1/**************************************************************************** 2 * Driver for Solarflare network controllers and boards 3 * Copyright 2005-2006 Fen Systems Ltd. 4 * Copyright 2005-2013 Solarflare Communications Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 as published 8 * by the Free Software Foundation, incorporated herein by reference. 9 */ 10 11#include <linux/pci.h> 12#include <linux/tcp.h> 13#include <linux/ip.h> 14#include <linux/in.h> 15#include <linux/ipv6.h> 16#include <linux/slab.h> 17#include <net/ipv6.h> 18#include <linux/if_ether.h> 19#include <linux/highmem.h> 20#include <linux/cache.h> 21#include "net_driver.h" 22#include "efx.h" 23#include "io.h" 24#include "nic.h" 25#include "workarounds.h" 26#include "ef10_regs.h" 27 28#ifdef EFX_USE_PIO 29 30#define EFX_PIOBUF_SIZE_MAX ER_DZ_TX_PIOBUF_SIZE 31#define EFX_PIOBUF_SIZE_DEF ALIGN(256, L1_CACHE_BYTES) 32unsigned int efx_piobuf_size __read_mostly = EFX_PIOBUF_SIZE_DEF; 33 34#endif /* EFX_USE_PIO */ 35 36static inline unsigned int 37efx_tx_queue_get_insert_index(const struct efx_tx_queue *tx_queue) 38{ 39 return tx_queue->insert_count & tx_queue->ptr_mask; 40} 41 42static inline struct efx_tx_buffer * 43__efx_tx_queue_get_insert_buffer(const struct efx_tx_queue *tx_queue) 44{ 45 return &tx_queue->buffer[efx_tx_queue_get_insert_index(tx_queue)]; 46} 47 48static inline struct efx_tx_buffer * 49efx_tx_queue_get_insert_buffer(const struct efx_tx_queue *tx_queue) 50{ 51 struct efx_tx_buffer *buffer = 52 __efx_tx_queue_get_insert_buffer(tx_queue); 53 54 EFX_BUG_ON_PARANOID(buffer->len); 55 EFX_BUG_ON_PARANOID(buffer->flags); 56 EFX_BUG_ON_PARANOID(buffer->unmap_len); 57 58 return buffer; 59} 60 61static void efx_dequeue_buffer(struct efx_tx_queue *tx_queue, 62 struct efx_tx_buffer *buffer, 63 unsigned int *pkts_compl, 64 unsigned int *bytes_compl) 65{ 66 if (buffer->unmap_len) { 67 struct device *dma_dev = &tx_queue->efx->pci_dev->dev; 68 dma_addr_t unmap_addr = buffer->dma_addr - buffer->dma_offset; 69 if (buffer->flags & EFX_TX_BUF_MAP_SINGLE) 70 dma_unmap_single(dma_dev, unmap_addr, buffer->unmap_len, 71 DMA_TO_DEVICE); 72 else 73 dma_unmap_page(dma_dev, unmap_addr, buffer->unmap_len, 74 DMA_TO_DEVICE); 75 buffer->unmap_len = 0; 76 } 77 78 if (buffer->flags & EFX_TX_BUF_SKB) { 79 (*pkts_compl)++; 80 (*bytes_compl) += buffer->skb->len; 81 dev_consume_skb_any((struct sk_buff *)buffer->skb); 82 netif_vdbg(tx_queue->efx, tx_done, tx_queue->efx->net_dev, 83 "TX queue %d transmission id %x complete\n", 84 tx_queue->queue, tx_queue->read_count); 85 } else if (buffer->flags & EFX_TX_BUF_HEAP) { 86 kfree(buffer->heap_buf); 87 } 88 89 buffer->len = 0; 90 buffer->flags = 0; 91} 92 93static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, 94 struct sk_buff *skb); 95 96static inline unsigned 97efx_max_tx_len(struct efx_nic *efx, dma_addr_t dma_addr) 98{ 99 /* Depending on the NIC revision, we can use descriptor 100 * lengths up to 8K or 8K-1. However, since PCI Express 101 * devices must split read requests at 4K boundaries, there is 102 * little benefit from using descriptors that cross those 103 * boundaries and we keep things simple by not doing so. 104 */ 105 unsigned len = (~dma_addr & (EFX_PAGE_SIZE - 1)) + 1; 106 107 /* Work around hardware bug for unaligned buffers. */ 108 if (EFX_WORKAROUND_5391(efx) && (dma_addr & 0xf)) 109 len = min_t(unsigned, len, 512 - (dma_addr & 0xf)); 110 111 return len; 112} 113 114unsigned int efx_tx_max_skb_descs(struct efx_nic *efx) 115{ 116 /* Header and payload descriptor for each output segment, plus 117 * one for every input fragment boundary within a segment 118 */ 119 unsigned int max_descs = EFX_TSO_MAX_SEGS * 2 + MAX_SKB_FRAGS; 120 121 /* Possibly one more per segment for the alignment workaround, 122 * or for option descriptors 123 */ 124 if (EFX_WORKAROUND_5391(efx) || efx_nic_rev(efx) >= EFX_REV_HUNT_A0) 125 max_descs += EFX_TSO_MAX_SEGS; 126 127 /* Possibly more for PCIe page boundaries within input fragments */ 128 if (PAGE_SIZE > EFX_PAGE_SIZE) 129 max_descs += max_t(unsigned int, MAX_SKB_FRAGS, 130 DIV_ROUND_UP(GSO_MAX_SIZE, EFX_PAGE_SIZE)); 131 132 return max_descs; 133} 134 135static void efx_tx_maybe_stop_queue(struct efx_tx_queue *txq1) 136{ 137 /* We need to consider both queues that the net core sees as one */ 138 struct efx_tx_queue *txq2 = efx_tx_queue_partner(txq1); 139 struct efx_nic *efx = txq1->efx; 140 unsigned int fill_level; 141 142 fill_level = max(txq1->insert_count - txq1->old_read_count, 143 txq2->insert_count - txq2->old_read_count); 144 if (likely(fill_level < efx->txq_stop_thresh)) 145 return; 146 147 /* We used the stale old_read_count above, which gives us a 148 * pessimistic estimate of the fill level (which may even 149 * validly be >= efx->txq_entries). Now try again using 150 * read_count (more likely to be a cache miss). 151 * 152 * If we read read_count and then conditionally stop the 153 * queue, it is possible for the completion path to race with 154 * us and complete all outstanding descriptors in the middle, 155 * after which there will be no more completions to wake it. 156 * Therefore we stop the queue first, then read read_count 157 * (with a memory barrier to ensure the ordering), then 158 * restart the queue if the fill level turns out to be low 159 * enough. 