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 <linux/dma-buf.h> 45 46 #include "ttm_memory.h" 47 48 /** 49 * enum ttm_ref_type 50 * 51 * Describes what type of reference a ref object holds. 52 * 53 * TTM_REF_USAGE is a simple refcount on a base object. 54 * 55 * TTM_REF_SYNCCPU_READ is a SYNCCPU_READ reference on a 56 * buffer object. 57 * 58 * TTM_REF_SYNCCPU_WRITE is a SYNCCPU_WRITE reference on a 59 * buffer object. 60 * 61 */ 62 63 enum ttm_ref_type { 64 TTM_REF_USAGE, 65 TTM_REF_SYNCCPU_READ, 66 TTM_REF_SYNCCPU_WRITE, 67 TTM_REF_NUM 68 }; 69 70 /** 71 * enum ttm_object_type 72 * 73 * One entry per ttm object type. 74 * Device-specific types should use the 75 * ttm_driver_typex types. 76 */ 77 78 enum ttm_object_type { 79 ttm_fence_type, 80 ttm_buffer_type, 81 ttm_lock_type, 82 ttm_prime_type, 83 ttm_driver_type0 = 256, 84 ttm_driver_type1, 85 ttm_driver_type2, 86 ttm_driver_type3, 87 ttm_driver_type4, 88 ttm_driver_type5 89 }; 90 91 struct ttm_object_file; 92 struct ttm_object_device; 93 94 /** 95 * struct ttm_base_object 96 * 97 * @hash: hash entry for the per-device object hash. 98 * @type: derived type this object is base class for. 99 * @shareable: Other ttm_object_files can access this object. 100 * 101 * @tfile: Pointer to ttm_object_file of the creator. 102 * NULL if the object was not created by a user request. 103 * (kernel object). 104 * 105 * @refcount: Number of references to this object, not 106 * including the hash entry. A reference to a base object can 107 * only be held by a ref object. 108 * 109 * @refcount_release: A function to be called when there are 110 * no more references to this object. This function should 111 * destroy the object (or make sure destruction eventually happens), 112 * and when it is called, the object has 113 * already been taken out of the per-device hash. The parameter 114 * "base" should be set to NULL by the function. 115 * 116 * @ref_obj_release: A function to be called when a reference object 117 * with another ttm_ref_type than TTM_REF_USAGE is deleted. 118 * This function may, for example, release a lock held by a user-space 119 * process. 120 * 121 * This struct is intended to be used as a base struct for objects that 122 * are visible to user-space. It provides a global name, race-safe 123 * access and refcounting, minimal access contol and hooks for unref actions. 124 */ 125 126 struct ttm_base_object { 127 struct rcu_head rhead; 128 struct drm_hash_item hash; 129 enum ttm_object_type object_type; 130 bool shareable; 131 struct ttm_object_file *tfile; 132 struct kref refcount; 133 void (*refcount_release) (struct ttm_base_object **base); 134 void (*ref_obj_release) (struct ttm_base_object *base, 135 enum ttm_ref_type ref_type); 136 }; 137 138 139 /** 140 * struct ttm_prime_object - Modified base object that is prime-aware 141 * 142 * @base: struct ttm_base_object that we derive from 143 * @mutex: Mutex protecting the @dma_buf member. 144 * @size: Size of the dma_buf associated with this object 145 * @real_type: Type of the underlying object. Needed since we're setting 146 * the value of @base::object_type to ttm_prime_type 147 * @dma_buf: Non ref-coutned pointer to a struct dma_buf created from this 148 * object. 149 * @refcount_release: The underlying object's release method. Needed since 150 * we set @base::refcount_release to our own release method. 151 */ 152 153 struct ttm_prime_object { 154 struct ttm_base_object base; 155 struct lock mutex; 156 size_t size; 157 enum ttm_object_type real_type; 158 struct dma_buf *dma_buf; 159 void (*refcount_release) (struct ttm_base_object **); 160 }; 161 162 /** 163 * ttm_base_object_init 164 * 165 * @tfile: Pointer to a struct ttm_object_file. 166 * @base: The struct ttm_base_object to initialize. 167 * @shareable: This object is shareable with other applcations. 168 * (different @tfile pointers.) 169 * @type: The object type. 170 * @refcount_release: See the struct ttm_base_object description. 171 * @ref_obj_release: See the struct ttm_base_object description. 172 * 173 * Initializes a struct ttm_base_object. 174 */ 175 176 extern int ttm_base_object_init(struct ttm_object_file *tfile, 177 struct ttm_base_object *base, 178 bool shareable, 179 enum ttm_object_type type, 180 void (*refcount_release) (struct ttm_base_object 181 **), 182 void (*ref_obj_release) (struct ttm_base_object 183 *, 184 enum ttm_ref_type 185 ref_type)); 186 187 /** 188 * ttm_base_object_lookup 189 * 190 * @tfile: Pointer to a struct ttm_object_file. 191 * @key: Hash key 192 * 193 * Looks up a struct ttm_base_object with the key @key. 194 */ 195 196 extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file 197 *tfile, uint32_t key); 198 199 /** 200 * ttm_base_object_lookup_for_ref 201 * 202 * @tdev: Pointer to a struct ttm_object_device. 203 * @key: Hash key 204 * 205 * Looks up a struct ttm_base_object with the key @key. 206 * This function should only be used when the struct tfile associated with the 207 * caller doesn't yet have a reference to the base object. 208 */ 209 210 extern struct ttm_base_object * 211 ttm_base_object_lookup_for_ref(struct ttm_object_device *tdev, uint32_t key); 212 213 /** 214 * ttm_base_object_unref 215 * 216 * @p_base: Pointer to a pointer referencing a struct ttm_base_object. 