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 && !channel->low_latency) {
  51                 vmbus_send_interrupt(channel->offermsg.child_relid);
  52
  53                 /* Get the child to parent monitor page */
  54                 monitorpage = vmbus_connection.monitor_pages[1];
  55
  56                 sync_set_bit(channel->monitor_bit,
  57                         (unsigned long *)&monitorpage->trigger_group
  58                                         [channel->monitor_grp].pending);
  59
  60         } else {
  61                 vmbus_set_event(channel);
  62         }
  63 }
  64 EXPORT_SYMBOL_GPL(vmbus_setevent);
  65
  66 /*
  67  * vmbus_open - Open the specified channel.
  68  */
  69 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
  70                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
  71                      void (*onchannelcallback)(void *context), void *context)
  72 {
  73         struct vmbus_channel_open_channel *open_msg;
  74         struct vmbus_channel_msginfo *open_info = NULL;
  75         unsigned long flags;
  76         int ret, err = 0;
  77         struct page *page;
  78
  79         if (send_ringbuffer_size % PAGE_SIZE ||
  80             recv_ringbuffer_size % PAGE_SIZE)
  81                 return -EINVAL;
  82
  83         spin_lock_irqsave(&newchannel->lock, flags);
  84         if (newchannel->state == CHANNEL_OPEN_STATE) {
  85                 newchannel->state = CHANNEL_OPENING_STATE;
  86         } else {
  87                 spin_unlock_irqrestore(&newchannel->lock, flags);
  88                 return -EINVAL;
  89         }
  90         spin_unlock_irqrestore(&newchannel->lock, flags);
  91
  92         newchannel->onchannel_callback = onchannelcallback;
  93         newchannel->channel_callback_context = context;
  94
  95         /* Allocate the ring buffer */
  96         page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
  97                                 GFP_KERNEL|__GFP_ZERO,
  98                                 get_order(send_ringbuffer_size +
  99                                 recv_ringbuffer_size));
 100
 101         if (!page)
 102                 page = alloc_pages(GFP_KERNEL|__GFP_ZERO,
 103                                    get_order(send_ringbuffer_size +
 104                                              recv_ringbuffer_size));
 105
 106         if (!page) {
 107                 err = -ENOMEM;
 108                 goto error_set_chnstate;
 109         }
 110
 111         newchannel->ringbuffer_pages = page_address(page);
 112         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 113                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 114
 115         ret = hv_ringbuffer_init(&newchannel->outbound, page,
 116                                  send_ringbuffer_size >> PAGE_SHIFT);
 117
 118         if (ret != 0) {
 119                 err = ret;
 120                 goto error_free_pages;
 121         }
 122
 123         ret = hv_ringbuffer_init(&newchannel->inbound,
 124                                  &page[send_ringbuffer_size >> PAGE_SHIFT],
 125                                  recv_ringbuffer_size >> PAGE_SHIFT);
 126         if (ret != 0) {
 127                 err = ret;
 128                 goto error_free_pages;
 129         }
 130
 131
 132         /* Establish the gpadl for the ring buffer */
 133         newchannel->ringbuffer_gpadlhandle = 0;
 134
 135         ret = vmbus_establish_gpadl(newchannel,
 136                                     page_address(page),
 137                                     send_ringbuffer_size +
 138                                     recv_ringbuffer_size,
 139                                     &newchannel->ringbuffer_gpadlhandle);
 140
 141         if (ret != 0) {
 142                 err = ret;
 143                 goto error_free_pages;
 144         }
 145
 146         /* Create and init the channel open message */
 147         open_info = kmalloc(sizeof(*open_info) +
 148                            sizeof(struct vmbus_channel_open_channel),
 149                            GFP_KERNEL);
 150         if (!open_info) {
 151                 err = -ENOMEM;
 152                 goto error_free_gpadl;
 153         }
 154
 155         init_completion(&open_info->waitevent);
 156         open_info->waiting_channel = newchannel;
 157
 158         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 159         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 160         open_msg->openid = newchannel->offermsg.child_relid;
 161         open_msg->child_relid = newchannel->offermsg.child_relid;
 162         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 163         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 164                                                   PAGE_SHIFT;
 165         open_msg->target_vp = newchannel->target_vp;
 166
 167         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 168                 err = -EINVAL;
 169                 goto error_free_gpadl;
 170         }
 171
 172         if (userdatalen)
 173                 memcpy(open_msg->userdata, userdata, userdatalen);
 174
 175         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 176         list_add_tail(&open_info->msglistentry,
 177                       &vmbus_connection.chn_msg_list);
 178         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 179
 180         ret = vmbus_post_msg(open_msg,
 181                              sizeof(struct vmbus_channel_open_channel), true);
 182
 183         if (ret != 0) {
 184                 err = ret;
