xref: /openbmc/linux/drivers/video/fbdev/hyperv_fb.c (revision f2d8e15b)
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/aperture.h>
49 #include <linux/module.h>
50 #include <linux/kernel.h>
51 #include <linux/vmalloc.h>
52 #include <linux/init.h>
53 #include <linux/completion.h>
54 #include <linux/fb.h>
55 #include <linux/pci.h>
56 #include <linux/panic_notifier.h>
57 #include <linux/efi.h>
58 #include <linux/console.h>
59 
60 #include <linux/hyperv.h>
61 
62 
63 /* Hyper-V Synthetic Video Protocol definitions and structures */
64 #define MAX_VMBUS_PKT_SIZE 0x4000
65 
66 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
67 /* Support for VERSION_WIN7 is removed. #define is retained for reference. */
68 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
69 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
70 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
71 
72 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
73 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
74 
75 #define SYNTHVID_DEPTH_WIN8 32
76 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
77 
78 #define PCI_VENDOR_ID_MICROSOFT 0x1414
79 #define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
80 
81 
82 enum pipe_msg_type {
83 	PIPE_MSG_INVALID,
84 	PIPE_MSG_DATA,
85 	PIPE_MSG_MAX
86 };
87 
88 struct pipe_msg_hdr {
89 	u32 type;
90 	u32 size; /* size of message after this field */
91 } __packed;
92 
93 
94 enum synthvid_msg_type {
95 	SYNTHVID_ERROR			= 0,
96 	SYNTHVID_VERSION_REQUEST	= 1,
97 	SYNTHVID_VERSION_RESPONSE	= 2,
98 	SYNTHVID_VRAM_LOCATION		= 3,
99 	SYNTHVID_VRAM_LOCATION_ACK	= 4,
100 	SYNTHVID_SITUATION_UPDATE	= 5,
101 	SYNTHVID_SITUATION_UPDATE_ACK	= 6,
102 	SYNTHVID_POINTER_POSITION	= 7,
103 	SYNTHVID_POINTER_SHAPE		= 8,
104 	SYNTHVID_FEATURE_CHANGE		= 9,
105 	SYNTHVID_DIRT			= 10,
106 	SYNTHVID_RESOLUTION_REQUEST	= 13,
107 	SYNTHVID_RESOLUTION_RESPONSE	= 14,
108 
109 	SYNTHVID_MAX			= 15
110 };
111 
112 #define		SYNTHVID_EDID_BLOCK_SIZE	128
113 #define		SYNTHVID_MAX_RESOLUTION_COUNT	64
114 
115 struct hvd_screen_info {
116 	u16 width;
117 	u16 height;
118 } __packed;
119 
120 struct synthvid_msg_hdr {
121 	u32 type;
122 	u32 size;  /* size of this header + payload after this field*/
123 } __packed;
124 
125 struct synthvid_version_req {
126 	u32 version;
127 } __packed;
128 
129 struct synthvid_version_resp {
130 	u32 version;
131 	u8 is_accepted;
132 	u8 max_video_outputs;
133 } __packed;
134 
135 struct synthvid_supported_resolution_req {
136 	u8 maximum_resolution_count;
137 } __packed;
138 
139 struct synthvid_supported_resolution_resp {
140 	u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
141 	u8 resolution_count;
142 	u8 default_resolution_index;
143 	u8 is_standard;
144 	struct hvd_screen_info
145 		supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
146 } __packed;
147 
148 struct synthvid_vram_location {
149 	u64 user_ctx;
150 	u8 is_vram_gpa_specified;
151 	u64 vram_gpa;
152 } __packed;
153 
154 struct synthvid_vram_location_ack {
155 	u64 user_ctx;
156 } __packed;
157 
158 struct video_output_situation {
159 	u8 active;
160 	u32 vram_offset;
161 	u8 depth_bits;
162 	u32 width_pixels;
163 	u32 height_pixels;
164 	u32 pitch_bytes;
165 } __packed;
166 
167 struct synthvid_situation_update {
168 	u64 user_ctx;
169 	u8 video_output_count;
170 	struct video_output_situation video_output[1];
171 } __packed;
172 
173 struct synthvid_situation_update_ack {
174 	u64 user_ctx;
175 } __packed;
176 
177 struct synthvid_pointer_position {
178 	u8 is_visible;
179 	u8 video_output;
180 	s32 image_x;
181 	s32 image_y;
182 } __packed;
183 
184 
185 #define CURSOR_MAX_X 96
186 #define CURSOR_MAX_Y 96
187 #define CURSOR_ARGB_PIXEL_SIZE 4
188 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
189 #define CURSOR_COMPLETE (-1)
190 
191 struct synthvid_pointer_shape {
192 	u8 part_idx;
193 	u8 is_argb;
194 	u32 width; /* CURSOR_MAX_X at most */
195 	u32 height; /* CURSOR_MAX_Y at most */
196 	u32 hot_x; /* hotspot relative to upper-left of pointer image */
197 	u32 hot_y;
198 	u8 data[4];
199 } __packed;
200 
201 struct synthvid_feature_change {
202 	u8 is_dirt_needed;
203 	u8 is_ptr_pos_needed;
204 	u8 is_ptr_shape_needed;
205 	u8 is_situ_needed;
206 } __packed;
207 
208 struct rect {
209 	s32 x1, y1; /* top left corner */
210 	s32 x2, y2; /* bottom right corner, exclusive */
211 } __packed;
212 
213 struct synthvid_dirt {
214 	u8 video_output;
215 	u8 dirt_count;
216 	struct rect rect[1];
217 } __packed;
218 
219 struct synthvid_msg {
220 	struct pipe_msg_hdr pipe_hdr;
221 	struct synthvid_msg_hdr vid_hdr;
222 	union {
223 		struct synthvid_version_req ver_req;
224 		struct synthvid_version_resp ver_resp;
225 		struct synthvid_vram_location vram;
226 		struct synthvid_vram_location_ack vram_ack;
227 		struct synthvid_situation_update situ;
228 		struct synthvid_situation_update_ack situ_ack;
229 		struct synthvid_pointer_position ptr_pos;
230 		struct synthvid_pointer_shape ptr_shape;
231 		struct synthvid_feature_change feature_chg;
232 		struct synthvid_dirt dirt;
233 		struct synthvid_supported_resolution_req resolution_req;
234 		struct synthvid_supported_resolution_resp resolution_resp;
235 	};
236 } __packed;
237 
