kernel/drivers/net/wireless/rsi/rsi_91x_core.c

   1 /**
   2  * Copyright (c) 2014 Redpine Signals Inc.
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include "rsi_mgmt.h"
  18 #include "rsi_common.h"
  19
  20 /**
  21  * rsi_determine_min_weight_queue() - This function determines the queue with
  22  *                                    the min weight.
  23  * @common: Pointer to the driver private structure.
  24  *
  25  * Return: q_num: Corresponding queue number.
  26  */
  27 static u8 rsi_determine_min_weight_queue(struct rsi_common *common)
  28 {
  29         struct wmm_qinfo *tx_qinfo = common->tx_qinfo;
  30         u32 q_len = 0;
  31         u8 ii = 0;
  32
  33         for (ii = 0; ii < NUM_EDCA_QUEUES; ii++) {
  34                 q_len = skb_queue_len(&common->tx_queue[ii]);
  35                 if ((tx_qinfo[ii].pkt_contended) && q_len) {
  36                         common->min_weight = tx_qinfo[ii].weight;
  37                         break;
  38                 }
  39         }
  40         return ii;
  41 }
  42
  43 /**
  44  * rsi_recalculate_weights() - This function recalculates the weights
  45  *                             corresponding to each queue.
  46  * @common: Pointer to the driver private structure.
  47  *
  48  * Return: recontend_queue bool variable
  49  */
  50 static bool rsi_recalculate_weights(struct rsi_common *common)
  51 {
  52         struct wmm_qinfo *tx_qinfo = common->tx_qinfo;
  53         bool recontend_queue = false;
  54         u8 ii = 0;
  55         u32 q_len = 0;
  56
  57         for (ii = 0; ii < NUM_EDCA_QUEUES; ii++) {
  58                 q_len = skb_queue_len(&common->tx_queue[ii]);
  59                 /* Check for the need of contention */
  60                 if (q_len) {
  61                         if (tx_qinfo[ii].pkt_contended) {
  62                                 tx_qinfo[ii].weight =
  63                                 ((tx_qinfo[ii].weight > common->min_weight) ?
  64                                  tx_qinfo[ii].weight - common->min_weight : 0);
  65                         } else {
  66                                 tx_qinfo[ii].pkt_contended = 1;
  67                                 tx_qinfo[ii].weight = tx_qinfo[ii].wme_params;
  68                                 recontend_queue = true;
  69                         }
  70                 } else { /* No packets so no contention */
  71                         tx_qinfo[ii].weight = 0;
  72                         tx_qinfo[ii].pkt_contended = 0;
  73                 }
  74         }
  75
  76         return recontend_queue;
  77 }
  78
  79 /**
  80  * rsi_get_num_pkts_dequeue() - This function determines the number of
  81  *                              packets to be dequeued based on the number
  82  *                              of bytes calculated using txop.
  83  *
  84  * @common: Pointer to the driver private structure.
  85  * @q_num: the queue from which pkts have to be dequeued
  86  *
  87  * Return: pkt_num: Number of pkts to be dequeued.
  88  */
  89 static u32 rsi_get_num_pkts_dequeue(struct rsi_common *common, u8 q_num)
  90 {
  91         struct rsi_hw *adapter = common->priv;
  92         struct sk_buff *skb;
  93         u32 pkt_cnt = 0;
  94         s16 txop = common->tx_qinfo[q_num].txop * 32;
  95         __le16 r_txop;
  96         struct ieee80211_rate rate;
  97
  98         rate.bitrate = RSI_RATE_MCS0 * 5 * 10; /* Convert to Kbps */
  99         if (q_num == VI_Q)
 100                 txop = ((txop << 5) / 80);
 101
 102         if (skb_queue_len(&common->tx_queue[q_num]))
 103                 skb = skb_peek(&common->tx_queue[q_num]);
 104         else
 105                 return 0;
 106
 107         do {
 108                 r_txop = ieee80211_generic_frame_duration(adapter->hw,
 109                                                           adapter->vifs[0],
 110                                                           common->band,
 111                                                           skb->len, &rate);
 112                 txop -= le16_to_cpu(r_txop);
 113                 pkt_cnt += 1;
 114                 /*checking if pkts are still there*/
 115                 if (skb_queue_len(&common->tx_queue[q_num]) - pkt_cnt)
 116                         skb = skb->next;
 117                 else
 118                         break;
 119
 120         } while (txop > 0);
 121
 122         return pkt_cnt;
 123 }
 124
 125 /**
 126  * rsi_core_determine_hal_queue() - This function determines the queue from
 127  *                                  which packet has to be dequeued.
 128  * @common: Pointer to the driver private structure.
 129  *
 130  * Return: q_num: Corresponding queue number on success.
