drivers/net/ethernet/sfc/rx_common.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /****************************************************************************
   3  * Driver for Solarflare network controllers and boards
   4  * Copyright 2018 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 "net_driver.h"
  12 #include <linux/module.h>
  13 #include <linux/iommu.h>
  14 #include "efx.h"
  15 #include "nic.h"
  16 #include "rx_common.h"
  17
  18 /* This is the percentage fill level below which new RX descriptors
  19  * will be added to the RX descriptor ring.
  20  */
  21 static unsigned int rx_refill_threshold;
  22 module_param(rx_refill_threshold, uint, 0444);
  23 MODULE_PARM_DESC(rx_refill_threshold,
  24                  "RX descriptor ring refill threshold (%)");
  25
  26 /* RX maximum head room required.
  27  *
  28  * This must be at least 1 to prevent overflow, plus one packet-worth
  29  * to allow pipelined receives.
  30  */
  31 #define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
  32
  33 /* Check the RX page recycle ring for a page that can be reused. */
  34 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
  35 {
  36         struct efx_nic *efx = rx_queue->efx;
  37         struct efx_rx_page_state *state;
  38         unsigned int index;
  39         struct page *page;
  40
  41         if (unlikely(!rx_queue->page_ring))
  42                 return NULL;
  43         index = rx_queue->page_remove & rx_queue->page_ptr_mask;
  44         page = rx_queue->page_ring[index];
  45         if (page == NULL)
  46                 return NULL;
  47
  48         rx_queue->page_ring[index] = NULL;
  49         /* page_remove cannot exceed page_add. */
  50         if (rx_queue->page_remove != rx_queue->page_add)
  51                 ++rx_queue->page_remove;
  52
  53         /* If page_count is 1 then we hold the only reference to this page. */
  54         if (page_count(page) == 1) {
  55                 ++rx_queue->page_recycle_count;
  56                 return page;
  57         } else {
  58                 state = page_address(page);
  59                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
  60                                PAGE_SIZE << efx->rx_buffer_order,
  61                                DMA_FROM_DEVICE);
  62                 put_page(page);
  63                 ++rx_queue->page_recycle_failed;
  64         }
  65
  66         return NULL;
  67 }
  68
  69 /* Attempt to recycle the page if there is an RX recycle ring; the page can
  70  * only be added if this is the final RX buffer, to prevent pages being used in
  71  * the descriptor ring and appearing in the recycle ring simultaneously.
  72  */
  73 static void efx_recycle_rx_page(struct efx_channel *channel,
  74                                 struct efx_rx_buffer *rx_buf)
  75 {
  76         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
  77         struct efx_nic *efx = rx_queue->efx;
  78         struct page *page = rx_buf->page;
  79         unsigned int index;
  80
  81         /* Only recycle the page after processing the final buffer. */
  82         if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
  83                 return;
  84
  85         index = rx_queue->page_add & rx_queue->page_ptr_mask;
  86         if (rx_queue->page_ring[index] == NULL) {
  87                 unsigned int read_index = rx_queue->page_remove &
  88                         rx_queue->page_ptr_mask;
  89
  90                 /* The next slot in the recycle ring is available, but
  91                  * increment page_remove if the read pointer currently
  92                  * points here.
  93                  */
  94                 if (read_index == index)
  95                         ++rx_queue->page_remove;
  96                 rx_queue->page_ring[index] = page;
  97                 ++rx_queue->page_add;
  98                 return;
  99         }
 100         ++rx_queue->page_recycle_full;
 101         efx_unmap_rx_buffer(efx, rx_buf);
 102         put_page(rx_buf->page);
 103 }
 104
 105 /* Recycle the pages that are used by buffers that have just been received. */
 106 void efx_recycle_rx_pages(struct efx_channel *channel,
 107                           struct efx_rx_buffer *rx_buf,
 108                           unsigned int n_frags)
 109 {
 110         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 111
 112         if (unlikely(!rx_queue->page_ring))
 113                 return;
 114
 115         do {
 116                 efx_recycle_rx_page(channel, rx_buf);
 117                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 118         } while (--n_frags);
 119 }
 120
 121 void efx_discard_rx_packet(struct efx_channel *channel,
 122                            struct efx_rx_buffer *rx_buf,
 123                            unsigned int n_frags)
 124 {
 125         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 126
 127         efx_recycle_rx_pages(channel, rx_buf, n_frags);
 128
 129         efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 130 }
 131
 132 static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 133 {
 134         unsigned int bufs_in_recycle_ring, page_ring_size;
 135         struct efx_nic *efx = rx_queue->efx;
 136
 137         bufs_in_recycle_ring = efx_rx_recycle_ring_size(efx);
 138         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 139                                             efx->rx_bufs_per_page);
 140         rx_queue->page_ring = kcalloc(page_ring_size,
 141                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 142         if (!rx_queue->page_ring)
 143                 rx_queue->page_ptr_mask = 0;
 144         else
 145                 rx_queue->page_ptr_mask = page_ring_size - 1;
 146 }
 147
 148 static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 149 {
 150         struct efx_nic *efx = rx_queue->efx;
 151         int i;
 152
 153         if (unlikely(!rx_queue->page_ring))
 154                 return;
 155
