xref: /linux/drivers/video/fbdev/hyperv_fb.c (revision 55f1b540d893da740a81200450014c45a8103f54)
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 /* Hyper-V Synthetic Video Protocol definitions and structures */
63 #define MAX_VMBUS_PKT_SIZE 0x4000
64 
65 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
66 /* Support for VERSION_WIN7 is removed. #define is retained for reference. */
67 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
68 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
69 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
70 
71 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
72 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
73 
74 #define SYNTHVID_DEPTH_WIN8 32
75 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
76 
77 enum pipe_msg_type {
78 	PIPE_MSG_INVALID,
79 	PIPE_MSG_DATA,
80 	PIPE_MSG_MAX
81 };
82 
83 struct pipe_msg_hdr {
84 	u32 type;
85 	u32 size; /* size of message after this field */
86 } __packed;
87 
88 
89 enum synthvid_msg_type {
90 	SYNTHVID_ERROR			= 0,
91 	SYNTHVID_VERSION_REQUEST	= 1,
92 	SYNTHVID_VERSION_RESPONSE	= 2,
93 	SYNTHVID_VRAM_LOCATION		= 3,
94 	SYNTHVID_VRAM_LOCATION_ACK	= 4,
95 	SYNTHVID_SITUATION_UPDATE	= 5,
96 	SYNTHVID_SITUATION_UPDATE_ACK	= 6,
97 	SYNTHVID_POINTER_POSITION	= 7,
98 	SYNTHVID_POINTER_SHAPE		= 8,
99 	SYNTHVID_FEATURE_CHANGE		= 9,
100 	SYNTHVID_DIRT			= 10,
101 	SYNTHVID_RESOLUTION_REQUEST	= 13,
102 	SYNTHVID_RESOLUTION_RESPONSE	= 14,
103 
104 	SYNTHVID_MAX			= 15
105 };
106 
107 #define		SYNTHVID_EDID_BLOCK_SIZE	128
108 #define		SYNTHVID_MAX_RESOLUTION_COUNT	64
109 
110 struct hvd_screen_info {
111 	u16 width;
112 	u16 height;
113 } __packed;
114 
115 struct synthvid_msg_hdr {
116 	u32 type;
117 	u32 size;  /* size of this header + payload after this field*/
118 } __packed;
119 
120 struct synthvid_version_req {
121 	u32 version;
122 } __packed;
123 
124 struct synthvid_version_resp {
125 	u32 version;
126 	u8 is_accepted;
127 	u8 max_video_outputs;
128 } __packed;
129 
130 struct synthvid_supported_resolution_req {
131 	u8 maximum_resolution_count;
132 } __packed;
133 
134 struct synthvid_supported_resolution_resp {
135 	u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
136 	u8 resolution_count;
137 	u8 default_resolution_index;
138 	u8 is_standard;
139 	struct hvd_screen_info
140 		supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
141 } __packed;
142 
143 struct synthvid_vram_location {
144 	u64 user_ctx;
145 	u8 is_vram_gpa_specified;
146 	u64 vram_gpa;
147 } __packed;
148 
149 struct synthvid_vram_location_ack {
150 	u64 user_ctx;
151 } __packed;
152 
153 struct video_output_situation {
154 	u8 active;
155 	u32 vram_offset;
156 	u8 depth_bits;
157 	u32 width_pixels;
158 	u32 height_pixels;
159 	u32 pitch_bytes;
160 } __packed;
161 
162 struct synthvid_situation_update {
163 	u64 user_ctx;
164 	u8 video_output_count;
165 	struct video_output_situation video_output[1];
166 } __packed;
167 
168 struct synthvid_situation_update_ack {
169 	u64 user_ctx;
170 } __packed;
171 
172 struct synthvid_pointer_position {
173 	u8 is_visible;
174 	u8 video_output;
175 	s32 image_x;
176 	s32 image_y;
177 } __packed;
178 
179 
180 #define CURSOR_MAX_X 96
181 #define CURSOR_MAX_Y 96
182 #define CURSOR_ARGB_PIXEL_SIZE 4
183 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
184 #define CURSOR_COMPLETE (-1)
185 
186 struct synthvid_pointer_shape {
187 	u8 part_idx;
188 	u8 is_argb;
189 	u32 width; /* CURSOR_MAX_X at most */
190 	u32 height; /* CURSOR_MAX_Y at most */
191 	u32 hot_x; /* hotspot relative to upper-left of pointer image */
192 	u32 hot_y;
193 	u8 data[4];
194 } __packed;
195 
196 struct synthvid_feature_change {
197 	u8 is_dirt_needed;
198 	u8 is_ptr_pos_needed;
199 	u8 is_ptr_shape_needed;
200 	u8 is_situ_needed;
201 } __packed;
202 
203 struct rect {
204 	s32 x1, y1; /* top left corner */
205 	s32 x2, y2; /* bottom right corner, exclusive */
206 } __packed;
207 
208 struct synthvid_dirt {
209 	u8 video_output;
210 	u8 dirt_count;
211 	struct rect rect[1];
212 } __packed;
213 
214 struct synthvid_msg {
215 	struct pipe_msg_hdr pipe_hdr;
216 	struct synthvid_msg_hdr vid_hdr;
217 	union {
218 		struct synthvid_version_req ver_req;
219 		struct synthvid_version_resp ver_resp;
220 		struct synthvid_vram_location vram;
221 		struct synthvid_vram_location_ack vram_ack;
222 		struct synthvid_situation_update situ;
223 		struct synthvid_situation_update_ack situ_ack;
224 		struct synthvid_pointer_position ptr_pos;
225 		struct synthvid_pointer_shape ptr_shape;
226 		struct synthvid_feature_change feature_chg;
227 		struct synthvid_dirt dirt;
228 		struct synthvid_supported_resolution_req resolution_req;
229 		struct synthvid_supported_resolution_resp resolution_resp;
230 	};
231 } __packed;
232 
233 
234 /* FB driver definitions and structures */
235 #define HVFB_WIDTH 1152 /* default screen width */
236 #define HVFB_HEIGHT 864 /* default screen height */
237 #define HVFB_WIDTH_MIN 640
238 #define HVFB_HEIGHT_MIN 480
239 
240 #define RING_BUFSIZE (256 * 1024)
241 #define VSP_TIMEOUT (10 * HZ)
242 #define HVFB_UPDATE_DELAY (HZ / 20)
