drivers/net/ethernet/sfc/rx_common.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /****************************************************************************
   3  * Driver for Solarflare network controllers and boards
   4  * Copyright 2018 Solarflare Communications Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 as published
   8  * by the Free Software Foundation, incorporated herein by reference.
   9  */
  10
  11 #include "net_driver.h"
  12 #include <linux/module.h>
  13 #include <linux/iommu.h>
  14 #include "efx.h"
  15 #include "nic.h"
  16 #include "rx_common.h"
  17
  18 /* This is the percentage fill level below which new RX descriptors
  19  * will be added to the RX descriptor ring.
  20  */
  21 static unsigned int rx_refill_threshold;
  22 module_param(rx_refill_threshold, uint, 0444);
  23 MODULE_PARM_DESC(rx_refill_threshold,
  24                  "RX descriptor ring refill threshold (%)");
  25
  26 /* RX maximum head room required.
  27  *
  28  * This must be at least 1 to prevent overflow, plus one packet-worth
  29  * to allow pipelined receives.
  30  */
  31 #define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
  32
  33 /* Check the RX page recycle ring for a page that can be reused. */
  34 static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
  35 {
  36         struct efx_nic *efx = rx_queue->efx;
  37         struct efx_rx_page_state *state;
  38         unsigned int index;
  39         struct page *page;
  40
  41         if (unlikely(!rx_queue->page_ring))
  42                 return NULL;
  43         index = rx_queue->page_remove & rx_queue->page_ptr_mask;
  44         page = rx_queue->page_ring[index];
  45         if (page == NULL)
  46                 return NULL;
  47
  48         rx_queue->page_ring[index] = NULL;
  49         /* page_remove cannot exceed page_add. */
  50         if (rx_queue->page_remove != rx_queue->page_add)
  51                 ++rx_queue->page_remove;
  52
  53         /* If page_count is 1 then we hold the only reference to this page. */
  54         if (page_count(page) == 1) {
  55                 ++rx_queue->page_recycle_count;
  56                 return page;
  57         } else {
  58                 state = page_address(page);
  59                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
  60                                PAGE_SIZE << efx->rx_buffer_order,
  61                                DMA_FROM_DEVICE);
  62                 put_page(page);
  63                 ++rx_queue->page_recycle_failed;
  64         }
  65
  66         return NULL;
  67 }
  68
  69 /* Attempt to recycle the page if there is an RX recycle ring; the page can
  70  * only be added if this is the final RX buffer, to prevent pages being used in
  71  * the descriptor ring and appearing in the recycle ring simultaneously.
  72  */
  73 static void efx_recycle_rx_page(struct efx_channel *channel,
  74                                 struct efx_rx_buffer *rx_buf)
  75 {
  76         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
  77         struct efx_nic *efx = rx_queue->efx;
  78         struct page *page = rx_buf->page;
  79         unsigned int index;
  80
  81         /* Only recycle the page after processing the final buffer. */
  82         if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
  83                 return;
  84
  85         index = rx_queue->page_add & rx_queue->page_ptr_mask;
  86         if (rx_queue->page_ring[index] == NULL) {
  87                 unsigned int read_index = rx_queue->page_remove &
  88                         rx_queue->page_ptr_mask;
  89
  90                 /* The next slot in the recycle ring is available, but
  91                  * increment page_remove if the read pointer currently
  92                  * points here.
  93                  */
  94                 if (read_index == index)
  95                         ++rx_queue->page_remove;
  96                 rx_queue->page_ring[index] = page;
  97                 ++rx_queue->page_add;
  98                 return;
  99         }
 100         ++rx_queue->page_recycle_full;
 101         efx_unmap_rx_buffer(efx, rx_buf);
 102         put_page(rx_buf->page);
 103 }
 104
 105 /* Recycle the pages that are used by buffers that have just been received. */
 106 void efx_recycle_rx_pages(struct efx_channel *channel,
 107                           struct efx_rx_buffer *rx_buf,
 108                           unsigned int n_frags)
 109 {
 110         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 111
 112         if (unlikely(!rx_queue->page_ring))
 113                 return;
 114
 115         do {
 116                 efx_recycle_rx_page(channel, rx_buf);
 117                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 118         } while (--n_frags);
 119 }
 120
 121 void efx_discard_rx_packet(struct efx_channel *channel,
 122                            struct efx_rx_buffer *rx_buf,
 123                            unsigned int n_frags)
 124 {
 125         struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
 126
 127         efx_recycle_rx_pages(channel, rx_buf, n_frags);
 128
 129         efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 130 }
 131
 132 static void efx_init_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 133 {
 134         unsigned int bufs_in_recycle_ring, page_ring_size;
 135         struct efx_nic *efx = rx_queue->efx;
 136
 137         bufs_in_recycle_ring = efx_rx_recycle_ring_size(efx);
 138         page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
 139                                             efx->rx_bufs_per_page);
 140         rx_queue->page_ring = kcalloc(page_ring_size,
 141                                       sizeof(*rx_queue->page_ring), GFP_KERNEL);
 142         if (!rx_queue->page_ring)
 143                 rx_queue->page_ptr_mask = 0;
 144         else
 145                 rx_queue->page_ptr_mask = page_ring_size - 1;
 146 }
 147
 148 static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue)
 149 {
 150         struct efx_nic *efx = rx_queue->efx;
 151         int i;
 152
 153         if (unlikely(!rx_queue->page_ring))
 154                 return;
 155
 156         /* Unmap and release the pages in the recycle ring. Remove the ring. */
