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 /* Number of RX buffers to recycle pages for.  When creating the RX page recycle
  27  * ring, this number is divided by the number of buffers per page to calculate
  28  * the number of pages to store in the RX page recycle ring.
  29  */
  30 #define EFX_RECYCLE_RING_SIZE_IOMMU 4096
  31 #define EFX_RECYCLE_RING_SIZE_NOIOMMU (2 * EFX_RX_PREFERRED_BATCH)
  32
  33 /* RX maximum head room required.
  34  *
  35  * This must be at least 1 to prevent overflow, plus one packet-worth
  36  * to allow pipelined receives.
  37  */
  38 #define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
  39
  40 /* Check the RX page recycle ring for a page that can be reused. */
  41 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
  42 {
  43         struct efx_nic *efx = rx_queue->efx;
  44         struct efx_rx_page_state *state;
  45         unsigned int index;
  46         struct page *page;
  47
  48         index = rx_queue->page_remove & rx_queue->page_ptr_mask;
  49         page = rx_queue->page_ring[index];
  50         if (page == NULL)
  51                 return NULL;
  52
  53         rx_queue->page_ring[index] = NULL;
  54         /* page_remove cannot exceed page_add. */
  55         if (rx_queue->page_remove != rx_queue->page_add)
  56                 ++rx_queue->page_remove;
  57
  58         /* If page_count is 1 then we hold the only reference to this page. */
  59         if (page_count(page) == 1) {
  60                 ++rx_queue->page_recycle_count;
  61                 return page;
  62         } else {
  63                 state = page_address(page);
  64                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
  65                                PAGE_SIZE << efx->rx_buffer_order,
  66                                DMA_FROM_DEVICE);
  67                 put_page(page);
  68                 ++rx_queue->page_recycle_failed;
  69         }
  70
  71         return NULL;
  72 }
  73
  74 /* Attempt to recycle the page if there is an RX recycle ring; the page can
  75  * only be added if this is the final RX buffer, to prevent pages being used in
  76  * the descriptor ring and appearing in the recycle ring simultaneously.
  77  */
  78 static void efx_recycle_rx_page(struct efx_channel *channel,
  79                                 struct efx_rx_buffer *rx_buf)
  80 {
  81         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
  82         struct efx_nic *efx = rx_queue->efx;
  83         struct page *page = rx_buf->page;
  84         unsigned int index;
  85
  86         /* Only recycle the page after processing the final buffer. */
  87         if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
  88                 return;
  89
  90         index = rx_queue->page_add & rx_queue->page_ptr_mask;
  91         if (rx_queue->page_ring[index] == NULL) {
  92                 unsigned int read_index = rx_queue->page_remove &
  93                         rx_queue->page_ptr_mask;
  94
  95                 /* The next slot in the recycle ring is available, but
  96                  * increment page_remove if the read pointer currently
  97                  * points here.
  98                  */
  99                 if (read_index == index)
 100                         ++rx_queue->page_remove;
 101                 rx_queue->page_ring[index] = page;
 102                 ++rx_queue->page_add;
 103                 return;
 104         }
 105         ++rx_queue->page_recycle_full;
 106         efx_unmap_rx_buffer(efx, rx_buf);
 107         put_page(rx_buf->page);
 108 }
 109
 110 /* Recycle the pages that are used by buffers that have just been received. */
 111 void efx_recycle_rx_pages(struct efx_channel *channel,
 112                           struct efx_rx_buffer *rx_buf,
 113                           unsigned int n_frags)
 114 {
 115         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 116
 117         do {
 118                 efx_recycle_rx_page(channel, rx_buf);
 119                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 120         } while (--n_frags);
 121 }
 122
 123 void efx_discard_rx_packet(struct efx_channel *channel,
 124                            struct efx_rx_buffer *rx_buf,
 125                            unsigned int n_frags)
 126 {
 127         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 128
 129         efx_recycle_rx_pages(channel, rx_buf, n_frags);
 130
 131         efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 132 }
 133
 134 static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 135 {
 136         unsigned int bufs_in_recycle_ring, page_ring_size;
 137         struct efx_nic *efx = rx_queue->efx;
 138
 139         /* Set the RX recycle ring size */
 140 #ifdef CONFIG_PPC64
 141         bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
 142 #else
 143         if (iommu_present(&pci_bus_type))
 144                 bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
 145         else
 146                 bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_NOIOMMU;
 147 #endif /* CONFIG_PPC64 */
 148
 149         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 150                                             efx->rx_bufs_per_page);
 151         rx_queue->page_ring = kcalloc(page_ring_size,
 152                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 153         rx_queue->page_ptr_mask = page_ring_size - 1;
 154 }
 155
 156 static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 157 {
 158         struct efx_nic *efx = rx_queue->efx;
 159         int i;
 160
 161         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 162         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 163                 struct page *page = rx_queue->page_ring[i];
 164                 struct efx_rx_page_state *state;
 165
