drivers/net/thunderbolt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Networking over Thunderbolt cable using Apple ThunderboltIP protocol
   4  *
   5  * Copyright (C) 2017, Intel Corporation
   6  * Authors: Amir Levy <amir.jer.levy@intel.com>
   7  *          Michael Jamet <michael.jamet@intel.com>
   8  *          Mika Westerberg <mika.westerberg@linux.intel.com>
   9  */
  10
  11 #include <linux/atomic.h>
  12 #include <linux/highmem.h>
  13 #include <linux/if_vlan.h>
  14 #include <linux/jhash.h>
  15 #include <linux/module.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/rtnetlink.h>
  18 #include <linux/sizes.h>
  19 #include <linux/thunderbolt.h>
  20 #include <linux/uuid.h>
  21 #include <linux/workqueue.h>
  22
  23 #include <net/ip6_checksum.h>
  24
  25 /* Protocol timeouts in ms */
  26 #define TBNET_LOGIN_DELAY       4500
  27 #define TBNET_LOGIN_TIMEOUT     500
  28 #define TBNET_LOGOUT_TIMEOUT    1000
  29
  30 #define TBNET_RING_SIZE         256
  31 #define TBNET_LOGIN_RETRIES     60
  32 #define TBNET_LOGOUT_RETRIES    10
  33 #define TBNET_MATCH_FRAGS_ID    BIT(1)
  34 #define TBNET_64K_FRAMES        BIT(2)
  35 #define TBNET_MAX_MTU           SZ_64K
  36 #define TBNET_FRAME_SIZE        SZ_4K
  37 #define TBNET_MAX_PAYLOAD_SIZE  \
  38         (TBNET_FRAME_SIZE - sizeof(struct thunderbolt_ip_frame_header))
  39 /* Rx packets need to hold space for skb_shared_info */
  40 #define TBNET_RX_MAX_SIZE       \
  41         (TBNET_FRAME_SIZE + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
  42 #define TBNET_RX_PAGE_ORDER     get_order(TBNET_RX_MAX_SIZE)
  43 #define TBNET_RX_PAGE_SIZE      (PAGE_SIZE << TBNET_RX_PAGE_ORDER)
  44
  45 #define TBNET_L0_PORT_NUM(route) ((route) & GENMASK(5, 0))
  46
  47 /**
  48  * struct thunderbolt_ip_frame_header - Header for each Thunderbolt frame
  49  * @frame_size: size of the data with the frame
  50  * @frame_index: running index on the frames
  51  * @frame_id: ID of the frame to match frames to specific packet
  52  * @frame_count: how many frames assembles a full packet
  53  *
  54  * Each data frame passed to the high-speed DMA ring has this header. If
  55  * the XDomain network directory announces that %TBNET_MATCH_FRAGS_ID is
  56  * supported then @frame_id is filled, otherwise it stays %0.
  57  */
  58 struct thunderbolt_ip_frame_header {
  59         u32 frame_size;
  60         u16 frame_index;
  61         u16 frame_id;
  62         u32 frame_count;
  63 };
  64
  65 enum thunderbolt_ip_frame_pdf {
  66         TBIP_PDF_FRAME_START = 1,
  67         TBIP_PDF_FRAME_END,
  68 };
  69
  70 enum thunderbolt_ip_type {
  71         TBIP_LOGIN,
  72         TBIP_LOGIN_RESPONSE,
  73         TBIP_LOGOUT,
  74         TBIP_STATUS,
  75 };
  76
  77 struct thunderbolt_ip_header {
  78         u32 route_hi;
  79         u32 route_lo;
  80         u32 length_sn;
  81         uuid_t uuid;
  82         uuid_t initiator_uuid;
  83         uuid_t target_uuid;
  84         u32 type;
  85         u32 command_id;
  86 };
  87
  88 #define TBIP_HDR_LENGTH_MASK            GENMASK(5, 0)
  89 #define TBIP_HDR_SN_MASK                GENMASK(28, 27)
  90 #define TBIP_HDR_SN_SHIFT               27
  91
  92 struct thunderbolt_ip_login {
  93         struct thunderbolt_ip_header hdr;
  94         u32 proto_version;
  95         u32 transmit_path;
  96         u32 reserved[4];
  97 };
  98
  99 #define TBIP_LOGIN_PROTO_VERSION        1
 100
 101 struct thunderbolt_ip_login_response {
 102         struct thunderbolt_ip_header hdr;
 103         u32 status;
 104         u32 receiver_mac[2];
 105         u32 receiver_mac_len;
 106         u32 reserved[4];
 107 };
 108
 109 struct thunderbolt_ip_logout {
 110         struct thunderbolt_ip_header hdr;
 111 };
 112
 113 struct thunderbolt_ip_status {
 114         struct thunderbolt_ip_header hdr;
 115         u32 status;
 116 };
 117
 118 struct tbnet_stats {
 119         u64 tx_packets;
 120         u64 rx_packets;
 121         u64 tx_bytes;
 122         u64 rx_bytes;
 123         u64 rx_errors;
 124         u64 tx_errors;
 125         u64 rx_length_errors;
 126         u64 rx_over_errors;
 127         u64 rx_crc_errors;
 128         u64 rx_missed_errors;
 129 };
 130
 131 struct tbnet_frame {
 132         struct net_device *dev;
 133         struct page *page;
 134         struct ring_frame frame;
 135 };
 136
 137 struct tbnet_ring {
 138         struct tbnet_frame frames[TBNET_RING_SIZE];
 139         unsigned int cons;
 140         unsigned int prod;
 141         struct tb_ring *ring;
 142 };
 143
 144 /**
 145  * struct tbnet - ThunderboltIP network driver private data
 146  * @svc: XDomain service the driver is bound to
 147  * @xd: XDomain the service blongs to
 148  * @handler: ThunderboltIP configuration protocol handler
 149  * @dev: Networking device
 150  * @napi: NAPI structure for Rx polling
 151  * @stats: Network statistics
 152  * @skb: Network packet that is currently processed on Rx path
 153  * @command_id: ID used for next configuration protocol packet
 154  * @login_sent: ThunderboltIP login message successfully sent
 155  * @login_received: ThunderboltIP login message received from the remote
 156  *                  host
 157  * @local_transmit_path: HopID we are using to send out packets
 158  * @remote_transmit_path: HopID the other end is using to send packets to us
 159  * @connection_lock: Lock serializing access to @login_sent,
 160  *                   @login_received and @transmit_path.
 161  * @login_retries: Number of login retries currently done
 162  * @login_work: Worker to send ThunderboltIP login packets
 163  * @connected_work: Worker that finalizes the ThunderboltIP connection
 164  *                  setup and enables DMA paths for high speed data
 165  *                  transfers
 166  * @disconnect_work: Worker that handles tearing down the ThunderboltIP
 167  *                   connection
 168  * @rx_hdr: Copy of the currently processed Rx frame. Used when a
 169  *          network packet consists of multiple Thunderbolt frames.
