1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Mediated virtual PCI display host device driver 4 * 5 * See mdpy-defs.h for device specs 6 * 7 * (c) Gerd Hoffmann <kraxel@redhat.com> 8 * 9 * based on mtty driver which is: 10 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. 11 * Author: Neo Jia <cjia@nvidia.com> 12 * Kirti Wankhede <kwankhede@nvidia.com> 13 * 14 * This program is free software; you can redistribute it and/or modify 15 * it under the terms of the GNU General Public License version 2 as 16 * published by the Free Software Foundation. 17 */ 18 #include <linux/init.h> 19 #include <linux/module.h> 20 #include <linux/device.h> 21 #include <linux/kernel.h> 22 #include <linux/slab.h> 23 #include <linux/vmalloc.h> 24 #include <linux/cdev.h> 25 #include <linux/vfio.h> 26 #include <linux/iommu.h> 27 #include <linux/sysfs.h> 28 #include <linux/mdev.h> 29 #include <linux/pci.h> 30 #include <drm/drm_fourcc.h> 31 #include "mdpy-defs.h" 32 33 #define MDPY_NAME "mdpy" 34 #define MDPY_CLASS_NAME "mdpy" 35 36 #define MDPY_CONFIG_SPACE_SIZE 0xff 37 #define MDPY_MEMORY_BAR_OFFSET PAGE_SIZE 38 #define MDPY_DISPLAY_REGION 16 39 40 #define STORE_LE16(addr, val) (*(u16 *)addr = val) 41 #define STORE_LE32(addr, val) (*(u32 *)addr = val) 42 43 44 MODULE_LICENSE("GPL v2"); 45 46 static int max_devices = 4; 47 module_param_named(count, max_devices, int, 0444); 48 MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices"); 49 50 51 #define MDPY_TYPE_1 "vga" 52 #define MDPY_TYPE_2 "xga" 53 #define MDPY_TYPE_3 "hd" 54 55 static const struct mdpy_type { 56 const char *name; 57 u32 format; 58 u32 bytepp; 59 u32 width; 60 u32 height; 61 } mdpy_types[] = { 62 { 63 .name = MDPY_CLASS_NAME "-" MDPY_TYPE_1, 64 .format = DRM_FORMAT_XRGB8888, 65 .bytepp = 4, 66 .width = 640, 67 .height = 480, 68 }, { 69 .name = MDPY_CLASS_NAME "-" MDPY_TYPE_2, 70 .format = DRM_FORMAT_XRGB8888, 71 .bytepp = 4, 72 .width = 1024, 73 .height = 768, 74 }, { 75 .name = MDPY_CLASS_NAME "-" MDPY_TYPE_3, 76 .format = DRM_FORMAT_XRGB8888, 77 .bytepp = 4, 78 .width = 1920, 79 .height = 1080, 80 }, 81 }; 82 83 static dev_t mdpy_devt; 84 static struct class *mdpy_class; 85 static struct cdev mdpy_cdev; 86 static struct device mdpy_dev; 87 static u32 mdpy_count; 88 static const struct vfio_device_ops mdpy_dev_ops; 89 90 /* State of each mdev device */ 91 struct mdev_state { 92 struct vfio_device vdev; 93 u8 *vconfig; 94 u32 bar_mask; 95 struct mutex ops_lock; 96 struct mdev_device *mdev; 97 struct vfio_device_info dev_info; 98 99 const struct mdpy_type *type; 100 u32 memsize; 101 void *memblk; 102 }; 103 104 static void mdpy_create_config_space(struct mdev_state *mdev_state) 105 { 106 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID], 107 MDPY_PCI_VENDOR_ID); 108 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID], 109 MDPY_PCI_DEVICE_ID); 110 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID], 111 MDPY_PCI_SUBVENDOR_ID); 112 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID], 113 MDPY_PCI_SUBDEVICE_ID); 114 115 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND], 116 PCI_COMMAND_IO | PCI_COMMAND_MEMORY); 117 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS], 118 PCI_STATUS_CAP_LIST); 119 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE], 120 PCI_CLASS_DISPLAY_OTHER); 121 mdev_state->vconfig[PCI_CLASS_REVISION] = 0x01; 122 123 STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0], 124 