Drivers: hv: Get rid of unnecessary request for offers
[linux-3.10.git] / drivers / hv / channel.c
1 /*
2  * Copyright (c) 2009, Microsoft Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15  * Place - Suite 330, Boston, MA 02111-1307 USA.
16  *
17  * Authors:
18  *   Haiyang Zhang <haiyangz@microsoft.com>
19  *   Hank Janssen  <hjanssen@microsoft.com>
20  */
21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23 #include <linux/kernel.h>
24 #include <linux/sched.h>
25 #include <linux/wait.h>
26 #include <linux/mm.h>
27 #include <linux/slab.h>
28 #include <linux/module.h>
29 #include <linux/hyperv.h>
30
31 #include "hyperv_vmbus.h"
32
33 #define NUM_PAGES_SPANNED(addr, len) \
34 ((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
35
36 /*
37  * vmbus_setevent- Trigger an event notification on the specified
38  * channel.
39  */
40 static void vmbus_setevent(struct vmbus_channel *channel)
41 {
42         struct hv_monitor_page *monitorpage;
43
44         if (channel->offermsg.monitor_allocated) {
45                 /* Each u32 represents 32 channels */
46                 sync_set_bit(channel->offermsg.child_relid & 31,
47                         (unsigned long *) vmbus_connection.send_int_page +
48                         (channel->offermsg.child_relid >> 5));
49
50                 monitorpage = vmbus_connection.monitor_pages;
51                 monitorpage++; /* Get the child to parent monitor page */
52
53                 sync_set_bit(channel->monitor_bit,
54                         (unsigned long *)&monitorpage->trigger_group
55                                         [channel->monitor_grp].pending);
56
57         } else {
58                 vmbus_set_event(channel);
59         }
60 }
61
62 /*
63  * vmbus_get_debug_info -Retrieve various channel debug info
64  */
65 void vmbus_get_debug_info(struct vmbus_channel *channel,
66                               struct vmbus_channel_debug_info *debuginfo)
67 {
68         struct hv_monitor_page *monitorpage;
69         u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
70         u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
71
72         debuginfo->relid = channel->offermsg.child_relid;
73         debuginfo->state = channel->state;
74         memcpy(&debuginfo->interfacetype,
75                &channel->offermsg.offer.if_type, sizeof(uuid_le));
76         memcpy(&debuginfo->interface_instance,
77                &channel->offermsg.offer.if_instance,
78                sizeof(uuid_le));
79
80         monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
81
82         debuginfo->monitorid = channel->offermsg.monitorid;
83
84         debuginfo->servermonitor_pending =
85                         monitorpage->trigger_group[monitor_group].pending;
86         debuginfo->servermonitor_latency =
87                         monitorpage->latency[monitor_group][monitor_offset];
88         debuginfo->servermonitor_connectionid =
89                         monitorpage->parameter[monitor_group]
90                                         [monitor_offset].connectionid.u.id;
91
92         monitorpage++;
93
94         debuginfo->clientmonitor_pending =
95                         monitorpage->trigger_group[monitor_group].pending;
96         debuginfo->clientmonitor_latency =
97                         monitorpage->latency[monitor_group][monitor_offset];
98         debuginfo->clientmonitor_connectionid =
99                         monitorpage->parameter[monitor_group]
100                                         [monitor_offset].connectionid.u.id;
101
102         hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
103         hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
104 }
105
106 /*
107  * vmbus_open - Open the specified channel.