238 
239 /* FB driver definitions and structures */
240 #define HVFB_WIDTH 1152 /* default screen width */
241 #define HVFB_HEIGHT 864 /* default screen height */
242 #define HVFB_WIDTH_MIN 640
243 #define HVFB_HEIGHT_MIN 480
244 
245 #define RING_BUFSIZE (256 * 1024)
246 #define VSP_TIMEOUT (10 * HZ)
247 #define HVFB_UPDATE_DELAY (HZ / 20)
248 #define HVFB_ONDEMAND_THROTTLE (HZ / 20)
249 
250 struct hvfb_par {
251 	struct fb_info *info;
252 	struct resource *mem;
253 	bool fb_ready; /* fb device is ready */
254 	struct completion wait;
255 	u32 synthvid_version;
256 
257 	struct delayed_work dwork;
258 	bool update;
259 	bool update_saved; /* The value of 'update' before hibernation */
260 
261 	u32 pseudo_palette[16];
262 	u8 init_buf[MAX_VMBUS_PKT_SIZE];
263 	u8 recv_buf[MAX_VMBUS_PKT_SIZE];
264 
265 	/* If true, the VSC notifies the VSP on every framebuffer change */
266 	bool synchronous_fb;
267 
268 	/* If true, need to copy from deferred IO mem to framebuffer mem */
269 	bool need_docopy;
270 
271 	struct notifier_block hvfb_panic_nb;
272 
273 	/* Memory for deferred IO and frame buffer itself */
274 	unsigned char *dio_vp;
275 	unsigned char *mmio_vp;
276 	phys_addr_t mmio_pp;
277 
278 	/* Dirty rectangle, protected by delayed_refresh_lock */
279 	int x1, y1, x2, y2;
280 	bool delayed_refresh;
281 	spinlock_t delayed_refresh_lock;
282 };
283 
284 static uint screen_width = HVFB_WIDTH;
285 static uint screen_height = HVFB_HEIGHT;
286 static uint screen_depth;
287 static uint screen_fb_size;
288 static uint dio_fb_size; /* FB size for deferred IO */
289 
290 /* Send message to Hyper-V host */
291 static inline int synthvid_send(struct hv_device *hdev,
292 				struct synthvid_msg *msg)
293 {
294 	static atomic64_t request_id = ATOMIC64_INIT(0);
295 	int ret;
296 
297 	msg->pipe_hdr.type = PIPE_MSG_DATA;
298 	msg->pipe_hdr.size = msg->vid_hdr.size;
299 
300 	ret = vmbus_sendpacket(hdev->channel, msg,
301 			       msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
302 			       atomic64_inc_return(&request_id),
303 			       VM_PKT_DATA_INBAND, 0);
304 
305 	if (ret)
306 		pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);
307 
308 	return ret;
309 }
310 
311 
312 /* Send screen resolution info to host */
313 static int synthvid_send_situ(struct hv_device *hdev)
314 {
315 	struct fb_info *info = hv_get_drvdata(hdev);
316 	struct synthvid_msg msg;
317 
318 	if (!info)
319 		return -ENODEV;
320 
321 	memset(&msg, 0, sizeof(struct synthvid_msg));
322 
323 	msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
324 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
325 		sizeof(struct synthvid_situation_update);
326 	msg.situ.user_ctx = 0;
327 	msg.situ.video_output_count = 1;
328 	msg.situ.video_output[0].active = 1;
329 	msg.situ.video_output[0].vram_offset = 0;
330 	msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
331 	msg.situ.video_output[0].width_pixels = info->var.xres;
332 	msg.situ.video_output[0].height_pixels = info->var.yres;
333 	msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
334 
335 	synthvid_send(hdev, &msg);
336 
337 	return 0;
338 }
339 
340 /* Send mouse pointer info to host */
341 static int synthvid_send_ptr(struct hv_device *hdev)
342 {
343 	struct synthvid_msg msg;
344 
345 	memset(&msg, 0, sizeof(struct synthvid_msg));
346 	msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
347 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
348 		sizeof(struct synthvid_pointer_position);
349 	msg.ptr_pos.is_visible = 1;
350 	msg.ptr_pos.video_output = 0;
351 	msg.ptr_pos.image_x = 0;
352 	msg.ptr_pos.image_y = 0;
353 	synthvid_send(hdev, &msg);
354 
355 	memset(&msg, 0, sizeof(struct synthvid_msg));
356 	msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
357 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
358 		sizeof(struct synthvid_pointer_shape);
359 	msg.ptr_shape.part_idx = CURSOR_COMPLETE;
360 	msg.ptr_shape.is_argb = 1;
361 	msg.ptr_shape.width = 1;
362 	msg.ptr_shape.height = 1;
363 	msg.ptr_shape.hot_x = 0;
364 	msg.ptr_shape.hot_y = 0;
365 	msg.ptr_shape.data[0] = 0;
366 	msg.ptr_shape.data[1] = 1;
367 	msg.ptr_shape.data[2] = 1;
368 	msg.ptr_shape.data[3] = 1;
369 	synthvid_send(hdev, &msg);
370 
371 	return 0;
372 }
373 
374 /* Send updated screen area (dirty rectangle) location to host */
375 static int
376 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
377 {
378 	struct hv_device *hdev = device_to_hv_device(info->device);
379 	struct synthvid_msg msg;
380 
381 	memset(&msg, 0, sizeof(struct synthvid_msg));
382 	if (x2 == INT_MAX)
383 		x2 = info->var.xres;
384 	if (y2 == INT_MAX)
385 		y2 = info->var.yres;
386 
387 	msg.vid_hdr.type = SYNTHVID_DIRT;
388 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
389 		sizeof(struct synthvid_dirt);
390 	msg.dirt.video_output = 0;
391 	msg.dirt.dirt_count = 1;
392 	msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
393 	msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
394 	msg.dirt.rect[0].x2 =
395 		(x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
396 	msg.dirt.rect[0].y2 =
397 		(y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
398 
399 	synthvid_send(hdev, &msg);
400 
401 	return 0;
402 }
