drivers/net/ethernet/sfc/falcon/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 EF4_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 EF4_RECYCLE_RING_SIZE_IOMMU 4096
  38 #define EF4_RECYCLE_RING_SIZE_NOIOMMU (2 * EF4_RX_PREFERRED_BATCH)
  39
  40 /* Size of buffer allocated for skb header area. */
  41 #define EF4_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 EF4_RX_MAX_FRAGS DIV_ROUND_UP(EF4_MAX_FRAME_LEN(EF4_MAX_MTU), \
  50                                       EF4_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 EF4_RXD_HEAD_ROOM (1 + EF4_RX_MAX_FRAGS)
  59
  60 static inline u8 *ef4_rx_buf_va(struct ef4_rx_buffer *buf)
  61 {
  62         return page_address(buf->page) + buf->page_offset;
  63 }
  64
  65 static inline u32 ef4_rx_buf_hash(struct ef4_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 ef4_rx_buffer *
  79 ef4_rx_buf_next(struct ef4_rx_queue *rx_queue, struct ef4_rx_buffer *rx_buf)
  80 {
  81         if (unlikely(rx_buf == ef4_rx_buffer(rx_queue, rx_queue->ptr_mask)))
  82                 return ef4_rx_buffer(rx_queue, 0);
  83         else
  84                 return rx_buf + 1;
  85 }
  86
  87 static inline void ef4_sync_rx_buffer(struct ef4_nic *efx,
  88                                       struct ef4_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 ef4_rx_config_page_split(struct ef4_nic *efx)
  96 {
  97         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align,
  98                                       EF4_RX_BUF_ALIGNMENT);
  99         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
 100                 ((PAGE_SIZE - sizeof(struct ef4_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(EF4_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 *ef4_reuse_page(struct ef4_rx_queue *rx_queue)
 110 {
 111         struct ef4_nic *efx = rx_queue->efx;
 112         struct page *page;
 113         struct ef4_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  * ef4_init_rx_buffers - create EF4_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 ef4_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 ef4_init_rx_buffers(struct ef4_rx_queue *rx_queue, bool atomic)
 153 {
 154         struct ef4_nic *efx = rx_queue->efx;
 155         struct ef4_rx_buffer *rx_buf;
 156         struct page *page;
 157         unsigned int page_offset;
 158         struct ef4_rx_page_state *state;
 159         dma_addr_t dma_addr;
 160         unsigned index, count;
 161
 162         count = 0;
 163         do {
 164                 page = ef4_reuse_page(rx_queue);
 165                 if (page == NULL) {
 166                         page = alloc_pages(__GFP_COLD | __GFP_COMP |
 167                                            (atomic ? GFP_ATOMIC : GFP_KERNEL),
 168                                            efx->rx_buffer_order);
 169                         if (unlikely(page == NULL))
 170                                 return -ENOMEM;
 171                         dma_addr =
 172                                 dma_map_page(&efx->pci_dev->dev, page, 0,
 173                                              PAGE_SIZE << efx->rx_buffer_order,
 174                                              DMA_FROM_DEVICE);
 175                         if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
 176                                                        dma_addr))) {
 177                                 __free_pages(page, efx->rx_buffer_order);
 178                                 return -EIO;
 179                         }
 180                         state = page_address(page);
 181                         state->dma_addr = dma_addr;
 182                 } else {
 183                         state = page_address(page);
 184                         dma_addr = state->dma_addr;
 185                 }
 186
 187                 dma_addr += sizeof(struct ef4_rx_page_state);
 188                 page_offset = sizeof(struct ef4_rx_page_state);
 189
 190                 do {
 191                         index = rx_queue->added_count & rx_queue->ptr_mask;
 192                         rx_buf = ef4_rx_buffer(rx_queue, index);
 193                         rx_buf->dma_addr = dma_addr + efx->rx_ip_align;
 194                         rx_buf->page = page;
 195                         rx_buf->page_offset = page_offset + efx->rx_ip_align;
 196                         rx_buf->len = efx->rx_dma_len;
 197                         rx_buf->flags = 0;
 198                         ++rx_queue->added_count;
 199                         get_page(page);
 200                         dma_addr += efx->rx_page_buf_step;
 201                         page_offset += efx->rx_page_buf_step;
 202                 } while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
 203
 204                 rx_buf->flags = EF4_RX_BUF_LAST_IN_PAGE;
 205         } while (++count < efx->rx_pages_per_batch);
 206
 207         return 0;
 208 }
 209
 210 /* Unmap a DMA-mapped page.  This function is only called for the final RX
 211  * buffer in a page.
