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/drm_hashtab.h> 42#include <linux/kref.h> 43#include <linux/rcupdate.h> 44#include <ttm/ttm_memory.h> 45 46/** 47 * enum ttm_ref_type 48 * 49 * Describes what type of reference a ref object holds. 50 * 51 * TTM_REF_USAGE is a simple refcount on a base object. 52 * 53 * TTM_REF_SYNCCPU_READ is a SYNCCPU_READ reference on a 54 * buffer object. 55 * 56 * TTM_REF_SYNCCPU_WRITE is a SYNCCPU_WRITE reference on a 57 * buffer object. 58 * 59 */ 60 61enum ttm_ref_type { 62 TTM_REF_USAGE, 63 TTM_REF_SYNCCPU_READ, 64 TTM_REF_SYNCCPU_WRITE, 65 TTM_REF_NUM 66}; 67 68/** 69 * enum ttm_object_type 70 * 71 * One entry per ttm object type. 72 * Device-specific types should use the 73 * ttm_driver_typex types. 74 */ 75 76enum ttm_object_type { 77 ttm_fence_type, 78 ttm_buffer_type, 79 ttm_lock_type, 80 ttm_driver_type0 = 256, 81 ttm_driver_type1, 82 ttm_driver_type2, 83 ttm_driver_type3, 84 ttm_driver_type4, 85 ttm_driver_type5 86}; 87 88struct ttm_object_file; 89struct ttm_object_device; 90 91/** 92 * struct ttm_base_object 93 * 94 * @hash: hash entry for the per-device object hash. 95 * @type: derived type this object is base class for. 96 * @shareable: Other ttm_object_files can access this object. 97 * 98 * @tfile: Pointer to ttm_object_file of the creator. 99 * NULL if the object was not created by a user request. 100 * (kernel object). 101 * 102 * @refcount: Number of references to this object, not 103 * including the hash entry. A reference to a base object can 104 * only be held by a ref object. 105 * 106 * @refcount_release: A function to be called when there are 107 * no more references to this object. This function should 108 * destroy the object (or make sure destruction eventually happens), 109 * and when it is called, the object has 110 * already been taken out of the per-device hash. The parameter 111 * "base" should be set to NULL by the function. 112 * 113 * @ref_obj_release: A function to be called when a reference object 114 * with another ttm_ref_type than TTM_REF_USAGE is deleted. 115 * This function may, for example, release a lock held by a user-space 116 * process. 117 * 118 * This struct is intended to be used as a base struct for objects that 119 * are visible to user-space. It provides a global name, race-safe 120 * access and refcounting, minimal access contol and hooks for unref actions. 121 */ 122 123struct ttm_base_object { 124 struct rcu_head rhead; 125 struct drm_hash_item hash; 126 enum ttm_object_type object_type; 127 bool shareable; 128 struct ttm_object_file *tfile; 129 struct kref refcount; 130 void (*refcount_release) (struct ttm_base_object **base); 131 void (*ref_obj_release) (struct ttm_base_object *base, 132 enum ttm_ref_type ref_type); 133}; 134 135/** 136 * ttm_base_object_init 137 * 138 * @tfile: Pointer to a struct ttm_object_file. 139 * @base: The struct ttm_base_object to initialize. 140 * @shareable: This object is shareable with other applcations. 141 * (different @tfile pointers.) 142 * @type: The object type. 143 * @refcount_release: See the struct ttm_base_object description. 144 * @ref_obj_release: See the struct ttm_base_object description. 145 * 146 * Initializes a struct ttm_base_object. 147 */ 148 149extern int ttm_base_object_init(struct ttm_object_file *tfile, 150 struct ttm_base_object *base, 151 bool shareable, 152 enum ttm_object_type type, 153 void (*refcount_release) (struct ttm_base_object 154 **), 155 void (*ref_obj_release) (struct ttm_base_object 156 *, 157 enum ttm_ref_type 158 ref_type)); 159 160/** 161 * ttm_base_object_lookup 162 * 163 * @tfile: Pointer to a struct ttm_object_file. 164 * @key: Hash key 165 * 166 * Looks up a struct ttm_base_object with the key @key. 167 * Also verifies that the object is visible to the application, by 168 * comparing the @tfile argument and checking the object shareable flag. 169 */ 170 171extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file 172 *tfile, uint32_t key); 173 174/** 175 * ttm_base_object_unref 176 * 177 * @p_base: Pointer to a pointer referencing a struct ttm_base_object. 