- patches.suse/msft-hv-0404-Drivers-hv-Cleanup-error-handling-in-vmbus_open.patch:
[opensuse:kernel.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 /* 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,
41         u32 *messagecount);
42 static void vmbus_setevent(struct vmbus_channel *channel);
43
44 /*
45  * vmbus_setevent- Trigger an event notification on the specified
46  * channel.
47  */
48 static void vmbus_setevent(struct vmbus_channel *channel)
49 {
50         struct hv_monitor_page *monitorpage;
51
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));
57
58                 monitorpage = vmbus_connection.monitor_pages;
59                 monitorpage++; /* Get the child to parent monitor page */
60
61                 sync_set_bit(channel->monitor_bit,
62                         (unsigned long *)&monitorpage->trigger_group
63                                         [channel->monitor_grp].pending);
64
65         } else {
66                 vmbus_set_event(channel->offermsg.child_relid);
67         }
68 }
69
70 /*
71  * vmbus_get_debug_info -Retrieve various channel debug info
72  */
73 void vmbus_get_debug_info(struct vmbus_channel *channel,
74                               struct vmbus_channel_debug_info *debuginfo)
75 {
76         struct hv_monitor_page *monitorpage;
77         u8 monitor_group = (u8)channel->offermsg.monitorid / 32;
78         u8 monitor_offset = (u8)channel->offermsg.monitorid % 32;
79
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,
86                sizeof(uuid_le));
87
88         monitorpage = (struct hv_monitor_page *)vmbus_connection.monitor_pages;
89
90         debuginfo->monitorid = channel->offermsg.monitorid;
91
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;
99
100         monitorpage++;
101
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;
109
110         hv_ringbuffer_get_debuginfo(&channel->inbound, &debuginfo->inbound);
111         hv_ringbuffer_get_debuginfo(&channel->outbound, &debuginfo->outbound);
112 }
113
114 /*
115  * vmbus_open - Open the specified channel.
116  */
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)
120 {
121         struct vmbus_channel_open_channel *open_msg;
122         struct vmbus_channel_msginfo *open_info = NULL;
123         void *in, *out;
124         unsigned long flags;
125         int ret, t, err = 0;
126
127         newchannel->onchannel_callback = onchannelcallback;
128         newchannel->channel_callback_context = context;
129
130         /* Allocate the ring buffer */
131         out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
132                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
133
134         if (!out)
135                 return -ENOMEM;
136
137
138         in = (void *)((unsigned long)out + send_ringbuffer_size);
139
140         newchannel->ringbuffer_pages = out;
141         newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
142                                            recv_ringbuffer_size) >> PAGE_SHIFT;
143
144         ret = hv_ringbuffer_init(
145                 &newchannel->outbound, out, send_ringbuffer_size);
146
147         if (ret != 0) {
148                 err = ret;
149                 goto error0;
150         }
151
152         ret = hv_ringbuffer_init(
153                 &newchannel->inbound, in, recv_ringbuffer_size);
154         if (ret != 0) {
155                 err = ret;
156                 goto error0;
157         }
158
159
160         /* Establish the gpadl for the ring buffer */
161         newchannel->ringbuffer_gpadlhandle = 0;
162
163         ret = vmbus_establish_gpadl(newchannel,
164                                          newchannel->outbound.ring_buffer,
165                                          send_ringbuffer_size +
166                                          recv_ringbuffer_size,
167                                          &newchannel->ringbuffer_gpadlhandle);
168
169         if (ret != 0) {
170                 err = ret;
171                 goto error0;
172         }
173
174         /* Create and init the channel open message */
175         open_info = kmalloc(sizeof(*open_info) +
176                            sizeof(struct vmbus_channel_open_channel),
177                            GFP_KERNEL);
178         if (!open_info) {
179                 err = -ENOMEM;
180                 goto error0;
181         }
182
183         init_completion(&open_info->waitevent);
184
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 >>
191                                                   PAGE_SHIFT;
192         open_msg->server_contextarea_gpadlhandle = 0;
193
194         if (userdatalen > MAX_USER_DEFINED_BYTES) {
195                 err = -EINVAL;
196                 goto error0;
197         }
198
199         if (userdatalen)
200                 memcpy(open_msg->userdata, userdata, userdatalen);
201
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);
206
207         ret = vmbus_post_msg(open_msg,
208                                sizeof(struct vmbus_channel_open_channel));
209
210         if (ret != 0)
211                 goto error1;
212
213         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
214         if (t == 0) {
215                 err = -ETIMEDOUT;
216                 goto error1;
217         }
