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 #include <linux/uio.h>
  31 #include <linux/interrupt.h>
  32
  33 #include "hyperv_vmbus.h"
  34
  35 #define NUM_PAGES_SPANNED(addr, len) \
  36 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
  37
  38 /*
  39  * vmbus_setevent- Trigger an event notification on the specified
  40  * channel.
  41  */
  42 void vmbus_setevent(struct vmbus_channel *channel)
  43 {
  44         struct hv_monitor_page *monitorpage;
  45
  46         /*
  47          * For channels marked as in "low latency" mode
  48          * bypass the monitor page mechanism.
  49          */
  50         if ((channel->offermsg.monitor_allocated) &&
  51             (!channel->low_latency)) {
  52                 /* Each u32 represents 32 channels */
  53                 sync_set_bit(channel->offermsg.child_relid & 31,
  54                         (unsigned long *) vmbus_connection.send_int_page +
  55                         (channel->offermsg.child_relid >> 5));
  56
  57                 /* Get the child to parent monitor page */
  58                 monitorpage = vmbus_connection.monitor_pages[1];
  59
  60                 sync_set_bit(channel->monitor_bit,
  61                         (unsigned long *)&monitorpage->trigger_group
  62                                         [channel->monitor_grp].pending);
  63
  64         } else {
  65                 vmbus_set_event(channel);
  66         }
  67 }
  68 EXPORT_SYMBOL_GPL(vmbus_setevent);
  69
  70 /*
  71  * vmbus_open - Open the specified channel.
  72  */
  73 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
  74                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
  75                      void (*onchannelcallback)(void *context), void *context)
  76 {
  77         struct vmbus_channel_open_channel *open_msg;
  78         struct vmbus_channel_msginfo *open_info = NULL;
  79         unsigned long flags;
  80         int ret, err = 0;
  81         struct page *page;
  82
  83         if (send_ringbuffer_size % PAGE_SIZE ||
  84             recv_ringbuffer_size % PAGE_SIZE)
  85                 return -EINVAL;
  86
  87         spin_lock_irqsave(&newchannel->lock, flags);
  88         if (newchannel->state == CHANNEL_OPEN_STATE) {
  89                 newchannel->state = CHANNEL_OPENING_STATE;
  90         } else {
  91                 spin_unlock_irqrestore(&newchannel->lock, flags);
  92                 return -EINVAL;
  93         }
  94         spin_unlock_irqrestore(&newchannel->lock, flags);
  95
  96         newchannel->onchannel_callback = onchannelcallback;
  97         newchannel->channel_callback_context = context;
  98
  99         /* Allocate the ring buffer */
 100         page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
 101                                 GFP_KERNEL|__GFP_ZERO,
 102                                 get_order(send_ringbuffer_size +
 103                                 recv_ringbuffer_size));
 104
 105         if (!page)
 106                 page = alloc_pages(GFP_KERNEL|__GFP_ZERO,
 107                                    get_order(send_ringbuffer_size +
 108                                              recv_ringbuffer_size));
 109
 110         if (!page) {
 111                 err = -ENOMEM;
 112                 goto error_set_chnstate;
 113         }
 114
 115         newchannel->ringbuffer_pages = page_address(page);
 116         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 117                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 118
 119         ret = hv_ringbuffer_init(&newchannel->outbound, page,
 120                                  send_ringbuffer_size >> PAGE_SHIFT);
 121
 122         if (ret != 0) {
 123                 err = ret;
 124                 goto error_free_pages;
 125         }
 126
 127         ret = hv_ringbuffer_init(&newchannel->inbound,
 128                                  &page[send_ringbuffer_size >> PAGE_SHIFT],
 129                                  recv_ringbuffer_size >> PAGE_SHIFT);
 130         if (ret != 0) {
 131                 err = ret;
 132                 goto error_free_pages;
 133         }
 134
 135
 136         /* Establish the gpadl for the ring buffer */
 137         newchannel->ringbuffer_gpadlhandle = 0;
 138
 139         ret = vmbus_establish_gpadl(newchannel,
 140                                     page_address(page),
 141                                     send_ringbuffer_size +
 142                                     recv_ringbuffer_size,
 143                                     &newchannel->ringbuffer_gpadlhandle);
 144
 145         if (ret != 0) {
 146                 err = ret;
 147                 goto error_free_pages;
 148         }
 149
 150         /* Create and init the channel open message */
 151         open_info = kmalloc(sizeof(*open_info) +
 152                            sizeof(struct vmbus_channel_open_channel),
 153                            GFP_KERNEL);
 154         if (!open_info) {
 155                 err = -ENOMEM;
 156                 goto error_free_gpadl;
