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 <net/rps.h>
  15 #include "efx.h"
  16 #include "nic.h"
  17 #include "rx_common.h"
  18
  19 /* This is the percentage fill level below which new RX descriptors
  20  * will be added to the RX descriptor ring.
  21  */
  22 static unsigned int rx_refill_threshold;
  23 module_param(rx_refill_threshold, uint, 0444);
  24 MODULE_PARM_DESC(rx_refill_threshold,
  25                  "RX descriptor ring refill threshold (%)");
  26
  27 /* RX maximum head room required.
  28  *
  29  * This must be at least 1 to prevent overflow, plus one packet-worth
  30  * to allow pipelined receives.
  31  */
  32 #define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
  33
  34 /* Check the RX page recycle ring for a page that can be reused. */
  35 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
  36 {
  37         struct efx_nic *efx = rx_queue->efx;
  38         struct efx_rx_page_state *state;
  39         unsigned int index;
  40         struct page *page;
  41
  42         if (unlikely(!rx_queue->page_ring))
  43                 return NULL;
  44         index = rx_queue->page_remove & rx_queue->page_ptr_mask;
  45         page = rx_queue->page_ring[index];
  46         if (page == NULL)
  47                 return NULL;
  48
  49         rx_queue->page_ring[index] = NULL;
  50         /* page_remove cannot exceed page_add. */
  51         if (rx_queue->page_remove != rx_queue->page_add)
  52                 ++rx_queue->page_remove;
  53
  54         /* If page_count is 1 then we hold the only reference to this page. */
  55         if (page_count(page) == 1) {
  56                 ++rx_queue->page_recycle_count;
  57                 return page;
  58         } else {
  59                 state = page_address(page);
  60                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
  61                                PAGE_SIZE << efx->rx_buffer_order,
  62                                DMA_FROM_DEVICE);
  63                 put_page(page);
  64                 ++rx_queue->page_recycle_failed;
  65         }
  66
  67         return NULL;
  68 }
  69
  70 /* Attempt to recycle the page if there is an RX recycle ring; the page can
  71  * only be added if this is the final RX buffer, to prevent pages being used in
  72  * the descriptor ring and appearing in the recycle ring simultaneously.
  73  */
  74 static void efx_recycle_rx_page(struct efx_channel *channel,
  75                                 struct efx_rx_buffer *rx_buf)
  76 {
  77         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
  78         struct efx_nic *efx = rx_queue->efx;
  79         struct page *page = rx_buf->page;
  80         unsigned int index;
  81
  82         /* Only recycle the page after processing the final buffer. */
  83         if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
  84                 return;
  85
  86         index = rx_queue->page_add & rx_queue->page_ptr_mask;
  87         if (rx_queue->page_ring[index] == NULL) {
  88                 unsigned int read_index = rx_queue->page_remove &
  89                         rx_queue->page_ptr_mask;
  90
  91                 /* The next slot in the recycle ring is available, but
  92                  * increment page_remove if the read pointer currently
  93                  * points here.
  94                  */
  95                 if (read_index == index)
  96                         ++rx_queue->page_remove;
  97                 rx_queue->page_ring[index] = page;
  98                 ++rx_queue->page_add;
  99                 return;
 100         }
 101         ++rx_queue->page_recycle_full;
 102         efx_unmap_rx_buffer(efx, rx_buf);
 103         put_page(rx_buf->page);
 104 }
 105
 106 /* Recycle the pages that are used by buffers that have just been received. */
 107 void efx_recycle_rx_pages(struct efx_channel *channel,
 108                           struct efx_rx_buffer *rx_buf,
 109                           unsigned int n_frags)
 110 {
 111         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 112
 113         if (unlikely(!rx_queue->page_ring))
 114                 return;
 115
 116         do {
 117                 efx_recycle_rx_page(channel, rx_buf);
 118                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 119         } while (--n_frags);
 120 }
 121
 122 void efx_discard_rx_packet(struct efx_channel *channel,
 123                            struct efx_rx_buffer *rx_buf,
 124                            unsigned int n_frags)
 125 {
 126         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 127
 128         efx_recycle_rx_pages(channel, rx_buf, n_frags);
 129
 130         efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 131 }
 132
 133 static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 134 {
 135         unsigned int bufs_in_recycle_ring, page_ring_size;
 136         struct efx_nic *efx = rx_queue->efx;
 137
 138         bufs_in_recycle_ring = efx_rx_recycle_ring_size(efx);
 139         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 140                                             efx->rx_bufs_per_page);
 141         rx_queue->page_ring = kcalloc(page_ring_size,
 142                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 143         if (!rx_queue->page_ring)
 144                 rx_queue->page_ptr_mask = 0;
 145         else
 146                 rx_queue->page_ptr_mask = page_ring_size - 1;
 147 }
 148
 149 static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 150 {
 151         struct efx_nic *efx = rx_queue->efx;
 152         int i;
 153
 154         if (unlikely(!rx_queue->page_ring))
 155                 return;
 156
 157         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 158         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 159                 struct page *page = rx_queue->page_ring[i];
 160                 struct efx_rx_page_state *state;
 161
 162                 if (page == NULL)
