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
  37         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
  38                 if (wl->tx_frames[i] == NULL) {
  39                         wl->tx_frames[i] = skb;
  40                         return i;
  41                 }
  42
  43         return -EBUSY;
  44 }
  45
  46 static int wl1271_tx_allocate(struct wl1271 *wl, struct sk_buff *skb, u32 extra)
  47 {
  48         struct wl1271_tx_hw_descr *desc;
  49         u32 total_len = skb->len + sizeof(struct wl1271_tx_hw_descr) + extra;
  50         u32 total_blocks, excluded;
  51         int id, ret = -EBUSY;
  52
  53         /* allocate free identifier for the packet */
  54         id = wl1271_tx_id(wl, skb);
  55         if (id < 0)
  56                 return id;
  57
  58         /* approximate the number of blocks required for this packet
  59            in the firmware */
  60         /* FIXME: try to figure out what is done here and make it cleaner */
  61         total_blocks = (skb->len) >> TX_HW_BLOCK_SHIFT_DIV;
  62         excluded = (total_blocks << 2) + (skb->len & 0xff) + 34;
  63         total_blocks += (excluded > 252) ? 2 : 1;
  64         total_blocks += TX_HW_BLOCK_SPARE;
  65
  66         if (total_blocks <= wl->tx_blocks_available) {
  67                 desc = (struct wl1271_tx_hw_descr *)skb_push(
  68                         skb, total_len - skb->len);
  69
  70                 desc->extra_mem_blocks = TX_HW_BLOCK_SPARE;
  71                 desc->total_mem_blocks = total_blocks;
  72                 desc->id = id;
  73
  74                 wl->tx_blocks_available -= total_blocks;
  75
  76                 ret = 0;
  77
  78                 wl1271_debug(DEBUG_TX,
  79                              "tx_allocate: size: %d, blocks: %d, id: %d",
  80                              total_len, total_blocks, id);
  81         } else
  82                 wl->tx_frames[id] = NULL;
  83
  84         return ret;
  85 }
  86
  87 static int wl1271_tx_fill_hdr(struct wl1271 *wl, struct sk_buff *skb,
  88                               u32 extra, struct ieee80211_tx_info *control)
  89 {
  90         struct wl1271_tx_hw_descr *desc;
  91         int pad;
  92
  93         desc = (struct wl1271_tx_hw_descr *) skb->data;
  94
  95         /* configure packet life time */
  96         desc->start_time = jiffies_to_usecs(jiffies) - wl->time_offset;
  97         desc->life_time = TX_HW_MGMT_PKT_LIFETIME_TU;
  98
  99         /* configure the tx attributes */
 100         desc->tx_attr = wl->session_counter << TX_HW_ATTR_OFST_SESSION_COUNTER;
 101         /* FIXME: do we know the packet priority? can we identify mgmt
 102            packets, and use max prio for them at least? */
 103         desc->tid = 0;
 104         desc->aid = TX_HW_DEFAULT_AID;
 105         desc->reserved = 0;
 106
 107         /* align the length (and store in terms of words) */
 108         pad = WL1271_TX_ALIGN(skb->len);
 109         desc->length = pad >> 2;
 110
 111         /* calculate number of padding bytes */
 112         pad = pad - skb->len;
 113         desc->tx_attr |= pad << TX_HW_ATTR_OFST_LAST_WORD_PAD;
 114
 115         wl1271_debug(DEBUG_TX, "tx_fill_hdr: pad: %d", pad);
 116         return 0;
 117 }
 118
 119 static int wl1271_tx_send_packet(struct wl1271 *wl, struct sk_buff *skb,
 120                                  struct ieee80211_tx_info *control)
 121 {
 122
 123         struct wl1271_tx_hw_descr *desc;
 124         int len;
 125
 126         /* FIXME: This is a workaround for getting non-aligned packets.
