FILE
mdpy.c
File preview with syntax highlighting.
linux-6.19.14/samples/vfio-mdev/mdpy.c
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/kernel.h> 21#include <linux/slab.h> 22#include <linux/vmalloc.h> 23#include <linux/cdev.h> 24#include <linux/vfio.h> 25#include <linux/iommu.h> 26#include <linux/sysfs.h> 27#include <linux/mdev.h> 28#include <linux/pci.h> 29#include <drm/drm_fourcc.h> 30#include "mdpy-defs.h" 31 32#define MDPY_NAME "mdpy" 33#define MDPY_CLASS_NAME "mdpy" 34 35#define MDPY_CONFIG_SPACE_SIZE 0xff 36#define MDPY_MEMORY_BAR_OFFSET PAGE_SIZE 37#define MDPY_DISPLAY_REGION 16 38 39#define STORE_LE16(addr, val) (*(u16 *)addr = val) 40#define STORE_LE32(addr, val) (*(u32 *)addr = val) 41 42 43MODULE_DESCRIPTION("Mediated virtual PCI display host device driver"); 44MODULE_LICENSE("GPL v2"); 45 46#define MDPY_TYPE_1 "vga" 47#define MDPY_TYPE_2 "xga" 48#define MDPY_TYPE_3 "hd" 49 50static struct mdpy_type { 51 struct mdev_type type; 52 u32 format; 53 u32 bytepp; 54 u32 width; 55 u32 height; 56} mdpy_types[] = { 57 { 58 .type.sysfs_name = MDPY_TYPE_1, 59 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_1, 60 .format = DRM_FORMAT_XRGB8888, 61 .bytepp = 4, 62 .width = 640, 63 .height = 480, 64 }, { 65 .type.sysfs_name = MDPY_TYPE_2, 66 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_2, 67 .format = DRM_FORMAT_XRGB8888, 68 .bytepp = 4, 69 .width = 1024, 70 .height = 768, 71 }, { 72 .type.sysfs_name = MDPY_TYPE_3, 73 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_3, 74 .format = DRM_FORMAT_XRGB8888, 75 .bytepp = 4, 76 .width = 1920, 77 .height = 1080, 78 }, 79}; 80 81static struct mdev_type *mdpy_mdev_types[] = { 82 &mdpy_types[0].type, 83 &mdpy_types[1].type, 84 &mdpy_types[2].type, 85}; 86 87static dev_t mdpy_devt; 88static const struct class mdpy_class = { 89 .name = MDPY_CLASS_NAME, 90}; 91static struct cdev mdpy_cdev; 92static struct device mdpy_dev; 93static struct mdev_parent mdpy_parent; 94static const struct vfio_device_ops mdpy_dev_ops; 95 96/* State of each mdev device */ 97struct mdev_state { 98 struct vfio_device vdev; 99 u8 *vconfig; 100 u32 bar_mask; 101 struct mutex ops_lock; 102 struct mdev_device *mdev; 103 struct vfio_device_info dev_info; 104 105 const struct mdpy_type *type; 106 u32 memsize; 107 void *memblk; 108}; 109 110static void mdpy_create_config_space(struct mdev_state *mdev_state) 111{ 112 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID], 113 MDPY_PCI_VENDOR_ID); 114 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID], 115 MDPY_PCI_DEVICE_ID); 116 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID], 117 MDPY_PCI_SUBVENDOR_ID); 118 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID], 119 MDPY_PCI_SUBDEVICE_ID); 120 121 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND], 122 PCI_COMMAND_IO | PCI_COMMAND_MEMORY); 123 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS], 124 PCI_STATUS_CAP_LIST); 125 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE], 126 PCI_CLASS_DISPLAY_OTHER); 127 mdev_state->vconfig[PCI_CLASS_REVISION] = 0x01; 128 129 STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0], 130 PCI_BASE_ADDRESS_SPACE_MEMORY | 131 PCI_BASE_ADDRESS_MEM_TYPE_32 | 132 PCI_BASE_ADDRESS_MEM_PREFETCH); 133 mdev_state->bar_mask = ~(mdev_state->memsize) + 1; 134 135 /* vendor specific capability for the config registers */ 136 mdev_state->vconfig[PCI_CAPABILITY_LIST] = MDPY_VENDORCAP_OFFSET; 137 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */ 138 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */ 139 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE; 140 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET], 141 mdev_state->type->format); 142 