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         open_info->waiting_channel = newchannel;
 161
 162         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 163         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 164         open_msg->openid = newchannel->offermsg.child_relid;
 165         open_msg->child_relid = newchannel->offermsg.child_relid;
 166         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 167         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 168                                                   PAGE_SHIFT;
 169         open_msg->target_vp = newchannel->target_vp;
 170
 171         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 172                 err = -EINVAL;
 173                 goto error_free_gpadl;
 174         }
 175
 176         if (userdatalen)
 177                 memcpy(open_msg->userdata, userdata, userdatalen);
 178
 179         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 180         list_add_tail(&open_info->msglistentry,
 181                       &vmbus_connection.chn_msg_list);
 182         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 183
 184         ret = vmbus_post_msg(open_msg,
 185                              sizeof(struct vmbus_channel_open_channel), true);
 186
 187         if (ret != 0) {
 188                 err = ret;
 189                 goto error_clean_msglist;
 190         }
 191
 192         wait_for_completion(&open_info->waitevent);
 193
 194         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 195         list_del(&open_info->msglistentry);
 196         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 197
 198         if (newchannel->rescind) {
 199                 err = -ENODEV;
 200                 goto error_free_gpadl;
 201         }
 202
 203         if (open_info->response.open_result.status) {
 204                 err = -EAGAIN;
 205                 goto error_free_gpadl;
 206         }
 207
 208         newchannel->state = CHANNEL_OPENED_STATE;
 209         kfree(open_info);
 210         return 0;
 211
 212 error_clean_msglist:
 213         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 214         list_del(&open_info->msglistentry);
 215         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 216
 217 error_free_gpadl:
 218         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 219         kfree(open_info);
 220 error_free_pages:
 221         hv_ringbuffer_cleanup(&newchannel->outbound);
 222         hv_ringbuffer_cleanup(&newchannel->inbound);
 223         __free_pages(page,
 224                      get_order(send_ringbuffer_size + recv_ringbuffer_size));
 225 error_set_chnstate:
 226         newchannel->state = CHANNEL_OPEN_STATE;
 227         return err;
 228 }
 229 EXPORT_SYMBOL_GPL(vmbus_open);
 230
 231 /* Used for Hyper-V Socket: a guest client's connect() to the host */
 232 int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
 233                                   const uuid_le *shv_host_servie_id)
 234 {
 235         struct vmbus_channel_tl_connect_request conn_msg;
 236
 237         memset(&conn_msg, 0, sizeof(conn_msg));
 238         conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
 239         conn_msg.guest_endpoint_id = *shv_guest_servie_id;
 240         conn_msg.host_service_id = *shv_host_servie_id;
 241
 242         return vmbus_post_msg(&conn_msg, sizeof(conn_msg), true);
 243 }
 244 EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
 245
 246 /*
 247  * create_gpadl_header - Creates a gpadl for the specified buffer
 248  */
 249 static int create_gpadl_header(void *kbuffer, u32 size,
 250                                struct vmbus_channel_msginfo **msginfo)
 251 {
 252         int i;
 253         int pagecount;
 254         struct vmbus_channel_gpadl_header *gpadl_header;
 255         struct vmbus_channel_gpadl_body *gpadl_body;
 256         struct vmbus_channel_msginfo *msgheader;
 257         struct vmbus_channel_msginfo *msgbody = NULL;
 258         u32 msgsize;
 259
 260         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 261
 262         pagecount = size >> PAGE_SHIFT;
 263
 264         /* do we need a gpadl body msg */
 265         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 266                   sizeof(struct vmbus_channel_gpadl_header) -
 267                   sizeof(struct gpa_range);
 268         pfncount = pfnsize / sizeof(u64);
 269
 270         if (pagecount > pfncount) {
 271                 /* we need a gpadl body */
 272                 /* fill in the header */
 273                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 274                           sizeof(struct vmbus_channel_gpadl_header) +
 275                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 276                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 277                 if (!msgheader)
 278                         goto nomem;
 279
 280                 INIT_LIST_HEAD(&msgheader->submsglist);
 281                 msgheader->msgsize = msgsize;
 282
 283                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 284                         msgheader->msg;
 285                 gpadl_header->rangecount = 1;
 286                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 287                                          pagecount * sizeof(u64);