 156         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 157         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 158                 struct page *page = rx_queue->page_ring[i];
 159                 struct efx_rx_page_state *state;
 160
 161                 if (page == NULL)
 162                         continue;
 163
 164                 state = page_address(page);
 165                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 166                                PAGE_SIZE << efx->rx_buffer_order,
 167                                DMA_FROM_DEVICE);
 168                 put_page(page);
 169         }
 170         kfree(rx_queue->page_ring);
 171         rx_queue->page_ring = NULL;
 172 }
 173
 174 static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
 175                                struct efx_rx_buffer *rx_buf)
 176 {
 177         /* Release the page reference we hold for the buffer. */
 178         if (rx_buf->page)
 179                 put_page(rx_buf->page);
 180
 181         /* If this is the last buffer in a page, unmap and free it. */
 182         if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
 183                 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
 184                 efx_free_rx_buffers(rx_queue, rx_buf, 1);
 185         }
 186         rx_buf->page = NULL;
 187 }
 188
 189 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
 190 {
 191         struct efx_nic *efx = rx_queue->efx;
 192         unsigned int entries;
 193         int rc;
 194
 195         /* Create the smallest power-of-two aligned ring */
 196         entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
 197         EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
 198         rx_queue->ptr_mask = entries - 1;
 199
 200         netif_dbg(efx, probe, efx->net_dev,
 201                   "creating RX queue %d size %#x mask %#x\n",
 202                   efx_rx_queue_index(rx_queue), efx->rxq_entries,
 203                   rx_queue->ptr_mask);
 204
 205         /* Allocate RX buffers */
 206         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 207                                    GFP_KERNEL);
 208         if (!rx_queue->buffer)
 209                 return -ENOMEM;
 210
 211         rc = efx_nic_probe_rx(rx_queue);
 212         if (rc) {
 213                 kfree(rx_queue->buffer);
 214                 rx_queue->buffer = NULL;
 215         }
 216
 217         return rc;
 218 }
 219
 220 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
 221 {
 222         unsigned int max_fill, trigger, max_trigger;
 223         struct efx_nic *efx = rx_queue->efx;
 224         int rc = 0;
 225
 226         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 227                   "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
 228
 229         /* Initialise ptr fields */
 230         rx_queue->added_count = 0;
 231         rx_queue->notified_count = 0;
 232         rx_queue->removed_count = 0;
 233         rx_queue->min_fill = -1U;
 234         efx_init_rx_recycle_ring(rx_queue);
 235
 236         rx_queue->page_remove = 0;
 237         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 238         rx_queue->page_recycle_count = 0;
 239         rx_queue->page_recycle_failed = 0;
 240         rx_queue->page_recycle_full = 0;
 241
 242         /* Initialise limit fields */
 243         max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
 244         max_trigger =
 245                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 246         if (rx_refill_threshold != 0) {
 247                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 248                 if (trigger > max_trigger)
 249                         trigger = max_trigger;
 250         } else {
 251                 trigger = max_trigger;
 252         }
 253
 254         rx_queue->max_fill = max_fill;
 255         rx_queue->fast_fill_trigger = trigger;
 256         rx_queue->refill_enabled = true;
 257
 258         /* Initialise XDP queue information */
 259         rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev,
 260                               rx_queue->core_index, 0);
 261
 262         if (rc) {
 263                 netif_err(efx, rx_err, efx->net_dev,
 264                           "Failure to initialise XDP queue information rc=%d\n",
 265                           rc);
 266                 efx->xdp_rxq_info_failed = true;
 267         } else {
 268                 rx_queue->xdp_rxq_info_valid = true;
 269         }
 270
 271         /* Set up RX descriptor ring */
 272         efx_nic_init_rx(rx_queue);
 273 }
 274
 275 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
 276 {
 277         struct efx_rx_buffer *rx_buf;
 278         int i;
 279
 280         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 281                   "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
 282
 283         del_timer_sync(&rx_queue->slow_fill);
 284
 285         /* Release RX buffers from the current read ptr to the write ptr */
 286         if (rx_queue->buffer) {
 287                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 288                      i++) {
 289                         unsigned int index = i & rx_queue->ptr_mask;
 290
 291                         rx_buf = efx_rx_buffer(rx_queue, index);
 292                         efx_fini_rx_buffer(rx_queue, rx_buf);
 293                 }
 294         }
 295
 296         efx_fini_rx_recycle_ring(rx_queue);
 297
 298         if (rx_queue->xdp_rxq_info_valid)
 299                 xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info);
 300
 301         rx_queue->xdp_rxq_info_valid = false;
 302 }
 303
 304 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
 305 {
 306         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 307                   "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
 308
 309         efx_nic_remove_rx(rx_queue);
 310
 311         kfree(rx_queue->buffer);
 312         rx_queue->buffer = NULL;
 313 }
 314
 315 /* Unmap a DMA-mapped page.  This function is only called for the final RX
 316  * buffer in a page.