 166                 if (page == NULL)
 167                         continue;
 168
 169                 state = page_address(page);
 170                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 171                                PAGE_SIZE << efx->rx_buffer_order,
 172                                DMA_FROM_DEVICE);
 173                 put_page(page);
 174         }
 175         kfree(rx_queue->page_ring);
 176         rx_queue->page_ring = NULL;
 177 }
 178
 179 static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
 180                                struct efx_rx_buffer *rx_buf)
 181 {
 182         /* Release the page reference we hold for the buffer. */
 183         if (rx_buf->page)
 184                 put_page(rx_buf->page);
 185
 186         /* If this is the last buffer in a page, unmap and free it. */
 187         if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
 188                 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
 189                 efx_free_rx_buffers(rx_queue, rx_buf, 1);
 190         }
 191         rx_buf->page = NULL;
 192 }
 193
 194 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
 195 {
 196         struct efx_nic *efx = rx_queue->efx;
 197         unsigned int entries;
 198         int rc;
 199
 200         /* Create the smallest power-of-two aligned ring */
 201         entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
 202         EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
 203         rx_queue->ptr_mask = entries - 1;
 204
 205         netif_dbg(efx, probe, efx->net_dev,
 206                   "creating RX queue %d size %#x mask %#x\n",
 207                   efx_rx_queue_index(rx_queue), efx->rxq_entries,
 208                   rx_queue->ptr_mask);
 209
 210         /* Allocate RX buffers */
 211         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 212                                    GFP_KERNEL);
 213         if (!rx_queue->buffer)
 214                 return -ENOMEM;
 215
 216         rc = efx_nic_probe_rx(rx_queue);
 217         if (rc) {
 218                 kfree(rx_queue->buffer);
 219                 rx_queue->buffer = NULL;
 220         }
 221
 222         return rc;
 223 }
 224
 225 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
 226 {
 227         unsigned int max_fill, trigger, max_trigger;
 228         struct efx_nic *efx = rx_queue->efx;
 229         int rc = 0;
 230
 231         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 232                   "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
 233
 234         /* Initialise ptr fields */
 235         rx_queue->added_count = 0;
 236         rx_queue->notified_count = 0;
 237         rx_queue->removed_count = 0;
 238         rx_queue->min_fill = -1U;
 239         efx_init_rx_recycle_ring(rx_queue);
 240
 241         rx_queue->page_remove = 0;
 242         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 243         rx_queue->page_recycle_count = 0;
 244         rx_queue->page_recycle_failed = 0;
 245         rx_queue->page_recycle_full = 0;
 246
 247         /* Initialise limit fields */
 248         max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
 249         max_trigger =
 250                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 251         if (rx_refill_threshold != 0) {
 252                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 253                 if (trigger > max_trigger)
 254                         trigger = max_trigger;
 255         } else {
 256                 trigger = max_trigger;
 257         }
 258
 259         rx_queue->max_fill = max_fill;
 260         rx_queue->fast_fill_trigger = trigger;
 261         rx_queue->refill_enabled = true;
 262
 263         /* Initialise XDP queue information */
 264         rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev,
 265                               rx_queue->core_index);
 266
 267         if (rc) {
 268                 netif_err(efx, rx_err, efx->net_dev,
 269                           "Failure to initialise XDP queue information rc=%d\n",
 270                           rc);
 271                 efx->xdp_rxq_info_failed = true;
 272         } else {
 273                 rx_queue->xdp_rxq_info_valid = true;
 274         }
 275
 276         /* Set up RX descriptor ring */
 277         efx_nic_init_rx(rx_queue);
 278 }
 279
 280 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
 281 {
 282         struct efx_rx_buffer *rx_buf;
 283         int i;
 284
 285         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 286                   "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
 287
 288         del_timer_sync(&rx_queue->slow_fill);
 289
 290         /* Release RX buffers from the current read ptr to the write ptr */
 291         if (rx_queue->buffer) {
 292                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 293                      i++) {
 294                         unsigned int index = i & rx_queue->ptr_mask;
 295
 296                         rx_buf = efx_rx_buffer(rx_queue, index);
 297                         efx_fini_rx_buffer(rx_queue, rx_buf);
 298                 }
 299         }
 300
 301         efx_fini_rx_recycle_ring(rx_queue);
 302
 303         if (rx_queue->xdp_rxq_info_valid)
 304                 xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info);
 305
 306         rx_queue->xdp_rxq_info_valid = false;
 307 }
 308
 309 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
 310 {
 311         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 312                   "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
 313
 314         efx_nic_remove_rx(rx_queue);
 315
 316         kfree(rx_queue->buffer);
 317         rx_queue->buffer = NULL;
 318 }
 319
 320 /* Unmap a DMA-mapped page.  This function is only called for the final RX
 321  * buffer in a page.