 185                 goto error_clean_msglist;
 186         }
 187
 188         wait_for_completion(&open_info->waitevent);
 189
 190         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 191         list_del(&open_info->msglistentry);
 192         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 193
 194         if (newchannel->rescind) {
 195                 err = -ENODEV;
 196                 goto error_free_gpadl;
 197         }
 198
 199         if (open_info->response.open_result.status) {
 200                 err = -EAGAIN;
 201                 goto error_free_gpadl;
 202         }
 203
 204         newchannel->state = CHANNEL_OPENED_STATE;
 205         kfree(open_info);
 206         return 0;
 207
 208 error_clean_msglist:
 209         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 210         list_del(&open_info->msglistentry);
 211         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 212
 213 error_free_gpadl:
 214         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 215         kfree(open_info);
 216 error_free_pages:
 217         hv_ringbuffer_cleanup(&newchannel->outbound);
 218         hv_ringbuffer_cleanup(&newchannel->inbound);
 219         __free_pages(page,
 220                      get_order(send_ringbuffer_size + recv_ringbuffer_size));
 221 error_set_chnstate:
 222         newchannel->state = CHANNEL_OPEN_STATE;
 223         return err;
 224 }
 225 EXPORT_SYMBOL_GPL(vmbus_open);
 226
 227 /* Used for Hyper-V Socket: a guest client's connect() to the host */
 228 int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
 229                                   const uuid_le *shv_host_servie_id)
 230 {
 231         struct vmbus_channel_tl_connect_request conn_msg;
 232
 233         memset(&conn_msg, 0, sizeof(conn_msg));
 234         conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
 235         conn_msg.guest_endpoint_id = *shv_guest_servie_id;
 236         conn_msg.host_service_id = *shv_host_servie_id;
 237
 238         return vmbus_post_msg(&conn_msg, sizeof(conn_msg), true);
 239 }
 240 EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
 241
 242 /*
 243  * create_gpadl_header - Creates a gpadl for the specified buffer
 244  */
 245 static int create_gpadl_header(void *kbuffer, u32 size,
 246                                struct vmbus_channel_msginfo **msginfo)
 247 {
 248         int i;
 249         int pagecount;
 250         struct vmbus_channel_gpadl_header *gpadl_header;
 251         struct vmbus_channel_gpadl_body *gpadl_body;
 252         struct vmbus_channel_msginfo *msgheader;
 253         struct vmbus_channel_msginfo *msgbody = NULL;
 254         u32 msgsize;
 255
 256         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 257
 258         pagecount = size >> PAGE_SHIFT;
 259
 260         /* do we need a gpadl body msg */
 261         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 262                   sizeof(struct vmbus_channel_gpadl_header) -
 263                   sizeof(struct gpa_range);
 264         pfncount = pfnsize / sizeof(u64);
 265
 266         if (pagecount > pfncount) {
 267                 /* we need a gpadl body */
 268                 /* fill in the header */
 269                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 270                           sizeof(struct vmbus_channel_gpadl_header) +
 271                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 272                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 273                 if (!msgheader)
 274                         goto nomem;
 275
 276                 INIT_LIST_HEAD(&msgheader->submsglist);
 277                 msgheader->msgsize = msgsize;
 278
 279                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 280                         msgheader->msg;
 281                 gpadl_header->rangecount = 1;
 282                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 283                                          pagecount * sizeof(u64);
 284                 gpadl_header->range[0].byte_offset = 0;
 285                 gpadl_header->range[0].byte_count = size;
 286                 for (i = 0; i < pfncount; i++)
 287                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 288                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 289                 *msginfo = msgheader;
 290
 291                 pfnsum = pfncount;
 292                 pfnleft = pagecount - pfncount;
 293
 294                 /* how many pfns can we fit */
 295                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 296                           sizeof(struct vmbus_channel_gpadl_body);
 297                 pfncount = pfnsize / sizeof(u64);
 298
 299                 /* fill in the body */
 300                 while (pfnleft) {
 301                         if (pfnleft > pfncount)
 302                                 pfncurr = pfncount;
 303                         else
 304                                 pfncurr = pfnleft;
 305
 306                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 307                                   sizeof(struct vmbus_channel_gpadl_body) +
 308                                   pfncurr * sizeof(u64);
 309                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 310
 311                         if (!msgbody) {
 312                                 struct vmbus_channel_msginfo *pos = NULL;
 313                                 struct vmbus_channel_msginfo *tmp = NULL;
 314                                 /*
 315                                  * Free up all the allocated messages.
