4a6a3303b6b4e59efa0b3a6a756e00392a39e6d9
[platform/kernel/linux-starfive.git] / drivers / video / fbdev / hyperv_fb.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2012, Microsoft Corporation.
4  *
5  * Author:
6  *   Haiyang Zhang <haiyangz@microsoft.com>
7  */
8
9 /*
10  * Hyper-V Synthetic Video Frame Buffer Driver
11  *
12  * This is the driver for the Hyper-V Synthetic Video, which supports
13  * screen resolution up to Full HD 1920x1080 with 32 bit color on Windows
14  * Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2
15  * or earlier.
16  *
17  * It also solves the double mouse cursor issue of the emulated video mode.
18  *
19  * The default screen resolution is 1152x864, which may be changed by a
20  * kernel parameter:
21  *     video=hyperv_fb:<width>x<height>
22  *     For example: video=hyperv_fb:1280x1024
23  *
24  * Portrait orientation is also supported:
25  *     For example: video=hyperv_fb:864x1152
26  *
27  * When a Windows 10 RS5+ host is used, the virtual machine screen
28  * resolution is obtained from the host. The "video=hyperv_fb" option is
29  * not needed, but still can be used to overwrite what the host specifies.
30  * The VM resolution on the host could be set by executing the powershell
31  * "set-vmvideo" command. For example
32  *     set-vmvideo -vmname name -horizontalresolution:1920 \
33  * -verticalresolution:1200 -resolutiontype single
34  *
35  * Gen 1 VMs also support direct using VM's physical memory for framebuffer.
36  * It could improve the efficiency and performance for framebuffer and VM.
37  * This requires to allocate contiguous physical memory from Linux kernel's
38  * CMA memory allocator. To enable this, supply a kernel parameter to give
39  * enough memory space to CMA allocator for framebuffer. For example:
40  *    cma=130m
41  * This gives 130MB memory to CMA allocator that can be allocated to
42  * framebuffer. For reference, 8K resolution (7680x4320) takes about
43  * 127MB memory.
44  */
45
46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47
48 #include <linux/aperture.h>
49 #include <linux/module.h>
50 #include <linux/kernel.h>
51 #include <linux/vmalloc.h>
52 #include <linux/init.h>
53 #include <linux/completion.h>
54 #include <linux/fb.h>
55 #include <linux/pci.h>
56 #include <linux/panic_notifier.h>
57 #include <linux/efi.h>
58 #include <linux/console.h>
59
60 #include <linux/hyperv.h>
61
62 /* Hyper-V Synthetic Video Protocol definitions and structures */
63 #define MAX_VMBUS_PKT_SIZE 0x4000
64
65 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
66 /* Support for VERSION_WIN7 is removed. #define is retained for reference. */
67 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
68 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
69 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
70
71 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
72 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
73
74 #define SYNTHVID_DEPTH_WIN8 32
75 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
76
77 enum pipe_msg_type {
78         PIPE_MSG_INVALID,
79         PIPE_MSG_DATA,
80         PIPE_MSG_MAX
81 };
82
83 struct pipe_msg_hdr {
84         u32 type;
85         u32 size; /* size of message after this field */
86 } __packed;
87
88
89 enum synthvid_msg_type {
90         SYNTHVID_ERROR                  = 0,
91         SYNTHVID_VERSION_REQUEST        = 1,
92         SYNTHVID_VERSION_RESPONSE       = 2,
93         SYNTHVID_VRAM_LOCATION          = 3,
94         SYNTHVID_VRAM_LOCATION_ACK      = 4,
95         SYNTHVID_SITUATION_UPDATE       = 5,
96         SYNTHVID_SITUATION_UPDATE_ACK   = 6,
97         SYNTHVID_POINTER_POSITION       = 7,
98         SYNTHVID_POINTER_SHAPE          = 8,
99         SYNTHVID_FEATURE_CHANGE         = 9,
100         SYNTHVID_DIRT                   = 10,
101         SYNTHVID_RESOLUTION_REQUEST     = 13,
102         SYNTHVID_RESOLUTION_RESPONSE    = 14,
103
104         SYNTHVID_MAX                    = 15
105 };
106
107 #define         SYNTHVID_EDID_BLOCK_SIZE        128
108 #define         SYNTHVID_MAX_RESOLUTION_COUNT   64
109
110 struct hvd_screen_info {
111         u16 width;
112         u16 height;
113 } __packed;
114
115 struct synthvid_msg_hdr {
116         u32 type;
117         u32 size;  /* size of this header + payload after this field*/
118 } __packed;
119
120 struct synthvid_version_req {
121         u32 version;
122 } __packed;
123
124 struct synthvid_version_resp {
125         u32 version;
126         u8 is_accepted;
127         u8 max_video_outputs;
128 } __packed;
129
130 struct synthvid_supported_resolution_req {
131         u8 maximum_resolution_count;
132 } __packed;
133
134 struct synthvid_supported_resolution_resp {
135         u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
136         u8 resolution_count;
137         u8 default_resolution_index;
138         u8 is_standard;
139         struct hvd_screen_info
140                 supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
141 } __packed;
142
143 struct synthvid_vram_location {
144         u64 user_ctx;
145         u8 is_vram_gpa_specified;
146         u64 vram_gpa;
147 } __packed;
148
149 struct synthvid_vram_location_ack {
150         u64 user_ctx;
151 } __packed;
152
153 struct video_output_situation {
154         u8 active;
