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         debuginfo->relid = channel->offermsg.child_relid;
  73         debuginfo->state = channel->state;
  74         memcpy(&debuginfo->interfacetype,
  75                &channel->offermsg.offer.if_type, sizeof(uuid_le));
  76         memcpy(&debuginfo->interface_instance,
  77                &channel->offermsg.offer.if_instance,
  78                sizeof(uuid_le));
  79
  80         monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
  81
  82         debuginfo->monitorid = channel->offermsg.monitorid;
  83
  84         debuginfo->servermonitor_pending =
  85                         monitorpage->trigger_group[monitor_group].pending;
  86         debuginfo->servermonitor_latency =
  87                         monitorpage->latency[monitor_group][monitor_offset];
  88         debuginfo->servermonitor_connectionid =
  89                         monitorpage->parameter[monitor_group]
  90                                         [monitor_offset].connectionid.u.id;
  91
  92         monitorpage++;
  93
  94         debuginfo->clientmonitor_pending =
  95                         monitorpage->trigger_group[monitor_group].pending;
  96         debuginfo->clientmonitor_latency =
  97                         monitorpage->latency[monitor_group][monitor_offset];
  98         debuginfo->clientmonitor_connectionid =
  99                         monitorpage->parameter[monitor_group]
 100                                         [monitor_offset].connectionid.u.id;
 101
 102         hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
 103         hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
 104 }
 105
 106 /*
 107  * vmbus_open - Open the specified channel.
 108  */
 109 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 110                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
 111                      void (*onchannelcallback)(void *context), void *context)
 112 {
 113         struct vmbus_channel_open_channel *open_msg;
 114         struct vmbus_channel_msginfo *open_info = NULL;
 115         void *in, *out;
 116         unsigned long flags;
 117         int ret, t, err = 0;
 118
 119         spin_lock_irqsave(&newchannel->sc_lock, flags);
 120         if (newchannel->state == CHANNEL_OPEN_STATE) {
 121                 newchannel->state = CHANNEL_OPENING_STATE;
 122         } else {
 123                 spin_unlock_irqrestore(&newchannel->sc_lock, flags);
 124                 return -EINVAL;
 125         }
 126         spin_unlock_irqrestore(&newchannel->sc_lock, flags);
 127
 128         newchannel->onchannel_callback = onchannelcallback;
 129         newchannel->channel_callback_context = context;
 130
 131         /* Allocate the ring buffer */
 132         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 133                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 134
 135         if (!out)
 136                 return -ENOMEM;
 137
 138
 139         in = (void *)((unsigned long)out + send_ringbuffer_size);
 140
 141         newchannel->ringbuffer_pages = out;
 142         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 143                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 144
 145         ret = hv_ringbuffer_init(
 146                 &newchannel->outbound, out, send_ringbuffer_size);
 147
 148         if (ret != 0) {
 149                 err = ret;
 150                 goto error0;
 151         }
 152
 153         ret = hv_ringbuffer_init(
 154                 &newchannel->inbound, in, recv_ringbuffer_size);
 155         if (ret != 0) {
 156                 err = ret;
 157                 goto error0;
 158         }
 159
 160
 161         /* Establish the gpadl for the ring buffer */
 162         newchannel->ringbuffer_gpadlhandle = 0;
 163
 164         ret = vmbus_establish_gpadl(newchannel,
 165                                          newchannel->outbound.ring_buffer,
 166                                          send_ringbuffer_size +
 167                                          recv_ringbuffer_size,
 168                                          &newchannel->ringbuffer_gpadlhandle);
 169
 170         if (ret != 0) {
 171                 err = ret;
 172                 goto error0;
 173         }
 174
 175         /* Create and init the channel open message */
 176         open_info = kmalloc(sizeof(*open_info) +
 177                            sizeof(struct vmbus_channel_open_channel),
 178                            GFP_KERNEL);
 179         if (!open_info) {
 180                 err = -ENOMEM;
 181                 goto error_gpadl;
 182         }
 183
 184         init_completion(&open_info->waitevent);
 185
 186         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 187         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 188         open_msg->openid = newchannel->offermsg.child_relid;
 189         open_msg->child_relid = newchannel->offermsg.child_relid;
 190         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 191         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 192                                                   PAGE_SHIFT;
 193         open_msg->target_vp = newchannel->target_vp;
 194
 195         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 196                 err = -EINVAL;
 197                 goto error_gpadl;
 198         }
 199
