summaryrefslogtreecommitdiff
path: root/drivers/video/fbdev/hyperv_fb.c
blob: 403d8cd3e5827569dbd5378e4031dc4f007f543d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
/*
 * Copyright (c) 2012, Microsoft Corporation.
 *
 * Author:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 */

/*
 * Hyper-V Synthetic Video Frame Buffer Driver
 *
 * This is the driver for the Hyper-V Synthetic Video, which supports
 * screen resolution up to Full HD 1920x1080 with 32 bit color on Windows
 * Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2
 * or earlier.
 *
 * It also solves the double mouse cursor issue of the emulated video mode.
 *
 * The default screen resolution is 1152x864, which may be changed by a
 * kernel parameter:
 *     video=hyperv_fb:<width>x<height>
 *     For example: video=hyperv_fb:1280x1024
 *
 * Portrait orientation is also supported:
 *     For example: video=hyperv_fb:864x1152
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/completion.h>
#include <linux/fb.h>
#include <linux/pci.h>
#include <linux/efi.h>

#include <linux/hyperv.h>


/* Hyper-V Synthetic Video Protocol definitions and structures */
#define MAX_VMBUS_PKT_SIZE 0x4000

#define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
#define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
#define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)

#define SYNTHVID_DEPTH_WIN7 16
#define SYNTHVID_DEPTH_WIN8 32

#define SYNTHVID_FB_SIZE_WIN7 (4 * 1024 * 1024)
#define SYNTHVID_WIDTH_MAX_WIN7 1600
#define SYNTHVID_HEIGHT_MAX_WIN7 1200

#define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)

#define PCI_VENDOR_ID_MICROSOFT 0x1414
#define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353


enum pipe_msg_type {
	PIPE_MSG_INVALID,
	PIPE_MSG_DATA,
	PIPE_MSG_MAX
};

struct pipe_msg_hdr {
	u32 type;
	u32 size; /* size of message after this field */
} __packed;


enum synthvid_msg_type {
	SYNTHVID_ERROR			= 0,
	SYNTHVID_VERSION_REQUEST	= 1,
	SYNTHVID_VERSION_RESPONSE	= 2,
	SYNTHVID_VRAM_LOCATION		= 3,
	SYNTHVID_VRAM_LOCATION_ACK	= 4,
	SYNTHVID_SITUATION_UPDATE	= 5,
	SYNTHVID_SITUATION_UPDATE_ACK	= 6,
	SYNTHVID_POINTER_POSITION	= 7,
	SYNTHVID_POINTER_SHAPE		= 8,
	SYNTHVID_FEATURE_CHANGE		= 9,
	SYNTHVID_DIRT			= 10,

	SYNTHVID_MAX			= 11
};

struct synthvid_msg_hdr {
	u32 type;
	u32 size;  /* size of this header + payload after this field*/
} __packed;


struct synthvid_version_req {
	u32 version;
} __packed;

struct synthvid_version_resp {
	u32 version;
	u8 is_accepted;
	u8 max_video_outputs;
} __packed;

struct synthvid_vram_location {
	u64 user_ctx;
	u8 is_vram_gpa_specified;
	u64 vram_gpa;
} __packed;

struct synthvid_vram_location_ack {
	u64 user_ctx;
} __packed;

struct video_output_situation {
	u8 active;
	u32 vram_offset;
	u8 depth_bits;
	u32 width_pixels;
	u32 height_pixels;
	u32 pitch_bytes;
} __packed;

struct synthvid_situation_update {
	u64 user_ctx;
	u8 video_output_count;
	struct video_output_situation video_output[1];
} __packed;

struct synthvid_situation_update_ack {
	u64 user_ctx;
} __packed;

struct synthvid_pointer_position {
	u8 is_visible;
	u8 video_output;
	s32 image_x;
	s32 image_y;
} __packed;