155         u32 vram_offset;
156         u8 depth_bits;
157         u32 width_pixels;
158         u32 height_pixels;
159         u32 pitch_bytes;
160 } __packed;
161
162 struct synthvid_situation_update {
163         u64 user_ctx;
164         u8 video_output_count;
165         struct video_output_situation video_output[1];
166 } __packed;
167
168 struct synthvid_situation_update_ack {
169         u64 user_ctx;
170 } __packed;
171
172 struct synthvid_pointer_position {
173         u8 is_visible;
174         u8 video_output;
175         s32 image_x;
176         s32 image_y;
177 } __packed;
178
179
180 #define CURSOR_MAX_X 96
181 #define CURSOR_MAX_Y 96
182 #define CURSOR_ARGB_PIXEL_SIZE 4
183 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
184 #define CURSOR_COMPLETE (-1)
185
186 struct synthvid_pointer_shape {
187         u8 part_idx;
188         u8 is_argb;
189         u32 width; /* CURSOR_MAX_X at most */
190         u32 height; /* CURSOR_MAX_Y at most */
191         u32 hot_x; /* hotspot relative to upper-left of pointer image */
192         u32 hot_y;
193         u8 data[4];
194 } __packed;
195
196 struct synthvid_feature_change {
197         u8 is_dirt_needed;
198         u8 is_ptr_pos_needed;
199         u8 is_ptr_shape_needed;
200         u8 is_situ_needed;
201 } __packed;
202
203 struct rect {
204         s32 x1, y1; /* top left corner */
205         s32 x2, y2; /* bottom right corner, exclusive */
206 } __packed;
207
208 struct synthvid_dirt {
209         u8 video_output;
210         u8 dirt_count;
211         struct rect rect[1];
212 } __packed;
213
214 struct synthvid_msg {
215         struct pipe_msg_hdr pipe_hdr;
216         struct synthvid_msg_hdr vid_hdr;
217         union {
218                 struct synthvid_version_req ver_req;
219                 struct synthvid_version_resp ver_resp;
220                 struct synthvid_vram_location vram;
221                 struct synthvid_vram_location_ack vram_ack;
222                 struct synthvid_situation_update situ;
223                 struct synthvid_situation_update_ack situ_ack;
224                 struct synthvid_pointer_position ptr_pos;
225                 struct synthvid_pointer_shape ptr_shape;
226                 struct synthvid_feature_change feature_chg;
227                 struct synthvid_dirt dirt;
228                 struct synthvid_supported_resolution_req resolution_req;
229                 struct synthvid_supported_resolution_resp resolution_resp;
230         };
231 } __packed;
232
233
234 /* FB driver definitions and structures */
235 #define HVFB_WIDTH 1152 /* default screen width */
236 #define HVFB_HEIGHT 864 /* default screen height */
237 #define HVFB_WIDTH_MIN 640
238 #define HVFB_HEIGHT_MIN 480
239
240 #define RING_BUFSIZE (256 * 1024)
241 #define VSP_TIMEOUT (10 * HZ)
242 #define HVFB_UPDATE_DELAY (HZ / 20)
243 #define HVFB_ONDEMAND_THROTTLE (HZ / 20)
244
245 struct hvfb_par {
246         struct fb_info *info;
247         struct resource *mem;
248         bool fb_ready; /* fb device is ready */
249         struct completion wait;
250         u32 synthvid_version;
251
252         struct delayed_work dwork;
253         bool update;
254         bool update_saved; /* The value of 'update' before hibernation */
255
256         u32 pseudo_palette[16];
257         u8 init_buf[MAX_VMBUS_PKT_SIZE];
258         u8 recv_buf[MAX_VMBUS_PKT_SIZE];
259
260         /* If true, the VSC notifies the VSP on every framebuffer change */
261         bool synchronous_fb;
262
263         /* If true, need to copy from deferred IO mem to framebuffer mem */
264         bool need_docopy;
265
266         struct notifier_block hvfb_panic_nb;
267
268         /* Memory for deferred IO and frame buffer itself */
269         unsigned char *dio_vp;
270         unsigned char *mmio_vp;
271         phys_addr_t mmio_pp;
272
273         /* Dirty rectangle, protected by delayed_refresh_lock */
274         int x1, y1, x2, y2;
275         bool delayed_refresh;
276         spinlock_t delayed_refresh_lock;
277 };
278
279 static uint screen_width = HVFB_WIDTH;
280 static uint screen_height = HVFB_HEIGHT;
281 static uint screen_depth;
282 static uint screen_fb_size;
283 static uint dio_fb_size; /* FB size for deferred IO */
284
285 /* Send message to Hyper-V host */
286 static inline int synthvid_send(struct hv_device *hdev,
287                                 struct synthvid_msg *msg)
288 {
289         static atomic64_t request_id = ATOMIC64_INIT(0);
290         int ret;
291
292         msg->pipe_hdr.type = PIPE_MSG_DATA;
293         msg->pipe_hdr.size = msg->vid_hdr.size;
294
295         ret = vmbus_sendpacket(hdev->channel, msg,
296                                msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
297                                atomic64_inc_return(&request_id),
298                                VM_PKT_DATA_INBAND, 0);
299
300         if (ret)
301                 pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);
302
303         return ret;
304 }
305
306
307 /* Send screen resolution info to host */
308 static int synthvid_send_situ(struct hv_device *hdev)
309 {
310         struct fb_info *info = hv_get_drvdata(hdev);
311         struct synthvid_msg msg;
312
313         if (!info)
314                 return -ENODEV;
315
