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 error_gpadl;
 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 error_gpadl;
 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 error_gpadl:
 238         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 239
 240 error0:
 241         free_pages((unsigned long)out,
 242                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 243         kfree(open_info);
 244         return err;
 245 }
 246 EXPORT_SYMBOL_GPL(vmbus_open);
 247
 248 /*
 249  * create_gpadl_header - Creates a gpadl for the specified buffer
 250  */
 251 static int create_gpadl_header(void *kbuffer, u32 size,
 252                                          struct vmbus_channel_msginfo **msginfo,
 253                                          u32 *messagecount)
 254 {
 255         int i;
 256         int pagecount;
 257         unsigned long long pfn;
 258         struct vmbus_channel_gpadl_header *gpadl_header;
 259         struct vmbus_channel_gpadl_body *gpadl_body;
 260         struct vmbus_channel_msginfo *msgheader;
 261         struct vmbus_channel_msginfo *msgbody = NULL;
 262         u32 msgsize;
 263
 264         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 265
 266         pagecount = size >> PAGE_SHIFT;
 267         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
 268
 269         /* do we need a gpadl body msg */
 270         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 271                   sizeof(struct vmbus_channel_gpadl_header) -
 272                   sizeof(struct gpa_range);
 273         pfncount = pfnsize / sizeof(u64);
 274
 275         if (pagecount > pfncount) {
 276                 /* we need a gpadl body */
 277                 /* fill in the header */
 278                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 279                           sizeof(struct vmbus_channel_gpadl_header) +
 280                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 281                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 282                 if (!msgheader)
 283                         goto nomem;
 284
 285                 INIT_LIST_HEAD(&msgheader->submsglist);
 286                 msgheader->msgsize = msgsize;
 287
 288                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 289                         msgheader->msg;
 290                 gpadl_header->rangecount = 1;
 291                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 292                                          pagecount * sizeof(u64);
 293                 gpadl_header->range[0].byte_offset = 0;
 294                 gpadl_header->range[0].byte_count = size;
 295                 for (i = 0; i < pfncount; i++)
 296                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 297                 *msginfo = msgheader;
 298                 *messagecount = 1;
 299
 300                 pfnsum = pfncount;
 301                 pfnleft = pagecount - pfncount;
 302
 303                 /* how many pfns can we fit */
 304                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 305                           sizeof(struct vmbus_channel_gpadl_body);
 306                 pfncount = pfnsize / sizeof(u64);
 307
 308                 /* fill in the body */
 309                 while (pfnleft) {
 310                         if (pfnleft > pfncount)
 311                                 pfncurr = pfncount;
 312                         else
 313                                 pfncurr = pfnleft;
 314
 315                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 316                                   sizeof(struct vmbus_channel_gpadl_body) +
 317                                   pfncurr * sizeof(u64);
 318                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 319
 320                         if (!msgbody) {
 321                                 struct vmbus_channel_msginfo *pos = NULL;
 322                                 struct vmbus_channel_msginfo *tmp = NULL;
 323                                 /*
 324                                  * Free up all the allocated messages.
 325                                  */
 326                                 list_for_each_entry_safe(pos, tmp,
 327                                         &msgheader->submsglist,
 328                                         msglistentry) {
 329
 330                                         list_del(&pos->msglistentry);
 331                                         kfree(pos);
 332                                 }
 333
 334                                 goto nomem;
 335                         }
 336
 337                         msgbody->msgsize = msgsize;
 338                         (*messagecount)++;
 339                         gpadl_body =
 340                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 341
 342                         /*
 343                          * Gpadl is u32 and we are using a pointer which could
 344                          * be 64-bit
 345                          * This is governed by the guest/host protocol and
 346                          * so the hypervisor gurantees that this is ok.
