forked from KolibriOS/kolibrios
248 lines
7.0 KiB
C
248 lines
7.0 KiB
C
/**************************************************************************
|
|
*
|
|
* Copyright (c) 2007-2009 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_lock.h
|
|
* This file implements a simple replacement for the buffer manager use
|
|
* of the DRM heavyweight hardware lock.
|
|
* The lock is a read-write lock. Taking it in read mode and write mode
|
|
* is relatively fast, and intended for in-kernel use only.
|
|
*
|
|
* The vt mode is used only when there is a need to block all
|
|
* user-space processes from validating buffers.
|
|
* It's allowed to leave kernel space with the vt lock held.
|
|
* If a user-space process dies while having the vt-lock,
|
|
* it will be released during the file descriptor release. The vt lock
|
|
* excludes write lock and read lock.
|
|
*
|
|
* The suspend mode is used to lock out all TTM users when preparing for
|
|
* and executing suspend operations.
|
|
*
|
|
*/
|
|
|
|
#ifndef _TTM_LOCK_H_
|
|
#define _TTM_LOCK_H_
|
|
|
|
#include <ttm/ttm_object.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/atomic.h>
|
|
|
|
/**
|
|
* struct ttm_lock
|
|
*
|
|
* @base: ttm base object used solely to release the lock if the client
|
|
* holding the lock dies.
|
|
* @queue: Queue for processes waiting for lock change-of-status.
|
|
* @lock: Spinlock protecting some lock members.
|
|
* @rw: Read-write lock counter. Protected by @lock.
|
|
* @flags: Lock state. Protected by @lock.
|
|
* @kill_takers: Boolean whether to kill takers of the lock.
|
|
* @signal: Signal to send when kill_takers is true.
|
|
*/
|
|
|
|
struct ttm_lock {
|
|
struct ttm_base_object base;
|
|
wait_queue_head_t queue;
|
|
spinlock_t lock;
|
|
int32_t rw;
|
|
uint32_t flags;
|
|
bool kill_takers;
|
|
int signal;
|
|
struct ttm_object_file *vt_holder;
|
|
};
|
|
|
|
|
|
/**
|
|
* ttm_lock_init
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
* Initializes the lock.
|
|
*/
|
|
extern void ttm_lock_init(struct ttm_lock *lock);
|
|
|
|
/**
|
|
* ttm_read_unlock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
*
|
|
* Releases a read lock.
|
|
*/
|
|
extern void ttm_read_unlock(struct ttm_lock *lock);
|
|
|
|
/**
|
|
* ttm_read_lock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
* @interruptible: Interruptible sleeping while waiting for a lock.
|
|
*
|
|
* Takes the lock in read mode.
|
|
* Returns:
|
|
* -ERESTARTSYS If interrupted by a signal and interruptible is true.
|
|
*/
|
|
extern int ttm_read_lock(struct ttm_lock *lock, bool interruptible);
|
|
|
|
/**
|
|
* ttm_read_trylock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
* @interruptible: Interruptible sleeping while waiting for a lock.
|
|
*
|
|
* Tries to take the lock in read mode. If the lock is already held
|
|
* in write mode, the function will return -EBUSY. If the lock is held
|
|
* in vt or suspend mode, the function will sleep until these modes
|
|
* are unlocked.
|
|
*
|
|
* Returns:
|
|
* -EBUSY The lock was already held in write mode.
|
|
* -ERESTARTSYS If interrupted by a signal and interruptible is true.
|
|
*/
|
|
extern int ttm_read_trylock(struct ttm_lock *lock, bool interruptible);
|
|
|
|
/**
|
|
* ttm_write_unlock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
*
|
|
* Releases a write lock.
|
|
*/
|
|
extern void ttm_write_unlock(struct ttm_lock *lock);
|
|
|
|
/**
|
|
* ttm_write_lock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
* @interruptible: Interruptible sleeping while waiting for a lock.
|
|
*
|
|
* Takes the lock in write mode.
|
|
* Returns:
|
|
* -ERESTARTSYS If interrupted by a signal and interruptible is true.
|
|
*/
|
|
extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
|
|
|
|
/**
|
|
* ttm_lock_downgrade
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
*
|
|
* Downgrades a write lock to a read lock.
|
|
*/
|
|
extern void ttm_lock_downgrade(struct ttm_lock *lock);
|
|
|
|
/**
|
|
* ttm_suspend_lock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
*
|
|
* Takes the lock in suspend mode. Excludes read and write mode.
|
|
*/
|
|
extern void ttm_suspend_lock(struct ttm_lock *lock);
|
|
|
|
/**
|
|
* ttm_suspend_unlock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
*
|
|
* Releases a suspend lock
|
|
*/
|
|
extern void ttm_suspend_unlock(struct ttm_lock *lock);
|
|
|
|
/**
|
|
* ttm_vt_lock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
* @interruptible: Interruptible sleeping while waiting for a lock.
|
|
* @tfile: Pointer to a struct ttm_object_file to register the lock with.
|
|
*
|
|
* Takes the lock in vt mode.
|
|
* Returns:
|
|
* -ERESTARTSYS If interrupted by a signal and interruptible is true.
|
|
* -ENOMEM: Out of memory when locking.
|
|
*/
|
|
extern int ttm_vt_lock(struct ttm_lock *lock, bool interruptible,
|
|
struct ttm_object_file *tfile);
|
|
|
|
/**
|
|
* ttm_vt_unlock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
*
|
|
* Releases a vt lock.
|
|
* Returns:
|
|
* -EINVAL If the lock was not held.
|
|
*/
|
|
extern int ttm_vt_unlock(struct ttm_lock *lock);
|
|
|
|
/**
|
|
* ttm_write_unlock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
*
|
|
* Releases a write lock.
|
|
*/
|
|
extern void ttm_write_unlock(struct ttm_lock *lock);
|
|
|
|
/**
|
|
* ttm_write_lock
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
* @interruptible: Interruptible sleeping while waiting for a lock.
|
|
*
|
|
* Takes the lock in write mode.
|
|
* Returns:
|
|
* -ERESTARTSYS If interrupted by a signal and interruptible is true.
|
|
*/
|
|
extern int ttm_write_lock(struct ttm_lock *lock, bool interruptible);
|
|
|
|
/**
|
|
* ttm_lock_set_kill
|
|
*
|
|
* @lock: Pointer to a struct ttm_lock
|
|
* @val: Boolean whether to kill processes taking the lock.
|
|
* @signal: Signal to send to the process taking the lock.
|
|
*
|
|
* The kill-when-taking-lock functionality is used to kill processes that keep
|
|
* on using the TTM functionality when its resources has been taken down, for
|
|
* example when the X server exits. A typical sequence would look like this:
|
|
* - X server takes lock in write mode.
|
|
* - ttm_lock_set_kill() is called with @val set to true.
|
|
* - As part of X server exit, TTM resources are taken down.
|
|
* - X server releases the lock on file release.
|
|
* - Another dri client wants to render, takes the lock and is killed.
|
|
*
|
|
*/
|
|
static inline void ttm_lock_set_kill(struct ttm_lock *lock, bool val,
|
|
int signal)
|
|
{
|
|
lock->kill_takers = val;
|
|
if (val)
|
|
lock->signal = signal;
|
|
}
|
|
|
|
#endif
|