drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Copyright(c) 2018 Intel Corporation. */
   3
   4 #include <linux/bpf_trace.h>
   5 #include <net/xdp_sock_drv.h>
   6 #include <net/xdp.h>
   7
   8 #include "ixgbe.h"
   9 #include "ixgbe_txrx_common.h"
  10
  11 struct xsk_buff_pool *ixgbe_xsk_pool(struct ixgbe_adapter *adapter,
  12                                      struct ixgbe_ring *ring)
  13 {
  14         bool xdp_on = READ_ONCE(adapter->xdp_prog);
  15         int qid = ring->ring_idx;
  16
  17         if (!xdp_on || !test_bit(qid, adapter->af_xdp_zc_qps))
  18                 return NULL;
  19
  20         return xsk_get_pool_from_qid(adapter->netdev, qid);
  21 }
  22
  23 static int ixgbe_xsk_pool_enable(struct ixgbe_adapter *adapter,
  24                                  struct xsk_buff_pool *pool,
  25                                  u16 qid)
  26 {
  27         struct net_device *netdev = adapter->netdev;
  28         bool if_running;
  29         int err;
  30
  31         if (qid >= adapter->num_rx_queues)
  32                 return -EINVAL;
  33
  34         if (qid >= netdev->real_num_rx_queues ||
  35             qid >= netdev->real_num_tx_queues)
  36                 return -EINVAL;
  37
  38         err = xsk_pool_dma_map(pool, &adapter->pdev->dev, IXGBE_RX_DMA_ATTR);
  39         if (err)
  40                 return err;
  41
  42         if_running = netif_running(adapter->netdev) &&
  43                      ixgbe_enabled_xdp_adapter(adapter);
  44
  45         if (if_running)
  46                 ixgbe_txrx_ring_disable(adapter, qid);
  47
  48         set_bit(qid, adapter->af_xdp_zc_qps);
  49
  50         if (if_running) {
  51                 ixgbe_txrx_ring_enable(adapter, qid);
  52
  53                 /* Kick start the NAPI context so that receiving will start */
  54                 err = ixgbe_xsk_wakeup(adapter->netdev, qid, XDP_WAKEUP_RX);
  55                 if (err)
  56                         return err;
  57         }
  58
  59         return 0;
  60 }
  61
  62 static int ixgbe_xsk_pool_disable(struct ixgbe_adapter *adapter, u16 qid)
  63 {
  64         struct xsk_buff_pool *pool;
  65         bool if_running;
  66
  67         pool = xsk_get_pool_from_qid(adapter->netdev, qid);
  68         if (!pool)
  69                 return -EINVAL;
  70
  71         if_running = netif_running(adapter->netdev) &&
  72                      ixgbe_enabled_xdp_adapter(adapter);
  73
  74         if (if_running)
  75                 ixgbe_txrx_ring_disable(adapter, qid);
  76
  77         clear_bit(qid, adapter->af_xdp_zc_qps);
  78         xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
  79
  80         if (if_running)
  81                 ixgbe_txrx_ring_enable(adapter, qid);
  82
  83         return 0;
  84 }
  85
  86 int ixgbe_xsk_pool_setup(struct ixgbe_adapter *adapter,
  87                          struct xsk_buff_pool *pool,
  88                          u16 qid)
  89 {
  90         return pool ? ixgbe_xsk_pool_enable(adapter, pool, qid) :
  91                 ixgbe_xsk_pool_disable(adapter, qid);
  92 }
  93
  94 static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
  95                             struct ixgbe_ring *rx_ring,
  96                             struct xdp_buff *xdp)
  97 {
  98         int err, result = IXGBE_XDP_PASS;
  99         struct bpf_prog *xdp_prog;
