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 void xp_put_pool(struct xsk_buff_pool *pool) 255 { 256 if (!pool) 257 return; 258 259 if (refcount_dec_and_test(&pool->users)) { 260 INIT_WORK(&pool->work, xp_release_deferred); 261 schedule_work(&pool->work); 262 } 263 } 264 265 static struct xsk_dma_map *xp_find_dma_map(struct xsk_buff_pool *pool) 266 { 267 struct xsk_dma_map *dma_map; 268 269 list_for_each_entry(dma_map, &pool->umem->xsk_dma_list, list) { 270 if (dma_map->netdev == pool->netdev) 271 return dma_map; 272 } 273 274 return NULL; 275 } 276 277 static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_device *netdev, 278 u32 nr_pages, struct xdp_umem *umem) 279 { 280 struct xsk_dma_map *dma_map; 281 282 dma_map = kzalloc(sizeof(*dma_map), GFP_KERNEL); 283 if (!dma_map) 284 return NULL; 285 286 dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL); 287 if (!dma_map->dma_pages) { 288 kfree(dma_map); 289 return NULL; 290 } 291 292 dma_map->netdev = netdev; 293 dma_map->dev = dev; 294 dma_map->dma_need_sync = false; 295 dma_map->dma_pages_cnt = nr_pages; 296 refcount_set(&dma_map->users, 1); 297 list_add(&dma_map->list, &umem->xsk_dma_list); 298 return dma_map; 299 } 300 301 static void xp_destroy_dma_map(struct xsk_dma_map *dma_map) 302 { 303 list_del(&dma_map->list); 304 kvfree(dma_map->dma_pages); 305 kfree(dma_map); 306 } 307 308 static void __xp_dma_unmap(struct xsk_dma_map *dma_map, unsigned long attrs) 309 { 310 dma_addr_t *dma; 311 u32 i; 312 313 for (i = 0; i < dma_map->dma_pages_cnt; i++) { 314 dma = &dma_map->dma_pages[i]; 315 if (*dma) { 316 dma_unmap_page_attrs(dma_map->dev, *dma, PAGE_SIZE, 317 DMA_BIDIRECTIONAL, attrs); 318 *dma = 0; 319 } 320 } 321 322 xp_destroy_dma_map(dma_map); 323 } 324 325 void xp_dma_unmap(struct xsk_buff_pool *pool, unsigned long attrs) 326 { 327 struct xsk_dma_map *dma_map; 328 329 if (pool->dma_pages_cnt == 0) 330 return; 331 332 dma_map = xp_find_dma_map(pool); 333 if (!dma_map) { 334 WARN(1, "Could not find dma_map for device"); 335 return; 336 } 337 338 if (!refcount_dec_and_test(&dma_map->users)) 339 return; 340 341 __xp_dma_unmap(dma_map, attrs); 342 kvfree(pool->dma_pages); 343 pool->dma_pages_cnt = 0; 344 pool->dev = NULL; 345 } 346 EXPORT_SYMBOL(xp_dma_unmap); 347 348 static void xp_check_dma_contiguity(struct xsk_dma_map *dma_map) 349 { 350 u32 i; 351 352 for (i = 0; i < dma_map->dma_pages_cnt - 1; i++) { 353 if (dma_map->dma_pages[i] + PAGE_SIZE == dma_map->dma_pages[i + 1]) 354 dma_map->dma_pages[i] |= XSK_NEXT_PG_CONTIG_MASK; 355 else 356 dma_map->dma_pages[i] &= ~XSK_NEXT_PG_CONTIG_MASK; 357 } 358 } 359 360 static int xp_init_dma_info(struct xsk_buff_pool *pool, struct xsk_dma_map *dma_map) 361 { 362 pool->dma_pages = kvcalloc(dma_map->dma_pages_cnt, sizeof(*pool->dma_pages), GFP_KERNEL); 363 if (!pool->dma_pages) 364 return -ENOMEM; 365 366 pool->dev = dma_map->dev; 367 pool->dma_pages_cnt = dma_map->dma_pages_cnt; 368 pool->dma_need_sync = dma_map->dma_need_sync; 369 memcpy(pool->dma_pages, dma_map->dma_pages, 370 pool->dma_pages_cnt * sizeof(*pool->dma_pages)); 371 372 return 0; 373 } 374 375 int xp_dma_map(struct xsk_buff_pool *pool, struct device *dev, 376 unsigned long attrs, struct page **pages, u32 nr_pages) 377 { 378 struct xsk_dma_map *dma_map; 379 dma_addr_t dma; 380 int err; 381 u32 i; 382 383 dma_map = xp_find_dma_map(pool); 384 if (dma_map) { 385 err = xp_init_dma_info(pool, dma_map); 386 if (err) 387 return err; 388 389 refcount_inc(&dma_map->users); 390 return 0; 391 } 392 393 dma_map = xp_create_dma_map(dev, pool->netdev, nr_pages, pool->umem); 394 if (!dma_map) 395 return -ENOMEM; 396 397 for (i = 0; i < dma_map->dma_pages_cnt; i++) { 398 dma = dma_map_page_attrs(dev, pages[i], 0, PAGE_SIZE, 399 DMA_BIDIRECTIONAL, attrs); 400 if (dma_mapping_error(dev, dma)) { 401 __xp_dma_unmap(dma_map, attrs); 402 return -ENOMEM; 403 } 404 if (dma_need_sync(dev, dma)) 405 dma_map->dma_need_sync = true; 406 dma_map->dma_pages[i] = dma; 407 } 408 409 if (pool->unaligned) 410 xp_check_dma_contiguity(dma_map); 411 412 err = xp_init_dma_info(pool, dma_map); 413 if (err) { 414 __xp_dma_unmap(dma_map, attrs); 415 return err; 416 } 417 418 return 0; 419 } 420 EXPORT_SYMBOL(xp_dma_map); 421 422 static bool xp_addr_crosses_non_contig_pg(struct xsk_buff_pool *pool, 423 u64 addr) 424 { 425 return xp_desc_crosses_non_contig_pg(pool, addr, pool->chunk_size); 426 } 427 428 static bool xp_check_unaligned(struct xsk_buff_pool *pool, u64 *addr) 429 { 430 *addr = xp_unaligned_extract_addr(*addr); 431 if (*addr >= pool->addrs_cnt || 432 *addr + pool->chunk_size > pool->addrs_cnt || 433 xp_addr_crosses_non_contig_pg(pool, *addr)) 434 return false; 435 return true; 436 } 437 438 static bool xp_check_aligned(struct xsk_buff_pool *pool, u64 *addr) 439 { 440 *addr = xp_aligned_extract_addr(pool, *addr); 441 return *addr < pool->addrs_cnt; 442 } 443 444 static struct xdp_buff_xsk *__xp_alloc(struct xsk_buff_pool *pool) 445 { 446 struct xdp_buff_xsk *xskb; 447 u64 addr; 448 bool ok; 449 450 if (pool->free_heads_cnt == 0) 451 return NULL; 452 453 xskb = pool->free_heads[--pool->free_heads_cnt]; 454 455 for (;;) { 456 if (!xskq_cons_peek_addr_unchecked(pool->fq, &addr)) { 457 pool->fq->queue_empty_descs++; 458 xp_release(xskb); 459 return NULL; 460 } 461 462 ok = pool->unaligned ? xp_check_unaligned(pool, &addr) : 463 xp_check_aligned(pool, &addr); 464 if (!ok) { 465 pool->fq->invalid_descs++; 466 xskq_cons_release(pool->fq); 467 continue; 468 } 469 break; 470 } 471 xskq_cons_release(pool->fq); 472 473 xskb->orig_addr = addr; 474 xskb->xdp.data_hard_start = pool->addrs + addr + pool->headroom; 475 if (pool->dma_pages_cnt) { 476 xskb->frame_dma = (pool->dma_pages[addr >> PAGE_SHIFT] & 477 ~XSK_NEXT_PG_CONTIG_MASK) + 478 (addr & ~PAGE_MASK); 479 xskb->dma = xskb->frame_dma + pool->headroom + 480 XDP_PACKET_HEADROOM; 481 } 482 return xskb; 483 } 484 485 struct xdp_buff *xp_alloc(struct xsk_buff_pool *pool) 486 { 487 struct xdp_buff_xsk *xskb; 488 489 if (!pool->free_list_cnt) { 490 xskb = __xp_alloc(pool); 491 if (!xskb) 492 return NULL; 493 } else { 494 pool->free_list_cnt--; 495 xskb = list_first_entry(&pool->free_list, struct xdp_buff_xsk, 496 free_list_node); 497 list_del(&xskb->free_list_node); 498 } 499 500 xskb->xdp.data = xskb->xdp.data_hard_start + XDP_PACKET_HEADROOM; 501 xskb->xdp.data_meta = xskb->xdp.data; 502 503 if (pool->dma_need_sync) { 504 dma_sync_single_range_for_device(pool->dev, xskb->dma, 0, 505 pool->frame_len, 506 DMA_BIDIRECTIONAL); 507 } 508 return &xskb->xdp; 509 } 510 EXPORT_SYMBOL(xp_alloc); 511 512 bool xp_can_alloc(struct xsk_buff_pool *pool, u32 count) 513 { 514 if (pool->free_list_cnt >= count) 515 return true; 516 return xskq_cons_has_entries(pool->fq, count - pool->free_list_cnt); 517 } 518 EXPORT_SYMBOL(xp_can_alloc); 519 520 void xp_free(struct xdp_buff_xsk *xskb) 521 { 522 xskb->pool->free_list_cnt++; 523 list_add(&xskb->free_list_node, &xskb->pool->free_list); 524 } 525 EXPORT_SYMBOL(xp_free); 526 527 void *xp_raw_get_data(struct xsk_buff_pool *pool, u64 addr) 528 { 529 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; 530 return pool->addrs + addr; 531 } 532 EXPORT_SYMBOL(xp_raw_get_data); 533 534 dma_addr_t xp_raw_get_dma(struct xsk_buff_pool *pool, u64 addr) 535 { 536 addr = pool->unaligned ? xp_unaligned_add_offset_to_addr(addr) : addr; 537 return (pool->dma_pages[addr >> PAGE_SHIFT] & 538 ~XSK_NEXT_PG_CONTIG_MASK) + 539 (addr & ~PAGE_MASK); 540 } 541 EXPORT_SYMBOL(xp_raw_get_dma); 542 543 void xp_dma_sync_for_cpu_slow(struct xdp_buff_xsk *xskb) 544 { 545 dma_sync_single_range_for_cpu(xskb->pool->dev, xskb->dma, 0, 546 xskb->pool->frame_len, DMA_BIDIRECTIONAL); 547 } 548 EXPORT_SYMBOL(xp_dma_sync_for_cpu_slow); 549 550 void xp_dma_sync_for_device_slow(struct xsk_buff_pool *pool, dma_addr_t dma, 551 size_t size) 552 { 553 dma_sync_single_range_for_device(pool->dev, dma, 0, 554 size, DMA_BIDIRECTIONAL); 555 } 556 EXPORT_SYMBOL(xp_dma_sync_for_device_slow); 557