xref: /openbmc/linux/drivers/hid/hid-hyperv.c (revision 5efb685b)
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 /*
26  * Current version
27  *
28  * History:
29  * Beta, RC < 2008/1/22        1,0
30  * RC > 2008/1/22              2,0
31  */
32 #define SYNTHHID_INPUT_VERSION_MAJOR	2
33 #define SYNTHHID_INPUT_VERSION_MINOR	0
34 #define SYNTHHID_INPUT_VERSION		(SYNTHHID_INPUT_VERSION_MINOR | \
35 					 (SYNTHHID_INPUT_VERSION_MAJOR << 16))
36 
37 
38 #pragma pack(push, 1)
39 /*
40  * Message types in the synthetic input protocol
41  */
42 enum synthhid_msg_type {
43 	SYNTH_HID_PROTOCOL_REQUEST,
44 	SYNTH_HID_PROTOCOL_RESPONSE,
45 	SYNTH_HID_INITIAL_DEVICE_INFO,
46 	SYNTH_HID_INITIAL_DEVICE_INFO_ACK,
47 	SYNTH_HID_INPUT_REPORT,
48 	SYNTH_HID_MAX
49 };
50 
51 /*
52  * Basic message structures.
53  */
54 struct synthhid_msg_hdr {
55 	enum synthhid_msg_type type;
56 	u32 size;
57 };
58 
59 union synthhid_version {
60 	struct {
61 		u16 minor_version;
62 		u16 major_version;
63 	};
64 	u32 version;
65 };
66 
67 /*
68  * Protocol messages
69  */
70 struct synthhid_protocol_request {
71 	struct synthhid_msg_hdr header;
72 	union synthhid_version version_requested;
73 };
74 
75 struct synthhid_protocol_response {
76 	struct synthhid_msg_hdr header;
77 	union synthhid_version version_requested;
78 	unsigned char approved;
79 };
80 
81 struct synthhid_device_info {
82 	struct synthhid_msg_hdr header;
83 	struct hv_input_dev_info hid_dev_info;
84 	struct hid_descriptor hid_descriptor;
85 };
86 
87 struct synthhid_device_info_ack {
88 	struct synthhid_msg_hdr header;
89 	unsigned char reserved;
90 };
91 
92 struct synthhid_input_report {
93 	struct synthhid_msg_hdr header;
94 	char buffer[];
95 };
96 
97 #pragma pack(pop)
98 
99 #define INPUTVSC_SEND_RING_BUFFER_SIZE	VMBUS_RING_SIZE(36 * 1024)
100 #define INPUTVSC_RECV_RING_BUFFER_SIZE	VMBUS_RING_SIZE(36 * 1024)
101 
102 
103 enum pipe_prot_msg_type {
104 	PIPE_MESSAGE_INVALID,
105 	PIPE_MESSAGE_DATA,
106 	PIPE_MESSAGE_MAXIMUM
107 };
108 
109 
110 struct pipe_prt_msg {
111 	enum pipe_prot_msg_type type;
112 	u32 size;
113 	char data[];
114 };
115 
116 struct  mousevsc_prt_msg {
117 	enum pipe_prot_msg_type type;
118 	u32 size;
119 	union {
120 		struct synthhid_protocol_request request;
121 		struct synthhid_protocol_response response;
122 		struct synthhid_device_info_ack ack;
123 	};
124 };
125 
126 /*
127  * Represents an mousevsc device
128  */
129 struct mousevsc_dev {
130 	struct hv_device	*device;
131 	bool			init_complete;
132 	bool			connected;
133 	struct mousevsc_prt_msg	protocol_req;
134 	struct mousevsc_prt_msg	protocol_resp;
135 	/* Synchronize the request/response if needed */
136 	struct completion	wait_event;
137 	int			dev_info_status;
138 
139 	struct hid_descriptor	*hid_desc;
140 	unsigned char		*report_desc;
141 	u32			report_desc_size;
142 	struct hv_input_dev_info hid_dev_info;
143 	struct hid_device       *hid_device;
144 	u8			input_buf[HID_MAX_BUFFER_SIZE];
145 };
146 
147 
148 static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
149 {
150 	struct mousevsc_dev *input_dev;
151 
152 	input_dev = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);
153 
154 	if (!input_dev)
155 		return NULL;
156 
157 	input_dev->device = device;
