>
  30 #include <linux/wireless.h>
  31 #include <net/mac80211.h>
  32 #include <net/ieee80211.h>
  33
  34 #include <linux/netdevice.h>
  35 #include <linux/etherdevice.h>
  36 #include <linux/delay.h>
  37
  38 #include <linux/workqueue.h>
  39
  40 #define IWL 3945
  41
  42 #include "../net/mac80211/ieee80211_rate.h"
  43
  44 #include "iwlwifi.h"
  45
  46 #define RS_NAME "iwl-3945-rs"
  47
  48 struct iwl_rate_scale_data {
  49         u64 data;
  50         s32 success_counter;
  51         s32 success_ratio;
  52         s32 counter;
  53         s32 average_tpt;
  54         unsigned long stamp;
  55 };
  56
  57 struct iwl_rate_scale_priv {
  58         spinlock_t lock;
  59         s32 *expected_tpt;
  60         unsigned long last_partial_flush;
  61         unsigned long last_flush;
  62         u32 flush_time;
  63         u32 last_tx_packets;
  64         u32 tx_packets;
  65         u8 tgg;
  66         u8 flush_pending;
  67         u8 start_rate;
  68         u8 ibss_sta_added;
  69         struct timer_list rate_scale_flush;
  70         struct iwl_rate_scale_data win[IWL_RATE_COUNT];
  71 };
  72
  73 static s32 iwl_expected_tpt_g[IWL_RATE_COUNT] = {
  74         7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
  75 };
  76
  77 static s32 iwl_expected_tpt_g_prot[IWL_RATE_COUNT] = {
  78         7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
  79 };
  80
  81 static s32 iwl_expected_tpt_a[IWL_RATE_COUNT] = {
  82         0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
  83 };
  84
  85 static s32 iwl_expected_tpt_b[IWL_RATE_COUNT] = {
  86         7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
  87 };
  88
  89 struct iwl_tpt_entry {
  90         s8 min_rssi;
  91         u8 index;
  92 };
  93
  94 static struct iwl_tpt_entry iwl_tpt_table_a[] = {
  95         {-60, IWL_RATE_54M_INDEX},
  96         {-64, IWL_RATE_48M_INDEX},
  97         {-72, IWL_RATE_36M_INDEX},
  98         {-80, IWL_RATE_24M_INDEX},
  99         {-84, IWL_RATE_18M_INDEX},
 100         {-85, IWL_RATE_12M_INDEX},
 101         {-87, IWL_RATE_9M_INDEX},
 102         {-89, IWL_RATE_6M_INDEX}
 103 };
 104
 105 static struct iwl_tpt_entry iwl_tpt_table_b[] = {
 106         {-86, IWL_RATE_11M_INDEX},
 107         {-88, IWL_RATE_5M_INDEX},
 108         {-90, IWL_RATE_2M_INDEX},
 109         {-92, IWL_RATE_1M_INDEX}
 110
 111 };
 112
 113 static struct iwl_tpt_entry iwl_tpt_table_g[] = {
 114         {-60, IWL_RATE_54M_INDEX},
 115         {-64, IWL_RATE_48M_INDEX},
 116         {-68, IWL_RATE_36M_INDEX},
 117         {-80, IWL_RATE_24M_INDEX},
 118         {-84, IWL_RATE_18M_INDEX},
 119         {-85, IWL_RATE_12M_INDEX},
 120         {-86, IWL_RATE_11M_INDEX},
 121         {-88, IWL_RATE_5M_INDEX},
 122         {-90, IWL_RATE_2M_INDEX},
 123         {-92, IWL_RATE_1M_INDEX}
 124 };
 125
 126 #define IWL_RATE_MAX_WINDOW          62
 127 #define IWL_RATE_FLUSH        (3*HZ/10)
 128 #define IWL_RATE_WIN_FLUSH       (HZ/2)
 129 #define IWL_RATE_HIGH_TH          11520
 130 #define IWL_RATE_MIN_FAILURE_TH       8
 131 #define IWL_RATE_MIN_SUCCESS_TH       8
 132 #define IWL_RATE_DECREASE_TH       1920
 133
 134 static u8 iwl_get_rate_index_by_rssi(s32 rssi, u8 mode)
 135 {
 136         u32 index = 0;
 137         u32 table_size = 0;
 138         struct iwl_tpt_entry *tpt_table = NULL;
 139
 140         if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
 141                 rssi = IWL_MIN_RSSI_VAL;
 142
 143         switch (mode) {
 144         case MODE_IEEE80211G:
 145                 tpt_table = iwl_tpt_table_g;
 146                 table_size = ARRAY_SIZE(iwl_tpt_table_g);
 147                 break;
 148
 149         case MODE_IEEE80211A:
 150                 tpt_table = iwl_tpt_table_a;
 151                 table_size = ARRAY_SIZE(iwl_tpt_table_a);
 152                 break;
 153
 154         default:
 155         case MODE_IEEE80211B:
 156                 tpt_table = iwl_tpt_table_b;
 157                 table_size = ARRAY_SIZE(iwl_tpt_table_b);
 158                 break;
 159         }
 160
 161         while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
 162                 index++;
 163
 164         index = min(index, (table_size - 1));
 165
 166         return tpt_table[index].index;
 167 }
 168
 169 static void iwl_clear_window(struct iwl_rate_scale_data *window)
 170 {
 171         window->data = 0;
 172         window->success_counter = 0;
 173         window->success_ratio = IWL_INVALID_VALUE;
 174         window->counter = 0;
 175         window->average_tpt = IWL_INVALID_VALUE;
 176         window->stamp = 0;
 177 }
 178
 179 /**
 180  * iwl_rate_scale_flush_windows - flush out the rate scale windows
 181  *
 182  * Returns the number of windows that have gathered data but were
 183  * not flushed.  If there were any that were not flushed, then
 184  * reschedule the rate flushing routine.