160 */ 161 netif_tx_stop_queue(txq1->core_txq); 162 smp_mb(); 163 txq1->old_read_count = ACCESS_ONCE(txq1->read_count); 164 txq2->old_read_count = ACCESS_ONCE(txq2->read_count); 165 166 fill_level = max(txq1->insert_count - txq1->old_read_count, 167 txq2->insert_count - txq2->old_read_count); 168 EFX_BUG_ON_PARANOID(fill_level >= efx->txq_entries); 169 if (likely(fill_level < efx->txq_stop_thresh)) { 170 smp_mb(); 171 if (likely(!efx->loopback_selftest)) 172 netif_tx_start_queue(txq1->core_txq); 173 } 174} 175 176#ifdef EFX_USE_PIO 177 178struct efx_short_copy_buffer { 179 int used; 180 u8 buf[L1_CACHE_BYTES]; 181}; 182 183/* Copy to PIO, respecting that writes to PIO buffers must be dword aligned. 184 * Advances piobuf pointer. Leaves additional data in the copy buffer. 185 */ 186static void efx_memcpy_toio_aligned(struct efx_nic *efx, u8 __iomem **piobuf, 187 u8 *data, int len, 188 struct efx_short_copy_buffer *copy_buf) 189{ 190 int block_len = len & ~(sizeof(copy_buf->buf) - 1); 191 192 __iowrite64_copy(*piobuf, data, block_len >> 3); 193 *piobuf += block_len; 194 len -= block_len; 195 196 if (len) { 197 data += block_len; 198 BUG_ON(copy_buf->used); 199 BUG_ON(len > sizeof(copy_buf->buf)); 200 memcpy(copy_buf->buf, data, len); 201 copy_buf->used = len; 202 } 203} 204 205/* Copy to PIO, respecting dword alignment, popping data from copy buffer first. 206 * Advances piobuf pointer. Leaves additional data in the copy buffer. 207 */ 208static void efx_memcpy_toio_aligned_cb(struct efx_nic *efx, u8 __iomem **piobuf, 209 u8 *data, int len, 210 struct efx_short_copy_buffer *copy_buf) 211{ 212 if (copy_buf->used) { 213 /* if the copy buffer is partially full, fill it up and write */ 214 int copy_to_buf = 215 min_t(int, sizeof(copy_buf->buf) - copy_buf->used, len); 216 217 memcpy(copy_buf->buf + copy_buf->used, data, copy_to_buf); 218 copy_buf->used += copy_to_buf; 219 220 /* if we didn't fill it up then we're done for now */ 221 if (copy_buf->used < sizeof(copy_buf->buf)) 222 return; 223 224 __iowrite64_copy(*piobuf, copy_buf->buf, 225 sizeof(copy_buf->buf) >> 3); 226 *piobuf += sizeof(copy_buf->buf); 227 data += copy_to_buf; 228 len -= copy_to_buf; 229 copy_buf->used = 0; 230 } 231 232 efx_memcpy_toio_aligned(efx, piobuf, data, len, copy_buf); 233} 234 235static void efx_flush_copy_buffer(struct efx_nic *efx, u8 __iomem *piobuf, 236 struct efx_short_copy_buffer *copy_buf) 237{ 238 /* if there's anything in it, write the whole buffer, including junk */ 239 if (copy_buf->used) 240 __iowrite64_copy(piobuf, copy_buf->buf, 241 sizeof(copy_buf->buf) >> 3); 242} 243 244/* Traverse skb structure and copy fragments in to PIO buffer. 245 * Advances piobuf pointer. 246 */ 247static void efx_skb_copy_bits_to_pio(struct efx_nic *efx, struct sk_buff *skb, 248 u8 __iomem **piobuf, 249 struct efx_short_copy_buffer *copy_buf) 250{ 251 int i; 252 253 efx_memcpy_toio_aligned(efx, piobuf, skb->data, skb_headlen(skb), 254 copy_buf); 255 256 for (i = 0; i < skb_shinfo(skb)->nr_frags; ++i) { 257 skb_frag_t *f = &skb_shinfo(skb)->frags[i]; 258 u8 *vaddr; 259 260 vaddr = kmap_atomic(skb_frag_page(f)); 261 262 efx_memcpy_toio_aligned_cb(efx, piobuf, vaddr + f->page_offset, 263 skb_frag_size(f), copy_buf); 264 kunmap_atomic(vaddr); 265 } 266 267 EFX_BUG_ON_PARANOID(skb_shinfo(skb)->frag_list); 268} 269 270static struct efx_tx_buffer * 271efx_enqueue_skb_pio(struct efx_tx_queue *tx_queue, struct sk_buff *skb) 272{ 273 struct efx_tx_buffer *buffer = 274 efx_tx_queue_get_insert_buffer(tx_queue); 275 u8 __iomem *piobuf = tx_queue->piobuf; 276 277 /* Copy to PIO buffer. Ensure the writes are padded to the end 278 * of a cache line, as this is required for write-combining to be 279 * effective on at least x86. 280 */ 281 282 if (skb_shinfo(skb)->nr_frags) { 283 /* The size of the copy buffer will ensure all writes 284 * are the size of a cache line. 285 */ 286 struct efx_short_copy_buffer copy_buf; 287 288 copy_buf.used = 0; 289 290 efx_skb_copy_bits_to_pio(tx_queue->efx, skb, 291 &piobuf, ©_buf); 292 efx_flush_copy_buffer(tx_queue->efx, piobuf, ©_buf); 293 } else { 294 /* Pad the write to the size of a cache line. 295 * We can do this because we know the skb_shared_info sruct is 296 * after the source, and the destination buffer is big enough. 297 */ 298 BUILD_BUG_ON(L1_CACHE_BYTES > 299 SKB_DATA_ALIGN(sizeof(struct skb_shared_info))); 300 __iowrite64_copy(tx_queue->piobuf, skb->data, 301 ALIGN(skb->len, L1_CACHE_BYTES) >> 3); 302 } 303 304 EFX_POPULATE_QWORD_5(buffer->option, 305 ESF_DZ_TX_DESC_IS_OPT, 1, 306 ESF_DZ_TX_OPTION_TYPE, ESE_DZ_TX_OPTION_DESC_PIO, 307 ESF_DZ_TX_PIO_CONT, 0, 308 ESF_DZ_TX_PIO_BYTE_CNT, skb->len, 309 ESF_DZ_TX_PIO_BUF_ADDR, 310 tx_queue->piobuf_offset); 311 ++tx_queue->pio_packets; 312 ++tx_queue->insert_count; 313 return buffer; 314} 315#endif /* EFX_USE_PIO */ 316 317/* 318 * Add a socket buffer to a TX queue 319 * 320 * This maps all fragments of a socket buffer for DMA and adds them to 321 * the TX queue. The queue's insert pointer will be incremented by 322 * the number of fragments in the socket buffer. 