xref: /openbmc/linux/drivers/video/fbdev/hyperv_fb.c (revision d2574c33)
1 /*
2  * Copyright (c) 2012, Microsoft Corporation.
3  *
4  * Author:
5  *   Haiyang Zhang <haiyangz@microsoft.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published
9  * by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
14  * NON INFRINGEMENT.  See the GNU General Public License for more
15  * details.
16  */
17 
18 /*
19  * Hyper-V Synthetic Video Frame Buffer Driver
20  *
21  * This is the driver for the Hyper-V Synthetic Video, which supports
22  * screen resolution up to Full HD 1920x1080 with 32 bit color on Windows
23  * Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2
24  * or earlier.
25  *
26  * It also solves the double mouse cursor issue of the emulated video mode.
27  *
28  * The default screen resolution is 1152x864, which may be changed by a
29  * kernel parameter:
30  *     video=hyperv_fb:<width>x<height>
31  *     For example: video=hyperv_fb:1280x1024
32  *
33  * Portrait orientation is also supported:
34  *     For example: video=hyperv_fb:864x1152
35  */
36 
37 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
38 
39 #include <linux/module.h>
40 #include <linux/kernel.h>
41 #include <linux/init.h>
42 #include <linux/completion.h>
43 #include <linux/fb.h>
44 #include <linux/pci.h>
45 #include <linux/efi.h>
46 
47 #include <linux/hyperv.h>
48 
49 
50 /* Hyper-V Synthetic Video Protocol definitions and structures */
51 #define MAX_VMBUS_PKT_SIZE 0x4000
52 
53 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
54 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
55 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
56 
57 #define SYNTHVID_DEPTH_WIN7 16
58 #define SYNTHVID_DEPTH_WIN8 32
59 
60 #define SYNTHVID_FB_SIZE_WIN7 (4 * 1024 * 1024)
61 #define SYNTHVID_WIDTH_MAX_WIN7 1600
62 #define SYNTHVID_HEIGHT_MAX_WIN7 1200
63 
64 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
65 
66 #define PCI_VENDOR_ID_MICROSOFT 0x1414
67 #define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
68 
69 
70 enum pipe_msg_type {
71 	PIPE_MSG_INVALID,
72 	PIPE_MSG_DATA,
73 	PIPE_MSG_MAX
74 };
75 
76 struct pipe_msg_hdr {
77 	u32 type;
78 	u32 size; /* size of message after this field */
79 } __packed;
80 
81 
82 enum synthvid_msg_type {
83 	SYNTHVID_ERROR			= 0,
84 	SYNTHVID_VERSION_REQUEST	= 1,
85 	SYNTHVID_VERSION_RESPONSE	= 2,
86 	SYNTHVID_VRAM_LOCATION		= 3,
87 	SYNTHVID_VRAM_LOCATION_ACK	= 4,
88 	SYNTHVID_SITUATION_UPDATE	= 5,
89 	SYNTHVID_SITUATION_UPDATE_ACK	= 6,
90 	SYNTHVID_POINTER_POSITION	= 7,
91 	SYNTHVID_POINTER_SHAPE		= 8,
92 	SYNTHVID_FEATURE_CHANGE		= 9,
93 	SYNTHVID_DIRT			= 10,
94 
95 	SYNTHVID_MAX			= 11
96 };
97 
98 struct synthvid_msg_hdr {
99 	u32 type;
100 	u32 size;  /* size of this header + payload after this field*/
101 } __packed;
102 
103 
104 struct synthvid_version_req {
105 	u32 version;
106 } __packed;
107 
108 struct synthvid_version_resp {
109 	u32 version;
110 	u8 is_accepted;
111 	u8 max_video_outputs;
112 } __packed;
113 
114 struct synthvid_vram_location {
115 	u64 user_ctx;
116 	u8 is_vram_gpa_specified;
117 	u64 vram_gpa;
118 } __packed;
119 
120 struct synthvid_vram_location_ack {
121 	u64 user_ctx;
122 } __packed;
123 
124 struct video_output_situation {