178 * 179 * Decrements the base object refcount and clears the pointer pointed to by 180 * p_base. 181 */ 182 183extern void ttm_base_object_unref(struct ttm_base_object **p_base); 184 185/** 186 * ttm_ref_object_add. 187 * 188 * @tfile: A struct ttm_object_file representing the application owning the 189 * ref_object. 190 * @base: The base object to reference. 191 * @ref_type: The type of reference. 192 * @existed: Upon completion, indicates that an identical reference object 193 * already existed, and the refcount was upped on that object instead. 194 * 195 * Adding a ref object to a base object is basically like referencing the 196 * base object, but a user-space application holds the reference. When the 197 * file corresponding to @tfile is closed, all its reference objects are 198 * deleted. A reference object can have different types depending on what 199 * it's intended for. It can be refcounting to prevent object destruction, 200 * When user-space takes a lock, it can add a ref object to that lock to 201 * make sure the lock is released if the application dies. A ref object 202 * will hold a single reference on a base object. 203 */ 204extern int ttm_ref_object_add(struct ttm_object_file *tfile, 205 struct ttm_base_object *base, 206 enum ttm_ref_type ref_type, bool *existed); 207/** 208 * ttm_ref_object_base_unref 209 * 210 * @key: Key representing the base object. 211 * @ref_type: Ref type of the ref object to be dereferenced. 212 * 213 * Unreference a ref object with type @ref_type 214 * on the base object identified by @key. If there are no duplicate 215 * references, the ref object will be destroyed and the base object 216 * will be unreferenced. 217 */ 218extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile, 219 unsigned long key, 220 enum ttm_ref_type ref_type); 221 222/** 223 * ttm_object_file_init - initialize a struct ttm_object file 224 * 225 * @tdev: A struct ttm_object device this file is initialized on. 226 * @hash_order: Order of the hash table used to hold the reference objects. 227 * 228 * This is typically called by the file_ops::open function. 229 */ 230 231extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device 232 *tdev, 233 unsigned int hash_order); 234 235/** 236 * ttm_object_file_release - release data held by a ttm_object_file 237 * 238 * @p_tfile: Pointer to pointer to the ttm_object_file object to release. 239 * *p_tfile will be set to NULL by this function. 240 * 241 * Releases all data associated by a ttm_object_file. 242 * Typically called from file_ops::release. The caller must 243 * ensure that there are no concurrent users of tfile. 244 */ 245 246extern void ttm_object_file_release(struct ttm_object_file **p_tfile); 247 248/** 249 * ttm_object device init - initialize a struct ttm_object_device 250 * 251 * @hash_order: Order of hash table used to hash the base objects. 252 * 253 * This function is typically called on device initialization to prepare 254 * data structures needed for ttm base and ref objects. 255 */ 256 257extern struct ttm_object_device *ttm_object_device_init 258 (struct ttm_mem_global *mem_glob, unsigned int hash_order); 259 260/** 261 * ttm_object_device_release - release data held by a ttm_object_device 262 * 263 * @p_tdev: Pointer to pointer to the ttm_object_device object to release. 264 * *p_tdev will be set to NULL by this function. 265 * 266 * Releases all data associated by a ttm_object_device. 267 * Typically called from driver::unload before the destruction of the 268 * device private data structure. 269 */ 270 271extern void ttm_object_device_release(struct ttm_object_device **p_tdev); 272 273#define ttm_base_object_kfree(__object, __base)\ 274 kfree_rcu(__object, __base.rhead) 275#endif 276