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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2009, Citrix Systems, Inc.
4 * Copyright (c) 2010, Microsoft Corporation.
5 * Copyright (c) 2011, Novell Inc.
6 */
7#include <linux/init.h>
8#include <linux/module.h>
9#include <linux/device.h>
10#include <linux/completion.h>
11#include <linux/input.h>
12#include <linux/hid.h>
13#include <linux/hiddev.h>
14#include <linux/hyperv.h>
15
16
17struct hv_input_dev_info {
18 unsigned int size;
19 unsigned short vendor;
20 unsigned short product;
21 unsigned short version;
22 unsigned short reserved[11];
23};
24
25/* The maximum size of a synthetic input message. */
26#define SYNTHHID_MAX_INPUT_REPORT_SIZE 16
27
28/*
29 * Current version
30 *
31 * History:
32 * Beta, RC < 2008/1/22 1,0
33 * RC > 2008/1/22 2,0
34 */
35#define SYNTHHID_INPUT_VERSION_MAJOR 2
36#define SYNTHHID_INPUT_VERSION_MINOR 0
37#define SYNTHHID_INPUT_VERSION (SYNTHHID_INPUT_VERSION_MINOR | \
38 (SYNTHHID_INPUT_VERSION_MAJOR << 16))
39
40
41#pragma pack(push, 1)
42/*
43 * Message types in the synthetic input protocol
44 */
45enum synthhid_msg_type {
46 SYNTH_HID_PROTOCOL_REQUEST,
47 SYNTH_HID_PROTOCOL_RESPONSE,
48 SYNTH_HID_INITIAL_DEVICE_INFO,
49 SYNTH_HID_INITIAL_DEVICE_INFO_ACK,
50 SYNTH_HID_INPUT_REPORT,
51 SYNTH_HID_MAX
52};
53
54/*
55 * Basic message structures.
56 */
57struct synthhid_msg_hdr {
58 enum synthhid_msg_type type;
59 u32 size;
60};
61
62struct synthhid_msg {
63 struct synthhid_msg_hdr header;
64 char data[1]; /* Enclosed message */
65};
66
67union synthhid_version {
68 struct {
69 u16 minor_version;
70 u16 major_version;
71 };
72 u32 version;
73};
74
75/*
76 * Protocol messages
77 */
78struct synthhid_protocol_request {
79 struct synthhid_msg_hdr header;
80 union synthhid_version version_requested;
81};
82
83struct synthhid_protocol_response {
84 struct synthhid_msg_hdr header;
85 union synthhid_version version_requested;
86 unsigned char approved;
87};
88
89struct synthhid_device_info {
90 struct synthhid_msg_hdr header;
91 struct hv_input_dev_info hid_dev_info;
92 struct hid_descriptor hid_descriptor;
93};
94
95struct synthhid_device_info_ack {
96 struct synthhid_msg_hdr header;
97 unsigned char reserved;
98};
99
100struct synthhid_input_report {
101 struct synthhid_msg_hdr header;
102 char buffer[1];
103};
104
105#pragma pack(pop)
106
107#define INPUTVSC_SEND_RING_BUFFER_SIZE (40 * 1024)
108#define INPUTVSC_RECV_RING_BUFFER_SIZE (40 * 1024)
109
110
111enum pipe_prot_msg_type {
112 PIPE_MESSAGE_INVALID,
113 PIPE_MESSAGE_DATA,
114 PIPE_MESSAGE_MAXIMUM
115};
116
117
118struct pipe_prt_msg {
119 enum pipe_prot_msg_type type;
120 u32 size;
121 char data[1];
122};
123
124struct mousevsc_prt_msg {
125 enum pipe_prot_msg_type type;
126 u32 size;
127 union {
128 struct synthhid_protocol_request request;
129 struct synthhid_protocol_response response;
130 struct synthhid_device_info_ack ack;
131 };
132};
133
134/*
135 * Represents an mousevsc device
136 */
137struct mousevsc_dev {
138 struct hv_device *device;
139 bool init_complete;
140 bool connected;
141 struct mousevsc_prt_msg protocol_req;
142 struct mousevsc_prt_msg protocol_resp;
143 /* Synchronize the request/response if needed */
144 struct completion wait_event;
145 int dev_info_status;
146
147 struct hid_descriptor *hid_desc;
148 unsigned char *report_desc;
149 u32 report_desc_size;
150 struct hv_input_dev_info hid_dev_info;
