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 vfio_free_device(vdev);
287 }
288
mdpy_remove(struct mdev_device * mdev)289 static void mdpy_remove(struct mdev_device *mdev)
290 {
291 struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);
292
293 dev_info(&mdev->dev, "%s\n", __func__);
294
295 vfio_unregister_group_dev(&mdev_state->vdev);
296 vfio_put_device(&mdev_state->vdev);
297 }
298
mdpy_read(struct vfio_device * vdev,char __user * buf,size_t count,loff_t * ppos)299 static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf,
300 size_t count, loff_t *ppos)
301 {
302 struct mdev_state *mdev_state =
303 container_of(vdev, struct mdev_state, vdev);
304 unsigned int done = 0;
305 int ret;
306
307 while (count) {
308 size_t filled;
309
310 if (count >= 4 && !(*ppos % 4)) {
311 u32 val;
312
313 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
314 *ppos, false);
315 if (ret <= 0)
316 goto read_err;
317
318 if (copy_to_user(buf, &val, sizeof(val)))
319 goto read_err;
320
321 filled = 4;
322 } else if (count >= 2 && !(*ppos % 2)) {
323 u16 val;
324
325 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
326 *ppos, false);
327 if (ret <= 0)
328 goto read_err;
329
330 if (copy_to_user(buf, &val, sizeof(val)))
331 goto read_err;
332
333 filled = 2;
334 } else {
335 u8 val;
336
337 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
338 *ppos, false);
339 if (ret <= 0)
340 goto read_err;
341
342 if (copy_to_user(buf, &val, sizeof(val)))
343 goto read_err;
344
345 filled = 1;
346 }
347
348 count -= filled;
349 done += filled;
350 *ppos += filled;
351 buf += filled;
352 }
353
354 return done;
355
356 read_err:
357 return -EFAULT;
358 }
359
mdpy_write(struct vfio_device * vdev,const char __user * buf,size_t count,loff_t * ppos)360 static ssize_t mdpy_write(struct vfio_device *vdev, const char __user *buf,
361 size_t count, loff_t *ppos)
362 {
363 struct mdev_state *mdev_state =
364 container_of(vdev, struct mdev_state, vdev);
365 unsigned int done = 0;
366 int ret;
367
368 while (count) {
369 size_t filled;
370
371 if (count >= 4 && !(*ppos % 4)) {
372 u32 val;
373
374 if (copy_from_user(&val, buf, sizeof(val)))
375 goto write_err;
376
377 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
378 *ppos, true);
379 if (ret <= 0)
380 goto write_err;
381
382 filled = 4;
383 } else if (count >= 2 && !(*ppos % 2)) {
384 u16 val;
385
386 if (copy_from_user(&val, buf, sizeof(val)))
387 goto write_err;
388
389 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
390 *ppos, true);
391 if (ret <= 0)
392 goto write_err;
393
394 filled = 2;
395 } else {
396 u8 val;
397
398 if (copy_from_user(&val, buf, sizeof(val)))
399 goto write_err;
400
401 ret = mdev_access(mdev_state, (char *)&val, sizeof(val),
402 *ppos, true);
403 if (ret <= 0)
404 goto write_err;
405
406 filled = 1;
407 }
408 count -= filled;
409 done += filled;
410 *ppos += filled;
411 buf += filled;
412 }
413
414 return done;
415 write_err:
416 return -EFAULT;
417 }
418
mdpy_mmap(struct vfio_device * vdev,struct vm_area_struct * vma)419 static int mdpy_mmap(struct vfio_device *vdev, struct vm_area_struct *vma)
420 {
421 struct mdev_state *mdev_state =
422 container_of(vdev, struct mdev_state, vdev);
423
424 if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT)
425 return -EINVAL;
426 if (vma->vm_end < vma->vm_start)
427 return -EINVAL;
428 if (vma->vm_end - vma->vm_start > mdev_state->memsize)
429 return -EINVAL;
430 if ((vma->vm_flags & VM_SHARED) == 0)
431 return -EINVAL;
432
433 return remap_vmalloc_range(vma, mdev_state->memblk, 0);
434 }
435
mdpy_get_region_info(struct mdev_state * mdev_state,struct vfio_region_info * region_info,u16 * cap_type_id,void ** cap_type)436 static int mdpy_get_region_info(struct mdev_state *mdev_state,
