WebSVN – Kolibri OS – Blame – /drivers/include/drm/ttm/ttm_lock.h

Rev	Author	Line No.	Line
3391	Serge	1	/**************************************************************************
		2	*
		3	* Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
		4	* All Rights Reserved.
		5	*
		6	* Permission is hereby granted, free of charge, to any person obtaining a
		7	* copy of this software and associated documentation files (the
		8	* "Software"), to deal in the Software without restriction, including
		9	* without limitation the rights to use, copy, modify, merge, publish,
		10	* distribute, sub license, and/or sell copies of the Software, and to
		11	* permit persons to whom the Software is furnished to do so, subject to
		12	* the following conditions:
		13	*
		14	* The above copyright notice and this permission notice (including the
		15	* next paragraph) shall be included in all copies or substantial portions
		16	* of the Software.
		17	*
		18	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
		19	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
		20	* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
		21	* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
		22	* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
		23	* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
		24	* USE OR OTHER DEALINGS IN THE SOFTWARE.
		25	*
		26	**************************************************************************/
		27	/*
		28	* Authors: Thomas Hellstrom
		29	*/
		30
		31	/** @file ttm_lock.h
		32	* This file implements a simple replacement for the buffer manager use
		33	* of the DRM heavyweight hardware lock.
		34	* The lock is a read-write lock. Taking it in read mode and write mode
		35	* is relatively fast, and intended for in-kernel use only.
		36	*
		37	* The vt mode is used only when there is a need to block all
		38	* user-space processes from validating buffers.
		39	* It's allowed to leave kernel space with the vt lock held.
		40	* If a user-space process dies while having the vt-lock,
		41	* it will be released during the file descriptor release. The vt lock
		42	* excludes write lock and read lock.
		43	*
		44	* The suspend mode is used to lock out all TTM users when preparing for
		45	* and executing suspend operations.
		46	*
		47	*/
		48
		49	#ifndef _TTM_LOCK_H_
		50	#define _TTM_LOCK_H_
		51
		52	#include
		53	#include
6082	serge	54	#include
3391	Serge	55
		56	/**
		57	* struct ttm_lock
		58	*
		59	* @base: ttm base object used solely to release the lock if the client
		60	* holding the lock dies.
		61	* @queue: Queue for processes waiting for lock change-of-status.
		62	* @lock: Spinlock protecting some lock members.
		63	* @rw: Read-write lock counter. Protected by @lock.
		64	* @flags: Lock state. Protected by @lock.
		65	* @kill_takers: Boolean whether to kill takers of the lock.
		66	* @signal: Signal to send when kill_takers is true.
		67	*/
		68
		69	struct ttm_lock {
		70	struct ttm_base_object base;
		71	wait_queue_head_t queue;
		72	spinlock_t lock;
		73	int32_t rw;
		74	uint32_t flags;
		75	bool kill_takers;
		76	int signal;
		77	struct ttm_object_file *vt_holder;
		78	};
		79
		80
		81	/**
		82	* ttm_lock_init
		83	*
		84	* @lock: Pointer to a struct ttm_lock
		85	* Initializes the lock.
		86	*/
		87	extern void ttm_lock_init(struct ttm_lock *lock);
		88
		89	/**
		90	* ttm_read_unlock
		91	*
		92	* @lock: Pointer to a struct ttm_lock
		93	*
		94	* Releases a read lock.
		95	*/
		96	extern void ttm_read_unlock(struct ttm_lock *lock);
		97
		98	/**
		99	* ttm_read_lock
		100	*
		101	* @lock: Pointer to a struct ttm_lock
		102	* @interruptible: Interruptible sleeping while waiting for a lock.
		103	*
		104	* Takes the lock in read mode.
		105	* Returns:
		106	* -ERESTARTSYS If interrupted by a signal and interruptible is true.
		107	*/
		108	extern int ttm_read_lock(struct ttm_lock *lock, bool interruptible);
		109
		110	/**
		111	* ttm_read_trylock
		112	*
		113	* @lock: Pointer to a struct ttm_lock
		114	* @interruptible: Interruptible sleeping while waiting for a lock.
		115	*
		116	* Tries to take the lock in read mode. If the lock is already held
		117	* in write mode, the function will return -EBUSY. If the lock is held
		118	* in vt or suspend mode, the function will sleep until these modes
		119	* are unlocked.
		120	*
		121	* Returns:
		122	* -EBUSY The lock was already held in write mode.
