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 /* Get the child to parent monitor page */ 51 monitorpage = vmbus_connection.monitor_pages[1]; 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_open - Open the specified channel. 64 */ 65 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size, 66 u32 recv_ringbuffer_size, void *userdata, u32 userdatalen, 67 void (*onchannelcallback)(void *context), void *context) 68 { 69 struct vmbus_channel_open_channel *open_msg; 70 struct vmbus_channel_msginfo *open_info = NULL; 71 void *in, *out; 72 unsigned long flags; 73 int ret, t, err = 0; 74 75 spin_lock_irqsave(&newchannel->sc_lock, flags); 76 if (newchannel->state == CHANNEL_OPEN_STATE) { 77 newchannel->state = CHANNEL_OPENING_STATE; 78 } else { 79 spin_unlock_irqrestore(&newchannel->sc_lock, flags); 80 return -EINVAL; 81 } 82 spin_unlock_irqrestore(&newchannel->sc_lock, flags); 83 84 newchannel->onchannel_callback = onchannelcallback; 85 newchannel->channel_callback_context = context; 86 87 /* Allocate the ring buffer */ 88 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 89 get_order(send_ringbuffer_size + recv_ringbuffer_size)); 90 91 if (!out) 92 return -ENOMEM; 93 94 95 in = (void *)((unsigned long)out + send_ringbuffer_size); 96 97 newchannel->ringbuffer_pages = out; 98 newchannel->ringbuffer_pagecount = (send_ringbuffer_size + 99 recv_ringbuffer_size) >> PAGE_SHIFT; 100 101 ret = hv_ringbuffer_init( 102 &newchannel->outbound, out, send_ringbuffer_size); 103 104 if (ret != 0) { 105 err = ret; 106 goto error0; 107 } 108 109 ret = hv_ringbuffer_init( 110 &newchannel->inbound, in, recv_ringbuffer_size); 111 if (ret != 0) { 112 err = ret; 113 goto error0; 114 } 115 116 117 /* Establish the gpadl for the ring buffer */ 118 newchannel->ringbuffer_gpadlhandle = 0; 119 120 ret = vmbus_establish_gpadl(newchannel, 121 newchannel->outbound.ring_buffer, 122 send_ringbuffer_size + 123 recv_ringbuffer_size, 124 &newchannel->ringbuffer_gpadlhandle); 125 126 if (ret != 0) { 127 err = ret; 128 goto error0; 129 } 130 131 /* Create and init the channel open message */ 132 open_info = kmalloc(sizeof(*open_info) + 133 sizeof(struct vmbus_channel_open_channel), 134 GFP_KERNEL); 135 if (!open_info) { 136 err = -ENOMEM; 137 goto error0; 138 } 139 140 init_completion(&open_info->waitevent); 141 142 open_msg = (struct vmbus_channel_open_channel *)open_info->msg; 143 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL; 144 open_msg->openid = newchannel->offermsg.child_relid; 145 open_msg->child_relid = newchannel->offermsg.child_relid; 146 open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle; 147 open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >> 148 PAGE_SHIFT; 149 open_msg->target_vp = newchannel->target_vp; 150 151 if (userdatalen > MAX_USER_DEFINED_BYTES) { 152 err = -EINVAL; 153 goto error0; 154 } 155 156 if (userdatalen) 157 memcpy(open_msg->userdata, userdata, userdatalen); 158 159 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 160 list_add_tail(&open_info->msglistentry, 161 &vmbus_connection.chn_msg_list); 162 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 163 164 ret = vmbus_post_msg(open_msg, 165 sizeof(struct vmbus_channel_open_channel)); 166 167 if (ret != 0) 168 goto error1; 169 170 t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ); 171 if (t == 0) { 172 err = -ETIMEDOUT; 173 goto error1; 174 } 175 176 177 if (open_info->response.open_result.status) 178 err = open_info->response.open_result.status; 179 180 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 181 list_del(&open_info->msglistentry); 182 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 183 184 