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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Networking over Thunderbolt cable using Apple ThunderboltIP protocol
  *
  * Copyright (C) 2017, Intel Corporation
  * Authors: Amir Levy <amir.jer.levy@intel.com>
  *          Michael Jamet <michael.jamet@intel.com>
  *          Mika Westerberg <mika.westerberg@linux.intel.com>
  */
 
 #include <linux/atomic.h>
 #include <linux/highmem.h>
 #include <linux/if_vlan.h>
 #include <linux/jhash.h>
 #include <linux/module.h>
 #include <linux/etherdevice.h>
 #include <linux/rtnetlink.h>
 #include <linux/sizes.h>
 #include <linux/thunderbolt.h>
 #include <linux/uuid.h>
 #include <linux/workqueue.h>
 
 #include <net/ip6_checksum.h>
 
 /* Protocol timeouts in ms */
 #define TBNET_LOGIN_DELAY   4500
 #define TBNET_LOGIN_TIMEOUT 500
 #define TBNET_LOGOUT_TIMEOUT    1000
 
 #define TBNET_RING_SIZE     256
 #define TBNET_LOGIN_RETRIES 60
 #define TBNET_LOGOUT_RETRIES    10
 #define TBNET_MATCH_FRAGS_ID    BIT(1)
 #define TBNET_64K_FRAMES    BIT(2)
 #define TBNET_MAX_MTU       SZ_64K
 #define TBNET_FRAME_SIZE    SZ_4K
 #define TBNET_MAX_PAYLOAD_SIZE  \
     (TBNET_FRAME_SIZE - sizeof(struct thunderbolt_ip_frame_header))
 /* Rx packets need to hold space for skb_shared_info */
 #define TBNET_RX_MAX_SIZE   \
     (TBNET_FRAME_SIZE + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)))
 #define TBNET_RX_PAGE_ORDER get_order(TBNET_RX_MAX_SIZE)
 #define TBNET_RX_PAGE_SIZE  (PAGE_SIZE << TBNET_RX_PAGE_ORDER)
 
 #define TBNET_L0_PORT_NUM(route) ((route) & GENMASK(5, 0))
 
 /**
  * struct thunderbolt_ip_frame_header - Header for each Thunderbolt frame
  * @frame_size: size of the data with the frame
  * @frame_index: running index on the frames
  * @frame_id: ID of the frame to match frames to specific packet
  * @frame_count: how many frames assembles a full packet
  *
  * Each data frame passed to the high-speed DMA ring has this header. If
  * the XDomain network directory announces that %TBNET_MATCH_FRAGS_ID is
  * supported then @frame_id is filled, otherwise it stays %0.
  */
 struct thunderbolt_ip_frame_header {
     u32 frame_size;
     u16 frame_index;
     u16 frame_id;
     u32 frame_count;
 };
 
 enum thunderbolt_ip_frame_pdf {
     TBIP_PDF_FRAME_START = 1,
     TBIP_PDF_FRAME_END,
 };
 
 enum thunderbolt_ip_type {
     TBIP_LOGIN,
     TBIP_LOGIN_RESPONSE,
     TBIP_LOGOUT,
     TBIP_STATUS,
 };
 
 struct thunderbolt_ip_header {
     u32 route_hi;
     u32 route_lo;
     u32 length_sn;
     uuid_t uuid;
     uuid_t initiator_uuid;
     uuid_t target_uuid;
     u32 type;
     u32 command_id;
 };
 
 #define TBIP_HDR_LENGTH_MASK        GENMASK(5, 0)
 #define TBIP_HDR_SN_MASK        GENMASK(28, 27)
 #define TBIP_HDR_SN_SHIFT       27
 
 struct thunderbolt_ip_login {
     struct thunderbolt_ip_header hdr;
     u32 proto_version;
     u32 transmit_path;
     u32 reserved[4];
 };
 
 #define TBIP_LOGIN_PROTO_VERSION    1
 
 struct thunderbolt_ip_login_response {
     struct thunderbolt_ip_header hdr;
     u32 status;
     u32 receiver_mac[2];
     u32 receiver_mac_len;
     u32 reserved[4];
 };
 
 struct thunderbolt_ip_logout {
     struct thunderbolt_ip_header hdr;
 };
 
 struct thunderbolt_ip_status {
     struct thunderbolt_ip_header hdr;
     u32 status;
 };
 
 struct tbnet_stats {
     u64 tx_packets;
     u64 rx_packets;
     u64 tx_bytes;
     u64 rx_bytes;
     u64 rx_errors;
     u64 tx_errors;
     u64 rx_length_errors;
     u64 rx_over_errors;
     u64 rx_crc_errors;
     u64 rx_missed_errors;
 };
 
 struct tbnet_frame {
     struct net_device *dev;
     struct page *page;
     struct ring_frame frame;
 };
 
 struct tbnet_ring {
     struct tbnet_frame frames[TBNET_RING_SIZE];
     unsigned int cons;
     unsigned int prod;
     struct tb_ring *ring;
 };
 
 /**
  * struct tbnet - ThunderboltIP network driver private data
  * @svc: XDomain service the driver is bound to
  * @xd: XDomain the service blongs to
  * @handler: ThunderboltIP configuration protocol handler
  * @dev: Networking device
  * @napi: NAPI structure for Rx polling
  * @stats: Network statistics
  * @skb: Network packet that is currently processed on Rx path
  * @command_id: ID used for next configuration protocol packet
  * @login_sent: ThunderboltIP login message successfully sent
  * @login_received: ThunderboltIP login message received from the remote
  *          host
  * @local_transmit_path: HopID we are using to send out packets
  * @remote_transmit_path: HopID the other end is using to send packets to us
  * @connection_lock: Lock serializing access to @login_sent,
  *           @login_received and @transmit_path.
  * @login_retries: Number of login retries currently done
  * @login_work: Worker to send ThunderboltIP login packets
  * @connected_work: Worker that finalizes the ThunderboltIP connection
  *          setup and enables DMA paths for high speed data
  *          transfers
  * @disconnect_work: Worker that handles tearing down the ThunderboltIP
  *           connection
  * @rx_hdr: Copy of the currently processed Rx frame. Used when a
  *      network packet consists of multiple Thunderbolt frames.
  *      In host byte order.
  * @rx_ring: Software ring holding Rx frames
  * @frame_id: Frame ID use for next Tx packet
  *            (if %TBNET_MATCH_FRAGS_ID is supported in both ends)
  * @tx_ring: Software ring holding Tx frames
  */
 struct tbnet {
     const struct tb_service *svc;
     struct tb_xdomain *xd;
     struct tb_protocol_handler handler;
     struct net_device *dev;
     struct napi_struct napi;
     struct tbnet_stats stats;
     struct sk_buff *skb;
     atomic_t command_id;
     bool login_sent;
     bool login_received;
     int local_transmit_path;
     int remote_transmit_path;
     struct mutex connection_lock;
     int login_retries;
     struct delayed_work login_work;
     struct work_struct connected_work;
     struct work_struct disconnect_work;
     struct thunderbolt_ip_frame_header rx_hdr;
     struct tbnet_ring rx_ring;
     atomic_t frame_id;
     struct tbnet_ring tx_ring;
 };
 
