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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /****************************************************************************
   3  * Driver for Solarflare network controllers and boards
   4  * Copyright 2005-2006 Fen Systems Ltd.
   5  * Copyright 2005-2013 Solarflare Communications Inc.
   6  */
   7
   8 #include <linux/socket.h>
   9 #include <linux/in.h>
  10 #include <linux/slab.h>
  11 #include <linux/ip.h>
  12 #include <linux/ipv6.h>
  13 #include <linux/tcp.h>
  14 #include <linux/udp.h>
  15 #include <linux/prefetch.h>
  16 #include <linux/moduleparam.h>
  17 #include <linux/iommu.h>
  18 #include <net/ip.h>
  19 #include <net/checksum.h>
  20 #include "net_driver.h"
  21 #include "efx.h"
  22 #include "filter.h"
  23 #include "nic.h"
  24 #include "selftest.h"
  25 #include "workarounds.h"
  26
  27 /* Preferred number of descriptors to fill at once */
  28 #define 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         if (unlikely(!rx_queue->page_ring))
 114                 return NULL;
 115         index = rx_queue->page_remove & rx_queue->page_ptr_mask;
 116         page = rx_queue->page_ring[index];
 117         if (page == NULL)
 118                 return NULL;
 119
 120         rx_queue->page_ring[index] = NULL;
 121         /* page_remove cannot exceed page_add. */
 122         if (rx_queue->page_remove != rx_queue->page_add)
 123                 ++rx_queue->page_remove;
 124
 125         /* If page_count is 1 then we hold the only reference to this page. */
 126         if (page_count(page) == 1) {
 127                 ++rx_queue->page_recycle_count;
 128                 return page;
 129         } else {
 130                 state = page_address(page);
 131                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 132                                PAGE_SIZE << efx->rx_buffer_order,
 133                                DMA_FROM_DEVICE);
 134                 put_page(page);
 135                 ++rx_queue->page_recycle_failed;
 136         }
 137
 138         return NULL;
 139 }
 140
 141 /**
 142  * ef4_init_rx_buffers - create EF4_RX_BATCH page-based RX buffers
 143  *
 144  * @rx_queue:           Efx RX queue
 145  * @atomic:             control memory allocation flags
 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_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         if (unlikely(!rx_queue->page_ring))
 299                 return;
 300
 301         do {
 302                 ef4_recycle_rx_page(channel, rx_buf);
 303                 rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
 304         } while (--n_frags);
 305 }
 306
 307 static void ef4_discard_rx_packet(struct ef4_channel *channel,
 308                                   struct ef4_rx_buffer *rx_buf,
 309                                   unsigned int n_frags)
 310 {
 311         struct ef4_rx_queue *rx_queue = ef4_channel_get_rx_queue(channel);
 312
 313         ef4_recycle_rx_pages(channel, rx_buf, n_frags);
 314
 315         ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 316 }
 317
 318 /**
 319  * ef4_fast_push_rx_descriptors - push new RX descriptors quickly
 320  * @rx_queue:           RX descriptor queue
 321  *
 322  * This will aim to fill the RX descriptor queue up to
 323  * @rx_queue->@max_fill. If there is insufficient atomic
 324  * memory to do so, a slow fill will be scheduled.
 325  * @atomic: control memory allocation flags
 326  *
 327  * The caller must provide serialisation (none is used here). In practise,
 328  * this means this function must run from the NAPI handler, or be called
 329  * when NAPI is disabled.