if (err == 0) 185 newchannel->state = CHANNEL_OPENED_STATE; 186 187 kfree(open_info); 188 return err; 189 190 error1: 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 error0: 196 free_pages((unsigned long)out, 197 get_order(send_ringbuffer_size + recv_ringbuffer_size)); 198 kfree(open_info); 199 return err; 200 } 201 EXPORT_SYMBOL_GPL(vmbus_open); 202 203 /* 204 * create_gpadl_header - Creates a gpadl for the specified buffer 205 */ 206 static int create_gpadl_header(void *kbuffer, u32 size, 207 struct vmbus_channel_msginfo **msginfo, 208 u32 *messagecount) 209 { 210 int i; 211 int pagecount; 212 unsigned long long pfn; 213 struct vmbus_channel_gpadl_header *gpadl_header; 214 struct vmbus_channel_gpadl_body *gpadl_body; 215 struct vmbus_channel_msginfo *msgheader; 216 struct vmbus_channel_msginfo *msgbody = NULL; 217 u32 msgsize; 218 219 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize; 220 221 pagecount = size >> PAGE_SHIFT; 222 pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT; 223 224 /* do we need a gpadl body msg */ 225 pfnsize = MAX_SIZE_CHANNEL_MESSAGE - 226 sizeof(struct vmbus_channel_gpadl_header) - 227 sizeof(struct gpa_range); 228 pfncount = pfnsize / sizeof(u64); 229 230 if (pagecount > pfncount) { 231 /* we need a gpadl body */ 232 /* fill in the header */ 233 msgsize = sizeof(struct vmbus_channel_msginfo) + 234 sizeof(struct vmbus_channel_gpadl_header) + 235 sizeof(struct gpa_range) + pfncount * sizeof(u64); 236 msgheader = kzalloc(msgsize, GFP_KERNEL); 237 if (!msgheader) 238 goto nomem; 239 240 INIT_LIST_HEAD(&msgheader->submsglist); 241 msgheader->msgsize = msgsize; 242 243 gpadl_header = (struct vmbus_channel_gpadl_header *) 244 msgheader->msg; 245 gpadl_header->rangecount = 1; 246 gpadl_header->range_buflen = sizeof(struct gpa_range) + 247 pagecount * sizeof(u64); 248 gpadl_header->range[0].byte_offset = 0; 249 gpadl_header->range[0].byte_count = size; 250 for (i = 0; i < pfncount; i++) 251 gpadl_header->range[0].pfn_array[i] = pfn+i; 252 *msginfo = msgheader; 253 *messagecount = 1; 254 255 pfnsum = pfncount; 256 pfnleft = pagecount - pfncount; 257 258 /* how many pfns can we fit */ 259 pfnsize = MAX_SIZE_CHANNEL_MESSAGE - 260 sizeof(struct vmbus_channel_gpadl_body); 261 pfncount = pfnsize / sizeof(u64); 262 263 /* fill in the body */ 264 while (pfnleft) { 265 if (pfnleft > pfncount) 266 pfncurr = pfncount; 267 else 268 pfncurr = pfnleft; 269 270 msgsize = sizeof(struct vmbus_channel_msginfo) + 271 sizeof(struct vmbus_channel_gpadl_body) + 272 pfncurr * sizeof(u64); 273 msgbody = kzalloc(msgsize, GFP_KERNEL); 274 275 if (!msgbody) { 276 struct vmbus_channel_msginfo *pos = NULL; 277 struct vmbus_channel_msginfo *tmp = NULL; 278 /* 279 * Free up all the allocated messages. 280 */ 281 list_for_each_entry_safe(pos, tmp, 282 &msgheader->submsglist, 283 msglistentry) { 284 285 list_del(&pos->msglistentry); 286 kfree(pos); 287 } 288 289 goto nomem; 290 } 291 292 msgbody->msgsize = msgsize; 293 (*messagecount)++; 294 gpadl_body = 295 (struct vmbus_channel_gpadl_body *)msgbody->msg; 296 297 /* 298 * Gpadl is u32 and we are using a pointer which could 299 * be 64-bit 300 * This is governed by the guest/host protocol and 301 * so the hypervisor gurantees that this is ok. 302 */ 303 for (i = 0; i < pfncurr; i++) 304 gpadl_body->pfn[i] = pfn + pfnsum + i; 305 306 /* add to msg header */ 307 list_add_tail(&msgbody->msglistentry, 308 &msgheader->submsglist); 309 pfnsum += pfncurr; 310 pfnleft -= pfncurr; 311 } 312 } else { 313 /* everything fits in a header */ 314 msgsize = sizeof(struct vmbus_channel_msginfo) + 315 sizeof(struct vmbus_channel_gpadl_header) + 316 sizeof(struct