Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /** |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 2 | * \file drm_lock.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 3 | * IOCTLs for locking |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 4 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | * \author Rickard E. (Rik) Faith <faith@valinux.com> |
| 6 | * \author Gareth Hughes <gareth@valinux.com> |
| 7 | */ |
| 8 | |
| 9 | /* |
| 10 | * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com |
| 11 | * |
| 12 | * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. |
| 13 | * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. |
| 14 | * All Rights Reserved. |
| 15 | * |
| 16 | * Permission is hereby granted, free of charge, to any person obtaining a |
| 17 | * copy of this software and associated documentation files (the "Software"), |
| 18 | * to deal in the Software without restriction, including without limitation |
| 19 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| 20 | * and/or sell copies of the Software, and to permit persons to whom the |
| 21 | * Software is furnished to do so, subject to the following conditions: |
| 22 | * |
| 23 | * The above copyright notice and this permission notice (including the next |
| 24 | * paragraph) shall be included in all copies or substantial portions of the |
| 25 | * Software. |
| 26 | * |
| 27 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 28 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 29 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 30 | * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR |
| 31 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, |
| 32 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| 33 | * OTHER DEALINGS IN THE SOFTWARE. |
| 34 | */ |
| 35 | |
| 36 | #include "drmP.h" |
| 37 | |
Dave Airlie | c94f702 | 2005-07-07 21:03:38 +1000 | [diff] [blame] | 38 | static int drm_notifier(void *priv); |
| 39 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 40 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | * Lock ioctl. |
| 42 | * |
| 43 | * \param inode device inode. |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 44 | * \param file_priv DRM file private. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | * \param cmd command. |
| 46 | * \param arg user argument, pointing to a drm_lock structure. |
| 47 | * \return zero on success or negative number on failure. |
| 48 | * |
| 49 | * Add the current task to the lock wait queue, and attempt to take to lock. |
| 50 | */ |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 51 | int drm_lock(struct drm_device *dev, void *data, struct drm_file *file_priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 53 | DECLARE_WAITQUEUE(entry, current); |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 54 | struct drm_lock *lock = data; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 55 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 57 | ++file_priv->lock_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 59 | if (lock->context == DRM_KERNEL_CONTEXT) { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 60 | DRM_ERROR("Process %d using kernel context %d\n", |
Pavel Emelyanov | ba25f9d | 2007-10-18 23:40:40 -0700 | [diff] [blame] | 61 | task_pid_nr(current), lock->context); |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 62 | return -EINVAL; |
| 63 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 64 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 65 | DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n", |
Pavel Emelyanov | ba25f9d | 2007-10-18 23:40:40 -0700 | [diff] [blame] | 66 | lock->context, task_pid_nr(current), |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 67 | dev->lock.hw_lock->lock, lock->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | |
| 69 | if (drm_core_check_feature(dev, DRIVER_DMA_QUEUE)) |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 70 | if (lock->context < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | return -EINVAL; |
| 72 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 73 | add_wait_queue(&dev->lock.lock_queue, &entry); |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 74 | spin_lock_bh(&dev->lock.spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 75 | dev->lock.user_waiters++; |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 76 | spin_unlock_bh(&dev->lock.spinlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | for (;;) { |
| 78 | __set_current_state(TASK_INTERRUPTIBLE); |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 79 | if (!dev->lock.hw_lock) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | /* Device has been unregistered */ |
| 81 | ret = -EINTR; |
| 82 | break; |
| 83 | } |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 84 | if (drm_lock_take(&dev->lock, lock->context)) { |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 85 | dev->lock.file_priv = file_priv; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 86 | dev->lock.lock_time = jiffies; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 87 | atomic_inc(&dev->counts[_DRM_STAT_LOCKS]); |
| 88 | break; /* Got lock */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | } |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 90 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | /* Contention */ |
| 92 | schedule(); |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 93 | if (signal_pending(current)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | ret = -ERESTARTSYS; |
