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->heads); 41 kvfree(pool); 42 } 43 44 struct xsk_buff_pool *xp_create_and_assign_umem(struct xdp_sock *xs, 45 struct xdp_umem *umem) 46 { 47 bool unaligned = umem->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG; 48 struct xsk_buff_pool *pool; 49 struct xdp_buff_xsk *xskb; 50 u32 i, entries; 51 52 entries = unaligned ? umem->chunks : 0; 53 pool = kvzalloc(struct_size(pool, free_heads, entries), GFP_KERNEL); 54 if (!pool) 55 goto out; 56 57 pool->heads = kvcalloc(umem->chunks, sizeof(*pool->heads), GFP_KERNEL); 58 if (!pool->heads) 59 goto out; 60 61 pool->chunk_mask = ~((u64)umem->chunk_size - 1); 62 pool->addrs_cnt = umem->size; 63 pool->heads_cnt = umem->chunks; 64 pool->free_heads_cnt = umem->chunks; 65 pool->headroom = umem->headroom; 66 pool->chunk_size = umem->chunk_size; 67 pool->chunk_shift = ffs(umem->chunk_size) - 1; 68 pool->unaligned = unaligned; 69 pool->frame_len = umem->chunk_size - umem->headroom - 70 XDP_PACKET_HEADROOM; 71 pool->umem = umem; 72 pool->addrs = umem->addrs; 73 INIT_LIST_HEAD(&pool->free_list); 74 INIT_LIST_HEAD(&pool->xsk_tx_list); 75 spin_lock_init(&pool->xsk_tx_list_lock); 76 spin_lock_init(&pool->cq_lock); 77 refcount_set(&pool->users, 1); 78 79 pool->fq = xs->fq_tmp; 80 pool->cq = xs->cq_tmp; 81 82 for (i = 0; i < pool->free_heads_cnt; i++) { 83 xskb = &pool->heads[i]; 84 xskb->pool = pool; 85 xskb->xdp.frame_sz = umem->chunk_size - umem->headroom; 86 INIT_LIST_HEAD(&xskb->free_list_node); 87 if (pool->unaligned) 88 pool->free_heads[i] = xskb; 89 else 90 xp_init_xskb_addr(xskb, pool, i * pool->chunk_size); 91 } 92 93 return pool; 94 95 out: 96 xp_destroy(pool); 97 return NULL; 98 } 99 100 void xp_set_rxq_info(struct xsk_buff_pool *pool, struct xdp_rxq_info *rxq) 101 { 102 u32 i; 103 104 for (i = 0; i < pool->heads_cnt; i++) 105 pool->heads[i].xdp.rxq = rxq; 106 } 107 EXPORT_SYMBOL(xp_set_rxq_info); 108 109 static void xp_disable_drv_zc(struct xsk_buff_pool *pool) 110 { 111 struct netdev_bpf bpf; 112 int err; 113 114 ASSERT_RTNL(); 115 116 if (pool->umem->zc) { 117 bpf.command = XDP_SETUP_XSK_POOL; 118 bpf.xsk.pool = NULL; 119 bpf.xsk.queue_id = pool->queue_id; 120 121 err = pool->netdev->netdev_ops->ndo_bpf(pool->netdev, &bpf); 122 123 if (err) 124 WARN(1, "Failed to disable zero-copy!\n"); 125 } 126 } 127 128 int xp_assign_dev(struct xsk_buff_pool *pool, 129 struct net_device *netdev, u16 queue_id, u16 flags) 130 { 131 bool force_zc, force_copy; 132 struct netdev_bpf bpf; 133 int err = 0; 134 135 ASSERT_RTNL(); 136 137 force_zc = flags & XDP_ZEROCOPY; 138 force_copy = flags & XDP_COPY; 139 140 if (force_zc && force_copy) 141 return -EINVAL; 142 143 if (xsk_get_pool_from_qid(netdev, queue_id)) 144 return -EBUSY; 145 146 pool->netdev = netdev; 147 pool->queue_id = queue_id; 148 err = xsk_reg_pool_at_qid(netdev, pool, queue_id); 149 if (err) 150 return err; 151 152 if (flags & XDP_USE_NEED_WAKEUP) 153 pool->uses_need_wakeup = true; 154 /* Tx needs to be explicitly woken up the first time. Also 155 * for supporting drivers that do not implement this 156 * feature. They will always have to call sendto() or poll(). 157 */ 158 pool->cached_need_wakeup = XDP_WAKEUP_TX; 159 160 dev_hold(netdev); 161 162 if (force_copy) 163 /* For copy-mode, we are done. */ 164 return 0; 165 166 if (!netdev->netdev_ops->ndo_bpf || 167 !netdev->netdev_ops->ndo_xsk_wakeup) { 168 err = -EOPNOTSUPP; 169 goto err_unreg_pool; 170 } 171 172 bpf.command = XDP_SETUP_XSK_POOL; 173 bpf.xsk.pool = pool; 174 bpf.xsk.queue_id = queue_id; 175 176 err = netdev->netdev_ops->ndo_bpf(netdev, &bpf); 177 if (err) 178 goto err_unreg_pool; 179 180 if (!pool->dma_pages) { 181 WARN(1, "Driver did not DMA map zero-copy buffers"); 182 err = -EINVAL; 183 goto err_unreg_xsk; 184 } 185 pool->umem->zc = true; 186 return 0; 187 188 err_unreg_xsk: 189 