 /* Network property directory UUID: c66189ca-1cce-4195-bdb8-49592e5f5a4f */
 static const uuid_t tbnet_dir_uuid =
     UUID_INIT(0xc66189ca, 0x1cce, 0x4195,
           0xbd, 0xb8, 0x49, 0x59, 0x2e, 0x5f, 0x5a, 0x4f);
 
 /* ThunderboltIP protocol UUID: 798f589e-3616-8a47-97c6-5664a920c8dd */
 static const uuid_t tbnet_svc_uuid =
     UUID_INIT(0x798f589e, 0x3616, 0x8a47,
           0x97, 0xc6, 0x56, 0x64, 0xa9, 0x20, 0xc8, 0xdd);
 
 static struct tb_property_dir *tbnet_dir;
 
 static void tbnet_fill_header(struct thunderbolt_ip_header *hdr, u64 route,
     u8 sequence, const uuid_t *initiator_uuid, const uuid_t *target_uuid,
     enum thunderbolt_ip_type type, size_t size, u32 command_id)
 {
     u32 length_sn;
 
     /* Length does not include route_hi/lo and length_sn fields */
     length_sn = (size - 3 * 4) / 4;
     length_sn |= (sequence << TBIP_HDR_SN_SHIFT) & TBIP_HDR_SN_MASK;
 
     hdr->route_hi = upper_32_bits(route);
     hdr->route_lo = lower_32_bits(route);
     hdr->length_sn = length_sn;
     uuid_copy(&hdr->uuid, &tbnet_svc_uuid);
     uuid_copy(&hdr->initiator_uuid, initiator_uuid);
     uuid_copy(&hdr->target_uuid, target_uuid);
     hdr->type = type;
     hdr->command_id = command_id;
 }
 
 static int tbnet_login_response(struct tbnet *net, u64 route, u8 sequence,
                 u32 command_id)
 {
     struct thunderbolt_ip_login_response reply;
     struct tb_xdomain *xd = net->xd;
 
     memset(&reply, 0, sizeof(reply));
     tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
               xd->remote_uuid, TBIP_LOGIN_RESPONSE, sizeof(reply),
               command_id);
     memcpy(reply.receiver_mac, net->dev->dev_addr, ETH_ALEN);
     reply.receiver_mac_len = ETH_ALEN;
 
     return tb_xdomain_response(xd, &reply, sizeof(reply),
                    TB_CFG_PKG_XDOMAIN_RESP);
 }
 
 static int tbnet_login_request(struct tbnet *net, u8 sequence)
 {
     struct thunderbolt_ip_login_response reply;
     struct thunderbolt_ip_login request;
     struct tb_xdomain *xd = net->xd;
 
     memset(&request, 0, sizeof(request));
     tbnet_fill_header(&request.hdr, xd->route, sequence, xd->local_uuid,
               xd->remote_uuid, TBIP_LOGIN, sizeof(request),
               atomic_inc_return(&net->command_id));
 
     request.proto_version = TBIP_LOGIN_PROTO_VERSION;
     request.transmit_path = net->local_transmit_path;
 
     return tb_xdomain_request(xd, &request, sizeof(request),
                   TB_CFG_PKG_XDOMAIN_RESP, &reply,
                   sizeof(reply), TB_CFG_PKG_XDOMAIN_RESP,
                   TBNET_LOGIN_TIMEOUT);
 }
 
 static int tbnet_logout_response(struct tbnet *net, u64 route, u8 sequence,
                  u32 command_id)
 {
     struct thunderbolt_ip_status reply;
     struct tb_xdomain *xd = net->xd;
 
     memset(&reply, 0, sizeof(reply));
     tbnet_fill_header(&reply.hdr, route, sequence, xd->local_uuid,
               xd->remote_uuid, TBIP_STATUS, sizeof(reply),
               atomic_inc_return(&net->command_id));
     return tb_xdomain_response(xd, &reply, sizeof(reply),
                    TB_CFG_PKG_XDOMAIN_RESP);
 }
 
 static int tbnet_logout_request(struct tbnet *net)
 {
     struct thunderbolt_ip_logout request;
     struct thunderbolt_ip_status reply;
     struct tb_xdomain *xd = net->xd;
 
     memset(&request, 0, sizeof(request));
     tbnet_fill_header(&request.hdr, xd->route, 0, xd->local_uuid,
               xd->remote_uuid, TBIP_LOGOUT, sizeof(request),
               atomic_inc_return(&net->command_id));
 
     return tb_xdomain_request(xd, &request, sizeof(request),
                   TB_CFG_PKG_XDOMAIN_RESP, &reply,
                   sizeof(reply), TB_CFG_PKG_XDOMAIN_RESP,
                   TBNET_LOGOUT_TIMEOUT);
 }
 
 static void start_login(struct tbnet *net)
 {
     mutex_lock(&net->connection_lock);
     net->login_sent = false;
     net->login_received = false;
     mutex_unlock(&net->connection_lock);
 
     queue_delayed_work(system_long_wq, &net->login_work,
                msecs_to_jiffies(1000));
 }
 