108  */
109 int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
110                      u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
111                      void (*onchannelcallback)(void *context), void *context)
112 {
113         struct vmbus_channel_open_channel *open_msg;
114         struct vmbus_channel_msginfo *open_info = NULL;
115         void *in, *out;
116         unsigned long flags;
117         int ret, t, err = 0;
118
119         newchannel->onchannel_callback = onchannelcallback;
120         newchannel->channel_callback_context = context;
121
122         /* Allocate the ring buffer */
123         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
124                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
125
126         if (!out)
127                 return -ENOMEM;
128
129
130         in = (void *)((unsigned long)out + send_ringbuffer_size);
131
132         newchannel->ringbuffer_pages = out;
133         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
134                                            recv_ringbuffer_size) >> PAGE_SHIFT;
135
136         ret = hv_ringbuffer_init(
137                 &newchannel->outbound, out, send_ringbuffer_size);
138
139         if (ret != 0) {
140                 err = ret;
141                 goto error0;
142         }
143
144         ret = hv_ringbuffer_init(
145                 &newchannel->inbound, in, recv_ringbuffer_size);
146         if (ret != 0) {
147                 err = ret;
148                 goto error0;
149         }
150
151
152         /* Establish the gpadl for the ring buffer */
153         newchannel->ringbuffer_gpadlhandle = 0;
154
155         ret = vmbus_establish_gpadl(newchannel,
156                                          newchannel->outbound.ring_buffer,
157                                          send_ringbuffer_size +
158                                          recv_ringbuffer_size,
159                                          &newchannel->ringbuffer_gpadlhandle);
160
161         if (ret != 0) {
162                 err = ret;
163                 goto error0;
164         }
165
166         /* Create and init the channel open message */
167         open_info = kmalloc(sizeof(*open_info) +
168                            sizeof(struct vmbus_channel_open_channel),
169                            GFP_KERNEL);
170         if (!open_info) {
171                 err = -ENOMEM;
172                 goto error0;
173         }
174
175         init_completion(&open_info->waitevent);
176
177         open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
178         open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
179         open_msg->openid = newchannel->offermsg.child_relid;
180         open_msg->child_relid = newchannel->offermsg.child_relid;
181         open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
182         open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
183                                                   PAGE_SHIFT;
184         open_msg->target_vp = newchannel->target_vp;
185
186         if (userdatalen > MAX_USER_DEFINED_BYTES) {
187                 err = -EINVAL;
188                 goto error0;
189         }
190
191         if (userdatalen)
192                 memcpy(open_msg->userdata, userdata, userdatalen);
193
194         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
195         list_add_tail(&open_info->msglistentry,
196                       &vmbus_connection.chn_msg_list);
197         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
198
199         ret = vmbus_post_msg(open_msg,
200                                sizeof(struct vmbus_channel_open_channel));
201
202         if (ret != 0)
203                 goto error1;
204
205         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
206         if (t == 0) {
207                 err = -ETIMEDOUT;
208                 goto error1;
209         }
210
211
212         if (open_info->response.open_result.status)
213                 err = open_info->response.open_result.status;
214
215         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
216         list_del(&open_info->msglistentry);
217         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
218
219         kfree(open_info);
220         return err;
221
222 error1:
223         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
224         list_del(&open_info->msglistentry);
225         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
226
227 error0:
228         free_pages((unsigned long)out,
229                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
230         kfree(open_info);
231         return err;
232 }
233 EXPORT_SYMBOL_GPL(vmbus_open);
234
235 /*
236  * create_gpadl_header - Creates a gpadl for the specified buffer
237  */
238 static int create_gpadl_header(void *kbuffer, u32 size,
239                                          struct vmbus_channel_msginfo **msginfo,
240                                          u32 *messagecount)
241 {
242         int i;
243         int pagecount;
244         unsigned long long pfn;
245         struct vmbus_channel_gpadl_header *gpadl_header;
246         struct vmbus_channel_gpadl_body *gpadl_body;
247         struct vmbus_channel_msginfo *msgheader;
248         struct vmbus_channel_msginfo *msgbody = NULL;
249         u32 msgsize;
250
251         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
252
253         pagecount = size >> PAGE_SHIFT;
254         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
255
256         /* do we need a gpadl body msg */
257         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
258                   sizeof(struct vmbus_channel_gpadl_header) -
259                   sizeof(struct gpa_range);
260         pfncount = pfnsize / sizeof(u64);
261
262         if (pagecount > pfncount) {
263                 /* we need a gpadl body */
264                 /* fill in the header */
265                 msgsize = sizeof(struct vmbus_channel_msginfo) +
266                           sizeof(struct vmbus_channel_gpadl_header) +
267                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
268                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
269                 if (!msgheader)
270                         goto nomem;
271
272                 INIT_LIST_HEAD(&msgheader->submsglist);
273                 msgheader->msgsize = msgsize;
274
275                 gpadl_header = (struct vmbus_channel_gpadl_header *)
276                         msgheader->msg;
277                 gpadl_header->rangecount = 1;
278                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
279                                          pagecount * sizeof(u64);
280                 gpadl_header->range[0].byte_offset = 0;
281                 gpadl_header->range[0].byte_count = size;
282                 for (i = 0; i < pfncount; i++)
283                         gpadl_header->range[0].pfn_array[i] = pfn+i;
284                 *msginfo = msgheader;
285                 *messagecount = 1;
286
287                 pfnsum = pfncount;
288                 pfnleft = pagecount - pfncount;
289
290                 /* how many pfns can we fit */
291                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
292                           sizeof(struct vmbus_channel_gpadl_body);
293                 pfncount = pfnsize / sizeof(u64);
294
295                 /* fill in the body */
296                 while (pfnleft) {
297                         if (pfnleft > pfncount)
298                                 pfncurr = pfncount;
299                         else
300                                 pfncurr = pfnleft;
301
302                         msgsize = sizeof(struct vmbus_channel_msginfo) +
303                                   sizeof(struct vmbus_channel_gpadl_body) +
304                                   pfncurr * sizeof(u64);
305                         msgbody = kzalloc(msgsize, GFP_KERNEL);
306
307                         if (!msgbody) {
308                                 struct vmbus_channel_msginfo *pos = NULL;
309                                 struct vmbus_channel_msginfo *tmp = NULL;
310                                 /*
311                                  * Free up all the allocated messages.