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET], 143 mdev_state->type->width); 144 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET], 145 mdev_state->type->height); 146} 147 148static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset, 149 char *buf, u32 count) 150{ 151 struct device *dev = mdev_dev(mdev_state->mdev); 152 u32 cfg_addr; 153 154 switch (offset) { 155 case PCI_BASE_ADDRESS_0: 156 cfg_addr = *(u32 *)buf; 157 158 if (cfg_addr == 0xffffffff) { 159 cfg_addr = (cfg_addr & mdev_state->bar_mask); 160 } else { 161 cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK; 162 if (cfg_addr) 163 dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr); 164 } 165 166 cfg_addr |= (mdev_state->vconfig[offset] & 167 ~PCI_BASE_ADDRESS_MEM_MASK); 168 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr); 169 break; 170 } 171} 172 173static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf, 174 size_t count, loff_t pos, bool is_write) 175{ 176 int ret = 0; 177 178 mutex_lock(&mdev_state->ops_lock); 179 180 if (pos < MDPY_CONFIG_SPACE_SIZE) { 181 if (is_write) 182 handle_pci_cfg_write(mdev_state, pos, buf, count); 183 else 184 memcpy(buf, (mdev_state->vconfig + pos), count); 185 186 } else if ((pos >= MDPY_MEMORY_BAR_OFFSET) && 187 (pos + count <= 188 MDPY_MEMORY_BAR_OFFSET + mdev_state->memsize)) { 189 pos -= MDPY_MEMORY_BAR_OFFSET; 190 if (is_write) 191 memcpy(mdev_state->memblk, buf, count); 192 else 193 memcpy(buf, mdev_state->memblk, count); 194 195 } else { 196 dev_info(mdev_state->vdev.dev, 197 "%s: %s @0x%llx (unhandled)\n", __func__, 198 is_write ? "WR" : "RD", pos); 199 ret = -1; 200 goto accessfailed; 201 } 202 203 ret = count; 204 205 206accessfailed: 207 mutex_unlock(&mdev_state->ops_lock); 208 209 return ret; 210} 211 212static int mdpy_reset(struct mdev_state *mdev_state) 213{ 214 u32 stride, i; 215 216 /* initialize with gray gradient */ 217 stride = mdev_state->type->width * mdev_state->type->bytepp; 218 for (i = 0; i < mdev_state->type->height; i++) 219 memset(mdev_state->memblk + i * stride, 220 i * 255 / mdev_state->type->height, 221 stride); 222 return 0; 223} 224 225static int mdpy_init_dev(struct vfio_device *vdev) 226{ 227 struct mdev_state *mdev_state = 228 container_of(vdev, struct mdev_state, vdev); 229 struct mdev_device *mdev = to_mdev_device(vdev->dev); 230 const struct mdpy_type *type = 231 container_of(mdev->type, struct mdpy_type, type); 232 u32 fbsize; 233 int ret = -ENOMEM; 234 235 mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL); 236 if (!mdev_state->vconfig) 237 return ret; 238 239 fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp); 240 241 mdev_state->memblk = vmalloc_user(fbsize); 242 if (!mdev_state->memblk) 243 goto out_vconfig; 244 245 mutex_init(&mdev_state->ops_lock); 246 mdev_state->mdev = mdev; 247 mdev_state->type = type; 248 mdev_state->memsize = fbsize; 249 mdpy_create_config_space(mdev_state); 250 mdpy_reset(mdev_state); 251 252 dev_info(vdev->dev, "%s: %s (%dx%d)\n", __func__, type->type.pretty_name, 253 type->width, type->height); 254 return 0; 255 256out_vconfig: 257 kfree(mdev_state->vconfig); 258 return ret; 259} 260 261static int mdpy_probe(struct mdev_device *mdev) 262{ 263 struct mdev_state *mdev_state; 264 int ret; 265 266 mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev, 267 &mdpy_dev_ops); 268 if (IS_ERR(mdev_state)) 269 return PTR_ERR(mdev_state); 270 271 ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev); 272 if (ret) 273 goto err_put_vdev; 274 dev_set_drvdata(&mdev->dev, mdev_state); 275 return 0; 276 277err_put_vdev: 278 vfio_put_device(&mdev_state->vdev); 279 return ret; 280} 281 282static void mdpy_release_dev(struct vfio_device *vdev) 283{ 284 struct mdev_state *mdev_state = 285 container_of(vdev, struct mdev_state, vdev); 286 287 vfree(mdev_state->memblk); 288 kfree(mdev_state->vconfig); 289} 290 291static void mdpy_remove(struct mdev_device *mdev) 292{ 293 struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev); 294 295 dev_info(&mdev->dev, "%s\n", __func__); 296 297 vfio_unregister_group_dev(&mdev_state->vdev); 298 vfio_put_device(&mdev_state->vdev); 299} 300 301static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf, 302 size_t count, loff_t *ppos) 303{ 304 struct mdev_state *mdev_state = 305 container_of(vdev, struct mdev_state, vdev); 306 unsigned int done = 0; 307 int ret; 308 309 while (count) { 310 size_t filled; 311 312 if (count >= 4 && !(*ppos % 4)) { 313 u32 val; 314 315 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 316 *ppos, false); 317 if (ret <= 0) 318 goto read_err; 319 320 if (copy_to_user(buf, &val, sizeof(val))) 321 goto read_err; 322 323 filled = 4; 324 } else if (count >= 2 && !(*ppos % 2)) { 325 u16 val; 326 327 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 328 *ppos, false); 329 if (ret <= 0) 330 goto read_err; 331 332 if (copy_to_user(buf, &val, sizeof(val))) 333 goto read_err; 334 335 filled = 2; 336 } else { 337 u8 val; 338 339 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 340 *ppos, false); 341 if (ret <= 0) 342 goto read_err; 343 344 if (copy_to_user(buf, &val, sizeof(val))) 345 goto read_err; 346 347 filled = 1; 348 } 349 350 count -= filled; 351 done += filled; 352 *ppos += filled; 353 buf += filled; 354 } 355 356 return done; 357 358read_err: 359 return -EFAULT; 360} 361 362static ssize_t mdpy_write(struct vfio_device *vdev, const char __user *buf, 363 size_t count, loff_t *ppos) 364{ 365 struct mdev_state *mdev_state = 366 container_of(vdev, struct mdev_state, vdev); 367 unsigned int done = 0; 368 int ret; 369 370 while (count) { 371 size_t filled; 372 373 if (count >= 4 && !(*ppos % 4)) { 374 u32 val; 375 376 if (copy_from_user(&val, buf, sizeof(val))) 377 goto write_err; 378 379 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 380 *ppos, true); 381 if (ret <= 0) 382 goto write_err; 383 384 filled = 4; 385 } else if (count >= 2 && !(*ppos % 2)) { 386 u16 val; 387 388 if (copy_from_user(&val, buf, sizeof(val))) 389 goto write_err; 390 391 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 392 *ppos, true); 393 if (ret <= 0) 394 goto write_err; 395 396 filled = 2; 397 } else { 398 u8 val; 399 400 if (copy_from_user(&val, buf, sizeof(val))) 401 goto write_err; 402 403 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 404 *ppos, true); 405 if (ret <= 0) 406 goto write_err; 407 408 filled = 1; 409 } 410 count -= filled; 411 done += filled; 412 *ppos += filled; 413 buf += filled; 414 } 415 416 return done; 417write_err: 418 return -EFAULT; 419} 420 421static int mdpy_mmap(struct vfio_device *vdev, struct vm_area_struct *vma) 422{ 423 struct mdev_state *mdev_state = 424 container_of(vdev, struct mdev_state, vdev); 425 426 if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT) 427 return -EINVAL; 428 if (vma->vm_end < vma->vm_start) 429 return -EINVAL; 430 if (vma->vm_end - vma->vm_start > mdev_state->memsize) 431 return -EINVAL; 432 if ((vma->vm_flags & VM_SHARED) == 0) 433 return -EINVAL; 434 435 return remap_vmalloc_range(vma, mdev_state->memblk, 0); 436} 437 438static int mdpy_ioctl_get_region_info(struct vfio_device *vdev, 439 struct vfio_region_info *region_info, 440 struct vfio_info_cap *caps) 441{ 442 struct mdev_state *mdev_state = 443 container_of(vdev, struct mdev_state, vdev); 444 445 if (region_info->index >= VFIO_PCI_NUM_REGIONS && 446 region_info->index != MDPY_DISPLAY_REGION) 447 return -EINVAL; 448 449 switch (region_info->index) { 