316         memset(&msg, 0, sizeof(struct synthvid_msg));
317
318         msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
319         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
320                 sizeof(struct synthvid_situation_update);
321         msg.situ.user_ctx = 0;
322         msg.situ.video_output_count = 1;
323         msg.situ.video_output[0].active = 1;
324         msg.situ.video_output[0].vram_offset = 0;
325         msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
326         msg.situ.video_output[0].width_pixels = info->var.xres;
327         msg.situ.video_output[0].height_pixels = info->var.yres;
328         msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
329
330         synthvid_send(hdev, &msg);
331
332         return 0;
333 }
334
335 /* Send mouse pointer info to host */
336 static int synthvid_send_ptr(struct hv_device *hdev)
337 {
338         struct synthvid_msg msg;
339
340         memset(&msg, 0, sizeof(struct synthvid_msg));
341         msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
342         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
343                 sizeof(struct synthvid_pointer_position);
344         msg.ptr_pos.is_visible = 1;
345         msg.ptr_pos.video_output = 0;
346         msg.ptr_pos.image_x = 0;
347         msg.ptr_pos.image_y = 0;
348         synthvid_send(hdev, &msg);
349
350         memset(&msg, 0, sizeof(struct synthvid_msg));
351         msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
352         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
353                 sizeof(struct synthvid_pointer_shape);
354         msg.ptr_shape.part_idx = CURSOR_COMPLETE;
355         msg.ptr_shape.is_argb = 1;
356         msg.ptr_shape.width = 1;
357         msg.ptr_shape.height = 1;
358         msg.ptr_shape.hot_x = 0;
359         msg.ptr_shape.hot_y = 0;
360         msg.ptr_shape.data[0] = 0;
361         msg.ptr_shape.data[1] = 1;
362         msg.ptr_shape.data[2] = 1;
363         msg.ptr_shape.data[3] = 1;
364         synthvid_send(hdev, &msg);
365
366         return 0;
367 }
368
369 /* Send updated screen area (dirty rectangle) location to host */
370 static int
371 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
372 {
373         struct hv_device *hdev = device_to_hv_device(info->device);
374         struct synthvid_msg msg;
375
376         memset(&msg, 0, sizeof(struct synthvid_msg));
377         if (x2 == INT_MAX)
378                 x2 = info->var.xres;
379         if (y2 == INT_MAX)
380                 y2 = info->var.yres;
381
382         msg.vid_hdr.type = SYNTHVID_DIRT;
383         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
384                 sizeof(struct synthvid_dirt);
385         msg.dirt.video_output = 0;
386         msg.dirt.dirt_count = 1;
387         msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
388         msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
389         msg.dirt.rect[0].x2 =
390                 (x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
391         msg.dirt.rect[0].y2 =
392                 (y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
393
394         synthvid_send(hdev, &msg);
395
396         return 0;
397 }
398
399 static void hvfb_docopy(struct hvfb_par *par,
400                         unsigned long offset,
401                         unsigned long size)
402 {
403         if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
404             size == 0 || offset >= dio_fb_size)
405                 return;
406
407         if (offset + size > dio_fb_size)
408                 size = dio_fb_size - offset;
409
410         memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
411 }
412
413 /* Deferred IO callback */
414 static void synthvid_deferred_io(struct fb_info *p, struct list_head *pagereflist)
415 {
416         struct hvfb_par *par = p->par;
417         struct fb_deferred_io_pageref *pageref;
418         unsigned long start, end;
419         int y1, y2, miny, maxy;
420
421         miny = INT_MAX;
422         maxy = 0;
423
424         /*
425          * Merge dirty pages. It is possible that last page cross
426          * over the end of frame buffer row yres. This is taken care of
427          * in synthvid_update function by clamping the y2
428          * value to yres.
429          */
430         list_for_each_entry(pageref, pagereflist, list) {
431                 start = pageref->offset;
432                 end = start + PAGE_SIZE - 1;
433                 y1 = start / p->fix.line_length;
434                 y2 = end / p->fix.line_length;
435                 miny = min_t(int, miny, y1);
436                 maxy = max_t(int, maxy, y2);
437
438                 /* Copy from dio space to mmio address */
439                 if (par->fb_ready && par->need_docopy)
440                         hvfb_docopy(par, start, PAGE_SIZE);
441         }
442
443         if (par->fb_ready && par->update)
444                 synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
445 }
446
447 static struct fb_deferred_io synthvid_defio = {
448         .delay          = HZ / 20,
449         .deferred_io    = synthvid_deferred_io,
450 };
451
452 /*
453  * Actions on received messages from host:
454  * Complete the wait event.
455  * Or, reply with screen and cursor info.
