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         pool->tx_metadata_len = umem->tx_metadata_len;
  89         pool->tx_sw_csum = umem->flags & XDP_UMEM_TX_SW_CSUM;
  90         INIT_LIST_HEAD(&pool->free_list);
  91         INIT_LIST_HEAD(&pool->xskb_list);
  92         INIT_LIST_HEAD(&pool->xsk_tx_list);
  93         spin_lock_init(&pool->xsk_tx_list_lock);
  94         spin_lock_init(&pool->cq_lock);
  95         refcount_set(&pool->users, 1);
  96
  97         pool->fq = xs->fq_tmp;
  98         pool->cq = xs->cq_tmp;
  99
 100         for (i = 0; i < pool->free_heads_cnt; i++) {
 101                 xskb = &pool->heads[i];
 102                 xskb->pool = pool;
 103                 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom;
 104                 INIT_LIST_HEAD(&xskb->free_list_node);
 105                 INIT_LIST_HEAD(&xskb->xskb_list_node);
 106                 if (pool->unaligned)
 107                         pool->free_heads[i] = xskb;
 108                 else
 109                         xp_init_xskb_addr(xskb, pool, i * pool->chunk_size);
 110         }
 111
 112         return pool;
 113
 114 out:
 115         xp_destroy(pool);
 116         return NULL;
 117 }
 118
 119 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq)
 120 {
 121         u32 i;
 122
 123         for (i = 0; i < pool->heads_cnt; i++)
 124                 pool->heads[i].xdp.rxq = rxq;
 125 }
 126 EXPORT_SYMBOL(xp_set_rxq_info);
 127
 128 void xp_fill_cb(struct xsk_buff_pool *pool, struct xsk_cb_desc *desc)
 129 {
 130         u32 i;
 131
 132         for (i = 0; i < pool->heads_cnt; i++) {
 133                 struct xdp_buff_xsk *xskb = &pool->heads[i];
 134
 135                 memcpy(xskb->cb + desc->off, desc->src, desc->bytes);
 136         }
 137 }
 138 EXPORT_SYMBOL(xp_fill_cb);
 139
 140 static void xp_disable_drv_zc(struct xsk_buff_pool *pool)
 141 {
 142         struct netdev_bpf bpf;
 143         int err;
 144
 145         ASSERT_RTNL();
 146
 147         if (pool->umem->zc) {
 148                 bpf.command = XDP_SETUP_XSK_POOL;
 149                 bpf.xsk.pool = NULL;
 150                 bpf.xsk.queue_id = pool->queue_id;
 151
 152                 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf);
 153
 154                 if (err)
 155                         WARN(1, "Failed to disable zero-copy!\n");
 156         }
 157 }
 158
 159 #define NETDEV_XDP_ACT_ZC       (NETDEV_XDP_ACT_BASIC |         \
 160                                  NETDEV_XDP_ACT_REDIRECT |      \
 161                                  NETDEV_XDP_ACT_XSK_ZEROCOPY)
 162
 163 int xp_assign_dev(struct xsk_buff_pool *pool,
 164                   struct net_device *netdev, u16 queue_id, u16 flags)
 165 {
 166         bool force_zc, force_copy;
 167         struct netdev_bpf bpf;
 168         int err = 0;
 169
 170         ASSERT_RTNL();
 171
 172         force_zc = flags & XDP_ZEROCOPY;
 173         force_copy = flags & XDP_COPY;
 174
 175         if (force_zc && force_copy)
 176                 return -EINVAL;
 177
 178         if (xsk_get_pool_from_qid(netdev, queue_id))
 179                 return -EBUSY;
 180
 181         pool->netdev = netdev;
 182         pool->queue_id = queue_id;
 183         err = xsk_reg_pool_at_qid(netdev, pool, queue_id);
 184         if (err)
 185                 return err;
 186
 187         if (flags & XDP_USE_SG)
 188                 pool->umem->flags |= XDP_UMEM_SG_FLAG;
 189
 190         if (flags & XDP_USE_NEED_WAKEUP)
 191                 pool->uses_need_wakeup = true;
 192         /* Tx needs to be explicitly woken up the first time.  Also
 193          * for supporting drivers that do not implement this
 194          * feature. They will always have to call sendto() or poll().
