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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 <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
44MODULE_LICENSE("GPL v2");
45
46static int max_devices = 4;
47module_param_named(count, max_devices, int, 0444);
48MODULE_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
55static 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
83static dev_t mdpy_devt;
84static struct class *mdpy_class;
85static struct cdev mdpy_cdev;
86static struct device mdpy_dev;
87static u32 mdpy_count;
88
89/* State of each mdev device */
90struct mdev_state {
91 u8 *vconfig;
92 u32 bar_mask;
93 struct mutex ops_lock;
94 struct mdev_device *mdev;
95 struct vfio_device_info dev_info;
96
97 const struct mdpy_type *type;
98 u32 memsize;
99 void *memblk;
100};
101
102static void mdpy_create_config_space(struct mdev_state *mdev_state)
103{
104 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
105 MDPY_PCI_VENDOR_ID);
106 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
107 MDPY_PCI_DEVICE_ID);
108 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
109 MDPY_PCI_SUBVENDOR_ID);
110 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
111 MDPY_PCI_SUBDEVICE_ID);
112
113 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
114 PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
115 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS],
116 PCI_STATUS_CAP_LIST);
117 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
118 PCI_CLASS_DISPLAY_OTHER);
119 mdev_state->vconfig[PCI_CLASS_REVISION] = 0x01;
120
121 STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
122 PCI_BASE_ADDRESS_SPACE_MEMORY |
123 PCI_BASE_ADDRESS_MEM_TYPE_32 |
124 PCI_BASE_ADDRESS_MEM_PREFETCH);
125 mdev_state->bar_mask = ~(mdev_state->memsize) + 1;
126
127 /* vendor specific capability for the config registers */
128 mdev_state->vconfig[PCI_CAPABILITY_LIST] = MDPY_VENDORCAP_OFFSET;
129 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */
130 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */
131 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE;
132 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET],
133 mdev_state->type->format);
134 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET],
135 mdev_state->type->width);
136 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET],
137 mdev_state->type->height);
138}
139
140static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
141 char *buf, u32 count)
142{
143 struct device *dev = mdev_dev(mdev_state->mdev);
144 u32 cfg_addr;
145
146 switch (offset) {
147 case PCI_BASE_ADDRESS_0:
148 cfg_addr = *(u32 *)buf;
149
150 if (cfg_addr == 0xffffffff) {
151 cfg_addr = (cfg_addr & mdev_state->bar_mask);
152 } else {
153 cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
154 if (cfg_addr)
155 dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr);
156 }
157
158 cfg_addr |= (mdev_state->vconfig[offset] &
159 ~PCI_BASE_ADDRESS_MEM_MASK);
160 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
161 break;
162 }
163}
164
165static ssize_t mdev_access(struct mdev_device *mdev, char *buf, size_t count,
166 loff_t pos, bool is_write)
167{
168 struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
169 struct device *dev = mdev_dev(mdev);
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(dev, "%s: %s @0x%llx (unhandled)\n",
191 __func__, is_write ? "WR" : "RD", pos);
192 ret = -1;
193 goto accessfailed;
194 }
195
196 ret = count;
197
198
199accessfailed:
200 mutex_unlock(&mdev_state->ops_lock);
201
202 return ret;
203}
204
205static int mdpy_reset(struct mdev_device *mdev)
206{
207 struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
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
219static int mdpy_create(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
227 if (mdpy_count >= max_devices)
228 return -ENOMEM;
229