 322  */
 323 void efx_unmap_rx_buffer(struct efx_nic *efx,
 324                          struct efx_rx_buffer *rx_buf)
 325 {
 326         struct page *page = rx_buf->page;
 327
 328         if (page) {
 329                 struct efx_rx_page_state *state = page_address(page);
 330
 331                 dma_unmap_page(&efx->pci_dev->dev,
 332                                state->dma_addr,
 333                                PAGE_SIZE << efx->rx_buffer_order,
 334                                DMA_FROM_DEVICE);
 335         }
 336 }
 337
 338 void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
 339                          struct efx_rx_buffer *rx_buf,
 340                          unsigned int num_bufs)
 341 {
 342         do {
 343                 if (rx_buf->page) {
 344                         put_page(rx_buf->page);
 345                         rx_buf->page = NULL;
 346                 }
 347                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 348         } while (--num_bufs);
 349 }
 350
 351 void efx_rx_slow_fill(struct timer_list *t)
 352 {
 353         struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
 354
 355         /* Post an event to cause NAPI to run and refill the queue */
 356         efx_nic_generate_fill_event(rx_queue);
 357         ++rx_queue->slow_fill_count;
 358 }
 359
 360 void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue)
 361 {
 362         mod_timer(&rx_queue->slow_fill, jiffies + msecs_to_jiffies(10));
 363 }
 364
 365 /* efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
 366  *
 367  * @rx_queue:           Efx RX queue
 368  *
 369  * This allocates a batch of pages, maps them for DMA, and populates
 370  * struct efx_rx_buffers for each one. Return a negative error code or
 371  * 0 on success. If a single page can be used for multiple buffers,
 372  * then the page will either be inserted fully, or not at all.
 373  */
 374 static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
 375 {
 376         unsigned int page_offset, index, count;
 377         struct efx_nic *efx = rx_queue->efx;
 378         struct efx_rx_page_state *state;
 379         struct efx_rx_buffer *rx_buf;
 380         dma_addr_t dma_addr;
 381         struct page *page;
 382
 383         count = 0;
 384         do {
 385                 page = efx_reuse_page(rx_queue);
 386                 if (page == NULL) {
 387                         page = alloc_pages(__GFP_COMP |
 388                                            (atomic ? GFP_ATOMIC : GFP_KERNEL),
 389                                            efx->rx_buffer_order);
 390                         if (unlikely(page == NULL))
 391                                 return -ENOMEM;
 392                         dma_addr =
 393                                 dma_map_page(&efx->pci_dev->dev, page, 0,
 394                                              PAGE_SIZE << efx->rx_buffer_order,
 395                                              DMA_FROM_DEVICE);
 396                         if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
 397                                                        dma_addr))) {
 398                                 __free_pages(page, efx->rx_buffer_order);
 399                                 return -EIO;
 400                         }
 401                         state = page_address(page);
 402                         state->dma_addr = dma_addr;
 403                 } else {
 404                         state = page_address(page);
 405                         dma_addr = state->dma_addr;
 406                 }
 407
 408                 dma_addr += sizeof(struct efx_rx_page_state);
 409                 page_offset = sizeof(struct efx_rx_page_state);
 410
 411                 do {
 412                         index = rx_queue->added_count & rx_queue->ptr_mask;
 413                         rx_buf = efx_rx_buffer(rx_queue, index);
 414                         rx_buf->dma_addr = dma_addr + efx->rx_ip_align +
 415                                            EFX_XDP_HEADROOM;
 416                         rx_buf->page = page;
 417                         rx_buf->page_offset = page_offset + efx->rx_ip_align +
 418                                               EFX_XDP_HEADROOM;
 419                         rx_buf->len = efx->rx_dma_len;
 420                         rx_buf->flags = 0;
 421                         ++rx_queue->added_count;
 422                         get_page(page);
 423                         dma_addr += efx->rx_page_buf_step;
 424                         page_offset += efx->rx_page_buf_step;
 425                 } while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
 426
 427                 rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
 428         } while (++count < efx->rx_pages_per_batch);
 429
 430         return 0;
 431 }
 432
 433 void efx_rx_config_page_split(struct efx_nic *efx)
 434 {
 435         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align +
 436                                       EFX_XDP_HEADROOM + EFX_XDP_TAILROOM,
 437                                       EFX_RX_BUF_ALIGNMENT);
 438         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
 439                 ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
 440                 efx->rx_page_buf_step);
 441         efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
 442                 efx->rx_bufs_per_page;
 443         efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
 444                                                efx->rx_bufs_per_page);
 445 }
 446
 447 /* efx_fast_push_rx_descriptors - push new RX descriptors quickly
 448  * @rx_queue:           RX descriptor queue
 449  *
 450  * This will aim to fill the RX descriptor queue up to
 451  * @rx_queue->@max_fill. If there is insufficient atomic
 452  * memory to do so, a slow fill will be scheduled.