 170  *          In host byte order.
 171  * @rx_ring: Software ring holding Rx frames
 172  * @frame_id: Frame ID use for next Tx packet
 173  *            (if %TBNET_MATCH_FRAGS_ID is supported in both ends)
 174  * @tx_ring: Software ring holding Tx frames
 175  */
 176 struct tbnet {
 177         const struct tb_service *svc;
 178         struct tb_xdomain *xd;
 179         struct tb_protocol_handler handler;
 180         struct net_device *dev;
 181         struct napi_struct napi;
 182         struct tbnet_stats stats;
 183         struct sk_buff *skb;
 184         atomic_t command_id;
 185         bool login_sent;
 186         bool login_received;
 187         int local_transmit_path;
 188         int remote_transmit_path;
 189         struct mutex connection_lock;
 190         int login_retries;
 191         struct delayed_work login_work;
 192         struct work_struct connected_work;
 193         struct work_struct disconnect_work;
 194         struct thunderbolt_ip_frame_header rx_hdr;
 195         struct tbnet_ring rx_ring;
 196         atomic_t frame_id;
 197         struct tbnet_ring tx_ring;
 198 };
 199
 200 /* Network property directory UUID: c66189ca-1cce-4195-bdb8-49592e5f5a4f */
 201 static const uuid_t tbnet_dir_uuid =
 202         UUID_INIT(0xc66189ca, 0x1cce, 0x4195,
 203                   0xbd, 0xb8, 0x49, 0x59, 0x2e, 0x5f, 0x5a, 0x4f);
 204
 205 /* ThunderboltIP protocol UUID: 798f589e-3616-8a47-97c6-5664a920c8dd */
 206 static const uuid_t tbnet_svc_uuid =
 207         UUID_INIT(0x798f589e, 0x3616, 0x8a47,
 208                   0x97, 0xc6, 0x56, 0x64, 0xa9, 0x20, 0xc8, 0xdd);
 209
 210 static struct tb_property_dir *tbnet_dir;
 211
 212 static void tbnet_fill_header(struct thunderbolt_ip_header *hdr, u64 route,
 213         u8 sequence, const uuid_t *initiator_uuid, const uuid_t *target_uuid,
 214         enum thunderbolt_ip_type type, size_t size, u32 command_id)
 215 {
 216         u32 length_sn;
 217
 218         /* Length does not include route_hi/lo and length_sn fields */
 219         length_sn = (size - 3 * 4) / 4;
 220         length_sn |= (sequence << TBIP_HDR_SN_SHIFT) & TBIP_HDR_SN_MASK;
 221
 222         hdr->route_hi = upper_32_bits(route);
 223         hdr->route_lo = lower_32_bits(route);
 224         hdr->length_sn = length_sn;
 225         uuid_copy(&hdr->uuid, &tbnet_svc_uuid);
 226         uuid_copy(&hdr->initiator_uuid, initiator_uuid);
 227         uuid_copy(&hdr->target_uuid, target_uuid);
 228         hdr->type = type;
 229         hdr->command_id = command_id;
 230 }
 231
 232 static int tbnet_login_response(struct tbnet *net, u64 route, u8 sequence,
 233                                 u32 command_id)
 234 {
 235         struct thunderbolt_ip_login_response reply;
 236         struct tb_xdomain *xd = net->xd;
 237
 238         memset(&reply, 0, sizeof(reply));
 239         tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
 240                           xd->remote_uuid, TBIP_LOGIN_RESPONSE, sizeof(reply),
 241                           command_id);
 242         memcpy(reply.receiver_mac, net->dev->dev_addr, ETH_ALEN);
 243         reply.receiver_mac_len = ETH_ALEN;
 244
 245         return tb_xdomain_response(xd, &reply, sizeof(reply),
 246                                    TB_CFG_PKG_XDOMAIN_RESP);
 247 }
 248
 249 static int tbnet_login_request(struct tbnet *net, u8 sequence)
 250 {
 251         struct thunderbolt_ip_login_response reply;
 252         struct thunderbolt_ip_login request;
 253         struct tb_xdomain *xd = net->xd;
 254
 255         memset(&request, 0, sizeof(request));
 256         tbnet_fill_header(&request.hdr, xd->route, sequence, xd->local_uuid,
 257                           xd->remote_uuid, TBIP_LOGIN, sizeof(request),
 258                           atomic_inc_return(&net->command_id));
 259
 260         request.proto_version = TBIP_LOGIN_PROTO_VERSION;
 261         request.transmit_path = net->local_transmit_path;
 262
 263         return tb_xdomain_request(xd, &request, sizeof(request),
 264                                   TB_CFG_PKG_XDOMAIN_RESP, &reply,
 265                                   sizeof(reply), TB_CFG_PKG_XDOMAIN_RESP,
 266                                   TBNET_LOGIN_TIMEOUT);
 267 }
 268
 269 static int tbnet_logout_response(struct tbnet *net, u64 route, u8 sequence,
 270                                  u32 command_id)
 271 {
 272         struct thunderbolt_ip_status reply;
 273         struct tb_xdomain *xd = net->xd;
 274
 275         memset(&reply, 0, sizeof(reply));
 276         tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
 277                           xd->remote_uuid, TBIP_STATUS, sizeof(reply),
 278                           atomic_inc_return(&net->command_id));
 279         return tb_xdomain_response(xd, &reply, sizeof(reply),
 280                                    TB_CFG_PKG_XDOMAIN_RESP);
 281 }
 282
 283 static int tbnet_logout_request(struct tbnet *net)
 284 {
 285         struct thunderbolt_ip_logout request;
 286         struct thunderbolt_ip_status reply;
 287         struct tb_xdomain *xd = net->xd;
 288
 289         memset(&request, 0, sizeof(request));
 290         tbnet_fill_header(&request.hdr, xd->route, 0, xd->local_uuid,
 291                           xd->remote_uuid, TBIP_LOGOUT, sizeof(request),
 292                           atomic_inc_return(&net->command_id));
 293
 294         return tb_xdomain_request(xd, &request, sizeof(request),
 295                                   TB_CFG_PKG_XDOMAIN_RESP, &reply,
 296                                   sizeof(reply), TB_CFG_PKG_XDOMAIN_RESP,
 297                                   TBNET_LOGOUT_TIMEOUT);
 298 }
 299
 300 static void start_login(struct tbnet *net)
 301 {
 302         mutex_lock(&net->connection_lock);
 303         net->login_sent = false;
 304         net->login_received = false;
 305         mutex_unlock(&net->connection_lock);
 306
 307         queue_delayed_work(system_long_wq, &net->login_work,
 308                            msecs_to_jiffies(1000));
 309 }
 310
 311 static void stop_login(struct tbnet *net)
 312 {
 313         cancel_delayed_work_sync(&net->login_work);
 314         cancel_work_sync(&net->connected_work);
 315 }
 316
 317 static inline unsigned int tbnet_frame_size(const struct tbnet_frame *tf)
 318 {
 319         return tf->frame.size ? : TBNET_FRAME_SIZE;
 320 }
 321
 322 static void tbnet_free_buffers(struct tbnet_ring *ring)
 323 {
 324         unsigned int i;
 325
 326         for (i = 0; i < TBNET_RING_SIZE; i++) {
