drivers/net/ethernet/sfc/rx.c

   1 /****************************************************************************
   2  * Driver for Solarflare network controllers and boards
   3  * Copyright 2005-2006 Fen Systems Ltd.
   4  * Copyright 2005-2013 Solarflare Communications Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published
   8  * by the Free Software Foundation, incorporated herein by reference.
   9  */
  10
  11 #include <linux/socket.h>
  12 #include <linux/in.h>
  13 #include <linux/slab.h>
  14 #include <linux/ip.h>
  15 #include <linux/ipv6.h>
  16 #include <linux/tcp.h>
  17 #include <linux/udp.h>
  18 #include <linux/prefetch.h>
  19 #include <linux/moduleparam.h>
  20 #include <linux/iommu.h>
  21 #include <net/ip.h>
  22 #include <net/checksum.h>
  23 #include "net_driver.h"
  24 #include "efx.h"
  25 #include "filter.h"
  26 #include "nic.h"
  27 #include "selftest.h"
  28 #include "workarounds.h"
  29
  30 /* Preferred number of descriptors to fill at once */
  31 #define EFX_RX_PREFERRED_BATCH 8U
  32
  33 /* Number of RX buffers to recycle pages for.  When creating the RX page recycle
  34  * ring, this number is divided by the number of buffers per page to calculate
  35  * the number of pages to store in the RX page recycle ring.
  36  */
  37 #define EFX_RECYCLE_RING_SIZE_IOMMU 4096
  38 #define EFX_RECYCLE_RING_SIZE_NOIOMMU (2 * EFX_RX_PREFERRED_BATCH)
  39
  40 /* Size of buffer allocated for skb header area. */
  41 #define EFX_SKB_HEADERS  128u
  42
  43 /* This is the percentage fill level below which new RX descriptors
  44  * will be added to the RX descriptor ring.
  45  */
  46 static unsigned int rx_refill_threshold;
  47
  48 /* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
  49 #define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
  50                                       EFX_RX_USR_BUF_SIZE)
  51
  52 /*
  53  * RX maximum head room required.
  54  *
  55  * This must be at least 1 to prevent overflow, plus one packet-worth
  56  * to allow pipelined receives.
  57  */
  58 #define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
  59
  60 static inline u8 *efx_rx_buf_va(struct efx_rx_buffer *buf)
  61 {
  62         return page_address(buf->page) + buf->page_offset;
  63 }
  64
  65 static inline u32 efx_rx_buf_hash(struct efx_nic *efx, const u8 *eh)
  66 {
  67 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  68         return __le32_to_cpup((const __le32 *)(eh + efx->rx_packet_hash_offset));
  69 #else
  70         const u8 *data = eh + efx->rx_packet_hash_offset;
  71         return (u32)data[0]       |
  72                (u32)data[1] << 8  |
  73                (u32)data[2] << 16 |
  74                (u32)data[3] << 24;
  75 #endif
  76 }
  77
  78 static inline struct efx_rx_buffer *
  79 efx_rx_buf_next(struct efx_rx_queue *rx_queue, struct efx_rx_buffer *rx_buf)
  80 {
  81         if (unlikely(rx_buf == efx_rx_buffer(rx_queue, rx_queue->ptr_mask)))
  82                 return efx_rx_buffer(rx_queue, 0);
  83         else
  84                 return rx_buf + 1;
  85 }
  86
  87 static inline void efx_sync_rx_buffer(struct efx_nic *efx,
  88                                       struct efx_rx_buffer *rx_buf,
  89                                       unsigned int len)
  90 {
  91         dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, len,
  92                                 DMA_FROM_DEVICE);
  93 }
  94
  95 void efx_rx_config_page_split(struct efx_nic *efx)
  96 {
  97         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align,
  98                                       EFX_RX_BUF_ALIGNMENT);
  99         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
 100                 ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
 101                  efx->rx_page_buf_step);
 102         efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
 103                 efx->rx_bufs_per_page;
 104         efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
 105                                                efx->rx_bufs_per_page);
 106 }
 107
 108 /* Check the RX page recycle ring for a page that can be reused. */
 109 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
 110 {
 111         struct efx_nic *efx = rx_queue->efx;
 112         struct page *page;
 113         struct efx_rx_page_state *state;
