drivers/hv/channel.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, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/wait.h>
  26 #include <linux/mm.h>
  27 #include <linux/slab.h>
  28 #include <linux/module.h>
  29 #include <linux/hyperv.h>
  30
  31 #include "hyperv_vmbus.h"
  32
  33 #define NUM_PAGES_SPANNED(addr, len) \
  34 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
  35
  36 /*
  37  * vmbus_setevent- Trigger an event notification on the specified
  38  * channel.
  39  */
  40 static void vmbus_setevent(struct vmbus_channel *channel)
  41 {
  42         struct hv_monitor_page *monitorpage;
  43
  44         if (channel->offermsg.monitor_allocated) {
  45                 /* Each u32 represents 32 channels */
  46                 sync_set_bit(channel->offermsg.child_relid & 31,
  47                         (unsigned long *) vmbus_connection.send_int_page +
  48                         (channel->offermsg.child_relid >> 5));
  49
  50                 monitorpage = vmbus_connection.monitor_pages;
  51                 monitorpage++; /* Get the child to parent monitor page */
  52
  53                 sync_set_bit(channel->monitor_bit,
  54                         (unsigned long *)&monitorpage->trigger_group
  55                                         [channel->monitor_grp].pending);
  56
  57         } else {
  58                 vmbus_set_event(channel);
  59         }
  60 }
  61
  62 /*
  63  * vmbus_get_debug_info -Retrieve various channel debug info
  64  */
  65 void vmbus_get_debug_info(struct vmbus_channel *channel,
  66                               struct vmbus_channel_debug_info *debuginfo)
  67 {
  68         struct hv_monitor_page *monitorpage;
  69         u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
  70         u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
  71
  72         memcpy(&debuginfo->interfacetype,
  73                &channel->offermsg.offer.if_type, sizeof(uuid_le));
  74         memcpy(&debuginfo->interface_instance,
  75                &channel->offermsg.offer.if_instance,
  76                sizeof(uuid_le));
  77
  78         monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
  79
  80         debuginfo->monitorid = channel->offermsg.monitorid;
  81
  82         debuginfo->servermonitor_pending =
  83                         monitorpage->trigger_group[monitor_group].pending;
  84         debuginfo->servermonitor_latency =
  85                         monitorpage->latency[monitor_group][monitor_offset];
  86         debuginfo->servermonitor_connectionid =
  87                         monitorpage->parameter[monitor_group]
  88                                         [monitor_offset].connectionid.u.id;
  89
  90         monitorpage++;
  91
  92         debuginfo->clientmonitor_pending =
  93                         monitorpage->trigger_group[monitor_group].pending;
  94         debuginfo->clientmonitor_latency =
  95                         monitorpage->latency[monitor_group][monitor_offset];
  96         debuginfo->clientmonitor_connectionid =
  97                         monitorpage->parameter[monitor_group]
  98                                         [monitor_offset].connectionid.u.id;
  99
 100         hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
 101         hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
 102 }
 103
 104 /*
 105  * vmbus_open - Open the specified channel.
