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 ixgbe_ring *ring;
 104         struct xdp_frame *xdpf;
 105         u32 act;
 106
 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                         return IXGBE_XDP_REDIR;
 114                 if (xsk_uses_need_wakeup(rx_ring->xsk_pool) && err == -ENOBUFS)
 115                         result = IXGBE_XDP_EXIT;
 116                 else
 117                         result = IXGBE_XDP_CONSUMED;
 118                 goto out_failure;
 119         }
 120
 121         switch (act) {
 122         case XDP_PASS:
 123                 break;
 124         case XDP_TX:
 125                 xdpf = xdp_convert_buff_to_frame(xdp);
 126                 if (unlikely(!xdpf))
 127                         goto out_failure;
 128                 ring = ixgbe_determine_xdp_ring(adapter);
 129                 if (static_branch_unlikely(&ixgbe_xdp_locking_key))
 130                         spin_lock(&ring->tx_lock);
 131                 result = ixgbe_xmit_xdp_ring(ring, xdpf);
 132                 if (static_branch_unlikely(&ixgbe_xdp_locking_key))
 133                         spin_unlock(&ring->tx_lock);
 134                 if (result == IXGBE_XDP_CONSUMED)
 135                         goto out_failure;
 136                 break;
 137         case XDP_DROP:
 138                 result = IXGBE_XDP_CONSUMED;
 139                 break;
 140         default:
 141                 bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act);
 142                 fallthrough;
 143         case XDP_ABORTED:
 144                 result = IXGBE_XDP_CONSUMED;
 145 out_failure:
 146                 trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
 147         }
 148         return result;
 149 }
 150
 151 bool ixgbe_alloc_rx_buffers_zc(struct ixgbe_ring *rx_ring, u16 count)
 152 {
 153         union ixgbe_adv_rx_desc *rx_desc;
 154         struct ixgbe_rx_buffer *bi;
 155         u16 i = rx_ring->next_to_use;
 156         dma_addr_t dma;
 157         bool ok = true;
 158
 159         /* nothing to do */
 160         if (!count)
 161                 return true;
 162
 163         rx_desc = IXGBE_RX_DESC(rx_ring, i);
 164         bi = &rx_ring->rx_buffer_info[i];
 165         i -= rx_ring->count;
 166
 167         do {
 168                 bi->xdp = xsk_buff_alloc(rx_ring->xsk_pool);
 169                 if (!bi->xdp) {
 170                         ok = false;
 171                         break;
 172                 }
 173
 174                 dma = xsk_buff_xdp_get_dma(bi->xdp);
 175
 176                 /* Refresh the desc even if buffer_addrs didn't change
 177                  * because each write-back erases this info.
 178                  */
 179                 rx_desc->read.pkt_addr = cpu_to_le64(dma);
 180
 181                 rx_desc++;
 182                 bi++;
 183                 i++;
 184                 if (unlikely(!i)) {
 185                         rx_desc = IXGBE_RX_DESC(rx_ring, 0);
 186                         bi = rx_ring->rx_buffer_info;
 187                         i -= rx_ring->count;
 188                 }
 189
 190                 /* clear the length for the next_to_use descriptor */
 191                 rx_desc->wb.upper.length = 0;
 192
 193                 count--;
 194         } while (count);
 195
 196         i += rx_ring->count;
 197
 198         if (rx_ring->next_to_use != i) {
 199                 rx_ring->next_to_use = i;
 200
 201                 /* Force memory writes to complete before letting h/w
 202                  * know there are new descriptors to fetch.  (Only
 203                  * applicable for weak-ordered memory model archs,
 204                  * such as IA-64).