 114         unsigned index;
 115
 116         index = rx_queue->page_remove & rx_queue->page_ptr_mask;
 117         page = rx_queue->page_ring[index];
 118         if (page == NULL)
 119                 return NULL;
 120
 121         rx_queue->page_ring[index] = NULL;
 122         /* page_remove cannot exceed page_add. */
 123         if (rx_queue->page_remove != rx_queue->page_add)
 124                 ++rx_queue->page_remove;
 125
 126         /* If page_count is 1 then we hold the only reference to this page. */
 127         if (page_count(page) == 1) {
 128                 ++rx_queue->page_recycle_count;
 129                 return page;
 130         } else {
 131                 state = page_address(page);
 132                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 133                                PAGE_SIZE << efx->rx_buffer_order,
 134                                DMA_FROM_DEVICE);
 135                 put_page(page);
 136                 ++rx_queue->page_recycle_failed;
 137         }
 138
 139         return NULL;
 140 }
 141
 142 /**
 143  * efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
 144  *
 145  * @rx_queue:           Efx RX queue
 146  *
 147  * This allocates a batch of pages, maps them for DMA, and populates
 148  * struct efx_rx_buffers for each one. Return a negative error code or
 149  * 0 on success. If a single page can be used for multiple buffers,
 150  * then the page will either be inserted fully, or not at all.
 151  */
 152 static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue)
 153 {
 154         struct efx_nic *efx = rx_queue->efx;
 155         struct efx_rx_buffer *rx_buf;
 156         struct page *page;
 157         unsigned int page_offset;
 158         struct efx_rx_page_state *state;
 159         dma_addr_t dma_addr;
 160         unsigned index, count;
 161
 162         count = 0;
 163         do {
 164                 page = efx_reuse_page(rx_queue);
 165                 if (page == NULL) {
 166                         page = alloc_pages(__GFP_COLD | __GFP_COMP | GFP_ATOMIC,
 167                                            efx->rx_buffer_order);
 168                         if (unlikely(page == NULL))
 169                                 return -ENOMEM;
 170                         dma_addr =
 171                                 dma_map_page(&efx->pci_dev->dev, page, 0,
 172                                              PAGE_SIZE << efx->rx_buffer_order,
 173                                              DMA_FROM_DEVICE);
 174                         if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
 175                                                        dma_addr))) {
 176                                 __free_pages(page, efx->rx_buffer_order);
 177                                 return -EIO;
 178                         }
 179                         state = page_address(page);
 180                         state->dma_addr = dma_addr;
 181                 } else {
 182                         state = page_address(page);
 183                         dma_addr = state->dma_addr;
 184                 }
 185
 186                 dma_addr += sizeof(struct efx_rx_page_state);
 187                 page_offset = sizeof(struct efx_rx_page_state);
 188
 189                 do {
 190                         index = rx_queue->added_count & rx_queue->ptr_mask;
 191                         rx_buf = efx_rx_buffer(rx_queue, index);
 192                         rx_buf->dma_addr = dma_addr + efx->rx_ip_align;
 193                         rx_buf->page = page;
 194                         rx_buf->page_offset = page_offset + efx->rx_ip_align;
 195                         rx_buf->len = efx->rx_dma_len;
 196                         rx_buf->flags = 0;
 197                         ++rx_queue->added_count;
 198                         get_page(page);
 199                         dma_addr += efx->rx_page_buf_step;
 200                         page_offset += efx->rx_page_buf_step;
 201                 } while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
 202
 203                 rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
 204         } while (++count < efx->rx_pages_per_batch);
 205
 206         return 0;
 207 }
 208
 209 /* Unmap a DMA-mapped page.  This function is only called for the final RX
 210  * buffer in a page.
