root/drivers/net/ethernet/sfc/falcon/rx.c

DEFINITIONS

1. ef4_rx_buf_va
2. ef4_rx_buf_hash
3. ef4_rx_buf_next
4. ef4_sync_rx_buffer
5. ef4_rx_config_page_split
6. ef4_reuse_page
7. ef4_init_rx_buffers
8. ef4_unmap_rx_buffer
9. ef4_free_rx_buffers
10. ef4_recycle_rx_page
11. ef4_fini_rx_buffer
12. ef4_recycle_rx_pages
13. ef4_discard_rx_packet
14. ef4_fast_push_rx_descriptors
15. ef4_rx_slow_fill
16. ef4_rx_packet__check_len
17. ef4_rx_packet_gro
18. ef4_rx_mk_skb
19. ef4_rx_packet
20. ef4_rx_deliver
21. __ef4_rx_packet
22. ef4_probe_rx_queue
23. ef4_init_rx_recycle_ring
24. ef4_init_rx_queue
25. ef4_fini_rx_queue
26. ef4_remove_rx_queue
27. ef4_filter_rfs
28. __ef4_filter_rfs_expire
29. ef4_filter_is_mc_recipient

   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 EF4_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 EF4_RECYCLE_RING_SIZE_IOMMU 4096
  35 #define EF4_RECYCLE_RING_SIZE_NOIOMMU (2 * EF4_RX_PREFERRED_BATCH)
  36 
  37 /* Size of buffer allocated for skb header area. */
  38 #define EF4_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 EF4_RX_MAX_FRAGS DIV_ROUND_UP(EF4_MAX_FRAME_LEN(EF4_MAX_MTU), \
  47                                       EF4_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 EF4_RXD_HEAD_ROOM (1 + EF4_RX_MAX_FRAGS)
  56 
  57 static inline u8 *ef4_rx_buf_va(struct ef4_rx_buffer *buf)
  58 {
  59         return page_address(buf->page) + buf->page_offset;
  60 }
  61 
  62 static inline u32 ef4_rx_buf_hash(struct ef4_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 ef4_rx_buffer *
  76 ef4_rx_buf_next(struct ef4_rx_queue *rx_queue, struct ef4_rx_buffer *rx_buf)
  77 {
  78         if (unlikely(rx_buf == ef4_rx_buffer(rx_queue, rx_queue->ptr_mask)))
  79                 return ef4_rx_buffer(rx_queue, 0);
  80         else
  81                 return rx_buf + 1;
  82 }
  83 
  84 static inline void ef4_sync_rx_buffer(struct ef4_nic *efx,
  85                                       struct ef4_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 ef4_rx_config_page_split(struct ef4_nic *efx)
  93 {
  94         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align,
  95                                       EF4_RX_BUF_ALIGNMENT);
  96         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
  97                 ((PAGE_SIZE - sizeof(struct ef4_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(EF4_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 *ef4_reuse_page(struct ef4_rx_queue *rx_queue)
 107 {
 108         struct ef4_nic *efx = rx_queue->efx;
 109         struct page *page;
 110         struct ef4_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  * ef4_init_rx_buffers - create EF4_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 ef4_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 ef4_init_rx_buffers(struct ef4_rx_queue *rx_queue, bool atomic)
 150 {
 151         struct ef4_nic *efx = rx_queue->efx;
 152         struct ef4_rx_buffer *rx_buf;
 153         struct page *page;
 154         unsigned int page_offset;
 155         struct ef4_rx_page_state *state;
 156         dma_addr_t dma_addr;
 157         unsigned index, count;
 158 
 159         count = 0;
 160         do {
 161                 page = ef4_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 ef4_rx_page_state);
 185                 page_offset = sizeof(struct ef4_rx_page_state);
 186 
 187                 do {
 188                         index = rx_queue->added_count & rx_queue->ptr_mask;
 189                         rx_buf = ef4_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 = EF4_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 ef4_unmap_rx_buffer(struct ef4_nic *efx,
 211                                 struct ef4_rx_buffer *rx_buf)
 212 {
 213         struct page *page = rx_buf->page;
 214 
 215         if (page) {
 216                 struct ef4_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 ef4_free_rx_buffers(struct ef4_rx_queue *rx_queue,
 225                                 struct ef4_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 = ef4_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 ef4_recycle_rx_page(struct ef4_channel *channel,
 242                                 struct ef4_rx_buffer *rx_buf)
 243 {
 244         struct page *page = rx_buf->page;
 245         struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