 288                 gpadl_header->range[0].byte_offset = 0;
 289                 gpadl_header->range[0].byte_count = size;
 290                 for (i = 0; i < pfncount; i++)
 291                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 292                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 293                 *msginfo = msgheader;
 294
 295                 pfnsum = pfncount;
 296                 pfnleft = pagecount - pfncount;
 297
 298                 /* how many pfns can we fit */
 299                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 300                           sizeof(struct vmbus_channel_gpadl_body);
 301                 pfncount = pfnsize / sizeof(u64);
 302
 303                 /* fill in the body */
 304                 while (pfnleft) {
 305                         if (pfnleft > pfncount)
 306                                 pfncurr = pfncount;
 307                         else
 308                                 pfncurr = pfnleft;
 309
 310                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 311                                   sizeof(struct vmbus_channel_gpadl_body) +
 312                                   pfncurr * sizeof(u64);
 313                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 314
 315                         if (!msgbody) {
 316                                 struct vmbus_channel_msginfo *pos = NULL;
 317                                 struct vmbus_channel_msginfo *tmp = NULL;
 318                                 /*
 319                                  * Free up all the allocated messages.
 320                                  */
 321                                 list_for_each_entry_safe(pos, tmp,
 322                                         &msgheader->submsglist,
 323                                         msglistentry) {
 324
 325                                         list_del(&pos->msglistentry);
 326                                         kfree(pos);
 327                                 }
 328
 329                                 goto nomem;
 330                         }
 331
 332                         msgbody->msgsize = msgsize;
 333                         gpadl_body =
 334                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 335
 336                         /*
 337                          * Gpadl is u32 and we are using a pointer which could
 338                          * be 64-bit
 339                          * This is governed by the guest/host protocol and
 340                          * so the hypervisor gurantees that this is ok.
 341                          */
 342                         for (i = 0; i < pfncurr; i++)
 343                                 gpadl_body->pfn[i] = slow_virt_to_phys(
 344                                         kbuffer + PAGE_SIZE * (pfnsum + i)) >>
 345                                         PAGE_SHIFT;
 346
 347                         /* add to msg header */
 348                         list_add_tail(&msgbody->msglistentry,
 349                                       &msgheader->submsglist);
 350                         pfnsum += pfncurr;
 351                         pfnleft -= pfncurr;
 352                 }
 353         } else {
 354                 /* everything fits in a header */
 355                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 356                           sizeof(struct vmbus_channel_gpadl_header) +
 357                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 358                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 359                 if (msgheader == NULL)
 360                         goto nomem;
 361
 362                 INIT_LIST_HEAD(&msgheader->submsglist);
 363                 msgheader->msgsize = msgsize;
 364
 365                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 366                         msgheader->msg;
 367                 gpadl_header->rangecount = 1;
 368                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 369                                          pagecount * sizeof(u64);
 370                 gpadl_header->range[0].byte_offset = 0;
 371                 gpadl_header->range[0].byte_count = size;
 372                 for (i = 0; i < pagecount; i++)
 373                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 374                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 375
 376                 *msginfo = msgheader;
 377         }
 378
 379         return 0;
 380 nomem:
 381         kfree(msgheader);
 382         kfree(msgbody);
 383         return -ENOMEM;
 384 }
 385
 386 /*
 387  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 388  *
 389  * @channel: a channel
 390  * @kbuffer: from kmalloc or vmalloc
 391  * @size: page-size multiple
 392  * @gpadl_handle: some funky thing
 393  */
 394 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 395                                u32 size, u32 *gpadl_handle)
 396 {
 397         struct vmbus_channel_gpadl_header *gpadlmsg;
 398         struct vmbus_channel_gpadl_body *gpadl_body;
 399         struct vmbus_channel_msginfo *msginfo = NULL;
 400         struct vmbus_channel_msginfo *submsginfo, *tmp;
 401         struct list_head *curr;
 402         u32 next_gpadl_handle;
 403         unsigned long flags;
 404         int ret = 0;
 405
 406         next_gpadl_handle =