456  */
457 static void synthvid_recv_sub(struct hv_device *hdev)
458 {
459         struct fb_info *info = hv_get_drvdata(hdev);
460         struct hvfb_par *par;
461         struct synthvid_msg *msg;
462
463         if (!info)
464                 return;
465
466         par = info->par;
467         msg = (struct synthvid_msg *)par->recv_buf;
468
469         /* Complete the wait event */
470         if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
471             msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
472             msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
473                 memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
474                 complete(&par->wait);
475                 return;
476         }
477
478         /* Reply with screen and cursor info */
479         if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
480                 if (par->fb_ready) {
481                         synthvid_send_ptr(hdev);
482                         synthvid_send_situ(hdev);
483                 }
484
485                 par->update = msg->feature_chg.is_dirt_needed;
486                 if (par->update)
487                         schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
488         }
489 }
490
491 /* Receive callback for messages from the host */
492 static void synthvid_receive(void *ctx)
493 {
494         struct hv_device *hdev = ctx;
495         struct fb_info *info = hv_get_drvdata(hdev);
496         struct hvfb_par *par;
497         struct synthvid_msg *recv_buf;
498         u32 bytes_recvd;
499         u64 req_id;
500         int ret;
501
502         if (!info)
503                 return;
504
505         par = info->par;
506         recv_buf = (struct synthvid_msg *)par->recv_buf;
507
508         do {
509                 ret = vmbus_recvpacket(hdev->channel, recv_buf,
510                                        MAX_VMBUS_PKT_SIZE,
511                                        &bytes_recvd, &req_id);
512                 if (bytes_recvd > 0 &&
513                     recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
514                         synthvid_recv_sub(hdev);
515         } while (bytes_recvd > 0 && ret == 0);
516 }
517
518 /* Check if the ver1 version is equal or greater than ver2 */
519 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
520 {
521         if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
522             (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
523              SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
524                 return true;
525
526         return false;
527 }
528
529 /* Check synthetic video protocol version with the host */
530 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
531 {
532         struct fb_info *info = hv_get_drvdata(hdev);
533         struct hvfb_par *par = info->par;
534         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
535         int ret = 0;
536         unsigned long t;
537
538         memset(msg, 0, sizeof(struct synthvid_msg));
539         msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
540         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
541                 sizeof(struct synthvid_version_req);
542         msg->ver_req.version = ver;
543         synthvid_send(hdev, msg);
544
545         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
546         if (!t) {
547                 pr_err("Time out on waiting version response\n");
548                 ret = -ETIMEDOUT;
549                 goto out;
550         }
551         if (!msg->ver_resp.is_accepted) {
552                 ret = -ENODEV;
553                 goto out;
554         }
555
556         par->synthvid_version = ver;
557         pr_info("Synthvid Version major %d, minor %d\n",
558                 SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
559
560 out:
561         return ret;
562 }
563
564 /* Get current resolution from the host */
565 static int synthvid_get_supported_resolution(struct hv_device *hdev)
566 {
567         struct fb_info *info = hv_get_drvdata(hdev);
568         struct hvfb_par *par = info->par;
569         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
570         int ret = 0;
571         unsigned long t;
572         u8 index;
573
574         memset(msg, 0, sizeof(struct synthvid_msg));
575         msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
576         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
577                 sizeof(struct synthvid_supported_resolution_req);
578
579         msg->resolution_req.maximum_resolution_count =
580                 SYNTHVID_MAX_RESOLUTION_COUNT;
581         synthvid_send(hdev, msg);
582
583         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
584         if (!t) {
585                 pr_err("Time out on waiting resolution response\n");
586                 ret = -ETIMEDOUT;
587                 goto out;
588         }
589
590         if (msg->resolution_resp.resolution_count == 0) {
591                 pr_err("No supported resolutions\n");
592                 ret = -ENODEV;
593                 goto out;
594         }
595
596         index = msg->resolution_resp.default_resolution_index;
597         if (index >= msg->resolution_resp.resolution_count) {
598                 pr_err("Invalid resolution index: %d\n", index);
599                 ret = -ENODEV;
600                 goto out;
601         }
602
603         screen_width =
604                 msg->resolution_resp.supported_resolution[index].width;
605         screen_height =
606                 msg->resolution_resp.supported_resolution[index].height;
607
608 out:
609         return ret;
610 }
611
612 /* Connect to VSP (Virtual Service Provider) on host */
613 static int synthvid_connect_vsp(struct hv_device *hdev)
614 {
615         struct fb_info *info = hv_get_drvdata(hdev);
616         struct hvfb_par *par = info->par;
617         int ret;
618
619         ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
620                          NULL, 0, synthvid_receive, hdev);
621         if (ret) {
622                 pr_err("Unable to open vmbus channel\n");
623                 return ret;
624         }
625
626         /* Negotiate the protocol version with host */
627         switch (vmbus_proto_version) {
628         case VERSION_WIN10:
629         case VERSION_WIN10_V5:
630                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
631                 if (!ret)
632                         break;
633                 fallthrough;
634         case VERSION_WIN8:
635         case VERSION_WIN8_1:
636                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
637                 break;
638         default:
639                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
640                 break;
641         }
642
643         if (ret) {
644                 pr_err("Synthetic video device version not accepted\n");
645                 goto error;
646         }
647
648         screen_depth = SYNTHVID_DEPTH_WIN8;
649         if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
650                 ret = synthvid_get_supported_resolution(hdev);
651                 if (ret)
652                         pr_info("Failed to get supported resolution from host, use default\n");
653         }
654
655         screen_fb_size = hdev->channel->offermsg.offer.
