drivers/net/wireless/wl12xx/wl1271_tx.c

   1 /*
   2  * This file is part of wl1271
   3  *
   4  * Copyright (C) 2009 Nokia Corporation
   5  *
   6  * Contact: Luciano Coelho <luciano.coelho@nokia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  20  * 02110-1301 USA
  21  *
  22  */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26
  27 #include "wl1271.h"
  28 #include "wl1271_spi.h"
  29 #include "wl1271_reg.h"
  30 #include "wl1271_ps.h"
  31 #include "wl1271_tx.h"
  32
  33 static int wl1271_tx_id(struct wl1271 *wl, struct sk_buff *skb)
  34 {
  35         int i;
  36         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
  37                 if (wl->tx_frames[i] == NULL) {
  38                         wl->tx_frames[i] = skb;
  39                         return i;
  40                 }
  41
  42         return -EBUSY;
  43 }
  44
  45 static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
  46 {
  47         struct wl1271_tx_hw_descr *desc;
  48         u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
  49         u32 total_blocks, excluded;
  50         int id, ret = -EBUSY;
  51
  52         /* allocate free identifier for the packet */
  53         id = wl1271_tx_id(wl, skb);
  54         if (id < 0)
  55                 return id;
  56
  57         /* approximate the number of blocks required for this packet
  58            in the firmware */
  59         /* FIXME: try to figure out what is done here and make it cleaner */
  60         total_blocks = (total_len + 20) >> TX_HW_BLOCK_SHIFT_DIV;
  61         excluded = (total_blocks << 2) + ((total_len + 20) & 0xff) + 34;
  62         total_blocks += (excluded > 252) ? 2 : 1;
  63         total_blocks += TX_HW_BLOCK_SPARE;
  64
  65         if (total_blocks <= wl->tx_blocks_available) {
  66                 desc = (struct wl1271_tx_hw_descr *)skb_push(
  67                         skb, total_len - skb->len);
  68
  69                 desc->extra_mem_blocks = TX_HW_BLOCK_SPARE;
  70                 desc->total_mem_blocks = total_blocks;
  71                 desc->id = id;
  72
  73                 wl->tx_blocks_available -= total_blocks;
  74
  75                 ret = 0;
  76
  77                 wl1271_debug(DEBUG_TX,
  78                              "tx_allocate: size: %d, blocks: %d, id: %d",
  79                              total_len, total_blocks, id);
  80         } else
  81                 wl->tx_frames[id] = NULL;
  82
  83         return ret;
  84 }
  85
  86 static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
  87                               u32 extra, struct ieee80211_tx_info *control)
  88 {
  89         struct wl1271_tx_hw_descr *desc;
  90         int pad;
  91         u16 tx_attr;
  92
  93         desc = (struct wl1271_tx_hw_descr *) skb->data;
  94
  95         /* relocate space for security header */
  96         if (extra) {
  97                 void *framestart = skb->data + sizeof(*desc);
  98                 u16 fc = *(u16 *)(framestart + extra);
  99                 int hdrlen = ieee80211_hdrlen(cpu_to_le16(fc));
 100                 memmove(framestart, framestart + extra, hdrlen);
 101         }
 102
 103         /* configure packet life time */
 104         desc->start_time = cpu_to_le32(jiffies_to_usecs(jiffies) -
 105                                        wl->time_offset);
 106         desc->life_time = cpu_to_le16(TX_HW_MGMT_PKT_LIFETIME_TU);
 107
 108         /* configure the tx attributes */
 109         tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
 110         /* FIXME: do we know the packet priority? can we identify mgmt
 111            packets, and use max prio for them at least? */
 112         desc->tid = 0;
 113         desc->aid = TX_HW_DEFAULT_AID;
 114         desc->reserved = 0;
 115
 116         /* align the length (and store in terms of words) */
 117         pad = WL1271_TX_ALIGN(skb->len);
 118         desc->length = cpu_to_le16(pad >> 2);
 119
 120         /* calculate number of padding bytes */
 121         pad = pad - skb->len;
 122         tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;
 123
 124         /* if the packets are destined for AP (have a STA entry) send them
 125            with AP rate policies, otherwise use default basic rates */
 126         if (control->control.sta)
 127                 tx_attr |= ACX_TX_AP_FULL_RATE << TX_HW_ATTR_OFST_RATE_POLICY;
 128
 129         desc->tx_attr = cpu_to_le16(tx_attr);
 130
 131         wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
 132         return 0;
 133 }
 134
 135 static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
 136                                  struct ieee80211_tx_info *control)
 137 {
 138
 139         struct wl1271_tx_hw_descr *desc;
 140         int len;
 141
 142         /* FIXME: This is a workaround for getting non-aligned packets.