 106  */
 107 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 108                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
 109                      void (*onchannelcallback)(void *context), void *context)
 110 {
 111         struct vmbus_channel_open_channel *open_msg;
 112         struct vmbus_channel_msginfo *open_info = NULL;
 113         void *in, *out;
 114         unsigned long flags;
 115         int ret, t, err = 0;
 116
 117         spin_lock_irqsave(&newchannel->sc_lock, flags);
 118         if (newchannel->state == CHANNEL_OPEN_STATE) {
 119                 newchannel->state = CHANNEL_OPENING_STATE;
 120         } else {
 121                 spin_unlock_irqrestore(&newchannel->sc_lock, flags);
 122                 return -EINVAL;
 123         }
 124         spin_unlock_irqrestore(&newchannel->sc_lock, flags);
 125
 126         newchannel->onchannel_callback = onchannelcallback;
 127         newchannel->channel_callback_context = context;
 128
 129         /* Allocate the ring buffer */
 130         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 131                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 132
 133         if (!out)
 134                 return -ENOMEM;
 135
 136
 137         in = (void *)((unsigned long)out + send_ringbuffer_size);
 138
 139         newchannel->ringbuffer_pages = out;
 140         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 141                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 142
 143         ret = hv_ringbuffer_init(
 144                 &newchannel->outbound, out, send_ringbuffer_size);
 145
 146         if (ret != 0) {
 147                 err = ret;
 148                 goto error0;
 149         }
 150
 151         ret = hv_ringbuffer_init(
 152                 &newchannel->inbound, in, recv_ringbuffer_size);
 153         if (ret != 0) {
 154                 err = ret;
 155                 goto error0;
 156         }
 157
 158
 159         /* Establish the gpadl for the ring buffer */
 160         newchannel->ringbuffer_gpadlhandle = 0;
 161
 162         ret = vmbus_establish_gpadl(newchannel,
 163                                          newchannel->outbound.ring_buffer,
 164                                          send_ringbuffer_size +
 165                                          recv_ringbuffer_size,
 166                                          &newchannel->ringbuffer_gpadlhandle);
 167
 168         if (ret != 0) {
 169                 err = ret;
 170                 goto error0;
 171         }
 172
 173         /* Create and init the channel open message */
 174         open_info = kmalloc(sizeof(*open_info) +
 175                            sizeof(struct vmbus_channel_open_channel),
 176                            GFP_KERNEL);
 177         if (!open_info) {
 178                 err = -ENOMEM;
 179                 goto error0;
 180         }
 181
 182         init_completion(&open_info->waitevent);
 183
 184         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 185         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 186         open_msg->openid = newchannel->offermsg.child_relid;
 187         open_msg->child_relid = newchannel->offermsg.child_relid;
 188         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 189         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 190                                                   PAGE_SHIFT;
 191         open_msg->target_vp = newchannel->target_vp;
 192
 193         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 194                 err = -EINVAL;
 195                 goto error0;
 196         }
 197
 198         if (userdatalen)
 199                 memcpy(open_msg->userdata, userdata, userdatalen);
 200
 201         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 202         list_add_tail(&open_info->msglistentry,
 203                       &vmbus_connection.chn_msg_list);
 204         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 205
 206         ret = vmbus_post_msg(open_msg,
 207                                sizeof(struct vmbus_channel_open_channel));
 208
 209         if (ret != 0)
 210                 goto error1;
 211
 212         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 213         if (t == 0) {
 214                 err = -ETIMEDOUT;
 215                 goto error1;
 216         }
 217
 218
 219         if (open_info->response.open_result.status)
 220                 err = open_info->response.open_result.status;
 221
 222         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 223         list_del(&open_info->msglistentry);
 224         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 225
 226         if (err == 0)
 227                 newchannel->state = CHANNEL_OPENED_STATE;
 228
 229         kfree(open_info);
 230         return err;
 231
 232 error1:
 233         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 234         list_del(&open_info->msglistentry);
 235         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 236
 237 error0:
 238         free_pages((unsigned long)out,
 239                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 240         kfree(open_info);
 241         return err;
 242 }
 243 EXPORT_SYMBOL_GPL(vmbus_open);
 244
 245 /*
 246  * create_gpadl_header - Creates a gpadl for the specified buffer
 247  */
 248 static int create_gpadl_header(void *kbuffer, u32 size,
 249                                          struct vmbus_channel_msginfo **msginfo,
 250                                          u32 *messagecount)
 251 {
 252         int i;
 253         int pagecount;
 254         unsigned long long pfn;
 255         struct vmbus_channel_gpadl_header *gpadl_header;
 256         struct vmbus_channel_gpadl_body *gpadl_body;
 257         struct vmbus_channel_msginfo *msgheader;
 258         struct vmbus_channel_msginfo *msgbody = NULL;
 259         u32 msgsize;
 260
 261         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 262
 263         pagecount = size >> PAGE_SHIFT;
 264         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
 265
