1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2012, Microsoft Corporation.
4 *
5 * Author:
6 *   Haiyang Zhang <haiyangz@microsoft.com>
7 */
8
9/*
10 * Hyper-V Synthetic Video Frame Buffer Driver
11 *
12 * This is the driver for the Hyper-V Synthetic Video, which supports
13 * screen resolution up to Full HD 1920x1080 with 32 bit color on Windows
14 * Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2
15 * or earlier.
16 *
17 * It also solves the double mouse cursor issue of the emulated video mode.
18 *
19 * The default screen resolution is 1152x864, which may be changed by a
20 * kernel parameter:
21 *     video=hyperv_fb:<width>x<height>
22 *     For example: video=hyperv_fb:1280x1024
23 *
24 * Portrait orientation is also supported:
25 *     For example: video=hyperv_fb:864x1152
26 *
27 * When a Windows 10 RS5+ host is used, the virtual machine screen
28 * resolution is obtained from the host. The "video=hyperv_fb" option is
29 * not needed, but still can be used to overwrite what the host specifies.
30 * The VM resolution on the host could be set by executing the powershell
31 * "set-vmvideo" command. For example
32 *     set-vmvideo -vmname name -horizontalresolution:1920 \
33 * -verticalresolution:1200 -resolutiontype single
34 *
35 * Gen 1 VMs also support direct using VM's physical memory for framebuffer.
36 * It could improve the efficiency and performance for framebuffer and VM.
37 * This requires to allocate contiguous physical memory from Linux kernel's
38 * CMA memory allocator. To enable this, supply a kernel parameter to give
39 * enough memory space to CMA allocator for framebuffer. For example:
40 *    cma=130m
41 * This gives 130MB memory to CMA allocator that can be allocated to
42 * framebuffer. For reference, 8K resolution (7680x4320) takes about
43 * 127MB memory.
44 */
45
46#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47
48#include <linux/module.h>
49#include <linux/kernel.h>
50#include <linux/vmalloc.h>
51#include <linux/init.h>
52#include <linux/completion.h>
53#include <linux/fb.h>
54#include <linux/pci.h>
55#include <linux/efi.h>
56#include <linux/console.h>
57
58#include <linux/hyperv.h>
59
60
61/* Hyper-V Synthetic Video Protocol definitions and structures */
62#define MAX_VMBUS_PKT_SIZE 0x4000
63
64#define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
65#define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
66#define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
67#define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
68
69#define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
70#define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
71
72#define SYNTHVID_DEPTH_WIN7 16
73#define SYNTHVID_DEPTH_WIN8 32
74
75#define SYNTHVID_FB_SIZE_WIN7 (4 * 1024 * 1024)
76#define SYNTHVID_WIDTH_MAX_WIN7 1600
77#define SYNTHVID_HEIGHT_MAX_WIN7 1200
78
79#define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
80
81#define PCI_VENDOR_ID_MICROSOFT 0x1414
82#define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
83
84
85enum pipe_msg_type {
86	PIPE_MSG_INVALID,
87	PIPE_MSG_DATA,
88	PIPE_MSG_MAX
89};
90
91struct pipe_msg_hdr {
92	u32 type;
93	u32 size; /* size of message after this field */
94} __packed;
95
96
97enum synthvid_msg_type {
98	SYNTHVID_ERROR			= 0,
99	SYNTHVID_VERSION_REQUEST	= 1,
100	SYNTHVID_VERSION_RESPONSE	= 2,
101	SYNTHVID_VRAM_LOCATION		= 3,
102	SYNTHVID_VRAM_LOCATION_ACK	= 4,
103	SYNTHVID_SITUATION_UPDATE	= 5,
104	SYNTHVID_SITUATION_UPDATE_ACK	= 6,
105	SYNTHVID_POINTER_POSITION	= 7,
106	SYNTHVID_POINTER_SHAPE		= 8,
107	SYNTHVID_FEATURE_CHANGE		= 9,
108	SYNTHVID_DIRT			= 10,
109	SYNTHVID_RESOLUTION_REQUEST	= 13,
110	SYNTHVID_RESOLUTION_RESPONSE	= 14,
111
112	SYNTHVID_MAX			= 15
113};
114
115#define		SYNTHVID_EDID_BLOCK_SIZE	128
116#define		SYNTHVID_MAX_RESOLUTION_COUNT	64
117
118struct hvd_screen_info {
119	u16 width;
120	u16 height;
121} __packed;
122
123struct synthvid_msg_hdr {
124	u32 type;
125	u32 size;  /* size of this header + payload after this field*/
126} __packed;
127
128struct synthvid_version_req {
129	u32 version;
130} __packed;
131
132struct synthvid_version_resp {
133	u32 version;
134	u8 is_accepted;
135	u8 max_video_outputs;
136} __packed;
137
138struct synthvid_supported_resolution_req {
139	u8 maximum_resolution_count;
140} __packed;
141
142struct synthvid_supported_resolution_resp {
143	u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
144	u8 resolution_count;
145	u8 default_resolution_index;
146	u8 is_standard;
147	struct hvd_screen_info
