linux/drivers/net/wireless/ti/wl1251/tx.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * This file is part of wl1251
   4 *
   5 * Copyright (c) 1998-2007 Texas Instruments Incorporated
   6 * Copyright (C) 2008 Nokia Corporation
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/module.h>
  11
  12#include "wl1251.h"
  13#include "reg.h"
  14#include "tx.h"
  15#include "ps.h"
  16#include "io.h"
  17#include "event.h"
  18
  19static bool wl1251_tx_double_buffer_busy(struct wl1251 *wl, u32 data_out_count)
  20{
  21        int used, data_in_count;
  22
  23        data_in_count = wl->data_in_count;
  24
  25        if (data_in_count < data_out_count)
  26                /* data_in_count has wrapped */
  27                data_in_count += TX_STATUS_DATA_OUT_COUNT_MASK + 1;
  28
  29        used = data_in_count - data_out_count;
  30
  31        WARN_ON(used < 0);
  32        WARN_ON(used > DP_TX_PACKET_RING_CHUNK_NUM);
  33
  34        if (used >= DP_TX_PACKET_RING_CHUNK_NUM)
  35                return true;
  36        else
  37                return false;
  38}
  39
  40static int wl1251_tx_path_status(struct wl1251 *wl)
  41{
  42        u32 status, addr, data_out_count;
  43        bool busy;
  44
  45        addr = wl->data_path->tx_control_addr;
  46        status = wl1251_mem_read32(wl, addr);
  47        data_out_count = status & TX_STATUS_DATA_OUT_COUNT_MASK;
  48        busy = wl1251_tx_double_buffer_busy(wl, data_out_count);
  49
  50        if (busy)
  51                return -EBUSY;
  52
  53        return 0;
  54}
  55
  56static int wl1251_tx_id(struct wl1251 *wl, struct sk_buff *skb)
  57{
  58        int i;
  59
  60        for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
  61                if (wl->tx_frames[i] == NULL) {
  62                        wl->tx_frames[i] = skb;
  63                        return i;
  64                }
  65
  66        return -EBUSY;
  67}
  68
  69static void wl1251_tx_control(struct tx_double_buffer_desc *tx_hdr,
  70                              struct ieee80211_tx_info *control, u16 fc)
  71{
  72        *(u16 *)&tx_hdr->control = 0;
  73
  74        tx_hdr->control.rate_policy = 0;
  75
  76        /* 802.11 packets */
  77        tx_hdr->control.packet_type = 0;
  78
  79        /* Also disable retry and ACK policy for injected packets */
  80        if ((control->flags & IEEE80211_TX_CTL_NO_ACK) ||
  81            (control->flags & IEEE80211_TX_CTL_INJECTED)) {
  82                tx_hdr->control.rate_policy = 1;
  83                tx_hdr->control.ack_policy = 1;
  84        }
  85
  86        tx_hdr->control.tx_complete = 1;
  87
  88        if ((fc & IEEE80211_FTYPE_DATA) &&
  89            ((fc & IEEE80211_STYPE_QOS_DATA) ||
  90             (fc & IEEE80211_STYPE_QOS_NULLFUNC)))
  91                tx_hdr->control.qos = 1;
  92}
  93
  94/* RSN + MIC = 8 + 8 = 16 bytes (worst case - AES). */
  95#define MAX_MSDU_SECURITY_LENGTH      16
  96#define MAX_MPDU_SECURITY_LENGTH      16
  97#define WLAN_QOS_HDR_LEN              26
  98#define MAX_MPDU_HEADER_AND_SECURITY  (MAX_MPDU_SECURITY_LENGTH + \
  99                                       WLAN_QOS_HDR_LEN)
 100#define HW_BLOCK_SIZE                 252
 101static void wl1251_tx_frag_block_num(struct tx_double_buffer_desc *tx_hdr)
 102{
 103        u16 payload_len, frag_threshold, mem_blocks;
