kernel/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 #include <linux/uio.h>
  31
  32 #include "hyperv_vmbus.h"
  33
  34 #define NUM_PAGES_SPANNED(addr, len) \
  35 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
  36
  37 /*
  38  * vmbus_setevent- Trigger an event notification on the specified
  39  * channel.
  40  */
  41 static void vmbus_setevent(struct vmbus_channel *channel)
  42 {
  43         struct hv_monitor_page *monitorpage;
  44
  45         if (channel->offermsg.monitor_allocated) {
  46                 /* Each u32 represents 32 channels */
  47                 sync_set_bit(channel->offermsg.child_relid & 31,
  48                         (unsigned long *) vmbus_connection.send_int_page +
  49                         (channel->offermsg.child_relid >> 5));
  50
  51                 /* Get the child to parent monitor page */
  52                 monitorpage = vmbus_connection.monitor_pages[1];
  53
  54                 sync_set_bit(channel->monitor_bit,
  55                         (unsigned long *)&monitorpage->trigger_group
  56                                         [channel->monitor_grp].pending);
  57
  58         } else {
  59                 vmbus_set_event(channel);
  60         }
  61 }
  62
  63 /*
  64  * vmbus_open - Open the specified channel.
  65  */
  66 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
  67                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
  68                      void (*onchannelcallback)(void *context), void *context)
  69 {
  70         struct vmbus_channel_open_channel *open_msg;
  71         struct vmbus_channel_msginfo *open_info = NULL;
  72         void *in, *out;
  73         unsigned long flags;
  74         int ret, err = 0;
  75         unsigned long t;
  76         struct page *page;
  77
  78         spin_lock_irqsave(&newchannel->lock, flags);
  79         if (newchannel->state == CHANNEL_OPEN_STATE) {
  80                 newchannel->state = CHANNEL_OPENING_STATE;
  81         } else {
  82                 spin_unlock_irqrestore(&newchannel->lock, flags);
  83                 return -EINVAL;
  84         }
  85         spin_unlock_irqrestore(&newchannel->lock, flags);
  86
  87         newchannel->onchannel_callback = onchannelcallback;
  88         newchannel->channel_callback_context = context;
  89
  90         /* Allocate the ring buffer */
  91         page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
  92                                 GFP_KERNEL|__GFP_ZERO,
  93                                 get_order(send_ringbuffer_size +
  94                                 recv_ringbuffer_size));
  95
  96         if (!page)
  97                 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
  98                                                get_order(send_ringbuffer_size +
  99                                                recv_ringbuffer_size));
 100         else
 101                 out = (void *)page_address(page);
 102
 103         if (!out) {
 104                 err = -ENOMEM;
 105                 goto error0;
 106         }
 107
 108         in = (void *)((unsigned long)out + send_ringbuffer_size);
 109
 110         newchannel->ringbuffer_pages = out;
 111         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 112                                            recv_ringbuffer_size) >> PAGE_SHIFT;
 113
 114         ret = hv_ringbuffer_init(
 115                 &newchannel->outbound, out, send_ringbuffer_size);
 116
 117         if (ret != 0) {
 118                 err = ret;
 119                 goto error0;
 120         }
 121
 122         ret = hv_ringbuffer_init(
 123                 &newchannel->inbound, in, recv_ringbuffer_size);
 124         if (ret != 0) {
 125                 err = ret;
 126                 goto error0;
 127         }
 128
 129
 130         /* Establish the gpadl for the ring buffer */
 131         newchannel->ringbuffer_gpadlhandle = 0;
 132
 133         ret = vmbus_establish_gpadl(newchannel,
 134                                          newchannel->outbound.ring_buffer,
 135                                          send_ringbuffer_size +
 136                                          recv_ringbuffer_size,
 137                                          &newchannel->ringbuffer_gpadlhandle);
 138
 139         if (ret != 0) {
 140                 err = ret;
 141                 goto error0;
 142         }
 143
 144         /* Create and init the channel open message */
 145         open_info = kmalloc(sizeof(*open_info) +
 146                            sizeof(struct vmbus_channel_open_channel),
 147                            GFP_KERNEL);
 148         if (!open_info) {
 149                 err = -ENOMEM;
 150                 goto error_gpadl;
 151         }
 152
 153         init_completion(&open_info->waitevent);
 154
 155         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
 156         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
 157         open_msg->openid = newchannel->offermsg.child_relid;
 158         open_msg->child_relid = newchannel->offermsg.child_relid;
 159         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
 160         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
 161                                                   PAGE_SHIFT;
 162         open_msg->target_vp = newchannel->target_vp;
 163
 164         if (userdatalen > MAX_USER_DEFINED_BYTES) {
 165                 err = -EINVAL;
