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