xp_disable_drv_zc(pool); 190 err_unreg_pool: 191 if (!force_zc) 192 err = 0; /* fallback to copy mode */ 193 if (err) { 194 xsk_clear_pool_at_qid(netdev, queue_id); 195 dev_put(netdev); 196 } 197 return err; 198 } 199 200 int xp_assign_dev_shared(struct xsk_buff_pool *pool, struct xdp_umem *umem, 201 struct net_device *dev, u16 queue_id) 202 { 203 u16 flags; 204 205 /* One fill and completion ring required for each queue id. */ 206 if (!pool->fq || !pool->cq) 207 return -EINVAL; 208 209 flags = umem->zc ? XDP_ZEROCOPY : XDP_COPY; 210 if (pool->uses_need_wakeup) 211 flags |= XDP_USE_NEED_WAKEUP; 212 213 return xp_assign_dev(pool, dev, queue_id, flags); 214 } 215 216 void xp_clear_dev(struct xsk_buff_pool *pool) 217 { 218 if (!pool->netdev) 219 return; 220 221 xp_disable_drv_zc(pool); 222 xsk_clear_pool_at_qid(pool->netdev, pool->queue_id); 223 dev_put(pool->netdev); 224 pool->netdev = NULL; 225 } 226 227 static void xp_release_deferred(struct work_struct *work) 228 { 229 struct xsk_buff_pool *pool = container_of(work, struct xsk_buff_pool, 230 work); 231 232 rtnl_lock(); 233 xp_clear_dev(pool); 234 rtnl_unlock(); 235 236 if (pool->fq) { 237 xskq_destroy(pool->fq); 238 pool->fq = NULL; 239 } 240 241 if (pool->cq) { 242 xskq_destroy(pool->cq); 243 pool->cq = NULL; 244 } 245 246 xdp_put_umem(pool->umem, false); 247 xp_destroy(pool); 248 } 249 250 void xp_get_pool(struct xsk_buff_pool *pool) 251 { 252 refcount_inc(&pool->users); 253 } 254 255 bool xp_put_pool(struct xsk_buff_pool *pool) 256 { 257 if (!pool) 258 return false; 259 260 if (refcount_dec_and_test(&pool->users)) { 261 INIT_WORK(&pool->work, xp_release_deferred); 262 schedule_work(&pool->work); 263 return true; 264 } 265 266 return false; 267 } 268 269 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool) 270 { 271 struct xsk_dma_map *dma_map; 272 273 list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) { 274 if (dma_map->netdev == pool->netdev) 275 return dma_map; 276 } 277 278 return NULL; 279 } 280 281 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev, 282 u32 nr_pages, struct xdp_umem *umem) 283 { 284 struct xsk_dma_map *dma_map; 285 286 dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL); 287 if (!dma_map) 288 return NULL; 289 290 dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL); 291 if (!dma_map->dma_pages) { 292 kfree(dma_map); 293 return NULL; 294 } 295 296 dma_map->netdev = netdev; 297 dma_map->dev = dev; 298 dma_map->dma_need_sync = false; 299 dma_map->dma_pages_cnt = nr_pages; 300 refcount_set(&dma_map->users, 1); 301 list_add(&dma_map->list, &umem->xsk_dma_list); 302 return dma_map; 303 } 304 305 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map) 306 { 307 list_del(&dma_map->list); 308 kvfree(dma_map->dma_pages); 309 kfree(dma_map); 310 } 311 312 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs) 313 { 314 dma_addr_t *dma; 315 u32 i; 316 317 for (i = 0; i < dma_map->dma_pages_cnt; i++) { 318 dma = &dma_map->dma_pages[i]; 319 if (*dma) { 320 dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE, 321 DMA_BIDIRECTIONAL, attrs); 322 *dma = 0; 323 } 324 } 325 326 xp_destroy_dma_map(dma_map); 327 } 328 329 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs) 330 { 331 struct xsk_dma_map *dma_map; 332 333 if (pool->dma_pages_cnt == 0) 334 return; 335 336 dma_map = xp_find_dma_map(pool); 337 if (!dma_map) { 338 WARN(1, "Could not find dma_map for device"); 339 return; 340 } 341 342 if (!refcount_dec_and_test(&dma_map->users)) 343 return; 344 345 __xp_dma_unmap(dma_map, attrs); 346 kvfree(pool->dma_pages); 347 pool->dma_pages_cnt = 0; 348 pool->dev = NULL; 349 } 350 EXPORT_SYMBOL(xp_dma_unmap); 351 352 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map) 353 { 354 u32 i; 355 356 for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) { 357 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1]) 