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