#define CURSOR_MAX_X 96
#define CURSOR_MAX_Y 96
#define CURSOR_ARGB_PIXEL_SIZE 4
#define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
#define CURSOR_COMPLETE (-1)

struct synthvid_pointer_shape {
	u8 part_idx;
	u8 is_argb;
	u32 width; /* CURSOR_MAX_X at most */
	u32 height; /* CURSOR_MAX_Y at most */
	u32 hot_x; /* hotspot relative to upper-left of pointer image */
	u32 hot_y;
	u8 data[4];
} __packed;

struct synthvid_feature_change {
	u8 is_dirt_needed;
	u8 is_ptr_pos_needed;
	u8 is_ptr_shape_needed;
	u8 is_situ_needed;
} __packed;

struct rect {
	s32 x1, y1; /* top left corner */
	s32 x2, y2; /* bottom right corner, exclusive */
} __packed;

struct synthvid_dirt {
	u8 video_output;
	u8 dirt_count;
	struct rect rect[1];
} __packed;

struct synthvid_msg {
	struct pipe_msg_hdr pipe_hdr;
	struct synthvid_msg_hdr vid_hdr;
	union {
		struct synthvid_version_req ver_req;
		struct synthvid_version_resp ver_resp;
		struct synthvid_vram_location vram;
		struct synthvid_vram_location_ack vram_ack;
		struct synthvid_situation_update situ;
		struct synthvid_situation_update_ack situ_ack;
		struct synthvid_pointer_position ptr_pos;
		struct synthvid_pointer_shape ptr_shape;
		struct synthvid_feature_change feature_chg;
		struct synthvid_dirt dirt;
	};
} __packed;



/* FB driver definitions and structures */
#define HVFB_WIDTH 1152 /* default screen width */
#define HVFB_HEIGHT 864 /* default screen height */
#define HVFB_WIDTH_MIN 640
#define HVFB_HEIGHT_MIN 480

#define RING_BUFSIZE (256 * 1024)
#define VSP_TIMEOUT (10 * HZ)
#define HVFB_UPDATE_DELAY (HZ / 20)

struct hvfb_par {
	struct fb_info *info;
	struct resource *mem;
	bool fb_ready; /* fb device is ready */
	struct completion wait;
	u32 synthvid_version;

	struct delayed_work dwork;
	bool update;

	u32 pseudo_palette[16];
	u8 init_buf[MAX_VMBUS_PKT_SIZE];
	u8 recv_buf[MAX_VMBUS_PKT_SIZE];

	/* If true, the VSC notifies the VSP on every framebuffer change */
	bool synchronous_fb;

	struct notifier_block hvfb_panic_nb;
};

static uint screen_width = HVFB_WIDTH;
static uint screen_height = HVFB_HEIGHT;
static uint screen_depth;
static uint screen_fb_size;

/* Send message to Hyper-V host */
static inline int synthvid_send(struct hv_device *hdev,
				struct synthvid_msg *msg)
{
	static atomic64_t request_id = ATOMIC64_INIT(0);
	int ret;

	msg->pipe_hdr.type = PIPE_MSG_DATA;
	msg->pipe_hdr.size = msg->vid_hdr.size;

	ret = vmbus_sendpacket(hdev->channel, msg,
			       msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
			       atomic64_inc_return(&request_id),
			       VM_PKT_DATA_INBAND, 0);

	if (ret)
		pr_err("Unable to send packet via vmbus\n");

	return ret;
}


/* Send screen resolution info to host */
static int synthvid_send_situ(struct hv_device *hdev)
{
	struct fb_info *info = hv_get_drvdata(hdev);
	struct synthvid_msg msg;

	if (!info)
		return -ENODEV;

	memset(&msg, 0, sizeof(struct synthvid_msg));

	msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
		sizeof(struct synthvid_situation_update);
	msg.situ.user_ctx = 0;
	msg.situ.video_output_count = 1;
	msg.situ.video_output[0].active = 1;
	msg.situ.video_output[0].vram_offset = 0;
	msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
	msg.situ.video_output[0].width_pixels = info->var.xres;
	msg.situ.video_output[0].height_pixels = info->var.yres;
	msg.situ.video_output[0].pitch_bytes = info->fix.line_length;

	synthvid_send(hdev, &msg);

	return 0;
}

/* Send mouse pointer info to host */
static int synthvid_send_ptr(struct hv_device *hdev)
{
	struct synthvid_msg msg;

	memset(&msg, 0, sizeof(struct synthvid_msg));
	msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
		sizeof(struct synthvid_pointer_position);
	msg.ptr_pos.is_visible = 1;
	msg.ptr_pos.video_output = 0;
	msg.ptr_pos.image_x = 0;
	msg.ptr_pos.image_y = 0;
	synthvid_send(hdev, &msg);

