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 /* Internal routines */
  37 static int create_gpadl_header(
  38         void *kbuffer,  /* must be phys and virt contiguous */
  39         u32 size,       /* page-size multiple */
  40         struct vmbus_channel_msginfo **msginfo,
  41         u32 *messagecount);
  42 static void vmbus_setevent(struct vmbus_channel *channel);
  43
  44 /*
  45  * vmbus_setevent- Trigger an event notification on the specified
  46  * channel.
  47  */
  48 static void vmbus_setevent(struct vmbus_channel *channel)
  49 {
  50         struct hv_monitor_page *monitorpage;
  51
  52         if (channel->offermsg.monitor_allocated) {
  53                 /* Each u32 represents 32 channels */
  54                 sync_set_bit(channel->offermsg.child_relid & 31,
  55                         (unsigned long *) vmbus_connection.send_int_page +
  56                         (channel->offermsg.child_relid >> 5));
  57
  58                 monitorpage = vmbus_connection.monitor_pages;
  59                 monitorpage++; /* Get the child to parent monitor page */
  60
  61                 sync_set_bit(channel->monitor_bit,
  62                         (unsigned long *)&monitorpage->trigger_group
  63                                         [channel->monitor_grp].pending);
  64
  65         } else {
  66                 vmbus_set_event(channel->offermsg.child_relid);
  67         }
  68 }
  69
  70 /*
  71  * vmbus_get_debug_info -Retrieve various channel debug info
  72  */
  73 void vmbus_get_debug_info(struct vmbus_channel *channel,
  74                               struct vmbus_channel_debug_info *debuginfo)
  75 {
  76         struct hv_monitor_page *monitorpage;
  77         u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
  78         u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
  79
  80         debuginfo->relid = channel->offermsg.child_relid;
  81         debuginfo->state = channel->state;
  82         memcpy(&debuginfo->interfacetype,
  83                &channel->offermsg.offer.if_type, sizeof(uuid_le));
  84         memcpy(&debuginfo->interface_instance,
  85                &channel->offermsg.offer.if_instance,
  86                sizeof(uuid_le));
  87
  88         monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
  89
  90         debuginfo->monitorid = channel->offermsg.monitorid;
  91
  92         debuginfo->servermonitor_pending =
  93                         monitorpage->trigger_group[monitor_group].pending;
  94         debuginfo->servermonitor_latency =
  95                         monitorpage->latency[monitor_group][monitor_offset];
  96         debuginfo->servermonitor_connectionid =
  97                         monitorpage->parameter[monitor_group]
  98                                         [monitor_offset].connectionid.u.id;
  99
 100         monitorpage++;
 101
 102         debuginfo->clientmonitor_pending =
 103                         monitorpage->trigger_group[monitor_group].pending;
 104         debuginfo->clientmonitor_latency =
 105                         monitorpage->latency[monitor_group][monitor_offset];
 106         debuginfo->clientmonitor_connectionid =
 107                         monitorpage->parameter[monitor_group]
 108                                         [monitor_offset].connectionid.u.id;
 109
 110         hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
 111         hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
 112 }
 113
 114 /*
 115  * vmbus_open - Open the specified channel.
 116  */
 117 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 118                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
 119                      void (*onchannelcallback)(void *context), void *context)
 120 {
 121         struct vmbus_channel_open_channel *open_msg;
 122         struct vmbus_channel_msginfo *open_info = NULL;
 123         void *in, *out;
 124         unsigned long flags;
 125         int ret, t, err = 0;
 126
 127         newchannel->onchannel_callback = onchannelcallback;
 128         newchannel->channel_callback_context = context;
 129
 130         /* Allocate the ring buffer */
 131         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 132                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 133
 134         if (!out)
 135                 return -ENOMEM;
 136
 137
 138         in = (void *)((unsigned long)out + send_ringbuffer_size);
 139
 140         newchannel->ringbuffer_pages = out;
 141         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 142                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 143
 144         ret = hv_ringbuffer_init(
 145                 &newchannel->outbound, out, send_ringbuffer_size);
 146
 147         if (ret != 0) {
 148                 err = ret;
 149                 goto error0;
 150         }
 151
 152         ret = hv_ringbuffer_init(
 153                 &newchannel->inbound, in, recv_ringbuffer_size);
 154         if (ret != 0) {
 155                 err = ret;
 156                 goto error0;
 157         }
 158
 159
 160         /* Establish the gpadl for the ring buffer */
 161         newchannel->ringbuffer_gpadlhandle = 0;
 162
 163         ret = vmbus_establish_gpadl(newchannel,
 164                                          newchannel->outbound.ring_buffer,
 165                                          send_ringbuffer_size +
 166                                          recv_ringbuffer_size,
 167                                          &newchannel->ringbuffer_gpadlhandle);
 168
 169         if (ret != 0) {
 170                 err = ret;
 171                 goto error0;
 172         }
 173
 174         /* Create and init the channel open message */
 175         open_info = kmalloc(sizeof(*open_info) +
 176                            sizeof(struct vmbus_channel_open_channel),
 177                            GFP_KERNEL);
 178         if (!open_info) {