 327                 struct device *dma_dev = tb_ring_dma_device(ring->ring);
 328                 struct tbnet_frame *tf = &ring->frames[i];
 329                 enum dma_data_direction dir;
 330                 unsigned int order;
 331                 size_t size;
 332
 333                 if (!tf->page)
 334                         continue;
 335
 336                 if (ring->ring->is_tx) {
 337                         dir = DMA_TO_DEVICE;
 338                         order = 0;
 339                         size = TBNET_FRAME_SIZE;
 340                 } else {
 341                         dir = DMA_FROM_DEVICE;
 342                         order = TBNET_RX_PAGE_ORDER;
 343                         size = TBNET_RX_PAGE_SIZE;
 344                 }
 345
 346                 if (tf->frame.buffer_phy)
 347                         dma_unmap_page(dma_dev, tf->frame.buffer_phy, size,
 348                                        dir);
 349
 350                 __free_pages(tf->page, order);
 351                 tf->page = NULL;
 352         }
 353
 354         ring->cons = 0;
 355         ring->prod = 0;
 356 }
 357
 358 static void tbnet_tear_down(struct tbnet *net, bool send_logout)
 359 {
 360         netif_carrier_off(net->dev);
 361         netif_stop_queue(net->dev);
 362
 363         stop_login(net);
 364
 365         mutex_lock(&net->connection_lock);
 366
 367         if (net->login_sent && net->login_received) {
 368                 int ret, retries = TBNET_LOGOUT_RETRIES;
 369
 370                 while (send_logout && retries-- > 0) {
 371                         ret = tbnet_logout_request(net);
 372                         if (ret != -ETIMEDOUT)
 373                                 break;
 374                 }
 375
 376                 tb_ring_stop(net->rx_ring.ring);
 377                 tb_ring_stop(net->tx_ring.ring);
 378                 tbnet_free_buffers(&net->rx_ring);
 379                 tbnet_free_buffers(&net->tx_ring);
 380
 381                 ret = tb_xdomain_disable_paths(net->xd,
 382                                                net->local_transmit_path,
 383                                                net->rx_ring.ring->hop,
 384                                                net->remote_transmit_path,
 385                                                net->tx_ring.ring->hop);
 386                 if (ret)
 387                         netdev_warn(net->dev, "failed to disable DMA paths\n");
 388
 389                 tb_xdomain_release_in_hopid(net->xd, net->remote_transmit_path);
 390                 net->remote_transmit_path = 0;
 391         }
 392
 393         net->login_retries = 0;
 394         net->login_sent = false;
 395         net->login_received = false;
 396
 397         mutex_unlock(&net->connection_lock);
 398 }
 399
 400 static int tbnet_handle_packet(const void *buf, size_t size, void *data)
 401 {
 402         const struct thunderbolt_ip_login *pkg = buf;
 403         struct tbnet *net = data;
 404         u32 command_id;
 405         int ret = 0;
 406         u32 sequence;
 407         u64 route;
 408
 409         /* Make sure the packet is for us */
 410         if (size < sizeof(struct thunderbolt_ip_header))
 411                 return 0;
 412         if (!uuid_equal(&pkg->hdr.initiator_uuid, net->xd->remote_uuid))
 413                 return 0;
 414         if (!uuid_equal(&pkg->hdr.target_uuid, net->xd->local_uuid))
 415                 return 0;
 416
 417         route = ((u64)pkg->hdr.route_hi << 32) | pkg->hdr.route_lo;
 418         route &= ~BIT_ULL(63);
 419         if (route != net->xd->route)
 420                 return 0;
 421
 422         sequence = pkg->hdr.length_sn & TBIP_HDR_SN_MASK;
 423         sequence >>= TBIP_HDR_SN_SHIFT;
 424         command_id = pkg->hdr.command_id;
 425
 426         switch (pkg->hdr.type) {
 427         case TBIP_LOGIN:
 428                 if (!netif_running(net->dev))
 429                         break;
 430
 431                 ret = tbnet_login_response(net, route, sequence,
 432                                            pkg->hdr.command_id);
 433                 if (!ret) {
 434                         mutex_lock(&net->connection_lock);
 435                         net->login_received = true;
 436                         net->remote_transmit_path = pkg->transmit_path;
 437
 438                         /* If we reached the number of max retries or
 439                          * previous logout, schedule another round of
 440                          * login retries
 441                          */
 442                         if (net->login_retries >= TBNET_LOGIN_RETRIES ||
 443                             !net->login_sent) {
 444                                 net->login_retries = 0;
 445                                 queue_delayed_work(system_long_wq,
 446                                                    &net->login_work, 0);
 447                         }
 448                         mutex_unlock(&net->connection_lock);
 449
 450                         queue_work(system_long_wq, &net->connected_work);
 451                 }
 452                 break;
 453
 454         case TBIP_LOGOUT:
 455                 ret = tbnet_logout_response(net, route, sequence, command_id);
 456                 if (!ret)
 457                         queue_work(system_long_wq, &net->disconnect_work);
 458                 break;
 459
 460         default:
 461                 return 0;
 462         }
 463
 464         if (ret)
 465                 netdev_warn(net->dev, "failed to send ThunderboltIP response\n");
 466
 467         return 1;
 468 }
 469
 470 static unsigned int tbnet_available_buffers(const struct tbnet_ring *ring)
 471 {
 472         return ring->prod - ring->cons;
 473 }
 474
 475 static int tbnet_alloc_rx_buffers(struct tbnet *net, unsigned int nbuffers)
 476 {
 477         struct tbnet_ring *ring = &net->rx_ring;
 478         int ret;
 479
 480         while (nbuffers--) {
 481                 struct device *dma_dev = tb_ring_dma_device(ring->ring);
 482                 unsigned int index = ring->prod & (TBNET_RING_SIZE - 1);
 483                 struct tbnet_frame *tf = &ring->frames[index];
 484                 dma_addr_t dma_addr;
 485
 486                 if (tf->page)
 487                         break;
 488
 489                 /* Allocate page (order > 0) so that it can hold maximum
 490                  * ThunderboltIP frame (4kB) and the additional room for
 491                  * SKB shared info required by build_skb().
