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         if (dev_get_min_mp_channel_count(netdev)) {
 215                 err = -EBUSY;
 216                 goto err_unreg_pool;
 217         }
 218
 219         bpf.command = XDP_SETUP_XSK_POOL;
 220         bpf.xsk.pool = pool;
 221         bpf.xsk.queue_id = queue_id;
 222
 223         err = netdev->netdev_ops->ndo_bpf(netdev, &bpf);
 224         if (err)
 225                 goto err_unreg_pool;
 226
 227         if (!pool->dma_pages) {
 228                 WARN(1, "Driver did not DMA map zero-copy buffers");
 229                 err = -EINVAL;
 230                 goto err_unreg_xsk;
 231         }
 232         pool->umem->zc = true;
 233         return 0;
 234
 235 err_unreg_xsk:
 236         xp_disable_drv_zc(pool);
 237 err_unreg_pool:
 238         if (!force_zc)
 239                 err = 0; /* fallback to copy mode */
 240         if (err) {
 241                 xsk_clear_pool_at_qid(netdev, queue_id);
 242                 dev_put(netdev);
 243         }
 244         return err;
 245 }
 246
 247 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs,
 248                          struct net_device *dev, u16 queue_id)
 249 {
 250         u16 flags;
 251         struct xdp_umem *umem = umem_xs->umem;
 252
 253         /* One fill and completion ring required for each queue id. */
 254         if (!pool->fq || !pool->cq)
 255                 return -EINVAL;
 256
 257         flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY;
 258         if (umem_xs->pool->uses_need_wakeup)
 259                 flags |= XDP_USE_NEED_WAKEUP;
 260
 261         return xp_assign_dev(pool, dev, queue_id, flags);
 262 }
 263
 264 void xp_clear_dev(struct xsk_buff_pool *pool)
 265 {
 266         if (!pool->netdev)
 267                 return;
 268
 269         xp_disable_drv_zc(pool);
 270         xsk_clear_pool_at_qid(pool->netdev, pool->queue_id);
 271         dev_put(pool->netdev);
 272         pool->netdev = NULL;
 273 }
 274
 275 static void xp_release_deferred(struct work_struct *work)
 276 {
 277         struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool,
 278                                                   work);
 279
 280         rtnl_lock();
 281         xp_clear_dev(pool);
 282         rtnl_unlock();
 283
 284         if (pool->fq) {
 285                 xskq_destroy(pool->fq);
 286                 pool->fq = NULL;
 287         }
 288
 289         if (pool->cq) {
 290                 xskq_destroy(pool->cq);
 291                 pool->cq = NULL;
 292         }
 293
 294         xdp_put_umem(pool->umem, false);
 295         xp_destroy(pool);
 296 }
 297
 298 void xp_get_pool(struct xsk_buff_pool *pool)
 299 {
 300         refcount_inc(&pool->users);
 301 }
 302
 303 bool xp_put_pool(struct xsk_buff_pool *pool)
 304 {
 305         if (!pool)
 306                 return false;
 307
 308         if (refcount_dec_and_test(&pool->users)) {
 309                 INIT_WORK(&pool->work, xp_release_deferred);
 310                 schedule_work(&pool->work);
 311                 return true;
 312         }
 313
 314         return false;
 315 }
 316
 317 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool)
 318 {
 319         struct xsk_dma_map *dma_map;
 320
 321         list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) {
 322                 if (dma_map->netdev == pool->netdev)
 323                         return dma_map;
 324         }
 325
 326         return NULL;
 327 }
 328
 329 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev,
 330                                              u32 nr_pages, struct xdp_umem *umem)
 331 {
 332         struct xsk_dma_map *dma_map;
 333
 334         dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL);
 335         if (!dma_map)
 336                 return NULL;
 337
 338         dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
 339         if (!dma_map->dma_pages) {
 340                 kfree(dma_map);
 341                 return NULL;
 342         }
 343
 344         dma_map->netdev = netdev;
 345         dma_map->dev = dev;
 346         dma_map->dma_pages_cnt = nr_pages;
 347         refcount_set(&dma_map->users, 1);
 348         list_add(&dma_map->list, &umem->xsk_dma_list);
 349         return dma_map;
 350 }
 351
 352 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map)
 353 {
 354         list_del(&dma_map->list);
 355         kvfree(dma_map->dma_pages);
 356         kfree(dma_map);
 357 }
 358
 359 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs)
 360 {
 361         dma_addr_t *dma;
 362         u32 i;
 363
 364         for (i = 0; i < dma_map->dma_pages_cnt; i++) {
 365                 dma = &dma_map->dma_pages[i];
 366                 if (*dma) {
 367                         *dma &= ~XSK_NEXT_PG_CONTIG_MASK;
 368                         dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE,
 369                                              DMA_BIDIRECTIONAL, attrs);
 370                         *dma = 0;
 371                 }
 372         }
 373
 374         xp_destroy_dma_map(dma_map);
 375 }
 376
 377 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs)
 378 {
 379         struct xsk_dma_map *dma_map;
 380
 381         if (!pool->dma_pages)
 382                 return;
 383
 384         dma_map = xp_find_dma_map(pool);
 385         if (!dma_map) {
 386                 WARN(1, "Could not find dma_map for device");
 387                 return;
 388         }
 389
