drivers/staging/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
  30 #include "hyperv.h"
  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 dump_vmbus_channel(struct vmbus_channel *channel);
  43 static void vmbus_setevent(struct vmbus_channel *channel);
  44
  45 /*
  46  * vmbus_setevent- Trigger an event notification on the specified
  47  * channel.
  48  */
  49 static void vmbus_setevent(struct vmbus_channel *channel)
  50 {
  51         struct hv_monitor_page *monitorpage;
  52
  53         if (channel->offermsg.monitor_allocated) {
  54                 /* Each u32 represents 32 channels */
  55                 sync_set_bit(channel->offermsg.child_relid & 31,
  56                         (unsigned long *) vmbus_connection.send_int_page +
  57                         (channel->offermsg.child_relid >> 5));
  58
  59                 monitorpage = vmbus_connection.monitor_pages;
  60                 monitorpage++; /* Get the child to parent monitor page */
  61
  62                 sync_set_bit(channel->monitor_bit,
  63                         (unsigned long *)&monitorpage->trigger_group
  64                                         [channel->monitor_grp].pending);
  65
  66         } else {
  67                 vmbus_set_event(channel->offermsg.child_relid);
  68         }
  69 }
  70
  71 /*
  72  * vmbus_get_debug_info -Retrieve various channel debug info
  73  */
  74 void vmbus_get_debug_info(struct vmbus_channel *channel,
  75                               struct vmbus_channel_debug_info *debuginfo)
  76 {
  77         struct hv_monitor_page *monitorpage;
  78         u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
  79         u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
  80         /* u32 monitorBit       = 1 << monitorOffset; */
  81
  82         debuginfo->relid = channel->offermsg.child_relid;
  83         debuginfo->state = channel->state;
  84         memcpy(&debuginfo->interfacetype,
  85                &channel->offermsg.offer.if_type, sizeof(struct hv_guid));
  86         memcpy(&debuginfo->interface_instance,
  87                &channel->offermsg.offer.if_instance,
  88                sizeof(struct hv_guid));
  89
  90         monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
  91
  92         debuginfo->monitorid = channel->offermsg.monitorid;
  93
  94         debuginfo->servermonitor_pending =
  95                         monitorpage->trigger_group[monitor_group].pending;
  96         debuginfo->servermonitor_latency =
  97                         monitorpage->latency[monitor_group][monitor_offset];
  98         debuginfo->servermonitor_connectionid =
  99                         monitorpage->parameter[monitor_group]
 100                                         [monitor_offset].connectionid.u.id;
 101
 102         monitorpage++;
 103
 104         debuginfo->clientmonitor_pending =
 105                         monitorpage->trigger_group[monitor_group].pending;
 106         debuginfo->clientmonitor_latency =
 107                         monitorpage->latency[monitor_group][monitor_offset];
 108         debuginfo->clientmonitor_connectionid =
 109                         monitorpage->parameter[monitor_group]
 110                                         [monitor_offset].connectionid.u.id;
 111
 112         hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
 113         hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
 114 }
 115
 116 /*
 117  * vmbus_open - Open the specified channel.