| 95 | break; |
| 96 | } |
| 97 | } |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 98 | spin_lock_bh(&dev->lock.spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 99 | dev->lock.user_waiters--; |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 100 | spin_unlock_bh(&dev->lock.spinlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | __set_current_state(TASK_RUNNING); |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 102 | remove_wait_queue(&dev->lock.lock_queue, &entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 104 | DRM_DEBUG("%d %s\n", lock->context, |
| 105 | ret ? "interrupted" : "has lock"); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 106 | if (ret) return ret; |
Dave Airlie | d985c10 | 2006-01-02 21:32:48 +1100 | [diff] [blame] | 107 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 108 | sigemptyset(&dev->sigmask); |
| 109 | sigaddset(&dev->sigmask, SIGSTOP); |
| 110 | sigaddset(&dev->sigmask, SIGTSTP); |
| 111 | sigaddset(&dev->sigmask, SIGTTIN); |
| 112 | sigaddset(&dev->sigmask, SIGTTOU); |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 113 | dev->sigdata.context = lock->context; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 114 | dev->sigdata.lock = dev->lock.hw_lock; |
| 115 | block_all_signals(drm_notifier, &dev->sigdata, &dev->sigmask); |
| 116 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 117 | if (dev->driver->dma_ready && (lock->flags & _DRM_LOCK_READY)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | dev->driver->dma_ready(dev); |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 119 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 120 | if (dev->driver->dma_quiescent && (lock->flags & _DRM_LOCK_QUIESCENT)) |
| 121 | { |
Dave Airlie | d985c10 | 2006-01-02 21:32:48 +1100 | [diff] [blame] | 122 | if (dev->driver->dma_quiescent(dev)) { |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 123 | DRM_DEBUG("%d waiting for DMA quiescent\n", |
| 124 | lock->context); |
Eric Anholt | 20caafa | 2007-08-25 19:22:43 +1000 | [diff] [blame] | 125 | return -EBUSY; |
Dave Airlie | d985c10 | 2006-01-02 21:32:48 +1100 | [diff] [blame] | 126 | } |
| 127 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 128 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 129 | if (dev->driver->kernel_context_switch && |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 130 | dev->last_context != lock->context) { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 131 | dev->driver->kernel_context_switch(dev, dev->last_context, |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 132 | lock->context); |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 133 | } |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 134 | |
Dave Airlie | d985c10 | 2006-01-02 21:32:48 +1100 | [diff] [blame] | 135 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 136 | } |
| 137 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 138 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | * Unlock ioctl. |
| 140 | * |
| 141 | * \param inode device inode. |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 142 | * \param file_priv DRM file private. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | * \param cmd command. |
| 144 | * \param arg user argument, pointing to a drm_lock structure. |
| 145 | * \return zero on success or negative number on failure. |
| 146 | * |
| 147 | * Transfer and free the lock. |
| 148 | */ |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 149 | int drm_unlock(struct drm_device *dev, void *data, struct drm_file *file_priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | { |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 151 | struct drm_lock *lock = data; |
Dave Airlie | 5c2df2b | 2006-10-24 11:36:59 -0700 | [diff] [blame] | 152 | unsigned long irqflags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 154 | if (lock->context == DRM_KERNEL_CONTEXT) { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 155 | DRM_ERROR("Process %d using kernel context %d\n", |
Pavel Emelyanov | ba25f9d | 2007-10-18 23:40:40 -0700 | [diff] [blame] | 156 | task_pid_nr(current), lock->context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | return -EINVAL; |
| 158 | } |
| 159 | |
=?utf-8?q?Michel_D=C3=A4nzer?= | 2e54a00 | 2006-10-24 23:08:16 +1000 | [diff] [blame] | 160 | spin_lock_irqsave(&dev->tasklet_lock, irqflags); |
| 161 | |
| 162 | if (dev->locked_tasklet_func) { |
| 163 | dev->locked_tasklet_func(dev); |
| 164 | |
| 165 | dev->locked_tasklet_func = NULL; |
| 166 | } |
| 167 | |
| 168 | spin_unlock_irqrestore(&dev->tasklet_lock, irqflags); |
| 169 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 170 | atomic_inc(&dev->counts[_DRM_STAT_UNLOCKS]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 171 | |
| 172 | /* kernel_context_switch isn't used by any of the x86 drm |
| 173 | * modules but is required by the Sparc driver. |
| 174 | */ |
| 175 | if (dev->driver->kernel_context_switch_unlock) |
Dave Airlie | 0c4dd90 | 2006-12-19 17:49:44 +1100 | [diff] [blame] | 176 | dev->driver->kernel_context_switch_unlock(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | else { |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 178 | if (drm_lock_free(&dev->lock,lock->context)) { |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 179 | /* FIXME: Should really bail out here. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | } |
| 181 | } |
