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                         clear_bit(qid, adapter->af_xdp_zc_qps);
  57                         xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
  58                         return err;
  59                 }
  60         }
  61
  62         return 0;
  63 }
  64
  65 static int ixgbe_xsk_pool_disable(struct ixgbe_adapter *adapter, u16 qid)
  66 {
  67         struct xsk_buff_pool *pool;
  68         bool if_running;
  69
  70         pool = xsk_get_pool_from_qid(adapter->netdev, qid);
  71         if (!pool)
  72                 return -EINVAL;
  73
  74         if_running = netif_running(adapter->netdev) &&
  75                      ixgbe_enabled_xdp_adapter(adapter);
  76
  77         if (if_running)
  78                 ixgbe_txrx_ring_disable(adapter, qid);
  79
  80         clear_bit(qid, adapter->af_xdp_zc_qps);
  81         xsk_pool_dma_unmap(pool, IXGBE_RX_DMA_ATTR);
  82
  83         if (if_running)
  84                 ixgbe_txrx_ring_enable(adapter, qid);
  85
  86         return 0;
  87 }
  88
  89 int ixgbe_xsk_pool_setup(struct ixgbe_adapter *adapter,
  90                          struct xsk_buff_pool *pool,
  91                          u16 qid)
  92 {
  93         return pool ? ixgbe_xsk_pool_enable(adapter, pool, qid) :
  94                 ixgbe_xsk_pool_disable(adapter, qid);
  95 }
  96
  97 static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
  98                             struct ixgbe_ring *rx_ring,
  99                             struct xdp_buff *xdp)
 100 {
 101         int err, result = IXGBE_XDP_PASS;
 102         struct bpf_prog *xdp_prog;
 103         struct xdp_frame *xdpf;
 104         u32 act;
 105
 106         rcu_read_lock();
 107         xdp_prog = READ_ONCE(rx_ring->xdp_prog);
 108         act = bpf_prog_run_xdp(xdp_prog, xdp);
 109
 110         if (likely(act == XDP_REDIRECT)) {
 111                 err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
 112                 if (err)
 113                         goto out_failure;
 114                 rcu_read_unlock();
 115                 return IXGBE_XDP_REDIR;
 116         }
 117
 118         switch (act) {
 119         case XDP_PASS:
 120                 break;
 121         case XDP_TX:
 122                 xdpf = xdp_convert_buff_to_frame(xdp);
 123                 if (unlikely(!xdpf))
 124                         goto out_failure;
 125                 result = ixgbe_xmit_xdp_ring(adapter, xdpf);
 126                 if (result == IXGBE_XDP_CONSUMED)
 127                         goto out_failure;
 128                 break;
 129         default:
 130                 bpf_warn_invalid_xdp_action(act);
 131                 fallthrough;
 132         case XDP_ABORTED:
 133 out_failure:
 134                 trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
 135                 fallthrough; /* handle aborts by dropping packet */
 136         case XDP_DROP:
 137                 result = IXGBE_XDP_CONSUMED;
 138                 break;
 139         }
 140         rcu_read_unlock();
 141         return result;
 142 }
 143
 144 bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
 145 {
 146         union ixgbe_adv_rx_desc *rx_desc;
 147         struct ixgbe_rx_buffer *bi;
 148         u16 i = rx_ring->next_to_use;
 149         dma_addr_t dma;
 150         bool ok = true;
 151
 152         /* nothing to do */
 153         if (!count)
 154                 return true;
 155
 156         rx_desc = IXGBE_RX_DESC(rx_ring, i);
 157         bi = &rx_ring->rx_buffer_info[i];
 158         i -= rx_ring->count;
 159
 160         do {
 161                 bi->xdp = xsk_buff_alloc(rx_ring->xsk_pool);
 162                 if (!bi->xdp) {
 163                         ok = false;
 164                         break;
 165                 }
 166
 167                 dma = xsk_buff_xdp_get_dma(bi->xdp);
 168
 169                 /* Refresh the desc even if buffer_addrs didn't change
 170                  * because each write-back erases this info.
 171                  */
 172                 rx_desc->read.pkt_addr = cpu_to_le64(dma);
 173
 174                 rx_desc++;
 175                 bi++;
 176                 i++;
 177                 if (unlikely(!i)) {
 178                         rx_desc = IXGBE_RX_DESC(rx_ring, 0);
 179                         bi = rx_ring->rx_buffer_info;
 180                         i -= rx_ring->count;
 181                 }
 182
 183                 /* clear the length for the next_to_use descriptor */
 184                 rx_desc->wb.upper.length = 0;
 185
 186                 count--;
 187         } while (count);
 188
 189         i += rx_ring->count;
 190
 191         if (rx_ring->next_to_use != i) {
 192                 rx_ring->next_to_use = i;
 193
 194                 /* Force memory writes to complete before letting h/w
 195                  * know there are new descriptors to fetch.  (Only
 196                  * applicable for weak-ordered memory model archs,
 197                  * such as IA-64).
