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
  32 #include "hyperv_vmbus.h"
  33
  34 #define NUM_PAGES_SPANNED(addr, len) \
  35 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
  36
  37 /*
  38  * vmbus_setevent- Trigger an event notification on the specified
  39  * channel.
  40  */
  41 static void vmbus_setevent(struct vmbus_channel *channel)
  42 {
  43         struct hv_monitor_page *monitorpage;
  44
  45         if (channel->offermsg.monitor_allocated) {
  46                 /* Each u32 represents 32 channels */
  47                 sync_set_bit(channel->offermsg.child_relid & 31,
  48                         (unsigned long *) vmbus_connection.send_int_page +
  49                         (channel->offermsg.child_relid >> 5));
  50
  51                 /* Get the child to parent monitor page */
  52                 monitorpage = vmbus_connection.monitor_pages[1];
  53
  54                 sync_set_bit(channel->monitor_bit,
  55                         (unsigned long *)&monitorpage->trigger_group
  56                                         [channel->monitor_grp].pending);
  57
  58         } else {
  59                 vmbus_set_event(channel);
  60         }
  61 }
  62
  63 /*
  64  * vmbus_open - Open the specified channel.
  65  */
  66 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
  67                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
  68                      void (*onchannelcallback)(void *context), void *context)
  69 {
  70         struct vmbus_channel_open_channel *open_msg;
  71         struct vmbus_channel_msginfo *open_info = NULL;
  72         void *in, *out;
  73         unsigned long flags;
  74         int ret, t, err = 0;
  75
  76         spin_lock_irqsave(&newchannel->sc_lock, flags);
  77         if (newchannel->state == CHANNEL_OPEN_STATE) {
  78                 newchannel->state = CHANNEL_OPENING_STATE;
  79         } else {
  80                 spin_unlock_irqrestore(&newchannel->sc_lock, flags);
  81                 return -EINVAL;
  82         }
  83         spin_unlock_irqrestore(&newchannel->sc_lock, flags);
  84
  85         newchannel->onchannel_callback = onchannelcallback;
  86         newchannel->channel_callback_context = context;
  87
  88         /* Allocate the ring buffer */
  89         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
  90                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
  91
  92         if (!out)
  93                 return -ENOMEM;
  94
  95
  96         in = (void *)((unsigned long)out + send_ringbuffer_size);
  97
  98         newchannel->ringbuffer_pages = out;
  99         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 100                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 101
 102         ret = hv_ringbuffer_init(
 103                 &newchannel->outbound, out, send_ringbuffer_size);
 104
 105         if (ret != 0) {
 106                 err = ret;
 107                 goto error0;
 108         }
 109
 110         ret = hv_ringbuffer_init(
 111                 &newchannel->inbound, in, recv_ringbuffer_size);
 112         if (ret != 0) {
 113                 err = ret;
 114                 goto error0;
 115         }
 116
 117
 118         /* Establish the gpadl for the ring buffer */
 119         newchannel->ringbuffer_gpadlhandle = 0;
 120
 121         ret = vmbus_establish_gpadl(newchannel,
 122                                          newchannel->outbound.ring_buffer,
 123                                          send_ringbuffer_size +
 124                                          recv_ringbuffer_size,
 125                                          &newchannel->ringbuffer_gpadlhandle);
 126
 127         if (ret != 0) {
 128                 err = ret;
 129                 goto error0;
 130         }
 131
 132         /* Create and init the channel open message */
 133         open_info = kmalloc(sizeof(*open_info) +
 134                            sizeof(struct vmbus_channel_open_channel),
 135                            GFP_KERNEL);
 136         if (!open_info) {
 137                 err = -ENOMEM;
 138                 goto error0;
 139         }
 140
 141         init_completion(&open_info->waitevent);
 142
 143         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 144         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 145         open_msg->openid = newchannel->offermsg.child_relid;
 146         open_msg->child_relid = newchannel->offermsg.child_relid;
 147         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 148         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 149                                                   PAGE_SHIFT;
 150         open_msg->target_vp = newchannel->target_vp;
 151
 152         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 153                 err = -EINVAL;
 154                 goto error0;
 155         }
 156
 157         if (userdatalen)
 158                 memcpy(open_msg->userdata, userdata, userdatalen);
 159