312                                  */
313                                 list_for_each_entry_safe(pos, tmp,
314                                         &msgheader->submsglist,
315                                         msglistentry) {
316
317                                         list_del(&pos->msglistentry);
318                                         kfree(pos);
319                                 }
320
321                                 goto nomem;
322                         }
323
324                         msgbody->msgsize = msgsize;
325                         (*messagecount)++;
326                         gpadl_body =
327                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
328
329                         /*
330                          * Gpadl is u32 and we are using a pointer which could
331                          * be 64-bit
332                          * This is governed by the guest/host protocol and
333                          * so the hypervisor gurantees that this is ok.
334                          */
335                         for (i = 0; i < pfncurr; i++)
336                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
337
338                         /* add to msg header */
339                         list_add_tail(&msgbody->msglistentry,
340                                       &msgheader->submsglist);
341                         pfnsum += pfncurr;
342                         pfnleft -= pfncurr;
343                 }
344         } else {
345                 /* everything fits in a header */
346                 msgsize = sizeof(struct vmbus_channel_msginfo) +
347                           sizeof(struct vmbus_channel_gpadl_header) +
348                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
349                 msgheader = kzalloc(msgsize, GFP_KERNEL);
350                 if (msgheader == NULL)
351                         goto nomem;
352                 msgheader->msgsize = msgsize;
353
354                 gpadl_header = (struct vmbus_channel_gpadl_header *)
355                         msgheader->msg;
356                 gpadl_header->rangecount = 1;
357                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
358                                          pagecount * sizeof(u64);
359                 gpadl_header->range[0].byte_offset = 0;
360                 gpadl_header->range[0].byte_count = size;
361                 for (i = 0; i < pagecount; i++)
362                         gpadl_header->range[0].pfn_array[i] = pfn+i;
363
364                 *msginfo = msgheader;
365                 *messagecount = 1;
366         }
367
368         return 0;
369 nomem:
370         kfree(msgheader);
371         kfree(msgbody);
372         return -ENOMEM;
373 }
374
375 /*
376  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
377  *
378  * @channel: a channel
379  * @kbuffer: from kmalloc
380  * @size: page-size multiple
381  * @gpadl_handle: some funky thing
382  */
383 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
384                                u32 size, u32 *gpadl_handle)
385 {
386         struct vmbus_channel_gpadl_header *gpadlmsg;
387         struct vmbus_channel_gpadl_body *gpadl_body;
388         struct vmbus_channel_msginfo *msginfo = NULL;
389         struct vmbus_channel_msginfo *submsginfo;
390         u32 msgcount;
391         struct list_head *curr;
392         u32 next_gpadl_handle;
393         unsigned long flags;
394         int ret = 0;
395         int t;
396
397         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
398         atomic_inc(&vmbus_connection.next_gpadl_handle);
399
400         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
401         if (ret)
402                 return ret;
403
404         init_completion(&msginfo->waitevent);
405
406         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
407         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
408         gpadlmsg->child_relid = channel->offermsg.child_relid;
409         gpadlmsg->gpadl = next_gpadl_handle;
410
411
412         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
413         list_add_tail(&msginfo->msglistentry,
414                       &vmbus_connection.chn_msg_list);
415
416         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
417
418         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
419                                sizeof(*msginfo));
420         if (ret != 0)
421                 goto cleanup;
422
423         if (msgcount > 1) {
424                 list_for_each(curr, &msginfo->submsglist) {
425
426                         submsginfo = (struct vmbus_channel_msginfo *)curr;
427                         gpadl_body =
428                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
429
430                         gpadl_body->header.msgtype =
431                                 CHANNELMSG_GPADL_BODY;
432                         gpadl_body->gpadl = next_gpadl_handle;
433
434                         ret = vmbus_post_msg(gpadl_body,
435                                                submsginfo->msgsize -
436                                                sizeof(*submsginfo));
437                         if (ret != 0)
438                                 goto cleanup;
439
440                 }
441         }
442         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
443         BUG_ON(t == 0);
444
445
446         /* At this point, we received the gpadl created msg */