 131  */
 132 static u8 rsi_core_determine_hal_queue(struct rsi_common *common)
 133 {
 134         bool recontend_queue = false;
 135         u32 q_len = 0;
 136         u8 q_num = INVALID_QUEUE;
 137         u8 ii = 0;
 138
 139         if (skb_queue_len(&common->tx_queue[MGMT_SOFT_Q])) {
 140                 if (!common->mgmt_q_block)
 141                         q_num = MGMT_SOFT_Q;
 142                 return q_num;
 143         }
 144
 145         if (common->hw_data_qs_blocked)
 146                 return q_num;
 147
 148         if (common->pkt_cnt != 0) {
 149                 --common->pkt_cnt;
 150                 return common->selected_qnum;
 151         }
 152
 153 get_queue_num:
 154         recontend_queue = false;
 155
 156         q_num = rsi_determine_min_weight_queue(common);
 157
 158         ii = q_num;
 159
 160         /* Selecting the queue with least back off */
 161         for (; ii < NUM_EDCA_QUEUES; ii++) {
 162                 q_len = skb_queue_len(&common->tx_queue[ii]);
 163                 if (((common->tx_qinfo[ii].pkt_contended) &&
 164                      (common->tx_qinfo[ii].weight < common->min_weight)) &&
 165                       q_len) {
 166                         common->min_weight = common->tx_qinfo[ii].weight;
 167                         q_num = ii;
 168                 }
 169         }
 170
 171         if (q_num < NUM_EDCA_QUEUES)
 172                 common->tx_qinfo[q_num].pkt_contended = 0;
 173
 174         /* Adjust the back off values for all queues again */
 175         recontend_queue = rsi_recalculate_weights(common);
 176
 177         q_len = skb_queue_len(&common->tx_queue[q_num]);
 178         if (!q_len) {
 179                 /* If any queues are freshly contended and the selected queue
 180                  * doesn't have any packets
 181                  * then get the queue number again with fresh values
 182                  */
 183                 if (recontend_queue)
 184                         goto get_queue_num;
 185
 186                 q_num = INVALID_QUEUE;
 187                 return q_num;
 188         }
 189
 190         common->selected_qnum = q_num;
 191         q_len = skb_queue_len(&common->tx_queue[q_num]);
 192
 193         if (q_num == VO_Q || q_num == VI_Q) {
 194                 common->pkt_cnt = rsi_get_num_pkts_dequeue(common, q_num);
 195                 common->pkt_cnt -= 1;
 196         }
 197
 198         return q_num;
 199 }
 200
 201 /**
 202  * rsi_core_queue_pkt() - This functions enqueues the packet to the queue
 203  *                        specified by the queue number.
 204  * @common: Pointer to the driver private structure.
 205  * @skb: Pointer to the socket buffer structure.
 206  *
 207  * Return: None.
 208  */
 209 static void rsi_core_queue_pkt(struct rsi_common *common,
 210                                struct sk_buff *skb)
 211 {
 212         u8 q_num = skb->priority;
 213         if (q_num >= NUM_SOFT_QUEUES) {
 214                 rsi_dbg(ERR_ZONE, "%s: Invalid Queue Number: q_num = %d\n",
 215                         __func__, q_num);
 216                 dev_kfree_skb(skb);
 217                 return;
 218         }
 219
 220         skb_queue_tail(&common->tx_queue[q_num], skb);
 221 }
 222
 223 /**
 224  * rsi_core_dequeue_pkt() - This functions dequeues the packet from the queue
 225  *                          specified by the queue number.
 226  * @common: Pointer to the driver private structure.
 227  * @q_num: Queue number.
 228  *
 229  * Return: Pointer to sk_buff structure.
 230  */
 231 static struct sk_buff *rsi_core_dequeue_pkt(struct rsi_common *common,
 232                                             u8 q_num)
 233 {
 234         if (q_num >= NUM_SOFT_QUEUES) {
 235                 rsi_dbg(ERR_ZONE, "%s: Invalid Queue Number: q_num = %d\n",
 236                         __func__, q_num);
 237                 return NULL;
 238         }
 239
 240         return skb_dequeue(&common->tx_queue[q_num]);
 241 }
 242
 243 /**
 244  * rsi_core_qos_processor() - This function is used to determine the wmm queue
 245  *                            based on the backoff procedure. Data packets are
 246  *                            dequeued from the selected hal queue and sent to
 247  *                            the below layers.
 248  * @common: Pointer to the driver private structure.
 249  *
 250  * Return: None.