 453  *
 454  * The caller must provide serialisation (none is used here). In practise,
 455  * this means this function must run from the NAPI handler, or be called
 456  * when NAPI is disabled.
 457  */
 458 void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
 459 {
 460         struct efx_nic *efx = rx_queue->efx;
 461         unsigned int fill_level, batch_size;
 462         int space, rc = 0;
 463
 464         if (!rx_queue->refill_enabled)
 465                 return;
 466
 467         /* Calculate current fill level, and exit if we don't need to fill */
 468         fill_level = (rx_queue->added_count - rx_queue->removed_count);
 469         EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
 470         if (fill_level >= rx_queue->fast_fill_trigger)
 471                 goto out;
 472
 473         /* Record minimum fill level */
 474         if (unlikely(fill_level < rx_queue->min_fill)) {
 475                 if (fill_level)
 476                         rx_queue->min_fill = fill_level;
 477         }
 478
 479         batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 480         space = rx_queue->max_fill - fill_level;
 481         EFX_WARN_ON_ONCE_PARANOID(space < batch_size);
 482
 483         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 484                    "RX queue %d fast-filling descriptor ring from"
 485                    " level %d to level %d\n",
 486                    efx_rx_queue_index(rx_queue), fill_level,
 487                    rx_queue->max_fill);
 488
 489         do {
 490                 rc = efx_init_rx_buffers(rx_queue, atomic);
 491                 if (unlikely(rc)) {
 492                         /* Ensure that we don't leave the rx queue empty */
 493                         efx_schedule_slow_fill(rx_queue);
 494                         goto out;
 495                 }
 496         } while ((space -= batch_size) >= batch_size);
 497
 498         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 499                    "RX queue %d fast-filled descriptor ring "
 500                    "to level %d\n", efx_rx_queue_index(rx_queue),
 501                    rx_queue->added_count - rx_queue->removed_count);
 502
 503  out:
 504         if (rx_queue->notified_count != rx_queue->added_count)
 505                 efx_nic_notify_rx_desc(rx_queue);
 506 }
 507
 508 /* Pass a received packet up through GRO.  GRO can handle pages
 509  * regardless of checksum state and skbs with a good checksum.
 510  */
 511 void
 512 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 513                   unsigned int n_frags, u8 *eh, __wsum csum)
 514 {
 515         struct napi_struct *napi = &channel->napi_str;
 516         struct efx_nic *efx = channel->efx;
 517         struct sk_buff *skb;
 518
 519         skb = napi_get_frags(napi);
 520         if (unlikely(!skb)) {
 521                 struct efx_rx_queue *rx_queue;
 522
 523                 rx_queue = efx_channel_get_rx_queue(channel);
 524                 efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 525                 return;
 526         }
 527
 528         if (efx->net_dev->features & NETIF_F_RXHASH &&
 529             efx_rx_buf_hash_valid(efx, eh))
 530                 skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
 531                              PKT_HASH_TYPE_L3);
 532         if (csum) {
 533                 skb->csum = csum;
 534                 skb->ip_summed = CHECKSUM_COMPLETE;
 535         } else {
 536                 skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
 537                                   CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 538         }
 539         skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
 540
 541         for (;;) {
 542                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 543                                    rx_buf->page, rx_buf->page_offset,
 544                                    rx_buf->len);
 545                 rx_buf->page = NULL;
 546                 skb->len += rx_buf->len;
 547                 if (skb_shinfo(skb)->nr_frags == n_frags)
 548                         break;
 549
 550                 rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 551         }
 552
 553         skb->data_len = skb->len;
 554         skb->truesize += n_frags * efx->rx_buffer_truesize;
 555
 556         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 557
 558         napi_gro_frags(napi);
 559 }
 560
 561 /* RSS contexts.  We're using linked lists and crappy O(n) algorithms, because
 562  * (a) this is an infrequent control-plane operation and (b) n is small (max 64)
 563  */
 564 struct efx_rss_context *efx_alloc_rss_context_entry(struct efx_nic *efx)
 565 {
 566         struct list_head *head = &efx->rss_context.list;
 567         struct efx_rss_context *ctx, *new;
 568         u32 id = 1; /* Don't use zero, that refers to the master RSS context */
 569
 570         WARN_ON(!mutex_is_locked(&efx->rss_lock));
 571
 572         /* Search for first gap in the numbering */
 573         list_for_each_entry(ctx, head, list) {
 574                 if (ctx->user_id != id)
 575                         break;
 576                 id++;
 577                 /* Check for wrap.  If this happens, we have nearly 2^32
 578                  * allocated RSS contexts, which seems unlikely.