 200         if (userdatalen)
 201                 memcpy(open_msg->userdata, userdata, userdatalen);
 202
 203         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 204         list_add_tail(&open_info->msglistentry,
 205                       &vmbus_connection.chn_msg_list);
 206         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 207
 208         ret = vmbus_post_msg(open_msg,
 209                                sizeof(struct vmbus_channel_open_channel));
 210
 211         if (ret != 0) {
 212                 err = ret;
 213                 goto error1;
 214         }
 215
 216         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 217         if (t == 0) {
 218                 err = -ETIMEDOUT;
 219                 goto error1;
 220         }
 221
 222
 223         if (open_info->response.open_result.status)
 224                 err = open_info->response.open_result.status;
 225
 226         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 227         list_del(&open_info->msglistentry);
 228         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 229
 230         if (err == 0)
 231                 newchannel->state = CHANNEL_OPENED_STATE;
 232
 233         kfree(open_info);
 234         return err;
 235
 236 error1:
 237         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 238         list_del(&open_info->msglistentry);
 239         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 240
 241 error_gpadl:
 242         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 243
 244 error0:
 245         free_pages((unsigned long)out,
 246                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 247         kfree(open_info);
 248         return err;
 249 }
 250 EXPORT_SYMBOL_GPL(vmbus_open);
 251
 252 /*
 253  * create_gpadl_header - Creates a gpadl for the specified buffer
 254  */
 255 static int create_gpadl_header(void *kbuffer, u32 size,
 256                                          struct vmbus_channel_msginfo **msginfo,
 257                                          u32 *messagecount)
 258 {
 259         int i;
 260         int pagecount;
 261         unsigned long long pfn;
 262         struct vmbus_channel_gpadl_header *gpadl_header;
 263         struct vmbus_channel_gpadl_body *gpadl_body;
 264         struct vmbus_channel_msginfo *msgheader;
 265         struct vmbus_channel_msginfo *msgbody = NULL;
 266         u32 msgsize;
 267
 268         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 269
 270         pagecount = size >> PAGE_SHIFT;
 271         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
 272
 273         /* do we need a gpadl body msg */
 274         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 275                   sizeof(struct vmbus_channel_gpadl_header) -
 276                   sizeof(struct gpa_range);
 277         pfncount = pfnsize / sizeof(u64);
 278
 279         if (pagecount > pfncount) {
 280                 /* we need a gpadl body */
 281                 /* fill in the header */
 282                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 283                           sizeof(struct vmbus_channel_gpadl_header) +
 284                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 285                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 286                 if (!msgheader)
 287                         goto nomem;
 288
 289                 INIT_LIST_HEAD(&msgheader->submsglist);
 290                 msgheader->msgsize = msgsize;
 291
 292                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 293                         msgheader->msg;
 294                 gpadl_header->rangecount = 1;
 295                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 296                                          pagecount * sizeof(u64);
 297                 gpadl_header->range[0].byte_offset = 0;
 298                 gpadl_header->range[0].byte_count = size;
 299                 for (i = 0; i < pfncount; i++)
 300                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 301                 *msginfo = msgheader;
 302                 *messagecount = 1;
 303
 304                 pfnsum = pfncount;
 305                 pfnleft = pagecount - pfncount;
 306
 307                 /* how many pfns can we fit */
 308                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 309                           sizeof(struct vmbus_channel_gpadl_body);
 310                 pfncount = pfnsize / sizeof(u64);
 311
 312                 /* fill in the body */
 313                 while (pfnleft) {
 314                         if (pfnleft > pfncount)
 315                                 pfncurr = pfncount;
 316                         else
 317                                 pfncurr = pfnleft;
 318
 319                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 320                                   sizeof(struct vmbus_channel_gpadl_body) +
 321                                   pfncurr * sizeof(u64);
 322                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 323
 324                         if (!msgbody) {
 325                                 struct vmbus_channel_msginfo *pos = NULL;
 326                                 struct vmbus_channel_msginfo *tmp = NULL;
 327                                 /*
 328                                  * Free up all the allocated messages.
