1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright(c) 2007-2010 Intel Corporation. All rights reserved. 24 */ 25 26 /* 27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. 28 */ 29 30 #include "igb_sw.h" 31 32 static boolean_t igb_tx(igb_tx_ring_t *, mblk_t *); 33 static int igb_tx_copy(igb_tx_ring_t *, tx_control_block_t *, mblk_t *, 34 uint32_t, boolean_t); 35 static int igb_tx_bind(igb_tx_ring_t *, tx_control_block_t *, mblk_t *, 36 uint32_t); 37 static int igb_tx_fill_ring(igb_tx_ring_t *, link_list_t *, tx_context_t *, 38 size_t); 39 static void igb_save_desc(tx_control_block_t *, uint64_t, size_t); 40 static tx_control_block_t *igb_get_free_list(igb_tx_ring_t *); 41 static int igb_get_tx_context(mblk_t *, tx_context_t *); 42 static boolean_t igb_check_tx_context(igb_tx_ring_t *, tx_context_t *); 43 static void igb_fill_tx_context(struct e1000_adv_tx_context_desc *, 44 tx_context_t *, uint32_t); 45 46 #ifndef IGB_DEBUG 47 #pragma inline(igb_save_desc) 48 #pragma inline(igb_get_tx_context) 49 #pragma inline(igb_check_tx_context) 50 #pragma inline(igb_fill_tx_context) 51 #endif 52 53 mblk_t * 54 igb_tx_ring_send(void *arg, mblk_t *mp) 55 { 56 igb_tx_ring_t *tx_ring = (igb_tx_ring_t *)arg; 57 igb_t *igb; 58 59 ASSERT(tx_ring != NULL); 60 61 igb = tx_ring->igb; 62 63 if ((igb->igb_state & IGB_SUSPENDED) || 64 (igb->igb_state & IGB_ERROR) || 65 !(igb->igb_state & IGB_STARTED) || 66 igb->link_state != LINK_STATE_UP) { 67 freemsg(mp); 68 return (NULL); 69 } 70 71 return ((igb_tx(tx_ring, mp)) ? NULL : mp); 72 } 73 74 /* 75 * igb_tx - Main transmit processing 76 * 77 * Called from igb_m_tx with an mblk ready to transmit. this 78 * routine sets up the transmit descriptors and sends data to 79 * the wire. 80 * 81 * One mblk can consist of several fragments, each fragment 82 * will be processed with different methods based on the size. 83 * For the fragments with size less than the bcopy threshold, 84 * they will be processed by using bcopy; otherwise, they will 85 * be processed by using DMA binding. 86 * 87 * To process the mblk, a tx control block is got from the 88 * free list. One tx control block contains one tx buffer, which 89 * is used to copy mblk fragments' data; and one tx DMA handle, 90 * which is used to bind a mblk fragment with DMA resource. 91 * 92 * Several small mblk fragments can be copied into one tx control 93 * block's buffer, and then the buffer will be transmitted with 94 * one tx descriptor. 95 * 96 * A large fragment only binds with one tx control block's DMA 97 * handle, and it can span several tx descriptors for transmitting. 98 * 99 * So to transmit a packet (mblk), several tx control blocks can 100 * be used. After the processing, those tx control blocks will 101 * be put to the work list. 102 */ 103 static boolean_t 104 igb_tx(igb_tx_ring_t *tx_ring, mblk_t *mp) 105 { 106 igb_t *igb = tx_ring->igb; 107 tx_type_t current_flag, next_flag; 108 uint32_t current_len, next_len; 109 uint32_t desc_total; 110 size_t mbsize; 111 int desc_num; 112 boolean_t copy_done, eop; 113 mblk_t *current_mp, *next_mp, *nmp; 114 tx_control_block_t *tcb; 115 tx_context_t tx_context, *ctx; 116 link_list_t pending_list; 117 mblk_t *hdr_new_mp = NULL; 118 mblk_t *hdr_previous_mp = NULL; 119 mblk_t *hdr_current_mp = NULL; 120 uint32_t hdr_frag_len; 121 uint32_t hdr_len, len; 122 uint32_t copy_thresh; 123 124 copy_thresh = igb->tx_copy_thresh; 125 126 /* Get the mblk size */ 127 mbsize = 0; 128 for (nmp = mp; nmp != NULL; nmp = nmp->b_cont) { 129 mbsize += MBLKL(nmp); 130 } 131 132 if (igb->tx_hcksum_enable) { 133 ctx = &tx_context; 134 /* 135 * Retrieve offloading context information from the mblk 136 * that will be used to decide whether/how to fill the 137 * context descriptor. 138 */ 139 if (igb_get_tx_context(mp, ctx) != TX_CXT_SUCCESS) { 140 freemsg(mp); 141 return (B_TRUE); 142 } 143 144 if ((ctx->lso_flag && 145 (mbsize > (ctx->mac_hdr_len + IGB_LSO_MAXLEN))) || 146 (!ctx->lso_flag && 147 (mbsize > (igb->max_frame_size - ETHERFCSL)))) { 148 freemsg(mp); 149 IGB_DEBUGLOG_0(igb, "igb_tx: packet oversize"); 150 return (B_TRUE); 151 } 152 } else { 153 ctx = NULL; 154 if (mbsize > (igb->max_frame_size - ETHERFCSL)) { 155 freemsg(mp); 156 IGB_DEBUGLOG_0(igb, "igb_tx: packet oversize"); 157 return (B_TRUE); 158 } 159 } 160 161 /* 162 * Check and recycle tx descriptors. 163 * The recycle threshold here should be selected carefully 164 */ 165 if (tx_ring->tbd_free < igb->tx_recycle_thresh) 166 tx_ring->tx_recycle(tx_ring); 167 168 /* 169 * After the recycling, if the tbd_free is less than the 170 * tx_overload_threshold, assert overload, return B_FALSE; 171 * and we need to re-schedule the tx again. 172 */ 173 if (tx_ring->tbd_free < igb->tx_overload_thresh) { 174 tx_ring->reschedule = B_TRUE; 175 IGB_DEBUG_STAT(tx_ring->stat_overload); 176 return (B_FALSE); 177 } 178 179 /* 180 * The software should guarantee LSO packet header(MAC+IP+TCP) 181 * to be within one descriptor - this is required by h/w. 182 * Here will reallocate and refill the header if 183 * the headers(MAC+IP+TCP) is physical memory non-contiguous. 