 160         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 161         list_add_tail(&open_info->msglistentry,
 162                       &vmbus_connection.chn_msg_list);
 163         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 164
 165         ret = vmbus_post_msg(open_msg,
 166                                sizeof(struct vmbus_channel_open_channel));
 167
 168         if (ret != 0) {
 169                 err = ret;
 170                 goto error1;
 171         }
 172
 173         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 174         if (t == 0) {
 175                 err = -ETIMEDOUT;
 176                 goto error1;
 177         }
 178
 179
 180         if (open_info->response.open_result.status)
 181                 err = open_info->response.open_result.status;
 182
 183         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 184         list_del(&open_info->msglistentry);
 185         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 186
 187         if (err == 0)
 188                 newchannel->state = CHANNEL_OPENED_STATE;
 189
 190         kfree(open_info);
 191         return err;
 192
 193 error1:
 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 error0:
 199         free_pages((unsigned long)out,
 200                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 201         kfree(open_info);
 202         return err;
 203 }
 204 EXPORT_SYMBOL_GPL(vmbus_open);
 205
 206 /*
 207  * create_gpadl_header - Creates a gpadl for the specified buffer
 208  */
 209 static int create_gpadl_header(void *kbuffer, u32 size,
 210                                          struct vmbus_channel_msginfo **msginfo,
 211                                          u32 *messagecount)
 212 {
 213         int i;
 214         int pagecount;
 215         struct vmbus_channel_gpadl_header *gpadl_header;
 216         struct vmbus_channel_gpadl_body *gpadl_body;
 217         struct vmbus_channel_msginfo *msgheader;
 218         struct vmbus_channel_msginfo *msgbody = NULL;
 219         u32 msgsize;
 220
 221         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 222
 223         pagecount = size >> PAGE_SHIFT;
 224
 225         /* do we need a gpadl body msg */
 226         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 227                   sizeof(struct vmbus_channel_gpadl_header) -
 228                   sizeof(struct gpa_range);
 229         pfncount = pfnsize / sizeof(u64);
 230
 231         if (pagecount > pfncount) {
 232                 /* we need a gpadl body */
 233                 /* fill in the header */
 234                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 235                           sizeof(struct vmbus_channel_gpadl_header) +
 236                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 237                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 238                 if (!msgheader)
 239                         goto nomem;
 240
 241                 INIT_LIST_HEAD(&msgheader->submsglist);
 242                 msgheader->msgsize = msgsize;
 243
 244                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 245                         msgheader->msg;
 246                 gpadl_header->rangecount = 1;
 247                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 248                                          pagecount * sizeof(u64);
 249                 gpadl_header->range[0].byte_offset = 0;
 250                 gpadl_header->range[0].byte_count = size;
 251                 for (i = 0; i < pfncount; i++)
 252                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 253                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 254                 *msginfo = msgheader;
 255                 *messagecount = 1;
 256
 257                 pfnsum = pfncount;
 258                 pfnleft = pagecount - pfncount;
 259
 260                 /* how many pfns can we fit */
 261                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 262                           sizeof(struct vmbus_channel_gpadl_body);
 263                 pfncount = pfnsize / sizeof(u64);
 264
 265                 /* fill in the body */
 266                 while (pfnleft) {
 267                         if (pfnleft > pfncount)
 268                                 pfncurr = pfncount;
 269                         else
 270                                 pfncurr = pfnleft;
 271
 272                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 273                                   sizeof(struct vmbus_channel_gpadl_body) +
 274                                   pfncurr * sizeof(u64);
 275                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 276
 277                         if (!msgbody) {
 278                                 struct vmbus_channel_msginfo *pos = NULL;
 279                                 struct vmbus_channel_msginfo *tmp = NULL;
 280                                 /*
 281                                  * Free up all the allocated messages.