 143            This happens at least with EAPOL packets from the user space.
 144            Our DMA requires packets to be aligned on a 4-byte boundary.
 145         */
 146         if (unlikely((long)skb->data & 0x03)) {
 147                 int offset = (4 - (long)skb->data) & 0x03;
 148                 wl1271_debug(DEBUG_TX, "skb offset %d", offset);
 149
 150                 /* check whether the current skb can be used */
 151                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 152                         unsigned char *src = skb->data;
 153
 154                         /* align the buffer on a 4-byte boundary */
 155                         skb_reserve(skb, offset);
 156                         memmove(skb->data, src, skb->len);
 157                 } else {
 158                         wl1271_info("No handler, fixme!");
 159                         return -EINVAL;
 160                 }
 161         }
 162
 163         len = WL1271_TX_ALIGN(skb->len);
 164
 165         /* perform a fixed address block write with the packet */
 166         wl1271_spi_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);
 167
 168         /* write packet new counter into the write access register */
 169         wl->tx_packets_count++;
 170         wl1271_spi_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
 171
 172         desc = (struct wl1271_tx_hw_descr *) skb->data;
 173         wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
 174                      desc->id, skb, len, desc->length);
 175
 176         return 0;
 177 }
 178
 179 /* caller must hold wl->mutex */
 180 static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
 181 {
 182         struct ieee80211_tx_info *info;
 183         u32 extra = 0;
 184         int ret = 0;
 185         u8 idx;
 186
 187         if (!skb)
 188                 return -EINVAL;
 189
 190         info = IEEE80211_SKB_CB(skb);
 191
 192         if (info->control.hw_key &&
 193             info->control.hw_key->alg == ALG_TKIP)
 194                 extra = WL1271_TKIP_IV_SPACE;
 195
 196         if (info->control.hw_key) {
 197                 idx = info->control.hw_key->hw_key_idx;
 198
 199                 /* FIXME: do we have to do this if we're not using WEP? */
 200                 if (unlikely(wl->default_key != idx)) {
 201                         ret = wl1271_cmd_set_default_wep_key(wl, idx);
 202                         if (ret < 0)
 203                                 return ret;
 204                 }
 205         }
 206
 207         ret = wl1271_tx_allocate(wl, skb, extra);
 208         if (ret < 0)
 209                 return ret;
 210
 211         ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
 212         if (ret < 0)
 213                 return ret;
 214
 215         ret = wl1271_tx_send_packet(wl, skb, info);
 216         if (ret < 0)
 217                 return ret;
 218
 219         return ret;
 220 }
 221
 222 static u32 wl1271_tx_enabled_rates_get(struct wl1271 *wl, u32 rate_set)
 223 {
 224         struct ieee80211_supported_band *band;
 225         u32 enabled_rates = 0;
 226         int bit;
 227
 228         band = wl->hw->wiphy->bands[wl->band];
 229         for (bit = 0; bit < band->n_bitrates; bit++) {
 230                 if (rate_set & 0x1)
 231                         enabled_rates |= band->bitrates[bit].hw_value;
 232                 rate_set >>= 1;
 233         }
 234
 235         return enabled_rates;
 236 }
 237
 238 void wl1271_tx_work(struct work_struct *work)
 239 {
 240         struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
 241         struct sk_buff *skb;
 242         bool woken_up = false;
 243         u32 sta_rates = 0;
 244         int ret;
 245
 246         /* check if the rates supported by the AP have changed */
 247         if (unlikely(test_and_clear_bit(WL1271_FLAG_STA_RATES_CHANGED,
 248                                         &wl->flags))) {
 249                 unsigned long flags;
 250                 spin_lock_irqsave(&wl->wl_lock, flags);
 251                 sta_rates = wl->sta_rate_set;
 252                 spin_unlock_irqrestore(&wl->wl_lock, flags);
 253         }
 254
 255         mutex_lock(&wl->mutex);
 256
 257         if (unlikely(wl->state == WL1271_STATE_OFF))
 258                 goto out;
 259
 260         /* if rates have changed, re-configure the rate policy */
 261         if (unlikely(sta_rates)) {
 262                 wl->rate_set = wl1271_tx_enabled_rates_get(wl, sta_rates);
 263                 wl1271_acx_rate_policies(wl);
 264         }
 265
 266         while ((skb = skb_dequeue(&wl->tx_queue))) {
 267                 if (!woken_up) {
 268                         ret = wl1271_ps_elp_wakeup(wl, false);
 269                         if (ret < 0)
 270                                 goto out;
 271                         woken_up = true;
 272                 }
 273
 274                 ret = wl1271_tx_frame(wl, skb);
 275                 if (ret == -EBUSY) {
 276                         /* firmware buffer is full, stop queues */
 277                         wl1271_debug(DEBUG_TX, "tx_work: fw buffer full, "
 278                                      "stop queues");
 279                         ieee80211_stop_queues(wl->hw);
 280                         set_bit(WL1271_FLAG_TX_QUEUE_STOPPED, &wl->flags);
 281                         skb_queue_head(&wl->tx_queue, skb);
 282                         goto out;
 283                 } else if (ret < 0) {
 284                         dev_kfree_skb(skb);
 285                         goto out;
 286                 } else if (test_and_clear_bit(WL1271_FLAG_TX_QUEUE_STOPPED,
 287                                               &wl->flags)) {
 288                         /* firmware buffer has space, restart queues */
