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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/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_get_region_info(struct mdev_state *mdev_state,
439				struct vfio_region_info *region_info,
440				u16 *cap_type_id, void **cap_type)
441{
442	if (region_info->index >= VFIO_PCI_NUM_REGIONS &&
443	    region_info->index != MDPY_DISPLAY_REGION)
444		return -EINVAL;
445
446	switch (region_info->index) {
447	case VFIO_PCI_CONFIG_REGION_INDEX:
448		region_info->offset = 0;
449		region_info->size   = MDPY_CONFIG_SPACE_SIZE;
450		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ |
451				       VFIO_REGION_INFO_FLAG_WRITE);
452		break;
453	case VFIO_PCI_BAR0_REGION_INDEX:
454	case MDPY_DISPLAY_REGION:
455		region_info->offset = MDPY_MEMORY_BAR_OFFSET;
456		region_info->size   = mdev_state->memsize;
457		region_info->flags  = (VFIO_REGION_INFO_FLAG_READ  |
458				       VFIO_REGION_INFO_FLAG_WRITE |
459				       VFIO_REGION_INFO_FLAG_MMAP);
460		break;
461	default:
462		region_info->size   = 0;
463		region_info->offset = 0;
464		region_info->flags  = 0;
465	}
466
467	return 0;
468}
469
470static int mdpy_get_irq_info(struct vfio_irq_info *irq_info)
471{
472	irq_info->count = 0;
473	return 0;
474}
475
476static int mdpy_get_device_info(struct vfio_device_info *dev_info)
477{
478	dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
479	dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
480	dev_info->num_irqs = VFIO_PCI_NUM_IRQS;
481	return 0;
482}
483
484static int mdpy_query_gfx_plane(struct mdev_state *mdev_state,
485				struct vfio_device_gfx_plane_info *plane)
486{
487	if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) {
488		if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE |
489				     VFIO_GFX_PLANE_TYPE_REGION))
490			return 0;
491		return -EINVAL;
492	}
493
494	if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION)
495		return -EINVAL;
496
497	plane->drm_format     = mdev_state->type->format;
498	plane->width	      = mdev_state->type->width;
499	plane->height	      = mdev_state->type->height;
500	plane->stride	      = (mdev_state->type->width *
501				 mdev_state->type->bytepp);
502	plane->size	      = mdev_state->memsize;
503	plane->region_index   = MDPY_DISPLAY_REGION;
504
505	/* unused */
506	plane->drm_format_mod = 0;
507	plane->x_pos	      = 0;
508	plane->y_pos	      = 0;
509	plane->x_hot	      = 0;
510	plane->y_hot	      = 0;
511
512	return 0;
513}
514
515static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd,
516		       unsigned long arg)
517{
518	int ret = 0;
519	unsigned long minsz;
520	struct mdev_state *mdev_state =
521		container_of(vdev, struct mdev_state, vdev);
522
523	switch (cmd) {
524	case VFIO_DEVICE_GET_INFO:
525	{
526		struct vfio_device_info info;
527
528		minsz = offsetofend(struct vfio_device_info, num_irqs);
529
530		if (copy_from_user(&info, (void __user *)arg, minsz))
531			return -EFAULT;
532
533		if (info.argsz < minsz)
534			return -EINVAL;
535
536		ret = mdpy_get_device_info(&info);
537		if (ret)
538			return ret;
539
540		memcpy(&mdev_state->dev_info, &info, sizeof(info));
541
542		if (copy_to_user((void __user *)arg, &info, minsz))
543			return -EFAULT;
544
545		return 0;
546	}
547	case VFIO_DEVICE_GET_REGION_INFO:
548	{
549		struct vfio_region_info info;
550		u16 cap_type_id = 0;
551		void *cap_type = NULL;
552
553		minsz = offsetofend(struct vfio_region_info, offset);
554
555		if (copy_from_user(&info, (void __user *)arg, minsz))
556			return -EFAULT;
557
558		if (info.argsz < minsz)
559			return -EINVAL;
560
561		ret = mdpy_get_region_info(mdev_state, &info, &cap_type_id,
562					   &cap_type);
563		if (ret)
564			return ret;
565
566		if (copy_to_user((void __user *)arg, &info, minsz))
567			return -EFAULT;
568
569		return 0;
570	}
571
572	case VFIO_DEVICE_GET_IRQ_INFO:
573	{
574		struct vfio_irq_info info;
575
576		minsz = offsetofend(struct vfio_irq_info, count);
577
578		if (copy_from_user(&info, (void __user *)arg, minsz))
579			return -EFAULT;
580
581		if ((info.argsz < minsz) ||
582		    (info.index >= mdev_state->dev_info.num_irqs))
583			return -EINVAL;
584
585		ret = mdpy_get_irq_info(&info);
586		if (ret)
587			return ret;
588
589		if (copy_to_user((void __user *)arg, &info, minsz))
590			return -EFAULT;
591
592		return 0;
593	}
594