158 	hv_set_drvdata(device, input_dev);
159 	init_completion(&input_dev->wait_event);
160 	input_dev->init_complete = false;
161 
162 	return input_dev;
163 }
164 
165 static void mousevsc_free_device(struct mousevsc_dev *device)
166 {
167 	kfree(device->hid_desc);
168 	kfree(device->report_desc);
169 	hv_set_drvdata(device->device, NULL);
170 	kfree(device);
171 }
172 
173 static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
174 				struct synthhid_device_info *device_info)
175 {
176 	int ret = 0;
177 	struct hid_descriptor *desc;
178 	struct mousevsc_prt_msg ack;
179 
180 	input_device->dev_info_status = -ENOMEM;
181 
182 	input_device->hid_dev_info = device_info->hid_dev_info;
183 	desc = &device_info->hid_descriptor;
184 	if (desc->bLength == 0)
185 		goto cleanup;
186 
187 	/* The pointer is not NULL when we resume from hibernation */
188 	kfree(input_device->hid_desc);
189 	input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
190 
191 	if (!input_device->hid_desc)
192 		goto cleanup;
193 
194 	input_device->report_desc_size = le16_to_cpu(
195 					desc->desc[0].wDescriptorLength);
196 	if (input_device->report_desc_size == 0) {
197 		input_device->dev_info_status = -EINVAL;
198 		goto cleanup;
199 	}
200 
201 	/* The pointer is not NULL when we resume from hibernation */
202 	kfree(input_device->report_desc);
203 	input_device->report_desc = kzalloc(input_device->report_desc_size,
204 					  GFP_ATOMIC);
205 
206 	if (!input_device->report_desc) {
207 		input_device->dev_info_status = -ENOMEM;
208 		goto cleanup;
209 	}
210 
211 	memcpy(input_device->report_desc,
212 	       ((unsigned char *)desc) + desc->bLength,
213 	       le16_to_cpu(desc->desc[0].wDescriptorLength));
214 
215 	/* Send the ack */
216 	memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
217 
218 	ack.type = PIPE_MESSAGE_DATA;
219 	ack.size = sizeof(struct synthhid_device_info_ack);
220 
221 	ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
222 	ack.ack.header.size = 1;
223 	ack.ack.reserved = 0;
224 
225 	ret = vmbus_sendpacket(input_device->device->channel,
226 			&ack,
227 			sizeof(struct pipe_prt_msg) +
228 			sizeof(struct synthhid_device_info_ack),
229 			(unsigned long)&ack,
230 			VM_PKT_DATA_INBAND,
231 			VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
232 
233 	if (!ret)
234 		input_device->dev_info_status = 0;
235 
236 cleanup:
237 	complete(&input_device->wait_event);
238 
239 	return;
240 }
241 
242 static void mousevsc_on_receive(struct hv_device *device,
243 				struct vmpacket_descriptor *packet)
244 {
245 	struct pipe_prt_msg *pipe_msg;
246 	struct synthhid_msg_hdr *hid_msg_hdr;
247 	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
248 	struct synthhid_input_report *input_report;
249 	size_t len;
250 
251 	pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
252 						(packet->offset8 << 3));
253 
254 	if (pipe_msg->type != PIPE_MESSAGE_DATA)
255 		return;
256 
257 	hid_msg_hdr = (struct synthhid_msg_hdr *)pipe_msg->data;
258 
259 	switch (hid_msg_hdr->type) {
260 	case SYNTH_HID_PROTOCOL_RESPONSE:
261 		/*
262 		 * While it will be impossible for us to protect against
263 		 * malicious/buggy hypervisor/host, add a check here to
264 		 * ensure we don't corrupt memory.