 246         struct ef4_nic *efx = rx_queue->efx;
 247         unsigned index;
 248 
 249         /* Only recycle the page after processing the final buffer. */
 250         if (!(rx_buf->flags & EF4_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         ef4_unmap_rx_buffer(efx, rx_buf);
 270         put_page(rx_buf->page);
 271 }
 272 
 273 static void ef4_fini_rx_buffer(struct ef4_rx_queue *rx_queue,
 274                                struct ef4_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 & EF4_RX_BUF_LAST_IN_PAGE) {
 282                 ef4_unmap_rx_buffer(rx_queue->efx, rx_buf);
 283                 ef4_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 ef4_recycle_rx_pages(struct ef4_channel *channel,
 290                                  struct ef4_rx_buffer *rx_buf,
 291                                  unsigned int n_frags)
 292 {
 293         struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
 294 
 295         do {
 296                 ef4_recycle_rx_page(channel, rx_buf);
 297                 rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
 298         } while (--n_frags);
 299 }
 300 
 301 static void ef4_discard_rx_packet(struct ef4_channel *channel,
 302                                   struct ef4_rx_buffer *rx_buf,
 303                                   unsigned int n_frags)
 304 {
 305         struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
 306 
 307         ef4_recycle_rx_pages(channel, rx_buf, n_frags);
 308 
 309         ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 310 }
 311 
 312 /**
 313  * ef4_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 ef4_fast_push_rx_descriptors(struct ef4_rx_queue *rx_queue, bool atomic)
 325 {
 326         struct ef4_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         EF4_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         EF4_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                    ef4_rx_queue_index(rx_queue), fill_level,
 353                    rx_queue->max_fill);
 354 
 355 
 356         do {
 357                 rc = ef4_init_rx_buffers(rx_queue, atomic);
 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                                 ef4_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", ef4_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                 ef4_nic_notify_rx_desc(rx_queue);
 374 }
 375 
 376 void ef4_rx_slow_fill(struct timer_list *t)
 377 {
 378         struct ef4_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
 379 
 380         /* Post an event to cause NAPI to run and refill the queue */
 381         ef4_nic_generate_fill_event(rx_queue);
 382         ++rx_queue->slow_fill_count;
 383 }
 384 
 385 static void ef4_rx_packet__check_len(struct ef4_rx_queue *rx_queue,
 386                                      struct ef4_rx_buffer *rx_buf,
 387                                      int len)
 388 {
 389         struct ef4_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 |= EF4_RX_PKT_DISCARD;
 399 
 400         if ((len > rx_buf->len) && EF4_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                                   ef4_rx_queue_index(rx_queue), len, max_len,
 406                                   efx->type->rx_buffer_padding);
 407                 ef4_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                                   ef4_rx_queue_index(rx_queue), len, max_len);
 414         }
 415 
 416         ef4_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 ef4_rx_packet_gro(struct ef4_channel *channel, struct ef4_rx_buffer *rx_buf,
 424                   unsigned int n_frags, u8 *eh)
 425 {
 426         struct napi_struct *napi = &channel->napi_str;
 427         struct ef4_nic *efx = channel->efx;
 428         struct sk_buff *skb;
 429 
 430         skb = napi_get_frags(napi);
 431         if (unlikely(!skb)) {
 432                 struct ef4_rx_queue *rx_queue;
 433 
 434                 rx_queue = ef4_channel_get_rx_queue(channel);
 435                 ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 436                 return;
 437         }
 438 
 439         if (efx->net_dev->features & NETIF_F_RXHASH)
 440                 skb_set_hash(skb, ef4_rx_buf_hash(efx, eh),
 441                              PKT_HASH_TYPE_L3);
 442         skb->ip_summed = ((rx_buf->flags & EF4_RX_PKT_CSUMMED) ?