243 #define HVFB_ONDEMAND_THROTTLE (HZ / 20)
244 
245 struct hvfb_par {
246 	struct fb_info *info;
247 	struct resource *mem;
248 	bool fb_ready; /* fb device is ready */
249 	struct completion wait;
250 	u32 synthvid_version;
251 
252 	struct delayed_work dwork;
253 	bool update;
254 	bool update_saved; /* The value of 'update' before hibernation */
255 
256 	u32 pseudo_palette[16];
257 	u8 init_buf[MAX_VMBUS_PKT_SIZE];
258 	u8 recv_buf[MAX_VMBUS_PKT_SIZE];
259 
260 	/* If true, the VSC notifies the VSP on every framebuffer change */
261 	bool synchronous_fb;
262 
263 	/* If true, need to copy from deferred IO mem to framebuffer mem */
264 	bool need_docopy;
265 
266 	struct notifier_block hvfb_panic_nb;
267 
268 	/* Memory for deferred IO and frame buffer itself */
269 	unsigned char *dio_vp;
270 	unsigned char *mmio_vp;
271 	phys_addr_t mmio_pp;
272 
273 	/* Dirty rectangle, protected by delayed_refresh_lock */
274 	int x1, y1, x2, y2;
275 	bool delayed_refresh;
276 	spinlock_t delayed_refresh_lock;
277 };
278 
279 static uint screen_width = HVFB_WIDTH;
280 static uint screen_height = HVFB_HEIGHT;
281 static uint screen_depth;
282 static uint screen_fb_size;
283 static uint dio_fb_size; /* FB size for deferred IO */
284 
285 /* Send message to Hyper-V host */
286 static inline int synthvid_send(struct hv_device *hdev,
287 				struct synthvid_msg *msg)
288 {
289 	static atomic64_t request_id = ATOMIC64_INIT(0);
290 	int ret;
291 
292 	msg->pipe_hdr.type = PIPE_MSG_DATA;
293 	msg->pipe_hdr.size = msg->vid_hdr.size;
294 
295 	ret = vmbus_sendpacket(hdev->channel, msg,
296 			       msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
297 			       atomic64_inc_return(&request_id),
298 			       VM_PKT_DATA_INBAND, 0);
299 
300 	if (ret)
301 		pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);
302 
303 	return ret;
304 }
305 
306 
307 /* Send screen resolution info to host */
308 static int synthvid_send_situ(struct hv_device *hdev)
309 {
310 	struct fb_info *info = hv_get_drvdata(hdev);
311 	struct synthvid_msg msg;
312 
313 	if (!info)
314 		return -ENODEV;
315 
316 	memset(&msg, 0, sizeof(struct synthvid_msg));
317 
318 	msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
319 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
320 		sizeof(struct synthvid_situation_update);
321 	msg.situ.user_ctx = 0;
322 	msg.situ.video_output_count = 1;
323 	msg.situ.video_output[0].active = 1;
324 	msg.situ.video_output[0].vram_offset = 0;
325 	msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
326 	msg.situ.video_output[0].width_pixels = info->var.xres;
327 	msg.situ.video_output[0].height_pixels = info->var.yres;
328 	msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
329 
330 	synthvid_send(hdev, &msg);
331 
332 	return 0;
333 }
334 
335 /* Send mouse pointer info to host */
336 static int synthvid_send_ptr(struct hv_device *hdev)
337 {
338 	struct synthvid_msg msg;
339 
340 	memset(&msg, 0, sizeof(struct synthvid_msg));
341 	msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
342 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
343 		sizeof(struct synthvid_pointer_position);
344 	msg.ptr_pos.is_visible = 1;
345 	msg.ptr_pos.video_output = 0;
346 	msg.ptr_pos.image_x = 0;
347 	msg.ptr_pos.image_y = 0;
348 	synthvid_send(hdev, &msg);
349 
350 	memset(&msg, 0, sizeof(struct synthvid_msg));
351 	msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
352 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
353 		sizeof(struct synthvid_pointer_shape);
354 	msg.ptr_shape.part_idx = CURSOR_COMPLETE;
355 	msg.ptr_shape.is_argb = 1;
356 	msg.ptr_shape.width = 1;
357 	msg.ptr_shape.height = 1;
358 	msg.ptr_shape.hot_x = 0;
359 	msg.ptr_shape.hot_y = 0;
360 	msg.ptr_shape.data[0] = 0;
361 	msg.ptr_shape.data[1] = 1;
362 	msg.ptr_shape.data[2] = 1;
363 	msg.ptr_shape.data[3] = 1;
364 	synthvid_send(hdev, &msg);
365 
366 	return 0;
367 }
368 
369 /* Send updated screen area (dirty rectangle) location to host */
370 static int
371 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
372 {
373 	struct hv_device *hdev = device_to_hv_device(info->device);
374 	struct synthvid_msg msg;
375 
376 	memset(&msg, 0, sizeof(struct synthvid_msg));
377 	if (x2 == INT_MAX)
378 		x2 = info->var.xres;
379 	if (y2 == INT_MAX)
380 		y2 = info->var.yres;
381 
382 	msg.vid_hdr.type = SYNTHVID_DIRT;
383 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
384 		sizeof(struct synthvid_dirt);
385 	msg.dirt.video_output = 0;
386 	msg.dirt.dirt_count = 1;
387 	msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
388 	msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
389 	msg.dirt.rect[0].x2 =
390 		(x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
391 	msg.dirt.rect[0].y2 =
392 		(y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
393 
394 	synthvid_send(hdev, &msg);
395 
396 	return 0;
397 }
398 
399 static void hvfb_docopy(struct hvfb_par *par,
400 			unsigned long offset,
401 			unsigned long size)
402 {
403 	if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
404 	    size == 0 || offset >= dio_fb_size)
