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 <linux/rtnetlink.h>
  33 #include <linux/prefetch.h>
  34 #include <linux/reciprocal_div.h>
  35
  36 #include <asm/sync_bitops.h>
  37
  38 #include "hyperv_net.h"
  39 #include "netvsc_trace.h"
  40
  41 /*
  42  * Switch the data path from the synthetic interface to the VF
  43  * interface.
  44  */
  45 void netvsc_switch_datapath(struct net_device *ndev, bool vf)
  46 {
  47         struct net_device_context *net_device_ctx = netdev_priv(ndev);
  48         struct hv_device *dev = net_device_ctx->device_ctx;
  49         struct netvsc_device *nv_dev = rtnl_dereference(net_device_ctx->nvdev);
  50         struct nvsp_message *init_pkt = &nv_dev->channel_init_pkt;
  51
  52         memset(init_pkt, 0, sizeof(struct nvsp_message));
  53         init_pkt->hdr.msg_type = NVSP_MSG4_TYPE_SWITCH_DATA_PATH;
  54         if (vf)
  55                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  56                         NVSP_DATAPATH_VF;
  57         else
  58                 init_pkt->msg.v4_msg.active_dp.active_datapath =
  59                         NVSP_DATAPATH_SYNTHETIC;
  60
  61         trace_nvsp_send(ndev, init_pkt);
  62
  63         vmbus_sendpacket(dev->channel, init_pkt,
  64                                sizeof(struct nvsp_message),
  65                                (unsigned long)init_pkt,
  66                                VM_PKT_DATA_INBAND, 0);
  67 }
  68
  69 static struct netvsc_device *alloc_net_device(void)
  70 {
  71         struct netvsc_device *net_device;
  72
  73         net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
  74         if (!net_device)
  75                 return NULL;
  76
  77         init_waitqueue_head(&net_device->wait_drain);
  78         net_device->destroy = false;
  79
  80         net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
  81         net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;
  82
  83         init_completion(&net_device->channel_init_wait);
  84         init_waitqueue_head(&net_device->subchan_open);
  85         INIT_WORK(&net_device->subchan_work, rndis_set_subchannel);
  86
  87         return net_device;
  88 }
  89
  90 static void free_netvsc_device(struct rcu_head *head)
  91 {
  92         struct netvsc_device *nvdev
  93                 = container_of(head, struct netvsc_device, rcu);
  94         int i;
  95
  96         kfree(nvdev->extension);
  97         vfree(nvdev->recv_buf);
  98         vfree(nvdev->send_buf);
  99         kfree(nvdev->send_section_map);
 100
 101         for (i = 0; i < VRSS_CHANNEL_MAX; i++)
 102                 vfree(nvdev->chan_table[i].mrc.slots);
 103
 104         kfree(nvdev);
 105 }
 106
 107 static void free_netvsc_device_rcu(struct netvsc_device *nvdev)
 108 {
 109         call_rcu(&nvdev->rcu, free_netvsc_device);
 110 }
 111
 112 static void netvsc_revoke_recv_buf(struct hv_device *device,
 113                                    struct netvsc_device *net_device)
 114 {
 115         struct net_device *ndev = hv_get_drvdata(device);
 116         struct nvsp_message *revoke_packet;
 117         int ret;
 118
 119         /*
 120          * If we got a section count, it means we received a
 121          * SendReceiveBufferComplete msg (ie sent
 122          * NvspMessage1TypeSendReceiveBuffer msg) therefore, we need
 123          * to send a revoke msg here
 124          */
 125         if (net_device->recv_section_cnt) {
 126                 /* Send the revoke receive buffer */
 127                 revoke_packet = &net_device->revoke_packet;
 128                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 129
 130                 revoke_packet->hdr.msg_type =
 131                         NVSP_MSG1_TYPE_REVOKE_RECV_BUF;
 132                 revoke_packet->msg.v1_msg.
 133                 revoke_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 134
 135                 trace_nvsp_send(ndev, revoke_packet);
 136
 137                 ret = vmbus_sendpacket(device->channel,
 138                                        revoke_packet,
 139                                        sizeof(struct nvsp_message),
 140                                        (unsigned long)revoke_packet,
 141                                        VM_PKT_DATA_INBAND, 0);
 142                 /* If the failure is because the channel is rescinded;
 143                  * ignore the failure since we cannot send on a rescinded
 144                  * channel. This would allow us to properly cleanup
 145                  * even when the channel is rescinded.
 146                  */
 147                 if (device->channel->rescind)
 148                         ret = 0;
 149                 /*
 150                  * If we failed here, we might as well return and
 151                  * have a leak rather than continue and a bugchk
 152                  */
 153                 if (ret != 0) {
 154                         netdev_err(ndev, "unable to send "
 155                                 "revoke receive buffer to netvsp\n");
 156                         return;
 157                 }
 158                 net_device->recv_section_cnt = 0;
 159         }
 160 }
 161
 162 static void netvsc_revoke_send_buf(struct hv_device *device,
 163                                    struct netvsc_device *net_device)
 164 {
 165         struct net_device *ndev = hv_get_drvdata(device);
 166         struct nvsp_message *revoke_packet;
 167         int ret;
 168
 169         /* Deal with the send buffer we may have setup.
 170          * If we got a  send section size, it means we received a
 171          * NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE msg (ie sent
 172          * NVSP_MSG1_TYPE_SEND_SEND_BUF msg) therefore, we need
 173          * to send a revoke msg here
 174          */
 175         if (net_device->send_section_cnt) {
 176                 /* Send the revoke receive buffer */
 177                 revoke_packet = &net_device->revoke_packet;
 178                 memset(revoke_packet, 0, sizeof(struct nvsp_message));
 179
 180                 revoke_packet->hdr.msg_type =
 181                         NVSP_MSG1_TYPE_REVOKE_SEND_BUF;
 182                 revoke_packet->msg.v1_msg.revoke_send_buf.id =
 183                         NETVSC_SEND_BUFFER_ID;
 184
 185                 trace_nvsp_send(ndev, revoke_packet);
 186
 187                 ret = vmbus_sendpacket(device->channel,
 188                                        revoke_packet,
 189                                        sizeof(struct nvsp_message),
 190                                        (unsigned long)revoke_packet,
 191                                        VM_PKT_DATA_INBAND, 0);
 192
 193                 /* If the failure is because the channel is rescinded;
 194                  * ignore the failure since we cannot send on a rescinded
 195                  * channel. This would allow us to properly cleanup
 196                  * even when the channel is rescinded.
