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 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, 46 struct xdp_umem *umem) 47 { 48 bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG; 49 struct xsk_buff_pool *pool; 50 struct xdp_buff_xsk *xskb; 51 u32 i, entries; 52 53 entries = unaligned ? umem->chunks : 0; 54 pool = kvzalloc(struct_size(pool, free_heads, entries), GFP_KERNEL); 55 if (!pool) 56 goto out; 57 58 pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL); 59 if (!pool->heads) 60 goto out; 61 62 if (xs->tx) { 63 pool->tx_descs = kcalloc(xs->tx->nentries, sizeof(*pool->tx_descs), GFP_KERNEL); 64 if (!pool->tx_descs) 65 goto out; 66 } 67 68 pool->chunk_mask = ~((u64)umem->chunk_size - 1); 69 pool->addrs_cnt = umem->size; 70 pool->heads_cnt = umem->chunks; 71 pool->free_heads_cnt = umem->chunks; 72 pool->headroom = umem->headroom; 73 pool->chunk_size = umem->chunk_size; 74 pool->chunk_shift = ffs(umem->chunk_size) - 1; 75 pool->unaligned = unaligned; 76 pool->frame_len = umem->chunk_size - umem->headroom - 77 XDP_PACKET_HEADROOM; 78 pool->umem = umem; 79 pool->addrs = umem->addrs; 80 INIT_LIST_HEAD(&pool->free_list); 81 INIT_LIST_HEAD(&pool->xsk_tx_list); 82 spin_lock_init(&pool->xsk_tx_list_lock); 83 spin_lock_init(&pool->cq_lock); 84 refcount_set(&pool->users, 1); 85 86 pool->fq = xs->fq_tmp; 87 pool->cq = xs->cq_tmp; 88 89 for (i = 0; i < pool->free_heads_cnt; i++) { 90 xskb = &pool->heads[i]; 91 xskb->pool = pool; 92 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom; 93 INIT_LIST_HEAD(&xskb->free_list_node); 94 if (pool->unaligned) 95 pool->free_heads[i] = xskb; 96 else 97 xp_init_xskb_addr(xskb, pool, i * pool->chunk_size); 98 } 99 100 return pool; 101 102 out: 103 xp_destroy(pool); 104 return NULL; 105 } 106 107 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq) 108 { 109 u32 i; 110 111 for (i = 0; i < pool->heads_cnt; i++) 112 pool->heads[i].xdp.rxq = rxq; 113 } 114 EXPORT_SYMBOL(xp_set_rxq_info); 115 116 static void xp_disable_drv_zc(struct xsk_buff_pool *pool) 117 { 118 struct netdev_bpf bpf; 119 int err; 120 121 ASSERT_RTNL(); 122 123 if (pool->umem->zc) { 124 bpf.command = XDP_SETUP_XSK_POOL; 125 bpf.xsk.pool = NULL; 126 bpf.xsk.queue_id = pool->queue_id; 127 128 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf); 129 130 if (err) 131 WARN(1, "Failed to disable zero-copy!\n"); 132 } 133 } 134 135 int xp_assign_dev(struct xsk_buff_pool *pool, 136 struct net_device *netdev, u16 queue_id, u16 flags) 137 { 138 bool force_zc, force_copy; 139 struct netdev_bpf bpf; 140 int err = 0; 141 142 ASSERT_RTNL(); 143 144 force_zc = flags & XDP_ZEROCOPY; 145 force_copy = flags & XDP_COPY; 146 147 if (force_zc && force_copy) 148 return -EINVAL; 149 150 if (xsk_get_pool_from_qid(netdev, queue_id)) 151 return -EBUSY; 152 153 pool->netdev = netdev; 154 pool->queue_id = queue_id; 155 err = xsk_reg_pool_at_qid(netdev, pool, queue_id); 156 if (err) 157 return err; 158 159 if (flags & XDP_USE_NEED_WAKEUP) 160 pool->uses_need_wakeup = true; 161 /* Tx needs to be explicitly woken up the first time. Also 162 * for supporting drivers that do not implement this 163 * feature. They will always have to call sendto() or poll(). 164 */ 165 pool->cached_need_wakeup = XDP_WAKEUP_TX; 166 167 dev_hold(netdev); 168 169 if (force_copy) 170 /* For copy-mode, we are done. */ 171 return 0; 172 173 if (!netdev->netdev_ops->ndo_bpf || 174 !netdev->netdev_ops->ndo_xsk_wakeup) { 175 err = -EOPNOTSUPP; 176 goto err_unreg_pool; 177 } 178 179 bpf.command = XDP_SETUP_XSK_POOL; 180 bpf.xsk.pool = pool; 181 bpf.xsk.queue_id = queue_id; 182 183 err = netdev->netdev_ops->ndo_bpf(netdev, &bpf); 184 if (err) 185 goto err_unreg_pool; 186 187 if (!pool->dma_pages) { 188 WARN(1, "Driver did not DMA map zero-copy buffers"); 189 err = -EINVAL; 190 goto err_unreg_xsk; 191 } 192 pool->umem->zc = true; 