1 /**************************************************************************
2 *
3 * Copyright (c) 2006-2022 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
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11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
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19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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26 **************************************************************************/
27 /*
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29 */
30 /** @file ttm_object.h
31 *
32 * Base- and reference object implementation for the various
33 * ttm objects. Implements reference counting, minimal security checks
34 * and release on file close.
35 */
36
37 #ifndef _TTM_OBJECT_H_
38 #define _TTM_OBJECT_H_
39
40 #include <linux/dma-buf.h>
41 #include <linux/kref.h>
42 #include <linux/list.h>
43 #include <linux/rcupdate.h>
44
45 #include <drm/ttm/ttm_bo.h>
46
47 /**
48 * enum ttm_object_type
49 *
50 * One entry per ttm object type.
51 * Device-specific types should use the
52 * ttm_driver_typex types.
53 */
54
55 enum ttm_object_type {
56 ttm_fence_type,
57 ttm_lock_type,
58 ttm_prime_type,
59 ttm_driver_type0 = 256,
60 ttm_driver_type1,
61 ttm_driver_type2,
62 ttm_driver_type3,
63 ttm_driver_type4,
64 ttm_driver_type5
65 };
66
67 struct ttm_object_file;
68 struct ttm_object_device;
69
70 /**
71 * struct ttm_base_object
72 *
73 * @hash: hash entry for the per-device object hash.
74 * @type: derived type this object is base class for.
75 * @shareable: Other ttm_object_files can access this object.
76 *
77 * @tfile: Pointer to ttm_object_file of the creator.
78 * NULL if the object was not created by a user request.
79 * (kernel object).
80 *
81 * @refcount: Number of references to this object, not
82 * including the hash entry. A reference to a base object can
83 * only be held by a ref object.
84 *
85 * @refcount_release: A function to be called when there are
86 * no more references to this object. This function should
87 * destroy the object (or make sure destruction eventually happens),
88 * and when it is called, the object has
89 * already been taken out of the per-device hash. The parameter
90 * "base" should be set to NULL by the function.
91 *
92 * @ref_obj_release: A function to be called when a reference object
93 * with another ttm_ref_type than TTM_REF_USAGE is deleted.
94 * This function may, for example, release a lock held by a user-space
95 * process.
96 *
97 * This struct is intended to be used as a base struct for objects that
98 * are visible to user-space. It provides a global name, race-safe
99 * access and refcounting, minimal access control and hooks for unref actions.
100 */
101
102 struct ttm_base_object {
103 struct rcu_head rhead;
104 struct ttm_object_file *tfile;
105 struct kref refcount;
106 void (*refcount_release) (struct ttm_base_object **base);
107 u64 handle;
108 enum ttm_object_type object_type;
109 u32 shareable;
110 };
111
112
113 /**
114 * struct ttm_prime_object - Modified base object that is prime-aware
115 *
116 * @base: struct ttm_base_object that we derive from
117 * @mutex: Mutex protecting the @dma_buf member.
118 * @size: Size of the dma_buf associated with this object
119 * @real_type: Type of the underlying object. Needed since we're setting
120 * the value of @base::object_type to ttm_prime_type
121 * @dma_buf: Non ref-coutned pointer to a struct dma_buf created from this
122 * object.
123 * @refcount_release: The underlying object's release method. Needed since
124 * we set @base::refcount_release to our own release method.
125 */
126
127 struct ttm_prime_object {
128 struct ttm_base_object base;
129 struct mutex mutex;
130 size_t size;
131 enum ttm_object_type real_type;
132 struct dma_buf *dma_buf;
133 void (*refcount_release) (struct ttm_base_object **);
134 };
135
136 /**
137 * ttm_base_object_init
138 *
139 * @tfile: Pointer to a struct ttm_object_file.
140 * @base: The struct ttm_base_object to initialize.
141 * @shareable: This object is shareable with other applications.
142 * (different @tfile pointers.)
143 * @type: The object type.
144 * @refcount_release: See the struct ttm_base_object description.
145 * @ref_obj_release: See the struct ttm_base_object description.
146 *
147 * Initializes a struct ttm_base_object.
148 */
149
150 extern int ttm_base_object_init(struct ttm_object_file *tfile,
151 struct ttm_base_object *base,
152 bool shareable,
153 enum ttm_object_type type,
154 void (*refcount_release) (struct ttm_base_object
155 **));
156
157 /**
158 * ttm_base_object_lookup
159 *
160 * @tfile: Pointer to a struct ttm_object_file.
161 * @key: Hash key
162 *
163 * Looks up a struct ttm_base_object with the key @key.
164 */
165
166 extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file
167 *tfile, uint64_t key);
168
169 /**
170 * ttm_base_object_lookup_for_ref
171 *
172 * @tdev: Pointer to a struct ttm_object_device.
173 * @key: Hash key
174 *
175 * Looks up a struct ttm_base_object with the key @key.
176 * This function should only be used when the struct tfile associated with the
177 * caller doesn't yet have a reference to the base object.