 197                  */
 198                 if (device->channel->rescind)
 199                         ret = 0;
 200
 201                 /* If we failed here, we might as well return and
 202                  * have a leak rather than continue and a bugchk
 203                  */
 204                 if (ret != 0) {
 205                         netdev_err(ndev, "unable to send "
 206                                    "revoke send buffer to netvsp\n");
 207                         return;
 208                 }
 209                 net_device->send_section_cnt = 0;
 210         }
 211 }
 212
 213 static void netvsc_teardown_recv_gpadl(struct hv_device *device,
 214                                        struct netvsc_device *net_device)
 215 {
 216         struct net_device *ndev = hv_get_drvdata(device);
 217         int ret;
 218
 219         if (net_device->recv_buf_gpadl_handle) {
 220                 ret = vmbus_teardown_gpadl(device->channel,
 221                                            net_device->recv_buf_gpadl_handle);
 222
 223                 /* If we failed here, we might as well return and have a leak
 224                  * rather than continue and a bugchk
 225                  */
 226                 if (ret != 0) {
 227                         netdev_err(ndev,
 228                                    "unable to teardown receive buffer's gpadl\n");
 229                         return;
 230                 }
 231                 net_device->recv_buf_gpadl_handle = 0;
 232         }
 233 }
 234
 235 static void netvsc_teardown_send_gpadl(struct hv_device *device,
 236                                        struct netvsc_device *net_device)
 237 {
 238         struct net_device *ndev = hv_get_drvdata(device);
 239         int ret;
 240
 241         if (net_device->send_buf_gpadl_handle) {
 242                 ret = vmbus_teardown_gpadl(device->channel,
 243                                            net_device->send_buf_gpadl_handle);
 244
 245                 /* If we failed here, we might as well return and have a leak
 246                  * rather than continue and a bugchk
 247                  */
 248                 if (ret != 0) {
 249                         netdev_err(ndev,
 250                                    "unable to teardown send buffer's gpadl\n");
 251                         return;
 252                 }
 253                 net_device->send_buf_gpadl_handle = 0;
 254         }
 255 }
 256
 257 int netvsc_alloc_recv_comp_ring(struct netvsc_device *net_device, u32 q_idx)
 258 {
 259         struct netvsc_channel *nvchan = &net_device->chan_table[q_idx];
 260         int node = cpu_to_node(nvchan->channel->target_cpu);
 261         size_t size;
 262
 263         size = net_device->recv_completion_cnt * sizeof(struct recv_comp_data);
 264         nvchan->mrc.slots = vzalloc_node(size, node);
 265         if (!nvchan->mrc.slots)
 266                 nvchan->mrc.slots = vzalloc(size);
 267
 268         return nvchan->mrc.slots ? 0 : -ENOMEM;
 269 }
 270
 271 static int netvsc_init_buf(struct hv_device *device,
 272                            struct netvsc_device *net_device,
 273                            const struct netvsc_device_info *device_info)
 274 {
 275         struct nvsp_1_message_send_receive_buffer_complete *resp;
 276         struct net_device *ndev = hv_get_drvdata(device);
 277         struct nvsp_message *init_packet;
 278         unsigned int buf_size;
 279         size_t map_words;
 280         int ret = 0;
 281
 282         /* Get receive buffer area. */
 283         buf_size = device_info->recv_sections * device_info->recv_section_size;
 284         buf_size = roundup(buf_size, PAGE_SIZE);
 285
 286         /* Legacy hosts only allow smaller receive buffer */
 287         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_2)
 288                 buf_size = min_t(unsigned int, buf_size,
 289                                  NETVSC_RECEIVE_BUFFER_SIZE_LEGACY);
 290
 291         net_device->recv_buf = vzalloc(buf_size);
 292         if (!net_device->recv_buf) {
 293                 netdev_err(ndev,
 294                            "unable to allocate receive buffer of size %u\n",
 295                            buf_size);
 296                 ret = -ENOMEM;
 297                 goto cleanup;
 298         }
 299
 300         net_device->recv_buf_size = buf_size;
 301
 302         /*
 303          * Establish the gpadl handle for this buffer on this
 304          * channel.  Note: This call uses the vmbus connection rather
 305          * than the channel to establish the gpadl handle.
 306          */
 307         ret = vmbus_establish_gpadl(device->channel, net_device->recv_buf,
 308                                     buf_size,
 309                                     &net_device->recv_buf_gpadl_handle);
 310         if (ret != 0) {
 311                 netdev_err(ndev,
 312                         "unable to establish receive buffer's gpadl\n");
 313                 goto cleanup;
 314         }
 315
 316         /* Notify the NetVsp of the gpadl handle */
 317         init_packet = &net_device->channel_init_pkt;
 318         memset(init_packet, 0, sizeof(struct nvsp_message));
 319         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_RECV_BUF;
 320         init_packet->msg.v1_msg.send_recv_buf.
 321                 gpadl_handle = net_device->recv_buf_gpadl_handle;
 322         init_packet->msg.v1_msg.
 323                 send_recv_buf.id = NETVSC_RECEIVE_BUFFER_ID;
 324
 325         trace_nvsp_send(ndev, init_packet);
 326
 327         /* Send the gpadl notification request */
 328         ret = vmbus_sendpacket(device->channel, init_packet,
 329                                sizeof(struct nvsp_message),
 330                                (unsigned long)init_packet,
 331                                VM_PKT_DATA_INBAND,
 332                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 333         if (ret != 0) {
 334                 netdev_err(ndev,
 335                         "unable to send receive buffer's gpadl to netvsp\n");
 336                 goto cleanup;
 337         }
 338
 339         wait_for_completion(&net_device->channel_init_wait);
 340
 341         /* Check the response */
 342         resp = &init_packet->msg.v1_msg.send_recv_buf_complete;
 343         if (resp->status != NVSP_STAT_SUCCESS) {
 344                 netdev_err(ndev,
 345                            "Unable to complete receive buffer initialization with NetVsp - status %d\n",
 346                            resp->status);
 347                 ret = -EINVAL;
 348                 goto cleanup;
 349         }
 350
 351         /* Parse the response */
 352         netdev_dbg(ndev, "Receive sections: %u sub_allocs: size %u count: %u\n",
 353                    resp->num_sections, resp->sections[0].sub_alloc_size,
 354                    resp->sections[0].num_sub_allocs);
 355
 356         /* There should only be one section for the entire receive buffer */
 357         if (resp->num_sections != 1 || resp->sections[0].offset != 0) {
 358                 ret = -EINVAL;
 359                 goto cleanup;
 360         }
 361
 362         net_device->recv_section_size = resp->sections[0].sub_alloc_size;
 363         net_device->recv_section_cnt = resp->sections[0].num_sub_allocs;
 364
 365         /* Setup receive completion ring */
 366         net_device->recv_completion_cnt
 367                 = round_up(net_device->recv_section_cnt + 1,
 368                            PAGE_SIZE / sizeof(u64));
 369         ret = netvsc_alloc_recv_comp_ring(net_device, 0);
 370         if (ret)
 371                 goto cleanup;
 372
 373         /* Now setup the send buffer. */
 374         buf_size = device_info->send_sections * device_info->send_section_size;
 375         buf_size = round_up(buf_size, PAGE_SIZE);
 376
 377         net_device->send_buf = vzalloc(buf_size);
 378         if (!net_device->send_buf) {
 379                 netdev_err(ndev, "unable to allocate send buffer of size %u\n",
 380                            buf_size);
 381                 ret = -ENOMEM;
 382                 goto cleanup;
 383         }
 384
 385         /* Establish the gpadl handle for this buffer on this
 386          * channel.  Note: This call uses the vmbus connection rather
 387          * than the channel to establish the gpadl handle.
