Staging: hv: netvsc: Fix a dereferencing issue
[linux-2.6.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 errorout;
150         }
151
152         ret = hv_ringbuffer_init(
153                 &newchannel->inbound, in, recv_ringbuffer_size);
154         if (ret != 0) {
155                 err = ret;
156                 goto errorout;
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 errorout;
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 errorout;
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 errorout;
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 cleanup;
212
213         t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
214         if (t == 0) {
215                 err = -ETIMEDOUT;
216                 goto errorout;
217         }
218
219
220         if (open_info->response.open_result.status)
221                 err = open_info->response.open_result.status;
222
223 cleanup:
224         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
225         list_del(&open_info->msglistentry);
226         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
227
228         kfree(open_info);
229         return err;
230
231 errorout:
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));
236         kfree(open_info);
237         return err;
238 }
239 EXPORT_SYMBOL_GPL(vmbus_open);
240
241 /*
242  * create_gpadl_header - Creates a gpadl for the specified buffer
243  */
244 static int create_gpadl_header(void *kbuffer, u32 size,
245                                          struct vmbus_channel_msginfo **msginfo,
246                                          u32 *messagecount)
247 {
248         int i;
249         int pagecount;
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;
255         u32 msgsize;
256
257         int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
258
259         pagecount = size >> PAGE_SHIFT;
260         pfn = virt_to_phys(kbuffer) >> PAGE_SHIFT;
261
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);
267
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);
275                 if (!msgheader)
276                         goto nomem;
277
278                 INIT_LIST_HEAD(&msgheader->submsglist);
279                 msgheader->msgsize = msgsize;
280
281                 gpadl_header = (struct vmbus_channel_gpadl_header *)
282                         msgheader->msg;
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;
291                 *messagecount = 1;
292
293                 pfnsum = pfncount;
294                 pfnleft = pagecount - pfncount;
295
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);
300
301                 /* fill in the body */
302                 while (pfnleft) {
303                         if (pfnleft > pfncount)
304                                 pfncurr = pfncount;
305                         else
306                                 pfncurr = pfnleft;
307
308                         msgsize = sizeof(struct vmbus_channel_msginfo) +
309                                   sizeof(struct vmbus_channel_gpadl_body) +
310                                   pfncurr * sizeof(u64);
311                         msgbody = kzalloc(msgsize, GFP_KERNEL);
312
313                         if (!msgbody) {
314                                 struct vmbus_channel_msginfo *pos = NULL;
315                                 struct vmbus_channel_msginfo *tmp = NULL;
316                                 /*
317                                  * Free up all the allocated messages.
318                                  */
319                                 list_for_each_entry_safe(pos, tmp,
320                                         &msgheader->submsglist,
321                                         msglistentry) {
322
323                                         list_del(&pos->msglistentry);
324                                         kfree(pos);
325                                 }
326
327                                 goto nomem;
328                         }
329
330                         msgbody->msgsize = msgsize;
331                         (*messagecount)++;
332                         gpadl_body =
333                                 (struct vmbus_channel_gpadl_body *)msgbody->msg;
334
335                         /*
336                          * Gpadl is u32 and we are using a pointer which could
337                          * be 64-bit
338                          * This is governed by the guest/host protocol and
339                          * so the hypervisor gurantees that this is ok.
