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
  62 static struct netvsc_device *alloc_net_device(void)
  63 {
  64         struct netvsc_device *net_device;
  65
  66         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  67         if (!net_device)
  68                 return NULL;
  69
  70         net_device->chan_table[0].mrc.buf
  71                 = vzalloc(NETVSC_RECVSLOT_MAX * sizeof(struct recv_comp_data));
  72
  73         init_waitqueue_head(&net_device->wait_drain);
  74         net_device->destroy = false;
  75         atomic_set(&net_device->open_cnt, 0);
  76         net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
  77         net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
  78         init_completion(&net_device->channel_init_wait);
  79
  80         return net_device;
  81 }
  82
  83 static void free_netvsc_device(struct rcu_head *head)
  84 {
  85         struct netvsc_device *nvdev
  86                 = container_of(head, struct netvsc_device, rcu);
  87         int i;
  88
  89         for (i = 0; i < VRSS_CHANNEL_MAX; i++)
  90                 vfree(nvdev->chan_table[i].mrc.buf);
  91
  92         kfree(nvdev);
  93 }
  94
  95 static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
  96 {
  97         call_rcu(&nvdev->rcu, free_netvsc_device);
  98 }
  99
 100 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
 101 {
 102         struct netvsc_device *net_device = hv_device_to_netvsc_device(device);
 103
 104         if (net_device && net_device->destroy)
 105                 net_device = NULL;
 106
 107         return net_device;
 108 }
 109
 110 static void netvsc_destroy_buf(struct hv_device *device)
 111 {
 112         struct nvsp_message *revoke_packet;
 113         struct net_device *ndev = hv_get_drvdata(device);
 114         struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
 115         int ret;
 116
 117         /*
 118          * If we got a section count, it means we received a
 119          * SendReceiveBufferComplete msg (ie sent
 120          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 121          * to send a revoke msg here
 122          */
 123         if (net_device->recv_section_cnt) {
 124                 /* Send the revoke receive buffer */
 125                 revoke_packet = &net_device->revoke_packet;
 126                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 127
 128                 revoke_packet->hdr.msg_type =
 129                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 130                 revoke_packet->msg.v1_msg.
 131                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 132
 133                 ret = vmbus_sendpacket(device->channel,
 134                                        revoke_packet,
 135                                        sizeof(struct nvsp_message),
 136                                        (unsigned long)revoke_packet,
 137                                        VM_PKT_DATA_INBAND, 0);
 138                 /* If the failure is because the channel is rescinded;
 139                  * ignore the failure since we cannot send on a rescinded
 140                  * channel. This would allow us to properly cleanup
 141                  * even when the channel is rescinded.
 142                  */
 143                 if (device->channel->rescind)
 144                         ret = 0;
 145                 /*
 146                  * If we failed here, we might as well return and
 147                  * have a leak rather than continue and a bugchk
 148                  */
 149                 if (ret != 0) {
 150                         netdev_err(ndev, "unable to send "
 151                                 "revoke receive buffer to netvsp\n");
 152                         return;
 153                 }
 154         }
 155
 156         /* Teardown the gpadl on the vsp end */
 157         if (net_device->recv_buf_gpadl_handle) {
 158                 ret = vmbus_teardown_gpadl(device->channel,
 159                                            net_device->recv_buf_gpadl_handle);
 160
 161                 /* If we failed here, we might as well return and have a leak
 162                  * rather than continue and a bugchk
 163                  */
 164                 if (ret != 0) {
 165                         netdev_err(ndev,
 166                                    "unable to teardown receive buffer's gpadl\n");
 167                         return;
 168                 }
 169                 net_device->recv_buf_gpadl_handle = 0;
 170         }
 171
 172         if (net_device->recv_buf) {
 173                 /* Free up the receive buffer */
 174                 vfree(net_device->recv_buf);
 175                 net_device->recv_buf = NULL;
 176         }
 177
 178         if (net_device->recv_section) {
 179                 net_device->recv_section_cnt = 0;
 180                 kfree(net_device->recv_section);
 181                 net_device->recv_section = NULL;
 182         }
 183
 184         /* Deal with the send buffer we may have setup.
 185          * If we got a  send section size, it means we received a
 186          * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 187          * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 188          * to send a revoke msg here
 189          */
 190         if (net_device->send_section_size) {
 191                 /* Send the revoke receive buffer */
 192                 revoke_packet = &net_device->revoke_packet;
 193                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 194
 195                 revoke_packet->hdr.msg_type =
 196                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 197                 revoke_packet->msg.v1_msg.revoke_send_buf.id =
 198                         NETVSC_SEND_BUFFER_ID;
 199
 200                 ret = vmbus_sendpacket(device->channel,
 201                                        revoke_packet,
 202                                        sizeof(struct nvsp_message),
 203                                        (unsigned long)revoke_packet,
 204                                        VM_PKT_DATA_INBAND, 0);
 205
 206                 /* If the failure is because the channel is rescinded;
 207                  * ignore the failure since we cannot send on a rescinded
 208                  * channel. This would allow us to properly cleanup
 209                  * even when the channel is rescinded.