437 struct vfio_region_info *region_info,
438 u16 *cap_type_id, void **cap_type)
439 {
440 if (region_info->index >= VFIO_PCI_NUM_REGIONS &&
441 region_info->index != MDPY_DISPLAY_REGION)
442 return -EINVAL;
443
444 switch (region_info->index) {
445 case VFIO_PCI_CONFIG_REGION_INDEX:
446 region_info->offset = 0;
447 region_info->size = MDPY_CONFIG_SPACE_SIZE;
448 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
449 VFIO_REGION_INFO_FLAG_WRITE);
450 break;
451 case VFIO_PCI_BAR0_REGION_INDEX:
452 case MDPY_DISPLAY_REGION:
453 region_info->offset = MDPY_MEMORY_BAR_OFFSET;
454 region_info->size = mdev_state->memsize;
455 region_info->flags = (VFIO_REGION_INFO_FLAG_READ |
456 VFIO_REGION_INFO_FLAG_WRITE |
457 VFIO_REGION_INFO_FLAG_MMAP);
458 break;
459 default:
460 region_info->size = 0;
461 region_info->offset = 0;
462 region_info->flags = 0;
463 }
464
465 return 0;
466 }
467
mdpy_get_irq_info(struct vfio_irq_info * irq_info)468 static int mdpy_get_irq_info(struct vfio_irq_info *irq_info)
469 {
470 irq_info->count = 0;
471 return 0;
472 }
473
mdpy_get_device_info(struct vfio_device_info * dev_info)474 static int mdpy_get_device_info(struct vfio_device_info *dev_info)
475 {
476 dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
477 dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
478 dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
479 return 0;
480 }
481
mdpy_query_gfx_plane(struct mdev_state * mdev_state,struct vfio_device_gfx_plane_info * plane)482 static int mdpy_query_gfx_plane(struct mdev_state *mdev_state,
483 struct vfio_device_gfx_plane_info *plane)
484 {
485 if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
486 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
487 VFIO_GFX_PLANE_TYPE_REGION))
488 return 0;
489 return -EINVAL;
490 }
491
492 if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION)
493 return -EINVAL;
494
495 plane->drm_format = mdev_state->type->format;
496 plane->width = mdev_state->type->width;
497 plane->height = mdev_state->type->height;
498 plane->stride = (mdev_state->type->width *
499 mdev_state->type->bytepp);
500 plane->size = mdev_state->memsize;
501 plane->region_index = MDPY_DISPLAY_REGION;
502
503 /* unused */
504 plane->drm_format_mod = 0;
505 plane->x_pos = 0;
506 plane->y_pos = 0;
507 plane->x_hot = 0;
508 plane->y_hot = 0;
509
510 return 0;
511 }
512
mdpy_ioctl(struct vfio_device * vdev,unsigned int cmd,unsigned long arg)513 static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd,
514 unsigned long arg)
515 {
516 int ret = 0;
517 unsigned long minsz;
518 struct mdev_state *mdev_state =
519 container_of(vdev, struct mdev_state, vdev);
520
521 switch (cmd) {
522 case VFIO_DEVICE_GET_INFO:
523 {
524 struct vfio_device_info info;
525
526 minsz = offsetofend(struct vfio_device_info, num_irqs);
527
528 if (copy_from_user(&info, (void __user *)arg, minsz))
529 return -EFAULT;
530
531 if (info.argsz < minsz)
532 return -EINVAL;
533
534 ret = mdpy_get_device_info(&info);
535 if (ret)
536 return ret;
537
538 memcpy(&mdev_state->dev_info, &info, sizeof(info));
539
540 if (copy_to_user((void __user *)arg, &info, minsz))
541 return -EFAULT;
542
543 return 0;
544 }
545 case VFIO_DEVICE_GET_REGION_INFO:
546 {
547 struct vfio_region_info info;
548 u16 cap_type_id = 0;
549 void *cap_type = NULL;
550
551 minsz = offsetofend(struct vfio_region_info, offset);
552
553 if (copy_from_user(&info, (void __user *)arg, minsz))
554 return -EFAULT;
555
556 if (info.argsz < minsz)
557 return -EINVAL;
558
559 ret = mdpy_get_region_info(mdev_state, &info, &cap_type_id,
560 &cap_type);
561 if (ret)
562 return ret;
563
564 if (copy_to_user((void __user *)arg, &info, minsz))