403 
404 static void hvfb_docopy(struct hvfb_par *par,
405 			unsigned long offset,
406 			unsigned long size)
407 {
408 	if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
409 	    size == 0 || offset >= dio_fb_size)
410 		return;
411 
412 	if (offset + size > dio_fb_size)
413 		size = dio_fb_size - offset;
414 
415 	memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
416 }
417 
418 /* Deferred IO callback */
419 static void synthvid_deferred_io(struct fb_info *p, struct list_head *pagereflist)
420 {
421 	struct hvfb_par *par = p->par;
422 	struct fb_deferred_io_pageref *pageref;
423 	unsigned long start, end;
424 	int y1, y2, miny, maxy;
425 
426 	miny = INT_MAX;
427 	maxy = 0;
428 
429 	/*
430 	 * Merge dirty pages. It is possible that last page cross
431 	 * over the end of frame buffer row yres. This is taken care of
432 	 * in synthvid_update function by clamping the y2
433 	 * value to yres.
434 	 */
435 	list_for_each_entry(pageref, pagereflist, list) {
436 		start = pageref->offset;
437 		end = start + PAGE_SIZE - 1;
438 		y1 = start / p->fix.line_length;
439 		y2 = end / p->fix.line_length;
440 		miny = min_t(int, miny, y1);
441 		maxy = max_t(int, maxy, y2);
442 
443 		/* Copy from dio space to mmio address */
444 		if (par->fb_ready && par->need_docopy)
445 			hvfb_docopy(par, start, PAGE_SIZE);
446 	}
447 
448 	if (par->fb_ready && par->update)
449 		synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
450 }
451 
452 static struct fb_deferred_io synthvid_defio = {
453 	.delay		= HZ / 20,
454 	.deferred_io	= synthvid_deferred_io,
455 };
456 
457 /*
458  * Actions on received messages from host:
459  * Complete the wait event.
460  * Or, reply with screen and cursor info.
461  */
462 static void synthvid_recv_sub(struct hv_device *hdev)
463 {
464 	struct fb_info *info = hv_get_drvdata(hdev);
465 	struct hvfb_par *par;
466 	struct synthvid_msg *msg;
467 
468 	if (!info)
469 		return;
470 
471 	par = info->par;
472 	msg = (struct synthvid_msg *)par->recv_buf;
473 
474 	/* Complete the wait event */
475 	if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
476 	    msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
477 	    msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
478 		memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
479 		complete(&par->wait);
480 		return;
481 	}
482 
483 	/* Reply with screen and cursor info */
484 	if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
485 		if (par->fb_ready) {
486 			synthvid_send_ptr(hdev);
487 			synthvid_send_situ(hdev);
488 		}
489 
490 		par->update = msg->feature_chg.is_dirt_needed;
491 		if (par->update)
492 			schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
493 	}
494 }
495 
496 /* Receive callback for messages from the host */
497 static void synthvid_receive(void *ctx)
498 {
499 	struct hv_device *hdev = ctx;
500 	struct fb_info *info = hv_get_drvdata(hdev);
501 	struct hvfb_par *par;
502 	struct synthvid_msg *recv_buf;
503 	u32 bytes_recvd;
504 	u64 req_id;
505 	int ret;
506 
507 	if (!info)
508 		return;
509 
510 	par = info->par;
511 	recv_buf = (struct synthvid_msg *)par->recv_buf;
512 
513 	do {
514 		ret = vmbus_recvpacket(hdev->channel, recv_buf,
515 				       MAX_VMBUS_PKT_SIZE,
516 				       &bytes_recvd, &req_id);
517 		if (bytes_recvd > 0 &&
518 		    recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
519 			synthvid_recv_sub(hdev);
520 	} while (bytes_recvd > 0 && ret == 0);
521 }
522 
523 /* Check if the ver1 version is equal or greater than ver2 */
524 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
525 {
526 	if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
527 	    (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
528 	     SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
529 		return true;
530 
531 	return false;
532 }
533 
534 /* Check synthetic video protocol version with the host */
535 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
536 {
537 	struct fb_info *info = hv_get_drvdata(hdev);
538 	struct hvfb_par *par = info->par;
539 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
540 	int ret = 0;
541 	unsigned long t;
542 
543 	memset(msg, 0, sizeof(struct synthvid_msg));
544 	msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
545 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
546 		sizeof(struct synthvid_version_req);
547 	msg->ver_req.version = ver;
548 	synthvid_send(hdev, msg);
549 
550 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
551 	if (!t) {
552 		pr_err("Time out on waiting version response\n");
553 		ret = -ETIMEDOUT;
554 		goto out;
555 	}
556 	if (!msg->ver_resp.is_accepted) {
557 		ret = -ENODEV;
558 		goto out;
559 	}
560 
561 	par->synthvid_version = ver;
562 	pr_info("Synthvid Version major %d, minor %d\n",
563 		SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
564 
565 out:
566 	return ret;
567 }
568 
569 /* Get current resolution from the host */
570 static int synthvid_get_supported_resolution(struct hv_device *hdev)
571 {
572 	struct fb_info *info = hv_get_drvdata(hdev);
573 	struct hvfb_par *par = info->par;
574 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
575 	int ret = 0;
576 	unsigned long t;
577 	u8 index;