148		supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
149} __packed;
150
151struct synthvid_vram_location {
152	u64 user_ctx;
153	u8 is_vram_gpa_specified;
154	u64 vram_gpa;
155} __packed;
156
157struct synthvid_vram_location_ack {
158	u64 user_ctx;
159} __packed;
160
161struct video_output_situation {
162	u8 active;
163	u32 vram_offset;
164	u8 depth_bits;
165	u32 width_pixels;
166	u32 height_pixels;
167	u32 pitch_bytes;
168} __packed;
169
170struct synthvid_situation_update {
171	u64 user_ctx;
172	u8 video_output_count;
173	struct video_output_situation video_output[1];
174} __packed;
175
176struct synthvid_situation_update_ack {
177	u64 user_ctx;
178} __packed;
179
180struct synthvid_pointer_position {
181	u8 is_visible;
182	u8 video_output;
183	s32 image_x;
184	s32 image_y;
185} __packed;
186
187
188#define CURSOR_MAX_X 96
189#define CURSOR_MAX_Y 96
190#define CURSOR_ARGB_PIXEL_SIZE 4
191#define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
192#define CURSOR_COMPLETE (-1)
193
194struct synthvid_pointer_shape {
195	u8 part_idx;
196	u8 is_argb;
197	u32 width; /* CURSOR_MAX_X at most */
198	u32 height; /* CURSOR_MAX_Y at most */
199	u32 hot_x; /* hotspot relative to upper-left of pointer image */
200	u32 hot_y;
201	u8 data[4];
202} __packed;
203
204struct synthvid_feature_change {
205	u8 is_dirt_needed;
206	u8 is_ptr_pos_needed;
207	u8 is_ptr_shape_needed;
208	u8 is_situ_needed;
209} __packed;
210
211struct rect {
212	s32 x1, y1; /* top left corner */
213	s32 x2, y2; /* bottom right corner, exclusive */
214} __packed;
215
216struct synthvid_dirt {
217	u8 video_output;
218	u8 dirt_count;
219	struct rect rect[1];
220} __packed;
221
222struct synthvid_msg {
223	struct pipe_msg_hdr pipe_hdr;
224	struct synthvid_msg_hdr vid_hdr;
225	union {
226		struct synthvid_version_req ver_req;
227		struct synthvid_version_resp ver_resp;
228		struct synthvid_vram_location vram;
229		struct synthvid_vram_location_ack vram_ack;
230		struct synthvid_situation_update situ;
231		struct synthvid_situation_update_ack situ_ack;
232		struct synthvid_pointer_position ptr_pos;
233		struct synthvid_pointer_shape ptr_shape;
234		struct synthvid_feature_change feature_chg;
235		struct synthvid_dirt dirt;
236		struct synthvid_supported_resolution_req resolution_req;
237		struct synthvid_supported_resolution_resp resolution_resp;
238	};
239} __packed;
240
241
242/* FB driver definitions and structures */
243#define HVFB_WIDTH 1152 /* default screen width */
244#define HVFB_HEIGHT 864 /* default screen height */
245#define HVFB_WIDTH_MIN 640
246#define HVFB_HEIGHT_MIN 480
247
248#define RING_BUFSIZE (256 * 1024)
249#define VSP_TIMEOUT (10 * HZ)
250#define HVFB_UPDATE_DELAY (HZ / 20)
251#define HVFB_ONDEMAND_THROTTLE (HZ / 20)
252
253struct hvfb_par {
254	struct fb_info *info;
255	struct resource *mem;
256	bool fb_ready; /* fb device is ready */
257	struct completion wait;
258	u32 synthvid_version;
259
260	struct delayed_work dwork;
261	bool update;
262	bool update_saved; /* The value of 'update' before hibernation */
263
264	u32 pseudo_palette[16];
265	u8 init_buf[MAX_VMBUS_PKT_SIZE];
266	u8 recv_buf[MAX_VMBUS_PKT_SIZE];
267
268	/* If true, the VSC notifies the VSP on every framebuffer change */
269	bool synchronous_fb;
270
271	/* If true, need to copy from deferred IO mem to framebuffer mem */
272	bool need_docopy;
273
274	struct notifier_block hvfb_panic_nb;
275
276	/* Memory for deferred IO and frame buffer itself */
277	unsigned char *dio_vp;
278	unsigned char *mmio_vp;
279	phys_addr_t mmio_pp;
280
281	/* Dirty rectangle, protected by delayed_refresh_lock */
282	int x1, y1, x2, y2;
283	bool delayed_refresh;
284	spinlock_t delayed_refresh_lock;
285};
286
287static uint screen_width = HVFB_WIDTH;
288static uint screen_height = HVFB_HEIGHT;
289static uint screen_depth;
290static uint screen_fb_size;
291static uint dio_fb_size; /* FB size for deferred IO */
292
293/* Send message to Hyper-V host */
294static inline int synthvid_send(struct hv_device *hdev,
295				struct synthvid_msg *msg)
296{
297	static atomic64_t request_id = ATOMIC64_INIT(0);
298	int ret;
299
300	msg->pipe_hdr.type = PIPE_MSG_DATA;
301	msg->pipe_hdr.size = msg->vid_hdr.size;
302
303	ret = vmbus_sendpacket(hdev->channel, msg,
304			       msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
305			       atomic64_inc_return(&request_id),
306			       VM_PKT_DATA_INBAND, 0);
307
308	if (ret)
309		pr_err("Unable to send packet via vmbus\n");
310
311	return ret;
312}
313
314
315/* Send screen resolution info to host */