218
219
220         if (open_info->response.open_result.status)
221                 err = open_info->response.open_result.status;
222
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         kfree(open_info);
228         return err;
229
230 error1:
231         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
232         list_del(&open_info->msglistentry);
233         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
234
235 error0:
236         free_pages((unsigned long)out,
237                 get_order(send_ringbuffer_size + recv_ringbuffer_size));
238         kfree(open_info);
239         return err;
240 }
241 EXPORT_SYMBOL_GPL(vmbus_open);
242
243 /*
244  * create_gpadl_header - Creates a gpadl for the specified buffer
245  */
246 static int create_gpadl_header(void *kbuffer, u32 size,
247                                          struct vmbus_channel_msginfo **msginfo,
248                                          u32 *messagecount)
249 {
250         int i;
251         int pagecount;
252         unsigned long long pfn;
253         struct vmbus_channel_gpadl_header *gpadl_header;
254         struct vmbus_channel_gpadl_body *gpadl_body;
255         struct vmbus_channel_msginfo *msgheader;
256         struct vmbus_channel_msginfo *msgbody = NULL;
257         u32 msgsize;
258
259         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
260
261         pagecount = size >> PAGE_SHIFT;
262         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
263
264         /* do we need a gpadl body msg */
265         pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
266                   sizeof(struct vmbus_channel_gpadl_header) -
267                   sizeof(struct gpa_range);
268         pfncount = pfnsize / sizeof(u64);
269
270         if (pagecount > pfncount) {
271                 /* we need a gpadl body */
272                 /* fill in the header */
273                 msgsize = sizeof(struct vmbus_channel_msginfo) +
274                           sizeof(struct vmbus_channel_gpadl_header) +
275                           sizeof(struct gpa_range) + pfncount * sizeof(u64);
276                 msgheader =  kzalloc(msgsize, GFP_KERNEL);
277                 if (!msgheader)
278                         goto nomem;
279
280                 INIT_LIST_HEAD(&msgheader->submsglist);
281                 msgheader->msgsize = msgsize;
282
283                 gpadl_header = (struct vmbus_channel_gpadl_header *)
284                         msgheader->msg;
285                 gpadl_header->rangecount = 1;
286                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
287                                          pagecount * sizeof(u64);
288                 gpadl_header->range[0].byte_offset = 0;
289                 gpadl_header->range[0].byte_count = size;
290                 for (i = 0; i < pfncount; i++)
291                         gpadl_header->range[0].pfn_array[i] = pfn+i;
292                 *msginfo = msgheader;
293                 *messagecount = 1;
294
295                 pfnsum = pfncount;
296                 pfnleft = pagecount - pfncount;
297
298                 /* how many pfns can we fit */
299                 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
300                           sizeof(struct vmbus_channel_gpadl_body);
301                 pfncount = pfnsize / sizeof(u64);
302
303                 /* fill in the body */
304                 while (pfnleft) {
305                         if (pfnleft > pfncount)
306                                 pfncurr = pfncount;
307                         else
308                                 pfncurr = pfnleft;
309
310                         msgsize = sizeof(struct vmbus_channel_msginfo) +
311                                   sizeof(struct vmbus_channel_gpadl_body) +
312                                   pfncurr * sizeof(u64);
313                         msgbody = kzalloc(msgsize, GFP_KERNEL);
314
315                         if (!msgbody) {
316                                 struct vmbus_channel_msginfo *pos = NULL;
317                                 struct vmbus_channel_msginfo *tmp = NULL;
318                                 /*
319                                  * Free up all the allocated messages.
320                                  */
321                                 list_for_each_entry_safe(pos, tmp,
322                                         &msgheader->submsglist,
323                                         msglistentry) {
324
325                                         list_del(&pos->msglistentry);
326                                         kfree(pos);
327                                 }
328
329                                 goto nomem;
330                         }
331
332                         msgbody->msgsize = msgsize;
333                         (*messagecount)++;
334                         gpadl_body =
335                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
336
337                         /*
338                          * Gpadl is u32 and we are using a pointer which could
339                          * be 64-bit
340                          * This is governed by the guest/host protocol and
341                          * so the hypervisor gurantees that this is ok.