 492                  */
 493                 tf->page = dev_alloc_pages(TBNET_RX_PAGE_ORDER);
 494                 if (!tf->page) {
 495                         ret = -ENOMEM;
 496                         goto err_free;
 497                 }
 498
 499                 dma_addr = dma_map_page(dma_dev, tf->page, 0,
 500                                         TBNET_RX_PAGE_SIZE, DMA_FROM_DEVICE);
 501                 if (dma_mapping_error(dma_dev, dma_addr)) {
 502                         ret = -ENOMEM;
 503                         goto err_free;
 504                 }
 505
 506                 tf->frame.buffer_phy = dma_addr;
 507                 tf->dev = net->dev;
 508
 509                 tb_ring_rx(ring->ring, &tf->frame);
 510
 511                 ring->prod++;
 512         }
 513
 514         return 0;
 515
 516 err_free:
 517         tbnet_free_buffers(ring);
 518         return ret;
 519 }
 520
 521 static struct tbnet_frame *tbnet_get_tx_buffer(struct tbnet *net)
 522 {
 523         struct tbnet_ring *ring = &net->tx_ring;
 524         struct device *dma_dev = tb_ring_dma_device(ring->ring);
 525         struct tbnet_frame *tf;
 526         unsigned int index;
 527
 528         if (!tbnet_available_buffers(ring))
 529                 return NULL;
 530
 531         index = ring->cons++ & (TBNET_RING_SIZE - 1);
 532
 533         tf = &ring->frames[index];
 534         tf->frame.size = 0;
 535
 536         dma_sync_single_for_cpu(dma_dev, tf->frame.buffer_phy,
 537                                 tbnet_frame_size(tf), DMA_TO_DEVICE);
 538
 539         return tf;
 540 }
 541
 542 static void tbnet_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
 543                               bool canceled)
 544 {
 545         struct tbnet_frame *tf = container_of(frame, typeof(*tf), frame);
 546         struct tbnet *net = netdev_priv(tf->dev);
 547
 548         /* Return buffer to the ring */
 549         net->tx_ring.prod++;
 550
 551         if (tbnet_available_buffers(&net->tx_ring) >= TBNET_RING_SIZE / 2)
 552                 netif_wake_queue(net->dev);
 553 }
 554
 555 static int tbnet_alloc_tx_buffers(struct tbnet *net)
 556 {
 557         struct tbnet_ring *ring = &net->tx_ring;
 558         struct device *dma_dev = tb_ring_dma_device(ring->ring);
 559         unsigned int i;
 560
 561         for (i = 0; i < TBNET_RING_SIZE; i++) {
 562                 struct tbnet_frame *tf = &ring->frames[i];
 563                 dma_addr_t dma_addr;
 564
 565                 tf->page = alloc_page(GFP_KERNEL);
 566                 if (!tf->page) {
 567                         tbnet_free_buffers(ring);
 568                         return -ENOMEM;
 569                 }
 570
 571                 dma_addr = dma_map_page(dma_dev, tf->page, 0, TBNET_FRAME_SIZE,
 572                                         DMA_TO_DEVICE);
 573                 if (dma_mapping_error(dma_dev, dma_addr)) {
 574                         __free_page(tf->page);
 575                         tf->page = NULL;
 576                         tbnet_free_buffers(ring);
 577                         return -ENOMEM;
 578                 }
 579
 580                 tf->dev = net->dev;
 581                 tf->frame.buffer_phy = dma_addr;
 582                 tf->frame.callback = tbnet_tx_callback;
 583                 tf->frame.sof = TBIP_PDF_FRAME_START;
 584                 tf->frame.eof = TBIP_PDF_FRAME_END;
 585         }
 586
 587         ring->cons = 0;
 588         ring->prod = TBNET_RING_SIZE - 1;
 589
 590         return 0;
 591 }
 592
 593 static void tbnet_connected_work(struct work_struct *work)
 594 {
 595         struct tbnet *net = container_of(work, typeof(*net), connected_work);
 596         bool connected;
 597         int ret;
 598
 599         if (netif_carrier_ok(net->dev))
 600                 return;
 601
 602         mutex_lock(&net->connection_lock);
 603         connected = net->login_sent && net->login_received;
 604         mutex_unlock(&net->connection_lock);
 605
 606         if (!connected)
 607                 return;
 608
 609         ret = tb_xdomain_alloc_in_hopid(net->xd, net->remote_transmit_path);
 610         if (ret != net->remote_transmit_path) {
 611                 netdev_err(net->dev, "failed to allocate Rx HopID\n");
 612                 return;
 613         }
 614
 615         /* Both logins successful so enable the high-speed DMA paths and
 616          * start the network device queue.
 617          */
 618         ret = tb_xdomain_enable_paths(net->xd, net->local_transmit_path,
 619                                       net->rx_ring.ring->hop,
 620                                       net->remote_transmit_path,
 621                                       net->tx_ring.ring->hop);
 622         if (ret) {
 623                 netdev_err(net->dev, "failed to enable DMA paths\n");
 624                 return;
 625         }
 626
 627         tb_ring_start(net->tx_ring.ring);
 628         tb_ring_start(net->rx_ring.ring);
 629
 630         ret = tbnet_alloc_rx_buffers(net, TBNET_RING_SIZE);
 631         if (ret)
 632                 goto err_stop_rings;
 633
 634         ret = tbnet_alloc_tx_buffers(net);
 635         if (ret)
 636                 goto err_free_rx_buffers;
 637
 638         netif_carrier_on(net->dev);
 639         netif_start_queue(net->dev);
 640         return;
 641
 642 err_free_rx_buffers:
 643         tbnet_free_buffers(&net->rx_ring);
 644 err_stop_rings:
 645         tb_ring_stop(net->rx_ring.ring);
 646         tb_ring_stop(net->tx_ring.ring);
 647         tb_xdomain_release_in_hopid(net->xd, net->remote_transmit_path);
 648 }
 649
 650 static void tbnet_login_work(struct work_struct *work)
 651 {
 652         struct tbnet *net = container_of(work, typeof(*net), login_work.work);
 653         unsigned long delay = msecs_to_jiffies(TBNET_LOGIN_DELAY);
 654         int ret;
 655
 656         if (netif_carrier_ok(net->dev))
 657                 return;
 658
 659         ret = tbnet_login_request(net, net->login_retries % 4);
 660         if (ret) {
 661                 if (net->login_retries++ < TBNET_LOGIN_RETRIES) {
 662                         queue_delayed_work(system_long_wq, &net->login_work,
 663                                            delay);
 664                 } else {
 665                         netdev_info(net->dev, "ThunderboltIP login timed out\n");
 666                 }
 667         } else {
 668                 net->login_retries = 0;
 669
 670                 mutex_lock(&net->connection_lock);
 671                 net->login_sent = true;
 672                 mutex_unlock(&net->connection_lock);
 673
 674                 queue_work(system_long_wq, &net->connected_work);
 675         }
 676 }
 677
 678 static void tbnet_disconnect_work(struct work_struct *work)
 679 {
 680         struct tbnet *net = container_of(work, typeof(*net), disconnect_work);
 681
 682         tbnet_tear_down(net, false);
 683 }
 684
 685 static bool tbnet_check_frame(struct tbnet *net, const struct tbnet_frame *tf,
 686                               const struct thunderbolt_ip_frame_header *hdr)
 687 {
 688         u32 frame_id, frame_count, frame_size, frame_index;
 689         unsigned int size;
 690
 691         if (tf->frame.flags & RING_DESC_CRC_ERROR) {
 692                 net->stats.rx_crc_errors++;
 693                 return false;
 694         } else if (tf->frame.flags & RING_DESC_BUFFER_OVERRUN) {
 695                 net->stats.rx_over_errors++;
 696                 return false;
 697         }
 698
 699         /* Should be greater than just header i.e. contains data */
 700         size = tbnet_frame_size(tf);
 701         if (size <= sizeof(*hdr)) {
 702                 net->stats.rx_length_errors++;
 703                 return false;
 704         }
 705
 706         frame_count = le32_to_cpu(hdr->frame_count);
 707         frame_size = le32_to_cpu(hdr->frame_size);
 708         frame_index = le16_to_cpu(hdr->frame_index);
 709         frame_id = le16_to_cpu(hdr->frame_id);
 710
 711         if ((frame_size > size - sizeof(*hdr)) || !frame_size) {
 712                 net->stats.rx_length_errors++;
 713                 return false;
 714         }
 715
 716         /* In case we're in the middle of packet, validate the frame
 717          * header based on first fragment of the packet.
