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28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
30 /** @file ttm_object.h
32 * Base- and reference object implementation for the various
33 * ttm objects. Implements reference counting, minimal security checks
34 * and release on file close.
37 #ifndef _TTM_OBJECT_H_
38 #define _TTM_OBJECT_H_
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 #include <ttm/ttm_memory.h>
50 * Describes what type of reference a ref object holds.
52 * TTM_REF_USAGE is a simple refcount on a base object.
54 * TTM_REF_SYNCCPU_READ is a SYNCCPU_READ reference on a
57 * TTM_REF_SYNCCPU_WRITE is a SYNCCPU_WRITE reference on a
65 TTM_REF_SYNCCPU_WRITE,
70 * enum ttm_object_type
72 * One entry per ttm object type.
73 * Device-specific types should use the
74 * ttm_driver_typex types.
77 enum ttm_object_type {
82 ttm_driver_type0 = 256,
90 struct ttm_object_file;
91 struct ttm_object_device;
94 * struct ttm_base_object
96 * @hash: hash entry for the per-device object hash.
97 * @type: derived type this object is base class for.
98 * @shareable: Other ttm_object_files can access this object.
100 * @tfile: Pointer to ttm_object_file of the creator.
101 * NULL if the object was not created by a user request.
104 * @refcount: Number of references to this object, not
105 * including the hash entry. A reference to a base object can
106 * only be held by a ref object.
108 * @refcount_release: A function to be called when there are
109 * no more references to this object. This function should
110 * destroy the object (or make sure destruction eventually happens),
111 * and when it is called, the object has
112 * already been taken out of the per-device hash. The parameter
113 * "base" should be set to NULL by the function.
115 * @ref_obj_release: A function to be called when a reference object
116 * with another ttm_ref_type than TTM_REF_USAGE is deleted.
117 * This function may, for example, release a lock held by a user-space
120 * This struct is intended to be used as a base struct for objects that
121 * are visible to user-space. It provides a global name, race-safe
122 * access and refcounting, minimal access contol and hooks for unref actions.
125 struct ttm_base_object {
126 struct rcu_head rhead;
127 struct drm_hash_item hash;
128 enum ttm_object_type object_type;
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);
139 * struct ttm_prime_object - Modified base object that is prime-aware
141 * @base: struct ttm_base_object that we derive from
142 * @mutex: Mutex protecting the @dma_buf member.
143 * @size: Size of the dma_buf associated with this object
144 * @real_type: Type of the underlying object. Needed since we're setting
145 * the value of @base::object_type to ttm_prime_type
146 * @dma_buf: Non ref-coutned pointer to a struct dma_buf created from this
148 * @refcount_release: The underlying object's release method. Needed since
149 * we set @base::refcount_release to our own release method.
152 struct ttm_prime_object {
153 struct ttm_base_object base;
156 enum ttm_object_type real_type;
157 struct dma_buf *dma_buf;
158 void (*refcount_release) (struct ttm_base_object **);
162 * ttm_base_object_init
164 * @tfile: Pointer to a struct ttm_object_file.
165 * @base: The struct ttm_base_object to initialize.
166 * @shareable: This object is shareable with other applcations.
167 * (different @tfile pointers.)
168 * @type: The object type.
169 * @refcount_release: See the struct ttm_base_object description.
170 * @ref_obj_release: See the struct ttm_base_object description.
172 * Initializes a struct ttm_base_object.
175 extern int ttm_base_object_init(struct ttm_object_file *tfile,
176 struct ttm_base_object *base,
178 enum ttm_object_type type,
179 void (*refcount_release) (struct ttm_base_object
181 void (*ref_obj_release) (struct ttm_base_object
187 * ttm_base_object_lookup
189 * @tfile: Pointer to a struct ttm_object_file.
192 * Looks up a struct ttm_base_object with the key @key.
195 extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file
196 *tfile, uint32_t key);
199 * ttm_base_object_lookup_for_ref
201 * @tdev: Pointer to a struct ttm_object_device.
204 * Looks up a struct ttm_base_object with the key @key.
205 * This function should only be used when the struct tfile associated with the
206 * caller doesn't yet have a reference to the base object.
209 extern struct ttm_base_object *
210 ttm_base_object_lookup_for_ref(struct ttm_object_device *tdev, uint32_t key);
213 * ttm_base_object_unref
215 * @p_base: Pointer to a pointer referencing a struct ttm_base_object.