 282                                  */
 283                                 list_for_each_entry_safe(pos, tmp,
 284                                         &msgheader->submsglist,
 285                                         msglistentry) {
 286
 287                                         list_del(&pos->msglistentry);
 288                                         kfree(pos);
 289                                 }
 290
 291                                 goto nomem;
 292                         }
 293
 294                         msgbody->msgsize = msgsize;
 295                         (*messagecount)++;
 296                         gpadl_body =
 297                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 298
 299                         /*
 300                          * Gpadl is u32 and we are using a pointer which could
 301                          * be 64-bit
 302                          * This is governed by the guest/host protocol and
 303                          * so the hypervisor gurantees that this is ok.
 304                          */
 305                         for (i = 0; i < pfncurr; i++)
 306                                 gpadl_body->pfn[i] = slow_virt_to_phys(
 307                                         kbuffer + PAGE_SIZE * (pfnsum + i)) >>
 308                                         PAGE_SHIFT;
 309
 310                         /* add to msg header */
 311                         list_add_tail(&msgbody->msglistentry,
 312                                       &msgheader->submsglist);
 313                         pfnsum += pfncurr;
 314                         pfnleft -= pfncurr;
 315                 }
 316         } else {
 317                 /* everything fits in a header */
 318                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 319                           sizeof(struct vmbus_channel_gpadl_header) +
 320                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 321                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 322                 if (msgheader == NULL)
 323                         goto nomem;
 324                 msgheader->msgsize = msgsize;
 325
 326                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 327                         msgheader->msg;
 328                 gpadl_header->rangecount = 1;
 329                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 330                                          pagecount * sizeof(u64);
 331                 gpadl_header->range[0].byte_offset = 0;
 332                 gpadl_header->range[0].byte_count = size;
 333                 for (i = 0; i < pagecount; i++)
 334                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 335                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 336
 337                 *msginfo = msgheader;
 338                 *messagecount = 1;
 339         }
 340
 341         return 0;
 342 nomem:
 343         kfree(msgheader);
 344         kfree(msgbody);
 345         return -ENOMEM;
 346 }
 347
 348 /*
 349  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 350  *
 351  * @channel: a channel
 352  * @kbuffer: from kmalloc or vmalloc
 353  * @size: page-size multiple
 354  * @gpadl_handle: some funky thing
 355  */
 356 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 357                                u32 size, u32 *gpadl_handle)
 358 {
 359         struct vmbus_channel_gpadl_header *gpadlmsg;
 360         struct vmbus_channel_gpadl_body *gpadl_body;
 361         struct vmbus_channel_msginfo *msginfo = NULL;
 362         struct vmbus_channel_msginfo *submsginfo;
 363         u32 msgcount;
 364         struct list_head *curr;
 365         u32 next_gpadl_handle;
 366         unsigned long flags;
 367         int ret = 0;
 368
 369         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
 370         atomic_inc(&vmbus_connection.next_gpadl_handle);
 371
 372         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 373         if (ret)
 374                 return ret;
 375
 376         init_completion(&msginfo->waitevent);
 377
 378         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 379         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 380         gpadlmsg->child_relid = channel->offermsg.child_relid;
 381         gpadlmsg->gpadl = next_gpadl_handle;
 382
 383
 384         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 385         list_add_tail(&msginfo->msglistentry,
 386                       &vmbus_connection.chn_msg_list);
 387
 388         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 389
 390         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 391                                sizeof(*msginfo));
 392         if (ret != 0)
 393                 goto cleanup;
 394
 395         if (msgcount > 1) {
 396                 list_for_each(curr, &msginfo->submsglist) {
 397
 398                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 399                         gpadl_body =
 400                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 401
 402                         gpadl_body->header.msgtype =
 403                                 CHANNELMSG_GPADL_BODY;
 404                         gpadl_body->gpadl = next_gpadl_handle;
 405
 406                         ret = vmbus_post_msg(gpadl_body,