 127            This happens at least with EAPOL packets from the user space.
 128            Our DMA requires packets to be aligned on a 4-byte boundary.
 129         */
 130         if (unlikely((long)skb->data & 0x03)) {
 131                 int offset = (4 - (long)skb->data) & 0x03;
 132                 wl1271_debug(DEBUG_TX, "skb offset %d", offset);
 133
 134                 /* check whether the current skb can be used */
 135                 if (!skb_cloned(skb) && (skb_tailroom(skb) >= offset)) {
 136                         unsigned char *src = skb->data;
 137
 138                         /* align the buffer on a 4-byte boundary */
 139                         skb_reserve(skb, offset);
 140                         memmove(skb->data, src, skb->len);
 141                 } else {
 142                         wl1271_info("No handler, fixme!");
 143                         return -EINVAL;
 144                 }
 145         }
 146
 147         len = WL1271_TX_ALIGN(skb->len);
 148
 149         /* perform a fixed address block write with the packet */
 150         wl1271_spi_reg_write(wl, WL1271_SLV_MEM_DATA, skb->data, len, true);
 151
 152         /* write packet new counter into the write access register */
 153         wl->tx_packets_count++;
 154         wl1271_reg_write32(wl, WL1271_HOST_WR_ACCESS, wl->tx_packets_count);
 155
 156         desc = (struct wl1271_tx_hw_descr *) skb->data;
 157         wl1271_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u (%u words)",
 158                      desc->id, skb, len, desc->length);
 159
 160         return 0;
 161 }
 162
 163 /* caller must hold wl->mutex */
 164 static int wl1271_tx_frame(struct wl1271 *wl, struct sk_buff *skb)
 165 {
 166         struct ieee80211_tx_info *info;
 167         u32 extra = 0;
 168         int ret = 0;
 169         u8 idx;
 170
 171         if (!skb)
 172                 return -EINVAL;
 173
 174         info = IEEE80211_SKB_CB(skb);
 175
 176         if (info->control.hw_key &&
 177             info->control.hw_key->alg == ALG_TKIP)
 178                 extra = WL1271_TKIP_IV_SPACE;
 179
 180         if (info->control.hw_key) {
 181                 idx = info->control.hw_key->hw_key_idx;
 182
 183                 /* FIXME: do we have to do this if we're not using WEP? */
 184                 if (unlikely(wl->default_key != idx)) {
 185                         ret = wl1271_cmd_set_default_wep_key(wl, idx);
 186                         if (ret < 0)
 187                                 return ret;
 188                 }
 189         }
 190
 191         ret = wl1271_tx_allocate(wl, skb, extra);
 192         if (ret < 0)
 193                 return ret;
 194
 195         ret = wl1271_tx_fill_hdr(wl, skb, extra, info);
 196         if (ret < 0)
 197                 return ret;
 198
 199         ret = wl1271_tx_send_packet(wl, skb, info);
 200         if (ret < 0)
 201                 return ret;
 202
 203         return ret;
 204 }
 205
 206 void wl1271_tx_work(struct work_struct *work)
 207 {
 208         struct wl1271 *wl = container_of(work, struct wl1271, tx_work);
 209         struct sk_buff *skb;
 210         bool woken_up = false;
 211         int ret;
 212
 213         mutex_lock(&wl->mutex);
 214
 215         if (unlikely(wl->state == WL1271_STATE_OFF))
 216                 goto out;
 217
 218         while ((skb = skb_dequeue(&wl->tx_queue))) {
 219                 if (!woken_up) {
 220                         ret = wl1271_ps_elp_wakeup(wl, false);
 221                         if (ret < 0)
 222                                 goto out;
 223                         woken_up = true;
 224                 }
 225
 226                 ret = wl1271_tx_frame(wl, skb);
 227                 if (ret == -EBUSY) {
 228                         /* firmware buffer is full, stop queues */
 229                         wl1271_debug(DEBUG_TX, "tx_work: fw buffer full, "
 230                                      "stop queues");
 231                         ieee80211_stop_queues(wl->hw);
 232                         wl->tx_queue_stopped = true;
 233                         skb_queue_head(&wl->tx_queue, skb);
 234                         goto out;
 235                 } else if (ret < 0) {
 236                         dev_kfree_skb(skb);
 237                         goto out;
 238                 } else if (wl->tx_queue_stopped) {
 239                         /* firmware buffer has space, restart queues */
 240                         wl1271_debug(DEBUG_TX,
 241                                      "complete_packet: waking queues");
 242                         ieee80211_wake_queues(wl->hw);
 243                         wl->tx_queue_stopped = false;
 244                 }
 245         }
 246
 247 out:
 248         if (woken_up)
 249                 wl1271_ps_elp_sleep(wl);
 250
 251         mutex_unlock(&wl->mutex);
 252 }
 253
 254 static void wl1271_tx_complete_packet(struct wl1271 *wl,
