drivers/net/ethernet/intel/i40e/i40e_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 "i40e.h"
   9 #include "i40e_txrx_common.h"
  10 #include "i40e_xsk.h"
  11
  12 int i40e_alloc_rx_bi_zc(struct i40e_ring *rx_ring)
  13 {
  14         unsigned long sz = sizeof(*rx_ring->rx_bi_zc) * rx_ring->count;
  15
  16         rx_ring->rx_bi_zc = kzalloc(sz, GFP_KERNEL);
  17         return rx_ring->rx_bi_zc ? 0 : -ENOMEM;
  18 }
  19
  20 void i40e_clear_rx_bi_zc(struct i40e_ring *rx_ring)
  21 {
  22         memset(rx_ring->rx_bi_zc, 0,
  23                sizeof(*rx_ring->rx_bi_zc) * rx_ring->count);
  24 }
  25
  26 static struct xdp_buff **i40e_rx_bi(struct i40e_ring *rx_ring, u32 idx)
  27 {
  28         return &rx_ring->rx_bi_zc[idx];
  29 }
  30
  31 /**
  32  * i40e_xsk_pool_enable - Enable/associate an AF_XDP buffer pool to a
  33  * certain ring/qid
  34  * @vsi: Current VSI
  35  * @pool: buffer pool
  36  * @qid: Rx ring to associate buffer pool with
  37  *
  38  * Returns 0 on success, <0 on failure
  39  **/
  40 static int i40e_xsk_pool_enable(struct i40e_vsi *vsi,
  41                                 struct xsk_buff_pool *pool,
  42                                 u16 qid)
  43 {
  44         struct net_device *netdev = vsi->netdev;
  45         bool if_running;
  46         int err;
  47
  48         if (vsi->type != I40E_VSI_MAIN)
  49                 return -EINVAL;
  50
  51         if (qid >= vsi->num_queue_pairs)
  52                 return -EINVAL;
  53
  54         if (qid >= netdev->real_num_rx_queues ||
  55             qid >= netdev->real_num_tx_queues)
  56                 return -EINVAL;
  57
  58         err = xsk_pool_dma_map(pool, &vsi->back->pdev->dev, I40E_RX_DMA_ATTR);
  59         if (err)
  60                 return err;
  61
  62         set_bit(qid, vsi->af_xdp_zc_qps);
  63
  64         if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);
  65
  66         if (if_running) {
  67                 err = i40e_queue_pair_disable(vsi, qid);
  68                 if (err)
  69                         return err;
  70
  71                 err = i40e_queue_pair_enable(vsi, qid);
  72                 if (err)
  73                         return err;
  74
  75                 /* Kick start the NAPI context so that receiving will start */
  76                 err = i40e_xsk_wakeup(vsi->netdev, qid, XDP_WAKEUP_RX);
  77                 if (err)
  78                         return err;
  79         }
  80
  81         return 0;
  82 }
  83
  84 /**
  85  * i40e_xsk_pool_disable - Disassociate an AF_XDP buffer pool from a
  86  * certain ring/qid
  87  * @vsi: Current VSI
  88  * @qid: Rx ring to associate buffer pool with
  89  *
  90  * Returns 0 on success, <0 on failure
  91  **/
  92 static int i40e_xsk_pool_disable(struct i40e_vsi *vsi, u16 qid)
  93 {
  94         struct net_device *netdev = vsi->netdev;
  95         struct xsk_buff_pool *pool;
  96         bool if_running;
  97         int err;
  98
  99         pool = xsk_get_pool_from_qid(netdev, qid);
 100         if (!pool)
 101                 return -EINVAL;
 102
 103         if_running = netif_running(vsi->netdev) && i40e_enabled_xdp_vsi(vsi);
 104
 105         if (if_running) {
 106                 err = i40e_queue_pair_disable(vsi, qid);
 107                 if (err)
 108                         return err;
 109         }
 110
 111         clear_bit(qid, vsi->af_xdp_zc_qps);
 112         xsk_pool_dma_unmap(pool, I40E_RX_DMA_ATTR);
 113
 114         if (if_running) {
 115                 err = i40e_queue_pair_enable(vsi, qid);
 116                 if (err)
 117                         return err;
 118         }
 119
 120         return 0;
 121 }
 122
 123 /**
 124  * i40e_xsk_pool_setup - Enable/disassociate an AF_XDP buffer pool to/from
 125  * a ring/qid
 126  * @vsi: Current VSI
 127  * @pool: Buffer pool to enable/associate to a ring, or NULL to disable
 128  * @qid: Rx ring to (dis)associate buffer pool (from)to
 129  *
 130  * This function enables or disables a buffer pool to a certain ring.