 185  */
 186 static int iwl_rate_scale_flush_windows(struct iwl_rate_scale_priv *rs_priv)
 187 {
 188         int unflushed = 0;
 189         int i;
 190         unsigned long flags;
 191
 192         /*
 193          * For each rate, if we have collected data on that rate
 194          * and it has been more than IWL_RATE_WIN_FLUSH
 195          * since we flushed, clear out the gathered statistics
 196          */
 197         for (i = 0; i < IWL_RATE_COUNT; i++) {
 198                 if (!rs_priv->win[i].counter)
 199                         continue;
 200
 201                 spin_lock_irqsave(&rs_priv->lock, flags);
 202                 if (time_after(jiffies, rs_priv->win[i].stamp +
 203                                IWL_RATE_WIN_FLUSH)) {
 204                         IWL_DEBUG_RATE("flushing %d samples of rate "
 205                                        "index %d\n",
 206                                        rs_priv->win[i].counter, i);
 207                         iwl_clear_window(&rs_priv->win[i]);
 208                 } else
 209                         unflushed++;
 210                 spin_unlock_irqrestore(&rs_priv->lock, flags);
 211         }
 212
 213         return unflushed;
 214 }
 215
 216 #define IWL_RATE_FLUSH_MAX              5000    /* msec */
 217 #define IWL_RATE_FLUSH_MIN              50      /* msec */
 218
 219 static void iwl_bg_rate_scale_flush(unsigned long data)
 220 {
 221         struct iwl_rate_scale_priv *rs_priv = (void *)data;
 222         int unflushed = 0;
 223         unsigned long flags;
 224         u32 packet_count, duration, pps;
 225
 226         IWL_DEBUG_RATE("enter\n");
 227
 228         unflushed = iwl_rate_scale_flush_windows(rs_priv);
 229
 230         spin_lock_irqsave(&rs_priv->lock, flags);
 231
 232         rs_priv->flush_pending = 0;
 233
 234         /* Number of packets Rx'd since last time this timer ran */
 235         packet_count = (rs_priv->tx_packets - rs_priv->last_tx_packets) + 1;
 236
 237         rs_priv->last_tx_packets = rs_priv->tx_packets + 1;
 238
 239         if (unflushed) {
 240                 duration =
 241                     jiffies_to_msecs(jiffies - rs_priv->last_partial_flush);
 242 /*              duration = jiffies_to_msecs(rs_priv->flush_time); */
 243
 244                 IWL_DEBUG_RATE("Tx'd %d packets in %dms\n",
 245                                packet_count, duration);
 246
 247                 /* Determine packets per second */
 248                 if (duration)
 249                         pps = (packet_count * 1000) / duration;
 250                 else
 251                         pps = 0;
 252
 253                 if (pps) {
 254                         duration = IWL_RATE_FLUSH_MAX / pps;
 255                         if (duration < IWL_RATE_FLUSH_MIN)
 256                                 duration = IWL_RATE_FLUSH_MIN;
 257                 } else
 258                         duration = IWL_RATE_FLUSH_MAX;
 259
 260                 rs_priv->flush_time = msecs_to_jiffies(duration);
 261
 262                 IWL_DEBUG_RATE("new flush period: %d msec ave %d\n",
 263                                duration, packet_count);
 264
 265                 mod_timer(&rs_priv->rate_scale_flush, jiffies +
 266                           rs_priv->flush_time);
 267
 268                 rs_priv->last_partial_flush = jiffies;
 269         }
 270
 271         /* If there weren't any unflushed entries, we don't schedule the timer
 272          * to run again */
 273
 274         rs_priv->last_flush = jiffies;
 275
 276         spin_unlock_irqrestore(&rs_priv->lock, flags);
 277
 278         IWL_DEBUG_RATE("leave\n");
 279 }
 280
 281 /**
 282  * iwl_collect_tx_data - Update the success/failure sliding window
 283  *
 284  * We keep a sliding window of the last 64 packets transmitted
 285  * at this rate.  window->data contains the bitmask of successful
 286  * packets.
