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->xskb_list);
  90         INIT_LIST_HEAD(&pool->xsk_tx_list);
  91         spin_lock_init(&pool->xsk_tx_list_lock);
  92         spin_lock_init(&pool->cq_lock);
  93         refcount_set(&pool->users, 1);
  94
  95         pool->fq = xs->fq_tmp;
  96         pool->cq = xs->cq_tmp;
  97
  98         for (i = 0; i < pool->free_heads_cnt; i++) {
  99                 xskb = &pool->heads[i];
 100                 xskb->pool = pool;
 101                 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
 102                 INIT_LIST_HEAD(&xskb->free_list_node);
 103                 INIT_LIST_HEAD(&xskb->xskb_list_node);
 104                 if (pool->unaligned)
 105                         pool->free_heads[i] = xskb;
 106                 else
 107                         xp_init_xskb_addr(xskb, pool, i * pool->chunk_size);
 108         }
 109
 110         return pool;
 111
 112 out:
 113         xp_destroy(pool);
 114         return NULL;
 115 }
 116
 117 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
 118 {
 119         u32 i;
 120
 121         for (i = 0; i < pool->heads_cnt; i++)
 122                 pool->heads[i].xdp.rxq = rxq;
 123 }
 124 EXPORT_SYMBOL(xp_set_rxq_info);
 125
 126 static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
 127 {
 128         struct netdev_bpf bpf;
 129         int err;
 130
 131         ASSERT_RTNL();
 132
 133         if (pool->umem->zc) {
 134                 bpf.command = XDP_SETUP_XSK_POOL;
 135                 bpf.xsk.pool = NULL;
 136                 bpf.xsk.queue_id = pool->queue_id;
 137
 138                 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
 139
 140                 if (err)
 141                         WARN(1, "Failed to disable zero-copy!\n");
 142         }
 143 }
 144
 145 #define NETDEV_XDP_ACT_ZC       (NETDEV_XDP_ACT_BASIC |         \
 146                                  NETDEV_XDP_ACT_REDIRECT |      \
 147                                  NETDEV_XDP_ACT_XSK_ZEROCOPY)
 148
 149 int xp_assign_dev(struct xsk_buff_pool *pool,
 150                   struct net_device *netdev, u16 queue_id, u16 flags)
 151 {
 152         bool force_zc, force_copy;
 153         struct netdev_bpf bpf;
 154         int err = 0;
 155
 156         ASSERT_RTNL();
 157
 158         force_zc = flags & XDP_ZEROCOPY;
 159         force_copy = flags & XDP_COPY;
 160
 161         if (force_zc && force_copy)
 162                 return -EINVAL;
 163
 164         if (xsk_get_pool_from_qid(netdev, queue_id))
 165                 return -EBUSY;
 166
 167         pool->netdev = netdev;
 168         pool->queue_id = queue_id;
 169         err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
 170         if (err)
 171                 return err;
 172
 173         if (flags & XDP_USE_SG)
 174                 pool->umem->flags |= XDP_UMEM_SG_FLAG;
 175
 176         if (flags & XDP_USE_NEED_WAKEUP)
 177                 pool->uses_need_wakeup = true;
 178         /* Tx needs to be explicitly woken up the first time.  Also
 179          * for supporting drivers that do not implement this
 180          * feature. They will always have to call sendto() or poll().