 131  *
 132  * Returns 0 on success, <0 on failure
 133  **/
 134 int i40e_xsk_pool_setup(struct i40e_vsi *vsi, struct xsk_buff_pool *pool,
 135                         u16 qid)
 136 {
 137         return pool ? i40e_xsk_pool_enable(vsi, pool, qid) :
 138                 i40e_xsk_pool_disable(vsi, qid);
 139 }
 140
 141 /**
 142  * i40e_run_xdp_zc - Executes an XDP program on an xdp_buff
 143  * @rx_ring: Rx ring
 144  * @xdp: xdp_buff used as input to the XDP program
 145  *
 146  * Returns any of I40E_XDP_{PASS, CONSUMED, TX, REDIR}
 147  **/
 148 static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp)
 149 {
 150         int err, result = I40E_XDP_PASS;
 151         struct i40e_ring *xdp_ring;
 152         struct bpf_prog *xdp_prog;
 153         u32 act;
 154
 155         rcu_read_lock();
 156         /* NB! xdp_prog will always be !NULL, due to the fact that
 157          * this path is enabled by setting an XDP program.
 158          */
 159         xdp_prog = READ_ONCE(rx_ring->xdp_prog);
 160         act = bpf_prog_run_xdp(xdp_prog, xdp);
 161
 162         switch (act) {
 163         case XDP_PASS:
 164                 break;
 165         case XDP_TX:
 166                 xdp_ring = rx_ring->vsi->xdp_rings[rx_ring->queue_index];
 167                 result = i40e_xmit_xdp_tx_ring(xdp, xdp_ring);
 168                 break;
 169         case XDP_REDIRECT:
 170                 err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog);
 171                 result = !err ? I40E_XDP_REDIR : I40E_XDP_CONSUMED;
 172                 break;
 173         default:
 174                 bpf_warn_invalid_xdp_action(act);
 175                 fallthrough;
 176         case XDP_ABORTED:
 177                 trace_xdp_exception(rx_ring->netdev, xdp_prog, act);
 178                 fallthrough; /* handle aborts by dropping packet */
 179         case XDP_DROP:
 180                 result = I40E_XDP_CONSUMED;
 181                 break;
 182         }
 183         rcu_read_unlock();
 184         return result;
 185 }
 186
 187 bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
 188 {
 189         u16 ntu = rx_ring->next_to_use;
 190         union i40e_rx_desc *rx_desc;
 191         struct xdp_buff **bi, *xdp;
 192         dma_addr_t dma;
 193         bool ok = true;
 194
 195         rx_desc = I40E_RX_DESC(rx_ring, ntu);
 196         bi = i40e_rx_bi(rx_ring, ntu);
 197         do {
 198                 xdp = xsk_buff_alloc(rx_ring->xsk_pool);
 199                 if (!xdp) {
 200                         ok = false;
 201                         goto no_buffers;
 202                 }
 203                 *bi = xdp;
 204                 dma = xsk_buff_xdp_get_dma(xdp);
 205                 rx_desc->read.pkt_addr = cpu_to_le64(dma);
 206                 rx_desc->read.hdr_addr = 0;
 207
 208                 rx_desc++;
 209                 bi++;
 210                 ntu++;
 211
 212                 if (unlikely(ntu == rx_ring->count)) {
 213                         rx_desc = I40E_RX_DESC(rx_ring, 0);
 214                         bi = i40e_rx_bi(rx_ring, 0);
 215                         ntu = 0;
 216                 }
 217
 218                 count--;
 219         } while (count);
 220
 221 no_buffers:
 222         if (rx_ring->next_to_use != ntu)
 223                 i40e_release_rx_desc(rx_ring, ntu);
 224
 225         return ok;
 226 }
 227
 228 /**
 229  * i40e_construct_skb_zc - Create skbuff from zero-copy Rx buffer
 230  * @rx_ring: Rx ring
 231  * @xdp: xdp_buff
 232  *
 233  * This functions allocates a new skb from a zero-copy Rx buffer.