 163                         continue;
 164
 165                 state = page_address(page);
 166                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 167                                PAGE_SIZE << efx->rx_buffer_order,
 168                                DMA_FROM_DEVICE);
 169                 put_page(page);
 170         }
 171         kfree(rx_queue->page_ring);
 172         rx_queue->page_ring = NULL;
 173 }
 174
 175 static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
 176                                struct efx_rx_buffer *rx_buf)
 177 {
 178         /* Release the page reference we hold for the buffer. */
 179         if (rx_buf->page)
 180                 put_page(rx_buf->page);
 181
 182         /* If this is the last buffer in a page, unmap and free it. */
 183         if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
 184                 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
 185                 efx_free_rx_buffers(rx_queue, rx_buf, 1);
 186         }
 187         rx_buf->page = NULL;
 188 }
 189
 190 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
 191 {
 192         struct efx_nic *efx = rx_queue->efx;
 193         unsigned int entries;
 194         int rc;
 195
 196         /* Create the smallest power-of-two aligned ring */
 197         entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
 198         EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
 199         rx_queue->ptr_mask = entries - 1;
 200
 201         netif_dbg(efx, probe, efx->net_dev,
 202                   "creating RX queue %d size %#x mask %#x\n",
 203                   efx_rx_queue_index(rx_queue), efx->rxq_entries,
 204                   rx_queue->ptr_mask);
 205
 206         /* Allocate RX buffers */
 207         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 208                                    GFP_KERNEL);
 209         if (!rx_queue->buffer)
 210                 return -ENOMEM;
 211
 212         rc = efx_nic_probe_rx(rx_queue);
 213         if (rc) {
 214                 kfree(rx_queue->buffer);
 215                 rx_queue->buffer = NULL;
 216         }
 217
 218         return rc;
 219 }
 220
 221 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
 222 {
 223         unsigned int max_fill, trigger, max_trigger;
 224         struct efx_nic *efx = rx_queue->efx;
 225         int rc = 0;
 226
 227         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 228                   "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
 229
 230         /* Initialise ptr fields */
 231         rx_queue->added_count = 0;
 232         rx_queue->notified_count = 0;
 233         rx_queue->granted_count = 0;
 234         rx_queue->removed_count = 0;
 235         rx_queue->min_fill = -1U;
 236         efx_init_rx_recycle_ring(rx_queue);
 237
 238         rx_queue->page_remove = 0;
 239         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 240         rx_queue->page_recycle_count = 0;
 241         rx_queue->page_recycle_failed = 0;
 242         rx_queue->page_recycle_full = 0;
 243
 244         /* Initialise limit fields */
 245         max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
 246         max_trigger =
 247                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 248         if (rx_refill_threshold != 0) {
 249                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 250                 if (trigger > max_trigger)
 251                         trigger = max_trigger;
 252         } else {
 253                 trigger = max_trigger;
 254         }
 255
 256         rx_queue->max_fill = max_fill;
 257         rx_queue->fast_fill_trigger = trigger;
 258         rx_queue->refill_enabled = true;
 259
 260         /* Initialise XDP queue information */
 261         rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev,
 262                               rx_queue->core_index, 0);
 263
 264         if (rc) {
 265                 netif_err(efx, rx_err, efx->net_dev,
 266                           "Failure to initialise XDP queue information rc=%d\n",
 267                           rc);
 268                 efx->xdp_rxq_info_failed = true;
 269         } else {
 270                 rx_queue->xdp_rxq_info_valid = true;
 271         }
 272
 273         /* Set up RX descriptor ring */
 274         efx_nic_init_rx(rx_queue);
 275 }
 276
 277 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
 278 {
 279         struct efx_rx_buffer *rx_buf;
 280         int i;
 281
 282         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 283                   "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
 284
 285         del_timer_sync(&rx_queue->slow_fill);
 286         if (rx_queue->grant_credits)
 287                 flush_work(&rx_queue->grant_work);
 288
 289         /* Release RX buffers from the current read ptr to the write ptr */
 290         if (rx_queue->buffer) {
 291                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 292                      i++) {
 293                         unsigned int index = i & rx_queue->ptr_mask;
 294
 295                         rx_buf = efx_rx_buffer(rx_queue, index);
 296                         efx_fini_rx_buffer(rx_queue, rx_buf);
 297                 }
 298         }
 299
 300         efx_fini_rx_recycle_ring(rx_queue);
 301
 302         if (rx_queue->xdp_rxq_info_valid)
 303                 xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info);
 304
 305         rx_queue->xdp_rxq_info_valid = false;
 306 }
 307
 308 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
 309 {
 310         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 311                   "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
 312
 313         efx_nic_remove_rx(rx_queue);
 314
 315         kfree(rx_queue->buffer);
 316         rx_queue->buffer = NULL;
 317 }
 318
 319 /* Unmap a DMA-mapped page.  This function is only called for the final RX
 320  * buffer in a page.