656                                 mmio_megabytes * 1024 * 1024;
657
658         return 0;
659
660 error:
661         vmbus_close(hdev->channel);
662         return ret;
663 }
664
665 /* Send VRAM and Situation messages to the host */
666 static int synthvid_send_config(struct hv_device *hdev)
667 {
668         struct fb_info *info = hv_get_drvdata(hdev);
669         struct hvfb_par *par = info->par;
670         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
671         int ret = 0;
672         unsigned long t;
673
674         /* Send VRAM location */
675         memset(msg, 0, sizeof(struct synthvid_msg));
676         msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
677         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
678                 sizeof(struct synthvid_vram_location);
679         msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
680         msg->vram.is_vram_gpa_specified = 1;
681         synthvid_send(hdev, msg);
682
683         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
684         if (!t) {
685                 pr_err("Time out on waiting vram location ack\n");
686                 ret = -ETIMEDOUT;
687                 goto out;
688         }
689         if (msg->vram_ack.user_ctx != par->mmio_pp) {
690                 pr_err("Unable to set VRAM location\n");
691                 ret = -ENODEV;
692                 goto out;
693         }
694
695         /* Send pointer and situation update */
696         synthvid_send_ptr(hdev);
697         synthvid_send_situ(hdev);
698
699 out:
700         return ret;
701 }
702
703
704 /*
705  * Delayed work callback:
706  * It is scheduled to call whenever update request is received and it has
707  * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
708  */
709 static void hvfb_update_work(struct work_struct *w)
710 {
711         struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
712         struct fb_info *info = par->info;
713         unsigned long flags;
714         int x1, x2, y1, y2;
715         int j;
716
717         spin_lock_irqsave(&par->delayed_refresh_lock, flags);
718         /* Reset the request flag */
719         par->delayed_refresh = false;
720
721         /* Store the dirty rectangle to local variables */
722         x1 = par->x1;
723         x2 = par->x2;
724         y1 = par->y1;
725         y2 = par->y2;
726
727         /* Clear dirty rectangle */
728         par->x1 = par->y1 = INT_MAX;
729         par->x2 = par->y2 = 0;
730
731         spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
732
733         if (x1 > info->var.xres || x2 > info->var.xres ||
734             y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
735                 return;
736
737         /* Copy the dirty rectangle to frame buffer memory */
738         if (par->need_docopy)
739                 for (j = y1; j < y2; j++)
740                         hvfb_docopy(par,
741                                     j * info->fix.line_length +
742                                     (x1 * screen_depth / 8),
743                                     (x2 - x1) * screen_depth / 8);
744
745         /* Refresh */
746         if (par->fb_ready && par->update)
747                 synthvid_update(info, x1, y1, x2, y2);
748 }
749
750 /*
751  * Control the on-demand refresh frequency. It schedules a delayed
752  * screen update if it has not yet.
753  */
754 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
755                                            int x1, int y1, int w, int h)
756 {
757         unsigned long flags;
758         int x2 = x1 + w;
759         int y2 = y1 + h;
760
761         spin_lock_irqsave(&par->delayed_refresh_lock, flags);
762
763         /* Merge dirty rectangle */
764         par->x1 = min_t(int, par->x1, x1);
765         par->y1 = min_t(int, par->y1, y1);
766         par->x2 = max_t(int, par->x2, x2);
767         par->y2 = max_t(int, par->y2, y2);
768
769         /* Schedule a delayed screen update if not yet */
770         if (par->delayed_refresh == false) {
771                 schedule_delayed_work(&par->dwork,
772                                       HVFB_ONDEMAND_THROTTLE);
773                 par->delayed_refresh = true;
774         }
775
776         spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
777 }
778
779 static int hvfb_on_panic(struct notifier_block *nb,
780                          unsigned long e, void *p)
781 {
782         struct hv_device *hdev;
783         struct hvfb_par *par;
784         struct fb_info *info;
785
786         par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
787         info = par->info;
788         hdev = device_to_hv_device(info->device);
789
790         if (hv_ringbuffer_spinlock_busy(hdev->channel))
791                 return NOTIFY_DONE;
792
793         par->synchronous_fb = true;
794         if (par->need_docopy)
795                 hvfb_docopy(par, 0, dio_fb_size);
796         synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
797
798         return NOTIFY_DONE;
799 }
800
801 /* Framebuffer operation handlers */
802
803 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
804 {
805         if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
806             var->xres > screen_width || var->yres >  screen_height ||
807             var->bits_per_pixel != screen_depth)
808                 return -EINVAL;
809
810         var->xres_virtual = var->xres;
811         var->yres_virtual = var->yres;
812
813         return 0;
814 }
815
816 static int hvfb_set_par(struct fb_info *info)
817 {
818         struct hv_device *hdev = device_to_hv_device(info->device);
819
820         return synthvid_send_situ(hdev);
821 }
822
823
824 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
825 {
826         return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
827 }
828
829 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
830                           unsigned blue, unsigned transp, struct fb_info *info)
831 {
832         u32 *pal = info->pseudo_palette;
833
834         if (regno > 15)
835                 return -EINVAL;
836
837         pal[regno] = chan_to_field(red, &info->var.red)
838                 | chan_to_field(green, &info->var.green)
839                 | chan_to_field(blue, &info->var.blue)
840                 | chan_to_field(transp, &info->var.transp);
841
842         return 0;
843 }
844
845 static int hvfb_blank(int blank, struct fb_info *info)
846 {
847         return 1;       /* get fb_blank to set the colormap to all black */
848 }
849
850 static void hvfb_cfb_fillrect(struct fb_info *p,
851                               const struct fb_fillrect *rect)
852 {
853         struct hvfb_par *par = p->par;
854
855         cfb_fillrect(p, rect);
856         if (par->synchronous_fb)
857                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
858         else
859                 hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
860                                                rect->width, rect->height);
861 }
862
863 static void hvfb_cfb_copyarea(struct fb_info *p,
864                               const struct fb_copyarea *area)
865 {
866         struct hvfb_par *par = p->par;
867
868         cfb_copyarea(p, area);
869         if (par->synchronous_fb)
870                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
871         else
872                 hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
873                                                area->width, area->height);
874 }
875
876 static void hvfb_cfb_imageblit(struct fb_info *p,
877                                const struct fb_image *image)
878 {
879         struct hvfb_par *par = p->par;
880
881         cfb_imageblit(p, image);
882         if (par->synchronous_fb)
883                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
884         else
885                 hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
886                                                image->width, image->height);
887 }
888
889 static const struct fb_ops hvfb_ops = {
890         .owner = THIS_MODULE,
891         .fb_check_var = hvfb_check_var,
892         .fb_set_par = hvfb_set_par,
893         .fb_setcolreg = hvfb_setcolreg,
894         .fb_fillrect = hvfb_cfb_fillrect,
895         .fb_copyarea = hvfb_cfb_copyarea,
896         .fb_imageblit = hvfb_cfb_imageblit,
897         .fb_blank = hvfb_blank,
898         .fb_mmap = fb_deferred_io_mmap,
899 };
900
901
902 /* Get options from kernel paramenter "video=" */
903 static void hvfb_get_option(struct fb_info *info)
904 {
905         struct hvfb_par *par = info->par;
906         char *opt = NULL, *p;
907         uint x = 0, y = 0;
908
909         if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
910                 return;
911
912         p = strsep(&opt, "x");
913         if (!*p || kstrtouint(p, 0, &x) ||
914             !opt || !*opt || kstrtouint(opt, 0, &y)) {
915                 pr_err("Screen option is invalid: skipped\n");
916                 return;
917         }
918
919         if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
920             (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
921             (x * y * screen_depth / 8 > screen_fb_size)) ||
922             (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
923              x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8)) {
924                 pr_err("Screen resolution option is out of range: skipped\n");
925                 return;
926         }
927
928         screen_width = x;
929         screen_height = y;
930         return;
931 }
932
933 /*
934  * Allocate enough contiguous physical memory.