 static void stop_login(struct tbnet *net)
 {
     cancel_delayed_work_sync(&net->login_work);
     cancel_work_sync(&net->connected_work);
 }
 
 static inline unsigned int tbnet_frame_size(const struct tbnet_frame *tf)
 {
     return tf->frame.size ? : TBNET_FRAME_SIZE;
 }
 
 static void tbnet_free_buffers(struct tbnet_ring *ring)
 {
     unsigned int i;
 
     for (i = 0; i < TBNET_RING_SIZE; i++) {
         struct device *dma_dev = tb_ring_dma_device(ring->ring);
         struct tbnet_frame *tf = &ring->frames[i];
         enum dma_data_direction dir;
         unsigned int order;
         size_t size;
 
         if (!tf->page)
             continue;
 
         if (ring->ring->is_tx) {
             dir = DMA_TO_DEVICE;
             order = 0;
             size = TBNET_FRAME_SIZE;
         } else {
             dir = DMA_FROM_DEVICE;
             order = TBNET_RX_PAGE_ORDER;
             size = TBNET_RX_PAGE_SIZE;
         }
 
         if (tf->frame.buffer_phy)
             dma_unmap_page(dma_dev, tf->frame.buffer_phy, size,
                        dir);
 
         __free_pages(tf->page, order);
         tf->page = NULL;
     }
 
     ring->cons = 0;
     ring->prod = 0;
 }
 
 static void tbnet_tear_down(struct tbnet *net, bool send_logout)
 {
     netif_carrier_off(net->dev);
     netif_stop_queue(net->dev);
 
     stop_login(net);
 
     mutex_lock(&net->connection_lock);
 
     if (net->login_sent && net->login_received) {
         int ret, retries = TBNET_LOGOUT_RETRIES;
 
         while (send_logout && retries-- > 0) {
             ret = tbnet_logout_request(net);
             if (ret != -ETIMEDOUT)
                 break;
         }
 
         tb_ring_stop(net->rx_ring.ring);
         tb_ring_stop(net->tx_ring.ring);
         tbnet_free_buffers(&net->rx_ring);
         tbnet_free_buffers(&net->tx_ring);
 
         ret = tb_xdomain_disable_paths(net->xd,
                            net->local_transmit_path,
                            net->rx_ring.ring->hop,
                            net->remote_transmit_path,
                            net->tx_ring.ring->hop);
         if (ret)
             netdev_warn(net->dev, "failed to disable DMA paths\n");
 
         tb_xdomain_release_in_hopid(net->xd, net->remote_transmit_path);
         net->remote_transmit_path = 0;
     }
 
     net->login_retries = 0;
     net->login_sent = false;
     net->login_received = false;
 
     mutex_unlock(&net->connection_lock);
 }
 
 static int tbnet_handle_packet(const void *buf, size_t size, void *data)
 {
     const struct thunderbolt_ip_login *pkg = buf;
     struct tbnet *net = data;
     u32 command_id;
     int ret = 0;
     u32 sequence;
     u64 route;
 
     /* Make sure the packet is for us */
     if (size < sizeof(struct thunderbolt_ip_header))
         return 0;
     if (!uuid_equal(&pkg->hdr.initiator_uuid, net->xd->remote_uuid))
         return 0;
     if (!uuid_equal(&pkg->hdr.target_uuid, net->xd->local_uuid))
         return 0;
 
     route = ((u64)pkg->hdr.route_hi << 32) | pkg->hdr.route_lo;
     route &= ~BIT_ULL(63);
     if (route != net->xd->route)
         return 0;
 
     sequence = pkg->hdr.length_sn & TBIP_HDR_SN_MASK;
     sequence >>= TBIP_HDR_SN_SHIFT;
     command_id = pkg->hdr.command_id;
 
     switch (pkg->hdr.type) {
     case TBIP_LOGIN:
         if (!netif_running(net->dev))
             break;
 
         ret = tbnet_login_response(net, route, sequence,
                        pkg->hdr.command_id);
         if (!ret) {
             mutex_lock(&net->connection_lock);
             net->login_received = true;
             net->remote_transmit_path = pkg->transmit_path;
 
             /* If we reached the number of max retries or
              * previous logout, schedule another round of
              * login retries
              */
             if (net->login_retries >= TBNET_LOGIN_RETRIES ||
                 !net->login_sent) {
                 net->login_retries = 0;
                 queue_delayed_work(system_long_wq,
                            &net->login_work, 0);
             }
             mutex_unlock(&net->connection_lock);
 
             queue_work(system_long_wq, &net->connected_work);
         }
         break;
 
     case TBIP_LOGOUT:
         ret = tbnet_logout_response(net, route, sequence, command_id);
         if (!ret)
             queue_work(system_long_wq, &net->disconnect_work);
         break;
 
     default:
         return 0;
     }
 
     if (ret)
         netdev_warn(net->dev, "failed to send ThunderboltIP response\n");
 
     return 1;
 }
 
 static unsigned int tbnet_available_buffers(const struct tbnet_ring *ring)
 {
     return ring->prod - ring->cons;
 }
 
 static int tbnet_alloc_rx_buffers(struct tbnet *net, unsigned int nbuffers)
 {
     struct tbnet_ring *ring = &net->rx_ring;
     int ret;
 
     while (nbuffers--) {
         struct device *dma_dev = tb_ring_dma_device(ring->ring);
         unsigned int index = ring->prod & (TBNET_RING_SIZE - 1);
         struct tbnet_frame *tf = &ring->frames[index];
         dma_addr_t dma_addr;
 
         if (tf->page)
             break;
 