 118  */
 119 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 120                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
 121                      void (*onchannelcallback)(void *context), void *context)
 122 {
 123         struct vmbus_channel_open_channel *openMsg;
 124         struct vmbus_channel_msginfo *openInfo = NULL;
 125         void *in, *out;
 126         unsigned long flags;
 127         int ret, t, err = 0;
 128
 129         newchannel->onchannel_callback = onchannelcallback;
 130         newchannel->channel_callback_context = context;
 131
 132         /* Allocate the ring buffer */
 133         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 134                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 135
 136         if (!out)
 137                 return -ENOMEM;
 138
 139
 140         in = (void *)((unsigned long)out + send_ringbuffer_size);
 141
 142         newchannel->ringbuffer_pages = out;
 143         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 144                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 145
 146         ret = hv_ringbuffer_init(
 147                 &newchannel->outbound, out, send_ringbuffer_size);
 148
 149         if (ret != 0) {
 150                 err = ret;
 151                 goto errorout;
 152         }
 153
 154         ret = hv_ringbuffer_init(
 155                 &newchannel->inbound, in, recv_ringbuffer_size);
 156         if (ret != 0) {
 157                 err = ret;
 158                 goto errorout;
 159         }
 160
 161
 162         /* Establish the gpadl for the ring buffer */
 163         newchannel->ringbuffer_gpadlhandle = 0;
 164
 165         ret = vmbus_establish_gpadl(newchannel,
 166                                          newchannel->outbound.ring_buffer,
 167                                          send_ringbuffer_size +
 168                                          recv_ringbuffer_size,
 169                                          &newchannel->ringbuffer_gpadlhandle);
 170
 171         if (ret != 0) {
 172                 err = ret;
 173                 goto errorout;
 174         }
 175
 176         /* Create and init the channel open message */
 177         openInfo = kmalloc(sizeof(*openInfo) +
 178                            sizeof(struct vmbus_channel_open_channel),
 179                            GFP_KERNEL);
 180         if (!openInfo) {
 181                 err = -ENOMEM;
 182                 goto errorout;
 183         }
 184
 185         init_completion(&openInfo->waitevent);
 186
 187         openMsg = (struct vmbus_channel_open_channel *)openInfo->msg;
 188         openMsg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 189         openMsg->openid = newchannel->offermsg.child_relid; /* FIXME */
 190         openMsg->child_relid = newchannel->offermsg.child_relid;
 191         openMsg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 192         openMsg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 193                                                   PAGE_SHIFT;
 194         openMsg->server_contextarea_gpadlhandle = 0; /* TODO */
 195
 196         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 197                 err = -EINVAL;
 198                 goto errorout;
 199         }
 200
 201         if (userdatalen)
 202                 memcpy(openMsg->userdata, userdata, userdatalen);
 203
 204         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 205         list_add_tail(&openInfo->msglistentry,
 206                       &vmbus_connection.chn_msg_list);
 207         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 208
 209         ret = vmbus_post_msg(openMsg,
 210                                sizeof(struct vmbus_channel_open_channel));
 211
 212         if (ret != 0)
 213                 goto Cleanup;
 214
 215         t = wait_for_completion_timeout(&openInfo->waitevent, HZ);
 216         if (t == 0) {
 217                 err = -ETIMEDOUT;
 218                 goto errorout;
 219         }
 220
 221
 222         if (openInfo->response.open_result.status)
 223                 err = openInfo->response.open_result.status;
 224
 225 Cleanup:
 226         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 227         list_del(&openInfo->msglistentry);
 228         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 229
 230         kfree(openInfo);
 231         return err;
 232
 233 errorout:
 234         hv_ringbuffer_cleanup(&newchannel->outbound);
 235         hv_ringbuffer_cleanup(&newchannel->inbound);
 236         free_pages((unsigned long)out,
 237                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 238         kfree(openInfo);
 239         return err;
 240 }
 241 EXPORT_SYMBOL_GPL(vmbus_open);
 242
 243 /*
 244  * dump_gpadl_body - Dump the gpadl body message to the console for
 245  * debugging purposes.
 246  */
 247 static void dump_gpadl_body(struct vmbus_channel_gpadl_body *gpadl, u32 len)
 248 {
 249         int i;
 250         int pfncount;
 251
 252         pfncount = (len - sizeof(struct vmbus_channel_gpadl_body)) /
 253                    sizeof(u64);
 254
 255         DPRINT_DBG(VMBUS, "gpadl body - len %d pfn count %d", len, pfncount);
 256
 257         for (i = 0; i < pfncount; i++)
 258                 DPRINT_DBG(VMBUS, "gpadl body  - %d) pfn %llu",
 259                            i, gpadl->pfn[i]);
 260 }
 261
 262 /*
 263  * dump_gpadl_header - Dump the gpadl header message to the console for
 264  * debugging purposes.
