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