root/drivers/net/ethernet/intel/iavf/iavf_txrx.c

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DEFINITIONS

This source file includes following definitions.
  1. build_ctob
  2. iavf_unmap_and_free_tx_resource
  3. iavf_clean_tx_ring
  4. iavf_free_tx_resources
  5. iavf_get_tx_pending
  6. iavf_detect_recover_hung
  7. iavf_clean_tx_irq
  8. iavf_enable_wb_on_itr
  9. iavf_force_wb
  10. iavf_container_is_rx
  11. iavf_itr_divisor
  12. iavf_update_itr
  13. iavf_setup_tx_descriptors
  14. iavf_clean_rx_ring
  15. iavf_free_rx_resources
  16. iavf_setup_rx_descriptors
  17. iavf_release_rx_desc
  18. iavf_rx_offset
  19. iavf_alloc_mapped_page
  20. iavf_receive_skb
  21. iavf_alloc_rx_buffers
  22. iavf_rx_checksum
  23. iavf_ptype_to_htype
  24. iavf_rx_hash
  25. iavf_process_skb_fields
  26. iavf_cleanup_headers
  27. iavf_reuse_rx_page
  28. iavf_page_is_reusable
  29. iavf_can_reuse_rx_page
  30. iavf_add_rx_frag
  31. iavf_get_rx_buffer
  32. iavf_construct_skb
  33. iavf_build_skb
  34. iavf_put_rx_buffer
  35. iavf_is_non_eop
  36. iavf_clean_rx_irq
  37. iavf_buildreg_itr
  38. iavf_update_enable_itr
  39. iavf_napi_poll
  40. iavf_tx_prepare_vlan_flags
  41. iavf_tso
  42. iavf_tx_enable_csum
  43. iavf_create_tx_ctx
  44. __iavf_chk_linearize
  45. __iavf_maybe_stop_tx
  46. iavf_tx_map
  47. iavf_xmit_frame_ring
  48. iavf_xmit_frame

   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         head = ring->next_to_clean;
 118         tail = readl(ring->tail);
 119 
 120         if (head != tail)
 121                 return (head < tail) ?
 122                         tail - head : (tail + ring->count - head);
 123 
 124         return 0;
 125 }
 126 
 127 /**
 128  * iavf_detect_recover_hung - Function to detect and recover hung_queues
 129  * @vsi:  pointer to vsi struct with tx queues
 130  *
 131  * VSI has netdev and netdev has TX queues. This function is to check each of
 132  * those TX queues if they are hung, trigger recovery by issuing SW interrupt.
 133  **/
 134 void iavf_detect_recover_hung(struct iavf_vsi *vsi)
 135 {
 136         struct iavf_ring *tx_ring = NULL;
 137         struct net_device *netdev;
 138         unsigned int i;
 139         int packets;
 140 
 141         if (!vsi)
 142                 return;
 143 
 144         if (test_bit(__IAVF_VSI_DOWN, vsi->state))
 145                 return;
 146 
 147         netdev = vsi->netdev;
 148         if (!netdev)
 149                 return;
 150 
 151         if (!netif_carrier_ok(netdev))
 152                 return;
 153 
 154         for (i = 0; i < vsi->back->num_active_queues; i++) {
 155                 tx_ring = &vsi->back->tx_rings[i];
 156                 if (tx_ring && tx_ring->desc) {
 157                         /* If packet counter has not changed the queue is
 158                          * likely stalled, so force an interrupt for this
 159                          * queue.
 160                          *
 161                          * prev_pkt_ctr would be negative if there was no
 162                          * pending work.
 163                          */
 164                         packets = tx_ring->stats.packets & INT_MAX;
 165                         if (tx_ring->tx_stats.prev_pkt_ctr == packets) {
 166                                 iavf_force_wb(vsi, tx_ring->q_vector);
 167                                 continue;
 168                         }
 169 
 170                         /* Memory barrier between read of packet count and call
 171                          * to iavf_get_tx_pending()
 172                          */
 173                         smp_rmb();
 174                         tx_ring->tx_stats.prev_pkt_ctr =
 175                           iavf_get_tx_pending(tx_ring, true) ? packets : -1;
 176                 }
 177         }
 178 }
 179 
 180 #define WB_STRIDE 4
 181 
 182 /**
 183  * iavf_clean_tx_irq - Reclaim resources after transmit completes
 184  * @vsi: the VSI we care about
 185  * @tx_ring: Tx ring to clean
 186  * @napi_budget: Used to determine if we are in netpoll
 187  *
 188  * Returns true if there's any budget left (e.g. the clean is finished)
 189  **/
 190 static bool iavf_clean_tx_irq(struct iavf_vsi *vsi,
 191                               struct iavf_ring *tx_ring, int napi_budget)
 192 {
 193         int i = tx_ring->next_to_clean;
 194         struct iavf_tx_buffer *tx_buf;
 195         struct iavf_tx_desc *tx_desc;
 196         unsigned int total_bytes = 0, total_packets = 0;
 197         unsigned int budget = vsi->work_limit;
 198 
 199         tx_buf = &tx_ring->tx_bi[i];
 200         tx_desc = IAVF_TX_DESC(tx_ring, i);
 201         i -= tx_ring->count;
 202 
 203         do {
 204                 struct iavf_tx_desc *eop_desc = tx_buf->next_to_watch;
 205 
 206                 /* if next_to_watch is not set then there is no work pending */
 207                 if (!eop_desc)
 208                         break;
 209 
 210                 /* prevent any other reads prior to eop_desc */
 211                 smp_rmb();
 212 
 213                 iavf_trace(clean_tx_irq, tx_ring, tx_desc, tx_buf);
 214                 /* if the descriptor isn't done, no work yet to do */
 215                 if (!(eop_desc->cmd_type_offset_bsz &
 216                       cpu_to_le64(IAVF_TX_DESC_DTYPE_DESC_DONE)))
 217                         break;
 218 
 219                 /* clear next_to_watch to prevent false hangs */
 220                 tx_buf->next_to_watch = NULL;
 221 
 222                 /* update the statistics for this packet */
 223                 total_bytes += tx_buf->bytecount;
 224                 total_packets += tx_buf->gso_segs;
 225 
 226                 /* free the skb */
 227                 napi_consume_skb(tx_buf->skb, napi_budget);
 228 
 229                 /* unmap skb header data */
 230                 dma_unmap_single(tx_ring->dev,
 231                                  dma_unmap_addr(tx_buf, dma),
 232                                  dma_unmap_len(tx_buf, len),
 233                                  DMA_TO_DEVICE);
 234 
 235                 /* clear tx_buffer data */
 236                 tx_buf->skb = NULL;
 237                 dma_unmap_len_set(tx_buf, len, 0);
 238 
 239                 /* unmap remaining buffers */
 240                 while (tx_desc != eop_desc) {
 241                         iavf_trace(clean_tx_irq_unmap,
 242                                    tx_ring, tx_desc, tx_buf);
 243 
 244                         tx_buf++;
 245                         tx_desc++;
 246                         i++;
 247                         if (unlikely(!i)) {
 248                                 i -= tx_ring->count;
 249                                 tx_buf = tx_ring->tx_bi;
 250                                 tx_desc = IAVF_TX_DESC(tx_ring, 0);
 251                         }
 252 
 253                         /* unmap any remaining paged data */
 254                         if (dma_unmap_len(tx_buf, len)) {
 255                                 dma_unmap_page(tx_ring->dev,
 256                                                dma_unmap_addr(tx_buf, dma),
 257                                                dma_unmap_len(tx_buf, len),
 258                                                DMA_TO_DEVICE);
 259                                 dma_unmap_len_set(tx_buf, len, 0);
 260                         }
 261                 }
 262 
 263                 /* move us one more past the eop_desc for start of next pkt */
 264                 tx_buf++;
 265                 tx_desc++;
 266                 i++;
 267                 if (unlikely(!i)) {
 268                         i -= tx_ring->count;
 269                         tx_buf = tx_ring->tx_bi;
 270                         tx_desc = IAVF_TX_DESC(tx_ring, 0);
 271                 }
 272 
 273                 prefetch(tx_desc);
 274 
 275                 /* update budget accounting */
 276                 budget--;
 277         } while (likely(budget));
 278 
 279         i += tx_ring->count;
 280         tx_ring->next_to_clean = i;
 281         u64_stats_update_begin(&tx_ring->syncp);
 282         tx_ring->stats.bytes += total_bytes;
 283         tx_ring->stats.packets += total_packets;
 284         u64_stats_update_end(&tx_ring->syncp);
 285         tx_ring->q_vector->tx.total_bytes += total_bytes;
 286         tx_ring->q_vector->tx.total_packets += total_packets;
 287 
 288         if (tx_ring->flags & IAVF_TXR_FLAGS_WB_ON_ITR) {
 289                 /* check to see if there are < 4 descriptors
 290                  * waiting to be written back, then kick the hardware to force
 291                  * them to be written back in case we stay in NAPI.
 292                  * In this mode on X722 we do not enable Interrupt.
 293                  */
 294                 unsigned int j = iavf_get_tx_pending(tx_ring, false);
 295 
 296                 if (budget &&
 297                     ((j / WB_STRIDE) == 0) && (j > 0) &&
 298                     !test_bit(__IAVF_VSI_DOWN, vsi->state) &&
 299                     (IAVF_DESC_UNUSED(tx_ring) != tx_ring->count))
 300                         tx_ring->arm_wb = true;
 301         }
 302 
 303         /* notify netdev of completed buffers */
 304         netdev_tx_completed_queue(txring_txq(tx_ring),
 305                                   total_packets, total_bytes);
 306 
 307 #define TX_WAKE_THRESHOLD ((s16)(DESC_NEEDED * 2))
 308         if (unlikely(total_packets && netif_carrier_ok(tx_ring->netdev) &&
 309                      (IAVF_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))) {
 310                 /* Make sure that anybody stopping the queue after this
 311                  * sees the new next_to_clean.
 312                  */
 313                 smp_mb();
 314                 if (__netif_subqueue_stopped(tx_ring->netdev,
 315                                              tx_ring->queue_index) &&
 316                    !test_bit(__IAVF_VSI_DOWN, vsi->state)) {
 317                         netif_wake_subqueue(tx_ring->netdev,
 318                                             tx_ring->queue_index);
 319                         ++tx_ring->tx_stats.restart_queue;
 320                 }
 321         }
 322 
 323         return !!budget;
 324 }
 325 
 326 /**
 327  * iavf_enable_wb_on_itr - Arm hardware to do a wb, interrupts are not enabled
 328  * @vsi: the VSI we care about
 329  * @q_vector: the vector on which to enable writeback
 330  *
 331  **/
 332 static void iavf_enable_wb_on_itr(struct iavf_vsi *vsi,
 333                                   struct iavf_q_vector *q_vector)
 334 {
 335         u16 flags = q_vector->tx.ring[0].flags;
 336         u32 val;
 337 
 338         if (!(flags & IAVF_TXR_FLAGS_WB_ON_ITR))
 339                 return;
 340 
 341         if (q_vector->arm_wb_state)
 342                 return;
 343 
 344         val = IAVF_VFINT_DYN_CTLN1_WB_ON_ITR_MASK |
 345               IAVF_VFINT_DYN_CTLN1_ITR_INDX_MASK; /* set noitr */
 346 
 347         wr32(&vsi->back->hw,
 348              IAVF_VFINT_DYN_CTLN1(q_vector->reg_idx), val);
 349         q_vector->arm_wb_state = true;
 350 }
 351 
 352 /**
 353  * iavf_force_wb - Issue SW Interrupt so HW does a wb
 354  * @vsi: the VSI we care about
 355  * @q_vector: the vector  on which to force writeback
 356  *
 357  **/
 358 void iavf_force_wb(struct iavf_vsi *vsi, struct iavf_q_vector *q_vector)
 359 {
 360         u32 val = IAVF_VFINT_DYN_CTLN1_INTENA_MASK |
 361                   IAVF_VFINT_DYN_CTLN1_ITR_INDX_MASK | /* set noitr */
 362                   IAVF_VFINT_DYN_CTLN1_SWINT_TRIG_MASK |
 363                   IAVF_VFINT_DYN_CTLN1_SW_ITR_INDX_ENA_MASK
 364                   /* allow 00 to be written to the index */;
 365 
 366         wr32(&vsi->back->hw,
 367              IAVF_VFINT_DYN_CTLN1(q_vector->reg_idx),
 368              val);
 369 }
 370 
 371 static inline bool iavf_container_is_rx(struct iavf_q_vector *q_vector,
 372                                         struct iavf_ring_container *rc)
 373 {
 374         return &q_vector->rx == rc;
 375 }
 376 
 377 static inline unsigned int iavf_itr_divisor(struct iavf_q_vector *q_vector)
 378 {
 379         unsigned int divisor;
 380 
 381         switch (q_vector->adapter->link_speed) {
 382         case IAVF_LINK_SPEED_40GB:
 383                 divisor = IAVF_ITR_ADAPTIVE_MIN_INC * 1024;
 384                 break;
 385         case IAVF_LINK_SPEED_25GB:
 386         case IAVF_LINK_SPEED_20GB:
 387                 divisor = IAVF_ITR_ADAPTIVE_MIN_INC * 512;
 388                 break;
 389         default:
 390         case IAVF_LINK_SPEED_10GB:
 391                 divisor = IAVF_ITR_ADAPTIVE_MIN_INC * 256;
 392                 break;
 393         case IAVF_LINK_SPEED_1GB:
 394         case IAVF_LINK_SPEED_100MB:
 395                 divisor = IAVF_ITR_ADAPTIVE_MIN_INC * 32;
 396                 break;
 397         }
 398 
 399         return divisor;
 400 }
 401 
 402 /**
 403  * iavf_update_itr - update the dynamic ITR value based on statistics
 404  * @q_vector: structure containing interrupt and ring information
 405  * @rc: structure containing ring performance data
 406  *
 407  * Stores a new ITR value based on packets and byte
 408  * counts during the last interrupt.  The advantage of per interrupt
 409  * computation is faster updates and more accurate ITR for the current
 410  * traffic pattern.  Constants in this function were computed
 411  * based on theoretical maximum wire speed and thresholds were set based
 412  * on testing data as well as attempting to minimize response time
 413  * while increasing bulk throughput.
