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         monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
  73
  74         debuginfo->servermonitor_pending =
  75                         monitorpage->trigger_group[monitor_group].pending;
  76         debuginfo->servermonitor_latency =
  77                         monitorpage->latency[monitor_group][monitor_offset];
  78         debuginfo->servermonitor_connectionid =
  79                         monitorpage->parameter[monitor_group]
  80                                         [monitor_offset].connectionid.u.id;
  81
  82         monitorpage++;
  83
  84         debuginfo->clientmonitor_pending =
  85                         monitorpage->trigger_group[monitor_group].pending;
  86         debuginfo->clientmonitor_latency =
  87                         monitorpage->latency[monitor_group][monitor_offset];
  88         debuginfo->clientmonitor_connectionid =
  89                         monitorpage->parameter[monitor_group]
  90                                         [monitor_offset].connectionid.u.id;
  91
  92         hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
  93         hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
  94 }
  95
  96 /*
  97  * vmbus_open - Open the specified channel.
  98  */
  99 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 100                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
 101                      void (*onchannelcallback)(void *context), void *context)
 102 {
 103         struct vmbus_channel_open_channel *open_msg;
 104         struct vmbus_channel_msginfo *open_info = NULL;
 105         void *in, *out;
 106         unsigned long flags;
 107         int ret, t, err = 0;
 108
 109         spin_lock_irqsave(&newchannel->sc_lock, flags);
 110         if (newchannel->state == CHANNEL_OPEN_STATE) {
 111                 newchannel->state = CHANNEL_OPENING_STATE;
 112         } else {
 113                 spin_unlock_irqrestore(&newchannel->sc_lock, flags);
 114                 return -EINVAL;
 115         }
 116         spin_unlock_irqrestore(&newchannel->sc_lock, flags);
 117
 118         newchannel->onchannel_callback = onchannelcallback;
 119         newchannel->channel_callback_context = context;
 120
 121         /* Allocate the ring buffer */
 122         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 123                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 124
 125         if (!out)
 126                 return -ENOMEM;
 127
 128
 129         in = (void *)((unsigned long)out + send_ringbuffer_size);
 130
 131         newchannel->ringbuffer_pages = out;
 132         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 133                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 134
 135         ret = hv_ringbuffer_init(
 136                 &newchannel->outbound, out, send_ringbuffer_size);
 137
 138         if (ret != 0) {
 139                 err = ret;
 140                 goto error0;
 141         }
 142
 143         ret = hv_ringbuffer_init(
 144                 &newchannel->inbound, in, recv_ringbuffer_size);
 145         if (ret != 0) {
 146                 err = ret;
 147                 goto error0;
 148         }
 149
 150
 151         /* Establish the gpadl for the ring buffer */
 152         newchannel->ringbuffer_gpadlhandle = 0;
 153
 154         ret = vmbus_establish_gpadl(newchannel,
 155                                          newchannel->outbound.ring_buffer,
 156                                          send_ringbuffer_size +
 157                                          recv_ringbuffer_size,
 158                                          &newchannel->ringbuffer_gpadlhandle);
 159
 160         if (ret != 0) {
 161                 err = ret;
 162                 goto error0;
 163         }
 164
 165         /* Create and init the channel open message */
 166         open_info = kmalloc(sizeof(*open_info) +
 167                            sizeof(struct vmbus_channel_open_channel),
 168                            GFP_KERNEL);
 169         if (!open_info) {
 170                 err = -ENOMEM;
 171                 goto error0;
 172         }
 173
 174         init_completion(&open_info->waitevent);
 175
 176         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 177         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 178         open_msg->openid = newchannel->offermsg.child_relid;
 179         open_msg->child_relid = newchannel->offermsg.child_relid;
 180         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 181         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 182                                                   PAGE_SHIFT;
 183         open_msg->target_vp = newchannel->target_vp;
 184
 185         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 186                 err = -EINVAL;
 187                 goto error0;
 188         }
 189
 190         if (userdatalen)
 191                 memcpy(open_msg->userdata, userdata, userdatalen);
 192
 193         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 194         list_add_tail(&open_info->msglistentry,