342                          */
343                         for (i = 0; i < pfncurr; i++)
344                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
345
346                         /* add to msg header */
347                         list_add_tail(&msgbody->msglistentry,
348                                       &msgheader->submsglist);
349                         pfnsum += pfncurr;
350                         pfnleft -= pfncurr;
351                 }
352         } else {
353                 /* everything fits in a header */
354                 msgsize = sizeof(struct vmbus_channel_msginfo) +
355                           sizeof(struct vmbus_channel_gpadl_header) +
356                           sizeof(struct gpa_range) + pagecount * sizeof(u64);
357                 msgheader = kzalloc(msgsize, GFP_KERNEL);
358                 if (msgheader == NULL)
359                         goto nomem;
360                 msgheader->msgsize = msgsize;
361
362                 gpadl_header = (struct vmbus_channel_gpadl_header *)
363                         msgheader->msg;
364                 gpadl_header->rangecount = 1;
365                 gpadl_header->range_buflen = sizeof(struct gpa_range) +
366                                          pagecount * sizeof(u64);
367                 gpadl_header->range[0].byte_offset = 0;
368                 gpadl_header->range[0].byte_count = size;
369                 for (i = 0; i < pagecount; i++)
370                         gpadl_header->range[0].pfn_array[i] = pfn+i;
371
372                 *msginfo = msgheader;
373                 *messagecount = 1;
374         }
375
376         return 0;
377 nomem:
378         kfree(msgheader);
379         kfree(msgbody);
380         return -ENOMEM;
381 }
382
383 /*
384  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
385  *
386  * @channel: a channel
387  * @kbuffer: from kmalloc
388  * @size: page-size multiple
389  * @gpadl_handle: some funky thing
390  */
391 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
392                                u32 size, u32 *gpadl_handle)
393 {
394         struct vmbus_channel_gpadl_header *gpadlmsg;
395         struct vmbus_channel_gpadl_body *gpadl_body;
396         struct vmbus_channel_msginfo *msginfo = NULL;
397         struct vmbus_channel_msginfo *submsginfo;
398         u32 msgcount;
399         struct list_head *curr;
400         u32 next_gpadl_handle;
401         unsigned long flags;
402         int ret = 0;
403         int t;
404
405         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
406         atomic_inc(&vmbus_connection.next_gpadl_handle);
407
408         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
409         if (ret)
410                 return ret;
411
412         init_completion(&msginfo->waitevent);
413
414         gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
415         gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
416         gpadlmsg->child_relid = channel->offermsg.child_relid;
417         gpadlmsg->gpadl = next_gpadl_handle;
418
419
420         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
421         list_add_tail(&msginfo->msglistentry,
422                       &vmbus_connection.chn_msg_list);
423
424         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
425
426         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
427                                sizeof(*msginfo));
428         if (ret != 0)
429                 goto cleanup;
430
431         if (msgcount > 1) {
432                 list_for_each(curr, &msginfo->submsglist) {
433
434                         submsginfo = (struct vmbus_channel_msginfo *)curr;
435                         gpadl_body =
436                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
437
438                         gpadl_body->header.msgtype =
439                                 CHANNELMSG_GPADL_BODY;
440                         gpadl_body->gpadl = next_gpadl_handle;
441
442                         ret = vmbus_post_msg(gpadl_body,
443                                                submsginfo->msgsize -
444                                                sizeof(*submsginfo));
445                         if (ret != 0)
446                                 goto cleanup;
447
448                 }
449         }
450         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
451         BUG_ON(t == 0);
452
453
454         /* At this point, we received the gpadl created msg */
455         *gpadl_handle = gpadlmsg->gpadl;
456
457 cleanup:
458         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
459         list_del(&msginfo->msglistentry);
460         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
461
462         kfree(msginfo);
463         return ret;
464 }
465 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
466
467 /*
468  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
469  */
470 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
471 {
472         struct vmbus_channel_gpadl_teardown *msg;
473         struct vmbus_channel_msginfo *info;
474         unsigned long flags;
475         int ret, t;
476
477         info = kmalloc(sizeof(*info) +
478                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
479         if (!info)
480                 return -ENOMEM;
481
482         init_completion(&info->waitevent);
483
484         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
485
486         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
487         msg->child_relid = channel->offermsg.child_relid;
488         msg->gpadl = gpadl_handle;
489
490         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
491         list_add_tail(&info->msglistentry,
492                       &vmbus_connection.chn_msg_list);
493         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
494         ret = vmbus_post_msg(msg,
495                                sizeof(struct vmbus_channel_gpadl_teardown));
496
497         BUG_ON(ret != 0);
498         t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
499         BUG_ON(t == 0);
500
501         /* Received a torndown response */