935  * Return physical address if succeeded or -1 if failed.
936  */
937 static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
938                                    unsigned int request_size)
939 {
940         struct page *page = NULL;
941         dma_addr_t dma_handle;
942         void *vmem;
943         phys_addr_t paddr = 0;
944         unsigned int order = get_order(request_size);
945
946         if (request_size == 0)
947                 return -1;
948
949         if (order < MAX_ORDER) {
950                 /* Call alloc_pages if the size is less than 2^MAX_ORDER */
951                 page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
952                 if (!page)
953                         return -1;
954
955                 paddr = (page_to_pfn(page) << PAGE_SHIFT);
956         } else {
957                 /* Allocate from CMA */
958                 hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
959
960                 vmem = dma_alloc_coherent(&hdev->device,
961                                           round_up(request_size, PAGE_SIZE),
962                                           &dma_handle,
963                                           GFP_KERNEL | __GFP_NOWARN);
964
965                 if (!vmem)
966                         return -1;
967
968                 paddr = virt_to_phys(vmem);
969         }
970
971         return paddr;
972 }
973
974 /* Release contiguous physical memory */
975 static void hvfb_release_phymem(struct hv_device *hdev,
976                                 phys_addr_t paddr, unsigned int size)
977 {
978         unsigned int order = get_order(size);
979
980         if (order < MAX_ORDER)
981                 __free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
982         else
983                 dma_free_coherent(&hdev->device,
984                                   round_up(size, PAGE_SIZE),
985                                   phys_to_virt(paddr),
986                                   paddr);
987 }
988
989
990 /* Get framebuffer memory from Hyper-V video pci space */
991 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
992 {
993         struct hvfb_par *par = info->par;
994         struct pci_dev *pdev  = NULL;
995         void __iomem *fb_virt;
996         int gen2vm = efi_enabled(EFI_BOOT);
997         resource_size_t base, size;
998         phys_addr_t paddr;
999         int ret;
1000
1001         if (!gen2vm) {
1002                 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
1003                         PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
1004                 if (!pdev) {
1005                         pr_err("Unable to find PCI Hyper-V video\n");
1006                         return -ENODEV;
1007                 }
1008
1009                 base = pci_resource_start(pdev, 0);
1010                 size = pci_resource_len(pdev, 0);
1011
1012                 /*
1013                  * For Gen 1 VM, we can directly use the contiguous memory
1014                  * from VM. If we succeed, deferred IO happens directly
1015                  * on this allocated framebuffer memory, avoiding extra
1016                  * memory copy.
1017                  */
1018                 paddr = hvfb_get_phymem(hdev, screen_fb_size);
1019                 if (paddr != (phys_addr_t) -1) {
1020                         par->mmio_pp = paddr;
1021                         par->mmio_vp = par->dio_vp = __va(paddr);
1022
1023                         info->fix.smem_start = paddr;
1024                         info->fix.smem_len = screen_fb_size;
1025                         info->screen_base = par->mmio_vp;
1026                         info->screen_size = screen_fb_size;
1027
1028                         par->need_docopy = false;
1029                         goto getmem_done;
1030                 }
1031                 pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1032         } else {
1033                 base = screen_info.lfb_base;
1034                 size = screen_info.lfb_size;
1035         }
1036
1037         /*
1038          * Cannot use the contiguous physical memory.
1039          * Allocate mmio space for framebuffer.
1040          */
1041         dio_fb_size =
1042                 screen_width * screen_height * screen_depth / 8;
1043
1044         ret = vmbus_allocate_mmio(&par->mem, hdev, 0, -1,
1045                                   screen_fb_size, 0x100000, true);
1046         if (ret != 0) {
1047                 pr_err("Unable to allocate framebuffer memory\n");
1048                 goto err1;
1049         }
1050
1051         /*
1052          * Map the VRAM cacheable for performance. This is also required for
1053          * VM Connect to display properly for ARM64 Linux VM, as the host also
1054          * maps the VRAM cacheable.