 287  */
 288 static void iwl_collect_tx_data(struct iwl_rate_scale_priv *rs_priv,
 289                                 struct iwl_rate_scale_data *window,
 290                                 int success, int retries)
 291 {
 292         unsigned long flags;
 293
 294         if (!retries) {
 295                 IWL_DEBUG_RATE("leave: retries == 0 -- should be at least 1\n");
 296                 return;
 297         }
 298
 299         while (retries--) {
 300                 spin_lock_irqsave(&rs_priv->lock, flags);
 301
 302                 /* If we have filled up the window then subtract one from the
 303                  * success counter if the high-bit is counting toward
 304                  * success */
 305                 if (window->counter == IWL_RATE_MAX_WINDOW) {
 306                         if (window->data & (1ULL << (IWL_RATE_MAX_WINDOW - 1)))
 307                                 window->success_counter--;
 308                 } else
 309                         window->counter++;
 310
 311                 /* Slide the window to the left one bit */
 312                 window->data = (window->data << 1);
 313
 314                 /* If this packet was a success then set the low bit high */
 315                 if (success) {
 316                         window->success_counter++;
 317                         window->data |= 1;
 318                 }
 319
 320                 /* window->counter can't be 0 -- it is either >0 or
 321                  * IWL_RATE_MAX_WINDOW */
 322                 window->success_ratio = 12800 * window->success_counter /
 323                     window->counter;
 324
 325                 /* Tag this window as having been updated */
 326                 window->stamp = jiffies;
 327
 328                 spin_unlock_irqrestore(&rs_priv->lock, flags);
 329         }
 330 }
 331
 332 static void rs_rate_init(void *priv_rate, void *priv_sta,
 333                          struct ieee80211_local *local, struct sta_info *sta)
 334 {
 335         int i;
 336
 337         IWL_DEBUG_RATE("enter\n");
 338
 339         /* TODO: what is a good starting rate for STA? About middle? Maybe not
 340          * the lowest or the highest rate.. Could consider using RSSI from
 341          * previous packets? Need to have IEEE 802.1X auth succeed immediately
 342          * after assoc.. */
 343
 344         for (i = IWL_RATE_COUNT - 1; i >= 0; i--) {
 345                 if (sta->supp_rates & (1 << i)) {
 346                         sta->txrate = i;
 347                         break;
 348                 }
 349         }
 350
 351         sta->last_txrate = sta->txrate;
 352
 353         /* For MODE_IEEE80211A mode it start at IWL_FIRST_OFDM_RATE */
 354         if (local->hw.conf.phymode == MODE_IEEE80211A)
 355                 sta->last_txrate += IWL_FIRST_OFDM_RATE;
 356
 357         IWL_DEBUG_RATE("leave\n");
 358 }
 359
 360 static void *rs_alloc(struct ieee80211_local *local)
 361 {
 362         return local->hw.priv;
 363 }
 364
 365 /* rate scale requires free function to be implmented */
 366 static void rs_free(void *priv)
 367 {
 368         return;
 369 }
 370 static void rs_clear(void *priv)
 371 {
 372         return;
 373 }
 374
 375
 376 static void *rs_alloc_sta(void *priv, gfp_t gfp)
 377 {
 378         struct iwl_rate_scale_priv *rs_priv;
 379         int i;
 380
 381         IWL_DEBUG_RATE("enter\n");
 382
 383         rs_priv = kzalloc(sizeof(struct iwl_rate_scale_priv), gfp);
 384         if (!rs_priv) {
 385                 IWL_DEBUG_RATE("leave: ENOMEM\n");
 386                 return NULL;
 387         }
 388
 389         spin_lock_init(&rs_priv->lock);
 390
 391         rs_priv->start_rate = IWL_RATE_INVALID;
 392
 393         /* default to just 802.11b */
 394         rs_priv->expected_tpt = iwl_expected_tpt_b;
 395
 396         rs_priv->last_partial_flush = jiffies;
 397         rs_priv->last_flush = jiffies;
 398         rs_priv->flush_time = IWL_RATE_FLUSH;
 399         rs_priv->last_tx_packets = 0;
 400         rs_priv->ibss_sta_added = 0;
 401
 402         init_timer(&rs_priv->rate_scale_flush);
 403         rs_priv->rate_scale_flush.data = (unsigned long)rs_priv;
 404         rs_priv->rate_scale_flush.function = &iwl_bg_rate_scale_flush;
 405
 406         for (i = 0; i < IWL_RATE_COUNT; i++)
 407                 iwl_clear_window(&rs_priv->win[i]);
 408
 409         IWL_DEBUG_RATE("leave\n");
 410
 411         return rs_priv;
 412 }
 413
 414 static void rs_free_sta(void *priv, void *priv_sta)
 415 {
 416         struct iwl_rate_scale_priv *rs_priv = priv_sta;
 417
 418         IWL_DEBUG_RATE("enter\n");
 419         del_timer_sync(&rs_priv->rate_scale_flush);
 420         kfree(rs_priv);
 421         IWL_DEBUG_RATE("leave\n");
 422 }
 423
 424
 425 /*
 426  * get ieee prev rate from rate scale table.