405 		return;
406 
407 	if (offset + size > dio_fb_size)
408 		size = dio_fb_size - offset;
409 
410 	memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
411 }
412 
413 /* Deferred IO callback */
414 static void synthvid_deferred_io(struct fb_info *p, struct list_head *pagereflist)
415 {
416 	struct hvfb_par *par = p->par;
417 	struct fb_deferred_io_pageref *pageref;
418 	unsigned long start, end;
419 	int y1, y2, miny, maxy;
420 
421 	miny = INT_MAX;
422 	maxy = 0;
423 
424 	/*
425 	 * Merge dirty pages. It is possible that last page cross
426 	 * over the end of frame buffer row yres. This is taken care of
427 	 * in synthvid_update function by clamping the y2
428 	 * value to yres.
429 	 */
430 	list_for_each_entry(pageref, pagereflist, list) {
431 		start = pageref->offset;
432 		end = start + PAGE_SIZE - 1;
433 		y1 = start / p->fix.line_length;
434 		y2 = end / p->fix.line_length;
435 		miny = min_t(int, miny, y1);
436 		maxy = max_t(int, maxy, y2);
437 
438 		/* Copy from dio space to mmio address */
439 		if (par->fb_ready && par->need_docopy)
440 			hvfb_docopy(par, start, PAGE_SIZE);
441 	}
442 
443 	if (par->fb_ready && par->update)
444 		synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
445 }
446 
447 static struct fb_deferred_io synthvid_defio = {
448 	.delay		= HZ / 20,
449 	.deferred_io	= synthvid_deferred_io,
450 };
451 
452 /*
453  * Actions on received messages from host:
454  * Complete the wait event.
455  * Or, reply with screen and cursor info.
456  */
457 static void synthvid_recv_sub(struct hv_device *hdev)
458 {
459 	struct fb_info *info = hv_get_drvdata(hdev);
460 	struct hvfb_par *par;
461 	struct synthvid_msg *msg;
462 
463 	if (!info)
464 		return;
465 
466 	par = info->par;
467 	msg = (struct synthvid_msg *)par->recv_buf;
468 
469 	/* Complete the wait event */
470 	if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
471 	    msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
472 	    msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
473 		memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
474 		complete(&par->wait);
475 		return;
476 	}
477 
478 	/* Reply with screen and cursor info */
479 	if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
480 		if (par->fb_ready) {
481 			synthvid_send_ptr(hdev);
482 			synthvid_send_situ(hdev);
483 		}
484 
485 		par->update = msg->feature_chg.is_dirt_needed;
486 		if (par->update)
487 			schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
488 	}
489 }
490 
491 /* Receive callback for messages from the host */
492 static void synthvid_receive(void *ctx)
493 {
494 	struct hv_device *hdev = ctx;
495 	struct fb_info *info = hv_get_drvdata(hdev);
496 	struct hvfb_par *par;
497 	struct synthvid_msg *recv_buf;
498 	u32 bytes_recvd;
499 	u64 req_id;
500 	int ret;
501 
502 	if (!info)
503 		return;
504 
505 	par = info->par;
506 	recv_buf = (struct synthvid_msg *)par->recv_buf;
507 
508 	do {
509 		ret = vmbus_recvpacket(hdev->channel, recv_buf,
510 				       MAX_VMBUS_PKT_SIZE,
511 				       &bytes_recvd, &req_id);
512 		if (bytes_recvd > 0 &&
513 		    recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
514 			synthvid_recv_sub(hdev);
515 	} while (bytes_recvd > 0 && ret == 0);
516 }
517 
518 /* Check if the ver1 version is equal or greater than ver2 */
519 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
520 {
521 	if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
522 	    (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
523 	     SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
524 		return true;
525 
526 	return false;
527 }
528 
529 /* Check synthetic video protocol version with the host */
530 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
531 {
532 	struct fb_info *info = hv_get_drvdata(hdev);
533 	struct hvfb_par *par = info->par;
534 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
535 	int ret = 0;
536 	unsigned long t;
537 
538 	memset(msg, 0, sizeof(struct synthvid_msg));
539 	msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
540 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
541 		sizeof(struct synthvid_version_req);
542 	msg->ver_req.version = ver;
543 	synthvid_send(hdev, msg);
544 
545 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
546 	if (!t) {
547 		pr_err("Time out on waiting version response\n");
548 		ret = -ETIMEDOUT;
549 		goto out;
550 	}
551 	if (!msg->ver_resp.is_accepted) {
552 		ret = -ENODEV;
553 		goto out;
554 	}
555 
556 	par->synthvid_version = ver;
557 	pr_info("Synthvid Version major %d, minor %d\n",
558 		SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
559 
560 out:
561 	return ret;
562 }
563 
564 /* Get current resolution from the host */
565 static int synthvid_get_supported_resolution(struct hv_device *hdev)
566 {
567 	struct fb_info *info = hv_get_drvdata(hdev);
568 	struct hvfb_par *par = info->par;
569 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
570 	int ret = 0;
571 	unsigned long t;
572 	u8 index;
573 
574 	memset(msg, 0, sizeof(struct synthvid_msg));
575 	msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
