drivers/net/ethernet/sfc/rx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /****************************************************************************
   3  * Driver for Solarflare network controllers and boards
   4  * Copyright 2005-2006 Fen Systems Ltd.
   5  * Copyright 2005-2013 Solarflare Communications Inc.
   6  */
   7
   8 #include <linux/socket.h>
   9 #include <linux/in.h>
  10 #include <linux/slab.h>
  11 #include <linux/ip.h>
  12 #include <linux/ipv6.h>
  13 #include <linux/tcp.h>
  14 #include <linux/udp.h>
  15 #include <linux/prefetch.h>
  16 #include <linux/moduleparam.h>
  17 #include <linux/iommu.h>
  18 #include <net/ip.h>
  19 #include <net/checksum.h>
  20 #include "net_driver.h"
  21 #include "efx.h"
  22 #include "filter.h"
  23 #include "nic.h"
  24 #include "selftest.h"
  25 #include "workarounds.h"
  26
  27 /* Preferred number of descriptors to fill at once */
  28 #define EFX_RX_PREFERRED_BATCH 8U
  29
  30 /* Number of RX buffers to recycle pages for.  When creating the RX page recycle
  31  * ring, this number is divided by the number of buffers per page to calculate
  32  * the number of pages to store in the RX page recycle ring.
  33  */
  34 #define EFX_RECYCLE_RING_SIZE_IOMMU 4096
  35 #define EFX_RECYCLE_RING_SIZE_NOIOMMU (2 * EFX_RX_PREFERRED_BATCH)
  36
  37 /* Size of buffer allocated for skb header area. */
  38 #define EFX_SKB_HEADERS  128u
  39
  40 /* This is the percentage fill level below which new RX descriptors
  41  * will be added to the RX descriptor ring.
  42  */
  43 static unsigned int rx_refill_threshold;
  44
  45 /* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
  46 #define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
  47                                       EFX_RX_USR_BUF_SIZE)
  48
  49 /*
  50  * RX maximum head room required.
  51  *
  52  * This must be at least 1 to prevent overflow, plus one packet-worth
  53  * to allow pipelined receives.
  54  */
  55 #define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
  56
  57 static inline u8 *efx_rx_buf_va(struct efx_rx_buffer *buf)
  58 {
  59         return page_address(buf->page) + buf->page_offset;
  60 }
  61
  62 static inline u32 efx_rx_buf_hash(struct efx_nic *efx, const u8 *eh)
  63 {
  64 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  65         return __le32_to_cpup((const __le32 *)(eh + efx->rx_packet_hash_offset));
  66 #else
  67         const u8 *data = eh + efx->rx_packet_hash_offset;
  68         return (u32)data[0]       |
  69                (u32)data[1] << 8  |
  70                (u32)data[2] << 16 |
  71                (u32)data[3] << 24;
  72 #endif
  73 }
  74
  75 static inline struct efx_rx_buffer *
  76 efx_rx_buf_next(struct efx_rx_queue *rx_queue, struct efx_rx_buffer *rx_buf)
  77 {
  78         if (unlikely(rx_buf == efx_rx_buffer(rx_queue, rx_queue->ptr_mask)))
  79                 return efx_rx_buffer(rx_queue, 0);
  80         else
  81                 return rx_buf + 1;
  82 }
  83
  84 static inline void efx_sync_rx_buffer(struct efx_nic *efx,
  85                                       struct efx_rx_buffer *rx_buf,
  86                                       unsigned int len)
  87 {
  88         dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, len,
  89                                 DMA_FROM_DEVICE);
  90 }
  91
  92 void efx_rx_config_page_split(struct efx_nic *efx)
  93 {
  94         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align,
  95                                       EFX_RX_BUF_ALIGNMENT);
  96         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
  97                 ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
  98                  efx->rx_page_buf_step);
  99         efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
 100                 efx->rx_bufs_per_page;
 101         efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
 102                                                efx->rx_bufs_per_page);
 103 }
 104
 105 /* Check the RX page recycle ring for a page that can be reused. */
 106 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
 107 {
 108         struct efx_nic *efx = rx_queue->efx;
 109         struct page *page;
 110         struct efx_rx_page_state *state;
 111         unsigned index;
 112
 113         index = rx_queue->page_remove & rx_queue->page_ptr_mask;
 114         page = rx_queue->page_ring[index];
 115         if (page == NULL)
 116                 return NULL;
 117
 118         rx_queue->page_ring[index] = NULL;
 119         /* page_remove cannot exceed page_add. */
 120         if (rx_queue->page_remove != rx_queue->page_add)
 121                 ++rx_queue->page_remove;
 122
 123         /* If page_count is 1 then we hold the only reference to this page. */
 124         if (page_count(page) == 1) {
 125                 ++rx_queue->page_recycle_count;
 126                 return page;
 127         } else {
 128                 state = page_address(page);
 129                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 130                                PAGE_SIZE << efx->rx_buffer_order,
 131                                DMA_FROM_DEVICE);
 132                 put_page(page);
 133                 ++rx_queue->page_recycle_failed;
 134         }
 135
 136         return NULL;
 137 }
 138
 139 /**
 140  * efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
 141  *
 142  * @rx_queue:           Efx RX queue
 143  *
 144  * This allocates a batch of pages, maps them for DMA, and populates
 145  * struct efx_rx_buffers for each one. Return a negative error code or
 146  * 0 on success. If a single page can be used for multiple buffers,
 147  * then the page will either be inserted fully, or not at all.