125 	u8 active;
126 	u32 vram_offset;
127 	u8 depth_bits;
128 	u32 width_pixels;
129 	u32 height_pixels;
130 	u32 pitch_bytes;
131 } __packed;
132 
133 struct synthvid_situation_update {
134 	u64 user_ctx;
135 	u8 video_output_count;
136 	struct video_output_situation video_output[1];
137 } __packed;
138 
139 struct synthvid_situation_update_ack {
140 	u64 user_ctx;
141 } __packed;
142 
143 struct synthvid_pointer_position {
144 	u8 is_visible;
145 	u8 video_output;
146 	s32 image_x;
147 	s32 image_y;
148 } __packed;
149 
150 
151 #define CURSOR_MAX_X 96
152 #define CURSOR_MAX_Y 96
153 #define CURSOR_ARGB_PIXEL_SIZE 4
154 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
155 #define CURSOR_COMPLETE (-1)
156 
157 struct synthvid_pointer_shape {
158 	u8 part_idx;
159 	u8 is_argb;
160 	u32 width; /* CURSOR_MAX_X at most */
161 	u32 height; /* CURSOR_MAX_Y at most */
162 	u32 hot_x; /* hotspot relative to upper-left of pointer image */
163 	u32 hot_y;
164 	u8 data[4];
165 } __packed;
166 
167 struct synthvid_feature_change {
168 	u8 is_dirt_needed;
169 	u8 is_ptr_pos_needed;
170 	u8 is_ptr_shape_needed;
171 	u8 is_situ_needed;
172 } __packed;
173 
174 struct rect {
175 	s32 x1, y1; /* top left corner */
176 	s32 x2, y2; /* bottom right corner, exclusive */
177 } __packed;
178 
179 struct synthvid_dirt {
180 	u8 video_output;
181 	u8 dirt_count;
182 	struct rect rect[1];
183 } __packed;
184 
185 struct synthvid_msg {
186 	struct pipe_msg_hdr pipe_hdr;
187 	struct synthvid_msg_hdr vid_hdr;
188 	union {
189 		struct synthvid_version_req ver_req;
190 		struct synthvid_version_resp ver_resp;
191 		struct synthvid_vram_location vram;
192 		struct synthvid_vram_location_ack vram_ack;
193 		struct synthvid_situation_update situ;
194 		struct synthvid_situation_update_ack situ_ack;
195 		struct synthvid_pointer_position ptr_pos;
196 		struct synthvid_pointer_shape ptr_shape;
197 		struct synthvid_feature_change feature_chg;
198 		struct synthvid_dirt dirt;
199 	};
200 } __packed;
201 
202 
203 
204 /* FB driver definitions and structures */
205 #define HVFB_WIDTH 1152 /* default screen width */
206 #define HVFB_HEIGHT 864 /* default screen height */
207 #define HVFB_WIDTH_MIN 640
208 #define HVFB_HEIGHT_MIN 480
209 
210 #define RING_BUFSIZE (256 * 1024)
211 #define VSP_TIMEOUT (10 * HZ)
212 #define HVFB_UPDATE_DELAY (HZ / 20)
213 
214 struct hvfb_par {
215 	struct fb_info *info;
216 	struct resource *mem;
217 	bool fb_ready; /* fb device is ready */
218 	struct completion wait;
219 	u32 synthvid_version;
220 
221 	struct delayed_work dwork;
222 	bool update;
223 
224 	u32 pseudo_palette[16];
225 	u8 init_buf[MAX_VMBUS_PKT_SIZE];
226 	u8 recv_buf[MAX_VMBUS_PKT_SIZE];
227 
228 	/* If true, the VSC notifies the VSP on every framebuffer change */
229 	bool synchronous_fb;
230 
231 	struct notifier_block hvfb_panic_nb;
232 };
233 
234 static uint screen_width = HVFB_WIDTH;
235 static uint screen_height = HVFB_HEIGHT;
236 static uint screen_depth;
237 static uint screen_fb_size;
238 
239 /* Send message to Hyper-V host */
240 static inline int synthvid_send(struct hv_device *hdev,
241 				struct synthvid_msg *msg)
242 {
243 	static atomic64_t request_id = ATOMIC64_INIT(0);
244 	int ret;