 157         }
 158
 159         init_completion(&open_info->waitevent);
 160
 161         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 162         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 163         open_msg->openid = newchannel->offermsg.child_relid;
 164         open_msg->child_relid = newchannel->offermsg.child_relid;
 165         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 166         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 167                                                   PAGE_SHIFT;
 168         open_msg->target_vp = newchannel->target_vp;
 169
 170         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 171                 err = -EINVAL;
 172                 goto error_free_gpadl;
 173         }
 174
 175         if (userdatalen)
 176                 memcpy(open_msg->userdata, userdata, userdatalen);
 177
 178         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 179         list_add_tail(&open_info->msglistentry,
 180                       &vmbus_connection.chn_msg_list);
 181         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 182
 183         ret = vmbus_post_msg(open_msg,
 184                                sizeof(struct vmbus_channel_open_channel));
 185
 186         if (ret != 0) {
 187                 err = ret;
 188                 goto error_clean_msglist;
 189         }
 190
 191         wait_for_completion(&open_info->waitevent);
 192
 193         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 194         list_del(&open_info->msglistentry);
 195         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 196
 197         if (open_info->response.open_result.status) {
 198                 err = -EAGAIN;
 199                 goto error_free_gpadl;
 200         }
 201
 202         newchannel->state = CHANNEL_OPENED_STATE;
 203         kfree(open_info);
 204         return 0;
 205
 206 error_clean_msglist:
 207         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 208         list_del(&open_info->msglistentry);
 209         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 210
 211 error_free_gpadl:
 212         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 213         kfree(open_info);
 214 error_free_pages:
 215         hv_ringbuffer_cleanup(&newchannel->outbound);
 216         hv_ringbuffer_cleanup(&newchannel->inbound);
 217         __free_pages(page,
 218                      get_order(send_ringbuffer_size + recv_ringbuffer_size));
 219 error_set_chnstate:
 220         newchannel->state = CHANNEL_OPEN_STATE;
 221         return err;
 222 }
 223 EXPORT_SYMBOL_GPL(vmbus_open);
 224
 225 /* Used for Hyper-V Socket: a guest client's connect() to the host */
 226 int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
 227                                   const uuid_le *shv_host_servie_id)
 228 {
 229         struct vmbus_channel_tl_connect_request conn_msg;
 230
 231         memset(&conn_msg, 0, sizeof(conn_msg));
 232         conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
 233         conn_msg.guest_endpoint_id = *shv_guest_servie_id;
 234         conn_msg.host_service_id = *shv_host_servie_id;
 235
 236         return vmbus_post_msg(&conn_msg, sizeof(conn_msg));
 237 }
 238 EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
 239
 240 /*
 241  * create_gpadl_header - Creates a gpadl for the specified buffer
 242  */
 243 static int create_gpadl_header(void *kbuffer, u32 size,
 244                                struct vmbus_channel_msginfo **msginfo)
 245 {
 246         int i;
 247         int pagecount;
 248         struct vmbus_channel_gpadl_header *gpadl_header;
 249         struct vmbus_channel_gpadl_body *gpadl_body;
 250         struct vmbus_channel_msginfo *msgheader;
 251         struct vmbus_channel_msginfo *msgbody = NULL;
 252         u32 msgsize;
 253
 254         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 255
 256         pagecount = size >> PAGE_SHIFT;
 257
 258         /* do we need a gpadl body msg */
 259         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 260                   sizeof(struct vmbus_channel_gpadl_header) -
 261                   sizeof(struct gpa_range);
 262         pfncount = pfnsize / sizeof(u64);
 263
 264         if (pagecount > pfncount) {
 265                 /* we need a gpadl body */
 266                 /* fill in the header */
 267                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 268                           sizeof(struct vmbus_channel_gpadl_header) +
 269                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 270                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 271                 if (!msgheader)
 272                         goto nomem;
 273
 274                 INIT_LIST_HEAD(&msgheader->submsglist);
 275                 msgheader->msgsize = msgsize;
 276
 277                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 278                         msgheader->msg;
 279                 gpadl_header->rangecount = 1;