 148  */
 149 static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
 150 {
 151         struct efx_nic *efx = rx_queue->efx;
 152         struct efx_rx_buffer *rx_buf;
 153         struct page *page;
 154         unsigned int page_offset;
 155         struct efx_rx_page_state *state;
 156         dma_addr_t dma_addr;
 157         unsigned index, count;
 158
 159         count = 0;
 160         do {
 161                 page = efx_reuse_page(rx_queue);
 162                 if (page == NULL) {
 163                         page = alloc_pages(__GFP_COMP |
 164                                            (atomic ? GFP_ATOMIC : GFP_KERNEL),
 165                                            efx->rx_buffer_order);
 166                         if (unlikely(page == NULL))
 167                                 return -ENOMEM;
 168                         dma_addr =
 169                                 dma_map_page(&efx->pci_dev->dev, page, 0,
 170                                              PAGE_SIZE << efx->rx_buffer_order,
 171                                              DMA_FROM_DEVICE);
 172                         if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
 173                                                        dma_addr))) {
 174                                 __free_pages(page, efx->rx_buffer_order);
 175                                 return -EIO;
 176                         }
 177                         state = page_address(page);
 178                         state->dma_addr = dma_addr;
 179                 } else {
 180                         state = page_address(page);
 181                         dma_addr = state->dma_addr;
 182                 }
 183
 184                 dma_addr += sizeof(struct efx_rx_page_state);
 185                 page_offset = sizeof(struct efx_rx_page_state);
 186
 187                 do {
 188                         index = rx_queue->added_count & rx_queue->ptr_mask;
 189                         rx_buf = efx_rx_buffer(rx_queue, index);
 190                         rx_buf->dma_addr = dma_addr + efx->rx_ip_align;
 191                         rx_buf->page = page;
 192                         rx_buf->page_offset = page_offset + efx->rx_ip_align;
 193                         rx_buf->len = efx->rx_dma_len;
 194                         rx_buf->flags = 0;
 195                         ++rx_queue->added_count;
 196                         get_page(page);
 197                         dma_addr += efx->rx_page_buf_step;
 198                         page_offset += efx->rx_page_buf_step;
 199                 } while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
 200
 201                 rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
 202         } while (++count < efx->rx_pages_per_batch);
 203
 204         return 0;
 205 }
 206
 207 /* Unmap a DMA-mapped page.  This function is only called for the final RX
 208  * buffer in a page.
 209  */
 210 static void efx_unmap_rx_buffer(struct efx_nic *efx,
 211                                 struct efx_rx_buffer *rx_buf)
 212 {
 213         struct page *page = rx_buf->page;
 214
 215         if (page) {
 216                 struct efx_rx_page_state *state = page_address(page);
 217                 dma_unmap_page(&efx->pci_dev->dev,
 218                                state->dma_addr,
 219                                PAGE_SIZE << efx->rx_buffer_order,
 220                                DMA_FROM_DEVICE);
 221         }
 222 }
 223
 224 static void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
 225                                 struct efx_rx_buffer *rx_buf,
 226                                 unsigned int num_bufs)
 227 {
 228         do {
 229                 if (rx_buf->page) {
 230                         put_page(rx_buf->page);
 231                         rx_buf->page = NULL;
 232                 }
 233                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 234         } while (--num_bufs);
 235 }
 236
 237 /* Attempt to recycle the page if there is an RX recycle ring; the page can
 238  * only be added if this is the final RX buffer, to prevent pages being used in
 239  * the descriptor ring and appearing in the recycle ring simultaneously.