 718          */
 719         if (net->skb && net->rx_hdr.frame_count) {
 720                 /* Check the frame count fits the count field */
 721                 if (frame_count != net->rx_hdr.frame_count) {
 722                         net->stats.rx_length_errors++;
 723                         return false;
 724                 }
 725
 726                 /* Check the frame identifiers are incremented correctly,
 727                  * and id is matching.
 728                  */
 729                 if (frame_index != net->rx_hdr.frame_index + 1 ||
 730                     frame_id != net->rx_hdr.frame_id) {
 731                         net->stats.rx_missed_errors++;
 732                         return false;
 733                 }
 734
 735                 if (net->skb->len + frame_size > TBNET_MAX_MTU) {
 736                         net->stats.rx_length_errors++;
 737                         return false;
 738                 }
 739
 740                 return true;
 741         }
 742
 743         /* Start of packet, validate the frame header */
 744         if (frame_count == 0 || frame_count > TBNET_RING_SIZE / 4) {
 745                 net->stats.rx_length_errors++;
 746                 return false;
 747         }
 748         if (frame_index != 0) {
 749                 net->stats.rx_missed_errors++;
 750                 return false;
 751         }
 752
 753         return true;
 754 }
 755
 756 static int tbnet_poll(struct napi_struct *napi, int budget)
 757 {
 758         struct tbnet *net = container_of(napi, struct tbnet, napi);
 759         unsigned int cleaned_count = tbnet_available_buffers(&net->rx_ring);
 760         struct device *dma_dev = tb_ring_dma_device(net->rx_ring.ring);
 761         unsigned int rx_packets = 0;
 762
 763         while (rx_packets < budget) {
 764                 const struct thunderbolt_ip_frame_header *hdr;
 765                 unsigned int hdr_size = sizeof(*hdr);
 766                 struct sk_buff *skb = NULL;
 767                 struct ring_frame *frame;
 768                 struct tbnet_frame *tf;
 769                 struct page *page;
 770                 bool last = true;
 771                 u32 frame_size;
 772
 773                 /* Return some buffers to hardware, one at a time is too
 774                  * slow so allocate MAX_SKB_FRAGS buffers at the same
 775                  * time.
 776                  */
 777                 if (cleaned_count >= MAX_SKB_FRAGS) {
 778                         tbnet_alloc_rx_buffers(net, cleaned_count);
 779                         cleaned_count = 0;
 780                 }
 781
 782                 frame = tb_ring_poll(net->rx_ring.ring);
 783                 if (!frame)
 784                         break;
 785
 786                 dma_unmap_page(dma_dev, frame->buffer_phy,
 787                                TBNET_RX_PAGE_SIZE, DMA_FROM_DEVICE);
 788
 789                 tf = container_of(frame, typeof(*tf), frame);
 790
 791                 page = tf->page;
 792                 tf->page = NULL;
 793                 net->rx_ring.cons++;
 794                 cleaned_count++;
 795
 796                 hdr = page_address(page);
 797                 if (!tbnet_check_frame(net, tf, hdr)) {
 798                         __free_pages(page, TBNET_RX_PAGE_ORDER);
 799                         dev_kfree_skb_any(net->skb);
 800                         net->skb = NULL;
 801                         continue;
 802                 }
 803
 804                 frame_size = le32_to_cpu(hdr->frame_size);
 805
 806                 skb = net->skb;
 807                 if (!skb) {
 808                         skb = build_skb(page_address(page),
 809                                         TBNET_RX_PAGE_SIZE);
 810                         if (!skb) {
 811                                 __free_pages(page, TBNET_RX_PAGE_ORDER);
 812                                 net->stats.rx_errors++;
 813                                 break;
 814                         }
 815
 816                         skb_reserve(skb, hdr_size);
 817                         skb_put(skb, frame_size);
 818
 819                         net->skb = skb;
 820                 } else {
 821                         skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
 822                                         page, hdr_size, frame_size,
 823                                         TBNET_RX_PAGE_SIZE - hdr_size);
 824                 }
 825
 826                 net->rx_hdr.frame_size = frame_size;
 827                 net->rx_hdr.frame_count = le32_to_cpu(hdr->frame_count);
 828                 net->rx_hdr.frame_index = le16_to_cpu(hdr->frame_index);
 829                 net->rx_hdr.frame_id = le16_to_cpu(hdr->frame_id);
 830                 last = net->rx_hdr.frame_index == net->rx_hdr.frame_count - 1;
 831
 832                 rx_packets++;
 833                 net->stats.rx_bytes += frame_size;
 834
 835                 if (last) {
 836                         skb->protocol = eth_type_trans(skb, net->dev);
 837                         napi_gro_receive(&net->napi, skb);
 838                         net->skb = NULL;
 839                 }
 840         }
 841
 842         net->stats.rx_packets += rx_packets;
 843
 844         if (cleaned_count)
 845                 tbnet_alloc_rx_buffers(net, cleaned_count);
 846
 847         if (rx_packets >= budget)
 848                 return budget;
 849
 850         napi_complete_done(napi, rx_packets);
 851         /* Re-enable the ring interrupt */
 852         tb_ring_poll_complete(net->rx_ring.ring);
 853
 854         return rx_packets;
 855 }
 856
 857 static void tbnet_start_poll(void *data)
 858 {
 859         struct tbnet *net = data;
 860
 861         napi_schedule(&net->napi);
 862 }
 863
 864 static int tbnet_open(struct net_device *dev)
 865 {
 866         struct tbnet *net = netdev_priv(dev);
 867         struct tb_xdomain *xd = net->xd;
 868         u16 sof_mask, eof_mask;
 869         struct tb_ring *ring;
 870         int hopid;
 871
 872         netif_carrier_off(dev);
 873
 874         ring = tb_ring_alloc_tx(xd->tb->nhi, -1, TBNET_RING_SIZE,
 875                                 RING_FLAG_FRAME);