1055          */
1056         fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1057         if (!fb_virt)
1058                 goto err2;
1059
1060         /* Allocate memory for deferred IO */
1061         par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1062         if (par->dio_vp == NULL)
1063                 goto err3;
1064
1065         /* Physical address of FB device */
1066         par->mmio_pp = par->mem->start;
1067         /* Virtual address of FB device */
1068         par->mmio_vp = (unsigned char *) fb_virt;
1069
1070         info->fix.smem_start = par->mem->start;
1071         info->fix.smem_len = dio_fb_size;
1072         info->screen_base = par->dio_vp;
1073         info->screen_size = dio_fb_size;
1074
1075 getmem_done:
1076         aperture_remove_conflicting_devices(base, size, false, KBUILD_MODNAME);
1077
1078         if (gen2vm) {
1079                 /* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
1080                 screen_info.lfb_size = 0;
1081                 screen_info.lfb_base = 0;
1082                 screen_info.orig_video_isVGA = 0;
1083         } else {
1084                 pci_dev_put(pdev);
1085         }
1086
1087         return 0;
1088
1089 err3:
1090         iounmap(fb_virt);
1091 err2:
1092         vmbus_free_mmio(par->mem->start, screen_fb_size);
1093         par->mem = NULL;
1094 err1:
1095         if (!gen2vm)
1096                 pci_dev_put(pdev);
1097
1098         return -ENOMEM;
1099 }
1100
1101 /* Release the framebuffer */
1102 static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1103 {
1104         struct hvfb_par *par = info->par;
1105
1106         if (par->need_docopy) {
1107                 vfree(par->dio_vp);
1108                 iounmap(info->screen_base);
1109                 vmbus_free_mmio(par->mem->start, screen_fb_size);
1110         } else {
1111                 hvfb_release_phymem(hdev, info->fix.smem_start,
1112                                     screen_fb_size);
1113         }
1114
1115         par->mem = NULL;
1116 }
1117
1118
1119 static int hvfb_probe(struct hv_device *hdev,
1120                       const struct hv_vmbus_device_id *dev_id)
1121 {
1122         struct fb_info *info;
1123         struct hvfb_par *par;
1124         int ret;
1125
1126         info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1127         if (!info)
1128                 return -ENOMEM;
1129
1130         par = info->par;
1131         par->info = info;
1132         par->fb_ready = false;
1133         par->need_docopy = true;
1134         init_completion(&par->wait);
1135         INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1136
1137         par->delayed_refresh = false;
1138         spin_lock_init(&par->delayed_refresh_lock);
1139         par->x1 = par->y1 = INT_MAX;
1140         par->x2 = par->y2 = 0;
1141
1142         /* Connect to VSP */
1143         hv_set_drvdata(hdev, info);
1144         ret = synthvid_connect_vsp(hdev);
1145         if (ret) {
1146                 pr_err("Unable to connect to VSP\n");
1147                 goto error1;
1148         }
1149
1150         hvfb_get_option(info);
1151         pr_info("Screen resolution: %dx%d, Color depth: %d, Frame buffer size: %d\n",
1152                 screen_width, screen_height, screen_depth, screen_fb_size);
1153
1154         ret = hvfb_getmem(hdev, info);
1155         if (ret) {
1156                 pr_err("No memory for framebuffer\n");
1157                 goto error2;
1158         }
1159
1160         /* Set up fb_info */
1161         info->flags = FBINFO_DEFAULT;
1162
1163         info->var.xres_virtual = info->var.xres = screen_width;
1164         info->var.yres_virtual = info->var.yres = screen_height;
1165         info->var.bits_per_pixel = screen_depth;
1166
1167         if (info->var.bits_per_pixel == 16) {
1168                 info->var.red = (struct fb_bitfield){11, 5, 0};
1169                 info->var.green = (struct fb_bitfield){5, 6, 0};
1170                 info->var.blue = (struct fb_bitfield){0, 5, 0};
1171                 info->var.transp = (struct fb_bitfield){0, 0, 0};
1172         } else {
1173                 info->var.red = (struct fb_bitfield){16, 8, 0};
1174                 info->var.green = (struct fb_bitfield){8, 8, 0};
1175                 info->var.blue = (struct fb_bitfield){0, 8, 0};
1176                 info->var.transp = (struct fb_bitfield){24, 8, 0};
1177         }
1178
1179         info->var.activate = FB_ACTIVATE_NOW;
1180         info->var.height = -1;
1181         info->var.width = -1;
1182         info->var.vmode = FB_VMODE_NONINTERLACED;
1183
1184         strcpy(info->fix.id, KBUILD_MODNAME);
1185         info->fix.type = FB_TYPE_PACKED_PIXELS;
1186         info->fix.visual = FB_VISUAL_TRUECOLOR;
1187         info->fix.line_length = screen_width * screen_depth / 8;
1188         info->fix.accel = FB_ACCEL_NONE;
1189
1190         info->fbops = &hvfb_ops;
1191         info->pseudo_palette = par->pseudo_palette;
1192
1193         /* Initialize deferred IO */
1194         info->fbdefio = &synthvid_defio;
1195         fb_deferred_io_init(info);
1196
1197         /* Send config to host */
1198         ret = synthvid_send_config(hdev);
1199         if (ret)
1200                 goto error;
1201
1202         ret = register_framebuffer(info);
1203         if (ret) {
1204                 pr_err("Unable to register framebuffer\n");
1205                 goto error;
1206         }
1207
1208         par->fb_ready = true;
1209
1210         par->synchronous_fb = false;
1211
1212         /*
1213          * We need to be sure this panic notifier runs _before_ the
1214          * vmbus disconnect, so order it by priority. It must execute
1215          * before the function hv_panic_vmbus_unload() [drivers/hv/vmbus_drv.c],
1216          * which is almost at the end of list, with priority = INT_MIN + 1.