 181          */
 182         pool->cached_need_wakeup = XDP_WAKEUP_TX;
 183
 184         dev_hold(netdev);
 185
 186         if (force_copy)
 187                 /* For copy-mode, we are done. */
 188                 return 0;
 189
 190         if ((netdev->xdp_features & NETDEV_XDP_ACT_ZC) != NETDEV_XDP_ACT_ZC) {
 191                 err = -EOPNOTSUPP;
 192                 goto err_unreg_pool;
 193         }
 194
 195         if (netdev->xdp_zc_max_segs == 1 && (flags & XDP_USE_SG)) {
 196                 err = -EOPNOTSUPP;
 197                 goto err_unreg_pool;
 198         }
 199
 200         bpf.command = XDP_SETUP_XSK_POOL;
 201         bpf.xsk.pool = pool;
 202         bpf.xsk.queue_id = queue_id;
 203
 204         err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
 205         if (err)
 206                 goto err_unreg_pool;
 207
 208         if (!pool->dma_pages) {
 209                 WARN(1, "Driver did not DMA map zero-copy buffers");
 210                 err = -EINVAL;
 211                 goto err_unreg_xsk;
 212         }
 213         pool->umem->zc = true;
 214         return 0;
 215
 216 err_unreg_xsk:
 217         xp_disable_drv_zc(pool);
 218 err_unreg_pool:
 219         if (!force_zc)
 220                 err = 0; /* fallback to copy mode */
 221         if (err) {
 222                 xsk_clear_pool_at_qid(netdev, queue_id);
 223                 dev_put(netdev);
 224         }
 225         return err;
 226 }
 227
 228 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
 229                          struct net_device *dev, u16 queue_id)
 230 {
 231         u16 flags;
 232         struct xdp_umem *umem = umem_xs->umem;
 233
 234         /* One fill and completion ring required for each queue id. */
 235         if (!pool->fq || !pool->cq)
 236                 return -EINVAL;
 237
 238         flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
 239         if (umem_xs->pool->uses_need_wakeup)
 240                 flags |= XDP_USE_NEED_WAKEUP;
 241
 242         return xp_assign_dev(pool, dev, queue_id, flags);
 243 }
 244
 245 void xp_clear_dev(struct xsk_buff_pool *pool)
 246 {
 247         if (!pool->netdev)
 248                 return;
 249
 250         xp_disable_drv_zc(pool);
 251         xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
 252         dev_put(pool->netdev);
 253         pool->netdev = NULL;
 254 }
 255
 256 static void xp_release_deferred(struct work_struct *work)
 257 {
 258         struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
 259                                                   work);
 260
 261         rtnl_lock();
 262         xp_clear_dev(pool);
 263         rtnl_unlock();
 264
 265         if (pool->fq) {
 266                 xskq_destroy(pool->fq);
 267                 pool->fq = NULL;
 268         }
 269
 270         if (pool->cq) {
 271                 xskq_destroy(pool->cq);
 272                 pool->cq = NULL;
 273         }
 274
 275         xdp_put_umem(pool->umem, false);
 276         xp_destroy(pool);
 277 }
 278
 279 void xp_get_pool(struct xsk_buff_pool *pool)
 280 {
 281         refcount_inc(&pool->users);
 282 }
 283
 284 bool xp_put_pool(struct xsk_buff_pool *pool)
 285 {
 286         if (!pool)
 287                 return false;
 288
 289         if (refcount_dec_and_test(&pool->users)) {
 290                 INIT_WORK(&pool->work, xp_release_deferred);
 291                 schedule_work(&pool->work);
 292                 return true;
 293         }
 294
 295         return false;
 296 }
 297
 298 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
 299 {
 300         struct xsk_dma_map *dma_map;
 301
 302         list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
 303                 if (dma_map->netdev == pool->netdev)
 304                         return dma_map;
 305         }
 306
 307         return NULL;
 308 }
 309
 310 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
 311                                              u32 nr_pages, struct xdp_umem *umem)
 312 {
 313         struct xsk_dma_map *dma_map;
 314
 315         dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
 316         if (!dma_map)
 317                 return NULL;
 318
 319         dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
 320         if (!dma_map->dma_pages) {
 321                 kfree(dma_map);
 322                 return NULL;
 323         }
 324
 325         dma_map->netdev = netdev;
 326         dma_map->dev = dev;
 327         dma_map->dma_need_sync = false;
 328         dma_map->dma_pages_cnt = nr_pages;
 329         refcount_set(&dma_map->users, 1);
 330         list_add(&dma_map->list, &umem->xsk_dma_list);
 331         return dma_map;
 332 }
 333
 334 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
 335 {
 336         list_del(&dma_map->list);
 337         kvfree(dma_map->dma_pages);
 338         kfree(dma_map);
 339 }
 340
 341 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
 342 {
 343         dma_addr_t *dma;
 344         u32 i;
 345
 346         for (i = 0; i < dma_map->dma_pages_cnt; i++) {
 347                 dma = &dma_map->dma_pages[i];
 348                 if (*dma) {
 349                         *dma &= ~XSK_NEXT_PG_CONTIG_MASK;
 350                         dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
 351                                              DMA_BIDIRECTIONAL, attrs);
 352                         *dma = 0;
 353                 }
 354         }
 355
 356         xp_destroy_dma_map(dma_map);
 357 }
 358
 359 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
 360 {
 361         struct xsk_dma_map *dma_map;
 362
 363         if (!pool->dma_pages)
 364                 return;
 365
