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
43 MODULE_LICENSE("GPL v2");
44
45 #define MDPY_TYPE_1 "vga"
46 #define MDPY_TYPE_2 "xga"
47 #define MDPY_TYPE_3 "hd"
48
49 static struct mdpy_type {
50 struct mdev_type type;
51 u32 format;
52 u32 bytepp;
53 u32 width;
54 u32 height;
55 } mdpy_types[] = {
56 {
57 .type.sysfs_name = MDPY_TYPE_1,
58 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_1,
59 .format = DRM_FORMAT_XRGB8888,
60 .bytepp = 4,
61 .width = 640,
62 .height = 480,
63 }, {
64 .type.sysfs_name = MDPY_TYPE_2,
65 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_2,
66 .format = DRM_FORMAT_XRGB8888,
67 .bytepp = 4,
68 .width = 1024,
69 .height = 768,
70 }, {
71 .type.sysfs_name = MDPY_TYPE_3,
72 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_3,
73 .format = DRM_FORMAT_XRGB8888,
74 .bytepp = 4,
75 .width = 1920,
76 .height = 1080,
77 },
78 };
79
80 static struct mdev_type *mdpy_mdev_types[] = {
81 &mdpy_types[0].type,
82 &mdpy_types[1].type,
83 &mdpy_types[2].type,
84 };
85
86 static dev_t mdpy_devt;
87 static struct class *mdpy_class;
88 static struct cdev mdpy_cdev;
89 static struct device mdpy_dev;
90 static struct mdev_parent mdpy_parent;
91 static const struct vfio_device_ops mdpy_dev_ops;
92
93 /* State of each mdev device */
94 struct mdev_state {
95 struct vfio_device vdev;
96 u8 *vconfig;
97 u32 bar_mask;
98 struct mutex ops_lock;
99 struct mdev_device *mdev;
100 struct vfio_device_info dev_info;
101
102 const struct mdpy_type *type;
103 u32 memsize;
104 void *memblk;
105 };
106
mdpy_create_config_space(struct mdev_state * mdev_state)107 static void mdpy_create_config_space(struct mdev_state *mdev_state)
108 {
109 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID],
110 MDPY_PCI_VENDOR_ID);
111 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID],
112 MDPY_PCI_DEVICE_ID);
113 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID],
114 MDPY_PCI_SUBVENDOR_ID);
115 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID],
116 MDPY_PCI_SUBDEVICE_ID);
117
118 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND],
119 PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
120 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS],
121 PCI_STATUS_CAP_LIST);
122 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE],
123 PCI_CLASS_DISPLAY_OTHER);
124 mdev_state->vconfig[PCI_CLASS_REVISION] = 0x01;
125
126 STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0],
127 PCI_BASE_ADDRESS_SPACE_MEMORY |
128 PCI_BASE_ADDRESS_MEM_TYPE_32 |
129 PCI_BASE_ADDRESS_MEM_PREFETCH);
130 mdev_state->bar_mask = ~(mdev_state->memsize) + 1;
131
132 /* vendor specific capability for the config registers */
133 mdev_state->vconfig[PCI_CAPABILITY_LIST] = MDPY_VENDORCAP_OFFSET;
134 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */
135 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */
136 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE;
137 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET],
138 mdev_state->type->format);
139 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET],
140 mdev_state->type->width);
141 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET],
142 mdev_state->type->height);
143 }
144
handle_pci_cfg_write(struct mdev_state * mdev_state,u16 offset,char * buf,u32 count)145 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset,
146 char *buf, u32 count)
147 {
148 struct device *dev = mdev_dev(mdev_state->mdev);
149 u32 cfg_addr;
150
151 switch (offset) {
152 case PCI_BASE_ADDRESS_0:
153 cfg_addr = *(u32 *)buf;
154
155 if (cfg_addr == 0xffffffff) {
156 cfg_addr = (cfg_addr & mdev_state->bar_mask);
157 } else {
158 cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK;
159 if (cfg_addr)
160 dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr);
161 }
162