 211  */
 212 static void efx_unmap_rx_buffer(struct efx_nic *efx,
 213                                 struct efx_rx_buffer *rx_buf)
 214 {
 215         struct page *page = rx_buf->page;
 216
 217         if (page) {
 218                 struct efx_rx_page_state *state = page_address(page);
 219                 dma_unmap_page(&efx->pci_dev->dev,
 220                                state->dma_addr,
 221                                PAGE_SIZE << efx->rx_buffer_order,
 222                                DMA_FROM_DEVICE);
 223         }
 224 }
 225
 226 static void efx_free_rx_buffer(struct efx_rx_buffer *rx_buf)
 227 {
 228         if (rx_buf->page) {
 229                 put_page(rx_buf->page);
 230                 rx_buf->page = NULL;
 231         }
 232 }
 233
 234 /* Attempt to recycle the page if there is an RX recycle ring; the page can
 235  * only be added if this is the final RX buffer, to prevent pages being used in
 236  * the descriptor ring and appearing in the recycle ring simultaneously.
 237  */
 238 static void efx_recycle_rx_page(struct efx_channel *channel,
 239                                 struct efx_rx_buffer *rx_buf)
 240 {
 241         struct page *page = rx_buf->page;
 242         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 243         struct efx_nic *efx = rx_queue->efx;
 244         unsigned index;
 245
 246         /* Only recycle the page after processing the final buffer. */
 247         if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
 248                 return;
 249
 250         index = rx_queue->page_add & rx_queue->page_ptr_mask;
 251         if (rx_queue->page_ring[index] == NULL) {
 252                 unsigned read_index = rx_queue->page_remove &
 253                         rx_queue->page_ptr_mask;
 254
 255                 /* The next slot in the recycle ring is available, but
 256                  * increment page_remove if the read pointer currently
 257                  * points here.
 258                  */
 259                 if (read_index == index)
 260                         ++rx_queue->page_remove;
 261                 rx_queue->page_ring[index] = page;
 262                 ++rx_queue->page_add;
 263                 return;
 264         }
 265         ++rx_queue->page_recycle_full;
 266         efx_unmap_rx_buffer(efx, rx_buf);
 267         put_page(rx_buf->page);
 268 }
 269
 270 static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
 271                                struct efx_rx_buffer *rx_buf)
 272 {
 273         /* Release the page reference we hold for the buffer. */
 274         if (rx_buf->page)
 275                 put_page(rx_buf->page);
 276
 277         /* If this is the last buffer in a page, unmap and free it. */
 278         if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
 279                 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
 280                 efx_free_rx_buffer(rx_buf);
 281         }
 282         rx_buf->page = NULL;
 283 }
 284
 285 /* Recycle the pages that are used by buffers that have just been received. */
 286 static void efx_recycle_rx_pages(struct efx_channel *channel,
 287                                  struct efx_rx_buffer *rx_buf,
 288                                  unsigned int n_frags)
 289 {
 290         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 291
 292         do {
 293                 efx_recycle_rx_page(channel, rx_buf);
 294                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 295         } while (--n_frags);
 296 }
 297
 298 static void efx_discard_rx_packet(struct efx_channel *channel,
 299                                   struct efx_rx_buffer *rx_buf,
 300                                   unsigned int n_frags)
 301 {
 302         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 303
 304         efx_recycle_rx_pages(channel, rx_buf, n_frags);
 305
 306         do {
 307                 efx_free_rx_buffer(rx_buf);
 308                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 309         } while (--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)
 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_BUG_ON_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_BUG_ON_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);
 358                 if (unlikely(rc)) {
 359                         /* Ensure that we don't leave the rx queue empty */
 360                         if (rx_queue->added_count == rx_queue->removed_count)
 361                                 efx_schedule_slow_fill(rx_queue);
 362                         goto out;
 363                 }
 364         } while ((space -= batch_size) >= batch_size);
 365
 366         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 367                    "RX queue %d fast-filled descriptor ring "
 368                    "to level %d\n", efx_rx_queue_index(rx_queue),
 369                    rx_queue->added_count - rx_queue->removed_count);
