drivers/net/wireless/mediatek/mt7601u/dma.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2015 Jakub Kicinski <kubakici@wp.pl>
   4  */
   5
   6 #include "mt7601u.h"
   7 #include "dma.h"
   8 #include "usb.h"
   9 #include "trace.h"
  10
  11 static int mt7601u_submit_rx_buf(struct mt7601u_dev *dev,
  12                                  struct mt7601u_dma_buf_rx *e, gfp_t gfp);
  13
  14 static unsigned int ieee80211_get_hdrlen_from_buf(const u8 *data, unsigned len)
  15 {
  16         const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)data;
  17         unsigned int hdrlen;
  18
  19         if (unlikely(len < 10))
  20                 return 0;
  21         hdrlen = ieee80211_hdrlen(hdr->frame_control);
  22         if (unlikely(hdrlen > len))
  23                 return 0;
  24         return hdrlen;
  25 }
  26
  27 static struct sk_buff *
  28 mt7601u_rx_skb_from_seg(struct mt7601u_dev *dev, struct mt7601u_rxwi *rxwi,
  29                         void *data, u32 seg_len, u32 truesize, struct page *p)
  30 {
  31         struct sk_buff *skb;
  32         u32 true_len, hdr_len = 0, copy, frag;
  33
  34         skb = alloc_skb(p ? 128 : seg_len, GFP_ATOMIC);
  35         if (!skb)
  36                 return NULL;
  37
  38         true_len = mt76_mac_process_rx(dev, skb, data, rxwi);
  39         if (!true_len || true_len > seg_len)
  40                 goto bad_frame;
  41
  42         hdr_len = ieee80211_get_hdrlen_from_buf(data, true_len);
  43         if (!hdr_len)
  44                 goto bad_frame;
  45
  46         if (rxwi->rxinfo & cpu_to_le32(MT_RXINFO_L2PAD)) {
  47                 skb_put_data(skb, data, hdr_len);
  48
  49                 data += hdr_len + 2;
  50                 true_len -= hdr_len;
  51                 hdr_len = 0;
  52         }
  53
  54         /* If not doing paged RX allocated skb will always have enough space */
  55         copy = (true_len <= skb_tailroom(skb)) ? true_len : hdr_len + 8;
  56         frag = true_len - copy;
  57
  58         skb_put_data(skb, data, copy);
  59         data += copy;
  60
  61         if (frag) {
  62                 skb_add_rx_frag(skb, 0, p, data - page_address(p),
  63                                 frag, truesize);
  64                 get_page(p);
  65         }
  66
  67         return skb;
  68
  69 bad_frame:
  70         dev_err_ratelimited(dev->dev, "Error: incorrect frame len:%u hdr:%u\n",
  71                             true_len, hdr_len);
  72         dev_kfree_skb(skb);
  73         return NULL;
  74 }
  75
  76 static void mt7601u_rx_process_seg(struct mt7601u_dev *dev, u8 *data,
  77                                    u32 seg_len, struct page *p,
  78                                    struct list_head *list)
  79 {
  80         struct sk_buff *skb;
  81         struct mt7601u_rxwi *rxwi;
  82         u32 fce_info, truesize = seg_len;
  83
  84         /* DMA_INFO field at the beginning of the segment contains only some of
  85          * the information, we need to read the FCE descriptor from the end.
