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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 <[email protected]>
8 *
9 * based on mtty driver which is:
10 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
11 * Author: Neo Jia <[email protected]>
12 * Kirti Wankhede <[email protected]>
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)