drivers/net/hyperv/netvsc.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, see <http://www.gnu.org/licenses/>.
  15  *
  16  * Authors:
  17  *   Haiyang Zhang <haiyangz@microsoft.com>
  18  *   Hank Janssen  <hjanssen@microsoft.com>
  19  */
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/kernel.h>
  23 #include <linux/sched.h>
  24 #include <linux/wait.h>
  25 #include <linux/mm.h>
  26 #include <linux/delay.h>
  27 #include <linux/io.h>
  28 #include <linux/slab.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_ether.h>
  31 #include <linux/vmalloc.h>
  32 #include <asm/sync_bitops.h>
  33
  34 #include "hyperv_net.h"
  35
  36 /*
  37  * Switch the data path from the synthetic interface to the VF
  38  * interface.
  39  */
  40 void netvsc_switch_datapath(struct net_device *ndev, bool vf)
  41 {
  42         struct net_device_context *net_device_ctx = netdev_priv(ndev);
  43         struct hv_device *dev = net_device_ctx->device_ctx;
  44         struct netvsc_device *nv_dev = net_device_ctx->nvdev;
  45         struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
  46
  47         memset(init_pkt, 0, sizeof(struct nvsp_message));
  48         init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
  49         if (vf)
  50                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  51                         NVSP_DATAPATH_VF;
  52         else
  53                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  54                         NVSP_DATAPATH_SYNTHETIC;
  55
  56         vmbus_sendpacket(dev->channel, init_pkt,
  57                                sizeof(struct nvsp_message),
  58                                (unsigned long)init_pkt,
  59                                VM_PKT_DATA_INBAND, 0);
  60
  61         net_device_ctx->datapath = vf;
  62 }
  63
  64 static struct netvsc_device *alloc_net_device(void)
  65 {
  66         struct netvsc_device *net_device;
  67
  68         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  69         if (!net_device)
  70                 return NULL;
  71
  72         net_device->chan_table[0].mrc.buf
  73                 = vzalloc(NETVSC_RECVSLOT_MAX * sizeof(struct recv_comp_data));
  74
  75         init_waitqueue_head(&net_device->wait_drain);
  76         net_device->destroy = false;
  77         atomic_set(&net_device->open_cnt, 0);
  78         net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
  79         net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
  80         init_completion(&net_device->channel_init_wait);
  81         init_waitqueue_head(&net_device->subchan_open);
  82
  83         return net_device;
  84 }
  85
  86 static void free_netvsc_device(struct rcu_head *head)
  87 {
  88         struct netvsc_device *nvdev
  89                 = container_of(head, struct netvsc_device, rcu);
  90         int i;
  91
  92         for (i = 0; i < VRSS_CHANNEL_MAX; i++)
  93                 vfree(nvdev->chan_table[i].mrc.buf);
  94
  95         kfree(nvdev);
  96 }
  97
  98 static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
  99 {
 100         call_rcu(&nvdev->rcu, free_netvsc_device);
 101 }
 102
 103 static void netvsc_destroy_buf(struct hv_device *device)
 104 {
 105         struct nvsp_message *revoke_packet;
 106         struct net_device *ndev = hv_get_drvdata(device);
 107         struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
 108         int ret;
 109
 110         /*
 111          * If we got a section count, it means we received a
 112          * SendReceiveBufferComplete msg (ie sent
 113          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 114          * to send a revoke msg here
 115          */
 116         if (net_device->recv_section_cnt) {
 117                 /* Send the revoke receive buffer */
 118                 revoke_packet = &net_device->revoke_packet;
 119                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 120
 121                 revoke_packet->hdr.msg_type =
 122                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 123                 revoke_packet->msg.v1_msg.
 124                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 125
 126                 ret = vmbus_sendpacket(device->channel,
 127                                        revoke_packet,
 128                                        sizeof(struct nvsp_message),
 129                                        (unsigned long)revoke_packet,
 130                                        VM_PKT_DATA_INBAND, 0);
 131                 /* If the failure is because the channel is rescinded;
 132                  * ignore the failure since we cannot send on a rescinded
 133                  * channel. This would allow us to properly cleanup
 134                  * even when the channel is rescinded.
 135                  */
 136                 if (device->channel->rescind)
 137                         ret = 0;
 138                 /*
 139                  * If we failed here, we might as well return and
 140                  * have a leak rather than continue and a bugchk
 141                  */
 142                 if (ret != 0) {
 143                         netdev_err(ndev, "unable to send "
 144                                 "revoke receive buffer to netvsp\n");
 145                         return;
 146                 }
 147         }
 148
 149         /* Teardown the gpadl on the vsp end */
 150         if (net_device->recv_buf_gpadl_handle) {
 151                 ret = vmbus_teardown_gpadl(device->channel,
 152                                            net_device->recv_buf_gpadl_handle);
 153
 154                 /* If we failed here, we might as well return and have a leak
 155                  * rather than continue and a bugchk
 156                  */
 157                 if (ret != 0) {
 158                         netdev_err(ndev,
 159                                    "unable to teardown receive buffer's gpadl\n");
 160                         return;
 161                 }
 162                 net_device->recv_buf_gpadl_handle = 0;
 163         }
 164
 165         if (net_device->recv_buf) {
 166                 /* Free up the receive buffer */
 167                 vfree(net_device->recv_buf);
 168                 net_device->recv_buf = NULL;
 169         }
 170
 171         if (net_device->recv_section) {
 172                 net_device->recv_section_cnt = 0;
 173                 kfree(net_device->recv_section);
 174                 net_device->recv_section = NULL;
 175         }
 176
 177         /* Deal with the send buffer we may have setup.