245 
246 	msg->pipe_hdr.type = PIPE_MSG_DATA;
247 	msg->pipe_hdr.size = msg->vid_hdr.size;
248 
249 	ret = vmbus_sendpacket(hdev->channel, msg,
250 			       msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
251 			       atomic64_inc_return(&request_id),
252 			       VM_PKT_DATA_INBAND, 0);
253 
254 	if (ret)
255 		pr_err("Unable to send packet via vmbus\n");
256 
257 	return ret;
258 }
259 
260 
261 /* Send screen resolution info to host */
262 static int synthvid_send_situ(struct hv_device *hdev)
263 {
264 	struct fb_info *info = hv_get_drvdata(hdev);
265 	struct synthvid_msg msg;
266 
267 	if (!info)
268 		return -ENODEV;
269 
270 	memset(&msg, 0, sizeof(struct synthvid_msg));
271 
272 	msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
273 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
274 		sizeof(struct synthvid_situation_update);
275 	msg.situ.user_ctx = 0;
276 	msg.situ.video_output_count = 1;
277 	msg.situ.video_output[0].active = 1;
278 	msg.situ.video_output[0].vram_offset = 0;
279 	msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
280 	msg.situ.video_output[0].width_pixels = info->var.xres;
281 	msg.situ.video_output[0].height_pixels = info->var.yres;
282 	msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
283 
284 	synthvid_send(hdev, &msg);
285 
286 	return 0;
287 }
288 
289 /* Send mouse pointer info to host */
290 static int synthvid_send_ptr(struct hv_device *hdev)
291 {
292 	struct synthvid_msg msg;
293 
294 	memset(&msg, 0, sizeof(struct synthvid_msg));
295 	msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
296 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
297 		sizeof(struct synthvid_pointer_position);
298 	msg.ptr_pos.is_visible = 1;
299 	msg.ptr_pos.video_output = 0;
300 	msg.ptr_pos.image_x = 0;
301 	msg.ptr_pos.image_y = 0;
302 	synthvid_send(hdev, &msg);
303 
304 	memset(&msg, 0, sizeof(struct synthvid_msg));
305 	msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
306 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
307 		sizeof(struct synthvid_pointer_shape);
308 	msg.ptr_shape.part_idx = CURSOR_COMPLETE;
309 	msg.ptr_shape.is_argb = 1;
310 	msg.ptr_shape.width = 1;
311 	msg.ptr_shape.height = 1;
312 	msg.ptr_shape.hot_x = 0;
313 	msg.ptr_shape.hot_y = 0;
314 	msg.ptr_shape.data[0] = 0;
315 	msg.ptr_shape.data[1] = 1;
316 	msg.ptr_shape.data[2] = 1;
317 	msg.ptr_shape.data[3] = 1;
318 	synthvid_send(hdev, &msg);
319 
320 	return 0;
321 }
322 
323 /* Send updated screen area (dirty rectangle) location to host */
324 static int synthvid_update(struct fb_info *info)
325 {
326 	struct hv_device *hdev = device_to_hv_device(info->device);
327 	struct synthvid_msg msg;
328 
329 	memset(&msg, 0, sizeof(struct synthvid_msg));
330 
331 	msg.vid_hdr.type = SYNTHVID_DIRT;
332 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
333 		sizeof(struct synthvid_dirt);
334 	msg.dirt.video_output = 0;
335 	msg.dirt.dirt_count = 1;
336 	msg.dirt.rect[0].x1 = 0;
337 	msg.dirt.rect[0].y1 = 0;
338 	msg.dirt.rect[0].x2 = info->var.xres;
339 	msg.dirt.rect[0].y2 = info->var.yres;
340 
341 	synthvid_send(hdev, &msg);
342 
343 	return 0;
344 }
345 
346 
347 /*
348  * Actions on received messages from host:
349  * Complete the wait event.