 316                                  */
 317                                 list_for_each_entry_safe(pos, tmp,
 318                                         &msgheader->submsglist,
 319                                         msglistentry) {
 320
 321                                         list_del(&pos->msglistentry);
 322                                         kfree(pos);
 323                                 }
 324
 325                                 goto nomem;
 326                         }
 327
 328                         msgbody->msgsize = msgsize;
 329                         gpadl_body =
 330                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 331
 332                         /*
 333                          * Gpadl is u32 and we are using a pointer which could
 334                          * be 64-bit
 335                          * This is governed by the guest/host protocol and
 336                          * so the hypervisor guarantees that this is ok.
 337                          */
 338                         for (i = 0; i < pfncurr; i++)
 339                                 gpadl_body->pfn[i] = slow_virt_to_phys(
 340                                         kbuffer + PAGE_SIZE * (pfnsum + i)) >>
 341                                         PAGE_SHIFT;
 342
 343                         /* add to msg header */
 344                         list_add_tail(&msgbody->msglistentry,
 345                                       &msgheader->submsglist);
 346                         pfnsum += pfncurr;
 347                         pfnleft -= pfncurr;
 348                 }
 349         } else {
 350                 /* everything fits in a header */
 351                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 352                           sizeof(struct vmbus_channel_gpadl_header) +
 353                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 354                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 355                 if (msgheader == NULL)
 356                         goto nomem;
 357
 358                 INIT_LIST_HEAD(&msgheader->submsglist);
 359                 msgheader->msgsize = msgsize;
 360
 361                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 362                         msgheader->msg;
 363                 gpadl_header->rangecount = 1;
 364                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 365                                          pagecount * sizeof(u64);
 366                 gpadl_header->range[0].byte_offset = 0;
 367                 gpadl_header->range[0].byte_count = size;
 368                 for (i = 0; i < pagecount; i++)
 369                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 370                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 371
 372                 *msginfo = msgheader;
 373         }
 374
 375         return 0;
 376 nomem:
 377         kfree(msgheader);
 378         kfree(msgbody);
 379         return -ENOMEM;
 380 }
 381
 382 /*
 383  * vmbus_establish_gpadl - Establish a GPADL for the specified buffer
 384  *
 385  * @channel: a channel
 386  * @kbuffer: from kmalloc or vmalloc
 387  * @size: page-size multiple
 388  * @gpadl_handle: some funky thing
 389  */
 390 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 391                                u32 size, u32 *gpadl_handle)
 392 {
 393         struct vmbus_channel_gpadl_header *gpadlmsg;
 394         struct vmbus_channel_gpadl_body *gpadl_body;
 395         struct vmbus_channel_msginfo *msginfo = NULL;
 396         struct vmbus_channel_msginfo *submsginfo, *tmp;
 397         struct list_head *curr;
 398         u32 next_gpadl_handle;
 399         unsigned long flags;
 400         int ret = 0;
 401
 402         next_gpadl_handle =
 403                 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
 404
 405         ret = create_gpadl_header(kbuffer, size, &msginfo);
 406         if (ret)
 407                 return ret;
 408
 409         init_completion(&msginfo->waitevent);
 410         msginfo->waiting_channel = channel;
 411
 412         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 413         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 414         gpadlmsg->child_relid = channel->offermsg.child_relid;
 415         gpadlmsg->gpadl = next_gpadl_handle;
 416
 417
 418         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 419         list_add_tail(&msginfo->msglistentry,
