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8bf48897 OG |
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> | |
2c204f3d | 11 | #include <linux/idr.h> |
8bf48897 OG |
12 | |
13 | #include <drm/drm_accel.h> | |
2c204f3d OG |
14 | #include <drm/drm_debugfs.h> |
15 | #include <drm/drm_drv.h> | |
16 | #include <drm/drm_file.h> | |
8bf48897 OG |
17 | #include <drm/drm_ioctl.h> |
18 | #include <drm/drm_print.h> | |
19 | ||
2c204f3d OG |
20 | static DEFINE_SPINLOCK(accel_minor_lock); |
21 | static struct idr accel_minors_idr; | |
22 | ||
8bf48897 OG |
23 | static struct dentry *accel_debugfs_root; |
24 | static struct class *accel_class; | |
25 | ||
2c204f3d OG |
26 | static struct device_type accel_sysfs_device_minor = { |
27 | .name = "accel_minor" | |
28 | }; | |
29 | ||
dcde56bb | 30 | static char *accel_devnode(const struct device *dev, umode_t *mode) |
8bf48897 OG |
31 | { |
32 | return kasprintf(GFP_KERNEL, "accel/%s", dev_name(dev)); | |
33 | } | |
34 | ||
35 | static int accel_sysfs_init(void) | |
36 | { | |
1aaba11d | 37 | accel_class = class_create("accel"); |
8bf48897 OG |
38 | if (IS_ERR(accel_class)) |
39 | return PTR_ERR(accel_class); | |
40 | ||
41 | accel_class->devnode = accel_devnode; | |
42 | ||
43 | return 0; | |
44 | } | |
45 | ||
46 | static void accel_sysfs_destroy(void) | |
47 | { | |
48 | if (IS_ERR_OR_NULL(accel_class)) | |
49 | return; | |
50 | class_destroy(accel_class); | |
51 | accel_class = NULL; | |
52 | } | |
53 | ||
2c204f3d OG |
54 | static int accel_name_info(struct seq_file *m, void *data) |
55 | { | |
56 | struct drm_info_node *node = (struct drm_info_node *) m->private; | |
57 | struct drm_minor *minor = node->minor; | |
58 | struct drm_device *dev = minor->dev; | |
59 | struct drm_master *master; | |
60 | ||
61 | mutex_lock(&dev->master_mutex); | |
62 | master = dev->master; | |
63 | seq_printf(m, "%s", dev->driver->name); | |
64 | if (dev->dev) | |
65 | seq_printf(m, " dev=%s", dev_name(dev->dev)); | |
66 | if (master && master->unique) | |
67 | seq_printf(m, " master=%s", master->unique); | |
68 | if (dev->unique) | |
69 | seq_printf(m, " unique=%s", dev->unique); | |
70 | seq_puts(m, "\n"); | |
71 | mutex_unlock(&dev->master_mutex); | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | static const struct drm_info_list accel_debugfs_list[] = { | |
77 | {"name", accel_name_info, 0} | |
78 | }; | |
79 | #define ACCEL_DEBUGFS_ENTRIES ARRAY_SIZE(accel_debugfs_list) | |
80 | ||
81 | /** | |
82 | * accel_debugfs_init() - Initialize debugfs for accel minor | |
83 | * @minor: Pointer to the drm_minor instance. | |
84 | * @minor_id: The minor's id | |
85 | * | |
86 | * This function initializes the drm minor's debugfs members and creates | |
87 | * a root directory for the minor in debugfs. It also creates common files | |
88 | * for accelerators and calls the driver's debugfs init callback. | |
89 | */ | |
90 | void accel_debugfs_init(struct drm_minor *minor, int minor_id) | |
91 | { | |
92 | struct drm_device *dev = minor->dev; | |
93 | char name[64]; | |
94 | ||
95 | INIT_LIST_HEAD(&minor->debugfs_list); | |
96 | mutex_init(&minor->debugfs_lock); | |
97 | sprintf(name, "%d", minor_id); | |
98 | minor->debugfs_root = debugfs_create_dir(name, accel_debugfs_root); | |
99 | ||
100 | drm_debugfs_create_files(accel_debugfs_list, ACCEL_DEBUGFS_ENTRIES, | |
101 | minor->debugfs_root, minor); | |
102 | ||
103 | if (dev->driver->debugfs_init) | |
104 | dev->driver->debugfs_init(minor); | |
105 | } | |
106 | ||
107 | /** | |
108 | * accel_set_device_instance_params() - Set some device parameters for accel device | |
109 | * @kdev: Pointer to the device instance. | |