323 * 324 * If any DMA mapping fails, any mapped fragments will be unmapped, 325 * the queue's insert pointer will be restored to its original value. 326 * 327 * This function is split out from efx_hard_start_xmit to allow the 328 * loopback test to direct packets via specific TX queues. 329 * 330 * Returns NETDEV_TX_OK. 331 * You must hold netif_tx_lock() to call this function. 332 */ 333netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) 334{ 335 struct efx_nic *efx = tx_queue->efx; 336 struct device *dma_dev = &efx->pci_dev->dev; 337 struct efx_tx_buffer *buffer; 338 unsigned int old_insert_count = tx_queue->insert_count; 339 skb_frag_t *fragment; 340 unsigned int len, unmap_len = 0; 341 dma_addr_t dma_addr, unmap_addr = 0; 342 unsigned int dma_len; 343 unsigned short dma_flags; 344 int i = 0; 345 346 if (skb_shinfo(skb)->gso_size) 347 return efx_enqueue_skb_tso(tx_queue, skb); 348 349 /* Get size of the initial fragment */ 350 len = skb_headlen(skb); 351 352 /* Pad if necessary */ 353 if (EFX_WORKAROUND_15592(efx) && skb->len <= 32) { 354 EFX_BUG_ON_PARANOID(skb->data_len); 355 len = 32 + 1; 356 if (skb_pad(skb, len - skb->len)) 357 return NETDEV_TX_OK; 358 } 359 360 /* Consider using PIO for short packets */ 361#ifdef EFX_USE_PIO 362 if (skb->len <= efx_piobuf_size && !skb->xmit_more && 363 efx_nic_may_tx_pio(tx_queue)) { 364 buffer = efx_enqueue_skb_pio(tx_queue, skb); 365 dma_flags = EFX_TX_BUF_OPTION; 366 goto finish_packet; 367 } 368#endif 369 370 /* Map for DMA. Use dma_map_single rather than dma_map_page 371 * since this is more efficient on machines with sparse 372 * memory. 373 */ 374 dma_flags = EFX_TX_BUF_MAP_SINGLE; 375 dma_addr = dma_map_single(dma_dev, skb->data, len, PCI_DMA_TODEVICE); 376 377 /* Process all fragments */ 378 while (1) { 379 if (unlikely(dma_mapping_error(dma_dev, dma_addr))) 380 goto dma_err; 381 382 /* Store fields for marking in the per-fragment final 383 * descriptor */ 384 unmap_len = len; 385 unmap_addr = dma_addr; 386 387 /* Add to TX queue, splitting across DMA boundaries */ 388 do { 389 buffer = efx_tx_queue_get_insert_buffer(tx_queue); 390 391 dma_len = efx_max_tx_len(efx, dma_addr); 392 if (likely(dma_len >= len)) 393 dma_len = len; 394 395 /* Fill out per descriptor fields */ 396 buffer->len = dma_len; 397 buffer->dma_addr = dma_addr; 398 buffer->flags = EFX_TX_BUF_CONT; 399 len -= dma_len; 400 dma_addr += dma_len; 401 ++tx_queue->insert_count; 402 } while (len); 403 404 /* Transfer ownership of the unmapping to the final buffer */ 405 buffer->flags = EFX_TX_BUF_CONT | dma_flags; 406 buffer->unmap_len = unmap_len; 407 buffer->dma_offset = buffer->dma_addr - unmap_addr; 408 unmap_len = 0; 409 410 /* Get address and size of next fragment */ 411 if (i >= skb_shinfo(skb)->nr_frags) 412 break; 413 fragment = &skb_shinfo(skb)->frags[i]; 414 len = skb_frag_size(fragment); 415 i++; 416 /* Map for DMA */ 417 dma_flags = 0; 418 dma_addr = skb_frag_dma_map(dma_dev, fragment, 0, len, 419 DMA_TO_DEVICE); 420 } 421 422 /* Transfer ownership of the skb to the final buffer */ 423#ifdef EFX_USE_PIO 424finish_packet: 425#endif 426 buffer->skb = skb; 427 buffer->flags = EFX_TX_BUF_SKB | dma_flags; 428 429 netdev_tx_sent_queue(tx_queue->core_txq, skb->len); 430 431 efx_tx_maybe_stop_queue(tx_queue); 432 433 /* Pass off to hardware */ 434 if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) { 435 struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue); 436 437 /* There could be packets left on the partner queue if those 438 * SKBs had skb->xmit_more set. If we do not push those they 439 * could be left for a long time and cause a netdev watchdog. 440 */ 441 if (txq2->xmit_more_available) 442 efx_nic_push_buffers(txq2); 443 444 efx_nic_push_buffers(tx_queue); 445 } else { 446 tx_queue->xmit_more_available = skb->xmit_more; 447 } 448 449 tx_queue->tx_packets++; 450 451 return NETDEV_TX_OK; 452 453 dma_err: 454 netif_err(efx, tx_err, efx->net_dev, 455 " TX queue %d could not map skb with %d bytes %d " 456 "fragments for DMA\n", tx_queue->queue, skb->len, 457 skb_shinfo(skb)->nr_frags + 1); 458 459 /* Mark the packet as transmitted, and free the SKB ourselves */ 460 dev_kfree_skb_any(skb); 461 462 /* Work backwards until we hit the original insert pointer value */ 463 while (tx_queue->insert_count != old_insert_count) { 464 unsigned int pkts_compl = 0, bytes_compl = 0; 465 --tx_queue->insert_count; 466 buffer = __efx_tx_queue_get_insert_buffer(tx_queue); 467 efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl); 468 } 469 470 /* Free the fragment we were mid-way through pushing */ 471 if (unmap_len) { 472 if (dma_flags & EFX_TX_BUF_MAP_SINGLE) 473 dma_unmap_single(dma_dev, unmap_addr, unmap_len, 474 DMA_TO_DEVICE); 475 else 476 dma_unmap_page(dma_dev, unmap_addr, unmap_len, 477 DMA_TO_DEVICE); 478 } 479 480 return NETDEV_TX_OK; 481} 482 483/* Remove packets from the TX queue 484 * 485 * This removes packets from the TX queue, up to and including the 486 * specified index. 