1 /*
2 * Header file for reservations for dma-buf and ttm
3 *
4 * Copyright(C) 2011 Linaro Limited. All rights reserved.
5 * Copyright (C) 2012-2013 Canonical Ltd
6 * Copyright (C) 2012 Texas Instruments
7 *
8 * Authors:
9 * Rob Clark <robdclark@gmail.com>
10 * Maarten Lankhorst <maarten.lankhorst@canonical.com>
11 * Thomas Hellstrom <thellstrom-at-vmware-dot-com>
12 *
13 * Based on bo.c which bears the following copyright notice,
14 * but is dual licensed:
15 *
16 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
17 * All Rights Reserved.
18 *
19 * Permission is hereby granted, free of charge, to any person obtaining a
20 * copy of this software and associated documentation files (the
21 * "Software"), to deal in the Software without restriction, including
22 * without limitation the rights to use, copy, modify, merge, publish,
23 * distribute, sub license, and/or sell copies of the Software, and to
24 * permit persons to whom the Software is furnished to do so, subject to
25 * the following conditions:
26 *
27 * The above copyright notice and this permission notice (including the
28 * next paragraph) shall be included in all copies or substantial portions
29 * of the Software.
30 *
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
32 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
33 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
34 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
35 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
36 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
37 * USE OR OTHER DEALINGS IN THE SOFTWARE.
38 */
39 #ifndef _LINUX_RESERVATION_H
40 #define _LINUX_RESERVATION_H
41
42 #include <linux/ww_mutex.h>
43 #include <linux/fence.h>
44 #include <linux/slab.h>
45 #include <linux/seqlock.h>
46 #include <linux/rcupdate.h>
47
48 extern struct ww_class reservation_ww_class;
49 extern struct lock_class_key reservation_seqcount_class;
50 extern const char reservation_seqcount_string[];
51
52 struct reservation_object_list {
53 struct rcu_head rcu;
54 u32 shared_count, shared_max;
55 struct fence __rcu *shared[];
56 };
57
58 struct reservation_object {
59 struct ww_mutex lock;
60 seqcount_t seq;
61
62 struct fence __rcu *fence_excl;
63 struct reservation_object_list __rcu *fence;
64 struct reservation_object_list *staged;
65 };
66
67 #define reservation_object_held(obj) lockdep_is_held(&(obj)->lock.base)
68 #define reservation_object_assert_held(obj) \
69 lockdep_assert_held(&(obj)->lock.base)
70
71 static inline void
reservation_object_init(struct reservation_object * obj)72 reservation_object_init(struct reservation_object *obj)
73 {
74 ww_mutex_init(&obj->lock, &reservation_ww_class);
75
76 __seqcount_init(&obj->seq, reservation_seqcount_string, &reservation_seqcount_class);
77 RCU_INIT_POINTER(obj->fence, NULL);
78 RCU_INIT_POINTER(obj->fence_excl, NULL);
79 obj->staged = NULL;
80 }
81
82 static inline void
reservation_object_fini(struct reservation_object * obj)83 reservation_object_fini(struct reservation_object *obj)
84 {
85 int i;
86 struct reservation_object_list *fobj;
87 struct fence *excl;
88
89 /*
90 * This object should be dead and all references must have
91 * been released to it, so no need to be protected with rcu.
92 */
93 excl = rcu_dereference_protected(obj->fence_excl, 1);
94 if (excl)
95 fence_put(excl);
96
97 fobj = rcu_dereference_protected(obj->fence, 1);
98 if (fobj) {
99 for (i = 0; i < fobj->shared_count; ++i)
100 fence_put(rcu_dereference_protected(fobj->shared[i], 1));
101
102 kfree(fobj);
103 }
104 kfree(obj->staged);
105
106 ww_mutex_destroy(&obj->lock);
107 }
108
109 static inline struct reservation_object_list *
reservation_object_get_list(struct reservation_object * obj)110 reservation_object_get_list(struct reservation_object *obj)
111 {
112 return rcu_dereference_protected(obj->fence,
113 reservation_object_held(obj));
114 }
115
116 static inline struct fence *
reservation_object_get_excl(struct reservation_object * obj)117 reservation_object_get_excl(struct reservation_object *obj)
118 {
119 return rcu_dereference_protected(obj->fence_excl,
120 reservation_object_held(obj));
121 }
122
123 int reservation_object_reserve_shared(struct reservation_object *obj);
124 void reservation_object_add_shared_fence(struct reservation_object *obj,
125 struct fence *fence);
126
127 void reservation_object_add_excl_fence(struct reservation_object *obj,
128 struct fence *fence);
129
130 int reservation_object_get_fences_rcu(struct reservation_object *obj,
131 struct fence **pfence_excl,
132 unsigned *pshared_count,
133 struct fence ***pshared);
134
135 long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
136 bool wait_all, bool intr,
137 unsigned long timeout);
138
139 bool reservation_object_test_signaled_rcu(struct reservation_object *obj,
140 bool test_all);
141
142 #endif /* _LINUX_RESERVATION_H */
143