         /* Allocate page (order > 0) so that it can hold maximum
          * ThunderboltIP frame (4kB) and the additional room for
          * SKB shared info required by build_skb().
          */
         tf->page = dev_alloc_pages(TBNET_RX_PAGE_ORDER);
         if (!tf->page) {
             ret = -ENOMEM;
             goto err_free;
         }
 
         dma_addr = dma_map_page(dma_dev, tf->page, 0,
                     TBNET_RX_PAGE_SIZE, DMA_FROM_DEVICE);
         if (dma_mapping_error(dma_dev, dma_addr)) {
             ret = -ENOMEM;
             goto err_free;
         }
 
         tf->frame.buffer_phy = dma_addr;
         tf->dev = net->dev;
 
         tb_ring_rx(ring->ring, &tf->frame);
 
         ring->prod++;
     }
 
     return 0;
 
 err_free:
     tbnet_free_buffers(ring);
     return ret;
 }
 
 static struct tbnet_frame *tbnet_get_tx_buffer(struct tbnet *net)
 {
     struct tbnet_ring *ring = &net->tx_ring;
     struct device *dma_dev = tb_ring_dma_device(ring->ring);
     struct tbnet_frame *tf;
     unsigned int index;
 
     if (!tbnet_available_buffers(ring))
         return NULL;
 
     index = ring->cons++ & (TBNET_RING_SIZE - 1);
 
     tf = &ring->frames[index];
     tf->frame.size = 0;
 
     dma_sync_single_for_cpu(dma_dev, tf->frame.buffer_phy,
                 tbnet_frame_size(tf), DMA_TO_DEVICE);
 
     return tf;
 }
 
 static void tbnet_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
                   bool canceled)
 {
     struct tbnet_frame *tf = container_of(frame, typeof(*tf), frame);
     struct tbnet *net = netdev_priv(tf->dev);
 
     /* Return buffer to the ring */
     net->tx_ring.prod++;
 
     if (tbnet_available_buffers(&net->tx_ring) >= TBNET_RING_SIZE / 2)
         netif_wake_queue(net->dev);
 }
 
 static int tbnet_alloc_tx_buffers(struct tbnet *net)
 {
     struct tbnet_ring *ring = &net->tx_ring;
     struct device *dma_dev = tb_ring_dma_device(ring->ring);
     unsigned int i;
 
     for (i = 0; i < TBNET_RING_SIZE; i++) {
         struct tbnet_frame *tf = &ring->frames[i];
         dma_addr_t dma_addr;
 
         tf->page = alloc_page(GFP_KERNEL);
         if (!tf->page) {
             tbnet_free_buffers(ring);
             return -ENOMEM;
         }
 
         dma_addr = dma_map_page(dma_dev, tf->page, 0, TBNET_FRAME_SIZE,
                     DMA_TO_DEVICE);
         if (dma_mapping_error(dma_dev, dma_addr)) {
             __free_page(tf->page);
             tf->page = NULL;
             tbnet_free_buffers(ring);
             return -ENOMEM;
         }
 
         tf->dev = net->dev;
         tf->frame.buffer_phy = dma_addr;
         tf->frame.callback = tbnet_tx_callback;
         tf->frame.sof = TBIP_PDF_FRAME_START;
         tf->frame.eof = TBIP_PDF_FRAME_END;
     }
 
     ring->cons = 0;
     ring->prod = TBNET_RING_SIZE - 1;
 
     return 0;
 }
 
 static void tbnet_connected_work(struct work_struct *work)
 {
     struct tbnet *net = container_of(work, typeof(*net), connected_work);
     bool connected;
     int ret;
 
     if (netif_carrier_ok(net->dev))
         return;
 
     mutex_lock(&net->connection_lock);
     connected = net->login_sent && net->login_received;
     mutex_unlock(&net->connection_lock);
 
     if (!connected)
         return;
 
     ret = tb_xdomain_alloc_in_hopid(net->xd, net->remote_transmit_path);
     if (ret != net->remote_transmit_path) {
         netdev_err(net->dev, "failed to allocate Rx HopID\n");
         return;
     }
 
     /* Both logins successful so enable the high-speed DMA paths and
      * start the network device queue.
      */
     ret = tb_xdomain_enable_paths(net->xd, net->local_transmit_path,
                       net->rx_ring.ring->hop,
                       net->remote_transmit_path,
                       net->tx_ring.ring->hop);
     if (ret) {
         netdev_err(net->dev, "failed to enable DMA paths\n");
         return;
     }
 
     tb_ring_start(net->tx_ring.ring);
     tb_ring_start(net->rx_ring.ring);
 
     ret = tbnet_alloc_rx_buffers(net, TBNET_RING_SIZE);
     if (ret)
         goto err_stop_rings;
 
     ret = tbnet_alloc_tx_buffers(net);
     if (ret)
         goto err_free_rx_buffers;
 
     netif_carrier_on(net->dev);
     netif_start_queue(net->dev);
     return;
 
 err_free_rx_buffers:
     tbnet_free_buffers(&net->rx_ring);
 err_stop_rings:
     tb_ring_stop(net->rx_ring.ring);
     tb_ring_stop(net->tx_ring.ring);
     tb_xdomain_release_in_hopid(net->xd, net->remote_transmit_path);
 }
 
 static void tbnet_login_work(struct work_struct *work)
 {
     struct tbnet *net = container_of(work, typeof(*net), login_work.work);
     unsigned long delay = msecs_to_jiffies(TBNET_LOGIN_DELAY);
     int ret;
 
     if (netif_carrier_ok(net->dev))
         return;
 
     ret = tbnet_login_request(net, net->login_retries % 4);
     if (ret) {
         if (net->login_retries++ < TBNET_LOGIN_RETRIES) {
             queue_delayed_work(system_long_wq, &net->login_work,
                        delay);
         } else {
             netdev_info(net->dev, "ThunderboltIP login timed out\n");
         }
     } else {
         net->login_retries = 0;
 
         mutex_lock(&net->connection_lock);
         net->login_sent = true;
         mutex_unlock(&net->connection_lock);
 
         queue_work(system_long_wq, &net->connected_work);
     }
 }
 
 static void tbnet_disconnect_work(struct work_struct *work)
 {
     struct tbnet *net = container_of(work, typeof(*net), disconnect_work);
 
     tbnet_tear_down(net, false);
 }
 
 static bool tbnet_check_frame(struct tbnet *net, const struct tbnet_frame *tf,
                   const struct thunderbolt_ip_frame_header *hdr)
 {
     u32 frame_id, frame_count, frame_size, frame_index;
     unsigned int size;
 
     if (tf->frame.flags & RING_DESC_CRC_ERROR) {
         net->stats.rx_crc_errors++;
         return false;
     } else if (tf->frame.flags & RING_DESC_BUFFER_OVERRUN) {
         net->stats.rx_over_errors++;
         return false;
     }
 
