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         newchannel->onchannel_callback = onchannelcallback;
 120         newchannel->channel_callback_context = context;
 121
 122         /* Allocate the ring buffer */
 123         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
 124                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 125
 126         if (!out)
 127                 return -ENOMEM;
 128
 129
 130         in = (void *)((unsigned long)out + send_ringbuffer_size);
 131
 132         newchannel->ringbuffer_pages = out;
 133         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 134                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 135
 136         ret = hv_ringbuffer_init(
 137                 &newchannel->outbound, out, send_ringbuffer_size);
 138
 139         if (ret != 0) {
 140                 err = ret;
 141                 goto error0;
 142         }
 143
 144         ret = hv_ringbuffer_init(
 145                 &newchannel->inbound, in, recv_ringbuffer_size);
 146         if (ret != 0) {
 147                 err = ret;
 148                 goto error0;
 149         }
 150
 151
 152         /* Establish the gpadl for the ring buffer */
 153         newchannel->ringbuffer_gpadlhandle = 0;
 154
 155         ret = vmbus_establish_gpadl(newchannel,
 156                                          newchannel->outbound.ring_buffer,
 157                                          send_ringbuffer_size +
 158                                          recv_ringbuffer_size,
 159                                          &newchannel->ringbuffer_gpadlhandle);
 160
 161         if (ret != 0) {
 162                 err = ret;
 163                 goto error0;
 164         }
 165
 166         /* Create and init the channel open message */
 167         open_info = kmalloc(sizeof(*open_info) +
 168                            sizeof(struct vmbus_channel_open_channel),
 169                            GFP_KERNEL);
 170         if (!open_info) {
 171                 err = -ENOMEM;
 172                 goto error_gpadl;
 173         }
 174
 175         init_completion(&open_info->waitevent);
 176
 177         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 178         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 179         open_msg->openid = newchannel->offermsg.child_relid;
 180         open_msg->child_relid = newchannel->offermsg.child_relid;
 181         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 182         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 183                                                   PAGE_SHIFT;
 184         open_msg->target_vp = newchannel->target_vp;
 185
 186         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 187                 err = -EINVAL;
 188                 goto error_gpadl;
 189         }
 190
 191         if (userdatalen)
 192                 memcpy(open_msg->userdata, userdata, userdatalen);
 193
 194         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 195         list_add_tail(&open_info->msglistentry,
 196                       &vmbus_connection.chn_msg_list);
 197         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 198
 199         ret = vmbus_post_msg(open_msg,
 200                                sizeof(struct vmbus_channel_open_channel));
 201
 202         if (ret != 0) {
 203                 err = ret;
 204                 goto error1;
 205         }
 206
 207         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 208         if (t == 0) {
 209                 err = -ETIMEDOUT;
 210                 goto error1;
 211         }
 212
 213
 214         if (open_info->response.open_result.status)
 215                 err = open_info->response.open_result.status;
 216
 217         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 218         list_del(&open_info->msglistentry);
 219         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 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 error_gpadl:
 230         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 231
 232 error0:
 233         free_pages((unsigned long)out,
 234                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 235         kfree(open_info);
 236         return err;
 237 }
 238 EXPORT_SYMBOL_GPL(vmbus_open);
 239
 240 /*
 241  * create_gpadl_header - Creates a gpadl for the specified buffer
 242  */
 243 static int create_gpadl_header(void *kbuffer, u32 size,
 244                                          struct vmbus_channel_msginfo **msginfo,
 245                                          u32 *messagecount)
 246 {
 247         int i;
 248         int pagecount;
 249         unsigned long long pfn;
 250         struct vmbus_channel_gpadl_header *gpadl_header;
 251         struct vmbus_channel_gpadl_body *gpadl_body;
 252         struct vmbus_channel_msginfo *msgheader;
 253         struct vmbus_channel_msginfo *msgbody = NULL;
 254         u32 msgsize;
 255
 256         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 257
 258         pagecount = size >> PAGE_SHIFT;
 259         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
 260
 261         /* do we need a gpadl body msg */
 262         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 263                   sizeof(struct vmbus_channel_gpadl_header) -
 264                   sizeof(struct gpa_range);
 265         pfncount = pfnsize / sizeof(u64);
 266
 267         if (pagecount > pfncount) {
 268                 /* we need a gpadl body */
 269                 /* fill in the header */
 270                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 271                           sizeof(struct vmbus_channel_gpadl_header) +
 272                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 273                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 274                 if (!msgheader)
