xref: /openbmc/linux/drivers/video/fbdev/hyperv_fb.c (revision 8ffdff6a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2012, Microsoft Corporation.
4  *
5  * Author:
6  *   Haiyang Zhang <haiyangz@microsoft.com>
7  */
8 
9 /*
10  * Hyper-V Synthetic Video Frame Buffer Driver
11  *
12  * This is the driver for the Hyper-V Synthetic Video, which supports
13  * screen resolution up to Full HD 1920x1080 with 32 bit color on Windows
14  * Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2
15  * or earlier.
16  *
17  * It also solves the double mouse cursor issue of the emulated video mode.
18  *
19  * The default screen resolution is 1152x864, which may be changed by a
20  * kernel parameter:
21  *     video=hyperv_fb:<width>x<height>
22  *     For example: video=hyperv_fb:1280x1024
23  *
24  * Portrait orientation is also supported:
25  *     For example: video=hyperv_fb:864x1152
26  *
27  * When a Windows 10 RS5+ host is used, the virtual machine screen
28  * resolution is obtained from the host. The "video=hyperv_fb" option is
29  * not needed, but still can be used to overwrite what the host specifies.
30  * The VM resolution on the host could be set by executing the powershell
31  * "set-vmvideo" command. For example
32  *     set-vmvideo -vmname name -horizontalresolution:1920 \
33  * -verticalresolution:1200 -resolutiontype single
34  *
35  * Gen 1 VMs also support direct using VM's physical memory for framebuffer.
36  * It could improve the efficiency and performance for framebuffer and VM.
37  * This requires to allocate contiguous physical memory from Linux kernel's
38  * CMA memory allocator. To enable this, supply a kernel parameter to give
39  * enough memory space to CMA allocator for framebuffer. For example:
40  *    cma=130m
41  * This gives 130MB memory to CMA allocator that can be allocated to
42  * framebuffer. For reference, 8K resolution (7680x4320) takes about
43  * 127MB memory.
44  */
45 
46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47 
48 #include <linux/module.h>
49 #include <linux/kernel.h>
50 #include <linux/vmalloc.h>
51 #include <linux/init.h>
52 #include <linux/completion.h>
53 #include <linux/fb.h>
54 #include <linux/pci.h>
55 #include <linux/efi.h>
56 #include <linux/console.h>
57 
58 #include <linux/hyperv.h>
59 
60 
61 /* Hyper-V Synthetic Video Protocol definitions and structures */
62 #define MAX_VMBUS_PKT_SIZE 0x4000
63 
64 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
65 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
66 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
67 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
68 
69 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
70 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
71 
72 #define SYNTHVID_DEPTH_WIN7 16
73 #define SYNTHVID_DEPTH_WIN8 32
74 
75 #define SYNTHVID_FB_SIZE_WIN7 (4 * 1024 * 1024)
76 #define SYNTHVID_WIDTH_MAX_WIN7 1600
77 #define SYNTHVID_HEIGHT_MAX_WIN7 1200
78 
79 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
80 
81 #define PCI_VENDOR_ID_MICROSOFT 0x1414
82 #define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
83 
84 
85 enum pipe_msg_type {
86 	PIPE_MSG_INVALID,
87 	PIPE_MSG_DATA,
88 	PIPE_MSG_MAX
89 };
90 
91 struct pipe_msg_hdr {
92 	u32 type;
93 	u32 size; /* size of message after this field */
94 } __packed;
95 
96 
97 enum synthvid_msg_type {
98 	SYNTHVID_ERROR			= 0,
99 	SYNTHVID_VERSION_REQUEST	= 1,
100 	SYNTHVID_VERSION_RESPONSE	= 2,
101 	SYNTHVID_VRAM_LOCATION		= 3,
102 	SYNTHVID_VRAM_LOCATION_ACK	= 4,
103 	SYNTHVID_SITUATION_UPDATE	= 5,
104 	SYNTHVID_SITUATION_UPDATE_ACK	= 6,
105 	SYNTHVID_POINTER_POSITION	= 7,
106 	SYNTHVID_POINTER_SHAPE		= 8,
107 	SYNTHVID_FEATURE_CHANGE		= 9,
108 	SYNTHVID_DIRT			= 10,
109 	SYNTHVID_RESOLUTION_REQUEST	= 13,
110 	SYNTHVID_RESOLUTION_RESPONSE	= 14,
111 
112 	SYNTHVID_MAX			= 15
113 };
114 
115 #define		SYNTHVID_EDID_BLOCK_SIZE	128
116 #define		SYNTHVID_MAX_RESOLUTION_COUNT	64
117 
118 struct hvd_screen_info {
119 	u16 width;
120 	u16 height;
121 } __packed;
122 
123 struct synthvid_msg_hdr {
124 	u32 type;
125 	u32 size;  /* size of this header + payload after this field*/
126 } __packed;
127 
128 struct synthvid_version_req {
129 	u32 version;
130 } __packed;
131 
132 struct synthvid_version_resp {
133 	u32 version;
134 	u8 is_accepted;
135 	u8 max_video_outputs;
136 } __packed;
137 
138 struct synthvid_supported_resolution_req {
139 	u8 maximum_resolution_count;
140 } __packed;
141 
142 struct synthvid_supported_resolution_resp {
143 	u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
144 	u8 resolution_count;
145 	u8 default_resolution_index;
146 	u8 is_standard;
147 	struct hvd_screen_info
