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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#include <linux/uio.h>
31
32#include "hyperv_vmbus.h"
33
34#define NUM_PAGES_SPANNED(addr, len) \
35((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
36
37/*
38 * vmbus_setevent- Trigger an event notification on the specified
39 * channel.
40 */
41static void vmbus_setevent(struct vmbus_channel *channel)
42{
43 struct hv_monitor_page *monitorpage;
44
45 if (channel->offermsg.monitor_allocated) {
46 /* Each u32 represents 32 channels */
47 sync_set_bit(channel->offermsg.child_relid & 31,
48 (unsigned long *) vmbus_connection.send_int_page +
49 (channel->offermsg.child_relid >> 5));
50
51 /* Get the child to parent monitor page */
52 monitorpage = vmbus_connection.monitor_pages[1];
53
54 sync_set_bit(channel->monitor_bit,
55 (unsigned long *)&monitorpage->trigger_group
56 [channel->monitor_grp].pending);
57
58 } else {
59 vmbus_set_event(channel);
60 }
61}
62
63/*
64 * vmbus_open - Open the specified channel.
65 */
66int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
67 u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
68 void (*onchannelcallback)(void *context), void *context)
69{
70 struct vmbus_channel_open_channel *open_msg;
71 struct vmbus_channel_msginfo *open_info = NULL;
72 void *in, *out;
73 unsigned long flags;
74 int ret, t, err = 0;
75
76 spin_lock_irqsave(&newchannel->sc_lock, flags);
77 if (newchannel->state == CHANNEL_OPEN_STATE) {
78 newchannel->state = CHANNEL_OPENING_STATE;
79 } else {
80 spin_unlock_irqrestore(&newchannel->sc_lock, flags);
81 return -EINVAL;
82 }
83 spin_unlock_irqrestore(&newchannel->sc_lock, flags);
84
85 newchannel->onchannel_callback = onchannelcallback;
86 newchannel->channel_callback_context = context;
87
88 /* Allocate the ring buffer */
89 out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
90 get_order(send_ringbuffer_size + recv_ringbuffer_size));
91
92 if (!out)
93 return -ENOMEM;
94
95
96 in = (void *)((unsigned long)out + send_ringbuffer_size);
97
98 newchannel->ringbuffer_pages = out;
99 newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
100 recv_ringbuffer_size) >> PAGE_SHIFT;
101
102 ret = hv_ringbuffer_init(
103 &newchannel->outbound, out, send_ringbuffer_size);
104
105 if (ret != 0) {
106 err = ret;
107 goto error0;
108 }
109
110 ret = hv_ringbuffer_init(
111 &newchannel->inbound, in, recv_ringbuffer_size);
112 if (ret != 0) {
113 err = ret;
114 goto error0;
115 }
116
117
118 /* Establish the gpadl for the ring buffer */
119 newchannel->ringbuffer_gpadlhandle = 0;
120
121 ret = vmbus_establish_gpadl(newchannel,
122 newchannel->outbound.ring_buffer,
123 send_ringbuffer_size +
124 recv_ringbuffer_size,
125 &newchannel->ringbuffer_gpadlhandle);
126
127 if (ret != 0) {
128 err = ret;
129 goto error0;
130 }
131
132 /* Create and init the channel open message */
133 open_info = kmalloc(sizeof(*open_info) +
134 sizeof(struct vmbus_channel_open_channel),
135 GFP_KERNEL);
136 if (!open_info) {
137 err = -ENOMEM;
138 goto error0;
139 }
140
141 init_completion(&open_info->waitevent);
142
143 open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
144 open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
145 open_msg->openid = newchannel->offermsg.child_relid;
146 open_msg->child_relid = newchannel->offermsg.child_relid;
147 open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
148 open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
149 PAGE_SHIFT;
150 open_msg->target_vp = newchannel->target_vp;
151
152 if (userdatalen > MAX_USER_DEFINED_BYTES) {
153 err = -EINVAL;
154 goto error0;
155 }
156
157 if (userdatalen)