 427  * for A and B mode we need to overright prev
 428  * value
 429  */
 430 static int rs_adjust_next_rate(struct iwl_priv *priv, int rate)
 431 {
 432         int next_rate = iwl_get_prev_ieee_rate(rate);
 433
 434         switch (priv->phymode) {
 435         case MODE_IEEE80211A:
 436                 if (rate == IWL_RATE_12M_INDEX)
 437                         next_rate = IWL_RATE_9M_INDEX;
 438                 else if (rate == IWL_RATE_6M_INDEX)
 439                         next_rate = IWL_RATE_6M_INDEX;
 440                 break;
 441         case MODE_IEEE80211B:
 442                 if (rate == IWL_RATE_11M_INDEX_TABLE)
 443                         next_rate = IWL_RATE_5M_INDEX_TABLE;
 444                 break;
 445         default:
 446                 break;
 447         }
 448
 449         return next_rate;
 450 }
 451 /**
 452  * rs_tx_status - Update rate control values based on Tx results
 453  *
 454  * NOTE: Uses iwl_priv->retry_rate for the # of retries attempted by
 455  * the hardware for each rate.
 456  */
 457 static void rs_tx_status(void *priv_rate,
 458                          struct net_device *dev,
 459                          struct sk_buff *skb,
 460                          struct ieee80211_tx_status *tx_resp)
 461 {
 462         u8 retries, current_count;
 463         int scale_rate_index, first_index, last_index;
 464         unsigned long flags;
 465         struct sta_info *sta;
 466         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 467         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 468         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 469         struct iwl_rate_scale_priv *rs_priv;
 470
 471         IWL_DEBUG_RATE("enter\n");
 472
 473         retries = tx_resp->retry_count;
 474
 475         first_index = tx_resp->control.tx_rate;
 476         if ((first_index < 0) || (first_index >= IWL_RATE_COUNT)) {
 477                 IWL_DEBUG_RATE("leave: Rate out of bounds: %0x for %d\n",
 478                                tx_resp->control.tx_rate, first_index);
 479                 return;
 480         }
 481
 482         sta = sta_info_get(local, hdr->addr1);
 483         if (!sta || !sta->rate_ctrl_priv) {
 484                 if (sta)
 485                         sta_info_put(sta);
 486                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 487                 return;
 488         }
 489
 490         rs_priv = (void *)sta->rate_ctrl_priv;
 491
 492         rs_priv->tx_packets++;
 493
 494         scale_rate_index = first_index;
 495         last_index = first_index;
 496
 497         /*
 498          * Update the window for each rate.  We determine which rates
 499          * were Tx'd based on the total number of retries vs. the number
 500          * of retries configured for each rate -- currently set to the
 501          * priv value 'retry_rate' vs. rate specific
 502          *
 503          * On exit from this while loop last_index indicates the rate
 504          * at which the frame was finally transmitted (or failed if no
 505          * ACK)
 506          */
 507         while (retries > 0) {
 508                 if (retries < priv->retry_rate) {
 509                         current_count = retries;
 510                         last_index = scale_rate_index;
 511                 } else {
 512                         current_count = priv->retry_rate;
 513                         last_index = rs_adjust_next_rate(priv,
 514                                                          scale_rate_index);
 515                 }
 516
 517                 /* Update this rate accounting for as many retries
 518                  * as was used for it (per current_count) */
 519                 iwl_collect_tx_data(rs_priv,
 520                                     &rs_priv->win[scale_rate_index],
 521                                     0, current_count);
 522                 IWL_DEBUG_RATE("Update rate %d for %d retries.\n",
 523                                scale_rate_index, current_count);
 524
 525                 retries -= current_count;
 526
 527                 if (retries)
 528                         scale_rate_index =
 529                             rs_adjust_next_rate(priv, scale_rate_index);
 530         }
 531
 532
 533         /* Update the last index window with success/failure based on ACK */
 534         IWL_DEBUG_RATE("Update rate %d with %s.\n",
 535                        last_index,
 536                        (tx_resp->flags & IEEE80211_TX_STATUS_ACK) ?
