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
  31 #include "hyperv_vmbus.h"
  32
  33 #define NUM_PAGES_SPANNED(addr, len) \
  34 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
  35
  36 /*
  37  * vmbus_setevent- Trigger an event notification on the specified
  38  * channel.
  39  */
  40 static void vmbus_setevent(struct vmbus_channel *channel)
  41 {
  42         struct hv_monitor_page *monitorpage;
  43
  44         if (channel->offermsg.monitor_allocated) {
  45                 /* Each u32 represents 32 channels */
  46                 sync_set_bit(channel->offermsg.child_relid & 31,
  47                         (unsigned long *) vmbus_connection.send_int_page +
  48                         (channel->offermsg.child_relid >> 5));
  49
  50                 monitorpage = vmbus_connection.monitor_pages;
  51                 monitorpage++; /* Get the child to parent monitor page */
  52
  53                 sync_set_bit(channel->monitor_bit,
  54                         (unsigned long *)&monitorpage->trigger_group
  55                                         [channel->monitor_grp].pending);
  56
  57         } else {
  58                 vmbus_set_event(channel);
  59         }
  60 }
  61
  62 /*
  63  * vmbus_get_debug_info -Retrieve various channel debug info
  64  */
  65 void vmbus_get_debug_info(struct vmbus_channel *channel,
  66                               struct vmbus_channel_debug_info *debuginfo)
  67 {
  68         struct hv_monitor_page *monitorpage;
  69         u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
  70         u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
  71
  72         memcpy(&debuginfo->interfacetype,
  73                &channel->offermsg.offer.if_type, sizeof(uuid_le));
  74         memcpy(&debuginfo->interface_instance,
  75                &channel->offermsg.offer.if_instance,
  76                sizeof(uuid_le));
  77
  78         monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
  79
  80         debuginfo->servermonitor_pending =
  81                         monitorpage->trigger_group[monitor_group].pending;
  82         debuginfo->servermonitor_latency =
  83                         monitorpage->latency[monitor_group][monitor_offset];
  84         debuginfo->servermonitor_connectionid =
  85                         monitorpage->parameter[monitor_group]
  86                                         [monitor_offset].connectionid.u.id;
  87
  88         monitorpage++;
  89
  90         debuginfo->clientmonitor_pending =
  91                         monitorpage->trigger_group[monitor_group].pending;
  92         debuginfo->clientmonitor_latency =
  93                         monitorpage->latency[monitor_group][monitor_offset];
  94         debuginfo->clientmonitor_connectionid =
  95                         monitorpage->parameter[monitor_group]
  96                                         [monitor_offset].connectionid.u.id;
  97
  98         hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
  99         hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
 100 }
 101
 102 /*
 103  * vmbus_open - Open the specified channel.
 104  */
 105 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 106                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
 107                      void (*onchannelcallback)(void *context), void *context)
 108 {
 109         struct vmbus_channel_open_channel *open_msg;
 110         struct vmbus_channel_msginfo *open_info = NULL;
 111         void *in, *out;
 112         unsigned long flags;
 113         int ret, t, err = 0;
 114
 115         spin_lock_irqsave(&newchannel->sc_lock, flags);
 116         if (newchannel->state == CHANNEL_OPEN_STATE) {
 117                 newchannel->state = CHANNEL_OPENING_STATE;
 118         } else {
 119                 spin_unlock_irqrestore(&newchannel->sc_lock, flags);
 120                 return -EINVAL;
 121         }
 122         spin_unlock_irqrestore(&newchannel->sc_lock, flags);
 123
 124         newchannel->onchannel_callback = onchannelcallback;
 125         newchannel->channel_callback_context = context;
 126
 127         /* Allocate the ring buffer */
 128         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 129                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 130
 131         if (!out)
 132                 return -ENOMEM;
 133
 134
 135         in = (void *)((unsigned long)out + send_ringbuffer_size);
 136
 137         newchannel->ringbuffer_pages = out;
 138         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 139                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 140
 141         ret = hv_ringbuffer_init(
 142                 &newchannel->outbound, out, send_ringbuffer_size);
 143
 144         if (ret != 0) {
 145                 err = ret;
 146                 goto error0;
 147         }
 148
 149         ret = hv_ringbuffer_init(
 150                 &newchannel->inbound, in, recv_ringbuffer_size);