 370
 371  out:
 372         if (rx_queue->notified_count != rx_queue->added_count)
 373                 efx_nic_notify_rx_desc(rx_queue);
 374 }
 375
 376 void efx_rx_slow_fill(unsigned long context)
 377 {
 378         struct efx_rx_queue *rx_queue = (struct efx_rx_queue *)context;
 379
 380         /* Post an event to cause NAPI to run and refill the queue */
 381         efx_nic_generate_fill_event(rx_queue);
 382         ++rx_queue->slow_fill_count;
 383 }
 384
 385 static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
 386                                      struct efx_rx_buffer *rx_buf,
 387                                      int len)
 388 {
 389         struct efx_nic *efx = rx_queue->efx;
 390         unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
 391
 392         if (likely(len <= max_len))
 393                 return;
 394
 395         /* The packet must be discarded, but this is only a fatal error
 396          * if the caller indicated it was
 397          */
 398         rx_buf->flags |= EFX_RX_PKT_DISCARD;
 399
 400         if ((len > rx_buf->len) && EFX_WORKAROUND_8071(efx)) {
 401                 if (net_ratelimit())
 402                         netif_err(efx, rx_err, efx->net_dev,
 403                                   " RX queue %d seriously overlength "
 404                                   "RX event (0x%x > 0x%x+0x%x). Leaking\n",
 405                                   efx_rx_queue_index(rx_queue), len, max_len,
 406                                   efx->type->rx_buffer_padding);
 407                 efx_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
 408         } else {
 409                 if (net_ratelimit())
 410                         netif_err(efx, rx_err, efx->net_dev,
 411                                   " RX queue %d overlength RX event "
 412                                   "(0x%x > 0x%x)\n",
 413                                   efx_rx_queue_index(rx_queue), len, max_len);
 414         }
 415
 416         efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
 417 }
 418
 419 /* Pass a received packet up through GRO.  GRO can handle pages
 420  * regardless of checksum state and skbs with a good checksum.
 421  */
 422 static void
 423 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 424                   unsigned int n_frags, u8 *eh)
 425 {
 426         struct napi_struct *napi = &channel->napi_str;
 427         gro_result_t gro_result;
 428         struct efx_nic *efx = channel->efx;
 429         struct sk_buff *skb;
 430
 431         skb = napi_get_frags(napi);
 432         if (unlikely(!skb)) {
 433                 while (n_frags--) {
 434                         put_page(rx_buf->page);
 435                         rx_buf->page = NULL;
 436                         rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 437                 }
 438                 return;
 439         }
 440
 441         if (efx->net_dev->features & NETIF_F_RXHASH)
 442                 skb->rxhash = efx_rx_buf_hash(efx, eh);
 443         skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
 444                           CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 445
 446         for (;;) {
 447                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 448                                    rx_buf->page, rx_buf->page_offset,
 449                                    rx_buf->len);
 450                 rx_buf->page = NULL;
 451                 skb->len += rx_buf->len;
 452                 if (skb_shinfo(skb)->nr_frags == n_frags)
 453                         break;
 454
 455                 rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 456         }
 457
 458         skb->data_len = skb->len;
 459         skb->truesize += n_frags * efx->rx_buffer_truesize;
 460
 461         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 462
 463         gro_result = napi_gro_frags(napi);
 464         if (gro_result != GRO_DROP)
 465                 channel->irq_mod_score += 2;
 466 }
 467
 468 /* Allocate and construct an SKB around page fragments */
 469 static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,
 470                                      struct efx_rx_buffer *rx_buf,
 471                                      unsigned int n_frags,
 472                                      u8 *eh, int hdr_len)
 473 {
 474         struct efx_nic *efx = channel->efx;
 475         struct sk_buff *skb;
 476
 477         /* Allocate an SKB to store the headers */
 478         skb = netdev_alloc_skb(efx->net_dev, hdr_len + EFX_PAGE_SKB_ALIGN);
 479         if (unlikely(skb == NULL))
 480                 return NULL;
 481
 482         EFX_BUG_ON_PARANOID(rx_buf->len < hdr_len);
 483
 484         skb_reserve(skb, EFX_PAGE_SKB_ALIGN);
 485         memcpy(__skb_put(skb, hdr_len), eh, hdr_len);
 486
 487         /* Append the remaining page(s) onto the frag list */
