xref: /openbmc/linux/drivers/hid/hid-hyperv.c (revision fb8d6c8d)
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 	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 
239 cleanup:
240 	complete(&input_device->wait_event);
241 
242 	return;
243 }
244 
245 static 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 
315 static 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 
337 static 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 
391 cleanup:
392 	return ret;
393 }
394 
395 static 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 
404 static int mousevsc_hid_open(struct hid_device *hid)
405 {
406 	return 0;
407 }
408 
409 static int mousevsc_hid_start(struct hid_device *hid)
410 {
411 	return 0;
412 }
413 
414 static void mousevsc_hid_close(struct hid_device *hid)
415 {
416 }
417 
418 static void mousevsc_hid_stop(struct hid_device *hid)
419 {
420 }
421 
422 static 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 
431 static 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 
440 static struct hid_driver mousevsc_hid_driver;
441 
442 static 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 
518 probe_err2:
519 	hid_destroy_device(hid_dev);
520 
521 probe_err1:
522 	vmbus_close(device->channel);
523 
524 probe_err0:
525 	mousevsc_free_device(input_dev);
526 
527 	return ret;
528 }
529 
530 
531 static 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 
544 static const struct hv_vmbus_device_id id_table[] = {
545 	/* Mouse guid */
546 	{ HV_MOUSE_GUID, },
547 	{ },
548 };
549 
550 MODULE_DEVICE_TABLE(vmbus, id_table);
551 
552 static 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 
562 static int __init mousevsc_init(void)
563 {
564 	return vmbus_driver_register(&mousevsc_drv);
565 }
566 
567 static void __exit mousevsc_exit(void)
568 {
569 	vmbus_driver_unregister(&mousevsc_drv);
570 }
571 
572 MODULE_LICENSE("GPL");
573 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
574 
575 module_init(mousevsc_init);
576 module_exit(mousevsc_exit);
577