 151         if (ret != 0) {
 152                 err = ret;
 153                 goto error0;
 154         }
 155
 156
 157         /* Establish the gpadl for the ring buffer */
 158         newchannel->ringbuffer_gpadlhandle = 0;
 159
 160         ret = vmbus_establish_gpadl(newchannel,
 161                                          newchannel->outbound.ring_buffer,
 162                                          send_ringbuffer_size +
 163                                          recv_ringbuffer_size,
 164                                          &newchannel->ringbuffer_gpadlhandle);
 165
 166         if (ret != 0) {
 167                 err = ret;
 168                 goto error0;
 169         }
 170
 171         /* Create and init the channel open message */
 172         open_info = kmalloc(sizeof(*open_info) +
 173                            sizeof(struct vmbus_channel_open_channel),
 174                            GFP_KERNEL);
 175         if (!open_info) {
 176                 err = -ENOMEM;
 177                 goto error0;
 178         }
 179
 180         init_completion(&open_info->waitevent);
 181
 182         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 183         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 184         open_msg->openid = newchannel->offermsg.child_relid;
 185         open_msg->child_relid = newchannel->offermsg.child_relid;
 186         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 187         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 188                                                   PAGE_SHIFT;
 189         open_msg->target_vp = newchannel->target_vp;
 190
 191         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 192                 err = -EINVAL;
 193                 goto error0;
 194         }
 195
 196         if (userdatalen)
 197                 memcpy(open_msg->userdata, userdata, userdatalen);
 198
 199         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 200         list_add_tail(&open_info->msglistentry,
 201                       &vmbus_connection.chn_msg_list);
 202         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 203
 204         ret = vmbus_post_msg(open_msg,
 205                                sizeof(struct vmbus_channel_open_channel));
 206
 207         if (ret != 0)
 208                 goto error1;
 209
 210         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 211         if (t == 0) {
 212                 err = -ETIMEDOUT;
 213                 goto error1;
 214         }
 215
 216
 217         if (open_info->response.open_result.status)
 218                 err = open_info->response.open_result.status;
 219
 220         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 221         list_del(&open_info->msglistentry);
 222         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 223
 224         if (err == 0)
 225                 newchannel->state = CHANNEL_OPENED_STATE;
 226
 227         kfree(open_info);
 228         return err;
 229
 230 error1:
 231         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 232         list_del(&open_info->msglistentry);
 233         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 234
 235 error0:
 236         free_pages((unsigned long)out,
 237                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 238         kfree(open_info);
 239         return err;
 240 }
 241 EXPORT_SYMBOL_GPL(vmbus_open);
 242
 243 /*
 244  * create_gpadl_header - Creates a gpadl for the specified buffer
 245  */
 246 static int create_gpadl_header(void *kbuffer, u32 size,
 247                                          struct vmbus_channel_msginfo **msginfo,
 248                                          u32 *messagecount)
 249 {
 250         int i;
 251         int pagecount;
 252         unsigned long long pfn;
 253         struct vmbus_channel_gpadl_header *gpadl_header;
 254         struct vmbus_channel_gpadl_body *gpadl_body;
 255         struct vmbus_channel_msginfo *msgheader;
 256         struct vmbus_channel_msginfo *msgbody = NULL;
 257         u32 msgsize;
 258
 259         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 260
 261         pagecount = size >> PAGE_SHIFT;
 262         pfn = virt_to_phys(kbuffer) >> 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] = pfn+i;
 292                 *msginfo = msgheader;
 293                 *messagecount = 1;
 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                         (*messagecount)++;
 334                         gpadl_body =
 335                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 336
 337                         /*
 338                          * Gpadl is u32 and we are using a pointer which could
 339                          * be 64-bit
 340                          * This is governed by the guest/host protocol and
 341                          * so the hypervisor gurantees that this is ok.