217 * Decrements the base object refcount and clears the pointer pointed to by
221 extern void ttm_base_object_unref(struct ttm_base_object **p_base);
224 * ttm_ref_object_add.
226 * @tfile: A struct ttm_object_file representing the application owning the
228 * @base: The base object to reference.
229 * @ref_type: The type of reference.
230 * @existed: Upon completion, indicates that an identical reference object
231 * already existed, and the refcount was upped on that object instead.
233 * Checks that the base object is shareable and adds a ref object to it.
235 * Adding a ref object to a base object is basically like referencing the
236 * base object, but a user-space application holds the reference. When the
237 * file corresponding to @tfile is closed, all its reference objects are
238 * deleted. A reference object can have different types depending on what
239 * it's intended for. It can be refcounting to prevent object destruction,
240 * When user-space takes a lock, it can add a ref object to that lock to
241 * make sure the lock is released if the application dies. A ref object
242 * will hold a single reference on a base object.
244 extern int ttm_ref_object_add(struct ttm_object_file *tfile,
245 struct ttm_base_object *base,
246 enum ttm_ref_type ref_type, bool *existed);
248 * ttm_ref_object_base_unref
250 * @key: Key representing the base object.
251 * @ref_type: Ref type of the ref object to be dereferenced.
253 * Unreference a ref object with type @ref_type
254 * on the base object identified by @key. If there are no duplicate
255 * references, the ref object will be destroyed and the base object
256 * will be unreferenced.
258 extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
260 enum ttm_ref_type ref_type);
263 * ttm_object_file_init - initialize a struct ttm_object file
265 * @tdev: A struct ttm_object device this file is initialized on.
266 * @hash_order: Order of the hash table used to hold the reference objects.
268 * This is typically called by the file_ops::open function.
271 extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device
273 unsigned int hash_order);
276 * ttm_object_file_release - release data held by a ttm_object_file
278 * @p_tfile: Pointer to pointer to the ttm_object_file object to release.
279 * *p_tfile will be set to NULL by this function.
281 * Releases all data associated by a ttm_object_file.
282 * Typically called from file_ops::release. The caller must
283 * ensure that there are no concurrent users of tfile.
286 extern void ttm_object_file_release(struct ttm_object_file **p_tfile);
289 * ttm_object device init - initialize a struct ttm_object_device
291 * @mem_glob: struct ttm_mem_global for memory accounting.
292 * @hash_order: Order of hash table used to hash the base objects.
293 * @ops: DMA buf ops for prime objects of this device.
295 * This function is typically called on device initialization to prepare
296 * data structures needed for ttm base and ref objects.
299 extern struct ttm_object_device *
300 ttm_object_device_init(struct ttm_mem_global *mem_glob,
301 unsigned int hash_order,
302 const struct dma_buf_ops *ops);
305 * ttm_object_device_release - release data held by a ttm_object_device
307 * @p_tdev: Pointer to pointer to the ttm_object_device object to release.
308 * *p_tdev will be set to NULL by this function.
310 * Releases all data associated by a ttm_object_device.
311 * Typically called from driver::unload before the destruction of the
312 * device private data structure.
315 extern void ttm_object_device_release(struct ttm_object_device **p_tdev);
317 #define ttm_base_object_kfree(__object, __base)\
318 kfree_rcu(__object, __base.rhead)
320 extern int ttm_prime_object_init(struct ttm_object_file *tfile,
322 struct ttm_prime_object *prime,
324 enum ttm_object_type type,
325 void (*refcount_release)
326 (struct ttm_base_object **),
327 void (*ref_obj_release)
328 (struct ttm_base_object *,
329 enum ttm_ref_type ref_type));
331 static inline enum ttm_object_type
332 ttm_base_object_type(struct ttm_base_object *base)
334 return (base->object_type == ttm_prime_type) ?
335 container_of(base, struct ttm_prime_object, base)->real_type :
338 extern int ttm_prime_fd_to_handle(struct ttm_object_file *tfile,
339 int fd, u32 *handle);
340 extern int ttm_prime_handle_to_fd(struct ttm_object_file *tfile,
341 uint32_t handle, uint32_t flags,
344 #define ttm_prime_object_kfree(__obj, __prime) \
345 kfree_rcu(__obj, __prime.base.rhead)