148 		supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
149 } __packed;
150 
151 struct synthvid_vram_location {
152 	u64 user_ctx;
153 	u8 is_vram_gpa_specified;
154 	u64 vram_gpa;
155 } __packed;
156 
157 struct synthvid_vram_location_ack {
158 	u64 user_ctx;
159 } __packed;
160 
161 struct video_output_situation {
162 	u8 active;
163 	u32 vram_offset;
164 	u8 depth_bits;
165 	u32 width_pixels;
166 	u32 height_pixels;
167 	u32 pitch_bytes;
168 } __packed;
169 
170 struct synthvid_situation_update {
171 	u64 user_ctx;
172 	u8 video_output_count;
173 	struct video_output_situation video_output[1];
174 } __packed;
175 
176 struct synthvid_situation_update_ack {
177 	u64 user_ctx;
178 } __packed;
179 
180 struct synthvid_pointer_position {
181 	u8 is_visible;
182 	u8 video_output;
183 	s32 image_x;
184 	s32 image_y;
185 } __packed;
186 
187 
188 #define CURSOR_MAX_X 96
189 #define CURSOR_MAX_Y 96
190 #define CURSOR_ARGB_PIXEL_SIZE 4
191 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
192 #define CURSOR_COMPLETE (-1)
193 
194 struct synthvid_pointer_shape {
195 	u8 part_idx;
196 	u8 is_argb;
197 	u32 width; /* CURSOR_MAX_X at most */
198 	u32 height; /* CURSOR_MAX_Y at most */
199 	u32 hot_x; /* hotspot relative to upper-left of pointer image */
200 	u32 hot_y;
201 	u8 data[4];
202 } __packed;
203 
204 struct synthvid_feature_change {
205 	u8 is_dirt_needed;
206 	u8 is_ptr_pos_needed;
207 	u8 is_ptr_shape_needed;
208 	u8 is_situ_needed;
209 } __packed;
210 
211 struct rect {
212 	s32 x1, y1; /* top left corner */
213 	s32 x2, y2; /* bottom right corner, exclusive */
214 } __packed;
215 
216 struct synthvid_dirt {
217 	u8 video_output;
218 	u8 dirt_count;
219 	struct rect rect[1];
220 } __packed;
221 
222 struct synthvid_msg {
223 	struct pipe_msg_hdr pipe_hdr;
224 	struct synthvid_msg_hdr vid_hdr;
225 	union {
226 		struct synthvid_version_req ver_req;
227 		struct synthvid_version_resp ver_resp;
228 		struct synthvid_vram_location vram;
229 		struct synthvid_vram_location_ack vram_ack;
230 		struct synthvid_situation_update situ;
231 		struct synthvid_situation_update_ack situ_ack;
232 		struct synthvid_pointer_position ptr_pos;
233 		struct synthvid_pointer_shape ptr_shape;
234 		struct synthvid_feature_change feature_chg;
235 		struct synthvid_dirt dirt;
236 		struct synthvid_supported_resolution_req resolution_req;
237 		struct synthvid_supported_resolution_resp resolution_resp;
238 	};
239 } __packed;
240 
241 
242 /* FB driver definitions and structures */
243 #define HVFB_WIDTH 1152 /* default screen width */
244 #define HVFB_HEIGHT 864 /* default screen height */
245 #define HVFB_WIDTH_MIN 640
246 #define HVFB_HEIGHT_MIN 480
247 
248 #define RING_BUFSIZE (256 * 1024)
249 #define VSP_TIMEOUT (10 * HZ)
250 #define HVFB_UPDATE_DELAY (HZ / 20)
251 #define HVFB_ONDEMAND_THROTTLE (HZ / 20)
252 
253 struct hvfb_par {
254 	struct fb_info *info;
255 	struct resource *mem;
256 	bool fb_ready; /* fb device is ready */
257 	struct completion wait;
258 	u32 synthvid_version;
259 
260 	struct delayed_work dwork;
261 	bool update;
262 	bool update_saved; /* The value of 'update' before hibernation */
263 
264 	u32 pseudo_palette[16];
265 	u8 init_buf[MAX_VMBUS_PKT_SIZE];
266 	u8 recv_buf[MAX_VMBUS_PKT_SIZE];
267 
268 	/* If true, the VSC notifies the VSP on every framebuffer change */
269 	bool synchronous_fb;
270 
271 	/* If true, need to copy from deferred IO mem to framebuffer mem */
272 	bool need_docopy;
273 
274 	struct notifier_block hvfb_panic_nb;
275 
276 	/* Memory for deferred IO and frame buffer itself */
277 	unsigned char *dio_vp;
278 	unsigned char *mmio_vp;
279 	phys_addr_t mmio_pp;
280 
281 	/* Dirty rectangle, protected by delayed_refresh_lock */
282 	int x1, y1, x2, y2;
283 	bool delayed_refresh;
284 	spinlock_t delayed_refresh_lock;
285 };
286 
287 static uint screen_width = HVFB_WIDTH;
288 static uint screen_height = HVFB_HEIGHT;
289 static uint screen_width_max = HVFB_WIDTH;
290 static uint screen_height_max = HVFB_HEIGHT;
291 static uint screen_depth;
292 static uint screen_fb_size;
293 static uint dio_fb_size; /* FB size for deferred IO */
294 
295 /* Send message to Hyper-V host */
296 static inline int synthvid_send(struct hv_device *hdev,
297 				struct synthvid_msg *msg)
298 {
299 	static atomic64_t request_id = ATOMIC64_INIT(0);
300 	int ret;
301 
302 	msg->pipe_hdr.type = PIPE_MSG_DATA;
303 	msg->pipe_hdr.size = msg->vid_hdr.size;
304 
305 	ret = vmbus_sendpacket(hdev->channel, msg,
306 			       msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
307 			       atomic64_inc_return(&request_id),
308 			       VM_PKT_DATA_INBAND, 0);
309 
310 	if (ret)
311 		pr_err("Unable to send packet via vmbus\n");
312 
313 	return ret;
314 }
315 
316 