265 		 */
266 		if (struct_size(pipe_msg, data, pipe_msg->size)
267 			> sizeof(struct mousevsc_prt_msg)) {
268 			WARN_ON(1);
269 			break;
270 		}
271 
272 		memcpy(&input_dev->protocol_resp, pipe_msg,
273 				struct_size(pipe_msg, data, pipe_msg->size));
274 		complete(&input_dev->wait_event);
275 		break;
276 
277 	case SYNTH_HID_INITIAL_DEVICE_INFO:
278 		WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
279 
280 		/*
281 		 * Parse out the device info into device attr,
282 		 * hid desc and report desc
283 		 */
284 		mousevsc_on_receive_device_info(input_dev,
285 			(struct synthhid_device_info *)pipe_msg->data);
286 		break;
287 	case SYNTH_HID_INPUT_REPORT:
288 		input_report =
289 			(struct synthhid_input_report *)pipe_msg->data;
290 		if (!input_dev->init_complete)
291 			break;
292 
293 		len = min(input_report->header.size,
294 			  (u32)sizeof(input_dev->input_buf));
295 		memcpy(input_dev->input_buf, input_report->buffer, len);
296 		hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
297 				 input_dev->input_buf, len, 1);
298 
299 		pm_wakeup_hard_event(&input_dev->device->device);
300 
301 		break;
302 	default:
303 		pr_err("unsupported hid msg type - type %d len %d\n",
304 		       hid_msg_hdr->type, hid_msg_hdr->size);
305 		break;
306 	}
307 
308 }
309 
310 static void mousevsc_on_channel_callback(void *context)
311 {
312 	struct hv_device *device = context;
313 	struct vmpacket_descriptor *desc;
314 
315 	foreach_vmbus_pkt(desc, device->channel) {
316 		switch (desc->type) {
317 		case VM_PKT_COMP:
318 			break;
319 
320 		case VM_PKT_DATA_INBAND:
321 			mousevsc_on_receive(device, desc);
322 			break;
323 
324 		default:
325 			pr_err("Unhandled packet type %d, tid %llx len %d\n",
326 			       desc->type, desc->trans_id, desc->len8 * 8);
327 			break;
328 		}
329 	}
330 }
331 
332 static int mousevsc_connect_to_vsp(struct hv_device *device)
333 {
334 	int ret = 0;
335 	unsigned long t;
336 	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
337 	struct mousevsc_prt_msg *request;
338 	struct mousevsc_prt_msg *response;
339 
340 	reinit_completion(&input_dev->wait_event);
341 
342 	request = &input_dev->protocol_req;
343 	memset(request, 0, sizeof(struct mousevsc_prt_msg));
344 
345 	request->type = PIPE_MESSAGE_DATA;
346 	request->size = sizeof(struct synthhid_protocol_request);
347 	request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
348 	request->request.header.size = sizeof(unsigned int);
349 	request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
350 
351 	ret = vmbus_sendpacket(device->channel, request,
352 				sizeof(struct pipe_prt_msg) +
353 				sizeof(struct synthhid_protocol_request),
354 				(unsigned long)request,
355 				VM_PKT_DATA_INBAND,
356 				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
357 	if (ret)
358 		goto cleanup;
359 
360 	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
361 	if (!t) {
362 		ret = -ETIMEDOUT;
363 		goto cleanup;
364 	}
365 
366 	response = &input_dev->protocol_resp;
367 
368 	if (!response->response.approved) {
369 		pr_err("synthhid protocol request failed (version %d)\n",
370 		       SYNTHHID_INPUT_VERSION);
371 		ret = -ENODEV;
372 		goto cleanup;
373 	}
374 
375 	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
376 	if (!t) {
377 		ret = -ETIMEDOUT;
378 		goto cleanup;
379 	}
380 
381 	/*
382 	 * We should have gotten the device attr, hid desc and report
383 	 * desc at this point
384 	 */
385 	ret = input_dev->dev_info_status;
386 
387 cleanup:
388 	return ret;
389 }
390 
391 static int mousevsc_hid_parse(struct hid_device *hid)
392 {
393 	struct hv_device *dev = hid_get_drvdata(hid);
394 	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
395 
396 	return hid_parse_report(hid, input_dev->report_desc,
397 				input_dev->report_desc_size);
398 }
399 
400 static int mousevsc_hid_open(struct hid_device *hid)
401 {
402 	return 0;
403 }
404 
405 static int mousevsc_hid_start(struct hid_device *hid)
406 {
407 	return 0;
408 }
409 
410 static void mousevsc_hid_close(struct hid_device *hid)
411 {
412 }
413 
414 static void mousevsc_hid_stop(struct hid_device *hid)
415 {
416 }
417 
418 static int mousevsc_hid_raw_request(struct hid_device *hid,
419 				    unsigned char report_num,