 321  */
 322 void efx_unmap_rx_buffer(struct efx_nic *efx,
 323                          struct efx_rx_buffer *rx_buf)
 324 {
 325         struct page *page = rx_buf->page;
 326
 327         if (page) {
 328                 struct efx_rx_page_state *state = page_address(page);
 329
 330                 dma_unmap_page(&efx->pci_dev->dev,
 331                                state->dma_addr,
 332                                PAGE_SIZE << efx->rx_buffer_order,
 333                                DMA_FROM_DEVICE);
 334         }
 335 }
 336
 337 void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
 338                          struct efx_rx_buffer *rx_buf,
 339                          unsigned int num_bufs)
 340 {
 341         do {
 342                 if (rx_buf->page) {
 343                         put_page(rx_buf->page);
 344                         rx_buf->page = NULL;
 345                 }
 346                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 347         } while (--num_bufs);
 348 }
 349
 350 void efx_rx_slow_fill(struct timer_list *t)
 351 {
 352         struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
 353
 354         /* Post an event to cause NAPI to run and refill the queue */
 355         efx_nic_generate_fill_event(rx_queue);
 356         ++rx_queue->slow_fill_count;
 357 }
 358
 359 void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue)
 360 {
 361         mod_timer(&rx_queue->slow_fill, jiffies + msecs_to_jiffies(10));
 362 }
 363
 364 /* efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
 365  *
 366  * @rx_queue:           Efx RX queue
 367  *
 368  * This allocates a batch of pages, maps them for DMA, and populates
 369  * struct efx_rx_buffers for each one. Return a negative error code or
 370  * 0 on success. If a single page can be used for multiple buffers,
 371  * then the page will either be inserted fully, or not at all.
 372  */
 373 static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
 374 {
 375         unsigned int page_offset, index, count;
 376         struct efx_nic *efx = rx_queue->efx;
 377         struct efx_rx_page_state *state;
 378         struct efx_rx_buffer *rx_buf;
 379         dma_addr_t dma_addr;
 380         struct page *page;
 381
 382         count = 0;
 383         do {
 384                 page = efx_reuse_page(rx_queue);
 385                 if (page == NULL) {
 386                         page = alloc_pages(__GFP_COMP |
 387                                            (atomic ? GFP_ATOMIC : GFP_KERNEL),
 388                                            efx->rx_buffer_order);
 389                         if (unlikely(page == NULL))
 390                                 return -ENOMEM;
 391                         dma_addr =
 392                                 dma_map_page(&efx->pci_dev->dev, page, 0,
 393                                              PAGE_SIZE << efx->rx_buffer_order,
 394                                              DMA_FROM_DEVICE);
 395                         if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
 396                                                        dma_addr))) {
 397                                 __free_pages(page, efx->rx_buffer_order);
 398                                 return -EIO;
 399                         }
 400                         state = page_address(page);
 401                         state->dma_addr = dma_addr;
 402                 } else {
 403                         state = page_address(page);
 404                         dma_addr = state->dma_addr;
 405                 }
 406
 407                 dma_addr += sizeof(struct efx_rx_page_state);
 408                 page_offset = sizeof(struct efx_rx_page_state);
 409
 410                 do {
 411                         index = rx_queue->added_count & rx_queue->ptr_mask;
 412                         rx_buf = efx_rx_buffer(rx_queue, index);
 413                         rx_buf->dma_addr = dma_addr + efx->rx_ip_align +
 414                                            EFX_XDP_HEADROOM;
 415                         rx_buf->page = page;
 416                         rx_buf->page_offset = page_offset + efx->rx_ip_align +
 417                                               EFX_XDP_HEADROOM;
 418                         rx_buf->len = efx->rx_dma_len;
 419                         rx_buf->flags = 0;
 420                         ++rx_queue->added_count;
 421                         get_page(page);
 422                         dma_addr += efx->rx_page_buf_step;
 423                         page_offset += efx->rx_page_buf_step;
 424                 } while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
 425
 426                 rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
 427         } while (++count < efx->rx_pages_per_batch);
 428
 429         return 0;
 430 }
 431
 432 void efx_rx_config_page_split(struct efx_nic *efx)
 433 {
 434         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align +
 435                                       EFX_XDP_HEADROOM + EFX_XDP_TAILROOM,
 436                                       EFX_RX_BUF_ALIGNMENT);
 437         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
 438                 ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
 439                 efx->rx_page_buf_step);
 440         efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
 441                 efx->rx_bufs_per_page;
 442         efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
 443                                                efx->rx_bufs_per_page);
 444 }
 445
 446 /* efx_fast_push_rx_descriptors - push new RX descriptors quickly
 447  * @rx_queue:           RX descriptor queue
 448  *
 449  * This will aim to fill the RX descriptor queue up to
 450  * @rx_queue->@max_fill. If there is insufficient atomic
 451  * memory to do so, a slow fill will be scheduled.
