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 | |
Dave Airlie | 5c2a5ce | 2011-12-22 19:09:01 +0000 | [diff] [blame] | 36 | #include <linux/export.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include "drmP.h" |
| 38 | |
Dave Airlie | c94f702 | 2005-07-07 21:03:38 +1000 | [diff] [blame] | 39 | static int drm_notifier(void *priv); |
| 40 | |
Daniel Vetter | 4ac5ec4 | 2010-08-23 22:53:34 +0200 | [diff] [blame] | 41 | static int drm_lock_take(struct drm_lock_data *lock_data, unsigned int context); |
| 42 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 43 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 44 | * Lock ioctl. |
| 45 | * |
| 46 | * \param inode device inode. |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 47 | * \param file_priv DRM file private. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | * \param cmd command. |
| 49 | * \param arg user argument, pointing to a drm_lock structure. |
| 50 | * \return zero on success or negative number on failure. |
| 51 | * |
| 52 | * Add the current task to the lock wait queue, and attempt to take to lock. |
| 53 | */ |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 54 | 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] | 55 | { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 56 | DECLARE_WAITQUEUE(entry, current); |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 57 | struct drm_lock *lock = data; |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 58 | struct drm_master *master = file_priv->master; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 59 | int ret = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 61 | ++file_priv->lock_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 63 | if (lock->context == DRM_KERNEL_CONTEXT) { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 64 | DRM_ERROR("Process %d using kernel context %d\n", |
Pavel Emelyanov | ba25f9d | 2007-10-18 23:40:40 -0700 | [diff] [blame] | 65 | task_pid_nr(current), lock->context); |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 66 | return -EINVAL; |
| 67 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 68 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 69 | 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] | 70 | lock->context, task_pid_nr(current), |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 71 | master->lock.hw_lock->lock, lock->flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | |
| 73 | if (drm_core_check_feature(dev, DRIVER_DMA_QUEUE)) |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 74 | if (lock->context < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | return -EINVAL; |
| 76 | |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 77 | add_wait_queue(&master->lock.lock_queue, &entry); |
| 78 | spin_lock_bh(&master->lock.spinlock); |
| 79 | master->lock.user_waiters++; |
| 80 | spin_unlock_bh(&master->lock.spinlock); |
| 81 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | for (;;) { |
| 83 | __set_current_state(TASK_INTERRUPTIBLE); |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 84 | if (!master->lock.hw_lock) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | /* Device has been unregistered */ |
Thomas Hellstrom | fda714c | 2009-03-02 11:10:56 +0100 | [diff] [blame] | 86 | send_sig(SIGTERM, current, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | ret = -EINTR; |
| 88 | break; |
| 89 | } |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 90 | if (drm_lock_take(&master->lock, lock->context)) { |
| 91 | master->lock.file_priv = file_priv; |
| 92 | master->lock.lock_time = jiffies; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 93 | atomic_inc(&dev->counts[_DRM_STAT_LOCKS]); |
| 94 | break; /* Got lock */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 95 | } |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 96 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | /* Contention */ |
Arnd Bergmann | 08f2e66 | 2010-08-27 08:55:28 +1000 | [diff] [blame] | 98 | mutex_unlock(&drm_global_mutex); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | schedule(); |
Arnd Bergmann | 08f2e66 | 2010-08-27 08:55:28 +1000 | [diff] [blame] | 100 | mutex_lock(&drm_global_mutex); |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 101 | if (signal_pending(current)) { |
Thomas Hellstrom | 4d77c88 | 2009-03-02 11:10:54 +0100 | [diff] [blame] | 102 | ret = -EINTR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | break; |
| 104 | } |
| 105 | } |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 106 | spin_lock_bh(&master->lock.spinlock); |
| 107 | master->lock.user_waiters--; |
| 108 | spin_unlock_bh(&master->lock.spinlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | __set_current_state(TASK_RUNNING); |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 110 | remove_wait_queue(&master->lock.lock_queue, &entry); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 112 | DRM_DEBUG("%d %s\n", lock->context, |
