patch-2.4.8 linux/drivers/char/drm/lock.c
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- Lines: 253
- Date:
Wed Dec 31 16:00:00 1969
- Orig file:
v2.4.7/linux/drivers/char/drm/lock.c
- Orig date:
Sun Oct 1 20:00:00 2000
diff -u --recursive --new-file v2.4.7/linux/drivers/char/drm/lock.c linux/drivers/char/drm/lock.c
@@ -1,252 +0,0 @@
-/* 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;
-}
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