 275                         goto nomem;
 276
 277                 INIT_LIST_HEAD(&msgheader->submsglist);
 278                 msgheader->msgsize = msgsize;
 279
 280                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 281                         msgheader->msg;
 282                 gpadl_header->rangecount = 1;
 283                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 284                                          pagecount * sizeof(u64);
 285                 gpadl_header->range[0].byte_offset = 0;
 286                 gpadl_header->range[0].byte_count = size;
 287                 for (i = 0; i < pfncount; i++)
 288                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 289                 *msginfo = msgheader;
 290                 *messagecount = 1;
 291
 292                 pfnsum = pfncount;
 293                 pfnleft = pagecount - pfncount;
 294
 295                 /* how many pfns can we fit */
 296                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 297                           sizeof(struct vmbus_channel_gpadl_body);
 298                 pfncount = pfnsize / sizeof(u64);
 299
 300                 /* fill in the body */
 301                 while (pfnleft) {
 302                         if (pfnleft > pfncount)
 303                                 pfncurr = pfncount;
 304                         else
 305                                 pfncurr = pfnleft;
 306
 307                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 308                                   sizeof(struct vmbus_channel_gpadl_body) +
 309                                   pfncurr * sizeof(u64);
 310                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 311
 312                         if (!msgbody) {
 313                                 struct vmbus_channel_msginfo *pos = NULL;
 314                                 struct vmbus_channel_msginfo *tmp = NULL;
 315                                 /*
 316                                  * Free up all the allocated messages.
 317                                  */
 318                                 list_for_each_entry_safe(pos, tmp,
 319                                         &msgheader->submsglist,
 320                                         msglistentry) {
 321
 322                                         list_del(&pos->msglistentry);
 323                                         kfree(pos);
 324                                 }
 325
 326                                 goto nomem;
 327                         }
 328
 329                         msgbody->msgsize = msgsize;
 330                         (*messagecount)++;
 331                         gpadl_body =
 332                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 333
 334                         /*
 335                          * Gpadl is u32 and we are using a pointer which could
 336                          * be 64-bit
 337                          * This is governed by the guest/host protocol and
 338                          * so the hypervisor gurantees that this is ok.
 339                          */
 340                         for (i = 0; i < pfncurr; i++)
 341                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
 342
 343                         /* add to msg header */
 344                         list_add_tail(&msgbody->msglistentry,
 345                                       &msgheader->submsglist);
 346                         pfnsum += pfncurr;
 347                         pfnleft -= pfncurr;
 348                 }
 349         } else {
 350                 /* everything fits in a header */
 351                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 352                           sizeof(struct vmbus_channel_gpadl_header) +
 353                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 354                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 355                 if (msgheader == NULL)
 356                         goto nomem;
 357                 msgheader->msgsize = msgsize;
 358
 359                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 360                         msgheader->msg;
 361                 gpadl_header->rangecount = 1;
 362                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 363                                          pagecount * sizeof(u64);
 364                 gpadl_header->range[0].byte_offset = 0;
 365                 gpadl_header->range[0].byte_count = size;
 366                 for (i = 0; i < pagecount; i++)
 367                         gpadl_header->range[0].pfn_array[i] = pfn+i;
 368
 369                 *msginfo = msgheader;
 370                 *messagecount = 1;
 371         }
 372
 373         return 0;
 374 nomem:
 375         kfree(msgheader);
 376         kfree(msgbody);
 377         return -ENOMEM;
 378 }
 379
 380 /*
 381  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 382  *
 383  * @channel: a channel
 384  * @kbuffer: from kmalloc
 385  * @size: page-size multiple
 386  * @gpadl_handle: some funky thing
 387  */
 388 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 389                                u32 size, u32 *gpadl_handle)
 390 {
 391         struct vmbus_channel_gpadl_header *gpadlmsg;
 392         struct vmbus_channel_gpadl_body *gpadl_body;
 393         struct vmbus_channel_msginfo *msginfo = NULL;
 394         struct vmbus_channel_msginfo *submsginfo;
 395         u32 msgcount;
 396         struct list_head *curr;
 397         u32 next_gpadl_handle;
 398         unsigned long flags;
 399         int ret = 0;
 400
 401         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
 402         atomic_inc(&vmbus_connection.next_gpadl_handle);
 403