 342                          */
 343                         for (i = 0; i < pfncurr; i++)
 344                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
 345
 346                         /* add to msg header */
 347                         list_add_tail(&msgbody->msglistentry,
 348                                       &msgheader->submsglist);
 349                         pfnsum += pfncurr;
 350                         pfnleft -= pfncurr;
 351                 }
 352         } else {
 353                 /* everything fits in a header */
 354                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 355                           sizeof(struct vmbus_channel_gpadl_header) +
 356                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 357                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 358                 if (msgheader == NULL)
 359                         goto nomem;
 360                 msgheader->msgsize = msgsize;
 361
 362                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 363                         msgheader->msg;
 364                 gpadl_header->rangecount = 1;
 365                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 366                                          pagecount * sizeof(u64);
 367                 gpadl_header->range[0].byte_offset = 0;
 368                 gpadl_header->range[0].byte_count = size;
 369                 for (i = 0; i < pagecount; i++)
 370                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 371
 372                 *msginfo = msgheader;
 373                 *messagecount = 1;
 374         }
 375
 376         return 0;
 377 nomem:
 378         kfree(msgheader);
 379         kfree(msgbody);
 380         return -ENOMEM;
 381 }
 382
 383 /*
 384  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 385  *
 386  * @channel: a channel
 387  * @kbuffer: from kmalloc
 388  * @size: page-size multiple
 389  * @gpadl_handle: some funky thing
 390  */
 391 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 392                                u32 size, u32 *gpadl_handle)
 393 {
 394         struct vmbus_channel_gpadl_header *gpadlmsg;
 395         struct vmbus_channel_gpadl_body *gpadl_body;
 396         struct vmbus_channel_msginfo *msginfo = NULL;
 397         struct vmbus_channel_msginfo *submsginfo;
 398         u32 msgcount;
 399         struct list_head *curr;
 400         u32 next_gpadl_handle;
 401         unsigned long flags;
 402         int ret = 0;
 403         int t;
 404
 405         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
 406         atomic_inc(&vmbus_connection.next_gpadl_handle);
 407
 408         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 409         if (ret)
 410                 return ret;
 411
 412         init_completion(&msginfo->waitevent);
 413
 414         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 415         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 416         gpadlmsg->child_relid = channel->offermsg.child_relid;
 417         gpadlmsg->gpadl = next_gpadl_handle;
 418
 419
 420         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 421         list_add_tail(&msginfo->msglistentry,
 422                       &vmbus_connection.chn_msg_list);
 423
 424         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 425
 426         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 427                                sizeof(*msginfo));
 428         if (ret != 0)
 429                 goto cleanup;
 430
 431         if (msgcount > 1) {
 432                 list_for_each(curr, &msginfo->submsglist) {
 433
 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 -
 444                                                sizeof(*submsginfo));
 445                         if (ret != 0)
 446                                 goto cleanup;
 447
 448                 }
 449         }
 450         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
 451         BUG_ON(t == 0);
 452
 453
 454         /* At this point, we received the gpadl created msg */
 455         *gpadl_handle = gpadlmsg->gpadl;
 456
 457 cleanup:
 458         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 459         list_del(&msginfo->msglistentry);
 460         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 461
 462         kfree(msginfo);
 463         return ret;
 464 }
 465 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 466
 467 /*
 468  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 469  */
 470 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 471 {
 472         struct vmbus_channel_gpadl_teardown *msg;
 473         struct vmbus_channel_msginfo *info;
 474         unsigned long flags;
 475         int ret, t;
 476
 477         info = kmalloc(sizeof(*info) +
 478                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 479         if (!info)
 480                 return -ENOMEM;
 481
 482         init_completion(&info->waitevent);
 483
 484         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 485
 486         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 487         msg->child_relid = channel->offermsg.child_relid;
 488         msg->gpadl = gpadl_handle;
 489
 490         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 491         list_add_tail(&info->msglistentry,
 492                       &vmbus_connection.chn_msg_list);
 493         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 494         ret = vmbus_post_msg(msg,
 495                                sizeof(struct vmbus_channel_gpadl_teardown));
 496
 497         BUG_ON(ret != 0);
 498         t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
 499         BUG_ON(t == 0);
 500
 501         /* Received a torndown response */
 502         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 503         list_del(&info->msglistentry);
 504         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 505
 506         kfree(info);
 507         return ret;
 508 }
 509 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 510
 511 static void vmbus_close_internal(struct vmbus_channel *channel)
 512 {
 513         struct vmbus_channel_close_channel *msg;
 514         int ret;
 515         unsigned long flags;
 516
 517         channel->state = CHANNEL_OPEN_STATE;
 518         channel->sc_creation_callback = NULL;
 519         /* Stop callback and cancel the timer asap */
 520         spin_lock_irqsave(&channel->inbound_lock, flags);
 521         channel->onchannel_callback = NULL;
 522         spin_unlock_irqrestore(&channel->inbound_lock, flags);
 523
 524         /* Send a closing message */
 525
 526         msg = &channel->close_msg.msg;
 527
 528         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 529         msg->child_relid = channel->offermsg.child_relid;
 530
 531         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 532
 533         BUG_ON(ret != 0);
 534         /* Tear down the gpadl for the channel's ring buffer */
 535         if (channel->ringbuffer_gpadlhandle)
 536                 vmbus_teardown_gpadl(channel,
 537                                           channel->ringbuffer_gpadlhandle);
 538
 539         /* Cleanup the ring buffers for this channel */
 540         hv_ringbuffer_cleanup(&channel->outbound);
 541         hv_ringbuffer_cleanup(&channel->inbound);
 542
 543         free_pages((unsigned long)channel->ringbuffer_pages,
 544                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 545
 546
 547 }
 548
 549 /*
 550  * vmbus_close - Close the specified channel
 551  */
 552 void vmbus_close(struct vmbus_channel *channel)
 553 {
 554         struct list_head *cur, *tmp;
 555         struct vmbus_channel *cur_channel;
 556
 557         if (channel->primary_channel != NULL) {
 558                 /*
 559                  * We will only close sub-channels when
 560                  * the primary is closed.