 212  */
 213 static void ef4_unmap_rx_buffer(struct ef4_nic *efx,
 214                                 struct ef4_rx_buffer *rx_buf)
 215 {
 216         struct page *page = rx_buf->page;
 217
 218         if (page) {
 219                 struct ef4_rx_page_state *state = page_address(page);
 220                 dma_unmap_page(&efx->pci_dev->dev,
 221                                state->dma_addr,
 222                                PAGE_SIZE << efx->rx_buffer_order,
 223                                DMA_FROM_DEVICE);
 224         }
 225 }
 226
 227 static void ef4_free_rx_buffers(struct ef4_rx_queue *rx_queue,
 228                                 struct ef4_rx_buffer *rx_buf,
 229                                 unsigned int num_bufs)
 230 {
 231         do {
 232                 if (rx_buf->page) {
 233                         put_page(rx_buf->page);
 234                         rx_buf->page = NULL;
 235                 }
 236                 rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
 237         } while (--num_bufs);
 238 }
 239
 240 /* Attempt to recycle the page if there is an RX recycle ring; the page can
 241  * only be added if this is the final RX buffer, to prevent pages being used in
 242  * the descriptor ring and appearing in the recycle ring simultaneously.
 243  */
 244 static void ef4_recycle_rx_page(struct ef4_channel *channel,
 245                                 struct ef4_rx_buffer *rx_buf)
 246 {
 247         struct page *page = rx_buf->page;
 248         struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
 249         struct ef4_nic *efx = rx_queue->efx;
 250         unsigned index;
 251
 252         /* Only recycle the page after processing the final buffer. */
 253         if (!(rx_buf->flags & EF4_RX_BUF_LAST_IN_PAGE))
 254                 return;
 255
 256         index = rx_queue->page_add & rx_queue->page_ptr_mask;
 257         if (rx_queue->page_ring[index] == NULL) {
 258                 unsigned read_index = rx_queue->page_remove &
 259                         rx_queue->page_ptr_mask;
 260
 261                 /* The next slot in the recycle ring is available, but
 262                  * increment page_remove if the read pointer currently
 263                  * points here.
 264                  */
 265                 if (read_index == index)
 266                         ++rx_queue->page_remove;
 267                 rx_queue->page_ring[index] = page;
 268                 ++rx_queue->page_add;
 269                 return;
 270         }
 271         ++rx_queue->page_recycle_full;
 272         ef4_unmap_rx_buffer(efx, rx_buf);
 273         put_page(rx_buf->page);
 274 }
 275
 276 static void ef4_fini_rx_buffer(struct ef4_rx_queue *rx_queue,
 277                                struct ef4_rx_buffer *rx_buf)
 278 {
 279         /* Release the page reference we hold for the buffer. */
 280         if (rx_buf->page)
 281                 put_page(rx_buf->page);
 282
 283         /* If this is the last buffer in a page, unmap and free it. */
 284         if (rx_buf->flags & EF4_RX_BUF_LAST_IN_PAGE) {
 285                 ef4_unmap_rx_buffer(rx_queue->efx, rx_buf);
 286                 ef4_free_rx_buffers(rx_queue, rx_buf, 1);
 287         }
 288         rx_buf->page = NULL;
 289 }
 290
 291 /* Recycle the pages that are used by buffers that have just been received. */
 292 static void ef4_recycle_rx_pages(struct ef4_channel *channel,
 293                                  struct ef4_rx_buffer *rx_buf,
 294                                  unsigned int n_frags)
 295 {
 296         struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
 297
 298         do {
 299                 ef4_recycle_rx_page(channel, rx_buf);
 300                 rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
 301         } while (--n_frags);
 302 }
 303
 304 static void ef4_discard_rx_packet(struct ef4_channel *channel,
 305                                   struct ef4_rx_buffer *rx_buf,
 306                                   unsigned int n_frags)
 307 {
 308         struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
 309
 310         ef4_recycle_rx_pages(channel, rx_buf, n_frags);
 311
 312         ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 313 }
 314
 315 /**
 316  * ef4_fast_push_rx_descriptors - push new RX descriptors quickly
 317  * @rx_queue:           RX descriptor queue
 318  *
 319  * This will aim to fill the RX descriptor queue up to
 320  * @rx_queue->@max_fill. If there is insufficient atomic
 321  * memory to do so, a slow fill will be scheduled.