 579                  */
 580                 if (WARN_ON_ONCE(!id))
 581                         return NULL;
 582         }
 583
 584         /* Create the new entry */
 585         new = kmalloc(sizeof(*new), GFP_KERNEL);
 586         if (!new)
 587                 return NULL;
 588         new->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
 589         new->rx_hash_udp_4tuple = false;
 590
 591         /* Insert the new entry into the gap */
 592         new->user_id = id;
 593         list_add_tail(&new->list, &ctx->list);
 594         return new;
 595 }
 596
 597 struct efx_rss_context *efx_find_rss_context_entry(struct efx_nic *efx, u32 id)
 598 {
 599         struct list_head *head = &efx->rss_context.list;
 600         struct efx_rss_context *ctx;
 601
 602         WARN_ON(!mutex_is_locked(&efx->rss_lock));
 603
 604         list_for_each_entry(ctx, head, list)
 605                 if (ctx->user_id == id)
 606                         return ctx;
 607         return NULL;
 608 }
 609
 610 void efx_free_rss_context_entry(struct efx_rss_context *ctx)
 611 {
 612         list_del(&ctx->list);
 613         kfree(ctx);
 614 }
 615
 616 void efx_set_default_rx_indir_table(struct efx_nic *efx,
 617                                     struct efx_rss_context *ctx)
 618 {
 619         size_t i;
 620
 621         for (i = 0; i < ARRAY_SIZE(ctx->rx_indir_table); i++)
 622                 ctx->rx_indir_table[i] =
 623                         ethtool_rxfh_indir_default(i, efx->rss_spread);
 624 }
 625
 626 /**
 627  * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
 628  * @spec: Specification to test
 629  *
 630  * Return: %true if the specification is a non-drop RX filter that
 631  * matches a local MAC address I/G bit value of 1 or matches a local
 632  * IPv4 or IPv6 address value in the respective multicast address
 633  * range.  Otherwise %false.
 634  */
 635 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
 636 {
 637         if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
 638             spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
 639                 return false;
 640
 641         if (spec->match_flags &
 642             (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
 643             is_multicast_ether_addr(spec->loc_mac))
 644                 return true;
 645
 646         if ((spec->match_flags &
 647              (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
 648             (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
 649                 if (spec->ether_type == htons(ETH_P_IP) &&
 650                     ipv4_is_multicast(spec->loc_host[0]))
 651                         return true;
 652                 if (spec->ether_type == htons(ETH_P_IPV6) &&
 653                     ((const u8 *)spec->loc_host)[0] == 0xff)
 654                         return true;
 655         }
 656
 657         return false;
 658 }
 659
 660 bool efx_filter_spec_equal(const struct efx_filter_spec *left,
 661                            const struct efx_filter_spec *right)
 662 {
 663         if ((left->match_flags ^ right->match_flags) |
 664             ((left->flags ^ right->flags) &
 665              (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)))
 666                 return false;
 667
 668         return memcmp(&left->outer_vid, &right->outer_vid,
 669                       sizeof(struct efx_filter_spec) -
 670                       offsetof(struct efx_filter_spec, outer_vid)) == 0;
 671 }
 672
 673 u32 efx_filter_spec_hash(const struct efx_filter_spec *spec)
 674 {
 675         BUILD_BUG_ON(offsetof(struct efx_filter_spec, outer_vid) & 3);
 676         return jhash2((const u32 *)&spec->outer_vid,
 677                       (sizeof(struct efx_filter_spec) -
 678                        offsetof(struct efx_filter_spec, outer_vid)) / 4,
 679                       0);
 680 }
 681
 682 #ifdef CONFIG_RFS_ACCEL
 683 bool efx_rps_check_rule(struct efx_arfs_rule *rule, unsigned int filter_idx,
 684                         bool *force)
 685 {
 686         if (rule->filter_id == EFX_ARFS_FILTER_ID_PENDING) {
 687                 /* ARFS is currently updating this entry, leave it */
 688                 return false;
 689         }
 690         if (rule->filter_id == EFX_ARFS_FILTER_ID_ERROR) {
 691                 /* ARFS tried and failed to update this, so it's probably out
 692                  * of date.  Remove the filter and the ARFS rule entry.
 693                  */
 694                 rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
 695                 *force = true;
 696                 return true;
 697         } else if (WARN_ON(rule->filter_id != filter_idx)) { /* can't happen */
 698                 /* ARFS has moved on, so old filter is not needed.  Since we did
 699                  * not mark the rule with EFX_ARFS_FILTER_ID_REMOVING, it will
 700                  * not be removed by efx_rps_hash_del() subsequently.