     /* Should be greater than just header i.e. contains data */
     size = tbnet_frame_size(tf);
     if (size <= sizeof(*hdr)) {
         net->stats.rx_length_errors++;
         return false;
     }
 
     frame_count = le32_to_cpu(hdr->frame_count);
     frame_size = le32_to_cpu(hdr->frame_size);
     frame_index = le16_to_cpu(hdr->frame_index);
     frame_id = le16_to_cpu(hdr->frame_id);
 
     if ((frame_size > size - sizeof(*hdr)) || !frame_size) {
         net->stats.rx_length_errors++;
         return false;
     }
 
     /* In case we're in the middle of packet, validate the frame
      * header based on first fragment of the packet.
      */
     if (net->skb && net->rx_hdr.frame_count) {
         /* Check the frame count fits the count field */
         if (frame_count != net->rx_hdr.frame_count) {
             net->stats.rx_length_errors++;
             return false;
         }
 
         /* Check the frame identifiers are incremented correctly,
          * and id is matching.
          */
         if (frame_index != net->rx_hdr.frame_index + 1 ||
             frame_id != net->rx_hdr.frame_id) {
             net->stats.rx_missed_errors++;
             return false;
         }
 
         if (net->skb->len + frame_size > TBNET_MAX_MTU) {
             net->stats.rx_length_errors++;
             return false;
         }
 
         return true;
     }
 
     /* Start of packet, validate the frame header */
     if (frame_count == 0 || frame_count > TBNET_RING_SIZE / 4) {
         net->stats.rx_length_errors++;
         return false;
     }
     if (frame_index != 0) {
         net->stats.rx_missed_errors++;
         return false;
     }
 
     return true;
 }
 
 static int tbnet_poll(struct napi_struct *napi, int budget)
 {
     struct tbnet *net = container_of(napi, struct tbnet, napi);
     unsigned int cleaned_count = tbnet_available_buffers(&net->rx_ring);
     struct device *dma_dev = tb_ring_dma_device(net->rx_ring.ring);
     unsigned int rx_packets = 0;
 
     while (rx_packets < budget) {
         const struct thunderbolt_ip_frame_header *hdr;
         unsigned int hdr_size = sizeof(*hdr);
         struct sk_buff *skb = NULL;
         struct ring_frame *frame;
         struct tbnet_frame *tf;
         struct page *page;
         bool last = true;
         u32 frame_size;
 
         /* Return some buffers to hardware, one at a time is too
          * slow so allocate MAX_SKB_FRAGS buffers at the same
          * time.
          */
         if (cleaned_count >= MAX_SKB_FRAGS) {
             tbnet_alloc_rx_buffers(net, cleaned_count);
             cleaned_count = 0;
         }
 
         frame = tb_ring_poll(net->rx_ring.ring);
         if (!frame)
             break;
 
         dma_unmap_page(dma_dev, frame->buffer_phy,
                    TBNET_RX_PAGE_SIZE, DMA_FROM_DEVICE);
 
         tf = container_of(frame, typeof(*tf), frame);
 
         page = tf->page;
         tf->page = NULL;
         net->rx_ring.cons++;
         cleaned_count++;
 
         hdr = page_address(page);
         if (!tbnet_check_frame(net, tf, hdr)) {
             __free_pages(page, TBNET_RX_PAGE_ORDER);
             dev_kfree_skb_any(net->skb);
             net->skb = NULL;
             continue;
         }
 
         frame_size = le32_to_cpu(hdr->frame_size);
 
         skb = net->skb;
         if (!skb) {
             skb = build_skb(page_address(page),
                     TBNET_RX_PAGE_SIZE);
             if (!skb) {
                 __free_pages(page, TBNET_RX_PAGE_ORDER);
                 net->stats.rx_errors++;
                 break;
             }
 
             skb_reserve(skb, hdr_size);
             skb_put(skb, frame_size);
 
             net->skb = skb;
         } else {
             skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
                     page, hdr_size, frame_size,
                     TBNET_RX_PAGE_SIZE - hdr_size);
         }
 
         net->rx_hdr.frame_size = frame_size;
         net->rx_hdr.frame_count = le32_to_cpu(hdr->frame_count);
         net->rx_hdr.frame_index = le16_to_cpu(hdr->frame_index);
         net->rx_hdr.frame_id = le16_to_cpu(hdr->frame_id);
         last = net->rx_hdr.frame_index == net->rx_hdr.frame_count - 1;
 
         rx_packets++;
         net->stats.rx_bytes += frame_size;
 
         if (last) {
             skb->protocol = eth_type_trans(skb, net->dev);
             napi_gro_receive(&net->napi, skb);
             net->skb = NULL;
         }
     }
 
     net->stats.rx_packets += rx_packets;
 
     if (cleaned_count)
         tbnet_alloc_rx_buffers(net, cleaned_count);
 
     if (rx_packets >= budget)
         return budget;
 
     napi_complete_done(napi, rx_packets);
     /* Re-enable the ring interrupt */
     tb_ring_poll_complete(net->rx_ring.ring);
 
     return rx_packets;
 }
 
 static void tbnet_start_poll(void *data)
 {
     struct tbnet *net = data;
 
     napi_schedule(&net->napi);
 }
 
 static int tbnet_open(struct net_device *dev)
 {
     struct tbnet *net = netdev_priv(dev);
     struct tb_xdomain *xd = net->xd;
     u16 sof_mask, eof_mask;
     struct tb_ring *ring;
     int hopid;
 
     netif_carrier_off(dev);
 
     ring = tb_ring_alloc_tx(xd->tb->nhi, -1, TBNET_RING_SIZE,
                 RING_FLAG_FRAME);
     if (!ring) {
         netdev_err(dev, "failed to allocate Tx ring\n");
         return -ENOMEM;
     }
     net->tx_ring.ring = ring;
 