158 memcpy(open_msg->userdata, userdata, userdatalen);
159
160 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
161 list_add_tail(&open_info->msglistentry,
162 &vmbus_connection.chn_msg_list);
163 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
164
165 ret = vmbus_post_msg(open_msg,
166 sizeof(struct vmbus_channel_open_channel));
167
168 if (ret != 0)
169 goto error1;
170
171 t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
172 if (t == 0) {
173 err = -ETIMEDOUT;
174 goto error1;
175 }
176
177
178 if (open_info->response.open_result.status)
179 err = open_info->response.open_result.status;
180
181 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
182 list_del(&open_info->msglistentry);
183 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
184
185 if (err == 0)
186 newchannel->state = CHANNEL_OPENED_STATE;
187
188 kfree(open_info);
189 return err;
190
191error1:
192 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
193 list_del(&open_info->msglistentry);
194 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
195
196error0:
197 free_pages((unsigned long)out,
198 get_order(send_ringbuffer_size + recv_ringbuffer_size));
199 kfree(open_info);
200 return err;
201}
202EXPORT_SYMBOL_GPL(vmbus_open);
203
204/*
205 * create_gpadl_header - Creates a gpadl for the specified buffer
206 */
207static int create_gpadl_header(void *kbuffer, u32 size,
208 struct vmbus_channel_msginfo **msginfo,
209 u32 *messagecount)
210{
211 int i;
212 int pagecount;
213 struct vmbus_channel_gpadl_header *gpadl_header;
214 struct vmbus_channel_gpadl_body *gpadl_body;
215 struct vmbus_channel_msginfo *msgheader;
216 struct vmbus_channel_msginfo *msgbody = NULL;
217 u32 msgsize;
218
219 int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
220
221 pagecount = size >> PAGE_SHIFT;
222
223 /* do we need a gpadl body msg */
224 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
225 sizeof(struct vmbus_channel_gpadl_header) -
226 sizeof(struct gpa_range);
227 pfncount = pfnsize / sizeof(u64);
228
229 if (pagecount > pfncount) {
230 /* we need a gpadl body */
231 /* fill in the header */
232 msgsize = sizeof(struct vmbus_channel_msginfo) +
233 sizeof(struct vmbus_channel_gpadl_header) +
234 sizeof(struct gpa_range) + pfncount * sizeof(u64);
235 msgheader = kzalloc(msgsize, GFP_KERNEL);
236 if (!msgheader)
237 goto nomem;
238
239 INIT_LIST_HEAD(&msgheader->submsglist);
240 msgheader->msgsize = msgsize;
241
242 gpadl_header = (struct vmbus_channel_gpadl_header *)
243 msgheader->msg;
244 gpadl_header->rangecount = 1;
245 gpadl_header->range_buflen = sizeof(struct gpa_range) +
246 pagecount * sizeof(u64);
247 gpadl_header->range[0].byte_offset = 0;
248 gpadl_header->range[0].byte_count = size;
249 for (i = 0; i < pfncount; i++)
250 gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
251 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
252 *msginfo = msgheader;
253 *messagecount = 1;
254
255 pfnsum = pfncount;
256 pfnleft = pagecount - pfncount;
257
258 /* how many pfns can we fit */
259 pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
260 sizeof(struct vmbus_channel_gpadl_body);
261 pfncount = pfnsize / sizeof(u64);
262
263 /* fill in the body */
264 while (pfnleft) {
265 if (pfnleft > pfncount)
266 pfncurr = pfncount;
267 else
268 pfncurr = pfnleft;
269
270 msgsize = sizeof(struct vmbus_channel_msginfo) +
271 sizeof(struct vmbus_channel_gpadl_body) +
272 pfncurr * sizeof(u64);
273 msgbody = kzalloc(msgsize, GFP_KERNEL);
274
275 if (!msgbody) {
276 struct vmbus_channel_msginfo *pos = NULL;
277 struct vmbus_channel_msginfo *tmp = NULL;
278 /*
279 * Free up all the allocated messages.
