mirror of
https://github.com/torvalds/linux.git
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1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
141 lines
3.9 KiB
C
141 lines
3.9 KiB
C
/* lock.c -- IOCTLs for locking -*- linux-c -*-
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* Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
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*
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* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
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* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
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* All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*
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* Authors:
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* Rickard E. (Rik) Faith <faith@valinux.com>
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* Gareth Hughes <gareth@valinux.com>
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*/
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/* Gamma-specific code extracted from drm_lock.h:
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*/
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static int DRM(flush_queue)(drm_device_t *dev, int context)
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{
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DECLARE_WAITQUEUE(entry, current);
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int ret = 0;
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drm_queue_t *q = dev->queuelist[context];
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DRM_DEBUG("\n");
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atomic_inc(&q->use_count);
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if (atomic_read(&q->use_count) > 1) {
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atomic_inc(&q->block_write);
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add_wait_queue(&q->flush_queue, &entry);
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atomic_inc(&q->block_count);
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for (;;) {
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current->state = TASK_INTERRUPTIBLE;
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if (!DRM_BUFCOUNT(&q->waitlist)) break;
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schedule();
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if (signal_pending(current)) {
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ret = -EINTR; /* Can't restart */
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break;
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}
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}
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atomic_dec(&q->block_count);
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current->state = TASK_RUNNING;
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remove_wait_queue(&q->flush_queue, &entry);
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}
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atomic_dec(&q->use_count);
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/* NOTE: block_write is still incremented!
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Use drm_flush_unlock_queue to decrement. */
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return ret;
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}
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static int DRM(flush_unblock_queue)(drm_device_t *dev, int context)
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{
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drm_queue_t *q = dev->queuelist[context];
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DRM_DEBUG("\n");
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atomic_inc(&q->use_count);
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if (atomic_read(&q->use_count) > 1) {
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if (atomic_read(&q->block_write)) {
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atomic_dec(&q->block_write);
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wake_up_interruptible(&q->write_queue);
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}
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}
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atomic_dec(&q->use_count);
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return 0;
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}
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int DRM(flush_block_and_flush)(drm_device_t *dev, int context,
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drm_lock_flags_t flags)
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{
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int ret = 0;
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int i;
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DRM_DEBUG("\n");
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if (flags & _DRM_LOCK_FLUSH) {
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ret = DRM(flush_queue)(dev, DRM_KERNEL_CONTEXT);
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if (!ret) ret = DRM(flush_queue)(dev, context);
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}
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if (flags & _DRM_LOCK_FLUSH_ALL) {
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for (i = 0; !ret && i < dev->queue_count; i++) {
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ret = DRM(flush_queue)(dev, i);
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}
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}
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return ret;
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}
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int DRM(flush_unblock)(drm_device_t *dev, int context, drm_lock_flags_t flags)
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{
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int ret = 0;
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int i;
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DRM_DEBUG("\n");
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if (flags & _DRM_LOCK_FLUSH) {
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ret = DRM(flush_unblock_queue)(dev, DRM_KERNEL_CONTEXT);
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if (!ret) ret = DRM(flush_unblock_queue)(dev, context);
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}
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if (flags & _DRM_LOCK_FLUSH_ALL) {
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for (i = 0; !ret && i < dev->queue_count; i++) {
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ret = DRM(flush_unblock_queue)(dev, i);
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}
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}
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return ret;
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}
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int DRM(finish)(struct inode *inode, struct file *filp, unsigned int cmd,
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unsigned long arg)
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{
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drm_file_t *priv = filp->private_data;
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drm_device_t *dev = priv->dev;
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int ret = 0;
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drm_lock_t lock;
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DRM_DEBUG("\n");
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if (copy_from_user(&lock, (drm_lock_t __user *)arg, sizeof(lock)))
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return -EFAULT;
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ret = DRM(flush_block_and_flush)(dev, lock.context, lock.flags);
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DRM(flush_unblock)(dev, lock.context, lock.flags);
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return ret;
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}
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