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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 input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
196
197 if (!input_device->hid_desc)
198 goto cleanup;
199
200 input_device->report_desc_size = desc->desc[0].wDescriptorLength;
201 if (input_device->report_desc_size == 0) {
202 input_device->dev_info_status = -EINVAL;
203 goto cleanup;
204 }
205
206 input_device->report_desc = kzalloc(input_device->report_desc_size,
207 GFP_ATOMIC);
208
209 if (!input_device->report_desc) {
210 input_device->dev_info_status = -ENOMEM;
211 goto cleanup;
212 }
213
214 memcpy(input_device->report_desc,
215 ((unsigned char *)desc) + desc->bLength,
216 desc->desc[0].wDescriptorLength);
217
218 /* Send the ack */
219 memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
220
221 ack.type = PIPE_MESSAGE_DATA;
222 ack.size = sizeof(struct synthhid_device_info_ack);
223
224 ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
225 ack.ack.header.size = 1;
226 ack.ack.reserved = 0;
227
228 ret = vmbus_sendpacket(input_device->device->channel,
229 &ack,
230 sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
231 sizeof(struct synthhid_device_info_ack),
232 (unsigned long)&ack,
233 VM_PKT_DATA_INBAND,
234 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
235
236 if (!ret)
237 input_device->dev_info_status = 0;
238
239cleanup:
240 complete(&input_device->wait_event);
241
242 return;
243}
244
245static void mousevsc_on_receive(struct hv_device *device,
246 struct vmpacket_descriptor *packet)
247{
248 struct pipe_prt_msg *pipe_msg;
249 struct synthhid_msg *hid_msg;
250 struct mousevsc_dev *input_dev = hv_get_drvdata(device);
251 struct synthhid_input_report *input_report;
252 size_t len;
253
254 pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
255 (packet->offset8 << 3));
256
257 if (pipe_msg->type != PIPE_MESSAGE_DATA)
258 return;
259
260 hid_msg = (struct synthhid_msg *)pipe_msg->data;
261
262 switch (hid_msg->header.type) {
263 case SYNTH_HID_PROTOCOL_RESPONSE:
264 /*
265 * While it will be impossible for us to protect against
266 * malicious/buggy hypervisor/host, add a check here to
267 * ensure we don't corrupt memory.
268 */
269 if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
270 - sizeof(unsigned char))
271 > sizeof(struct mousevsc_prt_msg)) {
272 WARN_ON(1);
273 break;
274 }
275
276 memcpy(&input_dev->protocol_resp, pipe_msg,
277 pipe_msg->size + sizeof(struct pipe_prt_msg) -
278 sizeof(unsigned char));
279 complete(&input_dev->wait_event);
280 break;
281
282 case SYNTH_HID_INITIAL_DEVICE_INFO:
283 WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
284
285 /*
286 * Parse out the device info into device attr,
287 * hid desc and report desc
288 */
289 mousevsc_on_receive_device_info(input_dev,
290 (struct synthhid_device_info *)pipe_msg->data);
291 break;
292 case SYNTH_HID_INPUT_REPORT:
293 input_report =
294 (struct synthhid_input_report *)pipe_msg->data;
295 if (!input_dev->init_complete)
296 break;
297
298 len = min(input_report->header.size,
299 (u32)sizeof(input_dev->input_buf));
300 memcpy(input_dev->input_buf, input_report->buffer, len);
301 hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
302 input_dev->input_buf, len, 1);
303
304 pm_wakeup_hard_event(&input_dev->device->device);
305
306 break;
307 default:
308 pr_err("unsupported hid msg type - type %d len %d\n",
309 hid_msg->header.type, hid_msg->header.size);
310 break;
311 }
312
313}
314
315static void mousevsc_on_channel_callback(void *context)
316{
317 struct hv_device *device = context;
318 struct vmpacket_descriptor *desc;
319
320 foreach_vmbus_pkt(desc, device->channel) {
321 switch (desc->type) {
322 case VM_PKT_COMP:
323 break;
324
325 case VM_PKT_DATA_INBAND:
326 mousevsc_on_receive(device, desc);
327 break;
328
329 default:
330 pr_err("Unhandled packet type %d, tid %llx len %d\n",
331 desc->type, desc->trans_id, desc->len8 * 8);
332 break;
333 }
334 }
335}
336
337static int mousevsc_connect_to_vsp(struct hv_device *device)
338{
339 int ret = 0;
340 unsigned long t;
341 struct mousevsc_dev *input_dev = hv_get_drvdata(device);
342 struct mousevsc_prt_msg *request;
343 struct mousevsc_prt_msg *response;
344
345 request = &input_dev->protocol_req;
346 memset(request, 0, sizeof(struct mousevsc_prt_msg));
347
348 request->type = PIPE_MESSAGE_DATA;
349 request->size = sizeof(struct synthhid_protocol_request);
350 request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
351 request->request.header.size = sizeof(unsigned int);
352 request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
353
354 ret = vmbus_sendpacket(device->channel, request,
355 sizeof(struct pipe_prt_msg) -
356 sizeof(unsigned char) +
357 sizeof(struct synthhid_protocol_request),
358 (unsigned long)request,
359 VM_PKT_DATA_INBAND,
360 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