 195                       &vmbus_connection.chn_msg_list);
 196         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 197
 198         ret = vmbus_post_msg(open_msg,
 199                                sizeof(struct vmbus_channel_open_channel));
 200
 201         if (ret != 0)
 202                 goto error1;
 203
 204         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 205         if (t == 0) {
 206                 err = -ETIMEDOUT;
 207                 goto error1;
 208         }
 209
 210
 211         if (open_info->response.open_result.status)
 212                 err = open_info->response.open_result.status;
 213
 214         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 215         list_del(&open_info->msglistentry);
 216         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 217
 218         if (err == 0)
 219                 newchannel->state = CHANNEL_OPENED_STATE;
 220
 221         kfree(open_info);
 222         return err;
 223
 224 error1:
 225         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 226         list_del(&open_info->msglistentry);
 227         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 228
 229 error0:
 230         free_pages((unsigned long)out,
 231                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 232         kfree(open_info);
 233         return err;
 234 }
 235 EXPORT_SYMBOL_GPL(vmbus_open);
 236
 237 /*
 238  * create_gpadl_header - Creates a gpadl for the specified buffer
 239  */
 240 static int create_gpadl_header(void *kbuffer, u32 size,
 241                                          struct vmbus_channel_msginfo **msginfo,
 242                                          u32 *messagecount)
 243 {
 244         int i;
 245         int pagecount;
 246         unsigned long long pfn;
 247         struct vmbus_channel_gpadl_header *gpadl_header;
 248         struct vmbus_channel_gpadl_body *gpadl_body;
 249         struct vmbus_channel_msginfo *msgheader;
 250         struct vmbus_channel_msginfo *msgbody = NULL;
 251         u32 msgsize;
 252
 253         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 254
 255         pagecount = size >> PAGE_SHIFT;
 256         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
 257
 258         /* do we need a gpadl body msg */
 259         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 260                   sizeof(struct vmbus_channel_gpadl_header) -
 261                   sizeof(struct gpa_range);
 262         pfncount = pfnsize / sizeof(u64);
 263
 264         if (pagecount > pfncount) {
 265                 /* we need a gpadl body */
 266                 /* fill in the header */
 267                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 268                           sizeof(struct vmbus_channel_gpadl_header) +
 269                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 270                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 271                 if (!msgheader)
 272                         goto nomem;
 273
 274                 INIT_LIST_HEAD(&msgheader->submsglist);
 275                 msgheader->msgsize = msgsize;
 276
 277                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 278                         msgheader->msg;
 279                 gpadl_header->rangecount = 1;
 280                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 281                                          pagecount * sizeof(u64);
 282                 gpadl_header->range[0].byte_offset = 0;
 283                 gpadl_header->range[0].byte_count = size;
 284                 for (i = 0; i < pfncount; i++)
 285                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 286                 *msginfo = msgheader;
 287                 *messagecount = 1;
 288
 289                 pfnsum = pfncount;
 290                 pfnleft = pagecount - pfncount;
 291
 292                 /* how many pfns can we fit */
 293                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 294                           sizeof(struct vmbus_channel_gpadl_body);
 295                 pfncount = pfnsize / sizeof(u64);
 296
 297                 /* fill in the body */
 298                 while (pfnleft) {
 299                         if (pfnleft > pfncount)
 300                                 pfncurr = pfncount;
 301                         else
 302                                 pfncurr = pfnleft;
 303
 304                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 305                                   sizeof(struct vmbus_channel_gpadl_body) +
 306                                   pfncurr * sizeof(u64);
 307                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 308
 309                         if (!msgbody) {
 310                                 struct vmbus_channel_msginfo *pos = NULL;
 311                                 struct vmbus_channel_msginfo *tmp = NULL;
 312                                 /*
 313                                  * Free up all the allocated messages.