 255                                       struct wl1271_tx_hw_res_descr *result)
 256 {
 257
 258         struct ieee80211_tx_info *info;
 259         struct sk_buff *skb;
 260         u32 header_len;
 261         int id = result->id;
 262
 263         /* check for id legality */
 264         if (id >= TX_HW_RESULT_QUEUE_LEN || wl->tx_frames[id] == NULL) {
 265                 wl1271_warning("TX result illegal id: %d", id);
 266                 return;
 267         }
 268
 269         skb = wl->tx_frames[id];
 270         info = IEEE80211_SKB_CB(skb);
 271
 272         /* update packet status */
 273         if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
 274                 if (result->status == TX_SUCCESS)
 275                         info->flags |= IEEE80211_TX_STAT_ACK;
 276                 if (result->status & TX_RETRY_EXCEEDED) {
 277                         /* FIXME */
 278                         /* info->status.excessive_retries = 1; */
 279                         wl->stats.excessive_retries++;
 280                 }
 281         }
 282
 283         /* FIXME */
 284         /* info->status.retry_count = result->ack_failures; */
 285         wl->stats.retry_count += result->ack_failures;
 286
 287         /* get header len */
 288         if (info->control.hw_key &&
 289             info->control.hw_key->alg == ALG_TKIP)
 290                 header_len = WL1271_TKIP_IV_SPACE +
 291                         sizeof(struct wl1271_tx_hw_descr);
 292         else
 293                 header_len = sizeof(struct wl1271_tx_hw_descr);
 294
 295         wl1271_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 296                      " status 0x%x",
 297                      result->id, skb, result->ack_failures,
 298                      result->rate_class_index, result->status);
 299
 300         /* remove private header from packet */
 301         skb_pull(skb, header_len);
 302
 303         /* return the packet to the stack */
 304         ieee80211_tx_status(wl->hw, skb);
 305         wl->tx_frames[result->id] = NULL;
 306 }
 307
 308 /* Called upon reception of a TX complete interrupt */
 309 void wl1271_tx_complete(struct wl1271 *wl, u32 count)
 310 {
 311         struct wl1271_acx_mem_map *memmap =
 312                 (struct wl1271_acx_mem_map *)wl->target_mem_map;
 313         u32 i;
 314
 315         wl1271_debug(DEBUG_TX, "tx_complete received, packets: %d", count);
 316
 317         /* read the tx results from the chipset */
 318         wl1271_spi_mem_read(wl, memmap->tx_result,
 319                             wl->tx_res_if, sizeof(*wl->tx_res_if));
 320
 321         /* verify that the result buffer is not getting overrun */
 322         if (count > TX_HW_RESULT_QUEUE_LEN) {
 323                 wl1271_warning("TX result overflow from chipset: %d", count);
 324                 count = TX_HW_RESULT_QUEUE_LEN;
 325         }
 326
 327         /* process the results */
 328         for (i = 0; i < count; i++) {
 329                 struct wl1271_tx_hw_res_descr *result;
 330                 u8 offset = wl->tx_results_count & TX_HW_RESULT_QUEUE_LEN_MASK;
 331
 332                 /* process the packet */
 333                 result =  &(wl->tx_res_if->tx_results_queue[offset]);
 334                 wl1271_tx_complete_packet(wl, result);
 335
 336                 wl->tx_results_count++;
 337         }
 338
 339         /* write host counter to chipset (to ack) */
 340         wl1271_mem_write32(wl, memmap->tx_result +
 341                            offsetof(struct wl1271_tx_hw_res_if,
 342                                     tx_result_host_counter),
 343                            wl->tx_res_if->tx_result_fw_counter);
 344 }
 345
 346 /* caller must hold wl->mutex */
 347 void wl1271_tx_flush(struct wl1271 *wl)
 348 {
 349         int i;
 350         struct sk_buff *skb;
 351         struct ieee80211_tx_info *info;
 352
 353         /* TX failure */
 354 /*      control->flags = 0; FIXME */
 355
 356         while ((skb = skb_dequeue(&wl->tx_queue))) {
 357                 info = IEEE80211_SKB_CB(skb);
 358
 359                 wl1271_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 360
 361                 if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 362                                 continue;
 363
 364                 ieee80211_tx_status(wl->hw, skb);
 365         }
 366
 367         for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 368                 if (wl->tx_frames[i] != NULL) {
 369                         skb = wl->tx_frames[i];
 370                         info = IEEE80211_SKB_CB(skb);
 371
 372                         if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 373                                 continue;
 374
 375                         ieee80211_tx_status(wl->hw, skb);
 376                         wl->tx_frames[i] = NULL;
 377                 }
 378 }