 488         if (rx_buf->len > hdr_len) {
 489                 rx_buf->page_offset += hdr_len;
 490                 rx_buf->len -= hdr_len;
 491
 492                 for (;;) {
 493                         skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 494                                            rx_buf->page, rx_buf->page_offset,
 495                                            rx_buf->len);
 496                         rx_buf->page = NULL;
 497                         skb->len += rx_buf->len;
 498                         skb->data_len += rx_buf->len;
 499                         if (skb_shinfo(skb)->nr_frags == n_frags)
 500                                 break;
 501
 502                         rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 503                 }
 504         } else {
 505                 __free_pages(rx_buf->page, efx->rx_buffer_order);
 506                 rx_buf->page = NULL;
 507                 n_frags = 0;
 508         }
 509
 510         skb->truesize += n_frags * efx->rx_buffer_truesize;
 511
 512         /* Move past the ethernet header */
 513         skb->protocol = eth_type_trans(skb, efx->net_dev);
 514
 515         return skb;
 516 }
 517
 518 void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
 519                    unsigned int n_frags, unsigned int len, u16 flags)
 520 {
 521         struct efx_nic *efx = rx_queue->efx;
 522         struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
 523         struct efx_rx_buffer *rx_buf;
 524
 525         rx_buf = efx_rx_buffer(rx_queue, index);
 526         rx_buf->flags |= flags;
 527
 528         /* Validate the number of fragments and completed length */
 529         if (n_frags == 1) {
 530                 if (!(flags & EFX_RX_PKT_PREFIX_LEN))
 531                         efx_rx_packet__check_len(rx_queue, rx_buf, len);
 532         } else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||
 533                    unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
 534                    unlikely(len > n_frags * efx->rx_dma_len) ||
 535                    unlikely(!efx->rx_scatter)) {
 536                 /* If this isn't an explicit discard request, either
 537                  * the hardware or the driver is broken.
 538                  */
 539                 WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));
 540                 rx_buf->flags |= EFX_RX_PKT_DISCARD;
 541         }
 542
 543         netif_vdbg(efx, rx_status, efx->net_dev,
 544                    "RX queue %d received ids %x-%x len %d %s%s\n",
 545                    efx_rx_queue_index(rx_queue), index,
 546                    (index + n_frags - 1) & rx_queue->ptr_mask, len,
 547                    (rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
 548                    (rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");
 549
 550         /* Discard packet, if instructed to do so.  Process the
 551          * previous receive first.
 552          */
 553         if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
 554                 efx_rx_flush_packet(channel);
 555                 efx_discard_rx_packet(channel, rx_buf, n_frags);
 556                 return;
 557         }
 558
 559         if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN))
 560                 rx_buf->len = len;
 561
 562         /* Release and/or sync the DMA mapping - assumes all RX buffers
 563          * consumed in-order per RX queue.
 564          */
 565         efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 566
 567         /* Prefetch nice and early so data will (hopefully) be in cache by
 568          * the time we look at it.
 569          */
 570         prefetch(efx_rx_buf_va(rx_buf));
 571
 572         rx_buf->page_offset += efx->rx_prefix_size;
 573         rx_buf->len -= efx->rx_prefix_size;
 574
 575         if (n_frags > 1) {
 576                 /* Release/sync DMA mapping for additional fragments.
 577                  * Fix length for last fragment.
 578                  */
 579                 unsigned int tail_frags = n_frags - 1;
 580
 581                 for (;;) {
 582                         rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 583                         if (--tail_frags == 0)
 584                                 break;
 585                         efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
 586                 }
 587                 rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
 588                 efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 589         }
 590
 591         /* All fragments have been DMA-synced, so recycle pages. */
 592         rx_buf = efx_rx_buffer(rx_queue, index);
 593         efx_recycle_rx_pages(channel, rx_buf, n_frags);
 594
 595         /* Pipeline receives so that we give time for packet headers to be
 596          * prefetched into cache.