 322  *
 323  * The caller must provide serialisation (none is used here). In practise,
 324  * this means this function must run from the NAPI handler, or be called
 325  * when NAPI is disabled.
 326  */
 327 void ef4_fast_push_rx_descriptors(struct ef4_rx_queue *rx_queue, bool atomic)
 328 {
 329         struct ef4_nic *efx = rx_queue->efx;
 330         unsigned int fill_level, batch_size;
 331         int space, rc = 0;
 332
 333         if (!rx_queue->refill_enabled)
 334                 return;
 335
 336         /* Calculate current fill level, and exit if we don't need to fill */
 337         fill_level = (rx_queue->added_count - rx_queue->removed_count);
 338         EF4_BUG_ON_PARANOID(fill_level > rx_queue->efx->rxq_entries);
 339         if (fill_level >= rx_queue->fast_fill_trigger)
 340                 goto out;
 341
 342         /* Record minimum fill level */
 343         if (unlikely(fill_level < rx_queue->min_fill)) {
 344                 if (fill_level)
 345                         rx_queue->min_fill = fill_level;
 346         }
 347
 348         batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 349         space = rx_queue->max_fill - fill_level;
 350         EF4_BUG_ON_PARANOID(space < batch_size);
 351
 352         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 353                    "RX queue %d fast-filling descriptor ring from"
 354                    " level %d to level %d\n",
 355                    ef4_rx_queue_index(rx_queue), fill_level,
 356                    rx_queue->max_fill);
 357
 358
 359         do {
 360                 rc = ef4_init_rx_buffers(rx_queue, atomic);
 361                 if (unlikely(rc)) {
 362                         /* Ensure that we don't leave the rx queue empty */
 363                         if (rx_queue->added_count == rx_queue->removed_count)
 364                                 ef4_schedule_slow_fill(rx_queue);
 365                         goto out;
 366                 }
 367         } while ((space -= batch_size) >= batch_size);
 368
 369         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 370                    "RX queue %d fast-filled descriptor ring "
 371                    "to level %d\n", ef4_rx_queue_index(rx_queue),
 372                    rx_queue->added_count - rx_queue->removed_count);
 373
 374  out:
 375         if (rx_queue->notified_count != rx_queue->added_count)
 376                 ef4_nic_notify_rx_desc(rx_queue);
 377 }
 378
 379 void ef4_rx_slow_fill(unsigned long context)
 380 {
 381         struct ef4_rx_queue *rx_queue = (struct ef4_rx_queue *)context;
 382
 383         /* Post an event to cause NAPI to run and refill the queue */
 384         ef4_nic_generate_fill_event(rx_queue);
 385         ++rx_queue->slow_fill_count;
 386 }
 387
 388 static void ef4_rx_packet__check_len(struct ef4_rx_queue *rx_queue,
 389                                      struct ef4_rx_buffer *rx_buf,
 390                                      int len)
 391 {
 392         struct ef4_nic *efx = rx_queue->efx;
 393         unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
 394
 395         if (likely(len <= max_len))
 396                 return;
 397
 398         /* The packet must be discarded, but this is only a fatal error
 399          * if the caller indicated it was
 400          */
 401         rx_buf->flags |= EF4_RX_PKT_DISCARD;
 402
 403         if ((len > rx_buf->len) && EF4_WORKAROUND_8071(efx)) {
 404                 if (net_ratelimit())
 405                         netif_err(efx, rx_err, efx->net_dev,
 406                                   " RX queue %d seriously overlength "
 407                                   "RX event (0x%x > 0x%x+0x%x). Leaking\n",
 408                                   ef4_rx_queue_index(rx_queue), len, max_len,
 409                                   efx->type->rx_buffer_padding);
 410                 ef4_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
 411         } else {
 412                 if (net_ratelimit())
 413                         netif_err(efx, rx_err, efx->net_dev,
 414                                   " RX queue %d overlength RX event "
 415                                   "(0x%x > 0x%x)\n",
 416                                   ef4_rx_queue_index(rx_queue), len, max_len);
 417         }
 418
 419         ef4_rx_queue_channel(rx_queue)->n_rx_overlength++;
 420 }
 421
 422 /* Pass a received packet up through GRO.  GRO can handle pages
 423  * regardless of checksum state and skbs with a good checksum.