317 /* Send screen resolution info to host */
318 static int synthvid_send_situ(struct hv_device *hdev)
319 {
320 	struct fb_info *info = hv_get_drvdata(hdev);
321 	struct synthvid_msg msg;
322 
323 	if (!info)
324 		return -ENODEV;
325 
326 	memset(&msg, 0, sizeof(struct synthvid_msg));
327 
328 	msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
329 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
330 		sizeof(struct synthvid_situation_update);
331 	msg.situ.user_ctx = 0;
332 	msg.situ.video_output_count = 1;
333 	msg.situ.video_output[0].active = 1;
334 	msg.situ.video_output[0].vram_offset = 0;
335 	msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
336 	msg.situ.video_output[0].width_pixels = info->var.xres;
337 	msg.situ.video_output[0].height_pixels = info->var.yres;
338 	msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
339 
340 	synthvid_send(hdev, &msg);
341 
342 	return 0;
343 }
344 
345 /* Send mouse pointer info to host */
346 static int synthvid_send_ptr(struct hv_device *hdev)
347 {
348 	struct synthvid_msg msg;
349 
350 	memset(&msg, 0, sizeof(struct synthvid_msg));
351 	msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
352 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
353 		sizeof(struct synthvid_pointer_position);
354 	msg.ptr_pos.is_visible = 1;
355 	msg.ptr_pos.video_output = 0;
356 	msg.ptr_pos.image_x = 0;
357 	msg.ptr_pos.image_y = 0;
358 	synthvid_send(hdev, &msg);
359 
360 	memset(&msg, 0, sizeof(struct synthvid_msg));
361 	msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
362 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
363 		sizeof(struct synthvid_pointer_shape);
364 	msg.ptr_shape.part_idx = CURSOR_COMPLETE;
365 	msg.ptr_shape.is_argb = 1;
366 	msg.ptr_shape.width = 1;
367 	msg.ptr_shape.height = 1;
368 	msg.ptr_shape.hot_x = 0;
369 	msg.ptr_shape.hot_y = 0;
370 	msg.ptr_shape.data[0] = 0;
371 	msg.ptr_shape.data[1] = 1;
372 	msg.ptr_shape.data[2] = 1;
373 	msg.ptr_shape.data[3] = 1;
374 	synthvid_send(hdev, &msg);
375 
376 	return 0;
377 }
378 
379 /* Send updated screen area (dirty rectangle) location to host */
380 static int
381 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
382 {
383 	struct hv_device *hdev = device_to_hv_device(info->device);
384 	struct synthvid_msg msg;
385 
386 	memset(&msg, 0, sizeof(struct synthvid_msg));
387 	if (x2 == INT_MAX)
388 		x2 = info->var.xres;
389 	if (y2 == INT_MAX)
390 		y2 = info->var.yres;
391 
392 	msg.vid_hdr.type = SYNTHVID_DIRT;
393 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
394 		sizeof(struct synthvid_dirt);
395 	msg.dirt.video_output = 0;
396 	msg.dirt.dirt_count = 1;
397 	msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
398 	msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
399 	msg.dirt.rect[0].x2 =
400 		(x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
401 	msg.dirt.rect[0].y2 =
402 		(y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
403 
404 	synthvid_send(hdev, &msg);
405 
406 	return 0;
407 }
408 
409 static void hvfb_docopy(struct hvfb_par *par,
410 			unsigned long offset,
411 			unsigned long size)
412 {
413 	if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
414 	    size == 0 || offset >= dio_fb_size)
415 		return;
416 
417 	if (offset + size > dio_fb_size)
418 		size = dio_fb_size - offset;
419 
420 	memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
421 }
422 
423 /* Deferred IO callback */
424 static void synthvid_deferred_io(struct fb_info *p,
425 				 struct list_head *pagelist)
426 {
427 	struct hvfb_par *par = p->par;
428 	struct page *page;
429 	unsigned long start, end;
430 	int y1, y2, miny, maxy;
431 
432 	miny = INT_MAX;
433 	maxy = 0;
434 
435 	/*
436 	 * Merge dirty pages. It is possible that last page cross
437 	 * over the end of frame buffer row yres. This is taken care of
438 	 * in synthvid_update function by clamping the y2
439 	 * value to yres.
440 	 */
441 	list_for_each_entry(page, pagelist, lru) {
442 		start = page->index << PAGE_SHIFT;
443 		end = start + PAGE_SIZE - 1;
444 		y1 = start / p->fix.line_length;
445 		y2 = end / p->fix.line_length;
446 		miny = min_t(int, miny, y1);
447 		maxy = max_t(int, maxy, y2);
448 
449 		/* Copy from dio space to mmio address */
450 		if (par->fb_ready && par->need_docopy)
451 			hvfb_docopy(par, start, PAGE_SIZE);
452 	}
453 
454 	if (par->fb_ready && par->update)
455 		synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
456 }
457 
458 static struct fb_deferred_io synthvid_defio = {
459 	.delay		= HZ / 20,
460 	.deferred_io	= synthvid_deferred_io,
461 };
462 
463 /*
464  * Actions on received messages from host:
465  * Complete the wait event.
466  * Or, reply with screen and cursor info.
