1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 2020 Intel |
4 | * |
5 | * Based on drivers/base/devres.c |
6 | */ |
7 | |
8 | #include <drm/drm_managed.h> |
9 | |
10 | #include <linux/list.h> |
11 | #include <linux/mutex.h> |
12 | #include <linux/slab.h> |
13 | #include <linux/spinlock.h> |
14 | |
15 | #include <drm/drm_device.h> |
16 | #include <drm/drm_print.h> |
17 | |
18 | #include "drm_internal.h" |
19 | |
20 | /** |
21 | * DOC: managed resources |
22 | * |
23 | * Inspired by struct &device managed resources, but tied to the lifetime of |
24 | * struct &drm_device, which can outlive the underlying physical device, usually |
25 | * when userspace has some open files and other handles to resources still open. |
26 | * |
27 | * Release actions can be added with drmm_add_action(), memory allocations can |
28 | * be done directly with drmm_kmalloc() and the related functions. Everything |
29 | * will be released on the final drm_dev_put() in reverse order of how the |
30 | * release actions have been added and memory has been allocated since driver |
31 | * loading started with devm_drm_dev_alloc(). |
32 | * |
33 | * Note that release actions and managed memory can also be added and removed |
34 | * during the lifetime of the driver, all the functions are fully concurrent |
35 | * safe. But it is recommended to use managed resources only for resources that |
36 | * change rarely, if ever, during the lifetime of the &drm_device instance. |
37 | */ |
38 | |
39 | struct drmres_node { |
40 | struct list_head entry; |
41 | drmres_release_t release; |
42 | const char *name; |
43 | size_t size; |
44 | }; |
45 | |
46 | struct drmres { |
47 | struct drmres_node node; |
48 | /* |
49 | * Some archs want to perform DMA into kmalloc caches |
50 | * and need a guaranteed alignment larger than |
51 | * the alignment of a 64-bit integer. |
52 | * Thus we use ARCH_DMA_MINALIGN for data[] which will force the same |
53 | * alignment for struct drmres when allocated by kmalloc(). |
54 | */ |
55 | u8 __aligned(ARCH_DMA_MINALIGN) data[]; |
56 | }; |
57 | |
58 | static void free_dr(struct drmres *dr) |
59 | { |
60 | kfree_const(x: dr->node.name); |
61 | kfree(objp: dr); |
62 | } |
63 | |
64 | void drm_managed_release(struct drm_device *dev) |
65 | { |
66 | struct drmres *dr, *tmp; |
67 | |
68 | drm_dbg_drmres(dev, "drmres release begin\n" ); |
69 | list_for_each_entry_safe(dr, tmp, &dev->managed.resources, node.entry) { |
70 | drm_dbg_drmres(dev, "REL %p %s (%zu bytes)\n" , |
71 | dr, dr->node.name, dr->node.size); |
72 | |
73 | if (dr->node.release) |
74 | dr->node.release(dev, dr->node.size ? *(void **)&dr->data : NULL); |
75 | |
76 | list_del(entry: &dr->node.entry); |
77 | free_dr(dr); |
78 | } |
79 | drm_dbg_drmres(dev, "drmres release end\n" ); |
80 | } |
81 | |
82 | /* |
83 | * Always inline so that kmalloc_track_caller tracks the actual interesting |
84 | * caller outside of drm_managed.c. |
85 | */ |
86 | static __always_inline struct drmres * alloc_dr(drmres_release_t release, |
87 | size_t size, gfp_t gfp, int nid) |
88 | { |
89 | size_t tot_size; |
90 | struct drmres *dr; |
91 | |
92 | /* We must catch any near-SIZE_MAX cases that could overflow. */ |
93 | if (unlikely(check_add_overflow(sizeof(*dr), size, &tot_size))) |
94 | return NULL; |
95 | |
96 | dr = kmalloc_node_track_caller(tot_size, gfp, nid); |