 424  */
 425 static void
 426 ef4_rx_packet_gro(struct ef4_channel *channel, struct ef4_rx_buffer *rx_buf,
 427                   unsigned int n_frags, u8 *eh)
 428 {
 429         struct napi_struct *napi = &channel->napi_str;
 430         gro_result_t gro_result;
 431         struct ef4_nic *efx = channel->efx;
 432         struct sk_buff *skb;
 433
 434         skb = napi_get_frags(napi);
 435         if (unlikely(!skb)) {
 436                 struct ef4_rx_queue *rx_queue;
 437
 438                 rx_queue = ef4_channel_get_rx_queue(channel);
 439                 ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 440                 return;
 441         }
 442
 443         if (efx->net_dev->features & NETIF_F_RXHASH)
 444                 skb_set_hash(skb, ef4_rx_buf_hash(efx, eh),
 445                              PKT_HASH_TYPE_L3);
 446         skb->ip_summed = ((rx_buf->flags & EF4_RX_PKT_CSUMMED) ?
 447                           CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 448
 449         for (;;) {
 450                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 451                                    rx_buf->page, rx_buf->page_offset,
 452                                    rx_buf->len);
 453                 rx_buf->page = NULL;
 454                 skb->len += rx_buf->len;
 455                 if (skb_shinfo(skb)->nr_frags == n_frags)
 456                         break;
 457
 458                 rx_buf = ef4_rx_buf_next(&channel->rx_queue, rx_buf);
 459         }
 460
 461         skb->data_len = skb->len;
 462         skb->truesize += n_frags * efx->rx_buffer_truesize;
 463
 464         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 465
 466         gro_result = napi_gro_frags(napi);
 467         if (gro_result != GRO_DROP)
 468                 channel->irq_mod_score += 2;
 469 }
 470
 471 /* Allocate and construct an SKB around page fragments */
 472 static struct sk_buff *ef4_rx_mk_skb(struct ef4_channel *channel,
 473                                      struct ef4_rx_buffer *rx_buf,
 474                                      unsigned int n_frags,
 475                                      u8 *eh, int hdr_len)
 476 {
 477         struct ef4_nic *efx = channel->efx;
 478         struct sk_buff *skb;
 479
 480         /* Allocate an SKB to store the headers */
 481         skb = netdev_alloc_skb(efx->net_dev,
 482                                efx->rx_ip_align + efx->rx_prefix_size +
 483                                hdr_len);
 484         if (unlikely(skb == NULL)) {
 485                 atomic_inc(&efx->n_rx_noskb_drops);
 486                 return NULL;
 487         }
 488
 489         EF4_BUG_ON_PARANOID(rx_buf->len < hdr_len);
 490
 491         memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
 492                efx->rx_prefix_size + hdr_len);
 493         skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
 494         __skb_put(skb, hdr_len);
 495
 496         /* Append the remaining page(s) onto the frag list */
 497         if (rx_buf->len > hdr_len) {
 498                 rx_buf->page_offset += hdr_len;
 499                 rx_buf->len -= hdr_len;
 500
 501                 for (;;) {
 502                         skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 503                                            rx_buf->page, rx_buf->page_offset,
 504                                            rx_buf->len);
 505                         rx_buf->page = NULL;
 506                         skb->len += rx_buf->len;
 507                         skb->data_len += rx_buf->len;
 508                         if (skb_shinfo(skb)->nr_frags == n_frags)
 509                                 break;
 510
 511                         rx_buf = ef4_rx_buf_next(&channel->rx_queue, rx_buf);
 512                 }
 513         } else {
 514                 __free_pages(rx_buf->page, efx->rx_buffer_order);
 515                 rx_buf->page = NULL;
 516                 n_frags = 0;
 517         }
 518
 519         skb->truesize += n_frags * efx->rx_buffer_truesize;
 520
 521         /* Move past the ethernet header */
 522         skb->protocol = eth_type_trans(skb, efx->net_dev);
 523
 524         skb_mark_napi_id(skb, &channel->napi_str);
 525
 526         return skb;
 527 }
 528
 529 void ef4_rx_packet(struct ef4_rx_queue *rx_queue, unsigned int index,
 530                    unsigned int n_frags, unsigned int len, u16 flags)
 531 {
 532         struct ef4_nic *efx = rx_queue->efx;
 533         struct ef4_channel *channel = ef4_rx_queue_channel(rx_queue);
 534         struct ef4_rx_buffer *rx_buf;
 535
 536         rx_queue->rx_packets++;
 537
 538         rx_buf = ef4_rx_buffer(rx_queue, index);
 539         rx_buf->flags |= flags;
 540
 541         /* Validate the number of fragments and completed length */
 542         if (n_frags == 1) {
 543                 if (!(flags & EF4_RX_PKT_PREFIX_LEN))
 544                         ef4_rx_packet__check_len(rx_queue, rx_buf, len);
 545         } else if (unlikely(n_frags > EF4_RX_MAX_FRAGS) ||
 546                    unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
 547                    unlikely(len > n_frags * efx->rx_dma_len) ||
 548                    unlikely(!efx->rx_scatter)) {
 549                 /* If this isn't an explicit discard request, either
 550                  * the hardware or the driver is broken.