 876         if (!ring) {
 877                 netdev_err(dev, "failed to allocate Tx ring\n");
 878                 return -ENOMEM;
 879         }
 880         net->tx_ring.ring = ring;
 881
 882         hopid = tb_xdomain_alloc_out_hopid(xd, -1);
 883         if (hopid < 0) {
 884                 netdev_err(dev, "failed to allocate Tx HopID\n");
 885                 tb_ring_free(net->tx_ring.ring);
 886                 net->tx_ring.ring = NULL;
 887                 return hopid;
 888         }
 889         net->local_transmit_path = hopid;
 890
 891         sof_mask = BIT(TBIP_PDF_FRAME_START);
 892         eof_mask = BIT(TBIP_PDF_FRAME_END);
 893
 894         ring = tb_ring_alloc_rx(xd->tb->nhi, -1, TBNET_RING_SIZE,
 895                                 RING_FLAG_FRAME, 0, sof_mask, eof_mask,
 896                                 tbnet_start_poll, net);
 897         if (!ring) {
 898                 netdev_err(dev, "failed to allocate Rx ring\n");
 899                 tb_ring_free(net->tx_ring.ring);
 900                 net->tx_ring.ring = NULL;
 901                 return -ENOMEM;
 902         }
 903         net->rx_ring.ring = ring;
 904
 905         napi_enable(&net->napi);
 906         start_login(net);
 907
 908         return 0;
 909 }
 910
 911 static int tbnet_stop(struct net_device *dev)
 912 {
 913         struct tbnet *net = netdev_priv(dev);
 914
 915         napi_disable(&net->napi);
 916
 917         cancel_work_sync(&net->disconnect_work);
 918         tbnet_tear_down(net, true);
 919
 920         tb_ring_free(net->rx_ring.ring);
 921         net->rx_ring.ring = NULL;
 922
 923         tb_xdomain_release_out_hopid(net->xd, net->local_transmit_path);
 924         tb_ring_free(net->tx_ring.ring);
 925         net->tx_ring.ring = NULL;
 926
 927         return 0;
 928 }
 929
 930 static bool tbnet_xmit_csum_and_map(struct tbnet *net, struct sk_buff *skb,
 931         struct tbnet_frame **frames, u32 frame_count)
 932 {
 933         struct thunderbolt_ip_frame_header *hdr = page_address(frames[0]->page);
 934         struct device *dma_dev = tb_ring_dma_device(net->tx_ring.ring);
 935         __wsum wsum = htonl(skb->len - skb_transport_offset(skb));
 936         unsigned int i, len, offset = skb_transport_offset(skb);
 937         __be16 protocol = skb->protocol;
 938         void *data = skb->data;
 939         void *dest = hdr + 1;
 940         __sum16 *tucso;
 941
 942         if (skb->ip_summed != CHECKSUM_PARTIAL) {
 943                 /* No need to calculate checksum so we just update the
 944                  * total frame count and sync the frames for DMA.
 945                  */
 946                 for (i = 0; i < frame_count; i++) {
 947                         hdr = page_address(frames[i]->page);
 948                         hdr->frame_count = cpu_to_le32(frame_count);
 949                         dma_sync_single_for_device(dma_dev,
 950                                 frames[i]->frame.buffer_phy,
 951                                 tbnet_frame_size(frames[i]), DMA_TO_DEVICE);
 952                 }
 953
 954                 return true;
 955         }
 956
 957         if (protocol == htons(ETH_P_8021Q)) {
 958                 struct vlan_hdr *vhdr, vh;
 959
 960                 vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(vh), &vh);
 961                 if (!vhdr)
 962                         return false;
 963
 964                 protocol = vhdr->h_vlan_encapsulated_proto;
 965         }
 966
 967         /* Data points on the beginning of packet.
 968          * Check is the checksum absolute place in the packet.
 969          * ipcso will update IP checksum.
 970          * tucso will update TCP/UPD checksum.
 971          */
 972         if (protocol == htons(ETH_P_IP)) {
 973                 __sum16 *ipcso = dest + ((void *)&(ip_hdr(skb)->check) - data);
 974
 975                 *ipcso = 0;
 976                 *ipcso = ip_fast_csum(dest + skb_network_offset(skb),
 977                                       ip_hdr(skb)->ihl);
 978
 979                 if (ip_hdr(skb)->protocol == IPPROTO_TCP)
 980                         tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
 981                 else if (ip_hdr(skb)->protocol == IPPROTO_UDP)
 982                         tucso = dest + ((void *)&(udp_hdr(skb)->check) - data);
 983                 else
 984                         return false;
 985
 986                 *tucso = ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
 987                                             ip_hdr(skb)->daddr, 0,
 988                                             ip_hdr(skb)->protocol, 0);
 989         } else if (skb_is_gso_v6(skb)) {
 990                 tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
 991                 *tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
 992                                           &ipv6_hdr(skb)->daddr, 0,
 993                                           IPPROTO_TCP, 0);
 994                 return false;
 995         } else if (protocol == htons(ETH_P_IPV6)) {
 996                 tucso = dest + skb_checksum_start_offset(skb) + skb->csum_offset;
 997                 *tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
 998                                           &ipv6_hdr(skb)->daddr, 0,
 999                                           ipv6_hdr(skb)->nexthdr, 0);
1000         } else {
1001                 return false;
1002         }
1003
1004         /* First frame was headers, rest of the frames contain data.
1005          * Calculate checksum over each frame.
1006          */
1007         for (i = 0; i < frame_count; i++) {
1008                 hdr = page_address(frames[i]->page);
1009                 dest = (void *)(hdr + 1) + offset;
1010                 len = le32_to_cpu(hdr->frame_size) - offset;
1011                 wsum = csum_partial(dest, len, wsum);
1012                 hdr->frame_count = cpu_to_le32(frame_count);
1013
1014                 offset = 0;
1015         }
1016
1017         *tucso = csum_fold(wsum);
1018
1019         /* Checksum is finally calculated and we don't touch the memory
1020          * anymore, so DMA sync the frames now.
