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
  92         desc = (struct wl1271_tx_hw_descr *) skb->data;
  93
  94         /* relocate space for security header */
  95         if (extra) {
  96                 void *framestart = skb->data + sizeof(*desc);
  97                 u16 fc = *(u16 *)(framestart + extra);
  98                 int hdrlen = ieee80211_hdrlen(fc);
  99                 memmove(framestart, framestart + extra, hdrlen);
 100         }
 101
 102         /* configure packet life time */
 103         desc->start_time = jiffies_to_usecs(jiffies) - wl->time_offset;
 104         desc->life_time = TX_HW_MGMT_PKT_LIFETIME_TU;
 105
 106         /* configure the tx attributes */
 107         desc->tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
 108         /* FIXME: do we know the packet priority? can we identify mgmt
 109            packets, and use max prio for them at least? */
 110         desc->tid = 0;
 111         desc->aid = TX_HW_DEFAULT_AID;
 112         desc->reserved = 0;
 113
 114         /* align the length (and store in terms of words) */
 115         pad = WL1271_TX_ALIGN(skb->len);
 116         desc->length = pad >> 2;
 117
 118         /* calculate number of padding bytes */
 119         pad = pad - skb->len;
 120         desc->tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;
 121
 122         wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
 123         return 0;
 124 }
 125
 126 static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
 127                                  struct ieee80211_tx_info *control)
 128 {
 129
 130         struct wl1271_tx_hw_descr *desc;
 131         int len;
 132
 133         /* FIXME: This is a workaround for getting non-aligned packets.
 134            This happens at least with EAPOL packets from the user space.
 135            Our DMA requires packets to be aligned on a 4-byte boundary.
 136         */
 137         if (unlikely((long)skb->data & 0x03)) {
 138                 int offset = (4 - (long)skb->data) & 0x03;
 139                 wl1271_debug(DEBUG_TX, "skb offset %d", offset);
 140
 141                 /* check whether the current skb can be used */
 142                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 143                         unsigned char *src = skb->data;
 144
 145                         /* align the buffer on a 4-byte boundary */
 146                         skb_reserve(skb, offset);
 147                         memmove(skb->data, src, skb->len);
 148                 } else {
 149                         wl1271_info("No handler, fixme!");
 150                         return -EINVAL;
 151                 }
 152         }
 153
 154         len = WL1271_TX_ALIGN(skb->len);
 155
 156         /* perform a fixed address block write with the packet */
 157         wl1271_spi_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);
 158
 159         /* write packet new counter into the write access register */
 160         wl->tx_packets_count++;
 161         wl1271_spi_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
 162
 163         desc = (struct wl1271_tx_hw_descr *) skb->data;
 164         wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
 165                      desc->id, skb, len, desc->length);
 166
 167         return 0;
 168 }
 169
 170 /* caller must hold wl->mutex */
 171 static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
 172 {
 173         struct ieee80211_tx_info *info;
 174         u32 extra = 0;
 175         int ret = 0;
 176         u8 idx;
 177
 178         if (!skb)
 179                 return -EINVAL;
 180
 181         info = IEEE80211_SKB_CB(skb);
 182
 183         if (info->control.hw_key &&
 184             info->control.hw_key->alg == ALG_TKIP)
 185                 extra = WL1271_TKIP_IV_SPACE;
 186
 187         if (info->control.hw_key) {
 188                 idx = info->control.hw_key->hw_key_idx;
 189
 190                 /* FIXME: do we have to do this if we're not using WEP? */
 191                 if (unlikely(wl->default_key != idx)) {
 192                         ret = wl1271_cmd_set_default_wep_key(wl, idx);
 193                         if (ret < 0)
 194                                 return ret;
 195                 }
 196         }
 197
 198         ret = wl1271_tx_allocate(wl, skb, extra);
 199         if (ret < 0)
 200                 return ret;
 201
 202         ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
 203         if (ret < 0)
 204                 return ret;
 205
 206         ret = wl1271_tx_send_packet(wl, skb, info);
 207         if (ret < 0)
 208                 return ret;
 209
 210         return ret;
 211 }
 212
 213 void wl1271_tx_work(struct work_struct *work)
 214 {
 215         struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
 216         struct sk_buff *skb;
 217         bool woken_up = false;
 218         int ret;
 219
 220         mutex_lock(&wl->mutex);
 221
 222         if (unlikely(wl->state == WL1271_STATE_OFF))
 223                 goto out;
 224
 225         while ((skb = skb_dequeue(&wl->tx_queue))) {
 226                 if (!woken_up) {
 227                         ret = wl1271_ps_elp_wakeup(wl, false);
 228                         if (ret < 0)
 229                                 goto out;
 230                         woken_up = true;
 231                 }
 232
 233                 ret = wl1271_tx_frame(wl, skb);
 234                 if (ret == -EBUSY) {
 235                         /* firmware buffer is full, stop queues */
 236                         wl1271_debug(DEBUG_TX, "tx_work: fw buffer full, "
 237                                      "stop queues");
 238                         ieee80211_stop_queues(wl->hw);
 239                         wl->tx_queue_stopped = true;
 240                         skb_queue_head(&wl->tx_queue, skb);
 241                         goto out;
 242                 } else if (ret < 0) {
 243                         dev_kfree_skb(skb);