163 cfg_addr |= (mdev_state->vconfig[offset] &
164 ~PCI_BASE_ADDRESS_MEM_MASK);
165 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr);
166 break;
167 }
168 }
169
mdev_access(struct mdev_state * mdev_state,char * buf,size_t count,loff_t pos,bool is_write)170 static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf,
171 size_t count, loff_t pos, bool is_write)
172 {
173 int ret = 0;
174
175 mutex_lock(&mdev_state->ops_lock);
176
177 if (pos < MDPY_CONFIG_SPACE_SIZE) {
178 if (is_write)
179 handle_pci_cfg_write(mdev_state, pos, buf, count);
180 else
181 memcpy(buf, (mdev_state->vconfig + pos), count);
182
183 } else if ((pos >= MDPY_MEMORY_BAR_OFFSET) &&
184 (pos + count <=
185 MDPY_MEMORY_BAR_OFFSET + mdev_state->memsize)) {
186 pos -= MDPY_MEMORY_BAR_OFFSET;
187 if (is_write)
188 memcpy(mdev_state->memblk, buf, count);
189 else
190 memcpy(buf, mdev_state->memblk, count);
191
192 } else {
193 dev_info(mdev_state->vdev.dev,
194 "%s: %s @0x%llx (unhandled)\n", __func__,
195 is_write ? "WR" : "RD", pos);
196 ret = -1;
197 goto accessfailed;
198 }
199
200 ret = count;
201
202
203 accessfailed:
204 mutex_unlock(&mdev_state->ops_lock);
205
206 return ret;
207 }
208
mdpy_reset(struct mdev_state * mdev_state)209 static int mdpy_reset(struct mdev_state *mdev_state)
210 {
211 u32 stride, i;
212
213 /* initialize with gray gradient */
214 stride = mdev_state->type->width * mdev_state->type->bytepp;
215 for (i = 0; i < mdev_state->type->height; i++)
216 memset(mdev_state->memblk + i * stride,
217 i * 255 / mdev_state->type->height,
218 stride);
219 return 0;
220 }
221
mdpy_init_dev(struct vfio_device * vdev)222 static int mdpy_init_dev(struct vfio_device *vdev)
223 {
224 struct mdev_state *mdev_state =
225 container_of(vdev, struct mdev_state, vdev);
226 struct mdev_device *mdev = to_mdev_device(vdev->dev);
227 const struct mdpy_type *type =
228 container_of(mdev->type, struct mdpy_type, type);
229 u32 fbsize;
230 int ret = -ENOMEM;
231
232 mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL);
233 if (!mdev_state->vconfig)
234 return ret;
235
236 fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp);
237
238 mdev_state->memblk = vmalloc_user(fbsize);
239 if (!mdev_state->memblk)
240 goto out_vconfig;
241
242 mutex_init(&mdev_state->ops_lock);
243 mdev_state->mdev = mdev;
244 mdev_state->type = type;
245 mdev_state->memsize = fbsize;
246 mdpy_create_config_space(mdev_state);
247 mdpy_reset(mdev_state);
248
249 dev_info(vdev->dev, "%s: %s (%dx%d)\n", __func__, type->type.pretty_name,
250 type->width, type->height);
251 return 0;
252
253 out_vconfig:
254 kfree(mdev_state->vconfig);
255 return ret;
256 }
257
mdpy_probe(struct mdev_device * mdev)258 static int mdpy_probe(struct mdev_device *mdev)
259 {
260 struct mdev_state *mdev_state;
261 int ret;
262
263 mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev,
264 &mdpy_dev_ops);
265 if (IS_ERR(mdev_state))
266 return PTR_ERR(mdev_state);
267
268 ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev);
269 if (ret)
270 goto err_put_vdev;
271 dev_set_drvdata(&mdev->dev, mdev_state);
272 return 0;
273
274 err_put_vdev:
275 vfio_put_device(&mdev_state->vdev);
276 return ret;
277 }
278
mdpy_release_dev(struct vfio_device * vdev)279 static void mdpy_release_dev(struct vfio_device *vdev)
280 {
281 struct mdev_state *mdev_state =
282 container_of(vdev, struct mdev_state, vdev);
283
284 vfree(mdev_state->memblk);
285 kfree(mdev_state->vconfig);
286 }
287
mdpy_remove(struct mdev_device * mdev)288 static void mdpy_remove(struct mdev_device *mdev)
289 {
290 struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
291
292 dev_info(&mdev->dev, "%s\n", __func__);
293
294 vfio_unregister_group_dev(&mdev_state->vdev);
295 vfio_put_device(&mdev_state->vdev);
296 }
297