 100         struct xdp_frame *xdpf;
 101         u32 act;
 102
 103         rcu_read_lock();
 104         xdp_prog = READ_ONCE(rx_ring->xdp_prog);
 105         act = bpf_prog_run_xdp(xdp_prog, xdp);
 106
 107         if (likely(act == XDP_REDIRECT)) {
 108                 err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
 109                 if (err)
 110                         goto out_failure;
 111                 rcu_read_unlock();
 112                 return IXGBE_XDP_REDIR;
 113         }
 114
 115         switch (act) {
 116         case XDP_PASS:
 117                 break;
 118         case XDP_TX:
 119                 xdpf = xdp_convert_buff_to_frame(xdp);
 120                 if (unlikely(!xdpf))
 121                         goto out_failure;
 122                 result = ixgbe_xmit_xdp_ring(adapter, xdpf);
 123                 if (result == IXGBE_XDP_CONSUMED)
 124                         goto out_failure;
 125                 break;
 126         default:
 127                 bpf_warn_invalid_xdp_action(act);
 128                 fallthrough;
 129         case XDP_ABORTED:
 130 out_failure:
 131                 trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
 132                 fallthrough; /* handle aborts by dropping packet */
 133         case XDP_DROP:
 134                 result = IXGBE_XDP_CONSUMED;
 135                 break;
 136         }
 137         rcu_read_unlock();
 138         return result;
 139 }
 140
 141 bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
 142 {
 143         union ixgbe_adv_rx_desc *rx_desc;
 144         struct ixgbe_rx_buffer *bi;
 145         u16 i = rx_ring->next_to_use;
 146         dma_addr_t dma;
 147         bool ok = true;
 148
 149         /* nothing to do */
 150         if (!count)
 151                 return true;
 152
 153         rx_desc = IXGBE_RX_DESC(rx_ring, i);
 154         bi = &rx_ring->rx_buffer_info[i];
 155         i -= rx_ring->count;
 156
 157         do {
 158                 bi->xdp = xsk_buff_alloc(rx_ring->xsk_pool);
 159                 if (!bi->xdp) {
 160                         ok = false;
 161                         break;
 162                 }
 163
 164                 dma = xsk_buff_xdp_get_dma(bi->xdp);
 165
 166                 /* Refresh the desc even if buffer_addrs didn't change
 167                  * because each write-back erases this info.
 168                  */
 169                 rx_desc->read.pkt_addr = cpu_to_le64(dma);
 170
 171                 rx_desc++;
 172                 bi++;
 173                 i++;
 174                 if (unlikely(!i)) {
 175                         rx_desc = IXGBE_RX_DESC(rx_ring, 0);
 176                         bi = rx_ring->rx_buffer_info;
 177                         i -= rx_ring->count;
 178                 }
 179
 180                 /* clear the length for the next_to_use descriptor */
 181                 rx_desc->wb.upper.length = 0;
 182
 183                 count--;
 184         } while (count);
 185
 186         i += rx_ring->count;
 187
 188         if (rx_ring->next_to_use != i) {
 189                 rx_ring->next_to_use = i;
 190
 191                 /* Force memory writes to complete before letting h/w
 192                  * know there are new descriptors to fetch.  (Only
 193                  * applicable for weak-ordered memory model archs,
 194                  * such as IA-64).