184 */ 185 if (ctx && ctx->lso_flag) { 186 hdr_len = ctx->mac_hdr_len + ctx->ip_hdr_len + ctx->l4_hdr_len; 187 len = MBLKL(mp); 188 hdr_current_mp = mp; 189 while (len < hdr_len) { 190 hdr_previous_mp = hdr_current_mp; 191 hdr_current_mp = hdr_current_mp->b_cont; 192 len += MBLKL(hdr_current_mp); 193 } 194 /* 195 * If the header and the payload are in different mblks, 196 * we simply force the header to be copied into pre-allocated 197 * page-aligned buffer. 198 */ 199 if (len == hdr_len) 200 goto adjust_threshold; 201 202 hdr_frag_len = hdr_len - (len - MBLKL(hdr_current_mp)); 203 /* 204 * There are two cases we will reallocate 205 * a mblk for the last header fragment. 206 * 1. the header is in multiple mblks and 207 * the last fragment shares the same mblk 208 * with the payload 209 * 2. the header is in a single mblk shared 210 * with the payload but the header crosses 211 * a page. 212 */ 213 if ((hdr_current_mp != mp) || 214 (P2NPHASE((uintptr_t)hdr_current_mp->b_rptr, igb->page_size) 215 < hdr_len)) { 216 /* 217 * reallocate the mblk for the last header fragment, 218 * expect it to be copied into pre-allocated 219 * page-aligned buffer 220 */ 221 hdr_new_mp = allocb(hdr_frag_len, NULL); 222 if (!hdr_new_mp) { 223 return (B_FALSE); 224 } 225 226 /* link the new header fragment with the other parts */ 227 bcopy(hdr_current_mp->b_rptr, 228 hdr_new_mp->b_rptr, hdr_frag_len); 229 hdr_new_mp->b_wptr = hdr_new_mp->b_rptr + hdr_frag_len; 230 hdr_new_mp->b_cont = hdr_current_mp; 231 if (hdr_previous_mp) 232 hdr_previous_mp->b_cont = hdr_new_mp; 233 else 234 mp = hdr_new_mp; 235 hdr_current_mp->b_rptr += hdr_frag_len; 236 } 237 adjust_threshold: 238 /* 239 * adjust the bcopy threshhold to guarantee 240 * the header to use bcopy way 241 */ 242 if (copy_thresh < hdr_len) 243 copy_thresh = hdr_len; 244 } 245 246 /* 247 * The pending_list is a linked list that is used to save 248 * the tx control blocks that have packet data processed 249 * but have not put the data to the tx descriptor ring. 250 * It is used to reduce the lock contention of the tx_lock. 251 */ 252 LINK_LIST_INIT(&pending_list); 253 desc_num = 0; 254 desc_total = 0; 255 256 current_mp = mp; 257 current_len = MBLKL(current_mp); 258 /* 259 * Decide which method to use for the first fragment 260 */ 261 current_flag = (current_len <= copy_thresh) ? 262 USE_COPY : USE_DMA; 263 /* 264 * If the mblk includes several contiguous small fragments, 265 * they may be copied into one buffer. This flag is used to 266 * indicate whether there are pending fragments that need to 267 * be copied to the current tx buffer. 268 * 269 * If this flag is B_TRUE, it indicates that a new tx control 270 * block is needed to process the next fragment using either 271 * copy or DMA binding. 272 * 273 * Otherwise, it indicates that the next fragment will be 274 * copied to the current tx buffer that is maintained by the 275 * current tx control block. No new tx control block is needed. 276 */ 277 copy_done = B_TRUE; 278 while (current_mp) { 279 next_mp = current_mp->b_cont; 280 eop = (next_mp == NULL); /* Last fragment of the packet? */ 281 next_len = eop ? 0: MBLKL(next_mp); 282 283 /* 284 * When the current fragment is an empty fragment, if 285 * the next fragment will still be copied to the current 286 * tx buffer, we cannot skip this fragment here. Because 287 * the copy processing is pending for completion. We have 288 * to process this empty fragment in the tx_copy routine. 289 * 290 * If the copy processing is completed or a DMA binding 291 * processing is just completed, we can just skip this 292 * empty fragment. 293 */ 294 if ((current_len == 0) && (copy_done)) { 295 current_mp = next_mp; 296 current_len = next_len; 297 current_flag = (current_len <= copy_thresh) ? 298 USE_COPY : USE_DMA; 299 continue; 300 } 301 302 if (copy_done) { 303 /* 304 * Get a new tx control block from the free list 305 */ 306 tcb = igb_get_free_list(tx_ring); 307 308 if (tcb == NULL) { 309 IGB_DEBUG_STAT(tx_ring->stat_fail_no_tcb); 310 goto tx_failure; 311 } 312 313 /* 314 * Push the tx control block to the pending list 315 * to avoid using lock too early 316 */ 317 LIST_PUSH_TAIL(&pending_list, &tcb->link); 318 } 319 320 if (current_flag == USE_COPY) { 321 /* 322 * Check whether to use bcopy or DMA binding to process 323 * the next fragment, and if using bcopy, whether we 324 * need to continue copying the next fragment into the 325 * current tx buffer. 326 */ 327 ASSERT((tcb->tx_buf.len + current_len) <= 328 tcb->tx_buf.size); 329 330 if (eop) { 331 /* 332 * This is the last fragment of the packet, so 333 * the copy processing will be completed with 334 * this fragment. 335 */ 336 next_flag = USE_NONE; 337 copy_done = B_TRUE; 338 } else if ((tcb->tx_buf.len + current_len + next_len) > 339 tcb->tx_buf.size) { 340 /* 341 * If the next fragment is too large to be 342 * copied to the current tx buffer, we need 343 * to complete the current copy processing. 344 */ 345 next_flag = (next_len > copy_thresh) ? 