blob: 0d9db099978b778e14301f04dac41a197d7ec88a [file] [log] [blame]
Thomas Hellstrom88071532009-12-06 21:46:24 +01001/**************************************************************************
2 *
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
5 *
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:
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 *
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.
25 *
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/list.h>
41#include "drm_hashtab.h"
42#include <linux/kref.h>
43#include <ttm/ttm_memory.h>
44
45/**
46 * enum ttm_ref_type
47 *
48 * Describes what type of reference a ref object holds.
49 *
50 * TTM_REF_USAGE is a simple refcount on a base object.
51 *
52 * TTM_REF_SYNCCPU_READ is a SYNCCPU_READ reference on a
53 * buffer object.
54 *
55 * TTM_REF_SYNCCPU_WRITE is a SYNCCPU_WRITE reference on a
56 * buffer object.
57 *
58 */
59
60enum ttm_ref_type {
61 TTM_REF_USAGE,
62 TTM_REF_SYNCCPU_READ,
63 TTM_REF_SYNCCPU_WRITE,
64 TTM_REF_NUM
65};
66
67/**
68 * enum ttm_object_type
69 *
70 * One entry per ttm object type.
71 * Device-specific types should use the
72 * ttm_driver_typex types.
73 */
74
75enum ttm_object_type {
76 ttm_fence_type,
77 ttm_buffer_type,
78 ttm_lock_type,
79 ttm_driver_type0 = 256,
Jakob Bornecrantzbe1cb862009-12-14 22:07:45 +000080 ttm_driver_type1,
81 ttm_driver_type2,
82 ttm_driver_type3,
83 ttm_driver_type4,
84 ttm_driver_type5
Thomas Hellstrom88071532009-12-06 21:46:24 +010085};
86
87struct ttm_object_file;
88struct ttm_object_device;
89
90/**
91 * struct ttm_base_object
92 *
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.
96 *
97 * @tfile: Pointer to ttm_object_file of the creator.
98 * NULL if the object was not created by a user request.
99 * (kernel object).
100 *
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.
104 *
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.
111 *
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
115 * process.
116 *
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.
120 */
121
122struct ttm_base_object {
123 struct drm_hash_item hash;
124 enum ttm_object_type object_type;
125 bool shareable;
126 struct ttm_object_file *tfile;
127 struct kref refcount;
128 void (*refcount_release) (struct ttm_base_object **base);
129 void (*ref_obj_release) (struct ttm_base_object *base,
130 enum ttm_ref_type ref_type);
131};
132
133/**
134 * ttm_base_object_init
135 *
136 * @tfile: Pointer to a struct ttm_object_file.
137 * @base: The struct ttm_base_object to initialize.
138 * @shareable: This object is shareable with other applcations.
139 * (different @tfile pointers.)
140 * @type: The object type.
141 * @refcount_release: See the struct ttm_base_object description.
142 * @ref_obj_release: See the struct ttm_base_object description.
143 *
144 * Initializes a struct ttm_base_object.
145 */
146
147extern int ttm_base_object_init(struct ttm_object_file *tfile,
148 struct ttm_base_object *base,
149 bool shareable,
150 enum ttm_object_type type,
151 void (*refcount_release) (struct ttm_base_object
152 **),
153 void (*ref_obj_release) (struct ttm_base_object
154 *,
155 enum ttm_ref_type
156 ref_type));
157
158/**
159 * ttm_base_object_lookup
160 *
161 * @tfile: Pointer to a struct ttm_object_file.
162 * @key: Hash key
163 *
164 * Looks up a struct ttm_base_object with the key @key.
165 * Also verifies that the object is visible to the application, by
166 * comparing the @tfile argument and checking the object shareable flag.
167 */
168
169extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file
170 *tfile, uint32_t key);
171
172/**
173 * ttm_base_object_unref
174 *
175 * @p_base: Pointer to a pointer referncing a struct ttm_base_object.
176 *
177 * Decrements the base object refcount and clears the pointer pointed to by
178 * p_base.
179 */
180
181extern void ttm_base_object_unref(struct ttm_base_object **p_base);
182
183/**
184 * ttm_ref_object_add.
185 *
186 * @tfile: A struct ttm_object_file representing the application owning the
187 * ref_object.
188 * @base: The base object to reference.
189 * @ref_type: The type of reference.
190 * @existed: Upon completion, indicates that an identical reference object
191 * already existed, and the refcount was upped on that object instead.
192 *
193 * Adding a ref object to a base object is basically like referencing the
194 * base object, but a user-space application holds the reference. When the
195 * file corresponding to @tfile is closed, all its reference objects are
196 * deleted. A reference object can have different types depending on what
197 * it's intended for. It can be refcounting to prevent object destruction,
198 * When user-space takes a lock, it can add a ref object to that lock to
199 * make sure the lock is released if the application dies. A ref object
200 * will hold a single reference on a base object.
201 */
202extern int ttm_ref_object_add(struct ttm_object_file *tfile,
203 struct ttm_base_object *base,
204 enum ttm_ref_type ref_type, bool *existed);
205/**
206 * ttm_ref_object_base_unref
207 *
208 * @key: Key representing the base object.
209 * @ref_type: Ref type of the ref object to be dereferenced.
210 *
211 * Unreference a ref object with type @ref_type
212 * on the base object identified by @key. If there are no duplicate
213 * references, the ref object will be destroyed and the base object
214 * will be unreferenced.
215 */
216extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
217 unsigned long key,
218 enum ttm_ref_type ref_type);
219
220/**
221 * ttm_object_file_init - initialize a struct ttm_object file
222 *
223 * @tdev: A struct ttm_object device this file is initialized on.
224 * @hash_order: Order of the hash table used to hold the reference objects.
225 *
226 * This is typically called by the file_ops::open function.
227 */
228
229extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device
230 *tdev,
231 unsigned int hash_order);
232
233/**
234 * ttm_object_file_release - release data held by a ttm_object_file
235 *
236 * @p_tfile: Pointer to pointer to the ttm_object_file object to release.
237 * *p_tfile will be set to NULL by this function.
238 *
239 * Releases all data associated by a ttm_object_file.
240 * Typically called from file_ops::release. The caller must
241 * ensure that there are no concurrent users of tfile.
242 */
243
244extern void ttm_object_file_release(struct ttm_object_file **p_tfile);
245
246/**
247 * ttm_object device init - initialize a struct ttm_object_device
248 *
249 * @hash_order: Order of hash table used to hash the base objects.
250 *
251 * This function is typically called on device initialization to prepare
252 * data structures needed for ttm base and ref objects.
253 */
254
255extern struct ttm_object_device *ttm_object_device_init
256 (struct ttm_mem_global *mem_glob, unsigned int hash_order);
257
258/**
259 * ttm_object_device_release - release data held by a ttm_object_device
260 *
261 * @p_tdev: Pointer to pointer to the ttm_object_device object to release.
262 * *p_tdev will be set to NULL by this function.
263 *
264 * Releases all data associated by a ttm_object_device.
265 * Typically called from driver::unload before the destruction of the
266 * device private data structure.
267 */
268
269extern void ttm_object_device_release(struct ttm_object_device **p_tdev);
270
271#endif