578 
579 	memset(msg, 0, sizeof(struct synthvid_msg));
580 	msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
581 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
582 		sizeof(struct synthvid_supported_resolution_req);
583 
584 	msg->resolution_req.maximum_resolution_count =
585 		SYNTHVID_MAX_RESOLUTION_COUNT;
586 	synthvid_send(hdev, msg);
587 
588 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
589 	if (!t) {
590 		pr_err("Time out on waiting resolution response\n");
591 		ret = -ETIMEDOUT;
592 		goto out;
593 	}
594 
595 	if (msg->resolution_resp.resolution_count == 0) {
596 		pr_err("No supported resolutions\n");
597 		ret = -ENODEV;
598 		goto out;
599 	}
600 
601 	index = msg->resolution_resp.default_resolution_index;
602 	if (index >= msg->resolution_resp.resolution_count) {
603 		pr_err("Invalid resolution index: %d\n", index);
604 		ret = -ENODEV;
605 		goto out;
606 	}
607 
608 	screen_width =
609 		msg->resolution_resp.supported_resolution[index].width;
610 	screen_height =
611 		msg->resolution_resp.supported_resolution[index].height;
612 
613 out:
614 	return ret;
615 }
616 
617 /* Connect to VSP (Virtual Service Provider) on host */
618 static int synthvid_connect_vsp(struct hv_device *hdev)
619 {
620 	struct fb_info *info = hv_get_drvdata(hdev);
621 	struct hvfb_par *par = info->par;
622 	int ret;
623 
624 	ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
625 			 NULL, 0, synthvid_receive, hdev);
626 	if (ret) {
627 		pr_err("Unable to open vmbus channel\n");
628 		return ret;
629 	}
630 
631 	/* Negotiate the protocol version with host */
632 	switch (vmbus_proto_version) {
633 	case VERSION_WIN10:
634 	case VERSION_WIN10_V5:
635 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
636 		if (!ret)
637 			break;
638 		fallthrough;
639 	case VERSION_WIN8:
640 	case VERSION_WIN8_1:
641 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
642 		break;
643 	default:
644 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
645 		break;
646 	}
647 
648 	if (ret) {
649 		pr_err("Synthetic video device version not accepted\n");
650 		goto error;
651 	}
652 
653 	screen_depth = SYNTHVID_DEPTH_WIN8;
654 	if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
655 		ret = synthvid_get_supported_resolution(hdev);
656 		if (ret)
657 			pr_info("Failed to get supported resolution from host, use default\n");
658 	}
659 
660 	screen_fb_size = hdev->channel->offermsg.offer.
661 				mmio_megabytes * 1024 * 1024;
662 
663 	return 0;
664 
665 error:
666 	vmbus_close(hdev->channel);
667 	return ret;
668 }
669 
670 /* Send VRAM and Situation messages to the host */
671 static int synthvid_send_config(struct hv_device *hdev)
672 {
673 	struct fb_info *info = hv_get_drvdata(hdev);
674 	struct hvfb_par *par = info->par;
675 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
676 	int ret = 0;
677 	unsigned long t;
678 
679 	/* Send VRAM location */
680 	memset(msg, 0, sizeof(struct synthvid_msg));
681 	msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
682 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
683 		sizeof(struct synthvid_vram_location);
684 	msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
685 	msg->vram.is_vram_gpa_specified = 1;
686 	synthvid_send(hdev, msg);
687 
688 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
689 	if (!t) {
690 		pr_err("Time out on waiting vram location ack\n");
691 		ret = -ETIMEDOUT;
692 		goto out;
693 	}
694 	if (msg->vram_ack.user_ctx != par->mmio_pp) {
695 		pr_err("Unable to set VRAM location\n");
696 		ret = -ENODEV;
697 		goto out;
698 	}
699 
700 	/* Send pointer and situation update */
701 	synthvid_send_ptr(hdev);
702 	synthvid_send_situ(hdev);
703 
704 out:
705 	return ret;
706 }
707 
708 
709 /*
710  * Delayed work callback:
711  * It is scheduled to call whenever update request is received and it has
712  * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
713  */
714 static void hvfb_update_work(struct work_struct *w)
715 {
716 	struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
717 	struct fb_info *info = par->info;
718 	unsigned long flags;
719 	int x1, x2, y1, y2;
720 	int j;
721 
722 	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
723 	/* Reset the request flag */
724 	par->delayed_refresh = false;
725 
726 	/* Store the dirty rectangle to local variables */
727 	x1 = par->x1;
728 	x2 = par->x2;
729 	y1 = par->y1;
730 	y2 = par->y2;
731 
732 	/* Clear dirty rectangle */
733 	par->x1 = par->y1 = INT_MAX;
734 	par->x2 = par->y2 = 0;
735 
736 	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
737 
738 	if (x1 > info->var.xres || x2 > info->var.xres ||
739 	    y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
740 		return;
741 
742 	/* Copy the dirty rectangle to frame buffer memory */
743 	if (par->need_docopy)
744 		for (j = y1; j < y2; j++)
745 			hvfb_docopy(par,
746 				    j * info->fix.line_length +
747 				    (x1 * screen_depth / 8),
748 				    (x2 - x1) * screen_depth / 8);
749 
750 	/* Refresh */
751 	if (par->fb_ready && par->update)
752 		synthvid_update(info, x1, y1, x2, y2);
753 }
754 
755 /*
756  * Control the on-demand refresh frequency. It schedules a delayed
757  * screen update if it has not yet.