 178          * If we got a  send section size, it means we received a
 179          * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 180          * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 181          * to send a revoke msg here
 182          */
 183         if (net_device->send_section_size) {
 184                 /* Send the revoke receive buffer */
 185                 revoke_packet = &net_device->revoke_packet;
 186                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 187
 188                 revoke_packet->hdr.msg_type =
 189                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 190                 revoke_packet->msg.v1_msg.revoke_send_buf.id =
 191                         NETVSC_SEND_BUFFER_ID;
 192
 193                 ret = vmbus_sendpacket(device->channel,
 194                                        revoke_packet,
 195                                        sizeof(struct nvsp_message),
 196                                        (unsigned long)revoke_packet,
 197                                        VM_PKT_DATA_INBAND, 0);
 198
 199                 /* If the failure is because the channel is rescinded;
 200                  * ignore the failure since we cannot send on a rescinded
 201                  * channel. This would allow us to properly cleanup
 202                  * even when the channel is rescinded.
 203                  */
 204                 if (device->channel->rescind)
 205                         ret = 0;
 206
 207                 /* If we failed here, we might as well return and
 208                  * have a leak rather than continue and a bugchk
 209                  */
 210                 if (ret != 0) {
 211                         netdev_err(ndev, "unable to send "
 212                                    "revoke send buffer to netvsp\n");
 213                         return;
 214                 }
 215         }
 216         /* Teardown the gpadl on the vsp end */
 217         if (net_device->send_buf_gpadl_handle) {
 218                 ret = vmbus_teardown_gpadl(device->channel,
 219                                            net_device->send_buf_gpadl_handle);
 220
 221                 /* If we failed here, we might as well return and have a leak
 222                  * rather than continue and a bugchk
 223                  */
 224                 if (ret != 0) {
 225                         netdev_err(ndev,
 226                                    "unable to teardown send buffer's gpadl\n");
 227                         return;
 228                 }
 229                 net_device->send_buf_gpadl_handle = 0;
 230         }
 231         if (net_device->send_buf) {
 232                 /* Free up the send buffer */
 233                 vfree(net_device->send_buf);
 234                 net_device->send_buf = NULL;
 235         }
 236         kfree(net_device->send_section_map);
 237 }
 238
 239 static int netvsc_init_buf(struct hv_device *device,
 240                            struct netvsc_device *net_device)
 241 {
 242         int ret = 0;
 243         struct nvsp_message *init_packet;
 244         struct net_device *ndev;
 245         size_t map_words;
 246         int node;
 247
 248         ndev = hv_get_drvdata(device);
 249
 250         node = cpu_to_node(device->channel->target_cpu);
 251         net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
 252         if (!net_device->recv_buf)
 253                 net_device->recv_buf = vzalloc(net_device->recv_buf_size);
 254
 255         if (!net_device->recv_buf) {
 256                 netdev_err(ndev, "unable to allocate receive "
 257                         "buffer of size %d\n", net_device->recv_buf_size);
 258                 ret = -ENOMEM;
 259                 goto cleanup;
 260         }
 261
 262         /*
 263          * Establish the gpadl handle for this buffer on this
 264          * channel.  Note: This call uses the vmbus connection rather
 265          * than the channel to establish the gpadl handle.
 266          */
 267         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 268                                     net_device->recv_buf_size,
 269                                     &net_device->recv_buf_gpadl_handle);
 270         if (ret != 0) {
 271                 netdev_err(ndev,
 272                         "unable to establish receive buffer's gpadl\n");
 273                 goto cleanup;
 274         }
 275
 276         /* Notify the NetVsp of the gpadl handle */
 277         init_packet = &net_device->channel_init_pkt;
 278         memset(init_packet, 0, sizeof(struct nvsp_message));
 279         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 280         init_packet->msg.v1_msg.send_recv_buf.
 281                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 282         init_packet->msg.v1_msg.
 283                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 284
 285         /* Send the gpadl notification request */
 286         ret = vmbus_sendpacket(device->channel, init_packet,
 287                                sizeof(struct nvsp_message),
 288                                (unsigned long)init_packet,
 289                                VM_PKT_DATA_INBAND,
 290                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 291         if (ret != 0) {
 292                 netdev_err(ndev,
 293                         "unable to send receive buffer's gpadl to netvsp\n");
 294                 goto cleanup;
 295         }
 296
 297         wait_for_completion(&net_device->channel_init_wait);
 298
 299         /* Check the response */
 300         if (init_packet->msg.v1_msg.
 301             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 302                 netdev_err(ndev, "Unable to complete receive buffer "
 303                            "initialization with NetVsp - status %d\n",
 304                            init_packet->msg.v1_msg.
 305                            send_recv_buf_complete.status);
 306                 ret = -EINVAL;
 307                 goto cleanup;
 308         }
 309
 310         /* Parse the response */
 311
 312         net_device->recv_section_cnt = init_packet->msg.
 313                 v1_msg.send_recv_buf_complete.num_sections;
 314
 315         net_device->recv_section = kmemdup(
 316                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 317                 net_device->recv_section_cnt *
 318                 sizeof(struct nvsp_1_receive_buffer_section),
 319                 GFP_KERNEL);
 320         if (net_device->recv_section == NULL) {
 321                 ret = -EINVAL;
 322                 goto cleanup;
 323         }
 324
 325         /*
 326          * For 1st release, there should only be 1 section that represents the
 327          * entire receive buffer
 328          */
 329         if (net_device->recv_section_cnt != 1 ||
 330             net_device->recv_section->offset != 0) {
 331                 ret = -EINVAL;
 332                 goto cleanup;
 333         }
 334
 335         /* Now setup the send buffer.
 336          */
 337         net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
 338         if (!net_device->send_buf)
 339                 net_device->send_buf = vzalloc(net_device->send_buf_size);
 340         if (!net_device->send_buf) {
 341                 netdev_err(ndev, "unable to allocate send "
 342                            "buffer of size %d\n", net_device->send_buf_size);
 343                 ret = -ENOMEM;
 344                 goto cleanup;
 345         }
 346
 347         /* Establish the gpadl handle for this buffer on this
 348          * channel.  Note: This call uses the vmbus connection rather
 349          * than the channel to establish the gpadl handle.