 166                 goto error_gpadl;
 167         }
 168
 169         if (userdatalen)
 170                 memcpy(open_msg->userdata, userdata, userdatalen);
 171
 172         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 173         list_add_tail(&open_info->msglistentry,
 174                       &vmbus_connection.chn_msg_list);
 175         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 176
 177         ret = vmbus_post_msg(open_msg,
 178                                sizeof(struct vmbus_channel_open_channel));
 179
 180         if (ret != 0) {
 181                 err = ret;
 182                 goto error1;
 183         }
 184
 185         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
 186         if (t == 0) {
 187                 err = -ETIMEDOUT;
 188                 goto error1;
 189         }
 190
 191         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 192         list_del(&open_info->msglistentry);
 193         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 194
 195         if (open_info->response.open_result.status) {
 196                 err = -EAGAIN;
 197                 goto error_gpadl;
 198         }
 199
 200         newchannel->state = CHANNEL_OPENED_STATE;
 201         kfree(open_info);
 202         return 0;
 203
 204 error1:
 205         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 206         list_del(&open_info->msglistentry);
 207         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 208
 209 error_gpadl:
 210         vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
 211
 212 error0:
 213         free_pages((unsigned long)out,
 214                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
 215         kfree(open_info);
 216         newchannel->state = CHANNEL_OPEN_STATE;
 217         return err;
 218 }
 219 EXPORT_SYMBOL_GPL(vmbus_open);
 220
 221 /*
 222  * create_gpadl_header - Creates a gpadl for the specified buffer
 223  */
 224 static int create_gpadl_header(void *kbuffer, u32 size,
 225                                          struct vmbus_channel_msginfo **msginfo,
 226                                          u32 *messagecount)
 227 {
 228         int i;
 229         int pagecount;
 230         struct vmbus_channel_gpadl_header *gpadl_header;
 231         struct vmbus_channel_gpadl_body *gpadl_body;
 232         struct vmbus_channel_msginfo *msgheader;
 233         struct vmbus_channel_msginfo *msgbody = NULL;
 234         u32 msgsize;
 235
 236         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
 237
 238         pagecount = size >> PAGE_SHIFT;
 239
 240         /* do we need a gpadl body msg */
 241         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 242                   sizeof(struct vmbus_channel_gpadl_header) -
 243                   sizeof(struct gpa_range);
 244         pfncount = pfnsize / sizeof(u64);
 245
 246         if (pagecount > pfncount) {
 247                 /* we need a gpadl body */
 248                 /* fill in the header */
 249                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 250                           sizeof(struct vmbus_channel_gpadl_header) +
 251                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
 252                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
 253                 if (!msgheader)
 254                         goto nomem;
 255
 256                 INIT_LIST_HEAD(&msgheader->submsglist);
 257                 msgheader->msgsize = msgsize;
 258
 259                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 260                         msgheader->msg;
 261                 gpadl_header->rangecount = 1;
 262                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 263                                          pagecount * sizeof(u64);
 264                 gpadl_header->range[0].byte_offset = 0;
 265                 gpadl_header->range[0].byte_count = size;
 266                 for (i = 0; i < pfncount; i++)
 267                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 268                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 269                 *msginfo = msgheader;
 270                 *messagecount = 1;
 271
 272                 pfnsum = pfncount;
 273                 pfnleft = pagecount - pfncount;
 274
 275                 /* how many pfns can we fit */
 276                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
 277                           sizeof(struct vmbus_channel_gpadl_body);
 278                 pfncount = pfnsize / sizeof(u64);
 279
 280                 /* fill in the body */
 281                 while (pfnleft) {
 282                         if (pfnleft > pfncount)
 283                                 pfncurr = pfncount;
 284                         else
 285                                 pfncurr = pfnleft;
 286
 287                         msgsize = sizeof(struct vmbus_channel_msginfo) +
 288                                   sizeof(struct vmbus_channel_gpadl_body) +
 289                                   pfncurr * sizeof(u64);
 290                         msgbody = kzalloc(msgsize, GFP_KERNEL);
 291
 292                         if (!msgbody) {
 293                                 struct vmbus_channel_msginfo *pos = NULL;
 294                                 struct vmbus_channel_msginfo *tmp = NULL;
 295                                 /*
 296                                  * Free up all the allocated messages.