758  */
759 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
760 					   int x1, int y1, int w, int h)
761 {
762 	unsigned long flags;
763 	int x2 = x1 + w;
764 	int y2 = y1 + h;
765 
766 	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
767 
768 	/* Merge dirty rectangle */
769 	par->x1 = min_t(int, par->x1, x1);
770 	par->y1 = min_t(int, par->y1, y1);
771 	par->x2 = max_t(int, par->x2, x2);
772 	par->y2 = max_t(int, par->y2, y2);
773 
774 	/* Schedule a delayed screen update if not yet */
775 	if (par->delayed_refresh == false) {
776 		schedule_delayed_work(&par->dwork,
777 				      HVFB_ONDEMAND_THROTTLE);
778 		par->delayed_refresh = true;
779 	}
780 
781 	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
782 }
783 
784 static int hvfb_on_panic(struct notifier_block *nb,
785 			 unsigned long e, void *p)
786 {
787 	struct hvfb_par *par;
788 	struct fb_info *info;
789 
790 	par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
791 	par->synchronous_fb = true;
792 	info = par->info;
793 	if (par->need_docopy)
794 		hvfb_docopy(par, 0, dio_fb_size);
795 	synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
796 
797 	return NOTIFY_DONE;
798 }
799 
800 /* Framebuffer operation handlers */
801 
802 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
803 {
804 	if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
805 	    var->xres > screen_width || var->yres >  screen_height ||
806 	    var->bits_per_pixel != screen_depth)
807 		return -EINVAL;
808 
809 	var->xres_virtual = var->xres;
810 	var->yres_virtual = var->yres;
811 
812 	return 0;
813 }
814 
815 static int hvfb_set_par(struct fb_info *info)
816 {
817 	struct hv_device *hdev = device_to_hv_device(info->device);
818 
819 	return synthvid_send_situ(hdev);
820 }
821 
822 
823 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
824 {
825 	return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
826 }
827 
828 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
829 			  unsigned blue, unsigned transp, struct fb_info *info)
830 {
831 	u32 *pal = info->pseudo_palette;
832 
833 	if (regno > 15)
834 		return -EINVAL;
835 
836 	pal[regno] = chan_to_field(red, &info->var.red)
837 		| chan_to_field(green, &info->var.green)
838 		| chan_to_field(blue, &info->var.blue)
839 		| chan_to_field(transp, &info->var.transp);
840 
841 	return 0;
842 }
843 
844 static int hvfb_blank(int blank, struct fb_info *info)
845 {
846 	return 1;	/* get fb_blank to set the colormap to all black */
847 }
848 
849 static void hvfb_cfb_fillrect(struct fb_info *p,
850 			      const struct fb_fillrect *rect)
851 {
852 	struct hvfb_par *par = p->par;
853 
854 	cfb_fillrect(p, rect);
855 	if (par->synchronous_fb)
856 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
857 	else
858 		hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
859 					       rect->width, rect->height);
860 }
861 
862 static void hvfb_cfb_copyarea(struct fb_info *p,
863 			      const struct fb_copyarea *area)
864 {
865 	struct hvfb_par *par = p->par;
866 
867 	cfb_copyarea(p, area);
868 	if (par->synchronous_fb)
869 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
870 	else
871 		hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
872 					       area->width, area->height);
873 }
874 
875 static void hvfb_cfb_imageblit(struct fb_info *p,
876 			       const struct fb_image *image)
877 {
878 	struct hvfb_par *par = p->par;
879 
880 	cfb_imageblit(p, image);
881 	if (par->synchronous_fb)
882 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
883 	else
884 		hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
885 					       image->width, image->height);
886 }
887 
888 static const struct fb_ops hvfb_ops = {
889 	.owner = THIS_MODULE,
890 	.fb_check_var = hvfb_check_var,
891 	.fb_set_par = hvfb_set_par,
892 	.fb_setcolreg = hvfb_setcolreg,
893 	.fb_fillrect = hvfb_cfb_fillrect,
894 	.fb_copyarea = hvfb_cfb_copyarea,
895 	.fb_imageblit = hvfb_cfb_imageblit,
896 	.fb_blank = hvfb_blank,
897 	.fb_mmap = fb_deferred_io_mmap,
898 };
899 
900 
901 /* Get options from kernel paramenter "video=" */
902 static void hvfb_get_option(struct fb_info *info)
903 {
904 	struct hvfb_par *par = info->par;
905 	char *opt = NULL, *p;
906 	uint x = 0, y = 0;
907 
908 	if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
909 		return;
910 
911 	p = strsep(&opt, "x");
912 	if (!*p || kstrtouint(p, 0, &x) ||
913 	    !opt || !*opt || kstrtouint(opt, 0, &y)) {
914 		pr_err("Screen option is invalid: skipped\n");
915 		return;
916 	}
917 
918 	if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
919 	    (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
920 	    (x * y * screen_depth / 8 > screen_fb_size)) ||
921 	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
922 	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8)) {
923 		pr_err("Screen resolution option is out of range: skipped\n");
924 		return;
925 	}
926 
927 	screen_width = x;
928 	screen_height = y;
929 	return;
930 }
931 
932 /*
933  * Allocate enough contiguous physical memory.