1021          */
1022         for (i = 0; i < frame_count; i++) {
1023                 dma_sync_single_for_device(dma_dev, frames[i]->frame.buffer_phy,
1024                         tbnet_frame_size(frames[i]), DMA_TO_DEVICE);
1025         }
1026
1027         return true;
1028 }
1029
1030 static void *tbnet_kmap_frag(struct sk_buff *skb, unsigned int frag_num,
1031                              unsigned int *len)
1032 {
1033         const skb_frag_t *frag = &skb_shinfo(skb)->frags[frag_num];
1034
1035         *len = skb_frag_size(frag);
1036         return kmap_atomic(skb_frag_page(frag)) + skb_frag_off(frag);
1037 }
1038
1039 static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb,
1040                                     struct net_device *dev)
1041 {
1042         struct tbnet *net = netdev_priv(dev);
1043         struct tbnet_frame *frames[MAX_SKB_FRAGS];
1044         u16 frame_id = atomic_read(&net->frame_id);
1045         struct thunderbolt_ip_frame_header *hdr;
1046         unsigned int len = skb_headlen(skb);
1047         unsigned int data_len = skb->len;
1048         unsigned int nframes, i;
1049         unsigned int frag = 0;
1050         void *src = skb->data;
1051         u32 frame_index = 0;
1052         bool unmap = false;
1053         void *dest;
1054
1055         nframes = DIV_ROUND_UP(data_len, TBNET_MAX_PAYLOAD_SIZE);
1056         if (tbnet_available_buffers(&net->tx_ring) < nframes) {
1057                 netif_stop_queue(net->dev);
1058                 return NETDEV_TX_BUSY;
1059         }
1060
1061         frames[frame_index] = tbnet_get_tx_buffer(net);
1062         if (!frames[frame_index])
1063                 goto err_drop;
1064
1065         hdr = page_address(frames[frame_index]->page);
1066         dest = hdr + 1;
1067
1068         /* If overall packet is bigger than the frame data size */
1069         while (data_len > TBNET_MAX_PAYLOAD_SIZE) {
1070                 unsigned int size_left = TBNET_MAX_PAYLOAD_SIZE;
1071
1072                 hdr->frame_size = cpu_to_le32(TBNET_MAX_PAYLOAD_SIZE);
1073                 hdr->frame_index = cpu_to_le16(frame_index);
1074                 hdr->frame_id = cpu_to_le16(frame_id);
1075
1076                 do {
1077                         if (len > size_left) {
1078                                 /* Copy data onto Tx buffer data with
1079                                  * full frame size then break and go to
1080                                  * next frame
1081                                  */
1082                                 memcpy(dest, src, size_left);
1083                                 len -= size_left;
1084                                 dest += size_left;
1085                                 src += size_left;
1086                                 break;
1087                         }
1088
1089                         memcpy(dest, src, len);
1090                         size_left -= len;
1091                         dest += len;
1092
1093                         if (unmap) {
1094                                 kunmap_atomic(src);
1095                                 unmap = false;
1096                         }
1097
1098                         /* Ensure all fragments have been processed */
1099                         if (frag < skb_shinfo(skb)->nr_frags) {
1100                                 /* Map and then unmap quickly */
1101                                 src = tbnet_kmap_frag(skb, frag++, &len);
1102                                 unmap = true;
1103                         } else if (unlikely(size_left > 0)) {
1104                                 goto err_drop;
1105                         }
1106                 } while (size_left > 0);
1107
1108                 data_len -= TBNET_MAX_PAYLOAD_SIZE;
1109                 frame_index++;
1110
1111                 frames[frame_index] = tbnet_get_tx_buffer(net);
1112                 if (!frames[frame_index])
1113                         goto err_drop;
1114
1115                 hdr = page_address(frames[frame_index]->page);
1116                 dest = hdr + 1;
1117         }
1118
1119         hdr->frame_size = cpu_to_le32(data_len);
1120         hdr->frame_index = cpu_to_le16(frame_index);
1121         hdr->frame_id = cpu_to_le16(frame_id);
1122
1123         frames[frame_index]->frame.size = data_len + sizeof(*hdr);
1124
1125         /* In case the remaining data_len is smaller than a frame */
1126         while (len < data_len) {
1127                 memcpy(dest, src, len);
1128                 data_len -= len;
1129                 dest += len;
1130
1131                 if (unmap) {
1132                         kunmap_atomic(src);
1133                         unmap = false;
1134                 }
1135
1136                 if (frag < skb_shinfo(skb)->nr_frags) {
1137                         src = tbnet_kmap_frag(skb, frag++, &len);
1138                         unmap = true;
1139                 } else if (unlikely(data_len > 0)) {
1140                         goto err_drop;
1141                 }
1142         }
1143
1144         memcpy(dest, src, data_len);
1145
1146         if (unmap)
1147                 kunmap_atomic(src);
1148
1149         if (!tbnet_xmit_csum_and_map(net, skb, frames, frame_index + 1))
1150                 goto err_drop;
1151
1152         for (i = 0; i < frame_index + 1; i++)
1153                 tb_ring_tx(net->tx_ring.ring, &frames[i]->frame);
1154
1155         if (net->svc->prtcstns & TBNET_MATCH_FRAGS_ID)
1156                 atomic_inc(&net->frame_id);
1157
1158         net->stats.tx_packets++;
1159         net->stats.tx_bytes += skb->len;
1160
1161         dev_consume_skb_any(skb);
1162
1163         return NETDEV_TX_OK;
1164
1165 err_drop:
1166         /* We can re-use the buffers */
1167         net->tx_ring.cons -= frame_index;
1168
1169         dev_kfree_skb_any(skb);
1170         net->stats.tx_errors++;
1171
1172         return NETDEV_TX_OK;
1173 }
1174
1175 static void tbnet_get_stats64(struct net_device *dev,
1176                               struct rtnl_link_stats64 *stats)
1177 {
1178         struct tbnet *net = netdev_priv(dev);
1179
1180         stats->tx_packets = net->stats.tx_packets;
1181         stats->rx_packets = net->stats.rx_packets;
1182         stats->tx_bytes = net->stats.tx_bytes;
1183         stats->rx_bytes = net->stats.rx_bytes;
1184         stats->rx_errors = net->stats.rx_errors + net->stats.rx_length_errors +
1185                 net->stats.rx_over_errors + net->stats.rx_crc_errors +
1186                 net->stats.rx_missed_errors;
1187         stats->tx_errors = net->stats.tx_errors;
1188         stats->rx_length_errors = net->stats.rx_length_errors;
1189         stats->rx_over_errors = net->stats.rx_over_errors;
1190         stats->rx_crc_errors = net->stats.rx_crc_errors;
1191         stats->rx_missed_errors = net->stats.rx_missed_errors;
1192 }
1193
1194 static const struct net_device_ops tbnet_netdev_ops = {
1195         .ndo_open = tbnet_open,
1196         .ndo_stop = tbnet_stop,
1197         .ndo_start_xmit = tbnet_start_xmit,
1198         .ndo_get_stats64 = tbnet_get_stats64,
1199 };
1200
1201 static void tbnet_generate_mac(struct net_device *dev)
1202 {
1203         const struct tbnet *net = netdev_priv(dev);
1204         const struct tb_xdomain *xd = net->xd;
1205         u8 phy_port;
1206         u32 hash;
1207
1208         phy_port = tb_phy_port_from_link(TBNET_L0_PORT_NUM(xd->route));
1209
1210         /* Unicast and locally administered MAC */
1211         dev->dev_addr[0] = phy_port << 4 | 0x02;
1212         hash = jhash2((u32 *)xd->local_uuid, 4, 0);
1213         memcpy(dev->dev_addr + 1, &hash, sizeof(hash));
1214         hash = jhash2((u32 *)xd->local_uuid, 4, hash);
1215         dev->dev_addr[5] = hash & 0xff;
1216 }
1217
1218 static int tbnet_probe(struct tb_service *svc, const struct tb_service_id *id)
1219 {
1220         struct tb_xdomain *xd = tb_service_parent(svc);
1221         struct net_device *dev;
1222         struct tbnet *net;
1223         int ret;
1224
1225         dev = alloc_etherdev(sizeof(*net));
1226         if (!dev)
1227                 return -ENOMEM;
1228
1229         SET_NETDEV_DEV(dev, &svc->dev);
1230
1231         net = netdev_priv(dev);
1232         INIT_DELAYED_WORK(&net->login_work, tbnet_login_work);
1233         INIT_WORK(&net->connected_work, tbnet_connected_work);
1234         INIT_WORK(&net->disconnect_work, tbnet_disconnect_work);
1235         mutex_init(&net->connection_lock);
1236         atomic_set(&net->command_id, 0);
1237         atomic_set(&net->frame_id, 0);
1238         net->svc = svc;
1239         net->dev = dev;
1240         net->xd = xd;
1241
1242         tbnet_generate_mac(dev);
1243
1244         strcpy(dev->name, "thunderbolt%d");
1245         dev->netdev_ops = &tbnet_netdev_ops;
1246
1247         /* ThunderboltIP takes advantage of TSO packets but instead of
1248          * segmenting them we just split the packet into Thunderbolt
1249          * frames (maximum payload size of each frame is 4084 bytes) and
1250          * calculate checksum over the whole packet here.