350  * Or, reply with screen and cursor info.
351  */
352 static void synthvid_recv_sub(struct hv_device *hdev)
353 {
354 	struct fb_info *info = hv_get_drvdata(hdev);
355 	struct hvfb_par *par;
356 	struct synthvid_msg *msg;
357 
358 	if (!info)
359 		return;
360 
361 	par = info->par;
362 	msg = (struct synthvid_msg *)par->recv_buf;
363 
364 	/* Complete the wait event */
365 	if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
366 	    msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
367 		memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
368 		complete(&par->wait);
369 		return;
370 	}
371 
372 	/* Reply with screen and cursor info */
373 	if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
374 		if (par->fb_ready) {
375 			synthvid_send_ptr(hdev);
376 			synthvid_send_situ(hdev);
377 		}
378 
379 		par->update = msg->feature_chg.is_dirt_needed;
380 		if (par->update)
381 			schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
382 	}
383 }
384 
385 /* Receive callback for messages from the host */
386 static void synthvid_receive(void *ctx)
387 {
388 	struct hv_device *hdev = ctx;
389 	struct fb_info *info = hv_get_drvdata(hdev);
390 	struct hvfb_par *par;
391 	struct synthvid_msg *recv_buf;
392 	u32 bytes_recvd;
393 	u64 req_id;
394 	int ret;
395 
396 	if (!info)
397 		return;
398 
399 	par = info->par;
400 	recv_buf = (struct synthvid_msg *)par->recv_buf;
401 
402 	do {
403 		ret = vmbus_recvpacket(hdev->channel, recv_buf,
404 				       MAX_VMBUS_PKT_SIZE,
405 				       &bytes_recvd, &req_id);
406 		if (bytes_recvd > 0 &&
407 		    recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
408 			synthvid_recv_sub(hdev);
409 	} while (bytes_recvd > 0 && ret == 0);
410 }
411 
412 /* Check synthetic video protocol version with the host */
413 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
414 {
415 	struct fb_info *info = hv_get_drvdata(hdev);
416 	struct hvfb_par *par = info->par;
417 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
418 	int ret = 0;
419 	unsigned long t;
420 
421 	memset(msg, 0, sizeof(struct synthvid_msg));
422 	msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
423 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
424 		sizeof(struct synthvid_version_req);
425 	msg->ver_req.version = ver;
426 	synthvid_send(hdev, msg);
427 
428 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
429 	if (!t) {
430 		pr_err("Time out on waiting version response\n");
431 		ret = -ETIMEDOUT;
432 		goto out;
433 	}
434 	if (!msg->ver_resp.is_accepted) {
435 		ret = -ENODEV;
436 		goto out;
437 	}
438 
439 	par->synthvid_version = ver;
440 
441 out:
442 	return ret;
443 }
444 
445 /* Connect to VSP (Virtual Service Provider) on host */
446 static int synthvid_connect_vsp(struct hv_device *hdev)
447 {
448 	struct fb_info *info = hv_get_drvdata(hdev);
449 	struct hvfb_par *par = info->par;
450 	int ret;
451 
452 	ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
453 			 NULL, 0, synthvid_receive, hdev);
454 	if (ret) {
455 		pr_err("Unable to open vmbus channel\n");
456 		return ret;
457 	}
458 
459 	/* Negotiate the protocol version with host */
460 	if (vmbus_proto_version == VERSION_WS2008 ||
461 	    vmbus_proto_version == VERSION_WIN7)
462 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
463 	else
464 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
465 
466 	if (ret) {
467 		pr_err("Synthetic video device version not accepted\n");
468 		goto error;
469 	}
470 
471 	if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
472 		screen_depth = SYNTHVID_DEPTH_WIN7;
473 	else
474 		screen_depth = SYNTHVID_DEPTH_WIN8;
475 
476 	screen_fb_size = hdev->channel->offermsg.offer.