 195          */
 196         pool->cached_need_wakeup = XDP_WAKEUP_TX;
 197
 198         dev_hold(netdev);
 199
 200         if (force_copy)
 201                 /* For copy-mode, we are done. */
 202                 return 0;
 203
 204         if ((netdev->xdp_features & NETDEV_XDP_ACT_ZC) != NETDEV_XDP_ACT_ZC) {
 205                 err = -EOPNOTSUPP;
 206                 goto err_unreg_pool;
 207         }
 208
 209         if (netdev->xdp_zc_max_segs == 1 && (flags & XDP_USE_SG)) {
 210                 err = -EOPNOTSUPP;
 211                 goto err_unreg_pool;
 212         }
 213
 214         bpf.command = XDP_SETUP_XSK_POOL;
 215         bpf.xsk.pool = pool;
 216         bpf.xsk.queue_id = queue_id;
 217
 218         err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
 219         if (err)
 220                 goto err_unreg_pool;
 221
 222         if (!pool->dma_pages) {
 223                 WARN(1, "Driver did not DMA map zero-copy buffers");
 224                 err = -EINVAL;
 225                 goto err_unreg_xsk;
 226         }
 227         pool->umem->zc = true;
 228         return 0;
 229
 230 err_unreg_xsk:
 231         xp_disable_drv_zc(pool);
 232 err_unreg_pool:
 233         if (!force_zc)
 234                 err = 0; /* fallback to copy mode */
 235         if (err) {
 236                 xsk_clear_pool_at_qid(netdev, queue_id);
 237                 dev_put(netdev);
 238         }
 239         return err;
 240 }
 241
 242 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
 243                          struct net_device *dev, u16 queue_id)
 244 {
 245         u16 flags;
 246         struct xdp_umem *umem = umem_xs->umem;
 247
 248         /* One fill and completion ring required for each queue id. */
 249         if (!pool->fq || !pool->cq)
 250                 return -EINVAL;
 251
 252         flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
 253         if (umem_xs->pool->uses_need_wakeup)
 254                 flags |= XDP_USE_NEED_WAKEUP;
 255
 256         return xp_assign_dev(pool, dev, queue_id, flags);
 257 }
 258
 259 void xp_clear_dev(struct xsk_buff_pool *pool)
 260 {
 261         if (!pool->netdev)
 262                 return;
 263
 264         xp_disable_drv_zc(pool);
 265         xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
 266         dev_put(pool->netdev);
 267         pool->netdev = NULL;
 268 }
 269
 270 static void xp_release_deferred(struct work_struct *work)
 271 {
 272         struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
 273                                                   work);
 274
 275         rtnl_lock();
 276         xp_clear_dev(pool);
 277         rtnl_unlock();
 278
 279         if (pool->fq) {
 280                 xskq_destroy(pool->fq);
 281                 pool->fq = NULL;
 282         }
 283
 284         if (pool->cq) {
 285                 xskq_destroy(pool->cq);
 286                 pool->cq = NULL;
 287         }
 288
 289         xdp_put_umem(pool->umem, false);
 290         xp_destroy(pool);
 291 }
 292
 293 void xp_get_pool(struct xsk_buff_pool *pool)
 294 {
 295         refcount_inc(&pool->users);
 296 }
 297
 298 bool xp_put_pool(struct xsk_buff_pool *pool)
 299 {
 300         if (!pool)
 301                 return false;
 302
 303         if (refcount_dec_and_test(&pool->users)) {
 304                 INIT_WORK(&pool->work, xp_release_deferred);
 305                 schedule_work(&pool->work);
 306                 return true;
 307         }
 308
 309         return false;
 310 }
 311
 312 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
 313 {
 314         struct xsk_dma_map *dma_map;
 315
 316         list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
 317                 if (dma_map->netdev == pool->netdev)
 318                         return dma_map;
 319         }
 320
 321         return NULL;
 322 }
 323
 324 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
 325                                              u32 nr_pages, struct xdp_umem *umem)
 326 {
 327         struct xsk_dma_map *dma_map;
 328
 329         dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
 330         if (!dma_map)
 331                 return NULL;
 332
 333         dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