 701                  */
 702                 *force = true;
 703                 return true;
 704         }
 705         /* Remove it iff ARFS wants to. */
 706         return true;
 707 }
 708
 709 static
 710 struct hlist_head *efx_rps_hash_bucket(struct efx_nic *efx,
 711                                        const struct efx_filter_spec *spec)
 712 {
 713         u32 hash = efx_filter_spec_hash(spec);
 714
 715         lockdep_assert_held(&efx->rps_hash_lock);
 716         if (!efx->rps_hash_table)
 717                 return NULL;
 718         return &efx->rps_hash_table[hash % EFX_ARFS_HASH_TABLE_SIZE];
 719 }
 720
 721 struct efx_arfs_rule *efx_rps_hash_find(struct efx_nic *efx,
 722                                         const struct efx_filter_spec *spec)
 723 {
 724         struct efx_arfs_rule *rule;
 725         struct hlist_head *head;
 726         struct hlist_node *node;
 727
 728         head = efx_rps_hash_bucket(efx, spec);
 729         if (!head)
 730                 return NULL;
 731         hlist_for_each(node, head) {
 732                 rule = container_of(node, struct efx_arfs_rule, node);
 733                 if (efx_filter_spec_equal(spec, &rule->spec))
 734                         return rule;
 735         }
 736         return NULL;
 737 }
 738
 739 struct efx_arfs_rule *efx_rps_hash_add(struct efx_nic *efx,
 740                                        const struct efx_filter_spec *spec,
 741                                        bool *new)
 742 {
 743         struct efx_arfs_rule *rule;
 744         struct hlist_head *head;
 745         struct hlist_node *node;
 746
 747         head = efx_rps_hash_bucket(efx, spec);
 748         if (!head)
 749                 return NULL;
 750         hlist_for_each(node, head) {
 751                 rule = container_of(node, struct efx_arfs_rule, node);
 752                 if (efx_filter_spec_equal(spec, &rule->spec)) {
 753                         *new = false;
 754                         return rule;
 755                 }
 756         }
 757         rule = kmalloc(sizeof(*rule), GFP_ATOMIC);
 758         *new = true;
 759         if (rule) {
 760                 memcpy(&rule->spec, spec, sizeof(rule->spec));
 761                 hlist_add_head(&rule->node, head);
 762         }
 763         return rule;
 764 }
 765
 766 void efx_rps_hash_del(struct efx_nic *efx, const struct efx_filter_spec *spec)
 767 {
 768         struct efx_arfs_rule *rule;
 769         struct hlist_head *head;
 770         struct hlist_node *node;
 771
 772         head = efx_rps_hash_bucket(efx, spec);
 773         if (WARN_ON(!head))
 774                 return;
 775         hlist_for_each(node, head) {
 776                 rule = container_of(node, struct efx_arfs_rule, node);
 777                 if (efx_filter_spec_equal(spec, &rule->spec)) {
 778                         /* Someone already reused the entry.  We know that if
 779                          * this check doesn't fire (i.e. filter_id == REMOVING)
 780                          * then the REMOVING mark was put there by our caller,
 781                          * because caller is holding a lock on filter table and
 782                          * only holders of that lock set REMOVING.
 783                          */
 784                         if (rule->filter_id != EFX_ARFS_FILTER_ID_REMOVING)
 785                                 return;
 786                         hlist_del(node);
 787                         kfree(rule);
 788                         return;
 789                 }
 790         }
 791         /* We didn't find it. */
 792         WARN_ON(1);
 793 }
 794 #endif
 795
 796 int efx_probe_filters(struct efx_nic *efx)
 797 {
 798         int rc;
 799
 800         init_rwsem(&efx->filter_sem);
 801         mutex_lock(&efx->mac_lock);
 802         down_write(&efx->filter_sem);
 803         rc = efx->type->filter_table_probe(efx);
 804         if (rc)
 805                 goto out_unlock;
 806
 807 #ifdef CONFIG_RFS_ACCEL
 808         if (efx->type->offload_features & NETIF_F_NTUPLE) {
 809                 struct efx_channel *channel;
 810                 int i, success = 1;
 811
 812                 efx_for_each_channel(channel, efx) {
 813                         channel->rps_flow_id =
 814                                 kcalloc(efx->type->max_rx_ip_filters,
 815                                         sizeof(*channel->rps_flow_id),
 816                                         GFP_KERNEL);
 817                         if (!channel->rps_flow_id)
 818                                 success = 0;
 819                         else
 820                                 for (i = 0;
 821                                      i < efx->type->max_rx_ip_filters;
 822                                      ++i)
 823                                         channel->rps_flow_id[i] =
 824                                                 RPS_FLOW_ID_INVALID;
 825                         channel->rfs_expire_index = 0;
 826                         channel->rfs_filter_count = 0;
 827                 }
 828
 829                 if (!success) {
 830                         efx_for_each_channel(channel, efx)
 831                                 kfree(channel->rps_flow_id);