 407                 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
 408
 409         ret = create_gpadl_header(kbuffer, size, &msginfo);
 410         if (ret)
 411                 return ret;
 412
 413         init_completion(&msginfo->waitevent);
 414         msginfo->waiting_channel = channel;
 415
 416         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 417         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 418         gpadlmsg->child_relid = channel->offermsg.child_relid;
 419         gpadlmsg->gpadl = next_gpadl_handle;
 420
 421
 422         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 423         list_add_tail(&msginfo->msglistentry,
 424                       &vmbus_connection.chn_msg_list);
 425
 426         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 427
 428         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 429                              sizeof(*msginfo), true);
 430         if (ret != 0)
 431                 goto cleanup;
 432
 433         list_for_each(curr, &msginfo->submsglist) {
 434                 submsginfo = (struct vmbus_channel_msginfo *)curr;
 435                 gpadl_body =
 436                         (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 437
 438                 gpadl_body->header.msgtype =
 439                         CHANNELMSG_GPADL_BODY;
 440                 gpadl_body->gpadl = next_gpadl_handle;
 441
 442                 ret = vmbus_post_msg(gpadl_body,
 443                                      submsginfo->msgsize - sizeof(*submsginfo),
 444                                      true);
 445                 if (ret != 0)
 446                         goto cleanup;
 447
 448         }
 449         wait_for_completion(&msginfo->waitevent);
 450
 451         if (msginfo->response.gpadl_created.creation_status != 0) {
 452                 pr_err("Failed to establish GPADL: err = 0x%x\n",
 453                        msginfo->response.gpadl_created.creation_status);
 454
 455                 ret = -EDQUOT;
 456                 goto cleanup;
 457         }
 458
 459         if (channel->rescind) {
 460                 ret = -ENODEV;
 461                 goto cleanup;
 462         }
 463
 464         /* At this point, we received the gpadl created msg */
 465         *gpadl_handle = gpadlmsg->gpadl;
 466
 467 cleanup:
 468         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 469         list_del(&msginfo->msglistentry);
 470         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 471         list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
 472                                  msglistentry) {
 473                 kfree(submsginfo);
 474         }
 475
 476         kfree(msginfo);
 477         return ret;
 478 }
 479 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 480
 481 /*
 482  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 483  */
 484 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 485 {
 486         struct vmbus_channel_gpadl_teardown *msg;
 487         struct vmbus_channel_msginfo *info;
 488         unsigned long flags;
 489         int ret;
 490
 491         info = kmalloc(sizeof(*info) +
 492                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 493         if (!info)
 494                 return -ENOMEM;
 495
 496         init_completion(&info->waitevent);
 497         info->waiting_channel = channel;
 498
 499         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 500
 501         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 502         msg->child_relid = channel->offermsg.child_relid;
 503         msg->gpadl = gpadl_handle;
 504
 505         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 506         list_add_tail(&info->msglistentry,
 507                       &vmbus_connection.chn_msg_list);
 508         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 509         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown),
 510                              true);
 511
 512         if (ret)
 513                 goto post_msg_err;
 514
 515         wait_for_completion(&info->waitevent);
 516
 517 post_msg_err:
 518         /*
 519          * If the channel has been rescinded;
 520          * we will be awakened by the rescind
 521          * handler; set the error code to zero so we don't leak memory.
 522          */
 523         if (channel->rescind)
 524                 ret = 0;
 525
 526         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 527         list_del(&info->msglistentry);
 528         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 529
 530         kfree(info);
 531         return ret;
 532 }
 533 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 534
 535 static void reset_channel_cb(void *arg)
 536 {
 537         struct vmbus_channel *channel = arg;
 538
 539         channel->onchannel_callback = NULL;
 540 }
 541
 542 static int vmbus_close_internal(struct vmbus_channel *channel)
 543 {
 544         struct vmbus_channel_close_channel *msg;
 545         int ret;
 546
 547         /*
 548          * process_chn_event(), running in the tasklet, can race
 549          * with vmbus_close_internal() in the case of SMP guest, e.g., when
 550          * the former is accessing channel->inbound.ring_buffer, the latter
 551          * could be freeing the ring_buffer pages.
