1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <linux/netdevice.h> 4 #include <net/netdev_lock.h> 5 #include <net/xsk_buff_pool.h> 6 #include <net/xdp_sock.h> 7 #include <net/xdp_sock_drv.h> 8 9 #include "xsk_queue.h" 10 #include "xdp_umem.h" 11 #include "xsk.h" 12 13 void xp_add_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs) 14 { 15 unsigned long flags; 16 17 if (!xs->tx) 18 return; 19 20 spin_lock_irqsave(&pool->xsk_tx_list_lock, flags); 21 list_add_rcu(&xs->tx_list, &pool->xsk_tx_list); 22 spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags); 23 } 24 25 void xp_del_xsk(struct xsk_buff_pool *pool, struct xdp_sock *xs) 26 { 27 unsigned long flags; 28 29 if (!xs->tx) 30 return; 31 32 spin_lock_irqsave(&pool->xsk_tx_list_lock, flags); 33 list_del_rcu(&xs->tx_list); 34 spin_unlock_irqrestore(&pool->xsk_tx_list_lock, flags); 35 } 36 37 void xp_destroy(struct xsk_buff_pool *pool) 38 { 39 if (!pool) 40 return; 41 42 kvfree(pool->tx_descs); 43 kvfree(pool->heads); 44 kvfree(pool); 45 } 46 47 int xp_alloc_tx_descs(struct xsk_buff_pool *pool, struct xdp_sock *xs) 48 { 49 pool->tx_descs = kvcalloc(xs->tx->nentries, sizeof(*pool->tx_descs), 50 GFP_KERNEL); 51 if (!pool->tx_descs) 52 return -ENOMEM; 53 54 return 0; 55 } 56 57 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, 58 struct xdp_umem *umem) 59 { 60 bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG; 61 struct xsk_buff_pool *pool; 62 struct xdp_buff_xsk *xskb; 63 u32 i, entries; 64 65 entries = unaligned ? umem->chunks : 0; 66 pool = kvzalloc(struct_size(pool, free_heads, entries), GFP_KERNEL); 67 if (!pool) 68 goto out; 69 70 pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL); 71 if (!pool->heads) 72 goto out; 73 74 if (xs->tx) 75 if (xp_alloc_tx_descs(pool, xs)) 76 goto out; 77 78 pool->chunk_mask = ~((u64)umem->chunk_size - 1); 79 pool->addrs_cnt = umem->size; 80 pool->heads_cnt = umem->chunks; 81 pool->free_heads_cnt = umem->chunks; 82 pool->headroom = umem->headroom; 83 pool->chunk_size = umem->chunk_size; 84 pool->chunk_shift = ffs(umem->chunk_size) - 1; 85 pool->unaligned = unaligned; 86 pool->frame_len = umem->chunk_size - umem->headroom - 87 XDP_PACKET_HEADROOM; 88 pool->umem = umem; 89 pool->addrs = umem->addrs; 90 pool->tx_metadata_len = umem->tx_metadata_len; 91 pool->tx_sw_csum = umem->flags & XDP_UMEM_TX_SW_CSUM; 92 INIT_LIST_HEAD(&pool->free_list); 93 INIT_LIST_HEAD(&pool->xskb_list); 94 INIT_LIST_HEAD(&pool->xsk_tx_list); 95 spin_lock_init(&pool->xsk_tx_list_lock); 96 spin_lock_init(&pool->cq_lock); 97 refcount_set(&pool->users, 1); 98 99 pool->fq = xs->fq_tmp; 100 pool->cq = xs->cq_tmp; 101 102 for (i = 0; i < pool->free_heads_cnt; i++) { 103 xskb = &pool->heads[i]; 104 xskb->pool = pool; 105 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom; 106 INIT_LIST_HEAD(&xskb->list_node); 107 if (pool->unaligned) 108 pool->free_heads[i] = xskb; 109 else 110 xp_init_xskb_addr(xskb, pool, i * pool->chunk_size); 111 } 112 113 return pool; 114 115 out: 116 xp_destroy(pool); 117 return NULL; 118 } 119 120 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq) 121 { 122 u32 i; 123 124 for (i = 0; i < pool->heads_cnt; i++) 125 pool->heads[i].xdp.rxq = rxq; 126 } 127 EXPORT_SYMBOL(xp_set_rxq_info); 128 129 void xp_fill_cb(struct xsk_buff_pool *pool, struct xsk_cb_desc *desc) 130 { 131 u32 i; 132 133 for (i = 0; i < pool->heads_cnt; i++) { 134 struct xdp_buff_xsk *xskb = &pool->heads[i]; 135 136 memcpy(xskb->cb + desc->off, desc->src, desc->bytes); 137 } 138 } 139 EXPORT_SYMBOL(xp_fill_cb); 140 141 static void xp_disable_drv_zc(struct xsk_buff_pool *pool) 142 { 143 struct netdev_bpf bpf; 144 int err; 145 146 ASSERT_RTNL(); 147 148 if (pool->umem->zc) { 149 bpf.command = XDP_SETUP_XSK_POOL; 150 bpf.xsk.pool = NULL; 151 bpf.xsk.queue_id = pool->queue_id; 152 153 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf); 154 155 if (err) 156 WARN(1, "Failed to disable zero-copy!