PCI_BASE_ADDRESS_SPACE_MEMORY | 125 PCI_BASE_ADDRESS_MEM_TYPE_32 | 126 PCI_BASE_ADDRESS_MEM_PREFETCH); 127 mdev_state->bar_mask = ~(mdev_state->memsize) + 1; 128 129 /* vendor specific capability for the config registers */ 130 mdev_state->vconfig[PCI_CAPABILITY_LIST] = MDPY_VENDORCAP_OFFSET; 131 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */ 132 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */ 133 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE; 134 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET], 135 mdev_state->type->format); 136 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET], 137 mdev_state->type->width); 138 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET], 139 mdev_state->type->height); 140 } 141 142 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset, 143 char *buf, u32 count) 144 { 145 struct device *dev = mdev_dev(mdev_state->mdev); 146 u32 cfg_addr; 147 148 switch (offset) { 149 case PCI_BASE_ADDRESS_0: 150 cfg_addr = *(u32 *)buf; 151 152 if (cfg_addr == 0xffffffff) { 153 cfg_addr = (cfg_addr & mdev_state->bar_mask); 154 } else { 155 cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK; 156 if (cfg_addr) 157 dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr); 158 } 159 160 cfg_addr |= (mdev_state->vconfig[offset] & 161 ~PCI_BASE_ADDRESS_MEM_MASK); 162 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr); 163 break; 164 } 165 } 166 167 static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf, 168 size_t count, loff_t pos, bool is_write) 169 { 170 int ret = 0; 171 172 mutex_lock(&mdev_state->ops_lock); 173 174 if (pos < MDPY_CONFIG_SPACE_SIZE) { 175 if (is_write) 176 handle_pci_cfg_write(mdev_state, pos, buf, count); 177 else 178 memcpy(buf, (mdev_state->vconfig + pos), count); 179 180 } else if ((pos >= MDPY_MEMORY_BAR_OFFSET) && 181 (pos + count <= 182 MDPY_MEMORY_BAR_OFFSET + mdev_state->memsize)) { 183 pos -= MDPY_MEMORY_BAR_OFFSET; 184 if (is_write) 185 memcpy(mdev_state->memblk, buf, count); 186 else 187 memcpy(buf, mdev_state->memblk, count); 188 189 } else { 190 dev_info(mdev_state->vdev.dev, 191 "%s: %s @0x%llx (unhandled)\n", __func__, 192 is_write ? "WR" : "RD", pos); 193 ret = -1; 194 goto accessfailed; 195 } 196 197 ret = count; 198 199 200 accessfailed: 201 mutex_unlock(&mdev_state->ops_lock); 202 203 return ret; 204 } 205 206 static int mdpy_reset(struct mdev_state *mdev_state) 207 { 208 u32 stride, i; 209 210 /* initialize with gray gradient */ 211 stride = mdev_state->type->width * mdev_state->type->bytepp; 212 for (i = 0; i < mdev_state->type->height; i++) 213 memset(mdev_state->memblk + i * stride, 214 i * 255 / mdev_state->type->height, 215 stride); 216 return 0; 217 } 218 219 static int mdpy_probe(struct mdev_device *mdev) 220 { 221 const struct mdpy_type *type = 222 &mdpy_types[mdev_get_type_group_id(mdev)]; 223 struct device *dev = mdev_dev(mdev); 224 struct mdev_state *mdev_state; 225 u32 fbsize; 226 int ret; 227 228 if (mdpy_count >= max_devices) 229 return -ENOMEM; 230 231 mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL); 232 if (mdev_state == NULL) 233 return -ENOMEM; 234 vfio_init_group_dev(&mdev_state->vdev, &mdev->dev, &mdpy_dev_ops); 235 236 mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL); 237 if (mdev_state->vconfig == NULL) { 238 kfree(mdev_state); 239 return -ENOMEM; 240 } 241 242 fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp); 243 244 mdev_state->memblk = vmalloc_user(fbsize); 245 if (!mdev_state->memblk) { 246 kfree(mdev_state->vconfig); 247 kfree(mdev_state); 248 return -ENOMEM; 249 } 250 dev_info(dev, "%s: %s (%dx%d)\n", __func__, type->name, type->width, 251 type->height); 252 253 mutex_init(&mdev_state->ops_lock); 254 mdev_state->mdev = mdev; 255 mdev_state->type = type; 256 mdev_state->memsize = fbsize; 257 mdpy_create_config_space(mdev_state); 258 mdpy_reset(mdev_state); 259 260 mdpy_count++; 261 262 ret = vfio_register_group_dev(&mdev_state->vdev); 263 if (ret) { 264 kfree(mdev_state->vconfig); 265 kfree(mdev_state); 266 return ret; 267 } 268 dev_set_drvdata(&mdev->dev, mdev_state); 269 return 0; 270 } 271 272 static void mdpy_remove(struct mdev_device *mdev) 273 { 274 struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev); 275 276 dev_info(&mdev->dev, "%s\n", __func__); 277 278 vfio_unregister_group_dev(&mdev_state->vdev); 279 vfree(mdev_state->memblk); 280 kfree(mdev_state->vconfig); 281 kfree(mdev_state); 282 283 mdpy_count--; 284 } 285 286 static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf, 287 size_t count, loff_t *ppos) 288 { 289 struct mdev_state *mdev_state = 290 container_of(vdev, struct mdev_state, vdev); 291 unsigned int done = 0; 292 int ret; 293 294 while (count) { 295 size_t filled; 296 297 if (count >= 4 && !(*ppos % 4)) { 298 u32 val; 299 300 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 301 *ppos, false); 302 if (ret <= 0) 303 goto read_err; 304 305 if (copy_to_user(buf, &val, sizeof(val))) 306 goto read_err; 307 308 filled = 4; 309 } else if (count >= 2 && !(*ppos % 2)) { 310 u16 val; 311 312 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 313 *ppos, false); 314 if (ret <= 0) 315 goto read_err; 316 317 if (copy_to_user(buf, &val, sizeof(val))) 318 goto read_err; 319 320 filled = 2; 321 } else { 322 u8 val; 323 324 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 325 *ppos, false); 326 if (ret <= 0) 327 goto read_err; 328 329 if (copy_to_user(buf, &val, sizeof(val))) 330 goto read_err; 331 332 filled = 1; 333 } 334 335 count -= filled; 336 done += filled; 337 *ppos += filled; 338 buf += filled; 339 } 340 341 return done; 342 343 read_err: 344 return -EFAULT; 345 } 346 347 static ssize_t mdpy_write(struct vfio_device *vdev, const char __user *buf, 348 size_t count, loff_t *ppos) 349 { 350 struct mdev_state *mdev_state = 351 container_of(vdev, struct mdev_state, vdev); 352 unsigned int done = 0; 353 int ret; 354 355 while (count) { 356 size_t filled; 357 358 if (count >= 4 && !(*ppos % 4)) { 359 u32 val; 360 361 if (copy_from_user(&val, buf, sizeof(val))) 362 goto write_err; 363 364 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 365 *ppos, true); 366 if (ret <= 0) 367 goto write_err; 368 369 filled = 4; 370 } else if (count >= 2 && !(*ppos % 2)) { 371 u16 val; 372 373 if (copy_from_user(&val, buf, sizeof(val))) 374 goto write_err; 375 376 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 377 *ppos, true); 378 if (ret <= 0) 379 goto write_err; 380 381 filled = 2; 382 } else { 383 u8 val; 384 385 if (copy_from_user(&val, buf, sizeof(val))) 386 goto write_err; 387 388 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 389 *ppos, true); 390 if (ret <= 0) 391 goto write_err; 392 393 filled = 1; 394 } 395 count -= filled; 396 done += filled; 397 *ppos += filled; 398 buf += filled; 399 } 400 401 return done; 402 write_err: 403 return -EFAULT; 404 } 405 406 static int mdpy_mmap(struct vfio_device *vdev, struct vm_area_struct *vma) 407 { 408 struct mdev_state *mdev_state = 409 container_of(vdev, struct mdev_state, vdev); 410 411 if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT) 412 return -EINVAL; 413 if (vma->vm_end < vma->vm_start) 414 return -EINVAL; 415 if (vma->vm_end - vma->vm_start > mdev_state->memsize) 416 return -EINVAL; 417 if ((vma->vm_flags & VM_SHARED) == 0) 418 return -EINVAL; 419 420 return remap_vmalloc_range(vma, mdev_state->memblk, 0); 421 } 422 423 static int mdpy_get_region_info(struct mdev_state *mdev_state, 424 struct vfio_region_info *region_info, 425 u16 *cap_type_id, void **cap_type) 426 { 427 if (region_info->index >= VFIO_PCI_NUM_REGIONS && 428 region_info->index != MDPY_DISPLAY_REGION) 429 return -EINVAL; 430 431 switch (region_info->index) { 432 case VFIO_PCI_CONFIG_REGION_INDEX: 433 region_info->offset = 0; 434 region_info->size = MDPY_CONFIG_SPACE_SIZE; 435 region_info->flags = (VFIO_REGION_INFO_FLAG_READ | 436 VFIO_REGION_INFO_FLAG_WRITE); 437 break; 438 case VFIO_PCI_BAR0_REGION_INDEX: 439 case MDPY_DISPLAY_REGION: 440 region_info->offset = MDPY_MEMORY_BAR_OFFSET; 441 region_info->size = mdev_state->memsize; 442 region_info->flags = (VFIO_REGION_INFO_FLAG_READ | 443 VFIO_REGION_INFO_FLAG_WRITE | 444 VFIO_REGION_INFO_FLAG_MMAP); 445 break; 446 default: 447 region_info->size = 0; 448 region_info->offset = 0; 449 region_info->flags = 0; 450 } 451 452 return 0; 453 } 454 455 static int mdpy_get_irq_info(struct vfio_irq_info *irq_info) 456 { 457 irq_info->count = 0; 458 return 0; 459 } 460 461 static int mdpy_get_device_info(struct vfio_device_info *dev_info) 462 { 463 dev_info->flags = VFIO_DEVICE_FLAGS_PCI; 464 dev_info->num_regions = VFIO_PCI_NUM_REGIONS; 465 dev_info->num_irqs = VFIO_PCI_NUM_IRQS; 466 return 0; 467 } 468 469 static int mdpy_query_gfx_plane(struct mdev_state *mdev_state, 470 struct vfio_device_gfx_plane_info *plane) 471 { 472 if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) { 473 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE | 474 VFIO_GFX_PLANE_TYPE_REGION)) 475 return 0; 476 return -EINVAL; 477 } 478 479 if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION) 480 return -EINVAL; 481 482 plane->drm_format = mdev_state->type->format; 483 plane->width = mdev_state->type->width; 484 plane->height = mdev_state->type->height; 485 plane->stride = (mdev_state->type->width * 486 mdev_state->type->bytepp); 487 plane->size = mdev_state->memsize; 488 plane->region_index = MDPY_DISPLAY_REGION; 489 490 /* unused */ 491 plane->drm_format_mod = 0; 492 plane->x_pos = 0; 493 plane->y_pos = 0; 494 plane->x_hot = 0; 495 plane->y_hot = 0; 496 497 return 0; 498 } 499 500 static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd, 501 unsigned long arg) 502 { 503 int ret = 0; 504 unsigned long minsz; 505 struct mdev_state *mdev_state = 506 container_of(vdev, struct mdev_state, vdev); 507 508 switch (cmd) { 509 case VFIO_DEVICE_GET_INFO: 510 { 511 struct vfio_device_info info; 512 513 minsz = offsetofend(struct vfio_device_info, num_irqs); 514 515 if (copy_from_user(&info, (void __user *)arg, minsz)) 516 return -EFAULT; 517 518 if (info.argsz < minsz) 519 return -EINVAL; 520 521 ret = mdpy_get_device_info(&info); 522 if (ret) 523 return ret; 524 525 memcpy(&mdev_state->dev_info, &info, sizeof(info)); 526 527 if (copy_to_user((void __user *)arg, &info, minsz)) 528 return -EFAULT; 529 530 return 0; 531 } 532 case VFIO_DEVICE_GET_REGION_INFO: 