1217          */
1218         par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1219         par->hvfb_panic_nb.priority = INT_MIN + 10,
1220         atomic_notifier_chain_register(&panic_notifier_list,
1221                                        &par->hvfb_panic_nb);
1222
1223         return 0;
1224
1225 error:
1226         fb_deferred_io_cleanup(info);
1227         hvfb_putmem(hdev, info);
1228 error2:
1229         vmbus_close(hdev->channel);
1230 error1:
1231         cancel_delayed_work_sync(&par->dwork);
1232         hv_set_drvdata(hdev, NULL);
1233         framebuffer_release(info);
1234         return ret;
1235 }
1236
1237
1238 static int hvfb_remove(struct hv_device *hdev)
1239 {
1240         struct fb_info *info = hv_get_drvdata(hdev);
1241         struct hvfb_par *par = info->par;
1242
1243         atomic_notifier_chain_unregister(&panic_notifier_list,
1244                                          &par->hvfb_panic_nb);
1245
1246         par->update = false;
1247         par->fb_ready = false;
1248
1249         fb_deferred_io_cleanup(info);
1250
1251         unregister_framebuffer(info);
1252         cancel_delayed_work_sync(&par->dwork);
1253
1254         vmbus_close(hdev->channel);
1255         hv_set_drvdata(hdev, NULL);
1256
1257         hvfb_putmem(hdev, info);
1258         framebuffer_release(info);
1259
1260         return 0;
1261 }
1262
1263 static int hvfb_suspend(struct hv_device *hdev)
1264 {
1265         struct fb_info *info = hv_get_drvdata(hdev);
1266         struct hvfb_par *par = info->par;
1267
1268         console_lock();
1269
1270         /* 1 means do suspend */
1271         fb_set_suspend(info, 1);
1272
1273         cancel_delayed_work_sync(&par->dwork);
1274         cancel_delayed_work_sync(&info->deferred_work);
1275
1276         par->update_saved = par->update;
1277         par->update = false;
1278         par->fb_ready = false;
1279
1280         vmbus_close(hdev->channel);
1281
1282         console_unlock();
1283
1284         return 0;
1285 }
1286
1287 static int hvfb_resume(struct hv_device *hdev)
1288 {
1289         struct fb_info *info = hv_get_drvdata(hdev);
1290         struct hvfb_par *par = info->par;
1291         int ret;
1292
1293         console_lock();
1294
1295         ret = synthvid_connect_vsp(hdev);
1296         if (ret != 0)
1297                 goto out;
1298
1299         ret = synthvid_send_config(hdev);
1300         if (ret != 0) {
1301                 vmbus_close(hdev->channel);
1302                 goto out;
1303         }
1304
1305         par->fb_ready = true;
1306         par->update = par->update_saved;
1307
1308         schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1309         schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1310
1311         /* 0 means do resume */
1312         fb_set_suspend(info, 0);
1313
1314 out:
1315         console_unlock();
1316
1317         return ret;
1318 }
1319
1320
1321 static const struct pci_device_id pci_stub_id_table[] = {
1322         {
1323                 .vendor      = PCI_VENDOR_ID_MICROSOFT,
1324                 .device      = PCI_DEVICE_ID_HYPERV_VIDEO,
1325         },
1326         { /* end of list */ }
1327 };
1328
1329 static const struct hv_vmbus_device_id id_table[] = {
1330         /* Synthetic Video Device GUID */
1331         {HV_SYNTHVID_GUID},
1332         {}
1333 };
1334
1335 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1336 MODULE_DEVICE_TABLE(vmbus, id_table);
1337
1338 static struct hv_driver hvfb_drv = {
1339         .name = KBUILD_MODNAME,
1340         .id_table = id_table,
1341         .probe = hvfb_probe,
1342         .remove = hvfb_remove,
1343         .suspend = hvfb_suspend,
1344         .resume = hvfb_resume,
1345         .driver = {
1346                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1347         },
1348 };
1349
1350 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1351                                const struct pci_device_id *ent)
1352 {
1353         return 0;
1354 }
1355
1356 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1357 {
1358 }
1359
1360 static struct pci_driver hvfb_pci_stub_driver = {
1361         .name =         KBUILD_MODNAME,
1362         .id_table =     pci_stub_id_table,
1363         .probe =        hvfb_pci_stub_probe,
1364         .remove =       hvfb_pci_stub_remove,
1365         .driver = {
1366                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1367         }
1368 };
1369
1370 static int __init hvfb_drv_init(void)
1371 {
1372         int ret;
1373
1374         if (fb_modesetting_disabled("hyper_fb"))
1375                 return -ENODEV;
1376
1377         ret = vmbus_driver_register(&hvfb_drv);
1378         if (ret != 0)
1379                 return ret;
1380
1381         ret = pci_register_driver(&hvfb_pci_stub_driver);
1382         if (ret != 0) {
1383                 vmbus_driver_unregister(&hvfb_drv);
1384                 return ret;
1385         }
1386
1387         return 0;
1388 }
1389
1390 static void __exit hvfb_drv_exit(void)
1391 {
1392         pci_unregister_driver(&hvfb_pci_stub_driver);
1393         vmbus_driver_unregister(&hvfb_drv);
1394 }
1395
1396 module_init(hvfb_drv_init);
1397 module_exit(hvfb_drv_exit);
1398
1399 MODULE_LICENSE("GPL");
1400 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");