 420                       &vmbus_connection.chn_msg_list);
 421
 422         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 423
 424         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 425                              sizeof(*msginfo), true);
 426         if (ret != 0)
 427                 goto cleanup;
 428
 429         list_for_each(curr, &msginfo->submsglist) {
 430                 submsginfo = (struct vmbus_channel_msginfo *)curr;
 431                 gpadl_body =
 432                         (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 433
 434                 gpadl_body->header.msgtype =
 435                         CHANNELMSG_GPADL_BODY;
 436                 gpadl_body->gpadl = next_gpadl_handle;
 437
 438                 ret = vmbus_post_msg(gpadl_body,
 439                                      submsginfo->msgsize - sizeof(*submsginfo),
 440                                      true);
 441                 if (ret != 0)
 442                         goto cleanup;
 443
 444         }
 445         wait_for_completion(&msginfo->waitevent);
 446
 447         if (channel->rescind) {
 448                 ret = -ENODEV;
 449                 goto cleanup;
 450         }
 451
 452         /* At this point, we received the gpadl created msg */
 453         *gpadl_handle = gpadlmsg->gpadl;
 454
 455 cleanup:
 456         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 457         list_del(&msginfo->msglistentry);
 458         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 459         list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
 460                                  msglistentry) {
 461                 kfree(submsginfo);
 462         }
 463
 464         kfree(msginfo);
 465         return ret;
 466 }
 467 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 468
 469 /*
 470  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 471  */
 472 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 473 {
 474         struct vmbus_channel_gpadl_teardown *msg;
 475         struct vmbus_channel_msginfo *info;
 476         unsigned long flags;
 477         int ret;
 478
 479         info = kmalloc(sizeof(*info) +
 480                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 481         if (!info)
 482                 return -ENOMEM;
 483
 484         init_completion(&info->waitevent);
 485         info->waiting_channel = channel;
 486
 487         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 488
 489         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 490         msg->child_relid = channel->offermsg.child_relid;
 491         msg->gpadl = gpadl_handle;
 492
 493         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 494         list_add_tail(&info->msglistentry,
 495                       &vmbus_connection.chn_msg_list);
 496         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 497         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown),
 498                              true);
 499
 500         if (ret)
 501                 goto post_msg_err;
 502
 503         wait_for_completion(&info->waitevent);
 504
 505 post_msg_err:
 506         /*
 507          * If the channel has been rescinded;
 508          * we will be awakened by the rescind
 509          * handler; set the error code to zero so we don't leak memory.
 510          */
 511         if (channel->rescind)
 512                 ret = 0;
 513
 514         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 515         list_del(&info->msglistentry);
 516         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 517
 518         kfree(info);
 519         return ret;
 520 }
 521 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 522
 523 static void reset_channel_cb(void *arg)
 524 {
 525         struct vmbus_channel *channel = arg;
 526
 527         channel->onchannel_callback = NULL;
 528 }
 529
 530 static int vmbus_close_internal(struct vmbus_channel *channel)
 531 {
 532         struct vmbus_channel_close_channel *msg;
 533         int ret;
 534
 535         /*
 536          * vmbus_on_event(), running in the per-channel tasklet, can race
 537          * with vmbus_close_internal() in the case of SMP guest, e.g., when
 538          * the former is accessing channel->inbound.ring_buffer, the latter
 539          * could be freeing the ring_buffer pages, so here we must stop it
 540          * first.
