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
 605
 606         /* Setup the descriptor */
 607         desc.type = type; /* VmbusPacketTypeDataInBand; */
 608         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
 609         /* in 8-bytes granularity */
 610         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
 611         desc.len8 = (u16)(packetlen_aligned >> 3);
 612         desc.trans_id = requestid;
 613
 614         bufferlist[0].iov_base = &desc;
 615         bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
 616         bufferlist[1].iov_base = buffer;
 617         bufferlist[1].iov_len = bufferlen;
 618         bufferlist[2].iov_base = &aligned_data;
 619         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 620
 621         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 622
 623         /*
 624          * Signalling the host is conditional on many factors:
 625          * 1. The ring state changed from being empty to non-empty.
 626          *    This is tracked by the variable "signal".
 627          * 2. The variable kick_q tracks if more data will be placed
 628          *    on the ring. We will not signal if more data is
 629          *    to be placed.
 630          *
 631          * If we cannot write to the ring-buffer; signal the host
 632          * even if we may not have written anything. This is a rare
 633          * enough condition that it should not matter.
 634          */
 635         if (((ret == 0) && kick_q && signal) || (ret))
 636                 vmbus_setevent(channel);
 637
 638         return ret;
 639 }
 640 EXPORT_SYMBOL(vmbus_sendpacket_ctl);
 641
 642 /**
 643  * vmbus_sendpacket() - Send the specified buffer on the given channel
 644  * @channel: Pointer to vmbus_channel structure.
 645  * @buffer: Pointer to the buffer you want to receive the data into.
 646  * @bufferlen: Maximum size of what the the buffer will hold
 647  * @requestid: Identifier of the request
 648  * @type: Type of packet that is being send e.g. negotiate, time
 649  * packet etc.
 650  *
 651  * Sends data in @buffer directly to hyper-v via the vmbus
 652  * This will send the data unparsed to hyper-v.
 653  *
 654  * Mainly used by Hyper-V drivers.
 655  */
 656 int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 657                            u32 bufferlen, u64 requestid,
 658                            enum vmbus_packet_type type, u32 flags)
 659 {
 660         return vmbus_sendpacket_ctl(channel, buffer, bufferlen, requestid,
 661                                     type, flags, true);
 662 }
 663 EXPORT_SYMBOL(vmbus_sendpacket);
 664
 665 /*
 666  * vmbus_sendpacket_pagebuffer_ctl - Send a range of single-page buffer
 667  * packets using a GPADL Direct packet type. This interface allows you
 668  * to control notifying the host. This will be useful for sending
 669  * batched data. Also the sender can control the send flags
 670  * explicitly.
 671  */
 672 int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 673                                      struct hv_page_buffer pagebuffers[],
 674                                      u32 pagecount, void *buffer, u32 bufferlen,
 675                                      u64 requestid,
 676                                      u32 flags,
 677                                      bool kick_q)
 678 {
 679         int ret;
 680         int i;
 681         struct vmbus_channel_packet_page_buffer desc;
 682         u32 descsize;
 683         u32 packetlen;
 684         u32 packetlen_aligned;
 685         struct kvec bufferlist[3];
 686         u64 aligned_data = 0;
 687         bool signal = false;
 688
 689         if (pagecount > MAX_PAGE_BUFFER_COUNT)
 690                 return -EINVAL;
 691
 692
 693         /*
 694          * Adjust the size down since vmbus_channel_packet_page_buffer is the
 695          * largest size we support
 696          */
 697         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
 698                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
 699                           sizeof(struct hv_page_buffer));
 700         packetlen = descsize + bufferlen;
 701         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 702
 703         /* Setup the descriptor */
 704         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 705         desc.flags = flags;
 706         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 707         desc.length8 = (u16)(packetlen_aligned >> 3);
 708         desc.transactionid = requestid;
 709         desc.rangecount = pagecount;
 710
 711         for (i = 0; i < pagecount; i++) {
 712                 desc.range[i].len = pagebuffers[i].len;
 713                 desc.range[i].offset = pagebuffers[i].offset;
 714                 desc.range[i].pfn        = pagebuffers[i].pfn;
 715         }
 716
 717         bufferlist[0].iov_base = &desc;
 718         bufferlist[0].iov_len = descsize;
 719         bufferlist[1].iov_base = buffer;
 720         bufferlist[1].iov_len = bufferlen;
 721         bufferlist[2].iov_base = &aligned_data;
 722         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 723
 724         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 725
 726         /*
 727          * Signalling the host is conditional on many factors:
 728          * 1. The ring state changed from being empty to non-empty.
 729          *    This is tracked by the variable "signal".
 730          * 2. The variable kick_q tracks if more data will be placed
 731          *    on the ring. We will not signal if more data is
 732          *    to be placed.
 733          *
 734          * If we cannot write to the ring-buffer; signal the host
 735          * even if we may not have written anything. This is a rare
 736          * enough condition that it should not matter.
 737          */
 738         if (((ret == 0) && kick_q && signal) || (ret))
 739                 vmbus_setevent(channel);
 740
 741         return ret;
 742 }
 743 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer_ctl);
 744
 745 /*
 746  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
 747  * packets using a GPADL Direct packet type.
 748  */
 749 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 750                                      struct hv_page_buffer pagebuffers[],
 751                                      u32 pagecount, void *buffer, u32 bufferlen,
 752                                      u64 requestid)
 753 {
 754         u32 flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 755         return vmbus_sendpacket_pagebuffer_ctl(channel, pagebuffers, pagecount,
 756                                                buffer, bufferlen, requestid,
 757                                                flags, true);
 758
 759 }
 760 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 761
 762 /*
 763  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 764  * using a GPADL Direct packet type.
 765  * The buffer includes the vmbus descriptor.