316static int synthvid_send_situ(struct hv_device *hdev)
317{
318	struct fb_info *info = hv_get_drvdata(hdev);
319	struct synthvid_msg msg;
320
321	if (!info)
322		return -ENODEV;
323
324	memset(&msg, 0, sizeof(struct synthvid_msg));
325
326	msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
327	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
328		sizeof(struct synthvid_situation_update);
329	msg.situ.user_ctx = 0;
330	msg.situ.video_output_count = 1;
331	msg.situ.video_output[0].active = 1;
332	msg.situ.video_output[0].vram_offset = 0;
333	msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
334	msg.situ.video_output[0].width_pixels = info->var.xres;
335	msg.situ.video_output[0].height_pixels = info->var.yres;
336	msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
337
338	synthvid_send(hdev, &msg);
339
340	return 0;
341}
342
343/* Send mouse pointer info to host */
344static int synthvid_send_ptr(struct hv_device *hdev)
345{
346	struct synthvid_msg msg;
347
348	memset(&msg, 0, sizeof(struct synthvid_msg));
349	msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
350	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
351		sizeof(struct synthvid_pointer_position);
352	msg.ptr_pos.is_visible = 1;
353	msg.ptr_pos.video_output = 0;
354	msg.ptr_pos.image_x = 0;
355	msg.ptr_pos.image_y = 0;
356	synthvid_send(hdev, &msg);
357
358	memset(&msg, 0, sizeof(struct synthvid_msg));
359	msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
360	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
361		sizeof(struct synthvid_pointer_shape);
362	msg.ptr_shape.part_idx = CURSOR_COMPLETE;
363	msg.ptr_shape.is_argb = 1;
364	msg.ptr_shape.width = 1;
365	msg.ptr_shape.height = 1;
366	msg.ptr_shape.hot_x = 0;
367	msg.ptr_shape.hot_y = 0;
368	msg.ptr_shape.data[0] = 0;
369	msg.ptr_shape.data[1] = 1;
370	msg.ptr_shape.data[2] = 1;
371	msg.ptr_shape.data[3] = 1;
372	synthvid_send(hdev, &msg);
373
374	return 0;
375}
376
377/* Send updated screen area (dirty rectangle) location to host */
378static int
379synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
380{
381	struct hv_device *hdev = device_to_hv_device(info->device);
382	struct synthvid_msg msg;
383
384	memset(&msg, 0, sizeof(struct synthvid_msg));
385	if (x2 == INT_MAX)
386		x2 = info->var.xres;
387	if (y2 == INT_MAX)
388		y2 = info->var.yres;
389
390	msg.vid_hdr.type = SYNTHVID_DIRT;
391	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
392		sizeof(struct synthvid_dirt);
393	msg.dirt.video_output = 0;
394	msg.dirt.dirt_count = 1;
395	msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
396	msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
397	msg.dirt.rect[0].x2 =
398		(x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
399	msg.dirt.rect[0].y2 =
400		(y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
401
402	synthvid_send(hdev, &msg);
403
404	return 0;
405}
406
407static void hvfb_docopy(struct hvfb_par *par,
408			unsigned long offset,
409			unsigned long size)
410{
411	if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
412	    size == 0 || offset >= dio_fb_size)
413		return;
414
415	if (offset + size > dio_fb_size)
416		size = dio_fb_size - offset;
417
418	memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
419}
420
421/* Deferred IO callback */
422static void synthvid_deferred_io(struct fb_info *p,
423				 struct list_head *pagelist)
424{
425	struct hvfb_par *par = p->par;
426	struct page *page;
427	unsigned long start, end;
428	int y1, y2, miny, maxy;
429
430	miny = INT_MAX;
431	maxy = 0;
432
433	/*
434	 * Merge dirty pages. It is possible that last page cross
435	 * over the end of frame buffer row yres. This is taken care of
436	 * in synthvid_update function by clamping the y2
437	 * value to yres.
438	 */
439	list_for_each_entry(page, pagelist, lru) {
440		start = page->index << PAGE_SHIFT;
441		end = start + PAGE_SIZE - 1;
442		y1 = start / p->fix.line_length;
443		y2 = end / p->fix.line_length;
444		miny = min_t(int, miny, y1);
445		maxy = max_t(int, maxy, y2);
446
447		/* Copy from dio space to mmio address */
448		if (par->fb_ready && par->need_docopy)
449			hvfb_docopy(par, start, PAGE_SIZE);
450	}
451
452	if (par->fb_ready && par->update)
453		synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
454}
455
456static struct fb_deferred_io synthvid_defio = {
457	.delay		= HZ / 20,
458	.deferred_io	= synthvid_deferred_io,
459};
460
461/*
462 * Actions on received messages from host:
463 * Complete the wait event.
464 * Or, reply with screen and cursor info.