| 113 | ret ? "interrupted" : "has lock"); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 114 | if (ret) return ret; |
Dave Airlie | d985c10 | 2006-01-02 21:32:48 +1100 | [diff] [blame] | 115 | |
Dave Airlie | 3e5fc80 | 2008-08-24 17:02:26 +1000 | [diff] [blame] | 116 | /* don't set the block all signals on the master process for now |
| 117 | * really probably not the correct answer but lets us debug xkb |
| 118 | * xserver for now */ |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 119 | if (!file_priv->is_master) { |
Dave Airlie | 3e5fc80 | 2008-08-24 17:02:26 +1000 | [diff] [blame] | 120 | sigemptyset(&dev->sigmask); |
| 121 | sigaddset(&dev->sigmask, SIGSTOP); |
| 122 | sigaddset(&dev->sigmask, SIGTSTP); |
| 123 | sigaddset(&dev->sigmask, SIGTTIN); |
| 124 | sigaddset(&dev->sigmask, SIGTTOU); |
| 125 | dev->sigdata.context = lock->context; |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 126 | dev->sigdata.lock = master->lock.hw_lock; |
Dave Airlie | 3e5fc80 | 2008-08-24 17:02:26 +1000 | [diff] [blame] | 127 | block_all_signals(drm_notifier, &dev->sigdata, &dev->sigmask); |
| 128 | } |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 129 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 130 | if (dev->driver->dma_quiescent && (lock->flags & _DRM_LOCK_QUIESCENT)) |
| 131 | { |
Dave Airlie | d985c10 | 2006-01-02 21:32:48 +1100 | [diff] [blame] | 132 | if (dev->driver->dma_quiescent(dev)) { |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 133 | DRM_DEBUG("%d waiting for DMA quiescent\n", |
| 134 | lock->context); |
Eric Anholt | 20caafa | 2007-08-25 19:22:43 +1000 | [diff] [blame] | 135 | return -EBUSY; |
Dave Airlie | d985c10 | 2006-01-02 21:32:48 +1100 | [diff] [blame] | 136 | } |
| 137 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | |
Dave Airlie | d985c10 | 2006-01-02 21:32:48 +1100 | [diff] [blame] | 139 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 140 | } |
| 141 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 142 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 143 | * Unlock ioctl. |
| 144 | * |
| 145 | * \param inode device inode. |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 146 | * \param file_priv DRM file private. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | * \param cmd command. |
| 148 | * \param arg user argument, pointing to a drm_lock structure. |
| 149 | * \return zero on success or negative number on failure. |
| 150 | * |
| 151 | * Transfer and free the lock. |
| 152 | */ |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 153 | 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] | 154 | { |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 155 | struct drm_lock *lock = data; |
Daniel Vetter | 45ff46c | 2010-09-26 00:24:48 +0200 | [diff] [blame] | 156 | struct drm_master *master = file_priv->master; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 158 | if (lock->context == DRM_KERNEL_CONTEXT) { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 159 | DRM_ERROR("Process %d using kernel context %d\n", |
Pavel Emelyanov | ba25f9d | 2007-10-18 23:40:40 -0700 | [diff] [blame] | 160 | task_pid_nr(current), lock->context); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | return -EINVAL; |
| 162 | } |
| 163 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 164 | atomic_inc(&dev->counts[_DRM_STAT_UNLOCKS]); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | |
Daniel Vetter | 45ff46c | 2010-09-26 00:24:48 +0200 | [diff] [blame] | 166 | if (drm_lock_free(&master->lock, lock->context)) { |
| 167 | /* FIXME: Should really bail out here. */ |
| 168 | } |
| 169 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | unblock_all_signals(); |
| 171 | return 0; |
| 172 | } |
| 173 | |
| 174 | /** |
| 175 | * Take the heavyweight lock. |
| 176 | * |
| 177 | * \param lock lock pointer. |
| 178 | * \param context locking context. |
| 179 | * \return one if the lock is held, or zero otherwise. |
| 180 | * |
| 181 | * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction. |
| 182 | */ |
Daniel Vetter | 4ac5ec4 | 2010-08-23 22:53:34 +0200 | [diff] [blame] | 183 | static |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 184 | int drm_lock_take(struct drm_lock_data *lock_data, |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 185 | unsigned int context) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 186 | { |
| 187 | unsigned int old, new, prev; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 188 | volatile unsigned int *lock = &lock_data->hw_lock->lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 189 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 190 | spin_lock_bh(&lock_data->spinlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | do { |
| 192 | old = *lock; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 193 | if (old & _DRM_LOCK_HELD) |
| 194 | new = old | _DRM_LOCK_CONT; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 195 | else { |
| 196 | new = context | _DRM_LOCK_HELD | |
