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