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 /* $FreeBSD: head/sys/dev/drm2/ttm/ttm_object.h 247835 2013-03-05 09:49:34Z kib $ */
31 /** @file ttm_object.h
33 * Base- and reference object implementation for the various
34 * ttm objects. Implements reference counting, minimal security checks
35 * and release on file close.
38 #ifndef _TTM_OBJECT_H_
39 #define _TTM_OBJECT_H_
41 #include <drm/drm_hashtab.h>
42 #include <drm/ttm/ttm_memory.h>
43 #include <linux/kref.h>
48 * Describes what type of reference a ref object holds.
50 * TTM_REF_USAGE is a simple refcount on a base object.
52 * TTM_REF_SYNCCPU_READ is a SYNCCPU_READ reference on a
55 * TTM_REF_SYNCCPU_WRITE is a SYNCCPU_WRITE reference on a
63 TTM_REF_SYNCCPU_WRITE,
68 * enum ttm_object_type
70 * One entry per ttm object type.
71 * Device-specific types should use the
72 * ttm_driver_typex types.
75 enum ttm_object_type {
79 ttm_driver_type0 = 256,
87 struct ttm_object_file;
88 struct ttm_object_device;
91 * struct ttm_base_object
93 * @hash: hash entry for the per-device object hash.
94 * @type: derived type this object is base class for.
95 * @shareable: Other ttm_object_files can access this object.
97 * @tfile: Pointer to ttm_object_file of the creator.
98 * NULL if the object was not created by a user request.
101 * @refcount: Number of references to this object, not
102 * including the hash entry. A reference to a base object can
103 * only be held by a ref object.
105 * @refcount_release: A function to be called when there are
106 * no more references to this object. This function should
107 * destroy the object (or make sure destruction eventually happens),
108 * and when it is called, the object has
109 * already been taken out of the per-device hash. The parameter
110 * "base" should be set to NULL by the function.
112 * @ref_obj_release: A function to be called when a reference object
113 * with another ttm_ref_type than TTM_REF_USAGE is deleted.
114 * This function may, for example, release a lock held by a user-space
117 * This struct is intended to be used as a base struct for objects that
118 * are visible to user-space. It provides a global name, race-safe
119 * access and refcounting, minimal access contol and hooks for unref actions.
122 struct ttm_base_object {
123 /* struct rcu_head rhead;XXXKIB */
124 struct drm_hash_item hash;
125 enum ttm_object_type object_type;
127 struct ttm_object_file *tfile;
128 struct kref refcount;
129 void (*refcount_release) (struct ttm_base_object **base);
130 void (*ref_obj_release) (struct ttm_base_object *base,
131 enum ttm_ref_type ref_type);
135 * ttm_base_object_init
137 * @tfile: Pointer to a struct ttm_object_file.
138 * @base: The struct ttm_base_object to initialize.
139 * @shareable: This object is shareable with other applcations.
140 * (different @tfile pointers.)
141 * @type: The object type.
142 * @refcount_release: See the struct ttm_base_object description.
143 * @ref_obj_release: See the struct ttm_base_object description.
145 * Initializes a struct ttm_base_object.
148 extern int ttm_base_object_init(struct ttm_object_file *tfile,
149 struct ttm_base_object *base,
151 enum ttm_object_type type,
152 void (*refcount_release) (struct ttm_base_object
154 void (*ref_obj_release) (struct ttm_base_object
160 * ttm_base_object_lookup
162 * @tfile: Pointer to a struct ttm_object_file.
165 * Looks up a struct ttm_base_object with the key @key.
166 * Also verifies that the object is visible to the application, by
167 * comparing the @tfile argument and checking the object shareable flag.
170 extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file
171 *tfile, uint32_t key);
174 * ttm_base_object_unref
176 * @p_base: Pointer to a pointer referencing a struct ttm_base_object.
178 * Decrements the base object refcount and clears the pointer pointed to by
182 extern void ttm_base_object_unref(struct ttm_base_object **p_base);
185 * ttm_ref_object_add.
187 * @tfile: A struct ttm_object_file representing the application owning the
189 * @base: The base object to reference.
190 * @ref_type: The type of reference.
191 * @existed: Upon completion, indicates that an identical reference object
192 * already existed, and the refcount was upped on that object instead.
194 * Adding a ref object to a base object is basically like referencing the
195 * base object, but a user-space application holds the reference. When the
196 * file corresponding to @tfile is closed, all its reference objects are
197 * deleted. A reference object can have different types depending on what
198 * it's intended for. It can be refcounting to prevent object destruction,
199 * When user-space takes a lock, it can add a ref object to that lock to
200 * make sure the lock is released if the application dies. A ref object
201 * will hold a single reference on a base object.
203 extern int ttm_ref_object_add(struct ttm_object_file *tfile,
204 struct ttm_base_object *base,
205 enum ttm_ref_type ref_type, bool *existed);
207 * ttm_ref_object_base_unref
209 * @key: Key representing the base object.
210 * @ref_type: Ref type of the ref object to be dereferenced.
212 * Unreference a ref object with type @ref_type
213 * on the base object identified by @key. If there are no duplicate
214 * references, the ref object will be destroyed and the base object
215 * will be unreferenced.
217 extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
219 enum ttm_ref_type ref_type);
222 * ttm_object_file_init - initialize a struct ttm_object file
224 * @tdev: A struct ttm_object device this file is initialized on.
225 * @hash_order: Order of the hash table used to hold the reference objects.
227 * This is typically called by the file_ops::open function.
230 extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device
232 unsigned int hash_order);
235 * ttm_object_file_release - release data held by a ttm_object_file
237 * @p_tfile: Pointer to pointer to the ttm_object_file object to release.
238 * *p_tfile will be set to NULL by this function.
240 * Releases all data associated by a ttm_object_file.
241 * Typically called from file_ops::release. The caller must
242 * ensure that there are no concurrent users of tfile.
245 extern void ttm_object_file_release(struct ttm_object_file **p_tfile);
248 * ttm_object device init - initialize a struct ttm_object_device
250 * @hash_order: Order of hash table used to hash the base objects.
252 * This function is typically called on device initialization to prepare
253 * data structures needed for ttm base and ref objects.
256 extern struct ttm_object_device *ttm_object_device_init
257 (struct ttm_mem_global *mem_glob, unsigned int hash_order);
260 * ttm_object_device_release - release data held by a ttm_object_device
262 * @p_tdev: Pointer to pointer to the ttm_object_device object to release.
263 * *p_tdev will be set to NULL by this function.
265 * Releases all data associated by a ttm_object_device.
266 * Typically called from driver::unload before the destruction of the
267 * device private data structure.
270 extern void ttm_object_device_release(struct ttm_object_device **p_tdev);
272 #define ttm_base_object_kfree(__object, __base)\
273 kfree_rcu(__object, __base.rhead)