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authorReinhard Tartler <siretart@tauware.de>2011-10-10 17:43:39 +0200
committerReinhard Tartler <siretart@tauware.de>2011-10-10 17:43:39 +0200
commitf4092abdf94af6a99aff944d6264bc1284e8bdd4 (patch)
tree2ac1c9cc16ceb93edb2c4382c088dac5aeafdf0f /nx-X11/extras/drm/linux/drm_lock.h
parenta840692edc9c6d19cd7c057f68e39c7d95eb767d (diff)
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Imported nx-X11-3.1.0-1.tar.gznx-X11/3.1.0-1
Summary: Imported nx-X11-3.1.0-1.tar.gz Keywords: Imported nx-X11-3.1.0-1.tar.gz into Git repository
Diffstat (limited to 'nx-X11/extras/drm/linux/drm_lock.h')
-rw-r--r--nx-X11/extras/drm/linux/drm_lock.h168
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diff --git a/nx-X11/extras/drm/linux/drm_lock.h b/nx-X11/extras/drm/linux/drm_lock.h
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+/**
+ * \file drm_lock.h
+ * IOCTLs for locking
+ *
+ * \author Rickard E. (Rik) Faith <faith@valinux.com>
+ * \author Gareth Hughes <gareth@valinux.com>
+ */
+
+/*
+ * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.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
+ * VA LINUX SYSTEMS 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.
+ */
+
+#include "drmP.h"
+
+/** No-op ioctl. */
+int DRM(noop)(struct inode *inode, struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ DRM_DEBUG("\n");
+ return 0;
+}
+
+/**
+ * Take the heavyweight lock.
+ *
+ * \param lock lock pointer.
+ * \param context locking context.
+ * \return one if the lock is held, or zero otherwise.
+ *
+ * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction.
+ */
+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.
+ *
+ * \param dev DRM device.
+ * \param lock lock pointer.
+ * \param context locking context.
+ * \return always one.
+ *
+ * Resets the lock file pointer.
+ * Marks the lock as held by the given context, via the \p cmpxchg instruction.
+ */
+int DRM(lock_transfer)(drm_device_t *dev,
+ __volatile__ unsigned int *lock, unsigned int context)
+{
+ unsigned int old, new, prev;
+
+ dev->lock.filp = NULL;
+ do {
+ old = *lock;
+ new = context | _DRM_LOCK_HELD;
+ prev = cmpxchg(lock, old, new);
+ } while (prev != old);
+ return 1;
+}
+
+/**
+ * Free lock.
+ *
+ * \param dev DRM device.
+ * \param lock lock.
+ * \param context context.
+ *
+ * Resets the lock file pointer.
+ * Marks the lock as not held, via the \p cmpxchg instruction. Wakes any task
+ * waiting on the lock queue.
+ */
+int DRM(lock_free)(drm_device_t *dev,
+ __volatile__ unsigned int *lock, unsigned int context)
+{
+ unsigned int old, new, prev;
+
+ dev->lock.filp = NULL;
+ 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\n",
+ context,
+ _DRM_LOCKING_CONTEXT(old));
+ return 1;
+ }
+ wake_up_interruptible(&dev->lock.lock_queue);
+ return 0;
+}
+
+/**
+ * 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.
+ *
+ * \param priv pointer to a drm_sigdata structure.
+ * \return one if the signal should be delivered normally, or zero 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 (!s->lock || !_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;
+}