 280                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 281                                          pagecount * sizeof(u64);
 282                 gpadl_header->range[0].byte_offset = 0;
 283                 gpadl_header->range[0].byte_count = size;
 284                 for (i = 0; i < pfncount; i++)
 285                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 286                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 287                 *msginfo = msgheader;
 288
 289                 pfnsum = pfncount;
 290                 pfnleft = pagecount - pfncount;
 291
 292                 /* how many pfns can we fit */
 293                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 294                           sizeof(struct vmbus_channel_gpadl_body);
 295                 pfncount = pfnsize / sizeof(u64);
 296
 297                 /* fill in the body */
 298                 while (pfnleft) {
 299                         if (pfnleft > pfncount)
 300                                 pfncurr = pfncount;
 301                         else
 302                                 pfncurr = pfnleft;
 303
 304                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 305                                   sizeof(struct vmbus_channel_gpadl_body) +
 306                                   pfncurr * sizeof(u64);
 307                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 308
 309                         if (!msgbody) {
 310                                 struct vmbus_channel_msginfo *pos = NULL;
 311                                 struct vmbus_channel_msginfo *tmp = NULL;
 312                                 /*
 313                                  * Free up all the allocated messages.
 314                                  */
 315                                 list_for_each_entry_safe(pos, tmp,
 316                                         &msgheader->submsglist,
 317                                         msglistentry) {
 318
 319                                         list_del(&pos->msglistentry);
 320                                         kfree(pos);
 321                                 }
 322
 323                                 goto nomem;
 324                         }
 325
 326                         msgbody->msgsize = msgsize;
 327                         gpadl_body =
 328                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 329
 330                         /*
 331                          * Gpadl is u32 and we are using a pointer which could
 332                          * be 64-bit
 333                          * This is governed by the guest/host protocol and
 334                          * so the hypervisor gurantees that this is ok.
 335                          */
 336                         for (i = 0; i < pfncurr; i++)
 337                                 gpadl_body->pfn[i] = slow_virt_to_phys(
 338                                         kbuffer + PAGE_SIZE * (pfnsum + i)) >>
 339                                         PAGE_SHIFT;
 340
 341                         /* add to msg header */
 342                         list_add_tail(&msgbody->msglistentry,
 343                                       &msgheader->submsglist);
 344                         pfnsum += pfncurr;
 345                         pfnleft -= pfncurr;
 346                 }
 347         } else {
 348                 /* everything fits in a header */
 349                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 350                           sizeof(struct vmbus_channel_gpadl_header) +
 351                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 352                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 353                 if (msgheader == NULL)
 354                         goto nomem;
 355
 356                 INIT_LIST_HEAD(&msgheader->submsglist);
 357                 msgheader->msgsize = msgsize;
 358
 359                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 360                         msgheader->msg;
 361                 gpadl_header->rangecount = 1;
 362                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 363                                          pagecount * sizeof(u64);
 364                 gpadl_header->range[0].byte_offset = 0;
 365                 gpadl_header->range[0].byte_count = size;
 366                 for (i = 0; i < pagecount; i++)
 367                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 368                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 369
 370                 *msginfo = msgheader;
 371         }
 372
 373         return 0;
 374 nomem:
 375         kfree(msgheader);
 376         kfree(msgbody);
 377         return -ENOMEM;
 378 }
 379
 380 /*
 381  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 382  *
 383  * @channel: a channel
 384  * @kbuffer: from kmalloc or vmalloc
 385  * @size: page-size multiple
 386  * @gpadl_handle: some funky thing
 387  */