 330  */
 331 void ef4_fast_push_rx_descriptors(struct ef4_rx_queue *rx_queue, bool atomic)
 332 {
 333         struct ef4_nic *efx = rx_queue->efx;
 334         unsigned int fill_level, batch_size;
 335         int space, rc = 0;
 336
 337         if (!rx_queue->refill_enabled)
 338                 return;
 339
 340         /* Calculate current fill level, and exit if we don't need to fill */
 341         fill_level = (rx_queue->added_count - rx_queue->removed_count);
 342         EF4_BUG_ON_PARANOID(fill_level > rx_queue->efx->rxq_entries);
 343         if (fill_level >= rx_queue->fast_fill_trigger)
 344                 goto out;
 345
 346         /* Record minimum fill level */
 347         if (unlikely(fill_level < rx_queue->min_fill)) {
 348                 if (fill_level)
 349                         rx_queue->min_fill = fill_level;
 350         }
 351
 352         batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 353         space = rx_queue->max_fill - fill_level;
 354         EF4_BUG_ON_PARANOID(space < batch_size);
 355
 356         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 357                    "RX queue %d fast-filling descriptor ring from"
 358                    " level %d to level %d\n",
 359                    ef4_rx_queue_index(rx_queue), fill_level,
 360                    rx_queue->max_fill);
 361
 362
 363         do {
 364                 rc = ef4_init_rx_buffers(rx_queue, atomic);
 365                 if (unlikely(rc)) {
 366                         /* Ensure that we don't leave the rx queue empty */
 367                         if (rx_queue->added_count == rx_queue->removed_count)
 368                                 ef4_schedule_slow_fill(rx_queue);
 369                         goto out;
 370                 }
 371         } while ((space -= batch_size) >= batch_size);
 372
 373         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 374                    "RX queue %d fast-filled descriptor ring "
 375                    "to level %d\n", ef4_rx_queue_index(rx_queue),
 376                    rx_queue->added_count - rx_queue->removed_count);
 377
 378  out:
 379         if (rx_queue->notified_count != rx_queue->added_count)
 380                 ef4_nic_notify_rx_desc(rx_queue);
 381 }
 382
 383 void ef4_rx_slow_fill(struct timer_list *t)
 384 {
 385         struct ef4_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
 386
 387         /* Post an event to cause NAPI to run and refill the queue */
 388         ef4_nic_generate_fill_event(rx_queue);
 389         ++rx_queue->slow_fill_count;
 390 }
 391
 392 static void ef4_rx_packet__check_len(struct ef4_rx_queue *rx_queue,
 393                                      struct ef4_rx_buffer *rx_buf,
 394                                      int len)
 395 {
 396         struct ef4_nic *efx = rx_queue->efx;
 397         unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
 398
 399         if (likely(len <= max_len))
 400                 return;
 401
 402         /* The packet must be discarded, but this is only a fatal error
 403          * if the caller indicated it was
 404          */
 405         rx_buf->flags |= EF4_RX_PKT_DISCARD;
 406
 407         if ((len > rx_buf->len) && EF4_WORKAROUND_8071(efx)) {
 408                 if (net_ratelimit())
 409                         netif_err(efx, rx_err, efx->net_dev,
 410                                   " RX queue %d seriously overlength "
 411                                   "RX event (0x%x > 0x%x+0x%x). Leaking\n",
 412                                   ef4_rx_queue_index(rx_queue), len, max_len,
 413                                   efx->type->rx_buffer_padding);
 414                 ef4_schedule_reset(efx, RESET_TYPE_RX_RECOVERY);
 415         } else {
 416                 if (net_ratelimit())
 417                         netif_err(efx, rx_err, efx->net_dev,
 418                                   " RX queue %d overlength RX event "
 419                                   "(0x%x > 0x%x)\n",
 420                                   ef4_rx_queue_index(rx_queue), len, max_len);
 421         }
 422
 423         ef4_rx_queue_channel(rx_queue)->n_rx_overlength++;
 424 }
 425
 426 /* Pass a received packet up through GRO.  GRO can handle pages
 427  * regardless of checksum state and skbs with a good checksum.
 428  */
 429 static void
 430 ef4_rx_packet_gro(struct ef4_channel *channel, struct ef4_rx_buffer *rx_buf,
 431                   unsigned int n_frags, u8 *eh)
 432 {
 433         struct napi_struct *napi = &channel->napi_str;
 434         struct ef4_nic *efx = channel->efx;
 435         struct sk_buff *skb;
 436
 437         skb = napi_get_frags(napi);
 438         if (unlikely(!skb)) {
 439                 struct ef4_rx_queue *rx_queue;
 440
 441                 rx_queue = ef4_channel_get_rx_queue(channel);
 442                 ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 443                 return;
 444         }
 445
 446         if (efx->net_dev->features & NETIF_F_RXHASH)
 447                 skb_set_hash(skb, ef4_rx_buf_hash(efx, eh),
 448                              PKT_HASH_TYPE_L3);
 449         skb->ip_summed = ((rx_buf->flags & EF4_RX_PKT_CSUMMED) ?
