/************************************************************************** * * Copyright (c) 2006-2023 VMware, Inc., Palo Alto, CA., USA * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, sub license, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial portions * of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * USE OR OTHER DEALINGS IN THE SOFTWARE. * **************************************************************************/ /* * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com> */ /** @file ttm_object.h * * Base- and reference object implementation for the various * ttm objects. Implements reference counting, minimal security checks * and release on file close. */ #ifndef _TTM_OBJECT_H_ #define _TTM_OBJECT_H_ #include <linux/dma-buf.h> #include <linux/kref.h> #include <linux/list.h> #include <linux/rcupdate.h> #include <drm/ttm/ttm_bo.h> /** * enum ttm_object_type * * One entry per ttm object type. * Device-specific types should use the * ttm_driver_typex types. */ enum ttm_object_type { … }; struct ttm_object_file; struct ttm_object_device; /** * struct ttm_base_object * * @hash: hash entry for the per-device object hash. * @type: derived type this object is base class for. * @shareable: Other ttm_object_files can access this object. * * @tfile: Pointer to ttm_object_file of the creator. * NULL if the object was not created by a user request. * (kernel object). * * @refcount: Number of references to this object, not * including the hash entry. A reference to a base object can * only be held by a ref object. * * @refcount_release: A function to be called when there are * no more references to this object. This function should * destroy the object (or make sure destruction eventually happens), * and when it is called, the object has * already been taken out of the per-device hash. The parameter * "base" should be set to NULL by the function. * * @ref_obj_release: A function to be called when a reference object * with another ttm_ref_type than TTM_REF_USAGE is deleted. * This function may, for example, release a lock held by a user-space * process. * * This struct is intended to be used as a base struct for objects that * are visible to user-space. It provides a global name, race-safe * access and refcounting, minimal access control and hooks for unref actions. */ struct ttm_base_object { … }; /** * struct ttm_prime_object - Modified base object that is prime-aware * * @base: struct ttm_base_object that we derive from * @mutex: Mutex protecting the @dma_buf member. * @size: Size of the dma_buf associated with this object * @real_type: Type of the underlying object. Needed since we're setting * the value of @base::object_type to ttm_prime_type * @dma_buf: Non ref-coutned pointer to a struct dma_buf created from this * object. * @refcount_release: The underlying object's release method. Needed since * we set @base::refcount_release to our own release method. */ struct ttm_prime_object { … }; /** * ttm_base_object_init * * @tfile: Pointer to a struct ttm_object_file. * @base: The struct ttm_base_object to initialize. * @shareable: This object is shareable with other applications. * (different @tfile pointers.) * @type: The object type. * @refcount_release: See the struct ttm_base_object description. * @ref_obj_release: See the struct ttm_base_object description. * * Initializes a struct ttm_base_object. */ extern int ttm_base_object_init(struct ttm_object_file *tfile, struct ttm_base_object *base, bool shareable, enum ttm_object_type type, void (*refcount_release) (struct ttm_base_object **)); /** * ttm_base_object_lookup * * @tfile: Pointer to a struct ttm_object_file. * @key: Hash key * * Looks up a struct ttm_base_object with the key @key. */ extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file *tfile, uint64_t key); /** * ttm_base_object_lookup_for_ref * * @tdev: Pointer to a struct ttm_object_device. * @key: Hash key * * Looks up a struct ttm_base_object with the key @key. * This function should only be used when the struct tfile associated with the * caller doesn't yet have a reference to the base object. */ extern struct ttm_base_object * ttm_base_object_lookup_for_ref(struct ttm_object_device *tdev, uint64_t key); /** * ttm_base_object_unref * * @p_base: Pointer to a pointer referencing a struct ttm_base_object. * * Decrements the base object refcount and clears the pointer pointed to by * p_base. */ extern void ttm_base_object_unref(struct ttm_base_object **p_base); /** * ttm_ref_object_add. * * @tfile: A struct ttm_object_file representing the application owning the * ref_object. * @base: The base object to reference. * @ref_type: The type of reference. * @existed: Upon completion, indicates that an identical reference object * already existed, and the refcount was upped on that object instead. * @require_existed: Fail with -EPERM if an identical ref object didn't * already exist. * * Checks that the base object is shareable and adds a ref object to it. * * Adding a ref object to a base object is basically like referencing the * base object, but a user-space application holds the reference. When the * file corresponding to @tfile is closed, all its reference objects are * deleted. A reference object can have different types depending on what * it's intended for. It can be refcounting to prevent object destruction, * When user-space takes a lock, it can add a ref object to that lock to * make sure the lock is released if the application dies. A ref object * will hold a single reference on a base object. */ extern int ttm_ref_object_add(struct ttm_object_file *tfile, struct ttm_base_object *base, bool *existed, bool require_existed); /** * ttm_ref_object_base_unref * * @key: Key representing the base object. * @ref_type: Ref type of the ref object to be dereferenced. * * Unreference a ref object with type @ref_type * on the base object identified by @key. If there are no duplicate * references, the ref object will be destroyed and the base object * will be unreferenced. */ extern int ttm_ref_object_base_unref(struct ttm_object_file *tfile, unsigned long key); /** * ttm_object_file_init - initialize a struct ttm_object file * * @tdev: A struct ttm_object device this file is initialized on. * * This is typically called by the file_ops::open function. */ extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device *tdev); /** * ttm_object_file_release - release data held by a ttm_object_file * * @p_tfile: Pointer to pointer to the ttm_object_file object to release. * *p_tfile will be set to NULL by this function. * * Releases all data associated by a ttm_object_file. * Typically called from file_ops::release. The caller must * ensure that there are no concurrent users of tfile. */ extern void ttm_object_file_release(struct ttm_object_file **p_tfile); /** * ttm_object device init - initialize a struct ttm_object_device * * @ops: DMA buf ops for prime objects of this device. * * This function is typically called on device initialization to prepare * data structures needed for ttm base and ref objects. */ extern struct ttm_object_device * ttm_object_device_init(const struct dma_buf_ops *ops); /** * ttm_object_device_release - release data held by a ttm_object_device * * @p_tdev: Pointer to pointer to the ttm_object_device object to release. * *p_tdev will be set to NULL by this function. * * Releases all data associated by a ttm_object_device. * Typically called from driver::unload before the destruction of the * device private data structure. */ extern void ttm_object_device_release(struct ttm_object_device **p_tdev); #define ttm_base_object_kfree(__object, __base) … extern int ttm_prime_object_init(struct ttm_object_file *tfile, size_t size, struct ttm_prime_object *prime, enum ttm_object_type type, void (*refcount_release) (struct ttm_base_object **)); static inline enum ttm_object_type ttm_base_object_type(struct ttm_base_object *base) { … } extern int ttm_prime_fd_to_handle(struct ttm_object_file *tfile, int fd, u32 *handle); extern int ttm_prime_handle_to_fd(struct ttm_object_file *tfile, uint32_t handle, uint32_t flags, int *prime_fd); #define ttm_prime_object_kfree(__obj, __prime) … static inline int ttm_bo_wait(struct ttm_buffer_object *bo, bool intr, bool no_wait) { … } #endif
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