1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright(c) 2013 - 2018 Intel Corporation. */ 3 4 #include <linux/prefetch.h> 5 6 #include "iavf.h" 7 #include "iavf_trace.h" 8 #include "iavf_prototype.h" 9 10 static inline __le64 build_ctob(u32 td_cmd, u32 td_offset, unsigned int size, 11 u32 td_tag) 12 { 13 return cpu_to_le64(IAVF_TX_DESC_DTYPE_DATA | 14 ((u64)td_cmd << IAVF_TXD_QW1_CMD_SHIFT) | 15 ((u64)td_offset << IAVF_TXD_QW1_OFFSET_SHIFT) | 16 ((u64)size << IAVF_TXD_QW1_TX_BUF_SZ_SHIFT) | 17 ((u64)td_tag << IAVF_TXD_QW1_L2TAG1_SHIFT)); 18 } 19 20 #define IAVF_TXD_CMD (IAVF_TX_DESC_CMD_EOP | IAVF_TX_DESC_CMD_RS) 21 22 /** 23 * iavf_unmap_and_free_tx_resource - Release a Tx buffer 24 * @ring: the ring that owns the buffer 25 * @tx_buffer: the buffer to free 26 **/ 27 static void iavf_unmap_and_free_tx_resource(struct iavf_ring *ring, 28 struct iavf_tx_buffer *tx_buffer) 29 { 30 if (tx_buffer->skb) { 31 if (tx_buffer->tx_flags & IAVF_TX_FLAGS_FD_SB) 32 kfree(tx_buffer->raw_buf); 33 else 34 dev_kfree_skb_any(tx_buffer->skb); 35 if (dma_unmap_len(tx_buffer, len)) 36 dma_unmap_single(ring->dev, 37 dma_unmap_addr(tx_buffer, dma), 38 dma_unmap_len(tx_buffer, len), 39 DMA_TO_DEVICE); 40 } else if (dma_unmap_len(tx_buffer, len)) { 41 dma_unmap_page(ring->dev, 42 dma_unmap_addr(tx_buffer, dma), 43 dma_unmap_len(tx_buffer, len), 44 DMA_TO_DEVICE); 45 } 46 47 tx_buffer->next_to_watch = NULL; 48 tx_buffer->skb = NULL; 49 dma_unmap_len_set(tx_buffer, len, 0); 50 /* tx_buffer must be completely set up in the transmit path */ 51 } 52 53 /** 54 * iavf_clean_tx_ring - Free any empty Tx buffers 55 * @tx_ring: ring to be cleaned 56 **/ 57 void iavf_clean_tx_ring(struct iavf_ring *tx_ring) 58 { 59 unsigned long bi_size; 60 u16 i; 61 62 /* ring already cleared, nothing to do */ 63 if (!tx_ring->tx_bi) 64 return; 65 66 /* Free all the Tx ring sk_buffs */ 67 for (i = 0; i < tx_ring->count; i++) 68 iavf_unmap_and_free_tx_resource(tx_ring, &tx_ring->tx_bi[i]); 69 70 bi_size = sizeof(struct iavf_tx_buffer) * tx_ring->count; 71 memset(tx_ring->tx_bi, 0, bi_size); 72 73 /* Zero out the descriptor ring */ 74 memset(tx_ring->desc, 0, tx_ring->size); 75 76 tx_ring->next_to_use = 0; 77 tx_ring->next_to_clean = 0; 78 79 if (!tx_ring->netdev) 80 return; 81 82 /* cleanup Tx queue statistics */ 83 netdev_tx_reset_queue(txring_txq(tx_ring)); 84 } 85 86 /** 87 * iavf_free_tx_resources - Free Tx resources per queue 88 * @tx_ring: Tx descriptor ring for a specific queue 89 * 90 * Free all transmit software resources 91 **/ 92 void iavf_free_tx_resources(struct iavf_ring *tx_ring) 93 { 94 iavf_clean_tx_ring(tx_ring); 95 kfree(tx_ring->tx_bi); 96 tx_ring->tx_bi = NULL; 97 98 if (tx_ring->desc) { 99 dma_free_coherent(tx_ring->dev, tx_ring->size, 100 tx_ring->desc, tx_ring->dma); 101 tx_ring->desc = NULL; 102 } 103 } 104 105 /** 106 * iavf_get_tx_pending - how many Tx descriptors not processed 107 * @ring: the ring of descriptors 108 * @in_sw: is tx_pending being checked in SW or HW 109 * 110 * Since there is no access to the ring head register 111 * in XL710, we need to use our local copies 112 **/ 113 u32 iavf_get_tx_pending(struct iavf_ring *ring, bool in_sw) 114 { 115 u32 head, tail; 116 117 /* underlying hardware might not allow access and/or always return 118 * 0 for the head/tail registers so just use the cached values 119 */ 120 head = ring->next_to_clean; 121 tail = ring->next_to_use; 122 123 if (head != tail) 124 return (head < tail) ? 125 tail - head : (tail + ring->count - head); 126 127 return 0; 128 } 129 130 /** 131 * iavf_detect_recover_hung - Function to detect and recover hung_queues 132 * @vsi: pointer to vsi struct with tx queues 133 * 134 * VSI has netdev and netdev has TX queues. This function is to check each of 135 * those TX queues if they are hung, trigger recovery by issuing SW interrupt. 136 **/ 137 void iavf_detect_recover_hung(struct iavf_vsi *vsi) 138 { 139 struct iavf_ring *tx_ring = NULL; 140 struct net_device *netdev; 141 unsigned int i; 142 int packets; 143 144 if (!vsi) 145 return; 146 147 if (test_bit(__IAVF_VSI_DOWN, vsi->state)) 148 return; 149 150 netdev = vsi->netdev; 151 if (!netdev) 152 return; 153 154 if (!netif_carrier_ok(netdev)) 155 return; 156 157 for (i = 0; i < vsi->back->num_active_queues; i++) { 158 tx_ring = &vsi->back->tx_rings[i]; 159 if (tx_ring && tx_ring->desc) { 160 /* If packet counter has not changed the queue is 161 * likely stalled, so force an interrupt for this 162 * queue. 163 * 164 * prev_pkt_ctr would be negative if there was no 165 * pending work. 166 */ 167 packets = tx_ring->stats.packets & INT_MAX; 168 if (tx_ring->tx_stats.prev_pkt_ctr == packets) { 169 iavf_force_wb(vsi, tx_ring->q_vector); 170 continue; 171 } 172 173 /* Memory barrier between read of packet count and call 174 * to iavf_get_tx_pending() 175 */ 176 smp_rmb(); 177 tx_ring->tx_stats.prev_pkt_ctr = 178 iavf_get_tx_pending(tx_ring, true) ? packets : -1; 179 } 180 } 181 } 182 183 #define WB_STRIDE 4 184 185 /** 186 * iavf_clean_tx_irq - Reclaim resources after transmit completes 187 * @vsi: the VSI we care about 188 * @tx_ring: Tx ring to clean 189 * @napi_budget: Used to determine if we are in netpoll 190 * 191 * Returns true if there's any budget left (e.g. the clean is finished) 192 **/ 193 static bool iavf_clean_tx_irq(struct iavf_vsi *vsi, 194 struct iavf_ring *tx_ring, int napi_budget) 195 { 196 int i = tx_ring->next_to_clean; 197 struct iavf_tx_buffer *tx_buf; 198 struct iavf_tx_desc *tx_desc; 199 unsigned int total_bytes = 0, total_packets = 0; 200 unsigned int budget = IAVF_DEFAULT_IRQ_WORK; 201 202 tx_buf = &tx_ring->tx_bi[i]; 203 tx_desc = IAVF_TX_DESC(tx_ring, i); 204 i -= tx_ring->count; 205 206 do { 207 struct iavf_tx_desc *eop_desc = tx_buf->next_to_watch; 208 209 /* if next_to_watch is not set then there is no work pending */ 210 if (!eop_desc) 211 break; 212 213 /* prevent any other reads prior to eop_desc */ 214 smp_rmb(); 215 216 iavf_trace(clean_tx_irq, tx_ring, tx_desc, tx_buf); 217 /* if the descriptor isn't done, no work yet to do */ 218 if (!(eop_desc->cmd_type_offset_bsz & 219 cpu_to_le64(IAVF_TX_DESC_DTYPE_DESC_DONE))) 220 break; 221 222 /* clear next_to_watch to prevent false hangs */ 223 tx_buf->next_to_watch = NULL; 224 225 /* update the statistics for this packet */ 226 total_bytes += tx_buf->bytecount; 227 total_packets += tx_buf->gso_segs; 228 229 /* free the skb */ 230 napi_consume_skb(tx_buf->skb, napi_budget); 231 232 /* unmap skb header data */ 233 dma_unmap_single(tx_ring->dev, 234 dma_unmap_addr(tx_buf, dma), 235 dma_unmap_len(tx_buf, len), 236 DMA_TO_DEVICE); 237 238 /* clear tx_buffer data */ 239 tx_buf->skb = NULL; 240 dma_unmap_len_set(tx_buf, len, 0); 241 242 /* unmap remaining buffers */ 243 while (tx_desc != eop_desc) { 244 iavf_trace(clean_tx_irq_unmap, 245 tx_ring, tx_desc, tx_buf); 246 247 tx_buf++; 248 tx_desc++; 249 i++; 250 if (unlikely(!i)) { 251 i -= tx_ring->count; 252 tx_buf = tx_ring->tx_bi; 253 tx_desc = IAVF_TX_DESC(tx_ring, 0); 254 } 255 256 /* unmap any remaining paged data */ 257 if (dma_unmap_len(tx_buf, len)) { 258 dma_unmap_page(tx_ring->dev, 259 dma_unmap_addr(tx_buf, dma), 260 dma_unmap_len(tx_buf, len), 261 DMA_TO_DEVICE); 262 dma_unmap_len_set(tx_buf, len, 0); 263 } 264 } 265 266 /* move us one more past the eop_desc for start of next pkt */ 267 tx_buf++; 268 tx_desc++; 269 i++; 270 if (unlikely(!i)) { 271 i -= tx_ring->count; 272 tx_buf = tx_ring->tx_bi; 273 tx_desc = IAVF_TX_DESC(tx_ring, 0); 274 } 275 276 prefetch(tx_desc); 277 278 /* update budget accounting */ 279 budget--; 280 } while (likely(budget)); 281 282 i += tx_ring->count; 283 tx_ring->next_to_clean = i; 284 u64_stats_update_begin(&tx_ring->syncp); 285 tx_ring->stats.bytes += total_bytes; 286 tx_ring->stats.packets += total_packets; 287 u64_stats_update_end(&tx_ring->syncp); 288 tx_ring->q_vector->tx.total_bytes += total_bytes; 289 tx_ring->q_vector->tx.total_packets += total_packets; 290 291 if (tx_ring->flags & IAVF_TXR_FLAGS_WB_ON_ITR) { 292 /* check to see if there are < 4 descriptors 293 * waiting to be written back, then kick the hardware to force 294 * them to be written back in case we stay in NAPI. 295 * In this mode on X722 we do not enable Interrupt. 296 */ 297 unsigned int j = iavf_get_tx_pending(tx_ring, false); 298 299 if (budget && 300 ((j / WB_STRIDE) == 0) && (j > 0) && 301 !test_bit(__IAVF_VSI_DOWN, vsi->state) && 302 (IAVF_DESC_UNUSED(tx_ring) != tx_ring->count)) 303 tx_ring->arm_wb = true; 304 } 305 306 /* notify netdev of completed buffers */ 307 netdev_tx_completed_queue(txring_txq(tx_ring), 308 total_packets, total_bytes); 309 310 #define TX_WAKE_THRESHOLD ((s16)(DESC_NEEDED * 2)) 311 if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) && 312 (IAVF_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))) { 313 /* Make sure that anybody stopping the queue after this 314 * sees the new next_to_clean. 315 */ 316 smp_mb(); 317 if (__netif_subqueue_stopped(tx_ring->netdev, 318 tx_ring->queue_index) && 319 !test_bit(__IAVF_VSI_DOWN, vsi->state)) { 320 netif_wake_subqueue(tx_ring->netdev, 321 tx_ring->queue_index); 322 ++tx_ring->tx_stats.restart_queue; 323 } 324 } 325 326 return !!budget; 327 } 328 329 /** 330 * iavf_enable_wb_on_itr - Arm hardware to do a wb, interrupts are not enabled 331 * @vsi: the VSI we care about 332 * @q_vector: the vector on which to enable writeback 333 * 334 **/ 335 static void iavf_enable_wb_on_itr(struct iavf_vsi *vsi, 336 struct iavf_q_vector *q_vector) 337 { 338 u16 flags = q_vector->tx.ring[0].flags; 339 u32 val; 340 341 if (!