 350          */
 351         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 352                                     net_device->send_buf_size,
 353                                     &net_device->send_buf_gpadl_handle);
 354         if (ret != 0) {
 355                 netdev_err(ndev,
 356                            "unable to establish send buffer's gpadl\n");
 357                 goto cleanup;
 358         }
 359
 360         /* Notify the NetVsp of the gpadl handle */
 361         init_packet = &net_device->channel_init_pkt;
 362         memset(init_packet, 0, sizeof(struct nvsp_message));
 363         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 364         init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 365                 net_device->send_buf_gpadl_handle;
 366         init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 367
 368         /* Send the gpadl notification request */
 369         ret = vmbus_sendpacket(device->channel, init_packet,
 370                                sizeof(struct nvsp_message),
 371                                (unsigned long)init_packet,
 372                                VM_PKT_DATA_INBAND,
 373                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 374         if (ret != 0) {
 375                 netdev_err(ndev,
 376                            "unable to send send buffer's gpadl to netvsp\n");
 377                 goto cleanup;
 378         }
 379
 380         wait_for_completion(&net_device->channel_init_wait);
 381
 382         /* Check the response */
 383         if (init_packet->msg.v1_msg.
 384             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 385                 netdev_err(ndev, "Unable to complete send buffer "
 386                            "initialization with NetVsp - status %d\n",
 387                            init_packet->msg.v1_msg.
 388                            send_send_buf_complete.status);
 389                 ret = -EINVAL;
 390                 goto cleanup;
 391         }
 392
 393         /* Parse the response */
 394         net_device->send_section_size = init_packet->msg.
 395                                 v1_msg.send_send_buf_complete.section_size;
 396
 397         /* Section count is simply the size divided by the section size.
 398          */
 399         net_device->send_section_cnt =
 400                 net_device->send_buf_size / net_device->send_section_size;
 401
 402         netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
 403                    net_device->send_section_size, net_device->send_section_cnt);
 404
 405         /* Setup state for managing the send buffer. */
 406         map_words = DIV_ROUND_UP(net_device->send_section_cnt, BITS_PER_LONG);
 407
 408         net_device->send_section_map = kcalloc(map_words, sizeof(ulong), GFP_KERNEL);
 409         if (net_device->send_section_map == NULL) {
 410                 ret = -ENOMEM;
 411                 goto cleanup;
 412         }
 413
 414         goto exit;
 415
 416 cleanup:
 417         netvsc_destroy_buf(device);
 418
 419 exit:
 420         return ret;
 421 }
 422
 423 /* Negotiate NVSP protocol version */
 424 static int negotiate_nvsp_ver(struct hv_device *device,
 425                               struct netvsc_device *net_device,
 426                               struct nvsp_message *init_packet,
 427                               u32 nvsp_ver)
 428 {
 429         struct net_device *ndev = hv_get_drvdata(device);
 430         int ret;
 431
 432         memset(init_packet, 0, sizeof(struct nvsp_message));
 433         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 434         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 435         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 436
 437         /* Send the init request */
 438         ret = vmbus_sendpacket(device->channel, init_packet,
 439                                sizeof(struct nvsp_message),
 440                                (unsigned long)init_packet,
 441                                VM_PKT_DATA_INBAND,
 442                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 443
 444         if (ret != 0)
 445                 return ret;
 446
 447         wait_for_completion(&net_device->channel_init_wait);
 448
 449         if (init_packet->msg.init_msg.init_complete.status !=
 450             NVSP_STAT_SUCCESS)
 451                 return -EINVAL;
 452
 453         if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 454                 return 0;
 455
 456         /* NVSPv2 or later: Send NDIS config */
 457         memset(init_packet, 0, sizeof(struct nvsp_message));
 458         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 459         init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
 460         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 461
 462         if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
 463                 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 464
 465                 /* Teaming bit is needed to receive link speed updates */
 466                 init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
 467         }
 468
 469         ret = vmbus_sendpacket(device->channel, init_packet,
 470                                 sizeof(struct nvsp_message),
 471                                 (unsigned long)init_packet,
 472                                 VM_PKT_DATA_INBAND, 0);
 473
 474         return ret;
 475 }
 476
 477 static int netvsc_connect_vsp(struct hv_device *device,
 478                               struct netvsc_device *net_device)
 479 {
 480         const u32 ver_list[] = {
 481                 NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 482                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5
 483         };
 484         struct nvsp_message *init_packet;
 485         int ndis_version, i, ret;
 486
 487         init_packet = &net_device->channel_init_pkt;
 488
 489         /* Negotiate the latest NVSP protocol supported */
 490         for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
 491                 if (negotiate_nvsp_ver(device, net_device, init_packet,
 492                                        ver_list[i])  == 0) {
 493                         net_device->nvsp_version = ver_list[i];
 494                         break;
 495                 }
 496
 497         if (i < 0) {
 498                 ret = -EPROTO;
 499                 goto cleanup;
 500         }
 501
 502         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 503
 504         /* Send the ndis version */
 505         memset(init_packet, 0, sizeof(struct nvsp_message));
 506
 507         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 508                 ndis_version = 0x00060001;
 509         else
 510                 ndis_version = 0x0006001e;
 511
 512         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 513         init_packet->msg.v1_msg.
 514                 send_ndis_ver.ndis_major_ver =
 515                                 (ndis_version & 0xFFFF0000) >> 16;
 516         init_packet->msg.v1_msg.