 266         /* do we need a gpadl body msg */
 267         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 268                   sizeof(struct vmbus_channel_gpadl_header) -
 269                   sizeof(struct gpa_range);
 270         pfncount = pfnsize / sizeof(u64);
 271
 272         if (pagecount > pfncount) {
 273                 /* we need a gpadl body */
 274                 /* fill in the header */
 275                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 276                           sizeof(struct vmbus_channel_gpadl_header) +
 277                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 278                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 279                 if (!msgheader)
 280                         goto nomem;
 281
 282                 INIT_LIST_HEAD(&msgheader->submsglist);
 283                 msgheader->msgsize = msgsize;
 284
 285                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 286                         msgheader->msg;
 287                 gpadl_header->rangecount = 1;
 288                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 289                                          pagecount * sizeof(u64);
 290                 gpadl_header->range[0].byte_offset = 0;
 291                 gpadl_header->range[0].byte_count = size;
 292                 for (i = 0; i < pfncount; i++)
 293                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 294                 *msginfo = msgheader;
 295                 *messagecount = 1;
 296
 297                 pfnsum = pfncount;
 298                 pfnleft = pagecount - pfncount;
 299
 300                 /* how many pfns can we fit */
 301                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 302                           sizeof(struct vmbus_channel_gpadl_body);
 303                 pfncount = pfnsize / sizeof(u64);
 304
 305                 /* fill in the body */
 306                 while (pfnleft) {
 307                         if (pfnleft > pfncount)
 308                                 pfncurr = pfncount;
 309                         else
 310                                 pfncurr = pfnleft;
 311
 312                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 313                                   sizeof(struct vmbus_channel_gpadl_body) +
 314                                   pfncurr * sizeof(u64);
 315                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 316
 317                         if (!msgbody) {
 318                                 struct vmbus_channel_msginfo *pos = NULL;
 319                                 struct vmbus_channel_msginfo *tmp = NULL;
 320                                 /*
 321                                  * Free up all the allocated messages.
 322                                  */
 323                                 list_for_each_entry_safe(pos, tmp,
 324                                         &msgheader->submsglist,
 325                                         msglistentry) {
 326
 327                                         list_del(&pos->msglistentry);
 328                                         kfree(pos);
 329                                 }
 330
 331                                 goto nomem;
 332                         }
 333
 334                         msgbody->msgsize = msgsize;
 335                         (*messagecount)++;
 336                         gpadl_body =
 337                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 338
 339                         /*
 340                          * Gpadl is u32 and we are using a pointer which could
 341                          * be 64-bit
 342                          * This is governed by the guest/host protocol and
 343                          * so the hypervisor gurantees that this is ok.
 344                          */
 345                         for (i = 0; i < pfncurr; i++)
 346                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
 347
 348                         /* add to msg header */
 349                         list_add_tail(&msgbody->msglistentry,
 350                                       &msgheader->submsglist);
 351                         pfnsum += pfncurr;
 352                         pfnleft -= pfncurr;
 353                 }
 354         } else {
 355                 /* everything fits in a header */
 356                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 357                           sizeof(struct vmbus_channel_gpadl_header) +
 358                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 359                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 360                 if (msgheader == NULL)
 361                         goto nomem;
 362                 msgheader->msgsize = msgsize;
 363
 364                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 365                         msgheader->msg;
 366                 gpadl_header->rangecount = 1;
 367                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 368                                          pagecount * sizeof(u64);
 369                 gpadl_header->range[0].byte_offset = 0;
 370                 gpadl_header->range[0].byte_count = size;
 371                 for (i = 0; i < pagecount; i++)
 372                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 373
 374                 *msginfo = msgheader;
 375                 *messagecount = 1;
 376         }
 377
 378         return 0;
 379 nomem:
 380         kfree(msgheader);
 381         kfree(msgbody);
 382         return -ENOMEM;
 383 }
 384
 385 /*
 386  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 387  *
 388  * @channel: a channel
 389  * @kbuffer: from kmalloc
 390  * @size: page-size multiple
 391  * @gpadl_handle: some funky thing
 392  */
 393 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 394                                u32 size, u32 *gpadl_handle)
 395 {
 396         struct vmbus_channel_gpadl_header *gpadlmsg;
 397         struct vmbus_channel_gpadl_body *gpadl_body;
 398         struct vmbus_channel_msginfo *msginfo = NULL;