(flags & IAVF_TXR_FLAGS_WB_ON_ITR)) 342 return; 343 344 if (q_vector->arm_wb_state) 345 return; 346 347 val = IAVF_VFINT_DYN_CTLN1_WB_ON_ITR_MASK | 348 IAVF_VFINT_DYN_CTLN1_ITR_INDX_MASK; /* set noitr */ 349 350 wr32(&vsi->back->hw, 351 IAVF_VFINT_DYN_CTLN1(q_vector->reg_idx), val); 352 q_vector->arm_wb_state = true; 353 } 354 355 /** 356 * iavf_force_wb - Issue SW Interrupt so HW does a wb 357 * @vsi: the VSI we care about 358 * @q_vector: the vector on which to force writeback 359 * 360 **/ 361 void iavf_force_wb(struct iavf_vsi *vsi, struct iavf_q_vector *q_vector) 362 { 363 u32 val = IAVF_VFINT_DYN_CTLN1_INTENA_MASK | 364 IAVF_VFINT_DYN_CTLN1_ITR_INDX_MASK | /* set noitr */ 365 IAVF_VFINT_DYN_CTLN1_SWINT_TRIG_MASK | 366 IAVF_VFINT_DYN_CTLN1_SW_ITR_INDX_ENA_MASK 367 /* allow 00 to be written to the index */; 368 369 wr32(&vsi->back->hw, 370 IAVF_VFINT_DYN_CTLN1(q_vector->reg_idx), 371 val); 372 } 373 374 static inline bool iavf_container_is_rx(struct iavf_q_vector *q_vector, 375 struct iavf_ring_container *rc) 376 { 377 return &q_vector->rx == rc; 378 } 379 380 #define IAVF_AIM_MULTIPLIER_100G 2560 381 #define IAVF_AIM_MULTIPLIER_50G 1280 382 #define IAVF_AIM_MULTIPLIER_40G 1024 383 #define IAVF_AIM_MULTIPLIER_20G 512 384 #define IAVF_AIM_MULTIPLIER_10G 256 385 #define IAVF_AIM_MULTIPLIER_1G 32 386 387 static unsigned int iavf_mbps_itr_multiplier(u32 speed_mbps) 388 { 389 switch (speed_mbps) { 390 case SPEED_100000: 391 return IAVF_AIM_MULTIPLIER_100G; 392 case SPEED_50000: 393 return IAVF_AIM_MULTIPLIER_50G; 394 case SPEED_40000: 395 return IAVF_AIM_MULTIPLIER_40G; 396 case SPEED_25000: 397 case SPEED_20000: 398 return IAVF_AIM_MULTIPLIER_20G; 399 case SPEED_10000: 400 default: 401 return IAVF_AIM_MULTIPLIER_10G; 402 case SPEED_1000: 403 case SPEED_100: 404 return IAVF_AIM_MULTIPLIER_1G; 405 } 406 } 407 408 static unsigned int 409 iavf_virtchnl_itr_multiplier(enum virtchnl_link_speed speed_virtchnl) 410 { 411 switch (speed_virtchnl) { 412 case VIRTCHNL_LINK_SPEED_40GB: 413 return IAVF_AIM_MULTIPLIER_40G; 414 case VIRTCHNL_LINK_SPEED_25GB: 415 case VIRTCHNL_LINK_SPEED_20GB: 416 return IAVF_AIM_MULTIPLIER_20G; 417 case VIRTCHNL_LINK_SPEED_10GB: 418 default: 419 return IAVF_AIM_MULTIPLIER_10G; 420 case VIRTCHNL_LINK_SPEED_1GB: 421 case VIRTCHNL_LINK_SPEED_100MB: 422 return IAVF_AIM_MULTIPLIER_1G; 423 } 424 } 425 426 static unsigned int iavf_itr_divisor(struct iavf_adapter *adapter) 427 { 428 if (ADV_LINK_SUPPORT(adapter)) 429 return IAVF_ITR_ADAPTIVE_MIN_INC * 430 iavf_mbps_itr_multiplier(adapter->link_speed_mbps); 431 else 432 return IAVF_ITR_ADAPTIVE_MIN_INC * 433 iavf_virtchnl_itr_multiplier(adapter->link_speed); 434 } 435 436 /** 437 * iavf_update_itr - update the dynamic ITR value based on statistics 438 * @q_vector: structure containing interrupt and ring information 439 * @rc: structure containing ring performance data 440 * 441 * Stores a new ITR value based on packets and byte 442 * counts during the last interrupt. The advantage of per interrupt 443 * computation is faster updates and more accurate ITR for the current 444 * traffic pattern. Constants in this function were computed 445 * based on theoretical maximum wire speed and thresholds were set based 446 * on testing data as well as attempting to minimize response time 447 * while increasing bulk throughput. 448 **/ 449 static void iavf_update_itr(struct iavf_q_vector *q_vector, 450 struct iavf_ring_container *rc) 451 { 452 unsigned int avg_wire_size, packets, bytes, itr; 453 unsigned long next_update = jiffies; 454 455 /* If we don't have any rings just leave ourselves set for maximum 456 * possible latency so we take ourselves out of the equation. 457 */ 458 if (!rc->ring || !ITR_IS_DYNAMIC(rc->ring->itr_setting)) 459 return; 460 461 /* For Rx we want to push the delay up and default to low latency. 462 * for Tx we want to pull the delay down and default to high latency. 463 */ 464 itr = iavf_container_is_rx(q_vector, rc) ? 465 IAVF_ITR_ADAPTIVE_MIN_USECS | IAVF_ITR_ADAPTIVE_LATENCY : 466 IAVF_ITR_ADAPTIVE_MAX_USECS | IAVF_ITR_ADAPTIVE_LATENCY; 467 468 /* If we didn't update within up to 1 - 2 jiffies we can assume 469 * that either packets are coming in so slow there hasn't been 470 * any work, or that there is so much work that NAPI is dealing 471 * with interrupt moderation and we don't need to do anything. 472 */ 473 if (time_after(next_update, rc->next_update)) 474 goto clear_counts; 475 476 /* If itr_countdown is set it means we programmed an ITR within 477 * the last 4 interrupt cycles. This has a side effect of us 478 * potentially firing an early interrupt. In order to work around 479 * this we need to throw out any data received for a few 480 * interrupts following the update. 481 */ 482 if (q_vector->itr_countdown) { 483 itr = rc->target_itr; 484 goto clear_counts; 485 } 486 487 packets = rc->total_packets; 488 bytes = rc->total_bytes; 489 490 if (iavf_container_is_rx(q_vector, rc)) { 491 /* If Rx there are 1 to 4 packets and bytes are less than 492 * 9000 assume insufficient data to use bulk rate limiting 493 * approach unless Tx is already in bulk rate limiting. We 494 * are likely latency driven. 495 */ 496 if (packets && packets < 4 && bytes < 9000 && 497 (q_vector->tx.target_itr & IAVF_ITR_ADAPTIVE_LATENCY)) { 498 itr = IAVF_ITR_ADAPTIVE_LATENCY; 499 goto adjust_by_size; 500 } 501 } else if (packets < 4) { 502 /* If we have Tx and Rx ITR maxed and Tx ITR is running in 503 * bulk mode and we are receiving 4 or fewer packets just 504 * reset the ITR_ADAPTIVE_LATENCY bit for latency mode so 505 * that the Rx can relax. 506 */ 507 if (rc->target_itr == IAVF_ITR_ADAPTIVE_MAX_USECS && 508 (q_vector->rx.target_itr & IAVF_ITR_MASK) == 509 IAVF_ITR_ADAPTIVE_MAX_USECS) 510 goto clear_counts; 511 } else if (packets > 32) { 512 /* If we have processed over 32 packets in a single interrupt 513 * for Tx assume we need to switch over to "bulk" mode. 514 */ 515 rc->target_itr &= ~IAVF_ITR_ADAPTIVE_LATENCY; 516 } 517 518 /* We have no packets to actually measure against. This means 519 * either one of the other queues on this vector is active or 520 * we are a Tx queue doing TSO with too high of an interrupt rate. 521 * 522 * Between 4 and 56 we can assume that our current interrupt delay 523 * is only slightly too low. As such we should increase it by a small 524 * fixed amount. 525 */ 526 if (packets < 56) { 527 itr = rc->target_itr + IAVF_ITR_ADAPTIVE_MIN_INC; 528 if ((itr & IAVF_ITR_MASK) > IAVF_ITR_ADAPTIVE_MAX_USECS) { 529 itr &= IAVF_ITR_ADAPTIVE_LATENCY; 530 itr += IAVF_ITR_ADAPTIVE_MAX_USECS; 531 } 532 goto clear_counts; 533 } 534 535 if (packets <= 256) { 536 itr = min(q_vector->tx.current_itr, q_vector->rx.current_itr); 537 itr &= IAVF_ITR_MASK; 538 539 /* Between 56 and 112 is our "goldilocks" zone where we are 540 * working out "just right". Just report that our current 541 * ITR is good for us. 542 */ 543 if (packets <= 112) 544 goto clear_counts; 545 546 /* If packet count is 128 or greater we are likely looking 547 * at a slight overrun of the delay we want. Try halving 548 * our delay to see if that will cut the number of packets 549 * in half per interrupt. 550 */ 551 itr /= 2; 552 itr &= IAVF_ITR_MASK; 553 if (itr < IAVF_ITR_ADAPTIVE_MIN_USECS) 554 itr = IAVF_ITR_ADAPTIVE_MIN_USECS; 555 556 goto clear_counts; 557 } 558 559 /* The paths below assume we are dealing with a bulk ITR since 560 * number of packets is greater than 256. We are just going to have 561 * to compute a value and try to bring the count under control, 562 * though for smaller packet sizes there isn't much we can do as 563 * NAPI polling will likely be kicking in sooner rather than later. 564 */ 565 itr = IAVF_ITR_ADAPTIVE_BULK; 566 567 adjust_by_size: 568 /* If packet counts are 256 or greater we can assume we have a gross 569 * overestimation of what the rate should be. Instead of trying to fine 570 * tune it just use the formula below to try and dial in an exact value 571 * give the current packet size of the frame. 572 */ 573 avg_wire_size = bytes / packets; 574 575 /* The following is a crude approximation of: 576 * wmem_default / (size + overhead) = desired_pkts_per_int 577 * rate / bits_per_byte / (size + ethernet overhead) = pkt_rate 578 * (desired_pkt_rate / pkt_rate) * usecs_per_sec = ITR value 579 * 580 * Assuming wmem_default is 212992 and overhead is 640 bytes per 581 * packet, (256 skb, 64 headroom, 320 shared info), we can reduce the 582 * formula down to 583 * 584 * (170 * (size + 24)) / (size + 640) = ITR 585 * 586 * We first do some math on the packet size and then finally bitshift 587 * by 8 after rounding up. We also have to account for PCIe link speed 588 * difference as ITR scales based on this. 589 */ 590 if (avg_wire_size <= 60) { 591 /* Start at 250k ints/sec */ 592 avg_wire_size = 4096; 593 } else if (avg_wire_size <= 380) { 594 /* 250K ints/sec to 60K ints/sec */ 595 avg_wire_size *= 40; 596 avg_wire_size += 1696; 597 } else if (avg_wire_size <= 1084) { 598 /* 60K ints/sec to 36K ints/sec */ 599 avg_wire_size *= 15; 600 avg_wire_size += 11452; 601 } else if (avg_wire_size <= 1980) { 602 /* 36K ints/sec to 30K ints/sec */ 603 avg_wire_size *= 5; 604 avg_wire_size += 22420; 605 } else { 606 /* plateau at a limit of 30K ints/sec */ 607 avg_wire_size = 32256; 608 } 609 610 /* If we are in low latency mode halve our delay which doubles the 611 * rate to somewhere between 100K to 16K ints/sec 612 */ 613 if (itr & IAVF_ITR_ADAPTIVE_LATENCY) 614 avg_wire_size /= 2; 615 616 /* Resultant value is 256 times larger than it needs to be. This 617 * gives us room to adjust the value as needed to either increase 618 * or decrease the value based on link speeds of 10G, 2.5G, 1G, etc. 619 * 620 * Use addition as we have already recorded the new latency flag 621 * for the ITR value. 