drm_lock.c revision 1450
* Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved. * Copyright (c) 2012 Intel Corporation. All rights reserved. * \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. * 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 * 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. * \param inode device inode. * \param file_priv DRM file private. * \param arg user argument, pointing to a drm_lock structure. * \return zero on success or negative number on failure. * Add the current task to the lock wait queue, and attempt to take to lock. DRM_ERROR(
"Process %d using kernel context %d\n",
DRM_DEBUG(
"%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n",
ret ?
"interrupted" :
"has lock");
* \param inode device inode. * \param file_priv DRM file private. * \param arg user argument, pointing to a drm_lock structure. * \return zero on success or negative number on failure. * Transfer and free the lock. DRM_ERROR(
"Process %d using kernel context %d\n",
/* kernel_context_switch isn't used by any of the x86 drm * modules but is required by the Sparc driver. /* FIXME: Should really bail out here. */ * 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. * 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 lock lock pointer. * \param context locking context. * Resets the lock file pointer. * Marks the lock as held by the given context, via the \p cmpxchg instruction. * \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. DRM_ERROR(
"%d freed heavyweight lock held by %d\n",
* This function returns immediately and takes the hw lock * with the kernel context if it is free, otherwise it gets the highest priority when and if * it is eventually released. * This guarantees that the kernel will _eventually_ have the lock _unless_ it is held * by a blocked process. (In the latter case an explicit wait for the hardware lock would cause * a deadlock, which is why the "idlelock" was invented). * This should be sufficient to wait for GPU idle without * having to worry about starvation.