358 dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK; 359 else 360 dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK; 361 } 362 } 363 364 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map) 365 { 366 pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL); 367 if (!pool->dma_pages) 368 return -ENOMEM; 369 370 pool->dev = dma_map->dev; 371 pool->dma_pages_cnt = dma_map->dma_pages_cnt; 372 pool->dma_need_sync = dma_map->dma_need_sync; 373 memcpy(pool->dma_pages, dma_map->dma_pages, 374 pool->dma_pages_cnt * sizeof(*pool->dma_pages)); 375 376 return 0; 377 } 378 379 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev, 380 unsigned long attrs, struct page **pages, u32 nr_pages) 381 { 382 struct xsk_dma_map *dma_map; 383 dma_addr_t dma; 384 int err; 385 u32 i; 386 387 dma_map = xp_find_dma_map(pool); 388 if (dma_map) { 389 err = xp_init_dma_info(pool, dma_map); 390 if (err) 391 return err; 392 393 refcount_inc(&dma_map->users); 394 return 0; 395 } 396 397 dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem); 398 if (!dma_map) 399 return -ENOMEM; 400 401 for (i = 0; i < dma_map->dma_pages_cnt; i++) { 402 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE, 403 DMA_BIDIRECTIONAL, attrs); 404 if (dma_mapping_error(dev, dma)) { 405 __xp_dma_unmap(dma_map, attrs); 406 return -ENOMEM; 407 } 408 if (dma_need_sync(dev, dma)) 409 dma_map->dma_need_sync = true; 410 dma_map->dma_pages[i] = dma; 411 } 412 413 if (pool->unaligned) 414 xp_check_dma_contiguity(dma_map); 415 else 416 for (i = 0; i < pool->heads_cnt; i++) { 417 struct xdp_buff_xsk *xskb = &pool->heads[i]; 418 419 xp_init_xskb_dma(xskb, pool, dma_map->dma_pages, xskb->orig_addr); 420 } 421 422 err = xp_init_dma_info(pool, dma_map); 423 if (err) { 424 __xp_dma_unmap(dma_map, attrs); 425 return err; 426 } 427 428 return 0; 429 } 430 EXPORT_SYMBOL(xp_dma_map); 431 432 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool, 433 u64 addr) 434 { 435 return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size); 436 } 437 438 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr) 439 { 440 *addr = xp_unaligned_extract_addr(*addr); 441 if (*addr >= pool->addrs_cnt || 442 *addr + pool->chunk_size > pool->addrs_cnt || 443 xp_addr_crosses_non_contig_pg(pool, *addr)) 444 return false; 445 return true; 446 } 447 448 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr) 449 { 450 *addr = xp_aligned_extract_addr(pool, *addr); 451 return *addr < pool->addrs_cnt; 452 } 453 454 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool) 455 { 456 struct xdp_buff_xsk *xskb; 457 u64 addr; 458 bool ok; 459 460 if (pool->free_heads_cnt == 0) 461 return NULL; 462 463 for (;;) { 464 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) { 465 pool->fq->queue_empty_descs++; 466 return NULL; 467 } 468 469 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) : 470 xp_check_aligned(pool, &addr); 471 if (!ok) { 472 pool->fq->invalid_descs++; 473 xskq_cons_release(pool->fq); 474 continue; 475 } 476 break; 477 } 478 479 if (pool->unaligned) { 480 xskb = pool->free_heads[--pool->free_heads_cnt]; 481 xp_init_xskb_addr(xskb, pool, addr); 482 if (pool->dma_pages_cnt) 483 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr); 484 } else { 485 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)]; 486 } 487 488 xskq_cons_release(pool->fq); 489 return xskb; 490 } 491 492 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool) 493 { 494 struct xdp_buff_xsk *xskb; 495 496 if (!pool->free_list_cnt) { 497 xskb = __xp_alloc(pool); 498 if (!xskb) 499 return NULL; 500 } else { 501 pool->free_list_cnt--; 502 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, 503 free_list_node); 504 list_del_init(&xskb->free_list_node); 505 } 506 507 xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM; 508 xskb->xdp.data_meta = xskb->xdp.data; 509 510 