622 */ 623 itr += DIV_ROUND_UP(avg_wire_size, 624 iavf_itr_divisor(q_vector->adapter)) * 625 IAVF_ITR_ADAPTIVE_MIN_INC; 626 627 if ((itr & IAVF_ITR_MASK) > IAVF_ITR_ADAPTIVE_MAX_USECS) { 628 itr &= IAVF_ITR_ADAPTIVE_LATENCY; 629 itr += IAVF_ITR_ADAPTIVE_MAX_USECS; 630 } 631 632 clear_counts: 633 /* write back value */ 634 rc->target_itr = itr; 635 636 /* next update should occur within next jiffy */ 637 rc->next_update = next_update + 1; 638 639 rc->total_bytes = 0; 640 rc->total_packets = 0; 641 } 642 643 /** 644 * iavf_setup_tx_descriptors - Allocate the Tx descriptors 645 * @tx_ring: the tx ring to set up 646 * 647 * Return 0 on success, negative on error 648 **/ 649 int iavf_setup_tx_descriptors(struct iavf_ring *tx_ring) 650 { 651 struct device *dev = tx_ring->dev; 652 int bi_size; 653 654 if (!dev) 655 return -ENOMEM; 656 657 /* warn if we are about to overwrite the pointer */ 658 WARN_ON(tx_ring->tx_bi); 659 bi_size = sizeof(struct iavf_tx_buffer) * tx_ring->count; 660 tx_ring->tx_bi = kzalloc(bi_size, GFP_KERNEL); 661 if (!tx_ring->tx_bi) 662 goto err; 663 664 /* round up to nearest 4K */ 665 tx_ring->size = tx_ring->count * sizeof(struct iavf_tx_desc); 666 tx_ring->size = ALIGN(tx_ring->size, 4096); 667 tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size, 668 &tx_ring->dma, GFP_KERNEL); 669 if (!tx_ring->desc) { 670 dev_info(dev, "Unable to allocate memory for the Tx descriptor ring, size=%d\n", 671 tx_ring->size); 672 goto err; 673 } 674 675 tx_ring->next_to_use = 0; 676 tx_ring->next_to_clean = 0; 677 tx_ring->tx_stats.prev_pkt_ctr = -1; 678 return 0; 679 680 err: 681 kfree(tx_ring->tx_bi); 682 tx_ring->tx_bi = NULL; 683 return -ENOMEM; 684 } 685 686 /** 687 * iavf_clean_rx_ring - Free Rx buffers 688 * @rx_ring: ring to be cleaned 689 **/ 690 void iavf_clean_rx_ring(struct iavf_ring *rx_ring) 691 { 692 unsigned long bi_size; 693 u16 i; 694 695 /* ring already cleared, nothing to do */ 696 if (!rx_ring->rx_bi) 697 return; 698 699 if (rx_ring->skb) { 700 dev_kfree_skb(rx_ring->skb); 701 rx_ring->skb = NULL; 702 } 703 704 /* Free all the Rx ring sk_buffs */ 705 for (i = 0; i < rx_ring->count; i++) { 706 struct iavf_rx_buffer *rx_bi = &rx_ring->rx_bi[i]; 707 708 if (!rx_bi->page) 709 continue; 710 711 /* Invalidate cache lines that may have been written to by 712 * device so that we avoid corrupting memory. 713 */ 714 dma_sync_single_range_for_cpu(rx_ring->dev, 715 rx_bi->dma, 716 rx_bi->page_offset, 717 rx_ring->rx_buf_len, 718 DMA_FROM_DEVICE); 719 720 /* free resources associated with mapping */ 721 dma_unmap_page_attrs(rx_ring->dev, rx_bi->dma, 722 iavf_rx_pg_size(rx_ring), 723 DMA_FROM_DEVICE, 724 IAVF_RX_DMA_ATTR); 725 726 __page_frag_cache_drain(rx_bi->page, rx_bi->pagecnt_bias); 727 728 rx_bi->page = NULL; 729 rx_bi->page_offset = 0; 730 } 731 732 bi_size = sizeof(struct iavf_rx_buffer) * rx_ring->count; 733 memset(rx_ring->rx_bi, 0, bi_size); 734 735 /* Zero out the descriptor ring */ 736 memset(rx_ring->desc, 0, rx_ring->size); 737 738 rx_ring->next_to_alloc = 0; 739 rx_ring->next_to_clean = 0; 740 rx_ring->next_to_use = 0; 741 } 742 743 /** 744 * iavf_free_rx_resources - Free Rx resources 745 * @rx_ring: ring to clean the resources from 746 * 747 * Free all receive software resources 748 **/ 749 void iavf_free_rx_resources(struct iavf_ring *rx_ring) 750 { 751 iavf_clean_rx_ring(rx_ring); 752 kfree(rx_ring->rx_bi); 753 rx_ring->rx_bi = NULL; 754 755 if (rx_ring->desc) { 756 dma_free_coherent(rx_ring->dev, rx_ring->size, 757 rx_ring->desc, rx_ring->dma); 758 rx_ring->desc = NULL; 759 } 760 } 761 762 /** 763 * iavf_setup_rx_descriptors - Allocate Rx descriptors 764 * @rx_ring: Rx descriptor ring (for a specific queue) to setup 765 * 766 * Returns 0 on success, negative on failure 767 **/ 768 int iavf_setup_rx_descriptors(struct iavf_ring *rx_ring) 769 { 770 struct device *dev = rx_ring->dev; 771 int bi_size; 772 773 /* warn if we are about to overwrite the pointer */ 774 WARN_ON(rx_ring->rx_bi); 775 bi_size = sizeof(struct iavf_rx_buffer) * rx_ring->count; 776 rx_ring->rx_bi = kzalloc(bi_size, GFP_KERNEL); 777 if (!rx_ring->rx_bi) 778 goto err; 779 780 u64_stats_init(&rx_ring->syncp); 781 782 /* Round up to nearest 4K */ 783 rx_ring->size = rx_ring->count * sizeof(union iavf_32byte_rx_desc); 784 rx_ring->size = ALIGN(rx_ring->size, 4096); 785 rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size, 786 &rx_ring->dma, GFP_KERNEL); 787 788 if (!rx_ring->desc) { 789 dev_info(dev, "Unable to allocate memory for the Rx descriptor ring, size=%d\n", 790 rx_ring->size); 791 goto err; 792 } 793 794 rx_ring->next_to_alloc = 0; 795 rx_ring->next_to_clean = 0; 796 rx_ring->next_to_use = 0; 797 798 return 0; 799 err: 800 kfree(rx_ring->rx_bi); 801 rx_ring->rx_bi = NULL; 802 return -ENOMEM; 803 } 804 805 /** 806 * iavf_release_rx_desc - Store the new tail and head values 807 * @rx_ring: ring to bump 808 * @val: new head index 809 **/ 810 static inline void iavf_release_rx_desc(struct iavf_ring *rx_ring, u32 val) 811 { 812 rx_ring->next_to_use = val; 813 814 /* update next to alloc since we have filled the ring */ 815 rx_ring->next_to_alloc = val; 816 817 /* Force memory writes to complete before letting h/w 818 * know there are new descriptors to fetch. (Only 819 * applicable for weak-ordered memory model archs, 820 * such as IA-64). 821 */ 822 wmb(); 823 writel(val, rx_ring->tail); 824 } 825 826 /** 827 * iavf_rx_offset - Return expected offset into page to access data 828 * @rx_ring: Ring we are requesting offset of 829 * 830 * Returns the offset value for ring into the data buffer. 831 */ 832 static inline unsigned int iavf_rx_offset(struct iavf_ring *rx_ring) 833 { 834 return ring_uses_build_skb(rx_ring) ? IAVF_SKB_PAD : 0; 835 } 836 837 /** 838 * iavf_alloc_mapped_page - recycle or make a new page 839 * @rx_ring: ring to use 840 * @bi: rx_buffer struct to modify 841 * 842 * Returns true if the page was successfully allocated or 843 * reused. 844 **/ 845 static bool iavf_alloc_mapped_page(struct iavf_ring *rx_ring, 846 struct iavf_rx_buffer *bi) 847 { 848 struct page *page = bi->page; 849 dma_addr_t dma; 850 851 /* since we are recycling buffers we should seldom need to alloc */ 852 if (likely(page)) { 853 rx_ring->rx_stats.page_reuse_count++; 854 return true; 855 } 856 857 /* alloc new page for storage */ 858 page = dev_alloc_pages(iavf_rx_pg_order(rx_ring)); 859 if (unlikely(!page)) { 860 rx_ring->rx_stats.alloc_page_failed++; 861 return false; 862 } 863 864 /* map page for use */ 865 dma = dma_map_page_attrs(rx_ring->dev, page, 0, 866 iavf_rx_pg_size(rx_ring), 867 DMA_FROM_DEVICE, 868 IAVF_RX_DMA_ATTR); 869 870 /* if mapping failed free memory back to system since 871 * there isn't much point in holding memory we can't use 872 */ 873 if (dma_mapping_error(rx_ring->dev, dma)) { 874 __free_pages(page, iavf_rx_pg_order(rx_ring)); 875 rx_ring->rx_stats.alloc_page_failed++; 876 return false; 877 } 878 879 bi->dma = dma; 880 bi->page = page; 881 bi->page_offset = iavf_rx_offset(rx_ring); 882 883 /* initialize pagecnt_bias to 1 representing we fully own page */ 884 bi->pagecnt_bias = 1; 885 886 return true; 887 } 888 889 /** 890 * iavf_receive_skb - Send a completed packet up the stack 891 * @rx_ring: rx ring in play 892 * @skb: packet to send up 893 * @vlan_tag: vlan tag for packet 894 **/ 895 static void iavf_receive_skb(struct iavf_ring *rx_ring, 896 struct sk_buff *skb, u16 vlan_tag) 897 { 898 struct iavf_q_vector *q_vector = rx_ring->q_vector; 899 900 if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) && 901 (vlan_tag & VLAN_VID_MASK)) 902 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag); 903 else if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_STAG_RX) && 904 vlan_tag & VLAN_VID_MASK) 905 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021AD), vlan_tag); 906 907 napi_gro_receive(&q_vector->napi, skb); 908 } 909 910 /** 911 * iavf_alloc_rx_buffers - Replace used receive buffers 912 * @rx_ring: ring to place buffers on 913 * @cleaned_count: number of buffers to replace 914 * 915 * Returns false if all allocations were successful, true if any fail 916 **/ 917 bool iavf_alloc_rx_buffers(struct iavf_ring *rx_ring, u16 cleaned_count) 918 { 919 u16 ntu = rx_ring->next_to_use; 920 union iavf_rx_desc *rx_desc; 921 struct iavf_rx_buffer *bi; 922 923 /* do nothing if no valid netdev defined */ 924 if (!rx_ring->netdev || !cleaned_count) 925 return false; 926 927 rx_desc = IAVF_RX_DESC(rx_ring, ntu); 928 bi = &rx_ring->rx_bi[ntu]; 929 930 do { 931 if (!iavf_alloc_mapped_page(rx_ring, bi)) 932 goto no_buffers; 933 934 /* sync the buffer for use by the device */ 935 dma_sync_single_range_for_device(rx_ring->dev, bi->dma, 936 bi->page_offset, 937 rx_ring->rx_buf_len, 938 DMA_FROM_DEVICE); 939 940 /* Refresh the desc even if buffer_addrs didn't change 941 * because each write-back erases this info. 942 */ 943 rx_desc->read.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset); 944 945 rx_desc++; 946 bi++; 947 ntu++; 948 if (unlikely(ntu == rx_ring->count)) { 949 rx_desc = IAVF_RX_DESC(rx_ring, 0); 950 bi = rx_ring->rx_bi; 951 ntu = 0; 952 } 953 954 /* clear the status bits for the next_to_use descriptor */ 955 rx_desc->wb.qword1.status_error_len = 0; 956 957 cleaned_count--; 958 } while (cleaned_count); 959 960 if (rx_ring->next_to_use != ntu) 961 iavf_release_rx_desc(rx_ring, ntu); 962 963 return false; 964 965 no_buffers: 966 if (rx_ring->next_to_use != ntu) 967 iavf_release_rx_desc(rx_ring, ntu); 968 969 /* make sure to come back via polling to try again after 970 * allocation failure 971 */ 972 return true; 973 } 974 975 /** 976 * iavf_rx_checksum - Indicate in skb if hw indicated a good cksum 977 * @vsi: the VSI we care about 978 * @skb: skb currently being received and modified 979 * @rx_desc: the receive descriptor 980 **/ 981 static inline void iavf_rx_checksum(struct iavf_vsi *vsi, 982 struct sk_buff *skb, 983 union iavf_rx_desc *rx_desc) 984 { 985 struct iavf_rx_ptype_decoded decoded; 986 u32 rx_error, rx_status; 987 bool ipv4, ipv6; 988 u8 ptype; 989 u64 qword; 990 991 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len); 992 ptype = (qword & IAVF_RXD_QW1_PTYPE_MASK) >> IAVF_RXD_QW1_PTYPE_SHIFT; 993 rx_error = (qword & IAVF_RXD_QW1_ERROR_MASK) >> 994 IAVF_RXD_QW1_ERROR_SHIFT; 995 rx_status = (qword & IAVF_RXD_QW1_STATUS_MASK) >> 996 IAVF_RXD_QW1_STATUS_SHIFT; 997 decoded = decode_rx_desc_ptype(ptype); 998 999 skb->ip_summed = CHECKSUM_NONE; 1000 1001 skb_checksum_none_assert(skb); 1002 1003 /* Rx csum enabled and ip headers found? */ 1004 if (!(vsi->netdev->features & NETIF_F_RXCSUM)) 1005 return; 1006 1007 /* did the hardware decode the packet and checksum? */ 1008 if (!