net/xdp/xsk_buff_pool.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <net/xsk_buff_pool.h>
   4 #include <net/xdp_sock.h>
   5 #include <net/xdp_sock_drv.h>
   6
   7 #include "xsk_queue.h"
   8 #include "xdp_umem.h"
   9 #include "xsk.h"
  10
  11 void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
  12 {
  13         unsigned long flags;
  14
  15         if (!xs->tx)
  16                 return;
  17
  18         spin_lock_irqsave(&pool->xsk_tx_list_lock, flags);
  19         list_add_rcu(&xs->tx_list, &pool->xsk_tx_list);
  20         spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
  21 }
  22
  23 void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs)
  24 {
  25         unsigned long flags;
  26
  27         if (!xs->tx)
  28                 return;
  29
  30         spin_lock_irqsave(&pool->xsk_tx_list_lock, flags);
  31         list_del_rcu(&xs->tx_list);
  32         spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags);
  33 }
  34
  35 void xp_destroy(struct xsk_buff_pool *pool)
  36 {
  37         if (!pool)
  38                 return;
  39
  40         kvfree(pool->tx_descs);
  41         kvfree(pool->heads);
  42         kvfree(pool);
  43 }
  44
  45 int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs)
  46 {
  47         pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs),
  48                                   GFP_KERNEL);
  49         if (!pool->tx_descs)
  50                 return -ENOMEM;
  51
  52         return 0;
  53 }
  54
  55 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs,
  56                                                 struct xdp_umem *umem)
  57 {
  58         bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
  59         struct xsk_buff_pool *pool;
  60         struct xdp_buff_xsk *xskb;
  61         u32 i, entries;
  62
  63         entries = unaligned ? umem->chunks : 0;
  64         pool = kvzalloc(struct_size(pool, free_heads, entries), GFP_KERNEL);
  65         if (!pool)
  66                 goto out;
  67
  68         pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL);
  69         if (!pool->heads)
  70                 goto out;
  71
  72         if (xs->tx)
  73                 if (xp_alloc_tx_descs(pool, xs))
  74                         goto out;
  75
  76         pool->chunk_mask = ~((u64)umem->chunk_size - 1);
  77         pool->addrs_cnt = umem->size;
  78         pool->heads_cnt = umem->chunks;
  79         pool->free_heads_cnt = umem->chunks;
  80         pool->headroom = umem->headroom;
  81         pool->chunk_size = umem->chunk_size;
  82         pool->chunk_shift = ffs(umem->chunk_size) - 1;
  83         pool->unaligned = unaligned;
  84         pool->frame_len = umem->chunk_size - umem->headroom -
  85                 XDP_PACKET_HEADROOM;
  86         pool->umem = umem;
  87         pool->addrs = umem->addrs;
  88         INIT_LIST_HEAD(&pool->free_list);
  89         INIT_LIST_HEAD(&pool->xsk_tx_list);
  90         spin_lock_init(&pool->xsk_tx_list_lock);
  91         spin_lock_init(&pool->cq_lock);
  92         refcount_set(&pool->users, 1);
  93
  94         pool->fq = xs->fq_tmp;
  95         pool->cq = xs->cq_tmp;
  96
  97         for (i = 0; i < pool->free_heads_cnt; i++) {
  98                 xskb = &pool->heads[i];
  99                 xskb->pool = pool;
 100                 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
 101                 INIT_LIST_HEAD(&xskb->free_list_node);
 102                 if (pool->unaligned)
 103                         pool->free_heads[i] = xskb;
 104                 else
 105                         xp_init_xskb_addr(xskb, pool, i * pool->chunk_size);
 106         }
 107
 108         return pool;
 109
 110 out:
 111         xp_destroy(pool);
 112         return NULL;
 113 }
 114
 115 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
 116 {
 117         u32 i;
 118
 119         for (i = 0; i < pool->heads_cnt; i++)
 120                 pool->heads[i].xdp.rxq = rxq;
 121 }
 122 EXPORT_SYMBOL(xp_set_rxq_info);
 123
 124 static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
 125 {
 126         struct netdev_bpf bpf;
 127         int err;
 128
 129         ASSERT_RTNL();
 130
 131         if (pool->umem->zc) {
 132                 bpf.command = XDP_SETUP_XSK_POOL;
 133                 bpf.xsk.pool = NULL;
 134                 bpf.xsk.queue_id = pool->queue_id;
 135
 136                 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
 137
 138                 if (err)