340                          */
341                         for (i = 0; i < pfncurr; i++)
342                                 gpadl_body->pfn[i] = pfn + pfnsum + i;
343
344                         /* add to msg header */
345                         list_add_tail(&msgbody->msglistentry,
346                                       &msgheader->submsglist);
347                         pfnsum += pfncurr;
348                         pfnleft -= pfncurr;
349                 }
350         } else {
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)
357                         goto nomem;
358                 msgheader->msgsize = msgsize;
359
360                 gpadl_header = (struct vmbus_channel_gpadl_header *)
361                         msgheader->msg;
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;
369
370                 *msginfo = msgheader;
371                 *messagecount = 1;
372         }
373
374         return 0;
375 nomem:
376         kfree(msgheader);
377         kfree(msgbody);
378         return -ENOMEM;
379 }
380
381 /*
382  * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
383  *
384  * @channel: a channel
385  * @kbuffer: from kmalloc
386  * @size: page-size multiple
387  * @gpadl_handle: some funky thing
388  */
389 int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
390                                u32 size, u32 *gpadl_handle)
391 {
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;
396         u32 msgcount;
397         struct list_head *curr;
398         u32 next_gpadl_handle;
399         unsigned long flags;
400         int ret = 0;
401         int t;
402
403         next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
404         atomic_inc(&vmbus_connection.next_gpadl_handle);
405
406         ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
407         if (ret)
408                 return ret;
409
410         init_completion(&msginfo->waitevent);
411
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;
416
417
418         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
419         list_add_tail(&msginfo->msglistentry,
420                       &vmbus_connection.chn_msg_list);
421
422         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
423
424         ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
425                                sizeof(*msginfo));
426         if (ret != 0)
427                 goto cleanup;
428
429         if (msgcount > 1) {
430                 list_for_each(curr, &msginfo->submsglist) {
431
432                         submsginfo = (struct vmbus_channel_msginfo *)curr;
433                         gpadl_body =
434                              (struct vmbus_channel_gpadl_body *)submsginfo->msg;
435
436                         gpadl_body->header.msgtype =
437                                 CHANNELMSG_GPADL_BODY;
438                         gpadl_body->gpadl = next_gpadl_handle;
439
440                         ret = vmbus_post_msg(gpadl_body,
441                                                submsginfo->msgsize -
442                                                sizeof(*submsginfo));
443                         if (ret != 0)
444                                 goto cleanup;
445
446                 }
447         }
448         t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
449         BUG_ON(t == 0);
450
451
452         /* At this point, we received the gpadl created msg */
453         *gpadl_handle = gpadlmsg->gpadl;
454
455 cleanup:
456         spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
457         list_del(&msginfo->msglistentry);
458         spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
459
460         kfree(msginfo);
461         return ret;
462 }
463 EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
464
465 /*
466  * vmbus_teardown_gpadl -Teardown the specified GPADL handle
467  */
468 int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
469 {
470         struct vmbus_channel_gpadl_teardown *msg;
471         struct vmbus_channel_msginfo *info;
472         unsigned long flags;
473         int ret, t;
474
475         info = kmalloc(sizeof(*info) +
476                        sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
477         if (!info)
478                 return -ENOMEM;
479
480         init_completion(&info->waitevent);
481
482         msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
483
484         msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
485         msg->child_relid = channel->offermsg.child_relid;
486         msg->gpadl = gpadl_handle;
487
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));
494
495         BUG_ON(ret != 0);
496         t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
497         BUG_ON(t == 0);
498
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);
503
504         kfree(info);
505         return ret;
506 }
507 EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
508
509 /*
510  * vmbus_close - Close the specified channel
511  */
512 void vmbus_close(struct vmbus_channel *channel)
513 {
514         struct vmbus_channel_close_channel *msg;
515         int ret;
516         unsigned long flags;
517
518         /* Stop callback and cancel the timer asap */
519         spin_lock_irqsave(&channel->inbound_lock, flags);
520         channel->onchannel_callback = NULL;
521         spin_unlock_irqrestore(&channel->inbound_lock, flags);
522
523         /* Send a closing message */
524
525         msg = &channel->close_msg.msg;
526
527         msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
528         msg->child_relid = channel->offermsg.child_relid;
529
530         ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
531
532         BUG_ON(ret != 0);
533         /* Tear down the gpadl for the channel's ring buffer */
534         if (channel->ringbuffer_gpadlhandle)
535                 vmbus_teardown_gpadl(channel,
536                                           channel->ringbuffer_gpadlhandle);
537
538         /* Cleanup the ring buffers for this channel */
539         hv_ringbuffer_cleanup(&channel->outbound);
540         hv_ringbuffer_cleanup(&channel->inbound);
541
542         free_pages((unsigned long)channel->ringbuffer_pages,
543                 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
544
545
546 }
547 EXPORT_SYMBOL_GPL(vmbus_close);
548
549 /**
550  * vmbus_sendpacket() - Send the specified buffer on the given channel
551  * @channel: Pointer to vmbus_channel structure.
552  * @buffer: Pointer to the buffer you want to receive the data into.