 334         if (!dma_map->dma_pages) {
 335                 kfree(dma_map);
 336                 return NULL;
 337         }
 338
 339         dma_map->netdev = netdev;
 340         dma_map->dev = dev;
 341         dma_map->dma_need_sync = false;
 342         dma_map->dma_pages_cnt = nr_pages;
 343         refcount_set(&dma_map->users, 1);
 344         list_add(&dma_map->list, &umem->xsk_dma_list);
 345         return dma_map;
 346 }
 347
 348 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
 349 {
 350         list_del(&dma_map->list);
 351         kvfree(dma_map->dma_pages);
 352         kfree(dma_map);
 353 }
 354
 355 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
 356 {
 357         dma_addr_t *dma;
 358         u32 i;
 359
 360         for (i = 0; i < dma_map->dma_pages_cnt; i++) {
 361                 dma = &dma_map->dma_pages[i];
 362                 if (*dma) {
 363                         *dma &= ~XSK_NEXT_PG_CONTIG_MASK;
 364                         dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
 365                                              DMA_BIDIRECTIONAL, attrs);
 366                         *dma = 0;
 367                 }
 368         }
 369
 370         xp_destroy_dma_map(dma_map);
 371 }
 372
 373 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
 374 {
 375         struct xsk_dma_map *dma_map;
 376
 377         if (!pool->dma_pages)
 378                 return;
 379
 380         dma_map = xp_find_dma_map(pool);
 381         if (!dma_map) {
 382                 WARN(1, "Could not find dma_map for device");
 383                 return;
 384         }
 385
 386         if (!refcount_dec_and_test(&dma_map->users))
 387                 return;
 388
 389         __xp_dma_unmap(dma_map, attrs);
 390         kvfree(pool->dma_pages);
 391         pool->dma_pages = NULL;
 392         pool->dma_pages_cnt = 0;
 393         pool->dev = NULL;
 394 }
 395 EXPORT_SYMBOL(xp_dma_unmap);
 396
 397 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
 398 {
 399         u32 i;
 400
 401         for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
 402                 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
 403                         dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
 404                 else
 405                         dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
 406         }
 407 }
 408
 409 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
 410 {
 411         if (!pool->unaligned) {
 412                 u32 i;
 413
 414                 for (i = 0; i < pool->heads_cnt; i++) {
 415                         struct xdp_buff_xsk *xskb = &pool->heads[i];
 416
 417                         xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
 418                 }
 419         }
 420
 421         pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
 422         if (!pool->dma_pages)
 423                 return -ENOMEM;
 424
 425         pool->dev = dma_map->dev;
 426         pool->dma_pages_cnt = dma_map->dma_pages_cnt;
 427         pool->dma_need_sync = dma_map->dma_need_sync;
 428         memcpy(pool->dma_pages, dma_map->dma_pages,
 429                pool->dma_pages_cnt * sizeof(*pool->dma_pages));
 430
 431         return 0;
 432 }
 433
 434 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
 435                unsigned long attrs, struct page **pages, u32 nr_pages)
 436 {
 437         struct xsk_dma_map *dma_map;
 438         dma_addr_t dma;
 439         int err;
 440         u32 i;
 441
 442         dma_map = xp_find_dma_map(pool);
 443         if (dma_map) {
 444                 err = xp_init_dma_info(pool, dma_map);
 445                 if (err)
 446                         return err;
 447
 448                 refcount_inc(&dma_map->users);
 449                 return 0;
 450         }
 451
 452         dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
 453         if (!dma_map)
 454                 return -ENOMEM;
 455
 456         for (i = 0; i < dma_map->dma_pages_cnt; i++) {
 457                 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
 458                                          DMA_BIDIRECTIONAL, attrs);
 459                 if (dma_mapping_error(dev, dma)) {
 460                         __xp_dma_unmap(dma_map, attrs);
