drivers/net/ethernet/amazon/ena/ena_xdp.c

   1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
   2 /*
   3  * Copyright 2015-2021 Amazon.com, Inc. or its affiliates. All rights reserved.
   4  */
   5
   6 #include "ena_xdp.h"
   7
   8 static int validate_xdp_req_id(struct ena_ring *tx_ring, u16 req_id)
   9 {
  10         struct ena_tx_buffer *tx_info;
  11
  12         tx_info = &tx_ring->tx_buffer_info[req_id];
  13         if (likely(tx_info->xdpf))
  14                 return 0;
  15
  16         return handle_invalid_req_id(tx_ring, req_id, tx_info, true);
  17 }
  18
  19 static int ena_xdp_tx_map_frame(struct ena_ring *tx_ring,
  20                                 struct ena_tx_buffer *tx_info,
  21                                 struct xdp_frame *xdpf,
  22                                 struct ena_com_tx_ctx *ena_tx_ctx)
  23 {
  24         struct ena_adapter *adapter = tx_ring->adapter;
  25         struct ena_com_buf *ena_buf;
  26         int push_len = 0;
  27         dma_addr_t dma;
  28         void *data;
  29         u32 size;
  30
  31         tx_info->xdpf = xdpf;
  32         data = tx_info->xdpf->data;
  33         size = tx_info->xdpf->len;
  34
  35         if (tx_ring->tx_mem_queue_type == ENA_ADMIN_PLACEMENT_POLICY_DEV) {
  36                 /* Designate part of the packet for LLQ */
  37                 push_len = min_t(u32, size, tx_ring->tx_max_header_size);
  38
  39                 ena_tx_ctx->push_header = data;
  40
  41                 size -= push_len;
  42                 data += push_len;
  43         }
  44
  45         ena_tx_ctx->header_len = push_len;
  46
  47         if (size > 0) {
  48                 dma = dma_map_single(tx_ring->dev,
  49                                      data,
  50                                      size,
  51                                      DMA_TO_DEVICE);
  52                 if (unlikely(dma_mapping_error(tx_ring->dev, dma)))
  53                         goto error_report_dma_error;
  54
  55                 tx_info->map_linear_data = 0;
  56
  57                 ena_buf = tx_info->bufs;
  58                 ena_buf->paddr = dma;
  59                 ena_buf->len = size;
  60
  61                 ena_tx_ctx->ena_bufs = ena_buf;
  62                 ena_tx_ctx->num_bufs = tx_info->num_of_bufs = 1;
  63         }
  64
  65         return 0;
  66
  67 error_report_dma_error:
  68         ena_increase_stat(&tx_ring->tx_stats.dma_mapping_err, 1,
  69                           &tx_ring->syncp);
  70         netif_warn(adapter, tx_queued, adapter->netdev, "Failed to map xdp buff\n");
  71
  72         return -EINVAL;
  73 }
  74
  75 int ena_xdp_xmit_frame(struct ena_ring *tx_ring,
  76                        struct ena_adapter *adapter,
  77                        struct xdp_frame *xdpf,
  78                        int flags)
  79 {
  80         struct ena_com_tx_ctx ena_tx_ctx = {};
  81         struct ena_tx_buffer *tx_info;
  82         u16 next_to_use, req_id;
  83         int rc;
  84
  85         next_to_use = tx_ring->next_to_use;
  86         req_id = tx_ring->free_ids[next_to_use];
  87         tx_info = &tx_ring->tx_buffer_info[req_id];
  88         tx_info->num_of_bufs = 0;
  89
  90         rc = ena_xdp_tx_map_frame(tx_ring, tx_info, xdpf, &ena_tx_ctx);
  91         if (unlikely(rc))
  92                 return rc;
  93
  94         ena_tx_ctx.req_id = req_id;
  95
  96         rc = ena_xmit_common(adapter,
  97                              tx_ring,
  98                              tx_info,
  99                              &ena_tx_ctx,
 100                              next_to_use,
 101                              xdpf->len);
 102         if (rc)
 103                 goto error_unmap_dma;
 104
 105         /* trigger the dma engine. ena_ring_tx_doorbell()
 106          * calls a memory barrier inside it.
