1 /**************************************************************************
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
26 **************************************************************************/
28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30 /** @file ttm_object.h
32 * Base- and reference object implementation for the various
33 * ttm objects. Implements reference counting, minimal security checks
34 * and release on file close.
37 #ifndef _TTM_OBJECT_H_
38 #define _TTM_OBJECT_H_
40 #include <linux/list.h>
41 #include <drm/drm_hashtab.h>
42 #include <linux/kref.h>
43 #include <linux/rcupdate.h>
44 #include <linux/dma-buf.h>
45 #include <ttm/ttm_memory.h>
50 * Describes what type of reference a ref object holds.
52 * TTM_REF_USAGE is a simple refcount on a base object.
54 * TTM_REF_SYNCCPU_READ is a SYNCCPU_READ reference on a
57 * TTM_REF_SYNCCPU_WRITE is a SYNCCPU_WRITE reference on a
65 TTM_REF_SYNCCPU_WRITE,
70 * enum ttm_object_type
72 * One entry per ttm object type.
73 * Device-specific types should use the
74 * ttm_driver_typex types.
77 enum ttm_object_type {
82 ttm_driver_type0 = 256,
90 struct ttm_object_file;
91 struct ttm_object_device;
94 * struct ttm_base_object
96 * @hash: hash entry for the per-device object hash.
97 * @type: derived type this object is base class for.
98 * @shareable: Other ttm_object_files can access this object.
100 * @tfile: Pointer to ttm_object_file of the creator.
101 * NULL if the object was not created by a user request.
104 * @refcount: Number of references to this object, not
105 * including the hash entry. A reference to a base object can
106 * only be held by a ref object.
108 * @refcount_release: A function to be called when there are
109 * no more references to this object. This function should
110 * destroy the object (or make sure destruction eventually happens),
111 * and when it is called, the object has
112 * already been taken out of the per-device hash. The parameter
113 * "base" should be set to NULL by the function.
115 * @ref_obj_release: A function to be called when a reference object
116 * with another ttm_ref_type than TTM_REF_USAGE is deleted.
117 * This function may, for example, release a lock held by a user-space
120 * This struct is intended to be used as a base struct for objects that
121 * are visible to user-space. It provides a global name, race-safe
122 * access and refcounting, minimal access contol and hooks for unref actions.
125 struct ttm_base_object {
126 struct rcu_head rhead;
127 struct drm_hash_item hash;
128 enum ttm_object_type object_type;
130 struct ttm_object_file *tfile;
131 struct kref refcount;
132 void (*refcount_release) (struct ttm_base_object **base);
133 void (*ref_obj_release) (struct ttm_base_object *base,
134 enum ttm_ref_type ref_type);
139 * struct ttm_prime_object - Modified base object that is prime-aware
141 * @base: struct ttm_base_object that we derive from
142 * @mutex: Mutex protecting the @dma_buf member.
143 * @size: Size of the dma_buf associated with this object
144 * @real_type: Type of the underlying object. Needed since we're setting
145 * the value of @base::object_type to ttm_prime_type
146 * @dma_buf: Non ref-coutned pointer to a struct dma_buf created from this
148 * @refcount_release: The underlying object's release method. Needed since
149 * we set @base::refcount_release to our own release method.
152 struct ttm_prime_object {
153 struct ttm_base_object base;
156 enum ttm_object_type real_type;
157 struct dma_buf *dma_buf;
158 void (*refcount_release) (struct ttm_base_object **);
162 * ttm_base_object_init
164 * @tfile: Pointer to a struct ttm_object_file.
165 * @base: The struct ttm_base_object to initialize.
166 * @shareable: This object is shareable with other applcations.
167 * (different @tfile pointers.)
168 * @type: The object type.
169 * @refcount_release: See the struct ttm_base_object description.
170 * @ref_obj_release: See the struct ttm_base_object description.
172 * Initializes a struct ttm_base_object.
175 extern int ttm_base_object_init(struct ttm_object_file *tfile,
176 struct ttm_base_object *base,
178 enum ttm_object_type type,
179 void (*refcount_release) (struct ttm_base_object
181 void (*ref_obj_release) (struct ttm_base_object
187 * ttm_base_object_lookup
189 * @tfile: Pointer to a struct ttm_object_file.
192 * Looks up a struct ttm_base_object with the key @key.
193 * Also verifies that the object is visible to the application, by
194 * comparing the @tfile argument and checking the object shareable flag.