467  */
468 static void synthvid_recv_sub(struct hv_device *hdev)
469 {
470 	struct fb_info *info = hv_get_drvdata(hdev);
471 	struct hvfb_par *par;
472 	struct synthvid_msg *msg;
473 
474 	if (!info)
475 		return;
476 
477 	par = info->par;
478 	msg = (struct synthvid_msg *)par->recv_buf;
479 
480 	/* Complete the wait event */
481 	if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
482 	    msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
483 	    msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
484 		memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
485 		complete(&par->wait);
486 		return;
487 	}
488 
489 	/* Reply with screen and cursor info */
490 	if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
491 		if (par->fb_ready) {
492 			synthvid_send_ptr(hdev);
493 			synthvid_send_situ(hdev);
494 		}
495 
496 		par->update = msg->feature_chg.is_dirt_needed;
497 		if (par->update)
498 			schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
499 	}
500 }
501 
502 /* Receive callback for messages from the host */
503 static void synthvid_receive(void *ctx)
504 {
505 	struct hv_device *hdev = ctx;
506 	struct fb_info *info = hv_get_drvdata(hdev);
507 	struct hvfb_par *par;
508 	struct synthvid_msg *recv_buf;
509 	u32 bytes_recvd;
510 	u64 req_id;
511 	int ret;
512 
513 	if (!info)
514 		return;
515 
516 	par = info->par;
517 	recv_buf = (struct synthvid_msg *)par->recv_buf;
518 
519 	do {
520 		ret = vmbus_recvpacket(hdev->channel, recv_buf,
521 				       MAX_VMBUS_PKT_SIZE,
522 				       &bytes_recvd, &req_id);
523 		if (bytes_recvd > 0 &&
524 		    recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
525 			synthvid_recv_sub(hdev);
526 	} while (bytes_recvd > 0 && ret == 0);
527 }
528 
529 /* Check if the ver1 version is equal or greater than ver2 */
530 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
531 {
532 	if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
533 	    (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
534 	     SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
535 		return true;
536 
537 	return false;
538 }
539 
540 /* Check synthetic video protocol version with the host */
541 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
542 {
543 	struct fb_info *info = hv_get_drvdata(hdev);
544 	struct hvfb_par *par = info->par;
545 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
546 	int ret = 0;
547 	unsigned long t;
548 
549 	memset(msg, 0, sizeof(struct synthvid_msg));
550 	msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
551 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
552 		sizeof(struct synthvid_version_req);
553 	msg->ver_req.version = ver;
554 	synthvid_send(hdev, msg);
555 
556 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
557 	if (!t) {
558 		pr_err("Time out on waiting version response\n");
559 		ret = -ETIMEDOUT;
560 		goto out;
561 	}
562 	if (!msg->ver_resp.is_accepted) {
563 		ret = -ENODEV;
564 		goto out;
565 	}
566 
567 	par->synthvid_version = ver;
568 	pr_info("Synthvid Version major %d, minor %d\n",
569 		SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
570 
571 out:
572 	return ret;
573 }
574 
575 /* Get current resolution from the host */
576 static int synthvid_get_supported_resolution(struct hv_device *hdev)
577 {
578 	struct fb_info *info = hv_get_drvdata(hdev);
579 	struct hvfb_par *par = info->par;
580 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
581 	int ret = 0;
582 	unsigned long t;
583 	u8 index;
584 	int i;
585 
586 	memset(msg, 0, sizeof(struct synthvid_msg));
587 	msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
588 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
589 		sizeof(struct synthvid_supported_resolution_req);
590 
591 	msg->resolution_req.maximum_resolution_count =
592 		SYNTHVID_MAX_RESOLUTION_COUNT;
593 	synthvid_send(hdev, msg);
594 
595 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
596 	if (!t) {
597 		pr_err("Time out on waiting resolution response\n");
598 		ret = -ETIMEDOUT;
599 		goto out;
600 	}
601 
602 	if (msg->resolution_resp.resolution_count == 0) {
603 		pr_err("No supported resolutions\n");
604 		ret = -ENODEV;
605 		goto out;
606 	}
607 
608 	index = msg->resolution_resp.default_resolution_index;
609 	if (index >= msg->resolution_resp.resolution_count) {
610 		pr_err("Invalid resolution index: %d\n", index);
611 		ret = -ENODEV;
612 		goto out;
613 	}
614 
615 	for (i = 0; i < msg->resolution_resp.resolution_count; i++) {
616 		screen_width_max = max_t(unsigned int, screen_width_max,
617 		    msg->resolution_resp.supported_resolution[i].width);
618 		screen_height_max = max_t(unsigned int, screen_height_max,
619 		    msg->resolution_resp.supported_resolution[i].height);
620 	}
621 
622 	screen_width =
623 		msg->resolution_resp.supported_resolution[index].width;
624 	screen_height =
625 		msg->resolution_resp.supported_resolution[index].height;
626 
627 out:
628 	return ret;
629 }
630 
631 /* Connect to VSP (Virtual Service Provider) on host */
632 static int synthvid_connect_vsp(struct hv_device *hdev)
633 {
634 	struct fb_info *info = hv_get_drvdata(hdev);
635 	struct hvfb_par *par = info->par;
636 	int ret;
637 
638 	ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
639 			 NULL, 0, synthvid_receive, hdev);
640 	if (ret) {
641 		pr_err("Unable to open vmbus channel\n");
642 		return ret;
643 	}
644 
645 	/* Negotiate the protocol version with host */
646 	switch (vmbus_proto_version) {
647 	case VERSION_WIN10:
648 	case VERSION_WIN10_V5:
649 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
650 		if (!ret)
651 			break;
652 		fallthrough;
653 	case VERSION_WIN8:
654 	case VERSION_WIN8_1:
655 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
656 		if (!ret)
657 			break;
658 		fallthrough;
659 	case VERSION_WS2008:
660 	case VERSION_WIN7:
661 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
662 		break;
663 	default:
664 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
665 		break;
666 	}
667 
668 	if (ret) {
669 		pr_err("Synthetic video device version not accepted\n");
670 		goto error;
671 	}
672 
673 	if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
674 		screen_depth = SYNTHVID_DEPTH_WIN7;
675 	else
676 		screen_depth = SYNTHVID_DEPTH_WIN8;
677 
678 	if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
679 		ret = synthvid_get_supported_resolution(hdev);
680 		if (ret)
681 			pr_info("Failed to get supported resolution from host, use default\n");
682 	}
683 
684 	screen_fb_size = hdev->channel->offermsg.offer.