 104        u16 num_mpdus, mem_blocks_per_frag;
 105
 106        frag_threshold = IEEE80211_MAX_FRAG_THRESHOLD;
 107        tx_hdr->frag_threshold = cpu_to_le16(frag_threshold);
 108
 109        payload_len = le16_to_cpu(tx_hdr->length) + MAX_MSDU_SECURITY_LENGTH;
 110
 111        if (payload_len > frag_threshold) {
 112                mem_blocks_per_frag =
 113                        ((frag_threshold + MAX_MPDU_HEADER_AND_SECURITY) /
 114                         HW_BLOCK_SIZE) + 1;
 115                num_mpdus = payload_len / frag_threshold;
 116                mem_blocks = num_mpdus * mem_blocks_per_frag;
 117                payload_len -= num_mpdus * frag_threshold;
 118                num_mpdus++;
 119
 120        } else {
 121                mem_blocks_per_frag = 0;
 122                mem_blocks = 0;
 123                num_mpdus = 1;
 124        }
 125
 126        mem_blocks += (payload_len / HW_BLOCK_SIZE) + 1;
 127
 128        if (num_mpdus > 1)
 129                mem_blocks += min(num_mpdus, mem_blocks_per_frag);
 130
 131        tx_hdr->num_mem_blocks = mem_blocks;
 132}
 133
 134static int wl1251_tx_fill_hdr(struct wl1251 *wl, struct sk_buff *skb,
 135                              struct ieee80211_tx_info *control)
 136{
 137        struct tx_double_buffer_desc *tx_hdr;
 138        struct ieee80211_rate *rate;
 139        int id;
 140        u16 fc;
 141
 142        if (!skb)
 143                return -EINVAL;
 144
 145        id = wl1251_tx_id(wl, skb);
 146        if (id < 0)
 147                return id;
 148
 149        fc = *(u16 *)skb->data;
 150        tx_hdr = skb_push(skb, sizeof(*tx_hdr));
 151
 152        tx_hdr->length = cpu_to_le16(skb->len - sizeof(*tx_hdr));
 153        rate = ieee80211_get_tx_rate(wl->hw, control);
 154        tx_hdr->rate = cpu_to_le16(rate->hw_value);
 155        tx_hdr->expiry_time = cpu_to_le32(1 << 16);
 156        tx_hdr->id = id;
 157
 158        tx_hdr->xmit_queue = wl1251_tx_get_queue(skb_get_queue_mapping(skb));
 159
 160        wl1251_tx_control(tx_hdr, control, fc);
 161        wl1251_tx_frag_block_num(tx_hdr);
 162
 163        return 0;
 164}
 165
 166/* We copy the packet to the target */
 167static int wl1251_tx_send_packet(struct wl1251 *wl, struct sk_buff *skb,
 168                                 struct ieee80211_tx_info *control)
 169{
 170        struct tx_double_buffer_desc *tx_hdr;
 171        int len;
 172        u32 addr;
 173
 174        if (!skb)
 175                return -EINVAL;
 176
 177        tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 178
 179        if (control->control.hw_key &&
 180            control->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 181                int hdrlen;
 182                __le16 fc;
 183                u16 length;
 184                u8 *pos;
 185
 186                fc = *(__le16 *)(skb->data + sizeof(*tx_hdr));
 187                length = le16_to_cpu(tx_hdr->length) + WL1251_TKIP_IV_SPACE;
 188                tx_hdr->length = cpu_to_le16(length);
 189
 190                hdrlen = ieee80211_hdrlen(fc);
 191
 192                pos = skb_push(skb, WL1251_TKIP_IV_SPACE);
 193                memmove(pos, pos + WL1251_TKIP_IV_SPACE,
 194                        sizeof(*tx_hdr) + hdrlen);
 195        }
 196
 197        /* Revisit. This is a workaround for getting non-aligned packets.