 198                  */
 199                 wmb();
 200                 writel(i, rx_ring->tail);
 201         }
 202
 203         return ok;
 204 }
 205
 206 static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
 207                                               struct ixgbe_rx_buffer *bi)
 208 {
 209         unsigned int metasize = bi->xdp->data - bi->xdp->data_meta;
 210         unsigned int datasize = bi->xdp->data_end - bi->xdp->data;
 211         struct sk_buff *skb;
 212
 213         /* allocate a skb to store the frags */
 214         skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
 215                                bi->xdp->data_end - bi->xdp->data_hard_start,
 216                                GFP_ATOMIC | __GFP_NOWARN);
 217         if (unlikely(!skb))
 218                 return NULL;
 219
 220         skb_reserve(skb, bi->xdp->data - bi->xdp->data_hard_start);
 221         memcpy(__skb_put(skb, datasize), bi->xdp->data, datasize);
 222         if (metasize)
 223                 skb_metadata_set(skb, metasize);
 224
 225         xsk_buff_free(bi->xdp);
 226         bi->xdp = NULL;
 227         return skb;
 228 }
 229
 230 static void ixgbe_inc_ntc(struct ixgbe_ring *rx_ring)
 231 {
 232         u32 ntc = rx_ring->next_to_clean + 1;
 233
 234         ntc = (ntc < rx_ring->count) ? ntc : 0;
 235         rx_ring->next_to_clean = ntc;
 236         prefetch(IXGBE_RX_DESC(rx_ring, ntc));
 237 }
 238
 239 int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
 240                           struct ixgbe_ring *rx_ring,
 241                           const int budget)
 242 {
 243         unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 244         struct ixgbe_adapter *adapter = q_vector->adapter;
 245         u16 cleaned_count = ixgbe_desc_unused(rx_ring);
 246         unsigned int xdp_res, xdp_xmit = 0;
 247         bool failure = false;
 248         struct sk_buff *skb;
 249
 250         while (likely(total_rx_packets < budget)) {
 251                 union ixgbe_adv_rx_desc *rx_desc;
 252                 struct ixgbe_rx_buffer *bi;
 253                 unsigned int size;
 254
 255                 /* return some buffers to hardware, one at a time is too slow */
 256                 if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
 257                         failure = failure ||
 258                                   !ixgbe_alloc_rx_buffers_zc(rx_ring,
 259                                                              cleaned_count);
 260                         cleaned_count = 0;
 261                 }
 262
 263                 rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean);
 264                 size = le16_to_cpu(rx_desc->wb.upper.length);
 265                 if (!size)
 266                         break;
 267
 268                 /* This memory barrier is needed to keep us from reading
 269                  * any other fields out of the rx_desc until we know the
 270                  * descriptor has been written back
 271                  */
 272                 dma_rmb();
 273
 274                 bi = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
 275
 276                 if (unlikely(!ixgbe_test_staterr(rx_desc,
 277                                                  IXGBE_RXD_STAT_EOP))) {
 278                         struct ixgbe_rx_buffer *next_bi;
 279
 280                         xsk_buff_free(bi->xdp);
 281                         bi->xdp = NULL;
 282                         ixgbe_inc_ntc(rx_ring);
 283                         next_bi =
 284                                &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
 285                         next_bi->discard = true;
 286                         continue;
 287                 }
 288
 289                 if (unlikely(bi->discard)) {
 290                         xsk_buff_free(bi->xdp);
 291                         bi->xdp = NULL;
 292                         bi->discard = false;
 293                         ixgbe_inc_ntc(rx_ring);
 294                         continue;
 295                 }
 296
 297                 bi->xdp->data_end = bi->xdp->data + size;
 298                 xsk_buff_dma_sync_for_cpu(bi->xdp, rx_ring->xsk_pool);
 299                 xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);
 300
 301                 if (xdp_res) {
 302                         if (xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))
 303                                 xdp_xmit |= xdp_res;
 304                         else
 305                                 xsk_buff_free(bi->xdp);
 306
 307                         bi->xdp = NULL;
 308                         total_rx_packets++;
 309                         total_rx_bytes += size;
 310
 311                         cleaned_count++;
 312                         ixgbe_inc_ntc(rx_ring);
 313                         continue;
 314                 }
 315
 316                 /* XDP_PASS path */
 317                 skb = ixgbe_construct_skb_zc(rx_ring, bi);
 318                 if (!skb) {
 319                         rx_ring->rx_stats.alloc_rx_buff_failed++;
 320                         break;
 321                 }
 322
 323                 cleaned_count++;
 324                 ixgbe_inc_ntc(rx_ring);
 325
 326                 if (eth_skb_pad(skb))
 327                         continue;
 328
 329                 total_rx_bytes += skb->len;
 330                 total_rx_packets++;
 331
 332                 ixgbe_process_skb_fields(rx_ring, rx_desc, skb);
 333                 ixgbe_rx_skb(q_vector, skb);
 334         }
 335
 336         if (xdp_xmit & IXGBE_XDP_REDIR)
 337                 xdp_do_flush_map();
 338
 339         if (xdp_xmit & IXGBE_XDP_TX) {
 340                 struct ixgbe_ring *ring = adapter->xdp_ring[smp_processor_id()];
 341
 342                 /* Force memory writes to complete before letting h/w
 343                  * know there are new descriptors to fetch.