217 * 218 * Decrements the base object refcount and clears the pointer pointed to by 219 * p_base. 220 */ 221 222 extern void ttm_base_object_unref(struct ttm_base_object **p_base); 223 224 /** 225 * ttm_ref_object_add. 226 * 227 * @tfile: A struct ttm_object_file representing the application owning the 228 * ref_object. 229 * @base: The base object to reference. 230 * @ref_type: The type of reference. 231 * @existed: Upon completion, indicates that an identical reference object 232 * already existed, and the refcount was upped on that object instead. 233 * @require_existed: Fail with -EPERM if an identical ref object didn't 234 * already exist. 235 * 236 * Checks that the base object is shareable and adds a ref object to it. 237 * 238 * Adding a ref object to a base object is basically like referencing the 239 * base object, but a user-space application holds the reference. When the 240 * file corresponding to @tfile is closed, all its reference objects are 241 * deleted. A reference object can have different types depending on what 242 * it's intended for. It can be refcounting to prevent object destruction, 243 * When user-space takes a lock, it can add a ref object to that lock to 244 * make sure the lock is released if the application dies. A ref object 245 * will hold a single reference on a base object. 246 */ 247 extern int ttm_ref_object_add(struct ttm_object_file *tfile, 248 struct ttm_base_object *base, 249 enum ttm_ref_type ref_type, bool *existed, 250 bool require_existed); 251 252 extern bool ttm_ref_object_exists(struct ttm_object_file *tfile, 253 struct ttm_base_object *base); 254 255 /** 256 * ttm_ref_object_base_unref 257 * 258 * @key: Key representing the base object. 259 * @ref_type: Ref type of the ref object to be dereferenced. 260 * 261 * Unreference a ref object with type @ref_type 262 * on the base object identified by @key. If there are no duplicate 263 * references, the ref object will be destroyed and the base object 264 * will be unreferenced. 265 */ 266 extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile, 267 unsigned long key, 268 enum ttm_ref_type ref_type); 269 270 /** 271 * ttm_object_file_init - initialize a struct ttm_object file 272 * 273 * @tdev: A struct ttm_object device this file is initialized on. 274 * @hash_order: Order of the hash table used to hold the reference objects. 275 * 276 * This is typically called by the file_ops::open function. 277 */ 278 279 extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device 280 *tdev, 281 unsigned int hash_order); 282 283 /** 284 * ttm_object_file_release - release data held by a ttm_object_file 285 * 286 * @p_tfile: Pointer to pointer to the ttm_object_file object to release. 287 * *p_tfile will be set to NULL by this function. 288 * 289 * Releases all data associated by a ttm_object_file. 290 * Typically called from file_ops::release. The caller must 291 * ensure that there are no concurrent users of tfile. 292 */ 293 294 extern void ttm_object_file_release(struct ttm_object_file **p_tfile); 295 296 /** 297 * ttm_object device init - initialize a struct ttm_object_device 298 * 299 * @mem_glob: struct ttm_mem_global for memory accounting. 300 * @hash_order: Order of hash table used to hash the base objects. 301 * @ops: DMA buf ops for prime objects of this device. 302 * 303 * This function is typically called on device initialization to prepare 304 * data structures needed for ttm base and ref objects. 305 */ 306 307 extern struct ttm_object_device * 308 ttm_object_device_init(struct ttm_mem_global *mem_glob, 309 unsigned int hash_order, 310 const struct dma_buf_ops *ops); 311 312 /** 313 * ttm_object_device_release - release data held by a ttm_object_device 314 * 315 * @p_tdev: Pointer to pointer to the ttm_object_device object to release. 316 * *p_tdev will be set to NULL by this function. 317 * 318 * Releases all data associated by a ttm_object_device. 319 * Typically called from driver::unload before the destruction of the 320 * device private data structure. 321 */ 322 323 extern void ttm_object_device_release(struct ttm_object_device **p_tdev); 324 325 #define ttm_base_object_kfree(__object, __base)\ 326 kfree_rcu(__object, __base.rhead) 327 328 extern int ttm_prime_object_init(struct ttm_object_file *tfile, 329 size_t size, 330 struct ttm_prime_object *prime, 331 bool shareable, 332 enum ttm_object_type type, 333 void (*refcount_release) 334 (struct ttm_base_object **), 335 void (*ref_obj_release) 336 (struct ttm_base_object *, 337 enum ttm_ref_type ref_type)); 338 339 static inline enum ttm_object_type 340 ttm_base_object_type(struct ttm_base_object *base) 341 { 342 return (base->object_type == ttm_prime_type) ? 343 container_of(base, struct ttm_prime_object, base)->real_type : 344 base->object_type; 345 } 346 extern int ttm_prime_fd_to_handle(struct ttm_object_file *tfile, 347 int fd, u32 *handle); 348 extern int ttm_prime_handle_to_fd(struct ttm_object_file *tfile, 349 uint32_t handle, uint32_t flags, 350 int *prime_fd); 351 352 #define ttm_prime_object_kfree(__obj, __prime) \ 353 kfree_rcu(__obj, __prime.base.rhead) 354 #endif 355