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/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_width_max = HVFB_WIDTH;
 291 static uint screen_height_max = HVFB_HEIGHT;
 292 static uint screen_depth;
 293 static uint screen_fb_size;
 294 static uint dio_fb_size; /* FB size for deferred IO */
 295
 296 /* Send message to Hyper-V host */
 297 static inline int synthvid_send(struct hv_device *hdev,
 298                                 struct synthvid_msg *msg)
 299 {
 300         static atomic64_t request_id = ATOMIC64_INIT(0);
 301         int ret;
 302
 303         msg->pipe_hdr.type = PIPE_MSG_DATA;
 304         msg->pipe_hdr.size = msg->vid_hdr.size;
 305
 306         ret = vmbus_sendpacket(hdev->channel, msg,
 307                                msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
 308                                atomic64_inc_return(&request_id),
 309                                VM_PKT_DATA_INBAND, 0);
 310
 311         if (ret)
 312                 pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);
 313
 314         return ret;
 315 }
 316
 317
 318 /* Send screen resolution info to host */
 319 static int synthvid_send_situ(struct hv_device *hdev)
 320 {
 321         struct fb_info *info = hv_get_drvdata(hdev);
 322         struct synthvid_msg msg;
 323
 324         if (!info)
 325                 return -ENODEV;
 326
 327         memset(&msg, 0, sizeof(struct synthvid_msg));
 328
 329         msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
 330         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 331                 sizeof(struct synthvid_situation_update);
 332         msg.situ.user_ctx = 0;
 333         msg.situ.video_output_count = 1;
 334         msg.situ.video_output[0].active = 1;
 335         msg.situ.video_output[0].vram_offset = 0;
 336         msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
 337         msg.situ.video_output[0].width_pixels = info->var.xres;
 338         msg.situ.video_output[0].height_pixels = info->var.yres;
 339         msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
 340
 341         synthvid_send(hdev, &msg);
 342
 343         return 0;
 344 }
 345
 346 /* Send mouse pointer info to host */
 347 static int synthvid_send_ptr(struct hv_device *hdev)
 348 {
 349         struct synthvid_msg msg;
 350
 351         memset(&msg, 0, sizeof(struct synthvid_msg));
 352         msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
 353         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 354                 sizeof(struct synthvid_pointer_position);
 355         msg.ptr_pos.is_visible = 1;
 356         msg.ptr_pos.video_output = 0;
 357         msg.ptr_pos.image_x = 0;
 358         msg.ptr_pos.image_y = 0;
 359         synthvid_send(hdev, &msg);
 360
 361         memset(&msg, 0, sizeof(struct synthvid_msg));
 362         msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
 363         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 364                 sizeof(struct synthvid_pointer_shape);
 365         msg.ptr_shape.part_idx = CURSOR_COMPLETE;
 366         msg.ptr_shape.is_argb = 1;
 367         msg.ptr_shape.width = 1;
 368         msg.ptr_shape.height = 1;
 369         msg.ptr_shape.hot_x = 0;
 370         msg.ptr_shape.hot_y = 0;
 371         msg.ptr_shape.data[0] = 0;
 372         msg.ptr_shape.data[1] = 1;
 373         msg.ptr_shape.data[2] = 1;
 374         msg.ptr_shape.data[3] = 1;
 375         synthvid_send(hdev, &msg);
 376
 377         return 0;
 378 }
 379
 380 /* Send updated screen area (dirty rectangle) location to host */
 381 static int
 382 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
 383 {
 384         struct hv_device *hdev = device_to_hv_device(info->device);
 385         struct synthvid_msg msg;
 386
 387         memset(&msg, 0, sizeof(struct synthvid_msg));
 388         if (x2 == INT_MAX)
 389                 x2 = info->var.xres;
 390         if (y2 == INT_MAX)
 391                 y2 = info->var.yres;
 392
 393         msg.vid_hdr.type = SYNTHVID_DIRT;
 394         msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 395                 sizeof(struct synthvid_dirt);
 396         msg.dirt.video_output = 0;
 397         msg.dirt.dirt_count = 1;
 398         msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
 399         msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
 400         msg.dirt.rect[0].x2 =
 401                 (x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
 402         msg.dirt.rect[0].y2 =
 403                 (y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
 404
 405         synthvid_send(hdev, &msg);
 406
 407         return 0;
 408 }
 409
 410 static void hvfb_docopy(struct hvfb_par *par,
 411                         unsigned long offset,
 412                         unsigned long size)
 413 {
 414         if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
 415             size == 0 || offset >= dio_fb_size)
 416                 return;
 417
 418         if (offset + size > dio_fb_size)
 419                 size = dio_fb_size - offset;
 420
 421         memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
 422 }
 423
 424 /* Deferred IO callback */
 425 static void synthvid_deferred_io(struct fb_info *p,
 426                                  struct list_head *pagelist)
 427 {
 428         struct hvfb_par *par = p->par;
 429         struct page *page;
 430         unsigned long start, end;
 431         int y1, y2, miny, maxy;
 432
 433         miny = INT_MAX;
 434         maxy = 0;
 435
 436         /*
 437          * Merge dirty pages. It is possible that last page cross
 438          * over the end of frame buffer row yres. This is taken care of
 439          * in synthvid_update function by clamping the y2
 440          * value to yres.