 390         if (!refcount_dec_and_test(&dma_map->users))
 391                 return;
 392
 393         __xp_dma_unmap(dma_map, attrs);
 394         kvfree(pool->dma_pages);
 395         pool->dma_pages = NULL;
 396         pool->dma_pages_cnt = 0;
 397         pool->dev = NULL;
 398 }
 399 EXPORT_SYMBOL(xp_dma_unmap);
 400
 401 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map)
 402 {
 403         u32 i;
 404
 405         for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) {
 406                 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1])
 407                         dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK;
 408                 else
 409                         dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK;
 410         }
 411 }
 412
 413 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map)
 414 {
 415         if (!pool->unaligned) {
 416                 u32 i;
 417
 418                 for (i = 0; i < pool->heads_cnt; i++) {
 419                         struct xdp_buff_xsk *xskb = &pool->heads[i];
 420
 421                         xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr);
 422                 }
 423         }
 424
 425         pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL);
 426         if (!pool->dma_pages)
 427                 return -ENOMEM;
 428
 429         pool->dev = dma_map->dev;
 430         pool->dma_pages_cnt = dma_map->dma_pages_cnt;
 431         memcpy(pool->dma_pages, dma_map->dma_pages,
 432                pool->dma_pages_cnt * sizeof(*pool->dma_pages));
 433
 434         return 0;
 435 }
 436
 437 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev,
 438                unsigned long attrs, struct page **pages, u32 nr_pages)
 439 {
 440         struct xsk_dma_map *dma_map;
 441         dma_addr_t dma;
 442         int err;
 443         u32 i;
 444
 445         dma_map = xp_find_dma_map(pool);
 446         if (dma_map) {
 447                 err = xp_init_dma_info(pool, dma_map);
 448                 if (err)
 449                         return err;
 450
 451                 refcount_inc(&dma_map->users);
 452                 return 0;
 453         }
 454
 455         dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem);
 456         if (!dma_map)
 457                 return -ENOMEM;
 458
 459         for (i = 0; i < dma_map->dma_pages_cnt; i++) {
 460                 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE,
 461                                          DMA_BIDIRECTIONAL, attrs);
 462                 if (dma_mapping_error(dev, dma)) {
 463                         __xp_dma_unmap(dma_map, attrs);
 464                         return -ENOMEM;
 465                 }
 466                 dma_map->dma_pages[i] = dma;
 467         }
 468
 469         if (pool->unaligned)
 470                 xp_check_dma_contiguity(dma_map);
 471
 472         err = xp_init_dma_info(pool, dma_map);
 473         if (err) {
 474                 __xp_dma_unmap(dma_map, attrs);
 475                 return err;
 476         }
 477
 478         return 0;
 479 }
 480 EXPORT_SYMBOL(xp_dma_map);
 481
 482 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool,
 483                                           u64 addr)
 484 {
 485         return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size);
 486 }
 487
 488 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr)
 489 {
 490         *addr = xp_unaligned_extract_addr(*addr);
 491         if (*addr >= pool->addrs_cnt ||
 492             *addr + pool->chunk_size > pool->addrs_cnt ||
 493             xp_addr_crosses_non_contig_pg(pool, *addr))
 494                 return false;
 495         return true;
 496 }
 497
 498 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr)
 499 {
 500         *addr = xp_aligned_extract_addr(pool, *addr);
 501         return *addr < pool->addrs_cnt;
 502 }
 503
 504 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool)
 505 {
 506         struct xdp_buff_xsk *xskb;
 507         u64 addr;
 508         bool ok;
 509
 510         if (pool->free_heads_cnt == 0)
 511                 return NULL;
 512
 513         for (;;) {
 514                 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) {
 515                         pool->fq->queue_empty_descs++;
 516                         return NULL;
 517                 }
 518
 519                 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
 520                      xp_check_aligned(pool, &addr);
 521                 if (!ok) {
 522                         pool->fq->invalid_descs++;
 523                         xskq_cons_release(pool->fq);
 524                         continue;
 525                 }
 526                 break;
 527         }
 528
 529         if (pool->unaligned) {
 530                 xskb = pool->free_heads[--pool->free_heads_cnt];
 531                 xp_init_xskb_addr(xskb, pool, addr);
 532                 if (pool->dma_pages)
 533                         xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
 534         } else {
 535                 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
 536         }
 537
 538         xskq_cons_release(pool->fq);
 539         return xskb;
 540 }
 541
 542 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool)
 543 {
 544         struct xdp_buff_xsk *xskb;
 545
 546         if (!pool->free_list_cnt) {
 547                 xskb = __xp_alloc(pool);
 548                 if (!xskb)
 549                         return NULL;