 107          */
 108         if (flags & XDP_XMIT_FLUSH)
 109                 ena_ring_tx_doorbell(tx_ring);
 110
 111         return rc;
 112
 113 error_unmap_dma:
 114         ena_unmap_tx_buff(tx_ring, tx_info);
 115         tx_info->xdpf = NULL;
 116         return rc;
 117 }
 118
 119 int ena_xdp_xmit(struct net_device *dev, int n,
 120                  struct xdp_frame **frames, u32 flags)
 121 {
 122         struct ena_adapter *adapter = netdev_priv(dev);
 123         struct ena_ring *tx_ring;
 124         int qid, i, nxmit = 0;
 125
 126         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 127                 return -EINVAL;
 128
 129         if (!test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
 130                 return -ENETDOWN;
 131
 132         /* We assume that all rings have the same XDP program */
 133         if (!READ_ONCE(adapter->rx_ring->xdp_bpf_prog))
 134                 return -ENXIO;
 135
 136         qid = smp_processor_id() % adapter->xdp_num_queues;
 137         qid += adapter->xdp_first_ring;
 138         tx_ring = &adapter->tx_ring[qid];
 139
 140         /* Other CPU ids might try to send thorugh this queue */
 141         spin_lock(&tx_ring->xdp_tx_lock);
 142
 143         for (i = 0; i < n; i++) {
 144                 if (ena_xdp_xmit_frame(tx_ring, adapter, frames[i], 0))
 145                         break;
 146                 nxmit++;
 147         }
 148
 149         /* Ring doorbell to make device aware of the packets */
 150         if (flags & XDP_XMIT_FLUSH)
 151                 ena_ring_tx_doorbell(tx_ring);
 152
 153         spin_unlock(&tx_ring->xdp_tx_lock);
 154
 155         /* Return number of packets sent */
 156         return nxmit;
 157 }
 158
 159 static void ena_init_all_xdp_queues(struct ena_adapter *adapter)
 160 {
 161         adapter->xdp_first_ring = adapter->num_io_queues;
 162         adapter->xdp_num_queues = adapter->num_io_queues;
 163
 164         ena_init_io_rings(adapter,
 165                           adapter->xdp_first_ring,
 166                           adapter->xdp_num_queues);
 167 }
 168
 169 int ena_setup_and_create_all_xdp_queues(struct ena_adapter *adapter)
 170 {
 171         u32 xdp_first_ring = adapter->xdp_first_ring;
 172         u32 xdp_num_queues = adapter->xdp_num_queues;
 173         int rc = 0;
 174
 175         rc = ena_setup_tx_resources_in_range(adapter, xdp_first_ring, xdp_num_queues);
 176         if (rc)
 177                 goto setup_err;
 178
 179         rc = ena_create_io_tx_queues_in_range(adapter, xdp_first_ring, xdp_num_queues);
 180         if (rc)
 181                 goto create_err;
 182
 183         return 0;
 184
 185 create_err:
 186         ena_free_all_io_tx_resources_in_range(adapter, xdp_first_ring, xdp_num_queues);
 187 setup_err:
 188         return rc;
 189 }
 190
 191 /* Provides a way for both kernel and bpf-prog to know
 192  * more about the RX-queue a given XDP frame arrived on.
 193  */
 194 int ena_xdp_register_rxq_info(struct ena_ring *rx_ring)
 195 {
 196         int rc;
 197
 198         rc = xdp_rxq_info_reg(&rx_ring->xdp_rxq, rx_ring->netdev, rx_ring->qid, 0);
 199
 200         netif_dbg(rx_ring->adapter, ifup, rx_ring->netdev, "Registering RX info for queue %d",
 201                   rx_ring->qid);
 202         if (rc) {
 203                 netif_err(rx_ring->adapter, ifup, rx_ring->netdev,
 204                           "Failed to register xdp rx queue info. RX queue num %d rc: %d\n",
 205                           rx_ring->qid, rc);
 206                 goto err;
 207         }
 208
 209         rc = xdp_rxq_info_reg_mem_model(&rx_ring->xdp_rxq, MEM_TYPE_PAGE_SHARED, NULL);
 210
 211         if (rc) {
 212                 netif_err(rx_ring->adapter, ifup, rx_ring->netdev,
 213                           "Failed to register xdp rx queue info memory model. RX queue num %d rc: %d\n",
 214                           rx_ring->qid, rc);
 215                 xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
 216         }
 217
 218 err:
 219         return rc;
 220 }
 221
 222 void ena_xdp_unregister_rxq_info(struct ena_ring *rx_ring)
 223 {
 224         netif_dbg(rx_ring->adapter, ifdown, rx_ring->netdev,
 225                   "Unregistering RX info for queue %d",
 226                   rx_ring->qid);
 227         xdp_rxq_info_unreg_mem_model(&rx_ring->xdp_rxq);
 228         xdp_rxq_info_unreg(&rx_ring->xdp_rxq);
 229 }
 230
 231 void ena_xdp_exchange_program_rx_in_range(struct ena_adapter *adapter,
 232                                           struct bpf_prog *prog,
 233                                           int first, int count)
 234 {
 235         struct bpf_prog *old_bpf_prog;
 236         struct ena_ring *rx_ring;
 237         int i = 0;
 238
 239         for (i = first; i < count; i++) {
 240                 rx_ring = &adapter->rx_ring[i];
 241                 old_bpf_prog = xchg(&rx_ring->xdp_bpf_prog, prog);
 242
 243                 if (!old_bpf_prog && prog) {