(rx_status & BIT(IAVF_RX_DESC_STATUS_L3L4P_SHIFT))) 1009 return; 1010 1011 /* both known and outer_ip must be set for the below code to work */ 1012 if (!(decoded.known && decoded.outer_ip)) 1013 return; 1014 1015 ipv4 = (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP) && 1016 (decoded.outer_ip_ver == IAVF_RX_PTYPE_OUTER_IPV4); 1017 ipv6 = (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP) && 1018 (decoded.outer_ip_ver == IAVF_RX_PTYPE_OUTER_IPV6); 1019 1020 if (ipv4 && 1021 (rx_error & (BIT(IAVF_RX_DESC_ERROR_IPE_SHIFT) | 1022 BIT(IAVF_RX_DESC_ERROR_EIPE_SHIFT)))) 1023 goto checksum_fail; 1024 1025 /* likely incorrect csum if alternate IP extension headers found */ 1026 if (ipv6 && 1027 rx_status & BIT(IAVF_RX_DESC_STATUS_IPV6EXADD_SHIFT)) 1028 /* don't increment checksum err here, non-fatal err */ 1029 return; 1030 1031 /* there was some L4 error, count error and punt packet to the stack */ 1032 if (rx_error & BIT(IAVF_RX_DESC_ERROR_L4E_SHIFT)) 1033 goto checksum_fail; 1034 1035 /* handle packets that were not able to be checksummed due 1036 * to arrival speed, in this case the stack can compute 1037 * the csum. 1038 */ 1039 if (rx_error & BIT(IAVF_RX_DESC_ERROR_PPRS_SHIFT)) 1040 return; 1041 1042 /* Only report checksum unnecessary for TCP, UDP, or SCTP */ 1043 switch (decoded.inner_prot) { 1044 case IAVF_RX_PTYPE_INNER_PROT_TCP: 1045 case IAVF_RX_PTYPE_INNER_PROT_UDP: 1046 case IAVF_RX_PTYPE_INNER_PROT_SCTP: 1047 skb->ip_summed = CHECKSUM_UNNECESSARY; 1048 fallthrough; 1049 default: 1050 break; 1051 } 1052 1053 return; 1054 1055 checksum_fail: 1056 vsi->back->hw_csum_rx_error++; 1057 } 1058 1059 /** 1060 * iavf_ptype_to_htype - get a hash type 1061 * @ptype: the ptype value from the descriptor 1062 * 1063 * Returns a hash type to be used by skb_set_hash 1064 **/ 1065 static inline int iavf_ptype_to_htype(u8 ptype) 1066 { 1067 struct iavf_rx_ptype_decoded decoded = decode_rx_desc_ptype(ptype); 1068 1069 if (!decoded.known) 1070 return PKT_HASH_TYPE_NONE; 1071 1072 if (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP && 1073 decoded.payload_layer == IAVF_RX_PTYPE_PAYLOAD_LAYER_PAY4) 1074 return PKT_HASH_TYPE_L4; 1075 else if (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP && 1076 decoded.payload_layer == IAVF_RX_PTYPE_PAYLOAD_LAYER_PAY3) 1077 return PKT_HASH_TYPE_L3; 1078 else 1079 return PKT_HASH_TYPE_L2; 1080 } 1081 1082 /** 1083 * iavf_rx_hash - set the hash value in the skb 1084 * @ring: descriptor ring 1085 * @rx_desc: specific descriptor 1086 * @skb: skb currently being received and modified 1087 * @rx_ptype: Rx packet type 1088 **/ 1089 static inline void iavf_rx_hash(struct iavf_ring *ring, 1090 union iavf_rx_desc *rx_desc, 1091 struct sk_buff *skb, 1092 u8 rx_ptype) 1093 { 1094 u32 hash; 1095 const __le64 rss_mask = 1096 cpu_to_le64((u64)IAVF_RX_DESC_FLTSTAT_RSS_HASH << 1097 IAVF_RX_DESC_STATUS_FLTSTAT_SHIFT); 1098 1099 if (!(ring->netdev->features & NETIF_F_RXHASH)) 1100 return; 1101 1102 if ((rx_desc->wb.qword1.status_error_len & rss_mask) == rss_mask) { 1103 hash = le32_to_cpu(rx_desc->wb.qword0.hi_dword.rss); 1104 skb_set_hash(skb, hash, iavf_ptype_to_htype(rx_ptype)); 1105 } 1106 } 1107 1108 /** 1109 * iavf_process_skb_fields - Populate skb header fields from Rx descriptor 1110 * @rx_ring: rx descriptor ring packet is being transacted on 1111 * @rx_desc: pointer to the EOP Rx descriptor 1112 * @skb: pointer to current skb being populated 1113 * @rx_ptype: the packet type decoded by hardware 1114 * 1115 * This function checks the ring, descriptor, and packet information in 1116 * order to populate the hash, checksum, VLAN, protocol, and 1117 * other fields within the skb. 1118 **/ 1119 static inline 1120 void iavf_process_skb_fields(struct iavf_ring *rx_ring, 1121 union iavf_rx_desc *rx_desc, struct sk_buff *skb, 1122 u8 rx_ptype) 1123 { 1124 iavf_rx_hash(rx_ring, rx_desc, skb, rx_ptype); 1125 1126 iavf_rx_checksum(rx_ring->vsi, skb, rx_desc); 1127 1128 skb_record_rx_queue(skb, rx_ring->queue_index); 1129 1130 /* modifies the skb - consumes the enet header */ 1131 skb->protocol = eth_type_trans(skb, rx_ring->netdev); 1132 } 1133 1134 /** 1135 * iavf_cleanup_headers - Correct empty headers 1136 * @rx_ring: rx descriptor ring packet is being transacted on 1137 * @skb: pointer to current skb being fixed 1138 * 1139 * Also address the case where we are pulling data in on pages only 1140 * and as such no data is present in the skb header. 1141 * 1142 * In addition if skb is not at least 60 bytes we need to pad it so that 1143 * it is large enough to qualify as a valid Ethernet frame. 1144 * 1145 * Returns true if an error was encountered and skb was freed. 1146 **/ 1147 static bool iavf_cleanup_headers(struct iavf_ring *rx_ring, struct sk_buff *skb) 1148 { 1149 /* if eth_skb_pad returns an error the skb was freed */ 1150 if (eth_skb_pad(skb)) 1151 return true; 1152 1153 return false; 1154 } 1155 1156 /** 1157 * iavf_reuse_rx_page - page flip buffer and store it back on the ring 1158 * @rx_ring: rx descriptor ring to store buffers on 1159 * @old_buff: donor buffer to have page reused 1160 * 1161 * Synchronizes page for reuse by the adapter 1162 **/ 1163 static void iavf_reuse_rx_page(struct iavf_ring *rx_ring, 1164 struct iavf_rx_buffer *old_buff) 1165 { 1166 struct iavf_rx_buffer *new_buff; 1167 u16 nta = rx_ring->next_to_alloc; 1168 1169 new_buff = &rx_ring->rx_bi[nta]; 1170 1171 /* update, and store next to alloc */ 1172 nta++; 1173 rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0; 1174 1175 /* transfer page from old buffer to new buffer */ 1176 new_buff->dma = old_buff->dma; 1177 new_buff->page = old_buff->page; 1178 new_buff->page_offset = old_buff->page_offset; 1179 new_buff->pagecnt_bias = old_buff->pagecnt_bias; 1180 } 1181 1182 /** 1183 * iavf_can_reuse_rx_page - Determine if this page can be reused by 1184 * the adapter for another receive 1185 * 1186 * @rx_buffer: buffer containing the page 1187 * 1188 * If page is reusable, rx_buffer->page_offset is adjusted to point to 1189 * an unused region in the page. 1190 * 1191 * For small pages, @truesize will be a constant value, half the size 1192 * of the memory at page. We'll attempt to alternate between high and 1193 * low halves of the page, with one half ready for use by the hardware 1194 * and the other half being consumed by the stack. We use the page 1195 * ref count to determine whether the stack has finished consuming the 1196 * portion of this page that was passed up with a previous packet. If 1197 * the page ref count is >1, we'll assume the "other" half page is 1198 * still busy, and this page cannot be reused. 1199 * 1200 * For larger pages, @truesize will be the actual space used by the 1201 * received packet (adjusted upward to an even multiple of the cache 1202 * line size). This will advance through the page by the amount 1203 * actually consumed by the received packets while there is still 1204 * space for a buffer. Each region of larger pages will be used at 1205 * most once, after which the page will not be reused. 1206 * 1207 * In either case, if the page is reusable its refcount is increased. 1208 **/ 1209 static bool iavf_can_reuse_rx_page(struct iavf_rx_buffer *rx_buffer) 1210 { 1211 unsigned int pagecnt_bias = rx_buffer->pagecnt_bias; 1212 struct page *page = rx_buffer->page; 1213 1214 /* Is any reuse possible? */ 1215 if (!dev_page_is_reusable(page)) 1216 return false; 1217 1218 #if (PAGE_SIZE < 8192) 1219 /* if we are only owner of page we can reuse it */ 1220 if (unlikely((page_count(page) - pagecnt_bias) > 1)) 1221 return false; 1222 #else 1223 #define IAVF_LAST_OFFSET \ 1224 (SKB_WITH_OVERHEAD(PAGE_SIZE) - IAVF_RXBUFFER_2048) 1225 if (rx_buffer->page_offset > IAVF_LAST_OFFSET) 1226 return false; 1227 #endif 1228 1229 /* If we have drained the page fragment pool we need to update 1230 * the pagecnt_bias and page count so that we fully restock the 1231 * number of references the driver holds. 1232 */ 1233 if (unlikely(!pagecnt_bias)) { 1234 page_ref_add(page, USHRT_MAX); 1235 rx_buffer->pagecnt_bias = USHRT_MAX; 1236 } 1237 1238 return true; 1239 } 1240 1241 /** 1242 * iavf_add_rx_frag - Add contents of Rx buffer to sk_buff 1243 * @rx_ring: rx descriptor ring to transact packets on 1244 * @rx_buffer: buffer containing page to add 1245 * @skb: sk_buff to place the data into 1246 * @size: packet length from rx_desc 1247 * 1248 * This function will add the data contained in rx_buffer->page to the skb. 1249 * It will just attach the page as a frag to the skb. 1250 * 1251 * The function will then update the page offset. 1252 **/ 1253 static void iavf_add_rx_frag(struct iavf_ring *rx_ring, 1254 struct iavf_rx_buffer *rx_buffer, 1255 struct sk_buff *skb, 1256 unsigned int size) 1257 { 1258 #if (PAGE_SIZE < 8192) 1259 unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2; 1260 #else 1261 unsigned int truesize = SKB_DATA_ALIGN(size + iavf_rx_offset(rx_ring)); 1262 #endif 1263 1264 if (!size) 1265 return; 1266 1267 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page, 1268 rx_buffer->page_offset, size, truesize); 1269 1270 /* page is being used so we must update the page offset */ 1271 #if (PAGE_SIZE < 8192) 1272 rx_buffer->page_offset ^= truesize; 1273 #else 1274 rx_buffer->page_offset += truesize; 1275 #endif 1276 } 1277 1278 /** 1279 * iavf_get_rx_buffer - Fetch Rx buffer and synchronize data for use 1280 * @rx_ring: rx descriptor ring to transact packets on 1281 * @size: size of buffer to add to skb 1282 * 1283 * This function will pull an Rx buffer from the ring and synchronize it 1284 * for use by the CPU. 1285 */ 1286 static struct iavf_rx_buffer *iavf_get_rx_buffer(struct iavf_ring *rx_ring, 1287 const unsigned int size) 1288 { 1289 struct iavf_rx_buffer *rx_buffer; 1290 1291 rx_buffer = &rx_ring->rx_bi[rx_ring->next_to_clean]; 1292 prefetchw(rx_buffer->page); 1293 if (!size) 1294 return rx_buffer; 1295 1296 /* we are reusing so sync this buffer for CPU use */ 1297 dma_sync_single_range_for_cpu(rx_ring->dev, 1298 rx_buffer->dma, 1299 rx_buffer->page_offset, 1300 size, 1301 DMA_FROM_DEVICE); 1302 1303 /* We have pulled a buffer for use, so decrement pagecnt_bias */ 1304 rx_buffer->pagecnt_bias--; 1305 1306 return rx_buffer; 1307 } 1308 1309 /** 1310 * iavf_construct_skb - Allocate skb and populate it 1311 * @rx_ring: rx descriptor ring to transact packets on 1312 * @rx_buffer: rx buffer to pull data from 1313 * @size: size of buffer to add to skb 1314 * 1315 * This function allocates an skb. It then populates it with the page 1316 * data from the current receive descriptor, taking care to set up the 1317 * skb correctly. 