 210                  */
 211                 if (device->channel->rescind)
 212                         ret = 0;
 213
 214                 /* If we failed here, we might as well return and
 215                  * have a leak rather than continue and a bugchk
 216                  */
 217                 if (ret != 0) {
 218                         netdev_err(ndev, "unable to send "
 219                                    "revoke send buffer to netvsp\n");
 220                         return;
 221                 }
 222         }
 223         /* Teardown the gpadl on the vsp end */
 224         if (net_device->send_buf_gpadl_handle) {
 225                 ret = vmbus_teardown_gpadl(device->channel,
 226                                            net_device->send_buf_gpadl_handle);
 227
 228                 /* If we failed here, we might as well return and have a leak
 229                  * rather than continue and a bugchk
 230                  */
 231                 if (ret != 0) {
 232                         netdev_err(ndev,
 233                                    "unable to teardown send buffer's gpadl\n");
 234                         return;
 235                 }
 236                 net_device->send_buf_gpadl_handle = 0;
 237         }
 238         if (net_device->send_buf) {
 239                 /* Free up the send buffer */
 240                 vfree(net_device->send_buf);
 241                 net_device->send_buf = NULL;
 242         }
 243         kfree(net_device->send_section_map);
 244 }
 245
 246 static int netvsc_init_buf(struct hv_device *device)
 247 {
 248         int ret = 0;
 249         struct netvsc_device *net_device;
 250         struct nvsp_message *init_packet;
 251         struct net_device *ndev;
 252         size_t map_words;
 253         int node;
 254
 255         net_device = get_outbound_net_device(device);
 256         if (!net_device)
 257                 return -ENODEV;
 258         ndev = hv_get_drvdata(device);
 259
 260         node = cpu_to_node(device->channel->target_cpu);
 261         net_device->recv_buf = vzalloc_node(net_device->recv_buf_size, node);
 262         if (!net_device->recv_buf)
 263                 net_device->recv_buf = vzalloc(net_device->recv_buf_size);
 264
 265         if (!net_device->recv_buf) {
 266                 netdev_err(ndev, "unable to allocate receive "
 267                         "buffer of size %d\n", net_device->recv_buf_size);
 268                 ret = -ENOMEM;
 269                 goto cleanup;
 270         }
 271
 272         /*
 273          * Establish the gpadl handle for this buffer on this
 274          * channel.  Note: This call uses the vmbus connection rather
 275          * than the channel to establish the gpadl handle.
 276          */
 277         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 278                                     net_device->recv_buf_size,
 279                                     &net_device->recv_buf_gpadl_handle);
 280         if (ret != 0) {
 281                 netdev_err(ndev,
 282                         "unable to establish receive buffer's gpadl\n");
 283                 goto cleanup;
 284         }
 285
 286         /* Notify the NetVsp of the gpadl handle */
 287         init_packet = &net_device->channel_init_pkt;
 288
 289         memset(init_packet, 0, sizeof(struct nvsp_message));
 290
 291         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 292         init_packet->msg.v1_msg.send_recv_buf.
 293                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 294         init_packet->msg.v1_msg.
 295                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 296
 297         /* Send the gpadl notification request */
 298         ret = vmbus_sendpacket(device->channel, init_packet,
 299                                sizeof(struct nvsp_message),
 300                                (unsigned long)init_packet,
 301                                VM_PKT_DATA_INBAND,
 302                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 303         if (ret != 0) {
 304                 netdev_err(ndev,
 305                         "unable to send receive buffer's gpadl to netvsp\n");
 306                 goto cleanup;
 307         }
 308
 309         wait_for_completion(&net_device->channel_init_wait);
 310
 311         /* Check the response */
 312         if (init_packet->msg.v1_msg.
 313             send_recv_buf_complete.status != NVSP_STAT_SUCCESS) {
 314                 netdev_err(ndev, "Unable to complete receive buffer "
 315                            "initialization with NetVsp - status %d\n",
 316                            init_packet->msg.v1_msg.
 317                            send_recv_buf_complete.status);
 318                 ret = -EINVAL;
 319                 goto cleanup;
 320         }
 321
 322         /* Parse the response */
 323
 324         net_device->recv_section_cnt = init_packet->msg.
 325                 v1_msg.send_recv_buf_complete.num_sections;
 326
 327         net_device->recv_section = kmemdup(
 328                 init_packet->msg.v1_msg.send_recv_buf_complete.sections,
 329                 net_device->recv_section_cnt *
 330                 sizeof(struct nvsp_1_receive_buffer_section),
 331                 GFP_KERNEL);
 332         if (net_device->recv_section == NULL) {
 333                 ret = -EINVAL;
 334                 goto cleanup;
 335         }
 336
 337         /*
 338          * For 1st release, there should only be 1 section that represents the
 339          * entire receive buffer
 340          */
 341         if (net_device->recv_section_cnt != 1 ||
 342             net_device->recv_section->offset != 0) {
 343                 ret = -EINVAL;
 344                 goto cleanup;
 345         }
 346
 347         /* Now setup the send buffer.
 348          */
 349         net_device->send_buf = vzalloc_node(net_device->send_buf_size, node);
 350         if (!net_device->send_buf)
 351                 net_device->send_buf = vzalloc(net_device->send_buf_size);
 352         if (!net_device->send_buf) {
 353                 netdev_err(ndev, "unable to allocate send "
 354                            "buffer of size %d\n", net_device->send_buf_size);
 355                 ret = -ENOMEM;
 356                 goto cleanup;
 357         }
 358
 359         /* Establish the gpadl handle for this buffer on this
 360          * channel.  Note: This call uses the vmbus connection rather
 361          * than the channel to establish the gpadl handle.
 362          */
 363         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 364                                     net_device->send_buf_size,
 365                                     &net_device->send_buf_gpadl_handle);
 366         if (ret != 0) {
 367                 netdev_err(ndev,
 368                            "unable to establish send buffer's gpadl\n");
 369                 goto cleanup;
 370         }
 371
 372         /* Notify the NetVsp of the gpadl handle */
 373         init_packet = &net_device->channel_init_pkt;
 374         memset(init_packet, 0, sizeof(struct nvsp_message));
 375         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 376         init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 377                 net_device->send_buf_gpadl_handle;
 378         init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 379
 380         /* Send the gpadl notification request */
 381         ret = vmbus_sendpacket(device->channel, init_packet,
 382                                sizeof(struct nvsp_message),
 383                                (unsigned long)init_packet,
 384                                VM_PKT_DATA_INBAND,
 385                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 386         if (ret != 0) {
 387                 netdev_err(ndev,
 388                            "unable to send send buffer's gpadl to netvsp\n");
 389                 goto cleanup;
 390         }
 391
 392         wait_for_completion(&net_device->channel_init_wait);
 393
 394         /* Check the response */
 395         if (init_packet->msg.v1_msg.