110 | * @index: The minor's index | |
111 | * | |
112 | * This function creates the dev_t of the device using the accel major and | |
113 | * the device's minor number. In addition, it sets the class and type of the | |
114 | * device instance to the accel sysfs class and device type, respectively. | |
115 | */ | |
116 | void accel_set_device_instance_params(struct device *kdev, int index) | |
117 | { | |
118 | kdev->devt = MKDEV(ACCEL_MAJOR, index); | |
119 | kdev->class = accel_class; | |
120 | kdev->type = &accel_sysfs_device_minor; | |
121 | } | |
122 | ||
123 | /** | |
124 | * accel_minor_alloc() - Allocates a new accel minor | |
125 | * | |
126 | * This function access the accel minors idr and allocates from it | |
127 | * a new id to represent a new accel minor | |
128 | * | |
129 | * Return: A new id on success or error code in case idr_alloc failed | |
130 | */ | |
131 | int accel_minor_alloc(void) | |
132 | { | |
133 | unsigned long flags; | |
134 | int r; | |
135 | ||
136 | spin_lock_irqsave(&accel_minor_lock, flags); | |
137 | r = idr_alloc(&accel_minors_idr, NULL, 0, ACCEL_MAX_MINORS, GFP_NOWAIT); | |
138 | spin_unlock_irqrestore(&accel_minor_lock, flags); | |
139 | ||
140 | return r; | |
141 | } | |
142 | ||
143 | /** | |
144 | * accel_minor_remove() - Remove an accel minor | |
145 | * @index: The minor id to remove. | |
146 | * | |
147 | * This function access the accel minors idr and removes from | |
148 | * it the member with the id that is passed to this function. | |
149 | */ | |
150 | void accel_minor_remove(int index) | |
151 | { | |
152 | unsigned long flags; | |
153 | ||
154 | spin_lock_irqsave(&accel_minor_lock, flags); | |
155 | idr_remove(&accel_minors_idr, index); | |
156 | spin_unlock_irqrestore(&accel_minor_lock, flags); | |
157 | } | |
158 | ||
159 | /** | |
160 | * accel_minor_replace() - Replace minor pointer in accel minors idr. | |
161 | * @minor: Pointer to the new minor. | |
162 | * @index: The minor id to replace. | |
163 | * | |
164 | * This function access the accel minors idr structure and replaces the pointer | |
165 | * that is associated with an existing id. Because the minor pointer can be | |
166 | * NULL, we need to explicitly pass the index. | |
167 | * | |
168 | * Return: 0 for success, negative value for error | |
169 | */ | |
170 | void accel_minor_replace(struct drm_minor *minor, int index) | |
171 | { | |
172 | unsigned long flags; | |
173 | ||
174 | spin_lock_irqsave(&accel_minor_lock, flags); | |
175 | idr_replace(&accel_minors_idr, minor, index); | |
176 | spin_unlock_irqrestore(&accel_minor_lock, flags); | |
177 | } | |
178 | ||
179 | /* | |
180 | * Looks up the given minor-ID and returns the respective DRM-minor object. The | |
181 | * refence-count of the underlying device is increased so you must release this | |
182 | * object with accel_minor_release(). | |
183 | * | |
184 | * The object can be only a drm_minor that represents an accel device. | |
185 | * | |
186 | * As long as you hold this minor, it is guaranteed that the object and the | |
187 | * minor->dev pointer will stay valid! However, the device may get unplugged and | |
188 | * unregistered while you hold the minor. | |
189 | */ | |
190 | static struct drm_minor *accel_minor_acquire(unsigned int minor_id) | |
191 | { | |
192 | struct drm_minor *minor; | |
193 | unsigned long flags; | |
194 | ||
195 | spin_lock_irqsave(&accel_minor_lock, flags); | |
196 | minor = idr_find(&accel_minors_idr, minor_id); | |
197 | if (minor) | |
198 | drm_dev_get(minor->dev); | |
199 | spin_unlock_irqrestore(&accel_minor_lock, flags); | |
200 | ||
201 | if (!minor) { | |
202 | return ERR_PTR(-ENODEV); | |