 198           This happens at least with EAPOL packets from the user space.
 199           Our DMA requires packets to be aligned on a 4-byte boundary.
 200        */
 201        if (unlikely((long)skb->data & 0x03)) {
 202                int offset = (4 - (long)skb->data) & 0x03;
 203                wl1251_debug(DEBUG_TX, "skb offset %d", offset);
 204
 205                /* check whether the current skb can be used */
 206                if (skb_cloned(skb) || (skb_tailroom(skb) < offset)) {
 207                        struct sk_buff *newskb = skb_copy_expand(skb, 0, 3,
 208                                                                 GFP_KERNEL);
 209
 210                        if (unlikely(newskb == NULL))
 211                                return -EINVAL;
 212
 213                        tx_hdr = (struct tx_double_buffer_desc *) newskb->data;
 214
 215                        dev_kfree_skb_any(skb);
 216                        wl->tx_frames[tx_hdr->id] = skb = newskb;
 217
 218                        offset = (4 - (long)skb->data) & 0x03;
 219                        wl1251_debug(DEBUG_TX, "new skb offset %d", offset);
 220                }
 221
 222                /* align the buffer on a 4-byte boundary */
 223                if (offset) {
 224                        unsigned char *src = skb->data;
 225                        skb_reserve(skb, offset);
 226                        memmove(skb->data, src, skb->len);
 227                        tx_hdr = (struct tx_double_buffer_desc *) skb->data;
 228                }
 229        }
 230
 231        /* Our skb->data at this point includes the HW header */
 232        len = WL1251_TX_ALIGN(skb->len);
 233
 234        if (wl->data_in_count & 0x1)
 235                addr = wl->data_path->tx_packet_ring_addr +
 236                        wl->data_path->tx_packet_ring_chunk_size;
 237        else
 238                addr = wl->data_path->tx_packet_ring_addr;
 239
 240        wl1251_mem_write(wl, addr, skb->data, len);
 241
 242        wl1251_debug(DEBUG_TX, "tx id %u skb 0x%p payload %u rate 0x%x "
 243                     "queue %d", tx_hdr->id, skb, tx_hdr->length,
 244                     tx_hdr->rate, tx_hdr->xmit_queue);
 245
 246        return 0;
 247}
 248
 249static void wl1251_tx_trigger(struct wl1251 *wl)
 250{
 251        u32 data, addr;
 252
 253        if (wl->data_in_count & 0x1) {
 254                addr = ACX_REG_INTERRUPT_TRIG_H;
 255                data = INTR_TRIG_TX_PROC1;
 256        } else {
 257                addr = ACX_REG_INTERRUPT_TRIG;
 258                data = INTR_TRIG_TX_PROC0;
 259        }
 260
 261        wl1251_reg_write32(wl, addr, data);
 262
 263        /* Bumping data in */
 264        wl->data_in_count = (wl->data_in_count + 1) &
 265                TX_STATUS_DATA_OUT_COUNT_MASK;
 266}
 267
 268static void enable_tx_for_packet_injection(struct wl1251 *wl)
 269{
 270        int ret;
 271
 272        ret = wl1251_cmd_join(wl, BSS_TYPE_STA_BSS, wl->channel,
 273                              wl->beacon_int, wl->dtim_period);
 274        if (ret < 0) {
 275                wl1251_warning("join failed");
 276                return;
 277        }
 278
 279        ret = wl1251_event_wait(wl, JOIN_EVENT_COMPLETE_ID, 100);
 280        if (ret < 0) {
 281                wl1251_warning("join timeout");
 282                return;
 283        }
 284
 285        wl->joined = true;
 286}
 287
 288/* caller must hold wl->mutex */
 289static int wl1251_tx_frame(struct wl1251 *wl, struct sk_buff *skb)
 290{
 291        struct ieee80211_tx_info *info;
 292        int ret = 0;
 293        u8 idx;
 294
 295        info = IEEE80211_SKB_CB(skb);
 296
 297        if (info->control.hw_key) {
 298                if (unlikely(wl->monitor_present))
 299                        return -EINVAL;
 300
 301                idx = info->control.hw_key->hw_key_idx;
 302                if (unlikely(wl->default_key != idx)) {
 303                        ret = wl1251_acx_default_key(wl, idx);
 304                        if (ret < 0)
 305                                return ret;
 306                }
 307        }
 308
 309        /* Enable tx path in monitor mode for packet injection */
 310        if ((wl->vif == NULL) && !wl->joined)
 311                enable_tx_for_packet_injection(wl);
 312
 313        ret = wl1251_tx_path_status(wl);
 314        if (ret < 0)
 315                return ret;
 316
 317        ret = wl1251_tx_fill_hdr(wl, skb, info);
 318        if (ret < 0)
 319                return ret;
 320
 321        ret = wl1251_tx_send_packet(wl, skb, info);
 322        if (ret < 0)
 323                return ret;
 324
 325        wl1251_tx_trigger(wl);
 326
 327        return ret;
 328}
 329
 330void wl1251_tx_work(struct work_struct *work)
 331{