 396             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 397                 netdev_err(ndev, "Unable to complete send buffer "
 398                            "initialization with NetVsp - status %d\n",
 399                            init_packet->msg.v1_msg.
 400                            send_send_buf_complete.status);
 401                 ret = -EINVAL;
 402                 goto cleanup;
 403         }
 404
 405         /* Parse the response */
 406         net_device->send_section_size = init_packet->msg.
 407                                 v1_msg.send_send_buf_complete.section_size;
 408
 409         /* Section count is simply the size divided by the section size.
 410          */
 411         net_device->send_section_cnt =
 412                 net_device->send_buf_size / net_device->send_section_size;
 413
 414         netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
 415                    net_device->send_section_size, net_device->send_section_cnt);
 416
 417         /* Setup state for managing the send buffer. */
 418         map_words = DIV_ROUND_UP(net_device->send_section_cnt, BITS_PER_LONG);
 419
 420         net_device->send_section_map = kcalloc(map_words, sizeof(ulong), GFP_KERNEL);
 421         if (net_device->send_section_map == NULL) {
 422                 ret = -ENOMEM;
 423                 goto cleanup;
 424         }
 425
 426         goto exit;
 427
 428 cleanup:
 429         netvsc_destroy_buf(device);
 430
 431 exit:
 432         return ret;
 433 }
 434
 435 /* Negotiate NVSP protocol version */
 436 static int negotiate_nvsp_ver(struct hv_device *device,
 437                               struct netvsc_device *net_device,
 438                               struct nvsp_message *init_packet,
 439                               u32 nvsp_ver)
 440 {
 441         struct net_device *ndev = hv_get_drvdata(device);
 442         int ret;
 443
 444         memset(init_packet, 0, sizeof(struct nvsp_message));
 445         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 446         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 447         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 448
 449         /* Send the init request */
 450         ret = vmbus_sendpacket(device->channel, init_packet,
 451                                sizeof(struct nvsp_message),
 452                                (unsigned long)init_packet,
 453                                VM_PKT_DATA_INBAND,
 454                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 455
 456         if (ret != 0)
 457                 return ret;
 458
 459         wait_for_completion(&net_device->channel_init_wait);
 460
 461         if (init_packet->msg.init_msg.init_complete.status !=
 462             NVSP_STAT_SUCCESS)
 463                 return -EINVAL;
 464
 465         if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 466                 return 0;
 467
 468         /* NVSPv2 or later: Send NDIS config */
 469         memset(init_packet, 0, sizeof(struct nvsp_message));
 470         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 471         init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
 472         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 473
 474         if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
 475                 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 476
 477                 /* Teaming bit is needed to receive link speed updates */
 478                 init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
 479         }
 480
 481         ret = vmbus_sendpacket(device->channel, init_packet,
 482                                 sizeof(struct nvsp_message),
 483                                 (unsigned long)init_packet,
 484                                 VM_PKT_DATA_INBAND, 0);
 485
 486         return ret;
 487 }
 488
 489 static int netvsc_connect_vsp(struct hv_device *device)
 490 {
 491         int ret;
 492         struct netvsc_device *net_device;
 493         struct nvsp_message *init_packet;
 494         int ndis_version;
 495         const u32 ver_list[] = {
 496                 NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 497                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5 };
 498         int i;
 499
 500         net_device = get_outbound_net_device(device);
 501         if (!net_device)
 502                 return -ENODEV;
 503
 504         init_packet = &net_device->channel_init_pkt;
 505
 506         /* Negotiate the latest NVSP protocol supported */
 507         for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
 508                 if (negotiate_nvsp_ver(device, net_device, init_packet,
 509                                        ver_list[i])  == 0) {
 510                         net_device->nvsp_version = ver_list[i];
 511                         break;
 512                 }
 513
 514         if (i < 0) {
 515                 ret = -EPROTO;
 516                 goto cleanup;
 517         }
 518
 519         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 520
 521         /* Send the ndis version */
 522         memset(init_packet, 0, sizeof(struct nvsp_message));
 523
 524         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 525                 ndis_version = 0x00060001;
 526         else
 527                 ndis_version = 0x0006001e;
 528
 529         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 530         init_packet->msg.v1_msg.
 531                 send_ndis_ver.ndis_major_ver =
 532                                 (ndis_version & 0xFFFF0000) >> 16;
 533         init_packet->msg.v1_msg.
