drivers/net/ethernet/sfc/rx_common.c

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