Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * Copyright 2022 HabanaLabs, Ltd.
5 * All Rights Reserved.
6 *
7 */
8
9#include <linux/debugfs.h>
10#include <linux/device.h>
11#include <linux/xarray.h>
12
13#include <drm/drm_accel.h>
14#include <drm/drm_auth.h>
15#include <drm/drm_debugfs.h>
16#include <drm/drm_drv.h>
17#include <drm/drm_file.h>
18#include <drm/drm_ioctl.h>
19#include <drm/drm_print.h>
20
21DEFINE_XARRAY_ALLOC(accel_minors_xa);
22
23static const struct device_type accel_sysfs_device_minor = {
24 .name = "accel_minor"
25};
26
27static char *accel_devnode(const struct device *dev, umode_t *mode)
28{
29 return kasprintf(GFP_KERNEL, "accel/%s", dev_name(dev));
30}
31
32static const struct class accel_class = {
33 .name = "accel",
34 .devnode = accel_devnode,
35};
36
37static int accel_sysfs_init(void)
38{
39 return class_register(&accel_class);
40}
41
42static void accel_sysfs_destroy(void)
43{
44 class_unregister(&accel_class);
45}
46
47static int accel_name_info(struct seq_file *m, void *data)
48{
49 struct drm_info_node *node = (struct drm_info_node *) m->private;
50 struct drm_minor *minor = node->minor;
51 struct drm_device *dev = minor->dev;
52 struct drm_master *master;
53
54 mutex_lock(&dev->master_mutex);
55 master = dev->master;
56 seq_printf(m, "%s", dev->driver->name);
57 if (dev->dev)
58 seq_printf(m, " dev=%s", dev_name(dev->dev));
59 if (master && master->unique)
60 seq_printf(m, " master=%s", master->unique);
61 if (dev->unique)
62 seq_printf(m, " unique=%s", dev->unique);
63 seq_puts(m, "\n");
64 mutex_unlock(&dev->master_mutex);
65
66 return 0;
67}
68
69static const struct drm_info_list accel_debugfs_list[] = {
70 {"name", accel_name_info, 0}
71};
72#define ACCEL_DEBUGFS_ENTRIES ARRAY_SIZE(accel_debugfs_list)
73
74/**
75 * accel_debugfs_register() - Register debugfs for device
76 * @dev: Pointer to the device instance.
77 *
78 * Creates common files for accelerators.
79 */
80void accel_debugfs_register(struct drm_device *dev)
81{
82 struct drm_minor *minor = dev->accel;
83
84 minor->debugfs_root = dev->debugfs_root;
85
86 drm_debugfs_create_files(accel_debugfs_list, ACCEL_DEBUGFS_ENTRIES,
87 dev->debugfs_root, minor);
88}
89
90/**
91 * accel_set_device_instance_params() - Set some device parameters for accel device
92 * @kdev: Pointer to the device instance.
93 * @index: The minor's index
94 *
95 * This function creates the dev_t of the device using the accel major and
96 * the device's minor number. In addition, it sets the class and type of the
97 * device instance to the accel sysfs class and device type, respectively.
98 */
99void accel_set_device_instance_params(struct device *kdev, int index)
100{
101 kdev->devt = MKDEV(ACCEL_MAJOR, index);
102 kdev->class = &accel_class;
103 kdev->type = &accel_sysfs_device_minor;
104}
105
106/**
107 * accel_open - open method for ACCEL file
108 * @inode: device inode
109 * @filp: file pointer.
110 *
111 * This function must be used by drivers as their &file_operations.open method.
112 * It looks up the correct ACCEL device and instantiates all the per-file
113 * resources for it. It also calls the &drm_driver.open driver callback.
114 *
115 * Return: 0 on success or negative errno value on failure.
116 */
117int accel_open(struct inode *inode, struct file *filp)
118{
119 struct drm_device *dev;
120 struct drm_minor *minor;
121 int retcode;
122
123 minor = drm_minor_acquire(&accel_minors_xa, iminor(inode));
124 if (IS_ERR(minor))
125 return PTR_ERR(minor);
126
127 dev = minor->dev;
128
129 atomic_fetch_inc(&dev->open_count);
130
131 /* share address_space across all char-devs of a single device */
132 filp->f_mapping = dev->anon_inode->i_mapping;
133
134 retcode = drm_open_helper(filp, minor);
135 if (retcode)
136 goto err_undo;
137
138 return 0;
139
140err_undo:
141 atomic_dec(&dev->open_count);
142 drm_minor_release(minor);
143 return retcode;
144}
145EXPORT_SYMBOL_GPL(accel_open);
146
147static int accel_stub_open(struct inode *inode, struct file *filp)
148{
149 const struct file_operations *new_fops;
150 struct drm_minor *minor;
151 int err;
152
153 minor = drm_minor_acquire(&accel_minors_xa, iminor(inode));
154 if (IS_ERR(minor))
155 return PTR_ERR(minor);
156
157 new_fops = fops_get(minor->dev->driver->fops);
158 if (!new_fops) {
159 err = -ENODEV;
160 goto out;
161 }
162
163 replace_fops(filp, new_fops);
164 if (filp->f_op->open)
165 err = filp->f_op->open(inode, filp);
166 else
167 err = 0;
168
169out:
170 drm_minor_release(minor);
171
172 return err;
173}
174
175static const struct file_operations accel_stub_fops = {
176 .owner = THIS_MODULE,
177 .open = accel_stub_open,
178 .llseek = noop_llseek,
179};
180
181void accel_core_exit(void)
182{
183 unregister_chrdev(ACCEL_MAJOR, "accel");
184 accel_sysfs_destroy();
185 WARN_ON(!xa_empty(&accel_minors_xa));
186}
187
188int __init accel_core_init(void)
189{
190 int ret;
191
192 ret = accel_sysfs_init();
193 if (ret < 0) {
194 DRM_ERROR("Cannot create ACCEL class: %d\n", ret);
195 goto error;
196 }
197
198 ret = register_chrdev(ACCEL_MAJOR, "accel", &accel_stub_fops);
199 if (ret < 0)
200 DRM_ERROR("Cannot register ACCEL major: %d\n", ret);
201
202error:
203 /*
204 * Any cleanup due to errors will be done in drm_core_exit() that
205 * will call accel_core_exit()
206 */
207 return ret;
208}