\n"); 157 } 158 } 159 160 #define NETDEV_XDP_ACT_ZC (NETDEV_XDP_ACT_BASIC | \ 161 NETDEV_XDP_ACT_REDIRECT | \ 162 NETDEV_XDP_ACT_XSK_ZEROCOPY) 163 164 int xp_assign_dev(struct xsk_buff_pool *pool, 165 struct net_device *netdev, u16 queue_id, u16 flags) 166 { 167 bool force_zc, force_copy; 168 struct netdev_bpf bpf; 169 int err = 0; 170 171 ASSERT_RTNL(); 172 173 force_zc = flags & XDP_ZEROCOPY; 174 force_copy = flags & XDP_COPY; 175 176 if (force_zc && force_copy) 177 return -EINVAL; 178 179 if (xsk_get_pool_from_qid(netdev, queue_id)) 180 return -EBUSY; 181 182 pool->netdev = netdev; 183 pool->queue_id = queue_id; 184 err = xsk_reg_pool_at_qid(netdev, pool, queue_id); 185 if (err) 186 return err; 187 188 if (flags & XDP_USE_SG) 189 pool->umem->flags |= XDP_UMEM_SG_FLAG; 190 191 if (flags & XDP_USE_NEED_WAKEUP) 192 pool->uses_need_wakeup = true; 193 /* Tx needs to be explicitly woken up the first time. Also 194 * for supporting drivers that do not implement this 195 * feature. They will always have to call sendto() or poll(). 196 */ 197 pool->cached_need_wakeup = XDP_WAKEUP_TX; 198 199 dev_hold(netdev); 200 201 if (force_copy) 202 /* For copy-mode, we are done. */ 203 return 0; 204 205 if ((netdev->xdp_features & NETDEV_XDP_ACT_ZC) != NETDEV_XDP_ACT_ZC) { 206 err = -EOPNOTSUPP; 207 goto err_unreg_pool; 208 } 209 210 if (netdev->xdp_zc_max_segs == 1 && (flags & XDP_USE_SG)) { 211 err = -EOPNOTSUPP; 212 goto err_unreg_pool; 213 } 214 215 if (dev_get_min_mp_channel_count(netdev)) { 216 err = -EBUSY; 217 goto err_unreg_pool; 218 } 219 220 bpf.command = XDP_SETUP_XSK_POOL; 221 bpf.xsk.pool = pool; 222 bpf.xsk.queue_id = queue_id; 223 224 netdev_ops_assert_locked(netdev); 225 err = netdev->netdev_ops->ndo_bpf(netdev, &bpf); 226 if (err) 227 goto err_unreg_pool; 228 229 if (!pool->dma_pages) { 230 WARN(1, "Driver did not DMA map zero-copy buffers"); 231 err = -EINVAL; 232 goto err_unreg_xsk; 233 } 234 pool->umem->zc = true; 235 pool->xdp_zc_max_segs = netdev->xdp_zc_max_segs; 236 return 0; 237 238 err_unreg_xsk: 239 xp_disable_drv_zc(pool); 240 err_unreg_pool: 241 if (!force_zc) 242 err = 0; /* fallback to copy mode */ 243 if (err) { 244 xsk_clear_pool_at_qid(netdev, queue_id); 245 dev_put(netdev); 246 } 247 return err; 248 } 249 250 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_sock *umem_xs, 251 struct net_device *dev, u16 queue_id) 252 { 253 u16 flags; 254 struct xdp_umem *umem = umem_xs->umem; 255 256 /* One fill and completion ring required for each queue id. */ 257 if (!pool->fq || !pool->cq) 258 return -EINVAL; 259 260 flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY; 261 if (umem_xs->pool->uses_need_wakeup) 262 flags |= XDP_USE_NEED_WAKEUP; 263 264 return xp_assign_dev(pool, dev, queue_id, flags); 265 } 266 267 void xp_clear_dev(struct xsk_buff_pool *pool) 268 { 269 if (!pool->netdev) 270 return; 271 272 xp_disable_drv_zc(pool); 273 xsk_clear_pool_at_qid(pool->netdev, pool->queue_id); 274 dev_put(pool->netdev); 275 pool->netdev = NULL; 276 } 277 278 static void xp_release_deferred(struct work_struct *work) 279 { 280 struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool, 281 work); 282 283 rtnl_lock(); 284 xp_clear_dev(pool); 285 rtnl_unlock(); 286 287 if (pool->fq) { 288 xskq_destroy(pool->fq); 289 pool->fq = NULL; 290 } 291 292 if (pool->cq) { 293 xskq_destroy(pool->cq); 294 pool->cq = NULL; 295 } 296 297 xdp_put_umem(pool->umem, false); 298 xp_destroy(pool); 299 } 300 301 void xp_get_pool(struct xsk_buff_pool *pool) 302 { 303 refcount_inc(&pool->users); 