1251          *
1252          * The receiving side does the opposite if the host OS supports
1253          * LRO, otherwise it needs to split the large packet into MTU
1254          * sized smaller packets.
1255          *
1256          * In order to receive large packets from the networking stack,
1257          * we need to announce support for most of the offloading
1258          * features here.
1259          */
1260         dev->hw_features = NETIF_F_SG | NETIF_F_ALL_TSO | NETIF_F_GRO |
1261                            NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
1262         dev->features = dev->hw_features | NETIF_F_HIGHDMA;
1263         dev->hard_header_len += sizeof(struct thunderbolt_ip_frame_header);
1264
1265         netif_napi_add(dev, &net->napi, tbnet_poll, NAPI_POLL_WEIGHT);
1266
1267         /* MTU range: 68 - 65522 */
1268         dev->min_mtu = ETH_MIN_MTU;
1269         dev->max_mtu = TBNET_MAX_MTU - ETH_HLEN;
1270
1271         net->handler.uuid = &tbnet_svc_uuid;
1272         net->handler.callback = tbnet_handle_packet;
1273         net->handler.data = net;
1274         tb_register_protocol_handler(&net->handler);
1275
1276         tb_service_set_drvdata(svc, net);
1277
1278         ret = register_netdev(dev);
1279         if (ret) {
1280                 tb_unregister_protocol_handler(&net->handler);
1281                 free_netdev(dev);
1282                 return ret;
1283         }
1284
1285         return 0;
1286 }
1287
1288 static void tbnet_remove(struct tb_service *svc)
1289 {
1290         struct tbnet *net = tb_service_get_drvdata(svc);
1291
1292         unregister_netdev(net->dev);
1293         tb_unregister_protocol_handler(&net->handler);
1294         free_netdev(net->dev);
1295 }
1296
1297 static void tbnet_shutdown(struct tb_service *svc)
1298 {
1299         tbnet_tear_down(tb_service_get_drvdata(svc), true);
1300 }
1301
1302 static int __maybe_unused tbnet_suspend(struct device *dev)
1303 {
1304         struct tb_service *svc = tb_to_service(dev);
1305         struct tbnet *net = tb_service_get_drvdata(svc);
1306
1307         stop_login(net);
1308         if (netif_running(net->dev)) {
1309                 netif_device_detach(net->dev);
1310                 tbnet_tear_down(net, true);
1311         }
1312
1313         tb_unregister_protocol_handler(&net->handler);
1314         return 0;
1315 }
1316
1317 static int __maybe_unused tbnet_resume(struct device *dev)
1318 {
1319         struct tb_service *svc = tb_to_service(dev);
1320         struct tbnet *net = tb_service_get_drvdata(svc);
1321
1322         tb_register_protocol_handler(&net->handler);
1323
1324         netif_carrier_off(net->dev);
1325         if (netif_running(net->dev)) {
1326                 netif_device_attach(net->dev);
1327                 start_login(net);
1328         }
1329
1330         return 0;
1331 }
1332
1333 static const struct dev_pm_ops tbnet_pm_ops = {
1334         SET_SYSTEM_SLEEP_PM_OPS(tbnet_suspend, tbnet_resume)
1335 };
1336
1337 static const struct tb_service_id tbnet_ids[] = {
1338         { TB_SERVICE("network", 1) },
1339         { },
1340 };
1341 MODULE_DEVICE_TABLE(tbsvc, tbnet_ids);
1342
1343 static struct tb_service_driver tbnet_driver = {
1344         .driver = {
1345                 .owner = THIS_MODULE,
1346                 .name = "thunderbolt-net",
1347                 .pm = &tbnet_pm_ops,
1348         },
1349         .probe = tbnet_probe,
1350         .remove = tbnet_remove,
1351         .shutdown = tbnet_shutdown,
1352         .id_table = tbnet_ids,
1353 };
1354
1355 static int __init tbnet_init(void)
1356 {
1357         int ret;
1358
1359         tbnet_dir = tb_property_create_dir(&tbnet_dir_uuid);
1360         if (!tbnet_dir)
1361                 return -ENOMEM;
1362
1363         tb_property_add_immediate(tbnet_dir, "prtcid", 1);
1364         tb_property_add_immediate(tbnet_dir, "prtcvers", 1);
1365         tb_property_add_immediate(tbnet_dir, "prtcrevs", 1);
1366         /* Currently only announce support for match frags ID (bit 1). Bit 0
1367          * is reserved for full E2E flow control which we do not support at
1368          * the moment.
1369          */
1370         tb_property_add_immediate(tbnet_dir, "prtcstns",
1371                                   TBNET_MATCH_FRAGS_ID | TBNET_64K_FRAMES);
1372
1373         ret = tb_register_property_dir("network", tbnet_dir);
1374         if (ret) {
1375                 tb_property_free_dir(tbnet_dir);
1376                 return ret;
1377         }
1378
1379         return tb_register_service_driver(&tbnet_driver);
1380 }
1381 module_init(tbnet_init);
1382
1383 static void __exit tbnet_exit(void)
1384 {
1385         tb_unregister_service_driver(&tbnet_driver);
1386         tb_unregister_property_dir("network", tbnet_dir);
1387         tb_property_free_dir(tbnet_dir);
1388 }
1389 module_exit(tbnet_exit);
1390
1391 MODULE_AUTHOR("Amir Levy <amir.jer.levy@intel.com>");
1392 MODULE_AUTHOR("Michael Jamet <michael.jamet@intel.com>");
1393 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
1394 MODULE_DESCRIPTION("Thunderbolt network driver");
1395 MODULE_LICENSE("GPL v2");