 240  */
 241 static void efx_recycle_rx_page(struct efx_channel *channel,
 242                                 struct efx_rx_buffer *rx_buf)
 243 {
 244         struct page *page = rx_buf->page;
 245         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 246         struct efx_nic *efx = rx_queue->efx;
 247         unsigned index;
 248
 249         /* Only recycle the page after processing the final buffer. */
 250         if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
 251                 return;
 252
 253         index = rx_queue->page_add & rx_queue->page_ptr_mask;
 254         if (rx_queue->page_ring[index] == NULL) {
 255                 unsigned read_index = rx_queue->page_remove &
 256                         rx_queue->page_ptr_mask;
 257
 258                 /* The next slot in the recycle ring is available, but
 259                  * increment page_remove if the read pointer currently
 260                  * points here.
 261                  */
 262                 if (read_index == index)
 263                         ++rx_queue->page_remove;
 264                 rx_queue->page_ring[index] = page;
 265                 ++rx_queue->page_add;
 266                 return;
 267         }
 268         ++rx_queue->page_recycle_full;
 269         efx_unmap_rx_buffer(efx, rx_buf);
 270         put_page(rx_buf->page);
 271 }
 272
 273 static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
 274                                struct efx_rx_buffer *rx_buf)
 275 {
 276         /* Release the page reference we hold for the buffer. */
 277         if (rx_buf->page)
 278                 put_page(rx_buf->page);
 279
 280         /* If this is the last buffer in a page, unmap and free it. */
 281         if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
 282                 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
 283                 efx_free_rx_buffers(rx_queue, rx_buf, 1);
 284         }
 285         rx_buf->page = NULL;
 286 }
 287
 288 /* Recycle the pages that are used by buffers that have just been received. */
 289 static void efx_recycle_rx_pages(struct efx_channel *channel,
 290                                  struct efx_rx_buffer *rx_buf,
 291                                  unsigned int n_frags)
 292 {
 293         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 294
 295         do {
 296                 efx_recycle_rx_page(channel, rx_buf);
 297                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 298         } while (--n_frags);
 299 }
 300
 301 static void efx_discard_rx_packet(struct efx_channel *channel,
 302                                   struct efx_rx_buffer *rx_buf,
 303                                   unsigned int n_frags)
 304 {
 305         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 306
 307         efx_recycle_rx_pages(channel, rx_buf, n_frags);
 308
 309         efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 310 }
 311
 312 /**
 313  * efx_fast_push_rx_descriptors - push new RX descriptors quickly
 314  * @rx_queue:           RX descriptor queue
 315  *
 316  * This will aim to fill the RX descriptor queue up to
 317  * @rx_queue->@max_fill. If there is insufficient atomic
 318  * memory to do so, a slow fill will be scheduled.
 319  *
 320  * The caller must provide serialisation (none is used here). In practise,
 321  * this means this function must run from the NAPI handler, or be called
 322  * when NAPI is disabled.
 323  */
 324 void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
 325 {
 326         struct efx_nic *efx = rx_queue->efx;
 327         unsigned int fill_level, batch_size;
 328         int space, rc = 0;
 329
 330         if (!rx_queue->refill_enabled)
 331                 return;
 332
 333         /* Calculate current fill level, and exit if we don't need to fill */
 334         fill_level = (rx_queue->added_count - rx_queue->removed_count);
 335         EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
 336         if (fill_level >= rx_queue->fast_fill_trigger)
 337                 goto out;
 338
 339         /* Record minimum fill level */
 340         if (unlikely(fill_level < rx_queue->min_fill)) {
 341                 if (fill_level)
 342                         rx_queue->min_fill = fill_level;
 343         }
 344
 345         batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 346         space = rx_queue->max_fill - fill_level;
 347         EFX_WARN_ON_ONCE_PARANOID(space < batch_size);
 348
 349         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 350                    "RX queue %d fast-filling descriptor ring from"
 351                    " level %d to level %d\n",
 352                    efx_rx_queue_index(rx_queue), fill_level,
 353                    rx_queue->max_fill);
 354
 355
 356         do {
 357                 rc = efx_init_rx_buffers(rx_queue, atomic);
 358                 if (unlikely(rc)) {
 359                         /* Ensure that we don't leave the rx queue empty */
 360                         efx_schedule_slow_fill(rx_queue);
 361                         goto out;
 362                 }
 363         } while ((space -= batch_size) >= batch_size);
 364
 365         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 366                    "RX queue %d fast-filled descriptor ring "
 367                    "to level %d\n", efx_rx_queue_index(rx_queue),
 368                    rx_queue->added_count - rx_queue->removed_count);
 369
 370  out:
 371         if (rx_queue->notified_count != rx_queue->added_count)
 372                 efx_nic_notify_rx_desc(rx_queue);
 373 }
 374
 375 void efx_rx_slow_fill(struct timer_list *t)
 376 {
 377         struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
 378
 379         /* Post an event to cause NAPI to run and refill the queue */
 380         efx_nic_generate_fill_event(rx_queue);
 381         ++rx_queue->slow_fill_count;
 382 }
 383
 384 static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
 385                                      struct efx_rx_buffer *rx_buf,
 386                                      int len)
 387 {
 388         struct efx_nic *efx = rx_queue->efx;
 389         unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
 390
 391         if (likely(len <= max_len))
 392                 return;
 393
 394         /* The packet must be discarded, but this is only a fatal error
 395          * if the caller indicated it was
 396          */
 397         rx_buf->flags |= EFX_RX_PKT_DISCARD;
 398
 399         if (net_ratelimit())
 400                 netif_err(efx, rx_err, efx->net_dev,
 401                           "RX queue %d overlength RX event (%#x > %#x)\n",
 402                           efx_rx_queue_index(rx_queue), len, max_len);
 403
 404         efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
 405 }
 406
 407 /* Pass a received packet up through GRO.  GRO can handle pages
 408  * regardless of checksum state and skbs with a good checksum.