 297                                  */
 298                                 list_for_each_entry_safe(pos, tmp,
 299                                         &msgheader->submsglist,
 300                                         msglistentry) {
 301
 302                                         list_del(&pos->msglistentry);
 303                                         kfree(pos);
 304                                 }
 305
 306                                 goto nomem;
 307                         }
 308
 309                         msgbody->msgsize = msgsize;
 310                         (*messagecount)++;
 311                         gpadl_body =
 312                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
 313
 314                         /*
 315                          * Gpadl is u32 and we are using a pointer which could
 316                          * be 64-bit
 317                          * This is governed by the guest/host protocol and
 318                          * so the hypervisor gurantees that this is ok.
 319                          */
 320                         for (i = 0; i < pfncurr; i++)
 321                                 gpadl_body->pfn[i] = slow_virt_to_phys(
 322                                         kbuffer + PAGE_SIZE * (pfnsum + i)) >>
 323                                         PAGE_SHIFT;
 324
 325                         /* add to msg header */
 326                         list_add_tail(&msgbody->msglistentry,
 327                                       &msgheader->submsglist);
 328                         pfnsum += pfncurr;
 329                         pfnleft -= pfncurr;
 330                 }
 331         } else {
 332                 /* everything fits in a header */
 333                 msgsize = sizeof(struct vmbus_channel_msginfo) +
 334                           sizeof(struct vmbus_channel_gpadl_header) +
 335                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
 336                 msgheader = kzalloc(msgsize, GFP_KERNEL);
 337                 if (msgheader == NULL)
 338                         goto nomem;
 339                 msgheader->msgsize = msgsize;
 340
 341                 gpadl_header = (struct vmbus_channel_gpadl_header *)
 342                         msgheader->msg;
 343                 gpadl_header->rangecount = 1;
 344                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
 345                                          pagecount * sizeof(u64);
 346                 gpadl_header->range[0].byte_offset = 0;
 347                 gpadl_header->range[0].byte_count = size;
 348                 for (i = 0; i < pagecount; i++)
 349                         gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 350                                 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 351
 352                 *msginfo = msgheader;
 353                 *messagecount = 1;
 354         }
 355
 356         return 0;
 357 nomem:
 358         kfree(msgheader);
 359         kfree(msgbody);
 360         return -ENOMEM;
 361 }
 362
 363 /*
 364  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
 365  *
 366  * @channel: a channel
 367  * @kbuffer: from kmalloc or vmalloc
 368  * @size: page-size multiple
 369  * @gpadl_handle: some funky thing
 370  */
 371 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 372                                u32 size, u32 *gpadl_handle)
 373 {
 374         struct vmbus_channel_gpadl_header *gpadlmsg;
 375         struct vmbus_channel_gpadl_body *gpadl_body;
 376         struct vmbus_channel_msginfo *msginfo = NULL;
 377         struct vmbus_channel_msginfo *submsginfo;
 378         u32 msgcount;
 379         struct list_head *curr;
 380         u32 next_gpadl_handle;
 381         unsigned long flags;
 382         int ret = 0;
 383
 384         next_gpadl_handle =
 385                 (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
 386
 387         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
 388         if (ret)
 389                 return ret;
 390
 391         init_completion(&msginfo->waitevent);
 392
 393         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
 394         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
 395         gpadlmsg->child_relid = channel->offermsg.child_relid;
 396         gpadlmsg->gpadl = next_gpadl_handle;
 397
 398
 399         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 400         list_add_tail(&msginfo->msglistentry,
 401                       &vmbus_connection.chn_msg_list);
 402
 403         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 404
 405         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
 406                                sizeof(*msginfo));
 407         if (ret != 0)
 408                 goto cleanup;
 409
 410         if (msgcount > 1) {
 411                 list_for_each(curr, &msginfo->submsglist) {
 412
 413                         submsginfo = (struct vmbus_channel_msginfo *)curr;
 414                         gpadl_body =
 415                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
 416