mdpy_read(struct vfio_device * vdev,char __user * buf,size_t count,loff_t * ppos)298 static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf,
299 size_t count, loff_t *ppos)
300 {
301 struct mdev_state *mdev_state =
302 container_of(vdev, struct mdev_state, vdev);
303 unsigned int done = 0;
304 int ret;
305
306 while (count) {
307 size_t filled;
308
309 if (count >= 4 && !(*ppos % 4)) {
310 u32 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 = 4;
321 } else if (count >= 2 && !(*ppos % 2)) {
322 u16 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 = 2;
333 } else {
334 u8 val;
335
336 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
337 *ppos, false);
338 if (ret <= 0)
339 goto read_err;
340
341 if (copy_to_user(buf, &val, sizeof(val)))
342 goto read_err;
343
344 filled = 1;
345 }
346
347 count -= filled;
348 done += filled;
349 *ppos += filled;
350 buf += filled;
351 }
352
353 return done;
354
355 read_err:
356 return -EFAULT;
357 }
358
mdpy_write(struct vfio_device * vdev,const char __user * buf,size_t count,loff_t * ppos)359 static ssize_t mdpy_write(struct vfio_device *vdev, const char __user *buf,
360 size_t count, loff_t *ppos)
361 {
362 struct mdev_state *mdev_state =
363 container_of(vdev, struct mdev_state, vdev);
364 unsigned int done = 0;
365 int ret;
366
367 while (count) {
368 size_t filled;
369
370 if (count >= 4 && !(*ppos % 4)) {
371 u32 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 = 4;
382 } else if (count >= 2 && !(*ppos % 2)) {
383 u16 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 = 2;
394 } else {
395 u8 val;
396
397 if (copy_from_user(&val, buf, sizeof(val)))
398 goto write_err;
399
400 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
401 *ppos, true);
402 if (ret <= 0)
403 goto write_err;
404
405 filled = 1;
406 }
407 count -= filled;
408 done += filled;
409 *ppos += filled;
410 buf += filled;
411 }
412
413 return done;
414 write_err:
415 return -EFAULT;
416 }
417
mdpy_mmap(struct vfio_device * vdev,struct vm_area_struct * vma)418 static int mdpy_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
419 {
420 struct mdev_state *mdev_state =
421 container_of(vdev, struct mdev_state, vdev);
422
423 if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
424 return -EINVAL;
425 if (vma->vm_end < vma->vm_start)
426 return -EINVAL;
427 if (vma->vm_end - vma->vm_start > mdev_state->memsize)
428 return -EINVAL;
429 if ((vma->vm_flags & VM_SHARED) == 0)
430 return -EINVAL;
431
432 return remap_vmalloc_range(vma, mdev_state->memblk, 0);
433 }
434
mdpy_get_region_info(struct mdev_state * mdev_state,struct vfio_region_info * region_info,u16 * cap_type_id,void ** cap_type)435 static int mdpy_get_region_info(struct mdev_state *mdev_state,
436 struct vfio_region_info *region_info,
437 u16 *cap_type_id, void **cap_type)
438 {
439 if (region_info->index >= VFIO_PCI_NUM_REGIONS &&
440 region_info->index != MDPY_DISPLAY_REGION)
441 return -EINVAL;
442
443 switch (region_info->index) {
444 case VFIO_PCI_CONFIG_REGION_INDEX:
445 region_info->offset = 0;
446 region_info->size = MDPY_CONFIG_SPACE_SIZE;
447 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
448 VFIO_REGION_INFO_FLAG_WRITE);
449 break;
450 case VFIO_PCI_BAR0_REGION_INDEX:
451 case MDPY_DISPLAY_REGION:
452 region_info->offset = MDPY_MEMORY_BAR_OFFSET;
453 region_info->size = mdev_state->memsize;
454 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
455 VFIO_REGION_INFO_FLAG_WRITE |
456 VFIO_REGION_INFO_FLAG_MMAP);
457 break;
458 default:
459 region_info->size = 0;
460 region_info->offset = 0;
461 region_info->flags = 0;
462 }
463
464 return 0;
465 }
466
mdpy_get_irq_info(struct vfio_irq_info * irq_info)467 static int mdpy_get_irq_info(struct vfio_irq_info *irq_info)
468 {
469 irq_info->count = 0;
470 return 0;
471 }
472