 314                                  */
 315                                 list_for_each_entry_safe(pos, tmp,
 316                                         &msgheader->submsglist,
 317                                         msglistentry) {
 318
 319                                         list_del(&pos->msglistentry);
 320                                         kfree(pos);
 321                                 }
 322
 323                                 goto nomem;
 324                         }
 325
 326                         msgbody->msgsize = msgsize;
 327                         (*messagecount)++;
 328                         gpadl_body =
 329                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 330
 331                         /*
 332                          * Gpadl is u32 and we are using a pointer which could
 333                          * be 64-bit
 334                          * This is governed by the guest/host protocol and
 335                          * so the hypervisor gurantees that this is ok.
 336                          */
 337                         for (i = 0; i < pfncurr; i++)
 338                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
 339
 340                         /* add to msg header */
 341                         list_add_tail(&msgbody->msglistentry,
 342                                       &msgheader->submsglist);
 343                         pfnsum += pfncurr;
 344                         pfnleft -= pfncurr;
 345                 }
 346         } else {
 347                 /* everything fits in a header */
 348                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 349                           sizeof(struct vmbus_channel_gpadl_header) +
 350                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 351                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 352                 if (msgheader == NULL)
 353                         goto nomem;
 354                 msgheader->msgsize = msgsize;
 355
 356                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 357                         msgheader->msg;
 358                 gpadl_header->rangecount = 1;
 359                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 360                                          pagecount * sizeof(u64);
 361                 gpadl_header->range[0].byte_offset = 0;
 362                 gpadl_header->range[0].byte_count = size;
 363                 for (i = 0; i < pagecount; i++)
 364                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 365
 366                 *msginfo = msgheader;
 367                 *messagecount = 1;
 368         }
 369
 370         return 0;
 371 nomem:
 372         kfree(msgheader);
 373         kfree(msgbody);
 374         return -ENOMEM;
 375 }
 376
 377 /*
 378  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 379  *
 380  * @channel: a channel
 381  * @kbuffer: from kmalloc
 382  * @size: page-size multiple
 383  * @gpadl_handle: some funky thing
 384  */
 385 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 386                                u32 size, u32 *gpadl_handle)
 387 {
 388         struct vmbus_channel_gpadl_header *gpadlmsg;
 389         struct vmbus_channel_gpadl_body *gpadl_body;
 390         struct vmbus_channel_msginfo *msginfo = NULL;
 391         struct vmbus_channel_msginfo *submsginfo;
 392         u32 msgcount;
 393         struct list_head *curr;
 394         u32 next_gpadl_handle;
 395         unsigned long flags;
 396         int ret = 0;
 397         int t;
 398
 399         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
 400         atomic_inc(&vmbus_connection.next_gpadl_handle);
 401
 402         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 403         if (ret)
 404                 return ret;
 405
 406         init_completion(&msginfo->waitevent);
 407
 408         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 409         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 410         gpadlmsg->child_relid = channel->offermsg.child_relid;
 411         gpadlmsg->gpadl = next_gpadl_handle;
 412
 413
 414         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 415         list_add_tail(&msginfo->msglistentry,
 416                       &vmbus_connection.chn_msg_list);
 417
 418         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 419
 420         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 421                                sizeof(*msginfo));
 422         if (ret != 0)
 423                 goto cleanup;
 424
 425         if (msgcount > 1) {
 426                 list_for_each(curr, &msginfo->submsglist) {
 427
 428                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 429                         gpadl_body =
 430                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 431
 432                         gpadl_body->header.msgtype =
 433                                 CHANNELMSG_GPADL_BODY;
 434                         gpadl_body->gpadl = next_gpadl_handle;
 435
 436                         ret = vmbus_post_msg(gpadl_body,