 409  */
 410 static void
 411 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 412                   unsigned int n_frags, u8 *eh)
 413 {
 414         struct napi_struct *napi = &channel->napi_str;
 415         struct efx_nic *efx = channel->efx;
 416         struct sk_buff *skb;
 417
 418         skb = napi_get_frags(napi);
 419         if (unlikely(!skb)) {
 420                 struct efx_rx_queue *rx_queue;
 421
 422                 rx_queue = efx_channel_get_rx_queue(channel);
 423                 efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 424                 return;
 425         }
 426
 427         if (efx->net_dev->features & NETIF_F_RXHASH)
 428                 skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
 429                              PKT_HASH_TYPE_L3);
 430         skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
 431                           CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 432         skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
 433
 434         for (;;) {
 435                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 436                                    rx_buf->page, rx_buf->page_offset,
 437                                    rx_buf->len);
 438                 rx_buf->page = NULL;
 439                 skb->len += rx_buf->len;
 440                 if (skb_shinfo(skb)->nr_frags == n_frags)
 441                         break;
 442
 443                 rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 444         }
 445
 446         skb->data_len = skb->len;
 447         skb->truesize += n_frags * efx->rx_buffer_truesize;
 448
 449         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 450
 451         napi_gro_frags(napi);
 452 }
 453
 454 /* Allocate and construct an SKB around page fragments */
 455 static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,
 456                                      struct efx_rx_buffer *rx_buf,
 457                                      unsigned int n_frags,
 458                                      u8 *eh, int hdr_len)
 459 {
 460         struct efx_nic *efx = channel->efx;
 461         struct sk_buff *skb;
 462
 463         /* Allocate an SKB to store the headers */
 464         skb = netdev_alloc_skb(efx->net_dev,
 465                                efx->rx_ip_align + efx->rx_prefix_size +
 466                                hdr_len);
 467         if (unlikely(skb == NULL)) {
 468                 atomic_inc(&efx->n_rx_noskb_drops);
 469                 return NULL;
 470         }
 471
 472         EFX_WARN_ON_ONCE_PARANOID(rx_buf->len < hdr_len);
 473
 474         memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
 475                efx->rx_prefix_size + hdr_len);
 476         skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
 477         __skb_put(skb, hdr_len);
 478
 479         /* Append the remaining page(s) onto the frag list */
 480         if (rx_buf->len > hdr_len) {
 481                 rx_buf->page_offset += hdr_len;
 482                 rx_buf->len -= hdr_len;
 483
 484                 for (;;) {
 485                         skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 486                                            rx_buf->page, rx_buf->page_offset,
 487                                            rx_buf->len);
 488                         rx_buf->page = NULL;
 489                         skb->len += rx_buf->len;
 490                         skb->data_len += rx_buf->len;
 491                         if (skb_shinfo(skb)->nr_frags == n_frags)
 492                                 break;
 493
 494                         rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 495                 }
 496         } else {
 497                 __free_pages(rx_buf->page, efx->rx_buffer_order);
 498                 rx_buf->page = NULL;
 499                 n_frags = 0;
 500         }
 501
 502         skb->truesize += n_frags * efx->rx_buffer_truesize;
 503
 504         /* Move past the ethernet header */
 505         skb->protocol = eth_type_trans(skb, efx->net_dev);
 506
 507         skb_mark_napi_id(skb, &channel->napi_str);
 508
 509         return skb;
 510 }
 511
 512 void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
 513                    unsigned int n_frags, unsigned int len, u16 flags)
 514 {
 515         struct efx_nic *efx = rx_queue->efx;
 516         struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
 517         struct efx_rx_buffer *rx_buf;
 518
 519         rx_queue->rx_packets++;
 520
 521         rx_buf = efx_rx_buffer(rx_queue, index);
 522         rx_buf->flags |= flags;
 523
 524         /* Validate the number of fragments and completed length */
 525         if (n_frags == 1) {
 526                 if (!(flags & EFX_RX_PKT_PREFIX_LEN))
 527                         efx_rx_packet__check_len(rx_queue, rx_buf, len);
 528         } else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||
 529                    unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
 530                    unlikely(len > n_frags * efx->rx_dma_len) ||
 531                    unlikely(!efx->rx_scatter)) {
 532                 /* If this isn't an explicit discard request, either
 533                  * the hardware or the driver is broken.