450 case VFIO_PCI_CONFIG_REGION_INDEX: 451 region_info->offset = 0; 452 region_info->size = MDPY_CONFIG_SPACE_SIZE; 453 region_info->flags = (VFIO_REGION_INFO_FLAG_READ | 454 VFIO_REGION_INFO_FLAG_WRITE); 455 break; 456 case VFIO_PCI_BAR0_REGION_INDEX: 457 case MDPY_DISPLAY_REGION: 458 region_info->offset = MDPY_MEMORY_BAR_OFFSET; 459 region_info->size = mdev_state->memsize; 460 region_info->flags = (VFIO_REGION_INFO_FLAG_READ | 461 VFIO_REGION_INFO_FLAG_WRITE | 462 VFIO_REGION_INFO_FLAG_MMAP); 463 break; 464 default: 465 region_info->size = 0; 466 region_info->offset = 0; 467 region_info->flags = 0; 468 } 469 470 return 0; 471} 472 473static int mdpy_get_irq_info(struct vfio_irq_info *irq_info) 474{ 475 irq_info->count = 0; 476 return 0; 477} 478 479static int mdpy_get_device_info(struct vfio_device_info *dev_info) 480{ 481 dev_info->flags = VFIO_DEVICE_FLAGS_PCI; 482 dev_info->num_regions = VFIO_PCI_NUM_REGIONS; 483 dev_info->num_irqs = VFIO_PCI_NUM_IRQS; 484 return 0; 485} 486 487static int mdpy_query_gfx_plane(struct mdev_state *mdev_state, 488 struct vfio_device_gfx_plane_info *plane) 489{ 490 if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) { 491 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE | 492 VFIO_GFX_PLANE_TYPE_REGION)) 493 return 0; 494 return -EINVAL; 495 } 496 497 if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION) 498 return -EINVAL; 499 500 plane->drm_format = mdev_state->type->format; 501 plane->width = mdev_state->type->width; 502 plane->height = mdev_state->type->height; 503 plane->stride = (mdev_state->type->width * 504 mdev_state->type->bytepp); 505 plane->size = mdev_state->memsize; 506 plane->region_index = MDPY_DISPLAY_REGION; 507 508 /* unused */ 509 plane->drm_format_mod = 0; 510 plane->x_pos = 0; 511 plane->y_pos = 0; 512 plane->x_hot = 0; 513 plane->y_hot = 0; 514 515 return 0; 516} 517 518static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd, 519 unsigned long arg) 520{ 521 int ret = 0; 522 unsigned long minsz; 523 struct mdev_state *mdev_state = 524 container_of(vdev, struct mdev_state, vdev); 525 526 switch (cmd) { 527 case VFIO_DEVICE_GET_INFO: 528 { 529 struct vfio_device_info info; 530 531 minsz = offsetofend(struct vfio_device_info, num_irqs); 532 533 if (copy_from_user(&info, (void __user *)arg, minsz)) 534 return -EFAULT; 535 536 if (info.argsz < minsz) 537 return -EINVAL; 538 539 ret = mdpy_get_device_info(&info); 540 if (ret) 541 return ret; 542 543 memcpy(&mdev_state->dev_info, &info, sizeof(info)); 544 545 if (copy_to_user((void __user *)arg, &info, minsz)) 546 return -EFAULT; 547 548 return 0; 549 } 550 551 case VFIO_DEVICE_GET_IRQ_INFO: 552 { 553 struct vfio_irq_info info; 554 555 minsz = offsetofend(struct vfio_irq_info, count); 556 557 if (copy_from_user(&info, (void __user *)arg, minsz)) 558 return -EFAULT; 559 560 if ((info.argsz < minsz) || 561 (info.index >= mdev_state->dev_info.num_irqs)) 562 return -EINVAL; 563 564 ret = mdpy_get_irq_info(&info); 565 if (ret) 566 return ret; 567 568 if (copy_to_user((void __user *)arg, &info, minsz)) 569 return -EFAULT; 570 571 return 0; 572 } 573 574 case VFIO_DEVICE_QUERY_GFX_PLANE: 575 { 576 struct vfio_device_gfx_plane_info plane = {}; 577 578 minsz = offsetofend(struct vfio_device_gfx_plane_info, 579 region_index); 580 581 if (copy_from_user(&plane, (void __user *)arg, minsz)) 582 return -EFAULT; 583 584 if (plane.argsz < minsz) 585 return -EINVAL; 586 587 ret = mdpy_query_gfx_plane(mdev_state, &plane); 588 if (ret) 589 return ret; 590 591 if (copy_to_user((void __user *)arg, &plane, minsz)) 592 return -EFAULT; 593 594 return 0; 595 } 596 597 case VFIO_DEVICE_SET_IRQS: 598 return -EINVAL; 599 600 case VFIO_DEVICE_RESET: 601 return