 443                           CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 444 
 445         for (;;) {
 446                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 447                                    rx_buf->page, rx_buf->page_offset,
 448                                    rx_buf->len);
 449                 rx_buf->page = NULL;
 450                 skb->len += rx_buf->len;
 451                 if (skb_shinfo(skb)->nr_frags == n_frags)
 452                         break;
 453 
 454                 rx_buf = ef4_rx_buf_next(&channel->rx_queue, rx_buf);
 455         }
 456 
 457         skb->data_len = skb->len;
 458         skb->truesize += n_frags * efx->rx_buffer_truesize;
 459 
 460         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 461 
 462         napi_gro_frags(napi);
 463 }
 464 
 465 /* Allocate and construct an SKB around page fragments */
 466 static struct sk_buff *ef4_rx_mk_skb(struct ef4_channel *channel,
 467                                      struct ef4_rx_buffer *rx_buf,
 468                                      unsigned int n_frags,
 469                                      u8 *eh, int hdr_len)
 470 {
 471         struct ef4_nic *efx = channel->efx;
 472         struct sk_buff *skb;
 473 
 474         /* Allocate an SKB to store the headers */
 475         skb = netdev_alloc_skb(efx->net_dev,
 476                                efx->rx_ip_align + efx->rx_prefix_size +
 477                                hdr_len);
 478         if (unlikely(skb == NULL)) {
 479                 atomic_inc(&efx->n_rx_noskb_drops);
 480                 return NULL;
 481         }
 482 
 483         EF4_BUG_ON_PARANOID(rx_buf->len < hdr_len);
 484 
 485         memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
 486                efx->rx_prefix_size + hdr_len);
 487         skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
 488         __skb_put(skb, hdr_len);
 489 
 490         /* Append the remaining page(s) onto the frag list */
 491         if (rx_buf->len > hdr_len) {
 492                 rx_buf->page_offset += hdr_len;
 493                 rx_buf->len -= hdr_len;
 494 
 495                 for (;;) {
 496                         skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 497                                            rx_buf->page, rx_buf->page_offset,
 498                                            rx_buf->len);
 499                         rx_buf->page = NULL;
 500                         skb->len += rx_buf->len;
 501                         skb->data_len += rx_buf->len;
 502                         if (skb_shinfo(skb)->nr_frags == n_frags)
 503                                 break;
 504 
 505                         rx_buf = ef4_rx_buf_next(&channel->rx_queue, rx_buf);
 506                 }
 507         } else {
 508                 __free_pages(rx_buf->page, efx->rx_buffer_order);
 509                 rx_buf->page = NULL;
 510                 n_frags = 0;
 511         }
 512 
 513         skb->truesize += n_frags * efx->rx_buffer_truesize;
 514 
 515         /* Move past the ethernet header */
 516         skb->protocol = eth_type_trans(skb, efx->net_dev);
 517 
 518         skb_mark_napi_id(skb, &channel->napi_str);
 519 
 520         return skb;
 521 }
 522 
 523 void ef4_rx_packet(struct ef4_rx_queue *rx_queue, unsigned int index,
 524                    unsigned int n_frags, unsigned int len, u16 flags)
 525 {
 526         struct ef4_nic *efx = rx_queue->efx;
 527         struct ef4_channel *channel = ef4_rx_queue_channel(rx_queue);
 528         struct ef4_rx_buffer *rx_buf;
 529 
 530         rx_queue->rx_packets++;
 531 
 532         rx_buf = ef4_rx_buffer(rx_queue, index);
 533         rx_buf->flags |= flags;
 534 
 535         /* Validate the number of fragments and completed length */
 536         if (n_frags == 1) {
 537                 if (!(flags & EF4_RX_PKT_PREFIX_LEN))
 538                         ef4_rx_packet__check_len(rx_queue, rx_buf, len);
 539         } else if (unlikely(n_frags > EF4_RX_MAX_FRAGS) ||
 540                    unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
 541                    unlikely(len > n_frags * efx->rx_dma_len) ||
 542                    unlikely(!efx->rx_scatter)) {
 543                 /* If this isn't an explicit discard request, either
 544                  * the hardware or the driver is broken.