553  * @bufferlen: Maximum size of what the the buffer will hold
554  * @requestid: Identifier of the request
555  * @type: Type of packet that is being send e.g. negotiate, time
556  * packet etc.
557  *
558  * Sends data in @buffer directly to hyper-v via the vmbus
559  * This will send the data unparsed to hyper-v.
560  *
561  * Mainly used by Hyper-V drivers.
562  */
563 int vmbus_sendpacket(struct vmbus_channel *channel, const void *buffer,
564                            u32 bufferlen, u64 requestid,
565                            enum vmbus_packet_type type, u32 flags)
566 {
567         struct vmpacket_descriptor desc;
568         u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
569         u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
570         struct scatterlist bufferlist[3];
571         u64 aligned_data = 0;
572         int ret;
573
574
575         /* Setup the descriptor */
576         desc.type = type; /* VmbusPacketTypeDataInBand; */
577         desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
578         /* in 8-bytes granularity */
579         desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
580         desc.len8 = (u16)(packetlen_aligned >> 3);
581         desc.trans_id = requestid;
582
583         sg_init_table(bufferlist, 3);
584         sg_set_buf(&bufferlist[0], &desc, sizeof(struct vmpacket_descriptor));
585         sg_set_buf(&bufferlist[1], buffer, bufferlen);
586         sg_set_buf(&bufferlist[2], &aligned_data,
587                    packetlen_aligned - packetlen);
588
589         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
590
591         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
592                 vmbus_setevent(channel);
593
594         return ret;
595 }
596 EXPORT_SYMBOL(vmbus_sendpacket);
597
598 /*
599  * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
600  * packets using a GPADL Direct packet type.
601  */
602 int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
603                                      struct hv_page_buffer pagebuffers[],
604                                      u32 pagecount, void *buffer, u32 bufferlen,
605                                      u64 requestid)
606 {
607         int ret;
608         int i;
609         struct vmbus_channel_packet_page_buffer desc;
610         u32 descsize;
611         u32 packetlen;
612         u32 packetlen_aligned;
613         struct scatterlist bufferlist[3];
614         u64 aligned_data = 0;
615
616         if (pagecount > MAX_PAGE_BUFFER_COUNT)
617                 return -EINVAL;
618
619
620         /*
621          * Adjust the size down since vmbus_channel_packet_page_buffer is the
622          * largest size we support
623          */
624         descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
625                           ((MAX_PAGE_BUFFER_COUNT - pagecount) *
626                           sizeof(struct hv_page_buffer));
627         packetlen = descsize + bufferlen;
628         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
629
630         /* Setup the descriptor */
631         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
632         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
633         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
634         desc.length8 = (u16)(packetlen_aligned >> 3);
635         desc.transactionid = requestid;
636         desc.rangecount = pagecount;
637
638         for (i = 0; i < pagecount; i++) {
639                 desc.range[i].len = pagebuffers[i].len;
640                 desc.range[i].offset = pagebuffers[i].offset;
641                 desc.range[i].pfn        = pagebuffers[i].pfn;
642         }
643
644         sg_init_table(bufferlist, 3);
645         sg_set_buf(&bufferlist[0], &desc, descsize);
646         sg_set_buf(&bufferlist[1], buffer, bufferlen);
647         sg_set_buf(&bufferlist[2], &aligned_data,
648                 packetlen_aligned - packetlen);
649
650         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
651
652         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
653                 vmbus_setevent(channel);
654
655         return ret;
656 }
657 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
658
659 /*
660  * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
661  * using a GPADL Direct packet type.