 205                  */
 206                 wmb();
 207                 writel(i, rx_ring->tail);
 208         }
 209
 210         return ok;
 211 }
 212
 213 static struct sk_buff *ixgbe_construct_skb_zc(struct ixgbe_ring *rx_ring,
 214                                               const struct xdp_buff *xdp)
 215 {
 216         unsigned int totalsize = xdp->data_end - xdp->data_meta;
 217         unsigned int metasize = xdp->data - xdp->data_meta;
 218         struct sk_buff *skb;
 219
 220         net_prefetch(xdp->data_meta);
 221
 222         /* allocate a skb to store the frags */
 223         skb = __napi_alloc_skb(&rx_ring->q_vector->napi, totalsize,
 224                                GFP_ATOMIC | __GFP_NOWARN);
 225         if (unlikely(!skb))
 226                 return NULL;
 227
 228         memcpy(__skb_put(skb, totalsize), xdp->data_meta,
 229                ALIGN(totalsize, sizeof(long)));
 230
 231         if (metasize) {
 232                 skb_metadata_set(skb, metasize);
 233                 __skb_pull(skb, metasize);
 234         }
 235
 236         return skb;
 237 }
 238
 239 static void ixgbe_inc_ntc(struct ixgbe_ring *rx_ring)
 240 {
 241         u32 ntc = rx_ring->next_to_clean + 1;
 242
 243         ntc = (ntc < rx_ring->count) ? ntc : 0;
 244         rx_ring->next_to_clean = ntc;
 245         prefetch(IXGBE_RX_DESC(rx_ring, ntc));
 246 }
 247
 248 int ixgbe_clean_rx_irq_zc(struct ixgbe_q_vector *q_vector,
 249                           struct ixgbe_ring *rx_ring,
 250                           const int budget)
 251 {
 252         unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 253         struct ixgbe_adapter *adapter = q_vector->adapter;
 254         u16 cleaned_count = ixgbe_desc_unused(rx_ring);
 255         unsigned int xdp_res, xdp_xmit = 0;
 256         bool failure = false;
 257         struct sk_buff *skb;
 258
 259         while (likely(total_rx_packets < budget)) {
 260                 union ixgbe_adv_rx_desc *rx_desc;
 261                 struct ixgbe_rx_buffer *bi;
 262                 unsigned int size;
 263
 264                 /* return some buffers to hardware, one at a time is too slow */
 265                 if (cleaned_count >= IXGBE_RX_BUFFER_WRITE) {
 266                         failure = failure ||
 267                                   !ixgbe_alloc_rx_buffers_zc(rx_ring,
 268                                                              cleaned_count);
 269                         cleaned_count = 0;
 270                 }
 271
 272                 rx_desc = IXGBE_RX_DESC(rx_ring, rx_ring->next_to_clean);
 273                 size = le16_to_cpu(rx_desc->wb.upper.length);
 274                 if (!size)
 275                         break;
 276
 277                 /* This memory barrier is needed to keep us from reading
 278                  * any other fields out of the rx_desc until we know the
 279                  * descriptor has been written back
 280                  */
 281                 dma_rmb();
 282
 283                 bi = &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
 284
 285                 if (unlikely(!ixgbe_test_staterr(rx_desc,
 286                                                  IXGBE_RXD_STAT_EOP))) {
 287                         struct ixgbe_rx_buffer *next_bi;
 288
 289                         xsk_buff_free(bi->xdp);
 290                         bi->xdp = NULL;
 291                         ixgbe_inc_ntc(rx_ring);
 292                         next_bi =
 293                                &rx_ring->rx_buffer_info[rx_ring->next_to_clean];
 294                         next_bi->discard = true;
 295                         continue;
 296                 }
 297
 298                 if (unlikely(bi->discard)) {
 299                         xsk_buff_free(bi->xdp);
 300                         bi->xdp = NULL;
 301                         bi->discard = false;
 302                         ixgbe_inc_ntc(rx_ring);
 303                         continue;
 304                 }
 305
 306                 bi->xdp->data_end = bi->xdp->data + size;
 307                 xsk_buff_dma_sync_for_cpu(bi->xdp, rx_ring->xsk_pool);
 308                 xdp_res = ixgbe_run_xdp_zc(adapter, rx_ring, bi->xdp);
 309
 310                 if (likely(xdp_res & (IXGBE_XDP_TX | IXGBE_XDP_REDIR))) {
 311                         xdp_xmit |= xdp_res;
 312                 } else if (xdp_res == IXGBE_XDP_EXIT) {
 313                         failure = true;
 314                         break;