 534                  */
 535                 WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));
 536                 rx_buf->flags |= EFX_RX_PKT_DISCARD;
 537         }
 538
 539         netif_vdbg(efx, rx_status, efx->net_dev,
 540                    "RX queue %d received ids %x-%x len %d %s%s\n",
 541                    efx_rx_queue_index(rx_queue), index,
 542                    (index + n_frags - 1) & rx_queue->ptr_mask, len,
 543                    (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
 544                    (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");
 545
 546         /* Discard packet, if instructed to do so.  Process the
 547          * previous receive first.
 548          */
 549         if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
 550                 efx_rx_flush_packet(channel);
 551                 efx_discard_rx_packet(channel, rx_buf, n_frags);
 552                 return;
 553         }
 554
 555         if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN))
 556                 rx_buf->len = len;
 557
 558         /* Release and/or sync the DMA mapping - assumes all RX buffers
 559          * consumed in-order per RX queue.
 560          */
 561         efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 562
 563         /* Prefetch nice and early so data will (hopefully) be in cache by
 564          * the time we look at it.
 565          */
 566         prefetch(efx_rx_buf_va(rx_buf));
 567
 568         rx_buf->page_offset += efx->rx_prefix_size;
 569         rx_buf->len -= efx->rx_prefix_size;
 570
 571         if (n_frags > 1) {
 572                 /* Release/sync DMA mapping for additional fragments.
 573                  * Fix length for last fragment.
 574                  */
 575                 unsigned int tail_frags = n_frags - 1;
 576
 577                 for (;;) {
 578                         rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 579                         if (--tail_frags == 0)
 580                                 break;
 581                         efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
 582                 }
 583                 rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
 584                 efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 585         }
 586
 587         /* All fragments have been DMA-synced, so recycle pages. */
 588         rx_buf = efx_rx_buffer(rx_queue, index);
 589         efx_recycle_rx_pages(channel, rx_buf, n_frags);
 590
 591         /* Pipeline receives so that we give time for packet headers to be
 592          * prefetched into cache.
 593          */
 594         efx_rx_flush_packet(channel);
 595         channel->rx_pkt_n_frags = n_frags;
 596         channel->rx_pkt_index = index;
 597 }
 598
 599 static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
 600                            struct efx_rx_buffer *rx_buf,
 601                            unsigned int n_frags)
 602 {
 603         struct sk_buff *skb;
 604         u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);
 605
 606         skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
 607         if (unlikely(skb == NULL)) {
 608                 struct efx_rx_queue *rx_queue;
 609
 610                 rx_queue = efx_channel_get_rx_queue(channel);
 611                 efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 612                 return;
 613         }
 614         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 615
 616         /* Set the SKB flags */
 617         skb_checksum_none_assert(skb);
 618         if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED)) {
 619                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 620                 skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
 621         }
 622
 623         efx_rx_skb_attach_timestamp(channel, skb);
 624
 625         if (channel->type->receive_skb)
 626                 if (channel->type->receive_skb(channel, skb))
 627                         return;
 628
 629         /* Pass the packet up */
 630         if (channel->rx_list != NULL)
 631                 /* Add to list, will pass up later */
 632                 list_add_tail(&skb->list, channel->rx_list);
 633         else
 634                 /* No list, so pass it up now */
 635                 netif_receive_skb(skb);
 636 }
 637
 638 /* Handle a received packet.  Second half: Touches packet payload. */
 639 void __efx_rx_packet(struct efx_channel *channel)
 640 {
 641         struct efx_nic *efx = channel->efx;
 642         struct efx_rx_buffer *rx_buf =
 643                 efx_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
 644         u8 *eh = efx_rx_buf_va(rx_buf);
 645
 646         /* Read length from the prefix if necessary.  This already
 647          * excludes the length of the prefix itself.