346 USE_DMA: USE_COPY; 347 copy_done = B_TRUE; 348 } else if (next_len > copy_thresh) { 349 /* 350 * The next fragment needs to be processed with 351 * DMA binding. So the copy prcessing will be 352 * completed with the current fragment. 353 */ 354 next_flag = USE_DMA; 355 copy_done = B_TRUE; 356 } else { 357 /* 358 * Continue to copy the next fragment to the 359 * current tx buffer. 360 */ 361 next_flag = USE_COPY; 362 copy_done = B_FALSE; 363 } 364 365 desc_num = igb_tx_copy(tx_ring, tcb, current_mp, 366 current_len, copy_done); 367 } else { 368 /* 369 * Check whether to use bcopy or DMA binding to process 370 * the next fragment. 371 */ 372 next_flag = (next_len > copy_thresh) ? 373 USE_DMA: USE_COPY; 374 ASSERT(copy_done == B_TRUE); 375 376 desc_num = igb_tx_bind(tx_ring, tcb, current_mp, 377 current_len); 378 } 379 380 if (desc_num > 0) 381 desc_total += desc_num; 382 else if (desc_num < 0) 383 goto tx_failure; 384 385 current_mp = next_mp; 386 current_len = next_len; 387 current_flag = next_flag; 388 } 389 390 /* 391 * Attach the mblk to the last tx control block 392 */ 393 ASSERT(tcb); 394 ASSERT(tcb->mp == NULL); 395 tcb->mp = mp; 396 397 /* 398 * Before fill the tx descriptor ring with the data, we need to 399 * ensure there are adequate free descriptors for transmit 400 * (including one context descriptor). 401 * Do not use up all the tx descriptors. 402 * Otherwise tx recycle will fail and cause false hang. 403 */ 404 if (tx_ring->tbd_free <= (desc_total + 1)) { 405 tx_ring->tx_recycle(tx_ring); 406 } 407 408 mutex_enter(&tx_ring->tx_lock); 409 410 /* 411 * If the number of free tx descriptors is not enough for transmit 412 * then return failure. 413 * 414 * Note: we must put this check under the mutex protection to 415 * ensure the correctness when multiple threads access it in 416 * parallel. 417 */ 418 if (tx_ring->tbd_free <= (desc_total + 1)) { 419 IGB_DEBUG_STAT(tx_ring->stat_fail_no_tbd); 420 mutex_exit(&tx_ring->tx_lock); 421 goto tx_failure; 422 } 423 424 desc_num = igb_tx_fill_ring(tx_ring, &pending_list, ctx, mbsize); 425 426 ASSERT((desc_num == desc_total) || (desc_num == (desc_total + 1))); 427 428 /* Update per-ring tx statistics */ 429 tx_ring->tx_pkts++; 430 tx_ring->tx_bytes += mbsize; 431 432 mutex_exit(&tx_ring->tx_lock); 433 434 return (B_TRUE); 435 436 tx_failure: 437 /* 438 * If new mblk has been allocted for the last header 439 * fragment of a LSO packet, we should restore the 440 * modified mp. 441 */ 442 if (hdr_new_mp) { 443 hdr_new_mp->b_cont = NULL; 444 freeb(hdr_new_mp); 445 hdr_current_mp->b_rptr -= hdr_frag_len; 446 if (hdr_previous_mp) 447 hdr_previous_mp->b_cont = hdr_current_mp; 448 else 449 mp = hdr_current_mp; 450 } 451 452 /* 453 * Discard the mblk and free the used resources 454 */ 455 tcb = (tx_control_block_t *)LIST_GET_HEAD(&pending_list); 456 while (tcb) { 457 tcb->mp = NULL; 458 459 igb_free_tcb(tcb); 460 461 tcb = (tx_control_block_t *) 462 LIST_GET_NEXT(&pending_list, &tcb->link); 463 } 464 465 /* 466 * Return the tx control blocks in the pending list to the free list. 467 */ 468 igb_put_free_list(tx_ring, &pending_list); 469 470 /* Transmit failed, do not drop the mblk, rechedule the transmit */ 471 tx_ring->reschedule = B_TRUE; 472 473 return (B_FALSE); 474 } 475 476 /* 477 * igb_tx_copy 478 * 479 * Copy the mblk fragment to the pre-allocated tx buffer 480 */ 481 static int 482 igb_tx_copy(igb_tx_ring_t *tx_ring, tx_control_block_t *tcb, mblk_t *mp, 483 uint32_t len, boolean_t copy_done) 484 { 485 dma_buffer_t *tx_buf; 486 uint32_t desc_num; 487 _NOTE(ARGUNUSED(tx_ring)); 488 489 tx_buf = &tcb->tx_buf; 490 491 /* 492 * Copy the packet data of the mblk fragment into the 493 * pre-allocated tx buffer, which is maintained by the 494 * tx control block. 495 * 496 * Several mblk fragments can be copied into one tx buffer. 497 * The destination address of the current copied fragment in 498 * the tx buffer is next to the end of the previous copied 499 * fragment. 500 */ 501 if (len > 0) { 502 bcopy(mp->b_rptr, tx_buf->address + tx_buf->len, len); 503 504 tx_buf->len += len; 505 tcb->frag_num++; 506 } 507 508 desc_num = 0; 509 510 /* 511 * If it is the last fragment copied to the current tx buffer, 512 * in other words, if there's no remaining fragment or the remaining 513 * fragment requires a new tx control block to process, we need to 514 * complete the current copy processing by syncing up the current 515 * DMA buffer and saving the descriptor data. 516 */ 517 if (copy_done) { 518 /* 519 * Sync the DMA buffer of the packet data 520 */ 521 DMA_SYNC(tx_buf, DDI_DMA_SYNC_FORDEV); 522 523 tcb->tx_type = USE_COPY; 524 525 /* 526 * Save the address and length to the private data structure 527 * of the tx control block, which will be used to fill the 528 * tx descriptor ring after all the fragments are processed. 