934  * Return physical address if succeeded or -1 if failed.
935  */
936 static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
937 				   unsigned int request_size)
938 {
939 	struct page *page = NULL;
940 	dma_addr_t dma_handle;
941 	void *vmem;
942 	phys_addr_t paddr = 0;
943 	unsigned int order = get_order(request_size);
944 
945 	if (request_size == 0)
946 		return -1;
947 
948 	if (order < MAX_ORDER) {
949 		/* Call alloc_pages if the size is less than 2^MAX_ORDER */
950 		page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
951 		if (!page)
952 			return -1;
953 
954 		paddr = (page_to_pfn(page) << PAGE_SHIFT);
955 	} else {
956 		/* Allocate from CMA */
957 		hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
958 
959 		vmem = dma_alloc_coherent(&hdev->device,
960 					  round_up(request_size, PAGE_SIZE),
961 					  &dma_handle,
962 					  GFP_KERNEL | __GFP_NOWARN);
963 
964 		if (!vmem)
965 			return -1;
966 
967 		paddr = virt_to_phys(vmem);
968 	}
969 
970 	return paddr;
971 }
972 
973 /* Release contiguous physical memory */
974 static void hvfb_release_phymem(struct hv_device *hdev,
975 				phys_addr_t paddr, unsigned int size)
976 {
977 	unsigned int order = get_order(size);
978 
979 	if (order < MAX_ORDER)
980 		__free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
981 	else
982 		dma_free_coherent(&hdev->device,
983 				  round_up(size, PAGE_SIZE),
984 				  phys_to_virt(paddr),
985 				  paddr);
986 }
987 
988 
989 /* Get framebuffer memory from Hyper-V video pci space */
990 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
991 {
992 	struct hvfb_par *par = info->par;
993 	struct pci_dev *pdev  = NULL;
994 	void __iomem *fb_virt;
995 	int gen2vm = efi_enabled(EFI_BOOT);
996 	phys_addr_t paddr;
997 	int ret;
998 
999 	info->apertures = alloc_apertures(1);
1000 	if (!info->apertures)
1001 		return -ENOMEM;
1002 
1003 	if (!gen2vm) {
1004 		pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
1005 			PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
1006 		if (!pdev) {
1007 			pr_err("Unable to find PCI Hyper-V video\n");
1008 			return -ENODEV;
1009 		}
1010 
1011 		info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
1012 		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
1013 
1014 		/*
1015 		 * For Gen 1 VM, we can directly use the contiguous memory
1016 		 * from VM. If we succeed, deferred IO happens directly
1017 		 * on this allocated framebuffer memory, avoiding extra
1018 		 * memory copy.
1019 		 */
1020 		paddr = hvfb_get_phymem(hdev, screen_fb_size);
1021 		if (paddr != (phys_addr_t) -1) {
1022 			par->mmio_pp = paddr;
1023 			par->mmio_vp = par->dio_vp = __va(paddr);
1024 
1025 			info->fix.smem_start = paddr;
1026 			info->fix.smem_len = screen_fb_size;
1027 			info->screen_base = par->mmio_vp;
1028 			info->screen_size = screen_fb_size;
1029 
1030 			par->need_docopy = false;
1031 			goto getmem_done;
1032 		}
1033 		pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1034 	} else {
1035 		info->apertures->ranges[0].base = screen_info.lfb_base;
1036 		info->apertures->ranges[0].size = screen_info.lfb_size;
1037 	}
1038 
1039 	/*
1040 	 * Cannot use the contiguous physical memory.
1041 	 * Allocate mmio space for framebuffer.
1042 	 */
1043 	dio_fb_size =
1044 		screen_width * screen_height * screen_depth / 8;
1045 
1046 	ret = vmbus_allocate_mmio(&par->mem, hdev, 0, -1,
1047 				  screen_fb_size, 0x100000, true);
1048 	if (ret != 0) {
1049 		pr_err("Unable to allocate framebuffer memory\n");
1050 		goto err1;
1051 	}
1052 
1053 	/*
1054 	 * Map the VRAM cacheable for performance. This is also required for
1055 	 * VM Connect to display properly for ARM64 Linux VM, as the host also
1056 	 * maps the VRAM cacheable.