533 { 534 struct vfio_region_info info; 535 u16 cap_type_id = 0; 536 void *cap_type = NULL; 537 538 minsz = offsetofend(struct vfio_region_info, offset); 539 540 if (copy_from_user(&info, (void __user *)arg, minsz)) 541 return -EFAULT; 542 543 if (info.argsz < minsz) 544 return -EINVAL; 545 546 ret = mdpy_get_region_info(mdev_state, &info, &cap_type_id, 547 &cap_type); 548 if (ret) 549 return ret; 550 551 if (copy_to_user((void __user *)arg, &info, minsz)) 552 return -EFAULT; 553 554 return 0; 555 } 556 557 case VFIO_DEVICE_GET_IRQ_INFO: 558 { 559 struct vfio_irq_info info; 560 561 minsz = offsetofend(struct vfio_irq_info, count); 562 563 if (copy_from_user(&info, (void __user *)arg, minsz)) 564 return -EFAULT; 565 566 if ((info.argsz < minsz) || 567 (info.index >= mdev_state->dev_info.num_irqs)) 568 return -EINVAL; 569 570 ret = mdpy_get_irq_info(&info); 571 if (ret) 572 return ret; 573 574 if (copy_to_user((void __user *)arg, &info, minsz)) 575 return -EFAULT; 576 577 return 0; 578 } 579 580 case VFIO_DEVICE_QUERY_GFX_PLANE: 581 { 582 struct vfio_device_gfx_plane_info plane; 583 584 minsz = offsetofend(struct vfio_device_gfx_plane_info, 585 region_index); 586 587 if (copy_from_user(&plane, (void __user *)arg, minsz)) 588 return -EFAULT; 589 590 if (plane.argsz < minsz) 591 return -EINVAL; 592 593 ret = mdpy_query_gfx_plane(mdev_state, &plane); 594 if (ret) 595 return ret; 596 597 if (copy_to_user((void __user *)arg, &plane, minsz)) 598 return -EFAULT; 599 600 return 0; 601 } 602 603 case VFIO_DEVICE_SET_IRQS: 604 return -EINVAL; 605 606 case VFIO_DEVICE_RESET: 607 return mdpy_reset(mdev_state); 608 } 609 return -ENOTTY; 610 } 611 612 static int mdpy_open(struct vfio_device *vdev) 613 { 614 if (!try_module_get(THIS_MODULE)) 615 return -ENODEV; 616 617 return 0; 618 } 619 620 static void mdpy_close(struct vfio_device *vdev) 621 { 622 module_put(THIS_MODULE); 623 } 624 625 static ssize_t 626 resolution_show(struct device *dev, struct device_attribute *attr, 627 char *buf) 628 { 629 struct mdev_state *mdev_state = dev_get_drvdata(dev); 630 631 return sprintf(buf, "%dx%d\n", 632 mdev_state->type->width, 633 mdev_state->type->height); 634 } 635 static DEVICE_ATTR_RO(resolution); 636 637 static struct attribute *mdev_dev_attrs[] = { 638 &dev_attr_resolution.attr, 639 NULL, 640 }; 641 642 static const struct attribute_group mdev_dev_group = { 643 .name = "vendor", 644 .attrs = mdev_dev_attrs, 645 }; 646 647 static const struct attribute_group *mdev_dev_groups[] = { 648 &mdev_dev_group, 649 NULL, 650 }; 651 652 static ssize_t name_show(struct mdev_type *mtype, 653 struct mdev_type_attribute *attr, char *buf) 654 { 655 const struct mdpy_type *type = 656 &mdpy_types[mtype_get_type_group_id(mtype)]; 657 658 return sprintf(buf, "%s\n", type->name); 659 } 660 static MDEV_TYPE_ATTR_RO(name); 661 662 static ssize_t description_show(struct mdev_type *mtype, 663 struct mdev_type_attribute *attr, char *buf) 664 { 665 const struct mdpy_type *type = 666 &mdpy_types[mtype_get_type_group_id(mtype)]; 667 668 return sprintf(buf, "virtual display, %dx%d framebuffer\n", 669 type->width, type->height); 670 } 671 static MDEV_TYPE_ATTR_RO(description); 672 673 static ssize_t available_instances_show(struct mdev_type *mtype, 674 struct mdev_type_attribute *attr, 675 char *buf) 676 { 677 return sprintf(buf, "%d\n", max_devices - mdpy_count); 678 } 679 static MDEV_TYPE_ATTR_RO(available_instances); 680 681 static