 534                 send_ndis_ver.ndis_minor_ver =
 535                                 ndis_version & 0xFFFF;
 536
 537         /* Send the init request */
 538         ret = vmbus_sendpacket(device->channel, init_packet,
 539                                 sizeof(struct nvsp_message),
 540                                 (unsigned long)init_packet,
 541                                 VM_PKT_DATA_INBAND, 0);
 542         if (ret != 0)
 543                 goto cleanup;
 544
 545         /* Post the big receive buffer to NetVSP */
 546         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 547                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE_LEGACY;
 548         else
 549                 net_device->recv_buf_size = NETVSC_RECEIVE_BUFFER_SIZE;
 550         net_device->send_buf_size = NETVSC_SEND_BUFFER_SIZE;
 551
 552         ret = netvsc_init_buf(device);
 553
 554 cleanup:
 555         return ret;
 556 }
 557
 558 static void netvsc_disconnect_vsp(struct hv_device *device)
 559 {
 560         netvsc_destroy_buf(device);
 561 }
 562
 563 /*
 564  * netvsc_device_remove - Callback when the root bus device is removed
 565  */
 566 void netvsc_device_remove(struct hv_device *device)
 567 {
 568         struct net_device *ndev = hv_get_drvdata(device);
 569         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 570         struct netvsc_device *net_device = net_device_ctx->nvdev;
 571         int i;
 572
 573         netvsc_disconnect_vsp(device);
 574
 575         RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
 576
 577         /*
 578          * At this point, no one should be accessing net_device
 579          * except in here
 580          */
 581         netdev_dbg(ndev, "net device safe to remove\n");
 582
 583         /* Now, we can close the channel safely */
 584         vmbus_close(device->channel);
 585
 586         /* And dissassociate NAPI context from device */
 587         for (i = 0; i < net_device->num_chn; i++)
 588                 netif_napi_del(&net_device->chan_table[i].napi);
 589
 590         /* Release all resources */
 591         free_netvsc_device_rcu(net_device);
 592 }
 593
 594 #define RING_AVAIL_PERCENT_HIWATER 20
 595 #define RING_AVAIL_PERCENT_LOWATER 10
 596
 597 /*
 598  * Get the percentage of available bytes to write in the ring.
 599  * The return value is in range from 0 to 100.
 600  */
 601 static inline u32 hv_ringbuf_avail_percent(
 602                 struct hv_ring_buffer_info *ring_info)
 603 {
 604         u32 avail_read, avail_write;
 605
 606         hv_get_ringbuffer_availbytes(ring_info, &avail_read, &avail_write);
 607
 608         return avail_write * 100 / ring_info->ring_datasize;
 609 }
 610
 611 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 612                                          u32 index)
 613 {
 614         sync_change_bit(index, net_device->send_section_map);
 615 }
 616
 617 static void netvsc_send_tx_complete(struct netvsc_device *net_device,
 618                                     struct vmbus_channel *incoming_channel,
 619                                     struct hv_device *device,
 620                                     const struct vmpacket_descriptor *desc,
 621                                     int budget)
 622 {
 623         struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
 624         struct net_device *ndev = hv_get_drvdata(device);
 625         struct vmbus_channel *channel = device->channel;
 626         u16 q_idx = 0;
 627         int queue_sends;
 628
 629         /* Notify the layer above us */
 630         if (likely(skb)) {
 631                 const struct hv_netvsc_packet *packet
 632                         = (struct hv_netvsc_packet *)skb->cb;
 633                 u32 send_index = packet->send_buf_index;
 634                 struct netvsc_stats *tx_stats;
 635
 636                 if (send_index != NETVSC_INVALID_INDEX)
 637                         netvsc_free_send_slot(net_device, send_index);
 638                 q_idx = packet->q_idx;
 639                 channel = incoming_channel;
 640
 641                 tx_stats = &net_device->chan_table[q_idx].tx_stats;
 642
 643                 u64_stats_update_begin(&tx_stats->syncp);
 644                 tx_stats->packets += packet->total_packets;
 645                 tx_stats->bytes += packet->total_bytes;
 646                 u64_stats_update_end(&tx_stats->syncp);
 647
 648                 napi_consume_skb(skb, budget);
 649         }
 650
 651         queue_sends =
 652                 atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
 653
 654         if (net_device->destroy && queue_sends == 0)
 655                 wake_up(&net_device->wait_drain);
 656
 657         if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) &&
 658             (hv_ringbuf_avail_percent(&channel->outbound) > RING_AVAIL_PERCENT_HIWATER ||
 659              queue_sends < 1))
 660                 netif_tx_wake_queue(netdev_get_tx_queue(ndev, q_idx));
 661 }
 662
 663 static void netvsc_send_completion(struct netvsc_device *net_device,
 664                                    struct vmbus_channel *incoming_channel,
 665                                    struct hv_device *device,
 666                                    const struct vmpacket_descriptor *desc,
 667                                    int budget)
 668 {
 669         struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
 670         struct net_device *ndev = hv_get_drvdata(device);
 671
 672         switch (nvsp_packet->hdr.msg_type) {
 673         case NVSP_MSG_TYPE_INIT_COMPLETE:
 674         case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
 675         case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
 676         case NVSP_MSG5_TYPE_SUBCHANNEL:
 677                 /* Copy the response back */
 678                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 679                        sizeof(struct nvsp_message));
 680                 complete(&net_device->channel_init_wait);
 681                 break;
 682
 683         case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
 684                 netvsc_send_tx_complete(net_device, incoming_channel,
 685                                         device, desc, budget);
 686                 break;
 687
 688         default:
 689                 netdev_err(ndev,
 690                            "Unknown send completion type %d received!!\n",
 691                            nvsp_packet->hdr.msg_type);
 692         }
 693 }
 694
 695 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 696 {
 697         unsigned long *map_addr = net_device->send_section_map;
 698         unsigned int i;
 699
 700         for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
 701                 if (sync_test_and_set_bit(i, map_addr) == 0)
 702                         return i;
 703         }
 704
 705         return NETVSC_INVALID_INDEX;
 706 }
 707
 708 static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 709                                    unsigned int section_index,