230 mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
231 if (mdev_state == NULL)
232 return -ENOMEM;
233
234 mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL);
235 if (mdev_state->vconfig == NULL) {
236 kfree(mdev_state);
237 return -ENOMEM;
238 }
239
240 fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp);
241
242 mdev_state->memblk = vmalloc_user(fbsize);
243 if (!mdev_state->memblk) {
244 kfree(mdev_state->vconfig);
245 kfree(mdev_state);
246 return -ENOMEM;
247 }
248 dev_info(dev, "%s: %s (%dx%d)\n", __func__, type->name, type->width,
249 type->height);
250
251 mutex_init(&mdev_state->ops_lock);
252 mdev_state->mdev = mdev;
253 mdev_set_drvdata(mdev, mdev_state);
254
255 mdev_state->type = type;
256 mdev_state->memsize = fbsize;
257 mdpy_create_config_space(mdev_state);
258 mdpy_reset(mdev);
259
260 mdpy_count++;
261 return 0;
262}
263
264static int mdpy_remove(struct mdev_device *mdev)
265{
266 struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
267 struct device *dev = mdev_dev(mdev);
268
269 dev_info(dev, "%s\n", __func__);
270
271 mdev_set_drvdata(mdev, NULL);
272 vfree(mdev_state->memblk);
273 kfree(mdev_state->vconfig);
274 kfree(mdev_state);
275
276 mdpy_count--;
277 return 0;
278}
279
280static ssize_t mdpy_read(struct mdev_device *mdev, char __user *buf,
281 size_t count, loff_t *ppos)
282{
283 unsigned int done = 0;
284 int ret;
285
286 while (count) {
287 size_t filled;
288
289 if (count >= 4 && !(*ppos % 4)) {
290 u32 val;
291
292 ret = mdev_access(mdev, (char *)&val, sizeof(val),
293 *ppos, false);
294 if (ret <= 0)
295 goto read_err;
296
297 if (copy_to_user(buf, &val, sizeof(val)))
298 goto read_err;
299
300 filled = 4;
301 } else if (count >= 2 && !(*ppos % 2)) {
302 u16 val;
303
304 ret = mdev_access(mdev, (char *)&val, sizeof(val),
305 *ppos, false);
306 if (ret <= 0)
307 goto read_err;
308
309 if (copy_to_user(buf, &val, sizeof(val)))
310 goto read_err;
311
312 filled = 2;
313 } else {
314 u8 val;
315
316 ret = mdev_access(mdev, (char *)&val, sizeof(val),
317 *ppos, false);
318 if (ret <= 0)
319 goto read_err;
320
321 if (copy_to_user(buf, &val, sizeof(val)))
322 goto read_err;
323
324 filled = 1;
325 }
326
327 count -= filled;
328 done += filled;
329 *ppos += filled;
330 buf += filled;
331 }
332
333 return done;
334
335read_err:
336 return -EFAULT;
337}
338
339static ssize_t mdpy_write(struct mdev_device *mdev, const char __user *buf,
340 size_t count, loff_t *ppos)
341{
342 unsigned int done = 0;
343 int ret;
344
345 while (count) {
346 size_t filled;
347
348 if (count >= 4 && !(*ppos % 4)) {
349 u32 val;
350
351 if (copy_from_user(&val, buf, sizeof(val)))
352 goto write_err;
353
354 ret = mdev_access(mdev, (char *)&val, sizeof(val),
355 *ppos, true);
356 if (ret <= 0)
357 goto write_err;
358
359 filled = 4;
360 } else if (count >= 2 && !(*ppos % 2)) {
361 u16 val;
362
363 if (copy_from_user(&val, buf, sizeof(val)))
364 goto write_err;
365
366 ret = mdev_access(mdev, (char *)&val, sizeof(val),
367 *ppos, true);
368 if (ret <= 0)
369 goto write_err;
370
371 filled = 2;
372 } else {
373 u8 val;
374
375 if (copy_from_user(&val, buf, sizeof(val)))
376 goto write_err;
377
378 ret = mdev_access(mdev, (char *)&val, sizeof(val),
379 *ppos, true);
380 if (ret <= 0)
381 goto write_err;
382
383 filled = 1;
384 }
385 count -= filled;
386 done += filled;
387 *ppos += filled;
388 buf += filled;
389 }
390
391 return done;
392write_err:
393 return -EFAULT;
394}
395
396static int mdpy_mmap(struct mdev_device *mdev, struct vm_area_struct *vma)
397{
398 struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
399
400 if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
401 return -EINVAL;
402 if (vma->vm_end < vma->vm_start)
403 return -EINVAL;
404 if (vma->vm_end - vma->vm_start > mdev_state->memsize)
405 return -EINVAL;
406 if ((vma->vm_flags & VM_SHARED) == 0)
407 return -EINVAL;
408
409 return remap_vmalloc_range(vma, mdev_state->memblk, 0);