 366         dma_map = xp_find_dma_map(pool);
 367         if (!dma_map) {
 368                 WARN(1, "Could not find dma_map for device");
 369                 return;
 370         }
 371
 372         if (!refcount_dec_and_test(&dma_map->users))
 373                 return;
 374
 375         __xp_dma_unmap(dma_map, attrs);
 376         kvfree(pool->dma_pages);
 377         pool->dma_pages = NULL;
 378         pool->dma_pages_cnt = 0;
 379         pool->dev = NULL;
 380 }
 381 EXPORT_SYMBOL(xp_dma_unmap);
 382
 383 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
 384 {
 385         u32 i;
 386
 387         for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
 388                 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
 389                         dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
 390                 else
 391                         dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
 392         }
 393 }
 394
 395 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
 396 {
 397         if (!pool->unaligned) {
 398                 u32 i;
 399
 400                 for (i = 0; i < pool->heads_cnt; i++) {
 401                         struct xdp_buff_xsk *xskb = &pool->heads[i];
 402
 403                         xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
 404                 }
 405         }
 406
 407         pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
 408         if (!pool->dma_pages)
 409                 return -ENOMEM;
 410
 411         pool->dev = dma_map->dev;
 412         pool->dma_pages_cnt = dma_map->dma_pages_cnt;
 413         pool->dma_need_sync = dma_map->dma_need_sync;
 414         memcpy(pool->dma_pages, dma_map->dma_pages,
 415                pool->dma_pages_cnt * sizeof(*pool->dma_pages));
 416
 417         return 0;
 418 }
 419
 420 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
 421                unsigned long attrs, struct page **pages, u32 nr_pages)
 422 {
 423         struct xsk_dma_map *dma_map;
 424         dma_addr_t dma;
 425         int err;
 426         u32 i;
 427
 428         dma_map = xp_find_dma_map(pool);
 429         if (dma_map) {
 430                 err = xp_init_dma_info(pool, dma_map);
 431                 if (err)
 432                         return err;
 433
 434                 refcount_inc(&dma_map->users);
 435                 return 0;
 436         }
 437
 438         dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
 439         if (!dma_map)
 440                 return -ENOMEM;
 441
 442         for (i = 0; i < dma_map->dma_pages_cnt; i++) {
 443                 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
 444                                          DMA_BIDIRECTIONAL, attrs);
 445                 if (dma_mapping_error(dev, dma)) {
 446                         __xp_dma_unmap(dma_map, attrs);
 447                         return -ENOMEM;
 448                 }
 449                 if (dma_need_sync(dev, dma))
 450                         dma_map->dma_need_sync = true;
 451                 dma_map->dma_pages[i] = dma;
 452         }
 453
 454         if (pool->unaligned)
 455                 xp_check_dma_contiguity(dma_map);
 456
 457         err = xp_init_dma_info(pool, dma_map);
 458         if (err) {
 459                 __xp_dma_unmap(dma_map, attrs);
 460                 return err;
 461         }
 462
 463         return 0;
 464 }
 465 EXPORT_SYMBOL(xp_dma_map);
 466
 467 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
 468                                           u64 addr)
 469 {
 470         return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
 471 }
 472
 473 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
 474 {
 475         *addr = xp_unaligned_extract_addr(*addr);
 476         if (*addr >= pool->addrs_cnt ||
 477             *addr + pool->chunk_size > pool->addrs_cnt ||
 478             xp_addr_crosses_non_contig_pg(pool, *addr))
 479                 return false;
 480         return true;
 481 }
 482
 483 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
 484 {
 485         *addr = xp_aligned_extract_addr(pool, *addr);
 486         return *addr < pool->addrs_cnt;
 487 }
 488
 489 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
 490 {
 491         struct xdp_buff_xsk *xskb;
 492         u64 addr;
 493         bool ok;
 494
 495         if (pool->free_heads_cnt == 0)
 496                 return NULL;
 497
 498         for (;;) {
 499                 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
 500                         pool->fq->queue_empty_descs++;
 501                         return NULL;
 502                 }
 503
 504                 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
 505                      xp_check_aligned(pool, &addr);
 506                 if (!ok) {
 507                         pool->fq->invalid_descs++;
 508                         xskq_cons_release(pool->fq);
 509                         continue;
 510                 }
 511                 break;
 512         }
 513
 514         if (pool->unaligned) {
 515                 xskb = pool->free_heads[--pool->free_heads_cnt];
 516                 xp_init_xskb_addr(xskb, pool, addr);
 517                 if (pool->dma_pages)
 518                         xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
 519         } else {
 520                 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
 521         }
 522
 523         xskq_cons_release(pool->fq);
 524         return xskb;
 525 }
 526
 527 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
 528 {
 529         struct xdp_buff_xsk *xskb;
 530
 531         if (!pool->free_list_cnt) {
 532                 xskb = __xp_alloc(pool);