 407                                                submsginfo->msgsize -
 408                                                sizeof(*submsginfo));
 409                         if (ret != 0)
 410                                 goto cleanup;
 411
 412                 }
 413         }
 414         wait_for_completion(&msginfo->waitevent);
 415
 416         /* At this point, we received the gpadl created msg */
 417         *gpadl_handle = gpadlmsg->gpadl;
 418
 419 cleanup:
 420         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 421         list_del(&msginfo->msglistentry);
 422         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 423
 424         kfree(msginfo);
 425         return ret;
 426 }
 427 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 428
 429 /*
 430  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 431  */
 432 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 433 {
 434         struct vmbus_channel_gpadl_teardown *msg;
 435         struct vmbus_channel_msginfo *info;
 436         unsigned long flags;
 437         int ret;
 438
 439         info = kmalloc(sizeof(*info) +
 440                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 441         if (!info)
 442                 return -ENOMEM;
 443
 444         init_completion(&info->waitevent);
 445
 446         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 447
 448         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 449         msg->child_relid = channel->offermsg.child_relid;
 450         msg->gpadl = gpadl_handle;
 451
 452         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 453         list_add_tail(&info->msglistentry,
 454                       &vmbus_connection.chn_msg_list);
 455         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 456         ret = vmbus_post_msg(msg,
 457                                sizeof(struct vmbus_channel_gpadl_teardown));
 458
 459         if (ret)
 460                 goto post_msg_err;
 461
 462         wait_for_completion(&info->waitevent);
 463
 464 post_msg_err:
 465         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 466         list_del(&info->msglistentry);
 467         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 468
 469         kfree(info);
 470         return ret;
 471 }
 472 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 473
 474 static void reset_channel_cb(void *arg)
 475 {
 476         struct vmbus_channel *channel = arg;
 477
 478         channel->onchannel_callback = NULL;
 479 }
 480
 481 static int vmbus_close_internal(struct vmbus_channel *channel)
 482 {
 483         struct vmbus_channel_close_channel *msg;
 484         int ret;
 485
 486         channel->state = CHANNEL_OPEN_STATE;
 487         channel->sc_creation_callback = NULL;
 488         /* Stop callback and cancel the timer asap */
 489         if (channel->target_cpu != get_cpu()) {
 490                 put_cpu();
 491                 smp_call_function_single(channel->target_cpu, reset_channel_cb,
 492                                          channel, true);
 493         } else {
 494                 reset_channel_cb(channel);
 495                 put_cpu();
 496         }
 497
 498         /* Send a closing message */
 499
 500         msg = &channel->close_msg.msg;
 501
 502         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 503         msg->child_relid = channel->offermsg.child_relid;
 504
 505         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 506
 507         if (ret) {
 508                 pr_err("Close failed: close post msg return is %d\n", ret);
 509                 /*
 510                  * If we failed to post the close msg,
 511                  * it is perhaps better to leak memory.
 512                  */
 513                 return ret;
 514         }
 515
 516         /* Tear down the gpadl for the channel's ring buffer */
 517         if (channel->ringbuffer_gpadlhandle) {
 518                 ret = vmbus_teardown_gpadl(channel,
 519                                            channel->ringbuffer_gpadlhandle);
 520                 if (ret) {
 521                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 522                         /*
 523                          * If we failed to teardown gpadl,
 524                          * it is perhaps better to leak memory.
 525                          */
 526                         return ret;
 527                 }
 528         }
 529
 530         /* Cleanup the ring buffers for this channel */
 531         hv_ringbuffer_cleanup(&channel->outbound);
 532         hv_ringbuffer_cleanup(&channel->inbound);
 533
 534         free_pages((unsigned long)channel->ringbuffer_pages,
 535                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 536
 537         return ret;
 538 }
 539
 540 /*
 541  * vmbus_close - Close the specified channel
 542  */
 543 void vmbus_close(struct vmbus_channel *channel)
 544 {
 545         struct list_head *cur, *tmp;
 546         struct vmbus_channel *cur_channel;
 547
 548         if (channel->primary_channel != NULL) {
 549                 /*
 550                  * We will only close sub-channels when
 551                  * the primary is closed.
 552                  */
 553                 return;
 554         }
 555         /*
 556          * Close all the sub-channels first and then close the
 557          * primary channel.