 195                  */
 196                 wmb();
 197                 writel(i, rx_ring->tail);
 198         }
 199
 200         return ok;
 201 }
 202
 203 static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
 204                                               struct ixgbe_rx_buffer *bi)
 205 {
 206         unsigned int metasize = bi->xdp->data - bi->xdp->data_meta;
 207         unsigned int datasize = bi->xdp->data_end - bi->xdp->data;
 208         struct sk_buff *skb;
 209
 210         /* allocate a skb to store the frags */
 211         skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
 212                                bi->xdp->data_end - bi->xdp->data_hard_start,
 213                                GFP_ATOMIC | __GFP_NOWARN);
 214         if (unlikely(!skb))
 215                 return NULL;
 216
 217         skb_reserve(skb, bi->xdp->data - bi->xdp->data_hard_start);
 218         memcpy(__skb_put(skb, datasize), bi->xdp->data, datasize);
 219         if (metasize)
 220                 skb_metadata_set(skb, metasize);
 221
 222         xsk_buff_free(bi->xdp);
 223         bi->xdp = NULL;
 224         return skb;
 225 }
 226
 227 static void ixgbe_inc_ntc(struct ixgbe_ring *rx_ring)
 228 {
 229         u32 ntc = rx_ring->next_to_clean + 1;
 230
 231         ntc = (ntc < rx_ring->count) ? ntc : 0;
 232         rx_ring->next_to_clean = ntc;
 233         prefetch(IXGBE_RX_DESC(rx_ring, ntc));
 234 }
 235
 236 int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
 237                           struct ixgbe_ring *rx_ring,
 238                           const int budget)
 239 {
 240         unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 241         struct ixgbe_adapter *adapter = q_vector->adapter;
 242         u16 cleaned_count = ixgbe_desc_unused(rx_ring);
 243         unsigned int xdp_res, xdp_xmit = 0;
 244         bool failure = false;
 245         struct sk_buff *skb;
 246
 247         while (likely(total_rx_packets < budget)) {
 248                 union ixgbe_adv_rx_desc *rx_desc;
 249                 struct ixgbe_rx_buffer *bi;
 250                 unsigned int size;
 251
 252                 /* return some buffers to hardware, one at a time is too slow */
 253                 if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
 254                         failure = failure ||
 255                                   !ixgbe_alloc_rx_buffers_zc(rx_ring,
 256                                                              cleaned_count);
 257                         cleaned_count = 0;
 258                 }
 259
 260                 rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean);
 261                 size = le16_to_cpu(rx_desc->wb.upper.length);
 262                 if (!size)
 263                         break;
 264
 265                 /* This memory barrier is needed to keep us from reading
 266                  * any other fields out of the rx_desc until we know the
 267                  * descriptor has been written back
 268                  */
 269                 dma_rmb();
 270
 271                 bi = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
 272
 273                 if (unlikely(!ixgbe_test_staterr(rx_desc,
 274                                                  IXGBE_RXD_STAT_EOP))) {
 275                         struct ixgbe_rx_buffer *next_bi;
 276
 277                         xsk_buff_free(bi->xdp);
 278                         bi->xdp = NULL;
 279                         ixgbe_inc_ntc(rx_ring);
 280                         next_bi =
 281                                &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
 282                         next_bi->discard = true;
 283                         continue;
 284                 }
 285
 286                 if (unlikely(bi->discard)) {
 287                         xsk_buff_free(bi->xdp);
 288                         bi->xdp = NULL;
 289                         bi->discard = false;
 290                         ixgbe_inc_ntc(rx_ring);
 291                         continue;
 292                 }
 293
 294                 bi->xdp->data_end = bi->xdp->data + size;
 295                 xsk_buff_dma_sync_for_cpu(bi->xdp, rx_ring->xsk_pool);
 296                 xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);
 297
 298                 if (xdp_res) {
 299                         if (xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))
 300                                 xdp_xmit |= xdp_res;
 301                         else
 302                                 xsk_buff_free(bi->xdp);
 303
 304                         bi->xdp = NULL;
 305                         total_rx_packets++;
 306                         total_rx_bytes += size;
 307
 308                         cleaned_count++;
 309                         ixgbe_inc_ntc(rx_ring);
 310                         continue;
 311                 }
 312
 313                 /* XDP_PASS path */
 314                 skb = ixgbe_construct_skb_zc(rx_ring, bi);
 315                 if (!skb) {
 316                         rx_ring->rx_stats.alloc_rx_buff_failed++;
 317                         break;
 318                 }
 319
 320                 cleaned_count++;
 321                 ixgbe_inc_ntc(rx_ring);
 322
 323                 if (eth_skb_pad(skb))
 324                         continue;
 325
 326                 total_rx_bytes += skb->len;
 327                 total_rx_packets++;
 328
 329                 ixgbe_process_skb_fields(rx_ring, rx_desc, skb);
 330                 ixgbe_rx_skb(q_vector, skb);
 331         }
 332
 333         if (xdp_xmit & IXGBE_XDP_REDIR)
 334                 xdp_do_flush_map();
 335
 336         if (xdp_xmit & IXGBE_XDP_TX) {
 337                 struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()];
 338
 339                 /* Force memory writes to complete before letting h/w
 340                  * know there are new descriptors to fetch.
