xref: /openbmc/linux/drivers/video/fbdev/hyperv_fb.c (revision 4a0a1436)
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/panic_notifier.h>
56 #include <linux/efi.h>
57 #include <linux/console.h>
58 
59 #include <linux/hyperv.h>
60 
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 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
67 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
68 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
69 
70 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
71 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
72 
73 #define SYNTHVID_DEPTH_WIN7 16
74 #define SYNTHVID_DEPTH_WIN8 32
75 
76 #define SYNTHVID_FB_SIZE_WIN7 (4 * 1024 * 1024)
77 #define SYNTHVID_WIDTH_MAX_WIN7 1600
78 #define SYNTHVID_HEIGHT_MAX_WIN7 1200
79 
80 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
81 
82 #define PCI_VENDOR_ID_MICROSOFT 0x1414
83 #define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
84 
85 
86 enum pipe_msg_type {
87 	PIPE_MSG_INVALID,
88 	PIPE_MSG_DATA,
89 	PIPE_MSG_MAX
90 };
91 
92 struct pipe_msg_hdr {
93 	u32 type;
94 	u32 size; /* size of message after this field */
95 } __packed;
96 
97 
98 enum synthvid_msg_type {
99 	SYNTHVID_ERROR			= 0,
100 	SYNTHVID_VERSION_REQUEST	= 1,
101 	SYNTHVID_VERSION_RESPONSE	= 2,
102 	SYNTHVID_VRAM_LOCATION		= 3,
103 	SYNTHVID_VRAM_LOCATION_ACK	= 4,
104 	SYNTHVID_SITUATION_UPDATE	= 5,
105 	SYNTHVID_SITUATION_UPDATE_ACK	= 6,
106 	SYNTHVID_POINTER_POSITION	= 7,
107 	SYNTHVID_POINTER_SHAPE		= 8,
108 	SYNTHVID_FEATURE_CHANGE		= 9,
109 	SYNTHVID_DIRT			= 10,
110 	SYNTHVID_RESOLUTION_REQUEST	= 13,
111 	SYNTHVID_RESOLUTION_RESPONSE	= 14,
112 
113 	SYNTHVID_MAX			= 15
114 };
115 
116 #define		SYNTHVID_EDID_BLOCK_SIZE	128
117 #define		SYNTHVID_MAX_RESOLUTION_COUNT	64
118 
119 struct hvd_screen_info {
120 	u16 width;
121 	u16 height;
122 } __packed;
123 
124 struct synthvid_msg_hdr {
125 	u32 type;
126 	u32 size;  /* size of this header + payload after this field*/
127 } __packed;
128 
129 struct synthvid_version_req {
130 	u32 version;
131 } __packed;
132 
133 struct synthvid_version_resp {
134 	u32 version;
135 	u8 is_accepted;
136 	u8 max_video_outputs;
137 } __packed;
138 
139 struct synthvid_supported_resolution_req {
140 	u8 maximum_resolution_count;
141 } __packed;
142 
143 struct synthvid_supported_resolution_resp {
144 	u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
145 	u8 resolution_count;
146 	u8 default_resolution_index;
147 	u8 is_standard;
148 	struct hvd_screen_info
149 		supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
150 } __packed;
151 
152 struct synthvid_vram_location {
153 	u64 user_ctx;
154 	u8 is_vram_gpa_specified;
155 	u64 vram_gpa;
156 } __packed;
157 
158 struct synthvid_vram_location_ack {
159 	u64 user_ctx;
160 } __packed;
161 
162 struct video_output_situation {
163 	u8 active;
164 	u32 vram_offset;
165 	u8 depth_bits;
166 	u32 width_pixels;
167 	u32 height_pixels;
168 	u32 pitch_bytes;
169 } __packed;
170 
171 struct synthvid_situation_update {
172 	u64 user_ctx;
173 	u8 video_output_count;
174 	struct video_output_situation video_output[1];
175 } __packed;
176 
177 struct synthvid_situation_update_ack {
178 	u64 user_ctx;
179 } __packed;
180 
181 struct synthvid_pointer_position {
182 	u8 is_visible;
183 	u8 video_output;
184 	s32 image_x;
185 	s32 image_y;
186 } __packed;
187 
188 
189 #define CURSOR_MAX_X 96
190 #define CURSOR_MAX_Y 96
191 #define CURSOR_ARGB_PIXEL_SIZE 4
192 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
193 #define CURSOR_COMPLETE (-1)
194 
195 struct synthvid_pointer_shape {
196 	u8 part_idx;
197 	u8 is_argb;
198 	u32 width; /* CURSOR_MAX_X at most */
199 	u32 height; /* CURSOR_MAX_Y at most */
200 	u32 hot_x; /* hotspot relative to upper-left of pointer image */
201 	u32 hot_y;
202 	u8 data[4];
203 } __packed;
204 
205 struct synthvid_feature_change {
206 	u8 is_dirt_needed;
207 	u8 is_ptr_pos_needed;
208 	u8 is_ptr_shape_needed;
209 	u8 is_situ_needed;
210 } __packed;
211 
212 struct rect {
213 	s32 x1, y1; /* top left corner */
214 	s32 x2, y2; /* bottom right corner, exclusive */
215 } __packed;
216 
217 struct synthvid_dirt {
218 	u8 video_output;
219 	u8 dirt_count;
220 	struct rect rect[1];
221 } __packed;
222 
223 struct synthvid_msg {
224 	struct pipe_msg_hdr pipe_hdr;
225 	struct synthvid_msg_hdr vid_hdr;
226 	union {
227 		struct synthvid_version_req ver_req;
228 		struct synthvid_version_resp ver_resp;
229 		struct synthvid_vram_location vram;
230 		struct synthvid_vram_location_ack vram_ack;
231 		struct synthvid_situation_update situ;
232 		struct synthvid_situation_update_ack situ_ack;
233 		struct synthvid_pointer_position ptr_pos;
234 		struct synthvid_pointer_shape ptr_shape;
235 		struct synthvid_feature_change feature_chg;
236 		struct synthvid_dirt dirt;
237 		struct synthvid_supported_resolution_req resolution_req;
238 		struct synthvid_supported_resolution_resp resolution_resp;
239 	};
240 } __packed;
241 
242 
243 /* FB driver definitions and structures */
244 #define HVFB_WIDTH 1152 /* default screen width */
245 #define HVFB_HEIGHT 864 /* default screen height */
246 #define HVFB_WIDTH_MIN 640
247 #define HVFB_HEIGHT_MIN 480
248 
249 #define RING_BUFSIZE (256 * 1024)