447         *gpadl_handle = gpadlmsg->gpadl;
448
449 cleanup:
450         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
451         list_del(&msginfo->msglistentry);
452         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
453
454         kfree(msginfo);
455         return ret;
456 }
457 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
458
459 /*
460  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
461  */
462 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
463 {
464         struct vmbus_channel_gpadl_teardown *msg;
465         struct vmbus_channel_msginfo *info;
466         unsigned long flags;
467         int ret, t;
468
469         info = kmalloc(sizeof(*info) +
470                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
471         if (!info)
472                 return -ENOMEM;
473
474         init_completion(&info->waitevent);
475
476         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
477
478         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
479         msg->child_relid = channel->offermsg.child_relid;
480         msg->gpadl = gpadl_handle;
481
482         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
483         list_add_tail(&info->msglistentry,
484                       &vmbus_connection.chn_msg_list);
485         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
486         ret = vmbus_post_msg(msg,
487                                sizeof(struct vmbus_channel_gpadl_teardown));
488
489         BUG_ON(ret != 0);
490         t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
491         BUG_ON(t == 0);
492
493         /* Received a torndown response */
494         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
495         list_del(&info->msglistentry);
496         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
497
498         kfree(info);
499         return ret;
500 }
501 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
502
503 /*
504  * vmbus_close - Close the specified channel
505  */
506 void vmbus_close(struct vmbus_channel *channel)
507 {
508         struct vmbus_channel_close_channel *msg;
509         int ret;
510         unsigned long flags;
511
512         /* Stop callback and cancel the timer asap */
513         spin_lock_irqsave(&channel->inbound_lock, flags);
514         channel->onchannel_callback = NULL;
515         spin_unlock_irqrestore(&channel->inbound_lock, flags);
516
517         /* Send a closing message */
518
519         msg = &channel->close_msg.msg;
520
521         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
522         msg->child_relid = channel->offermsg.child_relid;
523
524         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
525
526         BUG_ON(ret != 0);
527         /* Tear down the gpadl for the channel's ring buffer */
528         if (channel->ringbuffer_gpadlhandle)
529                 vmbus_teardown_gpadl(channel,
530                                           channel->ringbuffer_gpadlhandle);
531
532         /* Cleanup the ring buffers for this channel */
533         hv_ringbuffer_cleanup(&channel->outbound);
534         hv_ringbuffer_cleanup(&channel->inbound);
535
536         free_pages((unsigned long)channel->ringbuffer_pages,
537                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
538
539
540 }
541 EXPORT_SYMBOL_GPL(vmbus_close);
542
543 /**
544  * vmbus_sendpacket() - Send the specified buffer on the given channel
545  * @channel: Pointer to vmbus_channel structure.
546  * @buffer: Pointer to the buffer you want to receive the data into.
547  * @bufferlen: Maximum size of what the the buffer will hold
548  * @requestid: Identifier of the request
549  * @type: Type of packet that is being send e.g. negotiate, time
550  * packet etc.
551  *
552  * Sends data in @buffer directly to hyper-v via the vmbus
553  * This will send the data unparsed to hyper-v.
554  *
555  * Mainly used by Hyper-V drivers.
556  */
557 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
558                            u32 bufferlen, u64 requestid,
559                            enum vmbus_packet_type type, u32 flags)
560 {
561         struct vmpacket_descriptor desc;
562         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
563         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
564         struct scatterlist bufferlist[3];
565         u64 aligned_data = 0;
566         int ret;
567         bool signal = false;
568
569
570         /* Setup the descriptor */
571         desc.type = type; /* VmbusPacketTypeDataInBand; */
572         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
573         /* in 8-bytes granularity */
574         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
575         desc.len8 = (u16)(packetlen_aligned >> 3);
576         desc.trans_id = requestid;
577
578         sg_init_table(bufferlist, 3);
579         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
580         sg_set_buf(&bufferlist[1], buffer, bufferlen);
581         sg_set_buf(&bufferlist[2], &aligned_data,
582                    packetlen_aligned - packetlen);
583
584         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
585
586         if (ret == 0 && signal)
587                 vmbus_setevent(channel);
588
589         return ret;
590 }
591 EXPORT_SYMBOL(vmbus_sendpacket);
592
593 /*
594  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
595  * packets using a GPADL Direct packet type.
