linux/drivers/net/wireless/ti/wl1251/tx.c
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   1/*
   2 * This file is part of wl1251
   3 *
   4 * Copyright (c) 1998-2007 Texas Instruments Incorporated
   5 * Copyright (C) 2008 Nokia Corporation
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * version 2 as published by the Free Software Foundation.
  10 *
  11 * This program is distributed in the hope that it will be useful, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 * General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the Free Software
  18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  19 * 02110-1301 USA
  20 *
  21 */
  22
  23#include <linux/kernel.h>
  24#include <linux/module.h>
  25
  26#include "wl1251.h"
  27#include "reg.h"
  28#include "tx.h"
  29#include "ps.h"
  30#include "io.h"
  31
  32static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
  33{
  34        int used, data_in_count;
  35
  36        data_in_count = wl->data_in_count;
  37
  38        if (data_in_count < data_out_count)
  39                /* data_in_count has wrapped */
  40                data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
  41
  42        used = data_in_count - data_out_count;
  43
  44        WARN_ON(used < 0);
  45        WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
  46
  47        if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
  48                return true;
  49        else
  50                return false;
  51}
  52
  53static int wl1251_tx_path_status(struct wl1251 *wl)
  54{
  55        u32 status, addr, data_out_count;
  56        bool busy;
  57
  58        addr = wl->data_path->tx_control_addr;
  59        status = wl1251_mem_read32(wl, addr);
  60        data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
  61        busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
  62
  63        if (busy)
  64                return -EBUSY;
  65
  66        return 0;
  67}
  68
  69static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
  70{
  71        int i;
  72
  73        for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
  74                if (wl->tx_frames[i] == NULL) {
  75                        wl->tx_frames[i] = skb;
  76                        return i;
  77                }
  78
  79        return -EBUSY;
  80}
  81
  82static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
  83                              struct ieee80211_tx_info *control, u16 fc)
  84{
  85        *(u16 *)&tx_hdr->control = 0;
  86
  87        tx_hdr->control.rate_policy = 0;
  88
  89        /* 802.11 packets */
  90        tx_hdr->control.packet_type = 0;
  91
  92        if (control->flags & IEEE80211_TX_CTL_NO_ACK)
  93                tx_hdr->control.ack_policy = 1;
  94
  95        tx_hdr->control.tx_complete = 1;
  96
  97        if ((fc & IEEE80211_FTYPE_DATA) &&
  98            ((fc & IEEE80211_STYPE_QOS_DATA) ||
  99             (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
 100                tx_hdr->control.qos = 1;
 101}
 102
 103/* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
 104#define MAX_MSDU_SECURITY_LENGTH      16
 105#define MAX_MPDU_SECURITY_LENGTH      16
 106#define WLAN_QOS_HDR_LEN              26
 107#define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
 108                                       WLAN_QOS_HDR_LEN)
 109#define HW_BLOCK_SIZE                 252
 110static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
 111{
 112        u16 payload_len, frag_threshold, mem_blocks;
 113        u16 num_mpdus, mem_blocks_per_frag;
 114
 115        frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
 116        tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
 117
 118        payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
 119
 120        if (payload_len > frag_threshold) {
 121                mem_blocks_per_frag =
 122                        ((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
 123                         HW_BLOCK_SIZE) + 1;
 124                num_mpdus = payload_len / frag_threshold;
 125                mem_blocks = num_mpdus * mem_blocks_per_frag;
 126                payload_len -= num_mpdus * frag_threshold;
 127                num_mpdus++;
 128
 129        } else {
 130                mem_blocks_per_frag = 0;
 131                mem_blocks = 0;
 132                num_mpdus = 1;
 133        }
 134
 135        mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
 136
 137        if (num_mpdus > 1)
 138                mem_blocks += min(num_mpdus, mem_blocks_per_frag);
 139