 344                  */
 345                 wmb();
 346                 writel(ring->next_to_use, ring->tail);
 347         }
 348
 349         u64_stats_update_begin(&rx_ring->syncp);
 350         rx_ring->stats.packets += total_rx_packets;
 351         rx_ring->stats.bytes += total_rx_bytes;
 352         u64_stats_update_end(&rx_ring->syncp);
 353         q_vector->rx.total_packets += total_rx_packets;
 354         q_vector->rx.total_bytes += total_rx_bytes;
 355
 356         if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
 357                 if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
 358                         xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
 359                 else
 360                         xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
 361
 362                 return (int)total_rx_packets;
 363         }
 364         return failure ? budget : (int)total_rx_packets;
 365 }
 366
 367 void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring)
 368 {
 369         struct ixgbe_rx_buffer *bi;
 370         u16 i;
 371
 372         for (i = 0; i < rx_ring->count; i++) {
 373                 bi = &rx_ring->rx_buffer_info[i];
 374
 375                 if (!bi->xdp)
 376                         continue;
 377
 378                 xsk_buff_free(bi->xdp);
 379                 bi->xdp = NULL;
 380         }
 381 }
 382
 383 static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
 384 {
 385         struct xsk_buff_pool *pool = xdp_ring->xsk_pool;
 386         union ixgbe_adv_tx_desc *tx_desc = NULL;
 387         struct ixgbe_tx_buffer *tx_bi;
 388         bool work_done = true;
 389         struct xdp_desc desc;
 390         dma_addr_t dma;
 391         u32 cmd_type;
 392
 393         while (budget-- > 0) {
 394                 if (unlikely(!ixgbe_desc_unused(xdp_ring))) {
 395                         work_done = false;
 396                         break;
 397                 }
 398
 399                 if (!netif_carrier_ok(xdp_ring->netdev))
 400                         break;
 401
 402                 if (!xsk_tx_peek_desc(pool, &desc))
 403                         break;
 404
 405                 dma = xsk_buff_raw_get_dma(pool, desc.addr);
 406                 xsk_buff_raw_dma_sync_for_device(pool, dma, desc.len);
 407
 408                 tx_bi = &xdp_ring->tx_buffer_info[xdp_ring->next_to_use];
 409                 tx_bi->bytecount = desc.len;
 410                 tx_bi->xdpf = NULL;
 411                 tx_bi->gso_segs = 1;
 412
 413                 tx_desc = IXGBE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
 414                 tx_desc->read.buffer_addr = cpu_to_le64(dma);
 415
 416                 /* put descriptor type bits */
 417                 cmd_type = IXGBE_ADVTXD_DTYP_DATA |
 418                            IXGBE_ADVTXD_DCMD_DEXT |
 419                            IXGBE_ADVTXD_DCMD_IFCS;
 420                 cmd_type |= desc.len | IXGBE_TXD_CMD;
 421                 tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
 422                 tx_desc->read.olinfo_status =
 423                         cpu_to_le32(desc.len << IXGBE_ADVTXD_PAYLEN_SHIFT);
 424
 425                 xdp_ring->next_to_use++;
 426                 if (xdp_ring->next_to_use == xdp_ring->count)
 427                         xdp_ring->next_to_use = 0;
 428         }
 429
 430         if (tx_desc) {
 431                 ixgbe_xdp_ring_update_tail(xdp_ring);
 432                 xsk_tx_release(pool);
 433         }
 434
 435         return !!budget && work_done;
 436 }
 437
 438 static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
 439                                       struct ixgbe_tx_buffer *tx_bi)
 440 {
 441         xdp_return_frame(tx_bi->xdpf);
 442         dma_unmap_single(tx_ring->dev,
 443                          dma_unmap_addr(tx_bi, dma),
 444                          dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
 445         dma_unmap_len_set(tx_bi, len, 0);