685 				mmio_megabytes * 1024 * 1024;
686 
687 	return 0;
688 
689 error:
690 	vmbus_close(hdev->channel);
691 	return ret;
692 }
693 
694 /* Send VRAM and Situation messages to the host */
695 static int synthvid_send_config(struct hv_device *hdev)
696 {
697 	struct fb_info *info = hv_get_drvdata(hdev);
698 	struct hvfb_par *par = info->par;
699 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
700 	int ret = 0;
701 	unsigned long t;
702 
703 	/* Send VRAM location */
704 	memset(msg, 0, sizeof(struct synthvid_msg));
705 	msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
706 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
707 		sizeof(struct synthvid_vram_location);
708 	msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
709 	msg->vram.is_vram_gpa_specified = 1;
710 	synthvid_send(hdev, msg);
711 
712 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
713 	if (!t) {
714 		pr_err("Time out on waiting vram location ack\n");
715 		ret = -ETIMEDOUT;
716 		goto out;
717 	}
718 	if (msg->vram_ack.user_ctx != par->mmio_pp) {
719 		pr_err("Unable to set VRAM location\n");
720 		ret = -ENODEV;
721 		goto out;
722 	}
723 
724 	/* Send pointer and situation update */
725 	synthvid_send_ptr(hdev);
726 	synthvid_send_situ(hdev);
727 
728 out:
729 	return ret;
730 }
731 
732 
733 /*
734  * Delayed work callback:
735  * It is scheduled to call whenever update request is received and it has
736  * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
737  */
738 static void hvfb_update_work(struct work_struct *w)
739 {
740 	struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
741 	struct fb_info *info = par->info;
742 	unsigned long flags;
743 	int x1, x2, y1, y2;
744 	int j;
745 
746 	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
747 	/* Reset the request flag */
748 	par->delayed_refresh = false;
749 
750 	/* Store the dirty rectangle to local variables */
751 	x1 = par->x1;
752 	x2 = par->x2;
753 	y1 = par->y1;
754 	y2 = par->y2;
755 
756 	/* Clear dirty rectangle */
757 	par->x1 = par->y1 = INT_MAX;
758 	par->x2 = par->y2 = 0;
759 
760 	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
761 
762 	if (x1 > info->var.xres || x2 > info->var.xres ||
763 	    y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
764 		return;
765 
766 	/* Copy the dirty rectangle to frame buffer memory */
767 	if (par->need_docopy)
768 		for (j = y1; j < y2; j++)
769 			hvfb_docopy(par,
770 				    j * info->fix.line_length +
771 				    (x1 * screen_depth / 8),
772 				    (x2 - x1) * screen_depth / 8);
773 
774 	/* Refresh */
775 	if (par->fb_ready && par->update)
776 		synthvid_update(info, x1, y1, x2, y2);
777 }
778 
779 /*
780  * Control the on-demand refresh frequency. It schedules a delayed
781  * screen update if it has not yet.
782  */
783 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
784 					   int x1, int y1, int w, int h)
785 {
786 	unsigned long flags;
787 	int x2 = x1 + w;
788 	int y2 = y1 + h;
789 
790 	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
791 
792 	/* Merge dirty rectangle */
793 	par->x1 = min_t(int, par->x1, x1);
794 	par->y1 = min_t(int, par->y1, y1);
795 	par->x2 = max_t(int, par->x2, x2);
796 	par->y2 = max_t(int, par->y2, y2);
797 
798 	/* Schedule a delayed screen update if not yet */
799 	if (par->delayed_refresh == false) {
800 		schedule_delayed_work(&par->dwork,
801 				      HVFB_ONDEMAND_THROTTLE);
802 		par->delayed_refresh = true;
803 	}
804 
805 	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
806 }
807 
808 static int hvfb_on_panic(struct notifier_block *nb,
809 			 unsigned long e, void *p)
810 {
811 	struct hvfb_par *par;
812 	struct fb_info *info;
813 
814 	par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
815 	par->synchronous_fb = true;
816 	info = par->info;
817 	if (par->need_docopy)
818 		hvfb_docopy(par, 0, dio_fb_size);
819 	synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
820 
821 	return NOTIFY_DONE;
822 }
823 
824 /* Framebuffer operation handlers */
825 
826 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
827 {
828 	if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
829 	    var->xres > screen_width || var->yres >  screen_height ||
830 	    var->bits_per_pixel != screen_depth)
831 		return -EINVAL;
832 
833 	var->xres_virtual = var->xres;
834 	var->yres_virtual = var->yres;
835 
836 	return 0;
837 }
838 
839 static int hvfb_set_par(struct fb_info *info)
840 {
841 	struct hv_device *hdev = device_to_hv_device(info->device);
842 
843 	return synthvid_send_situ(hdev);
844 }
845 
846 
847 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
848 {
849 	return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
850 }
851 
852 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
853 			  unsigned blue, unsigned transp, struct fb_info *info)
854 {
855 	u32 *pal = info->pseudo_palette;
856 
857 	if (regno > 15)
858 		return -EINVAL;
859 
860 	pal[regno] = chan_to_field(red, &info->var.red)
861 		| chan_to_field(green, &info->var.green)
862 		| chan_to_field(blue, &info->var.blue)
863 		| chan_to_field(transp, &info->var.transp);
864 
865 	return 0;
866 }
867 
868 static int hvfb_blank(int blank, struct fb_info *info)
869 {
870 	return 1;	/* get fb_blank to set the colormap to all black */
871 }
872 
873 static void hvfb_cfb_fillrect(struct fb_info *p,
874 			      const struct fb_fillrect *rect)
875 {
876 	struct hvfb_par *par = p->par;
877 
878 	cfb_fillrect(p, rect);
879 	if (par->synchronous_fb)
880 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
881 	else
882 		hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
883 					       rect->width, rect->height);
884 }
885 
886 static void hvfb_cfb_copyarea(struct fb_info *p,
887 			      const struct fb_copyarea *area)
888 {
889 	struct hvfb_par *par = p->par;
890 
891 	cfb_copyarea(p, area);
892 	if (par->synchronous_fb)
893 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
894 	else
895 		hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
896 					       area->width, area->height);
897 }
898 
899 static void hvfb_cfb_imageblit(struct fb_info *p,
900 			       const struct fb_image *image)
901 {
902 	struct hvfb_par *par = p->par;
903 
904 	cfb_imageblit(p, image);
905 	if (par->synchronous_fb)
906 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
907 	else
908 		hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
909 					       image->width, image->height);
910 }
911 
912 static const struct fb_ops hvfb_ops = {
913 	.owner = THIS_MODULE,
914 	.fb_check_var = hvfb_check_var,
915 	.fb_set_par = hvfb_set_par,
916 	.fb_setcolreg = hvfb_setcolreg,
917 	.fb_fillrect = hvfb_cfb_fillrect,
918 	.fb_copyarea = hvfb_cfb_copyarea,
919 	.fb_imageblit = hvfb_cfb_imageblit,
920 	.fb_blank = hvfb_blank,
921 };
922 
923 
924 /* Get options from kernel paramenter "video=" */
925 static void hvfb_get_option(struct fb_info *info)
926 {
927 	struct hvfb_par *par = info->par;
928 	char *opt = NULL, *p;
929 	uint x = 0, y = 0;
930 
931 	if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
932 		return;
933 
934 	p = strsep(&opt, "x");
935 	if (!*p || kstrtouint(p, 0, &x) ||
936 	    !opt || !*opt || kstrtouint(opt, 0, &y)) {
937 		pr_err("Screen option is invalid: skipped\n");
938 		return;
939 	}
940 
941 	if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
942 	    (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
943 	    (x > screen_width_max || y > screen_height_max)) ||
944 	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
945 	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
946 	    (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
947 	     (x > SYNTHVID_WIDTH_MAX_WIN7 || y > SYNTHVID_HEIGHT_MAX_WIN7))) {
948 		pr_err("Screen resolution option is out of range: skipped\n");
949 		return;
950 	}
951 
952 	screen_width = x;
953 	screen_height = y;
954 	return;
955 }
956 
957 /*
958  * Allocate enough contiguous physical memory.