 399         struct vmbus_channel_msginfo *submsginfo;
 400         u32 msgcount;
 401         struct list_head *curr;
 402         u32 next_gpadl_handle;
 403         unsigned long flags;
 404         int ret = 0;
 405         int t;
 406
 407         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
 408         atomic_inc(&vmbus_connection.next_gpadl_handle);
 409
 410         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 411         if (ret)
 412                 return ret;
 413
 414         init_completion(&msginfo->waitevent);
 415
 416         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 417         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 418         gpadlmsg->child_relid = channel->offermsg.child_relid;
 419         gpadlmsg->gpadl = next_gpadl_handle;
 420
 421
 422         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 423         list_add_tail(&msginfo->msglistentry,
 424                       &vmbus_connection.chn_msg_list);
 425
 426         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 427
 428         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 429                                sizeof(*msginfo));
 430         if (ret != 0)
 431                 goto cleanup;
 432
 433         if (msgcount > 1) {
 434                 list_for_each(curr, &msginfo->submsglist) {
 435
 436                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 437                         gpadl_body =
 438                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 439
 440                         gpadl_body->header.msgtype =
 441                                 CHANNELMSG_GPADL_BODY;
 442                         gpadl_body->gpadl = next_gpadl_handle;
 443
 444                         ret = vmbus_post_msg(gpadl_body,
 445                                                submsginfo->msgsize -
 446                                                sizeof(*submsginfo));
 447                         if (ret != 0)
 448                                 goto cleanup;
 449
 450                 }
 451         }
 452         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
 453         BUG_ON(t == 0);
 454
 455
 456         /* At this point, we received the gpadl created msg */
 457         *gpadl_handle = gpadlmsg->gpadl;
 458
 459 cleanup:
 460         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 461         list_del(&msginfo->msglistentry);
 462         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 463
 464         kfree(msginfo);
 465         return ret;
 466 }
 467 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 468
 469 /*
 470  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 471  */
 472 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 473 {
 474         struct vmbus_channel_gpadl_teardown *msg;
 475         struct vmbus_channel_msginfo *info;
 476         unsigned long flags;
 477         int ret, t;
 478
 479         info = kmalloc(sizeof(*info) +
 480                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 481         if (!info)
 482                 return -ENOMEM;
 483
 484         init_completion(&info->waitevent);
 485
 486         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 487
 488         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 489         msg->child_relid = channel->offermsg.child_relid;
 490         msg->gpadl = gpadl_handle;
 491
 492         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 493         list_add_tail(&info->msglistentry,
 494                       &vmbus_connection.chn_msg_list);
 495         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 496         ret = vmbus_post_msg(msg,
 497                                sizeof(struct vmbus_channel_gpadl_teardown));
 498
 499         BUG_ON(ret != 0);
 500         t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
 501         BUG_ON(t == 0);
 502
 503         /* Received a torndown response */
 504         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 505         list_del(&info->msglistentry);
 506         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 507
 508         kfree(info);
 509         return ret;
 510 }
 511 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 512
 513 static void vmbus_close_internal(struct vmbus_channel *channel)
 514 {
 515         struct vmbus_channel_close_channel *msg;
 516         int ret;
 517         unsigned long flags;
 518
 519         channel->state = CHANNEL_OPEN_STATE;
 520         channel->sc_creation_callback = NULL;
 521         /* Stop callback and cancel the timer asap */
 522         spin_lock_irqsave(&channel->inbound_lock, flags);
 523         channel->onchannel_callback = NULL;
 524         spin_unlock_irqrestore(&channel->inbound_lock, flags);
 525
 526         /* Send a closing message */
 527
 528         msg = &channel->close_msg.msg;
 529
 530         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 531         msg->child_relid = channel->offermsg.child_relid;
 532
 533         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 534
 535         BUG_ON(ret != 0);
 536         /* Tear down the gpadl for the channel's ring buffer */
 537         if (channel->ringbuffer_gpadlhandle)
 538                 vmbus_teardown_gpadl(channel,
 539                                           channel->ringbuffer_gpadlhandle);
 540
 541         /* Cleanup the ring buffers for this channel */
 542         hv_ringbuffer_cleanup(&channel->outbound);
 543         hv_ringbuffer_cleanup(&channel->inbound);
 544
 545         free_pages((unsigned long)channel->ringbuffer_pages,
 546                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 547
 548
 549 }
 550
 551 /*
 552  * vmbus_close - Close the specified channel
 553  */
 554 void vmbus_close(struct vmbus_channel *channel)
 555 {
 556         struct list_head *cur, *tmp;
 557         struct vmbus_channel *cur_channel;
 558
 559         if (channel->primary_channel != NULL) {
 560                 /*
 561                  * We will only close sub-channels when
 562                  * the primary is closed.
