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