 315                 } else if (xdp_res == IXGBE_XDP_CONSUMED) {
 316                         xsk_buff_free(bi->xdp);
 317                 } else if (xdp_res == IXGBE_XDP_PASS) {
 318                         goto construct_skb;
 319                 }
 320
 321                 bi->xdp = NULL;
 322                 total_rx_packets++;
 323                 total_rx_bytes += size;
 324
 325                 cleaned_count++;
 326                 ixgbe_inc_ntc(rx_ring);
 327                 continue;
 328
 329 construct_skb:
 330                 /* XDP_PASS path */
 331                 skb = ixgbe_construct_skb_zc(rx_ring, bi->xdp);
 332                 if (!skb) {
 333                         rx_ring->rx_stats.alloc_rx_buff_failed++;
 334                         break;
 335                 }
 336
 337                 xsk_buff_free(bi->xdp);
 338                 bi->xdp = NULL;
 339
 340                 cleaned_count++;
 341                 ixgbe_inc_ntc(rx_ring);
 342
 343                 if (eth_skb_pad(skb))
 344                         continue;
 345
 346                 total_rx_bytes += skb->len;
 347                 total_rx_packets++;
 348
 349                 ixgbe_process_skb_fields(rx_ring, rx_desc, skb);
 350                 ixgbe_rx_skb(q_vector, skb);
 351         }
 352
 353         if (xdp_xmit & IXGBE_XDP_REDIR)
 354                 xdp_do_flush();
 355
 356         if (xdp_xmit & IXGBE_XDP_TX) {
 357                 struct ixgbe_ring *ring = ixgbe_determine_xdp_ring(adapter);
 358
 359                 ixgbe_xdp_ring_update_tail_locked(ring);
 360         }
 361
 362         ixgbe_update_rx_ring_stats(rx_ring, q_vector, total_rx_packets,
 363                                    total_rx_bytes);
 364
 365         if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
 366                 if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
 367                         xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
 368                 else
 369                         xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
 370
 371                 return (int)total_rx_packets;
 372         }
 373         return failure ? budget : (int)total_rx_packets;
 374 }
 375
 376 void ixgbe_xsk_clean_rx_ring(struct ixgbe_ring *rx_ring)
 377 {
 378         struct ixgbe_rx_buffer *bi;
 379         u16 i;
 380
 381         for (i = 0; i < rx_ring->count; i++) {
 382                 bi = &rx_ring->rx_buffer_info[i];
 383
 384                 if (!bi->xdp)
 385                         continue;
 386
 387                 xsk_buff_free(bi->xdp);
 388                 bi->xdp = NULL;
 389         }
 390 }
 391
 392 static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
 393 {
 394         struct xsk_buff_pool *pool = xdp_ring->xsk_pool;
 395         union ixgbe_adv_tx_desc *tx_desc = NULL;
 396         struct ixgbe_tx_buffer *tx_bi;
 397         bool work_done = true;
 398         struct xdp_desc desc;
 399         dma_addr_t dma;
 400         u32 cmd_type;
 401
 402         while (budget-- > 0) {
 403                 if (unlikely(!ixgbe_desc_unused(xdp_ring))) {
 404                         work_done = false;
 405                         break;
 406                 }
 407
 408                 if (!netif_carrier_ok(xdp_ring->netdev))
 409                         break;
 410
 411                 if (!xsk_tx_peek_desc(pool, &desc))
 412                         break;
 413
 414                 dma = xsk_buff_raw_get_dma(pool, desc.addr);
 415                 xsk_buff_raw_dma_sync_for_device(pool, dma, desc.len);
 416
 417                 tx_bi = &xdp_ring->tx_buffer_info[xdp_ring->next_to_use];
 418                 tx_bi->bytecount = desc.len;
 419                 tx_bi->xdpf = NULL;
 420                 tx_bi->gso_segs = 1;
 421
 422                 tx_desc = IXGBE_TX_DESC(xdp_ring, xdp_ring->next_to_use);
 423                 tx_desc->read.buffer_addr = cpu_to_le64(dma);
 424
 425                 /* put descriptor type bits */
 426                 cmd_type = IXGBE_ADVTXD_DTYP_DATA |
 427                            IXGBE_ADVTXD_DCMD_DEXT |
 428                            IXGBE_ADVTXD_DCMD_IFCS;
 429                 cmd_type |= desc.len | IXGBE_TXD_CMD;
 430                 tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
 431                 tx_desc->read.olinfo_status =
 432                         cpu_to_le32(desc.len << IXGBE_ADVTXD_PAYLEN_SHIFT);
 433
 434                 xdp_ring->next_to_use++;
 435                 if (xdp_ring->next_to_use == xdp_ring->count)