 404         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 405         if (ret)
 406                 return ret;
 407
 408         init_completion(&msginfo->waitevent);
 409
 410         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 411         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 412         gpadlmsg->child_relid = channel->offermsg.child_relid;
 413         gpadlmsg->gpadl = next_gpadl_handle;
 414
 415
 416         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 417         list_add_tail(&msginfo->msglistentry,
 418                       &vmbus_connection.chn_msg_list);
 419
 420         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 421
 422         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 423                                sizeof(*msginfo));
 424         if (ret != 0)
 425                 goto cleanup;
 426
 427         if (msgcount > 1) {
 428                 list_for_each(curr, &msginfo->submsglist) {
 429
 430                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 431                         gpadl_body =
 432                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 433
 434                         gpadl_body->header.msgtype =
 435                                 CHANNELMSG_GPADL_BODY;
 436                         gpadl_body->gpadl = next_gpadl_handle;
 437
 438                         ret = vmbus_post_msg(gpadl_body,
 439                                                submsginfo->msgsize -
 440                                                sizeof(*submsginfo));
 441                         if (ret != 0)
 442                                 goto cleanup;
 443
 444                 }
 445         }
 446         wait_for_completion(&msginfo->waitevent);
 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;
 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         if (ret)
 492                 goto post_msg_err;
 493
 494         wait_for_completion(&info->waitevent);
 495
 496 post_msg_err:
 497         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 498         list_del(&info->msglistentry);
 499         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 500
 501         kfree(info);
 502         return ret;
 503 }
 504 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 505
 506 /*
 507  * vmbus_close - Close the specified channel
 508  */
 509 void vmbus_close(struct vmbus_channel *channel)
 510 {
 511         struct vmbus_channel_close_channel *msg;
 512         int ret;
 513         unsigned long flags;
 514
 515         /* Stop callback and cancel the timer asap */
 516         spin_lock_irqsave(&channel->inbound_lock, flags);
 517         channel->onchannel_callback = NULL;
 518         spin_unlock_irqrestore(&channel->inbound_lock, flags);
 519
 520         /* Send a closing message */
 521
 522         msg = &channel->close_msg.msg;
 523
 524         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 525         msg->child_relid = channel->offermsg.child_relid;
 526
 527         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 528
 529         BUG_ON(ret != 0);
 530         /* Tear down the gpadl for the channel's ring buffer */
 531         if (channel->ringbuffer_gpadlhandle)
 532                 vmbus_teardown_gpadl(channel,
 533                                           channel->ringbuffer_gpadlhandle);
 534
 535         /* Cleanup the ring buffers for this channel */
 536         hv_ringbuffer_cleanup(&channel->outbound);
 537         hv_ringbuffer_cleanup(&channel->inbound);
 538
 539         free_pages((unsigned long)channel->ringbuffer_pages,
 540                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 541
 542
 543 }
 544 EXPORT_SYMBOL_GPL(vmbus_close);
 545
 546 /**
 547  * vmbus_sendpacket() - Send the specified buffer on the given channel
 548  * @channel: Pointer to vmbus_channel structure.
 549  * @buffer: Pointer to the buffer you want to receive the data into.
 550  * @bufferlen: Maximum size of what the the buffer will hold
 551  * @requestid: Identifier of the request
 552  * @type: Type of packet that is being send e.g. negotiate, time
 553  * packet etc.
 554  *
 555  * Sends data in @buffer directly to hyper-v via the vmbus
 556  * This will send the data unparsed to hyper-v.
 557  *
 558  * Mainly used by Hyper-V drivers.
 559  */
 560 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
 561                            u32 bufferlen, u64 requestid,
 562                            enum vmbus_packet_type type, u32 flags)
 563 {
 564         struct vmpacket_descriptor desc;
 565         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 566         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 567         struct scatterlist bufferlist[3];
 568         u64 aligned_data = 0;
 569         int ret;
 570         bool signal = false;
 571
 572
 573         /* Setup the descriptor */
 574         desc.type = type; /* VmbusPacketTypeDataInBand; */
 575         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 576         /* in 8-bytes granularity */
 577         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 578         desc.len8 = (u16)(packetlen_aligned >> 3);
 579         desc.trans_id = requestid;
 580
 581         sg_init_table(bufferlist, 3);
 582         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
 583         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 584         sg_set_buf(&bufferlist[2], &aligned_data,
 585                    packetlen_aligned - packetlen);
 586
 587         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 588
 589         if (ret == 0 && signal)
 590                 vmbus_setevent(channel);
 591
 592         return ret;
 593 }
 594 EXPORT_SYMBOL(vmbus_sendpacket);
 595
 596 /*
 597  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 598  * packets using a GPADL Direct packet type.