410}
411
412static int mdpy_get_region_info(struct mdev_device *mdev,
413 struct vfio_region_info *region_info,
414 u16 *cap_type_id, void **cap_type)
415{
416 struct mdev_state *mdev_state;
417
418 mdev_state = mdev_get_drvdata(mdev);
419 if (!mdev_state)
420 return -EINVAL;
421
422 if (region_info->index >= VFIO_PCI_NUM_REGIONS &&
423 region_info->index != MDPY_DISPLAY_REGION)
424 return -EINVAL;
425
426 switch (region_info->index) {
427 case VFIO_PCI_CONFIG_REGION_INDEX:
428 region_info->offset = 0;
429 region_info->size = MDPY_CONFIG_SPACE_SIZE;
430 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
431 VFIO_REGION_INFO_FLAG_WRITE);
432 break;
433 case VFIO_PCI_BAR0_REGION_INDEX:
434 case MDPY_DISPLAY_REGION:
435 region_info->offset = MDPY_MEMORY_BAR_OFFSET;
436 region_info->size = mdev_state->memsize;
437 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
438 VFIO_REGION_INFO_FLAG_WRITE |
439 VFIO_REGION_INFO_FLAG_MMAP);
440 break;
441 default:
442 region_info->size = 0;
443 region_info->offset = 0;
444 region_info->flags = 0;
445 }
446
447 return 0;
448}
449
450static int mdpy_get_irq_info(struct mdev_device *mdev,
451 struct vfio_irq_info *irq_info)
452{
453 irq_info->count = 0;
454 return 0;
455}
456
457static int mdpy_get_device_info(struct mdev_device *mdev,
458 struct vfio_device_info *dev_info)
459{
460 dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
461 dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
462 dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
463 return 0;
464}
465
466static int mdpy_query_gfx_plane(struct mdev_device *mdev,
467 struct vfio_device_gfx_plane_info *plane)
468{
469 struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
470
471 if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
472 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
473 VFIO_GFX_PLANE_TYPE_REGION))
474 return 0;
475 return -EINVAL;
476 }
477
478 if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION)
479 return -EINVAL;
480
481 plane->drm_format = mdev_state->type->format;
482 plane->width = mdev_state->type->width;
483 plane->height = mdev_state->type->height;
484 plane->stride = (mdev_state->type->width *
485 mdev_state->type->bytepp);
486 plane->size = mdev_state->memsize;
487 plane->region_index = MDPY_DISPLAY_REGION;
488
489 /* unused */
490 plane->drm_format_mod = 0;
491 plane->x_pos = 0;
492 plane->y_pos = 0;
493 plane->x_hot = 0;
494 plane->y_hot = 0;
495
496 return 0;
497}
498
499static long mdpy_ioctl(struct mdev_device *mdev, unsigned int cmd,
500 unsigned long arg)
501{
502 int ret = 0;
503 unsigned long minsz;
504 struct mdev_state *mdev_state;
505
506 mdev_state = mdev_get_drvdata(mdev);
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(mdev, &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, &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(mdev, &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, &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);
608 }
609 return -ENOTTY;
610}
611
612static int mdpy_open(struct mdev_device *mdev)
613{
614 if (!try_module_get(THIS_MODULE))
615 return -ENODEV;
616
617 return 0;
618}
619
620static void mdpy_close(struct mdev_device *mdev)
621{
622 module_put(THIS_MODULE);
623}
624
625static ssize_t
626resolution_show(struct device *dev, struct device_attribute *attr,
627 char *buf)
628{
629 struct mdev_device *mdev = mdev_from_dev(dev);
630 struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
631
632 return sprintf(buf, "%dx%d\n",
633 mdev_state->type->width,
634 mdev_state->type->height);
635}
636static DEVICE_ATTR_RO(resolution);
637
638static struct attribute *mdev_dev_attrs[] = {
639 &dev_attr_resolution.attr,
640 NULL,
641};
642
643static const struct attribute_group mdev_dev_group = {
644 .name = "vendor",
645 .attrs = mdev_dev_attrs,
646};
647
648static const struct attribute_group *mdev_dev_groups[] = {