 517                 send_ndis_ver.ndis_minor_ver =
 518                                 ndis_version & 0xFFFF;
 519
 520         /* Send the init request */
 521         ret = vmbus_sendpacket(device->channel, init_packet,
 522                                 sizeof(struct nvsp_message),
 523                                 (unsigned long)init_packet,
 524                                 VM_PKT_DATA_INBAND, 0);
 525         if (ret != 0)
 526                 goto cleanup;
 527
 528         /* Post the big receive buffer to NetVSP */
 529         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 530                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
 531         else
 532                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 533         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 534
 535         ret = netvsc_init_buf(device, net_device);
 536
 537 cleanup:
 538         return ret;
 539 }
 540
 541 static void netvsc_disconnect_vsp(struct hv_device *device)
 542 {
 543         netvsc_destroy_buf(device);
 544 }
 545
 546 /*
 547  * netvsc_device_remove - Callback when the root bus device is removed
 548  */
 549 void netvsc_device_remove(struct hv_device *device)
 550 {
 551         struct net_device *ndev = hv_get_drvdata(device);
 552         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 553         struct netvsc_device *net_device = net_device_ctx->nvdev;
 554         int i;
 555
 556         netvsc_disconnect_vsp(device);
 557
 558         RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
 559
 560         /*
 561          * At this point, no one should be accessing net_device
 562          * except in here
 563          */
 564         netdev_dbg(ndev, "net device safe to remove\n");
 565
 566         /* Now, we can close the channel safely */
 567         vmbus_close(device->channel);
 568
 569         /* And dissassociate NAPI context from device */
 570         for (i = 0; i < net_device->num_chn; i++)
 571                 netif_napi_del(&net_device->chan_table[i].napi);
 572
 573         /* Release all resources */
 574         free_netvsc_device_rcu(net_device);
 575 }
 576
 577 #define RING_AVAIL_PERCENT_HIWATER 20
 578 #define RING_AVAIL_PERCENT_LOWATER 10
 579
 580 /*
 581  * Get the percentage of available bytes to write in the ring.
 582  * The return value is in range from 0 to 100.
 583  */
 584 static inline u32 hv_ringbuf_avail_percent(
 585                 struct hv_ring_buffer_info *ring_info)
 586 {
 587         u32 avail_read, avail_write;
 588
 589         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 590
 591         return avail_write * 100 / ring_info->ring_datasize;
 592 }
 593
 594 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 595                                          u32 index)
 596 {
 597         sync_change_bit(index, net_device->send_section_map);
 598 }
 599
 600 static void netvsc_send_tx_complete(struct netvsc_device *net_device,
 601                                     struct vmbus_channel *incoming_channel,
 602                                     struct hv_device *device,
 603                                     const struct vmpacket_descriptor *desc,
 604                                     int budget)
 605 {
 606         struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
 607         struct net_device *ndev = hv_get_drvdata(device);
 608         struct vmbus_channel *channel = device->channel;
 609         u16 q_idx = 0;
 610         int queue_sends;
 611
 612         /* Notify the layer above us */
 613         if (likely(skb)) {
 614                 const struct hv_netvsc_packet *packet
 615                         = (struct hv_netvsc_packet *)skb->cb;
 616                 u32 send_index = packet->send_buf_index;
 617                 struct netvsc_stats *tx_stats;
 618
 619                 if (send_index != NETVSC_INVALID_INDEX)
 620                         netvsc_free_send_slot(net_device, send_index);
 621                 q_idx = packet->q_idx;
 622                 channel = incoming_channel;
 623
 624                 tx_stats = &net_device->chan_table[q_idx].tx_stats;
 625
 626                 u64_stats_update_begin(&tx_stats->syncp);
 627                 tx_stats->packets += packet->total_packets;
 628                 tx_stats->bytes += packet->total_bytes;
 629                 u64_stats_update_end(&tx_stats->syncp);
 630
 631                 napi_consume_skb(skb, budget);
 632         }
 633
 634         queue_sends =
 635                 atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
 636
 637         if (net_device->destroy && queue_sends == 0)
 638                 wake_up(&net_device->wait_drain);
 639
 640         if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
 641             (hv_ringbuf_avail_percent(&channel->outbound) > RING_AVAIL_PERCENT_HIWATER ||
 642              queue_sends < 1))
 643                 netif_tx_wake_queue(netdev_get_tx_queue(ndev, q_idx));
 644 }
 645
 646 static void netvsc_send_completion(struct netvsc_device *net_device,
 647                                    struct vmbus_channel *incoming_channel,
 648                                    struct hv_device *device,
 649                                    const struct vmpacket_descriptor *desc,
 650                                    int budget)
 651 {
 652         struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
 653         struct net_device *ndev = hv_get_drvdata(device);
 654
 655         switch (nvsp_packet->hdr.msg_type) {
 656         case NVSP_MSG_TYPE_INIT_COMPLETE:
 657         case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
 658         case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
 659         case NVSP_MSG5_TYPE_SUBCHANNEL:
 660                 /* Copy the response back */
 661                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 662                        sizeof(struct nvsp_message));
 663                 complete(&net_device->channel_init_wait);
 664                 break;
 665
 666         case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
 667                 netvsc_send_tx_complete(net_device, incoming_channel,
 668                                         device, desc, budget);
 669                 break;
 670
 671         default:
 672                 netdev_err(ndev,
 673                            "Unknown send completion type %d received!!\n",
 674                            nvsp_packet->hdr.msg_type);
 675         }
 676 }
 677
 678 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 679 {
 680         unsigned long *map_addr = net_device->send_section_map;
 681         unsigned int i;
 682
 683         for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
 684                 if (sync_test_and_set_bit(i, map_addr) == 0)
 685                         return i;
 686         }
 687
 688         return NETVSC_INVALID_INDEX;
 689 }
 690
 691 static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 692                                    unsigned int section_index,
 693                                    u32 pend_size,