 441          */
 442         list_for_each_entry(page, pagelist, lru) {
 443                 start = page->index << PAGE_SHIFT;
 444                 end = start + PAGE_SIZE - 1;
 445                 y1 = start / p->fix.line_length;
 446                 y2 = end / p->fix.line_length;
 447                 miny = min_t(int, miny, y1);
 448                 maxy = max_t(int, maxy, y2);
 449
 450                 /* Copy from dio space to mmio address */
 451                 if (par->fb_ready && par->need_docopy)
 452                         hvfb_docopy(par, start, PAGE_SIZE);
 453         }
 454
 455         if (par->fb_ready && par->update)
 456                 synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
 457 }
 458
 459 static struct fb_deferred_io synthvid_defio = {
 460         .delay          = HZ / 20,
 461         .deferred_io    = synthvid_deferred_io,
 462 };
 463
 464 /*
 465  * Actions on received messages from host:
 466  * Complete the wait event.
 467  * Or, reply with screen and cursor info.
 468  */
 469 static void synthvid_recv_sub(struct hv_device *hdev)
 470 {
 471         struct fb_info *info = hv_get_drvdata(hdev);
 472         struct hvfb_par *par;
 473         struct synthvid_msg *msg;
 474
 475         if (!info)
 476                 return;
 477
 478         par = info->par;
 479         msg = (struct synthvid_msg *)par->recv_buf;
 480
 481         /* Complete the wait event */
 482         if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
 483             msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
 484             msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
 485                 memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
 486                 complete(&par->wait);
 487                 return;
 488         }
 489
 490         /* Reply with screen and cursor info */
 491         if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
 492                 if (par->fb_ready) {
 493                         synthvid_send_ptr(hdev);
 494                         synthvid_send_situ(hdev);
 495                 }
 496
 497                 par->update = msg->feature_chg.is_dirt_needed;
 498                 if (par->update)
 499                         schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
 500         }
 501 }
 502
 503 /* Receive callback for messages from the host */
 504 static void synthvid_receive(void *ctx)
 505 {
 506         struct hv_device *hdev = ctx;
 507         struct fb_info *info = hv_get_drvdata(hdev);
 508         struct hvfb_par *par;
 509         struct synthvid_msg *recv_buf;
 510         u32 bytes_recvd;
 511         u64 req_id;
 512         int ret;
 513
 514         if (!info)
 515                 return;
 516
 517         par = info->par;
 518         recv_buf = (struct synthvid_msg *)par->recv_buf;
 519
 520         do {
 521                 ret = vmbus_recvpacket(hdev->channel, recv_buf,
 522                                        MAX_VMBUS_PKT_SIZE,
 523                                        &bytes_recvd, &req_id);
 524                 if (bytes_recvd > 0 &&
 525                     recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
 526                         synthvid_recv_sub(hdev);
 527         } while (bytes_recvd > 0 && ret == 0);
 528 }
 529
 530 /* Check if the ver1 version is equal or greater than ver2 */
 531 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
 532 {
 533         if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
 534             (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
 535              SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
 536                 return true;
 537
 538         return false;
 539 }
 540
 541 /* Check synthetic video protocol version with the host */
 542 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
 543 {
 544         struct fb_info *info = hv_get_drvdata(hdev);
 545         struct hvfb_par *par = info->par;
 546         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
 547         int ret = 0;
 548         unsigned long t;
 549
 550         memset(msg, 0, sizeof(struct synthvid_msg));
 551         msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
 552         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 553                 sizeof(struct synthvid_version_req);
 554         msg->ver_req.version = ver;
 555         synthvid_send(hdev, msg);
 556
 557         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
 558         if (!t) {
 559                 pr_err("Time out on waiting version response\n");
 560                 ret = -ETIMEDOUT;
 561                 goto out;
 562         }
 563         if (!msg->ver_resp.is_accepted) {