 139                         WARN(1, "Failed to disable zero-copy!\n");
 140         }
 141 }
 142
 143 int xp_assign_dev(struct xsk_buff_pool *pool,
 144                   struct net_device *netdev, u16 queue_id, u16 flags)
 145 {
 146         bool force_zc, force_copy;
 147         struct netdev_bpf bpf;
 148         int err = 0;
 149
 150         ASSERT_RTNL();
 151
 152         force_zc = flags & XDP_ZEROCOPY;
 153         force_copy = flags & XDP_COPY;
 154
 155         if (force_zc && force_copy)
 156                 return -EINVAL;
 157
 158         if (xsk_get_pool_from_qid(netdev, queue_id))
 159                 return -EBUSY;
 160
 161         pool->netdev = netdev;
 162         pool->queue_id = queue_id;
 163         err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
 164         if (err)
 165                 return err;
 166
 167         if (flags & XDP_USE_NEED_WAKEUP)
 168                 pool->uses_need_wakeup = true;
 169         /* Tx needs to be explicitly woken up the first time.  Also
 170          * for supporting drivers that do not implement this
 171          * feature. They will always have to call sendto() or poll().
 172          */
 173         pool->cached_need_wakeup = XDP_WAKEUP_TX;
 174
 175         dev_hold(netdev);
 176
 177         if (force_copy)
 178                 /* For copy-mode, we are done. */
 179                 return 0;
 180
 181         if (!netdev->netdev_ops->ndo_bpf ||
 182             !netdev->netdev_ops->ndo_xsk_wakeup) {
 183                 err = -EOPNOTSUPP;
 184                 goto err_unreg_pool;
 185         }
 186
 187         bpf.command = XDP_SETUP_XSK_POOL;
 188         bpf.xsk.pool = pool;
 189         bpf.xsk.queue_id = queue_id;
 190
 191         err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
 192         if (err)
 193                 goto err_unreg_pool;
 194
 195         if (!pool->dma_pages) {
 196                 WARN(1, "Driver did not DMA map zero-copy buffers");
 197                 err = -EINVAL;
 198                 goto err_unreg_xsk;
 199         }
 200         pool->umem->zc = true;
 201         return 0;
 202
 203 err_unreg_xsk:
 204         xp_disable_drv_zc(pool);
 205 err_unreg_pool:
 206         if (!force_zc)
 207                 err = 0; /* fallback to copy mode */
 208         if (err) {
 209                 xsk_clear_pool_at_qid(netdev, queue_id);
 210                 dev_put(netdev);
 211         }
 212         return err;
 213 }
 214
 215 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
 216                          struct net_device *dev, u16 queue_id)
 217 {
 218         u16 flags;
 219         struct xdp_umem *umem = umem_xs->umem;
 220
 221         /* One fill and completion ring required for each queue id. */
 222         if (!pool->fq || !pool->cq)
 223                 return -EINVAL;
 224
 225         flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
 226         if (umem_xs->pool->uses_need_wakeup)
 227                 flags |= XDP_USE_NEED_WAKEUP;
 228
 229         return xp_assign_dev(pool, dev, queue_id, flags);
 230 }
 231
 232 void xp_clear_dev(struct xsk_buff_pool *pool)
 233 {
 234         if (!pool->netdev)
 235                 return;
 236
 237         xp_disable_drv_zc(pool);
 238         xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
 239         dev_put(pool->netdev);
 240         pool->netdev = NULL;
 241 }
 242
 243 static void xp_release_deferred(struct work_struct *work)
 244 {
 245         struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
 246                                                   work);
 247
 248         rtnl_lock();
 249         xp_clear_dev(pool);
 250         rtnl_unlock();
 251
 252         if (pool->fq) {
 253                 xskq_destroy(pool->fq);
 254                 pool->fq = NULL;
 255         }
 256
 257         if (pool->cq) {
 258                 xskq_destroy(pool->cq);
 259                 pool->cq = NULL;
 260         }
 261
 262         xdp_put_umem(pool->umem, false);
 263         xp_destroy(pool);
 264 }
 265
 266 void xp_get_pool(struct xsk_buff_pool *pool)
 267 {
 268         refcount_inc(&pool->users);
 269 }
 270
 271 bool xp_put_pool(struct xsk_buff_pool *pool)
 272 {
 273         if (!pool)
 274                 return false;
 275
 276         if (refcount_dec_and_test(&pool->users)) {
 277                 INIT_WORK(&pool->work, xp_release_deferred);
 278                 schedule_work(&pool->work);
 279                 return true;
 280         }
 281
 282         return false;
 283 }
 284