487 */ 488static void efx_dequeue_buffers(struct efx_tx_queue *tx_queue, 489 unsigned int index, 490 unsigned int *pkts_compl, 491 unsigned int *bytes_compl) 492{ 493 struct efx_nic *efx = tx_queue->efx; 494 unsigned int stop_index, read_ptr; 495 496 stop_index = (index + 1) & tx_queue->ptr_mask; 497 read_ptr = tx_queue->read_count & tx_queue->ptr_mask; 498 499 while (read_ptr != stop_index) { 500 struct efx_tx_buffer *buffer = &tx_queue->buffer[read_ptr]; 501 502 if (!(buffer->flags & EFX_TX_BUF_OPTION) && 503 unlikely(buffer->len == 0)) { 504 netif_err(efx, tx_err, efx->net_dev, 505 "TX queue %d spurious TX completion id %x\n", 506 tx_queue->queue, read_ptr); 507 efx_schedule_reset(efx, RESET_TYPE_TX_SKIP); 508 return; 509 } 510 511 efx_dequeue_buffer(tx_queue, buffer, pkts_compl, bytes_compl); 512 513 ++tx_queue->read_count; 514 read_ptr = tx_queue->read_count & tx_queue->ptr_mask; 515 } 516} 517 518/* Initiate a packet transmission. We use one channel per CPU 519 * (sharing when we have more CPUs than channels). On Falcon, the TX 520 * completion events will be directed back to the CPU that transmitted 521 * the packet, which should be cache-efficient. 522 * 523 * Context: non-blocking. 524 * Note that returning anything other than NETDEV_TX_OK will cause the 525 * OS to free the skb. 526 */ 527netdev_tx_t efx_hard_start_xmit(struct sk_buff *skb, 528 struct net_device *net_dev) 529{ 530 struct efx_nic *efx = netdev_priv(net_dev); 531 struct efx_tx_queue *tx_queue; 532 unsigned index, type; 533 534 EFX_WARN_ON_PARANOID(!netif_device_present(net_dev)); 535 536 /* PTP "event" packet */ 537 if (unlikely(efx_xmit_with_hwtstamp(skb)) && 538 unlikely(efx_ptp_is_ptp_tx(efx, skb))) { 539 return efx_ptp_tx(efx, skb); 540 } 541 542 index = skb_get_queue_mapping(skb); 543 type = skb->ip_summed == CHECKSUM_PARTIAL ? EFX_TXQ_TYPE_OFFLOAD : 0; 544 if (index >= efx->n_tx_channels) { 545 index -= efx->n_tx_channels; 546 type |= EFX_TXQ_TYPE_HIGHPRI; 547 } 548 tx_queue = efx_get_tx_queue(efx, index, type); 549 550 return efx_enqueue_skb(tx_queue, skb); 551} 552 553void efx_init_tx_queue_core_txq(struct efx_tx_queue *tx_queue) 554{ 555 struct efx_nic *efx = tx_queue->efx; 556 557 /* Must be inverse of queue lookup in efx_hard_start_xmit() */ 558 tx_queue->core_txq = 559 netdev_get_tx_queue(efx->net_dev, 560 tx_queue->queue / EFX_TXQ_TYPES + 561 ((tx_queue->queue & EFX_TXQ_TYPE_HIGHPRI) ? 562 efx->n_tx_channels : 0)); 563} 564 565int efx_setup_tc(struct net_device *net_dev, u8 num_tc) 566{ 567 struct efx_nic *efx = netdev_priv(net_dev); 568 struct efx_channel *channel; 569 struct efx_tx_queue *tx_queue; 570 unsigned tc; 571 int rc; 572 573 if (efx_nic_rev(efx) < EFX_REV_FALCON_B0 || num_tc > EFX_MAX_TX_TC) 574 return -EINVAL; 575 576 if (num_tc == net_dev->num_tc) 577 return 0; 578 579 for (tc = 0; tc < num_tc; tc++) { 580 net_dev->tc_to_txq[tc].offset = tc * efx->n_tx_channels; 581 net_dev->tc_to_txq[tc].count = efx->n_tx_channels; 582 } 583 584 if (num_tc > net_dev->num_tc) { 585 /* Initialise high-priority queues as necessary */ 586 efx_for_each_channel(channel, efx) { 587 efx_for_each_possible_channel_tx_queue(tx_queue, 588 channel) { 589 if (!(tx_queue->queue & EFX_TXQ_TYPE_HIGHPRI)) 590 continue; 591 if (!tx_queue->buffer) { 592 rc = efx_probe_tx_queue(tx_queue); 593 if (rc) 594 return rc; 595 } 596 if (!tx_queue->initialised) 597 efx_init_tx_queue(tx_queue); 598 efx_init_tx_queue_core_txq(tx_queue); 599 } 600 } 601 } else { 602 /* Reduce number of classes before number of queues */ 603 net_dev->num_tc = num_tc; 604 } 605 606 rc = netif_set_real_num_tx_queues(net_dev, 607 max_t(int, num_tc, 1) * 608 efx->n_tx_channels); 609 if (rc) 610 return rc; 611 612 /* Do not destroy high-priority queues when they become 613 * unused. We would have to flush them first, and it is 614 * fairly difficult to flush a subset of TX queues. Leave 615 * it to efx_fini_channels(). 616 */ 617 618 net_dev->num_tc = num_tc; 619 return 0; 620} 621 622void efx_xmit_done(struct efx_tx_queue *tx_queue, unsigned int index) 623{ 624 unsigned fill_level; 625 struct efx_nic *efx = tx_queue->efx; 626 struct efx_tx_queue *txq2; 627 unsigned int pkts_compl = 0, bytes_compl = 0; 628 629 EFX_BUG_ON_PARANOID(index > tx_queue->ptr_mask); 630 631 efx_dequeue_buffers(tx_queue, index, &pkts_compl, &bytes_compl); 632 netdev_tx_completed_queue(tx_queue->core_txq, pkts_compl, bytes_compl); 633 634 if (pkts_compl > 1) 635 ++tx_queue->merge_events; 636 637 /* See if we need to restart the netif queue. This memory 638 * barrier ensures that we write read_count (inside 639 * efx_dequeue_buffers()) before reading the queue status. 