 563                  */
 564                 return;
 565         }
 566         /*
 567          * Close all the sub-channels first and then close the
 568          * primary channel.
 569          */
 570         list_for_each_safe(cur, tmp, &channel->sc_list) {
 571                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 572                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 573                         continue;
 574                 vmbus_close_internal(cur_channel);
 575         }
 576         /*
 577          * Now close the primary.
 578          */
 579         vmbus_close_internal(channel);
 580 }
 581 EXPORT_SYMBOL_GPL(vmbus_close);
 582
 583 /**
 584  * vmbus_sendpacket() - Send the specified buffer on the given channel
 585  * @channel: Pointer to vmbus_channel structure.
 586  * @buffer: Pointer to the buffer you want to receive the data into.
 587  * @bufferlen: Maximum size of what the the buffer will hold
 588  * @requestid: Identifier of the request
 589  * @type: Type of packet that is being send e.g. negotiate, time
 590  * packet etc.
 591  *
 592  * Sends data in @buffer directly to hyper-v via the vmbus
 593  * This will send the data unparsed to hyper-v.
 594  *
 595  * Mainly used by Hyper-V drivers.
 596  */
 597 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
 598                            u32 bufferlen, u64 requestid,
 599                            enum vmbus_packet_type type, u32 flags)
 600 {
 601         struct vmpacket_descriptor desc;
 602         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 603         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 604         struct scatterlist bufferlist[3];
 605         u64 aligned_data = 0;
 606         int ret;
 607         bool signal = false;
 608
 609
 610         /* Setup the descriptor */
 611         desc.type = type; /* VmbusPacketTypeDataInBand; */
 612         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 613         /* in 8-bytes granularity */
 614         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 615         desc.len8 = (u16)(packetlen_aligned >> 3);
 616         desc.trans_id = requestid;
 617
 618         sg_init_table(bufferlist, 3);
 619         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
 620         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 621         sg_set_buf(&bufferlist[2], &aligned_data,
 622                    packetlen_aligned - packetlen);
 623
 624         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 625
 626         if (ret == 0 && signal)
 627                 vmbus_setevent(channel);
 628
 629         return ret;
 630 }
 631 EXPORT_SYMBOL(vmbus_sendpacket);
 632
 633 /*
 634  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 635  * packets using a GPADL Direct packet type.
 636  */
 637 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 638                                      struct hv_page_buffer pagebuffers[],
 639                                      u32 pagecount, void *buffer, u32 bufferlen,
 640                                      u64 requestid)
 641 {
 642         int ret;
 643         int i;
 644         struct vmbus_channel_packet_page_buffer desc;
 645         u32 descsize;
 646         u32 packetlen;
 647         u32 packetlen_aligned;
 648         struct scatterlist bufferlist[3];
 649         u64 aligned_data = 0;
 650         bool signal = false;
 651
 652         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 653                 return -EINVAL;
 654
 655
 656         /*
 657          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 658          * largest size we support
 659          */
 660         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 661                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 662                           sizeof(struct hv_page_buffer));
 663         packetlen = descsize + bufferlen;
 664         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 665
 666         /* Setup the descriptor */
 667         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 668         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 669         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 670         desc.length8 = (u16)(packetlen_aligned >> 3);
 671         desc.transactionid = requestid;
 672         desc.rangecount = pagecount;
 673
 674         for (i = 0; i < pagecount; i++) {
 675                 desc.range[i].len = pagebuffers[i].len;
 676                 desc.range[i].offset = pagebuffers[i].offset;
 677                 desc.range[i].pfn        = pagebuffers[i].pfn;
 678         }
 679
 680         sg_init_table(bufferlist, 3);
 681         sg_set_buf(&bufferlist[0], &desc, descsize);
 682         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 683         sg_set_buf(&bufferlist[2], &aligned_data,
 684                 packetlen_aligned - packetlen);
 685
 686         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 687
 688         if (ret == 0 && signal)
 689                 vmbus_setevent(channel);
 690
 691         return ret;
 692 }
 693 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 694
 695 /*
 696  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 697  * using a GPADL Direct packet type.