  86          */
  87         fce_info = get_unaligned_le32(data + seg_len - MT_FCE_INFO_LEN);
  88         seg_len -= MT_FCE_INFO_LEN;
  89
  90         data += MT_DMA_HDR_LEN;
  91         seg_len -= MT_DMA_HDR_LEN;
  92
  93         rxwi = (struct mt7601u_rxwi *) data;
  94         data += sizeof(struct mt7601u_rxwi);
  95         seg_len -= sizeof(struct mt7601u_rxwi);
  96
  97         if (unlikely(rxwi->zero[0] || rxwi->zero[1] || rxwi->zero[2]))
  98                 dev_err_once(dev->dev, "Error: RXWI zero fields are set\n");
  99         if (unlikely(FIELD_GET(MT_RXD_INFO_TYPE, fce_info)))
 100                 dev_err_once(dev->dev, "Error: RX path seen a non-pkt urb\n");
 101
 102         trace_mt_rx(dev, rxwi, fce_info);
 103
 104         skb = mt7601u_rx_skb_from_seg(dev, rxwi, data, seg_len, truesize, p);
 105         if (!skb)
 106                 return;
 107
 108         local_bh_disable();
 109         rcu_read_lock();
 110
 111         ieee80211_rx_list(dev->hw, NULL, skb, list);
 112
 113         rcu_read_unlock();
 114         local_bh_enable();
 115 }
 116
 117 static u16 mt7601u_rx_next_seg_len(u8 *data, u32 data_len)
 118 {
 119         u32 min_seg_len = MT_DMA_HDR_LEN + MT_RX_INFO_LEN +
 120                 sizeof(struct mt7601u_rxwi) + MT_FCE_INFO_LEN;
 121         u16 dma_len = get_unaligned_le16(data);
 122
 123         if (data_len < min_seg_len ||
 124             WARN_ON_ONCE(!dma_len) ||
 125             WARN_ON_ONCE(dma_len + MT_DMA_HDRS > data_len) ||
 126             WARN_ON_ONCE(dma_len & 0x3))
 127                 return 0;
 128
 129         return MT_DMA_HDRS + dma_len;
 130 }
 131
 132 static void
 133 mt7601u_rx_process_entry(struct mt7601u_dev *dev, struct mt7601u_dma_buf_rx *e)
 134 {
 135         u32 seg_len, data_len = e->urb->actual_length;
 136         u8 *data = page_address(e->p);
 137         struct page *new_p = NULL;
 138         LIST_HEAD(list);
 139         int cnt = 0;
 140
 141         if (!test_bit(MT7601U_STATE_INITIALIZED, &dev->state))
 142                 return;
 143
 144         /* Copy if there is very little data in the buffer. */
 145         if (data_len > 512)
 146                 new_p = dev_alloc_pages(MT_RX_ORDER);
 147
 148         while ((seg_len = mt7601u_rx_next_seg_len(data, data_len))) {
 149                 mt7601u_rx_process_seg(dev, data, seg_len,
 150                                        new_p ? e->p : NULL, &list);
 151
 152                 data_len -= seg_len;
 153                 data += seg_len;
 154                 cnt++;
 155         }
 156
 157         if (cnt > 1)
 158                 trace_mt_rx_dma_aggr(dev, cnt, !!new_p);
 159
 160         netif_receive_skb_list(&list);
 161
 162         if (new_p) {
 163                 /* we have one extra ref from the allocator */
 164                 __free_pages(e->p, MT_RX_ORDER);
 165
 166                 e->p = new_p;
 167         }
 168 }
 169
 170 static struct mt7601u_dma_buf_rx *
 171 mt7601u_rx_get_pending_entry(struct mt7601u_dev *dev)
 172 {
 173         struct mt7601u_rx_queue *q = &dev->rx_q;
 174         struct mt7601u_dma_buf_rx *buf = NULL;
 175         unsigned long flags;
 176
 177         spin_lock_irqsave(&dev->rx_lock, flags);
 178
 179         if (!q->pending)
 180                 goto out;
 181
 182         buf = &q->e[q->start];
 183         q->pending--;
 184         q->start = (q->start + 1) % q->entries;
 185 out:
 186         spin_unlock_irqrestore(&dev->rx_lock, flags);
 187
 188         return buf;
 189 }
 190
 191 static void mt7601u_complete_rx(struct urb *urb)
 192 {
 193         struct mt7601u_dev *dev = urb->context;
 194         struct mt7601u_rx_queue *q = &dev->rx_q;
 195         unsigned long flags;
 196
 197         /* do no schedule rx tasklet if urb has been unlinked
 198          * or the device has been removed
 199          */
 200         switch (urb->status) {
 201         case -ECONNRESET:
 202         case -ESHUTDOWN:
 203         case -ENOENT:
 204         case -EPROTO:
 205                 return;
 206         default:
 207                 dev_err_ratelimited(dev->dev, "rx urb failed: %d\n",
 208                                     urb->status);
 209                 fallthrough;
 210         case 0:
 211                 break;
