1/* $NetBSD: ttm_object.h,v 1.2 2021/12/18 23:45:45 riastradh Exp $ */ 2 3/************************************************************************** 4 * 5 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA 6 * All Rights Reserved. 7 * 8 * Permission is hereby granted, free of charge, to any person obtaining a 9 * copy of this software and associated documentation files (the 10 * "Software"), to deal in the Software without restriction, including 11 * without limitation the rights to use, copy, modify, merge, publish, 12 * distribute, sub license, and/or sell copies of the Software, and to 13 * permit persons to whom the Software is furnished to do so, subject to 14 * the following conditions: 15 * 16 * The above copyright notice and this permission notice (including the 17 * next paragraph) shall be included in all copies or substantial portions 18 * of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL 23 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 24 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 25 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 26 * USE OR OTHER DEALINGS IN THE SOFTWARE. 27 * 28 **************************************************************************/ 29/* 30 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com> 31 */ 32/** @file ttm_object.h 33 * 34 * Base- and reference object implementation for the various 35 * ttm objects. Implements reference counting, minimal security checks 36 * and release on file close. 37 */ 38 39#ifndef _TTM_OBJECT_H_ 40#define _TTM_OBJECT_H_ 41 42#include <linux/dma-buf.h> 43#include <linux/kref.h> 44#include <linux/list.h> 45#include <linux/rcupdate.h> 46 47#include <drm/drm_hashtab.h> 48#include <drm/ttm/ttm_memory.h> 49 50/** 51 * enum ttm_ref_type 52 * 53 * Describes what type of reference a ref object holds. 54 * 55 * TTM_REF_USAGE is a simple refcount on a base object. 56 * 57 * TTM_REF_SYNCCPU_READ is a SYNCCPU_READ reference on a 58 * buffer object. 59 * 60 * TTM_REF_SYNCCPU_WRITE is a SYNCCPU_WRITE reference on a 61 * buffer object. 62 * 63 */ 64 65enum ttm_ref_type { 66 TTM_REF_USAGE, 67 TTM_REF_SYNCCPU_READ, 68 TTM_REF_SYNCCPU_WRITE, 69 TTM_REF_NUM 70}; 71 72/** 73 * enum ttm_object_type 74 * 75 * One entry per ttm object type. 76 * Device-specific types should use the 77 * ttm_driver_typex types. 78 */ 79 80enum ttm_object_type { 81 ttm_fence_type, 82 ttm_buffer_type, 83 ttm_lock_type, 84 ttm_prime_type, 85 ttm_driver_type0 = 256, 86 ttm_driver_type1, 87 ttm_driver_type2, 88 ttm_driver_type3, 89 ttm_driver_type4, 90 ttm_driver_type5 91}; 92 93struct ttm_object_file; 94struct ttm_object_device; 95 96/** 97 * struct ttm_base_object 98 * 99 * @hash: hash entry for the per-device object hash. 100 * @type: derived type this object is base class for. 101 * @shareable: Other ttm_object_files can access this object. 102 * 103 * @tfile: Pointer to ttm_object_file of the creator. 104 * NULL if the object was not created by a user request. 105 * (kernel object). 106 * 107 * @refcount: Number of references to this object, not 108 * including the hash entry. A reference to a base object can 109 * only be held by a ref object. 110 * 111 * @refcount_release: A function to be called when there are 112 * no more references to this object. This function should 113 * destroy the object (or make sure destruction eventually happens), 114 * and when it is called, the object has 115 * already been taken out of the per-device hash. The parameter 116 * "base" should be set to NULL by the function. 117 * 118 * @ref_obj_release: A function to be called when a reference object 119 * with another ttm_ref_type than TTM_REF_USAGE is deleted. 120 * This function may, for example, release a lock held by a user-space 121 * process. 122 * 123 * This struct is intended to be used as a base struct for objects that 124 * are visible to user-space. It provides a global name, race-safe 125 * access and refcounting, minimal access contol and hooks for unref actions. 