 698  */
 699 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 700                                 struct hv_multipage_buffer *multi_pagebuffer,
 701                                 void *buffer, u32 bufferlen, u64 requestid)
 702 {
 703         int ret;
 704         struct vmbus_channel_packet_multipage_buffer desc;
 705         u32 descsize;
 706         u32 packetlen;
 707         u32 packetlen_aligned;
 708         struct scatterlist bufferlist[3];
 709         u64 aligned_data = 0;
 710         bool signal = false;
 711         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 712                                          multi_pagebuffer->len);
 713
 714
 715         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
 716                 return -EINVAL;
 717
 718         /*
 719          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 720          * the largest size we support
 721          */
 722         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 723                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 724                           sizeof(u64));
 725         packetlen = descsize + bufferlen;
 726         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 727
 728
 729         /* Setup the descriptor */
 730         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 731         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 732         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 733         desc.length8 = (u16)(packetlen_aligned >> 3);
 734         desc.transactionid = requestid;
 735         desc.rangecount = 1;
 736
 737         desc.range.len = multi_pagebuffer->len;
 738         desc.range.offset = multi_pagebuffer->offset;
 739
 740         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 741                pfncount * sizeof(u64));
 742
 743         sg_init_table(bufferlist, 3);
 744         sg_set_buf(&bufferlist[0], &desc, descsize);
 745         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 746         sg_set_buf(&bufferlist[2], &aligned_data,
 747                 packetlen_aligned - packetlen);
 748
 749         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 750
 751         if (ret == 0 && signal)
 752                 vmbus_setevent(channel);
 753
 754         return ret;
 755 }
 756 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 757
 758 /**
 759  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 760  * @channel: Pointer to vmbus_channel structure.
 761  * @buffer: Pointer to the buffer you want to receive the data into.
 762  * @bufferlen: Maximum size of what the the buffer will hold
 763  * @buffer_actual_len: The actual size of the data after it was received
 764  * @requestid: Identifier of the request
 765  *
 766  * Receives directly from the hyper-v vmbus and puts the data it received
 767  * into Buffer. This will receive the data unparsed from hyper-v.
 768  *
 769  * Mainly used by Hyper-V drivers.
 770  */
 771 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 772                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 773 {
 774         struct vmpacket_descriptor desc;
 775         u32 packetlen;
 776         u32 userlen;
 777         int ret;
 778         bool signal = false;
 779
 780         *buffer_actual_len = 0;
 781         *requestid = 0;
 782
 783
 784         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 785                              sizeof(struct vmpacket_descriptor));
 786         if (ret != 0)
 787                 return 0;
 788
 789         packetlen = desc.len8 << 3;
 790         userlen = packetlen - (desc.offset8 << 3);
 791
 792         *buffer_actual_len = userlen;
 793
 794         if (userlen > bufferlen) {
 795
 796                 pr_err("Buffer too small - got %d needs %d\n",
 797                            bufferlen, userlen);
 798                 return -ETOOSMALL;
 799         }
 800
 801         *requestid = desc.trans_id;
 802
 803         /* Copy over the packet to the user buffer */
 804         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 805                              (desc.offset8 << 3), &signal);
 806
 807         if (signal)
 808                 vmbus_setevent(channel);
 809
 810         return 0;
 811 }
 812 EXPORT_SYMBOL(vmbus_recvpacket);
 813
 814 /*
 815  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 816  */
 817 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 818                               u32 bufferlen, u32 *buffer_actual_len,
 819                               u64 *requestid)
 820 {
 821         struct vmpacket_descriptor desc;
 822         u32 packetlen;
 823         int ret;
 824         bool signal = false;
 825
 826         *buffer_actual_len = 0;
 827         *requestid = 0;
 828
 829
 830         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 831                              sizeof(struct vmpacket_descriptor));
 832         if (ret != 0)
 833                 return 0;
 834
 835
 836         packetlen = desc.len8 << 3;
 837
 838         *buffer_actual_len = packetlen;
 839
 840         if (packetlen > bufferlen) {
 841                 pr_err("Buffer too small - needed %d bytes but "
 842                         "got space for only %d bytes\n",
 843                         packetlen, bufferlen);
 844                 return -ENOBUFS;
 845         }
 846
 847         *requestid = desc.trans_id;
 848
 849         /* Copy over the entire packet to the user buffer */
 850         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 851                                  &signal);
 852
 853         if (signal)
 854                 vmbus_setevent(channel);
 855
 856         return 0;
 857 }
 858 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);