mdpy_get_device_info(struct vfio_device_info * dev_info)473 static int mdpy_get_device_info(struct vfio_device_info *dev_info)
474 {
475 dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
476 dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
477 dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
478 return 0;
479 }
480
mdpy_query_gfx_plane(struct mdev_state * mdev_state,struct vfio_device_gfx_plane_info * plane)481 static int mdpy_query_gfx_plane(struct mdev_state *mdev_state,
482 struct vfio_device_gfx_plane_info *plane)
483 {
484 if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
485 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
486 VFIO_GFX_PLANE_TYPE_REGION))
487 return 0;
488 return -EINVAL;
489 }
490
491 if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION)
492 return -EINVAL;
493
494 plane->drm_format = mdev_state->type->format;
495 plane->width = mdev_state->type->width;
496 plane->height = mdev_state->type->height;
497 plane->stride = (mdev_state->type->width *
498 mdev_state->type->bytepp);
499 plane->size = mdev_state->memsize;
500 plane->region_index = MDPY_DISPLAY_REGION;
501
502 /* unused */
503 plane->drm_format_mod = 0;
504 plane->x_pos = 0;
505 plane->y_pos = 0;
506 plane->x_hot = 0;
507 plane->y_hot = 0;
508
509 return 0;
510 }
511
mdpy_ioctl(struct vfio_device * vdev,unsigned int cmd,unsigned long arg)512 static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd,
513 unsigned long arg)
514 {
515 int ret = 0;
516 unsigned long minsz;
517 struct mdev_state *mdev_state =
518 container_of(vdev, struct mdev_state, vdev);
519
520 switch (cmd) {
521 case VFIO_DEVICE_GET_INFO:
522 {
523 struct vfio_device_info info;
524
525 minsz = offsetofend(struct vfio_device_info, num_irqs);
526
527 if (copy_from_user(&info, (void __user *)arg, minsz))
528 return -EFAULT;
529
530 if (info.argsz < minsz)
531 return -EINVAL;
532
533 ret = mdpy_get_device_info(&info);
534 if (ret)
535 return ret;
536
537 memcpy(&mdev_state->dev_info, &info, sizeof(info));
538
539 if (copy_to_user((void __user *)arg, &info, minsz))
540 return -EFAULT;
541
542 return 0;
543 }
544 case VFIO_DEVICE_GET_REGION_INFO:
545 {
546 struct vfio_region_info info;
547 u16 cap_type_id = 0;
548 void *cap_type = NULL;
549
550 minsz = offsetofend(struct vfio_region_info, offset);
551
552 if (copy_from_user(&info, (void __user *)arg, minsz))
553 return -EFAULT;
554
555 if (info.argsz < minsz)
556 return -EINVAL;
557
558 ret = mdpy_get_region_info(mdev_state, &info, &cap_type_id,
559 &cap_type);
560 if (ret)
561 return ret;
562
563 if (copy_to_user((void __user *)arg, &info, minsz))
564 return -EFAULT;
565
566 return 0;
567 }
568
569 case VFIO_DEVICE_GET_IRQ_INFO:
570 {
571 struct vfio_irq_info info;
572
573 minsz = offsetofend(struct vfio_irq_info, count);
574
575 if (copy_from_user(&info, (void __user *)arg, minsz))
576 return -EFAULT;
577
578 if ((info.argsz < minsz) ||
579 (info.index >= mdev_state->dev_info.num_irqs))
580 return -EINVAL;
581
582 ret = mdpy_get_irq_info(&info);
583 if (ret)
584 return ret;
585
586 if (copy_to_user((void __user *)arg, &info, minsz))
587 return -EFAULT;
588
589 return 0;
590 }
591
592 case VFIO_DEVICE_QUERY_GFX_PLANE:
593 {
594 struct vfio_device_gfx_plane_info plane;
595
596 minsz = offsetofend(struct vfio_device_gfx_plane_info,
597 region_index);
598
599 if (copy_from_user(&plane, (void __user *)arg, minsz))
600 return -EFAULT;
601
602 if (plane.argsz < minsz)
603 return -EINVAL;
604
605 ret = mdpy_query_gfx_plane(mdev_state, &plane);
606 if (ret)
607 return ret;
608
609 if (copy_to_user((void __user *)arg, &plane, minsz))
610 return -EFAULT;
611
612 return 0;
613 }
614
615 case VFIO_DEVICE_SET_IRQS:
616 return -EINVAL;
617
618 case VFIO_DEVICE_RESET:
619 return mdpy_reset(mdev_state);
620 }
621 return -ENOTTY;
622 }
623
624 static ssize_t