 450                           CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 451
 452         for (;;) {
 453                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 454                                    rx_buf->page, rx_buf->page_offset,
 455                                    rx_buf->len);
 456                 rx_buf->page = NULL;
 457                 skb->len += rx_buf->len;
 458                 if (skb_shinfo(skb)->nr_frags == n_frags)
 459                         break;
 460
 461                 rx_buf = ef4_rx_buf_next(&channel->rx_queue, rx_buf);
 462         }
 463
 464         skb->data_len = skb->len;
 465         skb->truesize += n_frags * efx->rx_buffer_truesize;
 466
 467         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 468
 469         napi_gro_frags(napi);
 470 }
 471
 472 /* Allocate and construct an SKB around page fragments */
 473 static struct sk_buff *ef4_rx_mk_skb(struct ef4_channel *channel,
 474                                      struct ef4_rx_buffer *rx_buf,
 475                                      unsigned int n_frags,
 476                                      u8 *eh, int hdr_len)
 477 {
 478         struct ef4_nic *efx = channel->efx;
 479         struct sk_buff *skb;
 480
 481         /* Allocate an SKB to store the headers */
 482         skb = netdev_alloc_skb(efx->net_dev,
 483                                efx->rx_ip_align + efx->rx_prefix_size +
 484                                hdr_len);
 485         if (unlikely(skb == NULL)) {
 486                 atomic_inc(&efx->n_rx_noskb_drops);
 487                 return NULL;
 488         }
 489
 490         EF4_BUG_ON_PARANOID(rx_buf->len < hdr_len);
 491
 492         memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
 493                efx->rx_prefix_size + hdr_len);
 494         skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
 495         __skb_put(skb, hdr_len);
 496
 497         /* Append the remaining page(s) onto the frag list */
 498         if (rx_buf->len > hdr_len) {
 499                 rx_buf->page_offset += hdr_len;
 500                 rx_buf->len -= hdr_len;
 501
 502                 for (;;) {
 503                         skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 504                                            rx_buf->page, rx_buf->page_offset,
 505                                            rx_buf->len);
 506                         rx_buf->page = NULL;
 507                         skb->len += rx_buf->len;
 508                         skb->data_len += rx_buf->len;
 509                         if (skb_shinfo(skb)->nr_frags == n_frags)
 510                                 break;
 511
 512                         rx_buf = ef4_rx_buf_next(&channel->rx_queue, rx_buf);
 513                 }
 514         } else {
 515                 __free_pages(rx_buf->page, efx->rx_buffer_order);
 516                 rx_buf->page = NULL;
 517                 n_frags = 0;
 518         }
 519
 520         skb->truesize += n_frags * efx->rx_buffer_truesize;
 521
 522         /* Move past the ethernet header */
 523         skb->protocol = eth_type_trans(skb, efx->net_dev);
 524
 525         skb_mark_napi_id(skb, &channel->napi_str);
 526
 527         return skb;
 528 }
 529
 530 void ef4_rx_packet(struct ef4_rx_queue *rx_queue, unsigned int index,
 531                    unsigned int n_frags, unsigned int len, u16 flags)
 532 {
 533         struct ef4_nic *efx = rx_queue->efx;
 534         struct ef4_channel *channel = ef4_rx_queue_channel(rx_queue);
 535         struct ef4_rx_buffer *rx_buf;
 536
 537         rx_queue->rx_packets++;
 538
 539         rx_buf = ef4_rx_buffer(rx_queue, index);
 540         rx_buf->flags |= flags;
 541
 542         /* Validate the number of fragments and completed length */
 543         if (n_frags == 1) {
 544                 if (!(flags & EF4_RX_PKT_PREFIX_LEN))
 545                         ef4_rx_packet__check_len(rx_queue, rx_buf, len);
 546         } else if (unlikely(n_frags > EF4_RX_MAX_FRAGS) ||
 547                    unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
 548                    unlikely(len > n_frags * efx->rx_dma_len) ||
 549                    unlikely(!efx->rx_scatter)) {
 550                 /* If this isn't an explicit discard request, either
 551                  * the hardware or the driver is broken.