649 &mdev_dev_group,
650 NULL,
651};
652
653static ssize_t name_show(struct mdev_type *mtype,
654 struct mdev_type_attribute *attr, char *buf)
655{
656 const struct mdpy_type *type =
657 &mdpy_types[mtype_get_type_group_id(mtype)];
658
659 return sprintf(buf, "%s\n", type->name);
660}
661static MDEV_TYPE_ATTR_RO(name);
662
663static ssize_t description_show(struct mdev_type *mtype,
664 struct mdev_type_attribute *attr, char *buf)
665{
666 const struct mdpy_type *type =
667 &mdpy_types[mtype_get_type_group_id(mtype)];
668
669 return sprintf(buf, "virtual display, %dx%d framebuffer\n",
670 type->width, type->height);
671}
672static MDEV_TYPE_ATTR_RO(description);
673
674static ssize_t available_instances_show(struct mdev_type *mtype,
675 struct mdev_type_attribute *attr,
676 char *buf)
677{
678 return sprintf(buf, "%d\n", max_devices - mdpy_count);
679}
680static MDEV_TYPE_ATTR_RO(available_instances);
681
682static ssize_t device_api_show(struct mdev_type *mtype,
683 struct mdev_type_attribute *attr, char *buf)
684{
685 return sprintf(buf, "%s\n", VFIO_DEVICE_API_PCI_STRING);
686}
687static MDEV_TYPE_ATTR_RO(device_api);
688
689static struct attribute *mdev_types_attrs[] = {
690 &mdev_type_attr_name.attr,
691 &mdev_type_attr_description.attr,
692 &mdev_type_attr_device_api.attr,
693 &mdev_type_attr_available_instances.attr,
694 NULL,
695};
696
697static struct attribute_group mdev_type_group1 = {
698 .name = MDPY_TYPE_1,
699 .attrs = mdev_types_attrs,
700};
701
702static struct attribute_group mdev_type_group2 = {
703 .name = MDPY_TYPE_2,
704 .attrs = mdev_types_attrs,
705};
706
707static struct attribute_group mdev_type_group3 = {
708 .name = MDPY_TYPE_3,
709 .attrs = mdev_types_attrs,
710};
711
712static struct attribute_group *mdev_type_groups[] = {
713 &mdev_type_group1,
714 &mdev_type_group2,
715 &mdev_type_group3,
716 NULL,
717};
718
719static const struct mdev_parent_ops mdev_fops = {
720 .owner = THIS_MODULE,
721 .mdev_attr_groups = mdev_dev_groups,
722 .supported_type_groups = mdev_type_groups,
723 .create = mdpy_create,
724 .remove = mdpy_remove,
725 .open = mdpy_open,
726 .release = mdpy_close,
727 .read = mdpy_read,
728 .write = mdpy_write,
729 .ioctl = mdpy_ioctl,
730 .mmap = mdpy_mmap,
731};
732
733static const struct file_operations vd_fops = {
734 .owner = THIS_MODULE,
735};
736
737static void mdpy_device_release(struct device *dev)
738{
739 /* nothing */
740}
741
742static int __init mdpy_dev_init(void)
743{
744 int ret = 0;
745
746 ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME);
747 if (ret < 0) {
748 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret);
749 return ret;
750 }
751 cdev_init(&mdpy_cdev, &vd_fops);
752 cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1);
753 pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt));
754
755 mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME);
756 if (IS_ERR(mdpy_class)) {
757 pr_err("Error: failed to register mdpy_dev class\n");
758 ret = PTR_ERR(mdpy_class);
759 goto failed1;
760 }
761 mdpy_dev.class = mdpy_class;
762 mdpy_dev.release = mdpy_device_release;
763 dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
764
765 ret = device_register(&mdpy_dev);
766 if (ret)
767 goto failed2;
768
769 ret = mdev_register_device(&mdpy_dev, &mdev_fops);
770 if (ret)
771 goto failed3;
772
773 return 0;
774
775failed3:
776 device_unregister(&mdpy_dev);
777failed2:
778 class_destroy(mdpy_class);
779failed1:
780 cdev_del(&mdpy_cdev);
781 unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
782 return ret;
783}
784
785static void __exit mdpy_dev_exit(void)
786{
787 mdpy_dev.bus = NULL;
788 mdev_unregister_device(&mdpy_dev);
789
790 device_unregister(&mdpy_dev);
791 cdev_del(&mdpy_cdev);
792 unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
793 class_destroy(mdpy_class);
794 mdpy_class = NULL;
795}
796
797module_init(mdpy_dev_init)
798module_exit(mdpy_dev_exit)