 564                 ret = -ENODEV;
 565                 goto out;
 566         }
 567
 568         par->synthvid_version = ver;
 569         pr_info("Synthvid Version major %d, minor %d\n",
 570                 SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
 571
 572 out:
 573         return ret;
 574 }
 575
 576 /* Get current resolution from the host */
 577 static int synthvid_get_supported_resolution(struct hv_device *hdev)
 578 {
 579         struct fb_info *info = hv_get_drvdata(hdev);
 580         struct hvfb_par *par = info->par;
 581         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
 582         int ret = 0;
 583         unsigned long t;
 584         u8 index;
 585         int i;
 586
 587         memset(msg, 0, sizeof(struct synthvid_msg));
 588         msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
 589         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 590                 sizeof(struct synthvid_supported_resolution_req);
 591
 592         msg->resolution_req.maximum_resolution_count =
 593                 SYNTHVID_MAX_RESOLUTION_COUNT;
 594         synthvid_send(hdev, msg);
 595
 596         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
 597         if (!t) {
 598                 pr_err("Time out on waiting resolution response\n");
 599                 ret = -ETIMEDOUT;
 600                 goto out;
 601         }
 602
 603         if (msg->resolution_resp.resolution_count == 0) {
 604                 pr_err("No supported resolutions\n");
 605                 ret = -ENODEV;
 606                 goto out;
 607         }
 608
 609         index = msg->resolution_resp.default_resolution_index;
 610         if (index >= msg->resolution_resp.resolution_count) {
 611                 pr_err("Invalid resolution index: %d\n", index);
 612                 ret = -ENODEV;
 613                 goto out;
 614         }
 615
 616         for (i = 0; i < msg->resolution_resp.resolution_count; i++) {
 617                 screen_width_max = max_t(unsigned int, screen_width_max,
 618                     msg->resolution_resp.supported_resolution[i].width);
 619                 screen_height_max = max_t(unsigned int, screen_height_max,
 620                     msg->resolution_resp.supported_resolution[i].height);
 621         }
 622
 623         screen_width =
 624                 msg->resolution_resp.supported_resolution[index].width;
 625         screen_height =
 626                 msg->resolution_resp.supported_resolution[index].height;
 627
 628 out:
 629         return ret;
 630 }
 631
 632 /* Connect to VSP (Virtual Service Provider) on host */
 633 static int synthvid_connect_vsp(struct hv_device *hdev)
 634 {
 635         struct fb_info *info = hv_get_drvdata(hdev);
 636         struct hvfb_par *par = info->par;
 637         int ret;
 638
 639         ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
 640                          NULL, 0, synthvid_receive, hdev);
 641         if (ret) {
 642                 pr_err("Unable to open vmbus channel\n");
 643                 return ret;
 644         }
 645
 646         /* Negotiate the protocol version with host */
 647         switch (vmbus_proto_version) {
 648         case VERSION_WIN10:
 649         case VERSION_WIN10_V5:
 650                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
 651                 if (!ret)
 652                         break;
 653                 fallthrough;
 654         case VERSION_WIN8:
 655         case VERSION_WIN8_1:
 656                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
 657                 if (!ret)
 658                         break;
 659                 fallthrough;
 660         case VERSION_WS2008:
 661         case VERSION_WIN7:
 662                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
 663                 break;
 664         default:
 665                 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
 666                 break;
 667         }
 668
 669         if (ret) {
 670                 pr_err("Synthetic video device version not accepted\n");
 671                 goto error;
 672         }
 673
 674         if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
 675                 screen_depth = SYNTHVID_DEPTH_WIN7;
 676         else
 677                 screen_depth = SYNTHVID_DEPTH_WIN8;
 678
 679         if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
 680                 ret = synthvid_get_supported_resolution(hdev);
 681                 if (ret)
 682                         pr_info("Failed to get supported resolution from host, use default\n");
 683         }
 684
 685         screen_fb_size = hdev->channel->offermsg.offer.