 157         for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
 158                 struct page *page = rx_queue->page_ring[i];
 159                 struct efx_rx_page_state *state;
 160
 161                 if (page == NULL)
 162                         continue;
 163
 164                 state = page_address(page);
 165                 dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
 166                                PAGE_SIZE << efx->rx_buffer_order,
 167                                DMA_FROM_DEVICE);
 168                 put_page(page);
 169         }
 170         kfree(rx_queue->page_ring);
 171         rx_queue->page_ring = NULL;
 172 }
 173
 174 static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
 175                                struct efx_rx_buffer *rx_buf)
 176 {
 177         /* Release the page reference we hold for the buffer. */
 178         if (rx_buf->page)
 179                 put_page(rx_buf->page);
 180
 181         /* If this is the last buffer in a page, unmap and free it. */
 182         if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
 183                 efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
 184                 efx_free_rx_buffers(rx_queue, rx_buf, 1);
 185         }
 186         rx_buf->page = NULL;
 187 }
 188
 189 int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
 190 {
 191         struct efx_nic *efx = rx_queue->efx;
 192         unsigned int entries;
 193         int rc;
 194
 195         /* Create the smallest power-of-two aligned ring */
 196         entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
 197         EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
 198         rx_queue->ptr_mask = entries - 1;
 199
 200         netif_dbg(efx, probe, efx->net_dev,
 201                   "creating RX queue %d size %#x mask %#x\n",
 202                   efx_rx_queue_index(rx_queue), efx->rxq_entries,
 203                   rx_queue->ptr_mask);
 204
 205         /* Allocate RX buffers */
 206         rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
 207                                    GFP_KERNEL);
 208         if (!rx_queue->buffer)
 209                 return -ENOMEM;
 210
 211         rc = efx_nic_probe_rx(rx_queue);
 212         if (rc) {
 213                 kfree(rx_queue->buffer);
 214                 rx_queue->buffer = NULL;
 215         }
 216
 217         return rc;
 218 }
 219
 220 void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
 221 {
 222         unsigned int max_fill, trigger, max_trigger;
 223         struct efx_nic *efx = rx_queue->efx;
 224         int rc = 0;
 225
 226         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 227                   "initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
 228
 229         /* Initialise ptr fields */
 230         rx_queue->added_count = 0;
 231         rx_queue->notified_count = 0;
 232         rx_queue->granted_count = 0;
 233         rx_queue->removed_count = 0;
 234         rx_queue->min_fill = -1U;
 235         efx_init_rx_recycle_ring(rx_queue);
 236
 237         rx_queue->page_remove = 0;
 238         rx_queue->page_add = rx_queue->page_ptr_mask + 1;
 239         rx_queue->page_recycle_count = 0;
 240         rx_queue->page_recycle_failed = 0;
 241         rx_queue->page_recycle_full = 0;
 242
 243         /* Initialise limit fields */
 244         max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
 245         max_trigger =
 246                 max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 247         if (rx_refill_threshold != 0) {
 248                 trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
 249                 if (trigger > max_trigger)
 250                         trigger = max_trigger;
 251         } else {
 252                 trigger = max_trigger;
 253         }
 254
 255         rx_queue->max_fill = max_fill;
 256         rx_queue->fast_fill_trigger = trigger;
 257         rx_queue->refill_enabled = true;
 258
 259         /* Initialise XDP queue information */
 260         rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev,
 261                               rx_queue->core_index, 0);
 262
 263         if (rc) {
 264                 netif_err(efx, rx_err, efx->net_dev,
 265                           "Failure to initialise XDP queue information rc=%d\n",
 266                           rc);
 267                 efx->xdp_rxq_info_failed = true;
 268         } else {
 269                 rx_queue->xdp_rxq_info_valid = true;
 270         }
 271
 272         /* Set up RX descriptor ring */
 273         efx_nic_init_rx(rx_queue);
 274 }
 275
 276 void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
 277 {
 278         struct efx_rx_buffer *rx_buf;
 279         int i;
 280
 281         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 282                   "shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
 283
 284         del_timer_sync(&rx_queue->slow_fill);
 285         if (rx_queue->grant_credits)
 286                 flush_work(&rx_queue->grant_work);
 287
 288         /* Release RX buffers from the current read ptr to the write ptr */
 289         if (rx_queue->buffer) {
 290                 for (i = rx_queue->removed_count; i < rx_queue->added_count;
 291                      i++) {
 292                         unsigned int index = i & rx_queue->ptr_mask;
 293
 294                         rx_buf = efx_rx_buffer(rx_queue, index);
 295                         efx_fini_rx_buffer(rx_queue, rx_buf);
 296                 }
 297         }
 298
 299         efx_fini_rx_recycle_ring(rx_queue);
 300
 301         if (rx_queue->xdp_rxq_info_valid)
 302                 xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info);
 303
 304         rx_queue->xdp_rxq_info_valid = false;
 305 }
 306
 307 void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
 308 {
 309         netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
 310                   "destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
 311
 312         efx_nic_remove_rx(rx_queue);
 313
 314         kfree(rx_queue->buffer);
 315         rx_queue->buffer = NULL;
 316 }
 317
 318 /* Unmap a DMA-mapped page.  This function is only called for the final RX
 319  * buffer in a page.