 452  *
 453  * The caller must provide serialisation (none is used here). In practise,
 454  * this means this function must run from the NAPI handler, or be called
 455  * when NAPI is disabled.
 456  */
 457 void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
 458 {
 459         struct efx_nic *efx = rx_queue->efx;
 460         unsigned int fill_level, batch_size;
 461         int space, rc = 0;
 462
 463         if (!rx_queue->refill_enabled)
 464                 return;
 465
 466         /* Calculate current fill level, and exit if we don't need to fill */
 467         fill_level = (rx_queue->added_count - rx_queue->removed_count);
 468         EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
 469         if (fill_level >= rx_queue->fast_fill_trigger)
 470                 goto out;
 471
 472         /* Record minimum fill level */
 473         if (unlikely(fill_level < rx_queue->min_fill)) {
 474                 if (fill_level)
 475                         rx_queue->min_fill = fill_level;
 476         }
 477
 478         batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 479         space = rx_queue->max_fill - fill_level;
 480         EFX_WARN_ON_ONCE_PARANOID(space < batch_size);
 481
 482         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 483                    "RX queue %d fast-filling descriptor ring from"
 484                    " level %d to level %d\n",
 485                    efx_rx_queue_index(rx_queue), fill_level,
 486                    rx_queue->max_fill);
 487
 488         do {
 489                 rc = efx_init_rx_buffers(rx_queue, atomic);
 490                 if (unlikely(rc)) {
 491                         /* Ensure that we don't leave the rx queue empty */
 492                         efx_schedule_slow_fill(rx_queue);
 493                         goto out;
 494                 }
 495         } while ((space -= batch_size) >= batch_size);
 496
 497         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 498                    "RX queue %d fast-filled descriptor ring "
 499                    "to level %d\n", efx_rx_queue_index(rx_queue),
 500                    rx_queue->added_count - rx_queue->removed_count);
 501
 502  out:
 503         if (rx_queue->notified_count != rx_queue->added_count)
 504                 efx_nic_notify_rx_desc(rx_queue);
 505 }
 506
 507 /* Pass a received packet up through GRO.  GRO can handle pages
 508  * regardless of checksum state and skbs with a good checksum.
 509  */
 510 void
 511 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 512                   unsigned int n_frags, u8 *eh, __wsum csum)
 513 {
 514         struct napi_struct *napi = &channel->napi_str;
 515         struct efx_nic *efx = channel->efx;
 516         struct sk_buff *skb;
 517
 518         skb = napi_get_frags(napi);
 519         if (unlikely(!skb)) {
 520                 struct efx_rx_queue *rx_queue;
 521
 522                 rx_queue = efx_channel_get_rx_queue(channel);
 523                 efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 524                 return;
 525         }
 526
 527         if (efx->net_dev->features & NETIF_F_RXHASH &&
 528             efx_rx_buf_hash_valid(efx, eh))
 529                 skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
 530                              PKT_HASH_TYPE_L3);
 531         if (csum) {
 532                 skb->csum = csum;
 533                 skb->ip_summed = CHECKSUM_COMPLETE;
 534         } else {
 535                 skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
 536                                   CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 537         }
 538         skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
 539
 540         for (;;) {
 541                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 542                                    rx_buf->page, rx_buf->page_offset,
 543                                    rx_buf->len);
 544                 rx_buf->page = NULL;
 545                 skb->len += rx_buf->len;
 546                 if (skb_shinfo(skb)->nr_frags == n_frags)
 547                         break;
 548
 549                 rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 550         }
 551
 552         skb->data_len = skb->len;
 553         skb->truesize += n_frags * efx->rx_buffer_truesize;
 554
 555         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 556
 557         napi_gro_frags(napi);
 558 }
 559
 560 /* RSS contexts.  We're using linked lists and crappy O(n) algorithms, because
 561  * (a) this is an infrequent control-plane operation and (b) n is small (max 64)
 562  */
 563 struct efx_rss_context *efx_alloc_rss_context_entry(struct efx_nic *efx)
 564 {
 565         struct list_head *head = &efx->rss_context.list;
 566         struct efx_rss_context *ctx, *new;
 567         u32 id = 1; /* Don't use zero, that refers to the master RSS context */
 568
 569         WARN_ON(!mutex_is_locked(&efx->rss_lock));
 570
 571         /* Search for first gap in the numbering */
 572         list_for_each_entry(ctx, head, list) {
 573                 if (ctx->user_id != id)
 574                         break;
 575                 id++;
 576                 /* Check for wrap.  If this happens, we have nearly 2^32
 577                  * allocated RSS contexts, which seems unlikely.