 179                 err = -ENOMEM;
 180                 goto error0;
 181         }
 182
 183         init_completion(&open_info->waitevent);
 184
 185         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 186         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 187         open_msg->openid = newchannel->offermsg.child_relid;
 188         open_msg->child_relid = newchannel->offermsg.child_relid;
 189         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 190         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 191                                                   PAGE_SHIFT;
 192         open_msg->server_contextarea_gpadlhandle = 0;
 193
 194         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 195                 err = -EINVAL;
 196                 goto error0;
 197         }
 198
 199         if (userdatalen)
 200                 memcpy(open_msg->userdata, userdata, userdatalen);
 201
 202         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 203         list_add_tail(&open_info->msglistentry,
 204                       &vmbus_connection.chn_msg_list);
 205         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 206
 207         ret = vmbus_post_msg(open_msg,
 208                                sizeof(struct vmbus_channel_open_channel));
 209
 210         if (ret != 0)
 211                 goto error1;
 212
 213         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 214         if (t == 0) {
 215                 err = -ETIMEDOUT;
 216                 goto error1;
 217         }
 218
 219
 220         if (open_info->response.open_result.status)
 221                 err = open_info->response.open_result.status;
 222
 223         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 224         list_del(&open_info->msglistentry);
 225         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 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
 404         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
 405         atomic_inc(&vmbus_connection.next_gpadl_handle);
 406
 407         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 408         if (ret)
 409                 return ret;
 410
 411         init_completion(&msginfo->waitevent);
 412
 413         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 414         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 415         gpadlmsg->child_relid = channel->offermsg.child_relid;
 416         gpadlmsg->gpadl = next_gpadl_handle;
 417
 418
 419         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 420         list_add_tail(&msginfo->msglistentry,
 421                       &vmbus_connection.chn_msg_list);
 422
 423         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 424
 425         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 426                                sizeof(*msginfo));
 427         if (ret != 0)
 428                 goto cleanup;
 429
 430         if (msgcount > 1) {
 431                 list_for_each(curr, &msginfo->submsglist) {
 432
 433                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 434                         gpadl_body =
 435                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 436
 437                         gpadl_body->header.msgtype =
 438                                 CHANNELMSG_GPADL_BODY;
 439                         gpadl_body->gpadl = next_gpadl_handle;
 440
 441                         ret = vmbus_post_msg(gpadl_body,
 442                                                submsginfo->msgsize -
 443                                                sizeof(*submsginfo));
 444                         if (ret != 0)
 445                                 goto cleanup;
 446
 447                 }
 448         }
 449         wait_for_completion(&msginfo->waitevent);
 450
 451         /* At this point, we received the gpadl created msg */
 452         *gpadl_handle = gpadlmsg->gpadl;
 453
 454 cleanup:
 455         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 456         list_del(&msginfo->msglistentry);
 457         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 458
 459         kfree(msginfo);
 460         return ret;
 461 }
 462 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 463
 464 /*
 465  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 466  */
 467 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 468 {
 469         struct vmbus_channel_gpadl_teardown *msg;
 470         struct vmbus_channel_msginfo *info;
 471         unsigned long flags;
 472         int ret;
 473
 474         info = kmalloc(sizeof(*info) +
 475                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 476         if (!info)
 477                 return -ENOMEM;
 478
 479         init_completion(&info->waitevent);
 480
 481         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 482
 483         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 484         msg->child_relid = channel->offermsg.child_relid;
 485         msg->gpadl = gpadl_handle;
 486
 487         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 488         list_add_tail(&info->msglistentry,
 489                       &vmbus_connection.chn_msg_list);
 490         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 491         ret = vmbus_post_msg(msg,
 492                                sizeof(struct vmbus_channel_gpadl_teardown));
 493
 494         if (ret)
 495                 goto post_msg_err;
 496
 497         wait_for_completion(&info->waitevent);
 498
 499 post_msg_err:
 500         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 501         list_del(&info->msglistentry);
 502         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 503
 504         kfree(info);
 505         return ret;
 506 }
 507 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 508
 509 /*
 510  * vmbus_close - Close the specified channel
 511  */