 234  *
 235  * Returns the skb, or NULL on failure.
 236  **/
 237 static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
 238                                              struct xdp_buff *xdp)
 239 {
 240         unsigned int metasize = xdp->data - xdp->data_meta;
 241         unsigned int datasize = xdp->data_end - xdp->data;
 242         struct sk_buff *skb;
 243
 244         /* allocate a skb to store the frags */
 245         skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
 246                                xdp->data_end - xdp->data_hard_start,
 247                                GFP_ATOMIC | __GFP_NOWARN);
 248         if (unlikely(!skb))
 249                 return NULL;
 250
 251         skb_reserve(skb, xdp->data - xdp->data_hard_start);
 252         memcpy(__skb_put(skb, datasize), xdp->data, datasize);
 253         if (metasize)
 254                 skb_metadata_set(skb, metasize);
 255
 256         xsk_buff_free(xdp);
 257         return skb;
 258 }
 259
 260 /**
 261  * i40e_inc_ntc: Advance the next_to_clean index
 262  * @rx_ring: Rx ring
 263  **/
 264 static void i40e_inc_ntc(struct i40e_ring *rx_ring)
 265 {
 266         u32 ntc = rx_ring->next_to_clean + 1;
 267
 268         ntc = (ntc < rx_ring->count) ? ntc : 0;
 269         rx_ring->next_to_clean = ntc;
 270 }
 271
 272 /**
 273  * i40e_clean_rx_irq_zc - Consumes Rx packets from the hardware ring
 274  * @rx_ring: Rx ring
 275  * @budget: NAPI budget
 276  *
 277  * Returns amount of work completed
 278  **/
 279 int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget)
 280 {
 281         unsigned int total_rx_bytes = 0, total_rx_packets = 0;
 282         u16 cleaned_count = I40E_DESC_UNUSED(rx_ring);
 283         unsigned int xdp_res, xdp_xmit = 0;
 284         struct sk_buff *skb;
 285         bool failure;
 286
 287         while (likely(total_rx_packets < (unsigned int)budget)) {
 288                 union i40e_rx_desc *rx_desc;
 289                 struct xdp_buff **bi;
 290                 unsigned int size;
 291                 u64 qword;
 292
 293                 rx_desc = I40E_RX_DESC(rx_ring, rx_ring->next_to_clean);
 294                 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
 295
 296                 /* This memory barrier is needed to keep us from reading
 297                  * any other fields out of the rx_desc until we have
 298                  * verified the descriptor has been written back.
 299                  */
 300                 dma_rmb();
 301
 302                 if (i40e_rx_is_programming_status(qword)) {
 303                         i40e_clean_programming_status(rx_ring,
 304                                                       rx_desc->raw.qword[0],
 305                                                       qword);
 306                         bi = i40e_rx_bi(rx_ring, rx_ring->next_to_clean);
 307                         xsk_buff_free(*bi);
 308                         *bi = NULL;
 309                         cleaned_count++;
 310                         i40e_inc_ntc(rx_ring);
 311                         continue;
 312                 }
 313
 314                 bi = i40e_rx_bi(rx_ring, rx_ring->next_to_clean);
 315                 size = (qword & I40E_RXD_QW1_LENGTH_PBUF_MASK) >>
 316                        I40E_RXD_QW1_LENGTH_PBUF_SHIFT;
 317                 if (!size)
 318                         break;
 319
 320                 bi = i40e_rx_bi(rx_ring, rx_ring->next_to_clean);
 321                 (*bi)->data_end = (*bi)->data + size;
 322                 xsk_buff_dma_sync_for_cpu(*bi, rx_ring->xsk_pool);
 323
 324                 xdp_res = i40e_run_xdp_zc(rx_ring, *bi);
 325                 if (xdp_res) {
 326                         if (xdp_res & (I40E_XDP_TX | I40E_XDP_REDIR))
 327                                 xdp_xmit |= xdp_res;
 328                         else
 329                                 xsk_buff_free(*bi);
 330
 331                         *bi = NULL;
 332                         total_rx_bytes += size;
 333                         total_rx_packets++;
 334
 335                         cleaned_count++;
 336                         i40e_inc_ntc(rx_ring);
 337                         continue;
 338                 }
 339
 340                 /* XDP_PASS path */
 341
 342                 /* NB! We are not checking for errors using
 343                  * i40e_test_staterr with
 344                  * BIT(I40E_RXD_QW1_ERROR_SHIFT). This is due to that
 345                  * SBP is *not* set in PRT_SBPVSI (default not set).