		123	* -ERESTARTSYS If interrupted by a signal and interruptible is true.
		124	*/
		125	extern int ttm_read_trylock(struct ttm_lock *lock, bool interruptible);
		126
		127	/**
		128	* ttm_write_unlock
		129	*
		130	* @lock: Pointer to a struct ttm_lock
		131	*
		132	* Releases a write lock.
		133	*/
		134	extern void ttm_write_unlock(struct ttm_lock *lock);
		135
		136	/**
		137	* ttm_write_lock
		138	*
		139	* @lock: Pointer to a struct ttm_lock
		140	* @interruptible: Interruptible sleeping while waiting for a lock.
		141	*
		142	* Takes the lock in write mode.
		143	* Returns:
		144	* -ERESTARTSYS If interrupted by a signal and interruptible is true.
		145	*/
		146	extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
		147
		148	/**
		149	* ttm_lock_downgrade
		150	*
		151	* @lock: Pointer to a struct ttm_lock
		152	*
		153	* Downgrades a write lock to a read lock.
		154	*/
		155	extern void ttm_lock_downgrade(struct ttm_lock *lock);
		156
		157	/**
		158	* ttm_suspend_lock
		159	*
		160	* @lock: Pointer to a struct ttm_lock
		161	*
		162	* Takes the lock in suspend mode. Excludes read and write mode.
		163	*/
		164	extern void ttm_suspend_lock(struct ttm_lock *lock);
		165
		166	/**
		167	* ttm_suspend_unlock
		168	*
		169	* @lock: Pointer to a struct ttm_lock
		170	*
		171	* Releases a suspend lock
		172	*/
		173	extern void ttm_suspend_unlock(struct ttm_lock *lock);
		174
		175	/**
		176	* ttm_vt_lock
		177	*
		178	* @lock: Pointer to a struct ttm_lock
		179	* @interruptible: Interruptible sleeping while waiting for a lock.
		180	* @tfile: Pointer to a struct ttm_object_file to register the lock with.
		181	*
		182	* Takes the lock in vt mode.
		183	* Returns:
		184	* -ERESTARTSYS If interrupted by a signal and interruptible is true.
		185	* -ENOMEM: Out of memory when locking.
		186	*/
		187	extern int ttm_vt_lock(struct ttm_lock *lock, bool interruptible,
		188	struct ttm_object_file *tfile);
		189
		190	/**
		191	* ttm_vt_unlock
		192	*
		193	* @lock: Pointer to a struct ttm_lock
		194	*
		195	* Releases a vt lock.
		196	* Returns:
		197	* -EINVAL If the lock was not held.
		198	*/
		199	extern int ttm_vt_unlock(struct ttm_lock *lock);
		200
		201	/**
		202	* ttm_write_unlock
		203	*
		204	* @lock: Pointer to a struct ttm_lock
		205	*
		206	* Releases a write lock.
		207	*/
		208	extern void ttm_write_unlock(struct ttm_lock *lock);
		209
		210	/**
		211	* ttm_write_lock
		212	*
		213	* @lock: Pointer to a struct ttm_lock
		214	* @interruptible: Interruptible sleeping while waiting for a lock.
		215	*
		216	* Takes the lock in write mode.
		217	* Returns:
		218	* -ERESTARTSYS If interrupted by a signal and interruptible is true.
		219	*/
		220	extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
		221
		222	/**
		223	* ttm_lock_set_kill
		224	*
		225	* @lock: Pointer to a struct ttm_lock
		226	* @val: Boolean whether to kill processes taking the lock.
		227	* @signal: Signal to send to the process taking the lock.
		228	*
		229	* The kill-when-taking-lock functionality is used to kill processes that keep
		230	* on using the TTM functionality when its resources has been taken down, for
		231	* example when the X server exits. A typical sequence would look like this:
		232	* - X server takes lock in write mode.
		233	* - ttm_lock_set_kill() is called with @val set to true.
		234	* - As part of X server exit, TTM resources are taken down.
		235	* - X server releases the lock on file release.
		236	* - Another dri client wants to render, takes the lock and is killed.
		237	*
		238	*/
		239	static inline void ttm_lock_set_kill(struct ttm_lock *lock, bool val,
		240	int signal)
		241	{
		242	lock->kill_takers = val;
		243	if (val)
		244	lock->signal = signal;
		245	}
		246
		247	#endif

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(root)/drivers/include/drm/ttm/ttm_lock.h – Rev 6082