 244                         goto out;
 245                 } else if (wl->tx_queue_stopped) {
 246                         /* firmware buffer has space, restart queues */
 247                         wl1271_debug(DEBUG_TX,
 248                                      "complete_packet: waking queues");
 249                         ieee80211_wake_queues(wl->hw);
 250                         wl->tx_queue_stopped = false;
 251                 }
 252         }
 253
 254 out:
 255         if (woken_up)
 256                 wl1271_ps_elp_sleep(wl);
 257
 258         mutex_unlock(&wl->mutex);
 259 }
 260
 261 static void wl1271_tx_complete_packet(struct wl1271 *wl,
 262                                       struct wl1271_tx_hw_res_descr *result)
 263 {
 264         struct ieee80211_tx_info *info;
 265         struct sk_buff *skb;
 266         u16 seq;
 267         int id = result->id;
 268
 269         /* check for id legality */
 270         if (id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL) {
 271                 wl1271_warning("TX result illegal id: %d", id);
 272                 return;
 273         }
 274
 275         skb = wl->tx_frames[id];
 276         info = IEEE80211_SKB_CB(skb);
 277
 278         /* update packet status */
 279         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
 280                 if (result->status == TX_SUCCESS)
 281                         info->flags |= IEEE80211_TX_STAT_ACK;
 282                 if (result->status & TX_RETRY_EXCEEDED) {
 283                         /* FIXME */
 284                         /* info->status.excessive_retries = 1; */
 285                         wl->stats.excessive_retries++;
 286                 }
 287         }
 288
 289         /* FIXME */
 290         /* info->status.retry_count = result->ack_failures; */
 291         wl->stats.retry_count += result->ack_failures;
 292
 293         /* update security sequence number */
 294         seq = wl->tx_security_seq_16 +
 295                 (result->lsb_security_sequence_number -
 296                  wl->tx_security_last_seq);
 297         wl->tx_security_last_seq = result->lsb_security_sequence_number;
 298
 299         if (seq < wl->tx_security_seq_16)
 300                 wl->tx_security_seq_32++;
 301         wl->tx_security_seq_16 = seq;
 302
 303         /* remove private header from packet */
 304         skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));
 305
 306         /* remove TKIP header space if present */
 307         if (info->control.hw_key &&
 308             info->control.hw_key->alg == ALG_TKIP) {
 309                 int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 310                 memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen);
 311                 skb_pull(skb, WL1271_TKIP_IV_SPACE);
 312         }
 313
 314         wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 315                      " status 0x%x",
 316                      result->id, skb, result->ack_failures,
 317                      result->rate_class_index, result->status);
 318
 319         /* return the packet to the stack */
 320         ieee80211_tx_status(wl->hw, skb);
 321         wl->tx_frames[result->id] = NULL;
 322 }
 323
 324 /* Called upon reception of a TX complete interrupt */
 325 void wl1271_tx_complete(struct wl1271 *wl, u32 count)
 326 {
 327         struct wl1271_acx_mem_map *memmap =
 328                 (struct wl1271_acx_mem_map *)wl->target_mem_map;
 329         u32 i;
 330
 331         wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
 332
 333         /* read the tx results from the chipset */
 334         wl1271_spi_read(wl, memmap->tx_result,
 335                         wl->tx_res_if, sizeof(*wl->tx_res_if), false);
 336
 337         /* verify that the result buffer is not getting overrun */
 338         if (count > TX_HW_RESULT_QUEUE_LEN) {
 339                 wl1271_warning("TX result overflow from chipset: %d", count);
 340                 count = TX_HW_RESULT_QUEUE_LEN;
 341         }
 342
 343         /* process the results */
 344         for (i = 0; i < count; i++) {
 345                 struct wl1271_tx_hw_res_descr *result;
 346                 u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;
 347
 348                 /* process the packet */
 349                 result =  &(wl->tx_res_if->tx_results_queue[offset]);
 350                 wl1271_tx_complete_packet(wl, result);
 351
 352                 wl->tx_results_count++;
 353         }
 354
 355         /* write host counter to chipset (to ack) */
 356         wl1271_spi_write32(wl, memmap->tx_result +
 357                            offsetof(struct wl1271_tx_hw_res_if,
 358                                     tx_result_host_counter),
 359                            wl->tx_res_if->tx_result_fw_counter);
 360 }
 361
 362 /* caller must hold wl->mutex */
 363 void wl1271_tx_flush(struct wl1271 *wl)
 364 {
 365         int i;
 366         struct sk_buff *skb;
 367         struct ieee80211_tx_info *info;
 368
 369         /* TX failure */
 370 /*      control->flags = 0; FIXME */
 371
 372         while ((skb = skb_dequeue(&wl->tx_queue))) {
 373                 info = IEEE80211_SKB_CB(skb);
 374
 375                 wl1271_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 376
 377                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 378                                 continue;
 379
 380                 ieee80211_tx_status(wl->hw, skb);
 381         }
 382
 383         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
 384                 if (wl->tx_frames[i] != NULL) {
 385                         skb = wl->tx_frames[i];
 386                         info = IEEE80211_SKB_CB(skb);
 387
 388                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 389                                 continue;
 390
 391                         ieee80211_tx_status(wl->hw, skb);
 392                         wl->tx_frames[i] = NULL;
 393                 }
 394 }