 437                                                submsginfo->msgsize -
 438                                                sizeof(*submsginfo));
 439                         if (ret != 0)
 440                                 goto cleanup;
 441
 442                 }
 443         }
 444         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
 445         BUG_ON(t == 0);
 446
 447
 448         /* At this point, we received the gpadl created msg */
 449         *gpadl_handle = gpadlmsg->gpadl;
 450
 451 cleanup:
 452         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 453         list_del(&msginfo->msglistentry);
 454         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 455
 456         kfree(msginfo);
 457         return ret;
 458 }
 459 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 460
 461 /*
 462  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 463  */
 464 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 465 {
 466         struct vmbus_channel_gpadl_teardown *msg;
 467         struct vmbus_channel_msginfo *info;
 468         unsigned long flags;
 469         int ret, t;
 470
 471         info = kmalloc(sizeof(*info) +
 472                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 473         if (!info)
 474                 return -ENOMEM;
 475
 476         init_completion(&info->waitevent);
 477
 478         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 479
 480         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 481         msg->child_relid = channel->offermsg.child_relid;
 482         msg->gpadl = gpadl_handle;
 483
 484         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 485         list_add_tail(&info->msglistentry,
 486                       &vmbus_connection.chn_msg_list);
 487         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 488         ret = vmbus_post_msg(msg,
 489                                sizeof(struct vmbus_channel_gpadl_teardown));
 490
 491         BUG_ON(ret != 0);
 492         t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
 493         BUG_ON(t == 0);
 494
 495         /* Received a torndown response */
 496         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 497         list_del(&info->msglistentry);
 498         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 499
 500         kfree(info);
 501         return ret;
 502 }
 503 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 504
 505 static void vmbus_close_internal(struct vmbus_channel *channel)
 506 {
 507         struct vmbus_channel_close_channel *msg;
 508         int ret;
 509         unsigned long flags;
 510
 511         channel->state = CHANNEL_OPEN_STATE;
 512         channel->sc_creation_callback = NULL;
 513         /* Stop callback and cancel the timer asap */
 514         spin_lock_irqsave(&channel->inbound_lock, flags);
 515         channel->onchannel_callback = NULL;
 516         spin_unlock_irqrestore(&channel->inbound_lock, flags);
 517
 518         /* Send a closing message */
 519
 520         msg = &channel->close_msg.msg;
 521
 522         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 523         msg->child_relid = channel->offermsg.child_relid;
 524
 525         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 526
 527         BUG_ON(ret != 0);
 528         /* Tear down the gpadl for the channel's ring buffer */
 529         if (channel->ringbuffer_gpadlhandle)
 530                 vmbus_teardown_gpadl(channel,
 531                                           channel->ringbuffer_gpadlhandle);
 532
 533         /* Cleanup the ring buffers for this channel */
 534         hv_ringbuffer_cleanup(&channel->outbound);
 535         hv_ringbuffer_cleanup(&channel->inbound);
 536
 537         free_pages((unsigned long)channel->ringbuffer_pages,
 538                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 539
 540
 541 }
 542
 543 /*
 544  * vmbus_close - Close the specified channel
 545  */
 546 void vmbus_close(struct vmbus_channel *channel)
 547 {
 548         struct list_head *cur, *tmp;
 549         struct vmbus_channel *cur_channel;
 550
 551         if (channel->primary_channel != NULL) {
 552                 /*
 553                  * We will only close sub-channels when
 554                  * the primary is closed.
 555                  */
 556                 return;
 557         }
 558         /*
 559          * Close all the sub-channels first and then close the
 560          * primary channel.
 561          */
 562         list_for_each_safe(cur, tmp, &channel->sc_list) {
 563                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 564                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 565                         continue;
 566                 vmbus_close_internal(cur_channel);
 567         }
 568         /*
 569          * Now close the primary.
 570          */
 571         vmbus_close_internal(channel);
 572 }
 573 EXPORT_SYMBOL_GPL(vmbus_close);
 574
 575 /**
 576  * vmbus_sendpacket() - Send the specified buffer on the given channel
 577  * @channel: Pointer to vmbus_channel structure.