 388          */
 389         ret = vmbus_establish_gpadl(device->channel, net_device->send_buf,
 390                                     buf_size,
 391                                     &net_device->send_buf_gpadl_handle);
 392         if (ret != 0) {
 393                 netdev_err(ndev,
 394                            "unable to establish send buffer's gpadl\n");
 395                 goto cleanup;
 396         }
 397
 398         /* Notify the NetVsp of the gpadl handle */
 399         init_packet = &net_device->channel_init_pkt;
 400         memset(init_packet, 0, sizeof(struct nvsp_message));
 401         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_SEND_BUF;
 402         init_packet->msg.v1_msg.send_send_buf.gpadl_handle =
 403                 net_device->send_buf_gpadl_handle;
 404         init_packet->msg.v1_msg.send_send_buf.id = NETVSC_SEND_BUFFER_ID;
 405
 406         trace_nvsp_send(ndev, init_packet);
 407
 408         /* Send the gpadl notification request */
 409         ret = vmbus_sendpacket(device->channel, init_packet,
 410                                sizeof(struct nvsp_message),
 411                                (unsigned long)init_packet,
 412                                VM_PKT_DATA_INBAND,
 413                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 414         if (ret != 0) {
 415                 netdev_err(ndev,
 416                            "unable to send send buffer's gpadl to netvsp\n");
 417                 goto cleanup;
 418         }
 419
 420         wait_for_completion(&net_device->channel_init_wait);
 421
 422         /* Check the response */
 423         if (init_packet->msg.v1_msg.
 424             send_send_buf_complete.status != NVSP_STAT_SUCCESS) {
 425                 netdev_err(ndev, "Unable to complete send buffer "
 426                            "initialization with NetVsp - status %d\n",
 427                            init_packet->msg.v1_msg.
 428                            send_send_buf_complete.status);
 429                 ret = -EINVAL;
 430                 goto cleanup;
 431         }
 432
 433         /* Parse the response */
 434         net_device->send_section_size = init_packet->msg.
 435                                 v1_msg.send_send_buf_complete.section_size;
 436
 437         /* Section count is simply the size divided by the section size. */
 438         net_device->send_section_cnt = buf_size / net_device->send_section_size;
 439
 440         netdev_dbg(ndev, "Send section size: %d, Section count:%d\n",
 441                    net_device->send_section_size, net_device->send_section_cnt);
 442
 443         /* Setup state for managing the send buffer. */
 444         map_words = DIV_ROUND_UP(net_device->send_section_cnt, BITS_PER_LONG);
 445
 446         net_device->send_section_map = kcalloc(map_words, sizeof(ulong), GFP_KERNEL);
 447         if (net_device->send_section_map == NULL) {
 448                 ret = -ENOMEM;
 449                 goto cleanup;
 450         }
 451
 452         goto exit;
 453
 454 cleanup:
 455         netvsc_revoke_recv_buf(device, net_device);
 456         netvsc_revoke_send_buf(device, net_device);
 457         netvsc_teardown_recv_gpadl(device, net_device);
 458         netvsc_teardown_send_gpadl(device, net_device);
 459
 460 exit:
 461         return ret;
 462 }
 463
 464 /* Negotiate NVSP protocol version */
 465 static int negotiate_nvsp_ver(struct hv_device *device,
 466                               struct netvsc_device *net_device,
 467                               struct nvsp_message *init_packet,
 468                               u32 nvsp_ver)
 469 {
 470         struct net_device *ndev = hv_get_drvdata(device);
 471         int ret;
 472
 473         memset(init_packet, 0, sizeof(struct nvsp_message));
 474         init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT;
 475         init_packet->msg.init_msg.init.min_protocol_ver = nvsp_ver;
 476         init_packet->msg.init_msg.init.max_protocol_ver = nvsp_ver;
 477
 478         trace_nvsp_send(ndev, init_packet);
 479
 480         /* Send the init request */
 481         ret = vmbus_sendpacket(device->channel, init_packet,
 482                                sizeof(struct nvsp_message),
 483                                (unsigned long)init_packet,
 484                                VM_PKT_DATA_INBAND,
 485                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 486
 487         if (ret != 0)
 488                 return ret;
 489
 490         wait_for_completion(&net_device->channel_init_wait);
 491
 492         if (init_packet->msg.init_msg.init_complete.status !=
 493             NVSP_STAT_SUCCESS)
 494                 return -EINVAL;
 495
 496         if (nvsp_ver == NVSP_PROTOCOL_VERSION_1)
 497                 return 0;
 498
 499         /* NVSPv2 or later: Send NDIS config */
 500         memset(init_packet, 0, sizeof(struct nvsp_message));
 501         init_packet->hdr.msg_type = NVSP_MSG2_TYPE_SEND_NDIS_CONFIG;
 502         init_packet->msg.v2_msg.send_ndis_config.mtu = ndev->mtu + ETH_HLEN;
 503         init_packet->msg.v2_msg.send_ndis_config.capability.ieee8021q = 1;
 504
 505         if (nvsp_ver >= NVSP_PROTOCOL_VERSION_5) {
 506                 init_packet->msg.v2_msg.send_ndis_config.capability.sriov = 1;
 507
 508                 /* Teaming bit is needed to receive link speed updates */
 509                 init_packet->msg.v2_msg.send_ndis_config.capability.teaming = 1;
 510         }
 511
 512         trace_nvsp_send(ndev, init_packet);
 513
 514         ret = vmbus_sendpacket(device->channel, init_packet,
 515                                 sizeof(struct nvsp_message),
 516                                 (unsigned long)init_packet,
 517                                 VM_PKT_DATA_INBAND, 0);
 518
 519         return ret;
 520 }
 521
 522 static int netvsc_connect_vsp(struct hv_device *device,
 523                               struct netvsc_device *net_device,
 524                               const struct netvsc_device_info *device_info)
 525 {
 526         struct net_device *ndev = hv_get_drvdata(device);
 527         static const u32 ver_list[] = {
 528                 NVSP_PROTOCOL_VERSION_1, NVSP_PROTOCOL_VERSION_2,
 529                 NVSP_PROTOCOL_VERSION_4, NVSP_PROTOCOL_VERSION_5
 530         };
 531         struct nvsp_message *init_packet;
 532         int ndis_version, i, ret;
 533
 534         init_packet = &net_device->channel_init_pkt;
 535
 536         /* Negotiate the latest NVSP protocol supported */
 537         for (i = ARRAY_SIZE(ver_list) - 1; i >= 0; i--)
 538                 if (negotiate_nvsp_ver(device, net_device, init_packet,
 539                                        ver_list[i])  == 0) {
 540                         net_device->nvsp_version = ver_list[i];
 541                         break;
 542                 }
 543
 544         if (i < 0) {
 545                 ret = -EPROTO;
 546                 goto cleanup;
 547         }
 548
 549         pr_debug("Negotiated NVSP version:%x\n", net_device->nvsp_version);
 550
 551         /* Send the ndis version */
 552         memset(init_packet, 0, sizeof(struct nvsp_message));
 553
 554         if (net_device->nvsp_version <= NVSP_PROTOCOL_VERSION_4)
 555                 ndis_version = 0x00060001;
 556         else
 557                 ndis_version = 0x0006001e;
 558
 559         init_packet->hdr.msg_type = NVSP_MSG1_TYPE_SEND_NDIS_VER;
 560         init_packet->msg.v1_msg.