280 */
281 list_for_each_entry_safe(pos, tmp,
282 &msgheader->submsglist,
283 msglistentry) {
284
285 list_del(&pos->msglistentry);
286 kfree(pos);
287 }
288
289 goto nomem;
290 }
291
292 msgbody->msgsize = msgsize;
293 (*messagecount)++;
294 gpadl_body =
295 (struct vmbus_channel_gpadl_body *)msgbody->msg;
296
297 /*
298 * Gpadl is u32 and we are using a pointer which could
299 * be 64-bit
300 * This is governed by the guest/host protocol and
301 * so the hypervisor gurantees that this is ok.
302 */
303 for (i = 0; i < pfncurr; i++)
304 gpadl_body->pfn[i] = slow_virt_to_phys(
305 kbuffer + PAGE_SIZE * (pfnsum + i)) >>
306 PAGE_SHIFT;
307
308 /* add to msg header */
309 list_add_tail(&msgbody->msglistentry,
310 &msgheader->submsglist);
311 pfnsum += pfncurr;
312 pfnleft -= pfncurr;
313 }
314 } else {
315 /* everything fits in a header */
316 msgsize = sizeof(struct vmbus_channel_msginfo) +
317 sizeof(struct vmbus_channel_gpadl_header) +
318 sizeof(struct gpa_range) + pagecount * sizeof(u64);
319 msgheader = kzalloc(msgsize, GFP_KERNEL);
320 if (msgheader == NULL)
321 goto nomem;
322 msgheader->msgsize = msgsize;
323
324 gpadl_header = (struct vmbus_channel_gpadl_header *)
325 msgheader->msg;
326 gpadl_header->rangecount = 1;
327 gpadl_header->range_buflen = sizeof(struct gpa_range) +
328 pagecount * sizeof(u64);
329 gpadl_header->range[0].byte_offset = 0;
330 gpadl_header->range[0].byte_count = size;
331 for (i = 0; i < pagecount; i++)
332 gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
333 kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
334
335 *msginfo = msgheader;
336 *messagecount = 1;
337 }
338
339 return 0;
340nomem:
341 kfree(msgheader);
342 kfree(msgbody);
343 return -ENOMEM;
344}
345
346/*
347 * vmbus_establish_gpadl - Estabish a GPADL for the specified buffer
348 *
349 * @channel: a channel
350 * @kbuffer: from kmalloc or vmalloc
351 * @size: page-size multiple
352 * @gpadl_handle: some funky thing
353 */
354int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
355 u32 size, u32 *gpadl_handle)
356{
357 struct vmbus_channel_gpadl_header *gpadlmsg;
358 struct vmbus_channel_gpadl_body *gpadl_body;
359 struct vmbus_channel_msginfo *msginfo = NULL;
360 struct vmbus_channel_msginfo *submsginfo;
361 u32 msgcount;
362 struct list_head *curr;
363 u32 next_gpadl_handle;
364 unsigned long flags;
365 int ret = 0;
366 int t;
367
368 next_gpadl_handle = atomic_read(&vmbus_connection.next_gpadl_handle);
369 atomic_inc(&vmbus_connection.next_gpadl_handle);
370
371 ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
372 if (ret)
373 return ret;
374
375 init_completion(&msginfo->waitevent);
376
377 gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg;
378 gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER;
379 gpadlmsg->child_relid = channel->offermsg.child_relid;
380 gpadlmsg->gpadl = next_gpadl_handle;
381
382
383 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
384 list_add_tail(&msginfo->msglistentry,
385 &vmbus_connection.chn_msg_list);
386
387 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
388
389 ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize -
390 sizeof(*msginfo));
391 if (ret != 0)
392 goto cleanup;
393
394 if (msgcount > 1) {
395 list_for_each(curr, &msginfo->submsglist) {
396
397 submsginfo = (struct vmbus_channel_msginfo *)curr;
398 gpadl_body =
399 (struct vmbus_channel_gpadl_body *)submsginfo->msg;
400
401 gpadl_body->header.msgtype =
402 CHANNELMSG_GPADL_BODY;