477 				mmio_megabytes * 1024 * 1024;
478 
479 	return 0;
480 
481 error:
482 	vmbus_close(hdev->channel);
483 	return ret;
484 }
485 
486 /* Send VRAM and Situation messages to the host */
487 static int synthvid_send_config(struct hv_device *hdev)
488 {
489 	struct fb_info *info = hv_get_drvdata(hdev);
490 	struct hvfb_par *par = info->par;
491 	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
492 	int ret = 0;
493 	unsigned long t;
494 
495 	/* Send VRAM location */
496 	memset(msg, 0, sizeof(struct synthvid_msg));
497 	msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
498 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
499 		sizeof(struct synthvid_vram_location);
500 	msg->vram.user_ctx = msg->vram.vram_gpa = info->fix.smem_start;
501 	msg->vram.is_vram_gpa_specified = 1;
502 	synthvid_send(hdev, msg);
503 
504 	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
505 	if (!t) {
506 		pr_err("Time out on waiting vram location ack\n");
507 		ret = -ETIMEDOUT;
508 		goto out;
509 	}
510 	if (msg->vram_ack.user_ctx != info->fix.smem_start) {
511 		pr_err("Unable to set VRAM location\n");
512 		ret = -ENODEV;
513 		goto out;
514 	}
515 
516 	/* Send pointer and situation update */
517 	synthvid_send_ptr(hdev);
518 	synthvid_send_situ(hdev);
519 
520 out:
521 	return ret;
522 }
523 
524 
525 /*
526  * Delayed work callback:
527  * It is called at HVFB_UPDATE_DELAY or longer time interval to process
528  * screen updates. It is re-scheduled if further update is necessary.
529  */
530 static void hvfb_update_work(struct work_struct *w)
531 {
532 	struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
533 	struct fb_info *info = par->info;
534 
535 	if (par->fb_ready)
536 		synthvid_update(info);
537 
538 	if (par->update)
539 		schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
540 }
541 
542 static int hvfb_on_panic(struct notifier_block *nb,
543 			 unsigned long e, void *p)
544 {
545 	struct hvfb_par *par;
546 	struct fb_info *info;
547 
548 	par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
549 	par->synchronous_fb = true;
550 	info = par->info;
551 	synthvid_update(info);
552 
553 	return NOTIFY_DONE;
554 }
555 
556 /* Framebuffer operation handlers */
557 
558 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
559 {
560 	if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
561 	    var->xres > screen_width || var->yres >  screen_height ||
562 	    var->bits_per_pixel != screen_depth)
563 		return -EINVAL;
564 
565 	var->xres_virtual = var->xres;
566 	var->yres_virtual = var->yres;
567 
568 	return 0;
569 }
570 
571 static int hvfb_set_par(struct fb_info *info)
572 {
573 	struct hv_device *hdev = device_to_hv_device(info->device);
574 
575 	return synthvid_send_situ(hdev);
576 }
577 
578 
579 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
580 {
581 	return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
582 }
583 
584 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
585 			  unsigned blue, unsigned transp, struct fb_info *info)
586 {
587 	u32 *pal = info->pseudo_palette;
588 
589 	if (regno > 15)
590 		return -EINVAL;
591 
592 	pal[regno] = chan_to_field(red, &info->var.red)
593 		| chan_to_field(green, &info->var.green)
594 		| chan_to_field(blue, &info->var.blue)
595 		| chan_to_field(transp, &info->var.transp);