 541          */
 542         tasklet_disable(&channel->callback_event);
 543
 544         /*
 545          * In case a device driver's probe() fails (e.g.,
 546          * util_probe() -> vmbus_open() returns -ENOMEM) and the device is
 547          * rescinded later (e.g., we dynamically disable an Integrated Service
 548          * in Hyper-V Manager), the driver's remove() invokes vmbus_close():
 549          * here we should skip most of the below cleanup work.
 550          */
 551         if (channel->state != CHANNEL_OPENED_STATE) {
 552                 ret = -EINVAL;
 553                 goto out;
 554         }
 555
 556         channel->state = CHANNEL_OPEN_STATE;
 557         channel->sc_creation_callback = NULL;
 558         /* Stop callback and cancel the timer asap */
 559         if (channel->target_cpu != get_cpu()) {
 560                 put_cpu();
 561                 smp_call_function_single(channel->target_cpu, reset_channel_cb,
 562                                          channel, true);
 563         } else {
 564                 reset_channel_cb(channel);
 565                 put_cpu();
 566         }
 567
 568         /* Send a closing message */
 569
 570         msg = &channel->close_msg.msg;
 571
 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                              true);
 577
 578         if (ret) {
 579                 pr_err("Close failed: close post msg return is %d\n", ret);
 580                 /*
 581                  * If we failed to post the close msg,
 582                  * it is perhaps better to leak memory.
 583                  */
 584                 goto out;
 585         }
 586
 587         /* Tear down the gpadl for the channel's ring buffer */
 588         if (channel->ringbuffer_gpadlhandle) {
 589                 ret = vmbus_teardown_gpadl(channel,
 590                                            channel->ringbuffer_gpadlhandle);
 591                 if (ret) {
 592                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 593                         /*
 594                          * If we failed to teardown gpadl,
 595                          * it is perhaps better to leak memory.
 596                          */
 597                         goto out;
 598                 }
 599         }
 600
 601         /* Cleanup the ring buffers for this channel */
 602         hv_ringbuffer_cleanup(&channel->outbound);
 603         hv_ringbuffer_cleanup(&channel->inbound);
 604
 605         free_pages((unsigned long)channel->ringbuffer_pages,
 606                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 607
 608 out:
 609         /* re-enable tasklet for use on re-open */
 610         tasklet_enable(&channel->callback_event);
 611         return ret;
 612 }
 613
 614 /*
 615  * vmbus_close - Close the specified channel
 616  */
 617 void vmbus_close(struct vmbus_channel *channel)
 618 {
 619         struct list_head *cur, *tmp;
 620         struct vmbus_channel *cur_channel;
 621
 622         if (channel->primary_channel != NULL) {
 623                 /*
 624                  * We will only close sub-channels when
 625                  * the primary is closed.
 626                  */
 627                 return;
 628         }
 629         /*
 630          * Close all the sub-channels first and then close the
 631          * primary channel.
 632          */
 633         list_for_each_safe(cur, tmp, &channel->sc_list) {
 634                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 635                 vmbus_close_internal(cur_channel);
 636                 if (cur_channel->rescind) {
 637                         mutex_lock(&vmbus_connection.channel_mutex);
 638                         hv_process_channel_removal(cur_channel,
 639                                            cur_channel->offermsg.child_relid);
 640                         mutex_unlock(&vmbus_connection.channel_mutex);
 641                 }
 642         }
 643         /*
 644          * Now close the primary.
 645          */
 646         vmbus_close_internal(channel);
 647 }
 648 EXPORT_SYMBOL_GPL(vmbus_close);
 649
 650 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 651                          u32 bufferlen, u64 requestid,
 652                          enum vmbus_packet_type type, u32 flags)
 653 {
 654         struct vmpacket_descriptor desc;
 655         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 656         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 657         struct kvec bufferlist[3];
 658         u64 aligned_data = 0;
 659         int num_vecs = ((bufferlen != 0) ? 3 : 1);
 660
 661
 662         /* Setup the descriptor */
 663         desc.type = type; /* VmbusPacketTypeDataInBand; */
 664         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 665         /* in 8-bytes granularity */
 666         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 667         desc.len8 = (u16)(packetlen_aligned >> 3);
 668         desc.trans_id = requestid;
 669
 670         bufferlist[0].iov_base = &desc;
 671         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 672         bufferlist[1].iov_base = buffer;
 673         bufferlist[1].iov_len = bufferlen;
 674         bufferlist[2].iov_base = &aligned_data;
 675         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 676
 677         return hv_ringbuffer_write(channel, bufferlist, num_vecs);
 678 }
 679 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 680
 681 /**
 682  * vmbus_sendpacket() - Send the specified buffer on the given channel
 683  * @channel: Pointer to vmbus_channel structure.