 551                  */
 552                 WARN_ON(!(len == 0 && rx_buf->flags & EF4_RX_PKT_DISCARD));
 553                 rx_buf->flags |= EF4_RX_PKT_DISCARD;
 554         }
 555
 556         netif_vdbg(efx, rx_status, efx->net_dev,
 557                    "RX queue %d received ids %x-%x len %d %s%s\n",
 558                    ef4_rx_queue_index(rx_queue), index,
 559                    (index + n_frags - 1) & rx_queue->ptr_mask, len,
 560                    (rx_buf->flags & EF4_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
 561                    (rx_buf->flags & EF4_RX_PKT_DISCARD) ? " [DISCARD]" : "");
 562
 563         /* Discard packet, if instructed to do so.  Process the
 564          * previous receive first.
 565          */
 566         if (unlikely(rx_buf->flags & EF4_RX_PKT_DISCARD)) {
 567                 ef4_rx_flush_packet(channel);
 568                 ef4_discard_rx_packet(channel, rx_buf, n_frags);
 569                 return;
 570         }
 571
 572         if (n_frags == 1 && !(flags & EF4_RX_PKT_PREFIX_LEN))
 573                 rx_buf->len = len;
 574
 575         /* Release and/or sync the DMA mapping - assumes all RX buffers
 576          * consumed in-order per RX queue.
 577          */
 578         ef4_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 579
 580         /* Prefetch nice and early so data will (hopefully) be in cache by
 581          * the time we look at it.
 582          */
 583         prefetch(ef4_rx_buf_va(rx_buf));
 584
 585         rx_buf->page_offset += efx->rx_prefix_size;
 586         rx_buf->len -= efx->rx_prefix_size;
 587
 588         if (n_frags > 1) {
 589                 /* Release/sync DMA mapping for additional fragments.
 590                  * Fix length for last fragment.
 591                  */
 592                 unsigned int tail_frags = n_frags - 1;
 593
 594                 for (;;) {
 595                         rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
 596                         if (--tail_frags == 0)
 597                                 break;
 598                         ef4_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
 599                 }
 600                 rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
 601                 ef4_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 602         }
 603
 604         /* All fragments have been DMA-synced, so recycle pages. */
 605         rx_buf = ef4_rx_buffer(rx_queue, index);
 606         ef4_recycle_rx_pages(channel, rx_buf, n_frags);
 607
 608         /* Pipeline receives so that we give time for packet headers to be
 609          * prefetched into cache.
