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  1/*
  2 *  Copyright (c) 2009, Citrix Systems, Inc.
  3 *  Copyright (c) 2010, Microsoft Corporation.
  4 *  Copyright (c) 2011, Novell Inc.
  5 *
  6 *  This program is free software; you can redistribute it and/or modify it
  7 *  under the terms and conditions of the GNU General Public License,
  8 *  version 2, as published by the Free Software Foundation.
  9 *
 10 *  This program is distributed in the hope it will be useful, but WITHOUT
 11 *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12 *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 13 *  more details.
 14 */
 15#include <linux/init.h>
 16#include <linux/module.h>
 17#include <linux/device.h>
 18#include <linux/completion.h>
 19#include <linux/input.h>
 20#include <linux/hid.h>
 21#include <linux/hiddev.h>
 22#include <linux/hyperv.h>
 23
 24
 25struct hv_input_dev_info {
 26	unsigned int size;
 27	unsigned short vendor;
 28	unsigned short product;
 29	unsigned short version;
 30	unsigned short reserved[11];
 31};
 32
 33/* The maximum size of a synthetic input message. */
 34#define SYNTHHID_MAX_INPUT_REPORT_SIZE 16
 35
 36/*
 37 * Current version
 38 *
 39 * History:
 40 * Beta, RC < 2008/1/22        1,0
 41 * RC > 2008/1/22              2,0
 42 */
 43#define SYNTHHID_INPUT_VERSION_MAJOR	2
 44#define SYNTHHID_INPUT_VERSION_MINOR	0
 45#define SYNTHHID_INPUT_VERSION		(SYNTHHID_INPUT_VERSION_MINOR | \
 46					 (SYNTHHID_INPUT_VERSION_MAJOR << 16))
 47
 48
 49#pragma pack(push, 1)
 50/*
 51 * Message types in the synthetic input protocol
 52 */
 53enum synthhid_msg_type {
 54	SYNTH_HID_PROTOCOL_REQUEST,
 55	SYNTH_HID_PROTOCOL_RESPONSE,
 56	SYNTH_HID_INITIAL_DEVICE_INFO,
 57	SYNTH_HID_INITIAL_DEVICE_INFO_ACK,
 58	SYNTH_HID_INPUT_REPORT,
 59	SYNTH_HID_MAX
 60};
 61
 62/*
 63 * Basic message structures.
 64 */
 65struct synthhid_msg_hdr {
 66	enum synthhid_msg_type type;
 67	u32 size;
 68};
 69
 70struct synthhid_msg {
 71	struct synthhid_msg_hdr header;
 72	char data[1]; /* Enclosed message */
 73};
 74
 75union synthhid_version {
 76	struct {
 77		u16 minor_version;
 78		u16 major_version;
 79	};
 80	u32 version;
 81};
 82
 83/*
 84 * Protocol messages
 85 */
 86struct synthhid_protocol_request {
 87	struct synthhid_msg_hdr header;
 88	union synthhid_version version_requested;
 89};
 90
 91struct synthhid_protocol_response {
 92	struct synthhid_msg_hdr header;
 93	union synthhid_version version_requested;
 94	unsigned char approved;
 95};
 96
 97struct synthhid_device_info {
 98	struct synthhid_msg_hdr header;
 99	struct hv_input_dev_info hid_dev_info;
100	struct hid_descriptor hid_descriptor;
101};
102
103struct synthhid_device_info_ack {
104	struct synthhid_msg_hdr header;
105	unsigned char reserved;
106};
107
108struct synthhid_input_report {
109	struct synthhid_msg_hdr header;
110	char buffer[1];
111};
112
113#pragma pack(pop)
114
115#define INPUTVSC_SEND_RING_BUFFER_SIZE		(10*PAGE_SIZE)
116#define INPUTVSC_RECV_RING_BUFFER_SIZE		(10*PAGE_SIZE)
117
118
119enum pipe_prot_msg_type {
120	PIPE_MESSAGE_INVALID,
121	PIPE_MESSAGE_DATA,
122	PIPE_MESSAGE_MAXIMUM
123};
124
125
126struct pipe_prt_msg {
127	enum pipe_prot_msg_type type;
128	u32 size;
129	char data[1];
130};
131
132struct  mousevsc_prt_msg {
133	enum pipe_prot_msg_type type;
134	u32 size;
135	union {
136		struct synthhid_protocol_request request;
137		struct synthhid_protocol_response response;
138		struct synthhid_device_info_ack ack;
139	};
140};
141
142/*
143 * Represents an mousevsc device
144 */
145struct mousevsc_dev {
146	struct hv_device	*device;
147	bool			init_complete;
148	bool			connected;