529 */ 530 igb_save_desc(tcb, tx_buf->dma_address, tx_buf->len); 531 desc_num++; 532 } 533 534 return (desc_num); 535 } 536 537 /* 538 * igb_tx_bind 539 * 540 * Bind the mblk fragment with DMA 541 */ 542 static int 543 igb_tx_bind(igb_tx_ring_t *tx_ring, tx_control_block_t *tcb, mblk_t *mp, 544 uint32_t len) 545 { 546 int status, i; 547 ddi_dma_cookie_t dma_cookie; 548 uint_t ncookies; 549 int desc_num; 550 551 /* 552 * Use DMA binding to process the mblk fragment 553 */ 554 status = ddi_dma_addr_bind_handle(tcb->tx_dma_handle, NULL, 555 (caddr_t)mp->b_rptr, len, 556 DDI_DMA_WRITE | DDI_DMA_STREAMING, DDI_DMA_DONTWAIT, 557 0, &dma_cookie, &ncookies); 558 559 if (status != DDI_DMA_MAPPED) { 560 IGB_DEBUG_STAT(tx_ring->stat_fail_dma_bind); 561 return (-1); 562 } 563 564 tcb->frag_num++; 565 tcb->tx_type = USE_DMA; 566 /* 567 * Each fragment can span several cookies. One cookie will have 568 * one tx descriptor to transmit. 569 */ 570 desc_num = 0; 571 for (i = ncookies; i > 0; i--) { 572 /* 573 * Save the address and length to the private data structure 574 * of the tx control block, which will be used to fill the 575 * tx descriptor ring after all the fragments are processed. 576 */ 577 igb_save_desc(tcb, 578 dma_cookie.dmac_laddress, 579 dma_cookie.dmac_size); 580 581 desc_num++; 582 583 if (i > 1) 584 ddi_dma_nextcookie(tcb->tx_dma_handle, &dma_cookie); 585 } 586 587 return (desc_num); 588 } 589 590 /* 591 * igb_get_tx_context 592 * 593 * Get the tx context information from the mblk 594 */ 595 static int 596 igb_get_tx_context(mblk_t *mp, tx_context_t *ctx) 597 { 598 uint32_t start; 599 uint32_t flags; 600 uint32_t lso_flag; 601 uint32_t mss; 602 uint32_t len; 603 uint32_t size; 604 uint32_t offset; 605 unsigned char *pos; 606 ushort_t etype; 607 uint32_t mac_hdr_len; 608 uint32_t l4_proto; 609 uint32_t l4_hdr_len; 610 611 ASSERT(mp != NULL); 612 613 mac_hcksum_get(mp, &start, NULL, NULL, NULL, &flags); 614 bzero(ctx, sizeof (tx_context_t)); 615 616 ctx->hcksum_flags = flags; 617 618 if (flags == 0) 619 return (TX_CXT_SUCCESS); 620 621 mac_lso_get(mp, &mss, &lso_flag); 622 ctx->mss = mss; 623 ctx->lso_flag = (lso_flag == HW_LSO); 624 625 /* 626 * LSO relies on tx h/w checksum, so here the packet will be 627 * dropped if the h/w checksum flags are not set. 628 */ 629 if (ctx->lso_flag) { 630 if (!((ctx->hcksum_flags & HCK_PARTIALCKSUM) && 631 (ctx->hcksum_flags & HCK_IPV4_HDRCKSUM))) { 632 IGB_DEBUGLOG_0(NULL, "igb_tx: h/w " 633 "checksum flags are not set for LSO"); 634 return (TX_CXT_E_LSO_CSUM); 635 } 636 } 637 638 etype = 0; 639 mac_hdr_len = 0; 640 l4_proto = 0; 641 642 /* 643 * Firstly get the position of the ether_type/ether_tpid. 644 * Here we don't assume the ether (VLAN) header is fully included 645 * in one mblk fragment, so we go thourgh the fragments to parse 646 * the ether type. 647 */ 648 size = len = MBLKL(mp); 649 offset = offsetof(struct ether_header, ether_type); 650 while (size <= offset) { 651 mp = mp->b_cont; 652 ASSERT(mp != NULL); 653 len = MBLKL(mp); 654 size += len; 655 } 656 pos = mp->b_rptr + offset + len - size; 657 658 etype = ntohs(*(ushort_t *)(uintptr_t)pos); 659 if (etype == ETHERTYPE_VLAN) { 660 /* 661 * Get the position of the ether_type in VLAN header 662 */ 663 offset = offsetof(struct ether_vlan_header, ether_type); 664 while (size <= offset) { 665 mp = mp->b_cont; 666 ASSERT(mp != NULL); 667 len = MBLKL(mp); 668 size += len; 669 } 670 pos = mp->b_rptr + offset + len - size; 671 672 etype = ntohs(*(ushort_t *)(uintptr_t)pos); 673 mac_hdr_len = sizeof (struct ether_vlan_header); 674 } else { 675 mac_hdr_len = sizeof (struct ether_header); 676 } 677 678 /* 679 * Here we assume the IP(V6) header is fully included in one 680 * mblk fragment. 681 */ 682 switch (etype) { 683 case ETHERTYPE_IP: 684 offset = mac_hdr_len; 685 while (size <= offset) { 686 mp = mp->b_cont; 687 ASSERT(mp != NULL); 688 len = MBLKL(mp); 689 size += len; 690 } 691 pos = mp->b_rptr + offset + len - size; 692 693 if (ctx->lso_flag) { 694 *((uint16_t *)(uintptr_t)(pos + offsetof(ipha_t, 695 ipha_length))) = 0; 696 697 /* 698 * To utilize igb LSO, here need to fill 699 * the tcp checksum field of the packet with the 700 * following pseudo-header checksum: 701 * (ip_source_addr, ip_destination_addr, l4_proto) 702 * and also need to fill the ip header checksum 703 * with zero. Currently the tcp/ip stack has done 704 * these. 705 */ 706 } 707 708 l4_proto = *(uint8_t *)(pos + offsetof(ipha_t, ipha_protocol)); 709 break; 710 case ETHERTYPE_IPV6: 711 offset = offsetof(ip6_t, ip6_nxt) + mac_hdr_len; 712 while (size <= offset) { 713 mp = mp->b_cont; 714 ASSERT(mp != NULL); 715 len = MBLKL(mp); 716 size += len; 717 } 718 pos = mp->b_rptr + offset + len - size; 719 720 l4_proto = *(uint8_t *)pos; 721 break; 722 default: 723 /* Unrecoverable error */ 724 IGB_DEBUGLOG_0(NULL, "Ethernet type field error with " 725 "tx hcksum flag set"); 726 return (TX_CXT_E_ETHER_TYPE); 727 } 728 729 if (ctx->lso_flag) { 730 offset = mac_hdr_len + start; 731 while (size <= offset) { 732 mp = mp->b_cont; 733 ASSERT(mp != NULL); 734 len = MBLKL(mp); 735 size += len; 736 } 737 pos = mp->b_rptr + offset + len - size; 738 739 l4_hdr_len = TCP_HDR_LENGTH((tcph_t *)pos); 740 } else { 741 /* 742 * l4 header length