250 #define VSP_TIMEOUT (10 * HZ)
251 #define HVFB_UPDATE_DELAY (HZ / 20)
252 #define HVFB_ONDEMAND_THROTTLE (HZ / 20)
253 
254 struct hvfb_par {
255 	struct fb_info *info;
256 	struct resource *mem;
257 	bool fb_ready; /* fb device is ready */
258 	struct completion wait;
259 	u32 synthvid_version;
260 
261 	struct delayed_work dwork;
262 	bool update;
263 	bool update_saved; /* The value of 'update' before hibernation */
264 
265 	u32 pseudo_palette[16];
266 	u8 init_buf[MAX_VMBUS_PKT_SIZE];
267 	u8 recv_buf[MAX_VMBUS_PKT_SIZE];
268 
269 	/* If true, the VSC notifies the VSP on every framebuffer change */
270 	bool synchronous_fb;
271 
272 	/* If true, need to copy from deferred IO mem to framebuffer mem */
273 	bool need_docopy;
274 
275 	struct notifier_block hvfb_panic_nb;
276 
277 	/* Memory for deferred IO and frame buffer itself */
278 	unsigned char *dio_vp;
279 	unsigned char *mmio_vp;
280 	phys_addr_t mmio_pp;
281 
282 	/* Dirty rectangle, protected by delayed_refresh_lock */
283 	int x1, y1, x2, y2;
284 	bool delayed_refresh;
285 	spinlock_t delayed_refresh_lock;
286 };
287 
288 static uint screen_width = HVFB_WIDTH;
289 static uint screen_height = HVFB_HEIGHT;
290 static uint screen_depth;
291 static uint screen_fb_size;
292 static uint dio_fb_size; /* FB size for deferred IO */
293 
294 /* Send message to Hyper-V host */
295 static inline int synthvid_send(struct hv_device *hdev,
296 				struct synthvid_msg *msg)
297 {
298 	static atomic64_t request_id = ATOMIC64_INIT(0);
299 	int ret;
300 
301 	msg->pipe_hdr.type = PIPE_MSG_DATA;
302 	msg->pipe_hdr.size = msg->vid_hdr.size;
303 
304 	ret = vmbus_sendpacket(hdev->channel, msg,
305 			       msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
306 			       atomic64_inc_return(&request_id),
307 			       VM_PKT_DATA_INBAND, 0);
308 
309 	if (ret)
310 		pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);
311 
312 	return ret;
313 }
314 
315 
316 /* Send screen resolution info to host */
317 static int synthvid_send_situ(struct hv_device *hdev)
318 {
319 	struct fb_info *info = hv_get_drvdata(hdev);
320 	struct synthvid_msg msg;
321 
322 	if (!info)
323 		return -ENODEV;
324 
325 	memset(&msg, 0, sizeof(struct synthvid_msg));
326 
327 	msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
328 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
329 		sizeof(struct synthvid_situation_update);
330 	msg.situ.user_ctx = 0;
331 	msg.situ.video_output_count = 1;
332 	msg.situ.video_output[0].active = 1;
333 	msg.situ.video_output[0].vram_offset = 0;
334 	msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
335 	msg.situ.video_output[0].width_pixels = info->var.xres;
336 	msg.situ.video_output[0].height_pixels = info->var.yres;
337 	msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
338 
339 	synthvid_send(hdev, &msg);
340 
341 	return 0;
342 }
343 
344 /* Send mouse pointer info to host */
345 static int synthvid_send_ptr(struct hv_device *hdev)
346 {
347 	struct synthvid_msg msg;
348 
349 	memset(&msg, 0, sizeof(struct synthvid_msg));
350 	msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
351 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
352 		sizeof(struct synthvid_pointer_position);
353 	msg.ptr_pos.is_visible = 1;
354 	msg.ptr_pos.video_output = 0;
355 	msg.ptr_pos.image_x = 0;
356 	msg.ptr_pos.image_y = 0;
357 	synthvid_send(hdev, &msg);
358 
359 	memset(&msg, 0, sizeof(struct synthvid_msg));
360 	msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
361 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
362 		sizeof(struct synthvid_pointer_shape);
363 	msg.ptr_shape.part_idx = CURSOR_COMPLETE;
364 	msg.ptr_shape.is_argb = 1;
365 	msg.ptr_shape.width = 1;
366 	msg.ptr_shape.height = 1;
367 	msg.ptr_shape.hot_x = 0;
368 	msg.ptr_shape.hot_y = 0;
369 	msg.ptr_shape.data[0] = 0;
370 	msg.ptr_shape.data[1] = 1;
371 	msg.ptr_shape.data[2] = 1;
372 	msg.ptr_shape.data[3] = 1;
373 	synthvid_send(hdev, &msg);
374 
375 	return 0;
376 }
377 
378 /* Send updated screen area (dirty rectangle) location to host */
379 static int
380 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
381 {
382 	struct hv_device *hdev = device_to_hv_device(info->device);
383 	struct synthvid_msg msg;
384 
385 	memset(&msg, 0, sizeof(struct synthvid_msg));
386 	if (x2 == INT_MAX)
387 		x2 = info->var.xres;
388 	if (y2 == INT_MAX)
389 		y2 = info->var.yres;
390 
391 	msg.vid_hdr.type = SYNTHVID_DIRT;
392 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
393 		sizeof(struct synthvid_dirt);
394 	msg.dirt.video_output = 0;
395 	msg.dirt.dirt_count = 1;
396 	msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
397 	msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
398 	msg.dirt.rect[0].x2 =
399 		(x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
400 	msg.dirt.rect[0].y2 =
401 		(y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
402 
403 	synthvid_send(hdev, &msg);
404 
405 	return 0;
406 }
407 
408 static void hvfb_docopy(struct hvfb_par *par,
409 			unsigned long offset,
410 			unsigned long size)
411 {
412 	if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
413 	    size == 0 || offset >= dio_fb_size)
414 		return;
415 