 558          */
 559         list_for_each_safe(cur, tmp, &channel->sc_list) {
 560                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 561                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 562                         continue;
 563                 vmbus_close_internal(cur_channel);
 564         }
 565         /*
 566          * Now close the primary.
 567          */
 568         vmbus_close_internal(channel);
 569 }
 570 EXPORT_SYMBOL_GPL(vmbus_close);
 571
 572 /**
 573  * vmbus_sendpacket() - Send the specified buffer on the given channel
 574  * @channel: Pointer to vmbus_channel structure.
 575  * @buffer: Pointer to the buffer you want to receive the data into.
 576  * @bufferlen: Maximum size of what the the buffer will hold
 577  * @requestid: Identifier of the request
 578  * @type: Type of packet that is being send e.g. negotiate, time
 579  * packet etc.
 580  *
 581  * Sends data in @buffer directly to hyper-v via the vmbus
 582  * This will send the data unparsed to hyper-v.
 583  *
 584  * Mainly used by Hyper-V drivers.
 585  */
 586 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 587                            u32 bufferlen, u64 requestid,
 588                            enum vmbus_packet_type type, u32 flags)
 589 {
 590         struct vmpacket_descriptor desc;
 591         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 592         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 593         struct kvec bufferlist[3];
 594         u64 aligned_data = 0;
 595         int ret;
 596         bool signal = false;
 597
 598
 599         /* Setup the descriptor */
 600         desc.type = type; /* VmbusPacketTypeDataInBand; */
 601         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 602         /* in 8-bytes granularity */
 603         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 604         desc.len8 = (u16)(packetlen_aligned >> 3);
 605         desc.trans_id = requestid;
 606
 607         bufferlist[0].iov_base = &desc;
 608         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 609         bufferlist[1].iov_base = buffer;
 610         bufferlist[1].iov_len = bufferlen;
 611         bufferlist[2].iov_base = &aligned_data;
 612         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 613
 614         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 615
 616         if (ret == 0 && signal)
 617                 vmbus_setevent(channel);
 618
 619         return ret;
 620 }
 621 EXPORT_SYMBOL(vmbus_sendpacket);
 622
 623 /*
 624  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 625  * packets using a GPADL Direct packet type.
 626  */
 627 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 628                                      struct hv_page_buffer pagebuffers[],
 629                                      u32 pagecount, void *buffer, u32 bufferlen,
 630                                      u64 requestid)
 631 {
 632         int ret;
 633         int i;
 634         struct vmbus_channel_packet_page_buffer desc;
 635         u32 descsize;
 636         u32 packetlen;
 637         u32 packetlen_aligned;
 638         struct kvec bufferlist[3];
 639         u64 aligned_data = 0;
 640         bool signal = false;
 641
 642         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 643                 return -EINVAL;
 644
 645
 646         /*
 647          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 648          * largest size we support
 649          */
 650         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 651                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 652                           sizeof(struct hv_page_buffer));
 653         packetlen = descsize + bufferlen;
 654         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 655
 656         /* Setup the descriptor */
 657         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 658         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 659         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 660         desc.length8 = (u16)(packetlen_aligned >> 3);
 661         desc.transactionid = requestid;
 662         desc.rangecount = pagecount;
 663
 664         for (i = 0; i < pagecount; i++) {
 665                 desc.range[i].len = pagebuffers[i].len;
 666                 desc.range[i].offset = pagebuffers[i].offset;
 667                 desc.range[i].pfn        = pagebuffers[i].pfn;
 668         }
 669
 670         bufferlist[0].iov_base = &desc;
 671         bufferlist[0].iov_len = descsize;
 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         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 678
 679         if (ret == 0 && signal)
 680                 vmbus_setevent(channel);
 681
 682         return ret;
 683 }
 684 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 685
 686 /*
 687  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 688  * using a GPADL Direct packet type.