 648          */
 649         if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN)
 650                 rx_buf->len = le16_to_cpup((__le16 *)
 651                                            (eh + efx->rx_packet_len_offset));
 652
 653         /* If we're in loopback test, then pass the packet directly to the
 654          * loopback layer, and free the rx_buf here
 655          */
 656         if (unlikely(efx->loopback_selftest)) {
 657                 struct efx_rx_queue *rx_queue;
 658
 659                 efx_loopback_rx_packet(efx, eh, rx_buf->len);
 660                 rx_queue = efx_channel_get_rx_queue(channel);
 661                 efx_free_rx_buffers(rx_queue, rx_buf,
 662                                     channel->rx_pkt_n_frags);
 663                 goto out;
 664         }
 665
 666         if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
 667                 rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
 668
 669         if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb)
 670                 efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
 671         else
 672                 efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
 673 out:
 674         channel->rx_pkt_n_frags = 0;
 675 }
 676
 677 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
 678 {
 679         struct efx_nic *efx = rx_queue->efx;
 680         unsigned int entries;
 681         int rc;
 682
 683         /* Create the smallest power-of-two aligned ring */
 684         entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
 685         EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
 686         rx_queue->ptr_mask = entries - 1;
 687
 688         netif_dbg(efx, probe, efx->net_dev,
 689                   "creating RX queue %d size %#x mask %#x\n",
 690                   efx_rx_queue_index(rx_queue), efx->rxq_entries,
 691                   rx_queue->ptr_mask);
 692
 693         /* Allocate RX buffers */
 694         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 695                                    GFP_KERNEL);
 696         if (!rx_queue->buffer)
 697                 return -ENOMEM;
 698
 699         rc = efx_nic_probe_rx(rx_queue);
 700         if (rc) {
 701                 kfree(rx_queue->buffer);
 702                 rx_queue->buffer = NULL;
 703         }
 704
 705         return rc;
 706 }
 707
 708 static void efx_init_rx_recycle_ring(struct efx_nic *efx,
 709                                      struct efx_rx_queue *rx_queue)
 710 {
 711         unsigned int bufs_in_recycle_ring, page_ring_size;
 712
 713         /* Set the RX recycle ring size */
 714 #ifdef CONFIG_PPC64
 715         bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
 716 #else
 717         if (iommu_present(&pci_bus_type))
 718                 bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
 719         else
 720                 bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_NOIOMMU;
 721 #endif /* CONFIG_PPC64 */
 722
 723         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 724                                             efx->rx_bufs_per_page);
 725         rx_queue->page_ring = kcalloc(page_ring_size,
 726                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 727         rx_queue->page_ptr_mask = page_ring_size - 1;
 728 }
 729
 730 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
 731 {
 732         struct efx_nic *efx = rx_queue->efx;
 733         unsigned int max_fill, trigger, max_trigger;
 734
 735         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 736                   "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
 737
 738         /* Initialise ptr fields */
 739         rx_queue->added_count = 0;
 740         rx_queue->notified_count = 0;
 741         rx_queue->removed_count = 0;
 742         rx_queue->min_fill = -1U;
 743         efx_init_rx_recycle_ring(efx, rx_queue);
 744
 745         rx_queue->page_remove = 0;
 746         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 747         rx_queue->page_recycle_count = 0;
 748         rx_queue->page_recycle_failed = 0;
 749         rx_queue->page_recycle_full = 0;
 750
 751         /* Initialise limit fields */
 752         max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
 753         max_trigger =
 754                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 755         if (rx_refill_threshold != 0) {
 756                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 757                 if (trigger > max_trigger)
 758                         trigger = max_trigger;
 759         } else {
 760                 trigger = max_trigger;
 761         }
 762
 763         rx_queue->max_fill = max_fill;
 764         rx_queue->fast_fill_trigger = trigger;
 765         rx_queue->refill_enabled = true;
 766
 767         /* Set up RX descriptor ring */
 768         efx_nic_init_rx(rx_queue);
 769 }
 770
 771 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
 772 {
 773         int i;
 774         struct efx_nic *efx = rx_queue->efx;
 775         struct efx_rx_buffer *rx_buf;
 776
 777         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 778                   "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
 779
 780         del_timer_sync(&rx_queue->slow_fill);
 781
 782         /* Release RX buffers from the current read ptr to the write ptr */
 783         if (rx_queue->buffer) {
 784                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 785                      i++) {
 786                         unsigned index = i & rx_queue->ptr_mask;
 787                         rx_buf = efx_rx_buffer(rx_queue, index);
 788                         efx_fini_rx_buffer(rx_queue, rx_buf);
 789                 }
 790         }
 791