 446 }
 447
 448 bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
 449                             struct ixgbe_ring *tx_ring, int napi_budget)
 450 {
 451         u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 452         unsigned int total_packets = 0, total_bytes = 0;
 453         struct xsk_buff_pool *pool = tx_ring->xsk_pool;
 454         union ixgbe_adv_tx_desc *tx_desc;
 455         struct ixgbe_tx_buffer *tx_bi;
 456         u32 xsk_frames = 0;
 457
 458         tx_bi = &tx_ring->tx_buffer_info[ntc];
 459         tx_desc = IXGBE_TX_DESC(tx_ring, ntc);
 460
 461         while (ntc != ntu) {
 462                 if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
 463                         break;
 464
 465                 total_bytes += tx_bi->bytecount;
 466                 total_packets += tx_bi->gso_segs;
 467
 468                 if (tx_bi->xdpf)
 469                         ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
 470                 else
 471                         xsk_frames++;
 472
 473                 tx_bi->xdpf = NULL;
 474
 475                 tx_bi++;
 476                 tx_desc++;
 477                 ntc++;
 478                 if (unlikely(ntc == tx_ring->count)) {
 479                         ntc = 0;
 480                         tx_bi = tx_ring->tx_buffer_info;
 481                         tx_desc = IXGBE_TX_DESC(tx_ring, 0);
 482                 }
 483
 484                 /* issue prefetch for next Tx descriptor */
 485                 prefetch(tx_desc);
 486         }
 487
 488         tx_ring->next_to_clean = ntc;
 489
 490         u64_stats_update_begin(&tx_ring->syncp);
 491         tx_ring->stats.bytes += total_bytes;
 492         tx_ring->stats.packets += total_packets;
 493         u64_stats_update_end(&tx_ring->syncp);
 494         q_vector->tx.total_bytes += total_bytes;
 495         q_vector->tx.total_packets += total_packets;
 496
 497         if (xsk_frames)
 498                 xsk_tx_completed(pool, xsk_frames);
 499
 500         if (xsk_uses_need_wakeup(pool))
 501                 xsk_set_tx_need_wakeup(pool);
 502
 503         return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
 504 }
 505
 506 int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
 507 {
 508         struct ixgbe_adapter *adapter = netdev_priv(dev);
 509         struct ixgbe_ring *ring;
 510
 511         if (test_bit(__IXGBE_DOWN, &adapter->state))
 512                 return -ENETDOWN;
 513
 514         if (!READ_ONCE(adapter->xdp_prog))
 515                 return -ENXIO;
 516
 517         if (qid >= adapter->num_xdp_queues)
 518                 return -ENXIO;
 519
 520         ring = adapter->xdp_ring[qid];
 521
 522         if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
 523                 return -ENETDOWN;
 524
 525         if (!ring->xsk_pool)
 526                 return -ENXIO;
 527
 528         if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
 529                 u64 eics = BIT_ULL(ring->q_vector->v_idx);
 530
 531                 ixgbe_irq_rearm_queues(adapter, eics);
 532         }
 533
 534         return 0;
 535 }
 536
 537 void ixgbe_xsk_clean_tx_ring(struct ixgbe_ring *tx_ring)
 538 {
 539         u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 540         struct xsk_buff_pool *pool = tx_ring->xsk_pool;
 541         struct ixgbe_tx_buffer *tx_bi;
 542         u32 xsk_frames = 0;
 543
 544         while (ntc != ntu) {
 545                 tx_bi = &tx_ring->tx_buffer_info[ntc];
 546
 547                 if (tx_bi->xdpf)
 548                         ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
 549                 else
 550                         xsk_frames++;
 551
 552                 tx_bi->xdpf = NULL;
 553
 554                 ntc++;
 555                 if (ntc == tx_ring->count)
 556                         ntc = 0;
 557         }
 558
 559         if (xsk_frames)
 560                 xsk_tx_completed(pool, xsk_frames);
 561 }