596 
597 	return 0;
598 }
599 
600 static int hvfb_blank(int blank, struct fb_info *info)
601 {
602 	return 1;	/* get fb_blank to set the colormap to all black */
603 }
604 
605 static void hvfb_cfb_fillrect(struct fb_info *p,
606 			      const struct fb_fillrect *rect)
607 {
608 	struct hvfb_par *par = p->par;
609 
610 	cfb_fillrect(p, rect);
611 	if (par->synchronous_fb)
612 		synthvid_update(p);
613 }
614 
615 static void hvfb_cfb_copyarea(struct fb_info *p,
616 			      const struct fb_copyarea *area)
617 {
618 	struct hvfb_par *par = p->par;
619 
620 	cfb_copyarea(p, area);
621 	if (par->synchronous_fb)
622 		synthvid_update(p);
623 }
624 
625 static void hvfb_cfb_imageblit(struct fb_info *p,
626 			       const struct fb_image *image)
627 {
628 	struct hvfb_par *par = p->par;
629 
630 	cfb_imageblit(p, image);
631 	if (par->synchronous_fb)
632 		synthvid_update(p);
633 }
634 
635 static struct fb_ops hvfb_ops = {
636 	.owner = THIS_MODULE,
637 	.fb_check_var = hvfb_check_var,
638 	.fb_set_par = hvfb_set_par,
639 	.fb_setcolreg = hvfb_setcolreg,
640 	.fb_fillrect = hvfb_cfb_fillrect,
641 	.fb_copyarea = hvfb_cfb_copyarea,
642 	.fb_imageblit = hvfb_cfb_imageblit,
643 	.fb_blank = hvfb_blank,
644 };
645 
646 
647 /* Get options from kernel paramenter "video=" */
648 static void hvfb_get_option(struct fb_info *info)
649 {
650 	struct hvfb_par *par = info->par;
651 	char *opt = NULL, *p;
652 	uint x = 0, y = 0;
653 
654 	if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
655 		return;
656 
657 	p = strsep(&opt, "x");
658 	if (!*p || kstrtouint(p, 0, &x) ||
659 	    !opt || !*opt || kstrtouint(opt, 0, &y)) {
660 		pr_err("Screen option is invalid: skipped\n");
661 		return;
662 	}
663 
664 	if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
665 	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
666 	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
667 	    (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
668 	     (x > SYNTHVID_WIDTH_MAX_WIN7 || y > SYNTHVID_HEIGHT_MAX_WIN7))) {
669 		pr_err("Screen resolution option is out of range: skipped\n");
670 		return;
671 	}
672 
673 	screen_width = x;
674 	screen_height = y;
675 	return;
676 }
677 
678 
679 /* Get framebuffer memory from Hyper-V video pci space */
680 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
681 {
682 	struct hvfb_par *par = info->par;
683 	struct pci_dev *pdev  = NULL;
684 	void __iomem *fb_virt;
685 	int gen2vm = efi_enabled(EFI_BOOT);
686 	resource_size_t pot_start, pot_end;
687 	int ret;
688 
689 	if (gen2vm) {
690 		pot_start = 0;
691 		pot_end = -1;
692 	} else {
693 		pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
694 			      PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
695 		if (!pdev) {
696 			pr_err("Unable to find PCI Hyper-V video\n");
697 			return -ENODEV;
698 		}
699 
700 		if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
701 		    pci_resource_len(pdev, 0) < screen_fb_size)
702 			goto err1;
703 
704 		pot_end = pci_resource_end(pdev, 0);
705 		pot_start = pot_end - screen_fb_size + 1;
706 	}
707 
708 	ret = vmbus_allocate_mmio(&par->mem, hdev, pot_start, pot_end,
709 				  screen_fb_size, 0x100000, true);
710 	if (ret != 0) {
711 		pr_err("Unable to allocate framebuffer memory\n");
