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         desc->tx_attr = cpu_to_le16(tx_attr);
 125
 126         wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
 127         return 0;
 128 }
 129
 130 static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
 131                                  struct ieee80211_tx_info *control)
 132 {
 133
 134         struct wl1271_tx_hw_descr *desc;
 135         int len;
 136
 137         /* FIXME: This is a workaround for getting non-aligned packets.
 138            This happens at least with EAPOL packets from the user space.
 139            Our DMA requires packets to be aligned on a 4-byte boundary.
 140         */
 141         if (unlikely((long)skb->data & 0x03)) {
 142                 int offset = (4 - (long)skb->data) & 0x03;
 143                 wl1271_debug(DEBUG_TX, "skb offset %d", offset);
 144
 145                 /* check whether the current skb can be used */
 146                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 147                         unsigned char *src = skb->data;
 148
 149                         /* align the buffer on a 4-byte boundary */
 150                         skb_reserve(skb, offset);
 151                         memmove(skb->data, src, skb->len);
 152                 } else {
 153                         wl1271_info("No handler, fixme!");
 154                         return -EINVAL;
 155                 }
 156         }
 157
 158         len = WL1271_TX_ALIGN(skb->len);
 159
 160         /* perform a fixed address block write with the packet */
 161         wl1271_spi_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);
 162
 163         /* write packet new counter into the write access register */
 164         wl->tx_packets_count++;
 165         wl1271_spi_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
 166
 167         desc = (struct wl1271_tx_hw_descr *) skb->data;
 168         wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
 169                      desc->id, skb, len, desc->length);
 170
 171         return 0;
 172 }
 173
 174 /* caller must hold wl->mutex */
 175 static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
 176 {
 177         struct ieee80211_tx_info *info;
 178         u32 extra = 0;
 179         int ret = 0;
 180         u8 idx;
 181
 182         if (!skb)
 183                 return -EINVAL;
 184
 185         info = IEEE80211_SKB_CB(skb);
 186
 187         if (info->control.hw_key &&
 188             info->control.hw_key->alg == ALG_TKIP)
 189                 extra = WL1271_TKIP_IV_SPACE;
 190
 191         if (info->control.hw_key) {
 192                 idx = info->control.hw_key->hw_key_idx;
 193
 194                 /* FIXME: do we have to do this if we're not using WEP? */
 195                 if (unlikely(wl->default_key != idx)) {
 196                         ret = wl1271_cmd_set_default_wep_key(wl, idx);
 197                         if (ret < 0)
 198                                 return ret;
 199                 }
 200         }
 201
 202         ret = wl1271_tx_allocate(wl, skb, extra);
 203         if (ret < 0)
 204                 return ret;
 205
 206         ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
 207         if (ret < 0)
 208                 return ret;
 209
 210         ret = wl1271_tx_send_packet(wl, skb, info);
 211         if (ret < 0)
 212                 return ret;
 213
 214         return ret;
 215 }
 216
 217 void wl1271_tx_work(struct work_struct *work)
 218 {
 219         struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
 220         struct sk_buff *skb;
 221         bool woken_up = false;
 222         int ret;
 223
 224         mutex_lock(&wl->mutex);
 225
 226         if (unlikely(wl->state == WL1271_STATE_OFF))
 227                 goto out;
 228
 229         while ((skb = skb_dequeue(&wl->tx_queue))) {
 230                 if (!woken_up) {
 231                         ret = wl1271_ps_elp_wakeup(wl, false);
 232                         if (ret < 0)
 233                                 goto out;
 234                         woken_up = true;
 235                 }
 236
 237                 ret = wl1271_tx_frame(wl, skb);
 238                 if (ret == -EBUSY) {
 239                         /* firmware buffer is full, stop queues */
 240                         wl1271_debug(DEBUG_TX, "tx_work: fw buffer full, "
 241                                      "stop queues");
 242                         ieee80211_stop_queues(wl->hw);
 243                         wl->tx_queue_stopped = true;
 244                         skb_queue_head(&wl->tx_queue, skb);
 245                         goto out;
 246                 } else if (ret < 0) {
 247                         dev_kfree_skb(skb);
 248                         goto out;
 249                 } else if (wl->tx_queue_stopped) {
 250                         /* firmware buffer has space, restart queues */
 251                         wl1271_debug(DEBUG_TX,
 252                                      "complete_packet: waking queues");
 253                         ieee80211_wake_queues(wl->hw);
 254                         wl->tx_queue_stopped = false;
 255                 }
 256         }
 257
 258 out:
 259         if (woken_up)
 260                 wl1271_ps_elp_sleep(wl);
 261
 262         mutex_unlock(&wl->mutex);
 263 }
 264
 265 static void wl1271_tx_complete_packet(struct wl1271 *wl,