 414  **/
 415 static void iavf_update_itr(struct iavf_q_vector *q_vector,
 416                             struct iavf_ring_container *rc)
 417 {
 418         unsigned int avg_wire_size, packets, bytes, itr;
 419         unsigned long next_update = jiffies;
 420 
 421         /* If we don't have any rings just leave ourselves set for maximum
 422          * possible latency so we take ourselves out of the equation.
 423          */
 424         if (!rc->ring || !ITR_IS_DYNAMIC(rc->ring->itr_setting))
 425                 return;
 426 
 427         /* For Rx we want to push the delay up and default to low latency.
 428          * for Tx we want to pull the delay down and default to high latency.
 429          */
 430         itr = iavf_container_is_rx(q_vector, rc) ?
 431               IAVF_ITR_ADAPTIVE_MIN_USECS | IAVF_ITR_ADAPTIVE_LATENCY :
 432               IAVF_ITR_ADAPTIVE_MAX_USECS | IAVF_ITR_ADAPTIVE_LATENCY;
 433 
 434         /* If we didn't update within up to 1 - 2 jiffies we can assume
 435          * that either packets are coming in so slow there hasn't been
 436          * any work, or that there is so much work that NAPI is dealing
 437          * with interrupt moderation and we don't need to do anything.
 438          */
 439         if (time_after(next_update, rc->next_update))
 440                 goto clear_counts;
 441 
 442         /* If itr_countdown is set it means we programmed an ITR within
 443          * the last 4 interrupt cycles. This has a side effect of us
 444          * potentially firing an early interrupt. In order to work around
 445          * this we need to throw out any data received for a few
 446          * interrupts following the update.
 447          */
 448         if (q_vector->itr_countdown) {
 449                 itr = rc->target_itr;
 450                 goto clear_counts;
 451         }
 452 
 453         packets = rc->total_packets;
 454         bytes = rc->total_bytes;
 455 
 456         if (iavf_container_is_rx(q_vector, rc)) {
 457                 /* If Rx there are 1 to 4 packets and bytes are less than
 458                  * 9000 assume insufficient data to use bulk rate limiting
 459                  * approach unless Tx is already in bulk rate limiting. We
 460                  * are likely latency driven.
 461                  */
 462                 if (packets && packets < 4 && bytes < 9000 &&
 463                     (q_vector->tx.target_itr & IAVF_ITR_ADAPTIVE_LATENCY)) {
 464                         itr = IAVF_ITR_ADAPTIVE_LATENCY;
 465                         goto adjust_by_size;
 466                 }
 467         } else if (packets < 4) {
 468                 /* If we have Tx and Rx ITR maxed and Tx ITR is running in
 469                  * bulk mode and we are receiving 4 or fewer packets just
 470                  * reset the ITR_ADAPTIVE_LATENCY bit for latency mode so
 471                  * that the Rx can relax.
 472                  */
 473                 if (rc->target_itr == IAVF_ITR_ADAPTIVE_MAX_USECS &&
 474                     (q_vector->rx.target_itr & IAVF_ITR_MASK) ==
 475                      IAVF_ITR_ADAPTIVE_MAX_USECS)
 476                         goto clear_counts;
 477         } else if (packets > 32) {
 478                 /* If we have processed over 32 packets in a single interrupt
 479                  * for Tx assume we need to switch over to "bulk" mode.
 480                  */
 481                 rc->target_itr &= ~IAVF_ITR_ADAPTIVE_LATENCY;
 482         }
 483 
 484         /* We have no packets to actually measure against. This means
 485          * either one of the other queues on this vector is active or
 486          * we are a Tx queue doing TSO with too high of an interrupt rate.
 487          *
 488          * Between 4 and 56 we can assume that our current interrupt delay
 489          * is only slightly too low. As such we should increase it by a small
 490          * fixed amount.
 491          */
 492         if (packets < 56) {
 493                 itr = rc->target_itr + IAVF_ITR_ADAPTIVE_MIN_INC;
 494                 if ((itr & IAVF_ITR_MASK) > IAVF_ITR_ADAPTIVE_MAX_USECS) {
 495                         itr &= IAVF_ITR_ADAPTIVE_LATENCY;
 496                         itr += IAVF_ITR_ADAPTIVE_MAX_USECS;
 497                 }
 498                 goto clear_counts;
 499         }
 500 
 501         if (packets <= 256) {
 502                 itr = min(q_vector->tx.current_itr, q_vector->rx.current_itr);
 503                 itr &= IAVF_ITR_MASK;
 504 
 505                 /* Between 56 and 112 is our "goldilocks" zone where we are
 506                  * working out "just right". Just report that our current
 507                  * ITR is good for us.
 508                  */
 509                 if (packets <= 112)
 510                         goto clear_counts;
 511 
 512                 /* If packet count is 128 or greater we are likely looking
 513                  * at a slight overrun of the delay we want. Try halving
 514                  * our delay to see if that will cut the number of packets
 515                  * in half per interrupt.
 516                  */
 517                 itr /= 2;
 518                 itr &= IAVF_ITR_MASK;
 519                 if (itr < IAVF_ITR_ADAPTIVE_MIN_USECS)
 520                         itr = IAVF_ITR_ADAPTIVE_MIN_USECS;
 521 
 522                 goto clear_counts;
 523         }
 524 
 525         /* The paths below assume we are dealing with a bulk ITR since
 526          * number of packets is greater than 256. We are just going to have
 527          * to compute a value and try to bring the count under control,
 528          * though for smaller packet sizes there isn't much we can do as
 529          * NAPI polling will likely be kicking in sooner rather than later.
 530          */
 531         itr = IAVF_ITR_ADAPTIVE_BULK;
 532 
 533 adjust_by_size:
 534         /* If packet counts are 256 or greater we can assume we have a gross
 535          * overestimation of what the rate should be. Instead of trying to fine
 536          * tune it just use the formula below to try and dial in an exact value
 537          * give the current packet size of the frame.
 538          */
 539         avg_wire_size = bytes / packets;
 540 
 541         /* The following is a crude approximation of:
 542          *  wmem_default / (size + overhead) = desired_pkts_per_int
 543          *  rate / bits_per_byte / (size + ethernet overhead) = pkt_rate
 544          *  (desired_pkt_rate / pkt_rate) * usecs_per_sec = ITR value
 545          *
 546          * Assuming wmem_default is 212992 and overhead is 640 bytes per
 547          * packet, (256 skb, 64 headroom, 320 shared info), we can reduce the
 548          * formula down to
 549          *
 550          *  (170 * (size + 24)) / (size + 640) = ITR
 551          *
 552          * We first do some math on the packet size and then finally bitshift
 553          * by 8 after rounding up. We also have to account for PCIe link speed
 554          * difference as ITR scales based on this.
 555          */
 556         if (avg_wire_size <= 60) {
 557                 /* Start at 250k ints/sec */
 558                 avg_wire_size = 4096;
 559         } else if (avg_wire_size <= 380) {
 560                 /* 250K ints/sec to 60K ints/sec */
 561                 avg_wire_size *= 40;
 562                 avg_wire_size += 1696;
 563         } else if (avg_wire_size <= 1084) {
 564                 /* 60K ints/sec to 36K ints/sec */
 565                 avg_wire_size *= 15;
 566                 avg_wire_size += 11452;
 567         } else if (avg_wire_size <= 1980) {
 568                 /* 36K ints/sec to 30K ints/sec */
 569                 avg_wire_size *= 5;
 570                 avg_wire_size += 22420;
 571         } else {
 572                 /* plateau at a limit of 30K ints/sec */
 573                 avg_wire_size = 32256;
 574         }
 575 
 576         /* If we are in low latency mode halve our delay which doubles the
 577          * rate to somewhere between 100K to 16K ints/sec
 578          */
 579         if (itr & IAVF_ITR_ADAPTIVE_LATENCY)
 580                 avg_wire_size /= 2;
 581 
 582         /* Resultant value is 256 times larger than it needs to be. This
 583          * gives us room to adjust the value as needed to either increase
 584          * or decrease the value based on link speeds of 10G, 2.5G, 1G, etc.
 585          *
 586          * Use addition as we have already recorded the new latency flag
 587          * for the ITR value.
 588          */
 589         itr += DIV_ROUND_UP(avg_wire_size, iavf_itr_divisor(q_vector)) *
 590                IAVF_ITR_ADAPTIVE_MIN_INC;
 591 
 592         if ((itr & IAVF_ITR_MASK) > IAVF_ITR_ADAPTIVE_MAX_USECS) {
 593                 itr &= IAVF_ITR_ADAPTIVE_LATENCY;
 594                 itr += IAVF_ITR_ADAPTIVE_MAX_USECS;
 595         }
 596 
 597 clear_counts:
 598         /* write back value */
 599         rc->target_itr = itr;
 600 
 601         /* next update should occur within next jiffy */
 602         rc->next_update = next_update + 1;
 603 
 604         rc->total_bytes = 0;
 605         rc->total_packets = 0;
 606 }
 607 
 608 /**
 609  * iavf_setup_tx_descriptors - Allocate the Tx descriptors
 610  * @tx_ring: the tx ring to set up
 611  *
 612  * Return 0 on success, negative on error
 613  **/
 614 int iavf_setup_tx_descriptors(struct iavf_ring *tx_ring)
 615 {
 616         struct device *dev = tx_ring->dev;
 617         int bi_size;
 618 
 619         if (!dev)
 620                 return -ENOMEM;
 621 
 622         /* warn if we are about to overwrite the pointer */
 623         WARN_ON(tx_ring->tx_bi);
 624         bi_size = sizeof(struct iavf_tx_buffer) * tx_ring->count;
 625         tx_ring->tx_bi = kzalloc(bi_size, GFP_KERNEL);
 626         if (!tx_ring->tx_bi)
 627                 goto err;
 628 
 629         /* round up to nearest 4K */
 630         tx_ring->size = tx_ring->count * sizeof(struct iavf_tx_desc);
 631         tx_ring->size = ALIGN(tx_ring->size, 4096);
 632         tx_ring->desc = dma_alloc_coherent(dev, tx_ring->size,
 633                                            &tx_ring->dma, GFP_KERNEL);
 634         if (!tx_ring->desc) {
 635                 dev_info(dev, "Unable to allocate memory for the Tx descriptor ring, size=%d\n",
 636                          tx_ring->size);
 637                 goto err;
 638         }
 639 
 640         tx_ring->next_to_use = 0;
 641         tx_ring->next_to_clean = 0;
 642         tx_ring->tx_stats.prev_pkt_ctr = -1;
 643         return 0;
 644 
 645 err:
 646         kfree(tx_ring->tx_bi);
 647         tx_ring->tx_bi = NULL;
 648         return -ENOMEM;
 649 }
 650 
 651 /**
 652  * iavf_clean_rx_ring - Free Rx buffers
 653  * @rx_ring: ring to be cleaned
 654  **/
 655 void iavf_clean_rx_ring(struct iavf_ring *rx_ring)
 656 {
 657         unsigned long bi_size;
 658         u16 i;
 659 
 660         /* ring already cleared, nothing to do */
 661         if (!rx_ring->rx_bi)
 662                 return;
 663 
 664         if (rx_ring->skb) {
 665                 dev_kfree_skb(rx_ring->skb);
 666                 rx_ring->skb = NULL;
 667         }
 668 
 669         /* Free all the Rx ring sk_buffs */
 670         for (i = 0; i < rx_ring->count; i++) {
 671                 struct iavf_rx_buffer *rx_bi = &rx_ring->rx_bi[i];
 672 
 673                 if (!rx_bi->page)
 674                         continue;
 675 
 676                 /* Invalidate cache lines that may have been written to by
 677                  * device so that we avoid corrupting memory.