 694                                    struct hv_netvsc_packet *packet,
 695                                    struct rndis_message *rndis_msg,
 696                                    struct hv_page_buffer **pb,
 697                                    struct sk_buff *skb)
 698 {
 699         char *start = net_device->send_buf;
 700         char *dest = start + (section_index * net_device->send_section_size)
 701                      + pend_size;
 702         int i;
 703         u32 msg_size = 0;
 704         u32 padding = 0;
 705         u32 remain = packet->total_data_buflen % net_device->pkt_align;
 706         u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 707                 packet->page_buf_cnt;
 708
 709         /* Add padding */
 710         if (skb->xmit_more && remain && !packet->cp_partial) {
 711                 padding = net_device->pkt_align - remain;
 712                 rndis_msg->msg_len += padding;
 713                 packet->total_data_buflen += padding;
 714         }
 715
 716         for (i = 0; i < page_count; i++) {
 717                 char *src = phys_to_virt((*pb)[i].pfn << PAGE_SHIFT);
 718                 u32 offset = (*pb)[i].offset;
 719                 u32 len = (*pb)[i].len;
 720
 721                 memcpy(dest, (src + offset), len);
 722                 msg_size += len;
 723                 dest += len;
 724         }
 725
 726         if (padding) {
 727                 memset(dest, 0, padding);
 728                 msg_size += padding;
 729         }
 730
 731         return msg_size;
 732 }
 733
 734 static inline int netvsc_send_pkt(
 735         struct hv_device *device,
 736         struct hv_netvsc_packet *packet,
 737         struct netvsc_device *net_device,
 738         struct hv_page_buffer **pb,
 739         struct sk_buff *skb)
 740 {
 741         struct nvsp_message nvmsg;
 742         struct netvsc_channel *nvchan
 743                 = &net_device->chan_table[packet->q_idx];
 744         struct vmbus_channel *out_channel = nvchan->channel;
 745         struct net_device *ndev = hv_get_drvdata(device);
 746         struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
 747         u64 req_id;
 748         int ret;
 749         struct hv_page_buffer *pgbuf;
 750         u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
 751
 752         nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 753         if (skb != NULL) {
 754                 /* 0 is RMC_DATA; */
 755                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 756         } else {
 757                 /* 1 is RMC_CONTROL; */
 758                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 759         }
 760
 761         nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 762                 packet->send_buf_index;
 763         if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 764                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 765         else
 766                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
 767                         packet->total_data_buflen;
 768
 769         req_id = (ulong)skb;
 770
 771         if (out_channel->rescind)
 772                 return -ENODEV;
 773
 774         if (packet->page_buf_cnt) {
 775                 pgbuf = packet->cp_partial ? (*pb) +
 776                         packet->rmsg_pgcnt : (*pb);
 777                 ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
 778                                                       pgbuf,
 779                                                       packet->page_buf_cnt,
 780                                                       &nvmsg,
 781                                                       sizeof(struct nvsp_message),
 782                                                       req_id,
 783                                                       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 784         } else {
 785                 ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
 786                                            sizeof(struct nvsp_message),
 787                                            req_id,
 788                                            VM_PKT_DATA_INBAND,
 789                                            VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 790         }
 791
 792         if (ret == 0) {
 793                 atomic_inc_return(&nvchan->queue_sends);
 794
 795                 if (ring_avail < RING_AVAIL_PERCENT_LOWATER)
 796                         netif_tx_stop_queue(txq);
 797         } else if (ret == -EAGAIN) {
 798                 netif_tx_stop_queue(txq);
 799                 if (atomic_read(&nvchan->queue_sends) < 1) {
 800                         netif_tx_wake_queue(txq);
 801                         ret = -ENOSPC;
 802                 }
 803         } else {
 804                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 805                            packet, ret);
 806         }
 807
 808         return ret;
 809 }
 810
 811 /* Move packet out of multi send data (msd), and clear msd */
 812 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
 813                                 struct sk_buff **msd_skb,
 814                                 struct multi_send_data *msdp)
 815 {
 816         *msd_skb = msdp->skb;
 817         *msd_send = msdp->pkt;
 818         msdp->skb = NULL;
 819         msdp->pkt = NULL;
 820         msdp->count = 0;
 821 }
 822
 823 int netvsc_send(struct hv_device *device,
 824                 struct hv_netvsc_packet *packet,
 825                 struct rndis_message *rndis_msg,
 826                 struct hv_page_buffer **pb,
 827                 struct sk_buff *skb)
 828 {
 829         struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
 830         int ret = 0;
 831         struct netvsc_channel *nvchan;
 832         u32 pktlen = packet->total_data_buflen, msd_len = 0;
 833         unsigned int section_index = NETVSC_INVALID_INDEX;
 834         struct multi_send_data *msdp;
 835         struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
 836         struct sk_buff *msd_skb = NULL;
 837         bool try_batch;
 838         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 839
 840         /* If device is rescinded, return error and packet will get dropped. */
 841         if (unlikely(net_device->destroy))
 842                 return -ENODEV;
 843
 844         /* We may race with netvsc_connect_vsp()/netvsc_init_buf() and get
 845          * here before the negotiation with the host is finished and
 846          * send_section_map may not be allocated yet.
 847          */
 848         if (unlikely(!net_device->send_section_map))
 849                 return -EAGAIN;
 850
 851         nvchan = &net_device->chan_table[packet->q_idx];
 852         packet->send_buf_index = NETVSC_INVALID_INDEX;
 853         packet->cp_partial = false;
 854
 855         /* Send control message directly without accessing msd (Multi-Send
 856          * Data) field which may be changed during data packet processing.
