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); 711