 678                  */
 679                 dma_sync_single_range_for_cpu(rx_ring->dev,
 680                                               rx_bi->dma,
 681                                               rx_bi->page_offset,
 682                                               rx_ring->rx_buf_len,
 683                                               DMA_FROM_DEVICE);
 684 
 685                 /* free resources associated with mapping */
 686                 dma_unmap_page_attrs(rx_ring->dev, rx_bi->dma,
 687                                      iavf_rx_pg_size(rx_ring),
 688                                      DMA_FROM_DEVICE,
 689                                      IAVF_RX_DMA_ATTR);
 690 
 691                 __page_frag_cache_drain(rx_bi->page, rx_bi->pagecnt_bias);
 692 
 693                 rx_bi->page = NULL;
 694                 rx_bi->page_offset = 0;
 695         }
 696 
 697         bi_size = sizeof(struct iavf_rx_buffer) * rx_ring->count;
 698         memset(rx_ring->rx_bi, 0, bi_size);
 699 
 700         /* Zero out the descriptor ring */
 701         memset(rx_ring->desc, 0, rx_ring->size);
 702 
 703         rx_ring->next_to_alloc = 0;
 704         rx_ring->next_to_clean = 0;
 705         rx_ring->next_to_use = 0;
 706 }
 707 
 708 /**
 709  * iavf_free_rx_resources - Free Rx resources
 710  * @rx_ring: ring to clean the resources from
 711  *
 712  * Free all receive software resources
 713  **/
 714 void iavf_free_rx_resources(struct iavf_ring *rx_ring)
 715 {
 716         iavf_clean_rx_ring(rx_ring);
 717         kfree(rx_ring->rx_bi);
 718         rx_ring->rx_bi = NULL;
 719 
 720         if (rx_ring->desc) {
 721                 dma_free_coherent(rx_ring->dev, rx_ring->size,
 722                                   rx_ring->desc, rx_ring->dma);
 723                 rx_ring->desc = NULL;
 724         }
 725 }
 726 
 727 /**
 728  * iavf_setup_rx_descriptors - Allocate Rx descriptors
 729  * @rx_ring: Rx descriptor ring (for a specific queue) to setup
 730  *
 731  * Returns 0 on success, negative on failure
 732  **/
 733 int iavf_setup_rx_descriptors(struct iavf_ring *rx_ring)
 734 {
 735         struct device *dev = rx_ring->dev;
 736         int bi_size;
 737 
 738         /* warn if we are about to overwrite the pointer */
 739         WARN_ON(rx_ring->rx_bi);
 740         bi_size = sizeof(struct iavf_rx_buffer) * rx_ring->count;
 741         rx_ring->rx_bi = kzalloc(bi_size, GFP_KERNEL);
 742         if (!rx_ring->rx_bi)
 743                 goto err;
 744 
 745         u64_stats_init(&rx_ring->syncp);
 746 
 747         /* Round up to nearest 4K */
 748         rx_ring->size = rx_ring->count * sizeof(union iavf_32byte_rx_desc);
 749         rx_ring->size = ALIGN(rx_ring->size, 4096);
 750         rx_ring->desc = dma_alloc_coherent(dev, rx_ring->size,
 751                                            &rx_ring->dma, GFP_KERNEL);
 752 
 753         if (!rx_ring->desc) {
 754                 dev_info(dev, "Unable to allocate memory for the Rx descriptor ring, size=%d\n",
 755                          rx_ring->size);
 756                 goto err;
 757         }
 758 
 759         rx_ring->next_to_alloc = 0;
 760         rx_ring->next_to_clean = 0;
 761         rx_ring->next_to_use = 0;
 762 
 763         return 0;
 764 err:
 765         kfree(rx_ring->rx_bi);
 766         rx_ring->rx_bi = NULL;
 767         return -ENOMEM;
 768 }
 769 
 770 /**
 771  * iavf_release_rx_desc - Store the new tail and head values
 772  * @rx_ring: ring to bump
 773  * @val: new head index
 774  **/
 775 static inline void iavf_release_rx_desc(struct iavf_ring *rx_ring, u32 val)
 776 {
 777         rx_ring->next_to_use = val;
 778 
 779         /* update next to alloc since we have filled the ring */
 780         rx_ring->next_to_alloc = val;
 781 
 782         /* Force memory writes to complete before letting h/w
 783          * know there are new descriptors to fetch.  (Only
 784          * applicable for weak-ordered memory model archs,
 785          * such as IA-64).
 786          */
 787         wmb();
 788         writel(val, rx_ring->tail);
 789 }
 790 
 791 /**
 792  * iavf_rx_offset - Return expected offset into page to access data
 793  * @rx_ring: Ring we are requesting offset of
 794  *
 795  * Returns the offset value for ring into the data buffer.
 796  */
 797 static inline unsigned int iavf_rx_offset(struct iavf_ring *rx_ring)
 798 {
 799         return ring_uses_build_skb(rx_ring) ? IAVF_SKB_PAD : 0;
 800 }
 801 
 802 /**
 803  * iavf_alloc_mapped_page - recycle or make a new page
 804  * @rx_ring: ring to use
 805  * @bi: rx_buffer struct to modify
 806  *
 807  * Returns true if the page was successfully allocated or
 808  * reused.
 809  **/
 810 static bool iavf_alloc_mapped_page(struct iavf_ring *rx_ring,
 811                                    struct iavf_rx_buffer *bi)
 812 {
 813         struct page *page = bi->page;
 814         dma_addr_t dma;
 815 
 816         /* since we are recycling buffers we should seldom need to alloc */
 817         if (likely(page)) {
 818                 rx_ring->rx_stats.page_reuse_count++;
 819                 return true;
 820         }
 821 
 822         /* alloc new page for storage */
 823         page = dev_alloc_pages(iavf_rx_pg_order(rx_ring));
 824         if (unlikely(!page)) {
 825                 rx_ring->rx_stats.alloc_page_failed++;
 826                 return false;
 827         }
 828 
 829         /* map page for use */
 830         dma = dma_map_page_attrs(rx_ring->dev, page, 0,
 831                                  iavf_rx_pg_size(rx_ring),
 832                                  DMA_FROM_DEVICE,
 833                                  IAVF_RX_DMA_ATTR);
 834 
 835         /* if mapping failed free memory back to system since
 836          * there isn't much point in holding memory we can't use
 837          */
 838         if (dma_mapping_error(rx_ring->dev, dma)) {
 839                 __free_pages(page, iavf_rx_pg_order(rx_ring));
 840                 rx_ring->rx_stats.alloc_page_failed++;
 841                 return false;
 842         }
 843 
 844         bi->dma = dma;
 845         bi->page = page;
 846         bi->page_offset = iavf_rx_offset(rx_ring);
 847 
 848         /* initialize pagecnt_bias to 1 representing we fully own page */
 849         bi->pagecnt_bias = 1;
 850 
 851         return true;
 852 }
 853 
 854 /**
 855  * iavf_receive_skb - Send a completed packet up the stack
 856  * @rx_ring:  rx ring in play
 857  * @skb: packet to send up
 858  * @vlan_tag: vlan tag for packet
 859  **/
 860 static void iavf_receive_skb(struct iavf_ring *rx_ring,
 861                              struct sk_buff *skb, u16 vlan_tag)
 862 {
 863         struct iavf_q_vector *q_vector = rx_ring->q_vector;
 864 
 865         if ((rx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_RX) &&
 866             (vlan_tag & VLAN_VID_MASK))
 867                 __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tag);
 868 
 869         napi_gro_receive(&q_vector->napi, skb);
 870 }
 871 
 872 /**
 873  * iavf_alloc_rx_buffers - Replace used receive buffers
 874  * @rx_ring: ring to place buffers on
 875  * @cleaned_count: number of buffers to replace
 876  *
 877  * Returns false if all allocations were successful, true if any fail
 878  **/
 879 bool iavf_alloc_rx_buffers(struct iavf_ring *rx_ring, u16 cleaned_count)
 880 {
 881         u16 ntu = rx_ring->next_to_use;
 882         union iavf_rx_desc *rx_desc;
 883         struct iavf_rx_buffer *bi;
 884 
 885         /* do nothing if no valid netdev defined */
 886         if (!rx_ring->netdev || !cleaned_count)
 887                 return false;
 888 
 889         rx_desc = IAVF_RX_DESC(rx_ring, ntu);
 890         bi = &rx_ring->rx_bi[ntu];
 891 
 892         do {
 893                 if (!iavf_alloc_mapped_page(rx_ring, bi))
 894                         goto no_buffers;
 895 
 896                 /* sync the buffer for use by the device */
 897                 dma_sync_single_range_for_device(rx_ring->dev, bi->dma,
 898                                                  bi->page_offset,
 899                                                  rx_ring->rx_buf_len,
 900                                                  DMA_FROM_DEVICE);
 901 
 902                 /* Refresh the desc even if buffer_addrs didn't change
 903                  * because each write-back erases this info.
 904                  */
 905                 rx_desc->read.pkt_addr = cpu_to_le64(bi->dma + bi->page_offset);
 906 
 907                 rx_desc++;
 908                 bi++;
 909                 ntu++;
 910                 if (unlikely(ntu == rx_ring->count)) {
 911                         rx_desc = IAVF_RX_DESC(rx_ring, 0);
 912                         bi = rx_ring->rx_bi;
 913                         ntu = 0;
 914                 }
 915 
 916                 /* clear the status bits for the next_to_use descriptor */
 917                 rx_desc->wb.qword1.status_error_len = 0;
 918 
 919                 cleaned_count--;
 920         } while (cleaned_count);
 921 
 922         if (rx_ring->next_to_use != ntu)
 923                 iavf_release_rx_desc(rx_ring, ntu);
 924 
 925         return false;
 926 
 927 no_buffers:
 928         if (rx_ring->next_to_use != ntu)
 929                 iavf_release_rx_desc(rx_ring, ntu);
 930 
 931         /* make sure to come back via polling to try again after
 932          * allocation failure
 933          */
 934         return true;
 935 }
 936 
 937 /**
 938  * iavf_rx_checksum - Indicate in skb if hw indicated a good cksum
 939  * @vsi: the VSI we care about
 940  * @skb: skb currently being received and modified
 941  * @rx_desc: the receive descriptor
 942  **/
 943 static inline void iavf_rx_checksum(struct iavf_vsi *vsi,
 944                                     struct sk_buff *skb,
 945                                     union iavf_rx_desc *rx_desc)
 946 {
 947         struct iavf_rx_ptype_decoded decoded;
 948         u32 rx_error, rx_status;
 949         bool ipv4, ipv6;
 950         u8 ptype;
 951         u64 qword;
 952 
 953         qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
 954         ptype = (qword & IAVF_RXD_QW1_PTYPE_MASK) >> IAVF_RXD_QW1_PTYPE_SHIFT;
 955         rx_error = (qword & IAVF_RXD_QW1_ERROR_MASK) >>
 956                    IAVF_RXD_QW1_ERROR_SHIFT;
 957         rx_status = (qword & IAVF_RXD_QW1_STATUS_MASK) >>
 958                     IAVF_RXD_QW1_STATUS_SHIFT;
 959         decoded = decode_rx_desc_ptype(ptype);
 960 
 961         skb->ip_summed = CHECKSUM_NONE;
 962 
 963         skb_checksum_none_assert(skb);
 964 
 965         /* Rx csum enabled and ip headers found? */
 966         if (!(vsi->netdev->features & NETIF_F_RXCSUM))
 967                 return;
 968 
 969         /* did the hardware decode the packet and checksum? */
 970         if (!(rx_status & BIT(IAVF_RX_DESC_STATUS_L3L4P_SHIFT)))
 971                 return;
 972 
 973         /* both known and outer_ip must be set for the below code to work */
 974         if (!(decoded.known && decoded.outer_ip))
 975                 return;
 976 
 977         ipv4 = (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP) &&
 978                (decoded.outer_ip_ver == IAVF_RX_PTYPE_OUTER_IPV4);
 979         ipv6 = (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP) &&
 980                (decoded.outer_ip_ver == IAVF_RX_PTYPE_OUTER_IPV6);
 981 
 982         if (ipv4 &&
 983             (rx_error & (BIT(IAVF_RX_DESC_ERROR_IPE_SHIFT) |
 984                          BIT(IAVF_RX_DESC_ERROR_EIPE_SHIFT))))
 985                 goto checksum_fail;
 986 
 987         /* likely incorrect csum if alternate IP extension headers found */
 988         if (ipv6 &&
 989             rx_status & BIT(IAVF_RX_DESC_STATUS_IPV6EXADD_SHIFT))
 990                 /* don't increment checksum err here, non-fatal err */
 991                 return;
 992 
 993         /* there was some L4 error, count error and punt packet to the stack */
 994         if (rx_error & BIT(IAVF_RX_DESC_ERROR_L4E_SHIFT))
 995                 goto checksum_fail;
 996 
 997         /* handle packets that were not able to be checksummed due
 998          * to arrival speed, in this case the stack can compute
 999          * the csum.