 545                  */
 546                 WARN_ON(!(len == 0 && rx_buf->flags & EF4_RX_PKT_DISCARD));
 547                 rx_buf->flags |= EF4_RX_PKT_DISCARD;
 548         }
 549 
 550         netif_vdbg(efx, rx_status, efx->net_dev,
 551                    "RX queue %d received ids %x-%x len %d %s%s\n",
 552                    ef4_rx_queue_index(rx_queue), index,
 553                    (index + n_frags - 1) & rx_queue->ptr_mask, len,
 554                    (rx_buf->flags & EF4_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
 555                    (rx_buf->flags & EF4_RX_PKT_DISCARD) ? " [DISCARD]" : "");
 556 
 557         /* Discard packet, if instructed to do so.  Process the
 558          * previous receive first.
 559          */
 560         if (unlikely(rx_buf->flags & EF4_RX_PKT_DISCARD)) {
 561                 ef4_rx_flush_packet(channel);
 562                 ef4_discard_rx_packet(channel, rx_buf, n_frags);
 563                 return;
 564         }
 565 
 566         if (n_frags == 1 && !(flags & EF4_RX_PKT_PREFIX_LEN))
 567                 rx_buf->len = len;
 568 
 569         /* Release and/or sync the DMA mapping - assumes all RX buffers
 570          * consumed in-order per RX queue.
 571          */
 572         ef4_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 573 
 574         /* Prefetch nice and early so data will (hopefully) be in cache by
 575          * the time we look at it.
 576          */
 577         prefetch(ef4_rx_buf_va(rx_buf));
 578 
 579         rx_buf->page_offset += efx->rx_prefix_size;
 580         rx_buf->len -= efx->rx_prefix_size;
 581 
 582         if (n_frags > 1) {
 583                 /* Release/sync DMA mapping for additional fragments.
 584                  * Fix length for last fragment.
 585                  */
 586                 unsigned int tail_frags = n_frags - 1;
 587 
 588                 for (;;) {
 589                         rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
 590                         if (--tail_frags == 0)
 591                                 break;
 592                         ef4_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
 593                 }
 594                 rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
 595                 ef4_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 596         }
 597 
 598         /* All fragments have been DMA-synced, so recycle pages. */
 599         rx_buf = ef4_rx_buffer(rx_queue, index);
 600         ef4_recycle_rx_pages(channel, rx_buf, n_frags);
 601 
 602         /* Pipeline receives so that we give time for packet headers to be
 603          * prefetched into cache.
 604          */
 605         ef4_rx_flush_packet(channel);
 606         channel->rx_pkt_n_frags = n_frags;
 607         channel->rx_pkt_index = index;
 608 }
 609 
 610 static void ef4_rx_deliver(struct ef4_channel *channel, u8 *eh,
 611                            struct ef4_rx_buffer *rx_buf,
 612                            unsigned int n_frags)
 613 {
 614         struct sk_buff *skb;
 615         u16 hdr_len = min_t(u16, rx_buf->len, EF4_SKB_HEADERS);
 616 
 617         skb = ef4_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
 618         if (unlikely(skb == NULL)) {
 619                 struct ef4_rx_queue *rx_queue;
 620 
 621                 rx_queue = ef4_channel_get_rx_queue(channel);
 622                 ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 623                 return;
 624         }
 625         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 626 
 627         /* Set the SKB flags */
 628         skb_checksum_none_assert(skb);
 629         if (likely(rx_buf->flags & EF4_RX_PKT_CSUMMED))
 630                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 631 
 632         if (channel->type->receive_skb)
 633                 if (channel->type->receive_skb(channel, skb))
 634                         return;
 635 
 636         /* Pass the packet up */
 637         netif_receive_skb(skb);
 638 }
 639 
 640 /* Handle a received packet.  Second half: Touches packet payload. */
 641 void __ef4_rx_packet(struct ef4_channel *channel)
 642 {
 643         struct ef4_nic *efx = channel->efx;
 644         struct ef4_rx_buffer *rx_buf =
 645                 ef4_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
 646         u8 *eh = ef4_rx_buf_va(rx_buf);
 647 
 648         /* Read length from the prefix if necessary.  This already
 649          * excludes the length of the prefix itself.