 578  * @buffer: Pointer to the buffer you want to receive the data into.
 579  * @bufferlen: Maximum size of what the the buffer will hold
 580  * @requestid: Identifier of the request
 581  * @type: Type of packet that is being send e.g. negotiate, time
 582  * packet etc.
 583  *
 584  * Sends data in @buffer directly to hyper-v via the vmbus
 585  * This will send the data unparsed to hyper-v.
 586  *
 587  * Mainly used by Hyper-V drivers.
 588  */
 589 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
 590                            u32 bufferlen, u64 requestid,
 591                            enum vmbus_packet_type type, u32 flags)
 592 {
 593         struct vmpacket_descriptor desc;
 594         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 595         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 596         struct scatterlist bufferlist[3];
 597         u64 aligned_data = 0;
 598         int ret;
 599         bool signal = false;
 600
 601
 602         /* Setup the descriptor */
 603         desc.type = type; /* VmbusPacketTypeDataInBand; */
 604         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 605         /* in 8-bytes granularity */
 606         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 607         desc.len8 = (u16)(packetlen_aligned >> 3);
 608         desc.trans_id = requestid;
 609
 610         sg_init_table(bufferlist, 3);
 611         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
 612         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 613         sg_set_buf(&bufferlist[2], &aligned_data,
 614                    packetlen_aligned - packetlen);
 615
 616         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 617
 618         if (ret == 0 && signal)
 619                 vmbus_setevent(channel);
 620
 621         return ret;
 622 }
 623 EXPORT_SYMBOL(vmbus_sendpacket);
 624
 625 /*
 626  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 627  * packets using a GPADL Direct packet type.
 628  */
 629 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 630                                      struct hv_page_buffer pagebuffers[],
 631                                      u32 pagecount, void *buffer, u32 bufferlen,
 632                                      u64 requestid)
 633 {
 634         int ret;
 635         int i;
 636         struct vmbus_channel_packet_page_buffer desc;
 637         u32 descsize;
 638         u32 packetlen;
 639         u32 packetlen_aligned;
 640         struct scatterlist bufferlist[3];
 641         u64 aligned_data = 0;
 642         bool signal = false;
 643
 644         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 645                 return -EINVAL;
 646
 647
 648         /*
 649          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 650          * largest size we support
 651          */
 652         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 653                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 654                           sizeof(struct hv_page_buffer));
 655         packetlen = descsize + bufferlen;
 656         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 657
 658         /* Setup the descriptor */
 659         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 660         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 661         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 662         desc.length8 = (u16)(packetlen_aligned >> 3);
 663         desc.transactionid = requestid;
 664         desc.rangecount = pagecount;
 665
 666         for (i = 0; i < pagecount; i++) {
 667                 desc.range[i].len = pagebuffers[i].len;
 668                 desc.range[i].offset = pagebuffers[i].offset;
 669                 desc.range[i].pfn        = pagebuffers[i].pfn;
 670         }
 671
 672         sg_init_table(bufferlist, 3);
 673         sg_set_buf(&bufferlist[0], &desc, descsize);
 674         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 675         sg_set_buf(&bufferlist[2], &aligned_data,
 676                 packetlen_aligned - packetlen);
 677
 678         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 679
 680         if (ret == 0 && signal)
 681                 vmbus_setevent(channel);
 682
 683         return ret;
 684 }
 685 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 686
 687 /*
 688  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 689  * using a GPADL Direct packet type.
