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