1000          */
1001         if (rx_error & BIT(IAVF_RX_DESC_ERROR_PPRS_SHIFT))
1002                 return;
1003 
1004         /* Only report checksum unnecessary for TCP, UDP, or SCTP */
1005         switch (decoded.inner_prot) {
1006         case IAVF_RX_PTYPE_INNER_PROT_TCP:
1007         case IAVF_RX_PTYPE_INNER_PROT_UDP:
1008         case IAVF_RX_PTYPE_INNER_PROT_SCTP:
1009                 skb->ip_summed = CHECKSUM_UNNECESSARY;
1010                 /* fall though */
1011         default:
1012                 break;
1013         }
1014 
1015         return;
1016 
1017 checksum_fail:
1018         vsi->back->hw_csum_rx_error++;
1019 }
1020 
1021 /**
1022  * iavf_ptype_to_htype - get a hash type
1023  * @ptype: the ptype value from the descriptor
1024  *
1025  * Returns a hash type to be used by skb_set_hash
1026  **/
1027 static inline int iavf_ptype_to_htype(u8 ptype)
1028 {
1029         struct iavf_rx_ptype_decoded decoded = decode_rx_desc_ptype(ptype);
1030 
1031         if (!decoded.known)
1032                 return PKT_HASH_TYPE_NONE;
1033 
1034         if (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP &&
1035             decoded.payload_layer == IAVF_RX_PTYPE_PAYLOAD_LAYER_PAY4)
1036                 return PKT_HASH_TYPE_L4;
1037         else if (decoded.outer_ip == IAVF_RX_PTYPE_OUTER_IP &&
1038                  decoded.payload_layer == IAVF_RX_PTYPE_PAYLOAD_LAYER_PAY3)
1039                 return PKT_HASH_TYPE_L3;
1040         else
1041                 return PKT_HASH_TYPE_L2;
1042 }
1043 
1044 /**
1045  * iavf_rx_hash - set the hash value in the skb
1046  * @ring: descriptor ring
1047  * @rx_desc: specific descriptor
1048  * @skb: skb currently being received and modified
1049  * @rx_ptype: Rx packet type
1050  **/
1051 static inline void iavf_rx_hash(struct iavf_ring *ring,
1052                                 union iavf_rx_desc *rx_desc,
1053                                 struct sk_buff *skb,
1054                                 u8 rx_ptype)
1055 {
1056         u32 hash;
1057         const __le64 rss_mask =
1058                 cpu_to_le64((u64)IAVF_RX_DESC_FLTSTAT_RSS_HASH <<
1059                             IAVF_RX_DESC_STATUS_FLTSTAT_SHIFT);
1060 
1061         if (ring->netdev->features & NETIF_F_RXHASH)
1062                 return;
1063 
1064         if ((rx_desc->wb.qword1.status_error_len & rss_mask) == rss_mask) {
1065                 hash = le32_to_cpu(rx_desc->wb.qword0.hi_dword.rss);
1066                 skb_set_hash(skb, hash, iavf_ptype_to_htype(rx_ptype));
1067         }
1068 }
1069 
1070 /**
1071  * iavf_process_skb_fields - Populate skb header fields from Rx descriptor
1072  * @rx_ring: rx descriptor ring packet is being transacted on
1073  * @rx_desc: pointer to the EOP Rx descriptor
1074  * @skb: pointer to current skb being populated
1075  * @rx_ptype: the packet type decoded by hardware
1076  *
1077  * This function checks the ring, descriptor, and packet information in
1078  * order to populate the hash, checksum, VLAN, protocol, and
1079  * other fields within the skb.
1080  **/
1081 static inline
1082 void iavf_process_skb_fields(struct iavf_ring *rx_ring,
1083                              union iavf_rx_desc *rx_desc, struct sk_buff *skb,
1084                              u8 rx_ptype)
1085 {
1086         iavf_rx_hash(rx_ring, rx_desc, skb, rx_ptype);
1087 
1088         iavf_rx_checksum(rx_ring->vsi, skb, rx_desc);
1089 
1090         skb_record_rx_queue(skb, rx_ring->queue_index);
1091 
1092         /* modifies the skb - consumes the enet header */
1093         skb->protocol = eth_type_trans(skb, rx_ring->netdev);
1094 }
1095 
1096 /**
1097  * iavf_cleanup_headers - Correct empty headers
1098  * @rx_ring: rx descriptor ring packet is being transacted on
1099  * @skb: pointer to current skb being fixed
1100  *
1101  * Also address the case where we are pulling data in on pages only
1102  * and as such no data is present in the skb header.
1103  *
1104  * In addition if skb is not at least 60 bytes we need to pad it so that
1105  * it is large enough to qualify as a valid Ethernet frame.
1106  *
1107  * Returns true if an error was encountered and skb was freed.
1108  **/
1109 static bool iavf_cleanup_headers(struct iavf_ring *rx_ring, struct sk_buff *skb)
1110 {
1111         /* if eth_skb_pad returns an error the skb was freed */
1112         if (eth_skb_pad(skb))
1113                 return true;
1114 
1115         return false;
1116 }
1117 
1118 /**
1119  * iavf_reuse_rx_page - page flip buffer and store it back on the ring
1120  * @rx_ring: rx descriptor ring to store buffers on
1121  * @old_buff: donor buffer to have page reused
1122  *
1123  * Synchronizes page for reuse by the adapter
1124  **/
1125 static void iavf_reuse_rx_page(struct iavf_ring *rx_ring,
1126                                struct iavf_rx_buffer *old_buff)
1127 {
1128         struct iavf_rx_buffer *new_buff;
1129         u16 nta = rx_ring->next_to_alloc;
1130 
1131         new_buff = &rx_ring->rx_bi[nta];
1132 
1133         /* update, and store next to alloc */
1134         nta++;
1135         rx_ring->next_to_alloc = (nta < rx_ring->count) ? nta : 0;
1136 
1137         /* transfer page from old buffer to new buffer */
1138         new_buff->dma           = old_buff->dma;
1139         new_buff->page          = old_buff->page;
1140         new_buff->page_offset   = old_buff->page_offset;
1141         new_buff->pagecnt_bias  = old_buff->pagecnt_bias;
1142 }
1143 
1144 /**
1145  * iavf_page_is_reusable - check if any reuse is possible
1146  * @page: page struct to check
1147  *
1148  * A page is not reusable if it was allocated under low memory
1149  * conditions, or it's not in the same NUMA node as this CPU.
1150  */
1151 static inline bool iavf_page_is_reusable(struct page *page)
1152 {
1153         return (page_to_nid(page) == numa_mem_id()) &&
1154                 !page_is_pfmemalloc(page);
1155 }
1156 
1157 /**
1158  * iavf_can_reuse_rx_page - Determine if this page can be reused by
1159  * the adapter for another receive
1160  *
1161  * @rx_buffer: buffer containing the page
1162  *
1163  * If page is reusable, rx_buffer->page_offset is adjusted to point to
1164  * an unused region in the page.
1165  *
1166  * For small pages, @truesize will be a constant value, half the size
1167  * of the memory at page.  We'll attempt to alternate between high and
1168  * low halves of the page, with one half ready for use by the hardware
1169  * and the other half being consumed by the stack.  We use the page
1170  * ref count to determine whether the stack has finished consuming the
1171  * portion of this page that was passed up with a previous packet.  If
1172  * the page ref count is >1, we'll assume the "other" half page is
1173  * still busy, and this page cannot be reused.
1174  *
1175  * For larger pages, @truesize will be the actual space used by the
1176  * received packet (adjusted upward to an even multiple of the cache
1177  * line size).  This will advance through the page by the amount
1178  * actually consumed by the received packets while there is still
1179  * space for a buffer.  Each region of larger pages will be used at
1180  * most once, after which the page will not be reused.
1181  *
1182  * In either case, if the page is reusable its refcount is increased.
1183  **/
1184 static bool iavf_can_reuse_rx_page(struct iavf_rx_buffer *rx_buffer)
1185 {
1186         unsigned int pagecnt_bias = rx_buffer->pagecnt_bias;
1187         struct page *page = rx_buffer->page;
1188 
1189         /* Is any reuse possible? */
1190         if (unlikely(!iavf_page_is_reusable(page)))
1191                 return false;
1192 
1193 #if (PAGE_SIZE < 8192)
1194         /* if we are only owner of page we can reuse it */
1195         if (unlikely((page_count(page) - pagecnt_bias) > 1))
1196                 return false;
1197 #else
1198 #define IAVF_LAST_OFFSET \
1199         (SKB_WITH_OVERHEAD(PAGE_SIZE) - IAVF_RXBUFFER_2048)
1200         if (rx_buffer->page_offset > IAVF_LAST_OFFSET)
1201                 return false;
1202 #endif
1203 
1204         /* If we have drained the page fragment pool we need to update
1205          * the pagecnt_bias and page count so that we fully restock the
1206          * number of references the driver holds.
1207          */
1208         if (unlikely(!pagecnt_bias)) {
1209                 page_ref_add(page, USHRT_MAX);
1210                 rx_buffer->pagecnt_bias = USHRT_MAX;
1211         }
1212 
1213         return true;
1214 }
1215 
1216 /**
1217  * iavf_add_rx_frag - Add contents of Rx buffer to sk_buff
1218  * @rx_ring: rx descriptor ring to transact packets on
1219  * @rx_buffer: buffer containing page to add
1220  * @skb: sk_buff to place the data into
1221  * @size: packet length from rx_desc
1222  *
1223  * This function will add the data contained in rx_buffer->page to the skb.
1224  * It will just attach the page as a frag to the skb.
1225  *
1226  * The function will then update the page offset.
1227  **/
1228 static void iavf_add_rx_frag(struct iavf_ring *rx_ring,
1229                              struct iavf_rx_buffer *rx_buffer,
1230                              struct sk_buff *skb,
1231                              unsigned int size)
1232 {
1233 #if (PAGE_SIZE < 8192)
1234         unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2;
1235 #else
1236         unsigned int truesize = SKB_DATA_ALIGN(size + iavf_rx_offset(rx_ring));
1237 #endif
1238 
1239         if (!size)
1240                 return;
1241 
1242         skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buffer->page,
1243                         rx_buffer->page_offset, size, truesize);
1244 
1245         /* page is being used so we must update the page offset */
1246 #if (PAGE_SIZE < 8192)
1247         rx_buffer->page_offset ^= truesize;
1248 #else
1249         rx_buffer->page_offset += truesize;
1250 #endif
1251 }
1252 
1253 /**
1254  * iavf_get_rx_buffer - Fetch Rx buffer and synchronize data for use
1255  * @rx_ring: rx descriptor ring to transact packets on
1256  * @size: size of buffer to add to skb
1257  *
1258  * This function will pull an Rx buffer from the ring and synchronize it
1259  * for use by the CPU.
1260  */
1261 static struct iavf_rx_buffer *iavf_get_rx_buffer(struct iavf_ring *rx_ring,
1262                                                  const unsigned int size)
1263 {
1264         struct iavf_rx_buffer *rx_buffer;
1265 
1266         if (!size)
1267                 return NULL;
1268 
1269         rx_buffer = &rx_ring->rx_bi[rx_ring->next_to_clean];
1270         prefetchw(rx_buffer->page);
1271 
1272         /* we are reusing so sync this buffer for CPU use */
1273         dma_sync_single_range_for_cpu(rx_ring->dev,
1274                                       rx_buffer->dma,
1275                                       rx_buffer->page_offset,
1276                                       size,
1277                                       DMA_FROM_DEVICE);
1278 
1279         /* We have pulled a buffer for use, so decrement pagecnt_bias */
1280         rx_buffer->pagecnt_bias--;
1281 
1282         return rx_buffer;
1283 }
1284 
1285 /**
1286  * iavf_construct_skb - Allocate skb and populate it
1287  * @rx_ring: rx descriptor ring to transact packets on
1288  * @rx_buffer: rx buffer to pull data from
1289  * @size: size of buffer to add to skb
1290  *
1291  * This function allocates an skb.  It then populates it with the page
1292  * data from the current receive descriptor, taking care to set up the
1293  * skb correctly.