is only required for LSO 743 */ 744 l4_hdr_len = 0; 745 } 746 747 ctx->mac_hdr_len = mac_hdr_len; 748 ctx->ip_hdr_len = start; 749 ctx->l4_proto = l4_proto; 750 ctx->l4_hdr_len = l4_hdr_len; 751 752 return (TX_CXT_SUCCESS); 753 } 754 755 /* 756 * igb_check_tx_context 757 * 758 * Check if a new context descriptor is needed 759 */ 760 static boolean_t 761 igb_check_tx_context(igb_tx_ring_t *tx_ring, tx_context_t *ctx) 762 { 763 tx_context_t *last; 764 765 if (ctx == NULL) 766 return (B_FALSE); 767 768 /* 769 * Compare the context data retrieved from the mblk and the 770 * stored context data of the last context descriptor. The data 771 * need to be checked are: 772 * hcksum_flags 773 * l4_proto 774 * mss (only check for LSO) 775 * l4_hdr_len (only check for LSO) 776 * ip_hdr_len 777 * mac_hdr_len 778 * Either one of the above data is changed, a new context descriptor 779 * will be needed. 780 */ 781 last = &tx_ring->tx_context; 782 783 if (ctx->hcksum_flags != 0) { 784 if ((ctx->hcksum_flags != last->hcksum_flags) || 785 (ctx->l4_proto != last->l4_proto) || 786 (ctx->lso_flag && ((ctx->mss != last->mss) || 787 (ctx->l4_hdr_len != last->l4_hdr_len))) || 788 (ctx->ip_hdr_len != last->ip_hdr_len) || 789 (ctx->mac_hdr_len != last->mac_hdr_len)) { 790 return (B_TRUE); 791 } 792 } 793 794 return (B_FALSE); 795 } 796 797 /* 798 * igb_fill_tx_context 799 * 800 * Fill the context descriptor with hardware checksum informations 801 */ 802 static void 803 igb_fill_tx_context(struct e1000_adv_tx_context_desc *ctx_tbd, 804 tx_context_t *ctx, uint32_t ring_index) 805 { 806 /* 807 * Fill the context descriptor with the checksum 808 * context information we've got 809 */ 810 ctx_tbd->vlan_macip_lens = ctx->ip_hdr_len; 811 ctx_tbd->vlan_macip_lens |= ctx->mac_hdr_len << 812 E1000_ADVTXD_MACLEN_SHIFT; 813 814 ctx_tbd->type_tucmd_mlhl = 815 E1000_ADVTXD_DCMD_DEXT | E1000_ADVTXD_DTYP_CTXT; 816 817 if (ctx->hcksum_flags & HCK_IPV4_HDRCKSUM) 818 ctx_tbd->type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_IPV4; 819 820 if (ctx->hcksum_flags & HCK_PARTIALCKSUM) { 821 switch (ctx->l4_proto) { 822 case IPPROTO_TCP: 823 ctx_tbd->type_tucmd_mlhl |= E1000_ADVTXD_TUCMD_L4T_TCP; 824 break; 825 case IPPROTO_UDP: 826 /* 827 * We don't have to explicitly set: 828 * ctx_tbd->type_tucmd_mlhl |= 829 * E1000_ADVTXD_TUCMD_L4T_UDP; 830 * Because E1000_ADVTXD_TUCMD_L4T_UDP == 0b 831 */ 832 break; 833 default: 834 /* Unrecoverable error */ 835 IGB_DEBUGLOG_0(NULL, "L4 type error with tx hcksum"); 836 break; 837 } 838 } 839 840 ctx_tbd->seqnum_seed = 0; 841 ctx_tbd->mss_l4len_idx = ring_index << 4; 842 if (ctx->lso_flag) { 843 ctx_tbd->mss_l4len_idx |= 844 (ctx->l4_hdr_len << E1000_ADVTXD_L4LEN_SHIFT) | 845 (ctx->mss << E1000_ADVTXD_MSS_SHIFT); 846 } 847 } 848 849 /* 850 * igb_tx_fill_ring 851 * 852 * Fill the tx descriptor ring with the data 853 */ 854 static int 855 igb_tx_fill_ring(igb_tx_ring_t *tx_ring, link_list_t *pending_list, 856 tx_context_t *ctx, size_t mbsize) 857 { 858 struct e1000_hw *hw = &tx_ring->igb->hw; 859 boolean_t load_context; 860 uint32_t index, tcb_index, desc_num; 861 union e1000_adv_tx_desc *tbd, *first_tbd; 862 tx_control_block_t *tcb, *first_tcb; 863 uint32_t hcksum_flags; 864 int i; 865 igb_t *igb = tx_ring->igb; 866 867 ASSERT(mutex_owned(&tx_ring->tx_lock)); 868 869 tbd = NULL; 870 first_tbd = NULL; 871 first_tcb = NULL; 872 desc_num = 0; 873 hcksum_flags = 0; 874 load_context = B_FALSE; 875 876 /* 877 * Get the index of the first tx descriptor that will be filled, 878 * and the index of the first work list item that will be attached 879 * with the first used tx control block in the pending list. 880 * Note: the two indexes are the same. 881 */ 882 index = tx_ring->tbd_tail; 883 tcb_index = tx_ring->tbd_tail; 884 885 if (ctx != NULL) { 886 hcksum_flags = ctx->hcksum_flags; 887 888 /* 889 * Check if a new context descriptor is needed for this packet 890 */ 891 load_context = igb_check_tx_context(tx_ring, ctx); 892 if (load_context) { 893 tbd = &tx_ring->tbd_ring[index]; 894 895 /* 896 * Fill the context descriptor with the 897 * hardware checksum offload informations. 898 */ 899 igb_fill_tx_context( 900 (struct e1000_adv_tx_context_desc *)tbd, 901 ctx, tx_ring->index); 902 903 index = NEXT_INDEX(index, 1, tx_ring->ring_size); 904 desc_num++; 905 906 /* 907 * Store the checksum context data if 908 * a new context descriptor is added 909 */ 910 tx_ring->tx_context = *ctx; 911 } 912 } 913 914 first_tbd = &tx_ring->tbd_ring[index]; 915 916 /* 917 * Fill tx data descriptors with the data saved in the pending list. 918 * The tx control blocks in the pending list are added to the work list 919 * at the same time. 920 * 921 * The work list is strictly 1:1 corresponding to the descriptor ring. 922 * One item of the work list corresponds to one tx descriptor. Because 923 * one tx control block can span multiple tx descriptors, the tx 924 * control block will be added to the first work list item that 925 * corresponds to the first tx descriptor generated from that tx 926 * control block. 