595	case VFIO_DEVICE_QUERY_GFX_PLANE:
596	{
597		struct vfio_device_gfx_plane_info plane = {};
598
599		minsz = offsetofend(struct vfio_device_gfx_plane_info,
600				    region_index);
601
602		if (copy_from_user(&plane, (void __user *)arg, minsz))
603			return -EFAULT;
604
605		if (plane.argsz < minsz)
606			return -EINVAL;
607
608		ret = mdpy_query_gfx_plane(mdev_state, &plane);
609		if (ret)
610			return ret;
611
612		if (copy_to_user((void __user *)arg, &plane, minsz))
613			return -EFAULT;
614
615		return 0;
616	}
617
618	case VFIO_DEVICE_SET_IRQS:
619		return -EINVAL;
620
621	case VFIO_DEVICE_RESET:
622		return mdpy_reset(mdev_state);
623	}
624	return -ENOTTY;
625}
626
627static ssize_t
628resolution_show(struct device *dev, struct device_attribute *attr,
629		char *buf)
630{
631	struct mdev_state *mdev_state = dev_get_drvdata(dev);
632
633	return sprintf(buf, "%dx%d\n",
634		       mdev_state->type->width,
635		       mdev_state->type->height);
636}
637static DEVICE_ATTR_RO(resolution);
638
639static struct attribute *mdev_dev_attrs[] = {
640	&dev_attr_resolution.attr,
641	NULL,
642};
643
644static const struct attribute_group mdev_dev_group = {
645	.name  = "vendor",
646	.attrs = mdev_dev_attrs,
647};
648
649static const struct attribute_group *mdev_dev_groups[] = {
650	&mdev_dev_group,
651	NULL,
652};
653
654static ssize_t mdpy_show_description(struct mdev_type *mtype, char *buf)
655{
656	struct mdpy_type *type = container_of(mtype, struct mdpy_type, type);
657
658	return sprintf(buf, "virtual display, %dx%d framebuffer\n",
659		       type->width, type->height);
660}
661
662static const struct vfio_device_ops mdpy_dev_ops = {
663	.init = mdpy_init_dev,
664	.release = mdpy_release_dev,
665	.read = mdpy_read,
666	.write = mdpy_write,
667	.ioctl = mdpy_ioctl,
668	.mmap = mdpy_mmap,
669	.bind_iommufd	= vfio_iommufd_emulated_bind,
670	.unbind_iommufd	= vfio_iommufd_emulated_unbind,
671	.attach_ioas	= vfio_iommufd_emulated_attach_ioas,
672	.detach_ioas	= vfio_iommufd_emulated_detach_ioas,
673};
674
675static struct mdev_driver mdpy_driver = {
676	.device_api = VFIO_DEVICE_API_PCI_STRING,
677	.max_instances = 4,
678	.driver = {
679		.name = "mdpy",
680		.owner = THIS_MODULE,
681		.mod_name = KBUILD_MODNAME,
682		.dev_groups = mdev_dev_groups,
683	},
684	.probe = mdpy_probe,
685	.remove	= mdpy_remove,
686	.show_description = mdpy_show_description,
687};
688
689static const struct file_operations vd_fops = {
690	.owner		= THIS_MODULE,
691};
692
693static void mdpy_device_release(struct device *dev)
694{
695	/* nothing */
696}
697
698static int __init mdpy_dev_init(void)
699{
700	int ret = 0;
701
702	ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME);
703	if (ret < 0) {
704		pr_err("Error: failed to register mdpy_dev, err: %d\n", ret);
705		return ret;
706	}
707	cdev_init(&mdpy_cdev, &vd_fops);
708	cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1);
709	pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt));
710
711	ret = mdev_register_driver(&mdpy_driver);
712	if (ret)
713		goto err_cdev;
714
715	ret = class_register(&mdpy_class);
716	if (ret)
717		goto err_driver;
718	mdpy_dev.class = &mdpy_class;
719	mdpy_dev.release = mdpy_device_release;
720	dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
721
722	ret = device_register(&mdpy_dev);
723	if (ret)
724		goto err_put;
725
726	ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver,
727				   mdpy_mdev_types,
728				   ARRAY_SIZE(mdpy_mdev_types));
729	if (ret)
730		goto err_device;
731
732	return 0;
733
734err_device:
735	device_del(&mdpy_dev);
736err_put:
737	put_device(&mdpy_dev);
738	class_unregister(&mdpy_class);
739err_driver:
740	mdev_unregister_driver(&mdpy_driver);
741err_cdev:
742	cdev_del(&mdpy_cdev);
743	unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
744	return ret;
745}
746
747static void __exit mdpy_dev_exit(void)
748{
749	mdpy_dev.bus = NULL;
750	mdev_unregister_parent(&mdpy_parent);
751
752	device_unregister(&mdpy_dev);
753	mdev_unregister_driver(&mdpy_driver);
754	cdev_del(&mdpy_cdev);
755	unregister_chrdev_region(mdpy_devt, MINORMASK + 1);
756	class_unregister(&mdpy_class);
757}
758
759module_param_named(count, mdpy_driver.max_instances, int, 0444);
760MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices");
761
762module_init(mdpy_dev_init)
763module_exit(mdpy_dev_exit)