 561                 send_ndis_ver.ndis_major_ver =
 562                                 (ndis_version & 0xFFFF0000) >> 16;
 563         init_packet->msg.v1_msg.
 564                 send_ndis_ver.ndis_minor_ver =
 565                                 ndis_version & 0xFFFF;
 566
 567         trace_nvsp_send(ndev, init_packet);
 568
 569         /* Send the init request */
 570         ret = vmbus_sendpacket(device->channel, init_packet,
 571                                 sizeof(struct nvsp_message),
 572                                 (unsigned long)init_packet,
 573                                 VM_PKT_DATA_INBAND, 0);
 574         if (ret != 0)
 575                 goto cleanup;
 576
 577
 578         ret = netvsc_init_buf(device, net_device, device_info);
 579
 580 cleanup:
 581         return ret;
 582 }
 583
 584 /*
 585  * netvsc_device_remove - Callback when the root bus device is removed
 586  */
 587 void netvsc_device_remove(struct hv_device *device)
 588 {
 589         struct net_device *ndev = hv_get_drvdata(device);
 590         struct net_device_context *net_device_ctx = netdev_priv(ndev);
 591         struct netvsc_device *net_device
 592                 = rtnl_dereference(net_device_ctx->nvdev);
 593         int i;
 594
 595         /*
 596          * Revoke receive buffer. If host is pre-Win2016 then tear down
 597          * receive buffer GPADL. Do the same for send buffer.
 598          */
 599         netvsc_revoke_recv_buf(device, net_device);
 600         if (vmbus_proto_version < VERSION_WIN10)
 601                 netvsc_teardown_recv_gpadl(device, net_device);
 602
 603         netvsc_revoke_send_buf(device, net_device);
 604         if (vmbus_proto_version < VERSION_WIN10)
 605                 netvsc_teardown_send_gpadl(device, net_device);
 606
 607         RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
 608
 609         /* And disassociate NAPI context from device */
 610         for (i = 0; i < net_device->num_chn; i++)
 611                 netif_napi_del(&net_device->chan_table[i].napi);
 612
 613         /*
 614          * At this point, no one should be accessing net_device
 615          * except in here
 616          */
 617         netdev_dbg(ndev, "net device safe to remove\n");
 618
 619         /* Now, we can close the channel safely */
 620         vmbus_close(device->channel);
 621
 622         /*
 623          * If host is Win2016 or higher then we do the GPADL tear down
 624          * here after VMBus is closed.
 625         */
 626         if (vmbus_proto_version >= VERSION_WIN10) {
 627                 netvsc_teardown_recv_gpadl(device, net_device);
 628                 netvsc_teardown_send_gpadl(device, net_device);
 629         }
 630
 631         /* Release all resources */
 632         free_netvsc_device_rcu(net_device);
 633 }
 634
 635 #define RING_AVAIL_PERCENT_HIWATER 20
 636 #define RING_AVAIL_PERCENT_LOWATER 10
 637
 638 /*
 639  * Get the percentage of available bytes to write in the ring.
 640  * The return value is in range from 0 to 100.
 641  */
 642 static u32 hv_ringbuf_avail_percent(const struct hv_ring_buffer_info *ring_info)
 643 {
 644         u32 avail_write = hv_get_bytes_to_write(ring_info);
 645
 646         return reciprocal_divide(avail_write  * 100, netvsc_ring_reciprocal);
 647 }
 648
 649 static inline void netvsc_free_send_slot(struct netvsc_device *net_device,
 650                                          u32 index)
 651 {
 652         sync_change_bit(index, net_device->send_section_map);
 653 }
 654
 655 static void netvsc_send_tx_complete(struct netvsc_device *net_device,
 656                                     struct vmbus_channel *incoming_channel,
 657                                     struct hv_device *device,
 658                                     const struct vmpacket_descriptor *desc,
 659                                     int budget)
 660 {
 661         struct sk_buff *skb = (struct sk_buff *)(unsigned long)desc->trans_id;
 662         struct net_device *ndev = hv_get_drvdata(device);
 663         struct net_device_context *ndev_ctx = netdev_priv(ndev);
 664         struct vmbus_channel *channel = device->channel;
 665         u16 q_idx = 0;
 666         int queue_sends;
 667
 668         /* Notify the layer above us */
 669         if (likely(skb)) {
 670                 const struct hv_netvsc_packet *packet
 671                         = (struct hv_netvsc_packet *)skb->cb;
 672                 u32 send_index = packet->send_buf_index;
 673                 struct netvsc_stats *tx_stats;
 674
 675                 if (send_index != NETVSC_INVALID_INDEX)
 676                         netvsc_free_send_slot(net_device, send_index);
 677                 q_idx = packet->q_idx;
 678                 channel = incoming_channel;
 679
 680                 tx_stats = &net_device->chan_table[q_idx].tx_stats;
 681
 682                 u64_stats_update_begin(&tx_stats->syncp);
 683                 tx_stats->packets += packet->total_packets;
 684                 tx_stats->bytes += packet->total_bytes;
 685                 u64_stats_update_end(&tx_stats->syncp);
 686
 687                 napi_consume_skb(skb, budget);
 688         }
 689
 690         queue_sends =
 691                 atomic_dec_return(&net_device->chan_table[q_idx].queue_sends);
 692
 693         if (unlikely(net_device->destroy)) {
 694                 if (queue_sends == 0)
 695                         wake_up(&net_device->wait_drain);
 696         } else {
 697                 struct netdev_queue *txq = netdev_get_tx_queue(ndev, q_idx);
 698
 699                 if (netif_tx_queue_stopped(txq) &&
 700                     (hv_ringbuf_avail_percent(&channel->outbound) > RING_AVAIL_PERCENT_HIWATER ||
 701                      queue_sends < 1)) {
 702                         netif_tx_wake_queue(txq);
 703                         ndev_ctx->eth_stats.wake_queue++;
 704                 }
 705         }
 706 }
 707
 708 static void netvsc_send_completion(struct netvsc_device *net_device,
 709                                    struct vmbus_channel *incoming_channel,
 710                                    struct hv_device *device,
 711                                    const struct vmpacket_descriptor *desc,
 712                                    int budget)
 713 {
 714         struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
 715         struct net_device *ndev = hv_get_drvdata(device);
 716
 717         switch (nvsp_packet->hdr.msg_type) {
 718         case NVSP_MSG_TYPE_INIT_COMPLETE:
 719         case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
 720         case NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE:
 721         case NVSP_MSG5_TYPE_SUBCHANNEL:
 722                 /* Copy the response back */
 723                 memcpy(&net_device->channel_init_pkt, nvsp_packet,
 724                        sizeof(struct nvsp_message));
 725                 complete(&net_device->channel_init_wait);
 726                 break;
 727
 728         case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
 729                 netvsc_send_tx_complete(net_device, incoming_channel,
 730                                         device, desc, budget);
 731                 break;
 732
 733         default:
 734                 netdev_err(ndev,
 735                            "Unknown send completion type %d received!!\n",