304 } 305 306 bool xp_put_pool(struct xsk_buff_pool *pool) 307 { 308 if (!pool) 309 return false; 310 311 if (refcount_dec_and_test(&pool->users)) { 312 INIT_WORK(&pool->work, xp_release_deferred); 313 schedule_work(&pool->work); 314 return true; 315 } 316 317 return false; 318 } 319 320 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool) 321 { 322 struct xsk_dma_map *dma_map; 323 324 list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) { 325 if (dma_map->netdev == pool->netdev) 326 return dma_map; 327 } 328 329 return NULL; 330 } 331 332 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev, 333 u32 nr_pages, struct xdp_umem *umem) 334 { 335 struct xsk_dma_map *dma_map; 336 337 dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL); 338 if (!dma_map) 339 return NULL; 340 341 dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL); 342 if (!dma_map->dma_pages) { 343 kfree(dma_map); 344 return NULL; 345 } 346 347 dma_map->netdev = netdev; 348 dma_map->dev = dev; 349 dma_map->dma_pages_cnt = nr_pages; 350 refcount_set(&dma_map->users, 1); 351 list_add(&dma_map->list, &umem->xsk_dma_list); 352 return dma_map; 353 } 354 355 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map) 356 { 357 list_del(&dma_map->list); 358 kvfree(dma_map->dma_pages); 359 kfree(dma_map); 360 } 361 362 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs) 363 { 364 dma_addr_t *dma; 365 u32 i; 366 367 for (i = 0; i < dma_map->dma_pages_cnt; i++) { 368 dma = &dma_map->dma_pages[i]; 369 if (*dma) { 370 *dma &= ~XSK_NEXT_PG_CONTIG_MASK; 371 dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE, 372 DMA_BIDIRECTIONAL, attrs); 373 *dma = 0; 374 } 375 } 376 377 xp_destroy_dma_map(dma_map); 378 } 379 380 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs) 381 { 382 struct xsk_dma_map *dma_map; 383 384 if (!pool->dma_pages) 385 return; 386 387 dma_map = xp_find_dma_map(pool); 388 if (!dma_map) { 389 WARN(1, "Could not find dma_map for device"); 390 return; 391 } 392 393 if (refcount_dec_and_test(&dma_map->users)) 394 __xp_dma_unmap(dma_map, attrs); 395 396 kvfree(pool->dma_pages); 397 pool->dma_pages = NULL; 398 pool->dma_pages_cnt = 0; 399 pool->dev = NULL; 400 } 401 EXPORT_SYMBOL(xp_dma_unmap); 402 403 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map) 404 { 405 u32 i; 406 407 for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) { 408 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1]) 409 dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK; 410 else 411 dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK; 412 } 413 } 414 415 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map) 416 { 417 if (!pool->unaligned) { 418 u32 i; 419 420 for (i = 0; i < pool->heads_cnt; i++) { 421 struct xdp_buff_xsk *xskb = &pool->heads[i]; 422 u64 orig_addr; 423 424 orig_addr = xskb->xdp.data_hard_start - pool->addrs - pool->headroom; 425 xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, orig_addr); 426 } 427 } 428 429 pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL); 430 if (!pool->dma_pages) 431 return -ENOMEM; 432 433 pool->dev = dma_map->dev; 434 pool->dma_pages_cnt = dma_map->dma_pages_cnt; 435 memcpy(pool->dma_pages, dma_map->dma_pages, 436 pool->dma_pages_cnt * sizeof(*pool->dma_pages)); 437 438 return 0; 439 } 440 441 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev, 442 unsigned long attrs, struct page **pages, u32 nr_pages) 443 { 444 struct xsk_dma_map *dma_map; 445 dma_addr_t dma; 446 int err; 447 u32 i; 448 449 dma_map = xp_find_dma_map(pool); 450 if (dma_map) { 451 err = xp_init_dma_info(pool, dma_map); 452 if (err) 453 return err; 454 455 refcount_inc(&dma_map->users); 456 return 0; 457 } 458 459 dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem); 