178 */
179
180 extern struct ttm_base_object *
181 ttm_base_object_lookup_for_ref(struct ttm_object_device *tdev, uint64_t key);
182
183 /**
184 * ttm_base_object_unref
185 *
186 * @p_base: Pointer to a pointer referencing a struct ttm_base_object.
187 *
188 * Decrements the base object refcount and clears the pointer pointed to by
189 * p_base.
190 */
191
192 extern void ttm_base_object_unref(struct ttm_base_object **p_base);
193
194 /**
195 * ttm_ref_object_add.
196 *
197 * @tfile: A struct ttm_object_file representing the application owning the
198 * ref_object.
199 * @base: The base object to reference.
200 * @ref_type: The type of reference.
201 * @existed: Upon completion, indicates that an identical reference object
202 * already existed, and the refcount was upped on that object instead.
203 * @require_existed: Fail with -EPERM if an identical ref object didn't
204 * already exist.
205 *
206 * Checks that the base object is shareable and adds a ref object to it.
207 *
208 * Adding a ref object to a base object is basically like referencing the
209 * base object, but a user-space application holds the reference. When the
210 * file corresponding to @tfile is closed, all its reference objects are
211 * deleted. A reference object can have different types depending on what
212 * it's intended for. It can be refcounting to prevent object destruction,
213 * When user-space takes a lock, it can add a ref object to that lock to
214 * make sure the lock is released if the application dies. A ref object
215 * will hold a single reference on a base object.
216 */
217 extern int ttm_ref_object_add(struct ttm_object_file *tfile,
218 struct ttm_base_object *base,
219 bool *existed,
220 bool require_existed);
221
222 /**
223 * ttm_ref_object_base_unref
224 *
225 * @key: Key representing the base object.
226 * @ref_type: Ref type of the ref object to be dereferenced.
227 *
228 * Unreference a ref object with type @ref_type
229 * on the base object identified by @key. If there are no duplicate
230 * references, the ref object will be destroyed and the base object
231 * will be unreferenced.
232 */
233 extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
234 unsigned long key);
235
236 /**
237 * ttm_object_file_init - initialize a struct ttm_object file
238 *
239 * @tdev: A struct ttm_object device this file is initialized on.
240 *
241 * This is typically called by the file_ops::open function.
242 */
243
244 extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device
245 *tdev);
246
247 /**
248 * ttm_object_file_release - release data held by a ttm_object_file
249 *
250 * @p_tfile: Pointer to pointer to the ttm_object_file object to release.
251 * *p_tfile will be set to NULL by this function.
252 *
253 * Releases all data associated by a ttm_object_file.
254 * Typically called from file_ops::release. The caller must
255 * ensure that there are no concurrent users of tfile.
256 */
257
258 extern void ttm_object_file_release(struct ttm_object_file **p_tfile);
259
260 /**
261 * ttm_object device init - initialize a struct ttm_object_device
262 *
263 * @ops: DMA buf ops for prime objects of this device.
264 *
265 * This function is typically called on device initialization to prepare
266 * data structures needed for ttm base and ref objects.
267 */
268
269 extern struct ttm_object_device *
270 ttm_object_device_init(const struct dma_buf_ops *ops);
271
272 /**
273 * ttm_object_device_release - release data held by a ttm_object_device
274 *
275 * @p_tdev: Pointer to pointer to the ttm_object_device object to release.
276 * *p_tdev will be set to NULL by this function.
277 *
278 * Releases all data associated by a ttm_object_device.
279 * Typically called from driver::unload before the destruction of the
280 * device private data structure.
281 */
282
283 extern void ttm_object_device_release(struct ttm_object_device **p_tdev);
284
285 #define ttm_base_object_kfree(__object, __base)\
286 kfree_rcu(__object, __base.rhead)
287
288 extern int ttm_prime_object_init(struct ttm_object_file *tfile,
289 size_t size,
290 struct ttm_prime_object *prime,
291 bool shareable,
292 enum ttm_object_type type,
293 void (*refcount_release)
294 (struct ttm_base_object **));
295
296 static inline enum ttm_object_type
ttm_base_object_type(struct ttm_base_object * base)297 ttm_base_object_type(struct ttm_base_object *base)
298 {
299 return (base->object_type == ttm_prime_type) ?
300 container_of(base, struct ttm_prime_object, base)->real_type :
301 base->object_type;
302 }
303 extern int ttm_prime_fd_to_handle(struct ttm_object_file *tfile,
304 int fd, u32 *handle);
305 extern int ttm_prime_handle_to_fd(struct ttm_object_file *tfile,
306 uint32_t handle, uint32_t flags,
307 int *prime_fd);
308
309 #define ttm_prime_object_kfree(__obj, __prime) \
310 kfree_rcu(__obj, __prime.base.rhead)
311
ttm_bo_wait(struct ttm_buffer_object * bo,bool intr,bool no_wait)312 static inline int ttm_bo_wait(struct ttm_buffer_object *bo, bool intr,
313 bool no_wait)
314 {
315 struct ttm_operation_ctx ctx = { intr, no_wait };
316
317 return ttm_bo_wait_ctx(bo, &ctx);
318 }
319
320 #endif
321