712 		goto err1;
713 	}
714 
715 	fb_virt = ioremap(par->mem->start, screen_fb_size);
716 	if (!fb_virt)
717 		goto err2;
718 
719 	info->apertures = alloc_apertures(1);
720 	if (!info->apertures)
721 		goto err3;
722 
723 	if (gen2vm) {
724 		info->apertures->ranges[0].base = screen_info.lfb_base;
725 		info->apertures->ranges[0].size = screen_info.lfb_size;
726 		remove_conflicting_framebuffers(info->apertures,
727 						KBUILD_MODNAME, false);
728 	} else {
729 		info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
730 		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
731 	}
732 
733 	info->fix.smem_start = par->mem->start;
734 	info->fix.smem_len = screen_fb_size;
735 	info->screen_base = fb_virt;
736 	info->screen_size = screen_fb_size;
737 
738 	if (!gen2vm)
739 		pci_dev_put(pdev);
740 
741 	return 0;
742 
743 err3:
744 	iounmap(fb_virt);
745 err2:
746 	vmbus_free_mmio(par->mem->start, screen_fb_size);
747 	par->mem = NULL;
748 err1:
749 	if (!gen2vm)
750 		pci_dev_put(pdev);
751 
752 	return -ENOMEM;
753 }
754 
755 /* Release the framebuffer */
756 static void hvfb_putmem(struct fb_info *info)
757 {
758 	struct hvfb_par *par = info->par;
759 
760 	iounmap(info->screen_base);
761 	vmbus_free_mmio(par->mem->start, screen_fb_size);
762 	par->mem = NULL;
763 }
764 
765 
766 static int hvfb_probe(struct hv_device *hdev,
767 		      const struct hv_vmbus_device_id *dev_id)
768 {
769 	struct fb_info *info;
770 	struct hvfb_par *par;
771 	int ret;
772 
773 	info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
774 	if (!info) {
775 		pr_err("No memory for framebuffer info\n");
776 		return -ENOMEM;
777 	}
778 
779 	par = info->par;
780 	par->info = info;
781 	par->fb_ready = false;
782 	init_completion(&par->wait);
783 	INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
784 
785 	/* Connect to VSP */
786 	hv_set_drvdata(hdev, info);
787 	ret = synthvid_connect_vsp(hdev);
788 	if (ret) {
789 		pr_err("Unable to connect to VSP\n");
790 		goto error1;
791 	}
792 
793 	ret = hvfb_getmem(hdev, info);
794 	if (ret) {
795 		pr_err("No memory for framebuffer\n");
796 		goto error2;
797 	}
798 
799 	hvfb_get_option(info);
800 	pr_info("Screen resolution: %dx%d, Color depth: %d\n",
801 		screen_width, screen_height, screen_depth);
802 
803 
804 	/* Set up fb_info */
805 	info->flags = FBINFO_DEFAULT;
806 
807 	info->var.xres_virtual = info->var.xres = screen_width;
808 	info->var.yres_virtual = info->var.yres = screen_height;
809 	info->var.bits_per_pixel = screen_depth;
810 
811 	if (info->var.bits_per_pixel == 16) {
812 		info->var.red = (struct fb_bitfield){11, 5, 0};
813 		info->var.green = (struct fb_bitfield){5, 6, 0};
814 		info->var.blue = (struct fb_bitfield){0, 5, 0};
815 		info->var.transp = (struct fb_bitfield){0, 0, 0};
816 	} else {
817 		info->var.red = (struct fb_bitfield){16, 8, 0};
818 		info->var.green = (struct fb_bitfield){8, 8, 0};
819 		info->var.blue = (struct fb_bitfield){0, 8, 0};
820 		info->var.transp = (struct fb_bitfield){24, 8, 0};
821 	}
822 
823 	info->var.activate = FB_ACTIVATE_NOW;
824 	info->var.height = -1;
825 	info->var.width = -1;
826 	info->var.vmode = FB_VMODE_NONINTERLACED;
827 
828 	strcpy(info->fix.id, KBUILD_MODNAME);
829 	info->fix.type = FB_TYPE_PACKED_PIXELS;
830 	info->fix.visual = FB_VISUAL_TRUECOLOR;