 552                  */
 553                 WARN_ON(!(len == 0 && rx_buf->flags & EF4_RX_PKT_DISCARD));
 554                 rx_buf->flags |= EF4_RX_PKT_DISCARD;
 555         }
 556
 557         netif_vdbg(efx, rx_status, efx->net_dev,
 558                    "RX queue %d received ids %x-%x len %d %s%s\n",
 559                    ef4_rx_queue_index(rx_queue), index,
 560                    (index + n_frags - 1) & rx_queue->ptr_mask, len,
 561                    (rx_buf->flags & EF4_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
 562                    (rx_buf->flags & EF4_RX_PKT_DISCARD) ? " [DISCARD]" : "");
 563
 564         /* Discard packet, if instructed to do so.  Process the
 565          * previous receive first.
 566          */
 567         if (unlikely(rx_buf->flags & EF4_RX_PKT_DISCARD)) {
 568                 ef4_rx_flush_packet(channel);
 569                 ef4_discard_rx_packet(channel, rx_buf, n_frags);
 570                 return;
 571         }
 572
 573         if (n_frags == 1 && !(flags & EF4_RX_PKT_PREFIX_LEN))
 574                 rx_buf->len = len;
 575
 576         /* Release and/or sync the DMA mapping - assumes all RX buffers
 577          * consumed in-order per RX queue.
 578          */
 579         ef4_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 580
 581         /* Prefetch nice and early so data will (hopefully) be in cache by
 582          * the time we look at it.
 583          */
 584         prefetch(ef4_rx_buf_va(rx_buf));
 585
 586         rx_buf->page_offset += efx->rx_prefix_size;
 587         rx_buf->len -= efx->rx_prefix_size;
 588
 589         if (n_frags > 1) {
 590                 /* Release/sync DMA mapping for additional fragments.
 591                  * Fix length for last fragment.
 592                  */
 593                 unsigned int tail_frags = n_frags - 1;
 594
 595                 for (;;) {
 596                         rx_buf = ef4_rx_buf_next(rx_queue, rx_buf);
 597                         if (--tail_frags == 0)
 598                                 break;
 599                         ef4_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
 600                 }
 601                 rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
 602                 ef4_sync_rx_buffer(efx, rx_buf, rx_buf->len);
 603         }
 604
 605         /* All fragments have been DMA-synced, so recycle pages. */
 606         rx_buf = ef4_rx_buffer(rx_queue, index);
 607         ef4_recycle_rx_pages(channel, rx_buf, n_frags);
 608
 609         /* Pipeline receives so that we give time for packet headers to be
 610          * prefetched into cache.
 611          */
 612         ef4_rx_flush_packet(channel);
 613         channel->rx_pkt_n_frags = n_frags;
 614         channel->rx_pkt_index = index;
 615 }
 616
 617 static void ef4_rx_deliver(struct ef4_channel *channel, u8 *eh,
 618                            struct ef4_rx_buffer *rx_buf,
 619                            unsigned int n_frags)
 620 {
 621         struct sk_buff *skb;
 622         u16 hdr_len = min_t(u16, rx_buf->len, EF4_SKB_HEADERS);
 623
 624         skb = ef4_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
 625         if (unlikely(skb == NULL)) {
 626                 struct ef4_rx_queue *rx_queue;
 627
 628                 rx_queue = ef4_channel_get_rx_queue(channel);
 629                 ef4_free_rx_buffers(rx_queue, rx_buf, n_frags);
 630                 return;
 631         }
 632         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 633
 634         /* Set the SKB flags */
 635         skb_checksum_none_assert(skb);
 636         if (likely(rx_buf->flags & EF4_RX_PKT_CSUMMED))
 637                 skb->ip_summed = CHECKSUM_UNNECESSARY;
 638
 639         if (channel->type->receive_skb)
 640                 if (channel->type->receive_skb(channel, skb))
 641                         return;
 642
 643         /* Pass the packet up */
 644         netif_receive_skb(skb);
 645 }
 646
 647 /* Handle a received packet.  Second half: Touches packet payload. */
 648 void __ef4_rx_packet(struct ef4_channel *channel)
 649 {
 650         struct ef4_nic *efx = channel->efx;
 651         struct ef4_rx_buffer *rx_buf =
 652                 ef4_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
 653         u8 *eh = ef4_rx_buf_va(rx_buf);
 654
 655         /* Read length from the prefix if necessary.  This already
 656          * excludes the length of the prefix itself.