416 	if (offset + size > dio_fb_size)
417 		size = dio_fb_size - offset;
418 
419 	memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
420 }
421 
422 /* Deferred IO callback */
423 static void synthvid_deferred_io(struct fb_info *p,
424 				 struct list_head *pagelist)
425 {
426 	struct hvfb_par *par = p->par;
427 	struct page *page;
428 	unsigned long start, end;
429 	int y1, y2, miny, maxy;
430 
431 	miny = INT_MAX;
432 	maxy = 0;
433 
434 	/*
435 	 * Merge dirty pages. It is possible that last page cross
436 	 * over the end of frame buffer row yres. This is taken care of
437 	 * in synthvid_update function by clamping the y2
438 	 * value to yres.
439 	 */
440 	list_for_each_entry(page, pagelist, lru) {
441 		start = page->index << PAGE_SHIFT;
442 		end = start + PAGE_SIZE - 1;
443 		y1 = start / p->fix.line_length;
444 		y2 = end / p->fix.line_length;
445 		miny = min_t(int, miny, y1);
446 		maxy = max_t(int, maxy, y2);
447 
448 		/* Copy from dio space to mmio address */
449 		if (par->fb_ready && par->need_docopy)
450 			hvfb_docopy(par, start, PAGE_SIZE);
451 	}
452 
453 	if (par->fb_ready && par->update)
454 		synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
455 }
456 
457 static struct fb_deferred_io synthvid_defio = {
458 	.delay		= HZ / 20,
459 	.deferred_io	= synthvid_deferred_io,
460 };
461 
462 /*
463  * Actions on received messages from host:
464  * Complete the wait event.
465  * Or, reply with screen and cursor info.
466  */
467 static void synthvid_recv_sub(struct hv_device *hdev)
468 {
469 	struct fb_info *info = hv_get_drvdata(hdev);
470 	struct hvfb_par *par;
471 	struct synthvid_msg *msg;
472 
473 	if (!info)
474 		return;
475 
476 	par = info->par;
477 	msg = (struct synthvid_msg *)par->recv_buf;
478 
479 	/* Complete the wait event */
480 	if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
481 	    msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
482 	    msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
483 		memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
484 		complete(&par->wait);
485 		return;
486 	}
487 
488 	/* Reply with screen and cursor info */
489 	if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
490 		if (par->fb_ready) {
491 			synthvid_send_ptr(hdev);
492 			synthvid_send_situ(hdev);
493 		}
494 
495 		par->update = msg->feature_chg.is_dirt_needed;
496 		if (par->update)
497 			schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
498 	}
499 }
500 
501 /* Receive callback for messages from the host */
502 static void synthvid_receive(void *ctx)
503 {
504 	struct hv_device *hdev = ctx;
505 	struct fb_info *info = hv_get_drvdata(hdev);
506 	struct hvfb_par *par;
507 	struct synthvid_msg *recv_buf;
508 	u32 bytes_recvd;
509 	u64 req_id;
510 	int ret;
511 
512 	if (!info)
513 		return;
514 
515 	par = info->par;
516 	recv_buf = (struct synthvid_msg *)par->recv_buf;
517 
518 	do {
519 		ret = vmbus_recvpacket(hdev->channel, recv_buf,
520 				       MAX_VMBUS_PKT_SIZE,
521 				       &bytes_recvd, &req_id);
522 		if (bytes_recvd > 0 &&
523 		    recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
524 			synthvid_recv_sub(hdev);
525 	} while (bytes_recvd > 0 && ret == 0);
526 }
527 
528 /* Check if the ver1 version is equal or greater than ver2 */
529 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
530 {
531 	if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
532 	    (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
533 	     SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
534 		return true;
535 
536 	return false;
537 }
538 
539 /* Check synthetic video protocol version with the host */
540 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
541 {
542 	struct fb_info *info = hv_get_drvdata(hdev);
543 	struct hvfb_par *par = info->par;
544 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
545 	int ret = 0;
546 	unsigned long t;
547 
548 	memset(msg, 0, sizeof(struct synthvid_msg));
549 	msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
550 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
551 		sizeof(struct synthvid_version_req);
552 	msg->ver_req.version = ver;
553 	synthvid_send(hdev, msg);
554 
555 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
556 	if (!t) {
557 		pr_err("Time out on waiting version response\n");
558 		ret = -ETIMEDOUT;
559 		goto out;
560 	}
561 	if (!msg->ver_resp.is_accepted) {
562 		ret = -ENODEV;
563 		goto out;
564 	}
565 
566 	par->synthvid_version = ver;
567 	pr_info("Synthvid Version major %d, minor %d\n",
568 		SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
569 
570 out:
571 	return ret;
572 }
573 
574 /* Get current resolution from the host */
575 static int synthvid_get_supported_resolution(struct hv_device *hdev)
576 {
577 	struct fb_info *info = hv_get_drvdata(hdev);
578 	struct hvfb_par *par = info->par;
579 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
580 	int ret = 0;
581 	unsigned long t;
582 	u8 index;
583 
584 	memset(msg, 0, sizeof(struct synthvid_msg));
585 	msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
586 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
587 		sizeof(struct synthvid_supported_resolution_req);
588 
589 	msg->resolution_req.maximum_resolution_count =