 329                                  */
 330                                 list_for_each_entry_safe(pos, tmp,
 331                                         &msgheader->submsglist,
 332                                         msglistentry) {
 333
 334                                         list_del(&pos->msglistentry);
 335                                         kfree(pos);
 336                                 }
 337
 338                                 goto nomem;
 339                         }
 340
 341                         msgbody->msgsize = msgsize;
 342                         (*messagecount)++;
 343                         gpadl_body =
 344                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 345
 346                         /*
 347                          * Gpadl is u32 and we are using a pointer which could
 348                          * be 64-bit
 349                          * This is governed by the guest/host protocol and
 350                          * so the hypervisor gurantees that this is ok.
 351                          */
 352                         for (i = 0; i < pfncurr; i++)
 353                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
 354
 355                         /* add to msg header */
 356                         list_add_tail(&msgbody->msglistentry,
 357                                       &msgheader->submsglist);
 358                         pfnsum += pfncurr;
 359                         pfnleft -= pfncurr;
 360                 }
 361         } else {
 362                 /* everything fits in a header */
 363                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 364                           sizeof(struct vmbus_channel_gpadl_header) +
 365                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 366                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 367                 if (msgheader == NULL)
 368                         goto nomem;
 369                 msgheader->msgsize = msgsize;
 370
 371                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 372                         msgheader->msg;
 373                 gpadl_header->rangecount = 1;
 374                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 375                                          pagecount * sizeof(u64);
 376                 gpadl_header->range[0].byte_offset = 0;
 377                 gpadl_header->range[0].byte_count = size;
 378                 for (i = 0; i < pagecount; i++)
 379                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 380
 381                 *msginfo = msgheader;
 382                 *messagecount = 1;
 383         }
 384
 385         return 0;
 386 nomem:
 387         kfree(msgheader);
 388         kfree(msgbody);
 389         return -ENOMEM;
 390 }
 391
 392 /*
 393  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 394  *
 395  * @channel: a channel
 396  * @kbuffer: from kmalloc
 397  * @size: page-size multiple
 398  * @gpadl_handle: some funky thing
 399  */
 400 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 401                                u32 size, u32 *gpadl_handle)
 402 {
 403         struct vmbus_channel_gpadl_header *gpadlmsg;
 404         struct vmbus_channel_gpadl_body *gpadl_body;
 405         struct vmbus_channel_msginfo *msginfo = NULL;
 406         struct vmbus_channel_msginfo *submsginfo;
 407         u32 msgcount;
 408         struct list_head *curr;
 409         u32 next_gpadl_handle;
 410         unsigned long flags;
 411         int ret = 0;
 412
 413         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
 414         atomic_inc(&vmbus_connection.next_gpadl_handle);
 415
 416         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 417         if (ret)
 418                 return ret;
 419
 420         init_completion(&msginfo->waitevent);
 421
 422         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 423         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 424         gpadlmsg->child_relid = channel->offermsg.child_relid;
 425         gpadlmsg->gpadl = next_gpadl_handle;
 426
 427
 428         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 429         list_add_tail(&msginfo->msglistentry,
 430                       &vmbus_connection.chn_msg_list);
 431
 432         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 433
 434         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 435                                sizeof(*msginfo));
 436         if (ret != 0)
 437                 goto cleanup;
 438
 439         if (msgcount > 1) {
 440                 list_for_each(curr, &msginfo->submsglist) {
 441
 442                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 443                         gpadl_body =
 444                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 445
 446                         gpadl_body->header.msgtype =
 447                                 CHANNELMSG_GPADL_BODY;
 448                         gpadl_body->gpadl = next_gpadl_handle;
 449
 450                         ret = vmbus_post_msg(gpadl_body,
 451                                                submsginfo->msgsize -
 452                                                sizeof(*submsginfo));
 453                         if (ret != 0)