 650          */
 651         if (rx_buf->flags & EF4_RX_PKT_PREFIX_LEN)
 652                 rx_buf->len = le16_to_cpup((__le16 *)
 653                                            (eh + efx->rx_packet_len_offset));
 654 
 655         /* If we're in loopback test, then pass the packet directly to the
 656          * loopback layer, and free the rx_buf here
 657          */
 658         if (unlikely(efx->loopback_selftest)) {
 659                 struct ef4_rx_queue *rx_queue;
 660 
 661                 ef4_loopback_rx_packet(efx, eh, rx_buf->len);
 662                 rx_queue = ef4_channel_get_rx_queue(channel);
 663                 ef4_free_rx_buffers(rx_queue, rx_buf,
 664                                     channel->rx_pkt_n_frags);
 665                 goto out;
 666         }
 667 
 668         if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
 669                 rx_buf->flags &= ~EF4_RX_PKT_CSUMMED;
 670 
 671         if ((rx_buf->flags & EF4_RX_PKT_TCP) && !channel->type->receive_skb)
 672                 ef4_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
 673         else
 674                 ef4_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
 675 out:
 676         channel->rx_pkt_n_frags = 0;
 677 }
 678 
 679 int ef4_probe_rx_queue(struct ef4_rx_queue *rx_queue)
 680 {
 681         struct ef4_nic *efx = rx_queue->efx;
 682         unsigned int entries;
 683         int rc;
 684 
 685         /* Create the smallest power-of-two aligned ring */
 686         entries = max(roundup_pow_of_two(efx->rxq_entries), EF4_MIN_DMAQ_SIZE);
 687         EF4_BUG_ON_PARANOID(entries > EF4_MAX_DMAQ_SIZE);
 688         rx_queue->ptr_mask = entries - 1;
 689 
 690         netif_dbg(efx, probe, efx->net_dev,
 691                   "creating RX queue %d size %#x mask %#x\n",
 692                   ef4_rx_queue_index(rx_queue), efx->rxq_entries,
 693                   rx_queue->ptr_mask);
 694 
 695         /* Allocate RX buffers */
 696         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 697                                    GFP_KERNEL);
 698         if (!rx_queue->buffer)
 699                 return -ENOMEM;
 700 
 701         rc = ef4_nic_probe_rx(rx_queue);
 702         if (rc) {
 703                 kfree(rx_queue->buffer);
 704                 rx_queue->buffer = NULL;
 705         }
 706 
 707         return rc;
 708 }
 709 
 710 static void ef4_init_rx_recycle_ring(struct ef4_nic *efx,
 711                                      struct ef4_rx_queue *rx_queue)
 712 {
 713         unsigned int bufs_in_recycle_ring, page_ring_size;
 714 
 715         /* Set the RX recycle ring size */
 716 #ifdef CONFIG_PPC64
 717         bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU;
 718 #else
 719         if (iommu_present(&pci_bus_type))
 720                 bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU;
 721         else
 722                 bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_NOIOMMU;
 723 #endif /* CONFIG_PPC64 */
 724 
 725         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 726                                             efx->rx_bufs_per_page);
 727         rx_queue->page_ring = kcalloc(page_ring_size,
 728                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 729         rx_queue->page_ptr_mask = page_ring_size - 1;
 730 }
 731 
 732 void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue)
 733 {
 734         struct ef4_nic *efx = rx_queue->efx;
 735         unsigned int max_fill, trigger, max_trigger;
 736 
 737         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 738                   "initialising RX queue %d\n", ef4_rx_queue_index(rx_queue));
 739 
 740         /* Initialise ptr fields */
 741         rx_queue->added_count = 0;
 742         rx_queue->notified_count = 0;
 743         rx_queue->removed_count = 0;
 744         rx_queue->min_fill = -1U;
 745         ef4_init_rx_recycle_ring(efx, rx_queue);
 746 
 747         rx_queue->page_remove = 0;
 748         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 749         rx_queue->page_recycle_count = 0;
 750         rx_queue->page_recycle_failed = 0;
 751         rx_queue->page_recycle_full = 0;
 752 
 753         /* Initialise limit fields */
 754         max_fill = efx->rxq_entries - EF4_RXD_HEAD_ROOM;
 755         max_trigger =
 756                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 757         if (rx_refill_threshold != 0) {