1294  */
1295 static struct sk_buff *iavf_construct_skb(struct iavf_ring *rx_ring,
1296                                           struct iavf_rx_buffer *rx_buffer,
1297                                           unsigned int size)
1298 {
1299         void *va;
1300 #if (PAGE_SIZE < 8192)
1301         unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2;
1302 #else
1303         unsigned int truesize = SKB_DATA_ALIGN(size);
1304 #endif
1305         unsigned int headlen;
1306         struct sk_buff *skb;
1307 
1308         if (!rx_buffer)
1309                 return NULL;
1310         /* prefetch first cache line of first page */
1311         va = page_address(rx_buffer->page) + rx_buffer->page_offset;
1312         prefetch(va);
1313 #if L1_CACHE_BYTES < 128
1314         prefetch(va + L1_CACHE_BYTES);
1315 #endif
1316 
1317         /* allocate a skb to store the frags */
1318         skb = __napi_alloc_skb(&rx_ring->q_vector->napi,
1319                                IAVF_RX_HDR_SIZE,
1320                                GFP_ATOMIC | __GFP_NOWARN);
1321         if (unlikely(!skb))
1322                 return NULL;
1323 
1324         /* Determine available headroom for copy */
1325         headlen = size;
1326         if (headlen > IAVF_RX_HDR_SIZE)
1327                 headlen = eth_get_headlen(skb->dev, va, IAVF_RX_HDR_SIZE);
1328 
1329         /* align pull length to size of long to optimize memcpy performance */
1330         memcpy(__skb_put(skb, headlen), va, ALIGN(headlen, sizeof(long)));
1331 
1332         /* update all of the pointers */
1333         size -= headlen;
1334         if (size) {
1335                 skb_add_rx_frag(skb, 0, rx_buffer->page,
1336                                 rx_buffer->page_offset + headlen,
1337                                 size, truesize);
1338 
1339                 /* buffer is used by skb, update page_offset */
1340 #if (PAGE_SIZE < 8192)
1341                 rx_buffer->page_offset ^= truesize;
1342 #else
1343                 rx_buffer->page_offset += truesize;
1344 #endif
1345         } else {
1346                 /* buffer is unused, reset bias back to rx_buffer */
1347                 rx_buffer->pagecnt_bias++;
1348         }
1349 
1350         return skb;
1351 }
1352 
1353 /**
1354  * iavf_build_skb - Build skb around an existing buffer
1355  * @rx_ring: Rx descriptor ring to transact packets on
1356  * @rx_buffer: Rx buffer to pull data from
1357  * @size: size of buffer to add to skb
1358  *
1359  * This function builds an skb around an existing Rx buffer, taking care
1360  * to set up the skb correctly and avoid any memcpy overhead.
1361  */
1362 static struct sk_buff *iavf_build_skb(struct iavf_ring *rx_ring,
1363                                       struct iavf_rx_buffer *rx_buffer,
1364                                       unsigned int size)
1365 {
1366         void *va;
1367 #if (PAGE_SIZE < 8192)
1368         unsigned int truesize = iavf_rx_pg_size(rx_ring) / 2;
1369 #else
1370         unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
1371                                 SKB_DATA_ALIGN(IAVF_SKB_PAD + size);
1372 #endif
1373         struct sk_buff *skb;
1374 
1375         if (!rx_buffer)
1376                 return NULL;
1377         /* prefetch first cache line of first page */
1378         va = page_address(rx_buffer->page) + rx_buffer->page_offset;
1379         prefetch(va);
1380 #if L1_CACHE_BYTES < 128
1381         prefetch(va + L1_CACHE_BYTES);
1382 #endif
1383         /* build an skb around the page buffer */
1384         skb = build_skb(va - IAVF_SKB_PAD, truesize);
1385         if (unlikely(!skb))
1386                 return NULL;
1387 
1388         /* update pointers within the skb to store the data */
1389         skb_reserve(skb, IAVF_SKB_PAD);
1390         __skb_put(skb, size);
1391 
1392         /* buffer is used by skb, update page_offset */
1393 #if (PAGE_SIZE < 8192)
1394         rx_buffer->page_offset ^= truesize;
1395 #else
1396         rx_buffer->page_offset += truesize;
1397 #endif
1398 
1399         return skb;
1400 }
1401 
1402 /**
1403  * iavf_put_rx_buffer - Clean up used buffer and either recycle or free
1404  * @rx_ring: rx descriptor ring to transact packets on
1405  * @rx_buffer: rx buffer to pull data from
1406  *
1407  * This function will clean up the contents of the rx_buffer.  It will
1408  * either recycle the buffer or unmap it and free the associated resources.
1409  */
1410 static void iavf_put_rx_buffer(struct iavf_ring *rx_ring,
1411                                struct iavf_rx_buffer *rx_buffer)
1412 {
1413         if (!rx_buffer)
1414                 return;
1415 
1416         if (iavf_can_reuse_rx_page(rx_buffer)) {
1417                 /* hand second half of page back to the ring */
1418                 iavf_reuse_rx_page(rx_ring, rx_buffer);
1419                 rx_ring->rx_stats.page_reuse_count++;
1420         } else {
1421                 /* we are not reusing the buffer so unmap it */
1422                 dma_unmap_page_attrs(rx_ring->dev, rx_buffer->dma,
1423                                      iavf_rx_pg_size(rx_ring),
1424                                      DMA_FROM_DEVICE, IAVF_RX_DMA_ATTR);
1425                 __page_frag_cache_drain(rx_buffer->page,
1426                                         rx_buffer->pagecnt_bias);
1427         }
1428 
1429         /* clear contents of buffer_info */
1430         rx_buffer->page = NULL;
1431 }
1432 
1433 /**
1434  * iavf_is_non_eop - process handling of non-EOP buffers
1435  * @rx_ring: Rx ring being processed
1436  * @rx_desc: Rx descriptor for current buffer
1437  * @skb: Current socket buffer containing buffer in progress
1438  *
1439  * This function updates next to clean.  If the buffer is an EOP buffer
1440  * this function exits returning false, otherwise it will place the
1441  * sk_buff in the next buffer to be chained and return true indicating
1442  * that this is in fact a non-EOP buffer.
1443  **/
1444 static bool iavf_is_non_eop(struct iavf_ring *rx_ring,
1445                             union iavf_rx_desc *rx_desc,
1446                             struct sk_buff *skb)
1447 {
1448         u32 ntc = rx_ring->next_to_clean + 1;
1449 
1450         /* fetch, update, and store next to clean */
1451         ntc = (ntc < rx_ring->count) ? ntc : 0;
1452         rx_ring->next_to_clean = ntc;
1453 
1454         prefetch(IAVF_RX_DESC(rx_ring, ntc));
1455 
1456         /* if we are the last buffer then there is nothing else to do */
1457 #define IAVF_RXD_EOF BIT(IAVF_RX_DESC_STATUS_EOF_SHIFT)
1458         if (likely(iavf_test_staterr(rx_desc, IAVF_RXD_EOF)))
1459                 return false;
1460 
1461         rx_ring->rx_stats.non_eop_descs++;
1462 
1463         return true;
1464 }
1465 
1466 /**
1467  * iavf_clean_rx_irq - Clean completed descriptors from Rx ring - bounce buf
1468  * @rx_ring: rx descriptor ring to transact packets on
1469  * @budget: Total limit on number of packets to process
1470  *
1471  * This function provides a "bounce buffer" approach to Rx interrupt
1472  * processing.  The advantage to this is that on systems that have
1473  * expensive overhead for IOMMU access this provides a means of avoiding
1474  * it by maintaining the mapping of the page to the system.
1475  *
1476  * Returns amount of work completed
1477  **/
1478 static int iavf_clean_rx_irq(struct iavf_ring *rx_ring, int budget)
1479 {
1480         unsigned int total_rx_bytes = 0, total_rx_packets = 0;
1481         struct sk_buff *skb = rx_ring->skb;
1482         u16 cleaned_count = IAVF_DESC_UNUSED(rx_ring);
1483         bool failure = false;
1484 
1485         while (likely(total_rx_packets < (unsigned int)budget)) {
1486                 struct iavf_rx_buffer *rx_buffer;
1487                 union iavf_rx_desc *rx_desc;
1488                 unsigned int size;
1489                 u16 vlan_tag;
1490                 u8 rx_ptype;
1491                 u64 qword;
1492 
1493                 /* return some buffers to hardware, one at a time is too slow */
1494                 if (cleaned_count >= IAVF_RX_BUFFER_WRITE) {
1495                         failure = failure ||
1496                                   iavf_alloc_rx_buffers(rx_ring, cleaned_count);
1497                         cleaned_count = 0;
1498                 }
1499 
1500                 rx_desc = IAVF_RX_DESC(rx_ring, rx_ring->next_to_clean);
1501 
1502                 /* status_error_len will always be zero for unused descriptors
1503                  * because it's cleared in cleanup, and overlaps with hdr_addr
1504                  * which is always zero because packet split isn't used, if the
1505                  * hardware wrote DD then the length will be non-zero
1506                  */
1507                 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
1508 
1509                 /* This memory barrier is needed to keep us from reading
1510                  * any other fields out of the rx_desc until we have
1511                  * verified the descriptor has been written back.
1512                  */
1513                 dma_rmb();
1514 #define IAVF_RXD_DD BIT(IAVF_RX_DESC_STATUS_DD_SHIFT)
1515                 if (!iavf_test_staterr(rx_desc, IAVF_RXD_DD))
1516                         break;
1517 
1518                 size = (qword & IAVF_RXD_QW1_LENGTH_PBUF_MASK) >>
1519                        IAVF_RXD_QW1_LENGTH_PBUF_SHIFT;
1520 
1521                 iavf_trace(clean_rx_irq, rx_ring, rx_desc, skb);
1522                 rx_buffer = iavf_get_rx_buffer(rx_ring, size);
1523 
1524                 /* retrieve a buffer from the ring */
1525                 if (skb)
1526                         iavf_add_rx_frag(rx_ring, rx_buffer, skb, size);
1527                 else if (ring_uses_build_skb(rx_ring))
1528                         skb = iavf_build_skb(rx_ring, rx_buffer, size);
1529                 else
1530                         skb = iavf_construct_skb(rx_ring, rx_buffer, size);
1531 
1532                 /* exit if we failed to retrieve a buffer */
1533                 if (!skb) {
1534                         rx_ring->rx_stats.alloc_buff_failed++;
1535                         if (rx_buffer)
1536                                 rx_buffer->pagecnt_bias++;
1537                         break;
1538                 }
1539 
1540                 iavf_put_rx_buffer(rx_ring, rx_buffer);
1541                 cleaned_count++;
1542 
1543                 if (iavf_is_non_eop(rx_ring, rx_desc, skb))
1544                         continue;
1545 
1546                 /* ERR_MASK will only have valid bits if EOP set, and
1547                  * what we are doing here is actually checking
1548                  * IAVF_RX_DESC_ERROR_RXE_SHIFT, since it is the zeroth bit in
1549                  * the error field
1550                  */
1551                 if (unlikely(iavf_test_staterr(rx_desc, BIT(IAVF_RXD_QW1_ERROR_SHIFT)))) {
1552                         dev_kfree_skb_any(skb);
1553                         skb = NULL;
1554                         continue;
1555                 }
1556 
1557                 if (iavf_cleanup_headers(rx_ring, skb)) {
1558                         skb = NULL;
1559                         continue;
1560                 }
1561 
1562                 /* probably a little skewed due to removing CRC */
1563                 total_rx_bytes += skb->len;
1564 
1565                 qword = le64_to_cpu(rx_desc->wb.qword1.status_error_len);
1566                 rx_ptype = (qword & IAVF_RXD_QW1_PTYPE_MASK) >>
1567                            IAVF_RXD_QW1_PTYPE_SHIFT;
1568 
1569                 /* populate checksum, VLAN, and protocol */
1570                 iavf_process_skb_fields(rx_ring, rx_desc, skb, rx_ptype);
1571 
1572 
1573                 vlan_tag = (qword & BIT(IAVF_RX_DESC_STATUS_L2TAG1P_SHIFT)) ?
1574                            le16_to_cpu(rx_desc->wb.qword0.lo_dword.l2tag1) : 0;
1575 
1576                 iavf_trace(clean_rx_irq_rx, rx_ring, rx_desc, skb);
1577                 iavf_receive_skb(rx_ring, skb, vlan_tag);
1578                 skb = NULL;
1579 
1580                 /* update budget accounting */
1581                 total_rx_packets++;
1582         }
1583 
1584         rx_ring->skb = skb;
1585 
1586         u64_stats_update_begin(&rx_ring->syncp);
1587         rx_ring->stats.packets += total_rx_packets;
1588         rx_ring->stats.bytes += total_rx_bytes;
1589         u64_stats_update_end(&rx_ring->syncp);
1590         rx_ring->q_vector->rx.total_packets += total_rx_packets;
1591         rx_ring->q_vector->rx.total_bytes += total_rx_bytes;
1592 
1593         /* guarantee a trip back through this routine if there was a failure */
1594         return failure ? budget : (int)total_rx_packets;
1595 }
1596 
1597 static inline u32 iavf_buildreg_itr(const int type, u16 itr)
1598 {
1599         u32 val;
1600 
1601         /* We don't bother with setting the CLEARPBA bit as the data sheet
1602          * points out doing so is "meaningless since it was already
1603          * auto-cleared". The auto-clearing happens when the interrupt is
1604          * asserted.
1605          *
1606          * Hardware errata 28 for also indicates that writing to a
1607          * xxINT_DYN_CTLx CSR with INTENA_MSK (bit 31) set to 0 will clear
1608          * an event in the PBA anyway so we need to rely on the automask
1609          * to hold pending events for us until the interrupt is re-enabled
1610          *
1611          * The itr value is reported in microseconds, and the register
1612          * value is recorded in 2 microsecond units. For this reason we
1613          * only need to shift by the interval shift - 1 instead of the
1614          * full value.
