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