if (pool->dma_need_sync) { 511 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0, 512 pool->frame_len, 513 DMA_BIDIRECTIONAL); 514 } 515 return &xskb->xdp; 516 } 517 EXPORT_SYMBOL(xp_alloc); 518 519 static u32 xp_alloc_new_from_fq(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max) 520 { 521 u32 i, cached_cons, nb_entries; 522 523 if (max > pool->free_heads_cnt) 524 max = pool->free_heads_cnt; 525 max = xskq_cons_nb_entries(pool->fq, max); 526 527 cached_cons = pool->fq->cached_cons; 528 nb_entries = max; 529 i = max; 530 while (i--) { 531 struct xdp_buff_xsk *xskb; 532 u64 addr; 533 bool ok; 534 535 __xskq_cons_read_addr_unchecked(pool->fq, cached_cons++, &addr); 536 537 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) : 538 xp_check_aligned(pool, &addr); 539 if (unlikely(!ok)) { 540 pool->fq->invalid_descs++; 541 nb_entries--; 542 continue; 543 } 544 545 if (pool->unaligned) { 546 xskb = pool->free_heads[--pool->free_heads_cnt]; 547 xp_init_xskb_addr(xskb, pool, addr); 548 if (pool->dma_pages_cnt) 549 xp_init_xskb_dma(xskb, pool, pool->dma_pages, addr); 550 } else { 551 xskb = &pool->heads[xp_aligned_extract_idx(pool, addr)]; 552 } 553 554 *xdp = &xskb->xdp; 555 xdp++; 556 } 557 558 xskq_cons_release_n(pool->fq, max); 559 return nb_entries; 560 } 561 562 static u32 xp_alloc_reused(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 nb_entries) 563 { 564 struct xdp_buff_xsk *xskb; 565 u32 i; 566 567 nb_entries = min_t(u32, nb_entries, pool->free_list_cnt); 568 569 i = nb_entries; 570 while (i--) { 571 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, free_list_node); 572 list_del_init(&xskb->free_list_node); 573 574 *xdp = &xskb->xdp; 575 xdp++; 576 } 577 pool->free_list_cnt -= nb_entries; 578 579 return nb_entries; 580 } 581 582 u32 xp_alloc_batch(struct xsk_buff_pool *pool, struct xdp_buff **xdp, u32 max) 583 { 584 u32 nb_entries1 = 0, nb_entries2; 585 586 if (unlikely(pool->dma_need_sync)) { 587 /* Slow path */ 588 *xdp = xp_alloc(pool); 589 return !!*xdp; 590 } 591 592 if (unlikely(pool->free_list_cnt)) { 593 nb_entries1 = xp_alloc_reused(pool, xdp, max); 594 if (nb_entries1 == max) 595 return nb_entries1; 596 597 max -= nb_entries1; 598 xdp += nb_entries1; 599 } 600 601 nb_entries2 = xp_alloc_new_from_fq(pool, xdp, max); 602 if (!nb_entries2) 603 pool->fq->queue_empty_descs++; 604 605 return nb_entries1 + nb_entries2; 606 } 607 EXPORT_SYMBOL(xp_alloc_batch); 608 609 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count) 610 { 611 if (pool->free_list_cnt >= count) 612 return true; 613 return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt); 614 } 615 EXPORT_SYMBOL(xp_can_alloc); 616 617 void xp_free(struct xdp_buff_xsk *xskb) 618 { 619 if (!list_empty(&xskb->free_list_node)) 620 return; 621 622 xskb->pool->free_list_cnt++; 623 list_add(&xskb->free_list_node, &xskb->pool->free_list); 624 } 625 EXPORT_SYMBOL(xp_free); 626 627 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr) 628 { 629 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; 630 return pool->addrs + addr; 631 } 632 EXPORT_SYMBOL(xp_raw_get_data); 633 634 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr) 635 { 636 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; 637 return (pool->dma_pages[addr >> PAGE_SHIFT] & 638 ~XSK_NEXT_PG_CONTIG_MASK) + 639 (addr & ~PAGE_MASK); 640 } 641 EXPORT_SYMBOL(xp_raw_get_dma); 642 643 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb) 644 { 645 dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0, 646 xskb->pool->frame_len, DMA_BIDIRECTIONAL); 647 } 648 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow); 649 650 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma, 651 size_t size) 652 { 653 dma_sync_single_range_for_device(pool->dev, dma, 0, 654 size, DMA_BIDIRECTIONAL); 655 } 656 EXPORT_SYMBOL(xp_dma_sync_for_device_slow); 657