	memset(&msg, 0, sizeof(struct synthvid_msg));
	msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
		sizeof(struct synthvid_pointer_shape);
	msg.ptr_shape.part_idx = CURSOR_COMPLETE;
	msg.ptr_shape.is_argb = 1;
	msg.ptr_shape.width = 1;
	msg.ptr_shape.height = 1;
	msg.ptr_shape.hot_x = 0;
	msg.ptr_shape.hot_y = 0;
	msg.ptr_shape.data[0] = 0;
	msg.ptr_shape.data[1] = 1;
	msg.ptr_shape.data[2] = 1;
	msg.ptr_shape.data[3] = 1;
	synthvid_send(hdev, &msg);

	return 0;
}

/* Send updated screen area (dirty rectangle) location to host */
static int synthvid_update(struct fb_info *info)
{
	struct hv_device *hdev = device_to_hv_device(info->device);
	struct synthvid_msg msg;

	memset(&msg, 0, sizeof(struct synthvid_msg));

	msg.vid_hdr.type = SYNTHVID_DIRT;
	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
		sizeof(struct synthvid_dirt);
	msg.dirt.video_output = 0;
	msg.dirt.dirt_count = 1;
	msg.dirt.rect[0].x1 = 0;
	msg.dirt.rect[0].y1 = 0;
	msg.dirt.rect[0].x2 = info->var.xres;
	msg.dirt.rect[0].y2 = info->var.yres;

	synthvid_send(hdev, &msg);

	return 0;
}


/*
 * Actions on received messages from host:
 * Complete the wait event.
 * Or, reply with screen and cursor info.
 */
static void synthvid_recv_sub(struct hv_device *hdev)
{
	struct fb_info *info = hv_get_drvdata(hdev);
	struct hvfb_par *par;
	struct synthvid_msg *msg;

	if (!info)
		return;

	par = info->par;
	msg = (struct synthvid_msg *)par->recv_buf;

	/* Complete the wait event */
	if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
	    msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
		memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
		complete(&par->wait);
		return;
	}

	/* Reply with screen and cursor info */
	if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
		if (par->fb_ready) {
			synthvid_send_ptr(hdev);
			synthvid_send_situ(hdev);
		}

		par->update = msg->feature_chg.is_dirt_needed;
		if (par->update)
			schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
	}
}

/* Receive callback for messages from the host */
static void synthvid_receive(void *ctx)
{
	struct hv_device *hdev = ctx;
	struct fb_info *info = hv_get_drvdata(hdev);
	struct hvfb_par *par;
	struct synthvid_msg *recv_buf;
	u32 bytes_recvd;
	u64 req_id;
	int ret;

	if (!info)
		return;

	par = info->par;
	recv_buf = (struct synthvid_msg *)par->recv_buf;

	do {
		ret = vmbus_recvpacket(hdev->channel, recv_buf,
				       MAX_VMBUS_PKT_SIZE,
				       &bytes_recvd, &req_id);
		if (bytes_recvd > 0 &&
		    recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
			synthvid_recv_sub(hdev);
	} while (bytes_recvd > 0 && ret == 0);
}

/* Check synthetic video protocol version with the host */
static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
{
	struct fb_info *info = hv_get_drvdata(hdev);
	struct hvfb_par *par = info->par;
	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
	int ret = 0;
	unsigned long t;

	memset(msg, 0, sizeof(struct synthvid_msg));
	msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
		sizeof(struct synthvid_version_req);
	msg->ver_req.version = ver;
	synthvid_send(hdev, msg);

	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
	if (!t) {
		pr_err("Time out on waiting version response\n");
		ret = -ETIMEDOUT;
		goto out;
	}
	if (!msg->ver_resp.is_accepted) {
		ret = -ENODEV;
		goto out;
	}

	par->synthvid_version = ver;

out:
	return ret;
}

/* Connect to VSP (Virtual Service Provider) on host */
static int synthvid_connect_vsp(struct hv_device *hdev)
{
	struct fb_info *info = hv_get_drvdata(hdev);
	struct hvfb_par *par = info->par;
	int ret;

	ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
			 NULL, 0, synthvid_receive, hdev);
	if (ret) {
		pr_err("Unable to open vmbus channel\n");
		return ret;
	}