 244                         rx_ring->rx_headroom = XDP_PACKET_HEADROOM;
 245                 } else if (old_bpf_prog && !prog) {
 246                         rx_ring->rx_headroom = NET_SKB_PAD;
 247                 }
 248         }
 249 }
 250
 251 static void ena_xdp_exchange_program(struct ena_adapter *adapter,
 252                                      struct bpf_prog *prog)
 253 {
 254         struct bpf_prog *old_bpf_prog = xchg(&adapter->xdp_bpf_prog, prog);
 255
 256         ena_xdp_exchange_program_rx_in_range(adapter,
 257                                              prog,
 258                                              0,
 259                                              adapter->num_io_queues);
 260
 261         if (old_bpf_prog)
 262                 bpf_prog_put(old_bpf_prog);
 263 }
 264
 265 static int ena_destroy_and_free_all_xdp_queues(struct ena_adapter *adapter)
 266 {
 267         bool was_up;
 268         int rc;
 269
 270         was_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
 271
 272         if (was_up)
 273                 ena_down(adapter);
 274
 275         adapter->xdp_first_ring = 0;
 276         adapter->xdp_num_queues = 0;
 277         ena_xdp_exchange_program(adapter, NULL);
 278         if (was_up) {
 279                 rc = ena_up(adapter);
 280                 if (rc)
 281                         return rc;
 282         }
 283         return 0;
 284 }
 285
 286 static int ena_xdp_set(struct net_device *netdev, struct netdev_bpf *bpf)
 287 {
 288         struct ena_adapter *adapter = netdev_priv(netdev);
 289         struct bpf_prog *prog = bpf->prog;
 290         struct bpf_prog *old_bpf_prog;
 291         int rc, prev_mtu;
 292         bool is_up;
 293
 294         is_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
 295         rc = ena_xdp_allowed(adapter);
 296         if (rc == ENA_XDP_ALLOWED) {
 297                 old_bpf_prog = adapter->xdp_bpf_prog;
 298                 if (prog) {
 299                         if (!is_up) {
 300                                 ena_init_all_xdp_queues(adapter);
 301                         } else if (!old_bpf_prog) {
 302                                 ena_down(adapter);
 303                                 ena_init_all_xdp_queues(adapter);
 304                         }
 305                         ena_xdp_exchange_program(adapter, prog);
 306
 307                         netif_dbg(adapter, drv, adapter->netdev, "Set a new XDP program\n");
 308
 309                         if (is_up && !old_bpf_prog) {
 310                                 rc = ena_up(adapter);
 311                                 if (rc)
 312                                         return rc;
 313                         }
 314                         xdp_features_set_redirect_target(netdev, false);
 315                 } else if (old_bpf_prog) {
 316                         xdp_features_clear_redirect_target(netdev);
 317                         netif_dbg(adapter, drv, adapter->netdev, "Removing XDP program\n");
 318
 319                         rc = ena_destroy_and_free_all_xdp_queues(adapter);
 320                         if (rc)
 321                                 return rc;
 322                 }
 323
 324                 prev_mtu = netdev->max_mtu;
 325                 netdev->max_mtu = prog ? ENA_XDP_MAX_MTU : adapter->max_mtu;
 326
 327                 if (!old_bpf_prog)
 328                         netif_info(adapter, drv, adapter->netdev,
 329                                    "XDP program is set, changing the max_mtu from %d to %d",
 330                                    prev_mtu, netdev->max_mtu);
 331
 332         } else if (rc == ENA_XDP_CURRENT_MTU_TOO_LARGE) {
 333                 netif_err(adapter, drv, adapter->netdev,
 334                           "Failed to set xdp program, the current MTU (%d) is larger than the maximum allowed MTU (%lu) while xdp is on",
 335                           netdev->mtu, ENA_XDP_MAX_MTU);
 336                 NL_SET_ERR_MSG_MOD(bpf->extack,
 337                                    "Failed to set xdp program, the current MTU is larger than the maximum allowed MTU. Check the dmesg for more info");
 338                 return -EINVAL;
 339         } else if (rc == ENA_XDP_NO_ENOUGH_QUEUES) {
 340                 netif_err(adapter, drv, adapter->netdev,
 341                           "Failed to set xdp program, the Rx/Tx channel count should be at most half of the maximum allowed channel count. The current queue count (%d), the maximal queue count (%d)\n",
 342                           adapter->num_io_queues, adapter->max_num_io_queues);
 343                 NL_SET_ERR_MSG_MOD(bpf->extack,
 344                                    "Failed to set xdp program, there is no enough space for allocating XDP queues, Check the dmesg for more info");
 345                 return -EINVAL;
 346         }
 347
 348         return 0;
 349 }
 350
 351 /* This is the main xdp callback, it's used by the kernel to set/unset the xdp
 352  * program as well as to query the current xdp program id.