 346                  */
 347                 skb = i40e_construct_skb_zc(rx_ring, *bi);
 348                 *bi = NULL;
 349                 if (!skb) {
 350                         rx_ring->rx_stats.alloc_buff_failed++;
 351                         break;
 352                 }
 353
 354                 cleaned_count++;
 355                 i40e_inc_ntc(rx_ring);
 356
 357                 if (eth_skb_pad(skb))
 358                         continue;
 359
 360                 total_rx_bytes += skb->len;
 361                 total_rx_packets++;
 362
 363                 i40e_process_skb_fields(rx_ring, rx_desc, skb);
 364                 napi_gro_receive(&rx_ring->q_vector->napi, skb);
 365         }
 366
 367         if (cleaned_count >= I40E_RX_BUFFER_WRITE)
 368                 failure = !i40e_alloc_rx_buffers_zc(rx_ring, cleaned_count);
 369
 370         i40e_finalize_xdp_rx(rx_ring, xdp_xmit);
 371         i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets);
 372
 373         if (xsk_uses_need_wakeup(rx_ring->xsk_pool)) {
 374                 if (failure || rx_ring->next_to_clean == rx_ring->next_to_use)
 375                         xsk_set_rx_need_wakeup(rx_ring->xsk_pool);
 376                 else
 377                         xsk_clear_rx_need_wakeup(rx_ring->xsk_pool);
 378
 379                 return (int)total_rx_packets;
 380         }
 381         return failure ? budget : (int)total_rx_packets;
 382 }
 383
 384 /**
 385  * i40e_xmit_zc - Performs zero-copy Tx AF_XDP
 386  * @xdp_ring: XDP Tx ring
 387  * @budget: NAPI budget
 388  *
 389  * Returns true if the work is finished.
 390  **/
 391 static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
 392 {
 393         unsigned int sent_frames = 0, total_bytes = 0;
 394         struct i40e_tx_desc *tx_desc = NULL;
 395         struct i40e_tx_buffer *tx_bi;
 396         struct xdp_desc desc;
 397         dma_addr_t dma;
 398
 399         while (budget-- > 0) {
 400                 if (!xsk_tx_peek_desc(xdp_ring->xsk_pool, &desc))
 401                         break;
 402
 403                 dma = xsk_buff_raw_get_dma(xdp_ring->xsk_pool, desc.addr);
 404                 xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma,
 405                                                  desc.len);
 406
 407                 tx_bi = &xdp_ring->tx_bi[xdp_ring->next_to_use];
 408                 tx_bi->bytecount = desc.len;
 409
 410                 tx_desc = I40E_TX_DESC(xdp_ring, xdp_ring->next_to_use);
 411                 tx_desc->buffer_addr = cpu_to_le64(dma);
 412                 tx_desc->cmd_type_offset_bsz =
 413                         build_ctob(I40E_TX_DESC_CMD_ICRC
 414                                    | I40E_TX_DESC_CMD_EOP,
 415                                    0, desc.len, 0);
 416
 417                 sent_frames++;
 418                 total_bytes += tx_bi->bytecount;
 419
 420                 xdp_ring->next_to_use++;
 421                 if (xdp_ring->next_to_use == xdp_ring->count)
 422                         xdp_ring->next_to_use = 0;
 423         }
 424
 425         if (tx_desc) {
 426                 /* Request an interrupt for the last frame and bump tail ptr. */
 427                 tx_desc->cmd_type_offset_bsz |= (I40E_TX_DESC_CMD_RS <<