465 */
466static void synthvid_recv_sub(struct hv_device *hdev)
467{
468	struct fb_info *info = hv_get_drvdata(hdev);
469	struct hvfb_par *par;
470	struct synthvid_msg *msg;
471
472	if (!info)
473		return;
474
475	par = info->par;
476	msg = (struct synthvid_msg *)par->recv_buf;
477
478	/* Complete the wait event */
479	if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
480	    msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
481	    msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
482		memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
483		complete(&par->wait);
484		return;
485	}
486
487	/* Reply with screen and cursor info */
488	if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
489		if (par->fb_ready) {
490			synthvid_send_ptr(hdev);
491			synthvid_send_situ(hdev);
492		}
493
494		par->update = msg->feature_chg.is_dirt_needed;
495		if (par->update)
496			schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
497	}
498}
499
500/* Receive callback for messages from the host */
501static void synthvid_receive(void *ctx)
502{
503	struct hv_device *hdev = ctx;
504	struct fb_info *info = hv_get_drvdata(hdev);
505	struct hvfb_par *par;
506	struct synthvid_msg *recv_buf;
507	u32 bytes_recvd;
508	u64 req_id;
509	int ret;
510
511	if (!info)
512		return;
513
514	par = info->par;
515	recv_buf = (struct synthvid_msg *)par->recv_buf;
516
517	do {
518		ret = vmbus_recvpacket(hdev->channel, recv_buf,
519				       MAX_VMBUS_PKT_SIZE,
520				       &bytes_recvd, &req_id);
521		if (bytes_recvd > 0 &&
522		    recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
523			synthvid_recv_sub(hdev);
524	} while (bytes_recvd > 0 && ret == 0);
525}
526
527/* Check if the ver1 version is equal or greater than ver2 */
528static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
529{
530	if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
531	    (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
532	     SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
533		return true;
534
535	return false;
536}
537
538/* Check synthetic video protocol version with the host */
539static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
540{
541	struct fb_info *info = hv_get_drvdata(hdev);
542	struct hvfb_par *par = info->par;
543	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
544	int ret = 0;
545	unsigned long t;
546
547	memset(msg, 0, sizeof(struct synthvid_msg));
548	msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
549	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
550		sizeof(struct synthvid_version_req);
551	msg->ver_req.version = ver;
552	synthvid_send(hdev, msg);
553
554	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
555	if (!t) {
556		pr_err("Time out on waiting version response\n");
557		ret = -ETIMEDOUT;
558		goto out;
559	}
560	if (!msg->ver_resp.is_accepted) {
561		ret = -ENODEV;
562		goto out;
563	}
564
565	par->synthvid_version = ver;
566	pr_info("Synthvid Version major %d, minor %d\n",
567		SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
568
569out:
570	return ret;
571}
572
573/* Get current resolution from the host */
574static int synthvid_get_supported_resolution(struct hv_device *hdev)
575{
576	struct fb_info *info = hv_get_drvdata(hdev);
577	struct hvfb_par *par = info->par;
578	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
579	int ret = 0;
580	unsigned long t;
581	u8 index;
582
583	memset(msg, 0, sizeof(struct synthvid_msg));
584	msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
585	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
586		sizeof(struct synthvid_supported_resolution_req);
587
588	msg->resolution_req.maximum_resolution_count =
589		SYNTHVID_MAX_RESOLUTION_COUNT;
590	synthvid_send(hdev, msg);
591
592	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
593	if (!t) {
594		pr_err("Time out on waiting resolution response\n");
595		ret = -ETIMEDOUT;
596		goto out;
597	}
598
599	if (msg->resolution_resp.resolution_count == 0) {
600		pr_err("No supported resolutions\n");
601		ret = -ENODEV;
602		goto out;
603	}
604
605	index = msg->resolution_resp.default_resolution_index;
606	if (index >= msg->resolution_resp.resolution_count) {
607		pr_err("Invalid resolution index: %d\n", index);
608		ret = -ENODEV;
609		goto out;
610	}
611
612	screen_width =
613		msg->resolution_resp.supported_resolution[index].width;
614	screen_height =
615		msg->resolution_resp.supported_resolution[index].height;
616
617out:
618	return ret;
619}
620
621/* Connect to VSP (Virtual Service Provider) on host */
622static int synthvid_connect_vsp(struct hv_device *hdev)
623{
624	struct fb_info *info = hv_get_drvdata(hdev);
625	struct hvfb_par *par = info->par;
626	int ret;
627
628	ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
629			 NULL, 0, synthvid_receive, hdev);
630	if (ret) {
631		pr_err("Unable to open vmbus channel\n");
632		return ret;
633	}
634
635	/* Negotiate the protocol version with host */
636	switch (vmbus_proto_version) {
637	case VERSION_WIN10:
638	case VERSION_WIN10_V5:
639		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
640		if (!ret)
641			break;
642		fallthrough;
643	case VERSION_WIN8:
644	case VERSION_WIN8_1:
645		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
646		if (!ret)
647			break;
648		fallthrough;
649	case VERSION_WS2008:
650	case VERSION_WIN7:
651		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
652		break;
653	default:
654		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
655		break;
656	}
657
658	if (ret) {
659		pr_err("Synthetic video device version not accepted\n");
660		goto error;
661	}
662
663	if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
664		screen_depth = SYNTHVID_DEPTH_WIN7;
665	else
666		screen_depth = SYNTHVID_DEPTH_WIN8;
667
668	if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
669		ret = synthvid_get_supported_resolution(hdev);
670		if (ret)
671			pr_info("Failed to get supported resolution from host, use default\n");
672	}
673
674	screen_fb_size = hdev->channel->offermsg.offer.
