2 * Copyright (c) 2009, Microsoft Corporation.
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.
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
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.
18 * Haiyang Zhang <haiyangz@microsoft.com>
19 * Hank Janssen <hjanssen@microsoft.com>
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 #include <linux/kernel.h>
24 #include <linux/sched.h>
25 #include <linux/wait.h>
27 #include <linux/slab.h>
28 #include <linux/module.h>
31 #include "hyperv_vmbus.h"
33 #define NUM_PAGES_SPANNED(addr, len) \
34 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
36 /* Internal routines */
37 static int create_gpadl_header(
38 void *kbuffer, /* must be phys and virt contiguous */
39 u32 size, /* page-size multiple */
40 struct vmbus_channel_msginfo **msginfo,
42 static void vmbus_setevent(struct vmbus_channel *channel);
45 * vmbus_setevent- Trigger an event notification on the specified
48 static void vmbus_setevent(struct vmbus_channel *channel)
50 struct hv_monitor_page *monitorpage;
52 if (channel->offermsg.monitor_allocated) {
53 /* Each u32 represents 32 channels */
54 sync_set_bit(channel->offermsg.child_relid & 31,
55 (unsigned long *) vmbus_connection.send_int_page +
56 (channel->offermsg.child_relid >> 5));
58 monitorpage = vmbus_connection.monitor_pages;
59 monitorpage++; /* Get the child to parent monitor page */
61 sync_set_bit(channel->monitor_bit,
62 (unsigned long *)&monitorpage->trigger_group
63 [channel->monitor_grp].pending);
66 vmbus_set_event(channel->offermsg.child_relid);
71 * vmbus_get_debug_info -Retrieve various channel debug info
73 void vmbus_get_debug_info(struct vmbus_channel *channel,
74 struct vmbus_channel_debug_info *debuginfo)
76 struct hv_monitor_page *monitorpage;
77 u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
78 u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
80 debuginfo->relid = channel->offermsg.child_relid;
81 debuginfo->state = channel->state;
82 memcpy(&debuginfo->interfacetype,
83 &channel->offermsg.offer.if_type, sizeof(uuid_le));
84 memcpy(&debuginfo->interface_instance,
85 &channel->offermsg.offer.if_instance,
88 monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
90 debuginfo->monitorid = channel->offermsg.monitorid;
92 debuginfo->servermonitor_pending =
93 monitorpage->trigger_group[monitor_group].pending;
94 debuginfo->servermonitor_latency =
95 monitorpage->latency[monitor_group][monitor_offset];
96 debuginfo->servermonitor_connectionid =
97 monitorpage->parameter[monitor_group]
98 [monitor_offset].connectionid.u.id;
102 debuginfo->clientmonitor_pending =
103 monitorpage->trigger_group[monitor_group].pending;
104 debuginfo->clientmonitor_latency =
105 monitorpage->latency[monitor_group][monitor_offset];
106 debuginfo->clientmonitor_connectionid =
107 monitorpage->parameter[monitor_group]
108 [monitor_offset].connectionid.u.id;
110 hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
111 hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
115 * vmbus_open - Open the specified channel.