 610          */
 611         ef4_rx_flush_packet(channel);
 612         channel->rx_pkt_n_frags = n_frags;
 613         channel->rx_pkt_index = index;
 614 }
 615
 616 static void ef4_rx_deliver(struct ef4_channel *channel, u8 *eh,
 617                            struct ef4_rx_buffer *rx_buf,
 618                            unsigned int n_frags)
 619 {
 620         struct sk_buff *skb;
 621         u16 hdr_len = min_t(u16, rx_buf->len, EF4_SKB_HEADERS);
 622
 623         skb = ef4_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
 624         if (unlikely(skb == NULL)) {
 625                 struct ef4_rx_queue *rx_queue;
 626
 627                 rx_queue = ef4_channel_get_rx_queue(channel);
 628                 ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 629                 return;
 630         }
 631         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 632
 633         /* Set the SKB flags */
 634         skb_checksum_none_assert(skb);
 635         if (likely(rx_buf->flags & EF4_RX_PKT_CSUMMED))
 636                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 637
 638         if (channel->type->receive_skb)
 639                 if (channel->type->receive_skb(channel, skb))
 640                         return;
 641
 642         /* Pass the packet up */
 643         netif_receive_skb(skb);
 644 }
 645
 646 /* Handle a received packet.  Second half: Touches packet payload. */
 647 void __ef4_rx_packet(struct ef4_channel *channel)
 648 {
 649         struct ef4_nic *efx = channel->efx;
 650         struct ef4_rx_buffer *rx_buf =
 651                 ef4_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
 652         u8 *eh = ef4_rx_buf_va(rx_buf);
 653
 654         /* Read length from the prefix if necessary.  This already
 655          * excludes the length of the prefix itself.
 656          */
 657         if (rx_buf->flags & EF4_RX_PKT_PREFIX_LEN)
 658                 rx_buf->len = le16_to_cpup((__le16 *)
 659                                            (eh + efx->rx_packet_len_offset));
 660
 661         /* If we're in loopback test, then pass the packet directly to the
 662          * loopback layer, and free the rx_buf here
 663          */
 664         if (unlikely(efx->loopback_selftest)) {
 665                 struct ef4_rx_queue *rx_queue;
 666
 667                 ef4_loopback_rx_packet(efx, eh, rx_buf->len);
 668                 rx_queue = ef4_channel_get_rx_queue(channel);
 669                 ef4_free_rx_buffers(rx_queue, rx_buf,
 670                                     channel->rx_pkt_n_frags);
 671                 goto out;
 672         }
 673
 674         if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
 675                 rx_buf->flags &= ~EF4_RX_PKT_CSUMMED;
 676
 677         if ((rx_buf->flags & EF4_RX_PKT_TCP) && !channel->type->receive_skb)
 678                 ef4_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
 679         else
 680                 ef4_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
 681 out:
 682         channel->rx_pkt_n_frags = 0;
 683 }
 684
 685 int ef4_probe_rx_queue(struct ef4_rx_queue *rx_queue)
 686 {
 687         struct ef4_nic *efx = rx_queue->efx;
 688         unsigned int entries;
 689         int rc;
 690
 691         /* Create the smallest power-of-two aligned ring */
 692         entries = max(roundup_pow_of_two(efx->rxq_entries), EF4_MIN_DMAQ_SIZE);
 693         EF4_BUG_ON_PARANOID(entries > EF4_MAX_DMAQ_SIZE);
 694         rx_queue->ptr_mask = entries - 1;
 695
 696         netif_dbg(efx, probe, efx->net_dev,
 697                   "creating RX queue %d size %#x mask %#x\n",
 698                   ef4_rx_queue_index(rx_queue), efx->rxq_entries,
 699                   rx_queue->ptr_mask);
 700
 701         /* Allocate RX buffers */
 702         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 703                                    GFP_KERNEL);
 704         if (!rx_queue->buffer)
 705                 return -ENOMEM;
 706
 707         rc = ef4_nic_probe_rx(rx_queue);
 708         if (rc) {
 709                 kfree(rx_queue->buffer);
 710                 rx_queue->buffer = NULL;
 711         }
 712
 713         return rc;
 714 }
 715
 716 static void ef4_init_rx_recycle_ring(struct ef4_nic *efx,
 717                                      struct ef4_rx_queue *rx_queue)
 718 {
 719         unsigned int bufs_in_recycle_ring, page_ring_size;
 720
 721         /* Set the RX recycle ring size */
 722 #ifdef CONFIG_PPC64
 723         bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU;
 724 #else
 725         if (iommu_present(&pci_bus_type))
 726                 bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU;