126 */ 127 128struct ttm_base_object { 129 struct rcu_head rhead; 130 struct ttm_object_file *tfile; 131 struct kref refcount; 132 void (*refcount_release) (struct ttm_base_object **base); 133 void (*ref_obj_release) (struct ttm_base_object *base, 134 enum ttm_ref_type ref_type); 135 u32 handle; 136 enum ttm_object_type object_type; 137 u32 shareable; 138}; 139 140 141/** 142 * struct ttm_prime_object - Modified base object that is prime-aware 143 * 144 * @base: struct ttm_base_object that we derive from 145 * @mutex: Mutex protecting the @dma_buf member. 146 * @size: Size of the dma_buf associated with this object 147 * @real_type: Type of the underlying object. Needed since we're setting 148 * the value of @base::object_type to ttm_prime_type 149 * @dma_buf: Non ref-coutned pointer to a struct dma_buf created from this 150 * object. 151 * @refcount_release: The underlying object's release method. Needed since 152 * we set @base::refcount_release to our own release method. 153 */ 154 155struct ttm_prime_object { 156 struct ttm_base_object base; 157 struct mutex mutex; 158 size_t size; 159 enum ttm_object_type real_type; 160 struct dma_buf *dma_buf; 161 void (*refcount_release) (struct ttm_base_object **); 162}; 163 164/** 165 * ttm_base_object_init 166 * 167 * @tfile: Pointer to a struct ttm_object_file. 168 * @base: The struct ttm_base_object to initialize. 169 * @shareable: This object is shareable with other applcations. 170 * (different @tfile pointers.) 171 * @type: The object type. 172 * @refcount_release: See the struct ttm_base_object description. 173 * @ref_obj_release: See the struct ttm_base_object description. 174 * 175 * Initializes a struct ttm_base_object. 176 */ 177 178extern int ttm_base_object_init(struct ttm_object_file *tfile, 179 struct ttm_base_object *base, 180 bool shareable, 181 enum ttm_object_type type, 182 void (*refcount_release) (struct ttm_base_object 183 **), 184 void (*ref_obj_release) (struct ttm_base_object 185 *, 186 enum ttm_ref_type 187 ref_type)); 188 189/** 190 * ttm_base_object_lookup 191 * 192 * @tfile: Pointer to a struct ttm_object_file. 193 * @key: Hash key 194 * 195 * Looks up a struct ttm_base_object with the key @key. 196 */ 197 198extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file 199 *tfile, uint32_t key); 200 201/** 202 * ttm_base_object_lookup_for_ref 203 * 204 * @tdev: Pointer to a struct ttm_object_device. 205 * @key: Hash key 206 * 207 * Looks up a struct ttm_base_object with the key @key. 208 * This function should only be used when the struct tfile associated with the 209 * caller doesn't yet have a reference to the base object. 210 */ 211 212extern struct ttm_base_object * 213ttm_base_object_lookup_for_ref(struct ttm_object_device *tdev, uint32_t key); 214 215/** 216 * ttm_base_object_unref 217 * 218 * @p_base: Pointer to a pointer referencing a struct ttm_base_object. 219 * 220 * Decrements the base object refcount and clears the pointer pointed to by 221 * p_base. 222 */ 223 224extern void ttm_base_object_unref(struct ttm_base_object **p_base); 225 226/** 227 * ttm_ref_object_add. 228 * 229 * @tfile: A struct ttm_object_file representing the application owning the 230 * ref_object. 231 * @base: The base object to reference. 232 * @ref_type: The type of reference. 233 * @existed: Upon completion, indicates that an identical reference object 234 * already existed, and the refcount was upped on that object instead. 235 * @require_existed: Fail with -EPERM if an identical ref object didn't 236 * already exist. 237 * 238 * Checks that the base object is shareable and adds a ref object to it. 239 * 240 * Adding a ref object to a base object is basically like referencing the 241 * base object, but a user-space application holds the reference. When the 242 * file corresponding to @tfile is closed, all its reference objects are 243 * deleted. A reference object can have different types depending on what 244 * it's intended for. It can be refcounting to prevent object destruction, 245 * When user-space takes a lock, it can add a ref object to that lock to 246 * make sure the lock is released if the application dies. A ref object 247 * will hold a single reference on a base object. 248 */ 249extern int ttm_ref_object_add(struct ttm_object_file *tfile, 250 struct ttm_base_object *base, 251 enum ttm_ref_type ref_type, bool *existed, 252 bool require_existed); 253 254extern bool ttm_ref_object_exists(struct ttm_object_file *tfile, 255 struct ttm_base_object *base); 256 257/** 258 * ttm_ref_object_base_unref 259 * 260 * @key: Key representing the base object. 