927 */ 928 tcb = (tx_control_block_t *)LIST_POP_HEAD(pending_list); 929 first_tcb = tcb; 930 while (tcb != NULL) { 931 932 for (i = 0; i < tcb->desc_num; i++) { 933 tbd = &tx_ring->tbd_ring[index]; 934 935 tbd->read.buffer_addr = tcb->desc[i].address; 936 tbd->read.cmd_type_len = tcb->desc[i].length; 937 938 tbd->read.cmd_type_len |= E1000_ADVTXD_DCMD_RS | 939 E1000_ADVTXD_DCMD_DEXT | E1000_ADVTXD_DTYP_DATA | 940 E1000_ADVTXD_DCMD_IFCS; 941 942 tbd->read.olinfo_status = 0; 943 944 index = NEXT_INDEX(index, 1, tx_ring->ring_size); 945 desc_num++; 946 } 947 948 /* 949 * Add the tx control block to the work list 950 */ 951 ASSERT(tx_ring->work_list[tcb_index] == NULL); 952 tx_ring->work_list[tcb_index] = tcb; 953 954 tcb_index = index; 955 tcb = (tx_control_block_t *)LIST_POP_HEAD(pending_list); 956 } 957 958 if (load_context) { 959 /* 960 * Count the checksum context descriptor for 961 * the first tx control block. 962 */ 963 first_tcb->desc_num++; 964 } 965 first_tcb->last_index = PREV_INDEX(index, 1, tx_ring->ring_size); 966 967 /* 968 * The Insert Ethernet CRC (IFCS) bit and the checksum fields are only 969 * valid in the first descriptor of the packet. 970 * 82576 also requires the payload length setting even without LSO 971 */ 972 ASSERT(first_tbd != NULL); 973 first_tbd->read.cmd_type_len |= E1000_ADVTXD_DCMD_IFCS; 974 if (ctx != NULL && ctx->lso_flag) { 975 first_tbd->read.cmd_type_len |= E1000_ADVTXD_DCMD_TSE; 976 first_tbd->read.olinfo_status |= 977 (mbsize - ctx->mac_hdr_len - ctx->ip_hdr_len 978 - ctx->l4_hdr_len) << E1000_ADVTXD_PAYLEN_SHIFT; 979 } else { 980 if (hw->mac.type >= e1000_82576) { 981 first_tbd->read.olinfo_status |= 982 (mbsize << E1000_ADVTXD_PAYLEN_SHIFT); 983 } 984 } 985 986 /* Set hardware checksum bits */ 987 if (hcksum_flags != 0) { 988 if (hcksum_flags & HCK_IPV4_HDRCKSUM) 989 first_tbd->read.olinfo_status |= 990 E1000_TXD_POPTS_IXSM << 8; 991 if (hcksum_flags & HCK_PARTIALCKSUM) 992 first_tbd->read.olinfo_status |= 993 E1000_TXD_POPTS_TXSM << 8; 994 first_tbd->read.olinfo_status |= tx_ring->index << 4; 995 } 996 997 /* 998 * The last descriptor of packet needs End Of Packet (EOP), 999 * and Report Status (RS) bits set 1000 */ 1001 ASSERT(tbd != NULL); 1002 tbd->read.cmd_type_len |= 1003 E1000_ADVTXD_DCMD_EOP | E1000_ADVTXD_DCMD_RS; 1004 1005 IGB_DEBUG_STAT(tx_ring->stat_pkt_cnt); 1006 1007 /* 1008 * Sync the DMA buffer of the tx descriptor ring 1009 */ 1010 DMA_SYNC(&tx_ring->tbd_area, DDI_DMA_SYNC_FORDEV); 1011 1012 /* 1013 * Update the number of the free tx descriptors. 1014 * The mutual exclusion between the transmission and the recycling 1015 * (for the tx descriptor ring and the work list) is implemented 1016 * with the atomic operation on the number of the free tx descriptors. 1017 * 1018 * Note: we should always decrement the counter tbd_free before 1019 * advancing the hardware TDT pointer to avoid the race condition - 1020 * before the counter tbd_free is decremented, the transmit of the 1021 * tx descriptors has done and the counter tbd_free is increased by 1022 * the tx recycling. 1023 */ 1024 i = igb_atomic_reserve(&tx_ring->tbd_free, desc_num); 1025 ASSERT(i >= 0); 1026 1027 tx_ring->tbd_tail = index; 1028 1029 /* 1030 * Advance the hardware TDT pointer of the tx descriptor ring 1031 */ 1032 E1000_WRITE_REG(hw, E1000_TDT(tx_ring->index), index); 1033 1034 if (igb_check_acc_handle(igb->osdep.reg_handle) != DDI_FM_OK) { 1035 ddi_fm_service_impact(igb->dip, DDI_SERVICE_DEGRADED); 1036 atomic_or_32(&igb->igb_state, IGB_ERROR); 1037 } 1038 1039 return (desc_num); 1040 } 1041 1042 /* 1043 * igb_save_desc 1044 * 1045 * Save the address/length pair to the private array 1046 * of the tx control block. The address/length pairs 1047 * will be filled into the tx descriptor ring later. 1048 */ 1049 static void 1050 igb_save_desc(tx_control_block_t *tcb, uint64_t address, size_t length) 1051 { 1052 sw_desc_t *desc; 1053 1054 desc = &tcb->desc[tcb->desc_num]; 1055 desc->address = address; 1056 desc->length = length; 1057 1058 tcb->desc_num++; 1059 } 1060 1061 /* 1062 * igb_tx_recycle_legacy 1063 * 1064 * Recycle the tx descriptors and tx control blocks. 1065 * 1066 * The work list is traversed to check if the corresponding 1067 * tx descriptors have been transmitted. If so, the resources 1068 * bound to the tx control blocks will be freed, and those 1069 * tx control blocks will be returned to the free list. 1070 */ 1071 uint32_t 1072 igb_tx_recycle_legacy(igb_tx_ring_t *tx_ring) 1073 { 1074 uint32_t index, last_index, next_index; 1075 int desc_num; 1076 boolean_t desc_done; 1077 tx_control_block_t *tcb; 1078 link_list_t pending_list; 1079 igb_t *igb = tx_ring->igb; 1080 1081 /* 1082 * The mutex_tryenter() is used to avoid unnecessary 1083 * lock contention. 