 657          */
 658         if (rx_buf->flags & EF4_RX_PKT_PREFIX_LEN)
 659                 rx_buf->len = le16_to_cpup((__le16 *)
 660                                            (eh + efx->rx_packet_len_offset));
 661
 662         /* If we're in loopback test, then pass the packet directly to the
 663          * loopback layer, and free the rx_buf here
 664          */
 665         if (unlikely(efx->loopback_selftest)) {
 666                 struct ef4_rx_queue *rx_queue;
 667
 668                 ef4_loopback_rx_packet(efx, eh, rx_buf->len);
 669                 rx_queue = ef4_channel_get_rx_queue(channel);
 670                 ef4_free_rx_buffers(rx_queue, rx_buf,
 671                                     channel->rx_pkt_n_frags);
 672                 goto out;
 673         }
 674
 675         if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
 676                 rx_buf->flags &= ~EF4_RX_PKT_CSUMMED;
 677
 678         if ((rx_buf->flags & EF4_RX_PKT_TCP) && !channel->type->receive_skb)
 679                 ef4_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
 680         else
 681                 ef4_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
 682 out:
 683         channel->rx_pkt_n_frags = 0;
 684 }
 685
 686 int ef4_probe_rx_queue(struct ef4_rx_queue *rx_queue)
 687 {
 688         struct ef4_nic *efx = rx_queue->efx;
 689         unsigned int entries;
 690         int rc;
 691
 692         /* Create the smallest power-of-two aligned ring */
 693         entries = max(roundup_pow_of_two(efx->rxq_entries), EF4_MIN_DMAQ_SIZE);
 694         EF4_BUG_ON_PARANOID(entries > EF4_MAX_DMAQ_SIZE);
 695         rx_queue->ptr_mask = entries - 1;
 696
 697         netif_dbg(efx, probe, efx->net_dev,
 698                   "creating RX queue %d size %#x mask %#x\n",
 699                   ef4_rx_queue_index(rx_queue), efx->rxq_entries,
 700                   rx_queue->ptr_mask);
 701
 702         /* Allocate RX buffers */
 703         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 704                                    GFP_KERNEL);
 705         if (!rx_queue->buffer)
 706                 return -ENOMEM;
 707
 708         rc = ef4_nic_probe_rx(rx_queue);
 709         if (rc) {
 710                 kfree(rx_queue->buffer);
 711                 rx_queue->buffer = NULL;
 712         }
 713
 714         return rc;
 715 }
 716
 717 static void ef4_init_rx_recycle_ring(struct ef4_nic *efx,
 718                                      struct ef4_rx_queue *rx_queue)
 719 {
 720         unsigned int bufs_in_recycle_ring, page_ring_size;
 721         struct iommu_domain __maybe_unused *domain;
 722
 723         /* Set the RX recycle ring size */
 724 #ifdef CONFIG_PPC64
 725         bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU;
 726 #else
 727         domain = iommu_get_domain_for_dev(&efx->pci_dev->dev);
 728         if (domain && domain->type != IOMMU_DOMAIN_IDENTITY)
 729                 bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_IOMMU;
 730         else
 731                 bufs_in_recycle_ring = EF4_RECYCLE_RING_SIZE_NOIOMMU;
 732 #endif /* CONFIG_PPC64 */
 733
 734         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 735                                             efx->rx_bufs_per_page);
 736         rx_queue->page_ring = kcalloc(page_ring_size,
 737                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 738         if (!rx_queue->page_ring)
 739                 rx_queue->page_ptr_mask = 0;
 740         else
 741                 rx_queue->page_ptr_mask = page_ring_size - 1;
 742 }
 743
 744 void ef4_init_rx_queue(struct ef4_rx_queue *rx_queue)
 745 {
 746         struct ef4_nic *efx = rx_queue->efx;
 747         unsigned int max_fill, trigger, max_trigger;
 748
 749         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 750                   "initialising RX queue %d\n", ef4_rx_queue_index(rx_queue));
 751
 752         /* Initialise ptr fields */
 753         rx_queue->added_count = 0;
 754         rx_queue->notified_count = 0;
 755         rx_queue->removed_count = 0;
 756         rx_queue->min_fill = -1U;
 757         ef4_init_rx_recycle_ring(efx, rx_queue);
 758
 759         rx_queue->page_remove = 0;
 760         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 761         rx_queue->page_recycle_count = 0;
 762         rx_queue->page_recycle_failed = 0;
 763         rx_queue->page_recycle_full = 0;