 857          */
 858         if (!skb) {
 859                 cur_send = packet;
 860                 goto send_now;
 861         }
 862
 863         /* batch packets in send buffer if possible */
 864         msdp = &nvchan->msd;
 865         if (msdp->pkt)
 866                 msd_len = msdp->pkt->total_data_buflen;
 867
 868         try_batch =  msd_len > 0 && msdp->count < net_device->max_pkt;
 869         if (try_batch && msd_len + pktlen + net_device->pkt_align <
 870             net_device->send_section_size) {
 871                 section_index = msdp->pkt->send_buf_index;
 872
 873         } else if (try_batch && msd_len + packet->rmsg_size <
 874                    net_device->send_section_size) {
 875                 section_index = msdp->pkt->send_buf_index;
 876                 packet->cp_partial = true;
 877
 878         } else if (pktlen + net_device->pkt_align <
 879                    net_device->send_section_size) {
 880                 section_index = netvsc_get_next_send_section(net_device);
 881                 if (section_index != NETVSC_INVALID_INDEX) {
 882                         move_pkt_msd(&msd_send, &msd_skb, msdp);
 883                         msd_len = 0;
 884                 }
 885         }
 886
 887         if (section_index != NETVSC_INVALID_INDEX) {
 888                 netvsc_copy_to_send_buf(net_device,
 889                                         section_index, msd_len,
 890                                         packet, rndis_msg, pb, skb);
 891
 892                 packet->send_buf_index = section_index;
 893
 894                 if (packet->cp_partial) {
 895                         packet->page_buf_cnt -= packet->rmsg_pgcnt;
 896                         packet->total_data_buflen = msd_len + packet->rmsg_size;
 897                 } else {
 898                         packet->page_buf_cnt = 0;
 899                         packet->total_data_buflen += msd_len;
 900                 }
 901
 902                 if (msdp->pkt) {
 903                         packet->total_packets += msdp->pkt->total_packets;
 904                         packet->total_bytes += msdp->pkt->total_bytes;
 905                 }
 906
 907                 if (msdp->skb)
 908                         dev_consume_skb_any(msdp->skb);
 909
 910                 if (xmit_more && !packet->cp_partial) {
 911                         msdp->skb = skb;
 912                         msdp->pkt = packet;
 913                         msdp->count++;
 914                 } else {
 915                         cur_send = packet;
 916                         msdp->skb = NULL;
 917                         msdp->pkt = NULL;
 918                         msdp->count = 0;
 919                 }
 920         } else {
 921                 move_pkt_msd(&msd_send, &msd_skb, msdp);
 922                 cur_send = packet;
 923         }
 924
 925         if (msd_send) {
 926                 int m_ret = netvsc_send_pkt(device, msd_send, net_device,
 927                                             NULL, msd_skb);
 928
 929                 if (m_ret != 0) {
 930                         netvsc_free_send_slot(net_device,
 931                                               msd_send->send_buf_index);
 932                         dev_kfree_skb_any(msd_skb);
 933                 }
 934         }
 935
 936 send_now:
 937         if (cur_send)
 938                 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
 939
 940         if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
 941                 netvsc_free_send_slot(net_device, section_index);
 942
 943         return ret;
 944 }
 945
 946 static int netvsc_send_recv_completion(struct vmbus_channel *channel,
 947                                        u64 transaction_id, u32 status)
 948 {
 949         struct nvsp_message recvcompMessage;
 950         int ret;
 951
 952         recvcompMessage.hdr.msg_type =
 953                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 954
 955         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
 956
 957         /* Send the completion */
 958         ret = vmbus_sendpacket(channel, &recvcompMessage,
 959                                sizeof(struct nvsp_message_header) + sizeof(u32),
 960                                transaction_id, VM_PKT_COMP, 0);
 961
 962         return ret;
 963 }
 964
 965 static inline void count_recv_comp_slot(struct netvsc_device *nvdev, u16 q_idx,
 966                                         u32 *filled, u32 *avail)
 967 {
 968         struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc;
 969         u32 first = mrc->first;
 970         u32 next = mrc->next;
 971
 972         *filled = (first > next) ? NETVSC_RECVSLOT_MAX - first + next :
 973                   next - first;
 974
 975         *avail = NETVSC_RECVSLOT_MAX - *filled - 1;
 976 }
 977
 978 /* Read the first filled slot, no change to index */
 979 static inline struct recv_comp_data *read_recv_comp_slot(struct netvsc_device
 980                                                          *nvdev, u16 q_idx)
 981 {
 982         struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc;
 983         u32 filled, avail;
 984
 985         if (unlikely(!mrc->buf))
 986                 return NULL;
 987
 988         count_recv_comp_slot(nvdev, q_idx, &filled, &avail);
 989         if (!filled)
 990                 return NULL;
 991
 992         return mrc->buf + mrc->first * sizeof(struct recv_comp_data);
 993 }
 994
 995 /* Put the first filled slot back to available pool */
 996 static inline void put_recv_comp_slot(struct netvsc_device *nvdev, u16 q_idx)
 997 {
 998         struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc;
 999         int num_recv;
1000
1001         mrc->first = (mrc->first + 1) % NETVSC_RECVSLOT_MAX;
1002
1003         num_recv = atomic_dec_return(&nvdev->num_outstanding_recvs);
1004
1005         if (nvdev->destroy && num_recv == 0)
1006                 wake_up(&nvdev->wait_drain);
1007 }
1008
1009 /* Check and send pending recv completions */
1010 static void netvsc_chk_recv_comp(struct netvsc_device *nvdev,
1011                                  struct vmbus_channel *channel, u16 q_idx)
1012 {
1013         struct recv_comp_data *rcd;
1014         int ret;
1015
1016         while (true) {
1017                 rcd = read_recv_comp_slot(nvdev, q_idx);
1018                 if (!rcd)
1019                         break;
1020
1021                 ret = netvsc_send_recv_completion(channel, rcd->tid,
1022                                                   rcd->status);
1023                 if (ret)
1024                         break;
1025
1026                 put_recv_comp_slot(nvdev, q_idx);
1027         }
1028 }
1029
1030 #define NETVSC_RCD_WATERMARK 80
1031
1032 /* Get next available slot */
1033 static inline struct recv_comp_data *get_recv_comp_slot(
1034         struct netvsc_device *nvdev, struct vmbus_channel *channel, u16 q_idx)
1035 {
1036         struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc;
1037         u32 filled, avail, next;
1038         struct recv_comp_data *rcd;
1039
1040         if (unlikely(!nvdev->recv_section))
1041                 return NULL;
1042
1043         if (unlikely(!mrc->buf))
1044                 return NULL;
