renesas/periject.git - Renesas periject clone

Age	Commit message (Collapse)	Author
2019-12-09	wiki: Porting wiki: Porting 2016-10 MiniPeriCon	Kuninori Morimoto
	Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

/* lock.c -- IOCTLs for locking -*- linux-c -*- * 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. * All Rights Reserved. * * 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 * Software. * * 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. * * Authors: * Rickard E. (Rik) Faith <faith@valinux.com> * Gareth Hughes <gareth@valinux.com> * */ #include "drmP.h" int DRM(lock_take)(__volatile__ unsigned int *lock, unsigned int context) { unsigned int old, new; do { old = *lock; if (old & _DRM_LOCK_HELD) new = old | _DRM_LOCK_CONT; else new = context | _DRM_LOCK_HELD; } while (!atomic_cmpset_int(lock, old, new)); if (_DRM_LOCKING_CONTEXT(old) == context) { if (old & _DRM_LOCK_HELD) { if (context != DRM_KERNEL_CONTEXT) { DRM_ERROR("%d holds heavyweight lock\n", context); } return 0; } } if (new == (context | _DRM_LOCK_HELD)) { /* Have lock */ return 1; } return 0; } /* 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. */ int DRM(lock_transfer)(drm_device_t *dev, __volatile__ unsigned int *lock, unsigned int context) { unsigned int old, new; dev->lock.filp = NULL; do { old = *lock; new = context | _DRM_LOCK_HELD; } while (!atomic_cmpset_int(lock, old, new)); return 1; } int DRM(lock_free)(drm_device_t *dev, __volatile__ unsigned int *lock, unsigned int context) { unsigned int old, new; dev->lock.filp = NULL; do { old = *lock; new = 0; } while (!atomic_cmpset_int(lock, old, new)); if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) { DRM_ERROR("%d freed heavyweight lock held by %d\n", context, _DRM_LOCKING_CONTEXT(old)); return 1; } DRM_WAKEUP_INT((void *)&dev->lock.lock_queue); return 0; }