 550         } else {
 551                 pool->free_list_cnt--;
 552                 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk,
 553                                         free_list_node);
 554                 list_del_init(&xskb->free_list_node);
 555         }
 556
 557         xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM;
 558         xskb->xdp.data_meta = xskb->xdp.data;
 559         xskb->xdp.flags = 0;
 560
 561         if (pool->dev)
 562                 xp_dma_sync_for_device(pool, xskb->dma, pool->frame_len);
 563
 564         return &xskb->xdp;
 565 }
 566 EXPORT_SYMBOL(xp_alloc);
 567
 568 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 569 {
 570         u32 i, cached_cons, nb_entries;
 571
 572         if (max > pool->free_heads_cnt)
 573                 max = pool->free_heads_cnt;
 574         max = xskq_cons_nb_entries(pool->fq, max);
 575
 576         cached_cons = pool->fq->cached_cons;
 577         nb_entries = max;
 578         i = max;
 579         while (i--) {
 580                 struct xdp_buff_xsk *xskb;
 581                 u64 addr;
 582                 bool ok;
 583
 584                 __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr);
 585
 586                 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) :
 587                         xp_check_aligned(pool, &addr);
 588                 if (unlikely(!ok)) {
 589                         pool->fq->invalid_descs++;
 590                         nb_entries--;
 591                         continue;
 592                 }
 593
 594                 if (pool->unaligned) {
 595                         xskb = pool->free_heads[--pool->free_heads_cnt];
 596                         xp_init_xskb_addr(xskb, pool, addr);
 597                         if (pool->dma_pages)
 598                                 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr);
 599                 } else {
 600                         xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)];
 601                 }
 602
 603                 *xdp = &xskb->xdp;
 604                 xdp++;
 605         }
 606
 607         xskq_cons_release_n(pool->fq, max);
 608         return nb_entries;
 609 }
 610
 611 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries)
 612 {
 613         struct xdp_buff_xsk *xskb;
 614         u32 i;
 615
 616         nb_entries = min_t(u32, nb_entries, pool->free_list_cnt);
 617
 618         i = nb_entries;
 619         while (i--) {
 620                 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node);
 621                 list_del_init(&xskb->free_list_node);
 622
 623                 *xdp = &xskb->xdp;
 624                 xdp++;
 625         }
 626         pool->free_list_cnt -= nb_entries;
 627
 628         return nb_entries;
 629 }
 630
 631 static u32 xp_alloc_slow(struct xsk_buff_pool *pool, struct xdp_buff **xdp,
 632                          u32 max)
 633 {
 634         int i;
 635
 636         for (i = 0; i < max; i++) {
 637                 struct xdp_buff *buff;
 638
 639                 buff = xp_alloc(pool);
 640                 if (unlikely(!buff))
 641                         return i;
 642                 *xdp = buff;
 643                 xdp++;
 644         }
 645
 646         return max;
 647 }
 648
 649 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max)
 650 {
 651         u32 nb_entries1 = 0, nb_entries2;
 652
 653         if (unlikely(pool->dev && dma_dev_need_sync(pool->dev)))
 654                 return xp_alloc_slow(pool, xdp, max);
 655
 656         if (unlikely(pool->free_list_cnt)) {
 657                 nb_entries1 = xp_alloc_reused(pool, xdp, max);
 658                 if (nb_entries1 == max)
 659                         return nb_entries1;
 660
 661                 max -= nb_entries1;
 662                 xdp += nb_entries1;
 663         }
 664
 665         nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max);
 666         if (!nb_entries2)
 667                 pool->fq->queue_empty_descs++;
 668
 669         return nb_entries1 + nb_entries2;
 670 }
 671 EXPORT_SYMBOL(xp_alloc_batch);
 672
 673 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count)
 674 {
 675         u32 req_count, avail_count;
 676
 677         if (pool->free_list_cnt >= count)
 678                 return true;
 679
 680         req_count = count - pool->free_list_cnt;
 681         avail_count = xskq_cons_nb_entries(pool->fq, req_count);
 682         if (!avail_count)
 683                 pool->fq->queue_empty_descs++;
 684
 685         return avail_count >= req_count;
 686 }
 687 EXPORT_SYMBOL(xp_can_alloc);
 688
 689 void xp_free(struct xdp_buff_xsk *xskb)
 690 {
 691         if (!list_empty(&xskb->free_list_node))
 692                 return;
 693
 694         xskb->pool->free_list_cnt++;
 695         list_add(&xskb->free_list_node, &xskb->pool->free_list);
 696 }
 697 EXPORT_SYMBOL(xp_free);
 698
 699 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
 700 {
 701         addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
 702         return pool->addrs + addr;
 703 }
 704 EXPORT_SYMBOL(xp_raw_get_data);
 705
 706 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr)
 707 {
 708         addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr;
 709         return (pool->dma_pages[addr >> PAGE_SHIFT] &
 710                 ~XSK_NEXT_PG_CONTIG_MASK) +
 711                 (addr & ~PAGE_MASK);
 712 }
 713 EXPORT_SYMBOL(xp_raw_get_dma);