 537                        "success" : "failure");
 538         iwl_collect_tx_data(rs_priv,
 539                             &rs_priv->win[last_index],
 540                             tx_resp->flags & IEEE80211_TX_STATUS_ACK, 1);
 541
 542         /* We updated the rate scale window -- if its been more than
 543          * flush_time since the last run, schedule the flush
 544          * again */
 545         spin_lock_irqsave(&rs_priv->lock, flags);
 546
 547         if (!rs_priv->flush_pending &&
 548             time_after(jiffies, rs_priv->last_partial_flush +
 549                        rs_priv->flush_time)) {
 550
 551                 rs_priv->flush_pending = 1;
 552                 mod_timer(&rs_priv->rate_scale_flush,
 553                           jiffies + rs_priv->flush_time);
 554         }
 555
 556         spin_unlock_irqrestore(&rs_priv->lock, flags);
 557
 558         sta_info_put(sta);
 559
 560         IWL_DEBUG_RATE("leave\n");
 561
 562         return;
 563 }
 564
 565 static struct ieee80211_rate *iwl_get_lowest_rate(struct ieee80211_local
 566                                                   *local)
 567 {
 568         struct ieee80211_hw_mode *mode = local->oper_hw_mode;
 569         int i;
 570
 571         for (i = 0; i < mode->num_rates; i++) {
 572                 struct ieee80211_rate *rate = &mode->rates[i];
 573
 574                 if (rate->flags & IEEE80211_RATE_SUPPORTED)
 575                         return rate;
 576         }
 577
 578         return &mode->rates[0];
 579 }
 580
 581 static u16 iwl_get_adjacent_rate(struct iwl_rate_scale_priv *rs_priv,
 582                                  u8 index, u16 rate_mask, int phymode)
 583 {
 584         u8 high = IWL_RATE_INVALID;
 585         u8 low = IWL_RATE_INVALID;
 586
 587         /* 802.11A walks to the next literal adjascent rate in
 588          * the rate table */
 589         if (unlikely(phymode == MODE_IEEE80211A)) {
 590                 int i;
 591                 u32 mask;
 592
 593                 /* Find the previous rate that is in the rate mask */
 594                 i = index - 1;
 595                 for (mask = (1 << i); i >= 0; i--, mask >>= 1) {
 596                         if (rate_mask & mask) {
 597                                 low = i;
 598                                 break;
 599                         }
 600                 }
 601
 602                 /* Find the next rate that is in the rate mask */
 603                 i = index + 1;
 604                 for (mask = (1 << i); i < IWL_RATE_COUNT; i++, mask <<= 1) {
 605                         if (rate_mask & mask) {
 606                                 high = i;
 607                                 break;
 608                         }
 609                 }
 610
 611                 return (high << 8) | low;
 612         }
 613
 614         low = index;
 615         while (low != IWL_RATE_INVALID) {
 616                 if (rs_priv->tgg)
 617                         low = iwl_rates[low].prev_rs_tgg;
 618                 else
 619                         low = iwl_rates[low].prev_rs;
 620                 if (low == IWL_RATE_INVALID)
 621                         break;
 622                 if (rate_mask & (1 << low))
 623                         break;
 624                 IWL_DEBUG_RATE("Skipping masked lower rate: %d\n", low);
 625         }
 626
 627         high = index;
 628         while (high != IWL_RATE_INVALID) {
 629                 if (rs_priv->tgg)
 630                         high = iwl_rates[high].next_rs_tgg;
 631                 else
 632                         high = iwl_rates[high].next_rs;
 633                 if (high == IWL_RATE_INVALID)
 634                         break;
 635                 if (rate_mask & (1 << high))
 636                         break;
 637                 IWL_DEBUG_RATE("Skipping masked higher rate: %d\n", high);
 638         }
 639
 640         return (high << 8) | low;
 641 }
 642
 643 /**
 644  * rs_get_rate - find the rate for the requested packet
 645  *
 646  * Returns the ieee80211_rate structure allocated by the driver.
 647  *
 648  * The rate control algorithm has no internal mapping between hw_mode's
 649  * rate ordering and the rate ordering used by the rate control algorithm.
 650  *
 651  * The rate control algorithm uses a single table of rates that goes across
 652  * the entire A/B/G spectrum vs. being limited to just one particular
 653  * hw_mode.
