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/dma-buf.h> 41 #include <linux/kref.h> 42 #include <linux/list.h> 43 #include <linux/rcupdate.h> 44 45 #include "vmwgfx_hashtab.h" 46 47 /** 48 * enum ttm_object_type 49 * 50 * One entry per ttm object type. 51 * Device-specific types should use the 52 * ttm_driver_typex types. 53 */ 54 55 enum ttm_object_type { 56 ttm_fence_type, 57 ttm_lock_type, 58 ttm_prime_type, 59 ttm_driver_type0 = 256, 60 ttm_driver_type1, 61 ttm_driver_type2, 62 ttm_driver_type3, 63 ttm_driver_type4, 64 ttm_driver_type5 65 }; 66 67 struct ttm_object_file; 68 struct ttm_object_device; 69 70 /** 71 * struct ttm_base_object 72 * 73 * @hash: hash entry for the per-device object hash. 74 * @type: derived type this object is base class for. 75 * @shareable: Other ttm_object_files can access this object. 76 * 77 * @tfile: Pointer to ttm_object_file of the creator. 78 * NULL if the object was not created by a user request. 79 * (kernel object). 80 * 81 * @refcount: Number of references to this object, not 82 * including the hash entry. A reference to a base object can 83 * only be held by a ref object. 84 * 85 * @refcount_release: A function to be called when there are 86 * no more references to this object. This function should 87 * destroy the object (or make sure destruction eventually happens), 88 * and when it is called, the object has 89 * already been taken out of the per-device hash. The parameter 90 * "base" should be set to NULL by the function. 91 * 92 * @ref_obj_release: A function to be called when a reference object 93 * with another ttm_ref_type than TTM_REF_USAGE is deleted. 94 * This function may, for example, release a lock held by a user-space 95 * process. 96 * 97 * This struct is intended to be used as a base struct for objects that 98 * are visible to user-space. It provides a global name, race-safe 99 * access and refcounting, minimal access contol and hooks for unref actions. 100 */ 101 102 struct ttm_base_object { 103 struct rcu_head rhead; 104 struct ttm_object_file *tfile; 105 struct kref refcount; 106 void (*refcount_release) (struct ttm_base_object **base); 107 u32 handle; 108 enum ttm_object_type object_type; 109 u32 shareable; 110 }; 111 112 113 /** 114 * struct ttm_prime_object - Modified base object that is prime-aware 115 * 116 * @base: struct ttm_base_object that we derive from 117 * @mutex: Mutex protecting the @dma_buf member. 118 * @size: Size of the dma_buf associated with this object 119 * @real_type: Type of the underlying object. Needed since we're setting 120 * the value of @base::object_type to ttm_prime_type 121 * @dma_buf: Non ref-coutned pointer to a struct dma_buf created from this 122 * object. 123 * @refcount_release: The underlying object's release method. Needed since 124 * we set @base::refcount_release to our own release method. 125 */ 126 127 struct ttm_prime_object { 128 struct ttm_base_object base; 129 struct mutex mutex; 130 size_t size; 131 enum ttm_object_type real_type; 132 struct dma_buf *dma_buf; 133 void (*refcount_release) (struct ttm_base_object **); 134 }; 135 136 /** 137 * ttm_base_object_init 138 * 139 * @tfile: Pointer to a struct ttm_object_file. 140 * @base: The struct ttm_base_object to initialize. 141 * @shareable: This object is shareable with other applcations. 142 * (different @tfile pointers.) 143 * @type: The object type. 144 * @refcount_release: See the struct ttm_base_object description. 145 * @ref_obj_release: See the struct ttm_base_object description. 146 * 147 * Initializes a struct ttm_base_object. 148 */ 149 150 extern int ttm_base_object_init(struct ttm_object_file *tfile, 151 struct ttm_base_object *base, 152 bool shareable, 153 enum ttm_object_type type, 154 void (*refcount_release) (struct ttm_base_object 155 **)); 156 157 /** 158 * ttm_base_object_lookup 159 * 160 * @tfile: Pointer to a struct ttm_object_file. 161 * @key: Hash key 162 * 163 * Looks up a struct ttm_base_object with the key @key. 164 */ 165 166 extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file 167 *tfile, uint32_t key); 168 169 /** 170 * ttm_base_object_lookup_for_ref 171 * 172 * @tdev: Pointer to a struct ttm_object_device. 173 * @key: Hash key 174 * 175 * Looks up a struct ttm_base_object with the key @key. 176 * This function should only be used when the struct tfile associated with the 177 * caller doesn't yet have a reference to the base object. 178 */ 179 180 extern struct ttm_base_object * 181 ttm_base_object_lookup_for_ref(struct ttm_object_device *tdev, uint32_t key); 182 183 /** 184 * ttm_base_object_unref 185 * 186 * @p_base: Pointer to a pointer referencing a struct ttm_base_object. 187 * 188 * Decrements the base object refcount and clears the pointer pointed to by 189 * p_base. 190 */ 191 192 extern void ttm_base_object_unref(struct ttm_base_object **p_base); 193 194 /** 195 * ttm_ref_object_add. 196 * 197 * @tfile: A struct ttm_object_file representing the application owning the 198 * ref_object. 