ssize_t device_api_show(struct mdev_type *mtype, 682 struct mdev_type_attribute *attr, char *buf) 683 { 684 return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING); 685 } 686 static MDEV_TYPE_ATTR_RO(device_api); 687 688 static struct attribute *mdev_types_attrs[] = { 689 &mdev_type_attr_name.attr, 690 &mdev_type_attr_description.attr, 691 &mdev_type_attr_device_api.attr, 692 &mdev_type_attr_available_instances.attr, 693 NULL, 694 }; 695 696 static struct attribute_group mdev_type_group1 = { 697 .name = MDPY_TYPE_1, 698 .attrs = mdev_types_attrs, 699 }; 700 701 static struct attribute_group mdev_type_group2 = { 702 .name = MDPY_TYPE_2, 703 .attrs = mdev_types_attrs, 704 }; 705 706 static struct attribute_group mdev_type_group3 = { 707 .name = MDPY_TYPE_3, 708 .attrs = mdev_types_attrs, 709 }; 710 711 static struct attribute_group *mdev_type_groups[] = { 712 &mdev_type_group1, 713 &mdev_type_group2, 714 &mdev_type_group3, 715 NULL, 716 }; 717 718 static const struct vfio_device_ops mdpy_dev_ops = { 719 .open = mdpy_open, 720 .release = mdpy_close, 721 .read = mdpy_read, 722 .write = mdpy_write, 723 .ioctl = mdpy_ioctl, 724 .mmap = mdpy_mmap, 725 }; 726 727 static struct mdev_driver mdpy_driver = { 728 .driver = { 729 .name = "mdpy", 730 .owner = THIS_MODULE, 731 .mod_name = KBUILD_MODNAME, 732 .dev_groups = mdev_dev_groups, 733 }, 734 .probe = mdpy_probe, 735 .remove = mdpy_remove, 736 }; 737 738 static const struct mdev_parent_ops mdev_fops = { 739 .owner = THIS_MODULE, 740 .device_driver = &mdpy_driver, 741 .supported_type_groups = mdev_type_groups, 742 }; 743 744 static const struct file_operations vd_fops = { 745 .owner = THIS_MODULE, 746 }; 747 748 static void mdpy_device_release(struct device *dev) 749 { 750 /* nothing */ 751 } 752 753 static int __init mdpy_dev_init(void) 754 { 755 int ret = 0; 756 757 ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME); 758 if (ret < 0) { 759 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret); 760 return ret; 761 } 762 cdev_init(&mdpy_cdev, &vd_fops); 763 cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1); 764 pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt)); 765 766 ret = mdev_register_driver(&mdpy_driver); 767 if (ret) 768 goto err_cdev; 769 770 mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME); 771 if (IS_ERR(mdpy_class)) { 772 pr_err("Error: failed to register mdpy_dev class\n"); 773 ret = PTR_ERR(mdpy_class); 774 goto err_driver; 775 } 776 mdpy_dev.class = mdpy_class; 777 mdpy_dev.release = mdpy_device_release; 778 dev_set_name(&mdpy_dev, "%s", MDPY_NAME); 779 780 ret = device_register(&mdpy_dev); 781 if (ret) 782 goto err_class; 783 784 ret = mdev_register_device(&mdpy_dev, &mdev_fops); 785 if (ret) 786 goto err_device; 787 788 return 0; 789 790 err_device: 791 device_unregister(&mdpy_dev); 792 err_class: 793 class_destroy(mdpy_class); 794 err_driver: 795 mdev_unregister_driver(&mdpy_driver); 796 err_cdev: 797 cdev_del(&mdpy_cdev); 798 unregister_chrdev_region(mdpy_devt, MINORMASK + 1); 799 return ret; 800 } 801 802 static void __exit mdpy_dev_exit(void) 803 { 804 mdpy_dev.bus = NULL; 805 mdev_unregister_device(&mdpy_dev); 806 807 device_unregister(&mdpy_dev); 808 mdev_unregister_driver(&mdpy_driver); 809 cdev_del(&mdpy_cdev); 810 unregister_chrdev_region(mdpy_devt, MINORMASK + 1); 811 class_destroy(mdpy_class); 812 mdpy_class = NULL; 813 } 814 815 module_init(mdpy_dev_init) 816 module_exit(mdpy_dev_exit) 817