565 return -EFAULT;
566
567 return 0;
568 }
569
570 case VFIO_DEVICE_GET_IRQ_INFO:
571 {
572 struct vfio_irq_info info;
573
574 minsz = offsetofend(struct vfio_irq_info, count);
575
576 if (copy_from_user(&info, (void __user *)arg, minsz))
577 return -EFAULT;
578
579 if ((info.argsz < minsz) ||
580 (info.index >= mdev_state->dev_info.num_irqs))
581 return -EINVAL;
582
583 ret = mdpy_get_irq_info(&info);
584 if (ret)
585 return ret;
586
587 if (copy_to_user((void __user *)arg, &info, minsz))
588 return -EFAULT;
589
590 return 0;
591 }
592
593 case VFIO_DEVICE_QUERY_GFX_PLANE:
594 {
595 struct vfio_device_gfx_plane_info plane;
596
597 minsz = offsetofend(struct vfio_device_gfx_plane_info,
598 region_index);
599
600 if (copy_from_user(&plane, (void __user *)arg, minsz))
601 return -EFAULT;
602
603 if (plane.argsz < minsz)
604 return -EINVAL;
605
606 ret = mdpy_query_gfx_plane(mdev_state, &plane);
607 if (ret)
608 return ret;
609
610 if (copy_to_user((void __user *)arg, &plane, minsz))
611 return -EFAULT;
612
613 return 0;
614 }
615
616 case VFIO_DEVICE_SET_IRQS:
617 return -EINVAL;
618
619 case VFIO_DEVICE_RESET:
620 return mdpy_reset(mdev_state);
621 }
622 return -ENOTTY;
623 }
624
625 static ssize_t
resolution_show(struct device * dev,struct device_attribute * attr,char * buf)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
mdpy_show_description(struct mdev_type * mtype,char * buf)652 static ssize_t mdpy_show_description(struct mdev_type *mtype, char *buf)
653 {
654 struct mdpy_type *type = container_of(mtype, struct mdpy_type, type);
655
656 return sprintf(buf, "virtual display, %dx%d framebuffer\n",
657 type->width, type->height);
658 }
659
660 static const struct vfio_device_ops mdpy_dev_ops = {
661 .init = mdpy_init_dev,
662 .release = mdpy_release_dev,
663 .read = mdpy_read,
664 .write = mdpy_write,
665 .ioctl = mdpy_ioctl,
666 .mmap = mdpy_mmap,
667 };
668
669 static struct mdev_driver mdpy_driver = {
670 .device_api = VFIO_DEVICE_API_PCI_STRING,
671 .max_instances = 4,
672 .driver = {
673 .name = "mdpy",
674 .owner = THIS_MODULE,
675 .mod_name = KBUILD_MODNAME,
676 .dev_groups = mdev_dev_groups,
677 },
678 .probe = mdpy_probe,
679 .remove = mdpy_remove,
680 .show_description = mdpy_show_description,
681 };
682
683 static const struct file_operations vd_fops = {
684 .owner = THIS_MODULE,
685 };
686
mdpy_device_release(struct device * dev)687 static void mdpy_device_release(struct device *dev)
688 {
689 /* nothing */
690 }
691
mdpy_dev_init(void)692 static int __init mdpy_dev_init(void)
693 {
694 int ret = 0;
695
696 ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME);
697 if (ret < 0) {
698 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret);
699 return ret;
700 }
701 cdev_init(&mdpy_cdev, &vd_fops);
702 cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1);
703 pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt));
704
705 ret = mdev_register_driver(&mdpy_driver);
706 if (ret)
707 goto err_cdev;
708
709 mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME);
710 if (IS_ERR(mdpy_class)) {
711 pr_err("Error: failed to register mdpy_dev class\n");
712 ret = PTR_ERR(mdpy_class);
713 goto err_driver;
714 }
715 mdpy_dev.class = mdpy_class;
716 mdpy_dev.release = mdpy_device_release;
717 dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
718
719 ret = device_register(&mdpy_dev);
720 if (ret)
721 goto err_class;
722
723 ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver,
724 mdpy_mdev_types,
725 ARRAY_SIZE(mdpy_mdev_types));
726 if (ret)
727 goto err_device;
728
729 return 0;
730
731 err_device:
732 device_unregister(&mdpy_dev);
733 err_class:
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