 417                         gpadl_body->header.msgtype =
 418                                 CHANNELMSG_GPADL_BODY;
 419                         gpadl_body->gpadl = next_gpadl_handle;
 420
 421                         ret = vmbus_post_msg(gpadl_body,
 422                                                submsginfo->msgsize -
 423                                                sizeof(*submsginfo));
 424                         if (ret != 0)
 425                                 goto cleanup;
 426
 427                 }
 428         }
 429         wait_for_completion(&msginfo->waitevent);
 430
 431         /* At this point, we received the gpadl created msg */
 432         *gpadl_handle = gpadlmsg->gpadl;
 433
 434 cleanup:
 435         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 436         list_del(&msginfo->msglistentry);
 437         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 438
 439         kfree(msginfo);
 440         return ret;
 441 }
 442 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
 443
 444 /*
 445  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
 446  */
 447 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
 448 {
 449         struct vmbus_channel_gpadl_teardown *msg;
 450         struct vmbus_channel_msginfo *info;
 451         unsigned long flags;
 452         int ret;
 453
 454         info = kmalloc(sizeof(*info) +
 455                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
 456         if (!info)
 457                 return -ENOMEM;
 458
 459         init_completion(&info->waitevent);
 460
 461         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
 462
 463         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
 464         msg->child_relid = channel->offermsg.child_relid;
 465         msg->gpadl = gpadl_handle;
 466
 467         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 468         list_add_tail(&info->msglistentry,
 469                       &vmbus_connection.chn_msg_list);
 470         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 471         ret = vmbus_post_msg(msg,
 472                                sizeof(struct vmbus_channel_gpadl_teardown));
 473
 474         if (ret)
 475                 goto post_msg_err;
 476
 477         wait_for_completion(&info->waitevent);
 478
 479 post_msg_err:
 480         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 481         list_del(&info->msglistentry);
 482         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 483
 484         kfree(info);
 485         return ret;
 486 }
 487 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
 488
 489 static void reset_channel_cb(void *arg)
 490 {
 491         struct vmbus_channel *channel = arg;
 492
 493         channel->onchannel_callback = NULL;
 494 }
 495
 496 static int vmbus_close_internal(struct vmbus_channel *channel)
 497 {
 498         struct vmbus_channel_close_channel *msg;
 499         int ret;
 500
 501         channel->state = CHANNEL_OPEN_STATE;
 502         channel->sc_creation_callback = NULL;
 503         /* Stop callback and cancel the timer asap */
 504         if (channel->target_cpu != get_cpu()) {
 505                 put_cpu();
 506                 smp_call_function_single(channel->target_cpu, reset_channel_cb,
 507                                          channel, true);
 508         } else {
 509                 reset_channel_cb(channel);
 510                 put_cpu();
 511         }
 512
 513         /* Send a closing message */
 514
 515         msg = &channel->close_msg.msg;
 516
 517         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
 518         msg->child_relid = channel->offermsg.child_relid;
 519
 520         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
 521
 522         if (ret) {
 523                 pr_err("Close failed: close post msg return is %d\n", ret);
 524                 /*
 525                  * If we failed to post the close msg,
 526                  * it is perhaps better to leak memory.
 527                  */
 528                 return ret;
 529         }
 530
 531         /* Tear down the gpadl for the channel's ring buffer */
 532         if (channel->ringbuffer_gpadlhandle) {
 533                 ret = vmbus_teardown_gpadl(channel,
 534                                            channel->ringbuffer_gpadlhandle);
 535                 if (ret) {
 536                         pr_err("Close failed: teardown gpadl return %d\n", ret);
 537                         /*
 538                          * If we failed to teardown gpadl,
 539                          * it is perhaps better to leak memory.
 540                          */
 541                         return ret;
 542                 }
 543         }
 544
 545         /* Cleanup the ring buffers for this channel */
 546         hv_ringbuffer_cleanup(&channel->outbound);
 547         hv_ringbuffer_cleanup(&channel->inbound);
 548
 549         free_pages((unsigned long)channel->ringbuffer_pages,
 550                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 551
 552         /*
 553          * If the channel has been rescinded; process device removal.