590 		SYNTHVID_MAX_RESOLUTION_COUNT;
591 	synthvid_send(hdev, msg);
592 
593 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
594 	if (!t) {
595 		pr_err("Time out on waiting resolution response\n");
596 		ret = -ETIMEDOUT;
597 		goto out;
598 	}
599 
600 	if (msg->resolution_resp.resolution_count == 0) {
601 		pr_err("No supported resolutions\n");
602 		ret = -ENODEV;
603 		goto out;
604 	}
605 
606 	index = msg->resolution_resp.default_resolution_index;
607 	if (index >= msg->resolution_resp.resolution_count) {
608 		pr_err("Invalid resolution index: %d\n", index);
609 		ret = -ENODEV;
610 		goto out;
611 	}
612 
613 	screen_width =
614 		msg->resolution_resp.supported_resolution[index].width;
615 	screen_height =
616 		msg->resolution_resp.supported_resolution[index].height;
617 
618 out:
619 	return ret;
620 }
621 
622 /* Connect to VSP (Virtual Service Provider) on host */
623 static int synthvid_connect_vsp(struct hv_device *hdev)
624 {
625 	struct fb_info *info = hv_get_drvdata(hdev);
626 	struct hvfb_par *par = info->par;
627 	int ret;
628 
629 	ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
630 			 NULL, 0, synthvid_receive, hdev);
631 	if (ret) {
632 		pr_err("Unable to open vmbus channel\n");
633 		return ret;
634 	}
635 
636 	/* Negotiate the protocol version with host */
637 	switch (vmbus_proto_version) {
638 	case VERSION_WIN10:
639 	case VERSION_WIN10_V5:
640 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
641 		if (!ret)
642 			break;
643 		fallthrough;
644 	case VERSION_WIN8:
645 	case VERSION_WIN8_1:
646 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
647 		if (!ret)
648 			break;
649 		fallthrough;
650 	case VERSION_WS2008:
651 	case VERSION_WIN7:
652 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
653 		break;
654 	default:
655 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
656 		break;
657 	}
658 
659 	if (ret) {
660 		pr_err("Synthetic video device version not accepted\n");
661 		goto error;
662 	}
663 
664 	if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
665 		screen_depth = SYNTHVID_DEPTH_WIN7;
666 	else
667 		screen_depth = SYNTHVID_DEPTH_WIN8;
668 
669 	if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
670 		ret = synthvid_get_supported_resolution(hdev);
671 		if (ret)
672 			pr_info("Failed to get supported resolution from host, use default\n");
673 	}
674 
675 	screen_fb_size = hdev->channel->offermsg.offer.
676 				mmio_megabytes * 1024 * 1024;
677 
678 	return 0;
679 
680 error:
681 	vmbus_close(hdev->channel);
682 	return ret;
683 }
684 
685 /* Send VRAM and Situation messages to the host */
686 static int synthvid_send_config(struct hv_device *hdev)
687 {
688 	struct fb_info *info = hv_get_drvdata(hdev);
689 	struct hvfb_par *par = info->par;
690 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
691 	int ret = 0;
692 	unsigned long t;
693 
694 	/* Send VRAM location */
695 	memset(msg, 0, sizeof(struct synthvid_msg));
696 	msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
697 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
698 		sizeof(struct synthvid_vram_location);
699 	msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
700 	msg->vram.is_vram_gpa_specified = 1;
701 	synthvid_send(hdev, msg);
702 
703 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
704 	if (!t) {
705 		pr_err("Time out on waiting vram location ack\n");
706 		ret = -ETIMEDOUT;
707 		goto out;
708 	}
709 	if (msg->vram_ack.user_ctx != par->mmio_pp) {
710 		pr_err("Unable to set VRAM location\n");
711 		ret = -ENODEV;
712 		goto out;
713 	}
714 
715 	/* Send pointer and situation update */
716 	synthvid_send_ptr(hdev);
717 	synthvid_send_situ(hdev);
718 
719 out:
720 	return ret;
721 }
722 
723 
724 /*
725  * Delayed work callback:
726  * It is scheduled to call whenever update request is received and it has
727  * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
728  */
729 static void hvfb_update_work(struct work_struct *w)
730 {
731 	struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
732 	struct fb_info *info = par->info;
733 	unsigned long flags;
734 	int x1, x2, y1, y2;
735 	int j;
736 
737 	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
738 	/* Reset the request flag */
739 	par->delayed_refresh = false;
740 
741 	/* Store the dirty rectangle to local variables */
742 	x1 = par->x1;
743 	x2 = par->x2;
744 	y1 = par->y1;
745 	y2 = par->y2;
746 
747 	/* Clear dirty rectangle */
748 	par->x1 = par->y1 = INT_MAX;
749 	par->x2 = par->y2 = 0;
750 
751 	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
752 
753 	if (x1 > info->var.xres || x2 > info->var.xres ||
754 	    y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
755 		return;
756 
757 	/* Copy the dirty rectangle to frame buffer memory */
758 	if (par->need_docopy)
759 		for (j = y1; j < y2; j++)
760 			hvfb_docopy(par,
761 				    j * info->fix.line_length +
762 				    (x1 * screen_depth / 8),
763 				    (x2 - x1) * screen_depth / 8);
764 
765 	/* Refresh */
766 	if (par->fb_ready && par->update)
767 		synthvid_update(info, x1, y1, x2, y2);
768 }
769 
770 /*
771  * Control the on-demand refresh frequency. It schedules a delayed
772  * screen update if it has not yet.