149	struct mousevsc_prt_msg	protocol_req;
150	struct mousevsc_prt_msg	protocol_resp;
151	/* Synchronize the request/response if needed */
152	struct completion	wait_event;
153	int			dev_info_status;
154
155	struct hid_descriptor	*hid_desc;
156	unsigned char		*report_desc;
157	u32			report_desc_size;
158	struct hv_input_dev_info hid_dev_info;
159	struct hid_device       *hid_device;
160	u8			input_buf[HID_MAX_BUFFER_SIZE];
161};
162
163
164static struct mousevsc_dev *mousevsc_alloc_device(struct hv_device *device)
165{
166	struct mousevsc_dev *input_dev;
167
168	input_dev = kzalloc(sizeof(struct mousevsc_dev), GFP_KERNEL);
169
170	if (!input_dev)
171		return NULL;
172
173	input_dev->device = device;
174	hv_set_drvdata(device, input_dev);
175	init_completion(&input_dev->wait_event);
176	input_dev->init_complete = false;
177
178	return input_dev;
179}
180
181static void mousevsc_free_device(struct mousevsc_dev *device)
182{
183	kfree(device->hid_desc);
184	kfree(device->report_desc);
185	hv_set_drvdata(device->device, NULL);
186	kfree(device);
187}
188
189static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
190				struct synthhid_device_info *device_info)
191{
192	int ret = 0;
193	struct hid_descriptor *desc;
194	struct mousevsc_prt_msg ack;
195
196	input_device->dev_info_status = -ENOMEM;
197
198	input_device->hid_dev_info = device_info->hid_dev_info;
199	desc = &device_info->hid_descriptor;
200	if (desc->bLength == 0)
201		goto cleanup;
202
203	input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
204
205	if (!input_device->hid_desc)
206		goto cleanup;
207
208	input_device->report_desc_size = desc->desc[0].wDescriptorLength;
209	if (input_device->report_desc_size == 0) {
210		input_device->dev_info_status = -EINVAL;
211		goto cleanup;
212	}
213
214	input_device->report_desc = kzalloc(input_device->report_desc_size,
215					  GFP_ATOMIC);
216
217	if (!input_device->report_desc) {
218		input_device->dev_info_status = -ENOMEM;
219		goto cleanup;
220	}
221
222	memcpy(input_device->report_desc,
223	       ((unsigned char *)desc) + desc->bLength,
224	       desc->desc[0].wDescriptorLength);
225
226	/* Send the ack */
227	memset(&ack, 0, sizeof(struct mousevsc_prt_msg));
228
229	ack.type = PIPE_MESSAGE_DATA;
230	ack.size = sizeof(struct synthhid_device_info_ack);
231
232	ack.ack.header.type = SYNTH_HID_INITIAL_DEVICE_INFO_ACK;
233	ack.ack.header.size = 1;
234	ack.ack.reserved = 0;
235
236	ret = vmbus_sendpacket(input_device->device->channel,
237			&ack,
238			sizeof(struct pipe_prt_msg) - sizeof(unsigned char) +
239			sizeof(struct synthhid_device_info_ack),
240			(unsigned long)&ack,
241			VM_PKT_DATA_INBAND,
242			VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
243
244	if (!ret)
245		input_device->dev_info_status = 0;
246
247cleanup:
248	complete(&input_device->wait_event);
249
250	return;
251}
252
253static void mousevsc_on_receive(struct hv_device *device,
254				struct vmpacket_descriptor *packet)
255{
256	struct pipe_prt_msg *pipe_msg;
257	struct synthhid_msg *hid_msg;
258	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
259	struct synthhid_input_report *input_report;
260	size_t len;
261
262	pipe_msg = (struct pipe_prt_msg *)((unsigned long)packet +
263						(packet->offset8 << 3));
264
265	if (pipe_msg->type != PIPE_MESSAGE_DATA)
266		return;
267
268	hid_msg = (struct synthhid_msg *)pipe_msg->data;
269
270	switch (hid_msg->header.type) {
271	case SYNTH_HID_PROTOCOL_RESPONSE:
272		/*
273		 * While it will be impossible for us to protect against
274		 * malicious/buggy hypervisor/host, add a check here to
275		 * ensure we don't corrupt memory.
