drm/ttm: Add user-space objects.

ccflags-y := -Iinclude/drm

ttm-y := ttm_agp_backend.o ttm_memory.o ttm_tt.o ttm_bo.o \

	ttm_bo_util.o ttm_bo_vm.o ttm_module.o ttm_global.o

	ttm_bo_util.o ttm_bo_vm.o ttm_module.o ttm_global.o \

	ttm_object.o

obj-$(CONFIG_DRM_TTM) += ttm.o

/**************************************************************************

 *

 * Copyright (c) 2009 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_ref_object.c

 *

 * Base- and reference object implementation for the various

 * ttm objects. Implements reference counting, minimal security checks

 * and release on file close.

 */

/**

 * struct ttm_object_file

 *

 * @tdev: Pointer to the ttm_object_device.

 *

 * @lock: Lock that protects the ref_list list and the

 * ref_hash hash tables.

 *

 * @ref_list: List of ttm_ref_objects to be destroyed at

 * file release.

 *

 * @ref_hash: Hash tables of ref objects, one per ttm_ref_type,

 * for fast lookup of ref objects given a base object.

 */

#include "ttm/ttm_object.h"

#include "ttm/ttm_module.h"

#include <linux/list.h>

#include <linux/spinlock.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <asm/atomic.h>

struct ttm_object_file {

	struct ttm_object_device *tdev;

	rwlock_t lock;

	struct list_head ref_list;

	struct drm_open_hash ref_hash[TTM_REF_NUM];

	struct kref refcount;

};

/**

 * struct ttm_object_device

 *

 * @object_lock: lock that protects the object_hash hash table.

 *

 * @object_hash: hash table for fast lookup of object global names.

 *

 * @object_count: Per device object count.

 *

 * This is the per-device data structure needed for ttm object management.

 */

struct ttm_object_device {

	rwlock_t object_lock;

	struct drm_open_hash object_hash;

	atomic_t object_count;

	struct ttm_mem_global *mem_glob;

};

/**

 * struct ttm_ref_object

 *

 * @hash: Hash entry for the per-file object reference hash.

 *

 * @head: List entry for the per-file list of ref-objects.

 *

 * @kref: Ref count.

 *

 * @obj: Base object this ref object is referencing.

 *

 * @ref_type: Type of ref object.

 *

 * This is similar to an idr object, but it also has a hash table entry

 * that allows lookup with a pointer to the referenced object as a key. In

 * that way, one can easily detect whether a base object is referenced by

 * a particular ttm_object_file. It also carries a ref count to avoid creating

 * multiple ref objects if a ttm_object_file references the same base

 * object more than once.

 */

struct ttm_ref_object {

	struct drm_hash_item hash;

	struct list_head head;

	struct kref kref;

	struct ttm_base_object *obj;

	enum ttm_ref_type ref_type;

	struct ttm_object_file *tfile;

};

static inline struct ttm_object_file *

ttm_object_file_ref(struct ttm_object_file *tfile)

{

	kref_get(&tfile->refcount);

	return tfile;

}

static void ttm_object_file_destroy(struct kref *kref)

{

	struct ttm_object_file *tfile =

		container_of(kref, struct ttm_object_file, refcount);

	kfree(tfile);

}

static inline void ttm_object_file_unref(struct ttm_object_file **p_tfile)

{

	struct ttm_object_file *tfile = *p_tfile;

	*p_tfile = NULL;

	kref_put(&tfile->refcount, ttm_object_file_destroy);

}

int ttm_base_object_init(struct ttm_object_file *tfile,

			 struct ttm_base_object *base,

			 bool shareable,

			 enum ttm_object_type object_type,

			 void (*refcount_release) (struct ttm_base_object **),

			 void (*ref_obj_release) (struct ttm_base_object *,

						  enum ttm_ref_type ref_type))

{

	struct ttm_object_device *tdev = tfile->tdev;

	int ret;

	base->shareable = shareable;

	base->tfile = ttm_object_file_ref(tfile);

	base->refcount_release = refcount_release;

	base->ref_obj_release = ref_obj_release;

	base->object_type = object_type;

	write_lock(&tdev->object_lock);

	kref_init(&base->refcount);

	ret = drm_ht_just_insert_please(&tdev->object_hash,

					&base->hash,

					(unsigned long)base, 31, 0, 0);

	write_unlock(&tdev->object_lock);

	if (unlikely(ret != 0))

		goto out_err0;

	ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL);

	if (unlikely(ret != 0))

		goto out_err1;

	ttm_base_object_unref(&base);

	return 0;

out_err1:

	(void)drm_ht_remove_item(&tdev->object_hash, &base->hash);

out_err0:

	return ret;