773  */
774 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
775 					   int x1, int y1, int w, int h)
776 {
777 	unsigned long flags;
778 	int x2 = x1 + w;
779 	int y2 = y1 + h;
780 
781 	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
782 
783 	/* Merge dirty rectangle */
784 	par->x1 = min_t(int, par->x1, x1);
785 	par->y1 = min_t(int, par->y1, y1);
786 	par->x2 = max_t(int, par->x2, x2);
787 	par->y2 = max_t(int, par->y2, y2);
788 
789 	/* Schedule a delayed screen update if not yet */
790 	if (par->delayed_refresh == false) {
791 		schedule_delayed_work(&par->dwork,
792 				      HVFB_ONDEMAND_THROTTLE);
793 		par->delayed_refresh = true;
794 	}
795 
796 	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
797 }
798 
799 static int hvfb_on_panic(struct notifier_block *nb,
800 			 unsigned long e, void *p)
801 {
802 	struct hvfb_par *par;
803 	struct fb_info *info;
804 
805 	par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
806 	par->synchronous_fb = true;
807 	info = par->info;
808 	if (par->need_docopy)
809 		hvfb_docopy(par, 0, dio_fb_size);
810 	synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
811 
812 	return NOTIFY_DONE;
813 }
814 
815 /* Framebuffer operation handlers */
816 
817 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
818 {
819 	if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
820 	    var->xres > screen_width || var->yres >  screen_height ||
821 	    var->bits_per_pixel != screen_depth)
822 		return -EINVAL;
823 
824 	var->xres_virtual = var->xres;
825 	var->yres_virtual = var->yres;
826 
827 	return 0;
828 }
829 
830 static int hvfb_set_par(struct fb_info *info)
831 {
832 	struct hv_device *hdev = device_to_hv_device(info->device);
833 
834 	return synthvid_send_situ(hdev);
835 }
836 
837 
838 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
839 {
840 	return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
841 }
842 
843 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
844 			  unsigned blue, unsigned transp, struct fb_info *info)
845 {
846 	u32 *pal = info->pseudo_palette;
847 
848 	if (regno > 15)
849 		return -EINVAL;
850 
851 	pal[regno] = chan_to_field(red, &info->var.red)
852 		| chan_to_field(green, &info->var.green)
853 		| chan_to_field(blue, &info->var.blue)
854 		| chan_to_field(transp, &info->var.transp);
855 
856 	return 0;
857 }
858 
859 static int hvfb_blank(int blank, struct fb_info *info)
860 {
861 	return 1;	/* get fb_blank to set the colormap to all black */
862 }
863 
864 static void hvfb_cfb_fillrect(struct fb_info *p,
865 			      const struct fb_fillrect *rect)
866 {
867 	struct hvfb_par *par = p->par;
868 
869 	cfb_fillrect(p, rect);
870 	if (par->synchronous_fb)
871 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
872 	else
873 		hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
874 					       rect->width, rect->height);
875 }
876 
877 static void hvfb_cfb_copyarea(struct fb_info *p,
878 			      const struct fb_copyarea *area)
879 {
880 	struct hvfb_par *par = p->par;
881 
882 	cfb_copyarea(p, area);
883 	if (par->synchronous_fb)
884 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
885 	else
886 		hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
887 					       area->width, area->height);
888 }
889 
890 static void hvfb_cfb_imageblit(struct fb_info *p,
891 			       const struct fb_image *image)
892 {
893 	struct hvfb_par *par = p->par;
894 
895 	cfb_imageblit(p, image);
896 	if (par->synchronous_fb)
897 		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
898 	else
899 		hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
900 					       image->width, image->height);
901 }
902 
903 static const struct fb_ops hvfb_ops = {
904 	.owner = THIS_MODULE,
905 	.fb_check_var = hvfb_check_var,
906 	.fb_set_par = hvfb_set_par,
907 	.fb_setcolreg = hvfb_setcolreg,
908 	.fb_fillrect = hvfb_cfb_fillrect,
909 	.fb_copyarea = hvfb_cfb_copyarea,
910 	.fb_imageblit = hvfb_cfb_imageblit,
911 	.fb_blank = hvfb_blank,
912 };
913 
914 
915 /* Get options from kernel paramenter "video=" */
916 static void hvfb_get_option(struct fb_info *info)
917 {
918 	struct hvfb_par *par = info->par;
919 	char *opt = NULL, *p;
920 	uint x = 0, y = 0;
921 
922 	if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
923 		return;
924 
925 	p = strsep(&opt, "x");
926 	if (!*p || kstrtouint(p, 0, &x) ||
927 	    !opt || !*opt || kstrtouint(opt, 0, &y)) {
928 		pr_err("Screen option is invalid: skipped\n");
929 		return;
930 	}
931 
932 	if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
933 	    (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
934 	    (x * y * screen_depth / 8 > screen_fb_size)) ||
935 	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
936 	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
937 	    (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
938 	     (x > SYNTHVID_WIDTH_MAX_WIN7 || y > SYNTHVID_HEIGHT_MAX_WIN7))) {
939 		pr_err("Screen resolution option is out of range: skipped\n");
940 		return;
941 	}
942 
943 	screen_width = x;
944 	screen_height = y;
945 	return;
946 }
947 
948 /*
949  * Allocate enough contiguous physical memory.