460 if (!dma_map) 461 return -ENOMEM; 462 463 for (i = 0; i < dma_map->dma_pages_cnt; i++) { 464 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE, 465 DMA_BIDIRECTIONAL, attrs); 466 if (dma_mapping_error(dev, dma)) { 467 __xp_dma_unmap(dma_map, attrs); 468 return -ENOMEM; 469 } 470 dma_map->dma_pages[i] = dma; 471 } 472 473 if (pool->unaligned) 474 xp_check_dma_contiguity(dma_map); 475 476 err = xp_init_dma_info(pool, dma_map); 477 if (err) { 478 __xp_dma_unmap(dma_map, attrs); 479 return err; 480 } 481 482 return 0; 483 } 484 EXPORT_SYMBOL(xp_dma_map); 485 486 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool, 487 u64 addr) 488 { 489 return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size); 490 } 491 492 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr) 493 { 494 *addr = xp_unaligned_extract_addr(*addr); 495 if (*addr >= pool->addrs_cnt || 496 *addr + pool->chunk_size > pool->addrs_cnt || 497 xp_addr_crosses_non_contig_pg(pool, *addr)) 498 return false; 499 return true; 500 } 501 502 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr) 503 { 504 *addr = xp_aligned_extract_addr(pool, *addr); 505 return *addr < pool->addrs_cnt; 506 } 507 508 static struct xdp_buff_xsk *xp_get_xskb(struct xsk_buff_pool *pool, u64 addr) 509 { 510 struct xdp_buff_xsk *xskb; 511 512 if (pool->unaligned) { 513 xskb = pool->free_heads[--pool->free_heads_cnt]; 514 xp_init_xskb_addr(xskb, pool, addr); 515 if (pool->dma_pages) 516 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr); 517 } else { 518 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)]; 519 } 520 521 return xskb; 522 } 523 524 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool) 525 { 526 struct xdp_buff_xsk *xskb; 527 u64 addr; 528 bool ok; 529 530 if (pool->free_heads_cnt == 0) 531 return NULL; 532 533 for (;;) { 534 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) { 535 pool->fq->queue_empty_descs++; 536 return NULL; 537 } 538 539 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) : 540 xp_check_aligned(pool, &addr); 541 if (!ok) { 542 pool->fq->invalid_descs++; 543 xskq_cons_release(pool->fq); 544 continue; 545 } 546 break; 547 } 548 549 xskb = xp_get_xskb(pool, addr); 550 551 xskq_cons_release(pool->fq); 552 return xskb; 553 } 554 555 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool) 556 { 557 struct xdp_buff_xsk *xskb; 558 559 if (!pool->free_list_cnt) { 560 xskb = __xp_alloc(pool); 561 if (!xskb) 562 return NULL; 563 } else { 564 pool->free_list_cnt--; 565 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, 566 list_node); 567 list_del_init(&xskb->list_node); 568 } 569 570 xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM; 571 xskb->xdp.data_meta = xskb->xdp.data; 572 xskb->xdp.flags = 0; 573 574 if (pool->dev) 575 xp_dma_sync_for_device(pool, xskb->dma, pool->frame_len); 576 577 return &xskb->xdp; 578 } 579 EXPORT_SYMBOL(xp_alloc); 580 581 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max) 582 { 583 u32 i, cached_cons, nb_entries; 584 585 if (max > pool->free_heads_cnt) 586 max = pool->free_heads_cnt; 587 max = xskq_cons_nb_entries(pool->fq, max); 588 589 cached_cons = pool->fq->cached_cons; 590 nb_entries = max; 591 i = max; 592 while (i--) { 593 struct xdp_buff_xsk *xskb; 594 u64 addr; 595 bool ok; 596 597 __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr); 598 599 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) : 600 xp_check_aligned(pool, &addr); 601 if (unlikely(!ok)) { 602 pool->fq->invalid_descs++; 603 nb_entries--; 604 continue; 605 } 606 607 xskb = xp_get_xskb(pool, addr); 608 609 *xdp = &xskb->xdp; 610 xdp++; 611 } 612 613 xskq_cons_release_n(pool->fq, max); 614 return nb_entries; 615 } 616 617 