 686                                 mmio_megabytes * 1024 * 1024;
 687
 688         return 0;
 689
 690 error:
 691         vmbus_close(hdev->channel);
 692         return ret;
 693 }
 694
 695 /* Send VRAM and Situation messages to the host */
 696 static int synthvid_send_config(struct hv_device *hdev)
 697 {
 698         struct fb_info *info = hv_get_drvdata(hdev);
 699         struct hvfb_par *par = info->par;
 700         struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
 701         int ret = 0;
 702         unsigned long t;
 703
 704         /* Send VRAM location */
 705         memset(msg, 0, sizeof(struct synthvid_msg));
 706         msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
 707         msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 708                 sizeof(struct synthvid_vram_location);
 709         msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
 710         msg->vram.is_vram_gpa_specified = 1;
 711         synthvid_send(hdev, msg);
 712
 713         t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
 714         if (!t) {
 715                 pr_err("Time out on waiting vram location ack\n");
 716                 ret = -ETIMEDOUT;
 717                 goto out;
 718         }
 719         if (msg->vram_ack.user_ctx != par->mmio_pp) {
 720                 pr_err("Unable to set VRAM location\n");
 721                 ret = -ENODEV;
 722                 goto out;
 723         }
 724
 725         /* Send pointer and situation update */
 726         synthvid_send_ptr(hdev);
 727         synthvid_send_situ(hdev);
 728
 729 out:
 730         return ret;
 731 }
 732
 733
 734 /*
 735  * Delayed work callback:
 736  * It is scheduled to call whenever update request is received and it has
 737  * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
 738  */
 739 static void hvfb_update_work(struct work_struct *w)
 740 {
 741         struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
 742         struct fb_info *info = par->info;
 743         unsigned long flags;
 744         int x1, x2, y1, y2;
 745         int j;
 746
 747         spin_lock_irqsave(&par->delayed_refresh_lock, flags);
 748         /* Reset the request flag */
 749         par->delayed_refresh = false;
 750
 751         /* Store the dirty rectangle to local variables */
 752         x1 = par->x1;
 753         x2 = par->x2;
 754         y1 = par->y1;
 755         y2 = par->y2;
 756
 757         /* Clear dirty rectangle */
 758         par->x1 = par->y1 = INT_MAX;
 759         par->x2 = par->y2 = 0;
 760
 761         spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
 762
 763         if (x1 > info->var.xres || x2 > info->var.xres ||
 764             y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
 765                 return;
 766
 767         /* Copy the dirty rectangle to frame buffer memory */
 768         if (par->need_docopy)
 769                 for (j = y1; j < y2; j++)
 770                         hvfb_docopy(par,
 771                                     j * info->fix.line_length +
 772                                     (x1 * screen_depth / 8),
 773                                     (x2 - x1) * screen_depth / 8);
 774
 775         /* Refresh */
 776         if (par->fb_ready && par->update)
 777                 synthvid_update(info, x1, y1, x2, y2);
 778 }
 779
 780 /*
 781  * Control the on-demand refresh frequency. It schedules a delayed
 782  * screen update if it has not yet.
 783  */
 784 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
 785                                            int x1, int y1, int w, int h)
 786 {
 787         unsigned long flags;
 788         int x2 = x1 + w;
 789         int y2 = y1 + h;
 790
 791         spin_lock_irqsave(&par->delayed_refresh_lock, flags);
 792
 793         /* Merge dirty rectangle */
 794         par->x1 = min_t(int, par->x1, x1);
 795         par->y1 = min_t(int, par->y1, y1);
 796         par->x2 = max_t(int, par->x2, x2);
 797         par->y2 = max_t(int, par->y2, y2);
 798
 799         /* Schedule a delayed screen update if not yet */
 800         if (par->delayed_refresh == false) {
 801                 schedule_delayed_work(&par->dwork,
 802                                       HVFB_ONDEMAND_THROTTLE);
 803                 par->delayed_refresh = true;
 804         }
 805
 806         spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
 807 }
 808
 809 static int hvfb_on_panic(struct notifier_block *nb,
 810                          unsigned long e, void *p)
 811 {
 812         struct hvfb_par *par;
 813         struct fb_info *info;
 814
 815         par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
 816         par->synchronous_fb = true;
 817         info = par->info;
 818         if (par->need_docopy)
 819                 hvfb_docopy(par, 0, dio_fb_size);
 820         synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
 821
 822         return NOTIFY_DONE;
 823 }
 824
 825 /* Framebuffer operation handlers */
 826
 827 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
 828 {
 829         if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
 830             var->xres > screen_width || var->yres >  screen_height ||
 831             var->bits_per_pixel != screen_depth)
 832                 return -EINVAL;
 833
 834         var->xres_virtual = var->xres;
 835         var->yres_virtual = var->yres;
 836
 837         return 0;
 838 }
 839
 840 static int hvfb_set_par(struct fb_info *info)
 841 {
 842         struct hv_device *hdev = device_to_hv_device(info->device);
 843
 844         return synthvid_send_situ(hdev);
 845 }
 846
 847
 848 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
 849 {
 850         return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
 851 }
 852
 853 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
 854                           unsigned blue, unsigned transp, struct fb_info *info)
 855 {
 856         u32 *pal = info->pseudo_palette;
 857
 858         if (regno > 15)
 859                 return -EINVAL;
 860
 861         pal[regno] = chan_to_field(red, &info->var.red)
 862                 | chan_to_field(green, &info->var.green)
 863                 | chan_to_field(blue, &info->var.blue)
 864                 | chan_to_field(transp, &info->var.transp);
 865
 866         return 0;
 867 }
 868
 869 static int hvfb_blank(int blank, struct fb_info *info)
 870 {
 871         return 1;       /* get fb_blank to set the colormap to all black */
 872 }
 873
 874 static void hvfb_cfb_fillrect(struct fb_info *p,
 875                               const struct fb_fillrect *rect)