 320  */
 321 void efx_unmap_rx_buffer(struct efx_nic *efx,
 322                          struct efx_rx_buffer *rx_buf)
 323 {
 324         struct page *page = rx_buf->page;
 325
 326         if (page) {
 327                 struct efx_rx_page_state *state = page_address(page);
 328
 329                 dma_unmap_page(&efx->pci_dev->dev,
 330                                state->dma_addr,
 331                                PAGE_SIZE << efx->rx_buffer_order,
 332                                DMA_FROM_DEVICE);
 333         }
 334 }
 335
 336 void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
 337                          struct efx_rx_buffer *rx_buf,
 338                          unsigned int num_bufs)
 339 {
 340         do {
 341                 if (rx_buf->page) {
 342                         put_page(rx_buf->page);
 343                         rx_buf->page = NULL;
 344                 }
 345                 rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
 346         } while (--num_bufs);
 347 }
 348
 349 void efx_rx_slow_fill(struct timer_list *t)
 350 {
 351         struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
 352
 353         /* Post an event to cause NAPI to run and refill the queue */
 354         efx_nic_generate_fill_event(rx_queue);
 355         ++rx_queue->slow_fill_count;
 356 }
 357
 358 void efx_schedule_slow_fill(struct efx_rx_queue *rx_queue)
 359 {
 360         mod_timer(&rx_queue->slow_fill, jiffies + msecs_to_jiffies(10));
 361 }
 362
 363 /* efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
 364  *
 365  * @rx_queue:           Efx RX queue
 366  *
 367  * This allocates a batch of pages, maps them for DMA, and populates
 368  * struct efx_rx_buffers for each one. Return a negative error code or
 369  * 0 on success. If a single page can be used for multiple buffers,
 370  * then the page will either be inserted fully, or not at all.
 371  */
 372 static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
 373 {
 374         unsigned int page_offset, index, count;
 375         struct efx_nic *efx = rx_queue->efx;
 376         struct efx_rx_page_state *state;
 377         struct efx_rx_buffer *rx_buf;
 378         dma_addr_t dma_addr;
 379         struct page *page;
 380
 381         count = 0;
 382         do {
 383                 page = efx_reuse_page(rx_queue);
 384                 if (page == NULL) {
 385                         page = alloc_pages(__GFP_COMP |
 386                                            (atomic ? GFP_ATOMIC : GFP_KERNEL),
 387                                            efx->rx_buffer_order);
 388                         if (unlikely(page == NULL))
 389                                 return -ENOMEM;
 390                         dma_addr =
 391                                 dma_map_page(&efx->pci_dev->dev, page, 0,
 392                                              PAGE_SIZE << efx->rx_buffer_order,
 393                                              DMA_FROM_DEVICE);
 394                         if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
 395                                                        dma_addr))) {
 396                                 __free_pages(page, efx->rx_buffer_order);
 397                                 return -EIO;
 398                         }
 399                         state = page_address(page);
 400                         state->dma_addr = dma_addr;
 401                 } else {
 402                         state = page_address(page);
 403                         dma_addr = state->dma_addr;
 404                 }
 405
 406                 dma_addr += sizeof(struct efx_rx_page_state);
 407                 page_offset = sizeof(struct efx_rx_page_state);
 408
 409                 do {
 410                         index = rx_queue->added_count & rx_queue->ptr_mask;
 411                         rx_buf = efx_rx_buffer(rx_queue, index);
 412                         rx_buf->dma_addr = dma_addr + efx->rx_ip_align +
 413                                            EFX_XDP_HEADROOM;
 414                         rx_buf->page = page;
 415                         rx_buf->page_offset = page_offset + efx->rx_ip_align +
 416                                               EFX_XDP_HEADROOM;
 417                         rx_buf->len = efx->rx_dma_len;
 418                         rx_buf->flags = 0;
 419                         ++rx_queue->added_count;
 420                         get_page(page);
 421                         dma_addr += efx->rx_page_buf_step;
 422                         page_offset += efx->rx_page_buf_step;
 423                 } while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
 424
 425                 rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
 426         } while (++count < efx->rx_pages_per_batch);
 427
 428         return 0;
 429 }
 430
 431 void efx_rx_config_page_split(struct efx_nic *efx)
 432 {
 433         efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align +
 434                                       EFX_XDP_HEADROOM + EFX_XDP_TAILROOM,
 435                                       EFX_RX_BUF_ALIGNMENT);
 436         efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
 437                 ((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
 438                 efx->rx_page_buf_step);
 439         efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
 440                 efx->rx_bufs_per_page;
 441         efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
 442                                                efx->rx_bufs_per_page);
 443 }
 444
 445 /* efx_fast_push_rx_descriptors - push new RX descriptors quickly
 446  * @rx_queue:           RX descriptor queue
 447  *
 448  * This will aim to fill the RX descriptor queue up to
 449  * @rx_queue->@max_fill. If there is insufficient atomic
 450  * memory to do so, a slow fill will be scheduled.