 578                  */
 579                 if (WARN_ON_ONCE(!id))
 580                         return NULL;
 581         }
 582
 583         /* Create the new entry */
 584         new = kmalloc(sizeof(*new), GFP_KERNEL);
 585         if (!new)
 586                 return NULL;
 587         new->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
 588         new->rx_hash_udp_4tuple = false;
 589
 590         /* Insert the new entry into the gap */
 591         new->user_id = id;
 592         list_add_tail(&new->list, &ctx->list);
 593         return new;
 594 }
 595
 596 struct efx_rss_context *efx_find_rss_context_entry(struct efx_nic *efx, u32 id)
 597 {
 598         struct list_head *head = &efx->rss_context.list;
 599         struct efx_rss_context *ctx;
 600
 601         WARN_ON(!mutex_is_locked(&efx->rss_lock));
 602
 603         list_for_each_entry(ctx, head, list)
 604                 if (ctx->user_id == id)
 605                         return ctx;
 606         return NULL;
 607 }
 608
 609 void efx_free_rss_context_entry(struct efx_rss_context *ctx)
 610 {
 611         list_del(&ctx->list);
 612         kfree(ctx);
 613 }
 614
 615 void efx_set_default_rx_indir_table(struct efx_nic *efx,
 616                                     struct efx_rss_context *ctx)
 617 {
 618         size_t i;
 619
 620         for (i = 0; i < ARRAY_SIZE(ctx->rx_indir_table); i++)
 621                 ctx->rx_indir_table[i] =
 622                         ethtool_rxfh_indir_default(i, efx->rss_spread);
 623 }
 624
 625 /**
 626  * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
 627  * @spec: Specification to test
 628  *
 629  * Return: %true if the specification is a non-drop RX filter that
 630  * matches a local MAC address I/G bit value of 1 or matches a local
 631  * IPv4 or IPv6 address value in the respective multicast address
 632  * range.  Otherwise %false.
 633  */
 634 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
 635 {
 636         if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
 637             spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
 638                 return false;
 639
 640         if (spec->match_flags &
 641             (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
 642             is_multicast_ether_addr(spec->loc_mac))
 643                 return true;
 644
 645         if ((spec->match_flags &
 646              (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
 647             (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
 648                 if (spec->ether_type == htons(ETH_P_IP) &&
 649                     ipv4_is_multicast(spec->loc_host[0]))
 650                         return true;
 651                 if (spec->ether_type == htons(ETH_P_IPV6) &&
 652                     ((const u8 *)spec->loc_host)[0] == 0xff)
 653                         return true;
 654         }
 655
 656         return false;
 657 }
 658
 659 bool efx_filter_spec_equal(const struct efx_filter_spec *left,
 660                            const struct efx_filter_spec *right)
 661 {
 662         if ((left->match_flags ^ right->match_flags) |
 663             ((left->flags ^ right->flags) &
 664              (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)))
 665                 return false;
 666
 667         return memcmp(&left->vport_id, &right->vport_id,
 668                       sizeof(struct efx_filter_spec) -
 669                       offsetof(struct efx_filter_spec, vport_id)) == 0;
 670 }
 671
 672 u32 efx_filter_spec_hash(const struct efx_filter_spec *spec)
 673 {
 674         BUILD_BUG_ON(offsetof(struct efx_filter_spec, vport_id) & 3);
 675         return jhash2((const u32 *)&spec->vport_id,
 676                       (sizeof(struct efx_filter_spec) -
 677                        offsetof(struct efx_filter_spec, vport_id)) / 4,
 678                       0);
 679 }
 680
 681 #ifdef CONFIG_RFS_ACCEL
 682 bool efx_rps_check_rule(struct efx_arfs_rule *rule, unsigned int filter_idx,
 683                         bool *force)
 684 {
 685         if (rule->filter_id == EFX_ARFS_FILTER_ID_PENDING) {
 686                 /* ARFS is currently updating this entry, leave it */
 687                 return false;
 688         }
 689         if (rule->filter_id == EFX_ARFS_FILTER_ID_ERROR) {
 690                 /* ARFS tried and failed to update this, so it's probably out
 691                  * of date.  Remove the filter and the ARFS rule entry.
 692                  */
 693                 rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
 694                 *force = true;
 695                 return true;
 696         } else if (WARN_ON(rule->filter_id != filter_idx)) { /* can't happen */
 697                 /* ARFS has moved on, so old filter is not needed.  Since we did
 698                  * not mark the rule with EFX_ARFS_FILTER_ID_REMOVING, it will
 699                  * not be removed by efx_rps_hash_del() subsequently.