 265  */
 266 static void dump_gpadl_header(struct vmbus_channel_gpadl_header *gpadl)
 267 {
 268         int i, j;
 269         int pagecount;
 270
 271         DPRINT_DBG(VMBUS,
 272                    "gpadl header - relid %d, range count %d, range buflen %d",
 273                    gpadl->child_relid, gpadl->rangecount, gpadl->range_buflen);
 274         for (i = 0; i < gpadl->rangecount; i++) {
 275                 pagecount = gpadl->range[i].byte_count >> PAGE_SHIFT;
 276                 pagecount = (pagecount > 26) ? 26 : pagecount;
 277
 278                 DPRINT_DBG(VMBUS, "gpadl range %d - len %d offset %d "
 279                            "page count %d", i, gpadl->range[i].byte_count,
 280                            gpadl->range[i].byte_offset, pagecount);
 281
 282                 for (j = 0; j < pagecount; j++)
 283                         DPRINT_DBG(VMBUS, "%d) pfn %llu", j,
 284                                    gpadl->range[i].pfn_array[j]);
 285         }
 286 }
 287
 288 /*
 289  * create_gpadl_header - Creates a gpadl for the specified buffer
 290  */
 291 static int create_gpadl_header(void *kbuffer, u32 size,
 292                                          struct vmbus_channel_msginfo **msginfo,
 293                                          u32 *messagecount)
 294 {
 295         int i;
 296         int pagecount;
 297         unsigned long long pfn;
 298         struct vmbus_channel_gpadl_header *gpadl_header;
 299         struct vmbus_channel_gpadl_body *gpadl_body;
 300         struct vmbus_channel_msginfo *msgheader;
 301         struct vmbus_channel_msginfo *msgbody = NULL;
 302         u32 msgsize;
 303
 304         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 305
 306         pagecount = size >> PAGE_SHIFT;
 307         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
 308
 309         /* do we need a gpadl body msg */
 310         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 311                   sizeof(struct vmbus_channel_gpadl_header) -
 312                   sizeof(struct gpa_range);
 313         pfncount = pfnsize / sizeof(u64);
 314
 315         if (pagecount > pfncount) {
 316                 /* we need a gpadl body */
 317                 /* fill in the header */
 318                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 319                           sizeof(struct vmbus_channel_gpadl_header) +
 320                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 321                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 322                 if (!msgheader)
 323                         goto nomem;
 324
 325                 INIT_LIST_HEAD(&msgheader->submsglist);
 326                 msgheader->msgsize = msgsize;
 327
 328                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 329                         msgheader->msg;
 330                 gpadl_header->rangecount = 1;
 331                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 332                                          pagecount * sizeof(u64);
 333                 gpadl_header->range[0].byte_offset = 0;
 334                 gpadl_header->range[0].byte_count = size;
 335                 for (i = 0; i < pfncount; i++)
 336                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 337                 *msginfo = msgheader;
 338                 *messagecount = 1;
 339
 340                 pfnsum = pfncount;
 341                 pfnleft = pagecount - pfncount;
 342
 343                 /* how many pfns can we fit */
 344                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 345                           sizeof(struct vmbus_channel_gpadl_body);
 346                 pfncount = pfnsize / sizeof(u64);
 347
 348                 /* fill in the body */
 349                 while (pfnleft) {
 350                         if (pfnleft > pfncount)
 351                                 pfncurr = pfncount;
 352                         else
 353                                 pfncurr = pfnleft;
 354
 355                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 356                                   sizeof(struct vmbus_channel_gpadl_body) +
 357                                   pfncurr * sizeof(u64);
 358                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 359                         /* FIXME: we probably need to more if this fails */
 360                         if (!msgbody)
 361                                 goto nomem;
 362                         msgbody->msgsize = msgsize;
 363                         (*messagecount)++;
 364                         gpadl_body =
 365                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 366
 367                         /*
 368                          * FIXME:
 369                          * Gpadl is u32 and we are using a pointer which could
 370                          * be 64-bit
 371                          */
 372                         /* gpadl_body->Gpadl = kbuffer; */
 373                         for (i = 0; i < pfncurr; i++)
 374                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
 375
 376                         /* add to msg header */
 377                         list_add_tail(&msgbody->msglistentry,
 378                                       &msgheader->submsglist);
 379                         pfnsum += pfncurr;
 380                         pfnleft -= pfncurr;
 381                 }
 382         } else {
 383                 /* everything fits in a header */