 764
 765         /* Initialise limit fields */
 766         max_fill = efx->rxq_entries - EF4_RXD_HEAD_ROOM;
 767         max_trigger =
 768                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 769         if (rx_refill_threshold != 0) {
 770                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 771                 if (trigger > max_trigger)
 772                         trigger = max_trigger;
 773         } else {
 774                 trigger = max_trigger;
 775         }
 776
 777         rx_queue->max_fill = max_fill;
 778         rx_queue->fast_fill_trigger = trigger;
 779         rx_queue->refill_enabled = true;
 780
 781         /* Set up RX descriptor ring */
 782         ef4_nic_init_rx(rx_queue);
 783 }
 784
 785 void ef4_fini_rx_queue(struct ef4_rx_queue *rx_queue)
 786 {
 787         int i;
 788         struct ef4_nic *efx = rx_queue->efx;
 789         struct ef4_rx_buffer *rx_buf;
 790
 791         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 792                   "shutting down RX queue %d\n", ef4_rx_queue_index(rx_queue));
 793
 794         del_timer_sync(&rx_queue->slow_fill);
 795
 796         /* Release RX buffers from the current read ptr to the write ptr */
 797         if (rx_queue->buffer) {
 798                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 799                      i++) {
 800                         unsigned index = i & rx_queue->ptr_mask;
 801                         rx_buf = ef4_rx_buffer(rx_queue, index);
 802                         ef4_fini_rx_buffer(rx_queue, rx_buf);
 803                 }
 804         }
 805
 806         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 807         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 808                 struct page *page = rx_queue->page_ring[i];
 809                 struct ef4_rx_page_state *state;
 810
 811                 if (page == NULL)
 812                         continue;
 813
 814                 state = page_address(page);
 815                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 816                                PAGE_SIZE << efx->rx_buffer_order,
 817                                DMA_FROM_DEVICE);
 818                 put_page(page);
 819         }
 820         kfree(rx_queue->page_ring);
 821         rx_queue->page_ring = NULL;
 822 }
 823
 824 void ef4_remove_rx_queue(struct ef4_rx_queue *rx_queue)
 825 {
 826         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 827                   "destroying RX queue %d\n", ef4_rx_queue_index(rx_queue));
 828
 829         ef4_nic_remove_rx(rx_queue);
 830
 831         kfree(rx_queue->buffer);
 832         rx_queue->buffer = NULL;
 833 }
 834
 835
 836 module_param(rx_refill_threshold, uint, 0444);
 837 MODULE_PARM_DESC(rx_refill_threshold,
 838                  "RX descriptor ring refill threshold (%)");
 839
 840 #ifdef CONFIG_RFS_ACCEL
 841
 842 int ef4_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 843                    u16 rxq_index, u32 flow_id)
 844 {
 845         struct ef4_nic *efx = netdev_priv(net_dev);
 846         struct ef4_channel *channel;
 847         struct ef4_filter_spec spec;
 848         struct flow_keys fk;
 849         int rc;
 850
 851         if (flow_id == RPS_FLOW_ID_INVALID)
 852                 return -EINVAL;
 853
 854         if (!skb_flow_dissect_flow_keys(skb, &fk, 0))
 855                 return -EPROTONOSUPPORT;
 856
 857         if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6))
 858                 return -EPROTONOSUPPORT;
 859         if (fk.control.flags & FLOW_DIS_IS_FRAGMENT)
 860                 return -EPROTONOSUPPORT;
 861
 862         ef4_filter_init_rx(&spec, EF4_FILTER_PRI_HINT,
 863                            efx->rx_scatter ? EF4_FILTER_FLAG_RX_SCATTER : 0,
 864                            rxq_index);
 865         spec.match_flags =
 866                 EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_IP_PROTO |
 867                 EF4_FILTER_MATCH_LOC_HOST | EF4_FILTER_MATCH_LOC_PORT |
 868                 EF4_FILTER_MATCH_REM_HOST | EF4_FILTER_MATCH_REM_PORT;
 869         spec.ether_type = fk.basic.n_proto;
 870         spec.ip_proto = fk.basic.ip_proto;
 871
 872         if (fk.basic.n_proto == htons(ETH_P_IP)) {
 873                 spec.rem_host[0] = fk.addrs.v4addrs.src;
 874                 spec.loc_host[0] = fk.addrs.v4addrs.dst;
 875         } else {