 561                  */
 562                 return;
 563         }
 564         /*
 565          * Close all the sub-channels first and then close the
 566          * primary channel.
 567          */
 568         list_for_each_safe(cur, tmp, &channel->sc_list) {
 569                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 570                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 571                         continue;
 572                 vmbus_close_internal(cur_channel);
 573         }
 574         /*
 575          * Now close the primary.
 576          */
 577         vmbus_close_internal(channel);
 578 }
 579 EXPORT_SYMBOL_GPL(vmbus_close);
 580
 581 /**
 582  * vmbus_sendpacket() - Send the specified buffer on the given channel
 583  * @channel: Pointer to vmbus_channel structure.
 584  * @buffer: Pointer to the buffer you want to receive the data into.
 585  * @bufferlen: Maximum size of what the the buffer will hold
 586  * @requestid: Identifier of the request
 587  * @type: Type of packet that is being send e.g. negotiate, time
 588  * packet etc.
 589  *
 590  * Sends data in @buffer directly to hyper-v via the vmbus
 591  * This will send the data unparsed to hyper-v.
 592  *
 593  * Mainly used by Hyper-V drivers.
 594  */
 595 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
 596                            u32 bufferlen, u64 requestid,
 597                            enum vmbus_packet_type type, u32 flags)
 598 {
 599         struct vmpacket_descriptor desc;
 600         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 601         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 602         struct scatterlist bufferlist[3];
 603         u64 aligned_data = 0;
 604         int ret;
 605         bool signal = false;
 606
 607
 608         /* Setup the descriptor */
 609         desc.type = type; /* VmbusPacketTypeDataInBand; */
 610         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 611         /* in 8-bytes granularity */
 612         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 613         desc.len8 = (u16)(packetlen_aligned >> 3);
 614         desc.trans_id = requestid;
 615
 616         sg_init_table(bufferlist, 3);
 617         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
 618         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 619         sg_set_buf(&bufferlist[2], &aligned_data,
 620                    packetlen_aligned - packetlen);
 621
 622         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 623
 624         if (ret == 0 && signal)
 625                 vmbus_setevent(channel);
 626
 627         return ret;
 628 }
 629 EXPORT_SYMBOL(vmbus_sendpacket);
 630
 631 /*
 632  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 633  * packets using a GPADL Direct packet type.
 634  */
 635 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 636                                      struct hv_page_buffer pagebuffers[],
 637                                      u32 pagecount, void *buffer, u32 bufferlen,
 638                                      u64 requestid)
 639 {
 640         int ret;
 641         int i;
 642         struct vmbus_channel_packet_page_buffer desc;
 643         u32 descsize;
 644         u32 packetlen;
 645         u32 packetlen_aligned;
 646         struct scatterlist bufferlist[3];
 647         u64 aligned_data = 0;
 648         bool signal = false;
 649
 650         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 651                 return -EINVAL;
 652
 653
 654         /*
 655          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 656          * largest size we support
 657          */
 658         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 659                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 660                           sizeof(struct hv_page_buffer));
 661         packetlen = descsize + bufferlen;
 662         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 663
 664         /* Setup the descriptor */
 665         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 666         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 667         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 668         desc.length8 = (u16)(packetlen_aligned >> 3);
 669         desc.transactionid = requestid;
 670         desc.rangecount = pagecount;
 671
 672         for (i = 0; i < pagecount; i++) {
 673                 desc.range[i].len = pagebuffers[i].len;
 674                 desc.range[i].offset = pagebuffers[i].offset;
 675                 desc.range[i].pfn        = pagebuffers[i].pfn;
 676         }
 677
 678         sg_init_table(bufferlist, 3);
 679         sg_set_buf(&bufferlist[0], &desc, descsize);
 680         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 681         sg_set_buf(&bufferlist[2], &aligned_data,
 682                 packetlen_aligned - packetlen);
 683
 684         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 685
 686         if (ret == 0 && signal)
 687                 vmbus_setevent(channel);
 688
 689         return ret;
 690 }
 691 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 692
 693 /*
 694  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 695  * using a GPADL Direct packet type.