     hopid = tb_xdomain_alloc_out_hopid(xd, -1);
     if (hopid < 0) {
         netdev_err(dev, "failed to allocate Tx HopID\n");
         tb_ring_free(net->tx_ring.ring);
         net->tx_ring.ring = NULL;
         return hopid;
     }
     net->local_transmit_path = hopid;
 
     sof_mask = BIT(TBIP_PDF_FRAME_START);
     eof_mask = BIT(TBIP_PDF_FRAME_END);
 
     ring = tb_ring_alloc_rx(xd->tb->nhi, -1, TBNET_RING_SIZE,
                 RING_FLAG_FRAME, 0, sof_mask, eof_mask,
                 tbnet_start_poll, net);
     if (!ring) {
         netdev_err(dev, "failed to allocate Rx ring\n");
         tb_ring_free(net->tx_ring.ring);
         net->tx_ring.ring = NULL;
         return -ENOMEM;
     }
     net->rx_ring.ring = ring;
 
     napi_enable(&net->napi);
     start_login(net);
 
     return 0;
 }
 
 static int tbnet_stop(struct net_device *dev)
 {
     struct tbnet *net = netdev_priv(dev);
 
     napi_disable(&net->napi);
 
     cancel_work_sync(&net->disconnect_work);
     tbnet_tear_down(net, true);
 
     tb_ring_free(net->rx_ring.ring);
     net->rx_ring.ring = NULL;
 
     tb_xdomain_release_out_hopid(net->xd, net->local_transmit_path);
     tb_ring_free(net->tx_ring.ring);
     net->tx_ring.ring = NULL;
 
     return 0;
 }
 
 static bool tbnet_xmit_csum_and_map(struct tbnet *net, struct sk_buff *skb,
     struct tbnet_frame **frames, u32 frame_count)
 {
     struct thunderbolt_ip_frame_header *hdr = page_address(frames[0]->page);
     struct device *dma_dev = tb_ring_dma_device(net->tx_ring.ring);
     __wsum wsum = htonl(skb->len - skb_transport_offset(skb));
     unsigned int i, len, offset = skb_transport_offset(skb);
     __be16 protocol = skb->protocol;
     void *data = skb->data;
     void *dest = hdr + 1;
     __sum16 *tucso;
 
     if (skb->ip_summed != CHECKSUM_PARTIAL) {
         /* No need to calculate checksum so we just update the
          * total frame count and sync the frames for DMA.
          */
         for (i = 0; i < frame_count; i++) {
             hdr = page_address(frames[i]->page);
             hdr->frame_count = cpu_to_le32(frame_count);
             dma_sync_single_for_device(dma_dev,
                 frames[i]->frame.buffer_phy,
                 tbnet_frame_size(frames[i]), DMA_TO_DEVICE);
         }
 
         return true;
     }
 
     if (protocol == htons(ETH_P_8021Q)) {
         struct vlan_hdr *vhdr, vh;
 
         vhdr = skb_header_pointer(skb, ETH_HLEN, sizeof(vh), &vh);
         if (!vhdr)
             return false;
 
         protocol = vhdr->h_vlan_encapsulated_proto;
     }
 
     /* Data points on the beginning of packet.
      * Check is the checksum absolute place in the packet.
      * ipcso will update IP checksum.
      * tucso will update TCP/UPD checksum.
      */
     if (protocol == htons(ETH_P_IP)) {
         __sum16 *ipcso = dest + ((void *)&(ip_hdr(skb)->check) - data);
 
         *ipcso = 0;
         *ipcso = ip_fast_csum(dest + skb_network_offset(skb),
                       ip_hdr(skb)->ihl);
 
         if (ip_hdr(skb)->protocol == IPPROTO_TCP)
             tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
         else if (ip_hdr(skb)->protocol == IPPROTO_UDP)
             tucso = dest + ((void *)&(udp_hdr(skb)->check) - data);
         else
             return false;
 
         *tucso = ~csum_tcpudp_magic(ip_hdr(skb)->saddr,
                         ip_hdr(skb)->daddr, 0,
                         ip_hdr(skb)->protocol, 0);
     } else if (skb_is_gso_v6(skb)) {
         tucso = dest + ((void *)&(tcp_hdr(skb)->check) - data);
         *tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
                       &ipv6_hdr(skb)->daddr, 0,
                       IPPROTO_TCP, 0);
         return false;
     } else if (protocol == htons(ETH_P_IPV6)) {
         tucso = dest + skb_checksum_start_offset(skb) + skb->csum_offset;
         *tucso = ~csum_ipv6_magic(&ipv6_hdr(skb)->saddr,
                       &ipv6_hdr(skb)->daddr, 0,
                       ipv6_hdr(skb)->nexthdr, 0);
     } else {
         return false;
     }
 
     /* First frame was headers, rest of the frames contain data.
      * Calculate checksum over each frame.
      */
     for (i = 0; i < frame_count; i++) {
         hdr = page_address(frames[i]->page);
         dest = (void *)(hdr + 1) + offset;
         len = le32_to_cpu(hdr->frame_size) - offset;
         wsum = csum_partial(dest, len, wsum);
         hdr->frame_count = cpu_to_le32(frame_count);
 
         offset = 0;
     }
 
     *tucso = csum_fold(wsum);
 
     /* Checksum is finally calculated and we don't touch the memory
      * anymore, so DMA sync the frames now.
      */
     for (i = 0; i < frame_count; i++) {
         dma_sync_single_for_device(dma_dev, frames[i]->frame.buffer_phy,
             tbnet_frame_size(frames[i]), DMA_TO_DEVICE);
     }
 
     return true;
 }
 
 static void *tbnet_kmap_frag(struct sk_buff *skb, unsigned int frag_num,
                  unsigned int *len)
 {
     const skb_frag_t *frag = &skb_shinfo(skb)->frags[frag_num];
 