 876 {
 877         struct hvfb_par *par = p->par;
 878
 879         cfb_fillrect(p, rect);
 880         if (par->synchronous_fb)
 881                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
 882         else
 883                 hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
 884                                                rect->width, rect->height);
 885 }
 886
 887 static void hvfb_cfb_copyarea(struct fb_info *p,
 888                               const struct fb_copyarea *area)
 889 {
 890         struct hvfb_par *par = p->par;
 891
 892         cfb_copyarea(p, area);
 893         if (par->synchronous_fb)
 894                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
 895         else
 896                 hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
 897                                                area->width, area->height);
 898 }
 899
 900 static void hvfb_cfb_imageblit(struct fb_info *p,
 901                                const struct fb_image *image)
 902 {
 903         struct hvfb_par *par = p->par;
 904
 905         cfb_imageblit(p, image);
 906         if (par->synchronous_fb)
 907                 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
 908         else
 909                 hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
 910                                                image->width, image->height);
 911 }
 912
 913 static const struct fb_ops hvfb_ops = {
 914         .owner = THIS_MODULE,
 915         .fb_check_var = hvfb_check_var,
 916         .fb_set_par = hvfb_set_par,
 917         .fb_setcolreg = hvfb_setcolreg,
 918         .fb_fillrect = hvfb_cfb_fillrect,
 919         .fb_copyarea = hvfb_cfb_copyarea,
 920         .fb_imageblit = hvfb_cfb_imageblit,
 921         .fb_blank = hvfb_blank,
 922 };
 923
 924
 925 /* Get options from kernel paramenter "video=" */
 926 static void hvfb_get_option(struct fb_info *info)
 927 {
 928         struct hvfb_par *par = info->par;
 929         char *opt = NULL, *p;
 930         uint x = 0, y = 0;
 931
 932         if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
 933                 return;
 934
 935         p = strsep(&opt, "x");
 936         if (!*p || kstrtouint(p, 0, &x) ||
 937             !opt || !*opt || kstrtouint(opt, 0, &y)) {
 938                 pr_err("Screen option is invalid: skipped\n");
 939                 return;
 940         }
 941
 942         if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
 943             (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
 944             (x > screen_width_max || y > screen_height_max)) ||
 945             (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
 946              x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
 947             (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
 948              (x > SYNTHVID_WIDTH_MAX_WIN7 || y > SYNTHVID_HEIGHT_MAX_WIN7))) {
 949                 pr_err("Screen resolution option is out of range: skipped\n");
 950                 return;
 951         }
 952
 953         screen_width = x;
 954         screen_height = y;
 955         return;
 956 }
 957
 958 /*
 959  * Allocate enough contiguous physical memory.
 960  * Return physical address if succeeded or -1 if failed.
 961  */
 962 static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
 963                                    unsigned int request_size)
 964 {
 965         struct page *page = NULL;
 966         dma_addr_t dma_handle;
 967         void *vmem;
 968         phys_addr_t paddr = 0;
 969         unsigned int order = get_order(request_size);
 970
 971         if (request_size == 0)
 972                 return -1;
 973
 974         if (order < MAX_ORDER) {
 975                 /* Call alloc_pages if the size is less than 2^MAX_ORDER */
 976                 page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
 977                 if (!page)
 978                         return -1;
 979
 980                 paddr = (page_to_pfn(page) << PAGE_SHIFT);
 981         } else {
 982                 /* Allocate from CMA */
 983                 hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
 984
 985                 vmem = dma_alloc_coherent(&hdev->device,
 986                                           round_up(request_size, PAGE_SIZE),
 987                                           &dma_handle,
 988                                           GFP_KERNEL | __GFP_NOWARN);
 989
 990                 if (!vmem)
 991                         return -1;
 992
 993                 paddr = virt_to_phys(vmem);
 994         }
 995
 996         return paddr;
 997 }
 998
 999 /* Release contiguous physical memory */
1000 static void hvfb_release_phymem(struct hv_device *hdev,
1001                                 phys_addr_t paddr, unsigned int size)
1002 {
1003         unsigned int order = get_order(size);
1004
1005         if (order < MAX_ORDER)
1006                 __free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
1007         else
1008                 dma_free_coherent(&hdev->device,
1009                                   round_up(size, PAGE_SIZE),
1010                                   phys_to_virt(paddr),
1011                                   paddr);
1012 }
1013
1014
1015 /* Get framebuffer memory from Hyper-V video pci space */
1016 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
1017 {
1018         struct hvfb_par *par = info->par;
1019         struct pci_dev *pdev  = NULL;
1020         void __iomem *fb_virt;
1021         int gen2vm = efi_enabled(EFI_BOOT);
1022         resource_size_t pot_start, pot_end;
1023         phys_addr_t paddr;
1024         int ret;
1025
1026         info->apertures = alloc_apertures(1);
1027         if (!info->apertures)
1028                 return -ENOMEM;
1029
1030         if (!gen2vm) {
1031                 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
1032                         PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
1033                 if (!pdev) {
1034                         pr_err("Unable to find PCI Hyper-V video\n");
1035                         return -ENODEV;
1036                 }
1037
1038                 info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
1039                 info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
1040
1041                 /*
1042                  * For Gen 1 VM, we can directly use the contiguous memory
1043                  * from VM. If we succeed, deferred IO happens directly
1044                  * on this allocated framebuffer memory, avoiding extra
1045                  * memory copy.