 876                 memcpy(spec.rem_host, &fk.addrs.v6addrs.src, sizeof(struct in6_addr));
 877                 memcpy(spec.loc_host, &fk.addrs.v6addrs.dst, sizeof(struct in6_addr));
 878         }
 879
 880         spec.rem_port = fk.ports.src;
 881         spec.loc_port = fk.ports.dst;
 882
 883         rc = efx->type->filter_rfs_insert(efx, &spec);
 884         if (rc < 0)
 885                 return rc;
 886
 887         /* Remember this so we can check whether to expire the filter later */
 888         channel = ef4_get_channel(efx, rxq_index);
 889         channel->rps_flow_id[rc] = flow_id;
 890         ++channel->rfs_filters_added;
 891
 892         if (spec.ether_type == htons(ETH_P_IP))
 893                 netif_info(efx, rx_status, efx->net_dev,
 894                            "steering %s %pI4:%u:%pI4:%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         else
 899                 netif_info(efx, rx_status, efx->net_dev,
 900                            "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d]\n",
 901                            (spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 902                            spec.rem_host, ntohs(spec.rem_port), spec.loc_host,
 903                            ntohs(spec.loc_port), rxq_index, flow_id, rc);
 904
 905         return rc;
 906 }
 907
 908 bool __ef4_filter_rfs_expire(struct ef4_nic *efx, unsigned int quota)
 909 {
 910         bool (*expire_one)(struct ef4_nic *efx, u32 flow_id, unsigned int index);
 911         unsigned int channel_idx, index, size;
 912         u32 flow_id;
 913
 914         if (!spin_trylock_bh(&efx->filter_lock))
 915                 return false;
 916
 917         expire_one = efx->type->filter_rfs_expire_one;
 918         channel_idx = efx->rps_expire_channel;
 919         index = efx->rps_expire_index;
 920         size = efx->type->max_rx_ip_filters;
 921         while (quota--) {
 922                 struct ef4_channel *channel = ef4_get_channel(efx, channel_idx);
 923                 flow_id = channel->rps_flow_id[index];
 924
 925                 if (flow_id != RPS_FLOW_ID_INVALID &&
 926                     expire_one(efx, flow_id, index)) {
 927                         netif_info(efx, rx_status, efx->net_dev,
 928                                    "expired filter %d [queue %u flow %u]\n",
 929                                    index, channel_idx, flow_id);
 930                         channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
 931                 }
 932                 if (++index == size) {
 933                         if (++channel_idx == efx->n_channels)
 934                                 channel_idx = 0;
 935                         index = 0;
 936                 }
 937         }
 938         efx->rps_expire_channel = channel_idx;
 939         efx->rps_expire_index = index;
 940
 941         spin_unlock_bh(&efx->filter_lock);
 942         return true;
 943 }
 944
 945 #endif /* CONFIG_RFS_ACCEL */
 946
 947 /**
 948  * ef4_filter_is_mc_recipient - test whether spec is a multicast recipient
 949  * @spec: Specification to test
 950  *
 951  * Return: %true if the specification is a non-drop RX filter that
 952  * matches a local MAC address I/G bit value of 1 or matches a local
 953  * IPv4 or IPv6 address value in the respective multicast address
 954  * range.  Otherwise %false.
 955  */
 956 bool ef4_filter_is_mc_recipient(const struct ef4_filter_spec *spec)
 957 {
 958         if (!(spec->flags & EF4_FILTER_FLAG_RX) ||
 959             spec->dmaq_id == EF4_FILTER_RX_DMAQ_ID_DROP)
 960                 return false;
 961
 962         if (spec->match_flags &
 963             (EF4_FILTER_MATCH_LOC_MAC | EF4_FILTER_MATCH_LOC_MAC_IG) &&
 964             is_multicast_ether_addr(spec->loc_mac))
 965                 return true;
 966
 967         if ((spec->match_flags &
 968              (EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_LOC_HOST)) ==
 969             (EF4_FILTER_MATCH_ETHER_TYPE | EF4_FILTER_MATCH_LOC_HOST)) {
 970                 if (spec->ether_type == htons(ETH_P_IP) &&
 971                     ipv4_is_multicast(spec->loc_host[0]))
 972                         return true;
 973                 if (spec->ether_type == htons(ETH_P_IPV6) &&
 974                     ((const u8 *)spec->loc_host)[0] == 0xff)
 975                         return true;
 976         }
 977
 978         return false;
 979 }