 792         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 793         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 794                 struct page *page = rx_queue->page_ring[i];
 795                 struct efx_rx_page_state *state;
 796
 797                 if (page == NULL)
 798                         continue;
 799
 800                 state = page_address(page);
 801                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 802                                PAGE_SIZE << efx->rx_buffer_order,
 803                                DMA_FROM_DEVICE);
 804                 put_page(page);
 805         }
 806         kfree(rx_queue->page_ring);
 807         rx_queue->page_ring = NULL;
 808 }
 809
 810 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
 811 {
 812         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 813                   "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
 814
 815         efx_nic_remove_rx(rx_queue);
 816
 817         kfree(rx_queue->buffer);
 818         rx_queue->buffer = NULL;
 819 }
 820
 821
 822 module_param(rx_refill_threshold, uint, 0444);
 823 MODULE_PARM_DESC(rx_refill_threshold,
 824                  "RX descriptor ring refill threshold (%)");
 825
 826 #ifdef CONFIG_RFS_ACCEL
 827
 828 static void efx_filter_rfs_work(struct work_struct *data)
 829 {
 830         struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
 831                                                               work);
 832         struct efx_nic *efx = netdev_priv(req->net_dev);
 833         struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
 834         int slot_idx = req - efx->rps_slot;
 835         struct efx_arfs_rule *rule;
 836         u16 arfs_id = 0;
 837         int rc;
 838
 839         rc = efx->type->filter_insert(efx, &req->spec, true);
 840         if (rc >= 0)
 841                 rc %= efx->type->max_rx_ip_filters;
 842         if (efx->rps_hash_table) {
 843                 spin_lock_bh(&efx->rps_hash_lock);
 844                 rule = efx_rps_hash_find(efx, &req->spec);
 845                 /* The rule might have already gone, if someone else's request
 846                  * for the same spec was already worked and then expired before
 847                  * we got around to our work.  In that case we have nothing
 848                  * tying us to an arfs_id, meaning that as soon as the filter
 849                  * is considered for expiry it will be removed.
 850                  */
 851                 if (rule) {
 852                         if (rc < 0)
 853                                 rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
 854                         else
 855                                 rule->filter_id = rc;
 856                         arfs_id = rule->arfs_id;
 857                 }
 858                 spin_unlock_bh(&efx->rps_hash_lock);
 859         }
 860         if (rc >= 0) {
 861                 /* Remember this so we can check whether to expire the filter
 862                  * later.
 863                  */
 864                 mutex_lock(&efx->rps_mutex);
 865                 channel->rps_flow_id[rc] = req->flow_id;
 866                 ++channel->rfs_filters_added;
 867                 mutex_unlock(&efx->rps_mutex);
 868
 869                 if (req->spec.ether_type == htons(ETH_P_IP))
 870                         netif_info(efx, rx_status, efx->net_dev,
 871                                    "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
 872                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 873                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 874                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 875                                    req->rxq_index, req->flow_id, rc, arfs_id);
 876                 else
 877                         netif_info(efx, rx_status, efx->net_dev,
 878                                    "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
 879                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 880                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 881                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 882                                    req->rxq_index, req->flow_id, rc, arfs_id);
 883         }
 884
 885         /* Release references */
 886         clear_bit(slot_idx, &efx->rps_slot_map);
 887         dev_put(req->net_dev);
 888 }
 889
 890 int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 891                    u16 rxq_index, u32 flow_id)
 892 {
 893         struct efx_nic *efx = netdev_priv(net_dev);
 894         struct efx_async_filter_insertion *req;
 895         struct efx_arfs_rule *rule;
 896         struct flow_keys fk;
 897         int slot_idx;
 898         bool new;
 899         int rc;
 900
 901         /* find a free slot */
 902         for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
 903                 if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
 904                         break;
 905         if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
 906                 return -EBUSY;
 907
 908         if (flow_id == RPS_FLOW_ID_INVALID) {
 909                 rc = -EINVAL;
 910                 goto out_clear;
 911         }
 912
 913         if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
 914                 rc = -EPROTONOSUPPORT;
 915                 goto out_clear;
 916         }
 917
 918         if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
 919                 rc = -EPROTONOSUPPORT;
 920                 goto out_clear;
 921         }
 922         if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
 923                 rc = -EPROTONOSUPPORT;
 924                 goto out_clear;
 925         }
 926
 927         req = efx->rps_slot + slot_idx;
 928         efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