420 				    __u8 *buf, size_t len,
421 				    unsigned char rtype,
422 				    int reqtype)
423 {
424 	return 0;
425 }
426 
427 static const struct hid_ll_driver mousevsc_ll_driver = {
428 	.parse = mousevsc_hid_parse,
429 	.open = mousevsc_hid_open,
430 	.close = mousevsc_hid_close,
431 	.start = mousevsc_hid_start,
432 	.stop = mousevsc_hid_stop,
433 	.raw_request = mousevsc_hid_raw_request,
434 };
435 
436 static struct hid_driver mousevsc_hid_driver;
437 
438 static int mousevsc_probe(struct hv_device *device,
439 			const struct hv_vmbus_device_id *dev_id)
440 {
441 	int ret;
442 	struct mousevsc_dev *input_dev;
443 	struct hid_device *hid_dev;
444 
445 	input_dev = mousevsc_alloc_device(device);
446 
447 	if (!input_dev)
448 		return -ENOMEM;
449 
450 	ret = vmbus_open(device->channel,
451 		INPUTVSC_SEND_RING_BUFFER_SIZE,
452 		INPUTVSC_RECV_RING_BUFFER_SIZE,
453 		NULL,
454 		0,
455 		mousevsc_on_channel_callback,
456 		device
457 		);
458 
459 	if (ret)
460 		goto probe_err0;
461 
462 	ret = mousevsc_connect_to_vsp(device);
463 
464 	if (ret)
465 		goto probe_err1;
466 
467 	/* workaround SA-167 */
468 	if (input_dev->report_desc[14] == 0x25)
469 		input_dev->report_desc[14] = 0x29;
470 
471 	hid_dev = hid_allocate_device();
472 	if (IS_ERR(hid_dev)) {
473 		ret = PTR_ERR(hid_dev);
474 		goto probe_err1;
475 	}
476 
477 	hid_dev->ll_driver = &mousevsc_ll_driver;
478 	hid_dev->driver = &mousevsc_hid_driver;
479 	hid_dev->bus = BUS_VIRTUAL;
480 	hid_dev->vendor = input_dev->hid_dev_info.vendor;
481 	hid_dev->product = input_dev->hid_dev_info.product;
482 	hid_dev->version = input_dev->hid_dev_info.version;
483 	input_dev->hid_device = hid_dev;
484 
485 	sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
486 
487 	hid_set_drvdata(hid_dev, device);
488 
489 	ret = hid_add_device(hid_dev);
490 	if (ret)
491 		goto probe_err2;
492 
493 
494 	ret = hid_parse(hid_dev);
495 	if (ret) {
496 		hid_err(hid_dev, "parse failed\n");
497 		goto probe_err2;
498 	}
499 
500 	ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
501 
502 	if (ret) {
503 		hid_err(hid_dev, "hw start failed\n");
504 		goto probe_err2;
505 	}
506 
507 	device_init_wakeup(&device->device, true);
508 
509 	input_dev->connected = true;
510 	input_dev->init_complete = true;
511 
512 	return ret;
513 
514 probe_err2:
515 	hid_destroy_device(hid_dev);
516 
517 probe_err1:
518 	vmbus_close(device->channel);
519 
520 probe_err0:
521 	mousevsc_free_device(input_dev);
522 
523 	return ret;
524 }
525 
526 
527 static void mousevsc_remove(struct hv_device *dev)
528 {
529 	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
530 
531 	device_init_wakeup(&dev->device, false);
532 	vmbus_close(dev->channel);
533 	hid_hw_stop(input_dev->hid_device);
534 	hid_destroy_device(input_dev->hid_device);
535 	mousevsc_free_device(input_dev);
536 }
537 
538 static int mousevsc_suspend(struct hv_device *dev)
539 {
540 	vmbus_close(dev->channel);
541 
542 	return 0;
543 }
544 
545 static int mousevsc_resume(struct hv_device *dev)
546 {
547 	int ret;
548 
549 	ret = vmbus_open(dev->channel,
550 			 INPUTVSC_SEND_RING_BUFFER_SIZE,
551 			 INPUTVSC_RECV_RING_BUFFER_SIZE,
552 			 NULL, 0,
553 			 mousevsc_on_channel_callback,
554 			 dev);
555 	if (ret)
556 		return ret;
557 
558 	ret = mousevsc_connect_to_vsp(dev);
559 	return ret;
560 }
561 
562 static const struct hv_vmbus_device_id id_table[] = {
563 	/* Mouse guid */
564 	{ HV_MOUSE_GUID, },
565 	{ },
566 };
567 
568 MODULE_DEVICE_TABLE(vmbus, id_table);
569 
570 static struct  hv_driver mousevsc_drv = {
571 	.name = KBUILD_MODNAME,
572 	.id_table = id_table,
573 	.probe = mousevsc_probe,
574 	.remove = mousevsc_remove,
575 	.suspend = mousevsc_suspend,
576 	.resume = mousevsc_resume,
577 	.driver = {
578 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
579 	},
580 };
581 
582 static int __init mousevsc_init(void)
583 {
584 	return vmbus_driver_register(&mousevsc_drv);
585 }
586 
587 static void __exit mousevsc_exit(void)
588 {
589 	vmbus_driver_unregister(&mousevsc_drv);
590 }
591 
592 MODULE_LICENSE("GPL");
593 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic HID Driver");
594 
595 module_init(mousevsc_init);
596 module_exit(mousevsc_exit);
597