576 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
577 		sizeof(struct synthvid_supported_resolution_req);
578 
579 	msg->resolution_req.maximum_resolution_count =
580 		SYNTHVID_MAX_RESOLUTION_COUNT;
581 	synthvid_send(hdev, msg);
582 
583 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
584 	if (!t) {
585 		pr_err("Time out on waiting resolution response\n");
586 		ret = -ETIMEDOUT;
587 		goto out;
588 	}
589 
590 	if (msg->resolution_resp.resolution_count == 0) {
591 		pr_err("No supported resolutions\n");
592 		ret = -ENODEV;
593 		goto out;
594 	}
595 
596 	index = msg->resolution_resp.default_resolution_index;
597 	if (index >= msg->resolution_resp.resolution_count) {
598 		pr_err("Invalid resolution index: %d\n", index);
599 		ret = -ENODEV;
600 		goto out;
601 	}
602 
603 	screen_width =
604 		msg->resolution_resp.supported_resolution[index].width;
605 	screen_height =
606 		msg->resolution_resp.supported_resolution[index].height;
607 
608 out:
609 	return ret;
610 }
611 
612 /* Connect to VSP (Virtual Service Provider) on host */
613 static int synthvid_connect_vsp(struct hv_device *hdev)
614 {
615 	struct fb_info *info = hv_get_drvdata(hdev);
616 	struct hvfb_par *par = info->par;
617 	int ret;
618 
619 	ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
620 			 NULL, 0, synthvid_receive, hdev);
621 	if (ret) {
622 		pr_err("Unable to open vmbus channel\n");
623 		return ret;
624 	}
625 
626 	/* Negotiate the protocol version with host */
627 	switch (vmbus_proto_version) {
628 	case VERSION_WIN10:
629 	case VERSION_WIN10_V5:
630 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
631 		if (!ret)
632 			break;
633 		fallthrough;
634 	case VERSION_WIN8:
635 	case VERSION_WIN8_1:
636 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
637 		break;
638 	default:
639 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
640 		break;
641 	}
642 
643 	if (ret) {
644 		pr_err("Synthetic video device version not accepted\n");
645 		goto error;
646 	}
647 
648 	screen_depth = SYNTHVID_DEPTH_WIN8;
649 	if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
650 		ret = synthvid_get_supported_resolution(hdev);
651 		if (ret)
652 			pr_info("Failed to get supported resolution from host, use default\n");
653 	}
654 
655 	screen_fb_size = hdev->channel->offermsg.offer.
656 				mmio_megabytes * 1024 * 1024;
657 
658 	return 0;
659 
660 error:
661 	vmbus_close(hdev->channel);
662 	return ret;
663 }
664 
665 /* Send VRAM and Situation messages to the host */
666 static int synthvid_send_config(struct hv_device *hdev)
667 {
668 	struct fb_info *info = hv_get_drvdata(hdev);
669 	struct hvfb_par *par = info->par;
670 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
671 	int ret = 0;
672 	unsigned long t;
673 
674 	/* Send VRAM location */
675 	memset(msg, 0, sizeof(struct synthvid_msg));
676 	msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
677 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
678 		sizeof(struct synthvid_vram_location);
679 	msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
680 	msg->vram.is_vram_gpa_specified = 1;
681 	synthvid_send(hdev, msg);
682 
683 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
684 	if (!t) {
685 		pr_err("Time out on waiting vram location ack\n");
686 		ret = -ETIMEDOUT;
687 		goto out;
688 	}
689 	if (msg->vram_ack.user_ctx != par->mmio_pp) {
690 		pr_err("Unable to set VRAM location\n");
691 		ret = -ENODEV;
692 		goto out;
693 	}
694 
695 	/* Send pointer and situation update */
696 	synthvid_send_ptr(hdev);
697 	synthvid_send_situ(hdev);
698 
699 out:
700 	return ret;
701 }
702 
703 
704 /*
705  * Delayed work callback:
706  * It is scheduled to call whenever update request is received and it has
707  * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
708  */
709 static void hvfb_update_work(struct work_struct *w)
710 {
711 	struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
712 	struct fb_info *info = par->info;
713 	unsigned long flags;
714 	int x1, x2, y1, y2;
715 	int j;
716 
717 	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
718 	/* Reset the request flag */
719 	par->delayed_refresh = false;
720 
721 	/* Store the dirty rectangle to local variables */
722 	x1 = par->x1;
723 	x2 = par->x2;
724 	y1 = par->y1;
725 	y2 = par->y2;
726 
727 	/* Clear dirty rectangle */
728 	par->x1 = par->y1 = INT_MAX;
729 	par->x2 = par->y2 = 0;
730 
731 	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
732 
733 	if (x1 > info->var.xres || x2 > info->var.xres ||
734 	    y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
735 		return;
736 
737 	/* Copy the dirty rectangle to frame buffer memory */
738 	if (par->need_docopy)
739 		for (j = y1; j < y2; j++)
740 			hvfb_docopy(par,
741 				    j * info->fix.line_length +
742 				    (x1 * screen_depth / 8),
743 				    (x2 - x1) * screen_depth / 8);
744 
745 	/* Refresh */
746 	if (par->fb_ready && par->update)
747 		synthvid_update(info, x1, y1, x2, y2);
748 }
749 
750 /*
751  * Control the on-demand refresh frequency. It schedules a delayed
752  * screen update if it has not yet.