 454                                 goto cleanup;
 455
 456                 }
 457         }
 458         wait_for_completion(&msginfo->waitevent);
 459
 460         /* At this point, we received the gpadl created msg */
 461         *gpadl_handle = gpadlmsg->gpadl;
 462
 463 cleanup:
 464         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 465         list_del(&msginfo->msglistentry);
 466         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 467
 468         kfree(msginfo);
 469         return ret;
 470 }
 471 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 472
 473 /*
 474  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 475  */
 476 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 477 {
 478         struct vmbus_channel_gpadl_teardown *msg;
 479         struct vmbus_channel_msginfo *info;
 480         unsigned long flags;
 481         int ret;
 482
 483         info = kmalloc(sizeof(*info) +
 484                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 485         if (!info)
 486                 return -ENOMEM;
 487
 488         init_completion(&info->waitevent);
 489
 490         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 491
 492         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 493         msg->child_relid = channel->offermsg.child_relid;
 494         msg->gpadl = gpadl_handle;
 495
 496         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 497         list_add_tail(&info->msglistentry,
 498                       &vmbus_connection.chn_msg_list);
 499         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 500         ret = vmbus_post_msg(msg,
 501                                sizeof(struct vmbus_channel_gpadl_teardown));
 502
 503         if (ret)
 504                 goto post_msg_err;
 505
 506         wait_for_completion(&info->waitevent);
 507
 508 post_msg_err:
 509         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 510         list_del(&info->msglistentry);
 511         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 512
 513         kfree(info);
 514         return ret;
 515 }
 516 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 517
 518 static int vmbus_close_internal(struct vmbus_channel *channel)
 519 {
 520         struct vmbus_channel_close_channel *msg;
 521         int ret;
 522         unsigned long flags;
 523
 524         channel->state = CHANNEL_OPEN_STATE;
 525         channel->sc_creation_callback = NULL;
 526         /* Stop callback and cancel the timer asap */
 527         spin_lock_irqsave(&channel->inbound_lock, flags);
 528         channel->onchannel_callback = NULL;
 529         spin_unlock_irqrestore(&channel->inbound_lock, flags);
 530
 531         /* Send a closing message */
 532
 533         msg = &channel->close_msg.msg;
 534
 535         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 536         msg->child_relid = channel->offermsg.child_relid;
 537
 538         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 539
 540         if (ret) {
 541                 pr_err("Close failed: close post msg return is %d\n", ret);
 542                 /*
 543                  * If we failed to post the close msg,
 544                  * it is perhaps better to leak memory.
 545                  */
 546                 return ret;
 547         }
 548
 549         /* Tear down the gpadl for the channel's ring buffer */
 550         if (channel->ringbuffer_gpadlhandle) {
 551                 ret = vmbus_teardown_gpadl(channel,
 552                                            channel->ringbuffer_gpadlhandle);
 553                 if (ret) {
 554                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 555                         /*
 556                          * If we failed to teardown gpadl,
 557                          * it is perhaps better to leak memory.
 558                          */
 559                         return ret;
 560                 }
 561         }
 562
 563         /* Cleanup the ring buffers for this channel */
 564         hv_ringbuffer_cleanup(&channel->outbound);
 565         hv_ringbuffer_cleanup(&channel->inbound);
 566
 567         free_pages((unsigned long)channel->ringbuffer_pages,
 568                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 569
 570         return ret;
 571 }
 572
 573 /*
 574  * vmbus_close - Close the specified channel
 575  */
 576 void vmbus_close(struct vmbus_channel *channel)
 577 {
 578         struct list_head *cur, *tmp;
 579         struct vmbus_channel *cur_channel;
 580
 581         if (channel->primary_channel != NULL) {
 582                 /*
 583                  * We will only close sub-channels when
 584                  * the primary is closed.
 585                  */
 586                 return;
 587         }
 588         /*
 589          * Close all the sub-channels first and then close the
 590          * primary channel.
 591          */
 592         list_for_each_safe(cur, tmp, &channel->sc_list) {
 593                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 594                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 595                         continue;
 596                 vmbus_close_internal(cur_channel);
 597         }
 598         /*
 599          * Now close the primary.