1046                  */
1047                 paddr = hvfb_get_phymem(hdev, screen_fb_size);
1048                 if (paddr != (phys_addr_t) -1) {
1049                         par->mmio_pp = paddr;
1050                         par->mmio_vp = par->dio_vp = __va(paddr);
1051
1052                         info->fix.smem_start = paddr;
1053                         info->fix.smem_len = screen_fb_size;
1054                         info->screen_base = par->mmio_vp;
1055                         info->screen_size = screen_fb_size;
1056
1057                         par->need_docopy = false;
1058                         goto getmem_done;
1059                 }
1060                 pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1061         } else {
1062                 info->apertures->ranges[0].base = screen_info.lfb_base;
1063                 info->apertures->ranges[0].size = screen_info.lfb_size;
1064         }
1065
1066         /*
1067          * Cannot use the contiguous physical memory.
1068          * Allocate mmio space for framebuffer.
1069          */
1070         dio_fb_size =
1071                 screen_width * screen_height * screen_depth / 8;
1072
1073         if (gen2vm) {
1074                 pot_start = 0;
1075                 pot_end = -1;
1076         } else {
1077                 if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
1078                     pci_resource_len(pdev, 0) < screen_fb_size) {
1079                         pr_err("Resource not available or (0x%lx < 0x%lx)\n",
1080                                (unsigned long) pci_resource_len(pdev, 0),
1081                                (unsigned long) screen_fb_size);
1082                         goto err1;
1083                 }
1084
1085                 pot_end = pci_resource_end(pdev, 0);
1086                 pot_start = pot_end - screen_fb_size + 1;
1087         }
1088
1089         ret = vmbus_allocate_mmio(&par->mem, hdev, pot_start, pot_end,
1090                                   screen_fb_size, 0x100000, true);
1091         if (ret != 0) {
1092                 pr_err("Unable to allocate framebuffer memory\n");
1093                 goto err1;
1094         }
1095
1096         /*
1097          * Map the VRAM cacheable for performance. This is also required for
1098          * VM Connect to display properly for ARM64 Linux VM, as the host also
1099          * maps the VRAM cacheable.