	/* Negotiate the protocol version with host */
	if (vmbus_proto_version == VERSION_WS2008 ||
	    vmbus_proto_version == VERSION_WIN7)
		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
	else
		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);

	if (ret) {
		pr_err("Synthetic video device version not accepted\n");
		goto error;
	}

	if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
		screen_depth = SYNTHVID_DEPTH_WIN7;
	else
		screen_depth = SYNTHVID_DEPTH_WIN8;

	screen_fb_size = hdev->channel->offermsg.offer.
				mmio_megabytes * 1024 * 1024;

	return 0;

error:
	vmbus_close(hdev->channel);
	return ret;
}

/* Send VRAM and Situation messages to the host */
static int synthvid_send_config(struct hv_device *hdev)
{
	struct fb_info *info = hv_get_drvdata(hdev);
	struct hvfb_par *par = info->par;
	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
	int ret = 0;
	unsigned long t;

	/* Send VRAM location */
	memset(msg, 0, sizeof(struct synthvid_msg));
	msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
		sizeof(struct synthvid_vram_location);
	msg->vram.user_ctx = msg->vram.vram_gpa = info->fix.smem_start;
	msg->vram.is_vram_gpa_specified = 1;
	synthvid_send(hdev, msg);

	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
	if (!t) {
		pr_err("Time out on waiting vram location ack\n");
		ret = -ETIMEDOUT;
		goto out;
	}
	if (msg->vram_ack.user_ctx != info->fix.smem_start) {
		pr_err("Unable to set VRAM location\n");
		ret = -ENODEV;
		goto out;
	}

	/* Send pointer and situation update */
	synthvid_send_ptr(hdev);
	synthvid_send_situ(hdev);

out:
	return ret;
}


/*
 * Delayed work callback:
 * It is called at HVFB_UPDATE_DELAY or longer time interval to process
 * screen updates. It is re-scheduled if further update is necessary.
 */
static void hvfb_update_work(struct work_struct *w)
{
	struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
	struct fb_info *info = par->info;

	if (par->fb_ready)
		synthvid_update(info);

	if (par->update)
		schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
}

static int hvfb_on_panic(struct notifier_block *nb,
			 unsigned long e, void *p)
{
	struct hvfb_par *par;
	struct fb_info *info;

	par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
	par->synchronous_fb = true;
	info = par->info;
	synthvid_update(info);

	return NOTIFY_DONE;
}

/* Framebuffer operation handlers */

static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
	if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
	    var->xres > screen_width || var->yres >  screen_height ||
	    var->bits_per_pixel != screen_depth)
		return -EINVAL;

	var->xres_virtual = var->xres;
	var->yres_virtual = var->yres;

	return 0;
}

static int hvfb_set_par(struct fb_info *info)
{
	struct hv_device *hdev = device_to_hv_device(info->device);

	return synthvid_send_situ(hdev);
}


static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
{
	return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
}

static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
			  unsigned blue, unsigned transp, struct fb_info *info)
{
	u32 *pal = info->pseudo_palette;

	if (regno > 15)
		return -EINVAL;

	pal[regno] = chan_to_field(red, &info->var.red)
		| chan_to_field(green, &info->var.green)
		| chan_to_field(blue, &info->var.blue)
		| chan_to_field(transp, &info->var.transp);

	return 0;
}

static int hvfb_blank(int blank, struct fb_info *info)
{
	return 1;	/* get fb_blank to set the colormap to all black */
}

static void hvfb_cfb_fillrect(struct fb_info *p,
			      const struct fb_fillrect *rect)
{
	struct hvfb_par *par = p->par;

	cfb_fillrect(p, rect);
	if (par->synchronous_fb)
		synthvid_update(p);
}

static void hvfb_cfb_copyarea(struct fb_info *p,
			      const struct fb_copyarea *area)
{
	struct hvfb_par *par = p->par;

	cfb_copyarea(p, area);
	if (par->synchronous_fb)
		synthvid_update(p);
}

static void hvfb_cfb_imageblit(struct fb_info *p,
			       const struct fb_image *image)
{
	struct hvfb_par *par = p->par;

	cfb_imageblit(p, image);
	if (par->synchronous_fb)
		synthvid_update(p);
}

static struct fb_ops hvfb_ops = {
	.owner = THIS_MODULE,
	.fb_check_var = hvfb_check_var,
	.fb_set_par = hvfb_set_par,
	.fb_setcolreg = hvfb_setcolreg,
	.fb_fillrect = hvfb_cfb_fillrect,
	.fb_copyarea = hvfb_cfb_copyarea,
	.fb_imageblit = hvfb_cfb_imageblit,
	.fb_blank = hvfb_blank,
};