gpa_range) + pagecount * sizeof(u64); 317 msgheader = kzalloc(msgsize, GFP_KERNEL); 318 if (msgheader == NULL) 319 goto nomem; 320 msgheader->msgsize = msgsize; 321 322 gpadl_header = (struct vmbus_channel_gpadl_header *) 323 msgheader->msg; 324 gpadl_header->rangecount = 1; 325 gpadl_header->range_buflen = sizeof(struct gpa_range) + 326 pagecount * sizeof(u64); 327 gpadl_header->range[0].byte_offset = 0; 328 gpadl_header->range[0].byte_count = size; 329 for (i = 0; i < pagecount; i++) 330 gpadl_header->range[0].pfn_array[i] = pfn+i; 331 332 *msginfo = msgheader; 333 *messagecount = 1; 334 } 335 336 return 0; 337 nomem: 338 kfree(msgheader); 339 kfree(msgbody); 340 return -ENOMEM; 341 } 342 343 /* 344 * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer 345 * 346 * @channel: a channel 347 * @kbuffer: from kmalloc 348 * @size: page-size multiple 349 * @gpadl_handle: some funky thing 350 */ 351 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer, 352 u32 size, u32 *gpadl_handle) 353 { 354 struct vmbus_channel_gpadl_header *gpadlmsg; 355 struct vmbus_channel_gpadl_body *gpadl_body; 356 struct vmbus_channel_msginfo *msginfo = NULL; 357 struct vmbus_channel_msginfo *submsginfo; 358 u32 msgcount; 359 struct list_head *curr; 360 u32 next_gpadl_handle; 361 unsigned long flags; 362 int ret = 0; 363 int t; 364 365 next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle); 366 atomic_inc(&vmbus_connection.next_gpadl_handle); 367 368 ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount); 369 if (ret) 370 return ret; 371 372 init_completion(&msginfo->waitevent); 373 374 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg; 375 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER; 376 gpadlmsg->child_relid = channel->offermsg.child_relid; 377 gpadlmsg->gpadl = next_gpadl_handle; 378 379 380 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 381 list_add_tail(&msginfo->msglistentry, 382 &vmbus_connection.chn_msg_list); 383 384 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 385 386 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize - 387 sizeof(*msginfo)); 388 if (ret != 0) 389 goto cleanup; 390 391 if (msgcount > 1) { 392 list_for_each(curr, &msginfo->submsglist) { 393 394 submsginfo = (struct vmbus_channel_msginfo *)curr; 395 gpadl_body = 396 (struct vmbus_channel_gpadl_body *)submsginfo->msg; 397 398 gpadl_body->header.msgtype = 399 CHANNELMSG_GPADL_BODY; 400 gpadl_body->gpadl = next_gpadl_handle; 401 402 ret = vmbus_post_msg(gpadl_body, 403 submsginfo->msgsize - 404 sizeof(*submsginfo)); 405 if (ret != 0) 406 goto cleanup; 407 408 } 409 } 410 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ); 411 BUG_ON(t == 0); 412 413 414 /* At this point, we received the gpadl created msg */ 415 *gpadl_handle = gpadlmsg->gpadl; 416 417 cleanup: 418 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 419 list_del(&msginfo->msglistentry); 420 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 421 422 kfree(msginfo); 423 return ret; 424 } 425 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl); 426 427 /* 428 * vmbus_teardown_gpadl -Teardown the specified GPADL handle 429 */ 430 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle) 431 { 432 struct vmbus_channel_gpadl_teardown *msg; 433 struct vmbus_channel_msginfo *info; 434 unsigned long flags; 435 int ret, t; 436 437 info = kmalloc(sizeof(*info) + 438 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL); 439 if (!info) 440 return -ENOMEM; 441 442 init_completion(&info->waitevent); 443 444 msg = (struct vmbus_channel_gpadl_teardown *)info->msg; 445 446 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN; 447 msg->child_relid = channel->offermsg.child_relid; 448 msg->gpadl = gpadl_handle; 449 450 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 451 list_add_tail(&info->msglistentry, 452 &vmbus_connection.chn_msg_list); 453 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 454 ret = vmbus_post_msg(msg, 455 sizeof(struct vmbus_channel_gpadl_teardown)); 456 457 BUG_ON(ret != 0); 458 t = wait_for_completion_timeout(&info->waitevent, 5*HZ); 459 BUG_ON(t == 0); 460 461 /* Received a torndown response */ 462 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); 463 list_del(&info->msglistentry); 464 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); 465 466 kfree(info); 467 return ret; 468 } 469 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl); 470 471 static void vmbus_close_internal(struct vmbus_channel *channel) 472 { 473 struct vmbus_channel_close_channel *msg; 474 int ret; 475 unsigned long flags; 476 477 channel->state = CHANNEL_OPEN_STATE; 478 channel->sc_creation_callback = NULL; 479 /* Stop callback and cancel the timer asap */ 480 spin_lock_irqsave(&channel->inbound_lock, flags); 481 channel->onchannel_callback = NULL; 482 spin_unlock_irqrestore(&channel->inbound_lock, flags); 483 484 /* Send a closing message */ 485 486 msg = &channel->close_msg.msg; 487 488 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL; 489 msg->child_relid = channel->offermsg.child_relid; 490 491 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel)); 492 493 BUG_ON(ret != 0); 494 /* Tear down the gpadl for the channel's ring buffer */ 495 if (channel->ringbuffer_gpadlhandle) 496 vmbus_teardown_gpadl(channel, 497 channel->ringbuffer_gpadlhandle); 498 499 /* Cleanup the ring buffers for this channel */ 500 hv_ringbuffer_cleanup(&channel->outbound); 501 hv_ringbuffer_cleanup(&channel->inbound); 502 503 free_pages((unsigned long)channel->ringbuffer_pages, 504 get_order(channel->ringbuffer_pagecount * PAGE_SIZE)); 505 506 507 } 508 509 /* 510 * vmbus_close - Close the specified channel 511 */ 512 void vmbus_close(struct vmbus_channel *channel) 513 { 514 struct list_head *cur, *tmp; 515 struct vmbus_channel *cur_channel; 516 517 if (channel->primary_channel != NULL) { 518 /* 519 * We will only close sub-channels when 520 * the primary is closed. 521 */ 522 return; 523 } 524 /* 525 * Close all the sub-channels first and then close the 526 * primary channel. 527 */ 528 list_for_each_safe(cur, tmp, &channel->sc_list) { 529 cur_channel = list_entry(cur, struct vmbus_channel, sc_list); 530 if (cur_channel->state != CHANNEL_OPENED_STATE) 531 continue; 532 vmbus_close_internal(cur_channel); 533 } 534 /* 535 * Now close the primary. 536 */ 537 vmbus_close_internal(channel); 538 } 539 EXPORT_SYMBOL_GPL(vmbus_close); 540 541 /** 542 * vmbus_sendpacket() - Send the specified buffer on the given channel 543 * @channel: Pointer to vmbus_channel structure. 544 * @buffer: Pointer to the buffer you want to receive the data into. 545 * @bufferlen: Maximum size of what the the buffer will hold 546 * @requestid: Identifier of the request 547 * @type: Type of packet that is being send e.g. negotiate, time 548 * packet etc. 549 * 550 * Sends data in @buffer directly to hyper-v via the vmbus 551 * This will send the data unparsed to hyper-v. 552 * 553 * Mainly used by Hyper-V drivers. 