199 * @base: The base object to reference. 200 * @ref_type: The type of reference. 201 * @existed: Upon completion, indicates that an identical reference object 202 * already existed, and the refcount was upped on that object instead. 203 * @require_existed: Fail with -EPERM if an identical ref object didn't 204 * already exist. 205 * 206 * Checks that the base object is shareable and adds a ref object to it. 207 * 208 * Adding a ref object to a base object is basically like referencing the 209 * base object, but a user-space application holds the reference. When the 210 * file corresponding to @tfile is closed, all its reference objects are 211 * deleted. A reference object can have different types depending on what 212 * it's intended for. It can be refcounting to prevent object destruction, 213 * When user-space takes a lock, it can add a ref object to that lock to 214 * make sure the lock is released if the application dies. A ref object 215 * will hold a single reference on a base object. 216 */ 217 extern int ttm_ref_object_add(struct ttm_object_file *tfile, 218 struct ttm_base_object *base, 219 bool *existed, 220 bool require_existed); 221 222 /** 223 * ttm_ref_object_base_unref 224 * 225 * @key: Key representing the base object. 226 * @ref_type: Ref type of the ref object to be dereferenced. 227 * 228 * Unreference a ref object with type @ref_type 229 * on the base object identified by @key. If there are no duplicate 230 * references, the ref object will be destroyed and the base object 231 * will be unreferenced. 232 */ 233 extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile, 234 unsigned long key); 235 236 /** 237 * ttm_object_file_init - initialize a struct ttm_object file 238 * 239 * @tdev: A struct ttm_object device this file is initialized on. 240 * @hash_order: Order of the hash table used to hold the reference objects. 241 * 242 * This is typically called by the file_ops::open function. 243 */ 244 245 extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device 246 *tdev, 247 unsigned int hash_order); 248 249 /** 250 * ttm_object_file_release - release data held by a ttm_object_file 251 * 252 * @p_tfile: Pointer to pointer to the ttm_object_file object to release. 253 * *p_tfile will be set to NULL by this function. 254 * 255 * Releases all data associated by a ttm_object_file. 256 * Typically called from file_ops::release. The caller must 257 * ensure that there are no concurrent users of tfile. 258 */ 259 260 extern void ttm_object_file_release(struct ttm_object_file **p_tfile); 261 262 /** 263 * ttm_object device init - initialize a struct ttm_object_device 264 * 265 * @hash_order: Order of hash table used to hash the base objects. 266 * @ops: DMA buf ops for prime objects of this device. 267 * 268 * This function is typically called on device initialization to prepare 269 * data structures needed for ttm base and ref objects. 270 */ 271 272 extern struct ttm_object_device * 273 ttm_object_device_init(unsigned int hash_order, 274 const struct dma_buf_ops *ops); 275 276 /** 277 * ttm_object_device_release - release data held by a ttm_object_device 278 * 279 * @p_tdev: Pointer to pointer to the ttm_object_device object to release. 280 * *p_tdev will be set to NULL by this function. 281 * 282 * Releases all data associated by a ttm_object_device. 283 * Typically called from driver::unload before the destruction of the 284 * device private data structure. 285 */ 286 287 extern void ttm_object_device_release(struct ttm_object_device **p_tdev); 288 289 #define ttm_base_object_kfree(__object, __base)\ 290 kfree_rcu(__object, __base.rhead) 291 292 extern int ttm_prime_object_init(struct ttm_object_file *tfile, 293 size_t size, 294 struct ttm_prime_object *prime, 295 bool shareable, 296 enum ttm_object_type type, 297 void (*refcount_release) 298 (struct ttm_base_object **)); 299 300 static inline enum ttm_object_type 301 ttm_base_object_type(struct ttm_base_object *base) 302 { 303 return (base->object_type == ttm_prime_type) ? 304 container_of(base, struct ttm_prime_object, base)->real_type : 305 base->object_type; 306 } 307 extern int ttm_prime_fd_to_handle(struct ttm_object_file *tfile, 308 int fd, u32 *handle); 309 extern int ttm_prime_handle_to_fd(struct ttm_object_file *tfile, 310 uint32_t handle, uint32_t flags, 311 int *prime_fd); 312 313 #define ttm_prime_object_kfree(__obj, __prime) \ 314 kfree_rcu(__obj, __prime.base.rhead) 315 316 struct ttm_base_object * 317 ttm_base_object_noref_lookup(struct ttm_object_file *tfile, uint32_t key); 318 319 /** 320 * ttm_base_object_noref_release - release a base object pointer looked up 321 * without reference 322 * 323 * Releases a base object pointer looked up with ttm_base_object_noref_lookup(). 324 */ 325 static inline void ttm_base_object_noref_release(void) 326 { 327 __acquire(RCU); 328 rcu_read_unlock(); 329 } 330 #endif 331