 347                          */
 348                         for (i = 0; i < pfncurr; i++)
 349                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
 350
 351                         /* add to msg header */
 352                         list_add_tail(&msgbody->msglistentry,
 353                                       &msgheader->submsglist);
 354                         pfnsum += pfncurr;
 355                         pfnleft -= pfncurr;
 356                 }
 357         } else {
 358                 /* everything fits in a header */
 359                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 360                           sizeof(struct vmbus_channel_gpadl_header) +
 361                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 362                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 363                 if (msgheader == NULL)
 364                         goto nomem;
 365                 msgheader->msgsize = msgsize;
 366
 367                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 368                         msgheader->msg;
 369                 gpadl_header->rangecount = 1;
 370                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 371                                          pagecount * sizeof(u64);
 372                 gpadl_header->range[0].byte_offset = 0;
 373                 gpadl_header->range[0].byte_count = size;
 374                 for (i = 0; i < pagecount; i++)
 375                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 376
 377                 *msginfo = msgheader;
 378                 *messagecount = 1;
 379         }
 380
 381         return 0;
 382 nomem:
 383         kfree(msgheader);
 384         kfree(msgbody);
 385         return -ENOMEM;
 386 }
 387
 388 /*
 389  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 390  *
 391  * @channel: a channel
 392  * @kbuffer: from kmalloc
 393  * @size: page-size multiple
 394  * @gpadl_handle: some funky thing
 395  */
 396 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 397                                u32 size, u32 *gpadl_handle)
 398 {
 399         struct vmbus_channel_gpadl_header *gpadlmsg;
 400         struct vmbus_channel_gpadl_body *gpadl_body;
 401         struct vmbus_channel_msginfo *msginfo = NULL;
 402         struct vmbus_channel_msginfo *submsginfo;
 403         u32 msgcount;
 404         struct list_head *curr;
 405         u32 next_gpadl_handle;
 406         unsigned long flags;
 407         int ret = 0;
 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         wait_for_completion(&msginfo->waitevent);
 455
 456         /* At this point, we received the gpadl created msg */
 457         *gpadl_handle = gpadlmsg->gpadl;
 458
 459 cleanup:
 460         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 461         list_del(&msginfo->msglistentry);
 462         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 463
 464         kfree(msginfo);
 465         return ret;
 466 }
 467 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 468
 469 /*
 470  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 471  */
 472 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 473 {
 474         struct vmbus_channel_gpadl_teardown *msg;
 475         struct vmbus_channel_msginfo *info;
 476         unsigned long flags;
 477         int ret;
 478
 479         info = kmalloc(sizeof(*info) +
 480                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 481         if (!info)
 482                 return -ENOMEM;
 483
 484         init_completion(&info->waitevent);
 485
 486         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 487
 488         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 489         msg->child_relid = channel->offermsg.child_relid;
 490         msg->gpadl = gpadl_handle;
 491
 492         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 493         list_add_tail(&info->msglistentry,
 494                       &vmbus_connection.chn_msg_list);
 495         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 496         ret = vmbus_post_msg(msg,
 497                                sizeof(struct vmbus_channel_gpadl_teardown));
 498
 499         if (ret)
 500                 goto post_msg_err;
 501
 502         wait_for_completion(&info->waitevent);
 503
 504 post_msg_err:
 505         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 506         list_del(&info->msglistentry);
 507         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 508
 509         kfree(info);
 510         return ret;
 511 }
 512 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 513
 514 /*
 515  * vmbus_close - Close the specified channel
 516  */
 517 void vmbus_close(struct vmbus_channel *channel)
 518 {
 519         struct vmbus_channel_close_channel *msg;
 520         int ret;
 521         unsigned long flags;
 522
 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         if (ret) {
 538                 pr_err("Close failed: close post msg return is %d\n", ret);
 539                 /*
 540                  * If we failed to post the close msg,
 541                  * it is perhaps better to leak memory.
 542                  */
 543                 return;
 544         }
 545
 546         /* Tear down the gpadl for the channel's ring buffer */
 547         if (channel->ringbuffer_gpadlhandle) {
 548                 ret = vmbus_teardown_gpadl(channel,
 549                                            channel->ringbuffer_gpadlhandle);
 550                 if (ret) {
 551                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 552                         /*
 553                          * If we failed to teardown gpadl,
 554                          * it is perhaps better to leak memory.