 384                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 385                           sizeof(struct vmbus_channel_gpadl_header) +
 386                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 387                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 388                 if (msgheader == NULL)
 389                         goto nomem;
 390                 msgheader->msgsize = msgsize;
 391
 392                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 393                         msgheader->msg;
 394                 gpadl_header->rangecount = 1;
 395                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 396                                          pagecount * sizeof(u64);
 397                 gpadl_header->range[0].byte_offset = 0;
 398                 gpadl_header->range[0].byte_count = size;
 399                 for (i = 0; i < pagecount; i++)
 400                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 401
 402                 *msginfo = msgheader;
 403                 *messagecount = 1;
 404         }
 405
 406         return 0;
 407 nomem:
 408         kfree(msgheader);
 409         kfree(msgbody);
 410         return -ENOMEM;
 411 }
 412
 413 /*
 414  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 415  *
 416  * @channel: a channel
 417  * @kbuffer: from kmalloc
 418  * @size: page-size multiple
 419  * @gpadl_handle: some funky thing
 420  */
 421 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 422                                u32 size, u32 *gpadl_handle)
 423 {
 424         struct vmbus_channel_gpadl_header *gpadlmsg;
 425         struct vmbus_channel_gpadl_body *gpadl_body;
 426         /* struct vmbus_channel_gpadl_created *gpadlCreated; */
 427         struct vmbus_channel_msginfo *msginfo = NULL;
 428         struct vmbus_channel_msginfo *submsginfo;
 429         u32 msgcount;
 430         struct list_head *curr;
 431         u32 next_gpadl_handle;
 432         unsigned long flags;
 433         int ret = 0;
 434         int t;
 435
 436         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
 437         atomic_inc(&vmbus_connection.next_gpadl_handle);
 438
 439         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 440         if (ret)
 441                 return ret;
 442
 443         init_completion(&msginfo->waitevent);
 444
 445         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 446         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 447         gpadlmsg->child_relid = channel->offermsg.child_relid;
 448         gpadlmsg->gpadl = next_gpadl_handle;
 449
 450         dump_gpadl_header(gpadlmsg);
 451
 452         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 453         list_add_tail(&msginfo->msglistentry,
 454                       &vmbus_connection.chn_msg_list);
 455
 456         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 457
 458         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 459                                sizeof(*msginfo));
 460         if (ret != 0)
 461                 goto Cleanup;
 462
 463         if (msgcount > 1) {
 464                 list_for_each(curr, &msginfo->submsglist) {
 465
 466                         /* FIXME: should this use list_entry() instead ? */
 467                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 468                         gpadl_body =
 469                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 470
 471                         gpadl_body->header.msgtype =
 472                                 CHANNELMSG_GPADL_BODY;
 473                         gpadl_body->gpadl = next_gpadl_handle;
 474
 475                         dump_gpadl_body(gpadl_body, submsginfo->msgsize -
 476                                       sizeof(*submsginfo));
 477                         ret = vmbus_post_msg(gpadl_body,
 478                                                submsginfo->msgsize -
 479                                                sizeof(*submsginfo));
 480                         if (ret != 0)
 481                                 goto Cleanup;
 482
 483                 }
 484         }
 485         t = wait_for_completion_timeout(&msginfo->waitevent, HZ);
 486         BUG_ON(t == 0);
 487
 488
 489         /* At this point, we received the gpadl created msg */
 490         *gpadl_handle = gpadlmsg->gpadl;
 491
 492 Cleanup:
 493         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 494         list_del(&msginfo->msglistentry);
 495         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 496
 497         kfree(msginfo);
 498         return ret;
 499 }
 500 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 501
 502 /*
 503  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 504  */
 505 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 506 {
 507         struct vmbus_channel_gpadl_teardown *msg;
 508         struct vmbus_channel_msginfo *info;
 509         unsigned long flags;
 510         int ret, t;
 511
 512         /* ASSERT(gpadl_handle != 0); */
 513
 514         info = kmalloc(sizeof(*info) +
 515                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 516         if (!info)
 517                 return -ENOMEM;
 518
 519         init_completion(&info->waitevent);
 520
 521         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 522
 523         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 524         msg->child_relid = channel->offermsg.child_relid;