 654  *
 655  * As such, we can't convert the index obtained below into the hw_mode's
 656  * rate table and must reference the driver allocated rate table
 657  *
 658  */
 659 static struct ieee80211_rate *rs_get_rate(void *priv_rate,
 660                                           struct net_device *dev,
 661                                           struct sk_buff *skb,
 662                                           struct rate_control_extra *extra)
 663 {
 664         u8 low = IWL_RATE_INVALID;
 665         u8 high = IWL_RATE_INVALID;
 666         u16 high_low;
 667         int index;
 668         struct iwl_rate_scale_priv *rs_priv;
 669         struct iwl_rate_scale_data *window = NULL;
 670         int current_tpt = IWL_INVALID_VALUE;
 671         int low_tpt = IWL_INVALID_VALUE;
 672         int high_tpt = IWL_INVALID_VALUE;
 673         u32 fail_count;
 674         s8 scale_action = 0;
 675         unsigned long flags;
 676         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 677         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 678         struct sta_info *sta;
 679         u16 fc, rate_mask;
 680         struct iwl_priv *priv = (struct iwl_priv *)priv_rate;
 681         DECLARE_MAC_BUF(mac);
 682
 683         IWL_DEBUG_RATE("enter\n");
 684
 685         memset(extra, 0, sizeof(*extra));
 686
 687         fc = le16_to_cpu(hdr->frame_control);
 688         if (((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA) ||
 689             (is_multicast_ether_addr(hdr->addr1))) {
 690                 /* Send management frames and broadcast/multicast data using
 691                  * lowest rate. */
 692                 /* TODO: this could probably be improved.. */
 693                 IWL_DEBUG_RATE("leave: lowest rate (not data or is "
 694                                "multicast)\n");
 695
 696                 return iwl_get_lowest_rate(local);
 697         }
 698
 699         sta = sta_info_get(local, hdr->addr1);
 700         if (!sta || !sta->rate_ctrl_priv) {
 701                 IWL_DEBUG_RATE("leave: No STA priv data to update!\n");
 702                 if (sta)
 703                         sta_info_put(sta);
 704                 return NULL;
 705         }
 706
 707         rate_mask = sta->supp_rates;
 708         index = min(sta->last_txrate & 0xffff, IWL_RATE_COUNT - 1);
 709
 710         if (priv->phymode == (u8) MODE_IEEE80211A)
 711                 rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 712
 713         rs_priv = (void *)sta->rate_ctrl_priv;
 714
 715         if ((priv->iw_mode == IEEE80211_IF_TYPE_IBSS) &&
 716             !rs_priv->ibss_sta_added) {
 717                 u8 sta_id = iwl_hw_find_station(priv, hdr->addr1);
 718
 719                 if (sta_id == IWL_INVALID_STATION) {
 720                         IWL_DEBUG_RATE("LQ: ADD station %s\n",
 721                                        print_mac(mac, hdr->addr1));
 722                         sta_id = iwl_add_station(priv,
 723                                     hdr->addr1, 0, CMD_ASYNC);
 724                 }
 725                 if (sta_id != IWL_INVALID_STATION)
 726                         rs_priv->ibss_sta_added = 1;
 727         }
 728
 729         spin_lock_irqsave(&rs_priv->lock, flags);
 730
 731         if (rs_priv->start_rate != IWL_RATE_INVALID) {
 732                 index = rs_priv->start_rate;
 733                 rs_priv->start_rate = IWL_RATE_INVALID;
 734         }
 735
 736         window = &(rs_priv->win[index]);
 737
 738         fail_count = window->counter - window->success_counter;
 739
 740         if (((fail_count <= IWL_RATE_MIN_FAILURE_TH) &&
 741              (window->success_counter < IWL_RATE_MIN_SUCCESS_TH))) {
 742                 window->average_tpt = IWL_INVALID_VALUE;
 743                 spin_unlock_irqrestore(&rs_priv->lock, flags);
 744
 745                 IWL_DEBUG_RATE("Invalid average_tpt on rate %d: "
 746                                "counter: %d, success_counter: %d, "
 747                                "expected_tpt is %sNULL\n",
 748                                index,
 749                                window->counter,
 750                                window->success_counter,
 751                                rs_priv->expected_tpt ? "not " : "");
 752                 goto out;
 753
 754         }
 755
 756         window->average_tpt = ((window->success_ratio *
 757                                 rs_priv->expected_tpt[index] + 64) / 128);
 758         current_tpt = window->average_tpt;
 759
 760         high_low = iwl_get_adjacent_rate(rs_priv, index, rate_mask,
 761                                          local->hw.conf.phymode);
 762         low = high_low & 0xff;
 763         high = (high_low >> 8) & 0xff;
 764
 765         if (low != IWL_RATE_INVALID)
 766                 low_tpt = rs_priv->win[low].average_tpt;
 767
 768         if (high != IWL_RATE_INVALID)
 769                 high_tpt = rs_priv->win[high].average_tpt;
 770
 771         spin_unlock_irqrestore(&rs_priv->lock, flags);
 772
 773         scale_action = 1;
 774
 775         if ((window->success_ratio < IWL_RATE_DECREASE_TH) || !current_tpt) {
 776                 IWL_DEBUG_RATE("decrease rate because of low success_ratio\n");
 777                 scale_action = -1;
 778         } else if ((low_tpt == IWL_INVALID_VALUE) &&
 779                    (high_tpt == IWL_INVALID_VALUE))
 780                 scale_action = 1;
 781         else if ((low_tpt != IWL_INVALID_VALUE) &&
 782                    (high_tpt != IWL_INVALID_VALUE)
 783                    && (low_tpt < current_tpt)