 832                         efx->type->filter_table_remove(efx);
 833                         rc = -ENOMEM;
 834                         goto out_unlock;
 835                 }
 836         }
 837 #endif
 838 out_unlock:
 839         up_write(&efx->filter_sem);
 840         mutex_unlock(&efx->mac_lock);
 841         return rc;
 842 }
 843
 844 void efx_remove_filters(struct efx_nic *efx)
 845 {
 846 #ifdef CONFIG_RFS_ACCEL
 847         struct efx_channel *channel;
 848
 849         efx_for_each_channel(channel, efx) {
 850                 cancel_delayed_work_sync(&channel->filter_work);
 851                 kfree(channel->rps_flow_id);
 852                 channel->rps_flow_id = NULL;
 853         }
 854 #endif
 855         down_write(&efx->filter_sem);
 856         efx->type->filter_table_remove(efx);
 857         up_write(&efx->filter_sem);
 858 }
 859
 860 #ifdef CONFIG_RFS_ACCEL
 861
 862 static void efx_filter_rfs_work(struct work_struct *data)
 863 {
 864         struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
 865                                                               work);
 866         struct efx_nic *efx = netdev_priv(req->net_dev);
 867         struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
 868         int slot_idx = req - efx->rps_slot;
 869         struct efx_arfs_rule *rule;
 870         u16 arfs_id = 0;
 871         int rc;
 872
 873         rc = efx->type->filter_insert(efx, &req->spec, true);
 874         if (rc >= 0)
 875                 /* Discard 'priority' part of EF10+ filter ID (mcdi_filters) */
 876                 rc %= efx->type->max_rx_ip_filters;
 877         if (efx->rps_hash_table) {
 878                 spin_lock_bh(&efx->rps_hash_lock);
 879                 rule = efx_rps_hash_find(efx, &req->spec);
 880                 /* The rule might have already gone, if someone else's request
 881                  * for the same spec was already worked and then expired before
 882                  * we got around to our work.  In that case we have nothing
 883                  * tying us to an arfs_id, meaning that as soon as the filter
 884                  * is considered for expiry it will be removed.
 885                  */
 886                 if (rule) {
 887                         if (rc < 0)
 888                                 rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
 889                         else
 890                                 rule->filter_id = rc;
 891                         arfs_id = rule->arfs_id;
 892                 }
 893                 spin_unlock_bh(&efx->rps_hash_lock);
 894         }
 895         if (rc >= 0) {
 896                 /* Remember this so we can check whether to expire the filter
 897                  * later.
 898                  */
 899                 mutex_lock(&efx->rps_mutex);
 900                 if (channel->rps_flow_id[rc] == RPS_FLOW_ID_INVALID)
 901                         channel->rfs_filter_count++;
 902                 channel->rps_flow_id[rc] = req->flow_id;
 903                 mutex_unlock(&efx->rps_mutex);
 904
 905                 if (req->spec.ether_type == htons(ETH_P_IP))
 906                         netif_info(efx, rx_status, efx->net_dev,
 907                                    "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
 908                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 909                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 910                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 911                                    req->rxq_index, req->flow_id, rc, arfs_id);
 912                 else
 913                         netif_info(efx, rx_status, efx->net_dev,
 914                                    "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %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                 channel->n_rfs_succeeded++;
 920         } else {
 921                 if (req->spec.ether_type == htons(ETH_P_IP))
 922                         netif_dbg(efx, rx_status, efx->net_dev,
 923                                   "failed to steer %s %pI4:%u:%pI4:%u to queue %u [flow %u rc %d id %u]\n",
 924                                   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 925                                   req->spec.rem_host, ntohs(req->spec.rem_port),
 926                                   req->spec.loc_host, ntohs(req->spec.loc_port),
 927                                   req->rxq_index, req->flow_id, rc, arfs_id);
 928                 else
 929                         netif_dbg(efx, rx_status, efx->net_dev,
 930                                   "failed to steer %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u rc %d id %u]\n",
 931                                   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 932                                   req->spec.rem_host, ntohs(req->spec.rem_port),
 933                                   req->spec.loc_host, ntohs(req->spec.loc_port),
 934                                   req->rxq_index, req->flow_id, rc, arfs_id);
 935                 channel->n_rfs_failed++;
 936                 /* We're overloading the NIC's filter tables, so let's do a
 937                  * chunk of extra expiry work.