 710                                    u32 pend_size,
 711                                    struct hv_netvsc_packet *packet,
 712                                    struct rndis_message *rndis_msg,
 713                                    struct hv_page_buffer **pb,
 714                                    struct sk_buff *skb)
 715 {
 716         char *start = net_device->send_buf;
 717         char *dest = start + (section_index * net_device->send_section_size)
 718                      + pend_size;
 719         int i;
 720         u32 msg_size = 0;
 721         u32 padding = 0;
 722         u32 remain = packet->total_data_buflen % net_device->pkt_align;
 723         u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 724                 packet->page_buf_cnt;
 725
 726         /* Add padding */
 727         if (skb->xmit_more && remain && !packet->cp_partial) {
 728                 padding = net_device->pkt_align - remain;
 729                 rndis_msg->msg_len += padding;
 730                 packet->total_data_buflen += padding;
 731         }
 732
 733         for (i = 0; i < page_count; i++) {
 734                 char *src = phys_to_virt((*pb)[i].pfn << PAGE_SHIFT);
 735                 u32 offset = (*pb)[i].offset;
 736                 u32 len = (*pb)[i].len;
 737
 738                 memcpy(dest, (src + offset), len);
 739                 msg_size += len;
 740                 dest += len;
 741         }
 742
 743         if (padding) {
 744                 memset(dest, 0, padding);
 745                 msg_size += padding;
 746         }
 747
 748         return msg_size;
 749 }
 750
 751 static inline int netvsc_send_pkt(
 752         struct hv_device *device,
 753         struct hv_netvsc_packet *packet,
 754         struct netvsc_device *net_device,
 755         struct hv_page_buffer **pb,
 756         struct sk_buff *skb)
 757 {
 758         struct nvsp_message nvmsg;
 759         struct netvsc_channel *nvchan
 760                 = &net_device->chan_table[packet->q_idx];
 761         struct vmbus_channel *out_channel = nvchan->channel;
 762         struct net_device *ndev = hv_get_drvdata(device);
 763         struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
 764         u64 req_id;
 765         int ret;
 766         struct hv_page_buffer *pgbuf;
 767         u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
 768
 769         nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 770         if (skb != NULL) {
 771                 /* 0 is RMC_DATA; */
 772                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 0;
 773         } else {
 774                 /* 1 is RMC_CONTROL; */
 775                 nvmsg.msg.v1_msg.send_rndis_pkt.channel_type = 1;
 776         }
 777
 778         nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_index =
 779                 packet->send_buf_index;
 780         if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 781                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size = 0;
 782         else
 783                 nvmsg.msg.v1_msg.send_rndis_pkt.send_buf_section_size =
 784                         packet->total_data_buflen;
 785
 786         req_id = (ulong)skb;
 787
 788         if (out_channel->rescind)
 789                 return -ENODEV;
 790
 791         if (packet->page_buf_cnt) {
 792                 pgbuf = packet->cp_partial ? (*pb) +
 793                         packet->rmsg_pgcnt : (*pb);
 794                 ret = vmbus_sendpacket_pagebuffer_ctl(out_channel,
 795                                                       pgbuf,
 796                                                       packet->page_buf_cnt,
 797                                                       &nvmsg,
 798                                                       sizeof(struct nvsp_message),
 799                                                       req_id,
 800                                                       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 801         } else {
 802                 ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
 803                                            sizeof(struct nvsp_message),
 804                                            req_id,
 805                                            VM_PKT_DATA_INBAND,
 806                                            VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 807         }
 808
 809         if (ret == 0) {
 810                 atomic_inc_return(&nvchan->queue_sends);
 811
 812                 if (ring_avail < RING_AVAIL_PERCENT_LOWATER)
 813                         netif_tx_stop_queue(txq);
 814         } else if (ret == -EAGAIN) {
 815                 netif_tx_stop_queue(txq);
 816                 if (atomic_read(&nvchan->queue_sends) < 1) {
 817                         netif_tx_wake_queue(txq);
 818                         ret = -ENOSPC;
 819                 }
 820         } else {
 821                 netdev_err(ndev, "Unable to send packet %p ret %d\n",
 822                            packet, ret);
 823         }
 824
 825         return ret;
 826 }
 827
 828 /* Move packet out of multi send data (msd), and clear msd */
 829 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
 830                                 struct sk_buff **msd_skb,
 831                                 struct multi_send_data *msdp)
 832 {
 833         *msd_skb = msdp->skb;
 834         *msd_send = msdp->pkt;
 835         msdp->skb = NULL;
 836         msdp->pkt = NULL;
 837         msdp->count = 0;
 838 }
 839
 840 int netvsc_send(struct hv_device *device,
 841                 struct hv_netvsc_packet *packet,
 842                 struct rndis_message *rndis_msg,
 843                 struct hv_page_buffer **pb,
 844                 struct sk_buff *skb)
 845 {
 846         struct netvsc_device *net_device;
 847         int ret = 0;
 848         struct netvsc_channel *nvchan;
 849         u32 pktlen = packet->total_data_buflen, msd_len = 0;
 850         unsigned int section_index = NETVSC_INVALID_INDEX;
 851         struct multi_send_data *msdp;
 852         struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
 853         struct sk_buff *msd_skb = NULL;
 854         bool try_batch;
 855         bool xmit_more = (skb != NULL) ? skb->xmit_more : false;
 856
 857         net_device = get_outbound_net_device(device);
 858         if (!net_device)
 859                 return -ENODEV;
 860
 861         /* We may race with netvsc_connect_vsp()/netvsc_init_buf() and get
 862          * here before the negotiation with the host is finished and
 863          * send_section_map may not be allocated yet.
 864          */
 865         if (!net_device->send_section_map)
 866                 return -EAGAIN;
 867
 868         nvchan = &net_device->chan_table[packet->q_idx];
 869         packet->send_buf_index = NETVSC_INVALID_INDEX;
 870         packet->cp_partial = false;
 871
 872         /* Send control message directly without accessing msd (Multi-Send
 873          * Data) field which may be changed during data packet processing.