1057 	 */
1058 	fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1059 	if (!fb_virt)
1060 		goto err2;
1061 
1062 	/* Allocate memory for deferred IO */
1063 	par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1064 	if (par->dio_vp == NULL)
1065 		goto err3;
1066 
1067 	/* Physical address of FB device */
1068 	par->mmio_pp = par->mem->start;
1069 	/* Virtual address of FB device */
1070 	par->mmio_vp = (unsigned char *) fb_virt;
1071 
1072 	info->fix.smem_start = par->mem->start;
1073 	info->fix.smem_len = dio_fb_size;
1074 	info->screen_base = par->dio_vp;
1075 	info->screen_size = dio_fb_size;
1076 
1077 getmem_done:
1078 	aperture_remove_conflicting_devices(info->apertures->ranges[0].base,
1079 					    info->apertures->ranges[0].size,
1080 					    false, KBUILD_MODNAME);
1081 
1082 	if (gen2vm) {
1083 		/* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
1084 		screen_info.lfb_size = 0;
1085 		screen_info.lfb_base = 0;
1086 		screen_info.orig_video_isVGA = 0;
1087 	} else {
1088 		pci_dev_put(pdev);
1089 	}
1090 
1091 	return 0;
1092 
1093 err3:
1094 	iounmap(fb_virt);
1095 err2:
1096 	vmbus_free_mmio(par->mem->start, screen_fb_size);
1097 	par->mem = NULL;
1098 err1:
1099 	if (!gen2vm)
1100 		pci_dev_put(pdev);
1101 
1102 	return -ENOMEM;
1103 }
1104 
1105 /* Release the framebuffer */
1106 static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1107 {
1108 	struct hvfb_par *par = info->par;
1109 
1110 	if (par->need_docopy) {
1111 		vfree(par->dio_vp);
1112 		iounmap(info->screen_base);
1113 		vmbus_free_mmio(par->mem->start, screen_fb_size);
1114 	} else {
1115 		hvfb_release_phymem(hdev, info->fix.smem_start,
1116 				    screen_fb_size);
1117 	}
1118 
1119 	par->mem = NULL;
1120 }
1121 
1122 
1123 static int hvfb_probe(struct hv_device *hdev,
1124 		      const struct hv_vmbus_device_id *dev_id)
1125 {
1126 	struct fb_info *info;
1127 	struct hvfb_par *par;
1128 	int ret;
1129 
1130 	info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1131 	if (!info)
1132 		return -ENOMEM;
1133 
1134 	par = info->par;
1135 	par->info = info;
1136 	par->fb_ready = false;
1137 	par->need_docopy = true;
1138 	init_completion(&par->wait);
1139 	INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1140 
1141 	par->delayed_refresh = false;
1142 	spin_lock_init(&par->delayed_refresh_lock);
1143 	par->x1 = par->y1 = INT_MAX;
1144 	par->x2 = par->y2 = 0;
1145 
1146 	/* Connect to VSP */
1147 	hv_set_drvdata(hdev, info);
1148 	ret = synthvid_connect_vsp(hdev);
1149 	if (ret) {
1150 		pr_err("Unable to connect to VSP\n");
1151 		goto error1;
1152 	}
1153 
1154 	hvfb_get_option(info);
1155 	pr_info("Screen resolution: %dx%d, Color depth: %d, Frame buffer size: %d\n",
1156 		screen_width, screen_height, screen_depth, screen_fb_size);
1157 
1158 	ret = hvfb_getmem(hdev, info);
1159 	if (ret) {
1160 		pr_err("No memory for framebuffer\n");
1161 		goto error2;
1162 	}
1163 
1164 	/* Set up fb_info */
1165 	info->flags = FBINFO_DEFAULT;
1166 
1167 	info->var.xres_virtual = info->var.xres = screen_width;
1168 	info->var.yres_virtual = info->var.yres = screen_height;
1169 	info->var.bits_per_pixel = screen_depth;
1170 
1171 	if (info->var.bits_per_pixel == 16) {
1172 		info->var.red = (struct fb_bitfield){11, 5, 0};
1173 		info->var.green = (struct fb_bitfield){5, 6, 0};
1174 		info->var.blue = (struct fb_bitfield){0, 5, 0};
1175 		info->var.transp = (struct fb_bitfield){0, 0, 0};
1176 	} else {
1177 		info->var.red = (struct fb_bitfield){16, 8, 0};
1178 		info->var.green = (struct fb_bitfield){8, 8, 0};
1179 		info->var.blue = (struct fb_bitfield){0, 8, 0};
1180 		info->var.transp = (struct fb_bitfield){24, 8, 0};
1181 	}
1182 
1183 	info->var.activate = FB_ACTIVATE_NOW;
1184 	info->var.height = -1;
1185 	info->var.width = -1;
1186 	info->var.vmode = FB_VMODE_NONINTERLACED;
1187 
1188 	strcpy(info->fix.id, KBUILD_MODNAME);
1189 	info->fix.type = FB_TYPE_PACKED_PIXELS;
1190 	info->fix.visual = FB_VISUAL_TRUECOLOR;
1191 	info->fix.line_length = screen_width * screen_depth / 8;
1192 	info->fix.accel = FB_ACCEL_NONE;
1193 
1194 	info->fbops = &hvfb_ops;
1195 	info->pseudo_palette = par->pseudo_palette;
1196 
1197 	/* Initialize deferred IO */
1198 	info->fbdefio = &synthvid_defio;
1199 	fb_deferred_io_init(info);
1200 
1201 	/* Send config to host */
1202 	ret = synthvid_send_config(hdev);
1203 	if (ret)
1204 		goto error;
1205 
1206 	ret = register_framebuffer(info);
1207 	if (ret) {
1208 		pr_err("Unable to register framebuffer\n");