151 struct hid_device *hid_device;
152 u8 input_buf[HID_MAX_BUFFER_SIZE];
153};
154
155
156static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
157{
158 struct mousevsc_dev *input_dev;
159
160 input_dev = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);
161
162 if (!input_dev)
163 return NULL;
164
165 input_dev->device = device;
166 hv_set_drvdata(device, input_dev);
167 init_completion(&input_dev->wait_event);
168 input_dev->init_complete = false;
169
170 return input_dev;
171}
172
173static void mousevsc_free_device(struct mousevsc_dev *device)
174{
175 kfree(device->hid_desc);
176 kfree(device->report_desc);
177 hv_set_drvdata(device->device, NULL);
178 kfree(device);
179}
180
181static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
182 struct synthhid_device_info *device_info)
183{
184 int ret = 0;
185 struct hid_descriptor *desc;
186 struct mousevsc_prt_msg ack;
187
188 input_device->dev_info_status = -ENOMEM;
189
190 input_device->hid_dev_info = device_info->hid_dev_info;
191 desc = &device_info->hid_descriptor;
192 if (desc->bLength == 0)
193 goto cleanup;
194
195 /* The pointer is not NULL when we resume from hibernation */
196 kfree(input_device->hid_desc);
197 input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
198
199 if (!input_device->hid_desc)
200 goto cleanup;
201
202 input_device->report_desc_size = desc->desc[0].wDescriptorLength;
203 if (input_device->report_desc_size == 0) {
204 input_device->dev_info_status = -EINVAL;
205 goto cleanup;
206 }
207
208 /* The pointer is not NULL when we resume from hibernation */
209 kfree(input_device->report_desc);
210 input_device->report_desc = kzalloc(input_device->report_desc_size,
211 GFP_ATOMIC);
212
213 if (!input_device->report_desc) {
214 input_device->dev_info_status = -ENOMEM;
215 goto cleanup;
216 }
217
218 memcpy(input_device->report_desc,
219 ((unsigned char *)desc) + desc->bLength,
220 desc->desc[0].wDescriptorLength);
221
222 /* Send the ack */
223 memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
224
225 ack.type = PIPE_MESSAGE_DATA;
226 ack.size = sizeof(struct synthhid_device_info_ack);
227
228 ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
229 ack.ack.header.size = 1;
230 ack.ack.reserved = 0;
231
232 ret = vmbus_sendpacket(input_device->device->channel,
233 &ack,
234 sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
235 sizeof(struct synthhid_device_info_ack),
236 (unsigned long)&ack,
237 VM_PKT_DATA_INBAND,
238 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
239
240 if (!ret)
241 input_device->dev_info_status = 0;
242
243cleanup:
244 complete(&input_device->wait_event);
245
246 return;
247}
248
249static void mousevsc_on_receive(struct hv_device *device,
250 struct vmpacket_descriptor *packet)
251{
252 struct pipe_prt_msg *pipe_msg;
253 struct synthhid_msg *hid_msg;
254 struct mousevsc_dev *input_dev = hv_get_drvdata(device);
255 struct synthhid_input_report *input_report;
256 size_t len;
257
258 pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
259 (packet->offset8 << 3));
260
261 if (pipe_msg->type != PIPE_MESSAGE_DATA)
262 return;
263
264 hid_msg = (struct synthhid_msg *)pipe_msg->data;
265
266 switch (hid_msg->header.type) {
267 case SYNTH_HID_PROTOCOL_RESPONSE:
268 /*
269 * While it will be impossible for us to protect against
270 * malicious/buggy hypervisor/host, add a check here to
271 * ensure we don't corrupt memory.