 758                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 759                 if (trigger > max_trigger)
 760                         trigger = max_trigger;
 761         } else {
 762                 trigger = max_trigger;
 763         }
 764 
 765         rx_queue->max_fill = max_fill;
 766         rx_queue->fast_fill_trigger = trigger;
 767         rx_queue->refill_enabled = true;
 768 
 769         /* Set up RX descriptor ring */
 770         ef4_nic_init_rx(rx_queue);
 771 }
 772 
 773 void ef4_fini_rx_queue(struct ef4_rx_queue *rx_queue)
 774 {
 775         int i;
 776         struct ef4_nic *efx = rx_queue->efx;
 777         struct ef4_rx_buffer *rx_buf;
 778 
 779         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 780                   "shutting down RX queue %d\n", ef4_rx_queue_index(rx_queue));
 781 
 782         del_timer_sync(&rx_queue->slow_fill);
 783 
 784         /* Release RX buffers from the current read ptr to the write ptr */
 785         if (rx_queue->buffer) {
 786                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 787                      i++) {
 788                         unsigned index = i & rx_queue->ptr_mask;
 789                         rx_buf = ef4_rx_buffer(rx_queue, index);
 790                         ef4_fini_rx_buffer(rx_queue, rx_buf);
 791                 }
 792         }
 793 
 794         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 795         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 796                 struct page *page = rx_queue->page_ring[i];
 797                 struct ef4_rx_page_state *state;
 798 
 799                 if (page == NULL)
 800                         continue;
 801 
 802                 state = page_address(page);
 803                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 804                                PAGE_SIZE << efx->rx_buffer_order,
 805                                DMA_FROM_DEVICE);
 806                 put_page(page);
 807         }
 808         kfree(rx_queue->page_ring);
 809         rx_queue->page_ring = NULL;
 810 }
 811 
 812 void ef4_remove_rx_queue(struct ef4_rx_queue *rx_queue)
 813 {
 814         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 815                   "destroying RX queue %d\n", ef4_rx_queue_index(rx_queue));
 816 
 817         ef4_nic_remove_rx(rx_queue);
 818 
 819         kfree(rx_queue->buffer);
 820         rx_queue->buffer = NULL;
 821 }
 822 
 823 
 824 module_param(rx_refill_threshold, uint, 0444);
 825 MODULE_PARM_DESC(rx_refill_threshold,
 826                  "RX descriptor ring refill threshold (%)");
 827 
 828 #ifdef CONFIG_RFS_ACCEL
 829 
 830 int ef4_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 831                    u16 rxq_index, u32 flow_id)
 832 {
 833         struct ef4_nic *efx = netdev_priv(net_dev);
 834         struct ef4_channel *channel;
 835         struct ef4_filter_spec spec;
 836         struct flow_keys fk;
 837         int rc;
 838 
 839         if (flow_id == RPS_FLOW_ID_INVALID)
 840                 return -EINVAL;
 841 
 842         if (!skb_flow_dissect_flow_keys(skb, &fk, 0))
 843                 return -EPROTONOSUPPORT;
 844 
 845         if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6))
 846                 return -EPROTONOSUPPORT;
 847         if (fk.control.flags & FLOW_DIS_IS_FRAGMENT)
 848                 return -EPROTONOSUPPORT;
 849 
 850         ef4_filter_init_rx(&spec, EF4_FILTER_PRI_HINT,
 851                            efx->rx_scatter ? EF4_FILTER_FLAG_RX_SCATTER : 0,
 852                            rxq_index);
 853         spec.match_flags =
 854                 EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_IP_PROTO |
 855                 EF4_FILTER_MATCH_LOC_HOST | EF4_FILTER_MATCH_LOC_PORT |
 856                 EF4_FILTER_MATCH_REM_HOST | EF4_FILTER_MATCH_REM_PORT;
 857         spec.ether_type = fk.basic.n_proto;
 858         spec.ip_proto = fk.basic.ip_proto;
 859 
 860         if (fk.basic.n_proto == htons(ETH_P_IP)) {
 861                 spec.rem_host[0] = fk.addrs.v4addrs.src;
 862                 spec.loc_host[0] = fk.addrs.v4addrs.dst;
 863         } else {
 864                 memcpy(spec.rem_host, &fk.addrs.v6addrs.src, sizeof(struct in6_addr));
 865                 memcpy(spec.loc_host, &fk.addrs.v6addrs.dst, sizeof(struct in6_addr));
 866         }
 867 
 868         spec.rem_port = fk.ports.src;