 353  */
 354 int ena_xdp(struct net_device *netdev, struct netdev_bpf *bpf)
 355 {
 356         switch (bpf->command) {
 357         case XDP_SETUP_PROG:
 358                 return ena_xdp_set(netdev, bpf);
 359         default:
 360                 return -EINVAL;
 361         }
 362         return 0;
 363 }
 364
 365 static int ena_clean_xdp_irq(struct ena_ring *tx_ring, u32 budget)
 366 {
 367         u32 total_done = 0;
 368         u16 next_to_clean;
 369         int tx_pkts = 0;
 370         u16 req_id;
 371         int rc;
 372
 373         if (unlikely(!tx_ring))
 374                 return 0;
 375         next_to_clean = tx_ring->next_to_clean;
 376
 377         while (tx_pkts < budget) {
 378                 struct ena_tx_buffer *tx_info;
 379                 struct xdp_frame *xdpf;
 380
 381                 rc = ena_com_tx_comp_req_id_get(tx_ring->ena_com_io_cq,
 382                                                 &req_id);
 383                 if (rc) {
 384                         if (unlikely(rc == -EINVAL))
 385                                 handle_invalid_req_id(tx_ring, req_id, NULL, true);
 386                         break;
 387                 }
 388
 389                 /* validate that the request id points to a valid xdp_frame */
 390                 rc = validate_xdp_req_id(tx_ring, req_id);
 391                 if (rc)
 392                         break;
 393
 394                 tx_info = &tx_ring->tx_buffer_info[req_id];
 395
 396                 tx_info->last_jiffies = 0;
 397
 398                 xdpf = tx_info->xdpf;
 399                 tx_info->xdpf = NULL;
 400                 ena_unmap_tx_buff(tx_ring, tx_info);
 401                 xdp_return_frame(xdpf);
 402
 403                 tx_pkts++;
 404                 total_done += tx_info->tx_descs;
 405                 tx_ring->free_ids[next_to_clean] = req_id;
 406                 next_to_clean = ENA_TX_RING_IDX_NEXT(next_to_clean,
 407                                                      tx_ring->ring_size);
 408
 409                 netif_dbg(tx_ring->adapter, tx_done, tx_ring->netdev,
 410                           "tx_poll: q %d pkt #%d req_id %d\n", tx_ring->qid, tx_pkts, req_id);
 411         }
 412
 413         tx_ring->next_to_clean = next_to_clean;
 414         ena_com_comp_ack(tx_ring->ena_com_io_sq, total_done);
 415
 416         netif_dbg(tx_ring->adapter, tx_done, tx_ring->netdev,
 417                   "tx_poll: q %d done. total pkts: %d\n",
 418                   tx_ring->qid, tx_pkts);
 419
 420         return tx_pkts;
 421 }
 422
 423 /* This is the XDP napi callback. XDP queues use a separate napi callback
 424  * than Rx/Tx queues.
 425  */
 426 int ena_xdp_io_poll(struct napi_struct *napi, int budget)
 427 {
 428         struct ena_napi *ena_napi = container_of(napi, struct ena_napi, napi);
 429         struct ena_ring *tx_ring;
 430         u32 work_done;
 431         int ret;
 432
 433         tx_ring = ena_napi->tx_ring;
 434
 435         if (!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags) ||
 436             test_bit(ENA_FLAG_TRIGGER_RESET, &tx_ring->adapter->flags)) {
 437                 napi_complete_done(napi, 0);
 438                 return 0;
 439         }
 440
 441         work_done = ena_clean_xdp_irq(tx_ring, budget);
 442
 443         /* If the device is about to reset or down, avoid unmask
 444          * the interrupt and return 0 so NAPI won't reschedule
 445          */
 446         if (unlikely(!test_bit(ENA_FLAG_DEV_UP, &tx_ring->adapter->flags))) {
 447                 napi_complete_done(napi, 0);
 448                 ret = 0;
 449         } else if (budget > work_done) {
 450                 ena_increase_stat(&tx_ring->tx_stats.napi_comp, 1,
 451                                   &tx_ring->syncp);
 452                 if (napi_complete_done(napi, work_done))
 453                         ena_unmask_interrupt(tx_ring, NULL);
 454
 455                 ena_update_ring_numa_node(tx_ring, NULL);
 456                 ret = work_done;
 457         } else {
 458                 ret = budget;
 459         }
 460
 461         u64_stats_update_begin(&tx_ring->syncp);
 462         tx_ring->tx_stats.tx_poll++;
 463         u64_stats_update_end(&tx_ring->syncp);
 464         tx_ring->tx_stats.last_napi_jiffies = jiffies;
 465
 466         return ret;
 467 }