 736                            nvsp_packet->hdr.msg_type);
 737         }
 738 }
 739
 740 static u32 netvsc_get_next_send_section(struct netvsc_device *net_device)
 741 {
 742         unsigned long *map_addr = net_device->send_section_map;
 743         unsigned int i;
 744
 745         for_each_clear_bit(i, map_addr, net_device->send_section_cnt) {
 746                 if (sync_test_and_set_bit(i, map_addr) == 0)
 747                         return i;
 748         }
 749
 750         return NETVSC_INVALID_INDEX;
 751 }
 752
 753 static void netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 754                                     unsigned int section_index,
 755                                     u32 pend_size,
 756                                     struct hv_netvsc_packet *packet,
 757                                     struct rndis_message *rndis_msg,
 758                                     struct hv_page_buffer *pb,
 759                                     bool xmit_more)
 760 {
 761         char *start = net_device->send_buf;
 762         char *dest = start + (section_index * net_device->send_section_size)
 763                      + pend_size;
 764         int i;
 765         u32 padding = 0;
 766         u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 767                 packet->page_buf_cnt;
 768         u32 remain;
 769
 770         /* Add padding */
 771         remain = packet->total_data_buflen & (net_device->pkt_align - 1);
 772         if (xmit_more && remain) {
 773                 padding = net_device->pkt_align - remain;
 774                 rndis_msg->msg_len += padding;
 775                 packet->total_data_buflen += padding;
 776         }
 777
 778         for (i = 0; i < page_count; i++) {
 779                 char *src = phys_to_virt(pb[i].pfn << PAGE_SHIFT);
 780                 u32 offset = pb[i].offset;
 781                 u32 len = pb[i].len;
 782
 783                 memcpy(dest, (src + offset), len);
 784                 dest += len;
 785         }
 786
 787         if (padding)
 788                 memset(dest, 0, padding);
 789 }
 790
 791 static inline int netvsc_send_pkt(
 792         struct hv_device *device,
 793         struct hv_netvsc_packet *packet,
 794         struct netvsc_device *net_device,
 795         struct hv_page_buffer *pb,
 796         struct sk_buff *skb)
 797 {
 798         struct nvsp_message nvmsg;
 799         struct nvsp_1_message_send_rndis_packet *rpkt =
 800                 &nvmsg.msg.v1_msg.send_rndis_pkt;
 801         struct netvsc_channel * const nvchan =
 802                 &net_device->chan_table[packet->q_idx];
 803         struct vmbus_channel *out_channel = nvchan->channel;
 804         struct net_device *ndev = hv_get_drvdata(device);
 805         struct net_device_context *ndev_ctx = netdev_priv(ndev);
 806         struct netdev_queue *txq = netdev_get_tx_queue(ndev, packet->q_idx);
 807         u64 req_id;
 808         int ret;
 809         u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
 810
 811         nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
 812         if (skb)
 813                 rpkt->channel_type = 0;         /* 0 is RMC_DATA */
 814         else
 815                 rpkt->channel_type = 1;         /* 1 is RMC_CONTROL */
 816
 817         rpkt->send_buf_section_index = packet->send_buf_index;
 818         if (packet->send_buf_index == NETVSC_INVALID_INDEX)
 819                 rpkt->send_buf_section_size = 0;
 820         else
 821                 rpkt->send_buf_section_size = packet->total_data_buflen;
 822
 823         req_id = (ulong)skb;
 824
 825         if (out_channel->rescind)
 826                 return -ENODEV;
 827
 828         trace_nvsp_send_pkt(ndev, out_channel, rpkt);
 829
 830         if (packet->page_buf_cnt) {
 831                 if (packet->cp_partial)
 832                         pb += packet->rmsg_pgcnt;
 833
 834                 ret = vmbus_sendpacket_pagebuffer(out_channel,
 835                                                   pb, packet->page_buf_cnt,
 836                                                   &nvmsg, sizeof(nvmsg),
 837                                                   req_id);
 838         } else {
 839                 ret = vmbus_sendpacket(out_channel,
 840                                        &nvmsg, sizeof(nvmsg),
 841                                        req_id, VM_PKT_DATA_INBAND,
 842                                        VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 843         }
 844
 845         if (ret == 0) {
 846                 atomic_inc_return(&nvchan->queue_sends);
 847
 848                 if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
 849                         netif_tx_stop_queue(txq);
 850                         ndev_ctx->eth_stats.stop_queue++;
 851                 }
 852         } else if (ret == -EAGAIN) {
 853                 netif_tx_stop_queue(txq);
 854                 ndev_ctx->eth_stats.stop_queue++;
 855                 if (atomic_read(&nvchan->queue_sends) < 1) {
 856                         netif_tx_wake_queue(txq);
 857                         ndev_ctx->eth_stats.wake_queue++;
 858                         ret = -ENOSPC;
 859                 }
 860         } else {
 861                 netdev_err(ndev,
 862                            "Unable to send packet pages %u len %u, ret %d\n",
 863                            packet->page_buf_cnt, packet->total_data_buflen,
 864                            ret);
 865         }
 866
 867         return ret;
 868 }
 869
 870 /* Move packet out of multi send data (msd), and clear msd */
 871 static inline void move_pkt_msd(struct hv_netvsc_packet **msd_send,
 872                                 struct sk_buff **msd_skb,
 873                                 struct multi_send_data *msdp)
 874 {
 875         *msd_skb = msdp->skb;
 876         *msd_send = msdp->pkt;
 877         msdp->skb = NULL;
 878         msdp->pkt = NULL;
 879         msdp->count = 0;
 880 }
 881
 882 /* RCU already held by caller */
 883 int netvsc_send(struct net_device *ndev,
 884                 struct hv_netvsc_packet *packet,
 885                 struct rndis_message *rndis_msg,
 886                 struct hv_page_buffer *pb,
 887                 struct sk_buff *skb)
 888 {
 889         struct net_device_context *ndev_ctx = netdev_priv(ndev);
 890         struct netvsc_device *net_device
 891                 = rcu_dereference_bh(ndev_ctx->nvdev);
 892         struct hv_device *device = ndev_ctx->device_ctx;
 893         int ret = 0;
 894         struct netvsc_channel *nvchan;
 895         u32 pktlen = packet->total_data_buflen, msd_len = 0;
 896         unsigned int section_index = NETVSC_INVALID_INDEX;
 897         struct multi_send_data *msdp;
 898         struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
 899         struct sk_buff *msd_skb = NULL;
 900         bool try_batch, xmit_more;
 901
 902         /* If device is rescinded, return error and packet will get dropped. */
 903         if (unlikely(!net_device || net_device->destroy))
 904                 return -ENODEV;
 905
 906         nvchan = &net_device->chan_table[packet->q_idx];
 907         packet->send_buf_index = NETVSC_INVALID_INDEX;
 908         packet->cp_partial = false;
 909
 910         /* Send control message directly without accessing msd (Multi-Send
 911          * Data) field which may be changed during data packet processing.