753  */
754 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
755 					   int x1, int y1, int w, int h)
756 {
757 	unsigned long flags;
758 	int x2 = x1 + w;
759 	int y2 = y1 + h;
760 
761 	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
762 
763 	/* Merge dirty rectangle */
764 	par->x1 = min_t(int, par->x1, x1);
765 	par->y1 = min_t(int, par->y1, y1);
766 	par->x2 = max_t(int, par->x2, x2);
767 	par->y2 = max_t(int, par->y2, y2);
768 
769 	/* Schedule a delayed screen update if not yet */
770 	if (par->delayed_refresh == false) {
771 		schedule_delayed_work(&par->dwork,
772 				      HVFB_ONDEMAND_THROTTLE);
773 		par->delayed_refresh = true;
774 	}
775 
776 	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
777 }
778 
779 static int hvfb_on_panic(struct notifier_block *nb,
780 			 unsigned long e, void *p)
781 {
782 	struct hv_device *hdev;
783 	struct hvfb_par *par;
784 	struct fb_info *info;
785 
786 	par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
787 	info = par->info;
788 	hdev = device_to_hv_device(info->device);
789 
790 	if (hv_ringbuffer_spinlock_busy(hdev->channel))
791 		return NOTIFY_DONE;
792 
793 	par->synchronous_fb = true;
794 	if (par->need_docopy)
795 		hvfb_docopy(par, 0, dio_fb_size);
796 	synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
797 
798 	return NOTIFY_DONE;
799 }
800 
801 /* Framebuffer operation handlers */
802 
803 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
804 {
805 	if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
806 	    var->xres > screen_width || var->yres >  screen_height ||
807 	    var->bits_per_pixel != screen_depth)
808 		return -EINVAL;
809 
810 	var->xres_virtual = var->xres;
811 	var->yres_virtual = var->yres;
812 
813 	return 0;
814 }
815 
816 static int hvfb_set_par(struct fb_info *info)
817 {
818 	struct hv_device *hdev = device_to_hv_device(info->device);
819 
820 	return synthvid_send_situ(hdev);
821 }
822 
823 
824 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
825 {
826 	return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
827 }
828 
829 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
830 			  unsigned blue, unsigned transp, struct fb_info *info)
831 {
832 	u32 *pal = info->pseudo_palette;
833 
834 	if (regno > 15)
835 		return -EINVAL;
836 
837 	pal[regno] = chan_to_field(red, &info->var.red)
838 		| chan_to_field(green, &info->var.green)
839 		| chan_to_field(blue, &info->var.blue)
840 		| chan_to_field(transp, &info->var.transp);
841 
842 	return 0;
843 }
844 
845 static int hvfb_blank(int blank, struct fb_info *info)
846 {
847 	return 1;	/* get fb_blank to set the colormap to all black */
848 }
849 
850 static void hvfb_ops_damage_range(struct fb_info *info, off_t off, size_t len)
851 {
852 	/* TODO: implement damage handling */
853 }
854 
855 static void hvfb_ops_damage_area(struct fb_info *info, u32 x, u32 y, u32 width, u32 height)
856 {
857 	struct hvfb_par *par = info->par;
858 
859 	if (par->synchronous_fb)
860 		synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
861 	else
862 		hvfb_ondemand_refresh_throttle(par, x, y, width, height);
863 }
864 
865 /*
866  * TODO: GEN1 codepaths allocate from system or DMA-able memory. Fix the
867  *       driver to use the _SYSMEM_ or _DMAMEM_ helpers in these cases.
868  */
869 FB_GEN_DEFAULT_DEFERRED_IOMEM_OPS(hvfb_ops,
870 				  hvfb_ops_damage_range,
871 				  hvfb_ops_damage_area)
872 
873 static const struct fb_ops hvfb_ops = {
874 	.owner = THIS_MODULE,
875 	FB_DEFAULT_DEFERRED_OPS(hvfb_ops),
876 	.fb_check_var = hvfb_check_var,
877 	.fb_set_par = hvfb_set_par,
878 	.fb_setcolreg = hvfb_setcolreg,
879 	.fb_blank = hvfb_blank,
880 };
881 
882 /* Get options from kernel paramenter "video=" */
883 static void hvfb_get_option(struct fb_info *info)
884 {
885 	struct hvfb_par *par = info->par;
886 	char *opt = NULL, *p;
887 	uint x = 0, y = 0;
888 
889 	if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
890 		return;
891 
892 	p = strsep(&opt, "x");
893 	if (!*p || kstrtouint(p, 0, &x) ||
894 	    !opt || !*opt || kstrtouint(opt, 0, &y)) {
895 		pr_err("Screen option is invalid: skipped\n");
896 		return;
897 	}
898 
899 	if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
900 	    (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
901 	    (x * y * screen_depth / 8 > screen_fb_size)) ||
902 	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
903 	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8)) {
904 		pr_err("Screen resolution option is out of range: skipped\n");
905 		return;
906 	}
907 
908 	screen_width = x;
909 	screen_height = y;
910 	return;
911 }
912 
913 /*
914  * Allocate enough contiguous physical memory.
