Merge branch 'i2c/for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa...
[firefly-linux-kernel-4.4.55.git] / include / linux / reservation.h
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
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
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 *
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 *
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 */