 317  */
 318 void efx_unmap_rx_buffer(struct efx_nic *efx,
 319                          struct efx_rx_buffer *rx_buf)
 320 {
 321         struct page *page = rx_buf->page;
 322
 323         if (page) {
 324                 struct efx_rx_page_state *state = page_address(page);
 325
 326                 dma_unmap_page(&efx->pci_dev->dev,
 327                                state->dma_addr,
 328                                PAGE_SIZE << efx->rx_buffer_order,
 329                                DMA_FROM_DEVICE);
 330         }
 331 }
 332
 333 void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
 334                          struct efx_rx_buffer *rx_buf,
 335                          unsigned int num_bufs)
 336 {
 337         do {
 338                 if (rx_buf->page) {
 339                         put_page(rx_buf->page);
 340                         rx_buf->page = NULL;
 341                 }
 342                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 343         } while (--num_bufs);
 344 }
 345
 346 void efx_rx_slow_fill(struct timer_list *t)
 347 {
 348         struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
 349
 350         /* Post an event to cause NAPI to run and refill the queue */
 351         efx_nic_generate_fill_event(rx_queue);
 352         ++rx_queue->slow_fill_count;
 353 }
 354
 355 void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue)
 356 {
 357         mod_timer(&rx_queue->slow_fill, jiffies + msecs_to_jiffies(10));
 358 }
 359
 360 /* efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
 361  *
 362  * @rx_queue:           Efx RX queue
 363  *
 364  * This allocates a batch of pages, maps them for DMA, and populates
 365  * struct efx_rx_buffers for each one. Return a negative error code or
 366  * 0 on success. If a single page can be used for multiple buffers,
 367  * then the page will either be inserted fully, or not at all.
 368  */
 369 static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
 370 {
 371         unsigned int page_offset, index, count;
 372         struct efx_nic *efx = rx_queue->efx;
 373         struct efx_rx_page_state *state;
 374         struct efx_rx_buffer *rx_buf;
 375         dma_addr_t dma_addr;
 376         struct page *page;
 377
 378         count = 0;
 379         do {
 380                 page = efx_reuse_page(rx_queue);
 381                 if (page == NULL) {
 382                         page = alloc_pages(__GFP_COMP |
 383                                            (atomic ? GFP_ATOMIC : GFP_KERNEL),
 384                                            efx->rx_buffer_order);
 385                         if (unlikely(page == NULL))
 386                                 return -ENOMEM;
 387                         dma_addr =
 388                                 dma_map_page(&efx->pci_dev->dev, page, 0,
 389                                              PAGE_SIZE << efx->rx_buffer_order,
 390                                              DMA_FROM_DEVICE);
 391                         if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
 392                                                        dma_addr))) {
 393                                 __free_pages(page, efx->rx_buffer_order);
 394                                 return -EIO;
 395                         }
 396                         state = page_address(page);
 397                         state->dma_addr = dma_addr;
 398                 } else {
 399                         state = page_address(page);
 400                         dma_addr = state->dma_addr;
 401                 }
 402
 403                 dma_addr += sizeof(struct efx_rx_page_state);
 404                 page_offset = sizeof(struct efx_rx_page_state);
 405
 406                 do {
 407                         index = rx_queue->added_count & rx_queue->ptr_mask;
 408                         rx_buf = efx_rx_buffer(rx_queue, index);
 409                         rx_buf->dma_addr = dma_addr + efx->rx_ip_align +
 410                                            EFX_XDP_HEADROOM;
 411                         rx_buf->page = page;
 412                         rx_buf->page_offset = page_offset + efx->rx_ip_align +
 413                                               EFX_XDP_HEADROOM;
 414                         rx_buf->len = efx->rx_dma_len;
 415                         rx_buf->flags = 0;
 416                         ++rx_queue->added_count;
 417                         get_page(page);
 418                         dma_addr += efx->rx_page_buf_step;
 419                         page_offset += efx->rx_page_buf_step;
 420                 } while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
 421
 422                 rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
 423         } while (++count < efx->rx_pages_per_batch);
 424
 425         return 0;
 426 }
 427
 428 void efx_rx_config_page_split(struct efx_nic *efx)
 429 {
 430         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align +
 431                                       EFX_XDP_HEADROOM + EFX_XDP_TAILROOM,
 432                                       EFX_RX_BUF_ALIGNMENT);
 433         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
 434                 ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
 435                 efx->rx_page_buf_step);
 436         efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
 437                 efx->rx_bufs_per_page;
 438         efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
 439                                                efx->rx_bufs_per_page);
 440 }
 441
 442 /* efx_fast_push_rx_descriptors - push new RX descriptors quickly
 443  * @rx_queue:           RX descriptor queue
 444  *
 445  * This will aim to fill the RX descriptor queue up to
 446  * @rx_queue->@max_fill. If there is insufficient atomic
 447  * memory to do so, a slow fill will be scheduled.