261 * @ref_type: Ref type of the ref object to be dereferenced. 262 * 263 * Unreference a ref object with type @ref_type 264 * on the base object identified by @key. If there are no duplicate 265 * references, the ref object will be destroyed and the base object 266 * will be unreferenced. 267 */ 268extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile, 269 unsigned long key, 270 enum ttm_ref_type ref_type); 271 272/** 273 * ttm_object_file_init - initialize a struct ttm_object file 274 * 275 * @tdev: A struct ttm_object device this file is initialized on. 276 * @hash_order: Order of the hash table used to hold the reference objects. 277 * 278 * This is typically called by the file_ops::open function. 279 */ 280 281extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device 282 *tdev, 283 unsigned int hash_order); 284 285/** 286 * ttm_object_file_release - release data held by a ttm_object_file 287 * 288 * @p_tfile: Pointer to pointer to the ttm_object_file object to release. 289 * *p_tfile will be set to NULL by this function. 290 * 291 * Releases all data associated by a ttm_object_file. 292 * Typically called from file_ops::release. The caller must 293 * ensure that there are no concurrent users of tfile. 294 */ 295 296extern void ttm_object_file_release(struct ttm_object_file **p_tfile); 297 298/** 299 * ttm_object device init - initialize a struct ttm_object_device 300 * 301 * @mem_glob: struct ttm_mem_global for memory accounting. 302 * @hash_order: Order of hash table used to hash the base objects. 303 * @ops: DMA buf ops for prime objects of this device. 304 * 305 * This function is typically called on device initialization to prepare 306 * data structures needed for ttm base and ref objects. 307 */ 308 309extern struct ttm_object_device * 310ttm_object_device_init(struct ttm_mem_global *mem_glob, 311 unsigned int hash_order, 312 const struct dma_buf_ops *ops); 313 314/** 315 * ttm_object_device_release - release data held by a ttm_object_device 316 * 317 * @p_tdev: Pointer to pointer to the ttm_object_device object to release. 318 * *p_tdev will be set to NULL by this function. 319 * 320 * Releases all data associated by a ttm_object_device. 321 * Typically called from driver::unload before the destruction of the 322 * device private data structure. 323 */ 324 325extern void ttm_object_device_release(struct ttm_object_device **p_tdev); 326 327#define ttm_base_object_kfree(__object, __base)\ 328 kfree_rcu(__object, __base.rhead) 329 330extern int ttm_prime_object_init(struct ttm_object_file *tfile, 331 size_t size, 332 struct ttm_prime_object *prime, 333 bool shareable, 334 enum ttm_object_type type, 335 void (*refcount_release) 336 (struct ttm_base_object **), 337 void (*ref_obj_release) 338 (struct ttm_base_object *, 339 enum ttm_ref_type ref_type)); 340 341static inline enum ttm_object_type 342ttm_base_object_type(struct ttm_base_object *base) 343{ 344 return (base->object_type == ttm_prime_type) ? 345 container_of(base, struct ttm_prime_object, base)->real_type : 346 base->object_type; 347} 348extern int ttm_prime_fd_to_handle(struct ttm_object_file *tfile, 349 int fd, u32 *handle); 350extern int ttm_prime_handle_to_fd(struct ttm_object_file *tfile, 351 uint32_t handle, uint32_t flags, 352 int *prime_fd); 353 354#define ttm_prime_object_kfree(__obj, __prime) \ 355 kfree_rcu(__obj, __prime.base.rhead) 356 357/* 358 * Extra memory required by the base object's idr storage, which is allocated 359 * separately from the base object itself. We estimate an on-average 128 bytes 360 * per idr. 361 */ 362#define TTM_OBJ_EXTRA_SIZE 128 363 364struct ttm_base_object * 365ttm_base_object_noref_lookup(struct ttm_object_file *tfile, uint32_t key); 366 367/** 368 * ttm_base_object_noref_release - release a base object pointer looked up 369 * without reference 370 * 371 * Releases a base object pointer looked up with ttm_base_object_noref_lookup(). 372 */ 373static inline void ttm_base_object_noref_release(void) 374{ 375 __acquire(RCU); 376 rcu_read_unlock(); 377} 378#endif 379