915  * Return physical address if succeeded or -1 if failed.
916  */
917 static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
918 				   unsigned int request_size)
919 {
920 	struct page *page = NULL;
921 	dma_addr_t dma_handle;
922 	void *vmem;
923 	phys_addr_t paddr = 0;
924 	unsigned int order = get_order(request_size);
925 
926 	if (request_size == 0)
927 		return -1;
928 
929 	if (order <= MAX_PAGE_ORDER) {
930 		/* Call alloc_pages if the size is less than 2^MAX_PAGE_ORDER */
931 		page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
932 		if (!page)
933 			return -1;
934 
935 		paddr = (page_to_pfn(page) << PAGE_SHIFT);
936 	} else {
937 		/* Allocate from CMA */
938 		hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
939 
940 		vmem = dma_alloc_coherent(&hdev->device,
941 					  round_up(request_size, PAGE_SIZE),
942 					  &dma_handle,
943 					  GFP_KERNEL | __GFP_NOWARN);
944 
945 		if (!vmem)
946 			return -1;
947 
948 		paddr = virt_to_phys(vmem);
949 	}
950 
951 	return paddr;
952 }
953 
954 /* Release contiguous physical memory */
955 static void hvfb_release_phymem(struct hv_device *hdev,
956 				phys_addr_t paddr, unsigned int size)
957 {
958 	unsigned int order = get_order(size);
959 
960 	if (order <= MAX_PAGE_ORDER)
961 		__free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
962 	else
963 		dma_free_coherent(&hdev->device,
964 				  round_up(size, PAGE_SIZE),
965 				  phys_to_virt(paddr),
966 				  paddr);
967 }
968 
969 
970 /* Get framebuffer memory from Hyper-V video pci space */
971 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
972 {
973 	struct hvfb_par *par = info->par;
974 	struct pci_dev *pdev  = NULL;
975 	void __iomem *fb_virt;
976 	int gen2vm = efi_enabled(EFI_BOOT);
977 	resource_size_t base = 0;
978 	resource_size_t size = 0;
979 	phys_addr_t paddr;
980 	int ret;
981 
982 	if (!gen2vm) {
983 		pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
984 			PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
985 		if (!pdev) {
986 			pr_err("Unable to find PCI Hyper-V video\n");
987 			return -ENODEV;
988 		}
989 
990 		base = pci_resource_start(pdev, 0);
991 		size = pci_resource_len(pdev, 0);
992 
993 		/*
994 		 * For Gen 1 VM, we can directly use the contiguous memory
995 		 * from VM. If we succeed, deferred IO happens directly
996 		 * on this allocated framebuffer memory, avoiding extra
997 		 * memory copy.
998 		 */
999 		paddr = hvfb_get_phymem(hdev, screen_fb_size);
1000 		if (paddr != (phys_addr_t) -1) {
1001 			par->mmio_pp = paddr;
1002 			par->mmio_vp = par->dio_vp = __va(paddr);
1003 
1004 			info->fix.smem_start = paddr;
1005 			info->fix.smem_len = screen_fb_size;
1006 			info->screen_base = par->mmio_vp;
1007 			info->screen_size = screen_fb_size;
1008 
1009 			par->need_docopy = false;
1010 			goto getmem_done;
1011 		}
1012 		pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1013 	}
1014 
1015 	/*
1016 	 * Cannot use the contiguous physical memory.
1017 	 * Allocate mmio space for framebuffer.
1018 	 */
1019 	dio_fb_size =
1020 		screen_width * screen_height * screen_depth / 8;
1021 
1022 	ret = vmbus_allocate_mmio(&par->mem, hdev, 0, -1,
1023 				  screen_fb_size, 0x100000, true);
1024 	if (ret != 0) {
1025 		pr_err("Unable to allocate framebuffer memory\n");
1026 		goto err1;
1027 	}
1028 
1029 	/*
1030 	 * Map the VRAM cacheable for performance. This is also required for
1031 	 * VM Connect to display properly for ARM64 Linux VM, as the host also
1032 	 * maps the VRAM cacheable.
