From 16bd14926e02e4dbc6e74689bdb3eb90f30a0233 Mon Sep 17 00:00:00 2001 From: David Dawes Date: Sun, 27 Jan 2002 18:23:04 +0000 Subject: Initial revision --- bsd/drm_lock.h | 244 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 244 insertions(+) create mode 100644 bsd/drm_lock.h (limited to 'bsd/drm_lock.h') diff --git a/bsd/drm_lock.h b/bsd/drm_lock.h new file mode 100644 index 00000000..863a228c --- /dev/null +++ b/bsd/drm_lock.h @@ -0,0 +1,244 @@ +/* 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 + * Gareth Hughes + */ + +#define __NO_VERSION__ +#include "drmP.h" + +int DRM(block)( DRM_OS_IOCTL ) +{ + DRM_DEBUG("\n"); + return 0; +} + +int DRM(unblock)( DRM_OS_IOCTL ) +{ + DRM_DEBUG("\n"); + return 0; +} + +int DRM(lock_take)(__volatile__ unsigned int *lock, unsigned int context) +{ + unsigned int old, new; + + char failed; + + do { + old = *lock; + if (old & _DRM_LOCK_HELD) new = old | _DRM_LOCK_CONT; + else new = context | _DRM_LOCK_HELD; + _DRM_CAS(lock, old, new, failed); + } while (failed); + 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; + char failed; + + dev->lock.pid = 0; + do { + old = *lock; + new = context | _DRM_LOCK_HELD; + _DRM_CAS(lock, old, new, failed); + } while (failed); + return 1; +} + +int DRM(lock_free)(drm_device_t *dev, + __volatile__ unsigned int *lock, unsigned int context) +{ + unsigned int old, new; + pid_t pid = dev->lock.pid; + char failed; + + dev->lock.pid = 0; + do { + old = *lock; + new = 0; + _DRM_CAS(lock, old, new, failed); + } while (failed); + if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) { + DRM_ERROR("%d freed heavyweight lock held by %d (pid %d)\n", + context, + _DRM_LOCKING_CONTEXT(old), + pid); + return 1; + } + DRM_OS_WAKEUP_INT(&dev->lock.lock_queue); + return 0; +} + +static int DRM(flush_queue)(drm_device_t *dev, int context) +{ + int error; + int ret = 0; + drm_queue_t *q = dev->queuelist[context]; + + DRM_DEBUG("\n"); + + atomic_inc(&q->use_count); + if (atomic_read(&q->use_count) > 1) { + atomic_inc(&q->block_write); + atomic_inc(&q->block_count); + error = tsleep(&q->flush_queue, PZERO|PCATCH, "drmfq", 0); + if (error) + return error; + atomic_dec(&q->block_count); + } + atomic_dec(&q->use_count); + + /* NOTE: block_write is still incremented! + Use drm_flush_unlock_queue to decrement. */ + return ret; +} + +static int DRM(flush_unblock_queue)(drm_device_t *dev, int context) +{ + drm_queue_t *q = dev->queuelist[context]; + + DRM_DEBUG("\n"); + + atomic_inc(&q->use_count); + if (atomic_read(&q->use_count) > 1) { + if (atomic_read(&q->block_write)) { + atomic_dec(&q->block_write); + DRM_OS_WAKEUP_INT(&q->write_queue); + } + } + atomic_dec(&q->use_count); + return 0; +} + +int DRM(flush_block_and_flush)(drm_device_t *dev, int context, + drm_lock_flags_t flags) +{ + int ret = 0; + int i; + + DRM_DEBUG("\n"); + + if (flags & _DRM_LOCK_FLUSH) { + ret = DRM(flush_queue)(dev, DRM_KERNEL_CONTEXT); + if (!ret) ret = DRM(flush_queue)(dev, context); + } + if (flags & _DRM_LOCK_FLUSH_ALL) { + for (i = 0; !ret && i < dev->queue_count; i++) { + ret = DRM(flush_queue)(dev, i); + } + } + return ret; +} + +int DRM(flush_unblock)(drm_device_t *dev, int context, drm_lock_flags_t flags) +{ + int ret = 0; + int i; + + DRM_DEBUG("\n"); + + if (flags & _DRM_LOCK_FLUSH) { + ret = DRM(flush_unblock_queue)(dev, DRM_KERNEL_CONTEXT); + if (!ret) ret = DRM(flush_unblock_queue)(dev, context); + } + if (flags & _DRM_LOCK_FLUSH_ALL) { + for (i = 0; !ret && i < dev->queue_count; i++) { + ret = DRM(flush_unblock_queue)(dev, i); + } + } + + return ret; +} + +int DRM(finish)( DRM_OS_IOCTL ) +{ + DRM_OS_DEVICE; + int ret = 0; + drm_lock_t lock; + + DRM_DEBUG("\n"); + + DRM_OS_KRNFROMUSR( lock, (drm_lock_t *)data, sizeof(lock) ); + + ret = DRM(flush_block_and_flush)(dev, lock.context, lock.flags); + DRM(flush_unblock)(dev, lock.context, lock.flags); + return ret; +} + +/* If we get here, it means that the process has called DRM_IOCTL_LOCK + without calling DRM_IOCTL_UNLOCK. + + If the lock is not held, then let the signal proceed as usual. + + If the lock is held, then set the contended flag and keep the signal + blocked. + + + Return 1 if the signal should be delivered normally. + Return 0 if the signal should be blocked. */ + +int DRM(notifier)(void *priv) +{ + drm_sigdata_t *s = (drm_sigdata_t *)priv; + unsigned int old, new; + char failed; + + + /* Allow signal delivery if lock isn't held */ + if (!_DRM_LOCK_IS_HELD(s->lock->lock) + || _DRM_LOCKING_CONTEXT(s->lock->lock) != s->context) return 1; + + /* Otherwise, set flag to force call to + drmUnlock */ + do { + old = s->lock->lock; + new = old | _DRM_LOCK_CONT; + _DRM_CAS(&s->lock->lock, old, new, failed); + } while (failed); + return 0; +} + -- cgit v1.2.3