 552          *
 553          * To resolve the race, we can serialize them by disabling the
 554          * tasklet when the latter is running here.
 555          */
 556         hv_event_tasklet_disable(channel);
 557
 558         /*
 559          * In case a device driver's probe() fails (e.g.,
 560          * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
 561          * rescinded later (e.g., we dynamically disble an Integrated Service
 562          * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
 563          * here we should skip most of the below cleanup work.
 564          */
 565         if (channel->state != CHANNEL_OPENED_STATE) {
 566                 ret = -EINVAL;
 567                 goto out;
 568         }
 569
 570         channel->state = CHANNEL_OPEN_STATE;
 571         channel->sc_creation_callback = NULL;
 572         /* Stop callback and cancel the timer asap */
 573         if (channel->target_cpu != get_cpu()) {
 574                 put_cpu();
 575                 smp_call_function_single(channel->target_cpu, reset_channel_cb,
 576                                          channel, true);
 577         } else {
 578                 reset_channel_cb(channel);
 579                 put_cpu();
 580         }
 581
 582         /* Send a closing message */
 583
 584         msg = &channel->close_msg.msg;
 585
 586         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 587         msg->child_relid = channel->offermsg.child_relid;
 588
 589         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel),
 590                              true);
 591
 592         if (ret) {
 593                 pr_err("Close failed: close post msg return is %d\n", ret);
 594                 /*
 595                  * If we failed to post the close msg,
 596                  * it is perhaps better to leak memory.
 597                  */
 598                 goto out;
 599         }
 600
 601         /* Tear down the gpadl for the channel's ring buffer */
 602         if (channel->ringbuffer_gpadlhandle) {
 603                 ret = vmbus_teardown_gpadl(channel,
 604                                            channel->ringbuffer_gpadlhandle);
 605                 if (ret) {
 606                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 607                         /*
 608                          * If we failed to teardown gpadl,
 609                          * it is perhaps better to leak memory.
 610                          */
 611                         goto out;
 612                 }
 613         }
 614
 615         /* Cleanup the ring buffers for this channel */
 616         hv_ringbuffer_cleanup(&channel->outbound);
 617         hv_ringbuffer_cleanup(&channel->inbound);
 618
 619         free_pages((unsigned long)channel->ringbuffer_pages,
 620                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 621
 622 out:
 623         hv_event_tasklet_enable(channel);
 624
 625         return ret;
 626 }
 627
 628 /*
 629  * vmbus_close - Close the specified channel
 630  */
 631 void vmbus_close(struct vmbus_channel *channel)
 632 {
 633         struct list_head *cur, *tmp;
 634         struct vmbus_channel *cur_channel;
 635
 636         if (channel->primary_channel != NULL) {
 637                 /*
 638                  * We will only close sub-channels when
 639                  * the primary is closed.
 640                  */
 641                 return;
 642         }
 643         /*
 644          * Close all the sub-channels first and then close the
 645          * primary channel.
 646          */
 647         list_for_each_safe(cur, tmp, &channel->sc_list) {
 648                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 649                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 650                         continue;
 651                 vmbus_close_internal(cur_channel);
 652         }
 653         /*
 654          * Now close the primary.
 655          */
 656         vmbus_close_internal(channel);
 657 }
 658 EXPORT_SYMBOL_GPL(vmbus_close);
 659
 660 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 661                            u32 bufferlen, u64 requestid,
 662                            enum vmbus_packet_type type, u32 flags, bool kick_q)
 663 {
 664         struct vmpacket_descriptor desc;
 665         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 666         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 667         struct kvec bufferlist[3];
 668         u64 aligned_data = 0;
 669         bool lock = channel->acquire_ring_lock;
 670         int num_vecs = ((bufferlen != 0) ? 3 : 1);
 671
 672
 673         /* Setup the descriptor */
 674         desc.type = type; /* VmbusPacketTypeDataInBand; */
 675         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 676         /* in 8-bytes granularity */
 677         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 678         desc.len8 = (u16)(packetlen_aligned >> 3);
 679         desc.trans_id = requestid;
 680
 681         bufferlist[0].iov_base = &desc;
 682         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 683         bufferlist[1].iov_base = buffer;
 684         bufferlist[1].iov_len = bufferlen;
 685         bufferlist[2].iov_base = &aligned_data;
 686         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 687
 688         return hv_ringbuffer_write(channel, bufferlist, num_vecs,
 689                                    lock, kick_q);
 690
 691 }
 692 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 693
 694 /**
 695  * vmbus_sendpacket() - Send the specified buffer on the given channel
 696  * @channel: Pointer to vmbus_channel structure.