502         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
503         list_del(&info->msglistentry);
504         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
505
506         kfree(info);
507         return ret;
508 }
509 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
510
511 /*
512  * vmbus_close - Close the specified channel
513  */
514 void vmbus_close(struct vmbus_channel *channel)
515 {
516         struct vmbus_channel_close_channel *msg;
517         int ret;
518         unsigned long flags;
519
520         /* Stop callback and cancel the timer asap */
521         spin_lock_irqsave(&channel->inbound_lock, flags);
522         channel->onchannel_callback = NULL;
523         spin_unlock_irqrestore(&channel->inbound_lock, flags);
524
525         /* Send a closing message */
526
527         msg = &channel->close_msg.msg;
528
529         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
530         msg->child_relid = channel->offermsg.child_relid;
531
532         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
533
534         BUG_ON(ret != 0);
535         /* Tear down the gpadl for the channel's ring buffer */
536         if (channel->ringbuffer_gpadlhandle)
537                 vmbus_teardown_gpadl(channel,
538                                           channel->ringbuffer_gpadlhandle);
539
540         /* Cleanup the ring buffers for this channel */
541         hv_ringbuffer_cleanup(&channel->outbound);
542         hv_ringbuffer_cleanup(&channel->inbound);
543
544         free_pages((unsigned long)channel->ringbuffer_pages,
545                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
546
547
548 }
549 EXPORT_SYMBOL_GPL(vmbus_close);
550
551 /**
552  * vmbus_sendpacket() - Send the specified buffer on the given channel
553  * @channel: Pointer to vmbus_channel structure.
554  * @buffer: Pointer to the buffer you want to receive the data into.
555  * @bufferlen: Maximum size of what the the buffer will hold
556  * @requestid: Identifier of the request
557  * @type: Type of packet that is being send e.g. negotiate, time
558  * packet etc.
559  *
560  * Sends data in @buffer directly to hyper-v via the vmbus
561  * This will send the data unparsed to hyper-v.
562  *
563  * Mainly used by Hyper-V drivers.
564  */
565 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
566                            u32 bufferlen, u64 requestid,
567                            enum vmbus_packet_type type, u32 flags)
568 {
569         struct vmpacket_descriptor desc;
570         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
571         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
572         struct scatterlist bufferlist[3];
573         u64 aligned_data = 0;
574         int ret;
575
576
577         /* Setup the descriptor */
578         desc.type = type; /* VmbusPacketTypeDataInBand; */
579         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
580         /* in 8-bytes granularity */
581         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
582         desc.len8 = (u16)(packetlen_aligned >> 3);
583         desc.trans_id = requestid;
584
585         sg_init_table(bufferlist, 3);
586         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
587         sg_set_buf(&bufferlist[1], buffer, bufferlen);
588         sg_set_buf(&bufferlist[2], &aligned_data,
589                    packetlen_aligned - packetlen);
590
591         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
592
593         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
594                 vmbus_setevent(channel);
595
596         return ret;
597 }
598 EXPORT_SYMBOL(vmbus_sendpacket);
599
600 /*
601  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
602  * packets using a GPADL Direct packet type.
603  */
604 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
605                                      struct hv_page_buffer pagebuffers[],
606                                      u32 pagecount, void *buffer, u32 bufferlen,
607                                      u64 requestid)
608 {
609         int ret;
610         int i;
611         struct vmbus_channel_packet_page_buffer desc;
612         u32 descsize;
613         u32 packetlen;
614         u32 packetlen_aligned;
615         struct scatterlist bufferlist[3];
616         u64 aligned_data = 0;
617
618         if (pagecount > MAX_PAGE_BUFFER_COUNT)
619                 return -EINVAL;
620
621
622         /*
623          * Adjust the size down since vmbus_channel_packet_page_buffer is the
624          * largest size we support
625          */
626         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
627                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
628                           sizeof(struct hv_page_buffer));
629         packetlen = descsize + bufferlen;
630         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
631
632         /* Setup the descriptor */
633         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
634         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
635         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
636         desc.length8 = (u16)(packetlen_aligned >> 3);
637         desc.transactionid = requestid;
638         desc.rangecount = pagecount;
639
640         for (i = 0; i < pagecount; i++) {
641                 desc.range[i].len = pagebuffers[i].len;
642                 desc.range[i].offset = pagebuffers[i].offset;
643                 desc.range[i].pfn        = pagebuffers[i].pfn;
644         }
645
646         sg_init_table(bufferlist, 3);
647         sg_set_buf(&bufferlist[0], &desc, descsize);
648         sg_set_buf(&bufferlist[1], buffer, bufferlen);
649         sg_set_buf(&bufferlist[2], &aligned_data,
650                 packetlen_aligned - packetlen);
651
652         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
653
654         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
655                 vmbus_setevent(channel);
656
657         return ret;
658 }
659 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
660
661 /*
662  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
663  * using a GPADL Direct packet type.