 700                  */
 701                 *force = true;
 702                 return true;
 703         }
 704         /* Remove it iff ARFS wants to. */
 705         return true;
 706 }
 707
 708 static
 709 struct hlist_head *efx_rps_hash_bucket(struct efx_nic *efx,
 710                                        const struct efx_filter_spec *spec)
 711 {
 712         u32 hash = efx_filter_spec_hash(spec);
 713
 714         lockdep_assert_held(&efx->rps_hash_lock);
 715         if (!efx->rps_hash_table)
 716                 return NULL;
 717         return &efx->rps_hash_table[hash % EFX_ARFS_HASH_TABLE_SIZE];
 718 }
 719
 720 struct efx_arfs_rule *efx_rps_hash_find(struct efx_nic *efx,
 721                                         const struct efx_filter_spec *spec)
 722 {
 723         struct efx_arfs_rule *rule;
 724         struct hlist_head *head;
 725         struct hlist_node *node;
 726
 727         head = efx_rps_hash_bucket(efx, spec);
 728         if (!head)
 729                 return NULL;
 730         hlist_for_each(node, head) {
 731                 rule = container_of(node, struct efx_arfs_rule, node);
 732                 if (efx_filter_spec_equal(spec, &rule->spec))
 733                         return rule;
 734         }
 735         return NULL;
 736 }
 737
 738 struct efx_arfs_rule *efx_rps_hash_add(struct efx_nic *efx,
 739                                        const struct efx_filter_spec *spec,
 740                                        bool *new)
 741 {
 742         struct efx_arfs_rule *rule;
 743         struct hlist_head *head;
 744         struct hlist_node *node;
 745
 746         head = efx_rps_hash_bucket(efx, spec);
 747         if (!head)
 748                 return NULL;
 749         hlist_for_each(node, head) {
 750                 rule = container_of(node, struct efx_arfs_rule, node);
 751                 if (efx_filter_spec_equal(spec, &rule->spec)) {
 752                         *new = false;
 753                         return rule;
 754                 }
 755         }
 756         rule = kmalloc(sizeof(*rule), GFP_ATOMIC);
 757         *new = true;
 758         if (rule) {
 759                 memcpy(&rule->spec, spec, sizeof(rule->spec));
 760                 hlist_add_head(&rule->node, head);
 761         }
 762         return rule;
 763 }
 764
 765 void efx_rps_hash_del(struct efx_nic *efx, const struct efx_filter_spec *spec)
 766 {
 767         struct efx_arfs_rule *rule;
 768         struct hlist_head *head;
 769         struct hlist_node *node;
 770
 771         head = efx_rps_hash_bucket(efx, spec);
 772         if (WARN_ON(!head))
 773                 return;
 774         hlist_for_each(node, head) {
 775                 rule = container_of(node, struct efx_arfs_rule, node);
 776                 if (efx_filter_spec_equal(spec, &rule->spec)) {
 777                         /* Someone already reused the entry.  We know that if
 778                          * this check doesn't fire (i.e. filter_id == REMOVING)
 779                          * then the REMOVING mark was put there by our caller,
 780                          * because caller is holding a lock on filter table and
 781                          * only holders of that lock set REMOVING.
 782                          */
 783                         if (rule->filter_id != EFX_ARFS_FILTER_ID_REMOVING)
 784                                 return;
 785                         hlist_del(node);
 786                         kfree(rule);
 787                         return;
 788                 }
 789         }
 790         /* We didn't find it. */
 791         WARN_ON(1);
 792 }
 793 #endif
 794
 795 int efx_probe_filters(struct efx_nic *efx)
 796 {
 797         int rc;
 798
 799         mutex_lock(&efx->mac_lock);
 800         rc = efx->type->filter_table_probe(efx);
 801         if (rc)
 802                 goto out_unlock;
 803
 804 #ifdef CONFIG_RFS_ACCEL
 805         if (efx->type->offload_features & NETIF_F_NTUPLE) {
 806                 struct efx_channel *channel;
 807                 int i, success = 1;
 808
 809                 efx_for_each_channel(channel, efx) {
 810                         channel->rps_flow_id =
 811                                 kcalloc(efx->type->max_rx_ip_filters,
 812                                         sizeof(*channel->rps_flow_id),
 813                                         GFP_KERNEL);
 814                         if (!channel->rps_flow_id)
 815                                 success = 0;
 816                         else
 817                                 for (i = 0;
 818                                      i < efx->type->max_rx_ip_filters;
 819                                      ++i)
 820                                         channel->rps_flow_id[i] =
 821                                                 RPS_FLOW_ID_INVALID;
 822                         channel->rfs_expire_index = 0;
 823                         channel->rfs_filter_count = 0;
 824                 }
 825
 826                 if (!success) {
 827                         efx_for_each_channel(channel, efx) {
 828                                 kfree(channel->rps_flow_id);
 829                                 channel->rps_flow_id = NULL;
 830                         }
 831                         efx->type->filter_table_remove(efx);