1615          */
1616         itr &= IAVF_ITR_MASK;
1617 
1618         val = IAVF_VFINT_DYN_CTLN1_INTENA_MASK |
1619               (type << IAVF_VFINT_DYN_CTLN1_ITR_INDX_SHIFT) |
1620               (itr << (IAVF_VFINT_DYN_CTLN1_INTERVAL_SHIFT - 1));
1621 
1622         return val;
1623 }
1624 
1625 /* a small macro to shorten up some long lines */
1626 #define INTREG IAVF_VFINT_DYN_CTLN1
1627 
1628 /* The act of updating the ITR will cause it to immediately trigger. In order
1629  * to prevent this from throwing off adaptive update statistics we defer the
1630  * update so that it can only happen so often. So after either Tx or Rx are
1631  * updated we make the adaptive scheme wait until either the ITR completely
1632  * expires via the next_update expiration or we have been through at least
1633  * 3 interrupts.
1634  */
1635 #define ITR_COUNTDOWN_START 3
1636 
1637 /**
1638  * iavf_update_enable_itr - Update itr and re-enable MSIX interrupt
1639  * @vsi: the VSI we care about
1640  * @q_vector: q_vector for which itr is being updated and interrupt enabled
1641  *
1642  **/
1643 static inline void iavf_update_enable_itr(struct iavf_vsi *vsi,
1644                                           struct iavf_q_vector *q_vector)
1645 {
1646         struct iavf_hw *hw = &vsi->back->hw;
1647         u32 intval;
1648 
1649         /* These will do nothing if dynamic updates are not enabled */
1650         iavf_update_itr(q_vector, &q_vector->tx);
1651         iavf_update_itr(q_vector, &q_vector->rx);
1652 
1653         /* This block of logic allows us to get away with only updating
1654          * one ITR value with each interrupt. The idea is to perform a
1655          * pseudo-lazy update with the following criteria.
1656          *
1657          * 1. Rx is given higher priority than Tx if both are in same state
1658          * 2. If we must reduce an ITR that is given highest priority.
1659          * 3. We then give priority to increasing ITR based on amount.
1660          */
1661         if (q_vector->rx.target_itr < q_vector->rx.current_itr) {
1662                 /* Rx ITR needs to be reduced, this is highest priority */
1663                 intval = iavf_buildreg_itr(IAVF_RX_ITR,
1664                                            q_vector->rx.target_itr);
1665                 q_vector->rx.current_itr = q_vector->rx.target_itr;
1666                 q_vector->itr_countdown = ITR_COUNTDOWN_START;
1667         } else if ((q_vector->tx.target_itr < q_vector->tx.current_itr) ||
1668                    ((q_vector->rx.target_itr - q_vector->rx.current_itr) <
1669                     (q_vector->tx.target_itr - q_vector->tx.current_itr))) {
1670                 /* Tx ITR needs to be reduced, this is second priority
1671                  * Tx ITR needs to be increased more than Rx, fourth priority
1672                  */
1673                 intval = iavf_buildreg_itr(IAVF_TX_ITR,
1674                                            q_vector->tx.target_itr);
1675                 q_vector->tx.current_itr = q_vector->tx.target_itr;
1676                 q_vector->itr_countdown = ITR_COUNTDOWN_START;
1677         } else if (q_vector->rx.current_itr != q_vector->rx.target_itr) {
1678                 /* Rx ITR needs to be increased, third priority */
1679                 intval = iavf_buildreg_itr(IAVF_RX_ITR,
1680                                            q_vector->rx.target_itr);
1681                 q_vector->rx.current_itr = q_vector->rx.target_itr;
1682                 q_vector->itr_countdown = ITR_COUNTDOWN_START;
1683         } else {
1684                 /* No ITR update, lowest priority */
1685                 intval = iavf_buildreg_itr(IAVF_ITR_NONE, 0);
1686                 if (q_vector->itr_countdown)
1687                         q_vector->itr_countdown--;
1688         }
1689 
1690         if (!test_bit(__IAVF_VSI_DOWN, vsi->state))
1691                 wr32(hw, INTREG(q_vector->reg_idx), intval);
1692 }
1693 
1694 /**
1695  * iavf_napi_poll - NAPI polling Rx/Tx cleanup routine
1696  * @napi: napi struct with our devices info in it
1697  * @budget: amount of work driver is allowed to do this pass, in packets
1698  *
1699  * This function will clean all queues associated with a q_vector.
1700  *
1701  * Returns the amount of work done
1702  **/
1703 int iavf_napi_poll(struct napi_struct *napi, int budget)
1704 {
1705         struct iavf_q_vector *q_vector =
1706                                container_of(napi, struct iavf_q_vector, napi);
1707         struct iavf_vsi *vsi = q_vector->vsi;
1708         struct iavf_ring *ring;
1709         bool clean_complete = true;
1710         bool arm_wb = false;
1711         int budget_per_ring;
1712         int work_done = 0;
1713 
1714         if (test_bit(__IAVF_VSI_DOWN, vsi->state)) {
1715                 napi_complete(napi);
1716                 return 0;
1717         }
1718 
1719         /* Since the actual Tx work is minimal, we can give the Tx a larger
1720          * budget and be more aggressive about cleaning up the Tx descriptors.
1721          */
1722         iavf_for_each_ring(ring, q_vector->tx) {
1723                 if (!iavf_clean_tx_irq(vsi, ring, budget)) {
1724                         clean_complete = false;
1725                         continue;
1726                 }
1727                 arm_wb |= ring->arm_wb;
1728                 ring->arm_wb = false;
1729         }
1730 
1731         /* Handle case where we are called by netpoll with a budget of 0 */
1732         if (budget <= 0)
1733                 goto tx_only;
1734 
1735         /* We attempt to distribute budget to each Rx queue fairly, but don't
1736          * allow the budget to go below 1 because that would exit polling early.
1737          */
1738         budget_per_ring = max(budget/q_vector->num_ringpairs, 1);
1739 
1740         iavf_for_each_ring(ring, q_vector->rx) {
1741                 int cleaned = iavf_clean_rx_irq(ring, budget_per_ring);
1742 
1743                 work_done += cleaned;
1744                 /* if we clean as many as budgeted, we must not be done */
1745                 if (cleaned >= budget_per_ring)
1746                         clean_complete = false;
1747         }
1748 
1749         /* If work not completed, return budget and polling will return */
1750         if (!clean_complete) {
1751                 int cpu_id = smp_processor_id();
1752 
1753                 /* It is possible that the interrupt affinity has changed but,
1754                  * if the cpu is pegged at 100%, polling will never exit while
1755                  * traffic continues and the interrupt will be stuck on this
1756                  * cpu.  We check to make sure affinity is correct before we
1757                  * continue to poll, otherwise we must stop polling so the
1758                  * interrupt can move to the correct cpu.
1759                  */
1760                 if (!cpumask_test_cpu(cpu_id, &q_vector->affinity_mask)) {
1761                         /* Tell napi that we are done polling */
1762                         napi_complete_done(napi, work_done);
1763 
1764                         /* Force an interrupt */
1765                         iavf_force_wb(vsi, q_vector);
1766 
1767                         /* Return budget-1 so that polling stops */
1768                         return budget - 1;
1769                 }
1770 tx_only:
1771                 if (arm_wb) {
1772                         q_vector->tx.ring[0].tx_stats.tx_force_wb++;
1773                         iavf_enable_wb_on_itr(vsi, q_vector);
1774                 }
1775                 return budget;
1776         }
1777 
1778         if (vsi->back->flags & IAVF_TXR_FLAGS_WB_ON_ITR)
1779                 q_vector->arm_wb_state = false;
1780 
1781         /* Exit the polling mode, but don't re-enable interrupts if stack might
1782          * poll us due to busy-polling
1783          */
1784         if (likely(napi_complete_done(napi, work_done)))
1785                 iavf_update_enable_itr(vsi, q_vector);
1786 
1787         return min(work_done, budget - 1);
1788 }
1789 
1790 /**
1791  * iavf_tx_prepare_vlan_flags - prepare generic TX VLAN tagging flags for HW
1792  * @skb:     send buffer
1793  * @tx_ring: ring to send buffer on
1794  * @flags:   the tx flags to be set
1795  *
1796  * Checks the skb and set up correspondingly several generic transmit flags
1797  * related to VLAN tagging for the HW, such as VLAN, DCB, etc.
1798  *
1799  * Returns error code indicate the frame should be dropped upon error and the
1800  * otherwise  returns 0 to indicate the flags has been set properly.
1801  **/
1802 static inline int iavf_tx_prepare_vlan_flags(struct sk_buff *skb,
1803                                              struct iavf_ring *tx_ring,
1804                                              u32 *flags)
1805 {
1806         __be16 protocol = skb->protocol;
1807         u32  tx_flags = 0;
1808 
1809         if (protocol == htons(ETH_P_8021Q) &&
1810             !(tx_ring->netdev->features & NETIF_F_HW_VLAN_CTAG_TX)) {
1811                 /* When HW VLAN acceleration is turned off by the user the
1812                  * stack sets the protocol to 8021q so that the driver
1813                  * can take any steps required to support the SW only
1814                  * VLAN handling.  In our case the driver doesn't need
1815                  * to take any further steps so just set the protocol
1816                  * to the encapsulated ethertype.
1817                  */
1818                 skb->protocol = vlan_get_protocol(skb);
1819                 goto out;
1820         }
1821 
1822         /* if we have a HW VLAN tag being added, default to the HW one */
1823         if (skb_vlan_tag_present(skb)) {
1824                 tx_flags |= skb_vlan_tag_get(skb) << IAVF_TX_FLAGS_VLAN_SHIFT;
1825                 tx_flags |= IAVF_TX_FLAGS_HW_VLAN;
1826         /* else if it is a SW VLAN, check the next protocol and store the tag */
1827         } else if (protocol == htons(ETH_P_8021Q)) {
1828                 struct vlan_hdr *vhdr, _vhdr;
1829 
1830                 vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(_vhdr), &_vhdr);
1831                 if (!vhdr)
1832                         return -EINVAL;
1833 
1834                 protocol = vhdr->h_vlan_encapsulated_proto;
1835                 tx_flags |= ntohs(vhdr->h_vlan_TCI) << IAVF_TX_FLAGS_VLAN_SHIFT;
1836                 tx_flags |= IAVF_TX_FLAGS_SW_VLAN;
1837         }
1838 
1839 out:
1840         *flags = tx_flags;
1841         return 0;
1842 }
1843 
1844 /**
1845  * iavf_tso - set up the tso context descriptor
1846  * @first:    pointer to first Tx buffer for xmit
1847  * @hdr_len:  ptr to the size of the packet header
1848  * @cd_type_cmd_tso_mss: Quad Word 1
1849  *
1850  * Returns 0 if no TSO can happen, 1 if tso is going, or error
1851  **/
1852 static int iavf_tso(struct iavf_tx_buffer *first, u8 *hdr_len,
1853                     u64 *cd_type_cmd_tso_mss)
1854 {
1855         struct sk_buff *skb = first->skb;
1856         u64 cd_cmd, cd_tso_len, cd_mss;
1857         union {
1858                 struct iphdr *v4;
1859                 struct ipv6hdr *v6;
1860                 unsigned char *hdr;
1861         } ip;
1862         union {
1863                 struct tcphdr *tcp;
1864                 struct udphdr *udp;
1865                 unsigned char *hdr;
1866         } l4;
1867         u32 paylen, l4_offset;
1868         u16 gso_segs, gso_size;
1869         int err;
1870 
1871         if (skb->ip_summed != CHECKSUM_PARTIAL)
1872                 return 0;
1873 
1874         if (!skb_is_gso(skb))
1875                 return 0;
1876 
1877         err = skb_cow_head(skb, 0);
1878         if (err < 0)
1879                 return err;
1880 
1881         ip.hdr = skb_network_header(skb);
1882         l4.hdr = skb_transport_header(skb);
1883 
1884         /* initialize outer IP header fields */
1885         if (ip.v4->version == 4) {
1886                 ip.v4->tot_len = 0;
1887                 ip.v4->check = 0;
1888         } else {
1889                 ip.v6->payload_len = 0;
1890         }
1891 
1892         if (skb_shinfo(skb)->gso_type & (SKB_GSO_GRE |
1893                                          SKB_GSO_GRE_CSUM |
1894                                          SKB_GSO_IPXIP4 |
1895                                          SKB_GSO_IPXIP6 |
1896                                          SKB_GSO_UDP_TUNNEL |
1897                                          SKB_GSO_UDP_TUNNEL_CSUM)) {
1898                 if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) &&
1899                     (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM)) {
1900                         l4.udp->len = 0;
1901 
1902                         /* determine offset of outer transport header */
1903                         l4_offset = l4.hdr - skb->data;
1904 
1905                         /* remove payload length from outer checksum */
1906                         paylen = skb->len - l4_offset;
1907                         csum_replace_by_diff(&l4.udp->check,
1908                                              (__force __wsum)htonl(paylen));
1909                 }
1910 
1911                 /* reset pointers to inner headers */
1912                 ip.hdr = skb_inner_network_header(skb);
1913                 l4.hdr = skb_inner_transport_header(skb);
1914 
1915                 /* initialize inner IP header fields */
1916                 if (ip.v4->version == 4) {
1917                         ip.v4->tot_len = 0;
1918                         ip.v4->check = 0;
1919                 } else {
1920                         ip.v6->payload_len = 0;
1921                 }
1922         }
1923 
1924         /* determine offset of inner transport header */
1925         l4_offset = l4.hdr - skb->data;
1926 
1927         /* remove payload length from inner checksum */
1928         paylen = skb->len - l4_offset;
1929         csum_replace_by_diff(&l4.tcp->check, (__force __wsum)htonl(paylen));
1930 
1931         /* compute length of segmentation header */
1932         *hdr_len = (l4.tcp->doff * 4) + l4_offset;
1933 
1934         /* pull values out of skb_shinfo */
1935         gso_size = skb_shinfo(skb)->gso_size;
1936         gso_segs = skb_shinfo(skb)->gso_segs;
1937 
1938         /* update GSO size and bytecount with header size */
1939         first->gso_segs = gso_segs;
1940         first->bytecount += (first->gso_segs - 1) * *hdr_len;
1941 
1942         /* find the field values */
1943         cd_cmd = IAVF_TX_CTX_DESC_TSO;
1944         cd_tso_len = skb->len - *hdr_len;
1945         cd_mss = gso_size;
1946         *cd_type_cmd_tso_mss |= (cd_cmd << IAVF_TXD_CTX_QW1_CMD_SHIFT) |
1947                                 (cd_tso_len << IAVF_TXD_CTX_QW1_TSO_LEN_SHIFT) |
1948                                 (cd_mss << IAVF_TXD_CTX_QW1_MSS_SHIFT);
1949         return 1;
1950 }
1951 
1952 /**
1953  * iavf_tx_enable_csum - Enable Tx checksum offloads
1954  * @skb: send buffer
1955  * @tx_flags: pointer to Tx flags currently set
1956  * @td_cmd: Tx descriptor command bits to set
1957  * @td_offset: Tx descriptor header offsets to set
1958  * @tx_ring: Tx descriptor ring
1959  * @cd_tunneling: ptr to context desc bits
1960  **/
1961 static int iavf_tx_enable_csum(struct sk_buff *skb, u32 *tx_flags,
1962                                u32 *td_cmd, u32 *td_offset,
1963                                struct iavf_ring *tx_ring,
1964                                u32 *cd_tunneling)
1965 {
1966         union {
1967                 struct iphdr *v4;
1968                 struct ipv6hdr *v6;
1969                 unsigned char *hdr;
1970         } ip;
1971         union {
1972                 struct tcphdr *tcp;
1973                 struct udphdr *udp;
1974                 unsigned char *hdr;
1975         } l4;
1976         unsigned char *exthdr;
1977         u32 offset, cmd = 0;
1978         __be16 frag_off;
1979         u8 l4_proto = 0;
1980 
1981         if (skb->ip_summed != CHECKSUM_PARTIAL)
1982                 return 0;
1983 
1984         ip.hdr = skb_network_header(skb);
1985         l4.hdr = skb_transport_header(skb);
1986 
1987         /* compute outer L2 header size */
1988         offset = ((ip.hdr - skb->data) / 2) << IAVF_TX_DESC_LENGTH_MACLEN_SHIFT;
1989 
1990         if (skb->encapsulation) {
1991                 u32 tunnel = 0;
1992                 /* define outer network header type */
1993                 if (*tx_flags & IAVF_TX_FLAGS_IPV4) {
1994                         tunnel |= (*tx_flags & IAVF_TX_FLAGS_TSO) ?
