1/************************************************************************** 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, 80 ttm_driver_type1, 81 ttm_driver_type2, 82 ttm_driver_type3, 83 ttm_driver_type4, 84 ttm_driver_type5 85}; 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 referencing 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 272