     *len = skb_frag_size(frag);
     return kmap_atomic(skb_frag_page(frag)) + skb_frag_off(frag);
 }
 
 static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb,
                     struct net_device *dev)
 {
     struct tbnet *net = netdev_priv(dev);
     struct tbnet_frame *frames[MAX_SKB_FRAGS];
     u16 frame_id = atomic_read(&net->frame_id);
     struct thunderbolt_ip_frame_header *hdr;
     unsigned int len = skb_headlen(skb);
     unsigned int data_len = skb->len;
     unsigned int nframes, i;
     unsigned int frag = 0;
     void *src = skb->data;
     u32 frame_index = 0;
     bool unmap = false;
     void *dest;
 
     nframes = DIV_ROUND_UP(data_len, TBNET_MAX_PAYLOAD_SIZE);
     if (tbnet_available_buffers(&net->tx_ring) < nframes) {
         netif_stop_queue(net->dev);
         return NETDEV_TX_BUSY;
     }
 
     frames[frame_index] = tbnet_get_tx_buffer(net);
     if (!frames[frame_index])
         goto err_drop;
 
     hdr = page_address(frames[frame_index]->page);
     dest = hdr + 1;
 
     /* If overall packet is bigger than the frame data size */
     while (data_len > TBNET_MAX_PAYLOAD_SIZE) {
         unsigned int size_left = TBNET_MAX_PAYLOAD_SIZE;
 
         hdr->frame_size = cpu_to_le32(TBNET_MAX_PAYLOAD_SIZE);
         hdr->frame_index = cpu_to_le16(frame_index);
         hdr->frame_id = cpu_to_le16(frame_id);
 
         do {
             if (len > size_left) {
                 /* Copy data onto Tx buffer data with
                  * full frame size then break and go to
                  * next frame
                  */
                 memcpy(dest, src, size_left);
                 len -= size_left;
                 dest += size_left;
                 src += size_left;
                 break;
             }
 
             memcpy(dest, src, len);
             size_left -= len;
             dest += len;
 
             if (unmap) {
                 kunmap_atomic(src);
                 unmap = false;
             }
 
             /* Ensure all fragments have been processed */
             if (frag < skb_shinfo(skb)->nr_frags) {
                 /* Map and then unmap quickly */
                 src = tbnet_kmap_frag(skb, frag++, &len);
                 unmap = true;
             } else if (unlikely(size_left > 0)) {
                 goto err_drop;
             }
         } while (size_left > 0);
 
         data_len -= TBNET_MAX_PAYLOAD_SIZE;
         frame_index++;
 
         frames[frame_index] = tbnet_get_tx_buffer(net);
         if (!frames[frame_index])
             goto err_drop;
 
         hdr = page_address(frames[frame_index]->page);
         dest = hdr + 1;
     }
 
     hdr->frame_size = cpu_to_le32(data_len);
     hdr->frame_index = cpu_to_le16(frame_index);
     hdr->frame_id = cpu_to_le16(frame_id);
 
     frames[frame_index]->frame.size = data_len + sizeof(*hdr);
 
     /* In case the remaining data_len is smaller than a frame */
     while (len < data_len) {
         memcpy(dest, src, len);
         data_len -= len;
         dest += len;
 
         if (unmap) {
             kunmap_atomic(src);
             unmap = false;
         }
 
         if (frag < skb_shinfo(skb)->nr_frags) {
             src = tbnet_kmap_frag(skb, frag++, &len);
             unmap = true;
         } else if (unlikely(data_len > 0)) {
             goto err_drop;
         }
     }
 
     memcpy(dest, src, data_len);
 
     if (unmap)
         kunmap_atomic(src);
 
     if (!tbnet_xmit_csum_and_map(net, skb, frames, frame_index + 1))
         goto err_drop;
 
     for (i = 0; i < frame_index + 1; i++)
         tb_ring_tx(net->tx_ring.ring, &frames[i]->frame);
 
     if (net->svc->prtcstns & TBNET_MATCH_FRAGS_ID)
         atomic_inc(&net->frame_id);
 
     net->stats.tx_packets++;
     net->stats.tx_bytes += skb->len;
 
     dev_consume_skb_any(skb);
 
     return NETDEV_TX_OK;
 
 err_drop:
     /* We can re-use the buffers */
     net->tx_ring.cons -= frame_index;
 
     dev_kfree_skb_any(skb);
     net->stats.tx_errors++;
 
     return NETDEV_TX_OK;
 }
 
 static void tbnet_get_stats64(struct net_device *dev,
                   struct rtnl_link_stats64 *stats)
 {
     struct tbnet *net = netdev_priv(dev);
 
     stats->tx_packets = net->stats.tx_packets;
     stats->rx_packets = net->stats.rx_packets;
     stats->tx_bytes = net->stats.tx_bytes;
     stats->rx_bytes = net->stats.rx_bytes;
     stats->rx_errors = net->stats.rx_errors + net->stats.rx_length_errors +
         net->stats.rx_over_errors + net->stats.rx_crc_errors +
         net->stats.rx_missed_errors;
     stats->tx_errors = net->stats.tx_errors;
     stats->rx_length_errors = net->stats.rx_length_errors;
     stats->rx_over_errors = net->stats.rx_over_errors;
     stats->rx_crc_errors = net->stats.rx_crc_errors;
     stats->rx_missed_errors = net->stats.rx_missed_errors;
 }
 
 static const struct net_device_ops tbnet_netdev_ops = {
     .ndo_open = tbnet_open,
     .ndo_stop = tbnet_stop,
     .ndo_start_xmit = tbnet_start_xmit,
     .ndo_get_stats64 = tbnet_get_stats64,
 };
 
 static void tbnet_generate_mac(struct net_device *dev)
 {
     const struct tbnet *net = netdev_priv(dev);
     const struct tb_xdomain *xd = net->xd;
     u8 addr[ETH_ALEN];
     u8 phy_port;
     u32 hash;
 
     phy_port = tb_phy_port_from_link(TBNET_L0_PORT_NUM(xd->route));
 
     /* Unicast and locally administered MAC */
     addr[0] = phy_port << 4 | 0x02;
     hash = jhash2((u32 *)xd->local_uuid, 4, 0);
     memcpy(addr + 1, &hash, sizeof(hash));
     hash = jhash2((u32 *)xd->local_uuid, 4, hash);
     addr[5] = hash & 0xff;
     eth_hw_addr_set(dev, addr);
 }
 
 static int tbnet_probe(struct tb_service *svc, const struct tb_service_id *id)
 {
     struct tb_xdomain *xd = tb_service_parent(svc);
     struct net_device *dev;
     struct tbnet *net;
     int ret;
 
     dev = alloc_etherdev(sizeof(*net));
     if (!dev)
         return -ENOMEM;
 