 451  *
 452  * The caller must provide serialisation (none is used here). In practise,
 453  * this means this function must run from the NAPI handler, or be called
 454  * when NAPI is disabled.
 455  */
 456 void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
 457 {
 458         struct efx_nic *efx = rx_queue->efx;
 459         unsigned int fill_level, batch_size;
 460         int space, rc = 0;
 461
 462         if (!rx_queue->refill_enabled)
 463                 return;
 464
 465         /* Calculate current fill level, and exit if we don't need to fill */
 466         fill_level = (rx_queue->added_count - rx_queue->removed_count);
 467         EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
 468         if (fill_level >= rx_queue->fast_fill_trigger)
 469                 goto out;
 470
 471         /* Record minimum fill level */
 472         if (unlikely(fill_level < rx_queue->min_fill)) {
 473                 if (fill_level)
 474                         rx_queue->min_fill = fill_level;
 475         }
 476
 477         batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
 478         space = rx_queue->max_fill - fill_level;
 479         EFX_WARN_ON_ONCE_PARANOID(space < batch_size);
 480
 481         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 482                    "RX queue %d fast-filling descriptor ring from"
 483                    " level %d to level %d\n",
 484                    efx_rx_queue_index(rx_queue), fill_level,
 485                    rx_queue->max_fill);
 486
 487         do {
 488                 rc = efx_init_rx_buffers(rx_queue, atomic);
 489                 if (unlikely(rc)) {
 490                         /* Ensure that we don't leave the rx queue empty */
 491                         efx_schedule_slow_fill(rx_queue);
 492                         goto out;
 493                 }
 494         } while ((space -= batch_size) >= batch_size);
 495
 496         netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
 497                    "RX queue %d fast-filled descriptor ring "
 498                    "to level %d\n", efx_rx_queue_index(rx_queue),
 499                    rx_queue->added_count - rx_queue->removed_count);
 500
 501  out:
 502         if (rx_queue->notified_count != rx_queue->added_count)
 503                 efx_nic_notify_rx_desc(rx_queue);
 504 }
 505
 506 /* Pass a received packet up through GRO.  GRO can handle pages
 507  * regardless of checksum state and skbs with a good checksum.
 508  */
 509 void
 510 efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
 511                   unsigned int n_frags, u8 *eh, __wsum csum)
 512 {
 513         struct napi_struct *napi = &channel->napi_str;
 514         struct efx_nic *efx = channel->efx;
 515         struct sk_buff *skb;
 516
 517         skb = napi_get_frags(napi);
 518         if (unlikely(!skb)) {
 519                 struct efx_rx_queue *rx_queue;
 520
 521                 rx_queue = efx_channel_get_rx_queue(channel);
 522                 efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
 523                 return;
 524         }
 525
 526         if (efx->net_dev->features & NETIF_F_RXHASH &&
 527             efx_rx_buf_hash_valid(efx, eh))
 528                 skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
 529                              PKT_HASH_TYPE_L3);
 530         if (csum) {
 531                 skb->csum = csum;
 532                 skb->ip_summed = CHECKSUM_COMPLETE;
 533         } else {
 534                 skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
 535                                   CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
 536         }
 537         skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
 538
 539         for (;;) {
 540                 skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
 541                                    rx_buf->page, rx_buf->page_offset,
 542                                    rx_buf->len);
 543                 rx_buf->page = NULL;
 544                 skb->len += rx_buf->len;
 545                 if (skb_shinfo(skb)->nr_frags == n_frags)
 546                         break;
 547
 548                 rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
 549         }
 550
 551         skb->data_len = skb->len;
 552         skb->truesize += n_frags * efx->rx_buffer_truesize;
 553
 554         skb_record_rx_queue(skb, channel->rx_queue.core_index);
 555
 556         napi_gro_frags(napi);
 557 }
 558
 559 /* RSS contexts.  We're using linked lists and crappy O(n) algorithms, because
 560  * (a) this is an infrequent control-plane operation and (b) n is small (max 64)
 561  */
 562 struct efx_rss_context *efx_alloc_rss_context_entry(struct efx_nic *efx)
 563 {
 564         struct list_head *head = &efx->rss_context.list;
 565         struct efx_rss_context *ctx, *new;
 566         u32 id = 1; /* Don't use zero, that refers to the master RSS context */
 567
 568         WARN_ON(!mutex_is_locked(&efx->rss_lock));
 569
 570         /* Search for first gap in the numbering */
 571         list_for_each_entry(ctx, head, list) {
 572                 if (ctx->user_id != id)
 573                         break;
 574                 id++;
 575                 /* Check for wrap.  If this happens, we have nearly 2^32
 576                  * allocated RSS contexts, which seems unlikely.