 766  */
 767 int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 768                               struct vmbus_packet_mpb_array *desc,
 769                               u32 desc_size,
 770                               void *buffer, u32 bufferlen, u64 requestid)
 771 {
 772         int ret;
 773         u32 packetlen;
 774         u32 packetlen_aligned;
 775         struct kvec bufferlist[3];
 776         u64 aligned_data = 0;
 777         bool signal = false;
 778
 779         packetlen = desc_size + bufferlen;
 780         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 781
 782         /* Setup the descriptor */
 783         desc->type = VM_PKT_DATA_USING_GPA_DIRECT;
 784         desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 785         desc->dataoffset8 = desc_size >> 3; /* in 8-bytes grandularity */
 786         desc->length8 = (u16)(packetlen_aligned >> 3);
 787         desc->transactionid = requestid;
 788         desc->rangecount = 1;
 789
 790         bufferlist[0].iov_base = desc;
 791         bufferlist[0].iov_len = desc_size;
 792         bufferlist[1].iov_base = buffer;
 793         bufferlist[1].iov_len = bufferlen;
 794         bufferlist[2].iov_base = &aligned_data;
 795         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 796
 797         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 798
 799         if (ret == 0 && signal)
 800                 vmbus_setevent(channel);
 801
 802         return ret;
 803 }
 804 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 805
 806 /*
 807  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
 808  * using a GPADL Direct packet type.
 809  */
 810 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 811                                 struct hv_multipage_buffer *multi_pagebuffer,
 812                                 void *buffer, u32 bufferlen, u64 requestid)
 813 {
 814         int ret;
 815         struct vmbus_channel_packet_multipage_buffer desc;
 816         u32 descsize;
 817         u32 packetlen;
 818         u32 packetlen_aligned;
 819         struct kvec bufferlist[3];
 820         u64 aligned_data = 0;
 821         bool signal = false;
 822         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 823                                          multi_pagebuffer->len);
 824
 825         if (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)
 826                 return -EINVAL;
 827
 828         /*
 829          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
 830          * the largest size we support
 831          */
 832         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
 833                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
 834                           sizeof(u64));
 835         packetlen = descsize + bufferlen;
 836         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
 837
 838
 839         /* Setup the descriptor */
 840         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
 841         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
 842         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
 843         desc.length8 = (u16)(packetlen_aligned >> 3);
 844         desc.transactionid = requestid;
 845         desc.rangecount = 1;
 846
 847         desc.range.len = multi_pagebuffer->len;
 848         desc.range.offset = multi_pagebuffer->offset;
 849
 850         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
 851                pfncount * sizeof(u64));
 852
 853         bufferlist[0].iov_base = &desc;
 854         bufferlist[0].iov_len = descsize;
 855         bufferlist[1].iov_base = buffer;
 856         bufferlist[1].iov_len = bufferlen;
 857         bufferlist[2].iov_base = &aligned_data;
 858         bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 859
 860         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
 861
 862         if (ret == 0 && signal)
 863                 vmbus_setevent(channel);
 864
 865         return ret;
 866 }
 867 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
 868
 869 /**
 870  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
 871  * @channel: Pointer to vmbus_channel structure.
 872  * @buffer: Pointer to the buffer you want to receive the data into.
 873  * @bufferlen: Maximum size of what the the buffer will hold
 874  * @buffer_actual_len: The actual size of the data after it was received
 875  * @requestid: Identifier of the request
 876  *
 877  * Receives directly from the hyper-v vmbus and puts the data it received
 878  * into Buffer. This will receive the data unparsed from hyper-v.
 879  *
 880  * Mainly used by Hyper-V drivers.
 881  */
 882 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
 883                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
 884 {
 885         struct vmpacket_descriptor desc;
 886         u32 packetlen;
 887         u32 userlen;
 888         int ret;
 889         bool signal = false;
 890
 891         *buffer_actual_len = 0;
 892         *requestid = 0;
 893
 894
 895         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 896                              sizeof(struct vmpacket_descriptor));
 897         if (ret != 0)
 898                 return 0;
 899
 900         packetlen = desc.len8 << 3;
 901         userlen = packetlen - (desc.offset8 << 3);
 902
 903         *buffer_actual_len = userlen;
 904
 905         if (userlen > bufferlen) {
 906
 907                 pr_err("Buffer too small - got %d needs %d\n",
 908                            bufferlen, userlen);
 909                 return -ETOOSMALL;
 910         }
 911
 912         *requestid = desc.trans_id;
 913
 914         /* Copy over the packet to the user buffer */
 915         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
 916                              (desc.offset8 << 3), &signal);
 917
 918         if (signal)
 919                 vmbus_setevent(channel);
 920
 921         return 0;
 922 }
 923 EXPORT_SYMBOL(vmbus_recvpacket);
 924
 925 /*
 926  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
 927  */
 928 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
 929                               u32 bufferlen, u32 *buffer_actual_len,
 930                               u64 *requestid)
 931 {
 932         struct vmpacket_descriptor desc;
 933         u32 packetlen;
 934         int ret;
 935         bool signal = false;
 936
 937         *buffer_actual_len = 0;
 938         *requestid = 0;
 939
 940
 941         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
 942                              sizeof(struct vmpacket_descriptor));
 943         if (ret != 0)
 944                 return 0;
 945
 946
 947         packetlen = desc.len8 << 3;
 948
 949         *buffer_actual_len = packetlen;
 950
 951         if (packetlen > bufferlen)
 952                 return -ENOBUFS;
 953
 954         *requestid = desc.trans_id;
 955
 956         /* Copy over the entire packet to the user buffer */
 957         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
 958                                  &signal);
 959
 960         if (signal)
 961                 vmbus_setevent(channel);
 962
 963         return ret;
 964 }
 965 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);