 832                         rc = -ENOMEM;
 833                         goto out_unlock;
 834                 }
 835         }
 836 #endif
 837 out_unlock:
 838         mutex_unlock(&efx->mac_lock);
 839         return rc;
 840 }
 841
 842 void efx_remove_filters(struct efx_nic *efx)
 843 {
 844 #ifdef CONFIG_RFS_ACCEL
 845         struct efx_channel *channel;
 846
 847         efx_for_each_channel(channel, efx) {
 848                 cancel_delayed_work_sync(&channel->filter_work);
 849                 kfree(channel->rps_flow_id);
 850                 channel->rps_flow_id = NULL;
 851         }
 852 #endif
 853         efx->type->filter_table_remove(efx);
 854 }
 855
 856 #ifdef CONFIG_RFS_ACCEL
 857
 858 static void efx_filter_rfs_work(struct work_struct *data)
 859 {
 860         struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
 861                                                               work);
 862         struct efx_nic *efx = efx_netdev_priv(req->net_dev);
 863         struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
 864         int slot_idx = req - efx->rps_slot;
 865         struct efx_arfs_rule *rule;
 866         u16 arfs_id = 0;
 867         int rc;
 868
 869         rc = efx->type->filter_insert(efx, &req->spec, true);
 870         if (rc >= 0)
 871                 /* Discard 'priority' part of EF10+ filter ID (mcdi_filters) */
 872                 rc %= efx->type->max_rx_ip_filters;
 873         if (efx->rps_hash_table) {
 874                 spin_lock_bh(&efx->rps_hash_lock);
 875                 rule = efx_rps_hash_find(efx, &req->spec);
 876                 /* The rule might have already gone, if someone else's request
 877                  * for the same spec was already worked and then expired before
 878                  * we got around to our work.  In that case we have nothing
 879                  * tying us to an arfs_id, meaning that as soon as the filter
 880                  * is considered for expiry it will be removed.
 881                  */
 882                 if (rule) {
 883                         if (rc < 0)
 884                                 rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
 885                         else
 886                                 rule->filter_id = rc;
 887                         arfs_id = rule->arfs_id;
 888                 }
 889                 spin_unlock_bh(&efx->rps_hash_lock);
 890         }
 891         if (rc >= 0) {
 892                 /* Remember this so we can check whether to expire the filter
 893                  * later.
 894                  */
 895                 mutex_lock(&efx->rps_mutex);
 896                 if (channel->rps_flow_id[rc] == RPS_FLOW_ID_INVALID)
 897                         channel->rfs_filter_count++;
 898                 channel->rps_flow_id[rc] = req->flow_id;
 899                 mutex_unlock(&efx->rps_mutex);
 900
 901                 if (req->spec.ether_type == htons(ETH_P_IP))
 902                         netif_info(efx, rx_status, efx->net_dev,
 903                                    "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
 904                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 905                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 906                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 907                                    req->rxq_index, req->flow_id, rc, arfs_id);
 908                 else
 909                         netif_info(efx, rx_status, efx->net_dev,
 910                                    "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
 911                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 912                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 913                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 914                                    req->rxq_index, req->flow_id, rc, arfs_id);
 915                 channel->n_rfs_succeeded++;
 916         } else {
 917                 if (req->spec.ether_type == htons(ETH_P_IP))
 918                         netif_dbg(efx, rx_status, efx->net_dev,
 919                                   "failed to steer %s %pI4:%u:%pI4:%u to queue %u [flow %u rc %d id %u]\n",
 920                                   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 921                                   req->spec.rem_host, ntohs(req->spec.rem_port),
 922                                   req->spec.loc_host, ntohs(req->spec.loc_port),
 923                                   req->rxq_index, req->flow_id, rc, arfs_id);
 924                 else
 925                         netif_dbg(efx, rx_status, efx->net_dev,
 926                                   "failed to steer %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u rc %d id %u]\n",
 927                                   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 928                                   req->spec.rem_host, ntohs(req->spec.rem_port),
 929                                   req->spec.loc_host, ntohs(req->spec.loc_port),
 930                                   req->rxq_index, req->flow_id, rc, arfs_id);
 931                 channel->n_rfs_failed++;
 932                 /* We're overloading the NIC's filter tables, so let's do a
 933                  * chunk of extra expiry work.