 285 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
 286 {
 287         struct xsk_dma_map *dma_map;
 288
 289         list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
 290                 if (dma_map->netdev == pool->netdev)
 291                         return dma_map;
 292         }
 293
 294         return NULL;
 295 }
 296
 297 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
 298                                              u32 nr_pages, struct xdp_umem *umem)
 299 {
 300         struct xsk_dma_map *dma_map;
 301
 302         dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
 303         if (!dma_map)
 304                 return NULL;
 305
 306         dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
 307         if (!dma_map->dma_pages) {
 308                 kfree(dma_map);
 309                 return NULL;
 310         }
 311
 312         dma_map->netdev = netdev;
 313         dma_map->dev = dev;
 314         dma_map->dma_need_sync = false;
 315         dma_map->dma_pages_cnt = nr_pages;
 316         refcount_set(&dma_map->users, 1);
 317         list_add(&dma_map->list, &umem->xsk_dma_list);
 318         return dma_map;
 319 }
 320
 321 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
 322 {
 323         list_del(&dma_map->list);
 324         kvfree(dma_map->dma_pages);
 325         kfree(dma_map);
 326 }
 327
 328 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
 329 {
 330         dma_addr_t *dma;
 331         u32 i;
 332
 333         for (i = 0; i < dma_map->dma_pages_cnt; i++) {
 334                 dma = &dma_map->dma_pages[i];
 335                 if (*dma) {
 336                         *dma &= ~XSK_NEXT_PG_CONTIG_MASK;
 337                         dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
 338                                              DMA_BIDIRECTIONAL, attrs);
 339                         *dma = 0;
 340                 }
 341         }
 342
 343         xp_destroy_dma_map(dma_map);
 344 }
 345
 346 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
 347 {
 348         struct xsk_dma_map *dma_map;
 349
 350         if (pool->dma_pages_cnt == 0)
 351                 return;
 352
 353         dma_map = xp_find_dma_map(pool);
 354         if (!dma_map) {
 355                 WARN(1, "Could not find dma_map for device");
 356                 return;
 357         }
 358
 359         if (!refcount_dec_and_test(&dma_map->users))
 360                 return;
 361
 362         __xp_dma_unmap(dma_map, attrs);
 363         kvfree(pool->dma_pages);
 364         pool->dma_pages_cnt = 0;
 365         pool->dev = NULL;
 366 }
 367 EXPORT_SYMBOL(xp_dma_unmap);
 368
 369 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
 370 {
 371         u32 i;
 372
 373         for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
 374                 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
 375                         dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
 376                 else
 377                         dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
 378         }
 379 }
 380
 381 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
 382 {
 383         if (!pool->unaligned) {
 384                 u32 i;
 385
 386                 for (i = 0; i < pool->heads_cnt; i++) {
 387                         struct xdp_buff_xsk *xskb = &pool->heads[i];
 388
 389                         xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
 390                 }
 391         }
 392
 393         pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
 394         if (!pool->dma_pages)
 395                 return -ENOMEM;
 396
 397         pool->dev = dma_map->dev;
 398         pool->dma_pages_cnt = dma_map->dma_pages_cnt;
 399         pool->dma_need_sync = dma_map->dma_need_sync;
 400         memcpy(pool->dma_pages, dma_map->dma_pages,
 401                pool->dma_pages_cnt * sizeof(*pool->dma_pages));
 402
 403         return 0;
 404 }
 405
 406 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
 407                unsigned long attrs, struct page **pages, u32 nr_pages)
 408 {
 409         struct xsk_dma_map *dma_map;
 410         dma_addr_t dma;
 411         int err;
 412         u32 i;
 413
 414         dma_map = xp_find_dma_map(pool);
 415         if (dma_map) {
 416                 err = xp_init_dma_info(pool, dma_map);
 417                 if (err)
 418                         return err;
 419
 420                 refcount_inc(&dma_map->users);
 421                 return 0;