 597          */
 598         efx_rx_flush_packet(channel);
 599         channel->rx_pkt_n_frags = n_frags;
 600         channel->rx_pkt_index = index;
 601 }
 602
 603 static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
 604                            struct efx_rx_buffer *rx_buf,
 605                            unsigned int n_frags)
 606 {
 607         struct sk_buff *skb;
 608         u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);
 609
 610         skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
 611         if (unlikely(skb == NULL)) {
 612                 efx_free_rx_buffer(rx_buf);
 613                 return;
 614         }
 615         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 616
 617         /* Set the SKB flags */
 618         skb_checksum_none_assert(skb);
 619         if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED))
 620                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 621
 622         if (channel->type->receive_skb)
 623                 if (channel->type->receive_skb(channel, skb))
 624                         return;
 625
 626         /* Pass the packet up */
 627         netif_receive_skb(skb);
 628 }
 629
 630 /* Handle a received packet.  Second half: Touches packet payload. */
 631 void __efx_rx_packet(struct efx_channel *channel)
 632 {
 633         struct efx_nic *efx = channel->efx;
 634         struct efx_rx_buffer *rx_buf =
 635                 efx_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
 636         u8 *eh = efx_rx_buf_va(rx_buf);
 637
 638         /* Read length from the prefix if necessary.  This already
 639          * excludes the length of the prefix itself.
 640          */
 641         if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN)
 642                 rx_buf->len = le16_to_cpup((__le16 *)
 643                                            (eh + efx->rx_packet_len_offset));
 644
 645         /* If we're in loopback test, then pass the packet directly to the
 646          * loopback layer, and free the rx_buf here
 647          */
 648         if (unlikely(efx->loopback_selftest)) {
 649                 efx_loopback_rx_packet(efx, eh, rx_buf->len);
 650                 efx_free_rx_buffer(rx_buf);
 651                 goto out;
 652         }
 653
 654         if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
 655                 rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
 656
 657         if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb)
 658                 efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
 659         else
 660                 efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
 661 out:
 662         channel->rx_pkt_n_frags = 0;
 663 }
 664
 665 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
 666 {
 667         struct efx_nic *efx = rx_queue->efx;
 668         unsigned int entries;
 669         int rc;
 670
 671         /* Create the smallest power-of-two aligned ring */
 672         entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
 673         EFX_BUG_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
 674         rx_queue->ptr_mask = entries - 1;
 675
 676         netif_dbg(efx, probe, efx->net_dev,
 677                   "creating RX queue %d size %#x mask %#x\n",
 678                   efx_rx_queue_index(rx_queue), efx->rxq_entries,
 679                   rx_queue->ptr_mask);
 680
 681         /* Allocate RX buffers */
 682         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 683                                    GFP_KERNEL);
 684         if (!rx_queue->buffer)
 685                 return -ENOMEM;
 686
 687         rc = efx_nic_probe_rx(rx_queue);
 688         if (rc) {
 689                 kfree(rx_queue->buffer);
 690                 rx_queue->buffer = NULL;
 691         }
 692
 693         return rc;
 694 }
 695
 696 static void efx_init_rx_recycle_ring(struct efx_nic *efx,
 697                                      struct efx_rx_queue *rx_queue)
 698 {
 699         unsigned int bufs_in_recycle_ring, page_ring_size;
 700
 701         /* Set the RX recycle ring size */
 702 #ifdef CONFIG_PPC64
 703         bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
 704 #else
 705         if (iommu_present(&pci_bus_type))
 706                 bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
 707         else
 708                 bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_NOIOMMU;
 709 #endif /* CONFIG_PPC64 */
 710
 711         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 712                                             efx->rx_bufs_per_page);
 713         rx_queue->page_ring = kcalloc(page_ring_size,