403 gpadl_body->gpadl = next_gpadl_handle;
404
405 ret = vmbus_post_msg(gpadl_body,
406 submsginfo->msgsize -
407 sizeof(*submsginfo));
408 if (ret != 0)
409 goto cleanup;
410
411 }
412 }
413 t = wait_for_completion_timeout(&msginfo->waitevent, 5*HZ);
414 BUG_ON(t == 0);
415
416
417 /* At this point, we received the gpadl created msg */
418 *gpadl_handle = gpadlmsg->gpadl;
419
420cleanup:
421 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
422 list_del(&msginfo->msglistentry);
423 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
424
425 kfree(msginfo);
426 return ret;
427}
428EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
429
430/*
431 * vmbus_teardown_gpadl -Teardown the specified GPADL handle
432 */
433int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
434{
435 struct vmbus_channel_gpadl_teardown *msg;
436 struct vmbus_channel_msginfo *info;
437 unsigned long flags;
438 int ret, t;
439
440 info = kmalloc(sizeof(*info) +
441 sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL);
442 if (!info)
443 return -ENOMEM;
444
445 init_completion(&info->waitevent);
446
447 msg = (struct vmbus_channel_gpadl_teardown *)info->msg;
448
449 msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN;
450 msg->child_relid = channel->offermsg.child_relid;
451 msg->gpadl = gpadl_handle;
452
453 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
454 list_add_tail(&info->msglistentry,
455 &vmbus_connection.chn_msg_list);
456 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
457 ret = vmbus_post_msg(msg,
458 sizeof(struct vmbus_channel_gpadl_teardown));
459
460 BUG_ON(ret != 0);
461 t = wait_for_completion_timeout(&info->waitevent, 5*HZ);
462 BUG_ON(t == 0);
463
464 /* Received a torndown response */
465 spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
466 list_del(&info->msglistentry);
467 spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
468
469 kfree(info);
470 return ret;
471}
472EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
473
474static void vmbus_close_internal(struct vmbus_channel *channel)
475{
476 struct vmbus_channel_close_channel *msg;
477 int ret;
478 unsigned long flags;
479
480 channel->state = CHANNEL_OPEN_STATE;
481 channel->sc_creation_callback = NULL;
482 /* Stop callback and cancel the timer asap */
483 spin_lock_irqsave(&channel->inbound_lock, flags);
484 channel->onchannel_callback = NULL;
485 spin_unlock_irqrestore(&channel->inbound_lock, flags);
486
487 /* Send a closing message */
488
489 msg = &channel->close_msg.msg;
490
491 msg->header.msgtype = CHANNELMSG_CLOSECHANNEL;
492 msg->child_relid = channel->offermsg.child_relid;
493
494 ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel));
495
496 BUG_ON(ret != 0);
497 /* Tear down the gpadl for the channel's ring buffer */
498 if (channel->ringbuffer_gpadlhandle)
499 vmbus_teardown_gpadl(channel,
500 channel->ringbuffer_gpadlhandle);
501
502 /* Cleanup the ring buffers for this channel */
503 hv_ringbuffer_cleanup(&channel->outbound);
504 hv_ringbuffer_cleanup(&channel->inbound);
505
506 free_pages((unsigned long)channel->ringbuffer_pages,
507 get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
508
509
510}
511
512/*
513 * vmbus_close - Close the specified channel
514 */
515void vmbus_close(struct vmbus_channel *channel)
516{
517 struct list_head *cur, *tmp;
518 struct vmbus_channel *cur_channel;
519
520 if (channel->primary_channel != NULL) {
521 /*
522 * We will only close sub-channels when
523 * the primary is closed.