117 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
118 u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
119 void (*onchannelcallback)(void *context), void *context)
121 struct vmbus_channel_open_channel *open_msg;
122 struct vmbus_channel_msginfo *open_info = NULL;
127 newchannel->onchannel_callback = onchannelcallback;
128 newchannel->channel_callback_context = context;
130 /* Allocate the ring buffer */
131 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
132 get_order(send_ringbuffer_size + recv_ringbuffer_size));
138 in = (void *)((unsigned long)out + send_ringbuffer_size);
140 newchannel->ringbuffer_pages = out;
141 newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
142 recv_ringbuffer_size) >> PAGE_SHIFT;
144 ret = hv_ringbuffer_init(
145 &newchannel->outbound, out, send_ringbuffer_size);
152 ret = hv_ringbuffer_init(
153 &newchannel->inbound, in, recv_ringbuffer_size);
160 /* Establish the gpadl for the ring buffer */
161 newchannel->ringbuffer_gpadlhandle = 0;
163 ret = vmbus_establish_gpadl(newchannel,
164 newchannel->outbound.ring_buffer,
165 send_ringbuffer_size +
166 recv_ringbuffer_size,
167 &newchannel->ringbuffer_gpadlhandle);
174 /* Create and init the channel open message */
175 open_info = kmalloc(sizeof(*open_info) +
176 sizeof(struct vmbus_channel_open_channel),
183 init_completion(&open_info->waitevent);
185 open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
186 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
187 open_msg->openid = newchannel->offermsg.child_relid;
188 open_msg->child_relid = newchannel->offermsg.child_relid;
189 open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
190 open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
192 open_msg->server_contextarea_gpadlhandle = 0;
194 if (userdatalen > MAX_USER_DEFINED_BYTES) {
200 memcpy(open_msg->userdata, userdata, userdatalen);
202 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
203 list_add_tail(&open_info->msglistentry,
204 &vmbus_connection.chn_msg_list);
205 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
207 ret = vmbus_post_msg(open_msg,
208 sizeof(struct vmbus_channel_open_channel));
213 t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
220 if (open_info->response.open_result.status)
221 err = open_info->response.open_result.status;
224 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
225 list_del(&open_info->msglistentry);
226 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
232 hv_ringbuffer_cleanup(&newchannel->outbound);
233 hv_ringbuffer_cleanup(&newchannel->inbound);
234 free_pages((unsigned long)out,
235 get_order(send_ringbuffer_size + recv_ringbuffer_size));
239 EXPORT_SYMBOL_GPL(vmbus_open);
242 * create_gpadl_header - Creates a gpadl for the specified buffer
244 static int create_gpadl_header(void *kbuffer, u32 size,
245 struct vmbus_channel_msginfo **msginfo,
250 unsigned long long pfn;
251 struct vmbus_channel_gpadl_header *gpadl_header;
252 struct vmbus_channel_gpadl_body *gpadl_body;
253 struct vmbus_channel_msginfo *msgheader;
254 struct vmbus_channel_msginfo *msgbody = NULL;
257 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
259 pagecount = size >> PAGE_SHIFT;
260 pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
262 /* do we need a gpadl body msg */
263 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
264 sizeof(struct vmbus_channel_gpadl_header) -
265 sizeof(struct gpa_range);
266 pfncount = pfnsize / sizeof(u64);
268 if (pagecount > pfncount) {
269 /* we need a gpadl body */
270 /* fill in the header */
271 msgsize = sizeof(struct vmbus_channel_msginfo) +
272 sizeof(struct vmbus_channel_gpadl_header) +
273 sizeof(struct gpa_range) + pfncount * sizeof(u64);
274 msgheader = kzalloc(msgsize, GFP_KERNEL);
278 INIT_LIST_HEAD(&msgheader->submsglist);
279 msgheader->msgsize = msgsize;
281 gpadl_header = (struct vmbus_channel_gpadl_header *)
283 gpadl_header->rangecount = 1;
284 gpadl_header->range_buflen = sizeof(struct gpa_range) +
285 pagecount * sizeof(u64);
286 gpadl_header->range[0].byte_offset = 0;
287 gpadl_header->range[0].byte_count = size;
288 for (i = 0; i < pfncount; i++)
289 gpadl_header->range[0].pfn_array[i] = pfn+i;
290 *msginfo = msgheader;
294 pfnleft = pagecount - pfncount;
296 /* how many pfns can we fit */
297 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
298 sizeof(struct vmbus_channel_gpadl_body);
299 pfncount = pfnsize / sizeof(u64);
301 /* fill in the body */
303 if (pfnleft > pfncount)
308 msgsize = sizeof(struct vmbus_channel_msginfo) +
309 sizeof(struct vmbus_channel_gpadl_body) +
310 pfncurr * sizeof(u64);
311 msgbody = kzalloc(msgsize, GFP_KERNEL);
314 struct vmbus_channel_msginfo *pos = NULL;
315 struct vmbus_channel_msginfo *tmp = NULL;
317 * Free up all the allocated messages.
