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