| 197 | ((lock_data->user_waiters + lock_data->kernel_waiters > 1) ? |
| 198 | _DRM_LOCK_CONT : 0); |
| 199 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | prev = cmpxchg(lock, old, new); |
| 201 | } while (prev != old); |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 202 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 203 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | if (_DRM_LOCKING_CONTEXT(old) == context) { |
| 205 | if (old & _DRM_LOCK_HELD) { |
| 206 | if (context != DRM_KERNEL_CONTEXT) { |
| 207 | DRM_ERROR("%d holds heavyweight lock\n", |
| 208 | context); |
| 209 | } |
| 210 | return 0; |
| 211 | } |
| 212 | } |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 213 | |
| 214 | if ((_DRM_LOCKING_CONTEXT(new)) == context && (new & _DRM_LOCK_HELD)) { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 215 | /* Have lock */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 216 | return 1; |
| 217 | } |
| 218 | return 0; |
| 219 | } |
| 220 | |
| 221 | /** |
| 222 | * 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] | 223 | * inside *_unlock to give lock to kernel before calling *_dma_schedule. |
| 224 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | * \param dev DRM device. |
| 226 | * \param lock lock pointer. |
| 227 | * \param context locking context. |
| 228 | * \return always one. |
| 229 | * |
| 230 | * Resets the lock file pointer. |
| 231 | * Marks the lock as held by the given context, via the \p cmpxchg instruction. |
| 232 | */ |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 233 | static int drm_lock_transfer(struct drm_lock_data *lock_data, |
Dave Airlie | c94f702 | 2005-07-07 21:03:38 +1000 | [diff] [blame] | 234 | unsigned int context) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | { |
| 236 | unsigned int old, new, prev; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 237 | volatile unsigned int *lock = &lock_data->hw_lock->lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | |
Eric Anholt | 6c340ea | 2007-08-25 20:23:09 +1000 | [diff] [blame] | 239 | lock_data->file_priv = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | do { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 241 | old = *lock; |
| 242 | new = context | _DRM_LOCK_HELD; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 243 | prev = cmpxchg(lock, old, new); |
| 244 | } while (prev != old); |
| 245 | return 1; |
| 246 | } |
| 247 | |
| 248 | /** |
| 249 | * Free lock. |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 250 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | * \param dev DRM device. |
| 252 | * \param lock lock. |
| 253 | * \param context context. |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 254 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | * Resets the lock file pointer. |
| 256 | * Marks the lock as not held, via the \p cmpxchg instruction. Wakes any task |
| 257 | * waiting on the lock queue. |
| 258 | */ |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 259 | 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] | 260 | { |
| 261 | unsigned int old, new, prev; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 262 | volatile unsigned int *lock = &lock_data->hw_lock->lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 264 | spin_lock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 265 | if (lock_data->kernel_waiters != 0) { |
| 266 | drm_lock_transfer(lock_data, 0); |
| 267 | lock_data->idle_has_lock = 1; |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 268 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 269 | return 1; |
| 270 | } |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 271 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 272 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 273 | do { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 274 | old = *lock; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 275 | new = _DRM_LOCKING_CONTEXT(old); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 276 | prev = cmpxchg(lock, old, new); |
| 277 | } while (prev != old); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 278 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) { |
| 280 | DRM_ERROR("%d freed heavyweight lock held by %d\n", |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 281 | context, _DRM_LOCKING_CONTEXT(old)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 282 | return 1; |
| 283 | } |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 284 | wake_up_interruptible(&lock_data->lock_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 285 | return 0; |
| 286 | } |
| 287 | |
| 288 | /** |
| 289 | * If we get here, it means that the process has called DRM_IOCTL_LOCK |
| 290 | * without calling DRM_IOCTL_UNLOCK. |
| 291 | * |
| 292 | * If the lock is not held, then let the signal proceed as usual. If the lock |
| 293 | * is held, then set the contended flag and keep the signal blocked. |
| 294 | * |