| 182 | |
| 183 | unblock_all_signals(); |
| 184 | return 0; |
| 185 | } |
| 186 | |
| 187 | /** |
| 188 | * Take the heavyweight lock. |
| 189 | * |
| 190 | * \param lock lock pointer. |
| 191 | * \param context locking context. |
| 192 | * \return one if the lock is held, or zero otherwise. |
| 193 | * |
| 194 | * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction. |
| 195 | */ |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 196 | int drm_lock_take(struct drm_lock_data *lock_data, |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 197 | unsigned int context) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | { |
| 199 | unsigned int old, new, prev; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 200 | volatile unsigned int *lock = &lock_data->hw_lock->lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 202 | spin_lock_bh(&lock_data->spinlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | do { |
| 204 | old = *lock; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 205 | if (old & _DRM_LOCK_HELD) |
| 206 | new = old | _DRM_LOCK_CONT; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 207 | else { |
| 208 | new = context | _DRM_LOCK_HELD | |
| 209 | ((lock_data->user_waiters + lock_data->kernel_waiters > 1) ? |
| 210 | _DRM_LOCK_CONT : 0); |
| 211 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | prev = cmpxchg(lock, old, new); |
| 213 | } while (prev != old); |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 214 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 215 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | if (_DRM_LOCKING_CONTEXT(old) == context) { |
| 217 | if (old & _DRM_LOCK_HELD) { |
| 218 | if (context != DRM_KERNEL_CONTEXT) { |
| 219 | DRM_ERROR("%d holds heavyweight lock\n", |
| 220 | context); |
| 221 | } |
| 222 | return 0; |
| 223 | } |
| 224 | } |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 225 | |
| 226 | if ((_DRM_LOCKING_CONTEXT(new)) == context && (new & _DRM_LOCK_HELD)) { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 227 | /* Have lock */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 228 | return 1; |
| 229 | } |
| 230 | return 0; |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | * This takes a lock forcibly and hands it to context. Should ONLY be used |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 235 | * inside *_unlock to give lock to kernel before calling *_dma_schedule. |
| 236 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | * \param dev DRM device. |
| 238 | * \param lock lock pointer. |
| 239 | * \param context locking context. |
| 240 | * \return always one. |
| 241 | * |
| 242 | * Resets the lock file pointer. |
| 243 | * Marks the lock as held by the given context, via the \p cmpxchg instruction. |
| 244 | */ |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 245 | static int drm_lock_transfer(struct drm_lock_data *lock_data, |
Dave Airlie | c94f702 | 2005-07-07 21:03:38 +1000 | [diff] [blame] | 246 | unsigned int context) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 247 | { |
| 248 | unsigned int old, new, prev; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 249 | volatile unsigned int *lock = &lock_data->hw_lock->lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 250 | |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 251 | lock_data->file_priv = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | do { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 253 | old = *lock; |
| 254 | new = context | _DRM_LOCK_HELD; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | prev = cmpxchg(lock, old, new); |
| 256 | } while (prev != old); |
| 257 | return 1; |
| 258 | } |
| 259 | |
| 260 | /** |
| 261 | * Free lock. |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 262 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | * \param dev DRM device. |
| 264 | * \param lock lock. |
| 265 | * \param context context. |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 266 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | * Resets the lock file pointer. |
| 268 | * Marks the lock as not held, via the \p cmpxchg instruction. Wakes any task |
| 269 | * waiting on the lock queue. |
| 270 | */ |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 271 | int drm_lock_free(struct drm_lock_data *lock_data, unsigned int context) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | { |
| 273 | unsigned int old, new, prev; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 274 | volatile unsigned int *lock = &lock_data->hw_lock->lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 275 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 276 | spin_lock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 277 | if (lock_data->kernel_waiters != 0) { |
| 278 | drm_lock_transfer(lock_data, 0); |
| 279 | lock_data->idle_has_lock = 1; |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 280 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 281 | return 1; |
| 282 | } |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 283 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 284 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | do { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 286 | old = *lock; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 287 | new = _DRM_LOCKING_CONTEXT(old); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | prev = cmpxchg(lock, old, new); |