 600          */
 601         vmbus_close_internal(channel);
 602 }
 603 EXPORT_SYMBOL_GPL(vmbus_close);
 604
 605 /**
 606  * vmbus_sendpacket() - Send the specified buffer on the given channel
 607  * @channel: Pointer to vmbus_channel structure.
 608  * @buffer: Pointer to the buffer you want to receive the data into.
 609  * @bufferlen: Maximum size of what the the buffer will hold
 610  * @requestid: Identifier of the request
 611  * @type: Type of packet that is being send e.g. negotiate, time
 612  * packet etc.
 613  *
 614  * Sends data in @buffer directly to hyper-v via the vmbus
 615  * This will send the data unparsed to hyper-v.
 616  *
 617  * Mainly used by Hyper-V drivers.
 618  */
 619 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
 620                            u32 bufferlen, u64 requestid,
 621                            enum vmbus_packet_type type, u32 flags)
 622 {
 623         struct vmpacket_descriptor desc;
 624         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 625         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 626         struct scatterlist bufferlist[3];
 627         u64 aligned_data = 0;
 628         int ret;
 629         bool signal = false;
 630
 631
 632         /* Setup the descriptor */
 633         desc.type = type; /* VmbusPacketTypeDataInBand; */
 634         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 635         /* in 8-bytes granularity */
 636         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 637         desc.len8 = (u16)(packetlen_aligned >> 3);
 638         desc.trans_id = requestid;
 639
 640         sg_init_table(bufferlist, 3);
 641         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
 642         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 643         sg_set_buf(&bufferlist[2], &aligned_data,
 644                    packetlen_aligned - packetlen);
 645
 646         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 647
 648         if (ret == 0 && signal)
 649                 vmbus_setevent(channel);
 650
 651         return ret;
 652 }
 653 EXPORT_SYMBOL(vmbus_sendpacket);
 654
 655 /*
 656  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 657  * packets using a GPADL Direct packet type.
 658  */
 659 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 660                                      struct hv_page_buffer pagebuffers[],
 661                                      u32 pagecount, void *buffer, u32 bufferlen,
 662                                      u64 requestid)
 663 {
 664         int ret;
 665         int i;
 666         struct vmbus_channel_packet_page_buffer desc;
 667         u32 descsize;
 668         u32 packetlen;
 669         u32 packetlen_aligned;
 670         struct scatterlist bufferlist[3];
 671         u64 aligned_data = 0;
 672         bool signal = false;
 673
 674         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 675                 return -EINVAL;
 676
 677
 678         /*
 679          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 680          * largest size we support
 681          */
 682         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 683                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 684                           sizeof(struct hv_page_buffer));
 685         packetlen = descsize + bufferlen;
 686         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 687
 688         /* Setup the descriptor */
 689         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 690         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 691         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 692         desc.length8 = (u16)(packetlen_aligned >> 3);
 693         desc.transactionid = requestid;
 694         desc.rangecount = pagecount;
 695
 696         for (i = 0; i < pagecount; i++) {
 697                 desc.range[i].len = pagebuffers[i].len;
 698                 desc.range[i].offset = pagebuffers[i].offset;
 699                 desc.range[i].pfn        = pagebuffers[i].pfn;
 700         }
 701
 702         sg_init_table(bufferlist, 3);
 703         sg_set_buf(&bufferlist[0], &desc, descsize);
 704         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 705         sg_set_buf(&bufferlist[2], &aligned_data,
 706                 packetlen_aligned - packetlen);
 707
 708         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 709
 710         if (ret == 0 && signal)
 711                 vmbus_setevent(channel);
 712
 713         return ret;
 714 }
 715 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 716
 717 /*
 718  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 719  * using a GPADL Direct packet type.