 436                         xdp_ring->next_to_use = 0;
 437         }
 438
 439         if (tx_desc) {
 440                 ixgbe_xdp_ring_update_tail(xdp_ring);
 441                 xsk_tx_release(pool);
 442         }
 443
 444         return !!budget && work_done;
 445 }
 446
 447 static void ixgbe_clean_xdp_tx_buffer(struct ixgbe_ring *tx_ring,
 448                                       struct ixgbe_tx_buffer *tx_bi)
 449 {
 450         xdp_return_frame(tx_bi->xdpf);
 451         dma_unmap_single(tx_ring->dev,
 452                          dma_unmap_addr(tx_bi, dma),
 453                          dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
 454         dma_unmap_len_set(tx_bi, len, 0);
 455 }
 456
 457 bool ixgbe_clean_xdp_tx_irq(struct ixgbe_q_vector *q_vector,
 458                             struct ixgbe_ring *tx_ring, int napi_budget)
 459 {
 460         u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 461         unsigned int total_packets = 0, total_bytes = 0;
 462         struct xsk_buff_pool *pool = tx_ring->xsk_pool;
 463         union ixgbe_adv_tx_desc *tx_desc;
 464         struct ixgbe_tx_buffer *tx_bi;
 465         u32 xsk_frames = 0;
 466
 467         tx_bi = &tx_ring->tx_buffer_info[ntc];
 468         tx_desc = IXGBE_TX_DESC(tx_ring, ntc);
 469
 470         while (ntc != ntu) {
 471                 if (!(tx_desc->wb.status & cpu_to_le32(IXGBE_TXD_STAT_DD)))
 472                         break;
 473
 474                 total_bytes += tx_bi->bytecount;
 475                 total_packets += tx_bi->gso_segs;
 476
 477                 if (tx_bi->xdpf)
 478                         ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
 479                 else
 480                         xsk_frames++;
 481
 482                 tx_bi->xdpf = NULL;
 483
 484                 tx_bi++;
 485                 tx_desc++;
 486                 ntc++;
 487                 if (unlikely(ntc == tx_ring->count)) {
 488                         ntc = 0;
 489                         tx_bi = tx_ring->tx_buffer_info;
 490                         tx_desc = IXGBE_TX_DESC(tx_ring, 0);
 491                 }
 492
 493                 /* issue prefetch for next Tx descriptor */
 494                 prefetch(tx_desc);
 495         }
 496
 497         tx_ring->next_to_clean = ntc;
 498         ixgbe_update_tx_ring_stats(tx_ring, q_vector, total_packets,
 499                                    total_bytes);
 500
 501         if (xsk_frames)
 502                 xsk_tx_completed(pool, xsk_frames);
 503
 504         if (xsk_uses_need_wakeup(pool))
 505                 xsk_set_tx_need_wakeup(pool);
 506
 507         return ixgbe_xmit_zc(tx_ring, q_vector->tx.work_limit);
 508 }
 509
 510 int ixgbe_xsk_wakeup(struct net_device *dev, u32 qid, u32 flags)
 511 {
 512         struct ixgbe_adapter *adapter = netdev_priv(dev);
 513         struct ixgbe_ring *ring;
 514
 515         if (test_bit(__IXGBE_DOWN, &adapter->state))
 516                 return -ENETDOWN;
 517
 518         if (!READ_ONCE(adapter->xdp_prog))
 519                 return -EINVAL;
 520
 521         if (qid >= adapter->num_xdp_queues)
 522                 return -EINVAL;
 523
 524         ring = adapter->xdp_ring[qid];
 525
 526         if (test_bit(__IXGBE_TX_DISABLED, &ring->state))
 527                 return -ENETDOWN;
 528
 529         if (!ring->xsk_pool)
 530                 return -EINVAL;
 531
 532         if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi)) {
 533                 u64 eics = BIT_ULL(ring->q_vector->v_idx);
 534
 535                 ixgbe_irq_rearm_queues(adapter, eics);
 536         }
 537
 538         return 0;
 539 }
 540
 541 void ixgbe_xsk_clean_tx_ring(struct ixgbe_ring *tx_ring)
 542 {
 543         u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 544         struct xsk_buff_pool *pool = tx_ring->xsk_pool;
 545         struct ixgbe_tx_buffer *tx_bi;
 546         u32 xsk_frames = 0;
 547
 548         while (ntc != ntu) {
 549                 tx_bi = &tx_ring->tx_buffer_info[ntc];
 550
 551                 if (tx_bi->xdpf)
 552                         ixgbe_clean_xdp_tx_buffer(tx_ring, tx_bi);
 553                 else
 554                         xsk_frames++;
 555
 556                 tx_bi->xdpf = NULL;
 557
 558                 ntc++;
 559                 if (ntc == tx_ring->count)
 560                         ntc = 0;
 561         }
 562
 563         if (xsk_frames)
 564                 xsk_tx_completed(pool, xsk_frames);
 565 }