| 289 | } while (prev != old); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 290 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 291 | if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) { |
| 292 | DRM_ERROR("%d freed heavyweight lock held by %d\n", |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 293 | context, _DRM_LOCKING_CONTEXT(old)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | return 1; |
| 295 | } |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 296 | wake_up_interruptible(&lock_data->lock_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 297 | return 0; |
| 298 | } |
| 299 | |
| 300 | /** |
| 301 | * If we get here, it means that the process has called DRM_IOCTL_LOCK |
| 302 | * without calling DRM_IOCTL_UNLOCK. |
| 303 | * |
| 304 | * If the lock is not held, then let the signal proceed as usual. If the lock |
| 305 | * is held, then set the contended flag and keep the signal blocked. |
| 306 | * |
| 307 | * \param priv pointer to a drm_sigdata structure. |
| 308 | * \return one if the signal should be delivered normally, or zero if the |
| 309 | * signal should be blocked. |
| 310 | */ |
Dave Airlie | c94f702 | 2005-07-07 21:03:38 +1000 | [diff] [blame] | 311 | static int drm_notifier(void *priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | { |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 313 | struct drm_sigdata *s = (struct drm_sigdata *) priv; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 314 | unsigned int old, new, prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 316 | /* Allow signal delivery if lock isn't held */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | if (!s->lock || !_DRM_LOCK_IS_HELD(s->lock->lock) |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 318 | || _DRM_LOCKING_CONTEXT(s->lock->lock) != s->context) |
| 319 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 321 | /* Otherwise, set flag to force call to |
| 322 | drmUnlock */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | do { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 324 | old = s->lock->lock; |
| 325 | new = old | _DRM_LOCK_CONT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 326 | prev = cmpxchg(&s->lock->lock, old, new); |
| 327 | } while (prev != old); |
| 328 | return 0; |
| 329 | } |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 330 | |
| 331 | /** |
| 332 | * This function returns immediately and takes the hw lock |
| 333 | * with the kernel context if it is free, otherwise it gets the highest priority when and if |
| 334 | * it is eventually released. |
| 335 | * |
| 336 | * This guarantees that the kernel will _eventually_ have the lock _unless_ it is held |
| 337 | * by a blocked process. (In the latter case an explicit wait for the hardware lock would cause |
| 338 | * a deadlock, which is why the "idlelock" was invented). |
| 339 | * |
| 340 | * This should be sufficient to wait for GPU idle without |
| 341 | * having to worry about starvation. |
| 342 | */ |
| 343 | |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 344 | void drm_idlelock_take(struct drm_lock_data *lock_data) |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 345 | { |
| 346 | int ret = 0; |
| 347 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 348 | spin_lock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 349 | lock_data->kernel_waiters++; |
| 350 | if (!lock_data->idle_has_lock) { |
| 351 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 352 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 353 | ret = drm_lock_take(lock_data, DRM_KERNEL_CONTEXT); |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 354 | spin_lock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 355 | |
| 356 | if (ret == 1) |
| 357 | lock_data->idle_has_lock = 1; |
| 358 | } |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 359 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 360 | } |
| 361 | EXPORT_SYMBOL(drm_idlelock_take); |
| 362 | |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 363 | void drm_idlelock_release(struct drm_lock_data *lock_data) |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 364 | { |
| 365 | unsigned int old, prev; |
| 366 | volatile unsigned int *lock = &lock_data->hw_lock->lock; |
| 367 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 368 | spin_lock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 369 | if (--lock_data->kernel_waiters == 0) { |
| 370 | if (lock_data->idle_has_lock) { |
| 371 | do { |
| 372 | old = *lock; |
| 373 | prev = cmpxchg(lock, old, DRM_KERNEL_CONTEXT); |
| 374 | } while (prev != old); |
| 375 | wake_up_interruptible(&lock_data->lock_queue); |
| 376 | lock_data->idle_has_lock = 0; |
| 377 | } |
| 378 | } |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 379 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 380 | } |
| 381 | EXPORT_SYMBOL(drm_idlelock_release); |
| 382 | |
| 383 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 384 | int drm_i_have_hw_lock(struct drm_device *dev, struct drm_file *file_priv) |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 385 | { |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 386 | return (file_priv->lock_count && dev->lock.hw_lock && |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 387 | _DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock) && |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 388 | dev->lock.file_priv == file_priv); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 389 | } |
| 390 | |
| 391 | EXPORT_SYMBOL(drm_i_have_hw_lock); |