mdpy_reset(mdev_state); 602 } 603 return -ENOTTY; 604} 605 606static ssize_t 607resolution_show(struct device *dev, struct device_attribute *attr, 608 char *buf) 609{ 610 struct mdev_state *mdev_state = dev_get_drvdata(dev); 611 612 return sprintf(buf, "%dx%d\n", 613 mdev_state->type->width, 614 mdev_state->type->height); 615} 616static DEVICE_ATTR_RO(resolution); 617 618static struct attribute *mdev_dev_attrs[] = { 619 &dev_attr_resolution.attr, 620 NULL, 621}; 622 623static const struct attribute_group mdev_dev_group = { 624 .name = "vendor", 625 .attrs = mdev_dev_attrs, 626}; 627 628static const struct attribute_group *mdev_dev_groups[] = { 629 &mdev_dev_group, 630 NULL, 631}; 632 633static ssize_t mdpy_show_description(struct mdev_type *mtype, char *buf) 634{ 635 struct mdpy_type *type = container_of(mtype, struct mdpy_type, type); 636 637 return sprintf(buf, "virtual display, %dx%d framebuffer\n", 638 type->width, type->height); 639} 640 641static const struct vfio_device_ops mdpy_dev_ops = { 642 .init = mdpy_init_dev, 643 .release = mdpy_release_dev, 644 .read = mdpy_read, 645 .write = mdpy_write, 646 .ioctl = mdpy_ioctl, 647 .get_region_info_caps = mdpy_ioctl_get_region_info, 648 .mmap = mdpy_mmap, 649 .bind_iommufd = vfio_iommufd_emulated_bind, 650 .unbind_iommufd = vfio_iommufd_emulated_unbind, 651 .attach_ioas = vfio_iommufd_emulated_attach_ioas, 652 .detach_ioas = vfio_iommufd_emulated_detach_ioas, 653}; 654 655static struct mdev_driver mdpy_driver = { 656 .device_api = VFIO_DEVICE_API_PCI_STRING, 657 .max_instances = 4, 658 .driver = { 659 .name = "mdpy", 660 .owner = THIS_MODULE, 661 .mod_name = KBUILD_MODNAME, 662 .dev_groups = mdev_dev_groups, 663 }, 664 .probe = mdpy_probe, 665 .remove = mdpy_remove, 666 .show_description = mdpy_show_description, 667}; 668 669static const struct file_operations vd_fops = { 670 .owner = THIS_MODULE, 671}; 672 673static void mdpy_device_release(struct device *dev) 674{ 675 /* nothing */ 676} 677 678static int __init mdpy_dev_init(void) 679{ 680 int ret = 0; 681 682 ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME); 683 if (ret < 0) { 684 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret); 685 return ret; 686 } 687 cdev_init(&mdpy_cdev, &vd_fops); 688 cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1); 689 pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt)); 690 691 ret = mdev_register_driver(&mdpy_driver); 692 if (ret) 693 goto err_cdev; 694 695 ret = class_register(&mdpy_class); 696 if (ret) 697 goto err_driver; 698 mdpy_dev.class = &mdpy_class; 699 mdpy_dev.release = mdpy_device_release; 700 dev_set_name(&mdpy_dev, "%s", MDPY_NAME); 701 702 ret = device_register(&mdpy_dev); 703 if (ret) 704 goto err_put; 705 706 ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver, 707 mdpy_mdev_types, 708 ARRAY_SIZE(mdpy_mdev_types)); 709 if (ret) 710 goto err_device; 711 712 return 0; 713 714err_device: 715 device_del(&mdpy_dev); 716err_put: 717 put_device(&mdpy_dev); 718 class_unregister(&mdpy_class); 719err_driver: 720 mdev_unregister_driver(&mdpy_driver); 721err_cdev: 722 cdev_del(&mdpy_cdev); 723 unregister_chrdev_region(mdpy_devt, MINORMASK + 1); 724 return ret; 725} 726 727static void __exit mdpy_dev_exit(void) 728{ 729 mdpy_dev.bus = NULL; 730 mdev_unregister_parent(&mdpy_parent); 731 732 device_unregister(&mdpy_dev); 733 mdev_unregister_driver(&mdpy_driver); 734 cdev_del(&mdpy_cdev); 735 unregister_chrdev_region(mdpy_devt, MINORMASK + 1); 736 class_unregister(&mdpy_class); 737} 738 739module_param_named(count, mdpy_driver.max_instances, int, 0444); 740MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices"); 741 742module_init(mdpy_dev_init) 743module_exit(mdpy_dev_exit)
~/
Read-only file preview.