276		 */
277		if ((pipe_msg->size + sizeof(struct pipe_prt_msg)
278			- sizeof(unsigned char))
279			> sizeof(struct mousevsc_prt_msg)) {
280			WARN_ON(1);
281			break;
282		}
283
284		memcpy(&input_dev->protocol_resp, pipe_msg,
285		       pipe_msg->size + sizeof(struct pipe_prt_msg) -
286		       sizeof(unsigned char));
287		complete(&input_dev->wait_event);
288		break;
289
290	case SYNTH_HID_INITIAL_DEVICE_INFO:
291		WARN_ON(pipe_msg->size < sizeof(struct hv_input_dev_info));
292
293		/*
294		 * Parse out the device info into device attr,
295		 * hid desc and report desc
296		 */
297		mousevsc_on_receive_device_info(input_dev,
298			(struct synthhid_device_info *)pipe_msg->data);
299		break;
300	case SYNTH_HID_INPUT_REPORT:
301		input_report =
302			(struct synthhid_input_report *)pipe_msg->data;
303		if (!input_dev->init_complete)
304			break;
305
306		len = min(input_report->header.size,
307			  (u32)sizeof(input_dev->input_buf));
308		memcpy(input_dev->input_buf, input_report->buffer, len);
309		hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
310				 input_dev->input_buf, len, 1);
311
312		pm_wakeup_event(&input_dev->device->device, 0);
313
314		break;
315	default:
316		pr_err("unsupported hid msg type - type %d len %d\n",
317		       hid_msg->header.type, hid_msg->header.size);
318		break;
319	}
320
321}
322
323static void mousevsc_on_channel_callback(void *context)
324{
325	const int packet_size = 0x100;
326	int ret;
327	struct hv_device *device = context;
328	u32 bytes_recvd;
329	u64 req_id;
330	struct vmpacket_descriptor *desc;
331	unsigned char	*buffer;
332	int	bufferlen = packet_size;
333
334	buffer = kmalloc(bufferlen, GFP_ATOMIC);
335	if (!buffer)
336		return;
337
338	do {
339		ret = vmbus_recvpacket_raw(device->channel, buffer,
340					bufferlen, &bytes_recvd, &req_id);
341
342		switch (ret) {
343		case 0:
344			if (bytes_recvd <= 0) {
345				kfree(buffer);
346				return;
347			}
348			desc = (struct vmpacket_descriptor *)buffer;
349
350			switch (desc->type) {
351			case VM_PKT_COMP:
352				break;
353
354			case VM_PKT_DATA_INBAND:
355				mousevsc_on_receive(device, desc);
356				break;
357
358			default:
359				pr_err("unhandled packet type %d, tid %llx len %d\n",
360					desc->type, req_id, bytes_recvd);
361				break;
362			}
363
364			break;
365
366		case -ENOBUFS:
367			kfree(buffer);
368			/* Handle large packet */
369			bufferlen = bytes_recvd;
370			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
371
372			if (!buffer)
373				return;
374
375			break;
376		}
377	} while (1);
378
379}
380
381static int mousevsc_connect_to_vsp(struct hv_device *device)
382{
383	int ret = 0;
384	unsigned long t;
385	struct mousevsc_dev *input_dev = hv_get_drvdata(device);
386	struct mousevsc_prt_msg *request;
387	struct mousevsc_prt_msg *response;
388
389	request = &input_dev->protocol_req;
390	memset(request, 0, sizeof(struct mousevsc_prt_msg));
391
392	request->type = PIPE_MESSAGE_DATA;
393	request->size = sizeof(struct synthhid_protocol_request);
394	request->request.header.type = SYNTH_HID_PROTOCOL_REQUEST;
395	request->request.header.size = sizeof(unsigned int);
396	request->request.version_requested.version = SYNTHHID_INPUT_VERSION;
397
398	ret = vmbus_sendpacket(device->channel, request,
399				sizeof(struct pipe_prt_msg) -
400				sizeof(unsigned char) +
401				sizeof(struct synthhid_protocol_request),
402				(unsigned long)request,
403				VM_PKT_DATA_INBAND,
404				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
405	if (ret)
406		goto cleanup;
407
408	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
409	if (!t) {
410		ret = -ETIMEDOUT;
411		goto cleanup;
412	}
413
414	response = &input_dev->protocol_resp;
415
416	if (!response->response.approved) {
417		pr_err("synthhid protocol request failed (version %d)\n",
418		       SYNTHHID_INPUT_VERSION);
419		ret = -ENODEV;
420		goto cleanup;
421	}
422
423	t = wait_for_completion_timeout(&input_dev->wait_event, 5*HZ);
424	if (!t) {
425		ret = -ETIMEDOUT;
426		goto cleanup;
427	}
428
429	/*
430	 * We should have gotten the device attr, hid desc and report
431	 * desc at this point
432	 */