 251  */
 252 void rsi_core_qos_processor(struct rsi_common *common)
 253 {
 254         struct rsi_hw *adapter = common->priv;
 255         struct sk_buff *skb;
 256         unsigned long tstamp_1, tstamp_2;
 257         u8 q_num;
 258         int status;
 259
 260         tstamp_1 = jiffies;
 261         while (1) {
 262                 q_num = rsi_core_determine_hal_queue(common);
 263                 rsi_dbg(DATA_TX_ZONE,
 264                         "%s: Queue number = %d\n", __func__, q_num);
 265
 266                 if (q_num == INVALID_QUEUE) {
 267                         rsi_dbg(DATA_TX_ZONE, "%s: No More Pkt\n", __func__);
 268                         break;
 269                 }
 270
 271                 mutex_lock(&common->tx_rxlock);
 272
 273                 status = adapter->check_hw_queue_status(adapter, q_num);
 274                 if ((status <= 0)) {
 275                         mutex_unlock(&common->tx_rxlock);
 276                         break;
 277                 }
 278
 279                 if ((q_num < MGMT_SOFT_Q) &&
 280                     ((skb_queue_len(&common->tx_queue[q_num])) <=
 281                       MIN_DATA_QUEUE_WATER_MARK)) {
 282                         if (ieee80211_queue_stopped(adapter->hw, WME_AC(q_num)))
 283                                 ieee80211_wake_queue(adapter->hw,
 284                                                      WME_AC(q_num));
 285                 }
 286
 287                 skb = rsi_core_dequeue_pkt(common, q_num);
 288                 if (skb == NULL) {
 289                         rsi_dbg(ERR_ZONE, "skb null\n");
 290                         mutex_unlock(&common->tx_rxlock);
 291                         break;
 292                 }
 293
 294                 if (q_num == MGMT_SOFT_Q)
 295                         status = rsi_send_mgmt_pkt(common, skb);
 296                 else
 297                         status = rsi_send_data_pkt(common, skb);
 298
 299                 if (status) {
 300                         mutex_unlock(&common->tx_rxlock);
 301                         break;
 302                 }
 303
 304                 common->tx_stats.total_tx_pkt_send[q_num]++;
 305
 306                 tstamp_2 = jiffies;
 307                 mutex_unlock(&common->tx_rxlock);
 308
 309                 if (tstamp_2 > tstamp_1 + (300 * HZ / 1000))
 310                         schedule();
 311         }
 312 }
 313
 314 /**
 315  * rsi_core_xmit() - This function transmits the packets received from mac80211
 316  * @common: Pointer to the driver private structure.
 317  * @skb: Pointer to the socket buffer structure.
 318  *
 319  * Return: None.
 320  */
 321 void rsi_core_xmit(struct rsi_common *common, struct sk_buff *skb)
 322 {
 323         struct rsi_hw *adapter = common->priv;
 324         struct ieee80211_tx_info *info;
 325         struct skb_info *tx_params;
 326         struct ieee80211_hdr *tmp_hdr = NULL;
 327         u8 q_num, tid = 0;
 328
 329         if ((!skb) || (!skb->len)) {
 330                 rsi_dbg(ERR_ZONE, "%s: Null skb/zero Length packet\n",
 331                         __func__);
 332                 goto xmit_fail;
 333         }
 334         info = IEEE80211_SKB_CB(skb);
 335         tx_params = (struct skb_info *)info->driver_data;
 336         tmp_hdr = (struct ieee80211_hdr *)&skb->data[0];
 337
 338         if (common->fsm_state != FSM_MAC_INIT_DONE) {
 339                 rsi_dbg(ERR_ZONE, "%s: FSM state not open\n", __func__);
 340                 goto xmit_fail;
 341         }
 342
 343         if ((ieee80211_is_mgmt(tmp_hdr->frame_control)) ||
 344             (ieee80211_is_ctl(tmp_hdr->frame_control)) ||
 345             (ieee80211_is_qos_nullfunc(tmp_hdr->frame_control))) {
 346                 q_num = MGMT_SOFT_Q;
 347                 skb->priority = q_num;
 348         } else {
 349                 if (ieee80211_is_data_qos(tmp_hdr->frame_control)) {
 350                         tid = (skb->data[24] & IEEE80211_QOS_TID);
 351                         skb->priority = TID_TO_WME_AC(tid);
 352                 } else {
 353                         tid = IEEE80211_NONQOS_TID;
 354                         skb->priority = BE_Q;
 355                 }
 356                 q_num = skb->priority;
 357                 tx_params->tid = tid;
 358                 tx_params->sta_id = 0;
 359         }
 360
 361         if ((q_num != MGMT_SOFT_Q) &&
 362             ((skb_queue_len(&common->tx_queue[q_num]) + 1) >=
 363              DATA_QUEUE_WATER_MARK)) {
 364                 rsi_dbg(ERR_ZONE, "%s: sw queue full\n", __func__);
 365                 if (!ieee80211_queue_stopped(adapter->hw, WME_AC(q_num)))
 366                         ieee80211_stop_queue(adapter->hw, WME_AC(q_num));
 367                 rsi_set_event(&common->tx_thread.event);
 368                 goto xmit_fail;
 369         }
 370
 371         rsi_core_queue_pkt(common, skb);
 372         rsi_dbg(DATA_TX_ZONE, "%s: ===> Scheduling TX thead <===\n", __func__);
 373         rsi_set_event(&common->tx_thread.event);
 374
 375         return;
 376
 377 xmit_fail:
 378         rsi_dbg(ERR_ZONE, "%s: Failed to queue packet\n", __func__);
 379         /* Dropping pkt here */
 380         ieee80211_free_txskb(common->priv->hw, skb);
 381 }