xref: /openbmc/linux/drivers/hid/hid-hyperv.c (revision c6fddb28)
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 
17 struct 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  */
45 enum 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  */
57 struct synthhid_msg_hdr {
58 	enum synthhid_msg_type type;
59 	u32 size;
60 };
61 
62 struct synthhid_msg {
63 	struct synthhid_msg_hdr header;
64 	char data[1]; /* Enclosed message */
65 };
66 
67 union synthhid_version {
68 	struct {
69 		u16 minor_version;
70 		u16 major_version;
71 	};
72 	u32 version;
73 };
74 
75 /*
76  * Protocol messages
77  */
78 struct synthhid_protocol_request {
79 	struct synthhid_msg_hdr header;
80 	union synthhid_version version_requested;
81 };
82 
83 struct synthhid_protocol_response {
84 	struct synthhid_msg_hdr header;
85 	union synthhid_version version_requested;
86 	unsigned char approved;
87 };
88 
89 struct 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 
95 struct synthhid_device_info_ack {
96 	struct synthhid_msg_hdr header;
97 	unsigned char reserved;
98 };
99 
100 struct 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 
111 enum pipe_prot_msg_type {
112 	PIPE_MESSAGE_INVALID,
113 	PIPE_MESSAGE_DATA,
114 	PIPE_MESSAGE_MAXIMUM
115 };
116 
117 
118 struct pipe_prt_msg {
119 	enum pipe_prot_msg_type type;
120 	u32 size;
121 	char data[1];
122 };
123 
124 struct  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  */
137 struct 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 
156 static 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 
173 static 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 
181 static 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 
243 cleanup:
244 	complete(&input_device->wait_event);
245 
246 	return;
247 }
248 
249 static 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 
319 static 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 
341 static 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 
397 cleanup:
398 	return ret;
399 }
400 
401 static 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 
410 static int mousevsc_hid_open(struct hid_device *hid)
411 {
412 	return 0;
413 }
414 
415 static int mousevsc_hid_start(struct hid_device *hid)
416 {
417 	return 0;
418 }
419 
420 static void mousevsc_hid_close(struct hid_device *hid)
421 {
422 }
423 
424 static void mousevsc_hid_stop(struct hid_device *hid)
425 {
426 }
427 
428 static 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 
437 static 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 
446 static struct hid_driver mousevsc_hid_driver;
447 
448 static 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 
524 probe_err2:
525 	hid_destroy_device(hid_dev);
526 
527 probe_err1:
528 	vmbus_close(device->channel);
529 
530 probe_err0:
531 	mousevsc_free_device(input_dev);
532 
533 	return ret;
534 }
535 
536 
537 static 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 
550 static int mousevsc_suspend(struct hv_device *dev)
551 {
552 	vmbus_close(dev->channel);
553 
554 	return 0;
555 }
556 
557 static 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 
574 static const struct hv_vmbus_device_id id_table[] = {
575 	/* Mouse guid */
576 	{ HV_MOUSE_GUID, },
577 	{ },
578 };
579 
580 MODULE_DEVICE_TABLE(vmbus, id_table);
581 
582 static 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 
594 static int __init mousevsc_init(void)
595 {
596 	return vmbus_driver_register(&mousevsc_drv);
597 }
598 
599 static void __exit mousevsc_exit(void)
600 {
601 	vmbus_driver_unregister(&mousevsc_drv);
602 }
603 
604 MODULE_LICENSE("GPL");
605 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
606 
607 module_init(mousevsc_init);
608 module_exit(mousevsc_exit);
609