 388 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 389                                u32 size, u32 *gpadl_handle)
 390 {
 391         struct vmbus_channel_gpadl_header *gpadlmsg;
 392         struct vmbus_channel_gpadl_body *gpadl_body;
 393         struct vmbus_channel_msginfo *msginfo = NULL;
 394         struct vmbus_channel_msginfo *submsginfo, *tmp;
 395         struct list_head *curr;
 396         u32 next_gpadl_handle;
 397         unsigned long flags;
 398         int ret = 0;
 399
 400         next_gpadl_handle =
 401                 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
 402
 403         ret = create_gpadl_header(kbuffer, size, &msginfo);
 404         if (ret)
 405                 return ret;
 406
 407         init_completion(&msginfo->waitevent);
 408
 409         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 410         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 411         gpadlmsg->child_relid = channel->offermsg.child_relid;
 412         gpadlmsg->gpadl = next_gpadl_handle;
 413
 414
 415         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 416         list_add_tail(&msginfo->msglistentry,
 417                       &vmbus_connection.chn_msg_list);
 418
 419         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 420
 421         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 422                                sizeof(*msginfo));
 423         if (ret != 0)
 424                 goto cleanup;
 425
 426         list_for_each(curr, &msginfo->submsglist) {
 427                 submsginfo = (struct vmbus_channel_msginfo *)curr;
 428                 gpadl_body =
 429                         (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 430
 431                 gpadl_body->header.msgtype =
 432                         CHANNELMSG_GPADL_BODY;
 433                 gpadl_body->gpadl = next_gpadl_handle;
 434
 435                 ret = vmbus_post_msg(gpadl_body,
 436                                      submsginfo->msgsize -
 437                                      sizeof(*submsginfo));
 438                 if (ret != 0)
 439                         goto cleanup;
 440
 441         }
 442         wait_for_completion(&msginfo->waitevent);
 443
 444         /* At this point, we received the gpadl created msg */
 445         *gpadl_handle = gpadlmsg->gpadl;
 446
 447 cleanup:
 448         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 449         list_del(&msginfo->msglistentry);
 450         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 451         list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
 452                                  msglistentry) {
 453                 kfree(submsginfo);
 454         }
 455
 456         kfree(msginfo);
 457         return ret;
 458 }
 459 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 460
 461 /*
 462  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 463  */
 464 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 465 {
 466         struct vmbus_channel_gpadl_teardown *msg;
 467         struct vmbus_channel_msginfo *info;
 468         unsigned long flags;
 469         int ret;
 470
 471         info = kmalloc(sizeof(*info) +
 472                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 473         if (!info)
 474                 return -ENOMEM;
 475
 476         init_completion(&info->waitevent);
 477
 478         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 479
 480         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 481         msg->child_relid = channel->offermsg.child_relid;
 482         msg->gpadl = gpadl_handle;
 483
 484         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 485         list_add_tail(&info->msglistentry,
 486                       &vmbus_connection.chn_msg_list);
 487         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 488         ret = vmbus_post_msg(msg,
 489                                sizeof(struct vmbus_channel_gpadl_teardown));
 490
 491         if (ret)
 492                 goto post_msg_err;
 493
 494         wait_for_completion(&info->waitevent);
 495
 496 post_msg_err:
 497         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 498         list_del(&info->msglistentry);
 499         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 500
 501         kfree(info);
 502         return ret;
 503 }
 504 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 505
 506 static void reset_channel_cb(void *arg)
 507 {
 508         struct vmbus_channel *channel = arg;
 509
 510         channel->onchannel_callback = NULL;
 511 }
 512
 513 static int vmbus_close_internal(struct vmbus_channel *channel)
 514 {
 515         struct vmbus_channel_close_channel *msg;
 516         int ret;
 517
 518         /*
 519          * process_chn_event(), running in the tasklet, can race
 520          * with vmbus_close_internal() in the case of SMP guest, e.g., when
 521          * the former is accessing channel->inbound.ring_buffer, the latter
 522          * could be freeing the ring_buffer pages.