640 */ 641 smp_mb(); 642 if (unlikely(netif_tx_queue_stopped(tx_queue->core_txq)) && 643 likely(efx->port_enabled) && 644 likely(netif_device_present(efx->net_dev))) { 645 txq2 = efx_tx_queue_partner(tx_queue); 646 fill_level = max(tx_queue->insert_count - tx_queue->read_count, 647 txq2->insert_count - txq2->read_count); 648 if (fill_level <= efx->txq_wake_thresh) 649 netif_tx_wake_queue(tx_queue->core_txq); 650 } 651 652 /* Check whether the hardware queue is now empty */ 653 if ((int)(tx_queue->read_count - tx_queue->old_write_count) >= 0) { 654 tx_queue->old_write_count = ACCESS_ONCE(tx_queue->write_count); 655 if (tx_queue->read_count == tx_queue->old_write_count) { 656 smp_mb(); 657 tx_queue->empty_read_count = 658 tx_queue->read_count | EFX_EMPTY_COUNT_VALID; 659 } 660 } 661} 662 663/* Size of page-based TSO header buffers. Larger blocks must be 664 * allocated from the heap. 665 */ 666#define TSOH_STD_SIZE 128 667#define TSOH_PER_PAGE (PAGE_SIZE / TSOH_STD_SIZE) 668 669/* At most half the descriptors in the queue at any time will refer to 670 * a TSO header buffer, since they must always be followed by a 671 * payload descriptor referring to an skb. 672 */ 673static unsigned int efx_tsoh_page_count(struct efx_tx_queue *tx_queue) 674{ 675 return DIV_ROUND_UP(tx_queue->ptr_mask + 1, 2 * TSOH_PER_PAGE); 676} 677 678int efx_probe_tx_queue(struct efx_tx_queue *tx_queue) 679{ 680 struct efx_nic *efx = tx_queue->efx; 681 unsigned int entries; 682 int rc; 683 684 /* Create the smallest power-of-two aligned ring */ 685 entries = max(roundup_pow_of_two(efx->txq_entries), EFX_MIN_DMAQ_SIZE); 686 EFX_BUG_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE); 687 tx_queue->ptr_mask = entries - 1; 688 689 netif_dbg(efx, probe, efx->net_dev, 690 "creating TX queue %d size %#x mask %#x\n", 691 tx_queue->queue, efx->txq_entries, tx_queue->ptr_mask); 692 693 /* Allocate software ring */ 694 tx_queue->buffer = kcalloc(entries, sizeof(*tx_queue->buffer), 695 GFP_KERNEL); 696 if (!tx_queue->buffer) 697 return -ENOMEM; 698 699 if (tx_queue->queue & EFX_TXQ_TYPE_OFFLOAD) { 700 tx_queue->tsoh_page = 701 kcalloc(efx_tsoh_page_count(tx_queue), 702 sizeof(tx_queue->tsoh_page[0]), GFP_KERNEL); 703 if (!tx_queue->tsoh_page) { 704 rc = -ENOMEM; 705 goto fail1; 706 } 707 } 708 709 /* Allocate hardware ring */ 710 rc = efx_nic_probe_tx(tx_queue); 711 if (rc) 712 goto fail2; 713 714 return 0; 715 716fail2: 717 kfree(tx_queue->tsoh_page); 718 tx_queue->tsoh_page = NULL; 719fail1: 720 kfree(tx_queue->buffer); 721 tx_queue->buffer = NULL; 722 return rc; 723} 724 725void efx_init_tx_queue(struct efx_tx_queue *tx_queue) 726{ 727 netif_dbg(tx_queue->efx, drv, tx_queue->efx->net_dev, 728 "initialising TX queue %d\n", tx_queue->queue); 729 730 tx_queue->insert_count = 0; 731 tx_queue->write_count = 0; 732 tx_queue->old_write_count = 0; 733 tx_queue->read_count = 0; 734 tx_queue->old_read_count = 0; 735 tx_queue->empty_read_count = 0 | EFX_EMPTY_COUNT_VALID; 736 tx_queue->xmit_more_available = false; 737 738 /* Set up TX descriptor ring */ 739 efx_nic_init_tx(tx_queue); 740 741 tx_queue->initialised = true; 742} 743 744void efx_fini_tx_queue(struct efx_tx_queue *tx_queue) 745{ 746 struct efx_tx_buffer *buffer; 747 748 netif_dbg(tx_queue->efx, drv, tx_queue->efx->net_dev, 749 "shutting down TX queue %d\n", tx_queue->queue); 750 751 if (!tx_queue->buffer) 752 return; 753 754 /* Free any buffers left in the ring */ 755 while (tx_queue->read_count != tx_queue->write_count) { 756 unsigned int pkts_compl = 0, bytes_compl = 0; 757 buffer = &tx_queue->buffer[tx_queue->read_count & tx_queue->ptr_mask]; 758 efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl); 759 760 ++tx_queue->read_count; 761 } 762 tx_queue->xmit_more_available = false; 763 netdev_tx_reset_queue(tx_queue->core_txq); 764} 765 766void efx_remove_tx_queue(struct efx_tx_queue *tx_queue) 767{ 768 int i; 769 770 if (!tx_queue->buffer) 771 return; 772 773 netif_dbg(tx_queue->efx, drv, tx_queue->efx->net_dev, 774 "destroying TX queue %d\n", tx_queue->queue); 775 efx_nic_remove_tx(tx_queue); 776 777 if (tx_queue->tsoh_page) { 778 for (i = 0; i < efx_tsoh_page_count(tx_queue); i++) 779 efx_nic_free_buffer(tx_queue->efx, 780 &tx_queue->tsoh_page[i]); 781 kfree(tx_queue->tsoh_page); 782 tx_queue->tsoh_page = NULL; 783 } 784 785 kfree(tx_queue->buffer); 786 tx_queue->buffer = NULL; 787} 788 789 790/* Efx TCP segmentation acceleration. 791 * 792 * Why? Because by doing it here in the driver we can go significantly 793 * faster than the GSO. 794 * 795 * Requires TX checksum offload support. 796 */ 797 798#define PTR_DIFF(p1, p2) ((u8 *)(p1) - (u8 *)(p2)) 799 800/** 801 * struct tso_state - TSO state for an SKB 802 * @out_len: Remaining length in current segment 803 * @seqnum: Current sequence number 804 * @ipv4_id: Current IPv4 ID, host endian 805 * @packet_space: Remaining space in current packet 806 * @dma_addr: DMA address of current position 807 * @in_len: Remaining length in current SKB fragment 808 * @unmap_len: Length of SKB fragment 809 * @unmap_addr: DMA address of SKB fragment 810 * @dma_flags: TX buffer flags for DMA mapping - %EFX_TX_BUF_MAP_SINGLE or 0 811 * @protocol: Network protocol (after any VLAN header) 812 * @ip_off: Offset of IP header 813 * @tcp_off: Offset of TCP header 814 * @header_len: Number of bytes of header 815 * @ip_base_len: IPv4 tot_len or IPv6 payload_len, before TCP payload 816 * @header_dma_addr: Header DMA address, when using option descriptors 817 * @header_unmap_len: Header DMA mapped length, or 0 if not using option 818 * descriptors 819 * 820 * The state used during segmentation. It is put into this data structure 821 * just to make it easy to pass into inline functions. 