 714                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 715         rx_queue->page_ptr_mask = page_ring_size - 1;
 716 }
 717
 718 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
 719 {
 720         struct efx_nic *efx = rx_queue->efx;
 721         unsigned int max_fill, trigger, max_trigger;
 722
 723         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 724                   "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
 725
 726         /* Initialise ptr fields */
 727         rx_queue->added_count = 0;
 728         rx_queue->notified_count = 0;
 729         rx_queue->removed_count = 0;
 730         rx_queue->min_fill = -1U;
 731         efx_init_rx_recycle_ring(efx, rx_queue);
 732
 733         rx_queue->page_remove = 0;
 734         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 735         rx_queue->page_recycle_count = 0;
 736         rx_queue->page_recycle_failed = 0;
 737         rx_queue->page_recycle_full = 0;
 738
 739         /* Initialise limit fields */
 740         max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
 741         max_trigger =
 742                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 743         if (rx_refill_threshold != 0) {
 744                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 745                 if (trigger > max_trigger)
 746                         trigger = max_trigger;
 747         } else {
 748                 trigger = max_trigger;
 749         }
 750
 751         rx_queue->max_fill = max_fill;
 752         rx_queue->fast_fill_trigger = trigger;
 753         rx_queue->refill_enabled = true;
 754
 755         /* Set up RX descriptor ring */
 756         efx_nic_init_rx(rx_queue);
 757 }
 758
 759 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
 760 {
 761         int i;
 762         struct efx_nic *efx = rx_queue->efx;
 763         struct efx_rx_buffer *rx_buf;
 764
 765         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 766                   "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
 767
 768         del_timer_sync(&rx_queue->slow_fill);
 769
 770         /* Release RX buffers from the current read ptr to the write ptr */
 771         if (rx_queue->buffer) {
 772                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 773                      i++) {
 774                         unsigned index = i & rx_queue->ptr_mask;
 775                         rx_buf = efx_rx_buffer(rx_queue, index);
 776                         efx_fini_rx_buffer(rx_queue, rx_buf);
 777                 }
 778         }
 779
 780         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 781         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 782                 struct page *page = rx_queue->page_ring[i];
 783                 struct efx_rx_page_state *state;
 784
 785                 if (page == NULL)
 786                         continue;
 787
 788                 state = page_address(page);
 789                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 790                                PAGE_SIZE << efx->rx_buffer_order,
 791                                DMA_FROM_DEVICE);
 792                 put_page(page);
 793         }
 794         kfree(rx_queue->page_ring);
 795         rx_queue->page_ring = NULL;
 796 }
 797
 798 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
 799 {
 800         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 801                   "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
 802
 803         efx_nic_remove_rx(rx_queue);
 804
 805         kfree(rx_queue->buffer);
 806         rx_queue->buffer = NULL;
 807 }
 808
 809
 810 module_param(rx_refill_threshold, uint, 0444);
 811 MODULE_PARM_DESC(rx_refill_threshold,
 812                  "RX descriptor ring refill threshold (%)");
 813
 814 #ifdef CONFIG_RFS_ACCEL
 815
 816 int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 817                    u16 rxq_index, u32 flow_id)
 818 {
 819         struct efx_nic *efx = netdev_priv(net_dev);
 820         struct efx_channel *channel;
 821         struct efx_filter_spec spec;
 822         const __be16 *ports;
 823         __be16 ether_type;
 824         int nhoff;
 825         int rc;
 826
 827         /* The core RPS/RFS code has already parsed and validated
 828          * VLAN, IP and transport headers.  We assume they are in the
 829          * header area.
 830          */
 831
 832         if (skb->protocol == htons(ETH_P_8021Q)) {
 833                 const struct vlan_hdr *vh =
 834                         (const struct vlan_hdr *)skb->data;
 835
 836                 /* We can't filter on the IP 5-tuple and the vlan
 837                  * together, so just strip the vlan header and filter
 838                  * on the IP part.