1318 */ 1319 static struct sk_buff *iavf_construct_skb(struct iavf_ring *rx_ring, 1320 struct iavf_rx_buffer *rx_buffer, 1321 unsigned int size) 1322 { 1323 void *va; 1324 #if (PAGE_SIZE < 8192) 1325 unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2; 1326 #else 1327 unsigned int truesize = SKB_DATA_ALIGN(size); 1328 #endif 1329 unsigned int headlen; 1330 struct sk_buff *skb; 1331 1332 if (!rx_buffer) 1333 return NULL; 1334 /* prefetch first cache line of first page */ 1335 va = page_address(rx_buffer->page) + rx_buffer->page_offset; 1336 net_prefetch(va); 1337 1338 /* allocate a skb to store the frags */ 1339 skb = __napi_alloc_skb(&rx_ring->q_vector->napi, 1340 IAVF_RX_HDR_SIZE, 1341 GFP_ATOMIC | __GFP_NOWARN); 1342 if (unlikely(!skb)) 1343 return NULL; 1344 1345 /* Determine available headroom for copy */ 1346 headlen = size; 1347 if (headlen > IAVF_RX_HDR_SIZE) 1348 headlen = eth_get_headlen(skb->dev, va, IAVF_RX_HDR_SIZE); 1349 1350 /* align pull length to size of long to optimize memcpy performance */ 1351 memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long))); 1352 1353 /* update all of the pointers */ 1354 size -= headlen; 1355 if (size) { 1356 skb_add_rx_frag(skb, 0, rx_buffer->page, 1357 rx_buffer->page_offset + headlen, 1358 size, truesize); 1359 1360 /* buffer is used by skb, update page_offset */ 1361 #if (PAGE_SIZE < 8192) 1362 rx_buffer->page_offset ^= truesize; 1363 #else 1364 rx_buffer->page_offset += truesize; 1365 #endif 1366 } else { 1367 /* buffer is unused, reset bias back to rx_buffer */ 1368 rx_buffer->pagecnt_bias++; 1369 } 1370 1371 return skb; 1372 } 1373 1374 /** 1375 * iavf_build_skb - Build skb around an existing buffer 1376 * @rx_ring: Rx descriptor ring to transact packets on 1377 * @rx_buffer: Rx buffer to pull data from 1378 * @size: size of buffer to add to skb 1379 * 1380 * This function builds an skb around an existing Rx buffer, taking care 1381 * to set up the skb correctly and avoid any memcpy overhead. 1382 */ 1383 static struct sk_buff *iavf_build_skb(struct iavf_ring *rx_ring, 1384 struct iavf_rx_buffer *rx_buffer, 1385 unsigned int size) 1386 { 1387 void *va; 1388 #if (PAGE_SIZE < 8192) 1389 unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2; 1390 #else 1391 unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) + 1392 SKB_DATA_ALIGN(IAVF_SKB_PAD + size); 1393 #endif 1394 struct sk_buff *skb; 1395 1396 if (!rx_buffer || !size) 1397 return NULL; 1398 /* prefetch first cache line of first page */ 1399 va = page_address(rx_buffer->page) + rx_buffer->page_offset; 1400 net_prefetch(va); 1401 1402 /* build an skb around the page buffer */ 1403 skb = napi_build_skb(va - IAVF_SKB_PAD, truesize); 1404 if (unlikely(!skb)) 1405 return NULL; 1406 1407 /* update pointers within the skb to store the data */ 1408 skb_reserve(skb, IAVF_SKB_PAD); 1409 __skb_put(skb, size); 1410 1411 /* buffer is used by skb, update page_offset */ 1412 #if (PAGE_SIZE < 8192) 1413 rx_buffer->page_offset ^= truesize; 1414 #else 1415 rx_buffer->page_offset += truesize; 1416 #endif 1417 1418 return skb; 1419 } 1420 1421 /** 1422 * iavf_put_rx_buffer - Clean up used buffer and either recycle or free 1423 * @rx_ring: rx descriptor ring to transact packets on 1424 * @rx_buffer: rx buffer to pull data from 1425 * 1426 * This function will clean up the contents of the rx_buffer. It will 1427 * either recycle the buffer or unmap it and free the associated resources. 1428 */ 1429 static void iavf_put_rx_buffer(struct iavf_ring *rx_ring, 1430 struct iavf_rx_buffer *rx_buffer) 1431 { 1432 if (!rx_buffer) 1433 return; 1434 1435 if (iavf_can_reuse_rx_page(rx_buffer)) { 1436 /* hand second half of page back to the ring */ 1437 iavf_reuse_rx_page(rx_ring, rx_buffer); 1438 rx_ring->rx_stats.page_reuse_count++; 1439 } else { 1440 /* we are not reusing the buffer so unmap it */ 1441 dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma, 1442 iavf_rx_pg_size(rx_ring), 1443 DMA_FROM_DEVICE, IAVF_RX_DMA_ATTR); 1444 __page_frag_cache_drain(rx_buffer->page, 1445 rx_buffer->pagecnt_bias); 1446 } 1447 1448 /* clear contents of buffer_info */ 1449 rx_buffer->page = NULL; 1450 } 1451 1452 /** 1453 * iavf_is_non_eop - process handling of non-EOP buffers 1454 * @rx_ring: Rx ring being processed 1455 * @rx_desc: Rx descriptor for current buffer 1456 * @skb: Current socket buffer containing buffer in progress 1457 * 1458 * This function updates next to clean. If the buffer is an EOP buffer 1459 * this function exits returning false, otherwise it will place the 1460 * sk_buff in the next buffer to be chained and return true indicating 1461 * that this is in fact a non-EOP buffer. 1462 **/ 1463 static bool iavf_is_non_eop(struct iavf_ring *rx_ring, 1464 union iavf_rx_desc *rx_desc, 1465 struct sk_buff *skb) 1466 { 1467 u32 ntc = rx_ring->next_to_clean + 1; 1468 1469 /* fetch, update, and store next to clean */ 1470 ntc = (ntc < rx_ring->count) ? ntc : 0; 1471 rx_ring->next_to_clean = ntc; 1472 1473 prefetch(IAVF_RX_DESC(rx_ring, ntc)); 1474 1475 /* if we are the last buffer then there is nothing else to do */ 1476 #define IAVF_RXD_EOF BIT(IAVF_RX_DESC_STATUS_EOF_SHIFT) 1477 if (likely(iavf_test_staterr(rx_desc, IAVF_RXD_EOF))) 1478 return false; 1479 1480 rx_ring->rx_stats.non_eop_descs++; 1481 1482 return true; 1483 } 1484 1485 /** 1486 * iavf_clean_rx_irq - Clean completed descriptors from Rx ring - bounce buf 1487 * @rx_ring: rx descriptor ring to transact packets on 1488 * @budget: Total limit on number of packets to process 1489 * 1490 * This function provides a "bounce buffer" approach to Rx interrupt 1491 * processing. The advantage to this is that on systems that have 1492 * expensive overhead for IOMMU access this provides a means of avoiding 1493 * it by maintaining the mapping of the page to the system. 1494 * 1495 * Returns amount of work completed 1496 **/ 1497 static int iavf_clean_rx_irq(struct iavf_ring *rx_ring, int budget) 1498 { 1499 unsigned int total_rx_bytes = 0, total_rx_packets = 0; 1500 struct sk_buff *skb = rx_ring->skb; 1501 u16 cleaned_count = IAVF_DESC_UNUSED(rx_ring); 1502 bool failure = false; 1503 1504 while (likely(total_rx_packets < (unsigned int)budget)) { 1505 struct iavf_rx_buffer *rx_buffer; 1506 union iavf_rx_desc *rx_desc; 1507 unsigned int size; 1508 u16 vlan_tag = 0; 1509 u8 rx_ptype; 1510 u64 qword; 1511 1512 /* return some buffers to hardware, one at a time is too slow */ 1513 if (cleaned_count >= IAVF_RX_BUFFER_WRITE) { 1514 failure = failure || 1515 iavf_alloc_rx_buffers(rx_ring, cleaned_count); 1516 cleaned_count = 0; 1517 } 1518 1519 rx_desc = IAVF_RX_DESC(rx_ring, rx_ring->next_to_clean); 1520 1521 /* status_error_len will always be zero for unused descriptors 1522 * because it's cleared in cleanup, and overlaps with hdr_addr 1523 * which is always zero because packet split isn't used, if the 1524 * hardware wrote DD then the length will be non-zero 1525 */ 1526 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len); 1527 1528 /* This memory barrier is needed to keep us from reading 1529 * any other fields out of the rx_desc until we have 1530 * verified the descriptor has been written back. 1531 */ 1532 dma_rmb(); 1533 #define IAVF_RXD_DD BIT(IAVF_RX_DESC_STATUS_DD_SHIFT) 1534 if (!iavf_test_staterr(rx_desc, IAVF_RXD_DD)) 1535 break; 1536 1537 size = (qword & IAVF_RXD_QW1_LENGTH_PBUF_MASK) >> 1538 IAVF_RXD_QW1_LENGTH_PBUF_SHIFT; 1539 1540 iavf_trace(clean_rx_irq, rx_ring, rx_desc, skb); 1541 rx_buffer = iavf_get_rx_buffer(rx_ring, size); 1542 1543 /* retrieve a buffer from the ring */ 1544 if (skb) 1545 iavf_add_rx_frag(rx_ring, rx_buffer, skb, size); 1546 else if (ring_uses_build_skb(rx_ring)) 1547 skb = iavf_build_skb(rx_ring, rx_buffer, size); 1548 else 1549 skb = iavf_construct_skb(rx_ring, rx_buffer, size); 1550 1551 /* exit if we failed to retrieve a buffer */ 1552 if (!skb) { 1553 rx_ring->rx_stats.alloc_buff_failed++; 1554 if (rx_buffer && size) 1555 rx_buffer->pagecnt_bias++; 1556 break; 1557 } 1558 1559 iavf_put_rx_buffer(rx_ring, rx_buffer); 1560 cleaned_count++; 1561 1562 if (iavf_is_non_eop(rx_ring, rx_desc, skb)) 1563 continue; 1564 1565 /* ERR_MASK will only have valid bits if EOP set, and 1566 * what we are doing here is actually checking 1567 * IAVF_RX_DESC_ERROR_RXE_SHIFT, since it is the zeroth bit in 1568 * the error field 1569 */ 1570 if (unlikely(iavf_test_staterr(rx_desc, BIT(IAVF_RXD_QW1_ERROR_SHIFT)))) { 1571 dev_kfree_skb_any(skb); 1572 skb = NULL; 1573 continue; 1574 } 1575 1576 if (iavf_cleanup_headers(rx_ring, skb)) { 1577 skb = NULL; 1578 continue; 1579 } 1580 1581 /* probably a little skewed due to removing CRC */ 1582 total_rx_bytes += skb->len; 1583 1584 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len); 1585 rx_ptype = (qword & IAVF_RXD_QW1_PTYPE_MASK) >> 1586 IAVF_RXD_QW1_PTYPE_SHIFT; 1587 1588 /* populate checksum, VLAN, and protocol */ 1589 iavf_process_skb_fields(rx_ring, rx_desc, skb, rx_ptype); 1590 1591 if (qword & BIT(IAVF_RX_DESC_STATUS_L2TAG1P_SHIFT) && 1592 rx_ring->flags & IAVF_TXRX_FLAGS_VLAN_TAG_LOC_L2TAG1) 1593 vlan_tag = le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1); 1594 if (rx_desc->wb.qword2.ext_status & 1595 cpu_to_le16(BIT(IAVF_RX_DESC_EXT_STATUS_L2TAG2P_SHIFT)) && 1596 rx_ring->flags & IAVF_RXR_FLAGS_VLAN_TAG_LOC_L2TAG2_2) 1597 vlan_tag = le16_to_cpu(rx_desc->wb.qword2.l2tag2_2); 1598 1599 iavf_trace(clean_rx_irq_rx, rx_ring, rx_desc, skb); 1600 iavf_receive_skb(rx_ring, skb, vlan_tag); 1601 skb = NULL; 1602 1603 /* update budget accounting */ 1604 total_rx_packets++; 1605 } 1606 1607 rx_ring->skb = skb; 1608 1609 u64_stats_update_begin(&rx_ring->syncp); 1610 rx_ring->stats.packets += total_rx_packets; 1611 rx_ring->stats.bytes += total_rx_bytes; 1612 u64_stats_update_end(&rx_ring->syncp); 1613 rx_ring->q_vector->rx.total_packets += total_rx_packets; 1614 rx_ring->q_vector->rx.total_bytes += total_rx_bytes; 1615 1616 /* guarantee a trip back through this routine if there was a failure */ 1617 return failure ? budget : (int)total_rx_packets; 1618 } 1619 1620 static inline u32 iavf_buildreg_itr(const int type, u16 itr) 1621 { 1622 u32 val; 1623 1624 /* We don't bother with setting the CLEARPBA bit as the data sheet 1625 * points out doing so is "meaningless since it was already 1626 * auto-cleared". The auto-clearing happens when the interrupt is 1627 * asserted. 