1045
1046         if (atomic_read(&nvdev->num_outstanding_recvs) >
1047             nvdev->recv_section->num_sub_allocs * NETVSC_RCD_WATERMARK / 100)
1048                 netvsc_chk_recv_comp(nvdev, channel, q_idx);
1049
1050         count_recv_comp_slot(nvdev, q_idx, &filled, &avail);
1051         if (!avail)
1052                 return NULL;
1053
1054         next = mrc->next;
1055         rcd = mrc->buf + next * sizeof(struct recv_comp_data);
1056         mrc->next = (next + 1) % NETVSC_RECVSLOT_MAX;
1057
1058         atomic_inc(&nvdev->num_outstanding_recvs);
1059
1060         return rcd;
1061 }
1062
1063 static int netvsc_receive(struct net_device *ndev,
1064                    struct netvsc_device *net_device,
1065                    struct net_device_context *net_device_ctx,
1066                    struct hv_device *device,
1067                    struct vmbus_channel *channel,
1068                    const struct vmpacket_descriptor *desc,
1069                    struct nvsp_message *nvsp)
1070 {
1071         const struct vmtransfer_page_packet_header *vmxferpage_packet
1072                 = container_of(desc, const struct vmtransfer_page_packet_header, d);
1073         u16 q_idx = channel->offermsg.offer.sub_channel_index;
1074         char *recv_buf = net_device->recv_buf;
1075         u32 status = NVSP_STAT_SUCCESS;
1076         int i;
1077         int count = 0;
1078         int ret;
1079
1080         /* Make sure this is a valid nvsp packet */
1081         if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1082                 netif_err(net_device_ctx, rx_err, ndev,
1083                           "Unknown nvsp packet type received %u\n",
1084                           nvsp->hdr.msg_type);
1085                 return 0;
1086         }
1087
1088         if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1089                 netif_err(net_device_ctx, rx_err, ndev,
1090                           "Invalid xfer page set id - expecting %x got %x\n",
1091                           NETVSC_RECEIVE_BUFFER_ID,
1092                           vmxferpage_packet->xfer_pageset_id);
1093                 return 0;
1094         }
1095
1096         count = vmxferpage_packet->range_cnt;
1097
1098         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1099         for (i = 0; i < count; i++) {
1100                 void *data = recv_buf
1101                         + vmxferpage_packet->ranges[i].byte_offset;
1102                 u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1103
1104                 /* Pass it to the upper layer */
1105                 status = rndis_filter_receive(ndev, net_device, device,
1106                                               channel, data, buflen);
1107         }
1108
1109         if (net_device->chan_table[q_idx].mrc.buf) {
1110                 struct recv_comp_data *rcd;
1111
1112                 rcd = get_recv_comp_slot(net_device, channel, q_idx);
1113                 if (rcd) {
1114                         rcd->tid = vmxferpage_packet->d.trans_id;
1115                         rcd->status = status;
1116                 } else {
1117                         netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1118                                    q_idx, vmxferpage_packet->d.trans_id);
1119                 }
1120         } else {
1121                 ret = netvsc_send_recv_completion(channel,
1122                                                   vmxferpage_packet->d.trans_id,
1123                                                   status);
1124                 if (ret)
1125                         netdev_err(ndev, "Recv_comp q:%hd, tid:%llx, err:%d\n",
1126                                    q_idx, vmxferpage_packet->d.trans_id, ret);
1127         }
1128         return count;
1129 }
1130
1131 static void netvsc_send_table(struct hv_device *hdev,
1132                               struct nvsp_message *nvmsg)
1133 {
1134         struct net_device *ndev = hv_get_drvdata(hdev);
1135         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1136         int i;
1137         u32 count, *tab;
1138
1139         count = nvmsg->msg.v5_msg.send_table.count;
1140         if (count != VRSS_SEND_TAB_SIZE) {
1141                 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1142                 return;
1143         }
1144
1145         tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1146                       nvmsg->msg.v5_msg.send_table.offset);
1147
1148         for (i = 0; i < count; i++)
1149                 net_device_ctx->tx_send_table[i] = tab[i];
1150 }
1151
1152 static void netvsc_send_vf(struct net_device_context *net_device_ctx,
1153                            struct nvsp_message *nvmsg)
1154 {
1155         net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1156         net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1157 }
1158
1159 static inline void netvsc_receive_inband(struct hv_device *hdev,
1160                                  struct net_device_context *net_device_ctx,
1161                                  struct nvsp_message *nvmsg)
1162 {
1163         switch (nvmsg->hdr.msg_type) {
1164         case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1165                 netvsc_send_table(hdev, nvmsg);
1166                 break;
1167
1168         case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1169                 netvsc_send_vf(net_device_ctx, nvmsg);
1170                 break;
1171         }
1172 }
1173
1174 static int netvsc_process_raw_pkt(struct hv_device *device,
1175                                   struct vmbus_channel *channel,
1176                                   struct netvsc_device *net_device,
1177                                   struct net_device *ndev,
1178                                   const struct vmpacket_descriptor *desc,
1179                                   int budget)
1180 {
1181         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1182         struct nvsp_message *nvmsg = hv_pkt_data(desc);
1183
1184         switch (desc->type) {
1185         case VM_PKT_COMP:
1186                 netvsc_send_completion(net_device, channel, device,
1187                                        desc, budget);
1188                 break;
1189
1190         case VM_PKT_DATA_USING_XFER_PAGES:
1191                 return netvsc_receive(ndev, net_device, net_device_ctx,
1192                                       device, channel, desc, nvmsg);
1193                 break;
1194
1195         case VM_PKT_DATA_INBAND:
1196                 netvsc_receive_inband(device, net_device_ctx, nvmsg);
1197                 break;
1198
1199         default:
1200                 netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1201                            desc->type, desc->trans_id);
1202                 break;
1203         }
1204
1205         return 0;
1206 }
1207
1208 static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1209 {
1210         struct vmbus_channel *primary = channel->primary_channel;
1211
1212         return primary ? primary->device_obj : channel->device_obj;
1213 }
1214
1215 /* Network processing softirq
1216  * Process data in incoming ring buffer from host
1217  * Stops when ring is empty or budget is met or exceeded.