 555                          */
 556                         return;
 557                 }
 558         }
 559
 560         /* Cleanup the ring buffers for this channel */
 561         hv_ringbuffer_cleanup(&channel->outbound);
 562         hv_ringbuffer_cleanup(&channel->inbound);
 563
 564         free_pages((unsigned long)channel->ringbuffer_pages,
 565                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 566
 567
 568 }
 569 EXPORT_SYMBOL_GPL(vmbus_close);
 570
 571 /**
 572  * vmbus_sendpacket() - Send the specified buffer on the given channel
 573  * @channel: Pointer to vmbus_channel structure.
 574  * @buffer: Pointer to the buffer you want to receive the data into.
 575  * @bufferlen: Maximum size of what the the buffer will hold
 576  * @requestid: Identifier of the request
 577  * @type: Type of packet that is being send e.g. negotiate, time
 578  * packet etc.
 579  *
 580  * Sends data in @buffer directly to hyper-v via the vmbus
 581  * This will send the data unparsed to hyper-v.
 582  *
 583  * Mainly used by Hyper-V drivers.
 584  */
 585 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
 586                            u32 bufferlen, u64 requestid,
 587                            enum vmbus_packet_type type, u32 flags)
 588 {
 589         struct vmpacket_descriptor desc;
 590         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 591         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 592         struct scatterlist bufferlist[3];
 593         u64 aligned_data = 0;
 594         int ret;
 595
 596
 597         /* Setup the descriptor */
 598         desc.type = type; /* VmbusPacketTypeDataInBand; */
 599         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 600         /* in 8-bytes granularity */
 601         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 602         desc.len8 = (u16)(packetlen_aligned >> 3);
 603         desc.trans_id = requestid;
 604
 605         sg_init_table(bufferlist, 3);
 606         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
 607         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 608         sg_set_buf(&bufferlist[2], &aligned_data,
 609                    packetlen_aligned - packetlen);
 610
 611         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 612
 613         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 614                 vmbus_setevent(channel);
 615
 616         return ret;
 617 }
 618 EXPORT_SYMBOL(vmbus_sendpacket);
 619
 620 /*
 621  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 622  * packets using a GPADL Direct packet type.
 623  */
 624 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 625                                      struct hv_page_buffer pagebuffers[],
 626                                      u32 pagecount, void *buffer, u32 bufferlen,
 627                                      u64 requestid)
 628 {
 629         int ret;
 630         int i;
 631         struct vmbus_channel_packet_page_buffer desc;
 632         u32 descsize;
 633         u32 packetlen;
 634         u32 packetlen_aligned;
 635         struct scatterlist bufferlist[3];
 636         u64 aligned_data = 0;
 637
 638         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 639                 return -EINVAL;
 640
 641
 642         /*
 643          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 644          * largest size we support
 645          */
 646         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 647                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 648                           sizeof(struct hv_page_buffer));
 649         packetlen = descsize + bufferlen;
 650         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 651
 652         /* Setup the descriptor */
 653         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 654         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 655         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 656         desc.length8 = (u16)(packetlen_aligned >> 3);
 657         desc.transactionid = requestid;
 658         desc.rangecount = pagecount;
 659
 660         for (i = 0; i < pagecount; i++) {
 661                 desc.range[i].len = pagebuffers[i].len;
 662                 desc.range[i].offset = pagebuffers[i].offset;
 663                 desc.range[i].pfn        = pagebuffers[i].pfn;
 664         }
 665
 666         sg_init_table(bufferlist, 3);
 667         sg_set_buf(&bufferlist[0], &desc, descsize);
 668         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 669         sg_set_buf(&bufferlist[2], &aligned_data,
 670                 packetlen_aligned - packetlen);
 671
 672         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 673
 674         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 675                 vmbus_setevent(channel);
 676
 677         return ret;
 678 }
 679 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 680
 681 /*
 682  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 683  * using a GPADL Direct packet type.