1033 	 */
1034 	fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1035 	if (!fb_virt)
1036 		goto err2;
1037 
1038 	/* Allocate memory for deferred IO */
1039 	par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1040 	if (par->dio_vp == NULL)
1041 		goto err3;
1042 
1043 	/* Physical address of FB device */
1044 	par->mmio_pp = par->mem->start;
1045 	/* Virtual address of FB device */
1046 	par->mmio_vp = (unsigned char *) fb_virt;
1047 
1048 	info->fix.smem_start = par->mem->start;
1049 	info->fix.smem_len = dio_fb_size;
1050 	info->screen_base = par->dio_vp;
1051 	info->screen_size = dio_fb_size;
1052 
1053 getmem_done:
1054 	if (base && size)
1055 		aperture_remove_conflicting_devices(base, size, KBUILD_MODNAME);
1056 	else
1057 		aperture_remove_all_conflicting_devices(KBUILD_MODNAME);
1058 
1059 	if (!gen2vm)
1060 		pci_dev_put(pdev);
1061 
1062 	return 0;
1063 
1064 err3:
1065 	iounmap(fb_virt);
1066 err2:
1067 	vmbus_free_mmio(par->mem->start, screen_fb_size);
1068 	par->mem = NULL;
1069 err1:
1070 	if (!gen2vm)
1071 		pci_dev_put(pdev);
1072 
1073 	return -ENOMEM;
1074 }
1075 
1076 /* Release the framebuffer */
1077 static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1078 {
1079 	struct hvfb_par *par = info->par;
1080 
1081 	if (par->need_docopy) {
1082 		vfree(par->dio_vp);
1083 		iounmap(info->screen_base);
1084 		vmbus_free_mmio(par->mem->start, screen_fb_size);
1085 	} else {
1086 		hvfb_release_phymem(hdev, info->fix.smem_start,
1087 				    screen_fb_size);
1088 	}
1089 
1090 	par->mem = NULL;
1091 }
1092 
1093 
1094 static int hvfb_probe(struct hv_device *hdev,
1095 		      const struct hv_vmbus_device_id *dev_id)
1096 {
1097 	struct fb_info *info;
1098 	struct hvfb_par *par;
1099 	int ret;
1100 
1101 	info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1102 	if (!info)
1103 		return -ENOMEM;
1104 
1105 	par = info->par;
1106 	par->info = info;
1107 	par->fb_ready = false;
1108 	par->need_docopy = true;
1109 	init_completion(&par->wait);
1110 	INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1111 
1112 	par->delayed_refresh = false;
1113 	spin_lock_init(&par->delayed_refresh_lock);
1114 	par->x1 = par->y1 = INT_MAX;
1115 	par->x2 = par->y2 = 0;
1116 
1117 	/* Connect to VSP */
1118 	hv_set_drvdata(hdev, info);
1119 	ret = synthvid_connect_vsp(hdev);
1120 	if (ret) {
1121 		pr_err("Unable to connect to VSP\n");
1122 		goto error1;
1123 	}
1124 
1125 	hvfb_get_option(info);
1126 	pr_info("Screen resolution: %dx%d, Color depth: %d, Frame buffer size: %d\n",
1127 		screen_width, screen_height, screen_depth, screen_fb_size);
1128 
1129 	ret = hvfb_getmem(hdev, info);
1130 	if (ret) {
1131 		pr_err("No memory for framebuffer\n");
1132 		goto error2;
1133 	}
1134 
1135 	/* Set up fb_info */
1136 	info->var.xres_virtual = info->var.xres = screen_width;
1137 	info->var.yres_virtual = info->var.yres = screen_height;
1138 	info->var.bits_per_pixel = screen_depth;
1139 
1140 	if (info->var.bits_per_pixel == 16) {
1141 		info->var.red = (struct fb_bitfield){11, 5, 0};
1142 		info->var.green = (struct fb_bitfield){5, 6, 0};
1143 		info->var.blue = (struct fb_bitfield){0, 5, 0};
1144 		info->var.transp = (struct fb_bitfield){0, 0, 0};
1145 	} else {
1146 		info->var.red = (struct fb_bitfield){16, 8, 0};
1147 		info->var.green = (struct fb_bitfield){8, 8, 0};
1148 		info->var.blue = (struct fb_bitfield){0, 8, 0};
1149 		info->var.transp = (struct fb_bitfield){24, 8, 0};
1150 	}
1151 
1152 	info->var.activate = FB_ACTIVATE_NOW;
1153 	info->var.height = -1;
1154 	info->var.width = -1;
1155 	info->var.vmode = FB_VMODE_NONINTERLACED;
1156 
1157 	strcpy(info->fix.id, KBUILD_MODNAME);
1158 	info->fix.type = FB_TYPE_PACKED_PIXELS;
1159 	info->fix.visual = FB_VISUAL_TRUECOLOR;
1160 	info->fix.line_length = screen_width * screen_depth / 8;
1161 	info->fix.accel = FB_ACCEL_NONE;
1162 
1163 	info->fbops = &hvfb_ops;
1164 	info->pseudo_palette = par->pseudo_palette;
1165 
1166 	/* Initialize deferred IO */
1167 	info->fbdefio = &synthvid_defio;
1168 	fb_deferred_io_init(info);
1169 
1170 	/* Send config to host */
1171 	ret = synthvid_send_config(hdev);
1172 	if (ret)
1173 		goto error;
1174 
1175 	ret = register_framebuffer(info);
1176 	if (ret) {
1177 		pr_err("Unable to register framebuffer\n");
1178 		goto error;
1179 	}
1180 
1181 	par->fb_ready = true;
1182 
1183 	par->synchronous_fb = false;
1184 
1185 	/*
1186 	 * We need to be sure this panic notifier runs _before_ the
1187 	 * vmbus disconnect, so order it by priority. It must execute
1188 	 * before the function hv_panic_vmbus_unload() [drivers/hv/vmbus_drv.c],
1189 	 * which is almost at the end of list, with priority = INT_MIN + 1.