 727         else
 728                 bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_NOIOMMU;
 729 #endif /* CONFIG_PPC64 */
 730
 731         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 732                                             efx->rx_bufs_per_page);
 733         rx_queue->page_ring = kcalloc(page_ring_size,
 734                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 735         rx_queue->page_ptr_mask = page_ring_size - 1;
 736 }
 737
 738 void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue)
 739 {
 740         struct ef4_nic *efx = rx_queue->efx;
 741         unsigned int max_fill, trigger, max_trigger;
 742
 743         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 744                   "initialising RX queue %d\n", ef4_rx_queue_index(rx_queue));
 745
 746         /* Initialise ptr fields */
 747         rx_queue->added_count = 0;
 748         rx_queue->notified_count = 0;
 749         rx_queue->removed_count = 0;
 750         rx_queue->min_fill = -1U;
 751         ef4_init_rx_recycle_ring(efx, rx_queue);
 752
 753         rx_queue->page_remove = 0;
 754         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 755         rx_queue->page_recycle_count = 0;
 756         rx_queue->page_recycle_failed = 0;
 757         rx_queue->page_recycle_full = 0;
 758
 759         /* Initialise limit fields */
 760         max_fill = efx->rxq_entries - EF4_RXD_HEAD_ROOM;
 761         max_trigger =
 762                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 763         if (rx_refill_threshold != 0) {
 764                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 765                 if (trigger > max_trigger)
 766                         trigger = max_trigger;
 767         } else {
 768                 trigger = max_trigger;
 769         }
 770
 771         rx_queue->max_fill = max_fill;
 772         rx_queue->fast_fill_trigger = trigger;
 773         rx_queue->refill_enabled = true;
 774
 775         /* Set up RX descriptor ring */
 776         ef4_nic_init_rx(rx_queue);
 777 }
 778
 779 void ef4_fini_rx_queue(struct ef4_rx_queue *rx_queue)
 780 {
 781         int i;
 782         struct ef4_nic *efx = rx_queue->efx;
 783         struct ef4_rx_buffer *rx_buf;
 784
 785         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 786                   "shutting down RX queue %d\n", ef4_rx_queue_index(rx_queue));
 787
 788         del_timer_sync(&rx_queue->slow_fill);
 789
 790         /* Release RX buffers from the current read ptr to the write ptr */
 791         if (rx_queue->buffer) {
 792                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 793                      i++) {
 794                         unsigned index = i & rx_queue->ptr_mask;
 795                         rx_buf = ef4_rx_buffer(rx_queue, index);
 796                         ef4_fini_rx_buffer(rx_queue, rx_buf);
 797                 }
 798         }
 799
 800         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 801         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 802                 struct page *page = rx_queue->page_ring[i];
 803                 struct ef4_rx_page_state *state;
 804
 805                 if (page == NULL)
 806                         continue;
 807
 808                 state = page_address(page);
 809                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 810                                PAGE_SIZE << efx->rx_buffer_order,
 811                                DMA_FROM_DEVICE);
 812                 put_page(page);
 813         }
 814         kfree(rx_queue->page_ring);
 815         rx_queue->page_ring = NULL;
 816 }
 817
 818 void ef4_remove_rx_queue(struct ef4_rx_queue *rx_queue)
 819 {
 820         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 821                   "destroying RX queue %d\n", ef4_rx_queue_index(rx_queue));
 822
 823         ef4_nic_remove_rx(rx_queue);
 824
 825         kfree(rx_queue->buffer);
 826         rx_queue->buffer = NULL;
 827 }
 828
 829
 830 module_param(rx_refill_threshold, uint, 0444);
 831 MODULE_PARM_DESC(rx_refill_threshold,
 832                  "RX descriptor ring refill threshold (%)");
 833
 834 #ifdef CONFIG_RFS_ACCEL
 835
 836 int ef4_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 837                    u16 rxq_index, u32 flow_id)
 838 {
 839         struct ef4_nic *efx = netdev_priv(net_dev);
 840         struct ef4_channel *channel;
 841         struct ef4_filter_spec spec;
 842         struct flow_keys fk;
 843         int rc;
 844
 845         if (flow_id == RPS_FLOW_ID_INVALID)
 846                 return -EINVAL;
 847
