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