1 /* lock.c -- IOCTLs for locking -*- linux-c -*-
2 * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
5 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
6 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
9 * Permission is hereby granted, free of charge, to any person obtaining a
10 * copy of this software and associated documentation files (the "Software"),
11 * to deal in the Software without restriction, including without limitation
12 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13 * and/or sell copies of the Software, and to permit persons to whom the
14 * Software is furnished to do so, subject to the following conditions:
16 * The above copyright notice and this permission notice (including the next
17 * paragraph) shall be included in all copies or substantial portions of the
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
24 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
25 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
26 * OTHER DEALINGS IN THE SOFTWARE.
29 * Rickard E. (Rik) Faith <faith@valinux.com>
30 * Gareth Hughes <gareth@valinux.com>
35 #include "dev/drm/drmP.h"
37 int drm_lock_take(__volatile__ unsigned int *lock, unsigned int context)
39 unsigned int old, new;
43 if (old & _DRM_LOCK_HELD) new = old | _DRM_LOCK_CONT;
44 else new = context | _DRM_LOCK_HELD;
45 } while (!atomic_cmpset_int(lock, old, new));
47 if (_DRM_LOCKING_CONTEXT(old) == context) {
48 if (old & _DRM_LOCK_HELD) {
49 if (context != DRM_KERNEL_CONTEXT) {
50 DRM_ERROR("%d holds heavyweight lock\n",
56 if (new == (context | _DRM_LOCK_HELD)) {
63 /* This takes a lock forcibly and hands it to context. Should ONLY be used
64 inside *_unlock to give lock to kernel before calling *_dma_schedule. */
65 int drm_lock_transfer(drm_device_t *dev,
66 __volatile__ unsigned int *lock, unsigned int context)
68 unsigned int old, new;
70 dev->lock.filp = NULL;
73 new = context | _DRM_LOCK_HELD;
74 } while (!atomic_cmpset_int(lock, old, new));
79 int drm_lock_free(drm_device_t *dev,
80 __volatile__ unsigned int *lock, unsigned int context)
82 unsigned int old, new;
84 dev->lock.filp = NULL;
88 } while (!atomic_cmpset_int(lock, old, new));
90 if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) {
91 DRM_ERROR("%d freed heavyweight lock held by %d\n",
92 context, _DRM_LOCKING_CONTEXT(old));
95 DRM_WAKEUP_INT((void *)&dev->lock.lock_queue);
99 int drm_lock(DRM_IOCTL_ARGS)
105 DRM_COPY_FROM_USER_IOCTL(lock, (drm_lock_t *)data, sizeof(lock));
107 if (lock.context == DRM_KERNEL_CONTEXT) {
108 DRM_ERROR("Process %d using kernel context %d\n",
109 DRM_CURRENTPID, lock.context);
113 DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n",
114 lock.context, DRM_CURRENTPID, dev->lock.hw_lock->lock, lock.flags);
116 if (dev->use_dma_queue && lock.context < 0)
121 if (drm_lock_take(&dev->lock.hw_lock->lock, lock.context)) {
122 dev->lock.filp = (void *)(uintptr_t)DRM_CURRENTPID;
123 dev->lock.lock_time = jiffies;
124 atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);
125 break; /* Got lock */
129 #if defined(__FreeBSD__) && __FreeBSD_version > 500000
130 ret = msleep((void *)&dev->lock.lock_queue, &dev->dev_lock,
131 PZERO | PCATCH, "drmlk2", 0);
133 ret = tsleep((void *)&dev->lock.lock_queue, PZERO | PCATCH,
140 DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock");
145 /* XXX: Add signal blocking here */
147 if (dev->dma_quiescent != NULL && (lock.flags & _DRM_LOCK_QUIESCENT))
148 dev->dma_quiescent(dev);
153 int drm_unlock(DRM_IOCTL_ARGS)
158 DRM_COPY_FROM_USER_IOCTL(lock, (drm_lock_t *)data, sizeof(lock));
160 if (lock.context == DRM_KERNEL_CONTEXT) {
161 DRM_ERROR("Process %d using kernel context %d\n",
162 DRM_CURRENTPID, lock.context);
166 atomic_inc(&dev->counts[_DRM_STAT_UNLOCKS]);
169 drm_lock_transfer(dev, &dev->lock.hw_lock->lock, DRM_KERNEL_CONTEXT);
171 if (drm_lock_free(dev, &dev->lock.hw_lock->lock, DRM_KERNEL_CONTEXT)) {