 448  *
 449  * The caller must provide serialisation (none is used here). In practise,
 450  * this means this function must run from the NAPI handler, or be called
 451  * when NAPI is disabled.
 452  */
 453 void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
 454 {
 455         struct efx_nic *efx = rx_queue->efx;
 456         unsigned int fill_level, batch_size;
 457         int space, rc = 0;
 458
 459         if (!rx_queue->refill_enabled)
 460                 return;
 461
 462         /* Calculate current fill level, and exit if we don't need to fill */
 463         fill_level = (rx_queue->added_count - rx_queue->removed_count);
 464         EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
 465         if (fill_level >= rx_queue->fast_fill_trigger)
 466                 goto out;
 467
 468         /* Record minimum fill level */
 469         if (unlikely(fill_level < rx_queue->min_fill)) {
 470                 if (fill_level)
 471                         rx_queue->min_fill = fill_level;
 472         }
 473
 474         batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 475         space = rx_queue->max_fill - fill_level;
 476         EFX_WARN_ON_ONCE_PARANOID(space < batch_size);
 477
 478         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 479                    "RX queue %d fast-filling descriptor ring from"
 480                    " level %d to level %d\n",
 481                    efx_rx_queue_index(rx_queue), fill_level,
 482                    rx_queue->max_fill);
 483
 484         do {
 485                 rc = efx_init_rx_buffers(rx_queue, atomic);
 486                 if (unlikely(rc)) {
 487                         /* Ensure that we don't leave the rx queue empty */
 488                         efx_schedule_slow_fill(rx_queue);
 489                         goto out;
 490                 }
 491         } while ((space -= batch_size) >= batch_size);
 492
 493         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 494                    "RX queue %d fast-filled descriptor ring "
 495                    "to level %d\n", efx_rx_queue_index(rx_queue),
 496                    rx_queue->added_count - rx_queue->removed_count);
 497
 498  out:
 499         if (rx_queue->notified_count != rx_queue->added_count)
 500                 efx_nic_notify_rx_desc(rx_queue);
 501 }
 502
 503 /* Pass a received packet up through GRO.  GRO can handle pages
 504  * regardless of checksum state and skbs with a good checksum.
 505  */
 506 void
 507 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 508                   unsigned int n_frags, u8 *eh, __wsum csum)
 509 {
 510         struct napi_struct *napi = &channel->napi_str;
 511         struct efx_nic *efx = channel->efx;
 512         struct sk_buff *skb;
 513
 514         skb = napi_get_frags(napi);
 515         if (unlikely(!skb)) {
 516                 struct efx_rx_queue *rx_queue;
 517
 518                 rx_queue = efx_channel_get_rx_queue(channel);
 519                 efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 520                 return;
 521         }
 522
 523         if (efx->net_dev->features & NETIF_F_RXHASH &&
 524             efx_rx_buf_hash_valid(efx, eh))
 525                 skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
 526                              PKT_HASH_TYPE_L3);
 527         if (csum) {
 528                 skb->csum = csum;
 529                 skb->ip_summed = CHECKSUM_COMPLETE;
 530         } else {
 531                 skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
 532                                   CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 533         }
 534         skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
 535
 536         for (;;) {
 537                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 538                                    rx_buf->page, rx_buf->page_offset,
 539                                    rx_buf->len);
 540                 rx_buf->page = NULL;
 541                 skb->len += rx_buf->len;
 542                 if (skb_shinfo(skb)->nr_frags == n_frags)
 543                         break;
 544
 545                 rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 546         }
 547
 548         skb->data_len = skb->len;
 549         skb->truesize += n_frags * efx->rx_buffer_truesize;
 550
 551         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 552
 553         napi_gro_frags(napi);
 554 }
 555
 556 /* RSS contexts.  We're using linked lists and crappy O(n) algorithms, because
 557  * (a) this is an infrequent control-plane operation and (b) n is small (max 64)
 558  */
 559 struct efx_rss_context *efx_alloc_rss_context_entry(struct efx_nic *efx)
 560 {
 561         struct list_head *head = &efx->rss_context.list;
 562         struct efx_rss_context *ctx, *new;
 563         u32 id = 1; /* Don't use zero, that refers to the master RSS context */
 564
 565         WARN_ON(!mutex_is_locked(&efx->rss_lock));
 566
 567         /* Search for first gap in the numbering */
 568         list_for_each_entry(ctx, head, list) {
 569                 if (ctx->user_id != id)
 570                         break;
 571                 id++;
 572                 /* Check for wrap.  If this happens, we have nearly 2^32
 573                  * allocated RSS contexts, which seems unlikely.