 554          */
 555         if (channel->rescind)
 556                 hv_process_channel_removal(channel,
 557                                            channel->offermsg.child_relid);
 558         return ret;
 559 }
 560
 561 /*
 562  * vmbus_close - Close the specified channel
 563  */
 564 void vmbus_close(struct vmbus_channel *channel)
 565 {
 566         struct list_head *cur, *tmp;
 567         struct vmbus_channel *cur_channel;
 568
 569         if (channel->primary_channel != NULL) {
 570                 /*
 571                  * We will only close sub-channels when
 572                  * the primary is closed.
 573                  */
 574                 return;
 575         }
 576         /*
 577          * Close all the sub-channels first and then close the
 578          * primary channel.
 579          */
 580         list_for_each_safe(cur, tmp, &channel->sc_list) {
 581                 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
 582                 if (cur_channel->state != CHANNEL_OPENED_STATE)
 583                         continue;
 584                 vmbus_close_internal(cur_channel);
 585         }
 586         /*
 587          * Now close the primary.
 588          */
 589         vmbus_close_internal(channel);
 590 }
 591 EXPORT_SYMBOL_GPL(vmbus_close);
 592
 593 int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 594                            u32 bufferlen, u64 requestid,
 595                            enum vmbus_packet_type type, u32 flags, bool kick_q)
 596 {
 597         struct vmpacket_descriptor desc;
 598         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
 599         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 600         struct kvec bufferlist[3];
 601         u64 aligned_data = 0;
 602         int ret;
 603         bool signal = false;
 604         int num_vecs = ((bufferlen != 0) ? 3 : 1);
 605
 606
 607         /* Setup the descriptor */
 608         desc.type = type; /* VmbusPacketTypeDataInBand; */
 609         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 610         /* in 8-bytes granularity */
 611         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 612         desc.len8 = (u16)(packetlen_aligned >> 3);
 613         desc.trans_id = requestid;
 614
 615         bufferlist[0].iov_base = &desc;
 616         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 617         bufferlist[1].iov_base = buffer;
 618         bufferlist[1].iov_len = bufferlen;
 619         bufferlist[2].iov_base = &aligned_data;
 620         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 621
 622         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
 623                                   &signal);
 624
 625         /*
 626          * Signalling the host is conditional on many factors:
 627          * 1. The ring state changed from being empty to non-empty.
 628          *    This is tracked by the variable "signal".
 629          * 2. The variable kick_q tracks if more data will be placed
 630          *    on the ring. We will not signal if more data is
 631          *    to be placed.
 632          *
 633          * Based on the channel signal state, we will decide
 634          * which signaling policy will be applied.
 635          *
 636          * If we cannot write to the ring-buffer; signal the host
 637          * even if we may not have written anything. This is a rare
 638          * enough condition that it should not matter.
 639          */
 640
 641         if (channel->signal_policy)
 642                 signal = true;
 643         else
 644                 kick_q = true;
 645
 646         if (((ret == 0) && kick_q && signal) || (ret))
 647                 vmbus_setevent(channel);
 648
 649         return ret;
 650 }
 651 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 652
 653 /**
 654  * vmbus_sendpacket() - Send the specified buffer on the given channel
 655  * @channel: Pointer to vmbus_channel structure.
 656  * @buffer: Pointer to the buffer you want to receive the data into.
 657  * @bufferlen: Maximum size of what the the buffer will hold
 658  * @requestid: Identifier of the request
 659  * @type: Type of packet that is being send e.g. negotiate, time
 660  * packet etc.
 661  *
 662  * Sends data in @buffer directly to hyper-v via the vmbus
 663  * This will send the data unparsed to hyper-v.
 664  *
 665  * Mainly used by Hyper-V drivers.
 666  */
 667 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 668                            u32 bufferlen, u64 requestid,
 669                            enum vmbus_packet_type type, u32 flags)
 670 {
 671         return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
 672                                     type, flags, true);
 673 }
 674 EXPORT_SYMBOL(vmbus_sendpacket);
 675
 676 /*
 677  * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
 678  * packets using a GPADL Direct packet type. This interface allows you
 679  * to control notifying the host. This will be useful for sending
 680  * batched data. Also the sender can control the send flags
 681  * explicitly.