 140        tx_hdr->num_mem_blocks = mem_blocks;
 141}
 142
 143static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
 144                              struct ieee80211_tx_info *control)
 145{
 146        struct tx_double_buffer_desc *tx_hdr;
 147        struct ieee80211_rate *rate;
 148        int id;
 149        u16 fc;
 150
 151        if (!skb)
 152                return -EINVAL;
 153
 154        id = wl1251_tx_id(wl, skb);
 155        if (id < 0)
 156                return id;
 157
 158        fc = *(u16 *)skb->data;
 159        tx_hdr = (struct tx_double_buffer_desc *) skb_push(skb,
 160                                                           sizeof(*tx_hdr));
 161
 162        tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
 163        rate = ieee80211_get_tx_rate(wl->hw, control);
 164        tx_hdr->rate = cpu_to_le16(rate->hw_value);
 165        tx_hdr->expiry_time = cpu_to_le32(1 << 16);
 166        tx_hdr->id = id;
 167
 168        tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
 169
 170        wl1251_tx_control(tx_hdr, control, fc);
 171        wl1251_tx_frag_block_num(tx_hdr);
 172
 173        return 0;
 174}
 175
 176/* We copy the packet to the target */
 177static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
 178                                 struct ieee80211_tx_info *control)
 179{
 180        struct tx_double_buffer_desc *tx_hdr;
 181        int len;
 182        u32 addr;
 183
 184        if (!skb)
 185                return -EINVAL;
 186
 187        tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 188
 189        if (control->control.hw_key &&
 190            control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 191                int hdrlen;
 192                __le16 fc;
 193                u16 length;
 194                u8 *pos;
 195
 196                fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
 197                length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
 198                tx_hdr->length = cpu_to_le16(length);
 199
 200                hdrlen = ieee80211_hdrlen(fc);
 201
 202                pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
 203                memmove(pos, pos + WL1251_TKIP_IV_SPACE,
 204                        sizeof(*tx_hdr) + hdrlen);
 205        }
 206
 207        /* Revisit. This is a workaround for getting non-aligned packets.
 208           This happens at least with EAPOL packets from the user space.
 209           Our DMA requires packets to be aligned on a 4-byte boundary.
 210        */
 211        if (unlikely((long)skb->data & 0x03)) {
 212                int offset = (4 - (long)skb->data) & 0x03;
 213                wl1251_debug(DEBUG_TX, "skb offset %d", offset);
 214
 215                /* check whether the current skb can be used */
 216                if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
 217                        struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
 218                                                                 GFP_KERNEL);
 219
 220                        if (unlikely(newskb == NULL)) {
 221                                wl1251_error("Can't allocate skb!");
 222                                return -EINVAL;
 223                        }
 224
 225                        tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
 226
 227                        dev_kfree_skb_any(skb);
 228                        wl->tx_frames[tx_hdr->id] = skb = newskb;
 229
 230                        offset = (4 - (long)skb->data) & 0x03;
 231                        wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
 232                }
 233
 234                /* align the buffer on a 4-byte boundary */
 235                if (offset) {
 236                        unsigned char *src = skb->data;
 237                        skb_reserve(skb, offset);
 238                        memmove(skb->data, src, skb->len);
 239                        tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 240                }
 241        }
 242
 243        /* Our skb->data at this point includes the HW header */
 244        len = WL1251_TX_ALIGN(skb->len);
 245
 246        if (wl->data_in_count & 0x1)
 247                addr = wl->data_path->tx_packet_ring_addr +
 248                        wl->data_path->tx_packet_ring_chunk_size;
 249        else
 250                addr = wl->data_path->tx_packet_ring_addr;
 251
 252        wl1251_mem_write(wl, addr, skb->data, len);
 253
 254        wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
 255                     "queue %d", tx_hdr->id, skb, tx_hdr->length,