950  * Return physical address if succeeded or -1 if failed.
951  */
952 static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
953 				   unsigned int request_size)
954 {
955 	struct page *page = NULL;
956 	dma_addr_t dma_handle;
957 	void *vmem;
958 	phys_addr_t paddr = 0;
959 	unsigned int order = get_order(request_size);
960 
961 	if (request_size == 0)
962 		return -1;
963 
964 	if (order < MAX_ORDER) {
965 		/* Call alloc_pages if the size is less than 2^MAX_ORDER */
966 		page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
967 		if (!page)
968 			return -1;
969 
970 		paddr = (page_to_pfn(page) << PAGE_SHIFT);
971 	} else {
972 		/* Allocate from CMA */
973 		hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
974 
975 		vmem = dma_alloc_coherent(&hdev->device,
976 					  round_up(request_size, PAGE_SIZE),
977 					  &dma_handle,
978 					  GFP_KERNEL | __GFP_NOWARN);
979 
980 		if (!vmem)
981 			return -1;
982 
983 		paddr = virt_to_phys(vmem);
984 	}
985 
986 	return paddr;
987 }
988 
989 /* Release contiguous physical memory */
990 static void hvfb_release_phymem(struct hv_device *hdev,
991 				phys_addr_t paddr, unsigned int size)
992 {
993 	unsigned int order = get_order(size);
994 
995 	if (order < MAX_ORDER)
996 		__free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
997 	else
998 		dma_free_coherent(&hdev->device,
999 				  round_up(size, PAGE_SIZE),
1000 				  phys_to_virt(paddr),
1001 				  paddr);
1002 }
1003 
1004 
1005 /* Get framebuffer memory from Hyper-V video pci space */
1006 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
1007 {
1008 	struct hvfb_par *par = info->par;
1009 	struct pci_dev *pdev  = NULL;
1010 	void __iomem *fb_virt;
1011 	int gen2vm = efi_enabled(EFI_BOOT);
1012 	resource_size_t pot_start, pot_end;
1013 	phys_addr_t paddr;
1014 	int ret;
1015 
1016 	info->apertures = alloc_apertures(1);
1017 	if (!info->apertures)
1018 		return -ENOMEM;
1019 
1020 	if (!gen2vm) {
1021 		pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
1022 			PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
1023 		if (!pdev) {
1024 			pr_err("Unable to find PCI Hyper-V video\n");
1025 			return -ENODEV;
1026 		}
1027 
1028 		info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
1029 		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
1030 
1031 		/*
1032 		 * For Gen 1 VM, we can directly use the contiguous memory
1033 		 * from VM. If we succeed, deferred IO happens directly
1034 		 * on this allocated framebuffer memory, avoiding extra
1035 		 * memory copy.
1036 		 */
1037 		paddr = hvfb_get_phymem(hdev, screen_fb_size);
1038 		if (paddr != (phys_addr_t) -1) {
1039 			par->mmio_pp = paddr;
1040 			par->mmio_vp = par->dio_vp = __va(paddr);
1041 
1042 			info->fix.smem_start = paddr;
1043 			info->fix.smem_len = screen_fb_size;
1044 			info->screen_base = par->mmio_vp;
1045 			info->screen_size = screen_fb_size;
1046 
1047 			par->need_docopy = false;
1048 			goto getmem_done;
1049 		}
1050 		pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1051 	} else {
1052 		info->apertures->ranges[0].base = screen_info.lfb_base;
1053 		info->apertures->ranges[0].size = screen_info.lfb_size;
1054 	}
1055 
1056 	/*
1057 	 * Cannot use the contiguous physical memory.
1058 	 * Allocate mmio space for framebuffer.
1059 	 */
1060 	dio_fb_size =
1061 		screen_width * screen_height * screen_depth / 8;
1062 
1063 	if (gen2vm) {
1064 		pot_start = 0;
1065 		pot_end = -1;
1066 	} else {
1067 		if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
1068 		    pci_resource_len(pdev, 0) < screen_fb_size) {
1069 			pr_err("Resource not available or (0x%lx < 0x%lx)\n",
1070 			       (unsigned long) pci_resource_len(pdev, 0),
1071 			       (unsigned long) screen_fb_size);
1072 			goto err1;
1073 		}
1074 
1075 		pot_end = pci_resource_end(pdev, 0);
1076 		pot_start = pot_end - screen_fb_size + 1;
1077 	}
1078 
1079 	ret = vmbus_allocate_mmio(&par->mem, hdev, pot_start, pot_end,
1080 				  screen_fb_size, 0x100000, true);
1081 	if (ret != 0) {
1082 		pr_err("Unable to allocate framebuffer memory\n");
1083 		goto err1;
1084 	}
1085 
1086 	/*
1087 	 * Map the VRAM cacheable for performance. This is also required for
1088 	 * VM Connect to display properly for ARM64 Linux VM, as the host also
1089 	 * maps the VRAM cacheable.