 684  */
 685 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 686                                 struct hv_multipage_buffer *multi_pagebuffer,
 687                                 void *buffer, u32 bufferlen, u64 requestid)
 688 {
 689         int ret;
 690         struct vmbus_channel_packet_multipage_buffer desc;
 691         u32 descsize;
 692         u32 packetlen;
 693         u32 packetlen_aligned;
 694         struct scatterlist bufferlist[3];
 695         u64 aligned_data = 0;
 696         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 697                                          multi_pagebuffer->len);
 698
 699
 700         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
 701                 return -EINVAL;
 702
 703         /*
 704          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 705          * the largest size we support
 706          */
 707         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 708                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 709                           sizeof(u64));
 710         packetlen = descsize + bufferlen;
 711         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 712
 713
 714         /* Setup the descriptor */
 715         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 716         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 717         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 718         desc.length8 = (u16)(packetlen_aligned >> 3);
 719         desc.transactionid = requestid;
 720         desc.rangecount = 1;
 721
 722         desc.range.len = multi_pagebuffer->len;
 723         desc.range.offset = multi_pagebuffer->offset;
 724
 725         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 726                pfncount * sizeof(u64));
 727
 728         sg_init_table(bufferlist, 3);
 729         sg_set_buf(&bufferlist[0], &desc, descsize);
 730         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 731         sg_set_buf(&bufferlist[2], &aligned_data,
 732                 packetlen_aligned - packetlen);
 733
 734         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 735
 736         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 737                 vmbus_setevent(channel);
 738
 739         return ret;
 740 }
 741 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 742
 743 /**
 744  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 745  * @channel: Pointer to vmbus_channel structure.
 746  * @buffer: Pointer to the buffer you want to receive the data into.
 747  * @bufferlen: Maximum size of what the the buffer will hold
 748  * @buffer_actual_len: The actual size of the data after it was received
 749  * @requestid: Identifier of the request
 750  *
 751  * Receives directly from the hyper-v vmbus and puts the data it received
 752  * into Buffer. This will receive the data unparsed from hyper-v.
 753  *
 754  * Mainly used by Hyper-V drivers.
 755  */
 756 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 757                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 758 {
 759         struct vmpacket_descriptor desc;
 760         u32 packetlen;
 761         u32 userlen;
 762         int ret;
 763
 764         *buffer_actual_len = 0;
 765         *requestid = 0;
 766
 767
 768         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 769                              sizeof(struct vmpacket_descriptor));
 770         if (ret != 0)
 771                 return 0;
 772
 773         packetlen = desc.len8 << 3;
 774         userlen = packetlen - (desc.offset8 << 3);
 775
 776         *buffer_actual_len = userlen;
 777
 778         if (userlen > bufferlen) {
 779
 780                 pr_err("Buffer too small - got %d needs %d\n",
 781                            bufferlen, userlen);
 782                 return -ETOOSMALL;
 783         }
 784
 785         *requestid = desc.trans_id;
 786
 787         /* Copy over the packet to the user buffer */
 788         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 789                              (desc.offset8 << 3));
 790
 791
 792         return 0;
 793 }
 794 EXPORT_SYMBOL(vmbus_recvpacket);
 795
 796 /*
 797  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 798  */
 799 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 800                               u32 bufferlen, u32 *buffer_actual_len,
 801                               u64 *requestid)
 802 {
 803         struct vmpacket_descriptor desc;
 804         u32 packetlen;
 805         u32 userlen;
 806         int ret;
 807
 808         *buffer_actual_len = 0;
 809         *requestid = 0;
 810
 811
 812         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 813                              sizeof(struct vmpacket_descriptor));
 814         if (ret != 0)
 815                 return 0;
 816
 817
 818         packetlen = desc.len8 << 3;
 819         userlen = packetlen - (desc.offset8 << 3);
 820
 821         *buffer_actual_len = packetlen;
 822
 823         if (packetlen > bufferlen) {
 824                 pr_err("Buffer too small - needed %d bytes but "
 825                         "got space for only %d bytes\n",
 826                         packetlen, bufferlen);
 827                 return -ENOBUFS;
 828         }
 829
 830         *requestid = desc.trans_id;
 831
 832         /* Copy over the entire packet to the user buffer */
 833         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
 834
 835         return 0;
 836 }
 837 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);