675				mmio_megabytes * 1024 * 1024;
676
677	return 0;
678
679error:
680	vmbus_close(hdev->channel);
681	return ret;
682}
683
684/* Send VRAM and Situation messages to the host */
685static int synthvid_send_config(struct hv_device *hdev)
686{
687	struct fb_info *info = hv_get_drvdata(hdev);
688	struct hvfb_par *par = info->par;
689	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
690	int ret = 0;
691	unsigned long t;
692
693	/* Send VRAM location */
694	memset(msg, 0, sizeof(struct synthvid_msg));
695	msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
696	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
697		sizeof(struct synthvid_vram_location);
698	msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
699	msg->vram.is_vram_gpa_specified = 1;
700	synthvid_send(hdev, msg);
701
702	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
703	if (!t) {
704		pr_err("Time out on waiting vram location ack\n");
705		ret = -ETIMEDOUT;
706		goto out;
707	}
708	if (msg->vram_ack.user_ctx != par->mmio_pp) {
709		pr_err("Unable to set VRAM location\n");
710		ret = -ENODEV;
711		goto out;
712	}
713
714	/* Send pointer and situation update */
715	synthvid_send_ptr(hdev);
716	synthvid_send_situ(hdev);
717
718out:
719	return ret;
720}
721
722
723/*
724 * Delayed work callback:
725 * It is scheduled to call whenever update request is received and it has
726 * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
727 */
728static void hvfb_update_work(struct work_struct *w)
729{
730	struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
731	struct fb_info *info = par->info;
732	unsigned long flags;
733	int x1, x2, y1, y2;
734	int j;
735
736	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
737	/* Reset the request flag */
738	par->delayed_refresh = false;
739
740	/* Store the dirty rectangle to local variables */
741	x1 = par->x1;
742	x2 = par->x2;
743	y1 = par->y1;
744	y2 = par->y2;
745
746	/* Clear dirty rectangle */
747	par->x1 = par->y1 = INT_MAX;
748	par->x2 = par->y2 = 0;
749
750	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
751
752	if (x1 > info->var.xres || x2 > info->var.xres ||
753	    y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
754		return;
755
756	/* Copy the dirty rectangle to frame buffer memory */
757	if (par->need_docopy)
758		for (j = y1; j < y2; j++)
759			hvfb_docopy(par,
760				    j * info->fix.line_length +
761				    (x1 * screen_depth / 8),
762				    (x2 - x1) * screen_depth / 8);
763
764	/* Refresh */
765	if (par->fb_ready && par->update)
766		synthvid_update(info, x1, y1, x2, y2);
767}
768
769/*
770 * Control the on-demand refresh frequency. It schedules a delayed
771 * screen update if it has not yet.
772 */
773static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
774					   int x1, int y1, int w, int h)
775{
776	unsigned long flags;
777	int x2 = x1 + w;
778	int y2 = y1 + h;
779
780	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
781
782	/* Merge dirty rectangle */
783	par->x1 = min_t(int, par->x1, x1);
784	par->y1 = min_t(int, par->y1, y1);
785	par->x2 = max_t(int, par->x2, x2);
786	par->y2 = max_t(int, par->y2, y2);
787
788	/* Schedule a delayed screen update if not yet */
789	if (par->delayed_refresh == false) {
790		schedule_delayed_work(&par->dwork,
791				      HVFB_ONDEMAND_THROTTLE);
792		par->delayed_refresh = true;
793	}
794
795	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
796}
797
798static int hvfb_on_panic(struct notifier_block *nb,
799			 unsigned long e, void *p)
800{
801	struct hv_device *hdev;
802	struct hvfb_par *par;
803	struct fb_info *info;
804
805	par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
806	info = par->info;
807	hdev = device_to_hv_device(info->device);
808
809	if (hv_ringbuffer_spinlock_busy(hdev->channel))
810		return NOTIFY_DONE;
811
812	par->synchronous_fb = true;
813	if (par->need_docopy)
814		hvfb_docopy(par, 0, dio_fb_size);
815	synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
816
817	return NOTIFY_DONE;
818}
819
820/* Framebuffer operation handlers */
821
822static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
823{
824	if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
825	    var->xres > screen_width || var->yres >  screen_height ||
826	    var->bits_per_pixel != screen_depth)
827		return -EINVAL;
828
829	var->xres_virtual = var->xres;
830	var->yres_virtual = var->yres;
831
832	return 0;
833}
834
835static int hvfb_set_par(struct fb_info *info)
836{
837	struct hv_device *hdev = device_to_hv_device(info->device);
838
839	return synthvid_send_situ(hdev);
840}
841
842
843static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
844{
845	return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
846}
847
848static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
849			  unsigned blue, unsigned transp, struct fb_info *info)
850{
851	u32 *pal = info->pseudo_palette;
852
853	if (regno > 15)
854		return -EINVAL;
855
856	pal[regno] = chan_to_field(red, &info->var.red)
857		| chan_to_field(green, &info->var.green)
858		| chan_to_field(blue, &info->var.blue)
859		| chan_to_field(transp, &info->var.transp);
860
861	return 0;
862}
863
864static int hvfb_blank(int blank, struct fb_info *info)
865{
866	return 1;	/* get fb_blank to set the colormap to all black */
867}
868
869static void hvfb_cfb_fillrect(struct fb_info *p,
870			      const struct fb_fillrect *rect)
871{
872	struct hvfb_par *par = p->par;
873
874	cfb_fillrect(p, rect);
875	if (par->synchronous_fb)
876		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