 341                  */
 342                 wmb();
 343                 writel(ring->next_to_use, ring->tail);
 344         }
 345
 346         u64_stats_update_begin(&rx_ring->syncp);
 347         rx_ring->stats.packets += total_rx_packets;
 348         rx_ring->stats.bytes += total_rx_bytes;
 349         u64_stats_update_end(&rx_ring->syncp);
 350         q_vector->rx.total_packets += total_rx_packets;
 351         q_vector->rx.total_bytes += total_rx_bytes;
 352
 353         if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
 354                 if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
 355                         xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
 356                 else
 357                         xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
 358
 359                 return (int)total_rx_packets;
 360         }
 361         return failure ? budget : (int)total_rx_packets;
 362 }
 363
 364 void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring)
 365 {
 366         struct ixgbe_rx_buffer *bi;
 367         u16 i;
 368
 369         for (i = 0; i < rx_ring->count; i++) {
 370                 bi = &rx_ring->rx_buffer_info[i];
 371
 372                 if (!bi->xdp)
 373                         continue;
 374
 375                 xsk_buff_free(bi->xdp);
 376                 bi->xdp = NULL;
 377         }
 378 }
 379
 380 static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
 381 {
 382         struct xsk_buff_pool *pool = xdp_ring->xsk_pool;
 383         union ixgbe_adv_tx_desc *tx_desc = NULL;
 384         struct ixgbe_tx_buffer *tx_bi;
 385         bool work_done = true;
 386         struct xdp_desc desc;
 387         dma_addr_t dma;
 388         u32 cmd_type;
 389
 390         while (budget-- > 0) {
 391                 if (unlikely(!ixgbe_desc_unused(xdp_ring)) ||
 392                     !netif_carrier_ok(xdp_ring->netdev)) {
 393                         work_done = false;
 394                         break;
 395                 }
 396
 397                 if (!xsk_tx_peek_desc(pool, &desc))
 398                         break;
 399
 400                 dma = xsk_buff_raw_get_dma(pool, desc.addr);
 401                 xsk_buff_raw_dma_sync_for_device(pool, dma, desc.len);
 402
 403                 tx_bi = &xdp_ring->tx_buffer_info[xdp_ring->next_to_use];
 404                 tx_bi->bytecount = desc.len;
 405                 tx_bi->xdpf = NULL;
 406                 tx_bi->gso_segs = 1;
 407
 408                 tx_desc = IXGBE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
 409                 tx_desc->read.buffer_addr = cpu_to_le64(dma);
 410
 411                 /* put descriptor type bits */
 412                 cmd_type = IXGBE_ADVTXD_DTYP_DATA |
 413                            IXGBE_ADVTXD_DCMD_DEXT |
 414                            IXGBE_ADVTXD_DCMD_IFCS;
 415                 cmd_type |= desc.len | IXGBE_TXD_CMD;
 416                 tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
 417                 tx_desc->read.olinfo_status =
 418                         cpu_to_le32(desc.len << IXGBE_ADVTXD_PAYLEN_SHIFT);
 419
 420                 xdp_ring->next_to_use++;
 421                 if (xdp_ring->next_to_use == xdp_ring->count)
 422                         xdp_ring->next_to_use = 0;
 423         }
 424
 425         if (tx_desc) {
 426                 ixgbe_xdp_ring_update_tail(xdp_ring);
 427                 xsk_tx_release(pool);
 428         }
 429
 430         return !!budget && work_done;
 431 }
 432
 433 static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
 434                                       struct ixgbe_tx_buffer *tx_bi)
 435 {
 436         xdp_return_frame(tx_bi->xdpf);
 437         dma_unmap_single(tx_ring->dev,
 438                          dma_unmap_addr(tx_bi, dma),
 439                          dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
 440         dma_unmap_len_set(tx_bi, len, 0);
 441 }
 442