 929                            efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
 930                            rxq_index);
 931         req->spec.match_flags =
 932                 EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
 933                 EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
 934                 EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
 935         req->spec.ether_type = fk.basic.n_proto;
 936         req->spec.ip_proto = fk.basic.ip_proto;
 937
 938         if (fk.basic.n_proto == htons(ETH_P_IP)) {
 939                 req->spec.rem_host[0] = fk.addrs.v4addrs.src;
 940                 req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
 941         } else {
 942                 memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
 943                        sizeof(struct in6_addr));
 944                 memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
 945                        sizeof(struct in6_addr));
 946         }
 947
 948         req->spec.rem_port = fk.ports.src;
 949         req->spec.loc_port = fk.ports.dst;
 950
 951         if (efx->rps_hash_table) {
 952                 /* Add it to ARFS hash table */
 953                 spin_lock(&efx->rps_hash_lock);
 954                 rule = efx_rps_hash_add(efx, &req->spec, &new);
 955                 if (!rule) {
 956                         rc = -ENOMEM;
 957                         goto out_unlock;
 958                 }
 959                 if (new)
 960                         rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
 961                 rc = rule->arfs_id;
 962                 /* Skip if existing or pending filter already does the right thing */
 963                 if (!new && rule->rxq_index == rxq_index &&
 964                     rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
 965                         goto out_unlock;
 966                 rule->rxq_index = rxq_index;
 967                 rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
 968                 spin_unlock(&efx->rps_hash_lock);
 969         } else {
 970                 /* Without an ARFS hash table, we just use arfs_id 0 for all
 971                  * filters.  This means if multiple flows hash to the same
 972                  * flow_id, all but the most recently touched will be eligible
 973                  * for expiry.
 974                  */
 975                 rc = 0;
 976         }
 977
 978         /* Queue the request */
 979         dev_hold(req->net_dev = net_dev);
 980         INIT_WORK(&req->work, efx_filter_rfs_work);
 981         req->rxq_index = rxq_index;
 982         req->flow_id = flow_id;
 983         schedule_work(&req->work);
 984         return rc;
 985 out_unlock:
 986         spin_unlock(&efx->rps_hash_lock);
 987 out_clear:
 988         clear_bit(slot_idx, &efx->rps_slot_map);
 989         return rc;
 990 }
 991
 992 bool __efx_filter_rfs_expire(struct efx_nic *efx, unsigned int quota)
 993 {
 994         bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
 995         unsigned int channel_idx, index, size;
 996         u32 flow_id;
 997
 998         if (!mutex_trylock(&efx->rps_mutex))
 999                 return false;
1000         expire_one = efx->type->filter_rfs_expire_one;
1001         channel_idx = efx->rps_expire_channel;
1002         index = efx->rps_expire_index;
1003         size = efx->type->max_rx_ip_filters;
1004         while (quota--) {
1005                 struct efx_channel *channel = efx_get_channel(efx, channel_idx);
1006                 flow_id = channel->rps_flow_id[index];
1007
1008                 if (flow_id != RPS_FLOW_ID_INVALID &&
1009                     expire_one(efx, flow_id, index)) {
1010                         netif_info(efx, rx_status, efx->net_dev,
1011                                    "expired filter %d [queue %u flow %u]\n",
1012                                    index, channel_idx, flow_id);
1013                         channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
1014                 }
1015                 if (++index == size) {
1016                         if (++channel_idx == efx->n_channels)
1017                                 channel_idx = 0;
1018                         index = 0;
1019                 }
1020         }
1021         efx->rps_expire_channel = channel_idx;
1022         efx->rps_expire_index = index;
1023
1024         mutex_unlock(&efx->rps_mutex);
1025         return true;
1026 }
1027
1028 #endif /* CONFIG_RFS_ACCEL */
1029
1030 /**
1031  * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
1032  * @spec: Specification to test
1033  *
1034  * Return: %true if the specification is a non-drop RX filter that
1035  * matches a local MAC address I/G bit value of 1 or matches a local
1036  * IPv4 or IPv6 address value in the respective multicast address
1037  * range.  Otherwise %false.
1038  */
1039 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
1040 {
1041         if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
1042             spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
1043                 return false;
1044
1045         if (spec->match_flags &
1046             (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
1047             is_multicast_ether_addr(spec->loc_mac))
1048                 return true;
1049
1050         if ((spec->match_flags &
1051              (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
1052             (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
1053                 if (spec->ether_type == htons(ETH_P_IP) &&
1054                     ipv4_is_multicast(spec->loc_host[0]))
1055                         return true;
1056                 if (spec->ether_type == htons(ETH_P_IPV6) &&
1057                     ((const u8 *)spec->loc_host)[0] == 0xff)
1058                         return true;
1059         }
1060
1061         return false;
1062 }