822 */ 823struct tso_state { 824 /* Output position */ 825 unsigned out_len; 826 unsigned seqnum; 827 u16 ipv4_id; 828 unsigned packet_space; 829 830 /* Input position */ 831 dma_addr_t dma_addr; 832 unsigned in_len; 833 unsigned unmap_len; 834 dma_addr_t unmap_addr; 835 unsigned short dma_flags; 836 837 __be16 protocol; 838 unsigned int ip_off; 839 unsigned int tcp_off; 840 unsigned header_len; 841 unsigned int ip_base_len; 842 dma_addr_t header_dma_addr; 843 unsigned int header_unmap_len; 844}; 845 846 847/* 848 * Verify that our various assumptions about sk_buffs and the conditions 849 * under which TSO will be attempted hold true. Return the protocol number. 850 */ 851static __be16 efx_tso_check_protocol(struct sk_buff *skb) 852{ 853 __be16 protocol = skb->protocol; 854 855 EFX_BUG_ON_PARANOID(((struct ethhdr *)skb->data)->h_proto != 856 protocol); 857 if (protocol == htons(ETH_P_8021Q)) { 858 struct vlan_ethhdr *veh = (struct vlan_ethhdr *)skb->data; 859 protocol = veh->h_vlan_encapsulated_proto; 860 } 861 862 if (protocol == htons(ETH_P_IP)) { 863 EFX_BUG_ON_PARANOID(ip_hdr(skb)->protocol != IPPROTO_TCP); 864 } else { 865 EFX_BUG_ON_PARANOID(protocol != htons(ETH_P_IPV6)); 866 EFX_BUG_ON_PARANOID(ipv6_hdr(skb)->nexthdr != NEXTHDR_TCP); 867 } 868 EFX_BUG_ON_PARANOID((PTR_DIFF(tcp_hdr(skb), skb->data) 869 + (tcp_hdr(skb)->doff << 2u)) > 870 skb_headlen(skb)); 871 872 return protocol; 873} 874 875static u8 *efx_tsoh_get_buffer(struct efx_tx_queue *tx_queue, 876 struct efx_tx_buffer *buffer, unsigned int len) 877{ 878 u8 *result; 879 880 EFX_BUG_ON_PARANOID(buffer->len); 881 EFX_BUG_ON_PARANOID(buffer->flags); 882 EFX_BUG_ON_PARANOID(buffer->unmap_len); 883 884 if (likely(len <= TSOH_STD_SIZE - NET_IP_ALIGN)) { 885 unsigned index = 886 (tx_queue->insert_count & tx_queue->ptr_mask) / 2; 887 struct efx_buffer *page_buf = 888 &tx_queue->tsoh_page[index / TSOH_PER_PAGE]; 889 unsigned offset = 890 TSOH_STD_SIZE * (index % TSOH_PER_PAGE) + NET_IP_ALIGN; 891 892 if (unlikely(!page_buf->addr) && 893 efx_nic_alloc_buffer(tx_queue->efx, page_buf, PAGE_SIZE, 894 GFP_ATOMIC)) 895 return NULL; 896 897 result = (u8 *)page_buf->addr + offset; 898 buffer->dma_addr = page_buf->dma_addr + offset; 899 buffer->flags = EFX_TX_BUF_CONT; 900 } else { 901 tx_queue->tso_long_headers++; 902 903 buffer->heap_buf = kmalloc(NET_IP_ALIGN + len, GFP_ATOMIC); 904 if (unlikely(!buffer->heap_buf)) 905 return NULL; 906 result = (u8 *)buffer->heap_buf + NET_IP_ALIGN; 907 buffer->flags = EFX_TX_BUF_CONT | EFX_TX_BUF_HEAP; 908 } 909 910 buffer->len = len; 911 912 return result; 913} 914 915/** 916 * efx_tx_queue_insert - push descriptors onto the TX queue 917 * @tx_queue: Efx TX queue 918 * @dma_addr: DMA address of fragment 919 * @len: Length of fragment 920 * @final_buffer: The final buffer inserted into the queue 921 * 922 * Push descriptors onto the TX queue. 923 */ 924static void efx_tx_queue_insert(struct efx_tx_queue *tx_queue, 925 dma_addr_t dma_addr, unsigned len, 926 struct efx_tx_buffer **final_buffer) 927{ 928 struct efx_tx_buffer *buffer; 929 struct efx_nic *efx = tx_queue->efx; 930 unsigned dma_len; 931 932 EFX_BUG_ON_PARANOID(len <= 0); 933 934 while (1) { 935 buffer = efx_tx_queue_get_insert_buffer(tx_queue); 936 ++tx_queue->insert_count; 937 938 EFX_BUG_ON_PARANOID(tx_queue->insert_count - 939 tx_queue->read_count >= 940 efx->txq_entries); 941 942 buffer->dma_addr = dma_addr; 943 944 dma_len = efx_max_tx_len(efx, dma_addr); 945 946 /* If there is enough space to send then do so */ 947 if (dma_len >= len) 948 break; 949 950 buffer->len = dma_len; 951 buffer->flags = EFX_TX_BUF_CONT; 952 dma_addr += dma_len; 953 len -= dma_len; 954 } 955 956 EFX_BUG_ON_PARANOID(!len); 957 buffer->len = len; 958 *final_buffer = buffer; 959} 960 961 962/* 963 * Put a TSO header into the TX queue. 964 * 965 * This is special-cased because we know that it is small enough to fit in 966 * a single fragment, and we know it doesn't cross a page boundary. It 967 * also allows us to not worry about end-of-packet etc. 968 */ 969static int efx_tso_put_header(struct efx_tx_queue *tx_queue, 970 struct efx_tx_buffer *buffer, u8 *header) 971{ 972 if (unlikely(buffer->flags & EFX_TX_BUF_HEAP)) { 973 buffer->dma_addr = dma_map_single(&tx_queue->efx->pci_dev->dev, 974 header, buffer->len, 975 DMA_TO_DEVICE); 976 if (unlikely(dma_mapping_error(&tx_queue->efx->pci_dev->dev, 977 buffer->dma_addr))) { 978 kfree(buffer->heap_buf); 979 buffer->len = 0; 980 buffer->flags = 0; 981 return -ENOMEM; 982 } 983 buffer->unmap_len = buffer->len; 984 buffer->dma_offset = 0; 985 buffer->flags |= EFX_TX_BUF_MAP_SINGLE; 986 } 987 988 ++tx_queue->insert_count; 989 return 0; 990} 991 992 993/* Remove buffers put into a tx_queue. None of the buffers must have 994 * an skb attached. 