664  */
665 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
666                                 struct hv_multipage_buffer *multi_pagebuffer,
667                                 void *buffer, u32 bufferlen, u64 requestid)
668 {
669         int ret;
670         struct vmbus_channel_packet_multipage_buffer desc;
671         u32 descsize;
672         u32 packetlen;
673         u32 packetlen_aligned;
674         struct scatterlist bufferlist[3];
675         u64 aligned_data = 0;
676         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
677                                          multi_pagebuffer->len);
678
679
680         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
681                 return -EINVAL;
682
683         /*
684          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
685          * the largest size we support
686          */
687         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
688                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
689                           sizeof(u64));
690         packetlen = descsize + bufferlen;
691         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
692
693
694         /* Setup the descriptor */
695         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
696         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
697         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
698         desc.length8 = (u16)(packetlen_aligned >> 3);
699         desc.transactionid = requestid;
700         desc.rangecount = 1;
701
702         desc.range.len = multi_pagebuffer->len;
703         desc.range.offset = multi_pagebuffer->offset;
704
705         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
706                pfncount * sizeof(u64));
707
708         sg_init_table(bufferlist, 3);
709         sg_set_buf(&bufferlist[0], &desc, descsize);
710         sg_set_buf(&bufferlist[1], buffer, bufferlen);
711         sg_set_buf(&bufferlist[2], &aligned_data,
712                 packetlen_aligned - packetlen);
713
714         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
715
716         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
717                 vmbus_setevent(channel);
718
719         return ret;
720 }
721 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
722
723 /**
724  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
725  * @channel: Pointer to vmbus_channel structure.
726  * @buffer: Pointer to the buffer you want to receive the data into.
727  * @bufferlen: Maximum size of what the the buffer will hold
728  * @buffer_actual_len: The actual size of the data after it was received
729  * @requestid: Identifier of the request
730  *
731  * Receives directly from the hyper-v vmbus and puts the data it received
732  * into Buffer. This will receive the data unparsed from hyper-v.
733  *
734  * Mainly used by Hyper-V drivers.
735  */
736 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
737                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
738 {
739         struct vmpacket_descriptor desc;
740         u32 packetlen;
741         u32 userlen;
742         int ret;
743
744         *buffer_actual_len = 0;
745         *requestid = 0;
746
747
748         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
749                              sizeof(struct vmpacket_descriptor));
750         if (ret != 0)
751                 return 0;
752
753         packetlen = desc.len8 << 3;
754         userlen = packetlen - (desc.offset8 << 3);
755
756         *buffer_actual_len = userlen;
757
758         if (userlen > bufferlen) {
759
760                 pr_err("Buffer too small - got %d needs %d\n",
761                            bufferlen, userlen);
762                 return -ETOOSMALL;
763         }
764
765         *requestid = desc.trans_id;
766
767         /* Copy over the packet to the user buffer */
768         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
769                              (desc.offset8 << 3));
770
771
772         return 0;
773 }
774 EXPORT_SYMBOL(vmbus_recvpacket);
775
776 /*
777  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
778  */
779 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
780                               u32 bufferlen, u32 *buffer_actual_len,
781                               u64 *requestid)
782 {
783         struct vmpacket_descriptor desc;
784         u32 packetlen;
785         u32 userlen;
786         int ret;
787
788         *buffer_actual_len = 0;
789         *requestid = 0;
790
791
792         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
793                              sizeof(struct vmpacket_descriptor));
794         if (ret != 0)
795                 return 0;
796
797
798         packetlen = desc.len8 << 3;
799         userlen = packetlen - (desc.offset8 << 3);
800
801         *buffer_actual_len = packetlen;
802
803         if (packetlen > bufferlen) {
804                 pr_err("Buffer too small - needed %d bytes but "
805                         "got space for only %d bytes\n",
806                         packetlen, bufferlen);
807                 return -ENOBUFS;
808         }
809
810         *requestid = desc.trans_id;
811
812         /* Copy over the entire packet to the user buffer */
813         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
814
815         return 0;
816 }
817 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);