 874          */
 875         if (!skb) {
 876                 cur_send = packet;
 877                 goto send_now;
 878         }
 879
 880         /* batch packets in send buffer if possible */
 881         msdp = &nvchan->msd;
 882         if (msdp->pkt)
 883                 msd_len = msdp->pkt->total_data_buflen;
 884
 885         try_batch =  msd_len > 0 && msdp->count < net_device->max_pkt;
 886         if (try_batch && msd_len + pktlen + net_device->pkt_align <
 887             net_device->send_section_size) {
 888                 section_index = msdp->pkt->send_buf_index;
 889
 890         } else if (try_batch && msd_len + packet->rmsg_size <
 891                    net_device->send_section_size) {
 892                 section_index = msdp->pkt->send_buf_index;
 893                 packet->cp_partial = true;
 894
 895         } else if (pktlen + net_device->pkt_align <
 896                    net_device->send_section_size) {
 897                 section_index = netvsc_get_next_send_section(net_device);
 898                 if (section_index != NETVSC_INVALID_INDEX) {
 899                         move_pkt_msd(&msd_send, &msd_skb, msdp);
 900                         msd_len = 0;
 901                 }
 902         }
 903
 904         if (section_index != NETVSC_INVALID_INDEX) {
 905                 netvsc_copy_to_send_buf(net_device,
 906                                         section_index, msd_len,
 907                                         packet, rndis_msg, pb, skb);
 908
 909                 packet->send_buf_index = section_index;
 910
 911                 if (packet->cp_partial) {
 912                         packet->page_buf_cnt -= packet->rmsg_pgcnt;
 913                         packet->total_data_buflen = msd_len + packet->rmsg_size;
 914                 } else {
 915                         packet->page_buf_cnt = 0;
 916                         packet->total_data_buflen += msd_len;
 917                 }
 918
 919                 if (msdp->pkt) {
 920                         packet->total_packets += msdp->pkt->total_packets;
 921                         packet->total_bytes += msdp->pkt->total_bytes;
 922                 }
 923
 924                 if (msdp->skb)
 925                         dev_consume_skb_any(msdp->skb);
 926
 927                 if (xmit_more && !packet->cp_partial) {
 928                         msdp->skb = skb;
 929                         msdp->pkt = packet;
 930                         msdp->count++;
 931                 } else {
 932                         cur_send = packet;
 933                         msdp->skb = NULL;
 934                         msdp->pkt = NULL;
 935                         msdp->count = 0;
 936                 }
 937         } else {
 938                 move_pkt_msd(&msd_send, &msd_skb, msdp);
 939                 cur_send = packet;
 940         }
 941
 942         if (msd_send) {
 943                 int m_ret = netvsc_send_pkt(device, msd_send, net_device,
 944                                             NULL, msd_skb);
 945
 946                 if (m_ret != 0) {
 947                         netvsc_free_send_slot(net_device,
 948                                               msd_send->send_buf_index);
 949                         dev_kfree_skb_any(msd_skb);
 950                 }
 951         }
 952
 953 send_now:
 954         if (cur_send)
 955                 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
 956
 957         if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
 958                 netvsc_free_send_slot(net_device, section_index);
 959
 960         return ret;
 961 }
 962
 963 static int netvsc_send_recv_completion(struct vmbus_channel *channel,
 964                                        u64 transaction_id, u32 status)
 965 {
 966         struct nvsp_message recvcompMessage;
 967         int ret;
 968
 969         recvcompMessage.hdr.msg_type =
 970                                 NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE;
 971
 972         recvcompMessage.msg.v1_msg.send_rndis_pkt_complete.status = status;
 973
 974         /* Send the completion */
 975         ret = vmbus_sendpacket(channel, &recvcompMessage,
 976                                sizeof(struct nvsp_message_header) + sizeof(u32),
 977                                transaction_id, VM_PKT_COMP, 0);
 978
 979         return ret;
 980 }
 981
 982 static inline void count_recv_comp_slot(struct netvsc_device *nvdev, u16 q_idx,
 983                                         u32 *filled, u32 *avail)
 984 {
 985         struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc;
 986         u32 first = mrc->first;
 987         u32 next = mrc->next;
 988
 989         *filled = (first > next) ? NETVSC_RECVSLOT_MAX - first + next :
 990                   next - first;
 991
 992         *avail = NETVSC_RECVSLOT_MAX - *filled - 1;
 993 }
 994
 995 /* Read the first filled slot, no change to index */
 996 static inline struct recv_comp_data *read_recv_comp_slot(struct netvsc_device
 997                                                          *nvdev, u16 q_idx)
 998 {
 999         struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc;
1000         u32 filled, avail;
1001
1002         if (unlikely(!mrc->buf))
1003                 return NULL;
1004
1005         count_recv_comp_slot(nvdev, q_idx, &filled, &avail);
1006         if (!filled)
1007                 return NULL;
1008
1009         return mrc->buf + mrc->first * sizeof(struct recv_comp_data);
1010 }
1011
1012 /* Put the first filled slot back to available pool */
1013 static inline void put_recv_comp_slot(struct netvsc_device *nvdev, u16 q_idx)
1014 {
1015         struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc;
1016         int num_recv;
1017
1018         mrc->first = (mrc->first + 1) % NETVSC_RECVSLOT_MAX;
1019
1020         num_recv = atomic_dec_return(&nvdev->num_outstanding_recvs);
1021
1022         if (nvdev->destroy && num_recv == 0)
1023                 wake_up(&nvdev->wait_drain);
1024 }
1025
1026 /* Check and send pending recv completions */
1027 static void netvsc_chk_recv_comp(struct netvsc_device *nvdev,
1028                                  struct vmbus_channel *channel, u16 q_idx)
1029 {
1030         struct recv_comp_data *rcd;
1031         int ret;
1032
1033         while (true) {
1034                 rcd = read_recv_comp_slot(nvdev, q_idx);
1035                 if (!rcd)
1036                         break;
1037
1038                 ret = netvsc_send_recv_completion(channel, rcd->tid,
1039                                                   rcd->status);
1040                 if (ret)
1041                         break;
1042
1043                 put_recv_comp_slot(nvdev, q_idx);
1044         }
1045 }
1046
1047 #define NETVSC_RCD_WATERMARK 80
1048
1049 /* Get next available slot */
1050 static inline struct recv_comp_data *get_recv_comp_slot(
1051         struct netvsc_device *nvdev, struct vmbus_channel *channel, u16 q_idx)
1052 {
1053         struct multi_recv_comp *mrc = &nvdev->chan_table[q_idx].mrc;
1054         u32 filled, avail, next;
1055         struct recv_comp_data *rcd;
1056
1057         if (unlikely(!nvdev->recv_section))
1058                 return NULL;
1059
1060         if (unlikely(!mrc->buf))