 839                  */
 840                 EFX_BUG_ON_PARANOID(skb_headlen(skb) < sizeof(*vh));
 841                 ether_type = vh->h_vlan_encapsulated_proto;
 842                 nhoff = sizeof(struct vlan_hdr);
 843         } else {
 844                 ether_type = skb->protocol;
 845                 nhoff = 0;
 846         }
 847
 848         if (ether_type != htons(ETH_P_IP) && ether_type != htons(ETH_P_IPV6))
 849                 return -EPROTONOSUPPORT;
 850
 851         efx_filter_init_rx(&spec, EFX_FILTER_PRI_HINT,
 852                            efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
 853                            rxq_index);
 854         spec.match_flags =
 855                 EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
 856                 EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
 857                 EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
 858         spec.ether_type = ether_type;
 859
 860         if (ether_type == htons(ETH_P_IP)) {
 861                 const struct iphdr *ip =
 862                         (const struct iphdr *)(skb->data + nhoff);
 863
 864                 EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + sizeof(*ip));
 865                 if (ip_is_fragment(ip))
 866                         return -EPROTONOSUPPORT;
 867                 spec.ip_proto = ip->protocol;
 868                 spec.rem_host[0] = ip->saddr;
 869                 spec.loc_host[0] = ip->daddr;
 870                 EFX_BUG_ON_PARANOID(skb_headlen(skb) < nhoff + 4 * ip->ihl + 4);
 871                 ports = (const __be16 *)(skb->data + nhoff + 4 * ip->ihl);
 872         } else {
 873                 const struct ipv6hdr *ip6 =
 874                         (const struct ipv6hdr *)(skb->data + nhoff);
 875
 876                 EFX_BUG_ON_PARANOID(skb_headlen(skb) <
 877                                     nhoff + sizeof(*ip6) + 4);
 878                 spec.ip_proto = ip6->nexthdr;
 879                 memcpy(spec.rem_host, &ip6->saddr, sizeof(ip6->saddr));
 880                 memcpy(spec.loc_host, &ip6->daddr, sizeof(ip6->daddr));
 881                 ports = (const __be16 *)(ip6 + 1);
 882         }
 883
 884         spec.rem_port = ports[0];
 885         spec.loc_port = ports[1];
 886
 887         rc = efx->type->filter_rfs_insert(efx, &spec);
 888         if (rc < 0)
 889                 return rc;
 890
 891         /* Remember this so we can check whether to expire the filter later */
 892         efx->rps_flow_id[rc] = flow_id;
 893         channel = efx_get_channel(efx, skb_get_rx_queue(skb));
 894         ++channel->rfs_filters_added;
 895
 896         if (ether_type == htons(ETH_P_IP))
 897                 netif_info(efx, rx_status, efx->net_dev,
 898                            "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d]\n",
 899                            (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 900                            spec.rem_host, ntohs(ports[0]), spec.loc_host,
 901                            ntohs(ports[1]), rxq_index, flow_id, rc);
 902         else
 903                 netif_info(efx, rx_status, efx->net_dev,
 904                            "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d]\n",
 905                            (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 906                            spec.rem_host, ntohs(ports[0]), spec.loc_host,
 907                            ntohs(ports[1]), rxq_index, flow_id, rc);
 908
 909         return rc;
 910 }
 911
 912 bool __efx_filter_rfs_expire(struct efx_nic *efx, unsigned int quota)
 913 {
 914         bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
 915         unsigned int index, size;
 916         u32 flow_id;
 917
 918         if (!spin_trylock_bh(&efx->filter_lock))
 919                 return false;
 920
 921         expire_one = efx->type->filter_rfs_expire_one;
 922         index = efx->rps_expire_index;
 923         size = efx->type->max_rx_ip_filters;
 924         while (quota--) {
 925                 flow_id = efx->rps_flow_id[index];
 926                 if (expire_one(efx, flow_id, index))
 927                         netif_info(efx, rx_status, efx->net_dev,
 928                                    "expired filter %d [flow %u]\n",
 929                                    index, flow_id);
 930                 if (++index == size)
 931                         index = 0;
 932         }
 933         efx->rps_expire_index = index;
 934
 935         spin_unlock_bh(&efx->filter_lock);
 936         return true;
 937 }
 938
 939 #endif /* CONFIG_RFS_ACCEL */
 940
 941 /**
 942  * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
 943  * @spec: Specification to test
 944  *
 945  * Return: %true if the specification is a non-drop RX filter that
 946  * matches a local MAC address I/G bit value of 1 or matches a local
 947  * IPv4 or IPv6 address value in the respective multicast address
 948  * range.  Otherwise %false.
 949  */
 950 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
 951 {
 952         if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
 953             spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
 954                 return false;
 955
 956         if (spec->match_flags &
 957             (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
 958             is_multicast_ether_addr(spec->loc_mac))
 959                 return true;
 960
 961         if ((spec->match_flags &
 962              (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
 963             (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
 964                 if (spec->ether_type == htons(ETH_P_IP) &&
 965                     ipv4_is_multicast(spec->loc_host[0]))
 966                         return true;
 967                 if (spec->ether_type == htons(ETH_P_IPV6) &&
 968                     ((const u8 *)spec->loc_host)[0] == 0xff)
 969                         return true;
 970         }
 971
 972         return false;
 973 }