1090 	 */
1091 	fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1092 	if (!fb_virt)
1093 		goto err2;
1094 
1095 	/* Allocate memory for deferred IO */
1096 	par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1097 	if (par->dio_vp == NULL)
1098 		goto err3;
1099 
1100 	/* Physical address of FB device */
1101 	par->mmio_pp = par->mem->start;
1102 	/* Virtual address of FB device */
1103 	par->mmio_vp = (unsigned char *) fb_virt;
1104 
1105 	info->fix.smem_start = par->mem->start;
1106 	info->fix.smem_len = dio_fb_size;
1107 	info->screen_base = par->dio_vp;
1108 	info->screen_size = dio_fb_size;
1109 
1110 getmem_done:
1111 	remove_conflicting_framebuffers(info->apertures,
1112 					KBUILD_MODNAME, false);
1113 
1114 	if (gen2vm) {
1115 		/* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
1116 		screen_info.lfb_size = 0;
1117 		screen_info.lfb_base = 0;
1118 		screen_info.orig_video_isVGA = 0;
1119 	} else {
1120 		pci_dev_put(pdev);
1121 	}
1122 
1123 	return 0;
1124 
1125 err3:
1126 	iounmap(fb_virt);
1127 err2:
1128 	vmbus_free_mmio(par->mem->start, screen_fb_size);
1129 	par->mem = NULL;
1130 err1:
1131 	if (!gen2vm)
1132 		pci_dev_put(pdev);
1133 
1134 	return -ENOMEM;
1135 }
1136 
1137 /* Release the framebuffer */
1138 static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1139 {
1140 	struct hvfb_par *par = info->par;
1141 
1142 	if (par->need_docopy) {
1143 		vfree(par->dio_vp);
1144 		iounmap(info->screen_base);
1145 		vmbus_free_mmio(par->mem->start, screen_fb_size);
1146 	} else {
1147 		hvfb_release_phymem(hdev, info->fix.smem_start,
1148 				    screen_fb_size);
1149 	}
1150 
1151 	par->mem = NULL;
1152 }
1153 
1154 
1155 static int hvfb_probe(struct hv_device *hdev,
1156 		      const struct hv_vmbus_device_id *dev_id)
1157 {
1158 	struct fb_info *info;
1159 	struct hvfb_par *par;
1160 	int ret;
1161 
1162 	info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1163 	if (!info)
1164 		return -ENOMEM;
1165 
1166 	par = info->par;
1167 	par->info = info;
1168 	par->fb_ready = false;
1169 	par->need_docopy = true;
1170 	init_completion(&par->wait);
1171 	INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1172 
1173 	par->delayed_refresh = false;
1174 	spin_lock_init(&par->delayed_refresh_lock);
1175 	par->x1 = par->y1 = INT_MAX;
1176 	par->x2 = par->y2 = 0;
1177 
1178 	/* Connect to VSP */
1179 	hv_set_drvdata(hdev, info);
1180 	ret = synthvid_connect_vsp(hdev);
1181 	if (ret) {
1182 		pr_err("Unable to connect to VSP\n");
1183 		goto error1;
1184 	}
1185 
1186 	hvfb_get_option(info);
1187 	pr_info("Screen resolution: %dx%d, Color depth: %d, Frame buffer size: %d\n",
1188 		screen_width, screen_height, screen_depth, screen_fb_size);
1189 
1190 	ret = hvfb_getmem(hdev, info);
1191 	if (ret) {
1192 		pr_err("No memory for framebuffer\n");
1193 		goto error2;
1194 	}
1195 
1196 	/* Set up fb_info */
1197 	info->flags = FBINFO_DEFAULT;
1198 
1199 	info->var.xres_virtual = info->var.xres = screen_width;
1200 	info->var.yres_virtual = info->var.yres = screen_height;
1201 	info->var.bits_per_pixel = screen_depth;
1202 
1203 	if (info->var.bits_per_pixel == 16) {
1204 		info->var.red = (struct fb_bitfield){11, 5, 0};
1205 		info->var.green = (struct fb_bitfield){5, 6, 0};
1206 		info->var.blue = (struct fb_bitfield){0, 5, 0};
1207 		info->var.transp = (struct fb_bitfield){0, 0, 0};
1208 	} else {
1209 		info->var.red = (struct fb_bitfield){16, 8, 0};
1210 		info->var.green = (struct fb_bitfield){8, 8, 0};
1211 		info->var.blue = (struct fb_bitfield){0, 8, 0};
1212 		info->var.transp = (struct fb_bitfield){24, 8, 0};
1213 	}
1214 
1215 	info->var.activate = FB_ACTIVATE_NOW;
1216 	info->var.height = -1;
1217 	info->var.width = -1;
1218 	info->var.vmode = FB_VMODE_NONINTERLACED;
1219 
1220 	strcpy(info->fix.id, KBUILD_MODNAME);
1221 	info->fix.type = FB_TYPE_PACKED_PIXELS;
1222 	info->fix.visual = FB_VISUAL_TRUECOLOR;
1223 	info->fix.line_length = screen_width * screen_depth / 8;
1224 	info->fix.accel = FB_ACCEL_NONE;
1225 
1226 	info->fbops = &hvfb_ops;
1227 	info->pseudo_palette = par->pseudo_palette;
1228 
1229 	/* Initialize deferred IO */
1230 	info->fbdefio = &synthvid_defio;
1231 	fb_deferred_io_init(info);
1232 
1233 	/* Send config to host */
1234 	ret = synthvid_send_config(hdev);
1235 	if (ret)
1236 		goto error;
1237 
1238 	ret = register_framebuffer(info);
1239 	if (ret) {
1240 		pr_err("Unable to register framebuffer\n");
1241 		goto error;