 682  */
 683 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 684                                      struct hv_page_buffer pagebuffers[],
 685                                      u32 pagecount, void *buffer, u32 bufferlen,
 686                                      u64 requestid,
 687                                      u32 flags,
 688                                      bool kick_q)
 689 {
 690         int ret;
 691         int i;
 692         struct vmbus_channel_packet_page_buffer desc;
 693         u32 descsize;
 694         u32 packetlen;
 695         u32 packetlen_aligned;
 696         struct kvec bufferlist[3];
 697         u64 aligned_data = 0;
 698         bool signal = false;
 699
 700         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 701                 return -EINVAL;
 702
 703
 704         /*
 705          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 706          * largest size we support
 707          */
 708         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 709                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 710                           sizeof(struct hv_page_buffer));
 711         packetlen = descsize + bufferlen;
 712         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 713
 714         /* Setup the descriptor */
 715         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 716         desc.flags = flags;
 717         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 718         desc.length8 = (u16)(packetlen_aligned >> 3);
 719         desc.transactionid = requestid;
 720         desc.rangecount = pagecount;
 721
 722         for (i = 0; i < pagecount; i++) {
 723                 desc.range[i].len = pagebuffers[i].len;
 724                 desc.range[i].offset = pagebuffers[i].offset;
 725                 desc.range[i].pfn        = pagebuffers[i].pfn;
 726         }
 727
 728         bufferlist[0].iov_base = &desc;
 729         bufferlist[0].iov_len = descsize;
 730         bufferlist[1].iov_base = buffer;
 731         bufferlist[1].iov_len = bufferlen;
 732         bufferlist[2].iov_base = &aligned_data;
 733         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 734
 735         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 736
 737         /*
 738          * Signalling the host is conditional on many factors:
 739          * 1. The ring state changed from being empty to non-empty.
 740          *    This is tracked by the variable "signal".
 741          * 2. The variable kick_q tracks if more data will be placed
 742          *    on the ring. We will not signal if more data is
 743          *    to be placed.
 744          *
 745          * Based on the channel signal state, we will decide
 746          * which signaling policy will be applied.
 747          *
 748          * If we cannot write to the ring-buffer; signal the host
 749          * even if we may not have written anything. This is a rare
 750          * enough condition that it should not matter.
 751          */
 752
 753         if (channel->signal_policy)
 754                 signal = true;
 755         else
 756                 kick_q = true;
 757
 758         if (((ret == 0) && kick_q && signal) || (ret))
 759                 vmbus_setevent(channel);
 760
 761         return ret;
 762 }
 763 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 764
 765 /*
 766  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 767  * packets using a GPADL Direct packet type.
 768  */
 769 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 770                                      struct hv_page_buffer pagebuffers[],
 771                                      u32 pagecount, void *buffer, u32 bufferlen,
 772                                      u64 requestid)
 773 {
 774         u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 775         return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
 776                                                buffer, bufferlen, requestid,
 777                                                flags, true);
 778
 779 }
 780 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 781
 782 /*
 783  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 784  * using a GPADL Direct packet type.
 785  * The buffer includes the vmbus descriptor.
 786  */
 787 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 788                               struct vmbus_packet_mpb_array *desc,
 789                               u32 desc_size,
 790                               void *buffer, u32 bufferlen, u64 requestid)
 791 {
 792         int ret;
 793         u32 packetlen;
 794         u32 packetlen_aligned;
 795         struct kvec bufferlist[3];
 796         u64 aligned_data = 0;
 797         bool signal = false;
 798
 799         packetlen = desc_size + bufferlen;
 800         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 801
 802         /* Setup the descriptor */
 803         desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 804         desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 805         desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
 806         desc->length8 = (u16)(packetlen_aligned >> 3);
 807         desc->transactionid = requestid;
 808         desc->rangecount = 1;
 809
 810         bufferlist[0].iov_base = desc;
 811         bufferlist[0].iov_len = desc_size;
 812         bufferlist[1].iov_base = buffer;
 813         bufferlist[1].iov_len = bufferlen;
 814         bufferlist[2].iov_base = &aligned_data;
 815         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 816
 817         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 818
 819         if (ret == 0 && signal)
 820                 vmbus_setevent(channel);
 821
 822         return ret;
 823 }
 824 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 825
 826 /*
 827  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 828  * using a GPADL Direct packet type.