 574                  */
 575                 if (WARN_ON_ONCE(!id))
 576                         return NULL;
 577         }
 578
 579         /* Create the new entry */
 580         new = kmalloc(sizeof(*new), GFP_KERNEL);
 581         if (!new)
 582                 return NULL;
 583         new->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
 584         new->rx_hash_udp_4tuple = false;
 585
 586         /* Insert the new entry into the gap */
 587         new->user_id = id;
 588         list_add_tail(&new->list, &ctx->list);
 589         return new;
 590 }
 591
 592 struct efx_rss_context *efx_find_rss_context_entry(struct efx_nic *efx, u32 id)
 593 {
 594         struct list_head *head = &efx->rss_context.list;
 595         struct efx_rss_context *ctx;
 596
 597         WARN_ON(!mutex_is_locked(&efx->rss_lock));
 598
 599         list_for_each_entry(ctx, head, list)
 600                 if (ctx->user_id == id)
 601                         return ctx;
 602         return NULL;
 603 }
 604
 605 void efx_free_rss_context_entry(struct efx_rss_context *ctx)
 606 {
 607         list_del(&ctx->list);
 608         kfree(ctx);
 609 }
 610
 611 void efx_set_default_rx_indir_table(struct efx_nic *efx,
 612                                     struct efx_rss_context *ctx)
 613 {
 614         size_t i;
 615
 616         for (i = 0; i < ARRAY_SIZE(ctx->rx_indir_table); i++)
 617                 ctx->rx_indir_table[i] =
 618                         ethtool_rxfh_indir_default(i, efx->rss_spread);
 619 }
 620
 621 /**
 622  * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
 623  * @spec: Specification to test
 624  *
 625  * Return: %true if the specification is a non-drop RX filter that
 626  * matches a local MAC address I/G bit value of 1 or matches a local
 627  * IPv4 or IPv6 address value in the respective multicast address
 628  * range.  Otherwise %false.
 629  */
 630 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
 631 {
 632         if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
 633             spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
 634                 return false;
 635
 636         if (spec->match_flags &
 637             (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
 638             is_multicast_ether_addr(spec->loc_mac))
 639                 return true;
 640
 641         if ((spec->match_flags &
 642              (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
 643             (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
 644                 if (spec->ether_type == htons(ETH_P_IP) &&
 645                     ipv4_is_multicast(spec->loc_host[0]))
 646                         return true;
 647                 if (spec->ether_type == htons(ETH_P_IPV6) &&
 648                     ((const u8 *)spec->loc_host)[0] == 0xff)
 649                         return true;
 650         }
 651
 652         return false;
 653 }
 654
 655 bool efx_filter_spec_equal(const struct efx_filter_spec *left,
 656                            const struct efx_filter_spec *right)
 657 {
 658         if ((left->match_flags ^ right->match_flags) |
 659             ((left->flags ^ right->flags) &
 660              (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)))
 661                 return false;
 662
 663         return memcmp(&left->outer_vid, &right->outer_vid,
 664                       sizeof(struct efx_filter_spec) -
 665                       offsetof(struct efx_filter_spec, outer_vid)) == 0;
 666 }
 667
 668 u32 efx_filter_spec_hash(const struct efx_filter_spec *spec)
 669 {
 670         BUILD_BUG_ON(offsetof(struct efx_filter_spec, outer_vid) & 3);
 671         return jhash2((const u32 *)&spec->outer_vid,
 672                       (sizeof(struct efx_filter_spec) -
 673                        offsetof(struct efx_filter_spec, outer_vid)) / 4,
 674                       0);
 675 }
 676
 677 #ifdef CONFIG_RFS_ACCEL
 678 bool efx_rps_check_rule(struct efx_arfs_rule *rule, unsigned int filter_idx,
 679                         bool *force)
 680 {
 681         if (rule->filter_id == EFX_ARFS_FILTER_ID_PENDING) {
 682                 /* ARFS is currently updating this entry, leave it */
 683                 return false;
 684         }
 685         if (rule->filter_id == EFX_ARFS_FILTER_ID_ERROR) {
 686                 /* ARFS tried and failed to update this, so it's probably out
 687                  * of date.  Remove the filter and the ARFS rule entry.
 688                  */
 689                 rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
 690                 *force = true;
 691                 return true;
 692         } else if (WARN_ON(rule->filter_id != filter_idx)) { /* can't happen */
 693                 /* ARFS has moved on, so old filter is not needed.  Since we did
 694                  * not mark the rule with EFX_ARFS_FILTER_ID_REMOVING, it will
 695                  * not be removed by efx_rps_hash_del() subsequently.