 428                                                  I40E_TXD_QW1_CMD_SHIFT);
 429                 i40e_xdp_ring_update_tail(xdp_ring);
 430
 431                 xsk_tx_release(xdp_ring->xsk_pool);
 432                 i40e_update_tx_stats(xdp_ring, sent_frames, total_bytes);
 433         }
 434
 435         return !!budget;
 436 }
 437
 438 /**
 439  * i40e_clean_xdp_tx_buffer - Frees and unmaps an XDP Tx entry
 440  * @tx_ring: XDP Tx ring
 441  * @tx_bi: Tx buffer info to clean
 442  **/
 443 static void i40e_clean_xdp_tx_buffer(struct i40e_ring *tx_ring,
 444                                      struct i40e_tx_buffer *tx_bi)
 445 {
 446         xdp_return_frame(tx_bi->xdpf);
 447         tx_ring->xdp_tx_active--;
 448         dma_unmap_single(tx_ring->dev,
 449                          dma_unmap_addr(tx_bi, dma),
 450                          dma_unmap_len(tx_bi, len), DMA_TO_DEVICE);
 451         dma_unmap_len_set(tx_bi, len, 0);
 452 }
 453
 454 /**
 455  * i40e_clean_xdp_tx_irq - Completes AF_XDP entries, and cleans XDP entries
 456  * @vsi: Current VSI
 457  * @tx_ring: XDP Tx ring
 458  *
 459  * Returns true if cleanup/tranmission is done.
 460  **/
 461 bool i40e_clean_xdp_tx_irq(struct i40e_vsi *vsi, struct i40e_ring *tx_ring)
 462 {
 463         struct xsk_buff_pool *bp = tx_ring->xsk_pool;
 464         u32 i, completed_frames, xsk_frames = 0;
 465         u32 head_idx = i40e_get_head(tx_ring);
 466         struct i40e_tx_buffer *tx_bi;
 467         unsigned int ntc;
 468
 469         if (head_idx < tx_ring->next_to_clean)
 470                 head_idx += tx_ring->count;
 471         completed_frames = head_idx - tx_ring->next_to_clean;
 472
 473         if (completed_frames == 0)
 474                 goto out_xmit;
 475
 476         if (likely(!tx_ring->xdp_tx_active)) {
 477                 xsk_frames = completed_frames;
 478                 goto skip;
 479         }
 480
 481         ntc = tx_ring->next_to_clean;
 482
 483         for (i = 0; i < completed_frames; i++) {
 484                 tx_bi = &tx_ring->tx_bi[ntc];
 485
 486                 if (tx_bi->xdpf) {
 487                         i40e_clean_xdp_tx_buffer(tx_ring, tx_bi);
 488                         tx_bi->xdpf = NULL;
 489                 } else {
 490                         xsk_frames++;
 491                 }
 492
 493                 if (++ntc >= tx_ring->count)
 494                         ntc = 0;
 495         }
 496
 497 skip:
 498         tx_ring->next_to_clean += completed_frames;
 499         if (unlikely(tx_ring->next_to_clean >= tx_ring->count))
 500                 tx_ring->next_to_clean -= tx_ring->count;
 501
 502         if (xsk_frames)
 503                 xsk_tx_completed(bp, xsk_frames);
 504
 505         i40e_arm_wb(tx_ring, vsi, completed_frames);
 506
 507 out_xmit:
 508         if (xsk_uses_need_wakeup(tx_ring->xsk_pool))
 509                 xsk_set_tx_need_wakeup(tx_ring->xsk_pool);
 510
 511         return i40e_xmit_zc(tx_ring, I40E_DESC_UNUSED(tx_ring));
 512 }
 513
 514 /**
 515  * i40e_xsk_wakeup - Implements the ndo_xsk_wakeup
 516  * @dev: the netdevice
 517  * @queue_id: queue id to wake up
 518  * @flags: ignored in our case since we have Rx and Tx in the same NAPI.