 829  */
 830 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 831                                 struct hv_multipage_buffer *multi_pagebuffer,
 832                                 void *buffer, u32 bufferlen, u64 requestid)
 833 {
 834         int ret;
 835         struct vmbus_channel_packet_multipage_buffer desc;
 836         u32 descsize;
 837         u32 packetlen;
 838         u32 packetlen_aligned;
 839         struct kvec bufferlist[3];
 840         u64 aligned_data = 0;
 841         bool signal = false;
 842         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 843                                          multi_pagebuffer->len);
 844
 845         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 846                 return -EINVAL;
 847
 848         /*
 849          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 850          * the largest size we support
 851          */
 852         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 853                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 854                           sizeof(u64));
 855         packetlen = descsize + bufferlen;
 856         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 857
 858
 859         /* Setup the descriptor */
 860         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 861         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 862         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 863         desc.length8 = (u16)(packetlen_aligned >> 3);
 864         desc.transactionid = requestid;
 865         desc.rangecount = 1;
 866
 867         desc.range.len = multi_pagebuffer->len;
 868         desc.range.offset = multi_pagebuffer->offset;
 869
 870         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 871                pfncount * sizeof(u64));
 872
 873         bufferlist[0].iov_base = &desc;
 874         bufferlist[0].iov_len = descsize;
 875         bufferlist[1].iov_base = buffer;
 876         bufferlist[1].iov_len = bufferlen;
 877         bufferlist[2].iov_base = &aligned_data;
 878         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 879
 880         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 881
 882         if (ret == 0 && signal)
 883                 vmbus_setevent(channel);
 884
 885         return ret;
 886 }
 887 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 888
 889 /**
 890  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 891  * @channel: Pointer to vmbus_channel structure.
 892  * @buffer: Pointer to the buffer you want to receive the data into.
 893  * @bufferlen: Maximum size of what the the buffer will hold
 894  * @buffer_actual_len: The actual size of the data after it was received
 895  * @requestid: Identifier of the request
 896  *
 897  * Receives directly from the hyper-v vmbus and puts the data it received
 898  * into Buffer. This will receive the data unparsed from hyper-v.
 899  *
 900  * Mainly used by Hyper-V drivers.
 901  */
 902 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 903                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 904 {
 905         struct vmpacket_descriptor desc;
 906         u32 packetlen;
 907         u32 userlen;
 908         int ret;
 909         bool signal = false;
 910
 911         *buffer_actual_len = 0;
 912         *requestid = 0;
 913
 914
 915         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 916                              sizeof(struct vmpacket_descriptor));
 917         if (ret != 0)
 918                 return 0;
 919
 920         packetlen = desc.len8 << 3;
 921         userlen = packetlen - (desc.offset8 << 3);
 922
 923         *buffer_actual_len = userlen;
 924
 925         if (userlen > bufferlen) {
 926
 927                 pr_err("Buffer too small - got %d needs %d\n",
 928                            bufferlen, userlen);
 929                 return -ETOOSMALL;
 930         }
 931
 932         *requestid = desc.trans_id;
 933
 934         /* Copy over the packet to the user buffer */
 935         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 936                              (desc.offset8 << 3), &signal);
 937
 938         if (signal)
 939                 vmbus_setevent(channel);
 940
 941         return 0;
 942 }
 943 EXPORT_SYMBOL(vmbus_recvpacket);
 944
 945 /*
 946  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 947  */
 948 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 949                               u32 bufferlen, u32 *buffer_actual_len,
 950                               u64 *requestid)
 951 {
 952         struct vmpacket_descriptor desc;
 953         u32 packetlen;
 954         int ret;
 955         bool signal = false;
 956
 957         *buffer_actual_len = 0;
 958         *requestid = 0;
 959
 960
 961         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 962                              sizeof(struct vmpacket_descriptor));
 963         if (ret != 0)
 964                 return 0;
 965
 966
 967         packetlen = desc.len8 << 3;
 968
 969         *buffer_actual_len = packetlen;
 970
 971         if (packetlen > bufferlen)
 972                 return -ENOBUFS;
 973
 974         *requestid = desc.trans_id;
 975
 976         /* Copy over the entire packet to the user buffer */
 977         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 978                                  &signal);
 979
 980         if (signal)
 981                 vmbus_setevent(channel);
 982
 983         return ret;
 984 }
 985 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);