 784                    && (high_tpt < current_tpt)) {
 785                 IWL_DEBUG_RATE("No action -- low [%d] & high [%d] < "
 786                                "current_tpt [%d]\n",
 787                                low_tpt, high_tpt, current_tpt);
 788                 scale_action = 0;
 789         } else {
 790                 if (high_tpt != IWL_INVALID_VALUE) {
 791                         if (high_tpt > current_tpt)
 792                                 scale_action = 1;
 793                         else {
 794                                 IWL_DEBUG_RATE
 795                                     ("decrease rate because of high tpt\n");
 796                                 scale_action = -1;
 797                         }
 798                 } else if (low_tpt != IWL_INVALID_VALUE) {
 799                         if (low_tpt > current_tpt) {
 800                                 IWL_DEBUG_RATE
 801                                     ("decrease rate because of low tpt\n");
 802                                 scale_action = -1;
 803                         } else
 804                                 scale_action = 1;
 805                 }
 806         }
 807
 808         if ((window->success_ratio > IWL_RATE_HIGH_TH) ||
 809             (current_tpt > window->average_tpt)) {
 810                 IWL_DEBUG_RATE("No action -- success_ratio [%d] > HIGH_TH or "
 811                                "current_tpt [%d] > average_tpt [%d]\n",
 812                                window->success_ratio,
 813                                current_tpt, window->average_tpt);
 814                 scale_action = 0;
 815         }
 816
 817         switch (scale_action) {
 818         case -1:
 819                 if (low != IWL_RATE_INVALID)
 820                         index = low;
 821                 break;
 822
 823         case 1:
 824                 if (high != IWL_RATE_INVALID)
 825                         index = high;
 826
 827                 break;
 828
 829         case 0:
 830         default:
 831                 break;
 832         }
 833
 834         IWL_DEBUG_RATE("Selected %d (action %d) - low %d high %d\n",
 835                        index, scale_action, low, high);
 836
 837  out:
 838
 839         sta->last_txrate = index;
 840         if (priv->phymode == (u8) MODE_IEEE80211A)
 841                 sta->txrate = sta->last_txrate - IWL_FIRST_OFDM_RATE;
 842         else
 843                 sta->txrate = sta->last_txrate;
 844
 845         sta_info_put(sta);
 846
 847         IWL_DEBUG_RATE("leave: %d\n", index);
 848
 849         return &priv->ieee_rates[index];
 850 }
 851
 852 static struct rate_control_ops rs_ops = {
 853         .module = NULL,
 854         .name = RS_NAME,
 855         .tx_status = rs_tx_status,
 856         .get_rate = rs_get_rate,
 857         .rate_init = rs_rate_init,
 858         .clear = rs_clear,
 859         .alloc = rs_alloc,
 860         .free = rs_free,
 861         .alloc_sta = rs_alloc_sta,
 862         .free_sta = rs_free_sta,
 863 };
 864
 865 int iwl_fill_rs_info(struct ieee80211_hw *hw, char *buf, u8 sta_id)
 866 {
 867         struct ieee80211_local *local = hw_to_local(hw);
 868         struct iwl_priv *priv = hw->priv;
 869         struct iwl_rate_scale_priv *rs_priv;
 870         struct sta_info *sta;
 871         unsigned long flags;
 872         int count = 0, i;
 873         u32 samples = 0, success = 0, good = 0;
 874         unsigned long now = jiffies;
 875         u32 max_time = 0;
 876
 877         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 878         if (!sta || !sta->rate_ctrl_priv) {
 879                 if (sta) {
 880                         sta_info_put(sta);
 881                         IWL_DEBUG_RATE("leave - no private rate data!\n");
 882                 } else
 883                         IWL_DEBUG_RATE("leave - no station!\n");
 884                 return sprintf(buf, "station %d not found\n", sta_id);
 885         }
 886
 887         rs_priv = (void *)sta->rate_ctrl_priv;
 888         spin_lock_irqsave(&rs_priv->lock, flags);
 889         i = IWL_RATE_54M_INDEX;
 890         while (1) {
 891                 u64 mask;
 892                 int j;
 893
 894                 count +=
 895                     sprintf(&buf[count], " %2dMbs: ", iwl_rates[i].ieee / 2);
 896
 897                 mask = (1ULL << (IWL_RATE_MAX_WINDOW - 1));
 898                 for (j = 0; j < IWL_RATE_MAX_WINDOW; j++, mask >>= 1)
 899                         buf[count++] =
 900                             (rs_priv->win[i].data & mask) ? '1' : '0';
 901
 902                 samples += rs_priv->win[i].counter;
 903                 good += rs_priv->win[i].success_counter;
 904                 success += rs_priv->win[i].success_counter * iwl_rates[i].ieee;
 905
 906                 if (rs_priv->win[i].stamp) {
 907                         int delta =
 908                             jiffies_to_msecs(now - rs_priv->win[i].stamp);
 909
 910                         if (delta > max_time)
 911                                 max_time = delta;
 912
 913                         count += sprintf(&buf[count], "%5dms\n", delta);
 914                 } else
 915                         buf[count++] = '\n';
 916
 917                 j = iwl_get_prev_ieee_rate(i);
 918                 if (j == i)
 919                         break;
 920                 i = j;
 921         }
 922         spin_unlock_irqrestore(&rs_priv->lock, flags);
 923         sta_info_put(sta);
 924
 925         /* Display the average rate of all samples taken.