 696                  */
 697                 *force = true;
 698                 return true;
 699         }
 700         /* Remove it iff ARFS wants to. */
 701         return true;
 702 }
 703
 704 static
 705 struct hlist_head *efx_rps_hash_bucket(struct efx_nic *efx,
 706                                        const struct efx_filter_spec *spec)
 707 {
 708         u32 hash = efx_filter_spec_hash(spec);
 709
 710         lockdep_assert_held(&efx->rps_hash_lock);
 711         if (!efx->rps_hash_table)
 712                 return NULL;
 713         return &efx->rps_hash_table[hash % EFX_ARFS_HASH_TABLE_SIZE];
 714 }
 715
 716 struct efx_arfs_rule *efx_rps_hash_find(struct efx_nic *efx,
 717                                         const struct efx_filter_spec *spec)
 718 {
 719         struct efx_arfs_rule *rule;
 720         struct hlist_head *head;
 721         struct hlist_node *node;
 722
 723         head = efx_rps_hash_bucket(efx, spec);
 724         if (!head)
 725                 return NULL;
 726         hlist_for_each(node, head) {
 727                 rule = container_of(node, struct efx_arfs_rule, node);
 728                 if (efx_filter_spec_equal(spec, &rule->spec))
 729                         return rule;
 730         }
 731         return NULL;
 732 }
 733
 734 struct efx_arfs_rule *efx_rps_hash_add(struct efx_nic *efx,
 735                                        const struct efx_filter_spec *spec,
 736                                        bool *new)
 737 {
 738         struct efx_arfs_rule *rule;
 739         struct hlist_head *head;
 740         struct hlist_node *node;
 741
 742         head = efx_rps_hash_bucket(efx, spec);
 743         if (!head)
 744                 return NULL;
 745         hlist_for_each(node, head) {
 746                 rule = container_of(node, struct efx_arfs_rule, node);
 747                 if (efx_filter_spec_equal(spec, &rule->spec)) {
 748                         *new = false;
 749                         return rule;
 750                 }
 751         }
 752         rule = kmalloc(sizeof(*rule), GFP_ATOMIC);
 753         *new = true;
 754         if (rule) {
 755                 memcpy(&rule->spec, spec, sizeof(rule->spec));
 756                 hlist_add_head(&rule->node, head);
 757         }
 758         return rule;
 759 }
 760
 761 void efx_rps_hash_del(struct efx_nic *efx, const struct efx_filter_spec *spec)
 762 {
 763         struct efx_arfs_rule *rule;
 764         struct hlist_head *head;
 765         struct hlist_node *node;
 766
 767         head = efx_rps_hash_bucket(efx, spec);
 768         if (WARN_ON(!head))
 769                 return;
 770         hlist_for_each(node, head) {
 771                 rule = container_of(node, struct efx_arfs_rule, node);
 772                 if (efx_filter_spec_equal(spec, &rule->spec)) {
 773                         /* Someone already reused the entry.  We know that if
 774                          * this check doesn't fire (i.e. filter_id == REMOVING)
 775                          * then the REMOVING mark was put there by our caller,
 776                          * because caller is holding a lock on filter table and
 777                          * only holders of that lock set REMOVING.
 778                          */
 779                         if (rule->filter_id != EFX_ARFS_FILTER_ID_REMOVING)
 780                                 return;
 781                         hlist_del(node);
 782                         kfree(rule);
 783                         return;
 784                 }
 785         }
 786         /* We didn't find it. */
 787         WARN_ON(1);
 788 }
 789 #endif
 790
 791 int efx_probe_filters(struct efx_nic *efx)
 792 {
 793         int rc;
 794
 795         mutex_lock(&efx->mac_lock);
 796         down_write(&efx->filter_sem);
 797         rc = efx->type->filter_table_probe(efx);
 798         if (rc)
 799                 goto out_unlock;
 800
 801 #ifdef CONFIG_RFS_ACCEL
 802         if (efx->type->offload_features & NETIF_F_NTUPLE) {
 803                 struct efx_channel *channel;
 804                 int i, success = 1;
 805
 806                 efx_for_each_channel(channel, efx) {
 807                         channel->rps_flow_id =
 808                                 kcalloc(efx->type->max_rx_ip_filters,
 809                                         sizeof(*channel->rps_flow_id),
 810                                         GFP_KERNEL);
 811                         if (!channel->rps_flow_id)
 812                                 success = 0;
 813                         else
 814                                 for (i = 0;
 815                                      i < efx->type->max_rx_ip_filters;
 816                                      ++i)
 817                                         channel->rps_flow_id[i] =
 818                                                 RPS_FLOW_ID_INVALID;
 819                         channel->rfs_expire_index = 0;
 820                         channel->rfs_filter_count = 0;
 821                 }
 822
 823                 if (!success) {
 824                         efx_for_each_channel(channel, efx)
 825                                 kfree(channel->rps_flow_id);
 826                         efx->type->filter_table_remove(efx);
 827                         rc = -ENOMEM;
 828                         goto out_unlock;