 525         msg->gpadl = gpadl_handle;
 526
 527         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 528         list_add_tail(&info->msglistentry,
 529                       &vmbus_connection.chn_msg_list);
 530         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 531         ret = vmbus_post_msg(msg,
 532                                sizeof(struct vmbus_channel_gpadl_teardown));
 533
 534         BUG_ON(ret != 0);
 535         t = wait_for_completion_timeout(&info->waitevent, HZ);
 536         BUG_ON(t == 0);
 537
 538         /* Received a torndown response */
 539         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 540         list_del(&info->msglistentry);
 541         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 542
 543         kfree(info);
 544         return ret;
 545 }
 546 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 547
 548 /*
 549  * vmbus_close - Close the specified channel
 550  */
 551 void vmbus_close(struct vmbus_channel *channel)
 552 {
 553         struct vmbus_channel_close_channel *msg;
 554         struct vmbus_channel_msginfo *info;
 555         unsigned long flags;
 556         int ret;
 557
 558         /* Stop callback and cancel the timer asap */
 559         channel->onchannel_callback = NULL;
 560         del_timer_sync(&channel->poll_timer);
 561
 562         /* Send a closing message */
 563         info = kmalloc(sizeof(*info) +
 564                        sizeof(struct vmbus_channel_close_channel), GFP_KERNEL);
 565         /* FIXME: can't do anything other than return here because the
 566          *        function is void */
 567         if (!info)
 568                 return;
 569
 570
 571         msg = (struct vmbus_channel_close_channel *)info->msg;
 572         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 573         msg->child_relid = channel->offermsg.child_relid;
 574
 575         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 576
 577         BUG_ON(ret != 0);
 578         /* Tear down the gpadl for the channel's ring buffer */
 579         if (channel->ringbuffer_gpadlhandle)
 580                 vmbus_teardown_gpadl(channel,
 581                                           channel->ringbuffer_gpadlhandle);
 582
 583         /* TODO: Send a msg to release the childRelId */
 584
 585         /* Cleanup the ring buffers for this channel */
 586         hv_ringbuffer_cleanup(&channel->outbound);
 587         hv_ringbuffer_cleanup(&channel->inbound);
 588
 589         free_pages((unsigned long)channel->ringbuffer_pages,
 590                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 591
 592         kfree(info);
 593
 594         /*
 595          * If we are closing the channel during an error path in
 596          * opening the channel, don't free the channel since the
 597          * caller will free the channel
 598          */
 599
 600         if (channel->state == CHANNEL_OPEN_STATE) {
 601                 spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
 602                 list_del(&channel->listentry);
 603                 spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
 604
 605                 free_channel(channel);
 606         }
 607 }
 608 EXPORT_SYMBOL_GPL(vmbus_close);
 609
 610 /**
 611  * vmbus_sendpacket() - Send the specified buffer on the given channel
 612  * @channel: Pointer to vmbus_channel structure.
 613  * @buffer: Pointer to the buffer you want to receive the data into.
 614  * @bufferlen: Maximum size of what the the buffer will hold
 615  * @requestid: Identifier of the request
 616  * @type: Type of packet that is being send e.g. negotiate, time
 617  * packet etc.
 618  *
 619  * Sends data in @buffer directly to hyper-v via the vmbus
 620  * This will send the data unparsed to hyper-v.
 621  *
 622  * Mainly used by Hyper-V drivers.
 623  */
 624 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
 625                            u32 bufferlen, u64 requestid,
 626                            enum vmbus_packet_type type, u32 flags)
 627 {
 628         struct vmpacket_descriptor desc;
 629         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 630         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 631         struct scatterlist bufferlist[3];
 632         u64 aligned_data = 0;
 633         int ret;
 634
 635         dump_vmbus_channel(channel);
 636
 637         /* Setup the descriptor */
 638         desc.type = type; /* VmbusPacketTypeDataInBand; */
 639         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 640         /* in 8-bytes granularity */
 641         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 642         desc.len8 = (u16)(packetlen_aligned >> 3);
 643         desc.trans_id = requestid;
 644
 645         sg_init_table(bufferlist, 3);
 646         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
 647         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 648         sg_set_buf(&bufferlist[2], &aligned_data,
 649                    packetlen_aligned - packetlen);
 650
 651         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 652
 653         /* TODO: We should determine if this is optional */
 654         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 655                 vmbus_setevent(channel);
 656
 657         return ret;
 658 }
 659 EXPORT_SYMBOL(vmbus_sendpacket);
 660
 661 /*
 662  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 663  * packets using a GPADL Direct packet type.