 256                     tx_hdr->rate, tx_hdr->xmit_queue);
 257
 258        return 0;
 259}
 260
 261static void wl1251_tx_trigger(struct wl1251 *wl)
 262{
 263        u32 data, addr;
 264
 265        if (wl->data_in_count & 0x1) {
 266                addr = ACX_REG_INTERRUPT_TRIG_H;
 267                data = INTR_TRIG_TX_PROC1;
 268        } else {
 269                addr = ACX_REG_INTERRUPT_TRIG;
 270                data = INTR_TRIG_TX_PROC0;
 271        }
 272
 273        wl1251_reg_write32(wl, addr, data);
 274
 275        /* Bumping data in */
 276        wl->data_in_count = (wl->data_in_count + 1) &
 277                TX_STATUS_DATA_OUT_COUNT_MASK;
 278}
 279
 280/* caller must hold wl->mutex */
 281static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 282{
 283        struct ieee80211_tx_info *info;
 284        int ret = 0;
 285        u8 idx;
 286
 287        info = IEEE80211_SKB_CB(skb);
 288
 289        if (info->control.hw_key) {
 290                idx = info->control.hw_key->hw_key_idx;
 291                if (unlikely(wl->default_key != idx)) {
 292                        ret = wl1251_acx_default_key(wl, idx);
 293                        if (ret < 0)
 294                                return ret;
 295                }
 296        }
 297
 298        ret = wl1251_tx_path_status(wl);
 299        if (ret < 0)
 300                return ret;
 301
 302        ret = wl1251_tx_fill_hdr(wl, skb, info);
 303        if (ret < 0)
 304                return ret;
 305
 306        ret = wl1251_tx_send_packet(wl, skb, info);
 307        if (ret < 0)
 308                return ret;
 309
 310        wl1251_tx_trigger(wl);
 311
 312        return ret;
 313}
 314
 315void wl1251_tx_work(struct work_struct *work)
 316{
 317        struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 318        struct sk_buff *skb;
 319        bool woken_up = false;
 320        int ret;
 321
 322        mutex_lock(&wl->mutex);
 323
 324        if (unlikely(wl->state == WL1251_STATE_OFF))
 325                goto out;
 326
 327        while ((skb = skb_dequeue(&wl->tx_queue))) {
 328                if (!woken_up) {
 329                        ret = wl1251_ps_elp_wakeup(wl);
 330                        if (ret < 0)
 331                                goto out;
 332                        woken_up = true;
 333                }
 334
 335                ret = wl1251_tx_frame(wl, skb);
 336                if (ret == -EBUSY) {
 337                        skb_queue_head(&wl->tx_queue, skb);
 338                        goto out;
 339                } else if (ret < 0) {
 340                        dev_kfree_skb(skb);
 341                        goto out;
 342                }
 343        }
 344
 345out:
 346        if (woken_up)
 347                wl1251_ps_elp_sleep(wl);
 348
 349        mutex_unlock(&wl->mutex);
 350}
 351
 352static const char *wl1251_tx_parse_status(u8 status)
 353{
 354        /* 8 bit status field, one character per bit plus null */
 355        static char buf[9];
 356        int i = 0;
 357
 358        memset(buf, 0, sizeof(buf));
 359
 360        if (status & TX_DMA_ERROR)
 361                buf[i++] = 'm';
 362        if (status & TX_DISABLED)
 363                buf[i++] = 'd';
 364        if (status & TX_RETRY_EXCEEDED)
 365                buf[i++] = 'r';
 366        if (status & TX_TIMEOUT)
 367                buf[i++] = 't';
 368        if (status & TX_KEY_NOT_FOUND)
 369                buf[i++] = 'k';
 370        if (status & TX_ENCRYPT_FAIL)
 371                buf[i++] = 'e';
 372        if (status & TX_UNAVAILABLE_PRIORITY)
 373                buf[i++] = 'p';
 374
 375        /* bit 0 is unused apparently */
 376
 377        return buf;
 378}
 379
 380static void wl1251_tx_packet_cb(struct wl1251 *wl,
 381                                struct tx_result *result)
 382{
 383        struct ieee80211_tx_info *info;
 384        struct sk_buff *skb;
 385        int hdrlen;
 386        u8 *frame;
 387
 388        skb = wl->tx_frames[result->id];
 389        if (skb == NULL) {
 390                wl1251_error("SKB for packet %d is NULL", result->id);
 391                return;
 392        }
 393
 394        info = IEEE80211_SKB_CB(skb);
 395
 396        if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 397            (result->status == TX_SUCCESS))
 398                info->flags |= IEEE80211_TX_STAT_ACK;
 399
 400        info->status.rates[0].count = result->ack_failures + 1;
 401        wl->stats.retry_count += result->ack_failures;
 402
 403        /*
 404         * We have to remove our private TX header before pushing
 405         * the skb back to mac80211.
