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