/* lock.c -- IOCTLs for locking -*- linux-c -*- * Created: Tue Feb  2 08:37:54 1999 by faith@precisioninsight.com * * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. * 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, sublicense, * 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 NONINFRINGEMENT.  IN NO EVENT SHALL * PRECISION INSIGHT 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: *    Rickard E. (Rik) Faith <faith@valinux.com> * */#define __NO_VERSION__#include "drmP.h"int drm_block(struct inode *inode, struct file *filp, unsigned int cmd,	      unsigned long arg){	DRM_DEBUG("\n");	return 0;}int drm_unblock(struct inode *inode, struct file *filp, unsigned int cmd,		unsigned long arg){	DRM_DEBUG("\n");	return 0;}int drm_lock_take(__volatile__ unsigned int *lock, unsigned int context){	unsigned int old, new, prev;	do {		old = *lock;		if (old & _DRM_LOCK_HELD) new = old | _DRM_LOCK_CONT;		else			  new = context | _DRM_LOCK_HELD;		prev = cmpxchg(lock, old, new);	} while (prev != old);	if (_DRM_LOCKING_CONTEXT(old) == context) {		if (old & _DRM_LOCK_HELD) {			if (context != DRM_KERNEL_CONTEXT) {				DRM_ERROR("%d holds heavyweight lock\n",					  context);			}			return 0;		}	}	if (new == (context | _DRM_LOCK_HELD)) {				/* Have lock */		return 1;	}	return 0;}/* This takes a lock forcibly and hands it to context.	Should ONLY be used   inside *_unlock to give lock to kernel before calling *_dma_schedule. */int drm_lock_transfer(drm_device_t *dev,		      __volatile__ unsigned int *lock, unsigned int context){	unsigned int old, new, prev;	dev->lock.pid = 0;	do {		old  = *lock;		new  = context | _DRM_LOCK_HELD;		prev = cmpxchg(lock, old, new);	} while (prev != old);	return 1;}int drm_lock_free(drm_device_t *dev,		  __volatile__ unsigned int *lock, unsigned int context){	unsigned int old, new, prev;	pid_t        pid = dev->lock.pid;	dev->lock.pid = 0;	do {		old  = *lock;		new  = 0;		prev = cmpxchg(lock, old, new);	} while (prev != old);	if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) {		DRM_ERROR("%d freed heavyweight lock held by %d (pid %d)\n",			  context,			  _DRM_LOCKING_CONTEXT(old),			  pid);		return 1;	}	wake_up_interruptible(&dev->lock.lock_queue);	return 0;}static int drm_flush_queue(drm_device_t *dev, int context){	DECLARE_WAITQUEUE(entry, current);	int		  ret	= 0;	drm_queue_t	  *q	= dev->queuelist[context];		DRM_DEBUG("\n");		atomic_inc(&q->use_count);	if (atomic_read(&q->use_count) > 1) {		atomic_inc(&q->block_write);		add_wait_queue(&q->flush_queue, &entry);		atomic_inc(&q->block_count);		for (;;) {			current->state = TASK_INTERRUPTIBLE;			if (!DRM_BUFCOUNT(&q->waitlist)) break;			schedule();			if (signal_pending(current)) {				ret = -EINTR; /* Can't restart */				break;			}		}		atomic_dec(&q->block_count);		current->state = TASK_RUNNING;		remove_wait_queue(&q->flush_queue, &entry);	}	atomic_dec(&q->use_count);	atomic_inc(&q->total_flushed);						/* NOTE: block_write is still incremented!				   Use drm_flush_unlock_queue to decrement. */	return ret;}static int drm_flush_unblock_queue(drm_device_t *dev, int context){	drm_queue_t	  *q	= dev->queuelist[context];		DRM_DEBUG("\n");		atomic_inc(&q->use_count);	if (atomic_read(&q->use_count) > 1) {		if (atomic_read(&q->block_write)) {			atomic_dec(&q->block_write);			wake_up_interruptible(&q->write_queue);		}	}	atomic_dec(&q->use_count);	return 0;}int drm_flush_block_and_flush(drm_device_t *dev, int context,			      drm_lock_flags_t flags){	int ret = 0;	int i;		DRM_DEBUG("\n");		if (flags & _DRM_LOCK_FLUSH) {		ret = drm_flush_queue(dev, DRM_KERNEL_CONTEXT);		if (!ret) ret = drm_flush_queue(dev, context);	}	if (flags & _DRM_LOCK_FLUSH_ALL) {		for (i = 0; !ret && i < dev->queue_count; i++) {			ret = drm_flush_queue(dev, i);		}	}	return ret;}int drm_flush_unblock(drm_device_t *dev, int context, drm_lock_flags_t flags){	int ret = 0;	int i;		DRM_DEBUG("\n");		if (flags & _DRM_LOCK_FLUSH) {		ret = drm_flush_unblock_queue(dev, DRM_KERNEL_CONTEXT);		if (!ret) ret = drm_flush_unblock_queue(dev, context);	}	if (flags & _DRM_LOCK_FLUSH_ALL) {		for (i = 0; !ret && i < dev->queue_count; i++) {			ret = drm_flush_unblock_queue(dev, i);		}	}			return ret;}int drm_finish(struct inode *inode, struct file *filp, unsigned int cmd,	       unsigned long arg){	drm_file_t	  *priv	  = filp->private_data;	drm_device_t	  *dev	  = priv->dev;	int		  ret	  = 0;	drm_lock_t	  lock;	DRM_DEBUG("\n");	if (copy_from_user(&lock, (drm_lock_t *)arg, sizeof(lock)))		return -EFAULT;	ret = drm_flush_block_and_flush(dev, lock.context, lock.flags);	drm_flush_unblock(dev, lock.context, lock.flags);	return ret;}/* If we get here, it means that the process has called DRM_IOCTL_LOCK   without calling DRM_IOCTL_UNLOCK.      If the lock is not held, then let the signal proceed as usual.      If the lock is held, then set the contended flag and keep the signal   blocked.      Return 1 if the signal should be delivered normally.   Return 0 if the signal should be blocked.  */int drm_notifier(void *priv){	drm_sigdata_t *s = (drm_sigdata_t *)priv;	unsigned int  old, new, prev;				/* Allow signal delivery if lock isn't held */	if (!_DRM_LOCK_IS_HELD(s->lock->lock)	    || _DRM_LOCKING_CONTEXT(s->lock->lock) != s->context) return 1;					/* Otherwise, set flag to force call to                                   drmUnlock */	do {		old  = s->lock->lock;		new  = old | _DRM_LOCK_CONT;		prev = cmpxchg(&s->lock->lock, old, new);	} while (prev != old);	return 0;}