 332        struct wl1251 *wl = container_of(work, struct wl1251, tx_work);
 333        struct sk_buff *skb;
 334        bool woken_up = false;
 335        int ret;
 336
 337        mutex_lock(&wl->mutex);
 338
 339        if (unlikely(wl->state == WL1251_STATE_OFF))
 340                goto out;
 341
 342        while ((skb = skb_dequeue(&wl->tx_queue))) {
 343                if (!woken_up) {
 344                        ret = wl1251_ps_elp_wakeup(wl);
 345                        if (ret < 0)
 346                                goto out;
 347                        woken_up = true;
 348                }
 349
 350                ret = wl1251_tx_frame(wl, skb);
 351                if (ret == -EBUSY) {
 352                        skb_queue_head(&wl->tx_queue, skb);
 353                        goto out;
 354                } else if (ret < 0) {
 355                        dev_kfree_skb(skb);
 356                        goto out;
 357                }
 358        }
 359
 360out:
 361        if (woken_up)
 362                wl1251_ps_elp_sleep(wl);
 363
 364        mutex_unlock(&wl->mutex);
 365}
 366
 367static const char *wl1251_tx_parse_status(u8 status)
 368{
 369        /* 8 bit status field, one character per bit plus null */
 370        static char buf[9];
 371        int i = 0;
 372
 373        memset(buf, 0, sizeof(buf));
 374
 375        if (status & TX_DMA_ERROR)
 376                buf[i++] = 'm';
 377        if (status & TX_DISABLED)
 378                buf[i++] = 'd';
 379        if (status & TX_RETRY_EXCEEDED)
 380                buf[i++] = 'r';
 381        if (status & TX_TIMEOUT)
 382                buf[i++] = 't';
 383        if (status & TX_KEY_NOT_FOUND)
 384                buf[i++] = 'k';
 385        if (status & TX_ENCRYPT_FAIL)
 386                buf[i++] = 'e';
 387        if (status & TX_UNAVAILABLE_PRIORITY)
 388                buf[i++] = 'p';
 389
 390        /* bit 0 is unused apparently */
 391
 392        return buf;
 393}
 394
 395static void wl1251_tx_packet_cb(struct wl1251 *wl,
 396                                struct tx_result *result)
 397{
 398        struct ieee80211_tx_info *info;
 399        struct sk_buff *skb;
 400        int hdrlen;
 401        u8 *frame;
 402
 403        skb = wl->tx_frames[result->id];
 404        if (skb == NULL) {
 405                wl1251_error("SKB for packet %d is NULL", result->id);
 406                return;
 407        }
 408
 409        info = IEEE80211_SKB_CB(skb);
 410
 411        if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) &&
 412            !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 413            (result->status == TX_SUCCESS))
 414                info->flags |= IEEE80211_TX_STAT_ACK;
 415
 416        info->status.rates[0].count = result->ack_failures + 1;
 417        wl->stats.retry_count += result->ack_failures;
 418
 419        /*
 420         * We have to remove our private TX header before pushing
 421         * the skb back to mac80211.
 422         */
 423        frame = skb_pull(skb, sizeof(struct tx_double_buffer_desc));
 424        if (info->control.hw_key &&
 425            info->control.hw_key->cipher == WLAN_CIPHER_SUITE_TKIP) {
 426                hdrlen = ieee80211_get_hdrlen_from_skb(skb);
 427                memmove(frame + WL1251_TKIP_IV_SPACE, frame, hdrlen);
 428                skb_pull(skb, WL1251_TKIP_IV_SPACE);
 429        }
 430
 431        wl1251_debug(DEBUG_TX, "tx status id %u skb 0x%p failures %u rate 0x%x"
 432                     " status 0x%x (%s)",
 433                     result->id, skb, result->ack_failures, result->rate,
 434                     result->status, wl1251_tx_parse_status(result->status));
 435
 436
 437        ieee80211_tx_status(wl->hw, skb);
 438
 439        wl->tx_frames[result->id] = NULL;
 440}
 441
 442/* Called upon reception of a TX complete interrupt */
 443void wl1251_tx_complete(struct wl1251 *wl)
 444{
 445        int i, result_index, num_complete = 0, queue_len;
 446        struct tx_result result[FW_TX_CMPLT_BLOCK_SIZE], *result_ptr;
 447        unsigned long flags;
 448
 449        if (unlikely(wl->state != WL1251_STATE_ON))
 450                return;
 451
 452        /* First we read the result */
 453        wl1251_mem_read(wl, wl->data_path->tx_complete_addr,
 454                            result, sizeof(result));
 455
 456        result_index = wl->next_tx_complete;
 457
 458        for (i = 0; i < ARRAY_SIZE(result); i++) {
 459                result_ptr = &result[result_index];
 460
 461                if (result_ptr->done_1 == 1 &&
 462                    result_ptr->done_2 == 1) {
 463                        wl1251_tx_packet_cb(wl, result_ptr);
 464
 465                        result_ptr->done_1 = 0;
 466                        result_ptr->done_2 = 0;