 577                  */
 578                 if (WARN_ON_ONCE(!id))
 579                         return NULL;
 580         }
 581
 582         /* Create the new entry */
 583         new = kmalloc(sizeof(*new), GFP_KERNEL);
 584         if (!new)
 585                 return NULL;
 586         new->context_id = EFX_MCDI_RSS_CONTEXT_INVALID;
 587         new->rx_hash_udp_4tuple = false;
 588
 589         /* Insert the new entry into the gap */
 590         new->user_id = id;
 591         list_add_tail(&new->list, &ctx->list);
 592         return new;
 593 }
 594
 595 struct efx_rss_context *efx_find_rss_context_entry(struct efx_nic *efx, u32 id)
 596 {
 597         struct list_head *head = &efx->rss_context.list;
 598         struct efx_rss_context *ctx;
 599
 600         WARN_ON(!mutex_is_locked(&efx->rss_lock));
 601
 602         list_for_each_entry(ctx, head, list)
 603                 if (ctx->user_id == id)
 604                         return ctx;
 605         return NULL;
 606 }
 607
 608 void efx_free_rss_context_entry(struct efx_rss_context *ctx)
 609 {
 610         list_del(&ctx->list);
 611         kfree(ctx);
 612 }
 613
 614 void efx_set_default_rx_indir_table(struct efx_nic *efx,
 615                                     struct efx_rss_context *ctx)
 616 {
 617         size_t i;
 618
 619         for (i = 0; i < ARRAY_SIZE(ctx->rx_indir_table); i++)
 620                 ctx->rx_indir_table[i] =
 621                         ethtool_rxfh_indir_default(i, efx->rss_spread);
 622 }
 623
 624 /**
 625  * efx_filter_is_mc_recipient - test whether spec is a multicast recipient
 626  * @spec: Specification to test
 627  *
 628  * Return: %true if the specification is a non-drop RX filter that
 629  * matches a local MAC address I/G bit value of 1 or matches a local
 630  * IPv4 or IPv6 address value in the respective multicast address
 631  * range.  Otherwise %false.
 632  */
 633 bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
 634 {
 635         if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
 636             spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
 637                 return false;
 638
 639         if (spec->match_flags &
 640             (EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
 641             is_multicast_ether_addr(spec->loc_mac))
 642                 return true;
 643
 644         if ((spec->match_flags &
 645              (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
 646             (EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
 647                 if (spec->ether_type == htons(ETH_P_IP) &&
 648                     ipv4_is_multicast(spec->loc_host[0]))
 649                         return true;
 650                 if (spec->ether_type == htons(ETH_P_IPV6) &&
 651                     ((const u8 *)spec->loc_host)[0] == 0xff)
 652                         return true;
 653         }
 654
 655         return false;
 656 }
 657
 658 bool efx_filter_spec_equal(const struct efx_filter_spec *left,
 659                            const struct efx_filter_spec *right)
 660 {
 661         if ((left->match_flags ^ right->match_flags) |
 662             ((left->flags ^ right->flags) &
 663              (EFX_FILTER_FLAG_RX | EFX_FILTER_FLAG_TX)))
 664                 return false;
 665
 666         return memcmp(&left->vport_id, &right->vport_id,
 667                       sizeof(struct efx_filter_spec) -
 668                       offsetof(struct efx_filter_spec, vport_id)) == 0;
 669 }
 670
 671 u32 efx_filter_spec_hash(const struct efx_filter_spec *spec)
 672 {
 673         BUILD_BUG_ON(offsetof(struct efx_filter_spec, vport_id) & 3);
 674         return jhash2((const u32 *)&spec->vport_id,
 675                       (sizeof(struct efx_filter_spec) -
 676                        offsetof(struct efx_filter_spec, vport_id)) / 4,
 677                       0);
 678 }
 679
 680 #ifdef CONFIG_RFS_ACCEL
 681 bool efx_rps_check_rule(struct efx_arfs_rule *rule, unsigned int filter_idx,
 682                         bool *force)
 683 {
 684         if (rule->filter_id == EFX_ARFS_FILTER_ID_PENDING) {
 685                 /* ARFS is currently updating this entry, leave it */
 686                 return false;
 687         }
 688         if (rule->filter_id == EFX_ARFS_FILTER_ID_ERROR) {
 689                 /* ARFS tried and failed to update this, so it's probably out
 690                  * of date.  Remove the filter and the ARFS rule entry.