97 | if (unlikely(!dr)) |
98 | return NULL; |
99 | |
100 | memset(dr, 0, offsetof(struct drmres, data)); |
101 | |
102 | INIT_LIST_HEAD(list: &dr->node.entry); |
103 | dr->node.release = release; |
104 | dr->node.size = size; |
105 | |
106 | return dr; |
107 | } |
108 | |
109 | static void del_dr(struct drm_device *dev, struct drmres *dr) |
110 | { |
111 | list_del_init(entry: &dr->node.entry); |
112 | |
113 | drm_dbg_drmres(dev, "DEL %p %s (%lu bytes)\n" , |
114 | dr, dr->node.name, (unsigned long) dr->node.size); |
115 | } |
116 | |
117 | static void add_dr(struct drm_device *dev, struct drmres *dr) |
118 | { |
119 | unsigned long flags; |
120 | |
121 | spin_lock_irqsave(&dev->managed.lock, flags); |
122 | list_add(new: &dr->node.entry, head: &dev->managed.resources); |
123 | spin_unlock_irqrestore(lock: &dev->managed.lock, flags); |
124 | |
125 | drm_dbg_drmres(dev, "ADD %p %s (%lu bytes)\n" , |
126 | dr, dr->node.name, (unsigned long) dr->node.size); |
127 | } |
128 | |
129 | void drmm_add_final_kfree(struct drm_device *dev, void *container) |
130 | { |
131 | WARN_ON(dev->managed.final_kfree); |
132 | WARN_ON(dev < (struct drm_device *) container); |
133 | WARN_ON(dev + 1 > (struct drm_device *) (container + ksize(container))); |
134 | dev->managed.final_kfree = container; |
135 | } |
136 | |
137 | int __drmm_add_action(struct drm_device *dev, |
138 | drmres_release_t action, |
139 | void *data, const char *name) |
140 | { |
141 | struct drmres *dr; |
142 | void **void_ptr; |
143 | |
144 | dr = alloc_dr(release: action, size: data ? sizeof(void*) : 0, |
145 | GFP_KERNEL | __GFP_ZERO, |
146 | nid: dev_to_node(dev: dev->dev)); |
147 | if (!dr) { |
148 | drm_dbg_drmres(dev, "failed to add action %s for %p\n" , |
149 | name, data); |
150 | return -ENOMEM; |
151 | } |
152 | |
153 | dr->node.name = kstrdup_const(s: name, GFP_KERNEL); |
154 | if (data) { |
155 | void_ptr = (void **)&dr->data; |
156 | *void_ptr = data; |
157 | } |
158 | |
159 | add_dr(dev, dr); |
160 | |
161 | return 0; |
162 | } |
163 | EXPORT_SYMBOL(__drmm_add_action); |
164 | |
165 | int __drmm_add_action_or_reset(struct drm_device *dev, |
166 | drmres_release_t action, |
167 | void *data, const char *name) |
168 | { |
169 | int ret; |
170 | |
171 | ret = __drmm_add_action(dev, action, data, name); |
172 | if (ret) |
173 | action(dev, data); |
174 | |
175 | return ret; |
176 | } |
177 | EXPORT_SYMBOL(__drmm_add_action_or_reset); |
178 | |
179 | /** |
180 | * drmm_release_action - release a managed action from a &drm_device |
181 | * @dev: DRM device |
182 | * @action: function which would be called when @dev is released |
183 | * @data: opaque pointer, passed to @action |
184 | * |
185 | * This function calls the @action previously added by drmm_add_action() |
186 | * immediately. |
187 | * The @action is removed from the list of cleanup actions for @dev, |
188 | * which means that it won't be called in the final drm_dev_put(). |
189 | */ |
190 | void drmm_release_action(struct drm_device *dev, |
191 | drmres_release_t action, |
192 | void *data) |
193 | { |
194 | struct drmres *dr_match = NULL, *dr; |
195 | unsigned long flags; |
196 | |
197 | spin_lock_irqsave(&dev->managed.lock, flags); |
198 | list_for_each_entry_reverse(dr, &dev->managed.resources, node.entry) { |
199 | if (dr->node.release == action) { |
200 | if (!data || (data && *(void **)dr->data == data)) { |