 938                  */
 939                 __efx_filter_rfs_expire(channel, min(channel->rfs_filter_count,
 940                                                      100u));
 941         }
 942
 943         /* Release references */
 944         clear_bit(slot_idx, &efx->rps_slot_map);
 945         dev_put(req->net_dev);
 946 }
 947
 948 int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 949                    u16 rxq_index, u32 flow_id)
 950 {
 951         struct efx_nic *efx = netdev_priv(net_dev);
 952         struct efx_async_filter_insertion *req;
 953         struct efx_arfs_rule *rule;
 954         struct flow_keys fk;
 955         int slot_idx;
 956         bool new;
 957         int rc;
 958
 959         /* find a free slot */
 960         for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
 961                 if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
 962                         break;
 963         if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
 964                 return -EBUSY;
 965
 966         if (flow_id == RPS_FLOW_ID_INVALID) {
 967                 rc = -EINVAL;
 968                 goto out_clear;
 969         }
 970
 971         if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
 972                 rc = -EPROTONOSUPPORT;
 973                 goto out_clear;
 974         }
 975
 976         if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
 977                 rc = -EPROTONOSUPPORT;
 978                 goto out_clear;
 979         }
 980         if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
 981                 rc = -EPROTONOSUPPORT;
 982                 goto out_clear;
 983         }
 984
 985         req = efx->rps_slot + slot_idx;
 986         efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
 987                            efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
 988                            rxq_index);
 989         req->spec.match_flags =
 990                 EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
 991                 EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
 992                 EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
 993         req->spec.ether_type = fk.basic.n_proto;
 994         req->spec.ip_proto = fk.basic.ip_proto;
 995
 996         if (fk.basic.n_proto == htons(ETH_P_IP)) {
 997                 req->spec.rem_host[0] = fk.addrs.v4addrs.src;
 998                 req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
 999         } else {
1000                 memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
1001                        sizeof(struct in6_addr));
1002                 memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
1003                        sizeof(struct in6_addr));
1004         }
1005
1006         req->spec.rem_port = fk.ports.src;
1007         req->spec.loc_port = fk.ports.dst;
1008
1009         if (efx->rps_hash_table) {
1010                 /* Add it to ARFS hash table */
1011                 spin_lock(&efx->rps_hash_lock);
1012                 rule = efx_rps_hash_add(efx, &req->spec, &new);
1013                 if (!rule) {
1014                         rc = -ENOMEM;
1015                         goto out_unlock;
1016                 }
1017                 if (new)
1018                         rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
1019                 rc = rule->arfs_id;
1020                 /* Skip if existing or pending filter already does the right thing */
1021                 if (!new && rule->rxq_index == rxq_index &&
1022                     rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
1023                         goto out_unlock;
1024                 rule->rxq_index = rxq_index;
1025                 rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
1026                 spin_unlock(&efx->rps_hash_lock);
1027         } else {
1028                 /* Without an ARFS hash table, we just use arfs_id 0 for all
1029                  * filters.  This means if multiple flows hash to the same
1030                  * flow_id, all but the most recently touched will be eligible
1031                  * for expiry.
1032                  */
1033                 rc = 0;
1034         }
1035
1036         /* Queue the request */
1037         dev_hold(req->net_dev = net_dev);
1038         INIT_WORK(&req->work, efx_filter_rfs_work);
1039         req->rxq_index = rxq_index;
1040         req->flow_id = flow_id;
1041         schedule_work(&req->work);
1042         return rc;
1043 out_unlock:
1044         spin_unlock(&efx->rps_hash_lock);
1045 out_clear:
1046         clear_bit(slot_idx, &efx->rps_slot_map);
1047         return rc;
1048 }
1049
1050 bool __efx_filter_rfs_expire(struct efx_channel *channel, unsigned int quota)
1051 {
1052         bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
1053         struct efx_nic *efx = channel->efx;
1054         unsigned int index, size, start;
1055         u32 flow_id;
1056
1057         if (!mutex_trylock(&efx->rps_mutex))
1058                 return false;
1059         expire_one = efx->type->filter_rfs_expire_one;
1060         index = channel->rfs_expire_index;
1061         start = index;
1062         size = efx->type->max_rx_ip_filters;
1063         while (quota) {
1064                 flow_id = channel->rps_flow_id[index];
1065
1066                 if (flow_id != RPS_FLOW_ID_INVALID) {
1067                         quota--;
1068                         if (expire_one(efx, flow_id, index)) {
1069                                 netif_info(efx, rx_status, efx->net_dev,
1070                                            "expired filter %d [channel %u flow %u]\n",
1071                                            index, channel->channel, flow_id);
1072                                 channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
1073                                 channel->rfs_filter_count--;
1074                         }
1075                 }
1076                 if (++index == size)
1077                         index = 0;
1078                 /* If we were called with a quota that exceeds the total number
1079                  * of filters in the table (which shouldn't happen, but could
1080                  * if two callers race), ensure that we don't loop forever -
1081                  * stop when we've examined every row of the table.
1082                  */
1083                 if (index == start)
1084                         break;
1085         }
1086
1087         channel->rfs_expire_index = index;
1088         mutex_unlock(&efx->rps_mutex);
1089         return true;
1090 }
1091
1092 #endif /* CONFIG_RFS_ACCEL */