 512 void vmbus_close(struct vmbus_channel *channel)
 513 {
 514         struct vmbus_channel_close_channel *msg;
 515         int ret;
 516         unsigned long flags;
 517
 518         /* Stop callback and cancel the timer asap */
 519         spin_lock_irqsave(&channel->inbound_lock, flags);
 520         channel->onchannel_callback = NULL;
 521         spin_unlock_irqrestore(&channel->inbound_lock, flags);
 522
 523         /* Send a closing message */
 524
 525         msg = &channel->close_msg.msg;
 526
 527         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 528         msg->child_relid = channel->offermsg.child_relid;
 529
 530         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 531
 532         BUG_ON(ret != 0);
 533         /* Tear down the gpadl for the channel's ring buffer */
 534         if (channel->ringbuffer_gpadlhandle)
 535                 vmbus_teardown_gpadl(channel,
 536                                           channel->ringbuffer_gpadlhandle);
 537
 538         /* Cleanup the ring buffers for this channel */
 539         hv_ringbuffer_cleanup(&channel->outbound);
 540         hv_ringbuffer_cleanup(&channel->inbound);
 541
 542         free_pages((unsigned long)channel->ringbuffer_pages,
 543                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 544
 545
 546 }
 547 EXPORT_SYMBOL_GPL(vmbus_close);
 548
 549 /**
 550  * vmbus_sendpacket() - Send the specified buffer on the given channel
 551  * @channel: Pointer to vmbus_channel structure.
 552  * @buffer: Pointer to the buffer you want to receive the data into.
 553  * @bufferlen: Maximum size of what the the buffer will hold
 554  * @requestid: Identifier of the request
 555  * @type: Type of packet that is being send e.g. negotiate, time
 556  * packet etc.
 557  *
 558  * Sends data in @buffer directly to hyper-v via the vmbus
 559  * This will send the data unparsed to hyper-v.
 560  *
 561  * Mainly used by Hyper-V drivers.
 562  */
 563 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
 564                            u32 bufferlen, u64 requestid,
 565                            enum vmbus_packet_type type, u32 flags)
 566 {
 567         struct vmpacket_descriptor desc;
 568         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 569         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 570         struct scatterlist bufferlist[3];
 571         u64 aligned_data = 0;
 572         int ret;
 573
 574
 575         /* Setup the descriptor */
 576         desc.type = type; /* VmbusPacketTypeDataInBand; */
 577         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 578         /* in 8-bytes granularity */
 579         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 580         desc.len8 = (u16)(packetlen_aligned >> 3);
 581         desc.trans_id = requestid;
 582
 583         sg_init_table(bufferlist, 3);
 584         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
 585         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 586         sg_set_buf(&bufferlist[2], &aligned_data,
 587                    packetlen_aligned - packetlen);
 588
 589         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 590
 591         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 592                 vmbus_setevent(channel);
 593
 594         return ret;
 595 }
 596 EXPORT_SYMBOL(vmbus_sendpacket);
 597
 598 /*
 599  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 600  * packets using a GPADL Direct packet type.
 601  */
 602 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 603                                      struct hv_page_buffer pagebuffers[],
 604                                      u32 pagecount, void *buffer, u32 bufferlen,
 605                                      u64 requestid)
 606 {
 607         int ret;
 608         int i;
 609         struct vmbus_channel_packet_page_buffer desc;
 610         u32 descsize;
 611         u32 packetlen;
 612         u32 packetlen_aligned;
 613         struct scatterlist bufferlist[3];
 614         u64 aligned_data = 0;
 615
 616         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 617                 return -EINVAL;
 618
 619
 620         /*
 621          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 622          * largest size we support
 623          */
 624         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 625                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 626                           sizeof(struct hv_page_buffer));
 627         packetlen = descsize + bufferlen;
 628         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 629
 630         /* Setup the descriptor */
 631         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 632         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 633         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 634         desc.length8 = (u16)(packetlen_aligned >> 3);
 635         desc.transactionid = requestid;
 636         desc.rangecount = pagecount;
 637
 638         for (i = 0; i < pagecount; i++) {
 639                 desc.range[i].len = pagebuffers[i].len;
 640                 desc.range[i].offset = pagebuffers[i].offset;
 641                 desc.range[i].pfn        = pagebuffers[i].pfn;
 642         }
 643
 644         sg_init_table(bufferlist, 3);
 645         sg_set_buf(&bufferlist[0], &desc, descsize);
 646         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 647         sg_set_buf(&bufferlist[2], &aligned_data,
 648                 packetlen_aligned - packetlen);
 649
 650         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 651
 652         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 653                 vmbus_setevent(channel);
 654
 655         return ret;
 656 }
 657 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 658
 659 /*
 660  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 661  * using a GPADL Direct packet type.