361 if (ret)
362 goto cleanup;
363
364 t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
365 if (!t) {
366 ret = -ETIMEDOUT;
367 goto cleanup;
368 }
369
370 response = &input_dev->protocol_resp;
371
372 if (!response->response.approved) {
373 pr_err("synthhid protocol request failed (version %d)\n",
374 SYNTHHID_INPUT_VERSION);
375 ret = -ENODEV;
376 goto cleanup;
377 }
378
379 t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
380 if (!t) {
381 ret = -ETIMEDOUT;
382 goto cleanup;
383 }
384
385 /*
386 * We should have gotten the device attr, hid desc and report
387 * desc at this point
388 */
389 ret = input_dev->dev_info_status;
390
391cleanup:
392 return ret;
393}
394
395static int mousevsc_hid_parse(struct hid_device *hid)
396{
397 struct hv_device *dev = hid_get_drvdata(hid);
398 struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
399
400 return hid_parse_report(hid, input_dev->report_desc,
401 input_dev->report_desc_size);
402}
403
404static int mousevsc_hid_open(struct hid_device *hid)
405{
406 return 0;
407}
408
409static int mousevsc_hid_start(struct hid_device *hid)
410{
411 return 0;
412}
413
414static void mousevsc_hid_close(struct hid_device *hid)
415{
416}
417
418static void mousevsc_hid_stop(struct hid_device *hid)
419{
420}
421
422static int mousevsc_hid_raw_request(struct hid_device *hid,
423 unsigned char report_num,
424 __u8 *buf, size_t len,
425 unsigned char rtype,
426 int reqtype)
427{
428 return 0;
429}
430
431static struct hid_ll_driver mousevsc_ll_driver = {
432 .parse = mousevsc_hid_parse,
433 .open = mousevsc_hid_open,
434 .close = mousevsc_hid_close,
435 .start = mousevsc_hid_start,
436 .stop = mousevsc_hid_stop,
437 .raw_request = mousevsc_hid_raw_request,
438};
439
440static struct hid_driver mousevsc_hid_driver;
441
442static int mousevsc_probe(struct hv_device *device,
443 const struct hv_vmbus_device_id *dev_id)
444{
445 int ret;
446 struct mousevsc_dev *input_dev;
447 struct hid_device *hid_dev;
448
449 input_dev = mousevsc_alloc_device(device);
450
451 if (!input_dev)
452 return -ENOMEM;
453
454 ret = vmbus_open(device->channel,
455 INPUTVSC_SEND_RING_BUFFER_SIZE,
456 INPUTVSC_RECV_RING_BUFFER_SIZE,
457 NULL,
458 0,
459 mousevsc_on_channel_callback,
460 device
461 );
462
463 if (ret)
464 goto probe_err0;
465
466 ret = mousevsc_connect_to_vsp(device);
467
468 if (ret)
469 goto probe_err1;
470
471 /* workaround SA-167 */
472 if (input_dev->report_desc[14] == 0x25)
473 input_dev->report_desc[14] = 0x29;
474
475 hid_dev = hid_allocate_device();
476 if (IS_ERR(hid_dev)) {
477 ret = PTR_ERR(hid_dev);
478 goto probe_err1;
479 }
480
481 hid_dev->ll_driver = &mousevsc_ll_driver;
482 hid_dev->driver = &mousevsc_hid_driver;
483 hid_dev->bus = BUS_VIRTUAL;
484 hid_dev->vendor = input_dev->hid_dev_info.vendor;
485 hid_dev->product = input_dev->hid_dev_info.product;
486 hid_dev->version = input_dev->hid_dev_info.version;
487 input_dev->hid_device = hid_dev;
488
489 sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
490
491 hid_set_drvdata(hid_dev, device);
492
493 ret = hid_add_device(hid_dev);
494 if (ret)
495 goto probe_err1;
496
497
498 ret = hid_parse(hid_dev);
499 if (ret) {
500 hid_err(hid_dev, "parse failed\n");
501 goto probe_err2;
502 }
503
504 ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
505
506 if (ret) {
507 hid_err(hid_dev, "hw start failed\n");
508 goto probe_err2;
509 }
510
511 device_init_wakeup(&device->device, true);
512
513 input_dev->connected = true;
514 input_dev->init_complete = true;
515
516 return ret;
517
518probe_err2:
519 hid_destroy_device(hid_dev);
520
521probe_err1:
522 vmbus_close(device->channel);
523
524probe_err0:
525 mousevsc_free_device(input_dev);
526
527 return ret;
528}
529
530
531static int mousevsc_remove(struct hv_device *dev)
532{
533 struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
534
535 device_init_wakeup(&dev->device, false);
536 vmbus_close(dev->channel);
537 hid_hw_stop(input_dev->hid_device);
538 hid_destroy_device(input_dev->hid_device);
539 mousevsc_free_device(input_dev);
540
541 return 0;
542}
543
544static const struct hv_vmbus_device_id id_table[] = {
545 /* Mouse guid */
546 { HV_MOUSE_GUID, },
547 { },
548};
549
550MODULE_DEVICE_TABLE(vmbus, id_table);
551
552static struct hv_driver mousevsc_drv = {
553 .name = KBUILD_MODNAME,
554 .id_table = id_table,
555 .probe = mousevsc_probe,
556 .remove = mousevsc_remove,
557 .driver = {
558 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
559 },
560};
561
562static int __init mousevsc_init(void)
563{
564 return vmbus_driver_register(&mousevsc_drv);
565}
566
567static void __exit mousevsc_exit(void)
568{
569 vmbus_driver_unregister(&mousevsc_drv);
570}
571
572MODULE_LICENSE("GPL");
573MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
574
575module_init(mousevsc_init);
576module_exit(mousevsc_exit);