 926          *
 927          * NOTE:  We multiple # of samples by 2 since the IEEE measurement
 928          * added from iwl_rates is actually 2X the rate */
 929         if (samples)
 930                 count += sprintf(
 931                         &buf[count],
 932                         "\nAverage rate is %3d.%02dMbs over last %4dms\n"
 933                         "%3d%% success (%d good packets over %d tries)\n",
 934                         success / (2 * samples), (success * 5 / samples) % 10,
 935                         max_time, good * 100 / samples, good, samples);
 936         else
 937                 count += sprintf(&buf[count], "\nAverage rate: 0Mbs\n");
 938
 939         return count;
 940 }
 941
 942 void iwl_rate_scale_init(struct ieee80211_hw *hw, s32 sta_id)
 943 {
 944         struct iwl_priv *priv = hw->priv;
 945         s32 rssi = 0;
 946         unsigned long flags;
 947         struct ieee80211_local *local = hw_to_local(hw);
 948         struct iwl_rate_scale_priv *rs_priv;
 949         struct sta_info *sta;
 950
 951         IWL_DEBUG_RATE("enter\n");
 952
 953         if (!local->rate_ctrl->ops->name ||
 954             strcmp(local->rate_ctrl->ops->name, RS_NAME)) {
 955                 IWL_WARNING("iwl-3945-rs not selected as rate control algo!\n");
 956                 IWL_DEBUG_RATE("leave - mac80211 picked the wrong RC algo.\n");
 957                 return;
 958         }
 959
 960         sta = sta_info_get(local, priv->stations[sta_id].sta.sta.addr);
 961         if (!sta || !sta->rate_ctrl_priv) {
 962                 if (sta)
 963                         sta_info_put(sta);
 964                 IWL_DEBUG_RATE("leave - no private rate data!\n");
 965                 return;
 966         }
 967
 968         rs_priv = (void *)sta->rate_ctrl_priv;
 969
 970         spin_lock_irqsave(&rs_priv->lock, flags);
 971
 972         rs_priv->tgg = 0;
 973         switch (priv->phymode) {
 974         case MODE_IEEE80211G:
 975                 if (priv->active_rxon.flags & RXON_FLG_TGG_PROTECT_MSK) {
 976                         rs_priv->tgg = 1;
 977                         rs_priv->expected_tpt = iwl_expected_tpt_g_prot;
 978                 } else
 979                         rs_priv->expected_tpt = iwl_expected_tpt_g;
 980                 break;
 981
 982         case MODE_IEEE80211A:
 983                 rs_priv->expected_tpt = iwl_expected_tpt_a;
 984                 break;
 985
 986         default:
 987                 IWL_WARNING("Invalid phymode.  Defaulting to 802.11b\n");
 988         case MODE_IEEE80211B:
 989                 rs_priv->expected_tpt = iwl_expected_tpt_b;
 990                 break;
 991         }
 992
 993         sta_info_put(sta);
 994         spin_unlock_irqrestore(&rs_priv->lock, flags);
 995
 996         rssi = priv->last_rx_rssi;
 997         if (rssi == 0)
 998                 rssi = IWL_MIN_RSSI_VAL;
 999
1000         IWL_DEBUG(IWL_DL_INFO | IWL_DL_RATE, "Network RSSI: %d\n", rssi);
1001
1002         rs_priv->start_rate = iwl_get_rate_index_by_rssi(rssi, priv->phymode);
1003
1004         IWL_DEBUG_RATE("leave: rssi %d assign rate index: "
1005                        "%d (plcp 0x%x)\n", rssi, rs_priv->start_rate,
1006                        iwl_rates[rs_priv->start_rate].plcp);
1007 }
1008
1009 void iwl_rate_control_register(struct ieee80211_hw *hw)
1010 {
1011         ieee80211_rate_control_register(&rs_ops);
1012 }
1013
1014 void iwl_rate_control_unregister(struct ieee80211_hw *hw)
1015 {
1016         ieee80211_rate_control_unregister(&rs_ops);
1017 }
1018
1019