1 /* lock.c -- IOCTLs for locking -*- linux-c -*-
2 * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
4 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
15 * The above copyright notice and this permission notice (including the next
16 * paragraph) shall be included in all copies or substantial portions of the
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
23 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
24 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 * OTHER DEALINGS IN THE SOFTWARE.
28 * Rickard E. (Rik) Faith <faith@valinux.com>
29 * Gareth Hughes <gareth@valinux.com>
31 * $FreeBSD: src/sys/dev/drm/drm_lock.h,v 1.3.2.1 2003/04/26 07:05:28 anholt Exp $
34 #include "dev/drm/drmP.h"
36 int DRM(lock_take)(__volatile__ unsigned int *lock, unsigned int context)
38 unsigned int old, new;
42 if (old & _DRM_LOCK_HELD) new = old | _DRM_LOCK_CONT;
43 else new = context | _DRM_LOCK_HELD;
44 } while (!atomic_cmpset_int(lock, old, new));
46 if (_DRM_LOCKING_CONTEXT(old) == context) {
47 if (old & _DRM_LOCK_HELD) {
48 if (context != DRM_KERNEL_CONTEXT) {
49 DRM_ERROR("%d holds heavyweight lock\n",
55 if (new == (context | _DRM_LOCK_HELD)) {
62 /* This takes a lock forcibly and hands it to context. Should ONLY be used
63 inside *_unlock to give lock to kernel before calling *_dma_schedule. */
64 int DRM(lock_transfer)(drm_device_t *dev,
65 __volatile__ unsigned int *lock, unsigned int context)
67 unsigned int old, new;
69 dev->lock.filp = NULL;
72 new = context | _DRM_LOCK_HELD;
73 } while (!atomic_cmpset_int(lock, old, new));
78 int DRM(lock_free)(drm_device_t *dev,
79 __volatile__ unsigned int *lock, unsigned int context)
81 unsigned int old, new;
83 dev->lock.filp = NULL;
87 } while (!atomic_cmpset_int(lock, old, new));
89 if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) {
90 DRM_ERROR("%d freed heavyweight lock held by %d\n",
91 context, _DRM_LOCKING_CONTEXT(old));
94 DRM_WAKEUP_INT((void *)&dev->lock.lock_queue);