203 | } else if (drm_dev_is_unplugged(minor->dev)) { | |
204 | drm_dev_put(minor->dev); | |
205 | return ERR_PTR(-ENODEV); | |
206 | } | |
207 | ||
208 | return minor; | |
209 | } | |
210 | ||
211 | static void accel_minor_release(struct drm_minor *minor) | |
212 | { | |
213 | drm_dev_put(minor->dev); | |
214 | } | |
215 | ||
216 | /** | |
217 | * accel_open - open method for ACCEL file | |
218 | * @inode: device inode | |
219 | * @filp: file pointer. | |
220 | * | |
221 | * This function must be used by drivers as their &file_operations.open method. | |
222 | * It looks up the correct ACCEL device and instantiates all the per-file | |
223 | * resources for it. It also calls the &drm_driver.open driver callback. | |
224 | * | |
225 | * Return: 0 on success or negative errno value on failure. | |
226 | */ | |
227 | int accel_open(struct inode *inode, struct file *filp) | |
228 | { | |
229 | struct drm_device *dev; | |
230 | struct drm_minor *minor; | |
231 | int retcode; | |
232 | ||
233 | minor = accel_minor_acquire(iminor(inode)); | |
234 | if (IS_ERR(minor)) | |
235 | return PTR_ERR(minor); | |
236 | ||
237 | dev = minor->dev; | |
238 | ||
239 | atomic_fetch_inc(&dev->open_count); | |
240 | ||
241 | /* share address_space across all char-devs of a single device */ | |
242 | filp->f_mapping = dev->anon_inode->i_mapping; | |
243 | ||
244 | retcode = drm_open_helper(filp, minor); | |
245 | if (retcode) | |
246 | goto err_undo; | |
247 | ||
248 | return 0; | |
249 | ||
250 | err_undo: | |
251 | atomic_dec(&dev->open_count); | |
252 | accel_minor_release(minor); | |
253 | return retcode; | |
254 | } | |
255 | EXPORT_SYMBOL_GPL(accel_open); | |
256 | ||
8bf48897 OG |
257 | static int accel_stub_open(struct inode *inode, struct file *filp) |
258 | { | |
2c204f3d OG |
259 | const struct file_operations *new_fops; |
260 | struct drm_minor *minor; | |
261 | int err; | |
262 | ||
263 | minor = accel_minor_acquire(iminor(inode)); | |
264 | if (IS_ERR(minor)) | |
265 | return PTR_ERR(minor); | |
266 | ||
267 | new_fops = fops_get(minor->dev->driver->fops); | |
268 | if (!new_fops) { | |
269 | err = -ENODEV; | |
270 | goto out; | |
271 | } | |
272 | ||
273 | replace_fops(filp, new_fops); | |
274 | if (filp->f_op->open) | |
275 | err = filp->f_op->open(inode, filp); | |
276 | else | |
277 | err = 0; | |
278 | ||
279 | out: | |
280 | accel_minor_release(minor); | |
281 | ||
282 | return err; | |
8bf48897 OG |
283 | } |
284 | ||
285 | static const struct file_operations accel_stub_fops = { | |
286 | .owner = THIS_MODULE, | |
287 | .open = accel_stub_open, | |
288 | .llseek = noop_llseek, | |
289 | }; | |
290 | ||
291 | void accel_core_exit(void) | |
292 | { | |
293 | unregister_chrdev(ACCEL_MAJOR, "accel"); | |
294 | debugfs_remove(accel_debugfs_root); | |
295 | accel_sysfs_destroy(); | |
2c204f3d | 296 | idr_destroy(&accel_minors_idr); |
8bf48897 OG |
297 | } |
298 | ||
299 | int __init accel_core_init(void) | |
300 | { | |
301 | int ret; | |
302 | ||
2c204f3d OG |
303 | idr_init(&accel_minors_idr); |
304 | ||
8bf48897 OG |
305 | ret = accel_sysfs_init(); |
306 | if (ret < 0) { | |
307 | DRM_ERROR("Cannot create ACCEL class: %d\n", ret); | |
308 | goto error; | |
309 | } | |
310 | ||
311 | accel_debugfs_root = debugfs_create_dir("accel", NULL); | |
312 | ||
313 | ret = register_chrdev(ACCEL_MAJOR, "accel", &accel_stub_fops); | |
314 | if (ret < 0) | |
315 | DRM_ERROR("Cannot register ACCEL major: %d\n", ret); | |
316 | ||
317 | error: | |
318 | /* | |
319 | * Any cleanup due to errors will be done in drm_core_exit() that | |
320 | * will call accel_core_exit() | |
321 | */ | |
322 | return ret; | |
323 | } |