 912          */
 913         if (!skb)
 914                 return netvsc_send_pkt(device, packet, net_device, pb, skb);
 915
 916         /* batch packets in send buffer if possible */
 917         msdp = &nvchan->msd;
 918         if (msdp->pkt)
 919                 msd_len = msdp->pkt->total_data_buflen;
 920
 921         try_batch =  msd_len > 0 && msdp->count < net_device->max_pkt;
 922         if (try_batch && msd_len + pktlen + net_device->pkt_align <
 923             net_device->send_section_size) {
 924                 section_index = msdp->pkt->send_buf_index;
 925
 926         } else if (try_batch && msd_len + packet->rmsg_size <
 927                    net_device->send_section_size) {
 928                 section_index = msdp->pkt->send_buf_index;
 929                 packet->cp_partial = true;
 930
 931         } else if (pktlen + net_device->pkt_align <
 932                    net_device->send_section_size) {
 933                 section_index = netvsc_get_next_send_section(net_device);
 934                 if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
 935                         ++ndev_ctx->eth_stats.tx_send_full;
 936                 } else {
 937                         move_pkt_msd(&msd_send, &msd_skb, msdp);
 938                         msd_len = 0;
 939                 }
 940         }
 941
 942         /* Keep aggregating only if stack says more data is coming
 943          * and not doing mixed modes send and not flow blocked
 944          */
 945         xmit_more = skb->xmit_more &&
 946                 !packet->cp_partial &&
 947                 !netif_xmit_stopped(netdev_get_tx_queue(ndev, packet->q_idx));
 948
 949         if (section_index != NETVSC_INVALID_INDEX) {
 950                 netvsc_copy_to_send_buf(net_device,
 951                                         section_index, msd_len,
 952                                         packet, rndis_msg, pb, xmit_more);
 953
 954                 packet->send_buf_index = section_index;
 955
 956                 if (packet->cp_partial) {
 957                         packet->page_buf_cnt -= packet->rmsg_pgcnt;
 958                         packet->total_data_buflen = msd_len + packet->rmsg_size;
 959                 } else {
 960                         packet->page_buf_cnt = 0;
 961                         packet->total_data_buflen += msd_len;
 962                 }
 963
 964                 if (msdp->pkt) {
 965                         packet->total_packets += msdp->pkt->total_packets;
 966                         packet->total_bytes += msdp->pkt->total_bytes;
 967                 }
 968
 969                 if (msdp->skb)
 970                         dev_consume_skb_any(msdp->skb);
 971
 972                 if (xmit_more) {
 973                         msdp->skb = skb;
 974                         msdp->pkt = packet;
 975                         msdp->count++;
 976                 } else {
 977                         cur_send = packet;
 978                         msdp->skb = NULL;
 979                         msdp->pkt = NULL;
 980                         msdp->count = 0;
 981                 }
 982         } else {
 983                 move_pkt_msd(&msd_send, &msd_skb, msdp);
 984                 cur_send = packet;
 985         }
 986
 987         if (msd_send) {
 988                 int m_ret = netvsc_send_pkt(device, msd_send, net_device,
 989                                             NULL, msd_skb);
 990
 991                 if (m_ret != 0) {
 992                         netvsc_free_send_slot(net_device,
 993                                               msd_send->send_buf_index);
 994                         dev_kfree_skb_any(msd_skb);
 995                 }
 996         }
 997
 998         if (cur_send)
 999                 ret = netvsc_send_pkt(device, cur_send, net_device, pb, skb);
1000
1001         if (ret != 0 && section_index != NETVSC_INVALID_INDEX)
1002                 netvsc_free_send_slot(net_device, section_index);
1003
1004         return ret;
1005 }
1006
1007 /* Send pending recv completions */
1008 static int send_recv_completions(struct net_device *ndev,
1009                                  struct netvsc_device *nvdev,
1010                                  struct netvsc_channel *nvchan)
1011 {
1012         struct multi_recv_comp *mrc = &nvchan->mrc;
1013         struct recv_comp_msg {
1014                 struct nvsp_message_header hdr;
1015                 u32 status;
1016         }  __packed;
1017         struct recv_comp_msg msg = {
1018                 .hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,
1019         };
1020         int ret;
1021
1022         while (mrc->first != mrc->next) {
1023                 const struct recv_comp_data *rcd
1024                         = mrc->slots + mrc->first;
1025
1026                 msg.status = rcd->status;
1027                 ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
1028                                        rcd->tid, VM_PKT_COMP, 0);
1029                 if (unlikely(ret)) {
1030                         struct net_device_context *ndev_ctx = netdev_priv(ndev);
1031
1032                         ++ndev_ctx->eth_stats.rx_comp_busy;
1033                         return ret;
1034                 }
1035
1036                 if (++mrc->first == nvdev->recv_completion_cnt)
1037                         mrc->first = 0;
1038         }
1039
1040         /* receive completion ring has been emptied */
1041         if (unlikely(nvdev->destroy))
1042                 wake_up(&nvdev->wait_drain);
1043
1044         return 0;
1045 }
1046
1047 /* Count how many receive completions are outstanding */
1048 static void recv_comp_slot_avail(const struct netvsc_device *nvdev,
1049                                  const struct multi_recv_comp *mrc,
1050                                  u32 *filled, u32 *avail)
1051 {
1052         u32 count = nvdev->recv_completion_cnt;
1053
1054         if (mrc->next >= mrc->first)
1055                 *filled = mrc->next - mrc->first;
1056         else
1057                 *filled = (count - mrc->first) + mrc->next;
1058
1059         *avail = count - *filled - 1;
1060 }
1061
1062 /* Add receive complete to ring to send to host. */
1063 static void enq_receive_complete(struct net_device *ndev,
1064                                  struct netvsc_device *nvdev, u16 q_idx,
1065                                  u64 tid, u32 status)
1066 {
1067         struct netvsc_channel *nvchan = &nvdev->chan_table[q_idx];
1068         struct multi_recv_comp *mrc = &nvchan->mrc;
1069         struct recv_comp_data *rcd;
1070         u32 filled, avail;
1071
1072         recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1073
1074         if (unlikely(filled > NAPI_POLL_WEIGHT)) {
1075                 send_recv_completions(ndev, nvdev, nvchan);
1076                 recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
1077         }
1078
1079         if (unlikely(!avail)) {