 829                 }
 830         }
 831 #endif
 832 out_unlock:
 833         up_write(&efx->filter_sem);
 834         mutex_unlock(&efx->mac_lock);
 835         return rc;
 836 }
 837
 838 void efx_remove_filters(struct efx_nic *efx)
 839 {
 840 #ifdef CONFIG_RFS_ACCEL
 841         struct efx_channel *channel;
 842
 843         efx_for_each_channel(channel, efx) {
 844                 cancel_delayed_work_sync(&channel->filter_work);
 845                 kfree(channel->rps_flow_id);
 846                 channel->rps_flow_id = NULL;
 847         }
 848 #endif
 849         down_write(&efx->filter_sem);
 850         efx->type->filter_table_remove(efx);
 851         up_write(&efx->filter_sem);
 852 }
 853
 854 #ifdef CONFIG_RFS_ACCEL
 855
 856 static void efx_filter_rfs_work(struct work_struct *data)
 857 {
 858         struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
 859                                                               work);
 860         struct efx_nic *efx = netdev_priv(req->net_dev);
 861         struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
 862         int slot_idx = req - efx->rps_slot;
 863         struct efx_arfs_rule *rule;
 864         u16 arfs_id = 0;
 865         int rc;
 866
 867         rc = efx->type->filter_insert(efx, &req->spec, true);
 868         if (rc >= 0)
 869                 /* Discard 'priority' part of EF10+ filter ID (mcdi_filters) */
 870                 rc %= efx->type->max_rx_ip_filters;
 871         if (efx->rps_hash_table) {
 872                 spin_lock_bh(&efx->rps_hash_lock);
 873                 rule = efx_rps_hash_find(efx, &req->spec);
 874                 /* The rule might have already gone, if someone else's request
 875                  * for the same spec was already worked and then expired before
 876                  * we got around to our work.  In that case we have nothing
 877                  * tying us to an arfs_id, meaning that as soon as the filter
 878                  * is considered for expiry it will be removed.
 879                  */
 880                 if (rule) {
 881                         if (rc < 0)
 882                                 rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
 883                         else
 884                                 rule->filter_id = rc;
 885                         arfs_id = rule->arfs_id;
 886                 }
 887                 spin_unlock_bh(&efx->rps_hash_lock);
 888         }
 889         if (rc >= 0) {
 890                 /* Remember this so we can check whether to expire the filter
 891                  * later.
 892                  */
 893                 mutex_lock(&efx->rps_mutex);
 894                 if (channel->rps_flow_id[rc] == RPS_FLOW_ID_INVALID)
 895                         channel->rfs_filter_count++;
 896                 channel->rps_flow_id[rc] = req->flow_id;
 897                 mutex_unlock(&efx->rps_mutex);
 898
 899                 if (req->spec.ether_type == htons(ETH_P_IP))
 900                         netif_info(efx, rx_status, efx->net_dev,
 901                                    "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
 902                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 903                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 904                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 905                                    req->rxq_index, req->flow_id, rc, arfs_id);
 906                 else
 907                         netif_info(efx, rx_status, efx->net_dev,
 908                                    "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
 909                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 910                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 911                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 912                                    req->rxq_index, req->flow_id, rc, arfs_id);
 913                 channel->n_rfs_succeeded++;
 914         } else {
 915                 if (req->spec.ether_type == htons(ETH_P_IP))
 916                         netif_dbg(efx, rx_status, efx->net_dev,
 917                                   "failed to steer %s %pI4:%u:%pI4:%u to queue %u [flow %u rc %d id %u]\n",
 918                                   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 919                                   req->spec.rem_host, ntohs(req->spec.rem_port),
 920                                   req->spec.loc_host, ntohs(req->spec.loc_port),
 921                                   req->rxq_index, req->flow_id, rc, arfs_id);
 922                 else
 923                         netif_dbg(efx, rx_status, efx->net_dev,
 924                                   "failed to steer %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u rc %d id %u]\n",
 925                                   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 926                                   req->spec.rem_host, ntohs(req->spec.rem_port),
 927                                   req->spec.loc_host, ntohs(req->spec.loc_port),
 928                                   req->rxq_index, req->flow_id, rc, arfs_id);
 929                 channel->n_rfs_failed++;
 930                 /* We're overloading the NIC's filter tables, so let's do a
 931                  * chunk of extra expiry work.