     SET_NETDEV_DEV(dev, &svc->dev);
 
     net = netdev_priv(dev);
     INIT_DELAYED_WORK(&net->login_work, tbnet_login_work);
     INIT_WORK(&net->connected_work, tbnet_connected_work);
     INIT_WORK(&net->disconnect_work, tbnet_disconnect_work);
     mutex_init(&net->connection_lock);
     atomic_set(&net->command_id, 0);
     atomic_set(&net->frame_id, 0);
     net->svc = svc;
     net->dev = dev;
     net->xd = xd;
 
     tbnet_generate_mac(dev);
 
     strcpy(dev->name, "thunderbolt%d");
     dev->netdev_ops = &tbnet_netdev_ops;
 
     /* ThunderboltIP takes advantage of TSO packets but instead of
      * segmenting them we just split the packet into Thunderbolt
      * frames (maximum payload size of each frame is 4084 bytes) and
      * calculate checksum over the whole packet here.
      *
      * The receiving side does the opposite if the host OS supports
      * LRO, otherwise it needs to split the large packet into MTU
      * sized smaller packets.
      *
      * In order to receive large packets from the networking stack,
      * we need to announce support for most of the offloading
      * features here.
      */
     dev->hw_features = NETIF_F_SG | NETIF_F_ALL_TSO | NETIF_F_GRO |
                NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
     dev->features = dev->hw_features | NETIF_F_HIGHDMA;
     dev->hard_header_len += sizeof(struct thunderbolt_ip_frame_header);
 
     netif_napi_add(dev, &net->napi, tbnet_poll, NAPI_POLL_WEIGHT);
 
     /* MTU range: 68 - 65522 */
     dev->min_mtu = ETH_MIN_MTU;
     dev->max_mtu = TBNET_MAX_MTU - ETH_HLEN;
 
     net->handler.uuid = &tbnet_svc_uuid;
     net->handler.callback = tbnet_handle_packet;
     net->handler.data = net;
     tb_register_protocol_handler(&net->handler);
 
     tb_service_set_drvdata(svc, net);
 
     ret = register_netdev(dev);
     if (ret) {
         tb_unregister_protocol_handler(&net->handler);
         free_netdev(dev);
         return ret;
     }
 
     return 0;
 }
 
 static void tbnet_remove(struct tb_service *svc)
 {
     struct tbnet *net = tb_service_get_drvdata(svc);
 
     unregister_netdev(net->dev);
     tb_unregister_protocol_handler(&net->handler);
     free_netdev(net->dev);
 }
 
 static void tbnet_shutdown(struct tb_service *svc)
 {
     tbnet_tear_down(tb_service_get_drvdata(svc), true);
 }
 
 static int __maybe_unused tbnet_suspend(struct device *dev)
 {
     struct tb_service *svc = tb_to_service(dev);
     struct tbnet *net = tb_service_get_drvdata(svc);
 
     stop_login(net);
     if (netif_running(net->dev)) {
         netif_device_detach(net->dev);
         tbnet_tear_down(net, true);
     }
 
     tb_unregister_protocol_handler(&net->handler);
     return 0;
 }
 
 static int __maybe_unused tbnet_resume(struct device *dev)
 {
     struct tb_service *svc = tb_to_service(dev);
     struct tbnet *net = tb_service_get_drvdata(svc);
 
     tb_register_protocol_handler(&net->handler);
 
     netif_carrier_off(net->dev);
     if (netif_running(net->dev)) {
         netif_device_attach(net->dev);
         start_login(net);
     }
 
     return 0;
 }
 
 static const struct dev_pm_ops tbnet_pm_ops = {
     SET_SYSTEM_SLEEP_PM_OPS(tbnet_suspend, tbnet_resume)
 };
 
 static const struct tb_service_id tbnet_ids[] = {
     { TB_SERVICE("network", 1) },
     { },
 };
 MODULE_DEVICE_TABLE(tbsvc, tbnet_ids);
 
 static struct tb_service_driver tbnet_driver = {
     .driver = {
         .owner = THIS_MODULE,
         .name = "thunderbolt-net",
         .pm = &tbnet_pm_ops,
     },
     .probe = tbnet_probe,
     .remove = tbnet_remove,
     .shutdown = tbnet_shutdown,
     .id_table = tbnet_ids,
 };
 
 static int __init tbnet_init(void)
 {
     int ret;
 
     tbnet_dir = tb_property_create_dir(&tbnet_dir_uuid);
     if (!tbnet_dir)
         return -ENOMEM;
 
     tb_property_add_immediate(tbnet_dir, "prtcid", 1);
     tb_property_add_immediate(tbnet_dir, "prtcvers", 1);
     tb_property_add_immediate(tbnet_dir, "prtcrevs", 1);
     /* Currently only announce support for match frags ID (bit 1). Bit 0
      * is reserved for full E2E flow control which we do not support at
      * the moment.
      */
     tb_property_add_immediate(tbnet_dir, "prtcstns",
                   TBNET_MATCH_FRAGS_ID | TBNET_64K_FRAMES);
 
     ret = tb_register_property_dir("network", tbnet_dir);
     if (ret) {
         tb_property_free_dir(tbnet_dir);
         return ret;
     }
 
     return tb_register_service_driver(&tbnet_driver);
 }
 module_init(tbnet_init);
 
 static void __exit tbnet_exit(void)
 {
     tb_unregister_service_driver(&tbnet_driver);
     tb_unregister_property_dir("network", tbnet_dir);
     tb_property_free_dir(tbnet_dir);
 }
 module_exit(tbnet_exit);
 
 MODULE_AUTHOR("Amir Levy <amir.jer.levy@intel.com>");
 MODULE_AUTHOR("Michael Jamet <michael.jamet@intel.com>");
 MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
 MODULE_DESCRIPTION("Thunderbolt network driver");
 MODULE_LICENSE("GPL v2");

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