197 extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file
198 *tfile, uint32_t key);
201 * ttm_base_object_unref
203 * @p_base: Pointer to a pointer referencing a struct ttm_base_object.
205 * Decrements the base object refcount and clears the pointer pointed to by
209 extern void ttm_base_object_unref(struct ttm_base_object **p_base);
212 * ttm_ref_object_add.
214 * @tfile: A struct ttm_object_file representing the application owning the
216 * @base: The base object to reference.
217 * @ref_type: The type of reference.
218 * @existed: Upon completion, indicates that an identical reference object
219 * already existed, and the refcount was upped on that object instead.
221 * Adding a ref object to a base object is basically like referencing the
222 * base object, but a user-space application holds the reference. When the
223 * file corresponding to @tfile is closed, all its reference objects are
224 * deleted. A reference object can have different types depending on what
225 * it's intended for. It can be refcounting to prevent object destruction,
226 * When user-space takes a lock, it can add a ref object to that lock to
227 * make sure the lock is released if the application dies. A ref object
228 * will hold a single reference on a base object.
230 extern int ttm_ref_object_add(struct ttm_object_file *tfile,
231 struct ttm_base_object *base,
232 enum ttm_ref_type ref_type, bool *existed);
234 * ttm_ref_object_base_unref
236 * @key: Key representing the base object.
237 * @ref_type: Ref type of the ref object to be dereferenced.
239 * Unreference a ref object with type @ref_type
240 * on the base object identified by @key. If there are no duplicate
241 * references, the ref object will be destroyed and the base object
242 * will be unreferenced.
244 extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
246 enum ttm_ref_type ref_type);
249 * ttm_object_file_init - initialize a struct ttm_object file
251 * @tdev: A struct ttm_object device this file is initialized on.
252 * @hash_order: Order of the hash table used to hold the reference objects.
254 * This is typically called by the file_ops::open function.
257 extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device
259 unsigned int hash_order);
262 * ttm_object_file_release - release data held by a ttm_object_file
264 * @p_tfile: Pointer to pointer to the ttm_object_file object to release.
265 * *p_tfile will be set to NULL by this function.
267 * Releases all data associated by a ttm_object_file.
268 * Typically called from file_ops::release. The caller must
269 * ensure that there are no concurrent users of tfile.
272 extern void ttm_object_file_release(struct ttm_object_file **p_tfile);
275 * ttm_object device init - initialize a struct ttm_object_device
277 * @mem_glob: struct ttm_mem_global for memory accounting.
278 * @hash_order: Order of hash table used to hash the base objects.
279 * @ops: DMA buf ops for prime objects of this device.
281 * This function is typically called on device initialization to prepare
282 * data structures needed for ttm base and ref objects.
285 extern struct ttm_object_device *
286 ttm_object_device_init(struct ttm_mem_global *mem_glob,
287 unsigned int hash_order,
288 const struct dma_buf_ops *ops);
291 * ttm_object_device_release - release data held by a ttm_object_device
293 * @p_tdev: Pointer to pointer to the ttm_object_device object to release.
294 * *p_tdev will be set to NULL by this function.
296 * Releases all data associated by a ttm_object_device.
297 * Typically called from driver::unload before the destruction of the
298 * device private data structure.
301 extern void ttm_object_device_release(struct ttm_object_device **p_tdev);
303 #define ttm_base_object_kfree(__object, __base)\
304 kfree_rcu(__object, __base.rhead)
306 extern int ttm_prime_object_init(struct ttm_object_file *tfile,
308 struct ttm_prime_object *prime,
310 enum ttm_object_type type,
311 void (*refcount_release)
312 (struct ttm_base_object **),
313 void (*ref_obj_release)
314 (struct ttm_base_object *,
315 enum ttm_ref_type ref_type));
317 static inline enum ttm_object_type
318 ttm_base_object_type(struct ttm_base_object *base)
320 return (base->object_type == ttm_prime_type) ?
321 container_of(base, struct ttm_prime_object, base)->real_type :
324 extern int ttm_prime_fd_to_handle(struct ttm_object_file *tfile,
325 int fd, u32 *handle);
326 extern int ttm_prime_handle_to_fd(struct ttm_object_file *tfile,
327 uint32_t handle, uint32_t flags,
330 #define ttm_prime_object_kfree(__obj, __prime) \
331 kfree_rcu(__obj, __prime.base.rhead)