}

EXPORT_SYMBOL(ttm_base_object_init);

static void ttm_release_base(struct kref *kref)

{

	struct ttm_base_object *base =

	    container_of(kref, struct ttm_base_object, refcount);

	struct ttm_object_device *tdev = base->tfile->tdev;

	(void)drm_ht_remove_item(&tdev->object_hash, &base->hash);

	write_unlock(&tdev->object_lock);

	if (base->refcount_release) {

		ttm_object_file_unref(&base->tfile);

		base->refcount_release(&base);

	}

	write_lock(&tdev->object_lock);

}

void ttm_base_object_unref(struct ttm_base_object **p_base)

{

	struct ttm_base_object *base = *p_base;

	struct ttm_object_device *tdev = base->tfile->tdev;

	*p_base = NULL;

	/*

	 * Need to take the lock here to avoid racing with

	 * users trying to look up the object.

	 */

	write_lock(&tdev->object_lock);

	(void)kref_put(&base->refcount, &ttm_release_base);

	write_unlock(&tdev->object_lock);

}

EXPORT_SYMBOL(ttm_base_object_unref);

struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file *tfile,

					       uint32_t key)

{

	struct ttm_object_device *tdev = tfile->tdev;

	struct ttm_base_object *base;

	struct drm_hash_item *hash;

	int ret;

	read_lock(&tdev->object_lock);

	ret = drm_ht_find_item(&tdev->object_hash, key, &hash);

	if (likely(ret == 0)) {

		base = drm_hash_entry(hash, struct ttm_base_object, hash);

		kref_get(&base->refcount);

	}

	read_unlock(&tdev->object_lock);

	if (unlikely(ret != 0))

		return NULL;

	if (tfile != base->tfile && !base->shareable) {

		printk(KERN_ERR TTM_PFX

		       "Attempted access of non-shareable object.\n");

		ttm_base_object_unref(&base);

		return NULL;

	}

	return base;

}

EXPORT_SYMBOL(ttm_base_object_lookup);

int ttm_ref_object_add(struct ttm_object_file *tfile,

		       struct ttm_base_object *base,

		       enum ttm_ref_type ref_type, bool *existed)

{

	struct drm_open_hash *ht = &tfile->ref_hash[ref_type];

	struct ttm_ref_object *ref;

	struct drm_hash_item *hash;

	struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob;

	int ret = -EINVAL;

	if (existed != NULL)

		*existed = true;

	while (ret == -EINVAL) {

		read_lock(&tfile->lock);

		ret = drm_ht_find_item(ht, base->hash.key, &hash);

		if (ret == 0) {

			ref = drm_hash_entry(hash, struct ttm_ref_object, hash);

			kref_get(&ref->kref);

			read_unlock(&tfile->lock);

			break;

		}

		read_unlock(&tfile->lock);

		ret = ttm_mem_global_alloc(mem_glob, sizeof(*ref),

					   false, false);

		if (unlikely(ret != 0))

			return ret;

		ref = kmalloc(sizeof(*ref), GFP_KERNEL);

		if (unlikely(ref == NULL)) {

			ttm_mem_global_free(mem_glob, sizeof(*ref));

			return -ENOMEM;

		}

		ref->hash.key = base->hash.key;

		ref->obj = base;

		ref->tfile = tfile;

		ref->ref_type = ref_type;

		kref_init(&ref->kref);

		write_lock(&tfile->lock);

		ret = drm_ht_insert_item(ht, &ref->hash);

		if (likely(ret == 0)) {

			list_add_tail(&ref->head, &tfile->ref_list);

			kref_get(&base->refcount);

			write_unlock(&tfile->lock);

			if (existed != NULL)

				*existed = false;

			break;

		}

		write_unlock(&tfile->lock);

		BUG_ON(ret != -EINVAL);

		ttm_mem_global_free(mem_glob, sizeof(*ref));

		kfree(ref);

	}

	return ret;

}

EXPORT_SYMBOL(ttm_ref_object_add);

static void ttm_ref_object_release(struct kref *kref)

{

	struct ttm_ref_object *ref =

	    container_of(kref, struct ttm_ref_object, kref);

	struct ttm_base_object *base = ref->obj;

	struct ttm_object_file *tfile = ref->tfile;

	struct drm_open_hash *ht;

	struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob;

	ht = &tfile->ref_hash[ref->ref_type];

	(void)drm_ht_remove_item(ht, &ref->hash);

	list_del(&ref->head);

	write_unlock(&tfile->lock);

	if (ref->ref_type != TTM_REF_USAGE && base->ref_obj_release)

		base->ref_obj_release(base, ref->ref_type);

	ttm_base_object_unref(&ref->obj);

	ttm_mem_global_free(mem_glob, sizeof(*ref));

	kfree(ref);

	write_lock(&tfile->lock);