 289                         wl1271_debug(DEBUG_TX,
 290                                      "complete_packet: waking queues");
 291                         ieee80211_wake_queues(wl->hw);
 292                 }
 293         }
 294
 295 out:
 296         if (woken_up)
 297                 wl1271_ps_elp_sleep(wl);
 298
 299         mutex_unlock(&wl->mutex);
 300 }
 301
 302 static void wl1271_tx_complete_packet(struct wl1271 *wl,
 303                                       struct wl1271_tx_hw_res_descr *result)
 304 {
 305         struct ieee80211_tx_info *info;
 306         struct sk_buff *skb;
 307         u16 seq;
 308         int id = result->id;
 309
 310         /* check for id legality */
 311         if (id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL) {
 312                 wl1271_warning("TX result illegal id: %d", id);
 313                 return;
 314         }
 315
 316         skb = wl->tx_frames[id];
 317         info = IEEE80211_SKB_CB(skb);
 318
 319         /* update packet status */
 320         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
 321                 if (result->status == TX_SUCCESS)
 322                         info->flags |= IEEE80211_TX_STAT_ACK;
 323                 if (result->status & TX_RETRY_EXCEEDED) {
 324                         /* FIXME */
 325                         /* info->status.excessive_retries = 1; */
 326                         wl->stats.excessive_retries++;
 327                 }
 328         }
 329
 330         /* FIXME */
 331         /* info->status.retry_count = result->ack_failures; */
 332         wl->stats.retry_count += result->ack_failures;
 333
 334         /* update security sequence number */
 335         seq = wl->tx_security_seq_16 +
 336                 (result->lsb_security_sequence_number -
 337                  wl->tx_security_last_seq);
 338         wl->tx_security_last_seq = result->lsb_security_sequence_number;
 339
 340         if (seq < wl->tx_security_seq_16)
 341                 wl->tx_security_seq_32++;
 342         wl->tx_security_seq_16 = seq;
 343
 344         /* remove private header from packet */
 345         skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));
 346
 347         /* remove TKIP header space if present */
 348         if (info->control.hw_key &&
 349             info->control.hw_key->alg == ALG_TKIP) {
 350                 int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 351                 memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen);
 352                 skb_pull(skb, WL1271_TKIP_IV_SPACE);
 353         }
 354
 355         wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 356                      " status 0x%x",
 357                      result->id, skb, result->ack_failures,
 358                      result->rate_class_index, result->status);
 359
 360         /* return the packet to the stack */
 361         ieee80211_tx_status(wl->hw, skb);
 362         wl->tx_frames[result->id] = NULL;
 363 }
 364
 365 /* Called upon reception of a TX complete interrupt */
 366 void wl1271_tx_complete(struct wl1271 *wl, u32 count)
 367 {
 368         struct wl1271_acx_mem_map *memmap =
 369                 (struct wl1271_acx_mem_map *)wl->target_mem_map;
 370         u32 i;
 371
 372         wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
 373
 374         /* read the tx results from the chipset */
 375         wl1271_spi_read(wl, le32_to_cpu(memmap->tx_result),
 376                         wl->tx_res_if, sizeof(*wl->tx_res_if), false);
 377
 378         /* verify that the result buffer is not getting overrun */
 379         if (count > TX_HW_RESULT_QUEUE_LEN) {
 380                 wl1271_warning("TX result overflow from chipset: %d", count);
 381                 count = TX_HW_RESULT_QUEUE_LEN;
 382         }
 383
 384         /* process the results */
 385         for (i = 0; i < count; i++) {
 386                 struct wl1271_tx_hw_res_descr *result;
 387                 u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;
 388
 389                 /* process the packet */
 390                 result =  &(wl->tx_res_if->tx_results_queue[offset]);
 391                 wl1271_tx_complete_packet(wl, result);
 392
 393                 wl->tx_results_count++;
 394         }
 395
 396         /* write host counter to chipset (to ack) */
 397         wl1271_spi_write32(wl, le32_to_cpu(memmap->tx_result) +
 398                            offsetof(struct wl1271_tx_hw_res_if,
 399                                     tx_result_host_counter),
 400                            le32_to_cpu(wl->tx_res_if->tx_result_fw_counter));
 401 }
 402
 403 /* caller must hold wl->mutex */
 404 void wl1271_tx_flush(struct wl1271 *wl)
 405 {
 406         int i;
 407         struct sk_buff *skb;
 408         struct ieee80211_tx_info *info;
 409
 410         /* TX failure */
 411 /*      control->flags = 0; FIXME */
 412
 413         while ((skb = skb_dequeue(&wl->tx_queue))) {
 414                 info = IEEE80211_SKB_CB(skb);
 415
 416                 wl1271_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 417
 418                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 419                                 continue;
 420
 421                 ieee80211_tx_status(wl->hw, skb);
 422         }
 423
 424         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
 425                 if (wl->tx_frames[i] != NULL) {
 426                         skb = wl->tx_frames[i];
 427                         info = IEEE80211_SKB_CB(skb);
 428
 429                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 430                                 continue;
 431
 432                         ieee80211_tx_status(wl->hw, skb);
 433                         wl->tx_frames[i] = NULL;
 434                 }
 435 }