1100          */
1101         fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1102         if (!fb_virt)
1103                 goto err2;
1104
1105         /* Allocate memory for deferred IO */
1106         par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1107         if (par->dio_vp == NULL)
1108                 goto err3;
1109
1110         /* Physical address of FB device */
1111         par->mmio_pp = par->mem->start;
1112         /* Virtual address of FB device */
1113         par->mmio_vp = (unsigned char *) fb_virt;
1114
1115         info->fix.smem_start = par->mem->start;
1116         info->fix.smem_len = dio_fb_size;
1117         info->screen_base = par->dio_vp;
1118         info->screen_size = dio_fb_size;
1119
1120 getmem_done:
1121         remove_conflicting_framebuffers(info->apertures,
1122                                         KBUILD_MODNAME, false);
1123
1124         if (gen2vm) {
1125                 /* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
1126                 screen_info.lfb_size = 0;
1127                 screen_info.lfb_base = 0;
1128                 screen_info.orig_video_isVGA = 0;
1129         } else {
1130                 pci_dev_put(pdev);
1131         }
1132
1133         return 0;
1134
1135 err3:
1136         iounmap(fb_virt);
1137 err2:
1138         vmbus_free_mmio(par->mem->start, screen_fb_size);
1139         par->mem = NULL;
1140 err1:
1141         if (!gen2vm)
1142                 pci_dev_put(pdev);
1143
1144         return -ENOMEM;
1145 }
1146
1147 /* Release the framebuffer */
1148 static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1149 {
1150         struct hvfb_par *par = info->par;
1151
1152         if (par->need_docopy) {
1153                 vfree(par->dio_vp);
1154                 iounmap(info->screen_base);
1155                 vmbus_free_mmio(par->mem->start, screen_fb_size);
1156         } else {
1157                 hvfb_release_phymem(hdev, info->fix.smem_start,
1158                                     screen_fb_size);
1159         }
1160
1161         par->mem = NULL;
1162 }
1163
1164
1165 static int hvfb_probe(struct hv_device *hdev,
1166                       const struct hv_vmbus_device_id *dev_id)
1167 {
1168         struct fb_info *info;
1169         struct hvfb_par *par;
1170         int ret;
1171
1172         info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1173         if (!info)
1174                 return -ENOMEM;
1175
1176         par = info->par;
1177         par->info = info;
1178         par->fb_ready = false;
1179         par->need_docopy = true;
1180         init_completion(&par->wait);
1181         INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1182
1183         par->delayed_refresh = false;
1184         spin_lock_init(&par->delayed_refresh_lock);
1185         par->x1 = par->y1 = INT_MAX;
1186         par->x2 = par->y2 = 0;
1187
1188         /* Connect to VSP */
1189         hv_set_drvdata(hdev, info);
1190         ret = synthvid_connect_vsp(hdev);
1191         if (ret) {
1192                 pr_err("Unable to connect to VSP\n");
1193                 goto error1;
1194         }
1195
1196         hvfb_get_option(info);
1197         pr_info("Screen resolution: %dx%d, Color depth: %d\n",
1198                 screen_width, screen_height, screen_depth);
1199
1200         ret = hvfb_getmem(hdev, info);
1201         if (ret) {
1202                 pr_err("No memory for framebuffer\n");
1203                 goto error2;
1204         }
1205
1206         /* Set up fb_info */
1207         info->flags = FBINFO_DEFAULT;
1208
1209         info->var.xres_virtual = info->var.xres = screen_width;
1210         info->var.yres_virtual = info->var.yres = screen_height;
1211         info->var.bits_per_pixel = screen_depth;
1212
1213         if (info->var.bits_per_pixel == 16) {
1214                 info->var.red = (struct fb_bitfield){11, 5, 0};
1215                 info->var.green = (struct fb_bitfield){5, 6, 0};
1216                 info->var.blue = (struct fb_bitfield){0, 5, 0};
1217                 info->var.transp = (struct fb_bitfield){0, 0, 0};
1218         } else {
1219                 info->var.red = (struct fb_bitfield){16, 8, 0};
1220                 info->var.green = (struct fb_bitfield){8, 8, 0};
1221                 info->var.blue = (struct fb_bitfield){0, 8, 0};
1222                 info->var.transp = (struct fb_bitfield){24, 8, 0};
1223         }
1224
1225         info->var.activate = FB_ACTIVATE_NOW;
1226         info->var.height = -1;
1227         info->var.width = -1;
1228         info->var.vmode = FB_VMODE_NONINTERLACED;
1229
1230         strcpy(info->fix.id, KBUILD_MODNAME);
1231         info->fix.type = FB_TYPE_PACKED_PIXELS;
1232         info->fix.visual = FB_VISUAL_TRUECOLOR;
1233         info->fix.line_length = screen_width * screen_depth / 8;
1234         info->fix.accel = FB_ACCEL_NONE;
1235
1236         info->fbops = &hvfb_ops;
1237         info->pseudo_palette = par->pseudo_palette;
1238
1239         /* Initialize deferred IO */
1240         info->fbdefio = &synthvid_defio;
1241         fb_deferred_io_init(info);
1242
1243         /* Send config to host */
1244         ret = synthvid_send_config(hdev);
1245         if (ret)
1246                 goto error;
1247
1248         ret = register_framebuffer(info);
1249         if (ret) {