1080                 netdev_err(ndev, "Recv_comp full buf q:%hd, tid:%llx\n",
1081                            q_idx, tid);
1082                 return;
1083         }
1084
1085         rcd = mrc->slots + mrc->next;
1086         rcd->tid = tid;
1087         rcd->status = status;
1088
1089         if (++mrc->next == nvdev->recv_completion_cnt)
1090                 mrc->next = 0;
1091 }
1092
1093 static int netvsc_receive(struct net_device *ndev,
1094                           struct netvsc_device *net_device,
1095                           struct net_device_context *net_device_ctx,
1096                           struct hv_device *device,
1097                           struct vmbus_channel *channel,
1098                           const struct vmpacket_descriptor *desc,
1099                           struct nvsp_message *nvsp)
1100 {
1101         const struct vmtransfer_page_packet_header *vmxferpage_packet
1102                 = container_of(desc, const struct vmtransfer_page_packet_header, d);
1103         u16 q_idx = channel->offermsg.offer.sub_channel_index;
1104         char *recv_buf = net_device->recv_buf;
1105         u32 status = NVSP_STAT_SUCCESS;
1106         int i;
1107         int count = 0;
1108
1109         /* Make sure this is a valid nvsp packet */
1110         if (unlikely(nvsp->hdr.msg_type != NVSP_MSG1_TYPE_SEND_RNDIS_PKT)) {
1111                 netif_err(net_device_ctx, rx_err, ndev,
1112                           "Unknown nvsp packet type received %u\n",
1113                           nvsp->hdr.msg_type);
1114                 return 0;
1115         }
1116
1117         if (unlikely(vmxferpage_packet->xfer_pageset_id != NETVSC_RECEIVE_BUFFER_ID)) {
1118                 netif_err(net_device_ctx, rx_err, ndev,
1119                           "Invalid xfer page set id - expecting %x got %x\n",
1120                           NETVSC_RECEIVE_BUFFER_ID,
1121                           vmxferpage_packet->xfer_pageset_id);
1122                 return 0;
1123         }
1124
1125         count = vmxferpage_packet->range_cnt;
1126
1127         /* Each range represents 1 RNDIS pkt that contains 1 ethernet frame */
1128         for (i = 0; i < count; i++) {
1129                 u32 offset = vmxferpage_packet->ranges[i].byte_offset;
1130                 u32 buflen = vmxferpage_packet->ranges[i].byte_count;
1131                 void *data;
1132                 int ret;
1133
1134                 if (unlikely(offset + buflen > net_device->recv_buf_size)) {
1135                         status = NVSP_STAT_FAIL;
1136                         netif_err(net_device_ctx, rx_err, ndev,
1137                                   "Packet offset:%u + len:%u too big\n",
1138                                   offset, buflen);
1139
1140                         continue;
1141                 }
1142
1143                 data = recv_buf + offset;
1144
1145                 trace_rndis_recv(ndev, q_idx, data);
1146
1147                 /* Pass it to the upper layer */
1148                 ret = rndis_filter_receive(ndev, net_device,
1149                                            channel, data, buflen);
1150
1151                 if (unlikely(ret != NVSP_STAT_SUCCESS))
1152                         status = NVSP_STAT_FAIL;
1153         }
1154
1155         enq_receive_complete(ndev, net_device, q_idx,
1156                              vmxferpage_packet->d.trans_id, status);
1157
1158         return count;
1159 }
1160
1161 static void netvsc_send_table(struct hv_device *hdev,
1162                               struct nvsp_message *nvmsg)
1163 {
1164         struct net_device *ndev = hv_get_drvdata(hdev);
1165         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1166         int i;
1167         u32 count, *tab;
1168
1169         count = nvmsg->msg.v5_msg.send_table.count;
1170         if (count != VRSS_SEND_TAB_SIZE) {
1171                 netdev_err(ndev, "Received wrong send-table size:%u\n", count);
1172                 return;
1173         }
1174
1175         tab = (u32 *)((unsigned long)&nvmsg->msg.v5_msg.send_table +
1176                       nvmsg->msg.v5_msg.send_table.offset);
1177
1178         for (i = 0; i < count; i++)
1179                 net_device_ctx->tx_table[i] = tab[i];
1180 }
1181
1182 static void netvsc_send_vf(struct net_device_context *net_device_ctx,
1183                            struct nvsp_message *nvmsg)
1184 {
1185         net_device_ctx->vf_alloc = nvmsg->msg.v4_msg.vf_assoc.allocated;
1186         net_device_ctx->vf_serial = nvmsg->msg.v4_msg.vf_assoc.serial;
1187 }
1188
1189 static inline void netvsc_receive_inband(struct hv_device *hdev,
1190                                  struct net_device_context *net_device_ctx,
1191                                  struct nvsp_message *nvmsg)
1192 {
1193         switch (nvmsg->hdr.msg_type) {
1194         case NVSP_MSG5_TYPE_SEND_INDIRECTION_TABLE:
1195                 netvsc_send_table(hdev, nvmsg);
1196                 break;
1197
1198         case NVSP_MSG4_TYPE_SEND_VF_ASSOCIATION:
1199                 netvsc_send_vf(net_device_ctx, nvmsg);
1200                 break;
1201         }
1202 }
1203
1204 static int netvsc_process_raw_pkt(struct hv_device *device,
1205                                   struct vmbus_channel *channel,
1206                                   struct netvsc_device *net_device,
1207                                   struct net_device *ndev,
1208                                   const struct vmpacket_descriptor *desc,
1209                                   int budget)
1210 {
1211         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1212         struct nvsp_message *nvmsg = hv_pkt_data(desc);
1213
1214         trace_nvsp_recv(ndev, channel, nvmsg);
1215
1216         switch (desc->type) {
1217         case VM_PKT_COMP:
1218                 netvsc_send_completion(net_device, channel, device,
1219                                        desc, budget);
1220                 break;
1221
1222         case VM_PKT_DATA_USING_XFER_PAGES:
1223                 return netvsc_receive(ndev, net_device, net_device_ctx,
1224                                       device, channel, desc, nvmsg);
1225                 break;
1226
1227         case VM_PKT_DATA_INBAND:
1228                 netvsc_receive_inband(device, net_device_ctx, nvmsg);
1229                 break;
1230
1231         default:
1232                 netdev_err(ndev, "unhandled packet type %d, tid %llx\n",
1233                            desc->type, desc->trans_id);
1234                 break;
1235         }
1236
1237         return 0;
1238 }
1239
1240 static struct hv_device *netvsc_channel_to_device(struct vmbus_channel *channel)
1241 {
1242         struct vmbus_channel *primary = channel->primary_channel;
1243
1244         return primary ? primary->device_obj : channel->device_obj;
1245 }
1246
1247 /* Network processing softirq
1248  * Process data in incoming ring buffer from host
1249  * Stops when ring is empty or budget is met or exceeded.