 519  *
 520  * Returns <0 for errors, 0 otherwise.
 521  **/
 522 int i40e_xsk_wakeup(struct net_device *dev, u32 queue_id, u32 flags)
 523 {
 524         struct i40e_netdev_priv *np = netdev_priv(dev);
 525         struct i40e_vsi *vsi = np->vsi;
 526         struct i40e_pf *pf = vsi->back;
 527         struct i40e_ring *ring;
 528
 529         if (test_bit(__I40E_CONFIG_BUSY, pf->state))
 530                 return -EAGAIN;
 531
 532         if (test_bit(__I40E_VSI_DOWN, vsi->state))
 533                 return -ENETDOWN;
 534
 535         if (!i40e_enabled_xdp_vsi(vsi))
 536                 return -ENXIO;
 537
 538         if (queue_id >= vsi->num_queue_pairs)
 539                 return -ENXIO;
 540
 541         if (!vsi->xdp_rings[queue_id]->xsk_pool)
 542                 return -ENXIO;
 543
 544         ring = vsi->xdp_rings[queue_id];
 545
 546         /* The idea here is that if NAPI is running, mark a miss, so
 547          * it will run again. If not, trigger an interrupt and
 548          * schedule the NAPI from interrupt context. If NAPI would be
 549          * scheduled here, the interrupt affinity would not be
 550          * honored.
 551          */
 552         if (!napi_if_scheduled_mark_missed(&ring->q_vector->napi))
 553                 i40e_force_wb(vsi, ring->q_vector);
 554
 555         return 0;
 556 }
 557
 558 void i40e_xsk_clean_rx_ring(struct i40e_ring *rx_ring)
 559 {
 560         u16 i;
 561
 562         for (i = 0; i < rx_ring->count; i++) {
 563                 struct xdp_buff *rx_bi = *i40e_rx_bi(rx_ring, i);
 564
 565                 if (!rx_bi)
 566                         continue;
 567
 568                 xsk_buff_free(rx_bi);
 569                 rx_bi = NULL;
 570         }
 571 }
 572
 573 /**
 574  * i40e_xsk_clean_xdp_ring - Clean the XDP Tx ring on shutdown
 575  * @tx_ring: XDP Tx ring
 576  **/
 577 void i40e_xsk_clean_tx_ring(struct i40e_ring *tx_ring)
 578 {
 579         u16 ntc = tx_ring->next_to_clean, ntu = tx_ring->next_to_use;
 580         struct xsk_buff_pool *bp = tx_ring->xsk_pool;
 581         struct i40e_tx_buffer *tx_bi;
 582         u32 xsk_frames = 0;
 583
 584         while (ntc != ntu) {
 585                 tx_bi = &tx_ring->tx_bi[ntc];
 586
 587                 if (tx_bi->xdpf)
 588                         i40e_clean_xdp_tx_buffer(tx_ring, tx_bi);
 589                 else
 590                         xsk_frames++;
 591
 592                 tx_bi->xdpf = NULL;
 593
 594                 ntc++;
 595                 if (ntc >= tx_ring->count)
 596                         ntc = 0;
 597         }
 598
 599         if (xsk_frames)
 600                 xsk_tx_completed(bp, xsk_frames);
 601 }
 602
 603 /**
 604  * i40e_xsk_any_rx_ring_enabled - Checks if Rx rings have an AF_XDP
 605  * buffer pool attached
 606  * @vsi: vsi
 607  *
 608  * Returns true if any of the Rx rings has an AF_XDP buffer pool attached
 609  **/
 610 bool i40e_xsk_any_rx_ring_enabled(struct i40e_vsi *vsi)
 611 {
 612         struct net_device *netdev = vsi->netdev;
 613         int i;
 614
 615         for (i = 0; i < vsi->num_queue_pairs; i++) {
 616                 if (xsk_get_pool_from_qid(netdev, i))
 617                         return true;
 618         }
 619
 620         return false;
 621 }