1218  */
1219 int netvsc_poll(struct napi_struct *napi, int budget)
1220 {
1221         struct netvsc_channel *nvchan
1222                 = container_of(napi, struct netvsc_channel, napi);
1223         struct vmbus_channel *channel = nvchan->channel;
1224         struct hv_device *device = netvsc_channel_to_device(channel);
1225         u16 q_idx = channel->offermsg.offer.sub_channel_index;
1226         struct net_device *ndev = hv_get_drvdata(device);
1227         struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
1228         int work_done = 0;
1229
1230         /* If starting a new interval */
1231         if (!nvchan->desc)
1232                 nvchan->desc = hv_pkt_iter_first(channel);
1233
1234         while (nvchan->desc && work_done < budget) {
1235                 work_done += netvsc_process_raw_pkt(device, channel, net_device,
1236                                                     ndev, nvchan->desc, budget);
1237                 nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1238         }
1239
1240         /* If receive ring was exhausted
1241          * and not doing busy poll
1242          * then re-enable host interrupts
1243          *  and reschedule if ring is not empty.
1244          */
1245         if (work_done < budget &&
1246             napi_complete_done(napi, work_done) &&
1247             hv_end_read(&channel->inbound) != 0)
1248                 napi_reschedule(napi);
1249
1250         netvsc_chk_recv_comp(net_device, channel, q_idx);
1251
1252         /* Driver may overshoot since multiple packets per descriptor */
1253         return min(work_done, budget);
1254 }
1255
1256 /* Call back when data is available in host ring buffer.
1257  * Processing is deferred until network softirq (NAPI)
1258  */
1259 void netvsc_channel_cb(void *context)
1260 {
1261         struct netvsc_channel *nvchan = context;
1262
1263         if (napi_schedule_prep(&nvchan->napi)) {
1264                 /* disable interupts from host */
1265                 hv_begin_read(&nvchan->channel->inbound);
1266
1267                 __napi_schedule(&nvchan->napi);
1268         }
1269 }
1270
1271 /*
1272  * netvsc_device_add - Callback when the device belonging to this
1273  * driver is added
1274  */
1275 int netvsc_device_add(struct hv_device *device,
1276                       const struct netvsc_device_info *device_info)
1277 {
1278         int i, ret = 0;
1279         int ring_size = device_info->ring_size;
1280         struct netvsc_device *net_device;
1281         struct net_device *ndev = hv_get_drvdata(device);
1282         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1283
1284         net_device = alloc_net_device();
1285         if (!net_device)
1286                 return -ENOMEM;
1287
1288         net_device->ring_size = ring_size;
1289
1290         /* Because the device uses NAPI, all the interrupt batching and
1291          * control is done via Net softirq, not the channel handling
1292          */
1293         set_channel_read_mode(device->channel, HV_CALL_ISR);
1294
1295         /* If we're reopening the device we may have multiple queues, fill the
1296          * chn_table with the default channel to use it before subchannels are
1297          * opened.
1298          * Initialize the channel state before we open;
1299          * we can be interrupted as soon as we open the channel.
1300          */
1301
1302         for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1303                 struct netvsc_channel *nvchan = &net_device->chan_table[i];
1304
1305                 nvchan->channel = device->channel;
1306                 u64_stats_init(&nvchan->tx_stats.syncp);
1307                 u64_stats_init(&nvchan->rx_stats.syncp);
1308         }
1309
1310         /* Enable NAPI handler before init callbacks */
1311         netif_napi_add(ndev, &net_device->chan_table[0].napi,
1312                        netvsc_poll, NAPI_POLL_WEIGHT);
1313
1314         /* Open the channel */
1315         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
1316                          ring_size * PAGE_SIZE, NULL, 0,
1317                          netvsc_channel_cb,
1318                          net_device->chan_table);
1319
1320         if (ret != 0) {
1321                 netif_napi_del(&net_device->chan_table[0].napi);
1322                 netdev_err(ndev, "unable to open channel: %d\n", ret);
1323                 goto cleanup;
1324         }
1325
1326         /* Channel is opened */
1327         netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1328
1329         napi_enable(&net_device->chan_table[0].napi);
1330
1331         /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1332          * populated.
1333          */
1334         rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1335
1336         /* Connect with the NetVsp */
1337         ret = netvsc_connect_vsp(device, net_device);
1338         if (ret != 0) {
1339                 netdev_err(ndev,
1340                         "unable to connect to NetVSP - %d\n", ret);
1341                 goto close;
1342         }
1343
1344         return ret;
1345
1346 close:
1347         netif_napi_del(&net_device->chan_table[0].napi);
1348
1349         /* Now, we can close the channel safely */
1350         vmbus_close(device->channel);
1351
1352 cleanup:
1353         free_netvsc_device(&net_device->rcu);
1354
1355         return ret;
1356
1357 }