 461                         return -ENOMEM;
 462                 }
 463                 if (dma_need_sync(dev, dma))
 464                         dma_map->dma_need_sync = true;
 465                 dma_map->dma_pages[i] = dma;
 466         }
 467
 468         if (pool->unaligned)
 469                 xp_check_dma_contiguity(dma_map);
 470
 471         err = xp_init_dma_info(pool, dma_map);
 472         if (err) {
 473                 __xp_dma_unmap(dma_map, attrs);
 474                 return err;
 475         }
 476
 477         return 0;
 478 }
 479 EXPORT_SYMBOL(xp_dma_map);
 480
 481 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
 482                                           u64 addr)
 483 {
 484         return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
 485 }
 486
 487 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
 488 {
 489         *addr = xp_unaligned_extract_addr(*addr);
 490         if (*addr >= pool->addrs_cnt ||
 491             *addr + pool->chunk_size > pool->addrs_cnt ||
 492             xp_addr_crosses_non_contig_pg(pool, *addr))
 493                 return false;
 494         return true;
 495 }
 496
 497 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
 498 {
 499         *addr = xp_aligned_extract_addr(pool, *addr);
 500         return *addr < pool->addrs_cnt;
 501 }
 502
 503 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
 504 {
 505         struct xdp_buff_xsk *xskb;
 506         u64 addr;
 507         bool ok;
 508
 509         if (pool->free_heads_cnt == 0)
 510                 return NULL;
 511
 512         for (;;) {
 513                 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
 514                         pool->fq->queue_empty_descs++;
 515                         return NULL;
 516                 }
 517
 518                 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
 519                      xp_check_aligned(pool, &addr);
 520                 if (!ok) {
 521                         pool->fq->invalid_descs++;
 522                         xskq_cons_release(pool->fq);
 523                         continue;
 524                 }
 525                 break;
 526         }
 527
 528         if (pool->unaligned) {
 529                 xskb = pool->free_heads[--pool->free_heads_cnt];
 530                 xp_init_xskb_addr(xskb, pool, addr);
 531                 if (pool->dma_pages)
 532                         xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
 533         } else {
 534                 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
 535         }
 536
 537         xskq_cons_release(pool->fq);
 538         return xskb;
 539 }
 540
 541 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
 542 {
 543         struct xdp_buff_xsk *xskb;
 544
 545         if (!pool->free_list_cnt) {
 546                 xskb = __xp_alloc(pool);
 547                 if (!xskb)
 548                         return NULL;
 549         } else {
 550                 pool->free_list_cnt--;
 551                 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
 552                                         free_list_node);
 553                 list_del_init(&xskb->free_list_node);
 554         }
 555
 556         xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
 557         xskb->xdp.data_meta = xskb->xdp.data;
 558         xskb->xdp.flags = 0;
 559
 560         if (pool->dma_need_sync) {
 561                 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0,
 562                                                  pool->frame_len,
 563                                                  DMA_BIDIRECTIONAL);
 564         }
 565         return &xskb->xdp;
 566 }
 567 EXPORT_SYMBOL(xp_alloc);
 568
 569 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 570 {
 571         u32 i, cached_cons, nb_entries;
 572
 573         if (max > pool->free_heads_cnt)
 574                 max = pool->free_heads_cnt;
 575         max = xskq_cons_nb_entries(pool->fq, max);
 576
 577         cached_cons = pool->fq->cached_cons;
 578         nb_entries = max;
 579         i = max;
 580         while (i--) {
 581                 struct xdp_buff_xsk *xskb;
 582                 u64 addr;
 583                 bool ok;
 584
 585                 __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