 932                  */
 933                 __efx_filter_rfs_expire(channel, min(channel->rfs_filter_count,
 934                                                      100u));
 935         }
 936
 937         /* Release references */
 938         clear_bit(slot_idx, &efx->rps_slot_map);
 939         dev_put(req->net_dev);
 940 }
 941
 942 int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 943                    u16 rxq_index, u32 flow_id)
 944 {
 945         struct efx_nic *efx = netdev_priv(net_dev);
 946         struct efx_async_filter_insertion *req;
 947         struct efx_arfs_rule *rule;
 948         struct flow_keys fk;
 949         int slot_idx;
 950         bool new;
 951         int rc;
 952
 953         /* find a free slot */
 954         for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
 955                 if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
 956                         break;
 957         if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
 958                 return -EBUSY;
 959
 960         if (flow_id == RPS_FLOW_ID_INVALID) {
 961                 rc = -EINVAL;
 962                 goto out_clear;
 963         }
 964
 965         if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
 966                 rc = -EPROTONOSUPPORT;
 967                 goto out_clear;
 968         }
 969
 970         if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
 971                 rc = -EPROTONOSUPPORT;
 972                 goto out_clear;
 973         }
 974         if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
 975                 rc = -EPROTONOSUPPORT;
 976                 goto out_clear;
 977         }
 978
 979         req = efx->rps_slot + slot_idx;
 980         efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
 981                            efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
 982                            rxq_index);
 983         req->spec.match_flags =
 984                 EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
 985                 EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
 986                 EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
 987         req->spec.ether_type = fk.basic.n_proto;
 988         req->spec.ip_proto = fk.basic.ip_proto;
 989
 990         if (fk.basic.n_proto == htons(ETH_P_IP)) {
 991                 req->spec.rem_host[0] = fk.addrs.v4addrs.src;
 992                 req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
 993         } else {
 994                 memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
 995                        sizeof(struct in6_addr));
 996                 memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
 997                        sizeof(struct in6_addr));
 998         }
 999
1000         req->spec.rem_port = fk.ports.src;
1001         req->spec.loc_port = fk.ports.dst;
1002
1003         if (efx->rps_hash_table) {
1004                 /* Add it to ARFS hash table */
1005                 spin_lock(&efx->rps_hash_lock);
1006                 rule = efx_rps_hash_add(efx, &req->spec, &new);
1007                 if (!rule) {
1008                         rc = -ENOMEM;
1009                         goto out_unlock;
1010                 }
1011                 if (new)
1012                         rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
1013                 rc = rule->arfs_id;
1014                 /* Skip if existing or pending filter already does the right thing */
1015                 if (!new && rule->rxq_index == rxq_index &&
1016                     rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
1017                         goto out_unlock;
1018                 rule->rxq_index = rxq_index;
1019                 rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
1020                 spin_unlock(&efx->rps_hash_lock);
1021         } else {
1022                 /* Without an ARFS hash table, we just use arfs_id 0 for all
1023                  * filters.  This means if multiple flows hash to the same
1024                  * flow_id, all but the most recently touched will be eligible
1025                  * for expiry.
1026                  */
1027                 rc = 0;
1028         }
1029
1030         /* Queue the request */
1031         dev_hold(req->net_dev = net_dev);
1032         INIT_WORK(&req->work, efx_filter_rfs_work);
1033         req->rxq_index = rxq_index;
1034         req->flow_id = flow_id;
1035         schedule_work(&req->work);
1036         return rc;
1037 out_unlock:
1038         spin_unlock(&efx->rps_hash_lock);
1039 out_clear:
1040         clear_bit(slot_idx, &efx->rps_slot_map);
1041         return rc;
1042 }
1043
1044 bool __efx_filter_rfs_expire(struct efx_channel *channel, unsigned int quota)
1045 {
1046         bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
1047         struct efx_nic *efx = channel->efx;
1048         unsigned int index, size, start;
1049         u32 flow_id;
1050
1051         if (!mutex_trylock(&efx->rps_mutex))
1052                 return false;
1053         expire_one = efx->type->filter_rfs_expire_one;
1054         index = channel->rfs_expire_index;
1055         start = index;
1056         size = efx->type->max_rx_ip_filters;
1057         while (quota) {
1058                 flow_id = channel->rps_flow_id[index];
1059
1060                 if (flow_id != RPS_FLOW_ID_INVALID) {
1061                         quota--;
1062                         if (expire_one(efx, flow_id, index)) {
1063                                 netif_info(efx, rx_status, efx->net_dev,
1064                                            "expired filter %d [channel %u flow %u]\n",
1065                                            index, channel->channel, flow_id);
1066                                 channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
1067                                 channel->rfs_filter_count--;
1068                         }
1069                 }
1070                 if (++index == size)
1071                         index = 0;
1072                 /* If we were called with a quota that exceeds the total number
1073                  * of filters in the table (which shouldn't happen, but could
1074                  * if two callers race), ensure that we don't loop forever -
1075                  * stop when we've examined every row of the table.
1076                  */
1077                 if (index == start)
1078                         break;
1079         }
1080
1081         channel->rfs_expire_index = index;
1082         mutex_unlock(&efx->rps_mutex);
1083         return true;
1084 }
1085
1086 #endif /* CONFIG_RFS_ACCEL */