524 */
525 return;
526 }
527 /*
528 * Close all the sub-channels first and then close the
529 * primary channel.
530 */
531 list_for_each_safe(cur, tmp, &channel->sc_list) {
532 cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
533 if (cur_channel->state != CHANNEL_OPENED_STATE)
534 continue;
535 vmbus_close_internal(cur_channel);
536 }
537 /*
538 * Now close the primary.
539 */
540 vmbus_close_internal(channel);
541}
542EXPORT_SYMBOL_GPL(vmbus_close);
543
544/**
545 * vmbus_sendpacket() - Send the specified buffer on the given channel
546 * @channel: Pointer to vmbus_channel structure.
547 * @buffer: Pointer to the buffer you want to receive the data into.
548 * @bufferlen: Maximum size of what the the buffer will hold
549 * @requestid: Identifier of the request
550 * @type: Type of packet that is being send e.g. negotiate, time
551 * packet etc.
552 *
553 * Sends data in @buffer directly to hyper-v via the vmbus
554 * This will send the data unparsed to hyper-v.
555 *
556 * Mainly used by Hyper-V drivers.
557 */
558int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
559 u32 bufferlen, u64 requestid,
560 enum vmbus_packet_type type, u32 flags)
561{
562 struct vmpacket_descriptor desc;
563 u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen;
564 u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
565 struct kvec bufferlist[3];
566 u64 aligned_data = 0;
567 int ret;
568 bool signal = false;
569
570
571 /* Setup the descriptor */
572 desc.type = type; /* VmbusPacketTypeDataInBand; */
573 desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */
574 /* in 8-bytes granularity */
575 desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
576 desc.len8 = (u16)(packetlen_aligned >> 3);
577 desc.trans_id = requestid;
578
579 bufferlist[0].iov_base = &desc;
580 bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
581 bufferlist[1].iov_base = buffer;
582 bufferlist[1].iov_len = bufferlen;
583 bufferlist[2].iov_base = &aligned_data;
584 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
585
586 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
587
588 if (ret == 0 && signal)
589 vmbus_setevent(channel);
590
591 return ret;
592}
593EXPORT_SYMBOL(vmbus_sendpacket);
594
595/*
596 * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer
597 * packets using a GPADL Direct packet type.
598 */
599int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
600 struct hv_page_buffer pagebuffers[],
601 u32 pagecount, void *buffer, u32 bufferlen,
602 u64 requestid)
603{
604 int ret;
605 int i;
606 struct vmbus_channel_packet_page_buffer desc;
607 u32 descsize;
608 u32 packetlen;
609 u32 packetlen_aligned;
610 struct kvec bufferlist[3];
611 u64 aligned_data = 0;
612 bool signal = false;
613
614 if (pagecount > MAX_PAGE_BUFFER_COUNT)
615 return -EINVAL;
616
617
618 /*
619 * Adjust the size down since vmbus_channel_packet_page_buffer is the
620 * largest size we support
621 */
622 descsize = sizeof(struct vmbus_channel_packet_page_buffer) -
623 ((MAX_PAGE_BUFFER_COUNT - pagecount) *
624 sizeof(struct hv_page_buffer));
625 packetlen = descsize + bufferlen;
626 packetlen_aligned = ALIGN(packetlen, sizeof(u64));
627
628 /* Setup the descriptor */
629 desc.type = VM_PKT_DATA_USING_GPA_DIRECT;
630 desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
631 desc.dataoffset8 = descsize >> 3; /* in 8-bytes grandularity */
632 desc.length8 = (u16)(packetlen_aligned >> 3);
633 desc.transactionid = requestid;
634 desc.rangecount = pagecount;
635
636 for (i = 0; i < pagecount; i++) {
637 desc.range[i].len = pagebuffers[i].len;
638 desc.range[i].offset = pagebuffers[i].offset;
639 desc.range[i].pfn = pagebuffers[i].pfn;
640 }
641
642 bufferlist[0].iov_base = &desc;
643 bufferlist[0].iov_len = descsize;
644 bufferlist[1].iov_base = buffer;
645 bufferlist[1].iov_len = bufferlen;
646 bufferlist[2].iov_base = &aligned_data;
647 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
648
649 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
650
651 if (ret == 0 && signal)
652 vmbus_setevent(channel);
653
654 return ret;
655}
656EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
657
658/*
659 * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet
660 * using a GPADL Direct packet type.