 869         spec.loc_port = fk.ports.dst;
 870 
 871         rc = efx->type->filter_rfs_insert(efx, &spec);
 872         if (rc < 0)
 873                 return rc;
 874 
 875         /* Remember this so we can check whether to expire the filter later */
 876         channel = ef4_get_channel(efx, rxq_index);
 877         channel->rps_flow_id[rc] = flow_id;
 878         ++channel->rfs_filters_added;
 879 
 880         if (spec.ether_type == htons(ETH_P_IP))
 881                 netif_info(efx, rx_status, efx->net_dev,
 882                            "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d]\n",
 883                            (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 884                            spec.rem_host, ntohs(spec.rem_port), spec.loc_host,
 885                            ntohs(spec.loc_port), rxq_index, flow_id, rc);
 886         else
 887                 netif_info(efx, rx_status, efx->net_dev,
 888                            "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d]\n",
 889                            (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 890                            spec.rem_host, ntohs(spec.rem_port), spec.loc_host,
 891                            ntohs(spec.loc_port), rxq_index, flow_id, rc);
 892 
 893         return rc;
 894 }
 895 
 896 bool __ef4_filter_rfs_expire(struct ef4_nic *efx, unsigned int quota)
 897 {
 898         bool (*expire_one)(struct ef4_nic *efx, u32 flow_id, unsigned int index);
 899         unsigned int channel_idx, index, size;
 900         u32 flow_id;
 901 
 902         if (!spin_trylock_bh(&efx->filter_lock))
 903                 return false;
 904 
 905         expire_one = efx->type->filter_rfs_expire_one;
 906         channel_idx = efx->rps_expire_channel;
 907         index = efx->rps_expire_index;
 908         size = efx->type->max_rx_ip_filters;
 909         while (quota--) {
 910                 struct ef4_channel *channel = ef4_get_channel(efx, channel_idx);
 911                 flow_id = channel->rps_flow_id[index];
 912 
 913                 if (flow_id != RPS_FLOW_ID_INVALID &&
 914                     expire_one(efx, flow_id, index)) {
 915                         netif_info(efx, rx_status, efx->net_dev,
 916                                    "expired filter %d [queue %u flow %u]\n",
 917                                    index, channel_idx, flow_id);
 918                         channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
 919                 }
 920                 if (++index == size) {
 921                         if (++channel_idx == efx->n_channels)
 922                                 channel_idx = 0;
 923                         index = 0;
 924                 }
 925         }
 926         efx->rps_expire_channel = channel_idx;
 927         efx->rps_expire_index = index;
 928 
 929         spin_unlock_bh(&efx->filter_lock);
 930         return true;
 931 }
 932 
 933 #endif /* CONFIG_RFS_ACCEL */
 934 
 935 /**
 936  * ef4_filter_is_mc_recipient - test whether spec is a multicast recipient
 937  * @spec: Specification to test
 938  *
 939  * Return: %true if the specification is a non-drop RX filter that
 940  * matches a local MAC address I/G bit value of 1 or matches a local
 941  * IPv4 or IPv6 address value in the respective multicast address
 942  * range.  Otherwise %false.
 943  */
 944 bool ef4_filter_is_mc_recipient(const struct ef4_filter_spec *spec)
 945 {
 946         if (!(spec->flags & EF4_FILTER_FLAG_RX) ||
 947             spec->dmaq_id == EF4_FILTER_RX_DMAQ_ID_DROP)
 948                 return false;
 949 
 950         if (spec->match_flags &
 951             (EF4_FILTER_MATCH_LOC_MAC | EF4_FILTER_MATCH_LOC_MAC_IG) &&
 952             is_multicast_ether_addr(spec->loc_mac))
 953                 return true;
 954 
 955         if ((spec->match_flags &
 956              (EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_LOC_HOST)) ==
 957             (EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_LOC_HOST)) {
 958                 if (spec->ether_type == htons(ETH_P_IP) &&
 959                     ipv4_is_multicast(spec->loc_host[0]))
 960                         return true;
 961                 if (spec->ether_type == htons(ETH_P_IPV6) &&
 962                     ((const u8 *)spec->loc_host)[0] == 0xff)
 963                         return true;
 964         }
 965 
 966         return false;
 967 }