 212         }
 213
 214         spin_lock_irqsave(&dev->rx_lock, flags);
 215         if (WARN_ONCE(q->e[q->end].urb != urb, "RX urb mismatch"))
 216                 goto out;
 217
 218         q->end = (q->end + 1) % q->entries;
 219         q->pending++;
 220         tasklet_schedule(&dev->rx_tasklet);
 221 out:
 222         spin_unlock_irqrestore(&dev->rx_lock, flags);
 223 }
 224
 225 static void mt7601u_rx_tasklet(struct tasklet_struct *t)
 226 {
 227         struct mt7601u_dev *dev = from_tasklet(dev, t, rx_tasklet);
 228         struct mt7601u_dma_buf_rx *e;
 229
 230         while ((e = mt7601u_rx_get_pending_entry(dev))) {
 231                 if (e->urb->status)
 232                         continue;
 233
 234                 mt7601u_rx_process_entry(dev, e);
 235                 mt7601u_submit_rx_buf(dev, e, GFP_ATOMIC);
 236         }
 237 }
 238
 239 static void mt7601u_complete_tx(struct urb *urb)
 240 {
 241         struct mt7601u_tx_queue *q = urb->context;
 242         struct mt7601u_dev *dev = q->dev;
 243         struct sk_buff *skb;
 244         unsigned long flags;
 245
 246         switch (urb->status) {
 247         case -ECONNRESET:
 248         case -ESHUTDOWN:
 249         case -ENOENT:
 250         case -EPROTO:
 251                 return;
 252         default:
 253                 dev_err_ratelimited(dev->dev, "tx urb failed: %d\n",
 254                                     urb->status);
 255                 fallthrough;
 256         case 0:
 257                 break;
 258         }
 259
 260         spin_lock_irqsave(&dev->tx_lock, flags);
 261         if (WARN_ONCE(q->e[q->start].urb != urb, "TX urb mismatch"))
 262                 goto out;
 263
 264         skb = q->e[q->start].skb;
 265         q->e[q->start].skb = NULL;
 266         trace_mt_tx_dma_done(dev, skb);
 267
 268         __skb_queue_tail(&dev->tx_skb_done, skb);
 269         tasklet_schedule(&dev->tx_tasklet);
 270
 271         if (q->used == q->entries - q->entries / 8)
 272                 ieee80211_wake_queue(dev->hw, skb_get_queue_mapping(skb));
 273
 274         q->start = (q->start + 1) % q->entries;
 275         q->used--;
 276 out:
 277         spin_unlock_irqrestore(&dev->tx_lock, flags);
 278 }
 279
 280 static void mt7601u_tx_tasklet(struct tasklet_struct *t)
 281 {
 282         struct mt7601u_dev *dev = from_tasklet(dev, t, tx_tasklet);
 283         struct sk_buff_head skbs;
 284         unsigned long flags;
 285
 286         __skb_queue_head_init(&skbs);
 287
 288         spin_lock_irqsave(&dev->tx_lock, flags);
 289
 290         set_bit(MT7601U_STATE_MORE_STATS, &dev->state);
 291         if (!test_and_set_bit(MT7601U_STATE_READING_STATS, &dev->state))
 292                 queue_delayed_work(dev->stat_wq, &dev->stat_work,
 293                                    msecs_to_jiffies(10));
 294
 295         skb_queue_splice_init(&dev->tx_skb_done, &skbs);
 296
 297         spin_unlock_irqrestore(&dev->tx_lock, flags);
 298
 299         while (!skb_queue_empty(&skbs)) {
 300                 struct sk_buff *skb = __skb_dequeue(&skbs);
 301
 302                 mt7601u_tx_status(dev, skb);
 303         }
 304 }
 305
 306 static int mt7601u_dma_submit_tx(struct mt7601u_dev *dev,
 307                                  struct sk_buff *skb, u8 ep)
 308 {
 309         struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
 310         unsigned snd_pipe = usb_sndbulkpipe(usb_dev, dev->out_eps[ep]);
 311         struct mt7601u_dma_buf_tx *e;
 312         struct mt7601u_tx_queue *q = &dev->tx_q[ep];
 313         unsigned long flags;
 314         int ret;
 315
 316         spin_lock_irqsave(&dev->tx_lock, flags);
 317
 318         if (WARN_ON(q->entries <= q->used)) {
 319                 ret = -ENOSPC;
 320                 goto out;
 321         }
 322
 323         e = &q->e[q->end];
 324         e->skb = skb;
 325         usb_fill_bulk_urb(e->urb, usb_dev, snd_pipe, skb->data, skb->len,
 326                           mt7601u_complete_tx, q);
 327         ret = usb_submit_urb(e->urb, GFP_ATOMIC);
 328         if (ret) {
 329                 /* Special-handle ENODEV from TX urb submission because it will
 330                  * often be the first ENODEV we see after device is removed.