877	else
878		hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
879					       rect->width, rect->height);
880}
881
882static void hvfb_cfb_copyarea(struct fb_info *p,
883			      const struct fb_copyarea *area)
884{
885	struct hvfb_par *par = p->par;
886
887	cfb_copyarea(p, area);
888	if (par->synchronous_fb)
889		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
890	else
891		hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
892					       area->width, area->height);
893}
894
895static void hvfb_cfb_imageblit(struct fb_info *p,
896			       const struct fb_image *image)
897{
898	struct hvfb_par *par = p->par;
899
900	cfb_imageblit(p, image);
901	if (par->synchronous_fb)
902		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
903	else
904		hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
905					       image->width, image->height);
906}
907
908static const struct fb_ops hvfb_ops = {
909	.owner = THIS_MODULE,
910	.fb_check_var = hvfb_check_var,
911	.fb_set_par = hvfb_set_par,
912	.fb_setcolreg = hvfb_setcolreg,
913	.fb_fillrect = hvfb_cfb_fillrect,
914	.fb_copyarea = hvfb_cfb_copyarea,
915	.fb_imageblit = hvfb_cfb_imageblit,
916	.fb_blank = hvfb_blank,
917};
918
919
920/* Get options from kernel paramenter "video=" */
921static void hvfb_get_option(struct fb_info *info)
922{
923	struct hvfb_par *par = info->par;
924	char *opt = NULL, *p;
925	uint x = 0, y = 0;
926
927	if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
928		return;
929
930	p = strsep(&opt, "x");
931	if (!*p || kstrtouint(p, 0, &x) ||
932	    !opt || !*opt || kstrtouint(opt, 0, &y)) {
933		pr_err("Screen option is invalid: skipped\n");
934		return;
935	}
936
937	if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
938	    (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
939	    (x * y * screen_depth / 8 > screen_fb_size)) ||
940	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
941	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
942	    (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
943	     (x > SYNTHVID_WIDTH_MAX_WIN7 || y > SYNTHVID_HEIGHT_MAX_WIN7))) {
944		pr_err("Screen resolution option is out of range: skipped\n");
945		return;
946	}
947
948	screen_width = x;
949	screen_height = y;
950	return;
951}
952
953/*
954 * Allocate enough contiguous physical memory.
955 * Return physical address if succeeded or -1 if failed.
956 */
957static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
958				   unsigned int request_size)
959{
960	struct page *page = NULL;
961	dma_addr_t dma_handle;
962	void *vmem;
963	phys_addr_t paddr = 0;
964	unsigned int order = get_order(request_size);
965
966	if (request_size == 0)
967		return -1;
968
969	if (order < MAX_ORDER) {
970		/* Call alloc_pages if the size is less than 2^MAX_ORDER */
971		page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
972		if (!page)
973			return -1;
974
975		paddr = (page_to_pfn(page) << PAGE_SHIFT);
976	} else {
977		/* Allocate from CMA */
978		hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
979
980		vmem = dma_alloc_coherent(&hdev->device,
981					  round_up(request_size, PAGE_SIZE),
982					  &dma_handle,
983					  GFP_KERNEL | __GFP_NOWARN);
984
985		if (!vmem)
986			return -1;
987
988		paddr = virt_to_phys(vmem);
989	}
990
991	return paddr;
992}
993
994/* Release contiguous physical memory */
995static void hvfb_release_phymem(struct hv_device *hdev,
996				phys_addr_t paddr, unsigned int size)
997{
998	unsigned int order = get_order(size);
999
1000	if (order < MAX_ORDER)
1001		__free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
1002	else
1003		dma_free_coherent(&hdev->device,
1004				  round_up(size, PAGE_SIZE),
1005				  phys_to_virt(paddr),
1006				  paddr);
1007}
1008
1009
1010/* Get framebuffer memory from Hyper-V video pci space */
1011static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
1012{
1013	struct hvfb_par *par = info->par;
1014	struct pci_dev *pdev  = NULL;
1015	void __iomem *fb_virt;
1016	int gen2vm = efi_enabled(EFI_BOOT);
1017	phys_addr_t paddr;
1018	int ret;
1019
1020	info->apertures = alloc_apertures(1);
1021	if (!info->apertures)
1022		return -ENOMEM;
1023
1024	if (!gen2vm) {
1025		pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
1026			PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
1027		if (!pdev) {
1028			pr_err("Unable to find PCI Hyper-V video\n");
1029			return -ENODEV;
1030		}
1031
1032		info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
1033		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
1034
1035		/*
1036		 * For Gen 1 VM, we can directly use the contiguous memory
1037		 * from VM. If we succeed, deferred IO happens directly
1038		 * on this allocated framebuffer memory, avoiding extra
1039		 * memory copy.
1040		 */
1041		paddr = hvfb_get_phymem(hdev, screen_fb_size);
1042		if (paddr != (phys_addr_t) -1) {
1043			par->mmio_pp = paddr;
1044			par->mmio_vp = par->dio_vp = __va(paddr);
1045
1046			info->fix.smem_start = paddr;
1047			info->fix.smem_len = screen_fb_size;
1048			info->screen_base = par->mmio_vp;
1049			info->screen_size = screen_fb_size;
1050
1051			par->need_docopy = false;
1052			goto getmem_done;
1053		}
1054		pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1055	} else {
1056		info->apertures->ranges[0].base = screen_info.lfb_base;
1057		info->apertures->ranges[0].size = screen_info.lfb_size;
1058	}
1059
1060	/*
1061	 * Cannot use the contiguous physical memory.
1062	 * Allocate mmio space for framebuffer.