 934                  */
 935                 __efx_filter_rfs_expire(channel, min(channel->rfs_filter_count,
 936                                                      100u));
 937         }
 938
 939         /* Release references */
 940         clear_bit(slot_idx, &efx->rps_slot_map);
 941         dev_put(req->net_dev);
 942 }
 943
 944 int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 945                    u16 rxq_index, u32 flow_id)
 946 {
 947         struct efx_nic *efx = efx_netdev_priv(net_dev);
 948         struct efx_async_filter_insertion *req;
 949         struct efx_arfs_rule *rule;
 950         struct flow_keys fk;
 951         int slot_idx;
 952         bool new;
 953         int rc;
 954
 955         /* find a free slot */
 956         for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
 957                 if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
 958                         break;
 959         if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
 960                 return -EBUSY;
 961
 962         if (flow_id == RPS_FLOW_ID_INVALID) {
 963                 rc = -EINVAL;
 964                 goto out_clear;
 965         }
 966
 967         if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
 968                 rc = -EPROTONOSUPPORT;
 969                 goto out_clear;
 970         }
 971
 972         if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
 973                 rc = -EPROTONOSUPPORT;
 974                 goto out_clear;
 975         }
 976         if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
 977                 rc = -EPROTONOSUPPORT;
 978                 goto out_clear;
 979         }
 980
 981         req = efx->rps_slot + slot_idx;
 982         efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
 983                            efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
 984                            rxq_index);
 985         req->spec.match_flags =
 986                 EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
 987                 EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
 988                 EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
 989         req->spec.ether_type = fk.basic.n_proto;
 990         req->spec.ip_proto = fk.basic.ip_proto;
 991
 992         if (fk.basic.n_proto == htons(ETH_P_IP)) {
 993                 req->spec.rem_host[0] = fk.addrs.v4addrs.src;
 994                 req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
 995         } else {
 996                 memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
 997                        sizeof(struct in6_addr));
 998                 memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
 999                        sizeof(struct in6_addr));
1000         }
1001
1002         req->spec.rem_port = fk.ports.src;
1003         req->spec.loc_port = fk.ports.dst;
1004
1005         if (efx->rps_hash_table) {
1006                 /* Add it to ARFS hash table */
1007                 spin_lock(&efx->rps_hash_lock);
1008                 rule = efx_rps_hash_add(efx, &req->spec, &new);
1009                 if (!rule) {
1010                         rc = -ENOMEM;
1011                         goto out_unlock;
1012                 }
1013                 if (new)
1014                         rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
1015                 rc = rule->arfs_id;
1016                 /* Skip if existing or pending filter already does the right thing */
1017                 if (!new && rule->rxq_index == rxq_index &&
1018                     rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
1019                         goto out_unlock;
1020                 rule->rxq_index = rxq_index;
1021                 rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
1022                 spin_unlock(&efx->rps_hash_lock);
1023         } else {
1024                 /* Without an ARFS hash table, we just use arfs_id 0 for all
1025                  * filters.  This means if multiple flows hash to the same
1026                  * flow_id, all but the most recently touched will be eligible
1027                  * for expiry.
1028                  */
1029                 rc = 0;
1030         }
1031
1032         /* Queue the request */
1033         dev_hold(req->net_dev = net_dev);
1034         INIT_WORK(&req->work, efx_filter_rfs_work);
1035         req->rxq_index = rxq_index;
1036         req->flow_id = flow_id;
1037         schedule_work(&req->work);
1038         return rc;
1039 out_unlock:
1040         spin_unlock(&efx->rps_hash_lock);
1041 out_clear:
1042         clear_bit(slot_idx, &efx->rps_slot_map);
1043         return rc;
1044 }
1045
1046 bool __efx_filter_rfs_expire(struct efx_channel *channel, unsigned int quota)
1047 {
1048         bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
1049         struct efx_nic *efx = channel->efx;
1050         unsigned int index, size, start;
1051         u32 flow_id;
1052
1053         if (!mutex_trylock(&efx->rps_mutex))
1054                 return false;
1055         expire_one = efx->type->filter_rfs_expire_one;
1056         index = channel->rfs_expire_index;
1057         start = index;
1058         size = efx->type->max_rx_ip_filters;
1059         while (quota) {
1060                 flow_id = channel->rps_flow_id[index];
1061
1062                 if (flow_id != RPS_FLOW_ID_INVALID) {
1063                         quota--;
1064                         if (expire_one(efx, flow_id, index)) {
1065                                 netif_info(efx, rx_status, efx->net_dev,
1066                                            "expired filter %d [channel %u flow %u]\n",
1067                                            index, channel->channel, flow_id);
1068                                 channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
1069                                 channel->rfs_filter_count--;
1070                         }
1071                 }
1072                 if (++index == size)
1073                         index = 0;
1074                 /* If we were called with a quota that exceeds the total number
1075                  * of filters in the table (which shouldn't happen, but could
1076                  * if two callers race), ensure that we don't loop forever -
1077                  * stop when we've examined every row of the table.
1078                  */
1079                 if (index == start)
1080                         break;
1081         }
1082
1083         channel->rfs_expire_index = index;
1084         mutex_unlock(&efx->rps_mutex);
1085         return true;
1086 }
1087
1088 #endif /* CONFIG_RFS_ACCEL */