 696  */
 697 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 698                                 struct hv_multipage_buffer *multi_pagebuffer,
 699                                 void *buffer, u32 bufferlen, u64 requestid)
 700 {
 701         int ret;
 702         struct vmbus_channel_packet_multipage_buffer desc;
 703         u32 descsize;
 704         u32 packetlen;
 705         u32 packetlen_aligned;
 706         struct scatterlist bufferlist[3];
 707         u64 aligned_data = 0;
 708         bool signal = false;
 709         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 710                                          multi_pagebuffer->len);
 711
 712
 713         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
 714                 return -EINVAL;
 715
 716         /*
 717          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 718          * the largest size we support
 719          */
 720         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 721                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 722                           sizeof(u64));
 723         packetlen = descsize + bufferlen;
 724         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 725
 726
 727         /* Setup the descriptor */
 728         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 729         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 730         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 731         desc.length8 = (u16)(packetlen_aligned >> 3);
 732         desc.transactionid = requestid;
 733         desc.rangecount = 1;
 734
 735         desc.range.len = multi_pagebuffer->len;
 736         desc.range.offset = multi_pagebuffer->offset;
 737
 738         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 739                pfncount * sizeof(u64));
 740
 741         sg_init_table(bufferlist, 3);
 742         sg_set_buf(&bufferlist[0], &desc, descsize);
 743         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 744         sg_set_buf(&bufferlist[2], &aligned_data,
 745                 packetlen_aligned - packetlen);
 746
 747         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 748
 749         if (ret == 0 && signal)
 750                 vmbus_setevent(channel);
 751
 752         return ret;
 753 }
 754 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 755
 756 /**
 757  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 758  * @channel: Pointer to vmbus_channel structure.
 759  * @buffer: Pointer to the buffer you want to receive the data into.
 760  * @bufferlen: Maximum size of what the the buffer will hold
 761  * @buffer_actual_len: The actual size of the data after it was received
 762  * @requestid: Identifier of the request
 763  *
 764  * Receives directly from the hyper-v vmbus and puts the data it received
 765  * into Buffer. This will receive the data unparsed from hyper-v.
 766  *
 767  * Mainly used by Hyper-V drivers.
 768  */
 769 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 770                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 771 {
 772         struct vmpacket_descriptor desc;
 773         u32 packetlen;
 774         u32 userlen;
 775         int ret;
 776         bool signal = false;
 777
 778         *buffer_actual_len = 0;
 779         *requestid = 0;
 780
 781
 782         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 783                              sizeof(struct vmpacket_descriptor));
 784         if (ret != 0)
 785                 return 0;
 786
 787         packetlen = desc.len8 << 3;
 788         userlen = packetlen - (desc.offset8 << 3);
 789
 790         *buffer_actual_len = userlen;
 791
 792         if (userlen > bufferlen) {
 793
 794                 pr_err("Buffer too small - got %d needs %d\n",
 795                            bufferlen, userlen);
 796                 return -ETOOSMALL;
 797         }
 798
 799         *requestid = desc.trans_id;
 800
 801         /* Copy over the packet to the user buffer */
 802         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 803                              (desc.offset8 << 3), &signal);
 804
 805         if (signal)
 806                 vmbus_setevent(channel);
 807
 808         return 0;
 809 }
 810 EXPORT_SYMBOL(vmbus_recvpacket);
 811
 812 /*
 813  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 814  */
 815 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 816                               u32 bufferlen, u32 *buffer_actual_len,
 817                               u64 *requestid)
 818 {
 819         struct vmpacket_descriptor desc;
 820         u32 packetlen;
 821         int ret;
 822         bool signal = false;
 823
 824         *buffer_actual_len = 0;
 825         *requestid = 0;
 826
 827
 828         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 829                              sizeof(struct vmpacket_descriptor));
 830         if (ret != 0)
 831                 return 0;
 832
 833
 834         packetlen = desc.len8 << 3;
 835
 836         *buffer_actual_len = packetlen;
 837
 838         if (packetlen > bufferlen) {
 839                 pr_err("Buffer too small - needed %d bytes but "
 840                         "got space for only %d bytes\n",
 841                         packetlen, bufferlen);
 842                 return -ENOBUFS;
 843         }
 844
 845         *requestid = desc.trans_id;
 846
 847         /* Copy over the entire packet to the user buffer */
 848         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 849                                  &signal);
 850
 851         if (signal)
 852                 vmbus_setevent(channel);
 853
 854         return 0;
 855 }
 856 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);