 422         }
 423
 424         dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
 425         if (!dma_map)
 426                 return -ENOMEM;
 427
 428         for (i = 0; i < dma_map->dma_pages_cnt; i++) {
 429                 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
 430                                          DMA_BIDIRECTIONAL, attrs);
 431                 if (dma_mapping_error(dev, dma)) {
 432                         __xp_dma_unmap(dma_map, attrs);
 433                         return -ENOMEM;
 434                 }
 435                 if (dma_need_sync(dev, dma))
 436                         dma_map->dma_need_sync = true;
 437                 dma_map->dma_pages[i] = dma;
 438         }
 439
 440         if (pool->unaligned)
 441                 xp_check_dma_contiguity(dma_map);
 442
 443         err = xp_init_dma_info(pool, dma_map);
 444         if (err) {
 445                 __xp_dma_unmap(dma_map, attrs);
 446                 return err;
 447         }
 448
 449         return 0;
 450 }
 451 EXPORT_SYMBOL(xp_dma_map);
 452
 453 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
 454                                           u64 addr)
 455 {
 456         return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
 457 }
 458
 459 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
 460 {
 461         *addr = xp_unaligned_extract_addr(*addr);
 462         if (*addr >= pool->addrs_cnt ||
 463             *addr + pool->chunk_size > pool->addrs_cnt ||
 464             xp_addr_crosses_non_contig_pg(pool, *addr))
 465                 return false;
 466         return true;
 467 }
 468
 469 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
 470 {
 471         *addr = xp_aligned_extract_addr(pool, *addr);
 472         return *addr < pool->addrs_cnt;
 473 }
 474
 475 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
 476 {
 477         struct xdp_buff_xsk *xskb;
 478         u64 addr;
 479         bool ok;
 480
 481         if (pool->free_heads_cnt == 0)
 482                 return NULL;
 483
 484         for (;;) {
 485                 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
 486                         pool->fq->queue_empty_descs++;
 487                         return NULL;
 488                 }
 489
 490                 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
 491                      xp_check_aligned(pool, &addr);
 492                 if (!ok) {
 493                         pool->fq->invalid_descs++;
 494                         xskq_cons_release(pool->fq);
 495                         continue;
 496                 }
 497                 break;
 498         }
 499
 500         if (pool->unaligned) {
 501                 xskb = pool->free_heads[--pool->free_heads_cnt];
 502                 xp_init_xskb_addr(xskb, pool, addr);
 503                 if (pool->dma_pages_cnt)
 504                         xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
 505         } else {
 506                 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
 507         }
 508
 509         xskq_cons_release(pool->fq);
 510         return xskb;
 511 }
 512
 513 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
 514 {
 515         struct xdp_buff_xsk *xskb;
 516
 517         if (!pool->free_list_cnt) {
 518                 xskb = __xp_alloc(pool);
 519                 if (!xskb)
 520                         return NULL;
 521         } else {
 522                 pool->free_list_cnt--;
 523                 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
 524                                         free_list_node);
 525                 list_del_init(&xskb->free_list_node);
 526         }
 527
 528         xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
 529         xskb->xdp.data_meta = xskb->xdp.data;
 530
 531         if (pool->dma_need_sync) {
 532                 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
 533                                                  pool->frame_len,
 534                                                  DMA_BIDIRECTIONAL);
 535         }
 536         return &xskb->xdp;
 537 }
 538 EXPORT_SYMBOL(xp_alloc);
 539
 540 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 541 {
 542         u32 i, cached_cons, nb_entries;
 543
 544         if (max > pool->free_heads_cnt)
 545                 max = pool->free_heads_cnt;
 546         max = xskq_cons_nb_entries(pool->fq, max);
 547
 548         cached_cons = pool->fq->cached_cons;
 549         nb_entries = max;