554 */ 555 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer, 556 u32 bufferlen, u64 requestid, 557 enum vmbus_packet_type type, u32 flags) 558 { 559 struct vmpacket_descriptor desc; 560 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen; 561 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 562 struct scatterlist bufferlist[3]; 563 u64 aligned_data = 0; 564 int ret; 565 bool signal = false; 566 567 568 /* Setup the descriptor */ 569 desc.type = type; /* VmbusPacketTypeDataInBand; */ 570 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */ 571 /* in 8-bytes granularity */ 572 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3; 573 desc.len8 = (u16)(packetlen_aligned >> 3); 574 desc.trans_id = requestid; 575 576 sg_init_table(bufferlist, 3); 577 sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor)); 578 sg_set_buf(&bufferlist[1], buffer, bufferlen); 579 sg_set_buf(&bufferlist[2], &aligned_data, 580 packetlen_aligned - packetlen); 581 582 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal); 583 584 if (ret == 0 && signal) 585 vmbus_setevent(channel); 586 587 return ret; 588 } 589 EXPORT_SYMBOL(vmbus_sendpacket); 590 591 /* 592 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer 593 * packets using a GPADL Direct packet type. 594 */ 595 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel, 596 struct hv_page_buffer pagebuffers[], 597 u32 pagecount, void *buffer, u32 bufferlen, 598 u64 requestid) 599 { 600 int ret; 601 int i; 602 struct vmbus_channel_packet_page_buffer desc; 603 u32 descsize; 604 u32 packetlen; 605 u32 packetlen_aligned; 606 struct scatterlist bufferlist[3]; 607 u64 aligned_data = 0; 608 bool signal = false; 609 610 if (pagecount > MAX_PAGE_BUFFER_COUNT) 611 return -EINVAL; 612 613 614 /* 615 * Adjust the size down since vmbus_channel_packet_page_buffer is the 616 * largest size we support 617 */ 618 descsize = sizeof(struct vmbus_channel_packet_page_buffer) - 619 ((MAX_PAGE_BUFFER_COUNT - pagecount) * 620 sizeof(struct hv_page_buffer)); 621 packetlen = descsize + bufferlen; 622 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 623 624 /* Setup the descriptor */ 625 desc.type = VM_PKT_DATA_USING_GPA_DIRECT; 626 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; 627 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */ 628 desc.length8 = (u16)(packetlen_aligned >> 3); 629 desc.transactionid = requestid; 630 desc.rangecount = pagecount; 631 632 for (i = 0; i < pagecount; i++) { 633 desc.range[i].len = pagebuffers[i].len; 634 desc.range[i].offset = pagebuffers[i].offset; 635 desc.range[i].pfn = pagebuffers[i].pfn; 636 } 637 638 sg_init_table(bufferlist, 3); 639 sg_set_buf(&bufferlist[0], &desc, descsize); 640 sg_set_buf(&bufferlist[1], buffer, bufferlen); 641 sg_set_buf(&bufferlist[2], &aligned_data, 642 packetlen_aligned - packetlen); 643 644 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal); 645 646 if (ret == 0 && signal) 647 vmbus_setevent(channel); 648 649 return ret; 650 } 651 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer); 652 653 /* 654 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet 655 * using a GPADL Direct packet type. 656 */ 657 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel, 658 struct hv_multipage_buffer *multi_pagebuffer, 659 void *buffer, u32 bufferlen, u64 requestid) 660 { 661 int ret; 662 struct vmbus_channel_packet_multipage_buffer desc; 663 u32 descsize; 664 u32 packetlen; 665 u32 packetlen_aligned; 666 struct scatterlist bufferlist[3]; 667 u64 aligned_data = 0; 668 bool signal = false; 669 u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset, 670 multi_pagebuffer->len); 671 672 673 if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT)) 674 return -EINVAL; 675 676 /* 677 * Adjust the size down since vmbus_channel_packet_multipage_buffer is 678 * the largest size we support 679 */ 680 descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) - 681 ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) * 682 sizeof(u64)); 683 packetlen = descsize + bufferlen; 684 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); 685 686 687 /* Setup the descriptor */ 688 desc.type = VM_PKT_DATA_USING_GPA_DIRECT; 689 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; 690 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */ 691 desc.length8 = (u16)(packetlen_aligned >> 3); 692 desc.transactionid = requestid; 693 desc.rangecount = 1; 694 695 desc.range.len = multi_pagebuffer->len; 696 desc.range.offset = multi_pagebuffer->offset; 697 698 memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array, 699 pfncount * sizeof(u64)); 700 701 sg_init_table(bufferlist, 3); 702 sg_set_buf(&bufferlist[0], &desc, descsize); 703 sg_set_buf(&bufferlist[1], buffer, bufferlen); 704 sg_set_buf(&bufferlist[2], &aligned_data, 705 packetlen_aligned - packetlen); 706 707 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal); 708 709 if (ret == 0 && signal) 710 vmbus_setevent(channel); 711 712 return ret; 713 } 714 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer); 715 716 /** 717 * vmbus_recvpacket() - Retrieve the user packet on the specified channel 718 * @channel: Pointer to vmbus_channel structure. 719 * @buffer: Pointer to the buffer you want to receive the data into. 720 * @bufferlen: Maximum size of what the the buffer will hold 721 * @buffer_actual_len: The actual size of the data after it was received 722 * @requestid: Identifier of the request 723 * 724 * Receives directly from the hyper-v vmbus and puts the data it received 725 * into Buffer. This will receive the data unparsed from hyper-v. 726 * 727 * Mainly used by Hyper-V drivers. 728 */ 729 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, 730 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid) 731 { 732 struct vmpacket_descriptor desc; 733 u32 packetlen; 734 u32 userlen; 735 int ret; 736 bool signal = false; 737 738 *buffer_actual_len = 0; 739 *requestid = 0; 740 741 742 ret = hv_ringbuffer_peek(&channel->inbound, &desc, 743 sizeof(struct vmpacket_descriptor)); 744 if (ret != 0) 745 return 0; 746 747 packetlen = desc.len8 << 3; 748 userlen = packetlen - (desc.offset8 << 3); 749 750 *buffer_actual_len = userlen; 751 752 if (userlen > bufferlen) { 753 754 pr_err("Buffer too small - got %d needs %d\n", 755 bufferlen, userlen); 756 return -ETOOSMALL; 757 } 758 759 *requestid = desc.trans_id; 760 761 /* Copy over the packet to the user buffer */ 762 ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen, 763 (desc.offset8 << 3), &signal); 764 765 if (signal) 766 vmbus_setevent(channel); 767 768 return 0; 769 } 770 EXPORT_SYMBOL(vmbus_recvpacket); 771 772 /* 773 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel 774 */ 775 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer, 776 u32 bufferlen, u32 *buffer_actual_len, 777 u64 *requestid) 778 { 779 struct vmpacket_descriptor desc; 780 u32 packetlen; 781 int ret; 782 bool signal = false; 783 784 *buffer_actual_len = 0; 785 *requestid = 0; 786 787 788 ret = hv_ringbuffer_peek(&channel->inbound, &desc, 789 sizeof(struct vmpacket_descriptor)); 790 if (ret != 0) 791 return 0; 792 793 794 packetlen = desc.len8 << 3; 795 796 *buffer_actual_len = packetlen; 797 798 if (packetlen > bufferlen) { 799 pr_err("Buffer too small - needed %d bytes but " 800 "got space for only %d bytes\n", 801 packetlen, bufferlen); 802 return -ENOBUFS; 803 } 804 805 *requestid = desc.trans_id; 806 807 /* Copy over the entire packet to the user buffer */ 808 ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0, 809 &signal); 810 811 if (signal) 812 vmbus_setevent(channel); 813 814 return ret; 815 } 816 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw); 817