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries) 618 { 619 struct xdp_buff_xsk *xskb; 620 u32 i; 621 622 nb_entries = min_t(u32, nb_entries, pool->free_list_cnt); 623 624 i = nb_entries; 625 while (i--) { 626 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, list_node); 627 list_del_init(&xskb->list_node); 628 629 *xdp = &xskb->xdp; 630 xdp++; 631 } 632 pool->free_list_cnt -= nb_entries; 633 634 return nb_entries; 635 } 636 637 static u32 xp_alloc_slow(struct xsk_buff_pool *pool, struct xdp_buff **xdp, 638 u32 max) 639 { 640 int i; 641 642 for (i = 0; i < max; i++) { 643 struct xdp_buff *buff; 644 645 buff = xp_alloc(pool); 646 if (unlikely(!buff)) 647 return i; 648 *xdp = buff; 649 xdp++; 650 } 651 652 return max; 653 } 654 655 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max) 656 { 657 u32 nb_entries1 = 0, nb_entries2; 658 659 if (unlikely(pool->dev && dma_dev_need_sync(pool->dev))) 660 return xp_alloc_slow(pool, xdp, max); 661 662 if (unlikely(pool->free_list_cnt)) { 663 nb_entries1 = xp_alloc_reused(pool, xdp, max); 664 if (nb_entries1 == max) 665 return nb_entries1; 666 667 max -= nb_entries1; 668 xdp += nb_entries1; 669 } 670 671 nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max); 672 if (!nb_entries2) 673 pool->fq->queue_empty_descs++; 674 675 return nb_entries1 + nb_entries2; 676 } 677 EXPORT_SYMBOL(xp_alloc_batch); 678 679 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count) 680 { 681 u32 req_count, avail_count; 682 683 if (pool->free_list_cnt >= count) 684 return true; 685 686 req_count = count - pool->free_list_cnt; 687 avail_count = xskq_cons_nb_entries(pool->fq, req_count); 688 if (!avail_count) 689 pool->fq->queue_empty_descs++; 690 691 return avail_count >= req_count; 692 } 693 EXPORT_SYMBOL(xp_can_alloc); 694 695 void xp_free(struct xdp_buff_xsk *xskb) 696 { 697 if (!list_empty(&xskb->list_node)) 698 return; 699 700 xskb->pool->free_list_cnt++; 701 list_add(&xskb->list_node, &xskb->pool->free_list); 702 } 703 EXPORT_SYMBOL(xp_free); 704 705 static u64 __xp_raw_get_addr(const struct xsk_buff_pool *pool, u64 addr) 706 { 707 return pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; 708 } 709 710 static void *__xp_raw_get_data(const struct xsk_buff_pool *pool, u64 addr) 711 { 712 return pool->addrs + addr; 713 } 714 715 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr) 716 { 717 return __xp_raw_get_data(pool, __xp_raw_get_addr(pool, addr)); 718 } 719 EXPORT_SYMBOL(xp_raw_get_data); 720 721 static dma_addr_t __xp_raw_get_dma(const struct xsk_buff_pool *pool, u64 addr) 722 { 723 return (pool->dma_pages[addr >> PAGE_SHIFT] & 724 ~XSK_NEXT_PG_CONTIG_MASK) + 725 (addr & ~PAGE_MASK); 726 } 727 728 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr) 729 { 730 return __xp_raw_get_dma(pool, __xp_raw_get_addr(pool, addr)); 731 } 732 EXPORT_SYMBOL(xp_raw_get_dma); 733 734 /** 735 * xp_raw_get_ctx - get &xdp_desc context 736 * @pool: XSk buff pool desc address belongs to 737 * @addr: desc address (from userspace) 738 * 739 * Helper for getting desc's DMA address and metadata pointer, if present. 740 * Saves one call on hotpath, double calculation of the actual address, 741 * and inline checks for metadata presence and sanity. 742 * 743 * Return: new &xdp_desc_ctx struct containing desc's DMA address and metadata 744 * pointer, if it is present and valid (initialized to %NULL otherwise). 745 */ 746 struct xdp_desc_ctx xp_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr) 747 { 748 struct xdp_desc_ctx ret; 749 750 addr = __xp_raw_get_addr(pool, addr); 751 752 ret.dma = __xp_raw_get_dma(pool, addr); 753 ret.meta = __xsk_buff_get_metadata(pool, __xp_raw_get_data(pool, addr)); 754 755 return ret; 756 } 757 EXPORT_SYMBOL(xp_raw_get_ctx); 758