1190 	 */
1191 	par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1192 	par->hvfb_panic_nb.priority = INT_MIN + 10;
1193 	atomic_notifier_chain_register(&panic_notifier_list,
1194 				       &par->hvfb_panic_nb);
1195 
1196 	return 0;
1197 
1198 error:
1199 	fb_deferred_io_cleanup(info);
1200 	hvfb_putmem(hdev, info);
1201 error2:
1202 	vmbus_close(hdev->channel);
1203 error1:
1204 	cancel_delayed_work_sync(&par->dwork);
1205 	hv_set_drvdata(hdev, NULL);
1206 	framebuffer_release(info);
1207 	return ret;
1208 }
1209 
1210 static void hvfb_remove(struct hv_device *hdev)
1211 {
1212 	struct fb_info *info = hv_get_drvdata(hdev);
1213 	struct hvfb_par *par = info->par;
1214 
1215 	atomic_notifier_chain_unregister(&panic_notifier_list,
1216 					 &par->hvfb_panic_nb);
1217 
1218 	par->update = false;
1219 	par->fb_ready = false;
1220 
1221 	fb_deferred_io_cleanup(info);
1222 
1223 	unregister_framebuffer(info);
1224 	cancel_delayed_work_sync(&par->dwork);
1225 
1226 	vmbus_close(hdev->channel);
1227 	hv_set_drvdata(hdev, NULL);
1228 
1229 	hvfb_putmem(hdev, info);
1230 	framebuffer_release(info);
1231 }
1232 
1233 static int hvfb_suspend(struct hv_device *hdev)
1234 {
1235 	struct fb_info *info = hv_get_drvdata(hdev);
1236 	struct hvfb_par *par = info->par;
1237 
1238 	console_lock();
1239 
1240 	/* 1 means do suspend */
1241 	fb_set_suspend(info, 1);
1242 
1243 	cancel_delayed_work_sync(&par->dwork);
1244 	cancel_delayed_work_sync(&info->deferred_work);
1245 
1246 	par->update_saved = par->update;
1247 	par->update = false;
1248 	par->fb_ready = false;
1249 
1250 	vmbus_close(hdev->channel);
1251 
1252 	console_unlock();
1253 
1254 	return 0;
1255 }
1256 
1257 static int hvfb_resume(struct hv_device *hdev)
1258 {
1259 	struct fb_info *info = hv_get_drvdata(hdev);
1260 	struct hvfb_par *par = info->par;
1261 	int ret;
1262 
1263 	console_lock();
1264 
1265 	ret = synthvid_connect_vsp(hdev);
1266 	if (ret != 0)
1267 		goto out;
1268 
1269 	ret = synthvid_send_config(hdev);
1270 	if (ret != 0) {
1271 		vmbus_close(hdev->channel);
1272 		goto out;
1273 	}
1274 
1275 	par->fb_ready = true;
1276 	par->update = par->update_saved;
1277 
1278 	schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1279 	schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1280 
1281 	/* 0 means do resume */
1282 	fb_set_suspend(info, 0);
1283 
1284 out:
1285 	console_unlock();
1286 
1287 	return ret;
1288 }
1289 
1290 
1291 static const struct pci_device_id pci_stub_id_table[] = {
1292 	{
1293 		.vendor      = PCI_VENDOR_ID_MICROSOFT,
1294 		.device      = PCI_DEVICE_ID_HYPERV_VIDEO,
1295 	},
1296 	{ /* end of list */ }
1297 };
1298 
1299 static const struct hv_vmbus_device_id id_table[] = {
1300 	/* Synthetic Video Device GUID */
1301 	{HV_SYNTHVID_GUID},
1302 	{}
1303 };
1304 
1305 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1306 MODULE_DEVICE_TABLE(vmbus, id_table);
1307 
1308 static struct hv_driver hvfb_drv = {
1309 	.name = KBUILD_MODNAME,
1310 	.id_table = id_table,
1311 	.probe = hvfb_probe,
1312 	.remove = hvfb_remove,
1313 	.suspend = hvfb_suspend,
1314 	.resume = hvfb_resume,
1315 	.driver = {
1316 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1317 	},
1318 };
1319 
1320 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1321 			       const struct pci_device_id *ent)
1322 {
1323 	return 0;
1324 }
1325 
1326 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1327 {
1328 }
1329 
1330 static struct pci_driver hvfb_pci_stub_driver = {
1331 	.name =		KBUILD_MODNAME,
1332 	.id_table =	pci_stub_id_table,
1333 	.probe =	hvfb_pci_stub_probe,
1334 	.remove =	hvfb_pci_stub_remove,
1335 	.driver = {
1336 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1337 	}
1338 };
1339 
1340 static int __init hvfb_drv_init(void)
1341 {
1342 	int ret;
1343 
1344 	if (fb_modesetting_disabled("hyper_fb"))
1345 		return -ENODEV;
1346 
1347 	ret = vmbus_driver_register(&hvfb_drv);
1348 	if (ret != 0)
1349 		return ret;
1350 
1351 	ret = pci_register_driver(&hvfb_pci_stub_driver);
1352 	if (ret != 0) {
1353 		vmbus_driver_unregister(&hvfb_drv);
1354 		return ret;
1355 	}
1356 
1357 	return 0;
1358 }
1359 
1360 static void __exit hvfb_drv_exit(void)
1361 {
1362 	pci_unregister_driver(&hvfb_pci_stub_driver);
1363 	vmbus_driver_unregister(&hvfb_drv);
1364 }
1365 
1366 module_init(hvfb_drv_init);
1367 module_exit(hvfb_drv_exit);
1368 
1369 MODULE_LICENSE("GPL");
1370 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");
1371