Merge from vendor branch GCC:
[dragonfly.git] / sys / dev / drm / drm_lock.h
CommitLineData
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1/* lock.c -- IOCTLs for locking -*- linux-c -*-
2 * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
3 *
4 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6 * All Rights Reserved.
7 *
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:
14 *
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
17 * Software.
18 *
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.
26 *
27 * Authors:
28 * Rickard E. (Rik) Faith <faith@valinux.com>
29 * Gareth Hughes <gareth@valinux.com>
30 *
31 * $FreeBSD: src/sys/dev/drm/drm_lock.h,v 1.3.2.1 2003/04/26 07:05:28 anholt Exp $
1de703da 32 * $DragonFly: src/sys/dev/drm/Attic/drm_lock.h,v 1.2 2003/06/17 04:28:24 dillon Exp $
984263bc
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33 */
34
35#include "dev/drm/drmP.h"
36
37int DRM(lock_take)(__volatile__ unsigned int *lock, unsigned int context)
38{
39 unsigned int old, new;
40
41 do {
42 old = *lock;
43 if (old & _DRM_LOCK_HELD) new = old | _DRM_LOCK_CONT;
44 else new = context | _DRM_LOCK_HELD;
45 } while (!atomic_cmpset_int(lock, old, new));
46
47 if (_DRM_LOCKING_CONTEXT(old) == context) {
48 if (old & _DRM_LOCK_HELD) {
49 if (context != DRM_KERNEL_CONTEXT) {
50 DRM_ERROR("%d holds heavyweight lock\n",
51 context);
52 }
53 return 0;
54 }
55 }
56 if (new == (context | _DRM_LOCK_HELD)) {
57 /* Have lock */
58 return 1;
59 }
60 return 0;
61}
62
63/* This takes a lock forcibly and hands it to context. Should ONLY be used
64 inside *_unlock to give lock to kernel before calling *_dma_schedule. */
65int DRM(lock_transfer)(drm_device_t *dev,
66 __volatile__ unsigned int *lock, unsigned int context)
67{
68 unsigned int old, new;
69
70 dev->lock.filp = NULL;
71 do {
72 old = *lock;
73 new = context | _DRM_LOCK_HELD;
74 } while (!atomic_cmpset_int(lock, old, new));
75
76 return 1;
77}
78
79int DRM(lock_free)(drm_device_t *dev,
80 __volatile__ unsigned int *lock, unsigned int context)
81{
82 unsigned int old, new;
83
84 dev->lock.filp = NULL;
85 do {
86 old = *lock;
87 new = 0;
88 } while (!atomic_cmpset_int(lock, old, new));
89
90 if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) {
91 DRM_ERROR("%d freed heavyweight lock held by %d\n",
92 context, _DRM_LOCKING_CONTEXT(old));
93 return 1;
94 }
95 DRM_WAKEUP_INT((void *)&dev->lock.lock_queue);
96 return 0;
97}
98