 523          *
 524          * To resolve the race, we can serialize them by disabling the
 525          * tasklet when the latter is running here.
 526          */
 527         hv_event_tasklet_disable(channel);
 528
 529         /*
 530          * In case a device driver's probe() fails (e.g.,
 531          * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
 532          * rescinded later (e.g., we dynamically disble an Integrated Service
 533          * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
 534          * here we should skip most of the below cleanup work.
 535          */
 536         if (channel->state != CHANNEL_OPENED_STATE) {
 537                 ret = -EINVAL;
 538                 goto out;
 539         }
 540
 541         channel->state = CHANNEL_OPEN_STATE;
 542         channel->sc_creation_callback = NULL;
 543         /* Stop callback and cancel the timer asap */
 544         if (channel->target_cpu != get_cpu()) {
 545                 put_cpu();
 546                 smp_call_function_single(channel->target_cpu, reset_channel_cb,
 547                                          channel, true);
 548         } else {
 549                 reset_channel_cb(channel);
 550                 put_cpu();
 551         }
 552
 553         /* Send a closing message */
 554
 555         msg = &channel->close_msg.msg;
 556
 557         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 558         msg->child_relid = channel->offermsg.child_relid;
 559
 560         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 561
 562         if (ret) {
 563                 pr_err("Close failed: close post msg return is %d\n", ret);
 564                 /*
 565                  * If we failed to post the close msg,
 566                  * it is perhaps better to leak memory.
 567                  */
 568                 goto out;
 569         }
 570
 571         /* Tear down the gpadl for the channel's ring buffer */
 572         if (channel->ringbuffer_gpadlhandle) {
 573                 ret = vmbus_teardown_gpadl(channel,
 574                                            channel->ringbuffer_gpadlhandle);
 575                 if (ret) {
 576                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 577                         /*
 578                          * If we failed to teardown gpadl,
 579                          * it is perhaps better to leak memory.
 580                          */
 581                         goto out;
 582                 }
 583         }
 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 out:
 593         hv_event_tasklet_enable(channel);
 594
 595         return ret;
 596 }
 597
 598 /*
 599  * vmbus_close - Close the specified channel
 600  */
 601 void vmbus_close(struct vmbus_channel *channel)
 602 {
 603         struct list_head *cur, *tmp;
 604         struct vmbus_channel *cur_channel;
 605
 606         if (channel->primary_channel != NULL) {
 607                 /*
 608                  * We will only close sub-channels when
 609                  * the primary is closed.
 610                  */
 611                 return;
 612         }
 613         /*
 614          * Close all the sub-channels first and then close the
 615          * primary channel.
 616          */
 617         list_for_each_safe(cur, tmp, &channel->sc_list) {
 618                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 619                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 620                         continue;
 621                 vmbus_close_internal(cur_channel);
 622         }
 623         /*
 624          * Now close the primary.
 625          */
 626         vmbus_close_internal(channel);
 627 }
 628 EXPORT_SYMBOL_GPL(vmbus_close);
 629
 630 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 631                            u32 bufferlen, u64 requestid,
 632                            enum vmbus_packet_type type, u32 flags, bool kick_q)
 633 {
 634         struct vmpacket_descriptor desc;
 635         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 636         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 637         struct kvec bufferlist[3];
 638         u64 aligned_data = 0;
 639         bool lock = channel->acquire_ring_lock;
 640         int num_vecs = ((bufferlen != 0) ? 3 : 1);
 641
 642
 643         /* Setup the descriptor */
 644         desc.type = type; /* VmbusPacketTypeDataInBand; */
 645         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 646         /* in 8-bytes granularity */
 647         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 648         desc.len8 = (u16)(packetlen_aligned >> 3);
 649         desc.trans_id = requestid;
 650
 651         bufferlist[0].iov_base = &desc;
 652         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 653         bufferlist[1].iov_base = buffer;
 654         bufferlist[1].iov_len = bufferlen;
 655         bufferlist[2].iov_base = &aligned_data;
 656         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 657
 658         return hv_ringbuffer_write(channel, bufferlist, num_vecs,
 659                                    lock, kick_q);
 660
 661 }
 662 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 663
 664 /**
 665  * vmbus_sendpacket() - Send the specified buffer on the given channel
 666  * @channel: Pointer to vmbus_channel structure.