319 list_for_each_entry_safe(pos, tmp,
320 &msgheader->submsglist,
323 list_del(&pos->msglistentry);
330 msgbody->msgsize = msgsize;
333 (struct vmbus_channel_gpadl_body *)msgbody->msg;
336 * Gpadl is u32 and we are using a pointer which could
338 * This is governed by the guest/host protocol and
339 * so the hypervisor gurantees that this is ok.
341 for (i = 0; i < pfncurr; i++)
342 gpadl_body->pfn[i] = pfn + pfnsum + i;
344 /* add to msg header */
345 list_add_tail(&msgbody->msglistentry,
346 &msgheader->submsglist);
351 /* everything fits in a header */
352 msgsize = sizeof(struct vmbus_channel_msginfo) +
353 sizeof(struct vmbus_channel_gpadl_header) +
354 sizeof(struct gpa_range) + pagecount * sizeof(u64);
355 msgheader = kzalloc(msgsize, GFP_KERNEL);
356 if (msgheader == NULL)
358 msgheader->msgsize = msgsize;
360 gpadl_header = (struct vmbus_channel_gpadl_header *)
362 gpadl_header->rangecount = 1;
363 gpadl_header->range_buflen = sizeof(struct gpa_range) +
364 pagecount * sizeof(u64);
365 gpadl_header->range[0].byte_offset = 0;
366 gpadl_header->range[0].byte_count = size;
367 for (i = 0; i < pagecount; i++)
368 gpadl_header->range[0].pfn_array[i] = pfn+i;
370 *msginfo = msgheader;
382 * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
384 * @channel: a channel
385 * @kbuffer: from kmalloc
386 * @size: page-size multiple
387 * @gpadl_handle: some funky thing
389 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
390 u32 size, u32 *gpadl_handle)
392 struct vmbus_channel_gpadl_header *gpadlmsg;
393 struct vmbus_channel_gpadl_body *gpadl_body;
394 struct vmbus_channel_msginfo *msginfo = NULL;
395 struct vmbus_channel_msginfo *submsginfo;
397 struct list_head *curr;
398 u32 next_gpadl_handle;
403 next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
404 atomic_inc(&vmbus_connection.next_gpadl_handle);
406 ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
410 init_completion(&msginfo->waitevent);
412 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
413 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
414 gpadlmsg->child_relid = channel->offermsg.child_relid;
415 gpadlmsg->gpadl = next_gpadl_handle;
418 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
419 list_add_tail(&msginfo->msglistentry,
420 &vmbus_connection.chn_msg_list);
422 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
424 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
430 list_for_each(curr, &msginfo->submsglist) {
432 submsginfo = (struct vmbus_channel_msginfo *)curr;
434 (struct vmbus_channel_gpadl_body *)submsginfo->msg;
436 gpadl_body->header.msgtype =
437 CHANNELMSG_GPADL_BODY;
438 gpadl_body->gpadl = next_gpadl_handle;
440 ret = vmbus_post_msg(gpadl_body,
441 submsginfo->msgsize -
442 sizeof(*submsginfo));
448 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
452 /* At this point, we received the gpadl created msg */
453 *gpadl_handle = gpadlmsg->gpadl;
456 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
457 list_del(&msginfo->msglistentry);
458 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
463 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
466 * vmbus_teardown_gpadl -Teardown the specified GPADL handle
468 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
470 struct vmbus_channel_gpadl_teardown *msg;
471 struct vmbus_channel_msginfo *info;
475 info = kmalloc(sizeof(*info) +
476 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
480 init_completion(&info->waitevent);
482 msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
484 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
485 msg->child_relid = channel->offermsg.child_relid;
486 msg->gpadl = gpadl_handle;
488 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
489 list_add_tail(&info->msglistentry,
490 &vmbus_connection.chn_msg_list);
491 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
492 ret = vmbus_post_msg(msg,
493 sizeof(struct vmbus_channel_gpadl_teardown));
496 t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
499 /* Received a torndown response */
500 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
501 list_del(&info->msglistentry);
502 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
507 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
510 * vmbus_close - Close the specified channel