1250                 pr_err("Unable to register framebuffer\n");
1251                 goto error;
1252         }
1253
1254         par->fb_ready = true;
1255
1256         par->synchronous_fb = false;
1257         par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1258         atomic_notifier_chain_register(&panic_notifier_list,
1259                                        &par->hvfb_panic_nb);
1260
1261         return 0;
1262
1263 error:
1264         fb_deferred_io_cleanup(info);
1265         hvfb_putmem(hdev, info);
1266 error2:
1267         vmbus_close(hdev->channel);
1268 error1:
1269         cancel_delayed_work_sync(&par->dwork);
1270         hv_set_drvdata(hdev, NULL);
1271         framebuffer_release(info);
1272         return ret;
1273 }
1274
1275
1276 static int hvfb_remove(struct hv_device *hdev)
1277 {
1278         struct fb_info *info = hv_get_drvdata(hdev);
1279         struct hvfb_par *par = info->par;
1280
1281         atomic_notifier_chain_unregister(&panic_notifier_list,
1282                                          &par->hvfb_panic_nb);
1283
1284         par->update = false;
1285         par->fb_ready = false;
1286
1287         fb_deferred_io_cleanup(info);
1288
1289         unregister_framebuffer(info);
1290         cancel_delayed_work_sync(&par->dwork);
1291
1292         vmbus_close(hdev->channel);
1293         hv_set_drvdata(hdev, NULL);
1294
1295         hvfb_putmem(hdev, info);
1296         framebuffer_release(info);
1297
1298         return 0;
1299 }
1300
1301 static int hvfb_suspend(struct hv_device *hdev)
1302 {
1303         struct fb_info *info = hv_get_drvdata(hdev);
1304         struct hvfb_par *par = info->par;
1305
1306         console_lock();
1307
1308         /* 1 means do suspend */
1309         fb_set_suspend(info, 1);
1310
1311         cancel_delayed_work_sync(&par->dwork);
1312         cancel_delayed_work_sync(&info->deferred_work);
1313
1314         par->update_saved = par->update;
1315         par->update = false;
1316         par->fb_ready = false;
1317
1318         vmbus_close(hdev->channel);
1319
1320         console_unlock();
1321
1322         return 0;
1323 }
1324
1325 static int hvfb_resume(struct hv_device *hdev)
1326 {
1327         struct fb_info *info = hv_get_drvdata(hdev);
1328         struct hvfb_par *par = info->par;
1329         int ret;
1330
1331         console_lock();
1332
1333         ret = synthvid_connect_vsp(hdev);
1334         if (ret != 0)
1335                 goto out;
1336
1337         ret = synthvid_send_config(hdev);
1338         if (ret != 0) {
1339                 vmbus_close(hdev->channel);
1340                 goto out;
1341         }
1342
1343         par->fb_ready = true;
1344         par->update = par->update_saved;
1345
1346         schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1347         schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1348
1349         /* 0 means do resume */
1350         fb_set_suspend(info, 0);
1351
1352 out:
1353         console_unlock();
1354
1355         return ret;
1356 }
1357
1358
1359 static const struct pci_device_id pci_stub_id_table[] = {
1360         {
1361                 .vendor      = PCI_VENDOR_ID_MICROSOFT,
1362                 .device      = PCI_DEVICE_ID_HYPERV_VIDEO,
1363         },
1364         { /* end of list */ }
1365 };
1366
1367 static const struct hv_vmbus_device_id id_table[] = {
1368         /* Synthetic Video Device GUID */
1369         {HV_SYNTHVID_GUID},
1370         {}
1371 };
1372
1373 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1374 MODULE_DEVICE_TABLE(vmbus, id_table);
1375
1376 static struct hv_driver hvfb_drv = {
1377         .name = KBUILD_MODNAME,
1378         .id_table = id_table,
1379         .probe = hvfb_probe,
1380         .remove = hvfb_remove,
1381         .suspend = hvfb_suspend,
1382         .resume = hvfb_resume,
1383         .driver = {
1384                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1385         },
1386 };
1387
1388 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1389                                const struct pci_device_id *ent)
1390 {
1391         return 0;
1392 }
1393
1394 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1395 {
1396 }
1397
1398 static struct pci_driver hvfb_pci_stub_driver = {
1399         .name =         KBUILD_MODNAME,
1400         .id_table =     pci_stub_id_table,
1401         .probe =        hvfb_pci_stub_probe,
1402         .remove =       hvfb_pci_stub_remove,
1403         .driver = {
1404                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1405         }
1406 };
1407
1408 static int __init hvfb_drv_init(void)
1409 {
1410         int ret;
1411
1412         ret = vmbus_driver_register(&hvfb_drv);
1413         if (ret != 0)
1414                 return ret;
1415
1416         ret = pci_register_driver(&hvfb_pci_stub_driver);
1417         if (ret != 0) {
1418                 vmbus_driver_unregister(&hvfb_drv);
1419                 return ret;
1420         }
1421
1422         return 0;
1423 }
1424
1425 static void __exit hvfb_drv_exit(void)
1426 {
1427         pci_unregister_driver(&hvfb_pci_stub_driver);
1428         vmbus_driver_unregister(&hvfb_drv);
1429 }
1430
1431 module_init(hvfb_drv_init);
1432 module_exit(hvfb_drv_exit);
1433
1434 MODULE_LICENSE("GPL");
1435 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");