 691                  */
 692                 rule->filter_id = EFX_ARFS_FILTER_ID_REMOVING;
 693                 *force = true;
 694                 return true;
 695         } else if (WARN_ON(rule->filter_id != filter_idx)) { /* can't happen */
 696                 /* ARFS has moved on, so old filter is not needed.  Since we did
 697                  * not mark the rule with EFX_ARFS_FILTER_ID_REMOVING, it will
 698                  * not be removed by efx_rps_hash_del() subsequently.
 699                  */
 700                 *force = true;
 701                 return true;
 702         }
 703         /* Remove it iff ARFS wants to. */
 704         return true;
 705 }
 706
 707 static
 708 struct hlist_head *efx_rps_hash_bucket(struct efx_nic *efx,
 709                                        const struct efx_filter_spec *spec)
 710 {
 711         u32 hash = efx_filter_spec_hash(spec);
 712
 713         lockdep_assert_held(&efx->rps_hash_lock);
 714         if (!efx->rps_hash_table)
 715                 return NULL;
 716         return &efx->rps_hash_table[hash % EFX_ARFS_HASH_TABLE_SIZE];
 717 }
 718
 719 struct efx_arfs_rule *efx_rps_hash_find(struct efx_nic *efx,
 720                                         const struct efx_filter_spec *spec)
 721 {
 722         struct efx_arfs_rule *rule;
 723         struct hlist_head *head;
 724         struct hlist_node *node;
 725
 726         head = efx_rps_hash_bucket(efx, spec);
 727         if (!head)
 728                 return NULL;
 729         hlist_for_each(node, head) {
 730                 rule = container_of(node, struct efx_arfs_rule, node);
 731                 if (efx_filter_spec_equal(spec, &rule->spec))
 732                         return rule;
 733         }
 734         return NULL;
 735 }
 736
 737 struct efx_arfs_rule *efx_rps_hash_add(struct efx_nic *efx,
 738                                        const struct efx_filter_spec *spec,
 739                                        bool *new)
 740 {
 741         struct efx_arfs_rule *rule;
 742         struct hlist_head *head;
 743         struct hlist_node *node;
 744
 745         head = efx_rps_hash_bucket(efx, spec);
 746         if (!head)
 747                 return NULL;
 748         hlist_for_each(node, head) {
 749                 rule = container_of(node, struct efx_arfs_rule, node);
 750                 if (efx_filter_spec_equal(spec, &rule->spec)) {
 751                         *new = false;
 752                         return rule;
 753                 }
 754         }
 755         rule = kmalloc(sizeof(*rule), GFP_ATOMIC);
 756         *new = true;
 757         if (rule) {
 758                 memcpy(&rule->spec, spec, sizeof(rule->spec));
 759                 hlist_add_head(&rule->node, head);
 760         }
 761         return rule;
 762 }
 763
 764 void efx_rps_hash_del(struct efx_nic *efx, const struct efx_filter_spec *spec)
 765 {
 766         struct efx_arfs_rule *rule;
 767         struct hlist_head *head;
 768         struct hlist_node *node;
 769
 770         head = efx_rps_hash_bucket(efx, spec);
 771         if (WARN_ON(!head))
 772                 return;
 773         hlist_for_each(node, head) {
 774                 rule = container_of(node, struct efx_arfs_rule, node);
 775                 if (efx_filter_spec_equal(spec, &rule->spec)) {
 776                         /* Someone already reused the entry.  We know that if
 777                          * this check doesn't fire (i.e. filter_id == REMOVING)
 778                          * then the REMOVING mark was put there by our caller,
 779                          * because caller is holding a lock on filter table and
 780                          * only holders of that lock set REMOVING.
 781                          */
 782                         if (rule->filter_id != EFX_ARFS_FILTER_ID_REMOVING)
 783                                 return;
 784                         hlist_del(node);
 785                         kfree(rule);
 786                         return;
 787                 }
 788         }
 789         /* We didn't find it. */
 790         WARN_ON(1);
 791 }
 792 #endif
 793
 794 int efx_probe_filters(struct efx_nic *efx)
 795 {
 796         int rc;
 797
 798         mutex_lock(&efx->mac_lock);
 799         rc = efx->type->filter_table_probe(efx);
 800         if (rc)
 801                 goto out_unlock;
 802
 803 #ifdef CONFIG_RFS_ACCEL
 804         if (efx->type->offload_features & NETIF_F_NTUPLE) {
 805                 struct efx_channel *channel;
 806                 int i, success = 1;
 807
 808                 efx_for_each_channel(channel, efx) {
 809                         channel->rps_flow_id =
 810                                 kcalloc(efx->type->max_rx_ip_filters,
 811                                         sizeof(*channel->rps_flow_id),
 812                                         GFP_KERNEL);
 813                         if (!channel->rps_flow_id)
 814                                 success = 0;
 815                         else
 816                                 for (i = 0;
 817                                      i < efx->type->max_rx_ip_filters;
 818                                      ++i)
 819                                         channel->rps_flow_id[i] =
 820                                                 RPS_FLOW_ID_INVALID;
 821                         channel->rfs_expire_index = 0;
 822                         channel->rfs_filter_count = 0;
 823                 }
 824
 825                 if (!success) {
 826                         efx_for_each_channel(channel, efx) {