}

int ttm_ref_object_base_unref(struct ttm_object_file *tfile,

			      unsigned long key, enum ttm_ref_type ref_type)

{

	struct drm_open_hash *ht = &tfile->ref_hash[ref_type];

	struct ttm_ref_object *ref;

	struct drm_hash_item *hash;

	int ret;

	write_lock(&tfile->lock);

	ret = drm_ht_find_item(ht, key, &hash);

	if (unlikely(ret != 0)) {

		write_unlock(&tfile->lock);

		return -EINVAL;

	}

	ref = drm_hash_entry(hash, struct ttm_ref_object, hash);

	kref_put(&ref->kref, ttm_ref_object_release);

	write_unlock(&tfile->lock);

	return 0;

}

EXPORT_SYMBOL(ttm_ref_object_base_unref);

void ttm_object_file_release(struct ttm_object_file **p_tfile)

{

	struct ttm_ref_object *ref;

	struct list_head *list;

	unsigned int i;

	struct ttm_object_file *tfile = *p_tfile;

	*p_tfile = NULL;

	write_lock(&tfile->lock);

	/*

	 * Since we release the lock within the loop, we have to

	 * restart it from the beginning each time.

	 */

	while (!list_empty(&tfile->ref_list)) {

		list = tfile->ref_list.next;

		ref = list_entry(list, struct ttm_ref_object, head);

		ttm_ref_object_release(&ref->kref);

	}

	for (i = 0; i < TTM_REF_NUM; ++i)

		drm_ht_remove(&tfile->ref_hash[i]);

	write_unlock(&tfile->lock);

	ttm_object_file_unref(&tfile);

}

EXPORT_SYMBOL(ttm_object_file_release);

struct ttm_object_file *ttm_object_file_init(struct ttm_object_device *tdev,

					     unsigned int hash_order)

{

	struct ttm_object_file *tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);

	unsigned int i;

	unsigned int j = 0;

	int ret;

	if (unlikely(tfile == NULL))

		return NULL;

	rwlock_init(&tfile->lock);

	tfile->tdev = tdev;

	kref_init(&tfile->refcount);

	INIT_LIST_HEAD(&tfile->ref_list);

	for (i = 0; i < TTM_REF_NUM; ++i) {

		ret = drm_ht_create(&tfile->ref_hash[i], hash_order);

		if (ret) {

			j = i;

			goto out_err;

		}

	}

	return tfile;

out_err:

	for (i = 0; i < j; ++i)

		drm_ht_remove(&tfile->ref_hash[i]);

	kfree(tfile);

	return NULL;

}

EXPORT_SYMBOL(ttm_object_file_init);

struct ttm_object_device *ttm_object_device_init(struct ttm_mem_global

						 *mem_glob,

						 unsigned int hash_order)

{

	struct ttm_object_device *tdev = kmalloc(sizeof(*tdev), GFP_KERNEL);

	int ret;

	if (unlikely(tdev == NULL))

		return NULL;

	tdev->mem_glob = mem_glob;

	rwlock_init(&tdev->object_lock);

	atomic_set(&tdev->object_count, 0);

	ret = drm_ht_create(&tdev->object_hash, hash_order);

	if (likely(ret == 0))

		return tdev;

	kfree(tdev);

	return NULL;

}

EXPORT_SYMBOL(ttm_object_device_init);

void ttm_object_device_release(struct ttm_object_device **p_tdev)

{

	struct ttm_object_device *tdev = *p_tdev;

	*p_tdev = NULL;

	write_lock(&tdev->object_lock);

	drm_ht_remove(&tdev->object_hash);

	write_unlock(&tdev->object_lock);

	kfree(tdev);

}

EXPORT_SYMBOL(ttm_object_device_release);

/**************************************************************************

 *

 * Copyright (c) 2006-2009 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/list.h>

#include "drm_hashtab.h"

#include <linux/kref.h>

#include <ttm/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_driver_type0 = 256,

	ttm_driver_type1

};

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 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);

};

/**

 * 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.

 * Also verifies that the object is visible to the application, by

 * comparing the @tfile argument and checking the object shareable flag.

 */

extern struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file

						      *tfile, uint32_t key);

/**

 * ttm_base_object_unref

 *

 * @p_base: Pointer to a pointer referncing 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.

 *

 * 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);

/**

 * 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

 *

 * @hash_order: Order of hash table used to hash the base objects.

 *

 * 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);

/**

 * 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);

#endif