 533                 if (!xskb)
 534                         return NULL;
 535         } else {
 536                 pool->free_list_cnt--;
 537                 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
 538                                         free_list_node);
 539                 list_del_init(&xskb->free_list_node);
 540         }
 541
 542         xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
 543         xskb->xdp.data_meta = xskb->xdp.data;
 544         xskb->xdp.flags = 0;
 545
 546         if (pool->dma_need_sync) {
 547                 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
 548                                                  pool->frame_len,
 549                                                  DMA_BIDIRECTIONAL);
 550         }
 551         return &xskb->xdp;
 552 }
 553 EXPORT_SYMBOL(xp_alloc);
 554
 555 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 556 {
 557         u32 i, cached_cons, nb_entries;
 558
 559         if (max > pool->free_heads_cnt)
 560                 max = pool->free_heads_cnt;
 561         max = xskq_cons_nb_entries(pool->fq, max);
 562
 563         cached_cons = pool->fq->cached_cons;
 564         nb_entries = max;
 565         i = max;
 566         while (i--) {
 567                 struct xdp_buff_xsk *xskb;
 568                 u64 addr;
 569                 bool ok;
 570
 571                 __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
 572
 573                 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
 574                         xp_check_aligned(pool, &addr);
 575                 if (unlikely(!ok)) {
 576                         pool->fq->invalid_descs++;
 577                         nb_entries--;
 578                         continue;
 579                 }
 580
 581                 if (pool->unaligned) {
 582                         xskb = pool->free_heads[--pool->free_heads_cnt];
 583                         xp_init_xskb_addr(xskb, pool, addr);
 584                         if (pool->dma_pages)
 585                                 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
 586                 } else {
 587                         xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
 588                 }
 589
 590                 *xdp = &xskb->xdp;
 591                 xdp++;
 592         }
 593
 594         xskq_cons_release_n(pool->fq, max);
 595         return nb_entries;
 596 }
 597
 598 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
 599 {
 600         struct xdp_buff_xsk *xskb;
 601         u32 i;
 602
 603         nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
 604
 605         i = nb_entries;
 606         while (i--) {
 607                 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node);
 608                 list_del_init(&xskb->free_list_node);
 609
 610                 *xdp = &xskb->xdp;
 611                 xdp++;
 612         }
 613         pool->free_list_cnt -= nb_entries;
 614
 615         return nb_entries;
 616 }
 617
 618 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 619 {
 620         u32 nb_entries1 = 0, nb_entries2;
 621
 622         if (unlikely(pool->dma_need_sync)) {
 623                 struct xdp_buff *buff;
 624
 625                 /* Slow path */
 626                 buff = xp_alloc(pool);
 627                 if (buff)
 628                         *xdp = buff;
 629                 return !!buff;
 630         }
 631
 632         if (unlikely(pool->free_list_cnt)) {
 633                 nb_entries1 = xp_alloc_reused(pool, xdp, max);
 634                 if (nb_entries1 == max)
 635                         return nb_entries1;
 636
 637                 max -= nb_entries1;
 638                 xdp += nb_entries1;
 639         }
 640
 641         nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
 642         if (!nb_entries2)
 643                 pool->fq->queue_empty_descs++;
 644
 645         return nb_entries1 + nb_entries2;
 646 }
 647 EXPORT_SYMBOL(xp_alloc_batch);
 648
 649 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
 650 {
 651         if (pool->free_list_cnt >= count)
 652                 return true;
 653         return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
 654 }
 655 EXPORT_SYMBOL(xp_can_alloc);
 656
 657 void xp_free(struct xdp_buff_xsk *xskb)
 658 {
 659         if (!list_empty(&xskb->free_list_node))
 660                 return;
 661
 662         xskb->pool->free_list_cnt++;
 663         list_add(&xskb->free_list_node, &xskb->pool->free_list);
 664 }
 665 EXPORT_SYMBOL(xp_free);
 666
 667 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
 668 {
 669         addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
 670         return pool->addrs + addr;
 671 }
 672 EXPORT_SYMBOL(xp_raw_get_data);
 673
 674 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
 675 {
 676         addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
 677         return (pool->dma_pages[addr >> PAGE_SHIFT] &
 678                 ~XSK_NEXT_PG_CONTIG_MASK) +
 679                 (addr & ~PAGE_MASK);
 680 }
 681 EXPORT_SYMBOL(xp_raw_get_dma);
 682
 683 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
 684 {
 685         dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
 686                                       xskb->pool->frame_len, DMA_BIDIRECTIONAL);
 687 }
 688 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
 689
 690 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
 691                                  size_t size)
 692 {
 693         dma_sync_single_range_for_device(pool->dev, dma, 0,
 694                                          size, DMA_BIDIRECTIONAL);
 695 }
 696 EXPORT_SYMBOL(xp_dma_sync_for_device_slow);