433	ret = input_dev->dev_info_status;
434
435cleanup:
436	return ret;
437}
438
439static int mousevsc_hid_parse(struct hid_device *hid)
440{
441	struct hv_device *dev = hid_get_drvdata(hid);
442	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
443
444	return hid_parse_report(hid, input_dev->report_desc,
445				input_dev->report_desc_size);
446}
447
448static int mousevsc_hid_open(struct hid_device *hid)
449{
450	return 0;
451}
452
453static int mousevsc_hid_start(struct hid_device *hid)
454{
455	return 0;
456}
457
458static void mousevsc_hid_close(struct hid_device *hid)
459{
460}
461
462static void mousevsc_hid_stop(struct hid_device *hid)
463{
464}
465
466static int mousevsc_hid_raw_request(struct hid_device *hid,
467				    unsigned char report_num,
468				    __u8 *buf, size_t len,
469				    unsigned char rtype,
470				    int reqtype)
471{
472	return 0;
473}
474
475static struct hid_ll_driver mousevsc_ll_driver = {
476	.parse = mousevsc_hid_parse,
477	.open = mousevsc_hid_open,
478	.close = mousevsc_hid_close,
479	.start = mousevsc_hid_start,
480	.stop = mousevsc_hid_stop,
481	.raw_request = mousevsc_hid_raw_request,
482};
483
484static struct hid_driver mousevsc_hid_driver;
485
486static int mousevsc_probe(struct hv_device *device,
487			const struct hv_vmbus_device_id *dev_id)
488{
489	int ret;
490	struct mousevsc_dev *input_dev;
491	struct hid_device *hid_dev;
492
493	input_dev = mousevsc_alloc_device(device);
494
495	if (!input_dev)
496		return -ENOMEM;
497
498	ret = vmbus_open(device->channel,
499		INPUTVSC_SEND_RING_BUFFER_SIZE,
500		INPUTVSC_RECV_RING_BUFFER_SIZE,
501		NULL,
502		0,
503		mousevsc_on_channel_callback,
504		device
505		);
506
507	if (ret)
508		goto probe_err0;
509
510	ret = mousevsc_connect_to_vsp(device);
511
512	if (ret)
513		goto probe_err1;
514
515	/* workaround SA-167 */
516	if (input_dev->report_desc[14] == 0x25)
517		input_dev->report_desc[14] = 0x29;
518
519	hid_dev = hid_allocate_device();
520	if (IS_ERR(hid_dev)) {
521		ret = PTR_ERR(hid_dev);
522		goto probe_err1;
523	}
524
525	hid_dev->ll_driver = &mousevsc_ll_driver;
526	hid_dev->driver = &mousevsc_hid_driver;
527	hid_dev->bus = BUS_VIRTUAL;
528	hid_dev->vendor = input_dev->hid_dev_info.vendor;
529	hid_dev->product = input_dev->hid_dev_info.product;
530	hid_dev->version = input_dev->hid_dev_info.version;
531	input_dev->hid_device = hid_dev;
532
533	sprintf(hid_dev->name, "%s", "Microsoft Vmbus HID-compliant Mouse");
534
535	hid_set_drvdata(hid_dev, device);
536
537	ret = hid_add_device(hid_dev);
538	if (ret)
539		goto probe_err1;
540
541
542	ret = hid_parse(hid_dev);
543	if (ret) {
544		hid_err(hid_dev, "parse failed\n");
545		goto probe_err2;
546	}
547
548	ret = hid_hw_start(hid_dev, HID_CONNECT_HIDINPUT | HID_CONNECT_HIDDEV);
549
550	if (ret) {
551		hid_err(hid_dev, "hw start failed\n");
552		goto probe_err2;
553	}
554
555	device_init_wakeup(&device->device, true);
556
557	input_dev->connected = true;
558	input_dev->init_complete = true;
559
560	return ret;
561
562probe_err2:
563	hid_destroy_device(hid_dev);
564
565probe_err1:
566	vmbus_close(device->channel);
567
568probe_err0:
569	mousevsc_free_device(input_dev);
570
571	return ret;
572}
573
574
575static int mousevsc_remove(struct hv_device *dev)
576{
577	struct mousevsc_dev *input_dev = hv_get_drvdata(dev);
578
579	device_init_wakeup(&dev->device, false);
580	vmbus_close(dev->channel);
581	hid_hw_stop(input_dev->hid_device);
582	hid_destroy_device(input_dev->hid_device);
583	mousevsc_free_device(input_dev);
584
585	return 0;
586}
587
588static const struct hv_vmbus_device_id id_table[] = {
589	/* Mouse guid */
590	{ HV_MOUSE_GUID, },
591	{ },
592};
593
594MODULE_DEVICE_TABLE(vmbus, id_table);
595
596static struct  hv_driver mousevsc_drv = {
597	.name = KBUILD_MODNAME,
598	.id_table = id_table,
599	.probe = mousevsc_probe,
600	.remove = mousevsc_remove,
601};
602
603static int __init mousevsc_init(void)
604{
605	return vmbus_driver_register(&mousevsc_drv);
606}
607
608static void __exit mousevsc_exit(void)
609{
610	vmbus_driver_unregister(&mousevsc_drv);
611}
612
613MODULE_LICENSE("GPL");
614module_init(mousevsc_init);
615module_exit(mousevsc_exit);
1