995 */ 996static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue, 997 unsigned int insert_count) 998{ 999 struct efx_tx_buffer *buffer; 1000 1001 /* Work backwards until we hit the original insert pointer value */ 1002 while (tx_queue->insert_count != insert_count) { 1003 --tx_queue->insert_count; 1004 buffer = __efx_tx_queue_get_insert_buffer(tx_queue); 1005 efx_dequeue_buffer(tx_queue, buffer, NULL, NULL); 1006 } 1007} 1008 1009 1010/* Parse the SKB header and initialise state. */ 1011static int tso_start(struct tso_state *st, struct efx_nic *efx, 1012 const struct sk_buff *skb) 1013{ 1014 bool use_opt_desc = efx_nic_rev(efx) >= EFX_REV_HUNT_A0; 1015 struct device *dma_dev = &efx->pci_dev->dev; 1016 unsigned int header_len, in_len; 1017 dma_addr_t dma_addr; 1018 1019 st->ip_off = skb_network_header(skb) - skb->data; 1020 st->tcp_off = skb_transport_header(skb) - skb->data; 1021 header_len = st->tcp_off + (tcp_hdr(skb)->doff << 2u); 1022 in_len = skb_headlen(skb) - header_len; 1023 st->header_len = header_len; 1024 st->in_len = in_len; 1025 if (st->protocol == htons(ETH_P_IP)) { 1026 st->ip_base_len = st->header_len - st->ip_off; 1027 st->ipv4_id = ntohs(ip_hdr(skb)->id); 1028 } else { 1029 st->ip_base_len = st->header_len - st->tcp_off; 1030 st->ipv4_id = 0; 1031 } 1032 st->seqnum = ntohl(tcp_hdr(skb)->seq); 1033 1034 EFX_BUG_ON_PARANOID(tcp_hdr(skb)->urg); 1035 EFX_BUG_ON_PARANOID(tcp_hdr(skb)->syn); 1036 EFX_BUG_ON_PARANOID(tcp_hdr(skb)->rst); 1037 1038 st->out_len = skb->len - header_len; 1039 1040 if (!use_opt_desc) { 1041 st->header_unmap_len = 0; 1042 1043 if (likely(in_len == 0)) { 1044 st->dma_flags = 0; 1045 st->unmap_len = 0; 1046 return 0; 1047 } 1048 1049 dma_addr = dma_map_single(dma_dev, skb->data + header_len, 1050 in_len, DMA_TO_DEVICE); 1051 st->dma_flags = EFX_TX_BUF_MAP_SINGLE; 1052 st->dma_addr = dma_addr; 1053 st->unmap_addr = dma_addr; 1054 st->unmap_len = in_len; 1055 } else { 1056 dma_addr = dma_map_single(dma_dev, skb->data, 1057 skb_headlen(skb), DMA_TO_DEVICE); 1058 st->header_dma_addr = dma_addr; 1059 st->header_unmap_len = skb_headlen(skb); 1060 st->dma_flags = 0; 1061 st->dma_addr = dma_addr + header_len; 1062 st->unmap_len = 0; 1063 } 1064 1065 return unlikely(dma_mapping_error(dma_dev, dma_addr)) ? -ENOMEM : 0; 1066} 1067 1068static int tso_get_fragment(struct tso_state *st, struct efx_nic *efx, 1069 skb_frag_t *frag) 1070{ 1071 st->unmap_addr = skb_frag_dma_map(&efx->pci_dev->dev, frag, 0, 1072 skb_frag_size(frag), DMA_TO_DEVICE); 1073 if (likely(!dma_mapping_error(&efx->pci_dev->dev, st->unmap_addr))) { 1074 st->dma_flags = 0; 1075 st->unmap_len = skb_frag_size(frag); 1076 st->in_len = skb_frag_size(frag); 1077 st->dma_addr = st->unmap_addr; 1078 return 0; 1079 } 1080 return -ENOMEM; 1081} 1082 1083 1084/** 1085 * tso_fill_packet_with_fragment - form descriptors for the current fragment 1086 * @tx_queue: Efx TX queue 1087 * @skb: Socket buffer 1088 * @st: TSO state 1089 * 1090 * Form descriptors for the current fragment, until we reach the end 1091 * of fragment or end-of-packet. 1092 */ 1093static void tso_fill_packet_with_fragment(struct efx_tx_queue *tx_queue, 1094 const struct sk_buff *skb, 1095 struct tso_state *st) 1096{ 1097 struct efx_tx_buffer *buffer; 1098 int n; 1099 1100 if (st->in_len == 0) 1101 return; 1102 if (st->packet_space == 0) 1103 return; 1104 1105 EFX_BUG_ON_PARANOID(st->in_len <= 0); 1106 EFX_BUG_ON_PARANOID(st->packet_space <= 0); 1107 1108 n = min(st->in_len, st->packet_space); 1109 1110 st->packet_space -= n; 1111 st->out_len -= n; 1112 st->in_len -= n; 1113 1114 efx_tx_queue_insert(tx_queue, st->dma_addr, n, &buffer); 1115 1116 if (st->out_len == 0) { 1117 /* Transfer ownership of the skb */ 1118 buffer->skb = skb; 1119 buffer->flags = EFX_TX_BUF_SKB; 1120 } else if (st->packet_space != 0) { 1121 buffer->flags = EFX_TX_BUF_CONT; 1122 } 1123 1124 if (st->in_len == 0) { 1125 /* Transfer ownership of the DMA mapping */ 1126 buffer->unmap_len = st->unmap_len; 1127 buffer->dma_offset = buffer->unmap_len - buffer->len; 1128 buffer->flags |= st->dma_flags; 1129 st->unmap_len = 0; 1130 } 1131 1132 st->dma_addr += n; 1133} 1134 1135 1136/** 1137 * tso_start_new_packet - generate a new header and prepare for the new packet 1138 * @tx_queue: Efx TX queue 1139 * @skb: Socket buffer 1140 * @st: TSO state 1141 * 1142 * Generate a new header and prepare for the new packet. Return 0 on 1143 * success, or -%ENOMEM if failed to alloc header. 1144 */ 1145static int tso_start_new_packet(struct efx_tx_queue *tx_queue, 1146 const struct sk_buff *skb, 1147 struct tso_state *st) 1148{ 1149 struct efx_tx_buffer *buffer = 1150 efx_tx_queue_get_insert_buffer(tx_queue); 1151 bool is_last = st->out_len <= skb_shinfo(skb)->gso_size; 1152 u8 tcp_flags_clear; 1153 1154 if (!is_last) { 1155 st->packet_space = skb_shinfo(skb)->gso_size; 1156 tcp_flags_clear = 0x09; /* mask out FIN and PSH */ 1157 } else { 1158 st->packet_space = st->out_len; 1159 tcp_flags_clear = 0x00; 1160 } 1161 1162 if (!st->header_unmap_len) { 1163 /* Allocate and insert a DMA-mapped header buffer. */ 1164 struct tcphdr *tsoh_th; 1165 unsigned ip_length; 1166 u8 *header; 1167 int rc; 1168 1169 header = efx_tsoh_get_buffer(tx_queue, buffer, st->header_len); 1170 if (!header) 1171 return -ENOMEM; 1172 1173 tsoh_th = (struct tcphdr *)(header + st->tcp_off); 1174 1175 /* Copy and update the headers. */ 1176 memcpy(header, skb->data, st->header_len); 1177 1178 tsoh_th->seq = htonl(st->seqnum); 1179 ((u8 *)tsoh_th)[13] &= ~tcp_flags_clear; 1180 1181 ip_length = st->ip_base_len + st->packet_space; 1182 1183 if (st->protocol == htons(ETH_P_IP)) { 1184 struct iphdr *tsoh_iph = 1185 (struct