 467
 468                        result_index = (result_index + 1) &
 469                                (FW_TX_CMPLT_BLOCK_SIZE - 1);
 470                        num_complete++;
 471                } else {
 472                        break;
 473                }
 474        }
 475
 476        queue_len = skb_queue_len(&wl->tx_queue);
 477
 478        if ((num_complete > 0) && (queue_len > 0)) {
 479                /* firmware buffer has space, reschedule tx_work */
 480                wl1251_debug(DEBUG_TX, "tx_complete: reschedule tx_work");
 481                ieee80211_queue_work(wl->hw, &wl->tx_work);
 482        }
 483
 484        if (wl->tx_queue_stopped &&
 485            queue_len <= WL1251_TX_QUEUE_LOW_WATERMARK) {
 486                /* tx_queue has space, restart queues */
 487                wl1251_debug(DEBUG_TX, "tx_complete: waking queues");
 488                spin_lock_irqsave(&wl->wl_lock, flags);
 489                ieee80211_wake_queues(wl->hw);
 490                wl->tx_queue_stopped = false;
 491                spin_unlock_irqrestore(&wl->wl_lock, flags);
 492        }
 493
 494        /* Every completed frame needs to be acknowledged */
 495        if (num_complete) {
 496                /*
 497                 * If we've wrapped, we have to clear
 498                 * the results in 2 steps.
 499                 */
 500                if (result_index > wl->next_tx_complete) {
 501                        /* Only 1 write is needed */
 502                        wl1251_mem_write(wl,
 503                                         wl->data_path->tx_complete_addr +
 504                                         (wl->next_tx_complete *
 505                                          sizeof(struct tx_result)),
 506                                         &result[wl->next_tx_complete],
 507                                         num_complete *
 508                                         sizeof(struct tx_result));
 509
 510
 511                } else if (result_index < wl->next_tx_complete) {
 512                        /* 2 writes are needed */
 513                        wl1251_mem_write(wl,
 514                                         wl->data_path->tx_complete_addr +
 515                                         (wl->next_tx_complete *
 516                                          sizeof(struct tx_result)),
 517                                         &result[wl->next_tx_complete],
 518                                         (FW_TX_CMPLT_BLOCK_SIZE -
 519                                          wl->next_tx_complete) *
 520                                         sizeof(struct tx_result));
 521
 522                        wl1251_mem_write(wl,
 523                                         wl->data_path->tx_complete_addr,
 524                                         result,
 525                                         (num_complete -
 526                                          FW_TX_CMPLT_BLOCK_SIZE +
 527                                          wl->next_tx_complete) *
 528                                         sizeof(struct tx_result));
 529
 530                } else {
 531                        /* We have to write the whole array */
 532                        wl1251_mem_write(wl,
 533                                         wl->data_path->tx_complete_addr,
 534                                         result,
 535                                         FW_TX_CMPLT_BLOCK_SIZE *
 536                                         sizeof(struct tx_result));
 537                }
 538
 539        }
 540
 541        wl->next_tx_complete = result_index;
 542}
 543
 544/* caller must hold wl->mutex */
 545void wl1251_tx_flush(struct wl1251 *wl)
 546{
 547        int i;
 548        struct sk_buff *skb;
 549        struct ieee80211_tx_info *info;
 550
 551        /* TX failure */
 552/*      control->flags = 0; FIXME */
 553
 554        while ((skb = skb_dequeue(&wl->tx_queue))) {
 555                info = IEEE80211_SKB_CB(skb);
 556
 557                wl1251_debug(DEBUG_TX, "flushing skb 0x%p", skb);
 558
 559                if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 560                                continue;
 561
 562                ieee80211_tx_status(wl->hw, skb);
 563        }
 564
 565        for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 566                if (wl->tx_frames[i] != NULL) {
 567                        skb = wl->tx_frames[i];
 568                        info = IEEE80211_SKB_CB(skb);
 569
 570                        if (!(info->flags & IEEE80211_TX_CTL_REQ_TX_STATUS))
 571                                continue;
 572
 573                        ieee80211_tx_status(wl->hw, skb);
 574                        wl->tx_frames[i] = NULL;
 575                }
 576}
 577