272 */
273 if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
274 - sizeof(unsigned char))
275 > sizeof(struct mousevsc_prt_msg)) {
276 WARN_ON(1);
277 break;
278 }
279
280 memcpy(&input_dev->protocol_resp, pipe_msg,
281 pipe_msg->size + sizeof(struct pipe_prt_msg) -
282 sizeof(unsigned char));
283 complete(&input_dev->wait_event);
284 break;
285
286 case SYNTH_HID_INITIAL_DEVICE_INFO:
287 WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
288
289 /*
290 * Parse out the device info into device attr,
291 * hid desc and report desc
292 */
293 mousevsc_on_receive_device_info(input_dev,
294 (struct synthhid_device_info *)pipe_msg->data);
295 break;
296 case SYNTH_HID_INPUT_REPORT:
297 input_report =
298 (struct synthhid_input_report *)pipe_msg->data;
299 if (!input_dev->init_complete)
300 break;
301
302 len = min(input_report->header.size,
303 (u32)sizeof(input_dev->input_buf));
304 memcpy(input_dev->input_buf, input_report->buffer, len);
305 hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
306 input_dev->input_buf, len, 1);
307
308 pm_wakeup_hard_event(&input_dev->device->device);
309
310 break;
311 default:
312 pr_err("unsupported hid msg type - type %d len %d\n",
313 hid_msg->header.type, hid_msg->header.size);
314 break;
315 }
316
317}
318
319static void mousevsc_on_channel_callback(void *context)
320{
321 struct hv_device *device = context;
322 struct vmpacket_descriptor *desc;
323
324 foreach_vmbus_pkt(desc, device->channel) {
325 switch (desc->type) {
326 case VM_PKT_COMP:
327 break;
328
329 case VM_PKT_DATA_INBAND:
330 mousevsc_on_receive(device, desc);
331 break;
332
333 default:
334 pr_err("Unhandled packet type %d, tid %llx len %d\n",
335 desc->type, desc->trans_id, desc->len8 * 8);
336 break;
337 }
338 }
339}
340
341static int mousevsc_connect_to_vsp(struct hv_device *device)
342{
343 int ret = 0;
344 unsigned long t;
345 struct mousevsc_dev *input_dev = hv_get_drvdata(device);
346 struct mousevsc_prt_msg *request;
347 struct mousevsc_prt_msg *response;
348
349 reinit_completion(&input_dev->wait_event);
350
351 request = &input_dev->protocol_req;
352 memset(request, 0, sizeof(struct mousevsc_prt_msg));
353
354 request->type = PIPE_MESSAGE_DATA;
355 request->size = sizeof(struct synthhid_protocol_request);
356 request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
357 request->request.header.size = sizeof(unsigned int);
358 request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
359
360 ret = vmbus_sendpacket(device->channel, request,
361 sizeof(struct pipe_prt_msg) -
362 sizeof(unsigned char) +
363 sizeof(struct synthhid_protocol_request),
364 (unsigned long)request,
365 VM_PKT_DATA_INBAND,
366 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
367 if (ret)
368 goto cleanup;
369
370 t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
371 if (!t) {
372 ret = -ETIMEDOUT;
373 goto cleanup;
374 }
375
376 response = &input_dev->protocol_resp;
377
378 if (!response->response.approved) {
379 pr_err("synthhid protocol request failed (version %d)\n",
380 SYNTHHID_INPUT_VERSION);
381 ret = -ENODEV;
382 goto cleanup;
383 }
384
385 t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
386 if (!t) {
387 ret = -ETIMEDOUT;
388 goto cleanup;
389 }
390
391 /*
392 * We should have gotten the device attr, hid desc and report
393 * desc at this point
394 */
395 ret = input_dev->dev_info_status;
396
397cleanup:
398 return ret;
399}
400
401static int mousevsc_hid_parse(struct hid_device *hid)
402{
403 struct hv_device *dev = hid_get_drvdata(hid);
404 struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
405
406 return hid_parse_report(hid, input_dev->report_desc,
407 input_dev->report_desc_size);
408}
409
410static int mousevsc_hid_open(struct hid_device *hid)
411{
412 return 0;
413}
414
415static int mousevsc_hid_start(struct hid_device *hid)
416{
417 return 0;
418}
419
420static void mousevsc_hid_close(struct hid_device *hid)
421{
422}
423
424static void mousevsc_hid_stop(struct hid_device *hid)
425{
426}
427
428static int mousevsc_hid_raw_request(struct hid_device *hid,