831 	info->fix.line_length = screen_width * screen_depth / 8;
832 	info->fix.accel = FB_ACCEL_NONE;
833 
834 	info->fbops = &hvfb_ops;
835 	info->pseudo_palette = par->pseudo_palette;
836 
837 	/* Send config to host */
838 	ret = synthvid_send_config(hdev);
839 	if (ret)
840 		goto error;
841 
842 	ret = register_framebuffer(info);
843 	if (ret) {
844 		pr_err("Unable to register framebuffer\n");
845 		goto error;
846 	}
847 
848 	par->fb_ready = true;
849 
850 	par->synchronous_fb = false;
851 	par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
852 	atomic_notifier_chain_register(&panic_notifier_list,
853 				       &par->hvfb_panic_nb);
854 
855 	return 0;
856 
857 error:
858 	hvfb_putmem(info);
859 error2:
860 	vmbus_close(hdev->channel);
861 error1:
862 	cancel_delayed_work_sync(&par->dwork);
863 	hv_set_drvdata(hdev, NULL);
864 	framebuffer_release(info);
865 	return ret;
866 }
867 
868 
869 static int hvfb_remove(struct hv_device *hdev)
870 {
871 	struct fb_info *info = hv_get_drvdata(hdev);
872 	struct hvfb_par *par = info->par;
873 
874 	atomic_notifier_chain_unregister(&panic_notifier_list,
875 					 &par->hvfb_panic_nb);
876 
877 	par->update = false;
878 	par->fb_ready = false;
879 
880 	unregister_framebuffer(info);
881 	cancel_delayed_work_sync(&par->dwork);
882 
883 	vmbus_close(hdev->channel);
884 	hv_set_drvdata(hdev, NULL);
885 
886 	hvfb_putmem(info);
887 	framebuffer_release(info);
888 
889 	return 0;
890 }
891 
892 
893 static const struct pci_device_id pci_stub_id_table[] = {
894 	{
895 		.vendor      = PCI_VENDOR_ID_MICROSOFT,
896 		.device      = PCI_DEVICE_ID_HYPERV_VIDEO,
897 	},
898 	{ /* end of list */ }
899 };
900 
901 static const struct hv_vmbus_device_id id_table[] = {
902 	/* Synthetic Video Device GUID */
903 	{HV_SYNTHVID_GUID},
904 	{}
905 };
906 
907 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
908 MODULE_DEVICE_TABLE(vmbus, id_table);
909 
910 static struct hv_driver hvfb_drv = {
911 	.name = KBUILD_MODNAME,
912 	.id_table = id_table,
913 	.probe = hvfb_probe,
914 	.remove = hvfb_remove,
915 	.driver = {
916 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
917 	},
918 };
919 
920 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
921 			       const struct pci_device_id *ent)
922 {
923 	return 0;
924 }
925 
926 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
927 {
928 }
929 
930 static struct pci_driver hvfb_pci_stub_driver = {
931 	.name =		KBUILD_MODNAME,
932 	.id_table =	pci_stub_id_table,
933 	.probe =	hvfb_pci_stub_probe,
934 	.remove =	hvfb_pci_stub_remove,
935 	.driver = {
936 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
937 	}
938 };
939 
940 static int __init hvfb_drv_init(void)
941 {
942 	int ret;
943 
944 	ret = vmbus_driver_register(&hvfb_drv);
945 	if (ret != 0)
946 		return ret;
947 
948 	ret = pci_register_driver(&hvfb_pci_stub_driver);
949 	if (ret != 0) {
950 		vmbus_driver_unregister(&hvfb_drv);
951 		return ret;
952 	}
953 
954 	return 0;
955 }
956 
957 static void __exit hvfb_drv_exit(void)
958 {
959 	pci_unregister_driver(&hvfb_pci_stub_driver);
960 	vmbus_driver_unregister(&hvfb_drv);
961 }
962 
963 module_init(hvfb_drv_init);
964 module_exit(hvfb_drv_exit);
965 
966 MODULE_LICENSE("GPL");
967 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");
968