1061                 return NULL;
1062
1063         if (atomic_read(&nvdev->num_outstanding_recvs) >
1064             nvdev->recv_section->num_sub_allocs * NETVSC_RCD_WATERMARK / 100)
1065                 netvsc_chk_recv_comp(nvdev, channel, q_idx);
1066
1067         count_recv_comp_slot(nvdev, q_idx, &filled, &avail);
1068         if (!avail)
1069                 return NULL;
1070
1071         next = mrc->next;
1072         rcd = mrc->buf + next * sizeof(struct recv_comp_data);
1073         mrc->next = (next + 1) % NETVSC_RECVSLOT_MAX;
1074
1075         atomic_inc(&nvdev->num_outstanding_recvs);
1076
1077         return rcd;
1078 }
1079
1080 static int netvsc_receive(struct net_device *ndev,
1081                    struct netvsc_device *net_device,
1082                    struct net_device_context *net_device_ctx,
1083                    struct hv_device *device,
1084                    struct vmbus_channel *channel,
1085                    const struct vmpacket_descriptor *desc,
1086                    struct nvsp_message *nvsp)
1087 {
1088         const struct vmtransfer_page_packet_header *vmxferpage_packet
1089                 = container_of(desc, const struct vmtransfer_page_packet_header, d);
1090         u16 q_idx = channel->offermsg.offer.sub_channel_index;
1091         char *recv_buf = net_device->recv_buf;
1092         u32 status = NVSP_STAT_SUCCESS;
1093         int i;
1094         int count = 0;
1095         int ret;
1096
1097         /* Make sure this is a valid nvsp packet */
1098         if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1099                 netif_err(net_device_ctx, rx_err, ndev,
1100                           "Unknown nvsp packet type received %u\n",
1101                           nvsp->hdr.msg_type);
1102                 return 0;
1103         }
1104
1105         if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1106                 netif_err(net_device_ctx, rx_err, ndev,
1107                           "Invalid xfer page set id - expecting %x got %x\n",
1108                           NETVSC_RECEIVE_BUFFER_ID,
1109                           vmxferpage_packet->xfer_pageset_id);
1110                 return 0;
1111         }
1112
1113         count = vmxferpage_packet->range_cnt;
1114
1115         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1116         for (i = 0; i < count; i++) {
1117                 void *data = recv_buf
1118                         + vmxferpage_packet->ranges[i].byte_offset;
1119                 u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1120
1121                 /* Pass it to the upper layer */
1122                 status = rndis_filter_receive(ndev, net_device, device,
1123                                               channel, data, buflen);
1124         }
1125
1126         if (net_device->chan_table[q_idx].mrc.buf) {
1127                 struct recv_comp_data *rcd;
1128
1129                 rcd = get_recv_comp_slot(net_device, channel, q_idx);
1130                 if (rcd) {
1131                         rcd->tid = vmxferpage_packet->d.trans_id;
1132                         rcd->status = status;
1133                 } else {
1134                         netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1135                                    q_idx, vmxferpage_packet->d.trans_id);
1136                 }
1137         } else {
1138                 ret = netvsc_send_recv_completion(channel,
1139                                                   vmxferpage_packet->d.trans_id,
1140                                                   status);
1141                 if (ret)
1142                         netdev_err(ndev, "Recv_comp q:%hd, tid:%llx, err:%d\n",
1143                                    q_idx, vmxferpage_packet->d.trans_id, ret);
1144         }
1145         return count;
1146 }
1147
1148 static void netvsc_send_table(struct hv_device *hdev,
1149                               struct nvsp_message *nvmsg)
1150 {
1151         struct net_device *ndev = hv_get_drvdata(hdev);
1152         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1153         int i;
1154         u32 count, *tab;
1155
1156         count = nvmsg->msg.v5_msg.send_table.count;
1157         if (count != VRSS_SEND_TAB_SIZE) {
1158                 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1159                 return;
1160         }
1161
1162         tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1163                       nvmsg->msg.v5_msg.send_table.offset);
1164
1165         for (i = 0; i < count; i++)
1166                 net_device_ctx->tx_send_table[i] = tab[i];
1167 }
1168
1169 static void netvsc_send_vf(struct net_device_context *net_device_ctx,
1170                            struct nvsp_message *nvmsg)
1171 {
1172         net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1173         net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1174 }
1175
1176 static inline void netvsc_receive_inband(struct hv_device *hdev,
1177                                  struct net_device_context *net_device_ctx,
1178                                  struct nvsp_message *nvmsg)
1179 {
1180         switch (nvmsg->hdr.msg_type) {
1181         case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1182                 netvsc_send_table(hdev, nvmsg);
1183                 break;
1184
1185         case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1186                 netvsc_send_vf(net_device_ctx, nvmsg);
1187                 break;
1188         }
1189 }
1190
1191 static int netvsc_process_raw_pkt(struct hv_device *device,
1192                                   struct vmbus_channel *channel,
1193                                   struct netvsc_device *net_device,
1194                                   struct net_device *ndev,
1195                                   const struct vmpacket_descriptor *desc,
1196                                   int budget)
1197 {
1198         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1199         struct nvsp_message *nvmsg = hv_pkt_data(desc);
1200
1201         switch (desc->type) {
1202         case VM_PKT_COMP:
1203                 netvsc_send_completion(net_device, channel, device,
1204                                        desc, budget);
1205                 break;
1206
1207         case VM_PKT_DATA_USING_XFER_PAGES:
1208                 return netvsc_receive(ndev, net_device, net_device_ctx,
1209                                       device, channel, desc, nvmsg);
1210                 break;
1211
1212         case VM_PKT_DATA_INBAND:
1213                 netvsc_receive_inband(device, net_device_ctx, nvmsg);
1214                 break;
1215
1216         default:
1217                 netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1218                            desc->type, desc->trans_id);
1219                 break;
1220         }
1221
1222         return 0;
1223 }
1224
1225 static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1226 {
1227         struct vmbus_channel *primary = channel->primary_channel;
1228
1229         return primary ? primary->device_obj : channel->device_obj;
1230 }
1231
1232 /* Network processing softirq
1233  * Process data in incoming ring buffer from host
1234  * Stops when ring is empty or budget is met or exceeded.