1995                                   IAVF_TX_CTX_EXT_IP_IPV4 :
1996                                   IAVF_TX_CTX_EXT_IP_IPV4_NO_CSUM;
1997 
1998                         l4_proto = ip.v4->protocol;
1999                 } else if (*tx_flags & IAVF_TX_FLAGS_IPV6) {
2000                         tunnel |= IAVF_TX_CTX_EXT_IP_IPV6;
2001 
2002                         exthdr = ip.hdr + sizeof(*ip.v6);
2003                         l4_proto = ip.v6->nexthdr;
2004                         if (l4.hdr != exthdr)
2005                                 ipv6_skip_exthdr(skb, exthdr - skb->data,
2006                                                  &l4_proto, &frag_off);
2007                 }
2008 
2009                 /* define outer transport */
2010                 switch (l4_proto) {
2011                 case IPPROTO_UDP:
2012                         tunnel |= IAVF_TXD_CTX_UDP_TUNNELING;
2013                         *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL;
2014                         break;
2015                 case IPPROTO_GRE:
2016                         tunnel |= IAVF_TXD_CTX_GRE_TUNNELING;
2017                         *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL;
2018                         break;
2019                 case IPPROTO_IPIP:
2020                 case IPPROTO_IPV6:
2021                         *tx_flags |= IAVF_TX_FLAGS_VXLAN_TUNNEL;
2022                         l4.hdr = skb_inner_network_header(skb);
2023                         break;
2024                 default:
2025                         if (*tx_flags & IAVF_TX_FLAGS_TSO)
2026                                 return -1;
2027 
2028                         skb_checksum_help(skb);
2029                         return 0;
2030                 }
2031 
2032                 /* compute outer L3 header size */
2033                 tunnel |= ((l4.hdr - ip.hdr) / 4) <<
2034                           IAVF_TXD_CTX_QW0_EXT_IPLEN_SHIFT;
2035 
2036                 /* switch IP header pointer from outer to inner header */
2037                 ip.hdr = skb_inner_network_header(skb);
2038 
2039                 /* compute tunnel header size */
2040                 tunnel |= ((ip.hdr - l4.hdr) / 2) <<
2041                           IAVF_TXD_CTX_QW0_NATLEN_SHIFT;
2042 
2043                 /* indicate if we need to offload outer UDP header */
2044                 if ((*tx_flags & IAVF_TX_FLAGS_TSO) &&
2045                     !(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL) &&
2046                     (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM))
2047                         tunnel |= IAVF_TXD_CTX_QW0_L4T_CS_MASK;
2048 
2049                 /* record tunnel offload values */
2050                 *cd_tunneling |= tunnel;
2051 
2052                 /* switch L4 header pointer from outer to inner */
2053                 l4.hdr = skb_inner_transport_header(skb);
2054                 l4_proto = 0;
2055 
2056                 /* reset type as we transition from outer to inner headers */
2057                 *tx_flags &= ~(IAVF_TX_FLAGS_IPV4 | IAVF_TX_FLAGS_IPV6);
2058                 if (ip.v4->version == 4)
2059                         *tx_flags |= IAVF_TX_FLAGS_IPV4;
2060                 if (ip.v6->version == 6)
2061                         *tx_flags |= IAVF_TX_FLAGS_IPV6;
2062         }
2063 
2064         /* Enable IP checksum offloads */
2065         if (*tx_flags & IAVF_TX_FLAGS_IPV4) {
2066                 l4_proto = ip.v4->protocol;
2067                 /* the stack computes the IP header already, the only time we
2068                  * need the hardware to recompute it is in the case of TSO.
2069                  */
2070                 cmd |= (*tx_flags & IAVF_TX_FLAGS_TSO) ?
2071                        IAVF_TX_DESC_CMD_IIPT_IPV4_CSUM :
2072                        IAVF_TX_DESC_CMD_IIPT_IPV4;
2073         } else if (*tx_flags & IAVF_TX_FLAGS_IPV6) {
2074                 cmd |= IAVF_TX_DESC_CMD_IIPT_IPV6;
2075 
2076                 exthdr = ip.hdr + sizeof(*ip.v6);
2077                 l4_proto = ip.v6->nexthdr;
2078                 if (l4.hdr != exthdr)
2079                         ipv6_skip_exthdr(skb, exthdr - skb->data,
2080                                          &l4_proto, &frag_off);
2081         }
2082 
2083         /* compute inner L3 header size */
2084         offset |= ((l4.hdr - ip.hdr) / 4) << IAVF_TX_DESC_LENGTH_IPLEN_SHIFT;
2085 
2086         /* Enable L4 checksum offloads */
2087         switch (l4_proto) {
2088         case IPPROTO_TCP:
2089                 /* enable checksum offloads */
2090                 cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_TCP;
2091                 offset |= l4.tcp->doff << IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
2092                 break;
2093         case IPPROTO_SCTP:
2094                 /* enable SCTP checksum offload */
2095                 cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_SCTP;
2096                 offset |= (sizeof(struct sctphdr) >> 2) <<
2097                           IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
2098                 break;
2099         case IPPROTO_UDP:
2100                 /* enable UDP checksum offload */
2101                 cmd |= IAVF_TX_DESC_CMD_L4T_EOFT_UDP;
2102                 offset |= (sizeof(struct udphdr) >> 2) <<
2103                           IAVF_TX_DESC_LENGTH_L4_FC_LEN_SHIFT;
2104                 break;
2105         default:
2106                 if (*tx_flags & IAVF_TX_FLAGS_TSO)
2107                         return -1;
2108                 skb_checksum_help(skb);
2109                 return 0;
2110         }
2111 
2112         *td_cmd |= cmd;
2113         *td_offset |= offset;
2114 
2115         return 1;
2116 }
2117 
2118 /**
2119  * iavf_create_tx_ctx Build the Tx context descriptor
2120  * @tx_ring:  ring to create the descriptor on
2121  * @cd_type_cmd_tso_mss: Quad Word 1
2122  * @cd_tunneling: Quad Word 0 - bits 0-31
2123  * @cd_l2tag2: Quad Word 0 - bits 32-63
2124  **/
2125 static void iavf_create_tx_ctx(struct iavf_ring *tx_ring,
2126                                const u64 cd_type_cmd_tso_mss,
2127                                const u32 cd_tunneling, const u32 cd_l2tag2)
2128 {
2129         struct iavf_tx_context_desc *context_desc;
2130         int i = tx_ring->next_to_use;
2131 
2132         if ((cd_type_cmd_tso_mss == IAVF_TX_DESC_DTYPE_CONTEXT) &&
2133             !cd_tunneling && !cd_l2tag2)
2134                 return;
2135 
2136         /* grab the next descriptor */
2137         context_desc = IAVF_TX_CTXTDESC(tx_ring, i);
2138 
2139         i++;
2140         tx_ring->next_to_use = (i < tx_ring->count) ? i : 0;
2141 
2142         /* cpu_to_le32 and assign to struct fields */
2143         context_desc->tunneling_params = cpu_to_le32(cd_tunneling);
2144         context_desc->l2tag2 = cpu_to_le16(cd_l2tag2);
2145         context_desc->rsvd = cpu_to_le16(0);
2146         context_desc->type_cmd_tso_mss = cpu_to_le64(cd_type_cmd_tso_mss);
2147 }
2148 
2149 /**
2150  * __iavf_chk_linearize - Check if there are more than 8 buffers per packet
2151  * @skb:      send buffer
2152  *
2153  * Note: Our HW can't DMA more than 8 buffers to build a packet on the wire
2154  * and so we need to figure out the cases where we need to linearize the skb.
2155  *
2156  * For TSO we need to count the TSO header and segment payload separately.
2157  * As such we need to check cases where we have 7 fragments or more as we
2158  * can potentially require 9 DMA transactions, 1 for the TSO header, 1 for
2159  * the segment payload in the first descriptor, and another 7 for the
2160  * fragments.
2161  **/
2162 bool __iavf_chk_linearize(struct sk_buff *skb)
2163 {
2164         const skb_frag_t *frag, *stale;
2165         int nr_frags, sum;
2166 
2167         /* no need to check if number of frags is less than 7 */
2168         nr_frags = skb_shinfo(skb)->nr_frags;
2169         if (nr_frags < (IAVF_MAX_BUFFER_TXD - 1))
2170                 return false;
2171 
2172         /* We need to walk through the list and validate that each group
2173          * of 6 fragments totals at least gso_size.
2174          */
2175         nr_frags -= IAVF_MAX_BUFFER_TXD - 2;
2176         frag = &skb_shinfo(skb)->frags[0];
2177 
2178         /* Initialize size to the negative value of gso_size minus 1.  We
2179          * use this as the worst case scenerio in which the frag ahead
2180          * of us only provides one byte which is why we are limited to 6
2181          * descriptors for a single transmit as the header and previous
2182          * fragment are already consuming 2 descriptors.
2183          */
2184         sum = 1 - skb_shinfo(skb)->gso_size;
2185 
2186         /* Add size of frags 0 through 4 to create our initial sum */
2187         sum += skb_frag_size(frag++);
2188         sum += skb_frag_size(frag++);
2189         sum += skb_frag_size(frag++);
2190         sum += skb_frag_size(frag++);
2191         sum += skb_frag_size(frag++);
2192 
2193         /* Walk through fragments adding latest fragment, testing it, and
2194          * then removing stale fragments from the sum.
2195          */
2196         for (stale = &skb_shinfo(skb)->frags[0];; stale++) {
2197                 int stale_size = skb_frag_size(stale);
2198 
2199                 sum += skb_frag_size(frag++);
2200 
2201                 /* The stale fragment may present us with a smaller
2202                  * descriptor than the actual fragment size. To account
2203                  * for that we need to remove all the data on the front and
2204                  * figure out what the remainder would be in the last
2205                  * descriptor associated with the fragment.