1084 */ 1085 if (mutex_tryenter(&tx_ring->recycle_lock) == 0) 1086 return (0); 1087 1088 ASSERT(tx_ring->tbd_free <= tx_ring->ring_size); 1089 1090 if (tx_ring->tbd_free == tx_ring->ring_size) { 1091 tx_ring->recycle_fail = 0; 1092 tx_ring->stall_watchdog = 0; 1093 mutex_exit(&tx_ring->recycle_lock); 1094 return (0); 1095 } 1096 1097 /* 1098 * Sync the DMA buffer of the tx descriptor ring 1099 */ 1100 DMA_SYNC(&tx_ring->tbd_area, DDI_DMA_SYNC_FORKERNEL); 1101 1102 if (igb_check_dma_handle( 1103 tx_ring->tbd_area.dma_handle) != DDI_FM_OK) { 1104 mutex_exit(&tx_ring->recycle_lock); 1105 ddi_fm_service_impact(igb->dip, DDI_SERVICE_DEGRADED); 1106 atomic_or_32(&igb->igb_state, IGB_ERROR); 1107 return (0); 1108 } 1109 1110 LINK_LIST_INIT(&pending_list); 1111 desc_num = 0; 1112 index = tx_ring->tbd_head; /* Index of next tbd/tcb to recycle */ 1113 1114 tcb = tx_ring->work_list[index]; 1115 ASSERT(tcb != NULL); 1116 1117 while (tcb != NULL) { 1118 1119 /* 1120 * Get the last tx descriptor of this packet. 1121 * If the last tx descriptor is done, then 1122 * we can recycle all descriptors of a packet 1123 * which usually includes several tx control blocks. 1124 * For some chips, LSO descriptors can not be recycled 1125 * unless the whole packet's transmission is done. 1126 * That's why packet level recycling is used here. 1127 */ 1128 last_index = tcb->last_index; 1129 /* 1130 * MAX_TX_RING_SIZE is used to judge whether 1131 * the index is a valid value or not. 1132 */ 1133 if (last_index == MAX_TX_RING_SIZE) 1134 break; 1135 1136 next_index = NEXT_INDEX(last_index, 1, tx_ring->ring_size); 1137 1138 /* 1139 * Check if the Descriptor Done bit is set 1140 */ 1141 desc_done = tx_ring->tbd_ring[last_index].wb.status & 1142 E1000_TXD_STAT_DD; 1143 if (desc_done) { 1144 while (tcb != NULL) { 1145 /* 1146 * Strip off the tx control block from the work 1147 * list, and add it to the pending list. 1148 */ 1149 tx_ring->work_list[index] = NULL; 1150 LIST_PUSH_TAIL(&pending_list, &tcb->link); 1151 1152 /* 1153 * Count the total number of the tx descriptors 1154 * recycled. 1155 */ 1156 desc_num += tcb->desc_num; 1157 1158 /* 1159 * Advance the index of the tx descriptor ring 1160 */ 1161 index = NEXT_INDEX(index, tcb->desc_num, 1162 tx_ring->ring_size); 1163 1164 tcb = tx_ring->work_list[index]; 1165 if (index == next_index) 1166 break; 1167 } 1168 } else { 1169 break; 1170 } 1171 } 1172 1173 /* 1174 * If no tx descriptors are recycled, no need to do more processing 1175 */ 1176 if (desc_num == 0) { 1177 tx_ring->recycle_fail++; 1178 mutex_exit(&tx_ring->recycle_lock); 1179 return (0); 1180 } 1181 1182 tx_ring->recycle_fail = 0; 1183 tx_ring->stall_watchdog = 0; 1184 1185 /* 1186 * Update the head index of the tx descriptor ring 1187 */ 1188 tx_ring->tbd_head = index; 1189 1190 /* 1191 * Update the number of the free tx descriptors with atomic operations 1192 */ 1193 atomic_add_32(&tx_ring->tbd_free, desc_num); 1194 1195 mutex_exit(&tx_ring->recycle_lock); 1196 1197 /* 1198 * Free the resources used by the tx control blocks 1199 * in the pending list 1200 */ 1201 tcb = (tx_control_block_t *)LIST_GET_HEAD(&pending_list); 1202 while (tcb != NULL) { 1203 /* 1204 * Release the resources occupied by the tx control block 1205 */ 1206 igb_free_tcb(tcb); 1207 1208 tcb = (tx_control_block_t *) 1209 LIST_GET_NEXT(&pending_list, &tcb->link); 1210 } 1211 1212 /* 1213 * Add the tx control blocks in the pending list to the free list. 1214 */ 1215 igb_put_free_list(tx_ring, &pending_list); 1216 1217 return (desc_num); 1218 } 1219 1220 /* 1221 * igb_tx_recycle_head_wb 1222 * 1223 * Check the head write-back, and recycle all the transmitted 1224 * tx descriptors and tx control blocks. 1225 */ 1226 uint32_t 1227 igb_tx_recycle_head_wb(igb_tx_ring_t *tx_ring) 1228 { 1229 uint32_t index; 1230 uint32_t head_wb; 1231 int desc_num; 1232 tx_control_block_t *tcb; 1233 link_list_t pending_list; 1234 igb_t *igb = tx_ring->igb; 1235 1236 /* 1237 * The mutex_tryenter() is used to avoid unnecessary 1238 * lock contention. 1239 */ 1240 if (mutex_tryenter(&tx_ring->recycle_lock) == 0) 1241 return (0); 1242 1243 ASSERT(tx_ring->tbd_free <= tx_ring->ring_size); 1244 1245 if (tx_ring->tbd_free == tx_ring->ring_size) { 1246 tx_ring->recycle_fail = 0; 1247 tx_ring->stall_watchdog = 0; 1248 mutex_exit(&tx_ring->recycle_lock); 1249 return (0); 1250 } 1251 1252 /* 1253 * Sync the DMA buffer of the tx descriptor ring 1254 * 1255 * Note: For head write-back mode, the tx descriptors will not 1256 * be written back, but the head write-back value is stored at 1257 * the last extra tbd at the end of the DMA area, we still need 1258 * to sync the head write-back value for kernel. 