 662  */
 663 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 664                                 struct hv_multipage_buffer *multi_pagebuffer,
 665                                 void *buffer, u32 bufferlen, u64 requestid)
 666 {
 667         int ret;
 668         struct vmbus_channel_packet_multipage_buffer desc;
 669         u32 descsize;
 670         u32 packetlen;
 671         u32 packetlen_aligned;
 672         struct scatterlist bufferlist[3];
 673         u64 aligned_data = 0;
 674         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 675                                          multi_pagebuffer->len);
 676
 677
 678         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
 679                 return -EINVAL;
 680
 681         /*
 682          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 683          * the largest size we support
 684          */
 685         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 686                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 687                           sizeof(u64));
 688         packetlen = descsize + bufferlen;
 689         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 690
 691
 692         /* Setup the descriptor */
 693         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 694         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 695         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 696         desc.length8 = (u16)(packetlen_aligned >> 3);
 697         desc.transactionid = requestid;
 698         desc.rangecount = 1;
 699
 700         desc.range.len = multi_pagebuffer->len;
 701         desc.range.offset = multi_pagebuffer->offset;
 702
 703         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 704                pfncount * sizeof(u64));
 705
 706         sg_init_table(bufferlist, 3);
 707         sg_set_buf(&bufferlist[0], &desc, descsize);
 708         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 709         sg_set_buf(&bufferlist[2], &aligned_data,
 710                 packetlen_aligned - packetlen);
 711
 712         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
 713
 714         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
 715                 vmbus_setevent(channel);
 716
 717         return ret;
 718 }
 719 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 720
 721 /**
 722  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 723  * @channel: Pointer to vmbus_channel structure.
 724  * @buffer: Pointer to the buffer you want to receive the data into.
 725  * @bufferlen: Maximum size of what the the buffer will hold
 726  * @buffer_actual_len: The actual size of the data after it was received
 727  * @requestid: Identifier of the request
 728  *
 729  * Receives directly from the hyper-v vmbus and puts the data it received
 730  * into Buffer. This will receive the data unparsed from hyper-v.
 731  *
 732  * Mainly used by Hyper-V drivers.
 733  */
 734 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 735                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 736 {
 737         struct vmpacket_descriptor desc;
 738         u32 packetlen;
 739         u32 userlen;
 740         int ret;
 741
 742         *buffer_actual_len = 0;
 743         *requestid = 0;
 744
 745
 746         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 747                              sizeof(struct vmpacket_descriptor));
 748         if (ret != 0)
 749                 return 0;
 750
 751         packetlen = desc.len8 << 3;
 752         userlen = packetlen - (desc.offset8 << 3);
 753
 754         *buffer_actual_len = userlen;
 755
 756         if (userlen > bufferlen) {
 757
 758                 pr_err("Buffer too small - got %d needs %d\n",
 759                            bufferlen, userlen);
 760                 return -ETOOSMALL;
 761         }
 762
 763         *requestid = desc.trans_id;
 764
 765         /* Copy over the packet to the user buffer */
 766         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 767                              (desc.offset8 << 3));
 768
 769
 770         return 0;
 771 }
 772 EXPORT_SYMBOL(vmbus_recvpacket);
 773
 774 /*
 775  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 776  */
 777 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 778                               u32 bufferlen, u32 *buffer_actual_len,
 779                               u64 *requestid)
 780 {
 781         struct vmpacket_descriptor desc;
 782         u32 packetlen;
 783         u32 userlen;
 784         int ret;
 785
 786         *buffer_actual_len = 0;
 787         *requestid = 0;
 788
 789
 790         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 791                              sizeof(struct vmpacket_descriptor));
 792         if (ret != 0)
 793                 return 0;
 794
 795
 796         packetlen = desc.len8 << 3;
 797         userlen = packetlen - (desc.offset8 << 3);
 798
 799         *buffer_actual_len = packetlen;
 800
 801         if (packetlen > bufferlen) {
 802                 pr_err("Buffer too small - needed %d bytes but "
 803                         "got space for only %d bytes\n",
 804                         packetlen, bufferlen);
 805                 return -ENOBUFS;
 806         }
 807
 808         *requestid = desc.trans_id;
 809
 810         /* Copy over the entire packet to the user buffer */
 811         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
 812
 813         return 0;
 814 }
 815 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);