resolution_show(struct device * dev,struct device_attribute * attr,char * buf)625 resolution_show(struct device *dev, struct device_attribute *attr,
626 char *buf)
627 {
628 struct mdev_state *mdev_state = dev_get_drvdata(dev);
629
630 return sprintf(buf, "%dx%d\n",
631 mdev_state->type->width,
632 mdev_state->type->height);
633 }
634 static DEVICE_ATTR_RO(resolution);
635
636 static struct attribute *mdev_dev_attrs[] = {
637 &dev_attr_resolution.attr,
638 NULL,
639 };
640
641 static const struct attribute_group mdev_dev_group = {
642 .name = "vendor",
643 .attrs = mdev_dev_attrs,
644 };
645
646 static const struct attribute_group *mdev_dev_groups[] = {
647 &mdev_dev_group,
648 NULL,
649 };
650
mdpy_show_description(struct mdev_type * mtype,char * buf)651 static ssize_t mdpy_show_description(struct mdev_type *mtype, char *buf)
652 {
653 struct mdpy_type *type = container_of(mtype, struct mdpy_type, type);
654
655 return sprintf(buf, "virtual display, %dx%d framebuffer\n",
656 type->width, type->height);
657 }
658
659 static const struct vfio_device_ops mdpy_dev_ops = {
660 .init = mdpy_init_dev,
661 .release = mdpy_release_dev,
662 .read = mdpy_read,
663 .write = mdpy_write,
664 .ioctl = mdpy_ioctl,
665 .mmap = mdpy_mmap,
666 };
667
668 static struct mdev_driver mdpy_driver = {
669 .device_api = VFIO_DEVICE_API_PCI_STRING,
670 .max_instances = 4,
671 .driver = {
672 .name = "mdpy",
673 .owner = THIS_MODULE,
674 .mod_name = KBUILD_MODNAME,
675 .dev_groups = mdev_dev_groups,
676 },
677 .probe = mdpy_probe,
678 .remove = mdpy_remove,
679 .show_description = mdpy_show_description,
680 };
681
682 static const struct file_operations vd_fops = {
683 .owner = THIS_MODULE,
684 };
685
mdpy_device_release(struct device * dev)686 static void mdpy_device_release(struct device *dev)
687 {
688 /* nothing */
689 }
690
mdpy_dev_init(void)691 static int __init mdpy_dev_init(void)
692 {
693 int ret = 0;
694
695 ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME);
696 if (ret < 0) {
697 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret);
698 return ret;
699 }
700 cdev_init(&mdpy_cdev, &vd_fops);
701 cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1);
702 pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt));
703
704 ret = mdev_register_driver(&mdpy_driver);
705 if (ret)
706 goto err_cdev;
707
708 mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME);
709 if (IS_ERR(mdpy_class)) {
710 pr_err("Error: failed to register mdpy_dev class\n");
711 ret = PTR_ERR(mdpy_class);
712 goto err_driver;
713 }
714 mdpy_dev.class = mdpy_class;
715 mdpy_dev.release = mdpy_device_release;
716 dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
717
718 ret = device_register(&mdpy_dev);
719 if (ret)
720 goto err_put;
721
722 ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver,
723 mdpy_mdev_types,
724 ARRAY_SIZE(mdpy_mdev_types));
725 if (ret)
726 goto err_device;
727
728 return 0;
729
730 err_device:
731 device_del(&mdpy_dev);
732 err_put:
733 put_device(&mdpy_dev);
734 class_destroy(mdpy_class);
735 err_driver:
736 mdev_unregister_driver(&mdpy_driver);
737 err_cdev:
738 cdev_del(&mdpy_cdev);
739 unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
740 return ret;
741 }
742
mdpy_dev_exit(void)743 static void __exit mdpy_dev_exit(void)
744 {
745 mdpy_dev.bus = NULL;
746 mdev_unregister_parent(&mdpy_parent);
747
748 device_unregister(&mdpy_dev);
749 mdev_unregister_driver(&mdpy_driver);
750 cdev_del(&mdpy_cdev);
751 unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
752 class_destroy(mdpy_class);
753 mdpy_class = NULL;
754 }
755
756 module_param_named(count, mdpy_driver.max_instances, int, 0444);
757 MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices");
758
759 module_init(mdpy_dev_init)
760 module_exit(mdpy_dev_exit)
761