1250  */
1251 int netvsc_poll(struct napi_struct *napi, int budget)
1252 {
1253         struct netvsc_channel *nvchan
1254                 = container_of(napi, struct netvsc_channel, napi);
1255         struct netvsc_device *net_device = nvchan->net_device;
1256         struct vmbus_channel *channel = nvchan->channel;
1257         struct hv_device *device = netvsc_channel_to_device(channel);
1258         struct net_device *ndev = hv_get_drvdata(device);
1259         int work_done = 0;
1260
1261         /* If starting a new interval */
1262         if (!nvchan->desc)
1263                 nvchan->desc = hv_pkt_iter_first(channel);
1264
1265         while (nvchan->desc && work_done < budget) {
1266                 work_done += netvsc_process_raw_pkt(device, channel, net_device,
1267                                                     ndev, nvchan->desc, budget);
1268                 nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc);
1269         }
1270
1271         /* If send of pending receive completions suceeded
1272          *   and did not exhaust NAPI budget this time
1273          *   and not doing busy poll
1274          * then re-enable host interrupts
1275          *     and reschedule if ring is not empty.
1276          */
1277         if (send_recv_completions(ndev, net_device, nvchan) == 0 &&
1278             work_done < budget &&
1279             napi_complete_done(napi, work_done) &&
1280             hv_end_read(&channel->inbound) &&
1281             napi_schedule_prep(napi)) {
1282                 hv_begin_read(&channel->inbound);
1283                 __napi_schedule(napi);
1284         }
1285
1286         /* Driver may overshoot since multiple packets per descriptor */
1287         return min(work_done, budget);
1288 }
1289
1290 /* Call back when data is available in host ring buffer.
1291  * Processing is deferred until network softirq (NAPI)
1292  */
1293 void netvsc_channel_cb(void *context)
1294 {
1295         struct netvsc_channel *nvchan = context;
1296         struct vmbus_channel *channel = nvchan->channel;
1297         struct hv_ring_buffer_info *rbi = &channel->inbound;
1298
1299         /* preload first vmpacket descriptor */
1300         prefetch(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
1301
1302         if (napi_schedule_prep(&nvchan->napi)) {
1303                 /* disable interupts from host */
1304                 hv_begin_read(rbi);
1305
1306                 __napi_schedule_irqoff(&nvchan->napi);
1307         }
1308 }
1309
1310 /*
1311  * netvsc_device_add - Callback when the device belonging to this
1312  * driver is added
1313  */
1314 struct netvsc_device *netvsc_device_add(struct hv_device *device,
1315                                 const struct netvsc_device_info *device_info)
1316 {
1317         int i, ret = 0;
1318         struct netvsc_device *net_device;
1319         struct net_device *ndev = hv_get_drvdata(device);
1320         struct net_device_context *net_device_ctx = netdev_priv(ndev);
1321
1322         net_device = alloc_net_device();
1323         if (!net_device)
1324                 return ERR_PTR(-ENOMEM);
1325
1326         for (i = 0; i < VRSS_SEND_TAB_SIZE; i++)
1327                 net_device_ctx->tx_table[i] = 0;
1328
1329         /* Because the device uses NAPI, all the interrupt batching and
1330          * control is done via Net softirq, not the channel handling
1331          */
1332         set_channel_read_mode(device->channel, HV_CALL_ISR);
1333
1334         /* If we're reopening the device we may have multiple queues, fill the
1335          * chn_table with the default channel to use it before subchannels are
1336          * opened.
1337          * Initialize the channel state before we open;
1338          * we can be interrupted as soon as we open the channel.
1339          */
1340
1341         for (i = 0; i < VRSS_CHANNEL_MAX; i++) {
1342                 struct netvsc_channel *nvchan = &net_device->chan_table[i];
1343
1344                 nvchan->channel = device->channel;
1345                 nvchan->net_device = net_device;
1346                 u64_stats_init(&nvchan->tx_stats.syncp);
1347                 u64_stats_init(&nvchan->rx_stats.syncp);
1348         }
1349
1350         /* Enable NAPI handler before init callbacks */
1351         netif_napi_add(ndev, &net_device->chan_table[0].napi,
1352                        netvsc_poll, NAPI_POLL_WEIGHT);
1353
1354         /* Open the channel */
1355         ret = vmbus_open(device->channel, netvsc_ring_bytes,
1356                          netvsc_ring_bytes,  NULL, 0,
1357                          netvsc_channel_cb, net_device->chan_table);
1358
1359         if (ret != 0) {
1360                 netdev_err(ndev, "unable to open channel: %d\n", ret);
1361                 goto cleanup;
1362         }
1363
1364         /* Channel is opened */
1365         netdev_dbg(ndev, "hv_netvsc channel opened successfully\n");
1366
1367         napi_enable(&net_device->chan_table[0].napi);
1368
1369         /* Connect with the NetVsp */
1370         ret = netvsc_connect_vsp(device, net_device, device_info);
1371         if (ret != 0) {
1372                 netdev_err(ndev,
1373                         "unable to connect to NetVSP - %d\n", ret);
1374                 goto close;
1375         }
1376
1377         /* Writing nvdev pointer unlocks netvsc_send(), make sure chn_table is
1378          * populated.
1379          */
1380         rcu_assign_pointer(net_device_ctx->nvdev, net_device);
1381
1382         return net_device;
1383
1384 close:
1385         RCU_INIT_POINTER(net_device_ctx->nvdev, NULL);
1386         napi_disable(&net_device->chan_table[0].napi);
1387
1388         /* Now, we can close the channel safely */
1389         vmbus_close(device->channel);
1390
1391 cleanup:
1392         netif_napi_del(&net_device->chan_table[0].napi);
1393         free_netvsc_device(&net_device->rcu);
1394
1395         return ERR_PTR(ret);
1396 }