 689  */
 690 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 691                                 struct hv_multipage_buffer *multi_pagebuffer,
 692                                 void *buffer, u32 bufferlen, u64 requestid)
 693 {
 694         int ret;
 695         struct vmbus_channel_packet_multipage_buffer desc;
 696         u32 descsize;
 697         u32 packetlen;
 698         u32 packetlen_aligned;
 699         struct kvec bufferlist[3];
 700         u64 aligned_data = 0;
 701         bool signal = false;
 702         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 703                                          multi_pagebuffer->len);
 704
 705         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 706                 return -EINVAL;
 707
 708         /*
 709          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 710          * the largest size we support
 711          */
 712         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 713                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 714                           sizeof(u64));
 715         packetlen = descsize + bufferlen;
 716         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 717
 718
 719         /* Setup the descriptor */
 720         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 721         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 722         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 723         desc.length8 = (u16)(packetlen_aligned >> 3);
 724         desc.transactionid = requestid;
 725         desc.rangecount = 1;
 726
 727         desc.range.len = multi_pagebuffer->len;
 728         desc.range.offset = multi_pagebuffer->offset;
 729
 730         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 731                pfncount * sizeof(u64));
 732
 733         bufferlist[0].iov_base = &desc;
 734         bufferlist[0].iov_len = descsize;
 735         bufferlist[1].iov_base = buffer;
 736         bufferlist[1].iov_len = bufferlen;
 737         bufferlist[2].iov_base = &aligned_data;
 738         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 739
 740         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 741
 742         if (ret == 0 && signal)
 743                 vmbus_setevent(channel);
 744
 745         return ret;
 746 }
 747 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 748
 749 /**
 750  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 751  * @channel: Pointer to vmbus_channel structure.
 752  * @buffer: Pointer to the buffer you want to receive the data into.
 753  * @bufferlen: Maximum size of what the the buffer will hold
 754  * @buffer_actual_len: The actual size of the data after it was received
 755  * @requestid: Identifier of the request
 756  *
 757  * Receives directly from the hyper-v vmbus and puts the data it received
 758  * into Buffer. This will receive the data unparsed from hyper-v.
 759  *
 760  * Mainly used by Hyper-V drivers.
 761  */
 762 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 763                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 764 {
 765         struct vmpacket_descriptor desc;
 766         u32 packetlen;
 767         u32 userlen;
 768         int ret;
 769         bool signal = false;
 770
 771         *buffer_actual_len = 0;
 772         *requestid = 0;
 773
 774
 775         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 776                              sizeof(struct vmpacket_descriptor));
 777         if (ret != 0)
 778                 return 0;
 779
 780         packetlen = desc.len8 << 3;
 781         userlen = packetlen - (desc.offset8 << 3);
 782
 783         *buffer_actual_len = userlen;
 784
 785         if (userlen > bufferlen) {
 786
 787                 pr_err("Buffer too small - got %d needs %d\n",
 788                            bufferlen, userlen);
 789                 return -ETOOSMALL;
 790         }
 791
 792         *requestid = desc.trans_id;
 793
 794         /* Copy over the packet to the user buffer */
 795         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 796                              (desc.offset8 << 3), &signal);
 797
 798         if (signal)
 799                 vmbus_setevent(channel);
 800
 801         return 0;
 802 }
 803 EXPORT_SYMBOL(vmbus_recvpacket);
 804
 805 /*
 806  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 807  */
 808 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 809                               u32 bufferlen, u32 *buffer_actual_len,
 810                               u64 *requestid)
 811 {
 812         struct vmpacket_descriptor desc;
 813         u32 packetlen;
 814         int ret;
 815         bool signal = false;
 816
 817         *buffer_actual_len = 0;
 818         *requestid = 0;
 819
 820
 821         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 822                              sizeof(struct vmpacket_descriptor));
 823         if (ret != 0)
 824                 return 0;
 825
 826
 827         packetlen = desc.len8 << 3;
 828
 829         *buffer_actual_len = packetlen;
 830
 831         if (packetlen > bufferlen)
 832                 return -ENOBUFS;
 833
 834         *requestid = desc.trans_id;
 835
 836         /* Copy over the entire packet to the user buffer */
 837         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 838                                  &signal);
 839
 840         if (signal)
 841                 vmbus_setevent(channel);
 842
 843         return ret;
 844 }
 845 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);