 684  * @buffer: Pointer to the buffer you want to receive the data into.
 685  * @bufferlen: Maximum size of what the the buffer will hold
 686  * @requestid: Identifier of the request
 687  * @type: Type of packet that is being send e.g. negotiate, time
 688  * packet etc.
 689  *
 690  * Sends data in @buffer directly to hyper-v via the vmbus
 691  * This will send the data unparsed to hyper-v.
 692  *
 693  * Mainly used by Hyper-V drivers.
 694  */
 695 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 696                            u32 bufferlen, u64 requestid,
 697                            enum vmbus_packet_type type, u32 flags)
 698 {
 699         return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
 700                                     type, flags);
 701 }
 702 EXPORT_SYMBOL(vmbus_sendpacket);
 703
 704 /*
 705  * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
 706  * packets using a GPADL Direct packet type. This interface allows you
 707  * to control notifying the host. This will be useful for sending
 708  * batched data. Also the sender can control the send flags
 709  * explicitly.
 710  */
 711 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 712                                     struct hv_page_buffer pagebuffers[],
 713                                     u32 pagecount, void *buffer, u32 bufferlen,
 714                                     u64 requestid, u32 flags)
 715 {
 716         int i;
 717         struct vmbus_channel_packet_page_buffer desc;
 718         u32 descsize;
 719         u32 packetlen;
 720         u32 packetlen_aligned;
 721         struct kvec bufferlist[3];
 722         u64 aligned_data = 0;
 723
 724         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 725                 return -EINVAL;
 726
 727         /*
 728          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 729          * largest size we support
 730          */
 731         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 732                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 733                           sizeof(struct hv_page_buffer));
 734         packetlen = descsize + bufferlen;
 735         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 736
 737         /* Setup the descriptor */
 738         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 739         desc.flags = flags;
 740         desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */
 741         desc.length8 = (u16)(packetlen_aligned >> 3);
 742         desc.transactionid = requestid;
 743         desc.rangecount = pagecount;
 744
 745         for (i = 0; i < pagecount; i++) {
 746                 desc.range[i].len = pagebuffers[i].len;
 747                 desc.range[i].offset = pagebuffers[i].offset;
 748                 desc.range[i].pfn        = pagebuffers[i].pfn;
 749         }
 750
 751         bufferlist[0].iov_base = &desc;
 752         bufferlist[0].iov_len = descsize;
 753         bufferlist[1].iov_base = buffer;
 754         bufferlist[1].iov_len = bufferlen;
 755         bufferlist[2].iov_base = &aligned_data;
 756         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 757
 758         return hv_ringbuffer_write(channel, bufferlist, 3);
 759 }
 760 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 761
 762 /*
 763  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 764  * packets using a GPADL Direct packet type.
 765  */
 766 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 767                                      struct hv_page_buffer pagebuffers[],
 768                                      u32 pagecount, void *buffer, u32 bufferlen,
 769                                      u64 requestid)
 770 {
 771         u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 772
 773         return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
 774                                                buffer, bufferlen,
 775                                                requestid, flags);
 776
 777 }
 778 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 779
 780 /*
 781  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 782  * using a GPADL Direct packet type.
 783  * The buffer includes the vmbus descriptor.