 550         i = max;
 551         while (i--) {
 552                 struct xdp_buff_xsk *xskb;
 553                 u64 addr;
 554                 bool ok;
 555
 556                 __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
 557
 558                 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
 559                         xp_check_aligned(pool, &addr);
 560                 if (unlikely(!ok)) {
 561                         pool->fq->invalid_descs++;
 562                         nb_entries--;
 563                         continue;
 564                 }
 565
 566                 if (pool->unaligned) {
 567                         xskb = pool->free_heads[--pool->free_heads_cnt];
 568                         xp_init_xskb_addr(xskb, pool, addr);
 569                         if (pool->dma_pages_cnt)
 570                                 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
 571                 } else {
 572                         xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
 573                 }
 574
 575                 *xdp = &xskb->xdp;
 576                 xdp++;
 577         }
 578
 579         xskq_cons_release_n(pool->fq, max);
 580         return nb_entries;
 581 }
 582
 583 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
 584 {
 585         struct xdp_buff_xsk *xskb;
 586         u32 i;
 587
 588         nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
 589
 590         i = nb_entries;
 591         while (i--) {
 592                 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node);
 593                 list_del_init(&xskb->free_list_node);
 594
 595                 *xdp = &xskb->xdp;
 596                 xdp++;
 597         }
 598         pool->free_list_cnt -= nb_entries;
 599
 600         return nb_entries;
 601 }
 602
 603 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 604 {
 605         u32 nb_entries1 = 0, nb_entries2;
 606
 607         if (unlikely(pool->dma_need_sync)) {
 608                 struct xdp_buff *buff;
 609
 610                 /* Slow path */
 611                 buff = xp_alloc(pool);
 612                 if (buff)
 613                         *xdp = buff;
 614                 return !!buff;
 615         }
 616
 617         if (unlikely(pool->free_list_cnt)) {
 618                 nb_entries1 = xp_alloc_reused(pool, xdp, max);
 619                 if (nb_entries1 == max)
 620                         return nb_entries1;
 621
 622                 max -= nb_entries1;
 623                 xdp += nb_entries1;
 624         }
 625
 626         nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
 627         if (!nb_entries2)
 628                 pool->fq->queue_empty_descs++;
 629
 630         return nb_entries1 + nb_entries2;
 631 }
 632 EXPORT_SYMBOL(xp_alloc_batch);
 633
 634 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
 635 {
 636         if (pool->free_list_cnt >= count)
 637                 return true;
 638         return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
 639 }
 640 EXPORT_SYMBOL(xp_can_alloc);
 641
 642 void xp_free(struct xdp_buff_xsk *xskb)
 643 {
 644         if (!list_empty(&xskb->free_list_node))
 645                 return;
 646
 647         xskb->pool->free_list_cnt++;
 648         list_add(&xskb->free_list_node, &xskb->pool->free_list);
 649 }
 650 EXPORT_SYMBOL(xp_free);
 651
 652 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
 653 {
 654         addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
 655         return pool->addrs + addr;
 656 }
 657 EXPORT_SYMBOL(xp_raw_get_data);
 658
 659 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
 660 {
 661         addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
 662         return (pool->dma_pages[addr >> PAGE_SHIFT] &
 663                 ~XSK_NEXT_PG_CONTIG_MASK) +
 664                 (addr & ~PAGE_MASK);
 665 }
 666 EXPORT_SYMBOL(xp_raw_get_dma);
 667
 668 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
 669 {
 670         dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
 671                                       xskb->pool->frame_len, DMA_BIDIRECTIONAL);
 672 }
 673 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
 674
 675 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
 676                                  size_t size)
 677 {
 678         dma_sync_single_range_for_device(pool->dev, dma, 0,
 679                                          size, DMA_BIDIRECTIONAL);
 680 }
 681 EXPORT_SYMBOL(xp_dma_sync_for_device_slow);