959  * Return physical address if succeeded or -1 if failed.
960  */
961 static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
962 				   unsigned int request_size)
963 {
964 	struct page *page = NULL;
965 	dma_addr_t dma_handle;
966 	void *vmem;
967 	phys_addr_t paddr = 0;
968 	unsigned int order = get_order(request_size);
969 
970 	if (request_size == 0)
971 		return -1;
972 
973 	if (order < MAX_ORDER) {
974 		/* Call alloc_pages if the size is less than 2^MAX_ORDER */
975 		page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
976 		if (!page)
977 			return -1;
978 
979 		paddr = (page_to_pfn(page) << PAGE_SHIFT);
980 	} else {
981 		/* Allocate from CMA */
982 		hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
983 
984 		vmem = dma_alloc_coherent(&hdev->device,
985 					  round_up(request_size, PAGE_SIZE),
986 					  &dma_handle,
987 					  GFP_KERNEL | __GFP_NOWARN);
988 
989 		if (!vmem)
990 			return -1;
991 
992 		paddr = virt_to_phys(vmem);
993 	}
994 
995 	return paddr;
996 }
997 
998 /* Release contiguous physical memory */
999 static void hvfb_release_phymem(struct hv_device *hdev,
1000 				phys_addr_t paddr, unsigned int size)
1001 {
1002 	unsigned int order = get_order(size);
1003 
1004 	if (order < MAX_ORDER)
1005 		__free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
1006 	else
1007 		dma_free_coherent(&hdev->device,
1008 				  round_up(size, PAGE_SIZE),
1009 				  phys_to_virt(paddr),
1010 				  paddr);
1011 }
1012 
1013 
1014 /* Get framebuffer memory from Hyper-V video pci space */
1015 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
1016 {
1017 	struct hvfb_par *par = info->par;
1018 	struct pci_dev *pdev  = NULL;
1019 	void __iomem *fb_virt;
1020 	int gen2vm = efi_enabled(EFI_BOOT);
1021 	resource_size_t pot_start, pot_end;
1022 	phys_addr_t paddr;
1023 	int ret;
1024 
1025 	info->apertures = alloc_apertures(1);
1026 	if (!info->apertures)
1027 		return -ENOMEM;
1028 
1029 	if (!gen2vm) {
1030 		pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
1031 			PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
1032 		if (!pdev) {
1033 			pr_err("Unable to find PCI Hyper-V video\n");
1034 			return -ENODEV;
1035 		}
1036 
1037 		info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
1038 		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
1039 
1040 		/*
1041 		 * For Gen 1 VM, we can directly use the contiguous memory
1042 		 * from VM. If we succeed, deferred IO happens directly
1043 		 * on this allocated framebuffer memory, avoiding extra
1044 		 * memory copy.
1045 		 */
1046 		paddr = hvfb_get_phymem(hdev, screen_fb_size);
1047 		if (paddr != (phys_addr_t) -1) {
1048 			par->mmio_pp = paddr;
1049 			par->mmio_vp = par->dio_vp = __va(paddr);
1050 
1051 			info->fix.smem_start = paddr;
1052 			info->fix.smem_len = screen_fb_size;
1053 			info->screen_base = par->mmio_vp;
1054 			info->screen_size = screen_fb_size;
1055 
1056 			par->need_docopy = false;
1057 			goto getmem_done;
1058 		}
1059 		pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1060 	} else {
1061 		info->apertures->ranges[0].base = screen_info.lfb_base;
1062 		info->apertures->ranges[0].size = screen_info.lfb_size;
1063 	}
1064 
1065 	/*
1066 	 * Cannot use the contiguous physical memory.
1067 	 * Allocate mmio space for framebuffer.
1068 	 */
1069 	dio_fb_size =
1070 		screen_width * screen_height * screen_depth / 8;
1071 
1072 	if (gen2vm) {
1073 		pot_start = 0;
1074 		pot_end = -1;
1075 	} else {
1076 		if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
1077 		    pci_resource_len(pdev, 0) < screen_fb_size) {
1078 			pr_err("Resource not available or (0x%lx < 0x%lx)\n",
1079 			       (unsigned long) pci_resource_len(pdev, 0),
1080 			       (unsigned long) screen_fb_size);
1081 			goto err1;
1082 		}
1083 
1084 		pot_end = pci_resource_end(pdev, 0);
1085 		pot_start = pot_end - screen_fb_size + 1;
1086 	}
1087 
1088 	ret = vmbus_allocate_mmio(&par->mem, hdev, pot_start, pot_end,
1089 				  screen_fb_size, 0x100000, true);
1090 	if (ret != 0) {
1091 		pr_err("Unable to allocate framebuffer memory\n");
1092 		goto err1;
1093 	}
1094 
1095 	/*
1096 	 * Map the VRAM cacheable for performance. This is also required for
1097 	 * VM Connect to display properly for ARM64 Linux VM, as the host also
1098 	 * maps the VRAM cacheable.