 331                  */
 332                 if (ret == -ENODEV)
 333                         set_bit(MT7601U_STATE_REMOVED, &dev->state);
 334                 else
 335                         dev_err(dev->dev, "Error: TX urb submit failed:%d\n",
 336                                 ret);
 337                 goto out;
 338         }
 339
 340         q->end = (q->end + 1) % q->entries;
 341         q->used++;
 342
 343         if (q->used >= q->entries)
 344                 ieee80211_stop_queue(dev->hw, skb_get_queue_mapping(skb));
 345 out:
 346         spin_unlock_irqrestore(&dev->tx_lock, flags);
 347
 348         return ret;
 349 }
 350
 351 /* Map hardware Q to USB endpoint number */
 352 static u8 q2ep(u8 qid)
 353 {
 354         /* TODO: take management packets to queue 5 */
 355         return qid + 1;
 356 }
 357
 358 /* Map USB endpoint number to Q id in the DMA engine */
 359 static enum mt76_qsel ep2dmaq(u8 ep)
 360 {
 361         if (ep == 5)
 362                 return MT_QSEL_MGMT;
 363         return MT_QSEL_EDCA;
 364 }
 365
 366 int mt7601u_dma_enqueue_tx(struct mt7601u_dev *dev, struct sk_buff *skb,
 367                            struct mt76_wcid *wcid, int hw_q)
 368 {
 369         u8 ep = q2ep(hw_q);
 370         u32 dma_flags;
 371         int ret;
 372
 373         dma_flags = MT_TXD_PKT_INFO_80211;
 374         if (wcid->hw_key_idx == 0xff)
 375                 dma_flags |= MT_TXD_PKT_INFO_WIV;
 376
 377         ret = mt7601u_dma_skb_wrap_pkt(skb, ep2dmaq(ep), dma_flags);
 378         if (ret)
 379                 return ret;
 380
 381         ret = mt7601u_dma_submit_tx(dev, skb, ep);
 382         if (ret) {
 383                 ieee80211_free_txskb(dev->hw, skb);
 384                 return ret;
 385         }
 386
 387         return 0;
 388 }
 389
 390 static void mt7601u_kill_rx(struct mt7601u_dev *dev)
 391 {
 392         int i;
 393
 394         for (i = 0; i < dev->rx_q.entries; i++)
 395                 usb_poison_urb(dev->rx_q.e[i].urb);
 396 }
 397
 398 static int mt7601u_submit_rx_buf(struct mt7601u_dev *dev,
 399                                  struct mt7601u_dma_buf_rx *e, gfp_t gfp)
 400 {
 401         struct usb_device *usb_dev = mt7601u_to_usb_dev(dev);
 402         u8 *buf = page_address(e->p);
 403         unsigned pipe;
 404         int ret;
 405
 406         pipe = usb_rcvbulkpipe(usb_dev, dev->in_eps[MT_EP_IN_PKT_RX]);
 407
 408         usb_fill_bulk_urb(e->urb, usb_dev, pipe, buf, MT_RX_URB_SIZE,
 409                           mt7601u_complete_rx, dev);
 410
 411         trace_mt_submit_urb(dev, e->urb);
 412         ret = usb_submit_urb(e->urb, gfp);
 413         if (ret)
 414                 dev_err(dev->dev, "Error: submit RX URB failed:%d\n", ret);
 415
 416         return ret;
 417 }
 418
 419 static int mt7601u_submit_rx(struct mt7601u_dev *dev)
 420 {
 421         int i, ret;
 422
 423         for (i = 0; i < dev->rx_q.entries; i++) {
 424                 ret = mt7601u_submit_rx_buf(dev, &dev->rx_q.e[i], GFP_KERNEL);
 425                 if (ret)
 426                         return ret;
 427         }
 428
 429         return 0;
 430 }
 431
 432 static void mt7601u_free_rx(struct mt7601u_dev *dev)
 433 {
 434         int i;
 435
 436         for (i = 0; i < dev->rx_q.entries; i++) {