 667  * @buffer: Pointer to the buffer you want to receive the data into.
 668  * @bufferlen: Maximum size of what the the buffer will hold
 669  * @requestid: Identifier of the request
 670  * @type: Type of packet that is being send e.g. negotiate, time
 671  * packet etc.
 672  *
 673  * Sends data in @buffer directly to hyper-v via the vmbus
 674  * This will send the data unparsed to hyper-v.
 675  *
 676  * Mainly used by Hyper-V drivers.
 677  */
 678 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 679                            u32 bufferlen, u64 requestid,
 680                            enum vmbus_packet_type type, u32 flags)
 681 {
 682         return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
 683                                     type, flags, true);
 684 }
 685 EXPORT_SYMBOL(vmbus_sendpacket);
 686
 687 /*
 688  * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
 689  * packets using a GPADL Direct packet type. This interface allows you
 690  * to control notifying the host. This will be useful for sending
 691  * batched data. Also the sender can control the send flags
 692  * explicitly.
 693  */
 694 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 695                                      struct hv_page_buffer pagebuffers[],
 696                                      u32 pagecount, void *buffer, u32 bufferlen,
 697                                      u64 requestid,
 698                                      u32 flags,
 699                                      bool kick_q)
 700 {
 701         int i;
 702         struct vmbus_channel_packet_page_buffer desc;
 703         u32 descsize;
 704         u32 packetlen;
 705         u32 packetlen_aligned;
 706         struct kvec bufferlist[3];
 707         u64 aligned_data = 0;
 708         bool lock = channel->acquire_ring_lock;
 709
 710         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 711                 return -EINVAL;
 712
 713
 714         /*
 715          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 716          * largest size we support
 717          */
 718         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 719                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 720                           sizeof(struct hv_page_buffer));
 721         packetlen = descsize + bufferlen;
 722         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 723
 724         /* Setup the descriptor */
 725         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 726         desc.flags = flags;
 727         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 728         desc.length8 = (u16)(packetlen_aligned >> 3);
 729         desc.transactionid = requestid;
 730         desc.rangecount = pagecount;
 731
 732         for (i = 0; i < pagecount; i++) {
 733                 desc.range[i].len = pagebuffers[i].len;
 734                 desc.range[i].offset = pagebuffers[i].offset;
 735                 desc.range[i].pfn        = pagebuffers[i].pfn;
 736         }
 737
 738         bufferlist[0].iov_base = &desc;
 739         bufferlist[0].iov_len = descsize;
 740         bufferlist[1].iov_base = buffer;
 741         bufferlist[1].iov_len = bufferlen;
 742         bufferlist[2].iov_base = &aligned_data;
 743         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 744
 745         return hv_ringbuffer_write(channel, bufferlist, 3,
 746                                    lock, kick_q);
 747 }
 748 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 749
 750 /*
 751  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 752  * packets using a GPADL Direct packet type.
 753  */
 754 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 755                                      struct hv_page_buffer pagebuffers[],
 756                                      u32 pagecount, void *buffer, u32 bufferlen,
 757                                      u64 requestid)
 758 {
 759         u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 760         return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
 761                                                buffer, bufferlen, requestid,
 762                                                flags, true);
 763
 764 }
 765 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 766
 767 /*
 768  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 769  * using a GPADL Direct packet type.
 770  * The buffer includes the vmbus descriptor.