1259 * 1260 * DMA_SYNC(&tx_ring->tbd_area, DDI_DMA_SYNC_FORKERNEL); 1261 */ 1262 (void) ddi_dma_sync(tx_ring->tbd_area.dma_handle, 1263 sizeof (union e1000_adv_tx_desc) * tx_ring->ring_size, 1264 sizeof (uint32_t), 1265 DDI_DMA_SYNC_FORKERNEL); 1266 1267 if (igb_check_dma_handle( 1268 tx_ring->tbd_area.dma_handle) != DDI_FM_OK) { 1269 mutex_exit(&tx_ring->recycle_lock); 1270 ddi_fm_service_impact(igb->dip, DDI_SERVICE_DEGRADED); 1271 atomic_or_32(&igb->igb_state, IGB_ERROR); 1272 return (0); 1273 } 1274 1275 LINK_LIST_INIT(&pending_list); 1276 desc_num = 0; 1277 index = tx_ring->tbd_head; /* Next index to clean */ 1278 1279 /* 1280 * Get the value of head write-back 1281 */ 1282 head_wb = *tx_ring->tbd_head_wb; 1283 while (index != head_wb) { 1284 tcb = tx_ring->work_list[index]; 1285 ASSERT(tcb != NULL); 1286 1287 if (OFFSET(index, head_wb, tx_ring->ring_size) < 1288 tcb->desc_num) { 1289 /* 1290 * The current tx control block is not 1291 * completely transmitted, stop recycling 1292 */ 1293 break; 1294 } 1295 1296 /* 1297 * Strip off the tx control block from the work list, 1298 * and add it to the pending list. 1299 */ 1300 tx_ring->work_list[index] = NULL; 1301 LIST_PUSH_TAIL(&pending_list, &tcb->link); 1302 1303 /* 1304 * Advance the index of the tx descriptor ring 1305 */ 1306 index = NEXT_INDEX(index, tcb->desc_num, tx_ring->ring_size); 1307 1308 /* 1309 * Count the total number of the tx descriptors recycled 1310 */ 1311 desc_num += tcb->desc_num; 1312 } 1313 1314 /* 1315 * If no tx descriptors are recycled, no need to do more processing 1316 */ 1317 if (desc_num == 0) { 1318 tx_ring->recycle_fail++; 1319 mutex_exit(&tx_ring->recycle_lock); 1320 return (0); 1321 } 1322 1323 tx_ring->recycle_fail = 0; 1324 tx_ring->stall_watchdog = 0; 1325 1326 /* 1327 * Update the head index of the tx descriptor ring 1328 */ 1329 tx_ring->tbd_head = index; 1330 1331 /* 1332 * Update the number of the free tx descriptors with atomic operations 1333 */ 1334 atomic_add_32(&tx_ring->tbd_free, desc_num); 1335 1336 mutex_exit(&tx_ring->recycle_lock); 1337 1338 /* 1339 * Free the resources used by the tx control blocks 1340 * in the pending list 1341 */ 1342 tcb = (tx_control_block_t *)LIST_GET_HEAD(&pending_list); 1343 while (tcb) { 1344 /* 1345 * Release the resources occupied by the tx control block 1346 */ 1347 igb_free_tcb(tcb); 1348 1349 tcb = (tx_control_block_t *) 1350 LIST_GET_NEXT(&pending_list, &tcb->link); 1351 } 1352 1353 /* 1354 * Add the tx control blocks in the pending list to the free list. 1355 */ 1356 igb_put_free_list(tx_ring, &pending_list); 1357 1358 return (desc_num); 1359 } 1360 1361 /* 1362 * igb_free_tcb - free up the tx control block 1363 * 1364 * Free the resources of the tx control block, including 1365 * unbind the previously bound DMA handle, and reset other 1366 * control fields. 1367 */ 1368 void 1369 igb_free_tcb(tx_control_block_t *tcb) 1370 { 1371 switch (tcb->tx_type) { 1372 case USE_COPY: 1373 /* 1374 * Reset the buffer length that is used for copy 1375 */ 1376 tcb->tx_buf.len = 0; 1377 break; 1378 case USE_DMA: 1379 /* 1380 * Release the DMA resource that is used for 1381 * DMA binding. 1382 */ 1383 (void) ddi_dma_unbind_handle(tcb->tx_dma_handle); 1384 break; 1385 default: 1386 break; 1387 } 1388 1389 /* 1390 * Free the mblk 1391 */ 1392 if (tcb->mp != NULL) { 1393 freemsg(tcb->mp); 1394 tcb->mp = NULL; 1395 } 1396 1397 tcb->tx_type = USE_NONE; 1398 tcb->last_index = MAX_TX_RING_SIZE; 1399 tcb->frag_num = 0; 1400 tcb->desc_num = 0; 1401 } 1402 1403 /* 1404 * igb_get_free_list - Get a free tx control block from the free list 1405 * 1406 * The atomic operation on the number of the available tx control block 1407 * in the free list is used to keep this routine mutual exclusive with 1408 * the routine igb_put_check_list. 1409 */ 1410 static tx_control_block_t * 1411 igb_get_free_list(igb_tx_ring_t *tx_ring) 1412 { 1413 tx_control_block_t *tcb; 1414 1415 /* 1416 * Check and update the number of the free tx control block 1417 * in the free list. 1418 */ 1419 if (igb_atomic_reserve(&tx_ring->tcb_free, 1) < 0) 1420 return (NULL); 1421 1422 mutex_enter(&tx_ring->tcb_head_lock); 1423 1424 tcb = tx_ring->free_list[tx_ring->tcb_head]; 1425 ASSERT(tcb != NULL); 1426 tx_ring->free_list[tx_ring->tcb_head] = NULL; 1427 tx_ring->tcb_head = NEXT_INDEX(tx_ring->tcb_head, 1, 1428 tx_ring->free_list_size); 1429 1430 mutex_exit(&tx_ring->tcb_head_lock); 1431 1432 return (tcb); 1433 } 1434 1435 /* 1436 * igb_put_free_list 1437 * 1438 * Put a list of used tx control blocks back to the free list 1439 * 1440 * A mutex is used here to ensure the serialization. The mutual exclusion 1441 * between igb_get_free_list and igb_put_free_list is implemented with 1442 * the atomic operation on the counter tcb_free. 1443 */ 1444 void 1445 igb_put_free_list(igb_tx_ring_t *tx_ring, link_list_t *pending_list) 1446 { 1447 uint32_t index; 1448 int tcb_num; 1449 tx_control_block_t *tcb; 1450 1451 mutex_enter(&tx_ring->tcb_tail_lock); 1452 1453 index = tx_ring->tcb_tail; 1454 1455 tcb_num = 0; 1456 tcb = (tx_control_block_t *)LIST_POP_HEAD(pending_list); 1457 while (tcb != NULL) { 1458 ASSERT(tx_ring->free_list[index] == NULL); 1459 tx_ring->free_list[index] = tcb; 1460 1461 tcb_num++; 1462 1463 index = NEXT_INDEX(index, 1, tx_ring->free_list_size); 1464 1465 tcb = (tx_control_block_t *)LIST_POP_HEAD(pending_list); 1466 } 1467 1468 tx_ring->tcb_tail = index; 1469 1470 /* 1471 * Update the number of the free tx control block 1472 * in the free list. This operation must be placed 1473 * under the protection of the lock. 1474 */ 1475 atomic_add_32(&tx_ring->tcb_free, tcb_num); 1476 1477 mutex_exit(&tx_ring->tcb_tail_lock); 1478 } 1479