 266                                       struct wl1271_tx_hw_res_descr *result)
 267 {
 268         struct ieee80211_tx_info *info;
 269         struct sk_buff *skb;
 270         u16 seq;
 271         int id = result->id;
 272
 273         /* check for id legality */
 274         if (id >= ACX_TX_DESCRIPTORS || wl->tx_frames[id] == NULL) {
 275                 wl1271_warning("TX result illegal id: %d", id);
 276                 return;
 277         }
 278
 279         skb = wl->tx_frames[id];
 280         info = IEEE80211_SKB_CB(skb);
 281
 282         /* update packet status */
 283         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
 284                 if (result->status == TX_SUCCESS)
 285                         info->flags |= IEEE80211_TX_STAT_ACK;
 286                 if (result->status & TX_RETRY_EXCEEDED) {
 287                         /* FIXME */
 288                         /* info->status.excessive_retries = 1; */
 289                         wl->stats.excessive_retries++;
 290                 }
 291         }
 292
 293         /* FIXME */
 294         /* info->status.retry_count = result->ack_failures; */
 295         wl->stats.retry_count += result->ack_failures;
 296
 297         /* update security sequence number */
 298         seq = wl->tx_security_seq_16 +
 299                 (result->lsb_security_sequence_number -
 300                  wl->tx_security_last_seq);
 301         wl->tx_security_last_seq = result->lsb_security_sequence_number;
 302
 303         if (seq < wl->tx_security_seq_16)
 304                 wl->tx_security_seq_32++;
 305         wl->tx_security_seq_16 = seq;
 306
 307         /* remove private header from packet */
 308         skb_pull(skb, sizeof(struct wl1271_tx_hw_descr));
 309
 310         /* remove TKIP header space if present */
 311         if (info->control.hw_key &&
 312             info->control.hw_key->alg == ALG_TKIP) {
 313                 int hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 314                 memmove(skb->data + WL1271_TKIP_IV_SPACE, skb->data, hdrlen);
 315                 skb_pull(skb, WL1271_TKIP_IV_SPACE);
 316         }
 317
 318         wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 319                      " status 0x%x",
 320                      result->id, skb, result->ack_failures,
 321                      result->rate_class_index, result->status);
 322
 323         /* return the packet to the stack */
 324         ieee80211_tx_status(wl->hw, skb);
 325         wl->tx_frames[result->id] = NULL;
 326 }
 327
 328 /* Called upon reception of a TX complete interrupt */
 329 void wl1271_tx_complete(struct wl1271 *wl, u32 count)
 330 {
 331         struct wl1271_acx_mem_map *memmap =
 332                 (struct wl1271_acx_mem_map *)wl->target_mem_map;
 333         u32 i;
 334
 335         wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
 336
 337         /* read the tx results from the chipset */
 338         wl1271_spi_read(wl, le32_to_cpu(memmap->tx_result),
 339                         wl->tx_res_if, sizeof(*wl->tx_res_if), false);
 340
 341         /* verify that the result buffer is not getting overrun */
 342         if (count > TX_HW_RESULT_QUEUE_LEN) {
 343                 wl1271_warning("TX result overflow from chipset: %d", count);
 344                 count = TX_HW_RESULT_QUEUE_LEN;
 345         }
 346
 347         /* process the results */
 348         for (i = 0; i < count; i++) {
 349                 struct wl1271_tx_hw_res_descr *result;
 350                 u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;
 351
 352                 /* process the packet */
 353                 result =  &(wl->tx_res_if->tx_results_queue[offset]);
 354                 wl1271_tx_complete_packet(wl, result);
 355
 356                 wl->tx_results_count++;
 357         }
 358
 359         /* write host counter to chipset (to ack) */
 360         wl1271_spi_write32(wl, le32_to_cpu(memmap->tx_result) +
 361                            offsetof(struct wl1271_tx_hw_res_if,
 362                                     tx_result_host_counter),
 363                            le32_to_cpu(wl->tx_res_if->tx_result_fw_counter));
 364 }
 365
 366 /* caller must hold wl->mutex */
 367 void wl1271_tx_flush(struct wl1271 *wl)
 368 {
 369         int i;
 370         struct sk_buff *skb;
 371         struct ieee80211_tx_info *info;
 372
 373         /* TX failure */
 374 /*      control->flags = 0; FIXME */
 375
 376         while ((skb = skb_dequeue(&wl->tx_queue))) {
 377                 info = IEEE80211_SKB_CB(skb);
 378
 379                 wl1271_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 380
 381                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 382                                 continue;
 383
 384                 ieee80211_tx_status(wl->hw, skb);
 385         }
 386
 387         for (i = 0; i < ACX_TX_DESCRIPTORS; i++)
 388                 if (wl->tx_frames[i] != NULL) {
 389                         skb = wl->tx_frames[i];
 390                         info = IEEE80211_SKB_CB(skb);
 391
 392                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 393                                 continue;
 394
 395                         ieee80211_tx_status(wl->hw, skb);
 396                         wl->tx_frames[i] = NULL;
 397                 }
 398 }