429 unsigned char report_num,
430 __u8 *buf, size_t len,
431 unsigned char rtype,
432 int reqtype)
433{
434 return 0;
435}
436
437static struct hid_ll_driver mousevsc_ll_driver = {
438 .parse = mousevsc_hid_parse,
439 .open = mousevsc_hid_open,
440 .close = mousevsc_hid_close,
441 .start = mousevsc_hid_start,
442 .stop = mousevsc_hid_stop,
443 .raw_request = mousevsc_hid_raw_request,
444};
445
446static struct hid_driver mousevsc_hid_driver;
447
448static int mousevsc_probe(struct hv_device *device,
449 const struct hv_vmbus_device_id *dev_id)
450{
451 int ret;
452 struct mousevsc_dev *input_dev;
453 struct hid_device *hid_dev;
454
455 input_dev = mousevsc_alloc_device(device);
456
457 if (!input_dev)
458 return -ENOMEM;
459
460 ret = vmbus_open(device->channel,
461 INPUTVSC_SEND_RING_BUFFER_SIZE,
462 INPUTVSC_RECV_RING_BUFFER_SIZE,
463 NULL,
464 0,
465 mousevsc_on_channel_callback,
466 device
467 );
468
469 if (ret)
470 goto probe_err0;
471
472 ret = mousevsc_connect_to_vsp(device);
473
474 if (ret)
475 goto probe_err1;
476
477 /* workaround SA-167 */
478 if (input_dev->report_desc[14] == 0x25)
479 input_dev->report_desc[14] = 0x29;
480
481 hid_dev = hid_allocate_device();
482 if (IS_ERR(hid_dev)) {
483 ret = PTR_ERR(hid_dev);
484 goto probe_err1;
485 }
486
487 hid_dev->ll_driver = &mousevsc_ll_driver;
488 hid_dev->driver = &mousevsc_hid_driver;
489 hid_dev->bus = BUS_VIRTUAL;
490 hid_dev->vendor = input_dev->hid_dev_info.vendor;
491 hid_dev->product = input_dev->hid_dev_info.product;
492 hid_dev->version = input_dev->hid_dev_info.version;
493 input_dev->hid_device = hid_dev;
494
495 sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
496
497 hid_set_drvdata(hid_dev, device);
498
499 ret = hid_add_device(hid_dev);
500 if (ret)
501 goto probe_err1;
502
503
504 ret = hid_parse(hid_dev);
505 if (ret) {
506 hid_err(hid_dev, "parse failed\n");
507 goto probe_err2;
508 }
509
510 ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
511
512 if (ret) {
513 hid_err(hid_dev, "hw start failed\n");
514 goto probe_err2;
515 }
516
517 device_init_wakeup(&device->device, true);
518
519 input_dev->connected = true;
520 input_dev->init_complete = true;
521
522 return ret;
523
524probe_err2:
525 hid_destroy_device(hid_dev);
526
527probe_err1:
528 vmbus_close(device->channel);
529
530probe_err0:
531 mousevsc_free_device(input_dev);
532
533 return ret;
534}
535
536
537static int mousevsc_remove(struct hv_device *dev)
538{
539 struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
540
541 device_init_wakeup(&dev->device, false);
542 vmbus_close(dev->channel);
543 hid_hw_stop(input_dev->hid_device);
544 hid_destroy_device(input_dev->hid_device);
545 mousevsc_free_device(input_dev);
546
547 return 0;
548}
549
550static int mousevsc_suspend(struct hv_device *dev)
551{
552 vmbus_close(dev->channel);
553
554 return 0;
555}
556
557static int mousevsc_resume(struct hv_device *dev)
558{
559 int ret;
560
561 ret = vmbus_open(dev->channel,
562 INPUTVSC_SEND_RING_BUFFER_SIZE,
563 INPUTVSC_RECV_RING_BUFFER_SIZE,
564 NULL, 0,
565 mousevsc_on_channel_callback,
566 dev);
567 if (ret)
568 return ret;
569
570 ret = mousevsc_connect_to_vsp(dev);
571 return ret;
572}
573
574static const struct hv_vmbus_device_id id_table[] = {
575 /* Mouse guid */
576 { HV_MOUSE_GUID, },
577 { },
578};
579
580MODULE_DEVICE_TABLE(vmbus, id_table);
581
582static struct hv_driver mousevsc_drv = {
583 .name = KBUILD_MODNAME,
584 .id_table = id_table,
585 .probe = mousevsc_probe,
586 .remove = mousevsc_remove,
587 .suspend = mousevsc_suspend,
588 .resume = mousevsc_resume,
589 .driver = {
590 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
591 },
592};
593
594static int __init mousevsc_init(void)
595{
596 return vmbus_driver_register(&mousevsc_drv);
597}
598
599static void __exit mousevsc_exit(void)
600{
601 vmbus_driver_unregister(&mousevsc_drv);
602}
603
604MODULE_LICENSE("GPL");
605MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
606
607module_init(mousevsc_init);
608module_exit(mousevsc_exit);