1628 * 1629 * Hardware errata 28 for also indicates that writing to a 1630 * xxINT_DYN_CTLx CSR with INTENA_MSK (bit 31) set to 0 will clear 1631 * an event in the PBA anyway so we need to rely on the automask 1632 * to hold pending events for us until the interrupt is re-enabled 1633 * 1634 * The itr value is reported in microseconds, and the register 1635 * value is recorded in 2 microsecond units. For this reason we 1636 * only need to shift by the interval shift - 1 instead of the 1637 * full value. 1638 */ 1639 itr &= IAVF_ITR_MASK; 1640 1641 val = IAVF_VFINT_DYN_CTLN1_INTENA_MASK | 1642 (type << IAVF_VFINT_DYN_CTLN1_ITR_INDX_SHIFT) | 1643 (itr << (IAVF_VFINT_DYN_CTLN1_INTERVAL_SHIFT - 1)); 1644 1645 return val; 1646 } 1647 1648 /* a small macro to shorten up some long lines */ 1649 #define INTREG IAVF_VFINT_DYN_CTLN1 1650 1651 /* The act of updating the ITR will cause it to immediately trigger. In order 1652 * to prevent this from throwing off adaptive update statistics we defer the 1653 * update so that it can only happen so often. So after either Tx or Rx are 1654 * updated we make the adaptive scheme wait until either the ITR completely 1655 * expires via the next_update expiration or we have been through at least 1656 * 3 interrupts. 1657 */ 1658 #define ITR_COUNTDOWN_START 3 1659 1660 /** 1661 * iavf_update_enable_itr - Update itr and re-enable MSIX interrupt 1662 * @vsi: the VSI we care about 1663 * @q_vector: q_vector for which itr is being updated and interrupt enabled 1664 * 1665 **/ 1666 static inline void iavf_update_enable_itr(struct iavf_vsi *vsi, 1667 struct iavf_q_vector *q_vector) 1668 { 1669 struct iavf_hw *hw = &vsi->back->hw; 1670 u32 intval; 1671 1672 /* These will do nothing if dynamic updates are not enabled */ 1673 iavf_update_itr(q_vector, &q_vector->tx); 1674 iavf_update_itr(q_vector, &q_vector->rx); 1675 1676 /* This block of logic allows us to get away with only updating 1677 * one ITR value with each interrupt. The idea is to perform a 1678 * pseudo-lazy update with the following criteria. 1679 * 1680 * 1. Rx is given higher priority than Tx if both are in same state 1681 * 2. If we must reduce an ITR that is given highest priority. 1682 * 3. We then give priority to increasing ITR based on amount. 1683 */ 1684 if (q_vector->rx.target_itr < q_vector->rx.current_itr) { 1685 /* Rx ITR needs to be reduced, this is highest priority */ 1686 intval = iavf_buildreg_itr(IAVF_RX_ITR, 1687 q_vector->rx.target_itr); 1688 q_vector->rx.current_itr = q_vector->rx.target_itr; 1689 q_vector->itr_countdown = ITR_COUNTDOWN_START; 1690 } else if ((q_vector->tx.target_itr < q_vector->tx.current_itr) || 1691 ((q_vector->rx.target_itr - q_vector->rx.current_itr) < 1692 (q_vector->tx.target_itr - q_vector->tx.current_itr))) { 1693 /* Tx ITR needs to be reduced, this is second priority 1694 * Tx ITR needs to be increased more than Rx, fourth priority 1695 */ 1696 intval = iavf_buildreg_itr(IAVF_TX_ITR, 1697 q_vector->tx.target_itr); 1698 q_vector->tx.current_itr = q_vector->tx.target_itr; 1699 q_vector->itr_countdown = ITR_COUNTDOWN_START; 1700 } else if (q_vector->rx.current_itr != q_vector->rx.target_itr) { 1701 /* Rx ITR needs to be increased, third priority */ 1702 intval = iavf_buildreg_itr(IAVF_RX_ITR, 1703 q_vector->rx.target_itr); 1704 q_vector->rx.current_itr = q_vector->rx.target_itr; 1705 q_vector->itr_countdown = ITR_COUNTDOWN_START; 1706 } else { 1707 /* No ITR update, lowest priority */ 1708 intval = iavf_buildreg_itr(IAVF_ITR_NONE, 0); 1709 if (q_vector->itr_countdown) 1710 q_vector->itr_countdown--; 1711 } 1712 1713 if (!test_bit(__IAVF_VSI_DOWN, vsi->state)) 1714 wr32(hw, INTREG(q_vector->reg_idx), intval); 1715 } 1716 1717 /** 1718 * iavf_napi_poll - NAPI polling Rx/Tx cleanup routine 1719 * @napi: napi struct with our devices info in it 1720 * @budget: amount of work driver is allowed to do this pass, in packets 1721 * 1722 * This function will clean all queues associated with a q_vector. 1723 * 1724 * Returns the amount of work done 1725 **/ 1726 int iavf_napi_poll(struct napi_struct *napi, int budget) 1727 { 1728 struct iavf_q_vector *q_vector = 1729 container_of(napi, struct iavf_q_vector, napi); 1730 struct iavf_vsi *vsi = q_vector->vsi; 1731 struct iavf_ring *ring; 1732 bool clean_complete = true; 1733 bool arm_wb = false; 1734 int budget_per_ring; 1735 int work_done = 0; 1736 1737 if (test_bit(__IAVF_VSI_DOWN, vsi->state)) { 1738 napi_complete(napi); 1739 return 0; 1740 } 1741 1742 /* Since the actual Tx work is minimal, we can give the Tx a larger 1743 * budget and be more aggressive about cleaning up the Tx descriptors. 1744 */ 1745 iavf_for_each_ring(ring, q_vector->tx) { 1746 if (!iavf_clean_tx_irq(vsi, ring, budget)) { 1747 clean_complete = false; 1748 continue; 1749 } 1750 arm_wb |= ring->arm_wb; 1751 ring->arm_wb = false; 1752 } 1753 1754 /* Handle case where we are called by netpoll with a budget of 0 */ 1755 if (budget <= 0) 1756 goto tx_only; 1757 1758 /* We attempt to distribute budget to each Rx queue fairly, but don't 1759 * allow the budget to go below 1 because that would exit polling early. 1760 */ 1761 budget_per_ring = max(budget/q_vector->num_ringpairs, 1); 1762 1763 iavf_for_each_ring(ring, q_vector->rx) { 1764 int cleaned = iavf_clean_rx_irq(ring, budget_per_ring); 1765 1766 work_done += cleaned; 1767 /* if we clean as many as budgeted, we must not be done */ 1768 if (cleaned >= budget_per_ring) 1769 clean_complete = false; 1770 } 1771 1772 /* If work not completed, return budget and polling will return */ 1773 if (!clean_complete) { 1774 int cpu_id = smp_processor_id(); 1775 1776 /* It is possible that the interrupt affinity has changed but, 1777 * if the cpu is pegged at 100%, polling will never exit while 1778 * traffic continues and the interrupt will be stuck on this 1779 * cpu. We check to make sure affinity is correct before we 1780 * continue to poll, otherwise we must stop polling so the 1781 * interrupt can move to the correct cpu. 1782 */ 1783 if (!cpumask_test_cpu(cpu_id, &q_vector->affinity_mask)) { 1784 /* Tell napi that we are done polling */ 1785 napi_complete_done(napi, work_done); 1786 1787 /* Force an interrupt */ 1788 iavf_force_wb(vsi, q_vector); 1789 1790 /* Return budget-1 so that polling stops */ 1791 return budget - 1; 1792 } 1793 tx_only: 1794 if (arm_wb) { 1795 q_vector->tx.ring[0].tx_stats.tx_force_wb++; 1796 iavf_enable_wb_on_itr(vsi, q_vector); 1797 } 1798 return budget; 1799 } 1800 1801 if (vsi->back->flags & IAVF_TXR_FLAGS_WB_ON_ITR) 1802 q_vector->arm_wb_state = false; 1803 1804 /* Exit the polling mode, but don't re-enable interrupts if stack might 1805 * poll us due to busy-polling 1806 */ 1807 if (likely(napi_complete_done(napi, work_done))) 1808 iavf_update_enable_itr(vsi, q_vector); 1809 1810 return min_t(int, work_done, budget - 1); 1811 } 1812 1813 /** 1814 * iavf_tx_prepare_vlan_flags - prepare generic TX VLAN tagging flags for HW 1815 * @skb: send buffer 1816 * @tx_ring: ring to send buffer on 1817 * @flags: the tx flags to be set 1818 * 1819 * Checks the skb and set up correspondingly several generic transmit flags 1820 * related to VLAN tagging for the HW, such as VLAN, DCB, etc. 1821 * 1822 * Returns error code indicate the frame should be dropped upon error and the 1823 * otherwise returns 0 to indicate the flags has been set properly. 1824 **/ 1825 static void iavf_tx_prepare_vlan_flags(struct sk_buff *skb, 1826 struct iavf_ring *tx_ring, u32 *flags) 1827 { 1828 u32 tx_flags = 0; 1829 1830 1831 /* stack will only request hardware VLAN insertion offload for protocols 1832 * that the driver supports and has enabled 1833 */ 1834 if (!skb_vlan_tag_present(skb)) 1835 return; 1836 1837 tx_flags |= skb_vlan_tag_get(skb) << IAVF_TX_FLAGS_VLAN_SHIFT; 1838 if (tx_ring->flags & IAVF_TXR_FLAGS_VLAN_TAG_LOC_L2TAG2) { 1839 tx_flags |= IAVF_TX_FLAGS_HW_OUTER_SINGLE_VLAN; 1840 } else if (tx_ring->flags & IAVF_TXRX_FLAGS_VLAN_TAG_LOC_L2TAG1) { 1841 tx_flags |= IAVF_TX_FLAGS_HW_VLAN; 1842 } else { 1843 dev_dbg(tx_ring->dev, "Unsupported Tx VLAN tag location requested\n"); 1844 return; 1845 } 1846 1847 *flags = tx_flags; 1848 } 1849 1850 /** 1851 * iavf_tso - set up the tso context descriptor 1852 * @first: pointer to first Tx buffer for xmit 1853 * @hdr_len: ptr to the size of the packet header 1854 * @cd_type_cmd_tso_mss: Quad Word 1 1855 * 1856 * Returns 0 if no TSO can happen, 1 if tso is going, or error 1857 **/ 1858 static int iavf_tso(struct iavf_tx_buffer *first, u8 *hdr_len, 1859 u64 *cd_type_cmd_tso_mss) 1860 { 1861 struct sk_buff *skb = first->skb; 1862 u64 cd_cmd, cd_tso_len, cd_mss; 1863 union { 1864 struct iphdr *v4; 1865 struct ipv6hdr *v6; 1866 unsigned char *hdr; 1867 } ip; 1868 union { 1869 struct tcphdr *tcp; 1870 struct udphdr *udp; 1871 unsigned char *hdr; 1872 } l4; 1873 u32 paylen, l4_offset; 1874 u16 gso_segs, gso_size; 1875 int err; 1876 1877 if (skb->ip_summed != CHECKSUM_PARTIAL) 1878 return 0; 1879 1880 if (!skb_is_gso(skb)) 1881 return 0; 1882 1883 err = skb_cow_head(skb, 0); 1884 if (err < 0) 1885 return err; 1886 1887 ip.hdr = skb_network_header(skb); 1888 l4.hdr = skb_transport_header(skb); 1889 1890 /* initialize outer IP