596  */
597 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
598                                      struct hv_page_buffer pagebuffers[],
599                                      u32 pagecount, void *buffer, u32 bufferlen,
600                                      u64 requestid)
601 {
602         int ret;
603         int i;
604         struct vmbus_channel_packet_page_buffer desc;
605         u32 descsize;
606         u32 packetlen;
607         u32 packetlen_aligned;
608         struct scatterlist bufferlist[3];
609         u64 aligned_data = 0;
610         bool signal = false;
611
612         if (pagecount > MAX_PAGE_BUFFER_COUNT)
613                 return -EINVAL;
614
615
616         /*
617          * Adjust the size down since vmbus_channel_packet_page_buffer is the
618          * largest size we support
619          */
620         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
621                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
622                           sizeof(struct hv_page_buffer));
623         packetlen = descsize + bufferlen;
624         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
625
626         /* Setup the descriptor */
627         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
628         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
629         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
630         desc.length8 = (u16)(packetlen_aligned >> 3);
631         desc.transactionid = requestid;
632         desc.rangecount = pagecount;
633
634         for (i = 0; i < pagecount; i++) {
635                 desc.range[i].len = pagebuffers[i].len;
636                 desc.range[i].offset = pagebuffers[i].offset;
637                 desc.range[i].pfn        = pagebuffers[i].pfn;
638         }
639
640         sg_init_table(bufferlist, 3);
641         sg_set_buf(&bufferlist[0], &desc, descsize);
642         sg_set_buf(&bufferlist[1], buffer, bufferlen);
643         sg_set_buf(&bufferlist[2], &aligned_data,
644                 packetlen_aligned - packetlen);
645
646         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
647
648         if (ret == 0 && signal)
649                 vmbus_setevent(channel);
650
651         return ret;
652 }
653 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
654
655 /*
656  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
657  * using a GPADL Direct packet type.
658  */
659 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
660                                 struct hv_multipage_buffer *multi_pagebuffer,
661                                 void *buffer, u32 bufferlen, u64 requestid)
662 {
663         int ret;
664         struct vmbus_channel_packet_multipage_buffer desc;
665         u32 descsize;
666         u32 packetlen;
667         u32 packetlen_aligned;
668         struct scatterlist bufferlist[3];
669         u64 aligned_data = 0;
670         bool signal = false;
671         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
672                                          multi_pagebuffer->len);
673
674
675         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
676                 return -EINVAL;
677
678         /*
679          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
680          * the largest size we support
681          */
682         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
683                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
684                           sizeof(u64));
685         packetlen = descsize + bufferlen;
686         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
687
688
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;
695         desc.rangecount = 1;
696
697         desc.range.len = multi_pagebuffer->len;
698         desc.range.offset = multi_pagebuffer->offset;
699
700         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
701                pfncount * sizeof(u64));
702
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);
708
709         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
710
711         if (ret == 0 && signal)
712                 vmbus_setevent(channel);
713
714         return ret;
715 }
716 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
717
718 /**
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
725  *
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.
728  *
729  * Mainly used by Hyper-V drivers.
730  */
731 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
732                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
733 {
734         struct vmpacket_descriptor desc;
735         u32 packetlen;
736         u32 userlen;
737         int ret;
738
739         *buffer_actual_len = 0;
740         *requestid = 0;
741
742
743         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
744                              sizeof(struct vmpacket_descriptor));
745         if (ret != 0)
746                 return 0;
747
748         packetlen = desc.len8 << 3;
749         userlen = packetlen - (desc.offset8 << 3);
750
751         *buffer_actual_len = userlen;
752
753         if (userlen > bufferlen) {
754
755                 pr_err("Buffer too small - got %d needs %d\n",
756                            bufferlen, userlen);
757                 return -ETOOSMALL;
758         }
759
760         *requestid = desc.trans_id;
761
762         /* Copy over the packet to the user buffer */
763         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
764                              (desc.offset8 << 3));
765
766
767         return 0;
768 }
769 EXPORT_SYMBOL(vmbus_recvpacket);
770
771 /*
772  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
773  */
774 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
775                               u32 bufferlen, u32 *buffer_actual_len,
776                               u64 *requestid)
777 {
778         struct vmpacket_descriptor desc;
779         u32 packetlen;
780         u32 userlen;
781         int ret;
782
783         *buffer_actual_len = 0;
784         *requestid = 0;
785
786
787         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
788                              sizeof(struct vmpacket_descriptor));
789         if (ret != 0)
790                 return 0;
791
792
793         packetlen = desc.len8 << 3;
794         userlen = packetlen - (desc.offset8 << 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
810         return 0;
811 }
812 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);