 771  */
 772 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 773                               struct vmbus_packet_mpb_array *desc,
 774                               u32 desc_size,
 775                               void *buffer, u32 bufferlen, u64 requestid)
 776 {
 777         u32 packetlen;
 778         u32 packetlen_aligned;
 779         struct kvec bufferlist[3];
 780         u64 aligned_data = 0;
 781         bool lock = channel->acquire_ring_lock;
 782
 783         packetlen = desc_size + bufferlen;
 784         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 785
 786         /* Setup the descriptor */
 787         desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 788         desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 789         desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
 790         desc->length8 = (u16)(packetlen_aligned >> 3);
 791         desc->transactionid = requestid;
 792         desc->rangecount = 1;
 793
 794         bufferlist[0].iov_base = desc;
 795         bufferlist[0].iov_len = desc_size;
 796         bufferlist[1].iov_base = buffer;
 797         bufferlist[1].iov_len = bufferlen;
 798         bufferlist[2].iov_base = &aligned_data;
 799         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 800
 801         return hv_ringbuffer_write(channel, bufferlist, 3,
 802                                    lock, true);
 803 }
 804 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 805
 806 /*
 807  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 808  * using a GPADL Direct packet type.
 809  */
 810 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 811                                 struct hv_multipage_buffer *multi_pagebuffer,
 812                                 void *buffer, u32 bufferlen, u64 requestid)
 813 {
 814         struct vmbus_channel_packet_multipage_buffer desc;
 815         u32 descsize;
 816         u32 packetlen;
 817         u32 packetlen_aligned;
 818         struct kvec bufferlist[3];
 819         u64 aligned_data = 0;
 820         bool lock = channel->acquire_ring_lock;
 821         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 822                                          multi_pagebuffer->len);
 823
 824         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 825                 return -EINVAL;
 826
 827         /*
 828          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 829          * the largest size we support
 830          */
 831         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 832                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 833                           sizeof(u64));
 834         packetlen = descsize + bufferlen;
 835         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 836
 837
 838         /* Setup the descriptor */
 839         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 840         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 841         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 842         desc.length8 = (u16)(packetlen_aligned >> 3);
 843         desc.transactionid = requestid;
 844         desc.rangecount = 1;
 845
 846         desc.range.len = multi_pagebuffer->len;
 847         desc.range.offset = multi_pagebuffer->offset;
 848
 849         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 850                pfncount * sizeof(u64));
 851
 852         bufferlist[0].iov_base = &desc;
 853         bufferlist[0].iov_len = descsize;
 854         bufferlist[1].iov_base = buffer;
 855         bufferlist[1].iov_len = bufferlen;
 856         bufferlist[2].iov_base = &aligned_data;
 857         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 858
 859         return hv_ringbuffer_write(channel, bufferlist, 3,
 860                                    lock, true);
 861 }
 862 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 863
 864 /**
 865  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 866  * @channel: Pointer to vmbus_channel structure.
 867  * @buffer: Pointer to the buffer you want to receive the data into.
 868  * @bufferlen: Maximum size of what the the buffer will hold
 869  * @buffer_actual_len: The actual size of the data after it was received
 870  * @requestid: Identifier of the request
 871  *
 872  * Receives directly from the hyper-v vmbus and puts the data it received
 873  * into Buffer. This will receive the data unparsed from hyper-v.
 874  *
 875  * Mainly used by Hyper-V drivers.
 876  */
 877 static inline int
 878 __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 879                    u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
 880                    bool raw)
 881 {
 882         return hv_ringbuffer_read(channel, buffer, bufferlen,
 883                                   buffer_actual_len, requestid, raw);
 884
 885 }
 886
 887 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 888                      u32 bufferlen, u32 *buffer_actual_len,
 889                      u64 *requestid)
 890 {
 891         return __vmbus_recvpacket(channel, buffer, bufferlen,
 892                                   buffer_actual_len, requestid, false);
 893 }
 894 EXPORT_SYMBOL(vmbus_recvpacket);
 895
 896 /*
 897  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 898  */
 899 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 900                               u32 bufferlen, u32 *buffer_actual_len,
 901                               u64 *requestid)
 902 {
 903         return __vmbus_recvpacket(channel, buffer, bufferlen,
 904                                   buffer_actual_len, requestid, true);
 905 }
 906 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);