 437                 __free_pages(dev->rx_q.e[i].p, MT_RX_ORDER);
 438                 usb_free_urb(dev->rx_q.e[i].urb);
 439         }
 440 }
 441
 442 static int mt7601u_alloc_rx(struct mt7601u_dev *dev)
 443 {
 444         int i;
 445
 446         memset(&dev->rx_q, 0, sizeof(dev->rx_q));
 447         dev->rx_q.dev = dev;
 448         dev->rx_q.entries = N_RX_ENTRIES;
 449
 450         for (i = 0; i < N_RX_ENTRIES; i++) {
 451                 dev->rx_q.e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
 452                 dev->rx_q.e[i].p = dev_alloc_pages(MT_RX_ORDER);
 453
 454                 if (!dev->rx_q.e[i].urb || !dev->rx_q.e[i].p)
 455                         return -ENOMEM;
 456         }
 457
 458         return 0;
 459 }
 460
 461 static void mt7601u_free_tx_queue(struct mt7601u_tx_queue *q)
 462 {
 463         int i;
 464
 465         for (i = 0; i < q->entries; i++)  {
 466                 usb_poison_urb(q->e[i].urb);
 467                 if (q->e[i].skb)
 468                         mt7601u_tx_status(q->dev, q->e[i].skb);
 469                 usb_free_urb(q->e[i].urb);
 470         }
 471 }
 472
 473 static void mt7601u_free_tx(struct mt7601u_dev *dev)
 474 {
 475         int i;
 476
 477         if (!dev->tx_q)
 478                 return;
 479
 480         for (i = 0; i < __MT_EP_OUT_MAX; i++)
 481                 mt7601u_free_tx_queue(&dev->tx_q[i]);
 482 }
 483
 484 static int mt7601u_alloc_tx_queue(struct mt7601u_dev *dev,
 485                                   struct mt7601u_tx_queue *q)
 486 {
 487         int i;
 488
 489         q->dev = dev;
 490         q->entries = N_TX_ENTRIES;
 491
 492         for (i = 0; i < N_TX_ENTRIES; i++) {
 493                 q->e[i].urb = usb_alloc_urb(0, GFP_KERNEL);
 494                 if (!q->e[i].urb)
 495                         return -ENOMEM;
 496         }
 497
 498         return 0;
 499 }
 500
 501 static int mt7601u_alloc_tx(struct mt7601u_dev *dev)
 502 {
 503         int i;
 504
 505         dev->tx_q = devm_kcalloc(dev->dev, __MT_EP_OUT_MAX,
 506                                  sizeof(*dev->tx_q), GFP_KERNEL);
 507         if (!dev->tx_q)
 508                 return -ENOMEM;
 509
 510         for (i = 0; i < __MT_EP_OUT_MAX; i++)
 511                 if (mt7601u_alloc_tx_queue(dev, &dev->tx_q[i]))
 512                         return -ENOMEM;
 513
 514         return 0;
 515 }
 516
 517 int mt7601u_dma_init(struct mt7601u_dev *dev)
 518 {
 519         int ret = -ENOMEM;
 520
 521         tasklet_setup(&dev->tx_tasklet, mt7601u_tx_tasklet);
 522         tasklet_setup(&dev->rx_tasklet, mt7601u_rx_tasklet);
 523
 524         ret = mt7601u_alloc_tx(dev);
 525         if (ret)
 526                 goto err;
 527         ret = mt7601u_alloc_rx(dev);
 528         if (ret)
 529                 goto err;
 530
 531         ret = mt7601u_submit_rx(dev);
 532         if (ret)
 533                 goto err;
 534
 535         return 0;
 536 err:
 537         mt7601u_dma_cleanup(dev);
 538         return ret;
 539 }
 540
 541 void mt7601u_dma_cleanup(struct mt7601u_dev *dev)
 542 {
 543         mt7601u_kill_rx(dev);
 544
 545         tasklet_kill(&dev->rx_tasklet);
 546
 547         mt7601u_free_rx(dev);
 548         mt7601u_free_tx(dev);
 549
 550         tasklet_kill(&dev->tx_tasklet);
 551 }