512 void vmbus_close(struct vmbus_channel *channel)
514 struct vmbus_channel_close_channel *msg;
517 /* Stop callback and cancel the timer asap */
518 channel->onchannel_callback = NULL;
520 /* Send a closing message */
522 msg = &channel->close_msg.msg;
524 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
525 msg->child_relid = channel->offermsg.child_relid;
527 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
530 /* Tear down the gpadl for the channel's ring buffer */
531 if (channel->ringbuffer_gpadlhandle)
532 vmbus_teardown_gpadl(channel,
533 channel->ringbuffer_gpadlhandle);
535 /* Cleanup the ring buffers for this channel */
536 hv_ringbuffer_cleanup(&channel->outbound);
537 hv_ringbuffer_cleanup(&channel->inbound);
539 free_pages((unsigned long)channel->ringbuffer_pages,
540 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
544 EXPORT_SYMBOL_GPL(vmbus_close);
547 * vmbus_sendpacket() - Send the specified buffer on the given channel
548 * @channel: Pointer to vmbus_channel structure.
549 * @buffer: Pointer to the buffer you want to receive the data into.
550 * @bufferlen: Maximum size of what the the buffer will hold
551 * @requestid: Identifier of the request
552 * @type: Type of packet that is being send e.g. negotiate, time
555 * Sends data in @buffer directly to hyper-v via the vmbus
556 * This will send the data unparsed to hyper-v.
558 * Mainly used by Hyper-V drivers.
560 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
561 u32 bufferlen, u64 requestid,
562 enum vmbus_packet_type type, u32 flags)
564 struct vmpacket_descriptor desc;
565 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
566 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
567 struct scatterlist bufferlist[3];
568 u64 aligned_data = 0;
572 /* Setup the descriptor */
573 desc.type = type; /* VmbusPacketTypeDataInBand; */
574 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
575 /* in 8-bytes granularity */
576 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
577 desc.len8 = (u16)(packetlen_aligned >> 3);
578 desc.trans_id = requestid;
580 sg_init_table(bufferlist, 3);
581 sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
582 sg_set_buf(&bufferlist[1], buffer, bufferlen);
583 sg_set_buf(&bufferlist[2], &aligned_data,
584 packetlen_aligned - packetlen);
586 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
588 if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
589 vmbus_setevent(channel);
593 EXPORT_SYMBOL(vmbus_sendpacket);
596 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
597 * packets using a GPADL Direct packet type.
599 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
600 struct hv_page_buffer pagebuffers[],
601 u32 pagecount, void *buffer, u32 bufferlen,
606 struct vmbus_channel_packet_page_buffer desc;
609 u32 packetlen_aligned;
610 struct scatterlist bufferlist[3];
611 u64 aligned_data = 0;
613 if (pagecount > MAX_PAGE_BUFFER_COUNT)
618 * Adjust the size down since vmbus_channel_packet_page_buffer is the
619 * largest size we support
621 descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
622 ((MAX_PAGE_BUFFER_COUNT - pagecount) *
623 sizeof(struct hv_page_buffer));
624 packetlen = descsize + bufferlen;
625 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
627 /* Setup the descriptor */
628 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
629 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
630 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
631 desc.length8 = (u16)(packetlen_aligned >> 3);
632 desc.transactionid = requestid;
633 desc.rangecount = pagecount;
635 for (i = 0; i < pagecount; i++) {
636 desc.range[i].len = pagebuffers[i].len;
637 desc.range[i].offset = pagebuffers[i].offset;
638 desc.range[i].pfn = pagebuffers[i].pfn;
641 sg_init_table(bufferlist, 3);
642 sg_set_buf(&bufferlist[0], &desc, descsize);
643 sg_set_buf(&bufferlist[1], buffer, bufferlen);
644 sg_set_buf(&bufferlist[2], &aligned_data,
645 packetlen_aligned - packetlen);
647 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
649 if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
650 vmbus_setevent(channel);
654 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
657 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
658 * using a GPADL Direct packet type.