1235  */
1236 int netvsc_poll(struct napi_struct *napi, int budget)
1237 {
1238         struct netvsc_channel *nvchan
1239                 = container_of(napi, struct netvsc_channel, napi);
1240         struct vmbus_channel *channel = nvchan->channel;
1241         struct hv_device *device = netvsc_channel_to_device(channel);
1242         u16 q_idx = channel->offermsg.offer.sub_channel_index;
1243         struct net_device *ndev = hv_get_drvdata(device);
1244         struct netvsc_device *net_device = net_device_to_netvsc_device(ndev);
1245         int work_done = 0;
1246
1247         /* If starting a new interval */
1248         if (!nvchan->desc)
1249                 nvchan->desc = hv_pkt_iter_first(channel);
1250
1251         while (nvchan->desc && work_done < budget) {
1252                 work_done += netvsc_process_raw_pkt(device, channel, net_device,
1253                                                     ndev, nvchan->desc, budget);
1254                 nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1255         }
1256
1257         /* If receive ring was exhausted
1258          * and not doing busy poll
1259          * then re-enable host interrupts
1260          *  and reschedule if ring is not empty.
1261          */
1262         if (work_done < budget &&
1263             napi_complete_done(napi, work_done) &&
1264             hv_end_read(&channel->inbound) != 0)
1265                 napi_reschedule(napi);
1266
1267         netvsc_chk_recv_comp(net_device, channel, q_idx);
1268
1269         /* Driver may overshoot since multiple packets per descriptor */
1270         return min(work_done, budget);
1271 }
1272
1273 /* Call back when data is available in host ring buffer.
1274  * Processing is deferred until network softirq (NAPI)
1275  */
1276 void netvsc_channel_cb(void *context)
1277 {
1278         struct netvsc_channel *nvchan = context;
1279
1280         if (napi_schedule_prep(&nvchan->napi)) {
1281                 /* disable interupts from host */
1282                 hv_begin_read(&nvchan->channel->inbound);
1283
1284                 __napi_schedule(&nvchan->napi);
1285         }
1286 }
1287
1288 /*
1289  * netvsc_device_add - Callback when the device belonging to this
1290  * driver is added
1291  */
1292 int netvsc_device_add(struct hv_device *device,
1293                       const struct netvsc_device_info *device_info)
1294 {
1295         int i, ret = 0;
1296         int ring_size = device_info->ring_size;
1297         struct netvsc_device *net_device;
1298         struct net_device *ndev = hv_get_drvdata(device);
1299         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1300
1301         net_device = alloc_net_device();
1302         if (!net_device)
1303                 return -ENOMEM;
1304
1305         net_device->ring_size = ring_size;
1306
1307         /* Because the device uses NAPI, all the interrupt batching and
1308          * control is done via Net softirq, not the channel handling
1309          */
1310         set_channel_read_mode(device->channel, HV_CALL_ISR);
1311
1312         /* If we're reopening the device we may have multiple queues, fill the
1313          * chn_table with the default channel to use it before subchannels are
1314          * opened.
1315          * Initialize the channel state before we open;
1316          * we can be interrupted as soon as we open the channel.
1317          */
1318
1319         for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1320                 struct netvsc_channel *nvchan = &net_device->chan_table[i];
1321
1322                 nvchan->channel = device->channel;
1323         }
1324
1325         /* Enable NAPI handler before init callbacks */
1326         netif_napi_add(ndev, &net_device->chan_table[0].napi,
1327                        netvsc_poll, NAPI_POLL_WEIGHT);
1328
1329         /* Open the channel */
1330         ret = vmbus_open(device->channel, ring_size * PAGE_SIZE,
1331                          ring_size * PAGE_SIZE, NULL, 0,
1332                          netvsc_channel_cb,
1333                          net_device->chan_table);
1334
1335         if (ret != 0) {
1336                 netif_napi_del(&net_device->chan_table[0].napi);
1337                 netdev_err(ndev, "unable to open channel: %d\n", ret);
1338                 goto cleanup;
1339         }
1340
1341         /* Channel is opened */
1342         netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1343
1344         napi_enable(&net_device->chan_table[0].napi);
1345
1346         /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1347          * populated.
1348          */
1349         rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1350
1351         /* Connect with the NetVsp */
1352         ret = netvsc_connect_vsp(device);
1353         if (ret != 0) {
1354                 netdev_err(ndev,
1355                         "unable to connect to NetVSP - %d\n", ret);
1356                 goto close;
1357         }
1358
1359         return ret;
1360
1361 close:
1362         netif_napi_del(&net_device->chan_table[0].napi);
1363
1364         /* Now, we can close the channel safely */
1365         vmbus_close(device->channel);
1366
1367 cleanup:
1368         free_netvsc_device(&net_device->rcu);
1369
1370         return ret;
1371 }