 690  */
 691 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 692                                 struct hv_multipage_buffer *multi_pagebuffer,
 693                                 void *buffer, u32 bufferlen, u64 requestid)
 694 {
 695         int ret;
 696         struct vmbus_channel_packet_multipage_buffer desc;
 697         u32 descsize;
 698         u32 packetlen;
 699         u32 packetlen_aligned;
 700         struct scatterlist bufferlist[3];
 701         u64 aligned_data = 0;
 702         bool signal = false;
 703         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 704                                          multi_pagebuffer->len);
 705
 706
 707         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
 708                 return -EINVAL;
 709
 710         /*
 711          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 712          * the largest size we support
 713          */
 714         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 715                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 716                           sizeof(u64));
 717         packetlen = descsize + bufferlen;
 718         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 719
 720
 721         /* Setup the descriptor */
 722         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 723         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 724         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 725         desc.length8 = (u16)(packetlen_aligned >> 3);
 726         desc.transactionid = requestid;
 727         desc.rangecount = 1;
 728
 729         desc.range.len = multi_pagebuffer->len;
 730         desc.range.offset = multi_pagebuffer->offset;
 731
 732         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 733                pfncount * sizeof(u64));
 734
 735         sg_init_table(bufferlist, 3);
 736         sg_set_buf(&bufferlist[0], &desc, descsize);
 737         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 738         sg_set_buf(&bufferlist[2], &aligned_data,
 739                 packetlen_aligned - packetlen);
 740
 741         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 742
 743         if (ret == 0 && signal)
 744                 vmbus_setevent(channel);
 745
 746         return ret;
 747 }
 748 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 749
 750 /**
 751  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 752  * @channel: Pointer to vmbus_channel structure.
 753  * @buffer: Pointer to the buffer you want to receive the data into.
 754  * @bufferlen: Maximum size of what the the buffer will hold
 755  * @buffer_actual_len: The actual size of the data after it was received
 756  * @requestid: Identifier of the request
 757  *
 758  * Receives directly from the hyper-v vmbus and puts the data it received
 759  * into Buffer. This will receive the data unparsed from hyper-v.
 760  *
 761  * Mainly used by Hyper-V drivers.
 762  */
 763 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 764                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 765 {
 766         struct vmpacket_descriptor desc;
 767         u32 packetlen;
 768         u32 userlen;
 769         int ret;
 770         bool signal = false;
 771
 772         *buffer_actual_len = 0;
 773         *requestid = 0;
 774
 775
 776         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 777                              sizeof(struct vmpacket_descriptor));
 778         if (ret != 0)
 779                 return 0;
 780
 781         packetlen = desc.len8 << 3;
 782         userlen = packetlen - (desc.offset8 << 3);
 783
 784         *buffer_actual_len = userlen;
 785
 786         if (userlen > bufferlen) {
 787
 788                 pr_err("Buffer too small - got %d needs %d\n",
 789                            bufferlen, userlen);
 790                 return -ETOOSMALL;
 791         }
 792
 793         *requestid = desc.trans_id;
 794
 795         /* Copy over the packet to the user buffer */
 796         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 797                              (desc.offset8 << 3), &signal);
 798
 799         if (signal)
 800                 vmbus_setevent(channel);
 801
 802         return 0;
 803 }
 804 EXPORT_SYMBOL(vmbus_recvpacket);
 805
 806 /*
 807  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 808  */
 809 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 810                               u32 bufferlen, u32 *buffer_actual_len,
 811                               u64 *requestid)
 812 {
 813         struct vmpacket_descriptor desc;
 814         u32 packetlen;
 815         int ret;
 816         bool signal = false;
 817
 818         *buffer_actual_len = 0;
 819         *requestid = 0;
 820
 821
 822         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 823                              sizeof(struct vmpacket_descriptor));
 824         if (ret != 0)
 825                 return 0;
 826
 827
 828         packetlen = desc.len8 << 3;
 829
 830         *buffer_actual_len = packetlen;
 831
 832         if (packetlen > bufferlen) {
 833                 pr_err("Buffer too small - needed %d bytes but "
 834                         "got space for only %d bytes\n",
 835                         packetlen, bufferlen);
 836                 return -ENOBUFS;
 837         }
 838
 839         *requestid = desc.trans_id;
 840
 841         /* Copy over the entire packet to the user buffer */
 842         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 843                                  &signal);
 844
 845         if (signal)
 846                 vmbus_setevent(channel);
 847
 848         return 0;
 849 }
 850 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);