662  */
663 int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
664                                 struct hv_multipage_buffer *multi_pagebuffer,
665                                 void *buffer, u32 bufferlen, u64 requestid)
666 {
667         int ret;
668         struct vmbus_channel_packet_multipage_buffer desc;
669         u32 descsize;
670         u32 packetlen;
671         u32 packetlen_aligned;
672         struct scatterlist bufferlist[3];
673         u64 aligned_data = 0;
674         u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
675                                          multi_pagebuffer->len);
676
677
678         if ((pfncount < 0) || (pfncount > MAX_MULTIPAGE_BUFFER_COUNT))
679                 return -EINVAL;
680
681         /*
682          * Adjust the size down since vmbus_channel_packet_multipage_buffer is
683          * the largest size we support
684          */
685         descsize = sizeof(struct vmbus_channel_packet_multipage_buffer) -
686                           ((MAX_MULTIPAGE_BUFFER_COUNT - pfncount) *
687                           sizeof(u64));
688         packetlen = descsize + bufferlen;
689         packetlen_aligned = ALIGN(packetlen, sizeof(u64));
690
691
692         /* Setup the descriptor */
693         desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
694         desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
695         desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
696         desc.length8 = (u16)(packetlen_aligned >> 3);
697         desc.transactionid = requestid;
698         desc.rangecount = 1;
699
700         desc.range.len = multi_pagebuffer->len;
701         desc.range.offset = multi_pagebuffer->offset;
702
703         memcpy(desc.range.pfn_array, multi_pagebuffer->pfn_array,
704                pfncount * sizeof(u64));
705
706         sg_init_table(bufferlist, 3);
707         sg_set_buf(&bufferlist[0], &desc, descsize);
708         sg_set_buf(&bufferlist[1], buffer, bufferlen);
709         sg_set_buf(&bufferlist[2], &aligned_data,
710                 packetlen_aligned - packetlen);
711
712         ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3);
713
714         if (ret == 0 && !hv_get_ringbuffer_interrupt_mask(&channel->outbound))
715                 vmbus_setevent(channel);
716
717         return ret;
718 }
719 EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
720
721 /**
722  * vmbus_recvpacket() - Retrieve the user packet on the specified channel
723  * @channel: Pointer to vmbus_channel structure.
724  * @buffer: Pointer to the buffer you want to receive the data into.
725  * @bufferlen: Maximum size of what the the buffer will hold
726  * @buffer_actual_len: The actual size of the data after it was received
727  * @requestid: Identifier of the request
728  *
729  * Receives directly from the hyper-v vmbus and puts the data it received
730  * into Buffer. This will receive the data unparsed from hyper-v.
731  *
732  * Mainly used by Hyper-V drivers.
733  */
734 int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
735                         u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
736 {
737         struct vmpacket_descriptor desc;
738         u32 packetlen;
739         u32 userlen;
740         int ret;
741
742         *buffer_actual_len = 0;
743         *requestid = 0;
744
745
746         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
747                              sizeof(struct vmpacket_descriptor));
748         if (ret != 0)
749                 return 0;
750
751         packetlen = desc.len8 << 3;
752         userlen = packetlen - (desc.offset8 << 3);
753
754         *buffer_actual_len = userlen;
755
756         if (userlen > bufferlen) {
757
758                 pr_err("Buffer too small - got %d needs %d\n",
759                            bufferlen, userlen);
760                 return -ETOOSMALL;
761         }
762
763         *requestid = desc.trans_id;
764
765         /* Copy over the packet to the user buffer */
766         ret = hv_ringbuffer_read(&channel->inbound, buffer, userlen,
767                              (desc.offset8 << 3));
768
769
770         return 0;
771 }
772 EXPORT_SYMBOL(vmbus_recvpacket);
773
774 /*
775  * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
776  */
777 int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
778                               u32 bufferlen, u32 *buffer_actual_len,
779                               u64 *requestid)
780 {
781         struct vmpacket_descriptor desc;
782         u32 packetlen;
783         u32 userlen;
784         int ret;
785
786         *buffer_actual_len = 0;
787         *requestid = 0;
788
789
790         ret = hv_ringbuffer_peek(&channel->inbound, &desc,
791                              sizeof(struct vmpacket_descriptor));
792         if (ret != 0)
793                 return 0;
794
795
796         packetlen = desc.len8 << 3;
797         userlen = packetlen - (desc.offset8 << 3);
798
799         *buffer_actual_len = packetlen;
800
801         if (packetlen > bufferlen) {
802                 pr_err("Buffer too small - needed %d bytes but "
803                         "got space for only %d bytes\n",
804                         packetlen, bufferlen);
805                 return -ENOBUFS;
806         }
807
808         *requestid = desc.trans_id;
809
810         /* Copy over the entire packet to the user buffer */
811         ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0);
812
813         return 0;
814 }
815 EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);