 848         if (!skb_flow_dissect_flow_keys(skb, &fk, 0))
 849                 return -EPROTONOSUPPORT;
 850
 851         if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6))
 852                 return -EPROTONOSUPPORT;
 853         if (fk.control.flags & FLOW_DIS_IS_FRAGMENT)
 854                 return -EPROTONOSUPPORT;
 855
 856         ef4_filter_init_rx(&spec, EF4_FILTER_PRI_HINT,
 857                            efx->rx_scatter ? EF4_FILTER_FLAG_RX_SCATTER : 0,
 858                            rxq_index);
 859         spec.match_flags =
 860                 EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_IP_PROTO |
 861                 EF4_FILTER_MATCH_LOC_HOST | EF4_FILTER_MATCH_LOC_PORT |
 862                 EF4_FILTER_MATCH_REM_HOST | EF4_FILTER_MATCH_REM_PORT;
 863         spec.ether_type = fk.basic.n_proto;
 864         spec.ip_proto = fk.basic.ip_proto;
 865
 866         if (fk.basic.n_proto == htons(ETH_P_IP)) {
 867                 spec.rem_host[0] = fk.addrs.v4addrs.src;
 868                 spec.loc_host[0] = fk.addrs.v4addrs.dst;
 869         } else {
 870                 memcpy(spec.rem_host, &fk.addrs.v6addrs.src, sizeof(struct in6_addr));
 871                 memcpy(spec.loc_host, &fk.addrs.v6addrs.dst, sizeof(struct in6_addr));
 872         }
 873
 874         spec.rem_port = fk.ports.src;
 875         spec.loc_port = fk.ports.dst;
 876
 877         rc = efx->type->filter_rfs_insert(efx, &spec);
 878         if (rc < 0)
 879                 return rc;
 880
 881         /* Remember this so we can check whether to expire the filter later */
 882         channel = ef4_get_channel(efx, rxq_index);
 883         channel->rps_flow_id[rc] = flow_id;
 884         ++channel->rfs_filters_added;
 885
 886         if (spec.ether_type == htons(ETH_P_IP))
 887                 netif_info(efx, rx_status, efx->net_dev,
 888                            "steering %s %pI4:%u:%pI4:%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         else
 893                 netif_info(efx, rx_status, efx->net_dev,
 894                            "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d]\n",
 895                            (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 896                            spec.rem_host, ntohs(spec.rem_port), spec.loc_host,
 897                            ntohs(spec.loc_port), rxq_index, flow_id, rc);
 898
 899         return rc;
 900 }
 901
 902 bool __ef4_filter_rfs_expire(struct ef4_nic *efx, unsigned int quota)
 903 {
 904         bool (*expire_one)(struct ef4_nic *efx, u32 flow_id, unsigned int index);
 905         unsigned int channel_idx, index, size;
 906         u32 flow_id;
 907
 908         if (!spin_trylock_bh(&efx->filter_lock))
 909                 return false;
 910
 911         expire_one = efx->type->filter_rfs_expire_one;
 912         channel_idx = efx->rps_expire_channel;
 913         index = efx->rps_expire_index;
 914         size = efx->type->max_rx_ip_filters;
 915         while (quota--) {
 916                 struct ef4_channel *channel = ef4_get_channel(efx, channel_idx);
 917                 flow_id = channel->rps_flow_id[index];
 918
 919                 if (flow_id != RPS_FLOW_ID_INVALID &&
 920                     expire_one(efx, flow_id, index)) {
 921                         netif_info(efx, rx_status, efx->net_dev,
 922                                    "expired filter %d [queue %u flow %u]\n",
 923                                    index, channel_idx, flow_id);
 924                         channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
 925                 }
 926                 if (++index == size) {
 927                         if (++channel_idx == efx->n_channels)
 928                                 channel_idx = 0;
 929                         index = 0;
 930                 }
 931         }
 932         efx->rps_expire_channel = channel_idx;
 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  * ef4_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 ef4_filter_is_mc_recipient(const struct ef4_filter_spec *spec)
 951 {
 952         if (!(spec->flags & EF4_FILTER_FLAG_RX) ||
 953             spec->dmaq_id == EF4_FILTER_RX_DMAQ_ID_DROP)
 954                 return false;
 955
 956         if (spec->match_flags &
 957             (EF4_FILTER_MATCH_LOC_MAC | EF4_FILTER_MATCH_LOC_MAC_IG) &&
 958             is_multicast_ether_addr(spec->loc_mac))
 959                 return true;
 960
 961         if ((spec->match_flags &
 962              (EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_LOC_HOST)) ==
 963             (EF4_FILTER_MATCH_ETHER_TYPE | EF4_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 }