header fields */ 1891 if (ip.v4->version == 4) { 1892 ip.v4->tot_len = 0; 1893 ip.v4->check = 0; 1894 } else { 1895 ip.v6->payload_len = 0; 1896 } 1897 1898 if (skb_shinfo(skb)->gso_type & (SKB_GSO_GRE | 1899 SKB_GSO_GRE_CSUM | 1900 SKB_GSO_IPXIP4 | 1901 SKB_GSO_IPXIP6 | 1902 SKB_GSO_UDP_TUNNEL | 1903 SKB_GSO_UDP_TUNNEL_CSUM)) { 1904 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) && 1905 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM)) { 1906 l4.udp->len = 0; 1907 1908 /* determine offset of outer transport header */ 1909 l4_offset = l4.hdr - skb->data; 1910 1911 /* remove payload length from outer checksum */ 1912 paylen = skb->len - l4_offset; 1913 csum_replace_by_diff(&l4.udp->check, 1914 (__force __wsum)htonl(paylen)); 1915 } 1916 1917 /* reset pointers to inner headers */ 1918 ip.hdr = skb_inner_network_header(skb); 1919 l4.hdr = skb_inner_transport_header(skb); 1920 1921 /* initialize inner IP header fields */ 1922 if (ip.v4->version == 4) { 1923 ip.v4->tot_len = 0; 1924 ip.v4->check = 0; 1925 } else { 1926 ip.v6->payload_len = 0; 1927 } 1928 } 1929 1930 /* determine offset of inner transport header */ 1931 l4_offset = l4.hdr - skb->data; 1932 /* remove payload length from inner checksum */ 1933 paylen = skb->len - l4_offset; 1934 1935 if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { 1936 csum_replace_by_diff(&l4.udp->check, 1937 (__force __wsum)htonl(paylen)); 1938 /* compute length of UDP segmentation header */ 1939 *hdr_len = (u8)sizeof(l4.udp) + l4_offset; 1940 } else { 1941 csum_replace_by_diff(&l4.tcp->check, 1942 (__force __wsum)htonl(paylen)); 1943 /* compute length of TCP segmentation header */ 1944 *hdr_len = (u8)((l4.tcp->doff * 4) + l4_offset); 1945 } 1946 1947 /* pull values out of skb_shinfo */ 1948 gso_size = skb_shinfo(skb)->gso_size; 1949 gso_segs = skb_shinfo(skb)->gso_segs; 1950 1951 /* update GSO size and bytecount with header size */ 1952 first->gso_segs = gso_segs; 1953 first->bytecount += (first->gso_segs - 1) * *hdr_len; 1954 1955 /* find the field values */ 1956 cd_cmd = IAVF_TX_CTX_DESC_TSO; 1957 cd_tso_len = skb->len - *hdr_len; 1958 cd_mss = gso_size; 1959 *cd_type_cmd_tso_mss |= (cd_cmd << IAVF_TXD_CTX_QW1_CMD_SHIFT) | 1960 (cd_tso_len << IAVF_TXD_CTX_QW1_TSO_LEN_SHIFT) | 1961 (cd_mss << IAVF_TXD_CTX_QW1_MSS_SHIFT); 1962 return 1; 1963 } 1964 1965 /** 1966 * iavf_tx_enable_csum - Enable Tx checksum offloads 1967 * @skb: send buffer 1968 * @tx_flags: pointer to Tx flags currently set 1969 * @td_cmd: Tx descriptor command bits to set 1970 * @td_offset: Tx descriptor header offsets to set 1971 * @tx_ring: Tx descriptor ring 1972 * @cd_tunneling: ptr to context desc bits 1973 **/ 1974 static int iavf_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags, 1975 u32 *td_cmd, u32 *td_offset, 1976 struct iavf_ring *tx_ring, 1977 u32 *cd_tunneling) 1978 { 1979 union { 1980 struct iphdr *v4; 1981 struct ipv6hdr *v6; 1982 unsigned char *hdr; 1983 } ip; 1984 union { 1985 struct tcphdr *tcp; 1986 struct udphdr *udp; 1987 unsigned char *hdr; 1988 } l4; 1989 unsigned char *exthdr; 1990 u32 offset, cmd = 0; 1991 __be16 frag_off; 1992 u8 l4_proto = 0; 1993 1994 if (skb->ip_summed != CHECKSUM_PARTIAL) 1995 return 0; 1996 1997 ip.hdr = skb_network_header(skb); 1998 l4.hdr = skb_transport_header(skb); 1999 2000 /* compute outer L2 header size */ 2001 offset = ((ip.hdr - skb->data) / 2) << IAVF_TX_DESC_LENGTH_MACLEN_SHIFT; 2002 2003 if (skb->encapsulation) { 2004 u32 tunnel = 0; 2005 /* define outer network header type */ 2006 if (*tx_flags & IAVF_TX_FLAGS_IPV4) { 2007 tunnel |= (*tx_flags & IAVF_TX_FLAGS_TSO) ? 2008 IAVF_TX_CTX_EXT_IP_IPV4 : 2009 IAVF_TX_CTX_EXT_IP_IPV4_NO_CSUM; 2010 2011 l4_proto = ip.v4->protocol; 2012 } else if (*tx_flags & IAVF_TX_FLAGS_IPV6) { 2013 tunnel |= IAVF_TX_CTX_EXT_IP_IPV6; 2014 2015 exthdr = ip.hdr + sizeof(*ip.v6); 2016 l4_proto = ip.v6->nexthdr; 2017 if (l4.hdr != exthdr) 2018 ipv6_skip_exthdr(skb, exthdr - skb->data, 2019 &l4_proto, &frag_off); 2020 } 2021 2022 /* define outer transport */ 2023 switch (l4_proto) { 2024 case IPPROTO_UDP: 2025 tunnel |= IAVF_TXD_CTX_UDP_TUNNELING; 2026 *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL; 2027 break; 2028 case IPPROTO_GRE: 2029 tunnel |= IAVF_TXD_CTX_GRE_TUNNELING; 2030 *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL; 2031 break; 2032 case IPPROTO_IPIP: 2033 case IPPROTO_IPV6: 2034 *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL; 2035 l4.hdr = skb_inner_network_header(skb); 2036 break; 2037 default: 2038 if (*tx_flags & IAVF_TX_FLAGS_TSO) 2039 return -1; 2040 2041 skb_checksum_help(skb); 2042 return 0; 2043 } 2044 2045 /* compute outer L3 header size */ 2046 tunnel |= ((l4.hdr - ip.hdr) / 4) << 2047 IAVF_TXD_CTX_QW0_EXT_IPLEN_SHIFT; 2048 2049 /* switch IP header pointer from outer to inner header */ 2050 ip.hdr = skb_inner_network_header(skb); 2051 2052 /* compute tunnel header size */ 2053 tunnel |= ((ip.hdr - l4.hdr) / 2) << 2054 IAVF_TXD_CTX_QW0_NATLEN_SHIFT; 2055 2056 /* indicate if we need to offload outer UDP header */ 2057 if ((*tx_flags & IAVF_TX_FLAGS_TSO) && 2058 !(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) && 2059 (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM)) 2060 tunnel |= IAVF_TXD_CTX_QW0_L4T_CS_MASK; 2061 2062 /* record tunnel offload values */ 2063 *cd_tunneling |= tunnel; 2064 2065 /* switch L4 header pointer from outer to inner */ 2066 l4.hdr = skb_inner_transport_header(skb); 2067 l4_proto = 0; 2068 2069 /* reset type as we transition from outer to inner headers */ 2070 *tx_flags &= ~(IAVF_TX_FLAGS_IPV4 | IAVF_TX_FLAGS_IPV6); 2071 if (ip.v4->version == 4) 2072 *tx_flags |= IAVF_TX_FLAGS_IPV4; 2073 if (ip.v6->version == 6) 2074 *tx_flags |= IAVF_TX_FLAGS_IPV6; 2075 } 2076 2077 /* Enable IP checksum offloads */ 2078 if (*tx_flags & IAVF_TX_FLAGS_IPV4) { 2079 l4_proto = ip.v4->protocol; 2080 /* the stack computes the IP header already, the only time we 2081 * need the hardware to recompute it is in the case of TSO. 2082 */ 2083 cmd |= (*tx_flags & IAVF_TX_FLAGS_TSO) ? 2084 IAVF_TX_DESC_CMD_IIPT_IPV4_CSUM : 2085 IAVF_TX_DESC_CMD_IIPT_IPV4; 2086 } else if (*tx_flags & IAVF_TX_FLAGS_IPV6) { 2087 cmd |= IAVF_TX_DESC_CMD_IIPT_IPV6; 2088 2089 exthdr = ip.hdr + sizeof(*ip.v6); 2090 l4_proto = ip.v6->nexthdr; 2091 if (l4.hdr != exthdr) 2092 ipv6_skip_exthdr(skb, exthdr - skb->data, 2093 &l4_proto, &frag_off); 2094 } 2095 2096 /* compute inner L3 header size */ 2097 offset |= ((l4.hdr - ip.hdr) / 4) << IAVF_TX_DESC_LENGTH_IPLEN_SHIFT; 2098 2099 /* Enable L4 checksum offloads */ 2100 switch (l4_proto) { 2101 case IPPROTO_TCP: 2102 /* enable checksum offloads */ 2103 cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_TCP; 2104 offset |= l4.tcp->doff << IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT; 2105 break; 2106 case IPPROTO_SCTP: 2107 /* enable SCTP checksum offload */ 2108 cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_SCTP; 2109 offset |= (sizeof(struct sctphdr) >> 2) << 2110 IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT; 2111 break; 2112 case IPPROTO_UDP: 2113 /* enable UDP checksum offload */ 2114 cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_UDP; 2115 offset |= (sizeof(struct udphdr) >> 2) << 2116 IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT; 2117 break; 2118 default: 2119 if (*tx_flags & IAVF_TX_FLAGS_TSO) 2120 return -1; 2121 skb_checksum_help(skb); 2122 return 0; 2123 } 2124 2125 *td_cmd |= cmd; 2126 *td_offset |= offset; 2127 2128 return 1; 2129 } 2130 2131 /** 2132 * iavf_create_tx_ctx - Build the Tx context descriptor 2133 * @tx_ring: ring to create the descriptor on 2134 * @cd_type_cmd_tso_mss: Quad Word 1 2135 * @cd_tunneling: Quad Word 0 - bits 0-31 2136 * @cd_l2tag2: Quad Word 0 - bits 32-63 2137 **/ 2138 static void iavf_create_tx_ctx(struct iavf_ring *tx_ring, 2139 const u64 cd_type_cmd_tso_mss, 2140 const u32 cd_tunneling, const u32 cd_l2tag2) 2141 { 2142 struct iavf_tx_context_desc *context_desc; 2143 int i = tx_ring->next_to_use; 2144 2145 if ((cd_type_cmd_tso_mss == IAVF_TX_DESC_DTYPE_CONTEXT) && 2146 !cd_tunneling && !cd_l2tag2) 2147 return; 2148 2149 /* grab the next descriptor */ 2150 context_desc = IAVF_TX_CTXTDESC(tx_ring, i); 2151 2152 i++; 2153 tx_ring->next_to_use = (i < tx_ring->count) ? i : 0; 2154 2155 /* cpu_to_le32 and assign to struct fields */ 2156 context_desc->tunneling_params = cpu_to_le32(cd_tunneling); 2157 context_desc->l2tag2 = cpu_to_le16(cd_l2tag2); 2158 context_desc->rsvd = cpu_to_le16(0); 2159 context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss); 2160 } 2161 2162 /** 2163 * __iavf_chk_linearize - Check if there are more than 8 buffers per packet 2164 * @skb: send buffer 2165 * 2166 * Note: Our HW can't DMA more than 8 buffers to build a packet on the wire 2167 * and so we need to figure out the cases where we need to linearize the skb. 2168 * 2169 * For TSO we need to count the TSO header and segment payload separately. 2170 * As such we need to check cases where we have 7 fragments or more as we 2171 * can potentially require 9 DMA transactions, 1 for the TSO header, 1 for 2172 * the segment payload in the first descriptor, and another 7 for the 2173 * fragments. 2174 **/ 2175 bool __iavf_chk_linearize(struct sk_buff *skb) 2176 { 2177 const skb_frag_t *frag, *stale; 2178 int nr_frags, sum; 2179 2180 /* no need to check if number of frags is less than 7 */ 2181 nr_frags = skb_shinfo(skb)->nr_frags; 2182 if (nr_frags < (IAVF_MAX_BUFFER_TXD - 1)) 2183 return false; 2184 2185 /* We need to walk through the list and validate that each group 2186 * of 6 fragments totals at least gso_size. 2187 */ 2188 nr_frags -= IAVF_MAX_BUFFER_TXD - 2; 2189 frag = &skb_shinfo(skb)->frags[0]; 2190 2191 /* Initialize size to the negative value of gso_size minus 1. We 2192 * use this as the worst case scenerio in which the frag ahead 2193 * of us only provides one byte which is why we are limited to 6 2194 * descriptors for a single transmit as the header and previous 2195 * fragment are already consuming 2 descriptors. 