1063	 */
1064	dio_fb_size =
1065		screen_width * screen_height * screen_depth / 8;
1066
1067	ret = vmbus_allocate_mmio(&par->mem, hdev, 0, -1,
1068				  screen_fb_size, 0x100000, true);
1069	if (ret != 0) {
1070		pr_err("Unable to allocate framebuffer memory\n");
1071		goto err1;
1072	}
1073
1074	/*
1075	 * Map the VRAM cacheable for performance. This is also required for
1076	 * VM Connect to display properly for ARM64 Linux VM, as the host also
1077	 * maps the VRAM cacheable.
1078	 */
1079	fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1080	if (!fb_virt)
1081		goto err2;
1082
1083	/* Allocate memory for deferred IO */
1084	par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1085	if (par->dio_vp == NULL)
1086		goto err3;
1087
1088	/* Physical address of FB device */
1089	par->mmio_pp = par->mem->start;
1090	/* Virtual address of FB device */
1091	par->mmio_vp = (unsigned char *) fb_virt;
1092
1093	info->fix.smem_start = par->mem->start;
1094	info->fix.smem_len = dio_fb_size;
1095	info->screen_base = par->dio_vp;
1096	info->screen_size = dio_fb_size;
1097
1098getmem_done:
1099	remove_conflicting_framebuffers(info->apertures,
1100					KBUILD_MODNAME, false);
1101
1102	if (gen2vm) {
1103		/* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
1104		screen_info.lfb_size = 0;
1105		screen_info.lfb_base = 0;
1106		screen_info.orig_video_isVGA = 0;
1107	} else {
1108		pci_dev_put(pdev);
1109	}
1110
1111	return 0;
1112
1113err3:
1114	iounmap(fb_virt);
1115err2:
1116	vmbus_free_mmio(par->mem->start, screen_fb_size);
1117	par->mem = NULL;
1118err1:
1119	if (!gen2vm)
1120		pci_dev_put(pdev);
1121
1122	return -ENOMEM;
1123}
1124
1125/* Release the framebuffer */
1126static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1127{
1128	struct hvfb_par *par = info->par;
1129
1130	if (par->need_docopy) {
1131		vfree(par->dio_vp);
1132		iounmap(info->screen_base);
1133		vmbus_free_mmio(par->mem->start, screen_fb_size);
1134	} else {
1135		hvfb_release_phymem(hdev, info->fix.smem_start,
1136				    screen_fb_size);
1137	}
1138
1139	par->mem = NULL;
1140}
1141
1142
1143static int hvfb_probe(struct hv_device *hdev,
1144		      const struct hv_vmbus_device_id *dev_id)
1145{
1146	struct fb_info *info;
1147	struct hvfb_par *par;
1148	int ret;
1149
1150	info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1151	if (!info)
1152		return -ENOMEM;
1153
1154	par = info->par;
1155	par->info = info;
1156	par->fb_ready = false;
1157	par->need_docopy = true;
1158	init_completion(&par->wait);
1159	INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1160
1161	par->delayed_refresh = false;
1162	spin_lock_init(&par->delayed_refresh_lock);
1163	par->x1 = par->y1 = INT_MAX;
1164	par->x2 = par->y2 = 0;
1165
1166	/* Connect to VSP */
1167	hv_set_drvdata(hdev, info);
1168	ret = synthvid_connect_vsp(hdev);
1169	if (ret) {
1170		pr_err("Unable to connect to VSP\n");
1171		goto error1;
1172	}
1173
1174	hvfb_get_option(info);
1175	pr_info("Screen resolution: %dx%d, Color depth: %d, Frame buffer size: %d\n",
1176		screen_width, screen_height, screen_depth, screen_fb_size);
1177
1178	ret = hvfb_getmem(hdev, info);
1179	if (ret) {
1180		pr_err("No memory for framebuffer\n");
1181		goto error2;
1182	}
1183
1184	/* Set up fb_info */
1185	info->flags = FBINFO_DEFAULT;
1186
1187	info->var.xres_virtual = info->var.xres = screen_width;
1188	info->var.yres_virtual = info->var.yres = screen_height;
1189	info->var.bits_per_pixel = screen_depth;
1190
1191	if (info->var.bits_per_pixel == 16) {
1192		info->var.red = (struct fb_bitfield){11, 5, 0};
1193		info->var.green = (struct fb_bitfield){5, 6, 0};
1194		info->var.blue = (struct fb_bitfield){0, 5, 0};
1195		info->var.transp = (struct fb_bitfield){0, 0, 0};
1196	} else {
1197		info->var.red = (struct fb_bitfield){16, 8, 0};
1198		info->var.green = (struct fb_bitfield){8, 8, 0};
1199		info->var.blue = (struct fb_bitfield){0, 8, 0};
1200		info->var.transp = (struct fb_bitfield){24, 8, 0};
1201	}
1202
1203	info->var.activate = FB_ACTIVATE_NOW;
1204	info->var.height = -1;
1205	info->var.width = -1;
1206	info->var.vmode = FB_VMODE_NONINTERLACED;
1207
1208	strcpy(info->fix.id, KBUILD_MODNAME);
1209	info->fix.type = FB_TYPE_PACKED_PIXELS;
1210	info->fix.visual = FB_VISUAL_TRUECOLOR;
1211	info->fix.line_length = screen_width * screen_depth / 8;
1212	info->fix.accel = FB_ACCEL_NONE;
1213
1214	info->fbops = &hvfb_ops;
1215	info->pseudo_palette = par->pseudo_palette;
1216
1217	/* Initialize deferred IO */
1218	info->fbdefio = &synthvid_defio;
1219	fb_deferred_io_init(info);