 720  */
 721 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 722                                 struct hv_multipage_buffer *multi_pagebuffer,
 723                                 void *buffer, u32 bufferlen, u64 requestid)
 724 {
 725         int ret;
 726         struct vmbus_channel_packet_multipage_buffer desc;
 727         u32 descsize;
 728         u32 packetlen;
 729         u32 packetlen_aligned;
 730         struct scatterlist bufferlist[3];
 731         u64 aligned_data = 0;
 732         bool signal = false;
 733         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 734                                          multi_pagebuffer->len);
 735
 736
 737         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
 738                 return -EINVAL;
 739
 740         /*
 741          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 742          * the largest size we support
 743          */
 744         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 745                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 746                           sizeof(u64));
 747         packetlen = descsize + bufferlen;
 748         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 749
 750
 751         /* Setup the descriptor */
 752         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 753         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 754         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 755         desc.length8 = (u16)(packetlen_aligned >> 3);
 756         desc.transactionid = requestid;
 757         desc.rangecount = 1;
 758
 759         desc.range.len = multi_pagebuffer->len;
 760         desc.range.offset = multi_pagebuffer->offset;
 761
 762         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 763                pfncount * sizeof(u64));
 764
 765         sg_init_table(bufferlist, 3);
 766         sg_set_buf(&bufferlist[0], &desc, descsize);
 767         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 768         sg_set_buf(&bufferlist[2], &aligned_data,
 769                 packetlen_aligned - packetlen);
 770
 771         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 772
 773         if (ret == 0 && signal)
 774                 vmbus_setevent(channel);
 775
 776         return ret;
 777 }
 778 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 779
 780 /**
 781  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 782  * @channel: Pointer to vmbus_channel structure.
 783  * @buffer: Pointer to the buffer you want to receive the data into.
 784  * @bufferlen: Maximum size of what the the buffer will hold
 785  * @buffer_actual_len: The actual size of the data after it was received
 786  * @requestid: Identifier of the request
 787  *
 788  * Receives directly from the hyper-v vmbus and puts the data it received
 789  * into Buffer. This will receive the data unparsed from hyper-v.
 790  *
 791  * Mainly used by Hyper-V drivers.
 792  */
 793 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 794                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 795 {
 796         struct vmpacket_descriptor desc;
 797         u32 packetlen;
 798         u32 userlen;
 799         int ret;
 800         bool signal = false;
 801
 802         *buffer_actual_len = 0;
 803         *requestid = 0;
 804
 805
 806         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 807                              sizeof(struct vmpacket_descriptor));
 808         if (ret != 0)
 809                 return 0;
 810
 811         packetlen = desc.len8 << 3;
 812         userlen = packetlen - (desc.offset8 << 3);
 813
 814         *buffer_actual_len = userlen;
 815
 816         if (userlen > bufferlen) {
 817
 818                 pr_err("Buffer too small - got %d needs %d\n",
 819                            bufferlen, userlen);
 820                 return -ETOOSMALL;
 821         }
 822
 823         *requestid = desc.trans_id;
 824
 825         /* Copy over the packet to the user buffer */
 826         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 827                              (desc.offset8 << 3), &signal);
 828
 829         if (signal)
 830                 vmbus_setevent(channel);
 831
 832         return 0;
 833 }
 834 EXPORT_SYMBOL(vmbus_recvpacket);
 835
 836 /*
 837  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 838  */
 839 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 840                               u32 bufferlen, u32 *buffer_actual_len,
 841                               u64 *requestid)
 842 {
 843         struct vmpacket_descriptor desc;
 844         u32 packetlen;
 845         int ret;
 846         bool signal = false;
 847
 848         *buffer_actual_len = 0;
 849         *requestid = 0;
 850
 851
 852         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 853                              sizeof(struct vmpacket_descriptor));
 854         if (ret != 0)
 855                 return 0;
 856
 857
 858         packetlen = desc.len8 << 3;
 859
 860         *buffer_actual_len = packetlen;
 861
 862         if (packetlen > bufferlen) {
 863                 pr_err("Buffer too small - needed %d bytes but "
 864                         "got space for only %d bytes\n",
 865                         packetlen, bufferlen);
 866                 return -ENOBUFS;
 867         }
 868
 869         *requestid = desc.trans_id;
 870
 871         /* Copy over the entire packet to the user buffer */
 872         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 873                                  &signal);
 874
 875         if (signal)
 876                 vmbus_setevent(channel);
 877
 878         return 0;
 879 }
 880 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);