| 295 | * \param priv pointer to a drm_sigdata structure. |
| 296 | * \return one if the signal should be delivered normally, or zero if the |
| 297 | * signal should be blocked. |
| 298 | */ |
Dave Airlie | c94f702 | 2005-07-07 21:03:38 +1000 | [diff] [blame] | 299 | static int drm_notifier(void *priv) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 300 | { |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 301 | struct drm_sigdata *s = (struct drm_sigdata *) priv; |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 302 | unsigned int old, new, prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 304 | /* Allow signal delivery if lock isn't held */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | if (!s->lock || !_DRM_LOCK_IS_HELD(s->lock->lock) |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 306 | || _DRM_LOCKING_CONTEXT(s->lock->lock) != s->context) |
| 307 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 308 | |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 309 | /* Otherwise, set flag to force call to |
| 310 | drmUnlock */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | do { |
Dave Airlie | b5e89ed | 2005-09-25 14:28:13 +1000 | [diff] [blame] | 312 | old = s->lock->lock; |
| 313 | new = old | _DRM_LOCK_CONT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | prev = cmpxchg(&s->lock->lock, old, new); |
| 315 | } while (prev != old); |
| 316 | return 0; |
| 317 | } |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 318 | |
| 319 | /** |
| 320 | * This function returns immediately and takes the hw lock |
| 321 | * with the kernel context if it is free, otherwise it gets the highest priority when and if |
| 322 | * it is eventually released. |
| 323 | * |
| 324 | * This guarantees that the kernel will _eventually_ have the lock _unless_ it is held |
| 325 | * by a blocked process. (In the latter case an explicit wait for the hardware lock would cause |
| 326 | * a deadlock, which is why the "idlelock" was invented). |
| 327 | * |
| 328 | * This should be sufficient to wait for GPU idle without |
| 329 | * having to worry about starvation. |
| 330 | */ |
| 331 | |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 332 | void drm_idlelock_take(struct drm_lock_data *lock_data) |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 333 | { |
Laurent Pinchart | 4a1b071 | 2012-05-17 13:27:21 +0200 | [diff] [blame] | 334 | int ret; |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 335 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 336 | spin_lock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 337 | lock_data->kernel_waiters++; |
| 338 | if (!lock_data->idle_has_lock) { |
| 339 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 340 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 341 | ret = drm_lock_take(lock_data, DRM_KERNEL_CONTEXT); |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 342 | spin_lock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 343 | |
| 344 | if (ret == 1) |
| 345 | lock_data->idle_has_lock = 1; |
| 346 | } |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 347 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 348 | } |
Dave Airlie | 5c2a5ce | 2011-12-22 19:09:01 +0000 | [diff] [blame] | 349 | EXPORT_SYMBOL(drm_idlelock_take); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 350 | |
Dave Airlie | 5591051 | 2007-07-11 16:53:40 +1000 | [diff] [blame] | 351 | void drm_idlelock_release(struct drm_lock_data *lock_data) |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 352 | { |
| 353 | unsigned int old, prev; |
| 354 | volatile unsigned int *lock = &lock_data->hw_lock->lock; |
| 355 | |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 356 | spin_lock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 357 | if (--lock_data->kernel_waiters == 0) { |
| 358 | if (lock_data->idle_has_lock) { |
| 359 | do { |
| 360 | old = *lock; |
| 361 | prev = cmpxchg(lock, old, DRM_KERNEL_CONTEXT); |
| 362 | } while (prev != old); |
| 363 | wake_up_interruptible(&lock_data->lock_queue); |
| 364 | lock_data->idle_has_lock = 0; |
| 365 | } |
| 366 | } |
Thomas Hellstrom | f116cc5 | 2008-05-07 12:22:39 +1000 | [diff] [blame] | 367 | spin_unlock_bh(&lock_data->spinlock); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 368 | } |
Dave Airlie | 5c2a5ce | 2011-12-22 19:09:01 +0000 | [diff] [blame] | 369 | EXPORT_SYMBOL(drm_idlelock_release); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 370 | |
Eric Anholt | c153f45 | 2007-09-03 12:06:45 +1000 | [diff] [blame] | 371 | 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] | 372 | { |
Dave Airlie | 7c1c287 | 2008-11-28 14:22:24 +1000 | [diff] [blame] | 373 | struct drm_master *master = file_priv->master; |
| 374 | return (file_priv->lock_count && master->lock.hw_lock && |
| 375 | _DRM_LOCK_IS_HELD(master->lock.hw_lock->lock) && |
| 376 | master->lock.file_priv == file_priv); |
Thomas Hellstrom | 040ac32 | 2007-03-23 13:28:33 +1100 | [diff] [blame] | 377 | } |