2196 */ 2197 sum = 1 - skb_shinfo(skb)->gso_size; 2198 2199 /* Add size of frags 0 through 4 to create our initial sum */ 2200 sum += skb_frag_size(frag++); 2201 sum += skb_frag_size(frag++); 2202 sum += skb_frag_size(frag++); 2203 sum += skb_frag_size(frag++); 2204 sum += skb_frag_size(frag++); 2205 2206 /* Walk through fragments adding latest fragment, testing it, and 2207 * then removing stale fragments from the sum. 2208 */ 2209 for (stale = &skb_shinfo(skb)->frags[0];; stale++) { 2210 int stale_size = skb_frag_size(stale); 2211 2212 sum += skb_frag_size(frag++); 2213 2214 /* The stale fragment may present us with a smaller 2215 * descriptor than the actual fragment size. To account 2216 * for that we need to remove all the data on the front and 2217 * figure out what the remainder would be in the last 2218 * descriptor associated with the fragment. 2219 */ 2220 if (stale_size > IAVF_MAX_DATA_PER_TXD) { 2221 int align_pad = -(skb_frag_off(stale)) & 2222 (IAVF_MAX_READ_REQ_SIZE - 1); 2223 2224 sum -= align_pad; 2225 stale_size -= align_pad; 2226 2227 do { 2228 sum -= IAVF_MAX_DATA_PER_TXD_ALIGNED; 2229 stale_size -= IAVF_MAX_DATA_PER_TXD_ALIGNED; 2230 } while (stale_size > IAVF_MAX_DATA_PER_TXD); 2231 } 2232 2233 /* if sum is negative we failed to make sufficient progress */ 2234 if (sum < 0) 2235 return true; 2236 2237 if (!nr_frags--) 2238 break; 2239 2240 sum -= stale_size; 2241 } 2242 2243 return false; 2244 } 2245 2246 /** 2247 * __iavf_maybe_stop_tx - 2nd level check for tx stop conditions 2248 * @tx_ring: the ring to be checked 2249 * @size: the size buffer we want to assure is available 2250 * 2251 * Returns -EBUSY if a stop is needed, else 0 2252 **/ 2253 int __iavf_maybe_stop_tx(struct iavf_ring *tx_ring, int size) 2254 { 2255 netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index); 2256 /* Memory barrier before checking head and tail */ 2257 smp_mb(); 2258 2259 /* Check again in a case another CPU has just made room available. */ 2260 if (likely(IAVF_DESC_UNUSED(tx_ring) < size)) 2261 return -EBUSY; 2262 2263 /* A reprieve! - use start_queue because it doesn't call schedule */ 2264 netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index); 2265 ++tx_ring->tx_stats.restart_queue; 2266 return 0; 2267 } 2268 2269 /** 2270 * iavf_tx_map - Build the Tx descriptor 2271 * @tx_ring: ring to send buffer on 2272 * @skb: send buffer 2273 * @first: first buffer info buffer to use 2274 * @tx_flags: collected send information 2275 * @hdr_len: size of the packet header 2276 * @td_cmd: the command field in the descriptor 2277 * @td_offset: offset for checksum or crc 2278 **/ 2279 static inline void iavf_tx_map(struct iavf_ring *tx_ring, struct sk_buff *skb, 2280 struct iavf_tx_buffer *first, u32 tx_flags, 2281 const u8 hdr_len, u32 td_cmd, u32 td_offset) 2282 { 2283 unsigned int data_len = skb->data_len; 2284 unsigned int size = skb_headlen(skb); 2285 skb_frag_t *frag; 2286 struct iavf_tx_buffer *tx_bi; 2287 struct iavf_tx_desc *tx_desc; 2288 u16 i = tx_ring->next_to_use; 2289 u32 td_tag = 0; 2290 dma_addr_t dma; 2291 2292 if (tx_flags & IAVF_TX_FLAGS_HW_VLAN) { 2293 td_cmd |= IAVF_TX_DESC_CMD_IL2TAG1; 2294 td_tag = (tx_flags & IAVF_TX_FLAGS_VLAN_MASK) >> 2295 IAVF_TX_FLAGS_VLAN_SHIFT; 2296 } 2297 2298 first->tx_flags = tx_flags; 2299 2300 dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE); 2301 2302 tx_desc = IAVF_TX_DESC(tx_ring, i); 2303 tx_bi = first; 2304 2305 for (frag = &skb_shinfo(skb)->frags[0];; frag++) { 2306 unsigned int max_data = IAVF_MAX_DATA_PER_TXD_ALIGNED; 2307 2308 if (dma_mapping_error(tx_ring->dev, dma)) 2309 goto dma_error; 2310 2311 /* record length, and DMA address */ 2312 dma_unmap_len_set(tx_bi, len, size); 2313 dma_unmap_addr_set(tx_bi, dma, dma); 2314 2315 /* align size to end of page */ 2316 max_data += -dma & (IAVF_MAX_READ_REQ_SIZE - 1); 2317 tx_desc->buffer_addr = cpu_to_le64(dma); 2318 2319 while (unlikely(size > IAVF_MAX_DATA_PER_TXD)) { 2320 tx_desc->cmd_type_offset_bsz = 2321 build_ctob(td_cmd, td_offset, 2322 max_data, td_tag); 2323 2324 tx_desc++; 2325 i++; 2326 2327 if (i == tx_ring->count) { 2328 tx_desc = IAVF_TX_DESC(tx_ring, 0); 2329 i = 0; 2330 } 2331 2332 dma += max_data; 2333 size -= max_data; 2334 2335 max_data = IAVF_MAX_DATA_PER_TXD_ALIGNED; 2336 tx_desc->buffer_addr = cpu_to_le64(dma); 2337 } 2338 2339 if (likely(!data_len)) 2340 break; 2341 2342 tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset, 2343 size, td_tag); 2344 2345 tx_desc++; 2346 i++; 2347 2348 if (i == tx_ring->count) { 2349 tx_desc = IAVF_TX_DESC(tx_ring, 0); 2350 i = 0; 2351 } 2352 2353 size = skb_frag_size(frag); 2354 data_len -= size; 2355 2356 dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size, 2357 DMA_TO_DEVICE); 2358 2359 tx_bi = &tx_ring->tx_bi[i]; 2360 } 2361 2362 netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount); 2363 2364 i++; 2365 if (i == tx_ring->count) 2366 i = 0; 2367 2368 tx_ring->next_to_use = i; 2369 2370 iavf_maybe_stop_tx(tx_ring, DESC_NEEDED); 2371 2372 /* write last descriptor with RS and EOP bits */ 2373 td_cmd |= IAVF_TXD_CMD; 2374 tx_desc->cmd_type_offset_bsz = 2375 build_ctob(td_cmd, td_offset, size, td_tag); 2376 2377 skb_tx_timestamp(skb); 2378 2379 /* Force memory writes to complete before letting h/w know there 2380 * are new descriptors to fetch. 2381 * 2382 * We also use this memory barrier to make certain all of the 2383 * status bits have been updated before next_to_watch is written. 2384 */ 2385 wmb(); 2386 2387 /* set next_to_watch value indicating a packet is present */ 2388 first->next_to_watch = tx_desc; 2389 2390 /* notify HW of packet */ 2391 if (netif_xmit_stopped(txring_txq(tx_ring)) || !netdev_xmit_more()) { 2392 writel(i, tx_ring->tail); 2393 } 2394 2395 return; 2396 2397 dma_error: 2398 dev_info(tx_ring->dev, "TX DMA map failed\n"); 2399 2400 /* clear dma mappings for failed tx_bi map */ 2401 for (;;) { 2402 tx_bi = &tx_ring->tx_bi[i]; 2403 iavf_unmap_and_free_tx_resource(tx_ring, tx_bi); 2404 if (tx_bi == first) 2405 break; 2406 if (i == 0) 2407 i = tx_ring->count; 2408 i--; 2409 } 2410 2411 tx_ring->next_to_use = i; 2412 } 2413 2414 /** 2415 * iavf_xmit_frame_ring - Sends buffer on Tx ring 2416 * @skb: send buffer 2417 * @tx_ring: ring to send buffer on 2418 * 2419 * Returns NETDEV_TX_OK if sent, else an error code 2420 **/ 2421 static netdev_tx_t iavf_xmit_frame_ring(struct sk_buff *skb, 2422 struct iavf_ring *tx_ring) 2423 { 2424 u64 cd_type_cmd_tso_mss = IAVF_TX_DESC_DTYPE_CONTEXT; 2425 u32 cd_tunneling = 0, cd_l2tag2 = 0; 2426 struct iavf_tx_buffer *first; 2427 u32 td_offset = 0; 2428 u32 tx_flags = 0; 2429 __be16 protocol; 2430 u32 td_cmd = 0; 2431 u8 hdr_len = 0; 2432 int tso, count; 2433 2434 /* prefetch the data, we'll need it later */ 2435 prefetch(skb->data); 2436 2437 iavf_trace(xmit_frame_ring, skb, tx_ring); 2438 2439 count = iavf_xmit_descriptor_count(skb); 2440 if (iavf_chk_linearize(skb, count)) { 2441 if (__skb_linearize(skb)) { 2442 dev_kfree_skb_any(skb); 2443 return NETDEV_TX_OK; 2444 } 2445 count = iavf_txd_use_count(skb->len); 2446 tx_ring->tx_stats.tx_linearize++; 2447 } 2448 2449 /* need: 1 descriptor per page * PAGE_SIZE/IAVF_MAX_DATA_PER_TXD, 2450 * + 1 desc for skb_head_len/IAVF_MAX_DATA_PER_TXD, 2451 * + 4 desc gap to avoid the cache line where head is, 2452 * + 1 desc for context descriptor, 2453 * otherwise try next time 2454 */ 2455 if (iavf_maybe_stop_tx(tx_ring, count + 4 + 1)) { 2456 tx_ring->tx_stats.tx_busy++; 2457 return NETDEV_TX_BUSY; 2458 } 2459 2460 /* record the location of the first descriptor for this packet */ 2461 first = &tx_ring->tx_bi[tx_ring->next_to_use]; 2462 first->skb = skb; 2463 first->bytecount = skb->len; 2464 first->gso_segs = 1; 2465 2466 /* prepare the xmit flags */ 2467 iavf_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags); 2468 if (tx_flags & IAVF_TX_FLAGS_HW_OUTER_SINGLE_VLAN) { 2469 cd_type_cmd_tso_mss |= IAVF_TX_CTX_DESC_IL2TAG2 << 2470 IAVF_TXD_CTX_QW1_CMD_SHIFT; 2471 cd_l2tag2 = (tx_flags & IAVF_TX_FLAGS_VLAN_MASK) >> 2472 IAVF_TX_FLAGS_VLAN_SHIFT; 2473 } 2474 2475 /* obtain protocol of skb */ 2476 protocol = vlan_get_protocol(skb); 2477 2478 /* setup IPv4/IPv6 offloads */ 2479 if (protocol == htons(ETH_P_IP)) 2480 tx_flags |= IAVF_TX_FLAGS_IPV4; 2481 else if (protocol == htons(ETH_P_IPV6)) 2482 tx_flags |= IAVF_TX_FLAGS_IPV6; 2483 2484 tso = iavf_tso(first, &hdr_len, &cd_type_cmd_tso_mss); 2485 2486 if (tso < 0) 2487 goto out_drop; 2488 else if (tso) 2489 tx_flags |= IAVF_TX_FLAGS_TSO; 2490 2491 /* Always offload the checksum, since it's in the data descriptor */ 2492 tso = iavf_tx_enable_csum(skb, &tx_flags, &td_cmd, &td_offset, 2493 tx_ring, &cd_tunneling); 2494 if (tso < 0) 2495 goto out_drop; 2496 2497 /* always enable CRC insertion offload */ 2498 td_cmd |= IAVF_TX_DESC_CMD_ICRC; 2499 2500 iavf_create_tx_ctx(tx_ring, cd_type_cmd_tso_mss, 2501 cd_tunneling, cd_l2tag2); 2502 2503 iavf_tx_map(tx_ring, skb, first, tx_flags, hdr_len, 2504 td_cmd, td_offset); 2505 2506 return NETDEV_TX_OK; 2507 2508 out_drop: 2509 iavf_trace(xmit_frame_ring_drop, first->skb, tx_ring); 2510 dev_kfree_skb_any(first->skb); 2511 first->skb = NULL; 2512 return NETDEV_TX_OK; 2513 } 2514 2515 /** 2516 * iavf_xmit_frame - Selects the correct VSI and Tx queue to send buffer 2517 * @skb: send buffer 2518 * @netdev: network interface device structure 2519 * 2520 * Returns NETDEV_TX_OK if sent, else an error code 2521 **/ 2522 netdev_tx_t iavf_xmit_frame(struct sk_buff *skb, struct net_device *netdev) 2523 { 2524 struct iavf_adapter *adapter = netdev_priv(netdev); 2525 struct iavf_ring *tx_ring = &adapter->tx_rings[skb->queue_mapping]; 2526 2527 /* hardware can't handle really short frames, hardware padding works 2528 * beyond this point 2529 */ 2530 if (unlikely(skb->len < IAVF_MIN_TX_LEN)) { 2531 if (skb_pad(skb, IAVF_MIN_TX_LEN - skb->len)) 2532 return NETDEV_TX_OK; 2533 skb->len = IAVF_MIN_TX_LEN; 2534 skb_set_tail_pointer(skb, IAVF_MIN_TX_LEN); 2535 } 2536 2537 return iavf_xmit_frame_ring(skb, tx_ring); 2538 } 2539