1209 		goto error;
1210 	}
1211 
1212 	par->fb_ready = true;
1213 
1214 	par->synchronous_fb = false;
1215 	par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1216 	atomic_notifier_chain_register(&panic_notifier_list,
1217 				       &par->hvfb_panic_nb);
1218 
1219 	return 0;
1220 
1221 error:
1222 	fb_deferred_io_cleanup(info);
1223 	hvfb_putmem(hdev, info);
1224 error2:
1225 	vmbus_close(hdev->channel);
1226 error1:
1227 	cancel_delayed_work_sync(&par->dwork);
1228 	hv_set_drvdata(hdev, NULL);
1229 	framebuffer_release(info);
1230 	return ret;
1231 }
1232 
1233 
1234 static int hvfb_remove(struct hv_device *hdev)
1235 {
1236 	struct fb_info *info = hv_get_drvdata(hdev);
1237 	struct hvfb_par *par = info->par;
1238 
1239 	atomic_notifier_chain_unregister(&panic_notifier_list,
1240 					 &par->hvfb_panic_nb);
1241 
1242 	par->update = false;
1243 	par->fb_ready = false;
1244 
1245 	fb_deferred_io_cleanup(info);
1246 
1247 	unregister_framebuffer(info);
1248 	cancel_delayed_work_sync(&par->dwork);
1249 
1250 	vmbus_close(hdev->channel);
1251 	hv_set_drvdata(hdev, NULL);
1252 
1253 	hvfb_putmem(hdev, info);
1254 	framebuffer_release(info);
1255 
1256 	return 0;
1257 }
1258 
1259 static int hvfb_suspend(struct hv_device *hdev)
1260 {
1261 	struct fb_info *info = hv_get_drvdata(hdev);
1262 	struct hvfb_par *par = info->par;
1263 
1264 	console_lock();
1265 
1266 	/* 1 means do suspend */
1267 	fb_set_suspend(info, 1);
1268 
1269 	cancel_delayed_work_sync(&par->dwork);
1270 	cancel_delayed_work_sync(&info->deferred_work);
1271 
1272 	par->update_saved = par->update;
1273 	par->update = false;
1274 	par->fb_ready = false;
1275 
1276 	vmbus_close(hdev->channel);
1277 
1278 	console_unlock();
1279 
1280 	return 0;
1281 }
1282 
1283 static int hvfb_resume(struct hv_device *hdev)
1284 {
1285 	struct fb_info *info = hv_get_drvdata(hdev);
1286 	struct hvfb_par *par = info->par;
1287 	int ret;
1288 
1289 	console_lock();
1290 
1291 	ret = synthvid_connect_vsp(hdev);
1292 	if (ret != 0)
1293 		goto out;
1294 
1295 	ret = synthvid_send_config(hdev);
1296 	if (ret != 0) {
1297 		vmbus_close(hdev->channel);
1298 		goto out;
1299 	}
1300 
1301 	par->fb_ready = true;
1302 	par->update = par->update_saved;
1303 
1304 	schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1305 	schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1306 
1307 	/* 0 means do resume */
1308 	fb_set_suspend(info, 0);
1309 
1310 out:
1311 	console_unlock();
1312 
1313 	return ret;
1314 }
1315 
1316 
1317 static const struct pci_device_id pci_stub_id_table[] = {
1318 	{
1319 		.vendor      = PCI_VENDOR_ID_MICROSOFT,
1320 		.device      = PCI_DEVICE_ID_HYPERV_VIDEO,
1321 	},
1322 	{ /* end of list */ }
1323 };
1324 
1325 static const struct hv_vmbus_device_id id_table[] = {
1326 	/* Synthetic Video Device GUID */
1327 	{HV_SYNTHVID_GUID},
1328 	{}
1329 };
1330 
1331 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1332 MODULE_DEVICE_TABLE(vmbus, id_table);
1333 
1334 static struct hv_driver hvfb_drv = {
1335 	.name = KBUILD_MODNAME,
1336 	.id_table = id_table,
1337 	.probe = hvfb_probe,
1338 	.remove = hvfb_remove,
1339 	.suspend = hvfb_suspend,
1340 	.resume = hvfb_resume,
1341 	.driver = {
1342 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1343 	},
1344 };
1345 
1346 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1347 			       const struct pci_device_id *ent)
1348 {
1349 	return 0;
1350 }
1351 
1352 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1353 {
1354 }
1355 
1356 static struct pci_driver hvfb_pci_stub_driver = {
1357 	.name =		KBUILD_MODNAME,
1358 	.id_table =	pci_stub_id_table,
1359 	.probe =	hvfb_pci_stub_probe,
1360 	.remove =	hvfb_pci_stub_remove,
1361 	.driver = {
1362 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1363 	}
1364 };
1365 
1366 static int __init hvfb_drv_init(void)
1367 {
1368 	int ret;
1369 
1370 	ret = vmbus_driver_register(&hvfb_drv);
1371 	if (ret != 0)
1372 		return ret;
1373 
1374 	ret = pci_register_driver(&hvfb_pci_stub_driver);
1375 	if (ret != 0) {
1376 		vmbus_driver_unregister(&hvfb_drv);
1377 		return ret;
1378 	}
1379 
1380 	return 0;
1381 }
1382 
1383 static void __exit hvfb_drv_exit(void)
1384 {
1385 	pci_unregister_driver(&hvfb_pci_stub_driver);
1386 	vmbus_driver_unregister(&hvfb_drv);
1387 }
1388 
1389 module_init(hvfb_drv_init);
1390 module_exit(hvfb_drv_exit);
1391 
1392 MODULE_LICENSE("GPL");
1393 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");
1394