/* Get options from kernel paramenter "video=" */
static void hvfb_get_option(struct fb_info *info)
{
	struct hvfb_par *par = info->par;
	char *opt = NULL, *p;
	uint x = 0, y = 0;

	if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
		return;

	p = strsep(&opt, "x");
	if (!*p || kstrtouint(p, 0, &x) ||
	    !opt || !*opt || kstrtouint(opt, 0, &y)) {
		pr_err("Screen option is invalid: skipped\n");
		return;
	}

	if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
	    (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
	     (x > SYNTHVID_WIDTH_MAX_WIN7 || y > SYNTHVID_HEIGHT_MAX_WIN7))) {
		pr_err("Screen resolution option is out of range: skipped\n");
		return;
	}

	screen_width = x;
	screen_height = y;
	return;
}


/* Get framebuffer memory from Hyper-V video pci space */
static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
{
	struct hvfb_par *par = info->par;
	struct pci_dev *pdev  = NULL;
	void __iomem *fb_virt;
	int gen2vm = efi_enabled(EFI_BOOT);
	resource_size_t pot_start, pot_end;
	int ret;

	if (gen2vm) {
		pot_start = 0;
		pot_end = -1;
	} else {
		pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
			      PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
		if (!pdev) {
			pr_err("Unable to find PCI Hyper-V video\n");
			return -ENODEV;
		}

		if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
		    pci_resource_len(pdev, 0) < screen_fb_size)
			goto err1;

		pot_end = pci_resource_end(pdev, 0);
		pot_start = pot_end - screen_fb_size + 1;
	}

	ret = vmbus_allocate_mmio(&par->mem, hdev, pot_start, pot_end,
				  screen_fb_size, 0x100000, true);
	if (ret != 0) {
		pr_err("Unable to allocate framebuffer memory\n");
		goto err1;
	}

	fb_virt = ioremap(par->mem->start, screen_fb_size);
	if (!fb_virt)
		goto err2;

	info->apertures = alloc_apertures(1);
	if (!info->apertures)
		goto err3;

	if (gen2vm) {
		info->apertures->ranges[0].base = screen_info.lfb_base;
		info->apertures->ranges[0].size = screen_info.lfb_size;
		remove_conflicting_framebuffers(info->apertures,
						KBUILD_MODNAME, false);
	} else {
		info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
	}

	info->fix.smem_start = par->mem->start;
	info->fix.smem_len = screen_fb_size;
	info->screen_base = fb_virt;
	info->screen_size = screen_fb_size;

	if (!gen2vm)
		pci_dev_put(pdev);

	return 0;

err3:
	iounmap(fb_virt);
err2:
	vmbus_free_mmio(par->mem->start, screen_fb_size);
	par->mem = NULL;
err1:
	if (!gen2vm)
		pci_dev_put(pdev);

	return -ENOMEM;
}

/* Release the framebuffer */
static void hvfb_putmem(struct fb_info *info)
{
	struct hvfb_par *par = info->par;

	iounmap(info->screen_base);
	vmbus_free_mmio(par->mem->start, screen_fb_size);
	par->mem = NULL;
}


static int hvfb_probe(struct hv_device *hdev,
		      const struct hv_vmbus_device_id *dev_id)
{
	struct fb_info *info;
	struct hvfb_par *par;
	int ret;

	info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
	if (!info) {
		pr_err("No memory for framebuffer info\n");
		return -ENOMEM;
	}

	par = info->par;
	par->info = info;
	par->fb_ready = false;
	init_completion(&par->wait);
	INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);

	/* Connect to VSP */
	hv_set_drvdata(hdev, info);
	ret = synthvid_connect_vsp(hdev);
	if (ret) {
		pr_err("Unable to connect to VSP\n");
		goto error1;
	}

	ret = hvfb_getmem(hdev, info);
	if (ret) {
		pr_err("No memory for framebuffer\n");
		goto error2;
	}

	hvfb_get_option(info);
	pr_info("Screen resolution: %dx%d, Color depth: %d\n",
		screen_width, screen_height, screen_depth);