 586
 587                 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
 588                         xp_check_aligned(pool, &addr);
 589                 if (unlikely(!ok)) {
 590                         pool->fq->invalid_descs++;
 591                         nb_entries--;
 592                         continue;
 593                 }
 594
 595                 if (pool->unaligned) {
 596                         xskb = pool->free_heads[--pool->free_heads_cnt];
 597                         xp_init_xskb_addr(xskb, pool, addr);
 598                         if (pool->dma_pages)
 599                                 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
 600                 } else {
 601                         xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
 602                 }
 603
 604                 *xdp = &xskb->xdp;
 605                 xdp++;
 606         }
 607
 608         xskq_cons_release_n(pool->fq, max);
 609         return nb_entries;
 610 }
 611
 612 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
 613 {
 614         struct xdp_buff_xsk *xskb;
 615         u32 i;
 616
 617         nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
 618
 619         i = nb_entries;
 620         while (i--) {
 621                 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node);
 622                 list_del_init(&xskb->free_list_node);
 623
 624                 *xdp = &xskb->xdp;
 625                 xdp++;
 626         }
 627         pool->free_list_cnt -= nb_entries;
 628
 629         return nb_entries;
 630 }
 631
 632 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 633 {
 634         u32 nb_entries1 = 0, nb_entries2;
 635
 636         if (unlikely(pool->dma_need_sync)) {
 637                 struct xdp_buff *buff;
 638
 639                 /* Slow path */
 640                 buff = xp_alloc(pool);
 641                 if (buff)
 642                         *xdp = buff;
 643                 return !!buff;
 644         }
 645
 646         if (unlikely(pool->free_list_cnt)) {
 647                 nb_entries1 = xp_alloc_reused(pool, xdp, max);
 648                 if (nb_entries1 == max)
 649                         return nb_entries1;
 650
 651                 max -= nb_entries1;
 652                 xdp += nb_entries1;
 653         }
 654
 655         nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
 656         if (!nb_entries2)
 657                 pool->fq->queue_empty_descs++;
 658
 659         return nb_entries1 + nb_entries2;
 660 }
 661 EXPORT_SYMBOL(xp_alloc_batch);
 662
 663 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
 664 {
 665         if (pool->free_list_cnt >= count)
 666                 return true;
 667         return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt);
 668 }
 669 EXPORT_SYMBOL(xp_can_alloc);
 670
 671 void xp_free(struct xdp_buff_xsk *xskb)
 672 {
 673         if (!list_empty(&xskb->free_list_node))
 674                 return;
 675
 676         xskb->pool->free_list_cnt++;
 677         list_add(&xskb->free_list_node, &xskb->pool->free_list);
 678 }
 679 EXPORT_SYMBOL(xp_free);
 680
 681 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
 682 {
 683         addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
 684         return pool->addrs + addr;
 685 }
 686 EXPORT_SYMBOL(xp_raw_get_data);
 687
 688 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
 689 {
 690         addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
 691         return (pool->dma_pages[addr >> PAGE_SHIFT] &
 692                 ~XSK_NEXT_PG_CONTIG_MASK) +
 693                 (addr & ~PAGE_MASK);
 694 }
 695 EXPORT_SYMBOL(xp_raw_get_dma);
 696
 697 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb)
 698 {
 699         dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0,
 700                                       xskb->pool->frame_len, DMA_BIDIRECTIONAL);
 701 }
 702 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow);
 703
 704 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma,
 705                                  size_t size)
 706 {
 707         dma_sync_single_range_for_device(pool->dev, dma, 0,
 708                                          size, DMA_BIDIRECTIONAL);
 709 }
 710 EXPORT_SYMBOL(xp_dma_sync_for_device_slow);