 827                                 kfree(channel->rps_flow_id);
 828                                 channel->rps_flow_id = NULL;
 829                         }
 830                         efx->type->filter_table_remove(efx);
 831                         rc = -ENOMEM;
 832                         goto out_unlock;
 833                 }
 834         }
 835 #endif
 836 out_unlock:
 837         mutex_unlock(&efx->mac_lock);
 838         return rc;
 839 }
 840
 841 void efx_remove_filters(struct efx_nic *efx)
 842 {
 843 #ifdef CONFIG_RFS_ACCEL
 844         struct efx_channel *channel;
 845
 846         efx_for_each_channel(channel, efx) {
 847                 cancel_delayed_work_sync(&channel->filter_work);
 848                 kfree(channel->rps_flow_id);
 849                 channel->rps_flow_id = NULL;
 850         }
 851 #endif
 852         efx->type->filter_table_remove(efx);
 853 }
 854
 855 #ifdef CONFIG_RFS_ACCEL
 856
 857 static void efx_filter_rfs_work(struct work_struct *data)
 858 {
 859         struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
 860                                                               work);
 861         struct efx_nic *efx = efx_netdev_priv(req->net_dev);
 862         struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
 863         int slot_idx = req - efx->rps_slot;
 864         struct efx_arfs_rule *rule;
 865         u16 arfs_id = 0;
 866         int rc;
 867
 868         rc = efx->type->filter_insert(efx, &req->spec, true);
 869         if (rc >= 0)
 870                 /* Discard 'priority' part of EF10+ filter ID (mcdi_filters) */
 871                 rc %= efx->type->max_rx_ip_filters;
 872         if (efx->rps_hash_table) {
 873                 spin_lock_bh(&efx->rps_hash_lock);
 874                 rule = efx_rps_hash_find(efx, &req->spec);
 875                 /* The rule might have already gone, if someone else's request
 876                  * for the same spec was already worked and then expired before
 877                  * we got around to our work.  In that case we have nothing
 878                  * tying us to an arfs_id, meaning that as soon as the filter
 879                  * is considered for expiry it will be removed.
 880                  */
 881                 if (rule) {
 882                         if (rc < 0)
 883                                 rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
 884                         else
 885                                 rule->filter_id = rc;
 886                         arfs_id = rule->arfs_id;
 887                 }
 888                 spin_unlock_bh(&efx->rps_hash_lock);
 889         }
 890         if (rc >= 0) {
 891                 /* Remember this so we can check whether to expire the filter
 892                  * later.
 893                  */
 894                 mutex_lock(&efx->rps_mutex);
 895                 if (channel->rps_flow_id[rc] == RPS_FLOW_ID_INVALID)
 896                         channel->rfs_filter_count++;
 897                 channel->rps_flow_id[rc] = req->flow_id;
 898                 mutex_unlock(&efx->rps_mutex);
 899
 900                 if (req->spec.ether_type == htons(ETH_P_IP))
 901                         netif_info(efx, rx_status, efx->net_dev,
 902                                    "steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
 903                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 904                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 905                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 906                                    req->rxq_index, req->flow_id, rc, arfs_id);
 907                 else
 908                         netif_info(efx, rx_status, efx->net_dev,
 909                                    "steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
 910                                    (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 911                                    req->spec.rem_host, ntohs(req->spec.rem_port),
 912                                    req->spec.loc_host, ntohs(req->spec.loc_port),
 913                                    req->rxq_index, req->flow_id, rc, arfs_id);
 914                 channel->n_rfs_succeeded++;
 915         } else {
 916                 if (req->spec.ether_type == htons(ETH_P_IP))
 917                         netif_dbg(efx, rx_status, efx->net_dev,
 918                                   "failed to steer %s %pI4:%u:%pI4:%u to queue %u [flow %u rc %d id %u]\n",
 919                                   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 920                                   req->spec.rem_host, ntohs(req->spec.rem_port),
 921                                   req->spec.loc_host, ntohs(req->spec.loc_port),
 922                                   req->rxq_index, req->flow_id, rc, arfs_id);
 923                 else
 924                         netif_dbg(efx, rx_status, efx->net_dev,
 925                                   "failed to steer %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u rc %d id %u]\n",
 926                                   (req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
 927                                   req->spec.rem_host, ntohs(req->spec.rem_port),
 928                                   req->spec.loc_host, ntohs(req->spec.loc_port),
 929                                   req->rxq_index, req->flow_id, rc, arfs_id);
 930                 channel->n_rfs_failed++;
 931                 /* We're overloading the NIC's filter tables, so let's do a
 932                  * chunk of extra expiry work.