201 | dr_match = dr; |
202 | del_dr(dev, dr: dr_match); |
203 | break; |
204 | } |
205 | } |
206 | } |
207 | spin_unlock_irqrestore(lock: &dev->managed.lock, flags); |
208 | |
209 | if (WARN_ON(!dr_match)) |
210 | return; |
211 | |
212 | action(dev, data); |
213 | |
214 | free_dr(dr: dr_match); |
215 | } |
216 | EXPORT_SYMBOL(drmm_release_action); |
217 | |
218 | /** |
219 | * drmm_kmalloc - &drm_device managed kmalloc() |
220 | * @dev: DRM device |
221 | * @size: size of the memory allocation |
222 | * @gfp: GFP allocation flags |
223 | * |
224 | * This is a &drm_device managed version of kmalloc(). The allocated memory is |
225 | * automatically freed on the final drm_dev_put(). Memory can also be freed |
226 | * before the final drm_dev_put() by calling drmm_kfree(). |
227 | */ |
228 | void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp) |
229 | { |
230 | struct drmres *dr; |
231 | |
232 | dr = alloc_dr(NULL, size, gfp, nid: dev_to_node(dev: dev->dev)); |
233 | if (!dr) { |
234 | drm_dbg_drmres(dev, "failed to allocate %zu bytes, %u flags\n" , |
235 | size, gfp); |
236 | return NULL; |
237 | } |
238 | dr->node.name = kstrdup_const(s: "kmalloc" , gfp); |
239 | |
240 | add_dr(dev, dr); |
241 | |
242 | return dr->data; |
243 | } |
244 | EXPORT_SYMBOL(drmm_kmalloc); |
245 | |
246 | /** |
247 | * drmm_kstrdup - &drm_device managed kstrdup() |
248 | * @dev: DRM device |
249 | * @s: 0-terminated string to be duplicated |
250 | * @gfp: GFP allocation flags |
251 | * |
252 | * This is a &drm_device managed version of kstrdup(). The allocated memory is |
253 | * automatically freed on the final drm_dev_put() and works exactly like a |
254 | * memory allocation obtained by drmm_kmalloc(). |
255 | */ |
256 | char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp) |
257 | { |
258 | size_t size; |
259 | char *buf; |
260 | |
261 | if (!s) |
262 | return NULL; |
263 | |
264 | size = strlen(s) + 1; |
265 | buf = drmm_kmalloc(dev, size, gfp); |
266 | if (buf) |
267 | memcpy(buf, s, size); |
268 | return buf; |
269 | } |
270 | EXPORT_SYMBOL_GPL(drmm_kstrdup); |
271 | |
272 | /** |
273 | * drmm_kfree - &drm_device managed kfree() |
274 | * @dev: DRM device |
275 | * @data: memory allocation to be freed |
276 | * |
277 | * This is a &drm_device managed version of kfree() which can be used to |
278 | * release memory allocated through drmm_kmalloc() or any of its related |
279 | * functions before the final drm_dev_put() of @dev. |
280 | */ |
281 | void drmm_kfree(struct drm_device *dev, void *data) |
282 | { |
283 | struct drmres *dr_match = NULL, *dr; |
284 | unsigned long flags; |
285 | |
286 | if (!data) |
287 | return; |
288 | |
289 | spin_lock_irqsave(&dev->managed.lock, flags); |
290 | list_for_each_entry(dr, &dev->managed.resources, node.entry) { |
291 | if (dr->data == data) { |
292 | dr_match = dr; |
293 | del_dr(dev, dr: dr_match); |
294 | break; |
295 | } |
296 | } |
297 | spin_unlock_irqrestore(lock: &dev->managed.lock, flags); |
298 | |
299 | if (WARN_ON(!dr_match)) |
300 | return; |
301 | |
302 | free_dr(dr: dr_match); |
303 | } |
304 | EXPORT_SYMBOL(drmm_kfree); |
305 | |
306 | void __drmm_mutex_release(struct drm_device *dev, void *res) |
307 | { |
308 | struct mutex *lock = res; |
309 | |
310 | mutex_destroy(lock); |
311 | } |
312 | EXPORT_SYMBOL(__drmm_mutex_release); |
313 | |