1099 	 */
1100 	fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1101 	if (!fb_virt)
1102 		goto err2;
1103 
1104 	/* Allocate memory for deferred IO */
1105 	par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1106 	if (par->dio_vp == NULL)
1107 		goto err3;
1108 
1109 	/* Physical address of FB device */
1110 	par->mmio_pp = par->mem->start;
1111 	/* Virtual address of FB device */
1112 	par->mmio_vp = (unsigned char *) fb_virt;
1113 
1114 	info->fix.smem_start = par->mem->start;
1115 	info->fix.smem_len = dio_fb_size;
1116 	info->screen_base = par->dio_vp;
1117 	info->screen_size = dio_fb_size;
1118 
1119 getmem_done:
1120 	remove_conflicting_framebuffers(info->apertures,
1121 					KBUILD_MODNAME, false);
1122 
1123 	if (gen2vm) {
1124 		/* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
1125 		screen_info.lfb_size = 0;
1126 		screen_info.lfb_base = 0;
1127 		screen_info.orig_video_isVGA = 0;
1128 	} else {
1129 		pci_dev_put(pdev);
1130 	}
1131 
1132 	return 0;
1133 
1134 err3:
1135 	iounmap(fb_virt);
1136 err2:
1137 	vmbus_free_mmio(par->mem->start, screen_fb_size);
1138 	par->mem = NULL;
1139 err1:
1140 	if (!gen2vm)
1141 		pci_dev_put(pdev);
1142 
1143 	return -ENOMEM;
1144 }
1145 
1146 /* Release the framebuffer */
1147 static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1148 {
1149 	struct hvfb_par *par = info->par;
1150 
1151 	if (par->need_docopy) {
1152 		vfree(par->dio_vp);
1153 		iounmap(info->screen_base);
1154 		vmbus_free_mmio(par->mem->start, screen_fb_size);
1155 	} else {
1156 		hvfb_release_phymem(hdev, info->fix.smem_start,
1157 				    screen_fb_size);
1158 	}
1159 
1160 	par->mem = NULL;
1161 }
1162 
1163 
1164 static int hvfb_probe(struct hv_device *hdev,
1165 		      const struct hv_vmbus_device_id *dev_id)
1166 {
1167 	struct fb_info *info;
1168 	struct hvfb_par *par;
1169 	int ret;
1170 
1171 	info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1172 	if (!info)
1173 		return -ENOMEM;
1174 
1175 	par = info->par;
1176 	par->info = info;
1177 	par->fb_ready = false;
1178 	par->need_docopy = true;
1179 	init_completion(&par->wait);
1180 	INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1181 
1182 	par->delayed_refresh = false;
1183 	spin_lock_init(&par->delayed_refresh_lock);
1184 	par->x1 = par->y1 = INT_MAX;
1185 	par->x2 = par->y2 = 0;
1186 
1187 	/* Connect to VSP */
1188 	hv_set_drvdata(hdev, info);
1189 	ret = synthvid_connect_vsp(hdev);
1190 	if (ret) {
1191 		pr_err("Unable to connect to VSP\n");
1192 		goto error1;
1193 	}
1194 
1195 	hvfb_get_option(info);
1196 	pr_info("Screen resolution: %dx%d, Color depth: %d\n",
1197 		screen_width, screen_height, screen_depth);
1198 
1199 	ret = hvfb_getmem(hdev, info);
1200 	if (ret) {
1201 		pr_err("No memory for framebuffer\n");
1202 		goto error2;
1203 	}
1204 
1205 	/* Set up fb_info */
1206 	info->flags = FBINFO_DEFAULT;
1207 
1208 	info->var.xres_virtual = info->var.xres = screen_width;
1209 	info->var.yres_virtual = info->var.yres = screen_height;
1210 	info->var.bits_per_pixel = screen_depth;
1211 
1212 	if (info->var.bits_per_pixel == 16) {
1213 		info->var.red = (struct fb_bitfield){11, 5, 0};
1214 		info->var.green = (struct fb_bitfield){5, 6, 0};
1215 		info->var.blue = (struct fb_bitfield){0, 5, 0};
1216 		info->var.transp = (struct fb_bitfield){0, 0, 0};
1217 	} else {
1218 		info->var.red = (struct fb_bitfield){16, 8, 0};
1219 		info->var.green = (struct fb_bitfield){8, 8, 0};
1220 		info->var.blue = (struct fb_bitfield){0, 8, 0};
1221 		info->var.transp = (struct fb_bitfield){24, 8, 0};
1222 	}
1223 
1224 	info->var.activate = FB_ACTIVATE_NOW;
1225 	info->var.height = -1;
1226 	info->var.width = -1;
1227 	info->var.vmode = FB_VMODE_NONINTERLACED;
1228 
1229 	strcpy(info->fix.id, KBUILD_MODNAME);
1230 	info->fix.type = FB_TYPE_PACKED_PIXELS;
1231 	info->fix.visual = FB_VISUAL_TRUECOLOR;
1232 	info->fix.line_length = screen_width * screen_depth / 8;
1233 	info->fix.accel = FB_ACCEL_NONE;
1234 
1235 	info->fbops = &hvfb_ops;
1236 	info->pseudo_palette = par->pseudo_palette;
1237 
1238 	/* Initialize deferred IO */
1239 	info->fbdefio = &synthvid_defio;
1240 	fb_deferred_io_init(info);
1241 
1242 	/* Send config to host */
1243 	ret = synthvid_send_config(hdev);
1244 	if (ret)
1245 		goto error;
1246 
1247 	ret = register_framebuffer(info);
1248 	if (ret) {
1249 		pr_err("Unable to register framebuffer\n");
1250 		goto error;
1251 	}
1252 