 599  */
 600 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 601                                      struct hv_page_buffer pagebuffers[],
 602                                      u32 pagecount, void *buffer, u32 bufferlen,
 603                                      u64 requestid)
 604 {
 605         int ret;
 606         int i;
 607         struct vmbus_channel_packet_page_buffer desc;
 608         u32 descsize;
 609         u32 packetlen;
 610         u32 packetlen_aligned;
 611         struct scatterlist bufferlist[3];
 612         u64 aligned_data = 0;
 613         bool signal = false;
 614
 615         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 616                 return -EINVAL;
 617
 618
 619         /*
 620          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 621          * largest size we support
 622          */
 623         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 624                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 625                           sizeof(struct hv_page_buffer));
 626         packetlen = descsize + bufferlen;
 627         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 628
 629         /* Setup the descriptor */
 630         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 631         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 632         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 633         desc.length8 = (u16)(packetlen_aligned >> 3);
 634         desc.transactionid = requestid;
 635         desc.rangecount = pagecount;
 636
 637         for (i = 0; i < pagecount; i++) {
 638                 desc.range[i].len = pagebuffers[i].len;
 639                 desc.range[i].offset = pagebuffers[i].offset;
 640                 desc.range[i].pfn        = pagebuffers[i].pfn;
 641         }
 642
 643         sg_init_table(bufferlist, 3);
 644         sg_set_buf(&bufferlist[0], &desc, descsize);
 645         sg_set_buf(&bufferlist[1], buffer, bufferlen);
 646         sg_set_buf(&bufferlist[2], &aligned_data,
 647                 packetlen_aligned - packetlen);
 648
 649         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 650
 651         if (ret == 0 && signal)
 652                 vmbus_setevent(channel);
 653
 654         return ret;
 655 }
 656 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 657
 658 /*
 659  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 660  * using a GPADL Direct packet type.
 661  */
 662 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 663                                 struct hv_multipage_buffer *multi_pagebuffer,
 664                                 void *buffer, u32 bufferlen, u64 requestid)
 665 {
 666         int ret;
 667         struct vmbus_channel_packet_multipage_buffer desc;
 668         u32 descsize;
 669         u32 packetlen;
 670         u32 packetlen_aligned;
 671         struct scatterlist bufferlist[3];
 672         u64 aligned_data = 0;
 673         bool signal = false;
 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, &signal);
 713
 714         if (ret == 0 && signal)
 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         bool signal = false;
 742
 743         *buffer_actual_len = 0;
 744         *requestid = 0;
 745
 746
 747         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 748                              sizeof(struct vmpacket_descriptor));
 749         if (ret != 0)
 750                 return 0;
 751
 752         packetlen = desc.len8 << 3;
 753         userlen = packetlen - (desc.offset8 << 3);
 754
 755         *buffer_actual_len = userlen;
 756
 757         if (userlen > bufferlen) {
 758
 759                 pr_err("Buffer too small - got %d needs %d\n",
 760                            bufferlen, userlen);
 761                 return -ETOOSMALL;
 762         }
 763
 764         *requestid = desc.trans_id;
 765
 766         /* Copy over the packet to the user buffer */
 767         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 768                              (desc.offset8 << 3), &signal);
 769
 770         if (signal)
 771                 vmbus_setevent(channel);
 772
 773         return 0;
 774 }
 775 EXPORT_SYMBOL(vmbus_recvpacket);
 776
 777 /*
 778  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 779  */
 780 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 781                               u32 bufferlen, u32 *buffer_actual_len,
 782                               u64 *requestid)
 783 {
 784         struct vmpacket_descriptor desc;
 785         u32 packetlen;
 786         int ret;
 787         bool signal = false;
 788
 789         *buffer_actual_len = 0;
 790         *requestid = 0;
 791
 792
 793         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 794                              sizeof(struct vmpacket_descriptor));
 795         if (ret != 0)
 796                 return 0;
 797
 798
 799         packetlen = desc.len8 << 3;
 800
 801         *buffer_actual_len = packetlen;
 802
 803         if (packetlen > bufferlen) {
 804                 pr_err("Buffer too small - needed %d bytes but "
 805                         "got space for only %d bytes\n",
 806                         packetlen, bufferlen);
 807                 return -ENOBUFS;
 808         }
 809
 810         *requestid = desc.trans_id;
 811
 812         /* Copy over the entire packet to the user buffer */
 813         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 814                                  &signal);
 815
 816         if (signal)
 817                 vmbus_setevent(channel);
 818
 819         return 0;
 820 }
 821 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);