660 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
661 struct hv_multipage_buffer *multi_pagebuffer,
662 void *buffer, u32 bufferlen, u64 requestid)
665 struct vmbus_channel_packet_multipage_buffer desc;
668 u32 packetlen_aligned;
669 struct scatterlist bufferlist[3];
670 u64 aligned_data = 0;
671 u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
672 multi_pagebuffer->len);
675 if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
679 * Adjust the size down since vmbus_channel_packet_multipage_buffer is
680 * the largest size we support
682 descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
683 ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
685 packetlen = descsize + bufferlen;
686 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
689 /* Setup the descriptor */
690 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
691 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
692 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
693 desc.length8 = (u16)(packetlen_aligned >> 3);
694 desc.transactionid = requestid;
697 desc.range.len = multi_pagebuffer->len;
698 desc.range.offset = multi_pagebuffer->offset;
700 memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
701 pfncount * sizeof(u64));
703 sg_init_table(bufferlist, 3);
704 sg_set_buf(&bufferlist[0], &desc, descsize);
705 sg_set_buf(&bufferlist[1], buffer, bufferlen);
706 sg_set_buf(&bufferlist[2], &aligned_data,
707 packetlen_aligned - packetlen);
709 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
711 if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
712 vmbus_setevent(channel);
716 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
719 * vmbus_recvpacket() - Retrieve the user packet on the specified channel
720 * @channel: Pointer to vmbus_channel structure.
721 * @buffer: Pointer to the buffer you want to receive the data into.
722 * @bufferlen: Maximum size of what the the buffer will hold
723 * @buffer_actual_len: The actual size of the data after it was received
724 * @requestid: Identifier of the request
726 * Receives directly from the hyper-v vmbus and puts the data it received
727 * into Buffer. This will receive the data unparsed from hyper-v.
729 * Mainly used by Hyper-V drivers.
731 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
732 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
734 struct vmpacket_descriptor desc;
740 *buffer_actual_len = 0;
743 spin_lock_irqsave(&channel->inbound_lock, flags);
745 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
746 sizeof(struct vmpacket_descriptor));
748 spin_unlock_irqrestore(&channel->inbound_lock, flags);
752 packetlen = desc.len8 << 3;
753 userlen = packetlen - (desc.offset8 << 3);
755 *buffer_actual_len = userlen;
757 if (userlen > bufferlen) {
758 spin_unlock_irqrestore(&channel->inbound_lock, flags);
760 pr_err("Buffer too small - got %d needs %d\n",
765 *requestid = desc.trans_id;
767 /* Copy over the packet to the user buffer */
768 ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
769 (desc.offset8 << 3));
771 spin_unlock_irqrestore(&channel->inbound_lock, flags);
775 EXPORT_SYMBOL(vmbus_recvpacket);
778 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
780 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
781 u32 bufferlen, u32 *buffer_actual_len,
784 struct vmpacket_descriptor desc;
790 *buffer_actual_len = 0;
793 spin_lock_irqsave(&channel->inbound_lock, flags);
795 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
796 sizeof(struct vmpacket_descriptor));
798 spin_unlock_irqrestore(&channel->inbound_lock, flags);
803 packetlen = desc.len8 << 3;
804 userlen = packetlen - (desc.offset8 << 3);
806 *buffer_actual_len = packetlen;
808 if (packetlen > bufferlen) {
809 spin_unlock_irqrestore(&channel->inbound_lock, flags);
811 pr_err("Buffer too small - needed %d bytes but "
812 "got space for only %d bytes\n",
813 packetlen, bufferlen);
817 *requestid = desc.trans_id;
819 /* Copy over the entire packet to the user buffer */
820 ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
822 spin_unlock_irqrestore(&channel->inbound_lock, flags);
825 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);