iphdr *)(header + st->ip_off); 1186 1187 tsoh_iph->tot_len = htons(ip_length); 1188 tsoh_iph->id = htons(st->ipv4_id); 1189 } else { 1190 struct ipv6hdr *tsoh_iph = 1191 (struct ipv6hdr *)(header + st->ip_off); 1192 1193 tsoh_iph->payload_len = htons(ip_length); 1194 } 1195 1196 rc = efx_tso_put_header(tx_queue, buffer, header); 1197 if (unlikely(rc)) 1198 return rc; 1199 } else { 1200 /* Send the original headers with a TSO option descriptor 1201 * in front 1202 */ 1203 u8 tcp_flags = ((u8 *)tcp_hdr(skb))[13] & ~tcp_flags_clear; 1204 1205 buffer->flags = EFX_TX_BUF_OPTION; 1206 buffer->len = 0; 1207 buffer->unmap_len = 0; 1208 EFX_POPULATE_QWORD_5(buffer->option, 1209 ESF_DZ_TX_DESC_IS_OPT, 1, 1210 ESF_DZ_TX_OPTION_TYPE, 1211 ESE_DZ_TX_OPTION_DESC_TSO, 1212 ESF_DZ_TX_TSO_TCP_FLAGS, tcp_flags, 1213 ESF_DZ_TX_TSO_IP_ID, st->ipv4_id, 1214 ESF_DZ_TX_TSO_TCP_SEQNO, st->seqnum); 1215 ++tx_queue->insert_count; 1216 1217 /* We mapped the headers in tso_start(). Unmap them 1218 * when the last segment is completed. 1219 */ 1220 buffer = efx_tx_queue_get_insert_buffer(tx_queue); 1221 buffer->dma_addr = st->header_dma_addr; 1222 buffer->len = st->header_len; 1223 if (is_last) { 1224 buffer->flags = EFX_TX_BUF_CONT | EFX_TX_BUF_MAP_SINGLE; 1225 buffer->unmap_len = st->header_unmap_len; 1226 buffer->dma_offset = 0; 1227 /* Ensure we only unmap them once in case of a 1228 * later DMA mapping error and rollback 1229 */ 1230 st->header_unmap_len = 0; 1231 } else { 1232 buffer->flags = EFX_TX_BUF_CONT; 1233 buffer->unmap_len = 0; 1234 } 1235 ++tx_queue->insert_count; 1236 } 1237 1238 st->seqnum += skb_shinfo(skb)->gso_size; 1239 1240 /* Linux leaves suitable gaps in the IP ID space for us to fill. */ 1241 ++st->ipv4_id; 1242 1243 ++tx_queue->tso_packets; 1244 1245 ++tx_queue->tx_packets; 1246 1247 return 0; 1248} 1249 1250 1251/** 1252 * efx_enqueue_skb_tso - segment and transmit a TSO socket buffer 1253 * @tx_queue: Efx TX queue 1254 * @skb: Socket buffer 1255 * 1256 * Context: You must hold netif_tx_lock() to call this function. 1257 * 1258 * Add socket buffer @skb to @tx_queue, doing TSO or return != 0 if 1259 * @skb was not enqueued. In all cases @skb is consumed. Return 1260 * %NETDEV_TX_OK. 1261 */ 1262static int efx_enqueue_skb_tso(struct efx_tx_queue *tx_queue, 1263 struct sk_buff *skb) 1264{ 1265 struct efx_nic *efx = tx_queue->efx; 1266 unsigned int old_insert_count = tx_queue->insert_count; 1267 int frag_i, rc; 1268 struct tso_state state; 1269 1270 /* Find the packet protocol and sanity-check it */ 1271 state.protocol = efx_tso_check_protocol(skb); 1272 1273 rc = tso_start(&state, efx, skb); 1274 if (rc) 1275 goto mem_err; 1276 1277 if (likely(state.in_len == 0)) { 1278 /* Grab the first payload fragment. */ 1279 EFX_BUG_ON_PARANOID(skb_shinfo(skb)->nr_frags < 1); 1280 frag_i = 0; 1281 rc = tso_get_fragment(&state, efx, 1282 skb_shinfo(skb)->frags + frag_i); 1283 if (rc) 1284 goto mem_err; 1285 } else { 1286 /* Payload starts in the header area. */ 1287 frag_i = -1; 1288 } 1289 1290 if (tso_start_new_packet(tx_queue, skb, &state) < 0) 1291 goto mem_err; 1292 1293 while (1) { 1294 tso_fill_packet_with_fragment(tx_queue, skb, &state); 1295 1296 /* Move onto the next fragment? */ 1297 if (state.in_len == 0) { 1298 if (++frag_i >= skb_shinfo(skb)->nr_frags) 1299 /* End of payload reached. */ 1300 break; 1301 rc = tso_get_fragment(&state, efx, 1302 skb_shinfo(skb)->frags + frag_i); 1303 if (rc) 1304 goto mem_err; 1305 } 1306 1307 /* Start at new packet? */ 1308 if (state.packet_space == 0 && 1309 tso_start_new_packet(tx_queue, skb, &state) < 0) 1310 goto mem_err; 1311 } 1312 1313 netdev_tx_sent_queue(tx_queue->core_txq, skb->len); 1314 1315 efx_tx_maybe_stop_queue(tx_queue); 1316 1317 /* Pass off to hardware */ 1318 if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) { 1319 struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue); 1320 1321 /* There could be packets left on the partner queue if those 1322 * SKBs had skb->xmit_more set. If we do not push those they 1323 * could be left for a long time and cause a netdev watchdog. 1324 */ 1325 if (txq2->xmit_more_available) 1326 efx_nic_push_buffers(txq2); 1327 1328 efx_nic_push_buffers(tx_queue); 1329 } else { 1330 tx_queue->xmit_more_available = skb->xmit_more; 1331 } 1332 1333 tx_queue->tso_bursts++; 1334 return NETDEV_TX_OK; 1335 1336 mem_err: 1337 netif_err(efx, tx_err, efx->net_dev, 1338 "Out of memory for TSO headers, or DMA mapping error\n"); 1339 dev_kfree_skb_any(skb); 1340 1341 /* Free the DMA mapping we were in the process of writing out */ 1342 if (state.unmap_len) { 1343 if (state.dma_flags & EFX_TX_BUF_MAP_SINGLE) 1344 dma_unmap_single(&efx->pci_dev->dev, state.unmap_addr, 1345 state.unmap_len, DMA_TO_DEVICE); 1346 else 1347 dma_unmap_page(&efx->pci_dev->dev, state.unmap_addr, 1348 state.unmap_len, DMA_TO_DEVICE); 1349 } 1350 1351 /* Free the header DMA mapping, if using option descriptors */ 1352 if (state.header_unmap_len) 1353 dma_unmap_single(&efx->pci_dev->dev, state.header_dma_addr, 1354 state.header_unmap_len, DMA_TO_DEVICE); 1355 1356 efx_enqueue_unwind(tx_queue, old_insert_count); 1357 return NETDEV_TX_OK; 1358} 1359