1220
1221	/* Send config to host */
1222	ret = synthvid_send_config(hdev);
1223	if (ret)
1224		goto error;
1225
1226	ret = register_framebuffer(info);
1227	if (ret) {
1228		pr_err("Unable to register framebuffer\n");
1229		goto error;
1230	}
1231
1232	par->fb_ready = true;
1233
1234	par->synchronous_fb = false;
1235	par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1236	atomic_notifier_chain_register(&panic_notifier_list,
1237				       &par->hvfb_panic_nb);
1238
1239	return 0;
1240
1241error:
1242	fb_deferred_io_cleanup(info);
1243	hvfb_putmem(hdev, info);
1244error2:
1245	vmbus_close(hdev->channel);
1246error1:
1247	cancel_delayed_work_sync(&par->dwork);
1248	hv_set_drvdata(hdev, NULL);
1249	framebuffer_release(info);
1250	return ret;
1251}
1252
1253
1254static int hvfb_remove(struct hv_device *hdev)
1255{
1256	struct fb_info *info = hv_get_drvdata(hdev);
1257	struct hvfb_par *par = info->par;
1258
1259	atomic_notifier_chain_unregister(&panic_notifier_list,
1260					 &par->hvfb_panic_nb);
1261
1262	par->update = false;
1263	par->fb_ready = false;
1264
1265	fb_deferred_io_cleanup(info);
1266
1267	unregister_framebuffer(info);
1268	cancel_delayed_work_sync(&par->dwork);
1269
1270	vmbus_close(hdev->channel);
1271	hv_set_drvdata(hdev, NULL);
1272
1273	hvfb_putmem(hdev, info);
1274	framebuffer_release(info);
1275
1276	return 0;
1277}
1278
1279static int hvfb_suspend(struct hv_device *hdev)
1280{
1281	struct fb_info *info = hv_get_drvdata(hdev);
1282	struct hvfb_par *par = info->par;
1283
1284	console_lock();
1285
1286	/* 1 means do suspend */
1287	fb_set_suspend(info, 1);
1288
1289	cancel_delayed_work_sync(&par->dwork);
1290	cancel_delayed_work_sync(&info->deferred_work);
1291
1292	par->update_saved = par->update;
1293	par->update = false;
1294	par->fb_ready = false;
1295
1296	vmbus_close(hdev->channel);
1297
1298	console_unlock();
1299
1300	return 0;
1301}
1302
1303static int hvfb_resume(struct hv_device *hdev)
1304{
1305	struct fb_info *info = hv_get_drvdata(hdev);
1306	struct hvfb_par *par = info->par;
1307	int ret;
1308
1309	console_lock();
1310
1311	ret = synthvid_connect_vsp(hdev);
1312	if (ret != 0)
1313		goto out;
1314
1315	ret = synthvid_send_config(hdev);
1316	if (ret != 0) {
1317		vmbus_close(hdev->channel);
1318		goto out;
1319	}
1320
1321	par->fb_ready = true;
1322	par->update = par->update_saved;
1323
1324	schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1325	schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1326
1327	/* 0 means do resume */
1328	fb_set_suspend(info, 0);
1329
1330out:
1331	console_unlock();
1332
1333	return ret;
1334}
1335
1336
1337static const struct pci_device_id pci_stub_id_table[] = {
1338	{
1339		.vendor      = PCI_VENDOR_ID_MICROSOFT,
1340		.device      = PCI_DEVICE_ID_HYPERV_VIDEO,
1341	},
1342	{ /* end of list */ }
1343};
1344
1345static const struct hv_vmbus_device_id id_table[] = {
1346	/* Synthetic Video Device GUID */
1347	{HV_SYNTHVID_GUID},
1348	{}
1349};
1350
1351MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1352MODULE_DEVICE_TABLE(vmbus, id_table);
1353
1354static struct hv_driver hvfb_drv = {
1355	.name = KBUILD_MODNAME,
1356	.id_table = id_table,
1357	.probe = hvfb_probe,
1358	.remove = hvfb_remove,
1359	.suspend = hvfb_suspend,
1360	.resume = hvfb_resume,
1361	.driver = {
1362		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1363	},
1364};
1365
1366static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1367			       const struct pci_device_id *ent)
1368{
1369	return 0;
1370}
1371
1372static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1373{
1374}
1375
1376static struct pci_driver hvfb_pci_stub_driver = {
1377	.name =		KBUILD_MODNAME,
1378	.id_table =	pci_stub_id_table,
1379	.probe =	hvfb_pci_stub_probe,
1380	.remove =	hvfb_pci_stub_remove,
1381	.driver = {
1382		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1383	}
1384};
1385
1386static int __init hvfb_drv_init(void)
1387{
1388	int ret;
1389
1390	ret = vmbus_driver_register(&hvfb_drv);
1391	if (ret != 0)
1392		return ret;
1393
1394	ret = pci_register_driver(&hvfb_pci_stub_driver);
1395	if (ret != 0) {
1396		vmbus_driver_unregister(&hvfb_drv);
1397		return ret;
1398	}
1399
1400	return 0;
1401}
1402
1403static void __exit hvfb_drv_exit(void)
1404{
1405	pci_unregister_driver(&hvfb_pci_stub_driver);
1406	vmbus_driver_unregister(&hvfb_drv);
1407}
1408
1409module_init(hvfb_drv_init);
1410module_exit(hvfb_drv_exit);
1411
1412MODULE_LICENSE("GPL");
1413MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");
1414