2206                  */
2207                 if (stale_size > IAVF_MAX_DATA_PER_TXD) {
2208                         int align_pad = -(skb_frag_off(stale)) &
2209                                         (IAVF_MAX_READ_REQ_SIZE - 1);
2210 
2211                         sum -= align_pad;
2212                         stale_size -= align_pad;
2213 
2214                         do {
2215                                 sum -= IAVF_MAX_DATA_PER_TXD_ALIGNED;
2216                                 stale_size -= IAVF_MAX_DATA_PER_TXD_ALIGNED;
2217                         } while (stale_size > IAVF_MAX_DATA_PER_TXD);
2218                 }
2219 
2220                 /* if sum is negative we failed to make sufficient progress */
2221                 if (sum < 0)
2222                         return true;
2223 
2224                 if (!nr_frags--)
2225                         break;
2226 
2227                 sum -= stale_size;
2228         }
2229 
2230         return false;
2231 }
2232 
2233 /**
2234  * __iavf_maybe_stop_tx - 2nd level check for tx stop conditions
2235  * @tx_ring: the ring to be checked
2236  * @size:    the size buffer we want to assure is available
2237  *
2238  * Returns -EBUSY if a stop is needed, else 0
2239  **/
2240 int __iavf_maybe_stop_tx(struct iavf_ring *tx_ring, int size)
2241 {
2242         netif_stop_subqueue(tx_ring->netdev, tx_ring->queue_index);
2243         /* Memory barrier before checking head and tail */
2244         smp_mb();
2245 
2246         /* Check again in a case another CPU has just made room available. */
2247         if (likely(IAVF_DESC_UNUSED(tx_ring) < size))
2248                 return -EBUSY;
2249 
2250         /* A reprieve! - use start_queue because it doesn't call schedule */
2251         netif_start_subqueue(tx_ring->netdev, tx_ring->queue_index);
2252         ++tx_ring->tx_stats.restart_queue;
2253         return 0;
2254 }
2255 
2256 /**
2257  * iavf_tx_map - Build the Tx descriptor
2258  * @tx_ring:  ring to send buffer on
2259  * @skb:      send buffer
2260  * @first:    first buffer info buffer to use
2261  * @tx_flags: collected send information
2262  * @hdr_len:  size of the packet header
2263  * @td_cmd:   the command field in the descriptor
2264  * @td_offset: offset for checksum or crc
2265  **/
2266 static inline void iavf_tx_map(struct iavf_ring *tx_ring, struct sk_buff *skb,
2267                                struct iavf_tx_buffer *first, u32 tx_flags,
2268                                const u8 hdr_len, u32 td_cmd, u32 td_offset)
2269 {
2270         unsigned int data_len = skb->data_len;
2271         unsigned int size = skb_headlen(skb);
2272         skb_frag_t *frag;
2273         struct iavf_tx_buffer *tx_bi;
2274         struct iavf_tx_desc *tx_desc;
2275         u16 i = tx_ring->next_to_use;
2276         u32 td_tag = 0;
2277         dma_addr_t dma;
2278 
2279         if (tx_flags & IAVF_TX_FLAGS_HW_VLAN) {
2280                 td_cmd |= IAVF_TX_DESC_CMD_IL2TAG1;
2281                 td_tag = (tx_flags & IAVF_TX_FLAGS_VLAN_MASK) >>
2282                          IAVF_TX_FLAGS_VLAN_SHIFT;
2283         }
2284 
2285         first->tx_flags = tx_flags;
2286 
2287         dma = dma_map_single(tx_ring->dev, skb->data, size, DMA_TO_DEVICE);
2288 
2289         tx_desc = IAVF_TX_DESC(tx_ring, i);
2290         tx_bi = first;
2291 
2292         for (frag = &skb_shinfo(skb)->frags[0];; frag++) {
2293                 unsigned int max_data = IAVF_MAX_DATA_PER_TXD_ALIGNED;
2294 
2295                 if (dma_mapping_error(tx_ring->dev, dma))
2296                         goto dma_error;
2297 
2298                 /* record length, and DMA address */
2299                 dma_unmap_len_set(tx_bi, len, size);
2300                 dma_unmap_addr_set(tx_bi, dma, dma);
2301 
2302                 /* align size to end of page */
2303                 max_data += -dma & (IAVF_MAX_READ_REQ_SIZE - 1);
2304                 tx_desc->buffer_addr = cpu_to_le64(dma);
2305 
2306                 while (unlikely(size > IAVF_MAX_DATA_PER_TXD)) {
2307                         tx_desc->cmd_type_offset_bsz =
2308                                 build_ctob(td_cmd, td_offset,
2309                                            max_data, td_tag);
2310 
2311                         tx_desc++;
2312                         i++;
2313 
2314                         if (i == tx_ring->count) {
2315                                 tx_desc = IAVF_TX_DESC(tx_ring, 0);
2316                                 i = 0;
2317                         }
2318 
2319                         dma += max_data;
2320                         size -= max_data;
2321 
2322                         max_data = IAVF_MAX_DATA_PER_TXD_ALIGNED;
2323                         tx_desc->buffer_addr = cpu_to_le64(dma);
2324                 }
2325 
2326                 if (likely(!data_len))
2327                         break;
2328 
2329                 tx_desc->cmd_type_offset_bsz = build_ctob(td_cmd, td_offset,
2330                                                           size, td_tag);
2331 
2332                 tx_desc++;
2333                 i++;
2334 
2335                 if (i == tx_ring->count) {
2336                         tx_desc = IAVF_TX_DESC(tx_ring, 0);
2337                         i = 0;
2338                 }
2339 
2340                 size = skb_frag_size(frag);
2341                 data_len -= size;
2342 
2343                 dma = skb_frag_dma_map(tx_ring->dev, frag, 0, size,
2344                                        DMA_TO_DEVICE);
2345 
2346                 tx_bi = &tx_ring->tx_bi[i];
2347         }
2348 
2349         netdev_tx_sent_queue(txring_txq(tx_ring), first->bytecount);
2350 
2351         i++;
2352         if (i == tx_ring->count)
2353                 i = 0;
2354 
2355         tx_ring->next_to_use = i;
2356 
2357         iavf_maybe_stop_tx(tx_ring, DESC_NEEDED);
2358 
2359         /* write last descriptor with RS and EOP bits */
2360         td_cmd |= IAVF_TXD_CMD;
2361         tx_desc->cmd_type_offset_bsz =
2362                         build_ctob(td_cmd, td_offset, size, td_tag);
2363 
2364         skb_tx_timestamp(skb);
2365 
2366         /* Force memory writes to complete before letting h/w know there
2367          * are new descriptors to fetch.
2368          *
2369          * We also use this memory barrier to make certain all of the
2370          * status bits have been updated before next_to_watch is written.
2371          */
2372         wmb();
2373 
2374         /* set next_to_watch value indicating a packet is present */
2375         first->next_to_watch = tx_desc;
2376 
2377         /* notify HW of packet */
2378         if (netif_xmit_stopped(txring_txq(tx_ring)) || !netdev_xmit_more()) {
2379                 writel(i, tx_ring->tail);
2380         }
2381 
2382         return;
2383 
2384 dma_error:
2385         dev_info(tx_ring->dev, "TX DMA map failed\n");
2386 
2387         /* clear dma mappings for failed tx_bi map */
2388         for (;;) {
2389                 tx_bi = &tx_ring->tx_bi[i];
2390                 iavf_unmap_and_free_tx_resource(tx_ring, tx_bi);
2391                 if (tx_bi == first)
2392                         break;
2393                 if (i == 0)
2394                         i = tx_ring->count;
2395                 i--;
2396         }
2397 
2398         tx_ring->next_to_use = i;
2399 }
2400 
2401 /**
2402  * iavf_xmit_frame_ring - Sends buffer on Tx ring
2403  * @skb:     send buffer
2404  * @tx_ring: ring to send buffer on
2405  *
2406  * Returns NETDEV_TX_OK if sent, else an error code
2407  **/
2408 static netdev_tx_t iavf_xmit_frame_ring(struct sk_buff *skb,
2409                                         struct iavf_ring *tx_ring)
2410 {
2411         u64 cd_type_cmd_tso_mss = IAVF_TX_DESC_DTYPE_CONTEXT;
2412         u32 cd_tunneling = 0, cd_l2tag2 = 0;
2413         struct iavf_tx_buffer *first;
2414         u32 td_offset = 0;
2415         u32 tx_flags = 0;
2416         __be16 protocol;
2417         u32 td_cmd = 0;
2418         u8 hdr_len = 0;
2419         int tso, count;
2420 
2421         /* prefetch the data, we'll need it later */
2422         prefetch(skb->data);
2423 
2424         iavf_trace(xmit_frame_ring, skb, tx_ring);
2425 
2426         count = iavf_xmit_descriptor_count(skb);
2427         if (iavf_chk_linearize(skb, count)) {
2428                 if (__skb_linearize(skb)) {
2429                         dev_kfree_skb_any(skb);
2430                         return NETDEV_TX_OK;
2431                 }
2432                 count = iavf_txd_use_count(skb->len);
2433                 tx_ring->tx_stats.tx_linearize++;
2434         }
2435 
2436         /* need: 1 descriptor per page * PAGE_SIZE/IAVF_MAX_DATA_PER_TXD,
2437          *       + 1 desc for skb_head_len/IAVF_MAX_DATA_PER_TXD,
2438          *       + 4 desc gap to avoid the cache line where head is,
2439          *       + 1 desc for context descriptor,
2440          * otherwise try next time
2441          */
2442         if (iavf_maybe_stop_tx(tx_ring, count + 4 + 1)) {
2443                 tx_ring->tx_stats.tx_busy++;
2444                 return NETDEV_TX_BUSY;
2445         }
2446 
2447         /* record the location of the first descriptor for this packet */
2448         first = &tx_ring->tx_bi[tx_ring->next_to_use];
2449         first->skb = skb;
2450         first->bytecount = skb->len;
2451         first->gso_segs = 1;
2452 
2453         /* prepare the xmit flags */
2454         if (iavf_tx_prepare_vlan_flags(skb, tx_ring, &tx_flags))
2455                 goto out_drop;
2456 
2457         /* obtain protocol of skb */
2458         protocol = vlan_get_protocol(skb);
2459 
2460         /* setup IPv4/IPv6 offloads */
2461         if (protocol == htons(ETH_P_IP))
2462                 tx_flags |= IAVF_TX_FLAGS_IPV4;
2463         else if (protocol == htons(ETH_P_IPV6))
2464                 tx_flags |= IAVF_TX_FLAGS_IPV6;
2465 
2466         tso = iavf_tso(first, &hdr_len, &cd_type_cmd_tso_mss);
2467 
2468         if (tso < 0)
2469                 goto out_drop;
2470         else if (tso)
2471                 tx_flags |= IAVF_TX_FLAGS_TSO;
2472 
2473         /* Always offload the checksum, since it's in the data descriptor */
2474         tso = iavf_tx_enable_csum(skb, &tx_flags, &td_cmd, &td_offset,
2475                                   tx_ring, &cd_tunneling);
2476         if (tso < 0)
2477                 goto out_drop;
2478 
2479         /* always enable CRC insertion offload */
2480         td_cmd |= IAVF_TX_DESC_CMD_ICRC;
2481 
2482         iavf_create_tx_ctx(tx_ring, cd_type_cmd_tso_mss,
2483                            cd_tunneling, cd_l2tag2);
2484 
2485         iavf_tx_map(tx_ring, skb, first, tx_flags, hdr_len,
2486                     td_cmd, td_offset);
2487 
2488         return NETDEV_TX_OK;
2489 
2490 out_drop:
2491         iavf_trace(xmit_frame_ring_drop, first->skb, tx_ring);
2492         dev_kfree_skb_any(first->skb);
2493         first->skb = NULL;
2494         return NETDEV_TX_OK;
2495 }
2496 
2497 /**
2498  * iavf_xmit_frame - Selects the correct VSI and Tx queue to send buffer
2499  * @skb:    send buffer
2500  * @netdev: network interface device structure
2501  *
2502  * Returns NETDEV_TX_OK if sent, else an error code
2503  **/
2504 netdev_tx_t iavf_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
2505 {
2506         struct iavf_adapter *adapter = netdev_priv(netdev);
2507         struct iavf_ring *tx_ring = &adapter->tx_rings[skb->queue_mapping];
2508 
2509         /* hardware can't handle really short frames, hardware padding works
2510          * beyond this point
2511          */
2512         if (unlikely(skb->len < IAVF_MIN_TX_LEN)) {
2513                 if (skb_pad(skb, IAVF_MIN_TX_LEN - skb->len))
2514                         return NETDEV_TX_OK;
2515                 skb->len = IAVF_MIN_TX_LEN;
2516                 skb_set_tail_pointer(skb, IAVF_MIN_TX_LEN);
2517         }
2518 
2519         return iavf_xmit_frame_ring(skb, tx_ring);
2520 }

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