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