 933                  */
 934                 __efx_filter_rfs_expire(channel, min(channel->rfs_filter_count,
 935                                                      100u));
 936         }
 937
 938         /* Release references */
 939         clear_bit(slot_idx, &efx->rps_slot_map);
 940         dev_put(req->net_dev);
 941 }
 942
 943 int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
 944                    u16 rxq_index, u32 flow_id)
 945 {
 946         struct efx_nic *efx = efx_netdev_priv(net_dev);
 947         struct efx_async_filter_insertion *req;
 948         struct efx_arfs_rule *rule;
 949         struct flow_keys fk;
 950         int slot_idx;
 951         bool new;
 952         int rc;
 953
 954         /* find a free slot */
 955         for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
 956                 if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
 957                         break;
 958         if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
 959                 return -EBUSY;
 960
 961         if (flow_id == RPS_FLOW_ID_INVALID) {
 962                 rc = -EINVAL;
 963                 goto out_clear;
 964         }
 965
 966         if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
 967                 rc = -EPROTONOSUPPORT;
 968                 goto out_clear;
 969         }
 970
 971         if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
 972                 rc = -EPROTONOSUPPORT;
 973                 goto out_clear;
 974         }
 975         if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
 976                 rc = -EPROTONOSUPPORT;
 977                 goto out_clear;
 978         }
 979
 980         req = efx->rps_slot + slot_idx;
 981         efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
 982                            efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
 983                            rxq_index);
 984         req->spec.match_flags =
 985                 EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
 986                 EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
 987                 EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
 988         req->spec.ether_type = fk.basic.n_proto;
 989         req->spec.ip_proto = fk.basic.ip_proto;
 990
 991         if (fk.basic.n_proto == htons(ETH_P_IP)) {
 992                 req->spec.rem_host[0] = fk.addrs.v4addrs.src;
 993                 req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
 994         } else {
 995                 memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
 996                        sizeof(struct in6_addr));
 997                 memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
 998                        sizeof(struct in6_addr));
 999         }
1000
1001         req->spec.rem_port = fk.ports.src;
1002         req->spec.loc_port = fk.ports.dst;
1003
1004         if (efx->rps_hash_table) {
1005                 /* Add it to ARFS hash table */
1006                 spin_lock(&efx->rps_hash_lock);
1007                 rule = efx_rps_hash_add(efx, &req->spec, &new);
1008                 if (!rule) {
1009                         rc = -ENOMEM;
1010                         goto out_unlock;
1011                 }
1012                 if (new)
1013                         rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
1014                 rc = rule->arfs_id;
1015                 /* Skip if existing or pending filter already does the right thing */
1016                 if (!new && rule->rxq_index == rxq_index &&
1017                     rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
1018                         goto out_unlock;
1019                 rule->rxq_index = rxq_index;
1020                 rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
1021                 spin_unlock(&efx->rps_hash_lock);
1022         } else {
1023                 /* Without an ARFS hash table, we just use arfs_id 0 for all
1024                  * filters.  This means if multiple flows hash to the same
1025                  * flow_id, all but the most recently touched will be eligible
1026                  * for expiry.
1027                  */
1028                 rc = 0;
1029         }
1030
1031         /* Queue the request */
1032         dev_hold(req->net_dev = net_dev);
1033         INIT_WORK(&req->work, efx_filter_rfs_work);
1034         req->rxq_index = rxq_index;
1035         req->flow_id = flow_id;
1036         schedule_work(&req->work);
1037         return rc;
1038 out_unlock:
1039         spin_unlock(&efx->rps_hash_lock);
1040 out_clear:
1041         clear_bit(slot_idx, &efx->rps_slot_map);
1042         return rc;
1043 }
1044
1045 bool __efx_filter_rfs_expire(struct efx_channel *channel, unsigned int quota)
1046 {
1047         bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
1048         struct efx_nic *efx = channel->efx;
1049         unsigned int index, size, start;
1050         u32 flow_id;
1051
1052         if (!mutex_trylock(&efx->rps_mutex))
1053                 return false;
1054         expire_one = efx->type->filter_rfs_expire_one;
1055         index = channel->rfs_expire_index;
1056         start = index;
1057         size = efx->type->max_rx_ip_filters;
1058         while (quota) {
1059                 flow_id = channel->rps_flow_id[index];
1060
1061                 if (flow_id != RPS_FLOW_ID_INVALID) {
1062                         quota--;
1063                         if (expire_one(efx, flow_id, index)) {
1064                                 netif_info(efx, rx_status, efx->net_dev,
1065                                            "expired filter %d [channel %u flow %u]\n",
1066                                            index, channel->channel, flow_id);
1067                                 channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
1068                                 channel->rfs_filter_count--;
1069                         }
1070                 }
1071                 if (++index == size)
1072                         index = 0;
1073                 /* If we were called with a quota that exceeds the total number
1074                  * of filters in the table (which shouldn't happen, but could
1075                  * if two callers race), ensure that we don't loop forever -
1076                  * stop when we've examined every row of the table.
1077                  */
1078                 if (index == start)
1079                         break;
1080         }
1081
1082         channel->rfs_expire_index = index;
1083         mutex_unlock(&efx->rps_mutex);
1084         return true;
1085 }
1086
1087 #endif /* CONFIG_RFS_ACCEL */