 664  */
 665 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 666                                      struct hv_page_buffer pagebuffers[],
 667                                      u32 pagecount, void *buffer, u32 bufferlen,
 668                                      u64 requestid)
 669 {
 670         int ret;
 671         int i;
 672         struct vmbus_channel_packet_page_buffer desc;
 673         u32 descsize;
 674         u32 packetlen;
 675         u32 packetlen_aligned;
 676         struct scatterlist bufferlist[3];
 677         u64 aligned_data = 0;
 678
 679         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 680                 return -EINVAL;
 681
 682         dump_vmbus_channel(channel);
 683
 684         /*
 685          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 686          * largest size we support
 687          */
 688         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 689                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 690                           sizeof(struct hv_page_buffer));
 691         packetlen = descsize + bufferlen;
 692         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 693
 694         /* Setup the descriptor */
 695         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 696         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 697         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 698         desc.length8 = (u16)(packetlen_aligned >> 3);
 699         desc.transactionid = requestid;
 700         desc.rangecount = pagecount;
 701
 702         for (i = 0; i < pagecount; i++) {
 703                 desc.range[i].len = pagebuffers[i].len;
 704                 desc.range[i].offset = pagebuffers[i].offset;
 705                 desc.range[i].pfn        = pagebuffers[i].pfn;
 706         }
 707
 708         sg_init_table(bufferlist, 3);
 709         sg_set_buf(&bufferlist[0], &desc, descsize);
 710         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 711         sg_set_buf(&bufferlist[2], &aligned_data,
 712                 packetlen_aligned - packetlen);
 713
 714         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 715
 716         /* TODO: We should determine if this is optional */
 717         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 718                 vmbus_setevent(channel);
 719
 720         return ret;
 721 }
 722 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 723
 724 /*
 725  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 726  * using a GPADL Direct packet type.
 727  */
 728 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 729                                 struct hv_multipage_buffer *multi_pagebuffer,
 730                                 void *buffer, u32 bufferlen, u64 requestid)
 731 {
 732         int ret;
 733         struct vmbus_channel_packet_multipage_buffer desc;
 734         u32 descsize;
 735         u32 packetlen;
 736         u32 packetlen_aligned;
 737         struct scatterlist bufferlist[3];
 738         u64 aligned_data = 0;
 739         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 740                                          multi_pagebuffer->len);
 741
 742         dump_vmbus_channel(channel);
 743
 744         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
 745                 return -EINVAL;
 746
 747         /*
 748          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 749          * the largest size we support
 750          */
 751         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 752                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 753                           sizeof(u64));
 754         packetlen = descsize + bufferlen;
 755         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 756
 757
 758         /* Setup the descriptor */
 759         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 760         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 761         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 762         desc.length8 = (u16)(packetlen_aligned >> 3);
 763         desc.transactionid = requestid;
 764         desc.rangecount = 1;
 765
 766         desc.range.len = multi_pagebuffer->len;
 767         desc.range.offset = multi_pagebuffer->offset;
 768
 769         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 770                pfncount * sizeof(u64));
 771
 772         sg_init_table(bufferlist, 3);
 773         sg_set_buf(&bufferlist[0], &desc, descsize);
 774         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 775         sg_set_buf(&bufferlist[2], &aligned_data,
 776                 packetlen_aligned - packetlen);
 777
 778         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 779
 780         /* TODO: We should determine if this is optional */
 781         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 782                 vmbus_setevent(channel);
 783
 784         return ret;
 785 }
 786 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 787
 788 /**
 789  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 790  * @channel: Pointer to vmbus_channel structure.
 791  * @buffer: Pointer to the buffer you want to receive the data into.
 792  * @bufferlen: Maximum size of what the the buffer will hold
 793  * @buffer_actual_len: The actual size of the data after it was received
 794  * @requestid: Identifier of the request
 795  *
 796  * Receives directly from the hyper-v vmbus and puts the data it received
 797  * into Buffer. This will receive the data unparsed from hyper-v.