 697  * @buffer: Pointer to the buffer you want to receive the data into.
 698  * @bufferlen: Maximum size of what the the buffer will hold
 699  * @requestid: Identifier of the request
 700  * @type: Type of packet that is being send e.g. negotiate, time
 701  * packet etc.
 702  *
 703  * Sends data in @buffer directly to hyper-v via the vmbus
 704  * This will send the data unparsed to hyper-v.
 705  *
 706  * Mainly used by Hyper-V drivers.
 707  */
 708 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 709                            u32 bufferlen, u64 requestid,
 710                            enum vmbus_packet_type type, u32 flags)
 711 {
 712         return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
 713                                     type, flags, true);
 714 }
 715 EXPORT_SYMBOL(vmbus_sendpacket);
 716
 717 /*
 718  * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
 719  * packets using a GPADL Direct packet type. This interface allows you
 720  * to control notifying the host. This will be useful for sending
 721  * batched data. Also the sender can control the send flags
 722  * explicitly.
 723  */
 724 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 725                                      struct hv_page_buffer pagebuffers[],
 726                                      u32 pagecount, void *buffer, u32 bufferlen,
 727                                      u64 requestid,
 728                                      u32 flags,
 729                                      bool kick_q)
 730 {
 731         int i;
 732         struct vmbus_channel_packet_page_buffer desc;
 733         u32 descsize;
 734         u32 packetlen;
 735         u32 packetlen_aligned;
 736         struct kvec bufferlist[3];
 737         u64 aligned_data = 0;
 738         bool lock = channel->acquire_ring_lock;
 739
 740         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 741                 return -EINVAL;
 742
 743
 744         /*
 745          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 746          * largest size we support
 747          */
 748         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 749                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 750                           sizeof(struct hv_page_buffer));
 751         packetlen = descsize + bufferlen;
 752         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 753
 754         /* Setup the descriptor */
 755         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 756         desc.flags = flags;
 757         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 758         desc.length8 = (u16)(packetlen_aligned >> 3);
 759         desc.transactionid = requestid;
 760         desc.rangecount = pagecount;
 761
 762         for (i = 0; i < pagecount; i++) {
 763                 desc.range[i].len = pagebuffers[i].len;
 764                 desc.range[i].offset = pagebuffers[i].offset;
 765                 desc.range[i].pfn        = pagebuffers[i].pfn;
 766         }
 767
 768         bufferlist[0].iov_base = &desc;
 769         bufferlist[0].iov_len = descsize;
 770         bufferlist[1].iov_base = buffer;
 771         bufferlist[1].iov_len = bufferlen;
 772         bufferlist[2].iov_base = &aligned_data;
 773         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 774
 775         return hv_ringbuffer_write(channel, bufferlist, 3,
 776                                    lock, kick_q);
 777 }
 778 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 779
 780 /*
 781  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 782  * packets using a GPADL Direct packet type.
 783  */
 784 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 785                                      struct hv_page_buffer pagebuffers[],
 786                                      u32 pagecount, void *buffer, u32 bufferlen,
 787                                      u64 requestid)
 788 {
 789         u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 790         return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
 791                                                buffer, bufferlen, requestid,
 792                                                flags, true);
 793
 794 }
 795 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 796
 797 /*
 798  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 799  * using a GPADL Direct packet type.
 800  * The buffer includes the vmbus descriptor.