193 return 0; 194 195 err_unreg_xsk: 196 xp_disable_drv_zc(pool); 197 err_unreg_pool: 198 if (!force_zc) 199 err = 0; /* fallback to copy mode */ 200 if (err) { 201 xsk_clear_pool_at_qid(netdev, queue_id); 202 dev_put(netdev); 203 } 204 return err; 205 } 206 207 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, 208 struct net_device *dev, u16 queue_id) 209 { 210 u16 flags; 211 212 /* One fill and completion ring required for each queue id. */ 213 if (!pool->fq || !pool->cq) 214 return -EINVAL; 215 216 flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY; 217 if (pool->uses_need_wakeup) 218 flags |= XDP_USE_NEED_WAKEUP; 219 220 return xp_assign_dev(pool, dev, queue_id, flags); 221 } 222 223 void xp_clear_dev(struct xsk_buff_pool *pool) 224 { 225 if (!pool->netdev) 226 return; 227 228 xp_disable_drv_zc(pool); 229 xsk_clear_pool_at_qid(pool->netdev, pool->queue_id); 230 dev_put(pool->netdev); 231 pool->netdev = NULL; 232 } 233 234 static void xp_release_deferred(struct work_struct *work) 235 { 236 struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool, 237 work); 238 239 rtnl_lock(); 240 xp_clear_dev(pool); 241 rtnl_unlock(); 242 243 if (pool->fq) { 244 xskq_destroy(pool->fq); 245 pool->fq = NULL; 246 } 247 248 if (pool->cq) { 249 xskq_destroy(pool->cq); 250 pool->cq = NULL; 251 } 252 253 xdp_put_umem(pool->umem, false); 254 xp_destroy(pool); 255 } 256 257 void xp_get_pool(struct xsk_buff_pool *pool) 258 { 259 refcount_inc(&pool->users); 260 } 261 262 bool xp_put_pool(struct xsk_buff_pool *pool) 263 { 264 if (!pool) 265 return false; 266 267 if (refcount_dec_and_test(&pool->users)) { 268 INIT_WORK(&pool->work, xp_release_deferred); 269 schedule_work(&pool->work); 270 return true; 271 } 272 273 return false; 274 } 275 276 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool) 277 { 278 struct xsk_dma_map *dma_map; 279 280 list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) { 281 if (dma_map->netdev == pool->netdev) 282 return dma_map; 283 } 284 285 return NULL; 286 } 287 288 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev, 289 u32 nr_pages, struct xdp_umem *umem) 290 { 291 struct xsk_dma_map *dma_map; 292 293 dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL); 294 if (!dma_map) 295 return NULL; 296 297 dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL); 298 if (!dma_map->dma_pages) { 299 kfree(dma_map); 300 return NULL; 301 } 302 303 dma_map->netdev = netdev; 304 dma_map->dev = dev; 305 dma_map->dma_need_sync = false; 306 dma_map->dma_pages_cnt = nr_pages; 307 refcount_set(&dma_map->users, 1); 308 list_add(&dma_map->list, &umem->xsk_dma_list); 309 return dma_map; 310 } 311 312 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map) 313 { 314 list_del(&dma_map->list); 315 kvfree(dma_map->dma_pages); 316 kfree(dma_map); 317 } 318 319 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs) 320 { 321 dma_addr_t *dma; 322 u32 i; 323 324 for (i = 0; i < dma_map->dma_pages_cnt; i++) { 325 dma = &dma_map->dma_pages[i]; 326 if (*dma) { 327 dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE, 328 DMA_BIDIRECTIONAL, attrs); 329 *dma = 0; 330 } 331 } 332 333 xp_destroy_dma_map(dma_map); 334 } 335 336 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs) 337 { 338 struct xsk_dma_map *dma_map; 339 340 if (pool->dma_pages_cnt == 0) 341 return; 342 343 dma_map = xp_find_dma_map(pool); 344 if (!dma_map) { 345 WARN(1, "Could not find dma_map for device"); 346 return; 347 } 348 349 if (!refcount_dec_and_test(&dma_map->users)) 350 return; 351 352 __xp_dma_unmap(dma_map, attrs); 353 kvfree(pool->dma_pages); 354 pool->dma_pages_cnt = 0; 355 pool->dev = NULL; 356 } 357 EXPORT_SYMBOL(xp_dma_unmap); 358 359 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map) 360 { 361 u32 i; 362 363 for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) { 364 