1242 	}
1243 
1244 	par->fb_ready = true;
1245 
1246 	par->synchronous_fb = false;
1247 	par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1248 	atomic_notifier_chain_register(&panic_notifier_list,
1249 				       &par->hvfb_panic_nb);
1250 
1251 	return 0;
1252 
1253 error:
1254 	fb_deferred_io_cleanup(info);
1255 	hvfb_putmem(hdev, info);
1256 error2:
1257 	vmbus_close(hdev->channel);
1258 error1:
1259 	cancel_delayed_work_sync(&par->dwork);
1260 	hv_set_drvdata(hdev, NULL);
1261 	framebuffer_release(info);
1262 	return ret;
1263 }
1264 
1265 
1266 static int hvfb_remove(struct hv_device *hdev)
1267 {
1268 	struct fb_info *info = hv_get_drvdata(hdev);
1269 	struct hvfb_par *par = info->par;
1270 
1271 	atomic_notifier_chain_unregister(&panic_notifier_list,
1272 					 &par->hvfb_panic_nb);
1273 
1274 	par->update = false;
1275 	par->fb_ready = false;
1276 
1277 	fb_deferred_io_cleanup(info);
1278 
1279 	unregister_framebuffer(info);
1280 	cancel_delayed_work_sync(&par->dwork);
1281 
1282 	vmbus_close(hdev->channel);
1283 	hv_set_drvdata(hdev, NULL);
1284 
1285 	hvfb_putmem(hdev, info);
1286 	framebuffer_release(info);
1287 
1288 	return 0;
1289 }
1290 
1291 static int hvfb_suspend(struct hv_device *hdev)
1292 {
1293 	struct fb_info *info = hv_get_drvdata(hdev);
1294 	struct hvfb_par *par = info->par;
1295 
1296 	console_lock();
1297 
1298 	/* 1 means do suspend */
1299 	fb_set_suspend(info, 1);
1300 
1301 	cancel_delayed_work_sync(&par->dwork);
1302 	cancel_delayed_work_sync(&info->deferred_work);
1303 
1304 	par->update_saved = par->update;
1305 	par->update = false;
1306 	par->fb_ready = false;
1307 
1308 	vmbus_close(hdev->channel);
1309 
1310 	console_unlock();
1311 
1312 	return 0;
1313 }
1314 
1315 static int hvfb_resume(struct hv_device *hdev)
1316 {
1317 	struct fb_info *info = hv_get_drvdata(hdev);
1318 	struct hvfb_par *par = info->par;
1319 	int ret;
1320 
1321 	console_lock();
1322 
1323 	ret = synthvid_connect_vsp(hdev);
1324 	if (ret != 0)
1325 		goto out;
1326 
1327 	ret = synthvid_send_config(hdev);
1328 	if (ret != 0) {
1329 		vmbus_close(hdev->channel);
1330 		goto out;
1331 	}
1332 
1333 	par->fb_ready = true;
1334 	par->update = par->update_saved;
1335 
1336 	schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1337 	schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1338 
1339 	/* 0 means do resume */
1340 	fb_set_suspend(info, 0);
1341 
1342 out:
1343 	console_unlock();
1344 
1345 	return ret;
1346 }
1347 
1348 
1349 static const struct pci_device_id pci_stub_id_table[] = {
1350 	{
1351 		.vendor      = PCI_VENDOR_ID_MICROSOFT,
1352 		.device      = PCI_DEVICE_ID_HYPERV_VIDEO,
1353 	},
1354 	{ /* end of list */ }
1355 };
1356 
1357 static const struct hv_vmbus_device_id id_table[] = {
1358 	/* Synthetic Video Device GUID */
1359 	{HV_SYNTHVID_GUID},
1360 	{}
1361 };
1362 
1363 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1364 MODULE_DEVICE_TABLE(vmbus, id_table);
1365 
1366 static struct hv_driver hvfb_drv = {
1367 	.name = KBUILD_MODNAME,
1368 	.id_table = id_table,
1369 	.probe = hvfb_probe,
1370 	.remove = hvfb_remove,
1371 	.suspend = hvfb_suspend,
1372 	.resume = hvfb_resume,
1373 	.driver = {
1374 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1375 	},
1376 };
1377 
1378 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1379 			       const struct pci_device_id *ent)
1380 {
1381 	return 0;
1382 }
1383 
1384 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1385 {
1386 }
1387 
1388 static struct pci_driver hvfb_pci_stub_driver = {
1389 	.name =		KBUILD_MODNAME,
1390 	.id_table =	pci_stub_id_table,
1391 	.probe =	hvfb_pci_stub_probe,
1392 	.remove =	hvfb_pci_stub_remove,
1393 	.driver = {
1394 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
1395 	}
1396 };
1397 
1398 static int __init hvfb_drv_init(void)
1399 {
1400 	int ret;
1401 
1402 	ret = vmbus_driver_register(&hvfb_drv);
1403 	if (ret != 0)
1404 		return ret;
1405 
1406 	ret = pci_register_driver(&hvfb_pci_stub_driver);
1407 	if (ret != 0) {
1408 		vmbus_driver_unregister(&hvfb_drv);
1409 		return ret;
1410 	}
1411 
1412 	return 0;
1413 }
1414 
1415 static void __exit hvfb_drv_exit(void)
1416 {
1417 	pci_unregister_driver(&hvfb_pci_stub_driver);
1418 	vmbus_driver_unregister(&hvfb_drv);
1419 }
1420 
1421 module_init(hvfb_drv_init);
1422 module_exit(hvfb_drv_exit);
1423 
1424 MODULE_LICENSE("GPL");
1425 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");
1426