 784  */
 785 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 786                               struct vmbus_packet_mpb_array *desc,
 787                               u32 desc_size,
 788                               void *buffer, u32 bufferlen, u64 requestid)
 789 {
 790         u32 packetlen;
 791         u32 packetlen_aligned;
 792         struct kvec bufferlist[3];
 793         u64 aligned_data = 0;
 794
 795         packetlen = desc_size + bufferlen;
 796         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 797
 798         /* Setup the descriptor */
 799         desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 800         desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 801         desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */
 802         desc->length8 = (u16)(packetlen_aligned >> 3);
 803         desc->transactionid = requestid;
 804         desc->rangecount = 1;
 805
 806         bufferlist[0].iov_base = desc;
 807         bufferlist[0].iov_len = desc_size;
 808         bufferlist[1].iov_base = buffer;
 809         bufferlist[1].iov_len = bufferlen;
 810         bufferlist[2].iov_base = &aligned_data;
 811         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 812
 813         return hv_ringbuffer_write(channel, bufferlist, 3);
 814 }
 815 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 816
 817 /*
 818  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 819  * using a GPADL Direct packet type.
 820  */
 821 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 822                                 struct hv_multipage_buffer *multi_pagebuffer,
 823                                 void *buffer, u32 bufferlen, u64 requestid)
 824 {
 825         struct vmbus_channel_packet_multipage_buffer desc;
 826         u32 descsize;
 827         u32 packetlen;
 828         u32 packetlen_aligned;
 829         struct kvec bufferlist[3];
 830         u64 aligned_data = 0;
 831         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 832                                          multi_pagebuffer->len);
 833
 834         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 835                 return -EINVAL;
 836
 837         /*
 838          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 839          * the largest size we support
 840          */
 841         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 842                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 843                           sizeof(u64));
 844         packetlen = descsize + bufferlen;
 845         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 846
 847
 848         /* Setup the descriptor */
 849         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 850         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 851         desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */
 852         desc.length8 = (u16)(packetlen_aligned >> 3);
 853         desc.transactionid = requestid;
 854         desc.rangecount = 1;
 855
 856         desc.range.len = multi_pagebuffer->len;
 857         desc.range.offset = multi_pagebuffer->offset;
 858
 859         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 860                pfncount * sizeof(u64));
 861
 862         bufferlist[0].iov_base = &desc;
 863         bufferlist[0].iov_len = descsize;
 864         bufferlist[1].iov_base = buffer;
 865         bufferlist[1].iov_len = bufferlen;
 866         bufferlist[2].iov_base = &aligned_data;
 867         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 868
 869         return hv_ringbuffer_write(channel, bufferlist, 3);
 870 }
 871 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 872
 873 /**
 874  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 875  * @channel: Pointer to vmbus_channel structure.
 876  * @buffer: Pointer to the buffer you want to receive the data into.
 877  * @bufferlen: Maximum size of what the the buffer will hold
 878  * @buffer_actual_len: The actual size of the data after it was received
 879  * @requestid: Identifier of the request
 880  *
 881  * Receives directly from the hyper-v vmbus and puts the data it received
 882  * into Buffer. This will receive the data unparsed from hyper-v.
 883  *
 884  * Mainly used by Hyper-V drivers.
 885  */
 886 static inline int
 887 __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 888                    u32 bufferlen, u32 *buffer_actual_len, u64 *requestid,
 889                    bool raw)
 890 {
 891         return hv_ringbuffer_read(channel, buffer, bufferlen,
 892                                   buffer_actual_len, requestid, raw);
 893
 894 }
 895
 896 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 897                      u32 bufferlen, u32 *buffer_actual_len,
 898                      u64 *requestid)
 899 {
 900         return __vmbus_recvpacket(channel, buffer, bufferlen,
 901                                   buffer_actual_len, requestid, false);
 902 }
 903 EXPORT_SYMBOL(vmbus_recvpacket);
 904
 905 /*
 906  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 907  */
 908 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 909                               u32 bufferlen, u32 *buffer_actual_len,
 910                               u64 *requestid)
 911 {
 912         return __vmbus_recvpacket(channel, buffer, bufferlen,
 913                                   buffer_actual_len, requestid, true);
 914 }
 915 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);