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1]) 365 dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK; 366 else 367 dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK; 368 } 369 } 370 371 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map) 372 { 373 pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL); 374 if (!pool->dma_pages) 375 return -ENOMEM; 376 377 pool->dev = dma_map->dev; 378 pool->dma_pages_cnt = dma_map->dma_pages_cnt; 379 pool->dma_need_sync = dma_map->dma_need_sync; 380 memcpy(pool->dma_pages, dma_map->dma_pages, 381 pool->dma_pages_cnt * sizeof(*pool->dma_pages)); 382 383 return 0; 384 } 385 386 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev, 387 unsigned long attrs, struct page **pages, u32 nr_pages) 388 { 389 struct xsk_dma_map *dma_map; 390 dma_addr_t dma; 391 int err; 392 u32 i; 393 394 dma_map = xp_find_dma_map(pool); 395 if (dma_map) { 396 err = xp_init_dma_info(pool, dma_map); 397 if (err) 398 return err; 399 400 refcount_inc(&dma_map->users); 401 return 0; 402 } 403 404 dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem); 405 if (!dma_map) 406 return -ENOMEM; 407 408 for (i = 0; i < dma_map->dma_pages_cnt; i++) { 409 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE, 410 DMA_BIDIRECTIONAL, attrs); 411 if (dma_mapping_error(dev, dma)) { 412 __xp_dma_unmap(dma_map, attrs); 413 return -ENOMEM; 414 } 415 if (dma_need_sync(dev, dma)) 416 dma_map->dma_need_sync = true; 417 dma_map->dma_pages[i] = dma; 418 } 419 420 if (pool->unaligned) 421 xp_check_dma_contiguity(dma_map); 422 else 423 for (i = 0; i < pool->heads_cnt; i++) { 424 struct xdp_buff_xsk *xskb = &pool->heads[i]; 425 426 xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr); 427 } 428 429 err = xp_init_dma_info(pool, dma_map); 430 if (err) { 431 __xp_dma_unmap(dma_map, attrs); 432 return err; 433 } 434 435 return 0; 436 } 437 EXPORT_SYMBOL(xp_dma_map); 438 439 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool, 440 u64 addr) 441 { 442 return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size); 443 } 444 445 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr) 446 { 447 *addr = xp_unaligned_extract_addr(*addr); 448 if (*addr >= pool->addrs_cnt || 449 *addr + pool->chunk_size > pool->addrs_cnt || 450 xp_addr_crosses_non_contig_pg(pool, *addr)) 451 return false; 452 return true; 453 } 454 455 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr) 456 { 457 *addr = xp_aligned_extract_addr(pool, *addr); 458 return *addr < pool->addrs_cnt; 459 } 460 461 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool) 462 { 463 struct xdp_buff_xsk *xskb; 464 u64 addr; 465 bool ok; 466 467 if (pool->free_heads_cnt == 0) 468 return NULL; 469 470 for (;;) { 471 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) { 472 pool->fq->queue_empty_descs++; 473 return NULL; 474 } 475 476 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) : 477 xp_check_aligned(pool, &addr); 478 if (!ok) { 479 pool->fq->invalid_descs++; 480 xskq_cons_release(pool->fq); 481 continue; 482 } 483 break; 484 } 485 486 if (pool->unaligned) { 487 xskb = pool->free_heads[--pool->free_heads_cnt]; 488 xp_init_xskb_addr(xskb, pool, addr); 489 if (pool->dma_pages_cnt) 490 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr); 491 } else { 492 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)]; 493 } 494 495 xskq_cons_release(pool->fq); 496 return xskb; 497 } 498 499 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool) 500 { 501 struct xdp_buff_xsk *xskb; 502 503 if (!pool->free_list_cnt) { 504 xskb = __xp_alloc(pool); 505 if (!xskb) 506 return NULL; 507 } else { 508 pool->free_list_cnt--; 509 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, 510 free_list_node); 511 list_del_init(&xskb->free_list_node); 512 } 513 514 xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM; 515 xskb->xdp.data_meta = xskb->xdp.data; 516 517 if (pool->dma_need_sync) { 518 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0, 519 pool->frame_len, 520 DMA_BIDIRECTIONAL); 521 } 522 return &xskb->xdp; 523 } 524 EXPORT_SYMBOL(xp_alloc); 525 526 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max) 527 { 528 u32 i, cached_cons, nb_entries; 529 530 if (max > pool->free_heads_cnt) 531 max = pool->free_heads_cnt; 532 max = xskq_cons_nb_entries(pool->fq, max); 533 534 cached_cons = pool->fq->cached_cons; 535 nb_entries = max; 536 i = max; 537 while (i--) { 538 struct xdp_buff_xsk *xskb; 539 u64 addr; 540 bool ok; 541 542 __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr); 543 544 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) : 545 xp_check_aligned(pool, &addr); 546 if (unlikely(!ok)) { 547 pool->fq->invalid_descs++; 548 nb_entries--; 549 continue; 550 } 551 552 if (pool->unaligned) { 553 xskb = pool->free_heads[--pool->free_heads_cnt]; 554 xp_init_xskb_addr(xskb, pool, addr); 555 if (pool->dma_pages_cnt) 556 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr); 557 } else { 558 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)]; 559 } 560 561 *xdp = &xskb->xdp; 562 xdp++; 563 } 564 565 xskq_cons_release_n(pool->fq, max); 566 return nb_entries; 567 } 568 569 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries) 570 { 571 struct xdp_buff_xsk *xskb; 572 u32 i; 573 574 nb_entries = min_t(u32, nb_entries, pool->free_list_cnt); 575 576 i = nb_entries; 577 while (i--) { 578 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node); 579 list_del_init(&xskb->free_list_node); 580 581 *xdp = &xskb->xdp; 582 xdp++; 583 } 584 pool->free_list_cnt -= nb_entries; 585 586 return nb_entries; 587 } 588 589 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max) 590 { 591 u32 nb_entries1 = 0, nb_entries2; 592 593 if (unlikely(pool->dma_need_sync)) { 594 struct xdp_buff *buff; 595 596 /* Slow path */ 597 buff = xp_alloc(pool); 598 if (buff) 599 *xdp = buff; 600 return !!buff; 601 } 602 603 if (unlikely(pool->free_list_cnt)) { 604 nb_entries1 = xp_alloc_reused(pool, xdp, max); 605 if (nb_entries1 == max) 606 return nb_entries1; 607 608 max -= nb_entries1; 609 xdp += nb_entries1; 610 } 611 612 nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max); 613 if (!nb_entries2) 614 pool->fq->queue_empty_descs++; 615 616 return nb_entries1 + nb_entries2; 617 } 618 EXPORT_SYMBOL(xp_alloc_batch); 619 620 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count) 621 { 622 if (pool->free_list_cnt >= count) 623 return true; 624 return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt); 625 } 626 EXPORT_SYMBOL(xp_can_alloc); 627 628 void xp_free(struct xdp_buff_xsk *xskb) 629 { 630 if (!list_empty(&xskb->free_list_node)) 631 return; 632 633 xskb->pool->free_list_cnt++; 634 list_add(&xskb->free_list_node, &xskb->pool->free_list); 635 } 636 EXPORT_SYMBOL(xp_free); 637 638 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr) 639 { 640 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; 641 return pool->addrs + addr; 642 } 643 EXPORT_SYMBOL(xp_raw_get_data); 644 645 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr) 646 { 647 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; 648 return (pool->dma_pages[addr >> PAGE_SHIFT] & 649 ~XSK_NEXT_PG_CONTIG_MASK) + 650 (addr & ~PAGE_MASK); 651 } 652 EXPORT_SYMBOL(xp_raw_get_dma); 653 654 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb) 655 { 656 dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0, 657 xskb->pool->frame_len, DMA_BIDIRECTIONAL); 658 } 659 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow); 660 661 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma, 662 size_t size) 663 { 664 dma_sync_single_range_for_device(pool->dev, dma, 0, 665 size, DMA_BIDIRECTIONAL); 666 } 667 EXPORT_SYMBOL(xp_dma_sync_for_device_slow); 668