 798  *
 799  * Mainly used by Hyper-V drivers.
 800  */
 801 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 802                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 803 {
 804         struct vmpacket_descriptor desc;
 805         u32 packetlen;
 806         u32 userlen;
 807         int ret;
 808         unsigned long flags;
 809
 810         *buffer_actual_len = 0;
 811         *requestid = 0;
 812
 813         spin_lock_irqsave(&channel->inbound_lock, flags);
 814
 815         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 816                              sizeof(struct vmpacket_descriptor));
 817         if (ret != 0) {
 818                 spin_unlock_irqrestore(&channel->inbound_lock, flags);
 819                 return 0;
 820         }
 821
 822         packetlen = desc.len8 << 3;
 823         userlen = packetlen - (desc.offset8 << 3);
 824
 825         *buffer_actual_len = userlen;
 826
 827         if (userlen > bufferlen) {
 828                 spin_unlock_irqrestore(&channel->inbound_lock, flags);
 829
 830                 pr_err("Buffer too small - got %d needs %d\n",
 831                            bufferlen, userlen);
 832                 return -1;
 833         }
 834
 835         *requestid = desc.trans_id;
 836
 837         /* Copy over the packet to the user buffer */
 838         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 839                              (desc.offset8 << 3));
 840
 841         spin_unlock_irqrestore(&channel->inbound_lock, flags);
 842
 843         return 0;
 844 }
 845 EXPORT_SYMBOL(vmbus_recvpacket);
 846
 847 /*
 848  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 849  */
 850 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 851                               u32 bufferlen, u32 *buffer_actual_len,
 852                               u64 *requestid)
 853 {
 854         struct vmpacket_descriptor desc;
 855         u32 packetlen;
 856         u32 userlen;
 857         int ret;
 858         unsigned long flags;
 859
 860         *buffer_actual_len = 0;
 861         *requestid = 0;
 862
 863         spin_lock_irqsave(&channel->inbound_lock, flags);
 864
 865         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 866                              sizeof(struct vmpacket_descriptor));
 867         if (ret != 0) {
 868                 spin_unlock_irqrestore(&channel->inbound_lock, flags);
 869                 return 0;
 870         }
 871
 872
 873         packetlen = desc.len8 << 3;
 874         userlen = packetlen - (desc.offset8 << 3);
 875
 876         *buffer_actual_len = packetlen;
 877
 878         if (packetlen > bufferlen) {
 879                 spin_unlock_irqrestore(&channel->inbound_lock, flags);
 880
 881                 pr_err("Buffer too small - needed %d bytes but "
 882                         "got space for only %d bytes\n",
 883                         packetlen, bufferlen);
 884                 return -2;
 885         }
 886
 887         *requestid = desc.trans_id;
 888
 889         /* Copy over the entire packet to the user buffer */
 890         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
 891
 892         spin_unlock_irqrestore(&channel->inbound_lock, flags);
 893         return 0;
 894 }
 895 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
 896
 897 /*
 898  * vmbus_onchannel_event - Channel event callback
 899  */
 900 void vmbus_onchannel_event(struct vmbus_channel *channel)
 901 {
 902         dump_vmbus_channel(channel);
 903
 904         channel->onchannel_callback(channel->channel_callback_context);
 905
 906         mod_timer(&channel->poll_timer, jiffies + usecs_to_jiffies(100));
 907 }
 908
 909 /*
 910  * vmbus_ontimer - Timer event callback
 911  */
 912 void vmbus_ontimer(unsigned long data)
 913 {
 914         struct vmbus_channel *channel = (struct vmbus_channel *)data;
 915
 916         if (channel->onchannel_callback)
 917                 channel->onchannel_callback(channel->channel_callback_context);
 918 }
 919
 920 /*
 921  * dump_vmbus_channel- Dump vmbus channel info to the console
 922  */
 923 static void dump_vmbus_channel(struct vmbus_channel *channel)
 924 {
 925         DPRINT_DBG(VMBUS, "Channel (%d)", channel->offermsg.child_relid);
 926         hv_dump_ring_info(&channel->outbound, "Outbound ");
 927         hv_dump_ring_info(&channel->inbound, "Inbound ");
 928 }