 406         */
 407        frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 408        if (info->control.hw_key &&
 409            info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 410                hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 411                memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 412                skb_pull(skb, WL1251_TKIP_IV_SPACE);
 413        }
 414
 415        wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 416                     " status 0x%x (%s)",
 417                     result->id, skb, result->ack_failures, result->rate,
 418                     result->status, wl1251_tx_parse_status(result->status));
 419
 420
 421        ieee80211_tx_status(wl->hw, skb);
 422
 423        wl->tx_frames[result->id] = NULL;
 424}
 425
 426/* Called upon reception of a TX complete interrupt */
 427void wl1251_tx_complete(struct wl1251 *wl)
 428{
 429        int i, result_index, num_complete = 0, queue_len;
 430        struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 431        unsigned long flags;
 432
 433        if (unlikely(wl->state != WL1251_STATE_ON))
 434                return;
 435
 436        /* First we read the result */
 437        wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 438                            result, sizeof(result));
 439
 440        result_index = wl->next_tx_complete;
 441
 442        for (i = 0; i < ARRAY_SIZE(result); i++) {
 443                result_ptr = &result[result_index];
 444
 445                if (result_ptr->done_1 == 1 &&
 446                    result_ptr->done_2 == 1) {
 447                        wl1251_tx_packet_cb(wl, result_ptr);
 448
 449                        result_ptr->done_1 = 0;
 450                        result_ptr->done_2 = 0;
 451
 452                        result_index = (result_index + 1) &
 453                                (FW_TX_CMPLT_BLOCK_SIZE - 1);
 454                        num_complete++;
 455                } else {
 456                        break;
 457                }
 458        }
 459
 460        queue_len = skb_queue_len(&wl->tx_queue);
 461
 462        if ((num_complete > 0) && (queue_len > 0)) {
 463                /* firmware buffer has space, reschedule tx_work */
 464                wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
 465                ieee80211_queue_work(wl->hw, &wl->tx_work);
 466        }
 467
 468        if (wl->tx_queue_stopped &&
 469            queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
 470                /* tx_queue has space, restart queues */
 471                wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 472                spin_lock_irqsave(&wl->wl_lock, flags);
 473                ieee80211_wake_queues(wl->hw);
 474                wl->tx_queue_stopped = false;
 475                spin_unlock_irqrestore(&wl->wl_lock, flags);
 476        }
 477
 478        /* Every completed frame needs to be acknowledged */
 479        if (num_complete) {
 480                /*
 481                 * If we've wrapped, we have to clear
 482                 * the results in 2 steps.
 483                 */
 484                if (result_index > wl->next_tx_complete) {
 485                        /* Only 1 write is needed */
 486                        wl1251_mem_write(wl,
 487                                         wl->data_path->tx_complete_addr +
 488                                         (wl->next_tx_complete *
 489                                          sizeof(struct tx_result)),
 490                                         &result[wl->next_tx_complete],
 491                                         num_complete *
 492                                         sizeof(struct tx_result));
 493
 494
 495                } else if (result_index < wl->next_tx_complete) {
 496                        /* 2 writes are needed */
 497                        wl1251_mem_write(wl,
 498                                         wl->data_path->tx_complete_addr +
 499                                         (wl->next_tx_complete *
 500                                          sizeof(struct tx_result)),
 501                                         &result[wl->next_tx_complete],
 502                                         (FW_TX_CMPLT_BLOCK_SIZE -
 503                                          wl->next_tx_complete) *
 504                                         sizeof(struct tx_result));
 505
 506                        wl1251_mem_write(wl,
 507                                         wl->data_path->tx_complete_addr,
 508                                         result,
 509                                         (num_complete -
 510                                          FW_TX_CMPLT_BLOCK_SIZE +
 511                                          wl->next_tx_complete) *
 512                                         sizeof(struct tx_result));
 513
 514                } else {
 515                        /* We have to write the whole array */
 516                        wl1251_mem_write(wl,
 517                                         wl->data_path->tx_complete_addr,
 518                                         result,
 519                                         FW_TX_CMPLT_BLOCK_SIZE *
 520                                         sizeof(struct tx_result));
 521                }
 522
 523        }
 524
 525        wl->next_tx_complete = result_index;
 526}
 527
 528/* caller must hold wl->mutex */
 529void wl1251_tx_flush(struct wl1251 *wl)
 530{
 531        int i;
 532        struct sk_buff *skb;
 533        struct ieee80211_tx_info *info;
 534
 535        /* TX failure */
 536/*      control->flags = 0; FIXME */
 537
 538        while ((skb = skb_dequeue(&wl->tx_queue))) {
 539                info = IEEE80211_SKB_CB(skb);
 540
 541                wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 542
 543                if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 544                                continue;
 545
 546                ieee80211_tx_status(wl->hw, skb);
 547        }
 548
 549        for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 550                if (wl->tx_frames[i] != NULL) {
 551                        skb = wl->tx_frames[i];
 552                        info = IEEE80211_SKB_CB(skb);
 553
 554                        if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 555                                continue;
 556
 557                        ieee80211_tx_status(wl->hw, skb);
 558                        wl->tx_frames[i] = NULL;
 559                }
 560}
 561