	/* Set up fb_info */
	info->flags = FBINFO_DEFAULT;

	info->var.xres_virtual = info->var.xres = screen_width;
	info->var.yres_virtual = info->var.yres = screen_height;
	info->var.bits_per_pixel = screen_depth;

	if (info->var.bits_per_pixel == 16) {
		info->var.red = (struct fb_bitfield){11, 5, 0};
		info->var.green = (struct fb_bitfield){5, 6, 0};
		info->var.blue = (struct fb_bitfield){0, 5, 0};
		info->var.transp = (struct fb_bitfield){0, 0, 0};
	} else {
		info->var.red = (struct fb_bitfield){16, 8, 0};
		info->var.green = (struct fb_bitfield){8, 8, 0};
		info->var.blue = (struct fb_bitfield){0, 8, 0};
		info->var.transp = (struct fb_bitfield){24, 8, 0};
	}

	info->var.activate = FB_ACTIVATE_NOW;
	info->var.height = -1;
	info->var.width = -1;
	info->var.vmode = FB_VMODE_NONINTERLACED;

	strcpy(info->fix.id, KBUILD_MODNAME);
	info->fix.type = FB_TYPE_PACKED_PIXELS;
	info->fix.visual = FB_VISUAL_TRUECOLOR;
	info->fix.line_length = screen_width * screen_depth / 8;
	info->fix.accel = FB_ACCEL_NONE;

	info->fbops = &hvfb_ops;
	info->pseudo_palette = par->pseudo_palette;

	/* Send config to host */
	ret = synthvid_send_config(hdev);
	if (ret)
		goto error;

	ret = register_framebuffer(info);
	if (ret) {
		pr_err("Unable to register framebuffer\n");
		goto error;
	}

	par->fb_ready = true;

	par->synchronous_fb = false;
	par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
	atomic_notifier_chain_register(&panic_notifier_list,
				       &par->hvfb_panic_nb);

	return 0;

error:
	hvfb_putmem(info);
error2:
	vmbus_close(hdev->channel);
error1:
	cancel_delayed_work_sync(&par->dwork);
	hv_set_drvdata(hdev, NULL);
	framebuffer_release(info);
	return ret;
}


static int hvfb_remove(struct hv_device *hdev)
{
	struct fb_info *info = hv_get_drvdata(hdev);
	struct hvfb_par *par = info->par;

	atomic_notifier_chain_unregister(&panic_notifier_list,
					 &par->hvfb_panic_nb);

	par->update = false;
	par->fb_ready = false;

	unregister_framebuffer(info);
	cancel_delayed_work_sync(&par->dwork);

	vmbus_close(hdev->channel);
	hv_set_drvdata(hdev, NULL);

	hvfb_putmem(info);
	framebuffer_release(info);

	return 0;
}


static const struct pci_device_id pci_stub_id_table[] = {
	{
		.vendor      = PCI_VENDOR_ID_MICROSOFT,
		.device      = PCI_DEVICE_ID_HYPERV_VIDEO,
	},
	{ /* end of list */ }
};

static const struct hv_vmbus_device_id id_table[] = {
	/* Synthetic Video Device GUID */
	{HV_SYNTHVID_GUID},
	{}
};

MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
MODULE_DEVICE_TABLE(vmbus, id_table);

static struct hv_driver hvfb_drv = {
	.name = KBUILD_MODNAME,
	.id_table = id_table,
	.probe = hvfb_probe,
	.remove = hvfb_remove,
	.driver = {
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	},
};

static int hvfb_pci_stub_probe(struct pci_dev *pdev,
			       const struct pci_device_id *ent)
{
	return 0;
}

static void hvfb_pci_stub_remove(struct pci_dev *pdev)
{
}

static struct pci_driver hvfb_pci_stub_driver = {
	.name =		KBUILD_MODNAME,
	.id_table =	pci_stub_id_table,
	.probe =	hvfb_pci_stub_probe,
	.remove =	hvfb_pci_stub_remove,
	.driver = {
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	}
};

static int __init hvfb_drv_init(void)
{
	int ret;

	ret = vmbus_driver_register(&hvfb_drv);
	if (ret != 0)
		return ret;

	ret = pci_register_driver(&hvfb_pci_stub_driver);
	if (ret != 0) {
		vmbus_driver_unregister(&hvfb_drv);
		return ret;
	}

	return 0;
}

static void __exit hvfb_drv_exit(void)
{
	pci_unregister_driver(&hvfb_pci_stub_driver);
	vmbus_driver_unregister(&hvfb_drv);
}

module_init(hvfb_drv_init);
module_exit(hvfb_drv_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");