1450N/A * Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved. 1450N/A * Copyright (c) 2012 Intel Corporation. All rights reserved. 1450N/A * \author Rickard E. (Rik) Faith <faith@valinux.com> 1450N/A * \author Gareth Hughes <gareth@valinux.com> 1450N/A * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com 1450N/A * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. 1450N/A * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 1450N/A * Permission is hereby granted, free of charge, to any person obtaining a 1450N/A * copy of this software and associated documentation files (the "Software"), 1450N/A * to deal in the Software without restriction, including without limitation 1450N/A * the rights to use, copy, modify, merge, publish, distribute, sublicense, 1450N/A * and/or sell copies of the Software, and to permit persons to whom the 1450N/A * Software is furnished to do so, subject to the following conditions: 1450N/A * The above copyright notice and this permission notice (including the next 1450N/A * paragraph) shall be included in all copies or substantial portions of the 1450N/A * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 1450N/A * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 1450N/A * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 1450N/A * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 1450N/A * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 1450N/A * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 1450N/A * OTHER DEALINGS IN THE SOFTWARE. 1450N/A * \param inode device inode. 1450N/A * \param file_priv DRM file private. 1450N/A * \param arg user argument, pointing to a drm_lock structure. 1450N/A * \return zero on success or negative number on failure. 1450N/A * Add the current task to the lock wait queue, and attempt to take to lock. 1450N/A * \param inode device inode. 1450N/A * \param file_priv DRM file private. 1450N/A * \param arg user argument, pointing to a drm_lock structure. 1450N/A * \return zero on success or negative number on failure. 1450N/A * Transfer and free the lock. 1450N/A /* kernel_context_switch isn't used by any of the x86 drm 1450N/A * modules but is required by the Sparc driver. 1450N/A /* FIXME: Should really bail out here. */ 1450N/A * Take the heavyweight lock. 1450N/A * \param lock lock pointer. 1450N/A * \param context locking context. 1450N/A * \return one if the lock is held, or zero otherwise. 1450N/A * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction. 1450N/A * This takes a lock forcibly and hands it to context. Should ONLY be used 1450N/A * inside *_unlock to give lock to kernel before calling *_dma_schedule. 1450N/A * \param lock lock pointer. 1450N/A * \param context locking context. 1450N/A * Resets the lock file pointer. 1450N/A * Marks the lock as held by the given context, via the \p cmpxchg instruction. 1450N/A * Resets the lock file pointer. 1450N/A * Marks the lock as not held, via the \p cmpxchg instruction. Wakes any task 1450N/A * waiting on the lock queue. 1450N/A * This function returns immediately and takes the hw lock 1450N/A * with the kernel context if it is free, otherwise it gets the highest priority when and if 1450N/A * it is eventually released. 1450N/A * This guarantees that the kernel will _eventually_ have the lock _unless_ it is held 1450N/A * by a blocked process. (In the latter case an explicit wait for the hardware lock would cause 1450N/A * a deadlock, which is why the "idlelock" was invented). 1450N/A * This should be sufficient to wait for GPU idle without 1450N/A * having to worry about starvation.