661 */
662int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
663 struct hv_multipage_buffer *multi_pagebuffer,
664 void *buffer, u32 bufferlen, u64 requestid)
665{
666 int ret;
667 struct vmbus_channel_packet_multipage_buffer desc;
668 u32 descsize;
669 u32 packetlen;
670 u32 packetlen_aligned;
671 struct kvec bufferlist[3];
672 u64 aligned_data = 0;
673 bool signal = false;
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 bufferlist[0].iov_base = &desc;
707 bufferlist[0].iov_len = descsize;
708 bufferlist[1].iov_base = buffer;
709 bufferlist[1].iov_len = bufferlen;
710 bufferlist[2].iov_base = &aligned_data;
711 bufferlist[2].iov_len = (packetlen_aligned - packetlen);
712
713 ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
714
715 if (ret == 0 && signal)
716 vmbus_setevent(channel);
717
718 return ret;
719}
720EXPORT_SYMBOL_GPL(vmbus_sendpacket_multipagebuffer);
721
722/**
723 * vmbus_recvpacket() - Retrieve the user packet on the specified channel
724 * @channel: Pointer to vmbus_channel structure.
725 * @buffer: Pointer to the buffer you want to receive the data into.
726 * @bufferlen: Maximum size of what the the buffer will hold
727 * @buffer_actual_len: The actual size of the data after it was received
728 * @requestid: Identifier of the request
729 *
730 * Receives directly from the hyper-v vmbus and puts the data it received
731 * into Buffer. This will receive the data unparsed from hyper-v.
732 *
733 * Mainly used by Hyper-V drivers.
734 */
735int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer,
736 u32 bufferlen, u32 *buffer_actual_len, u64 *requestid)
737{
738 struct vmpacket_descriptor desc;
739 u32 packetlen;
740 u32 userlen;
741 int ret;
742 bool signal = false;
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), &signal);
770
771 if (signal)
772 vmbus_setevent(channel);
773
774 return 0;
775}
776EXPORT_SYMBOL(vmbus_recvpacket);
777
778/*
779 * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel
780 */
781int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer,
782 u32 bufferlen, u32 *buffer_actual_len,
783 u64 *requestid)
784{
785 struct vmpacket_descriptor desc;
786 u32 packetlen;
787 int ret;
788 bool signal = false;
789
790 *buffer_actual_len = 0;
791 *requestid = 0;
792
793
794 ret = hv_ringbuffer_peek(&channel->inbound, &desc,
795 sizeof(struct vmpacket_descriptor));
796 if (ret != 0)
797 return 0;
798
799
800 packetlen = desc.len8 << 3;
801
802 *buffer_actual_len = packetlen;
803
804 if (packetlen > bufferlen) {
805 pr_err("Buffer too small - needed %d bytes but "
806 "got space for only %d bytes\n",
807 packetlen, bufferlen);
808 return -ENOBUFS;
809 }
810
811 *requestid = desc.trans_id;
812
813 /* Copy over the entire packet to the user buffer */
814 ret = hv_ringbuffer_read(&channel->inbound, buffer, packetlen, 0,
815 &signal);
816
817 if (signal)
818 vmbus_setevent(channel);
819
820 return ret;
821}
822EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);