1253 	par->fb_ready = true;
1254 
1255 	par->synchronous_fb = false;
1256 	par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1257 	atomic_notifier_chain_register(&panic_notifier_list,
1258 				       &par->hvfb_panic_nb);
1259 
1260 	return 0;
1261 
1262 error:
1263 	fb_deferred_io_cleanup(info);
1264 	hvfb_putmem(hdev, info);
1265 error2:
1266 	vmbus_close(hdev->channel);
1267 error1:
1268 	cancel_delayed_work_sync(&par->dwork);
1269 	hv_set_drvdata(hdev, NULL);
1270 	framebuffer_release(info);
1271 	return ret;
1272 }
1273 
1274 
1275 static int hvfb_remove(struct hv_device *hdev)
1276 {
1277 	struct fb_info *info = hv_get_drvdata(hdev);
1278 	struct hvfb_par *par = info->par;
1279 
1280 	atomic_notifier_chain_unregister(&panic_notifier_list,
1281 					 &par->hvfb_panic_nb);
1282 
1283 	par->update = false;
1284 	par->fb_ready = false;
1285 
1286 	fb_deferred_io_cleanup(info);
1287 
1288 	unregister_framebuffer(info);
1289 	cancel_delayed_work_sync(&par->dwork);
1290 
1291 	vmbus_close(hdev->channel);
1292 	hv_set_drvdata(hdev, NULL);
1293 
1294 	hvfb_putmem(hdev, info);
1295 	framebuffer_release(info);
1296 
1297 	return 0;
1298 }
1299 
1300 static int hvfb_suspend(struct hv_device *hdev)
1301 {
1302 	struct fb_info *info = hv_get_drvdata(hdev);
1303 	struct hvfb_par *par = info->par;
1304 
1305 	console_lock();
1306 
1307 	/* 1 means do suspend */
1308 	fb_set_suspend(info, 1);
1309 
1310 	cancel_delayed_work_sync(&par->dwork);
1311 	cancel_delayed_work_sync(&info->deferred_work);
1312 
1313 	par->update_saved = par->update;
1314 	par->update = false;
1315 	par->fb_ready = false;
1316 
1317 	vmbus_close(hdev->channel);
1318 
1319 	console_unlock();
1320 
1321 	return 0;
1322 }
1323 
1324 static int hvfb_resume(struct hv_device *hdev)
1325 {
1326 	struct fb_info *info = hv_get_drvdata(hdev);
1327 	struct hvfb_par *par = info->par;
1328 	int ret;
1329 
1330 	console_lock();
1331 
1332 	ret = synthvid_connect_vsp(hdev);
1333 	if (ret != 0)
1334 		goto out;
1335 
1336 	ret = synthvid_send_config(hdev);
1337 	if (ret != 0) {
1338 		vmbus_close(hdev->channel);
1339 		goto out;
1340 	}
1341 
1342 	par->fb_ready = true;
1343 	par->update = par->update_saved;
1344 
1345 	schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1346 	schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1347 
1348 	/* 0 means do resume */
1349 	fb_set_suspend(info, 0);
1350 
1351 out:
1352 	console_unlock();
1353 
1354 	return ret;
1355 }
1356 
1357 
1358 static const struct pci_device_id pci_stub_id_table[] = {
1359 	{
1360 		.vendor      = PCI_VENDOR_ID_MICROSOFT,
1361 		.device      = PCI_DEVICE_ID_HYPERV_VIDEO,
1362 	},
1363 	{ /* end of list */ }
1364 };
1365 
1366 static const struct hv_vmbus_device_id id_table[] = {
1367 	/* Synthetic Video Device GUID */
1368 	{HV_SYNTHVID_GUID},
1369 	{}
1370 };
1371 
1372 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1373 MODULE_DEVICE_TABLE(vmbus, id_table);
1374 
1375 static struct hv_driver hvfb_drv = {
1376 	.name = KBUILD_MODNAME,
1377 	.id_table = id_table,
1378 	.probe = hvfb_probe,
1379 	.remove = hvfb_remove,
1380 	.suspend = hvfb_suspend,
1381 	.resume = hvfb_resume,
1382 	.driver = {
1383 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1384 	},
1385 };
1386 
1387 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1388 			       const struct pci_device_id *ent)
1389 {
1390 	return 0;
1391 }
1392 
1393 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1394 {
1395 }
1396 
1397 static struct pci_driver hvfb_pci_stub_driver = {
1398 	.name =		KBUILD_MODNAME,
1399 	.id_table =	pci_stub_id_table,
1400 	.probe =	hvfb_pci_stub_probe,
1401 	.remove =	hvfb_pci_stub_remove,
1402 	.driver = {
1403 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1404 	}
1405 };
1406 
1407 static int __init hvfb_drv_init(void)
1408 {
1409 	int ret;
1410 
1411 	ret = vmbus_driver_register(&hvfb_drv);
1412 	if (ret != 0)
1413 		return ret;
1414 
1415 	ret = pci_register_driver(&hvfb_pci_stub_driver);
1416 	if (ret != 0) {
1417 		vmbus_driver_unregister(&hvfb_drv);
1418 		return ret;
1419 	}
1420 
1421 	return 0;
1422 }
1423 
1424 static void __exit hvfb_drv_exit(void)
1425 {
1426 	pci_unregister_driver(&hvfb_pci_stub_driver);
1427 	vmbus_driver_unregister(&hvfb_drv);
1428 }
1429 
1430 module_init(hvfb_drv_init);
1431 module_exit(hvfb_drv_exit);
1432 
1433 MODULE_LICENSE("GPL");
1434 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");
1435