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* Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
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/*
* 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/list.h>
#include <drm/drm_hashtab.h>
#include <linux/kref.h>
#include <linux/rcupdate.h>
#include <linux/dma-buf.h>
#include "ttm_memory.h"
/**
* enum ttm_ref_type
*
* Describes what type of reference a ref object holds.
*
* TTM_REF_USAGE is a simple refcount on a base object.
*
* TTM_REF_SYNCCPU_READ is a SYNCCPU_READ reference on a
* buffer object.
*
* TTM_REF_SYNCCPU_WRITE is a SYNCCPU_WRITE reference on a
* buffer object.
*
*/
enum ttm_ref_type {
TTM_REF_USAGE,
TTM_REF_SYNCCPU_READ,
TTM_REF_SYNCCPU_WRITE,
TTM_REF_NUM
};
/**
* enum ttm_object_type
*
* One entry per ttm object type.
* Device-specific types should use the
* ttm_driver_typex types.
*/
enum ttm_object_type {
ttm_fence_type,
ttm_buffer_type,
ttm_lock_type,
ttm_prime_type,
ttm_driver_type0 = 256,
ttm_driver_type1,
ttm_driver_type2,
ttm_driver_type3,
ttm_driver_type4,
ttm_driver_type5
};
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 contol and hooks for unref actions.
*/
struct ttm_base_object {
struct rcu_head rhead;
struct drm_hash_item hash;
enum ttm_object_type object_type;
bool shareable;
struct ttm_object_file *tfile;
struct kref refcount;
void (*refcount_release) (struct ttm_base_object **base);
void (*ref_obj_release) (struct ttm_base_object *base,
enum ttm_ref_type ref_type);
};
/**
* 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 {
struct ttm_base_object base;
struct mutex mutex;
size_t size;
enum ttm_object_type real_type;
struct dma_buf *dma_buf;
void (*refcount_release) (struct ttm_base_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 applcations.
* (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
**),
void (*ref_obj_release) (struct ttm_base_object
*,
enum ttm_ref_type
ref_type));
/**
* 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, uint32_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, uint32_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,
enum ttm_ref_type ref_type, bool *existed,
bool require_existed);
extern bool ttm_ref_object_exists(struct ttm_object_file *tfile,
struct ttm_base_object *base);
/**
* 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,
enum ttm_ref_type ref_type);
/**
* ttm_object_file_init - initialize a struct ttm_object file
*
* @tdev: A struct ttm_object device this file is initialized on.
* @hash_order: Order of the hash table used to hold the reference objects.
*
* This is typically called by the file_ops::open function.
*/
extern struct ttm_object_file *ttm_object_file_init(struct ttm_object_device
*tdev,
unsigned int hash_order);
/**
* 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
*
* @mem_glob: struct ttm_mem_global for memory accounting.
* @hash_order: Order of hash table used to hash the base objects.
* @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(struct ttm_mem_global *mem_glob,
unsigned int hash_order,
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)\
kfree_rcu(__object, __base.rhead)
extern int ttm_prime_object_init(struct ttm_object_file *tfile,
size_t size,
struct ttm_prime_object *prime,
bool shareable,
enum ttm_object_type type,
void (*refcount_release)
(struct ttm_base_object **),
void (*ref_obj_release)
(struct ttm_base_object *,
enum ttm_ref_type ref_type));
static inline enum ttm_object_type
ttm_base_object_type(struct ttm_base_object *base)
{
return (base->object_type == ttm_prime_type) ?
container_of(base, struct ttm_prime_object, base)->real_type :
base->object_type;
}
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) \
kfree_rcu(__obj, __prime.base.rhead)
#endif
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