 443 bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
 444                             struct ixgbe_ring *tx_ring, int napi_budget)
 445 {
 446         u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 447         unsigned int total_packets = 0, total_bytes = 0;
 448         struct xsk_buff_pool *pool = tx_ring->xsk_pool;
 449         union ixgbe_adv_tx_desc *tx_desc;
 450         struct ixgbe_tx_buffer *tx_bi;
 451         u32 xsk_frames = 0;
 452
 453         tx_bi = &tx_ring->tx_buffer_info[ntc];
 454         tx_desc = IXGBE_TX_DESC(tx_ring, ntc);
 455
 456         while (ntc != ntu) {
 457                 if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
 458                         break;
 459
 460                 total_bytes += tx_bi->bytecount;
 461                 total_packets += tx_bi->gso_segs;
 462
 463                 if (tx_bi->xdpf)
 464                         ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
 465                 else
 466                         xsk_frames++;
 467
 468                 tx_bi->xdpf = NULL;
 469
 470                 tx_bi++;
 471                 tx_desc++;
 472                 ntc++;
 473                 if (unlikely(ntc == tx_ring->count)) {
 474                         ntc = 0;
 475                         tx_bi = tx_ring->tx_buffer_info;
 476                         tx_desc = IXGBE_TX_DESC(tx_ring, 0);
 477                 }
 478
 479                 /* issue prefetch for next Tx descriptor */
 480                 prefetch(tx_desc);
 481         }
 482
 483         tx_ring->next_to_clean = ntc;
 484
 485         u64_stats_update_begin(&tx_ring->syncp);
 486         tx_ring->stats.bytes += total_bytes;
 487         tx_ring->stats.packets += total_packets;
 488         u64_stats_update_end(&tx_ring->syncp);
 489         q_vector->tx.total_bytes += total_bytes;
 490         q_vector->tx.total_packets += total_packets;
 491
 492         if (xsk_frames)
 493                 xsk_tx_completed(pool, xsk_frames);
 494
 495         if (xsk_uses_need_wakeup(pool))
 496                 xsk_set_tx_need_wakeup(pool);
 497
 498         return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
 499 }
 500
 501 int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
 502 {
 503         struct ixgbe_adapter *adapter = netdev_priv(dev);
 504         struct ixgbe_ring *ring;
 505
 506         if (test_bit(__IXGBE_DOWN, &adapter->state))
 507                 return -ENETDOWN;
 508
 509         if (!READ_ONCE(adapter->xdp_prog))
 510                 return -ENXIO;
 511
 512         if (qid >= adapter->num_xdp_queues)
 513                 return -ENXIO;
 514
 515         ring = adapter->xdp_ring[qid];
 516
 517         if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
 518                 return -ENETDOWN;
 519
 520         if (!ring->xsk_pool)
 521                 return -ENXIO;
 522
 523         if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
 524                 u64 eics = BIT_ULL(ring->q_vector->v_idx);
 525
 526                 ixgbe_irq_rearm_queues(adapter, eics);
 527         }
 528
 529         return 0;
 530 }
 531
 532 void ixgbe_xsk_clean_tx_ring(struct ixgbe_ring *tx_ring)
 533 {
 534         u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 535         struct xsk_buff_pool *pool = tx_ring->xsk_pool;
 536         struct ixgbe_tx_buffer *tx_bi;
 537         u32 xsk_frames = 0;
 538
 539         while (ntc != ntu) {
 540                 tx_bi = &tx_ring->tx_buffer_info[ntc];
 541
 542                 if (tx_bi->xdpf)
 543                         ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
 544                 else
 545                         xsk_frames++;
 546
 547                 tx_bi->xdpf = NULL;
 548
 549                 ntc++;
 550                 if (ntc == tx_ring->count)
 551                         ntc = 0;
 552         }
 553
 554         if (xsk_frames)
 555                 xsk_tx_completed(pool, xsk_frames);
 556 }