 801  */
 802 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 803                               struct vmbus_packet_mpb_array *desc,
 804                               u32 desc_size,
 805                               void *buffer, u32 bufferlen, u64 requestid)
 806 {
 807         u32 packetlen;
 808         u32 packetlen_aligned;
 809         struct kvec bufferlist[3];
 810         u64 aligned_data = 0;
 811         bool lock = channel->acquire_ring_lock;
 812
 813         packetlen = desc_size + bufferlen;
 814         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 815
 816         /* Setup the descriptor */
 817         desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 818         desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 819         desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
 820         desc->length8 = (u16)(packetlen_aligned >> 3);
 821         desc->transactionid = requestid;
 822         desc->rangecount = 1;
 823
 824         bufferlist[0].iov_base = desc;
 825         bufferlist[0].iov_len = desc_size;
 826         bufferlist[1].iov_base = buffer;
 827         bufferlist[1].iov_len = bufferlen;
 828         bufferlist[2].iov_base = &aligned_data;
 829         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 830
 831         return hv_ringbuffer_write(channel, bufferlist, 3,
 832                                    lock, true);
 833 }
 834 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 835
 836 /*
 837  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 838  * using a GPADL Direct packet type.
 839  */
 840 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 841                                 struct hv_multipage_buffer *multi_pagebuffer,
 842                                 void *buffer, u32 bufferlen, u64 requestid)
 843 {
 844         struct vmbus_channel_packet_multipage_buffer desc;
 845         u32 descsize;
 846         u32 packetlen;
 847         u32 packetlen_aligned;
 848         struct kvec bufferlist[3];
 849         u64 aligned_data = 0;
 850         bool lock = channel->acquire_ring_lock;
 851         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 852                                          multi_pagebuffer->len);
 853
 854         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 855                 return -EINVAL;
 856
 857         /*
 858          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 859          * the largest size we support
 860          */
 861         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 862                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 863                           sizeof(u64));
 864         packetlen = descsize + bufferlen;
 865         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 866
 867
 868         /* Setup the descriptor */
 869         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 870         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 871         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 872         desc.length8 = (u16)(packetlen_aligned >> 3);
 873         desc.transactionid = requestid;
 874         desc.rangecount = 1;
 875
 876         desc.range.len = multi_pagebuffer->len;
 877         desc.range.offset = multi_pagebuffer->offset;
 878
 879         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 880                pfncount * sizeof(u64));
 881
 882         bufferlist[0].iov_base = &desc;
 883         bufferlist[0].iov_len = descsize;
 884         bufferlist[1].iov_base = buffer;
 885         bufferlist[1].iov_len = bufferlen;
 886         bufferlist[2].iov_base = &aligned_data;
 887         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 888
 889         return hv_ringbuffer_write(channel, bufferlist, 3,
 890                                    lock, true);
 891 }
 892 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 893
 894 /**
 895  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 896  * @channel: Pointer to vmbus_channel structure.
 897  * @buffer: Pointer to the buffer you want to receive the data into.
 898  * @bufferlen: Maximum size of what the the buffer will hold
 899  * @buffer_actual_len: The actual size of the data after it was received
 900  * @requestid: Identifier of the request
 901  *
 902  * Receives directly from the hyper-v vmbus and puts the data it received
 903  * into Buffer. This will receive the data unparsed from hyper-v.
 904  *
 905  * Mainly used by Hyper-V drivers.
 906  */
 907 static inline int
 908 __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 909                    u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
 910                    bool raw)
 911 {
 912         return hv_ringbuffer_read(channel, buffer, bufferlen,
 913                                   buffer_actual_len, requestid, raw);
 914
 915 }
 916
 917 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 918                      u32 bufferlen, u32 *buffer_actual_len,
 919                      u64 *requestid)
 920 {
 921         return __vmbus_recvpacket(channel, buffer, bufferlen,
 922                                   buffer_actual_len, requestid, false);
 923 }
 924 EXPORT_SYMBOL(vmbus_recvpacket);
 925
 926 /*
 927  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 928  */
 929 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 930                               u32 bufferlen, u32 *buffer_actual_len,
 931                               u64 *requestid)
 932 {
 933         return __vmbus_recvpacket(channel, buffer, bufferlen,
 934                                   buffer_actual_len, requestid, true);
 935 }
 936 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);