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786d7257 ML |
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: | |
0ba6b8fb | 9 | * Rob Clark <robdclark@gmail.com> |
786d7257 ML |
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 | ||
1b375dc3 | 42 | #include <linux/ww_mutex.h> |
0ba6b8fb ML |
43 | #include <linux/fence.h> |
44 | #include <linux/slab.h> | |
3c3b177a ML |
45 | #include <linux/seqlock.h> |
46 | #include <linux/rcupdate.h> | |
786d7257 ML |
47 | |
48 | extern struct ww_class reservation_ww_class; | |
3c3b177a ML |
49 | extern struct lock_class_key reservation_seqcount_class; |
50 | extern const char reservation_seqcount_string[]; | |
786d7257 | 51 | |
dad6c394 RC |
52 | /** |
53 | * struct reservation_object_list - a list of shared fences | |
54 | * @rcu: for internal use | |
55 | * @shared_count: table of shared fences | |
56 | * @shared_max: for growing shared fence table | |
57 | * @shared: shared fence table | |
58 | */ | |
04a5faa8 | 59 | struct reservation_object_list { |
3c3b177a | 60 | struct rcu_head rcu; |
04a5faa8 | 61 | u32 shared_count, shared_max; |
3c3b177a | 62 | struct fence __rcu *shared[]; |
04a5faa8 ML |
63 | }; |
64 | ||
dad6c394 RC |
65 | /** |
66 | * struct reservation_object - a reservation object manages fences for a buffer | |
67 | * @lock: update side lock | |
68 | * @seq: sequence count for managing RCU read-side synchronization | |
69 | * @fence_excl: the exclusive fence, if there is one currently | |
70 | * @fence: list of current shared fences | |
71 | * @staged: staged copy of shared fences for RCU updates | |
72 | */ | |
786d7257 ML |
73 | struct reservation_object { |
74 | struct ww_mutex lock; | |
3c3b177a | 75 | seqcount_t seq; |
0ba6b8fb | 76 | |
3c3b177a ML |
77 | struct fence __rcu *fence_excl; |
78 | struct reservation_object_list __rcu *fence; | |
04a5faa8 | 79 | struct reservation_object_list *staged; |
786d7257 ML |
80 | }; |
81 | ||
3c3b177a | 82 | #define reservation_object_held(obj) lockdep_is_held(&(obj)->lock.base) |
04a5faa8 ML |
83 | #define reservation_object_assert_held(obj) \ |
84 | lockdep_assert_held(&(obj)->lock.base) | |
85 | ||
dad6c394 RC |
86 | /** |
87 | * reservation_object_init - initialize a reservation object | |
88 | * @obj: the reservation object | |
89 | */ | |
786d7257 ML |
90 | static inline void |
91 | reservation_object_init(struct reservation_object *obj) | |
92 | { | |
93 | ww_mutex_init(&obj->lock, &reservation_ww_class); | |
0ba6b8fb | 94 | |
3c3b177a ML |
95 | __seqcount_init(&obj->seq, reservation_seqcount_string, &reservation_seqcount_class); |
96 | RCU_INIT_POINTER(obj->fence, NULL); | |
97 | RCU_INIT_POINTER(obj->fence_excl, NULL); | |
04a5faa8 | 98 | obj->staged = NULL; |
786d7257 ML |
99 | } |
100 | ||
dad6c394 RC |
101 | /** |
102 | * reservation_object_fini - destroys a reservation object | |
103 | * @obj: the reservation object | |
104 | */ | |
786d7257 ML |
105 | static inline void |
106 | reservation_object_fini(struct reservation_object *obj) | |
107 | { | |
0ba6b8fb | 108 | int i; |
04a5faa8 | 109 | struct reservation_object_list *fobj; |
3c3b177a | 110 | struct fence *excl; |
0ba6b8fb | 111 | |
04a5faa8 ML |
112 | /* |
113 | * This object should be dead and all references must have | |
3c3b177a | 114 | * been released to it, so no need to be protected with rcu. |
04a5faa8 | 115 | */ |
3c3b177a ML |
116 | excl = rcu_dereference_protected(obj->fence_excl, 1); |
117 | if (excl) | |
118 | fence_put(excl); | |
04a5faa8 | 119 | |
3c3b177a | 120 | fobj = rcu_dereference_protected(obj->fence, 1); |
04a5faa8 ML |
121 | if (fobj) { |
122 | for (i = 0; i < fobj->shared_count; ++i) | |
3c3b177a | 123 | fence_put(rcu_dereference_protected(fobj->shared[i], 1)); |
04a5faa8 ML |
124 | |
125 | kfree(fobj); | |
126 | } | |
127 | kfree(obj->staged); | |
0ba6b8fb | 128 | |
786d7257 ML |
129 | ww_mutex_destroy(&obj->lock); |
130 | } | |
131 | ||
dad6c394 RC |
132 | /** |
133 | * reservation_object_get_list - get the reservation object's | |
134 | * shared fence list, with update-side lock held | |
135 | * @obj: the reservation object | |
136 | * | |
137 | * Returns the shared fence list. Does NOT take references to | |
138 | * the fence. The obj->lock must be held. | |
139 | */ | |
04a5faa8 ML |
140 | static inline struct reservation_object_list * |
141 | reservation_object_get_list(struct reservation_object *obj) | |
142 | { | |
3c3b177a ML |
143 | return rcu_dereference_protected(obj->fence, |
144 | reservation_object_held(obj)); | |
04a5faa8 ML |
145 | } |
146 | ||
dad6c394 RC |
147 | /** |
148 | * reservation_object_get_excl - get the reservation object's | |
149 | * exclusive fence, with update-side lock held | |
150 | * @obj: the reservation object | |
151 | * | |
152 | * Returns the exclusive fence (if any). Does NOT take a | |
153 | * reference. The obj->lock must be held. | |
154 | * | |
155 | * RETURNS | |
156 | * The exclusive fence or NULL | |
157 | */ | |
04a5faa8 ML |
158 | static inline struct fence * |
159 | reservation_object_get_excl(struct reservation_object *obj) | |
160 | { | |
3c3b177a ML |
161 | return rcu_dereference_protected(obj->fence_excl, |
162 | reservation_object_held(obj)); | |
04a5faa8 ML |
163 | } |
164 | ||
dad6c394 RC |
165 | /** |
166 | * reservation_object_get_excl_rcu - get the reservation object's | |
167 | * exclusive fence, without lock held. | |
168 | * @obj: the reservation object | |
169 | * | |
170 | * If there is an exclusive fence, this atomically increments it's | |
171 | * reference count and returns it. | |
172 | * | |
173 | * RETURNS | |
174 | * The exclusive fence or NULL if none | |
175 | */ | |
824815c4 RC |
176 | static inline struct fence * |
177 | reservation_object_get_excl_rcu(struct reservation_object *obj) | |
178 | { | |
179 | struct fence *fence; | |
180 | unsigned seq; | |
181 | retry: | |
182 | seq = read_seqcount_begin(&obj->seq); | |
183 | rcu_read_lock(); | |
184 | fence = rcu_dereference(obj->fence_excl); | |
185 | if (read_seqcount_retry(&obj->seq, seq)) { | |
186 | rcu_read_unlock(); | |
187 | goto retry; | |
188 | } | |
189 | fence = fence_get(fence); | |
190 | rcu_read_unlock(); | |
191 | return fence; | |
192 | } | |
193 | ||
04a5faa8 ML |
194 | int reservation_object_reserve_shared(struct reservation_object *obj); |
195 | void reservation_object_add_shared_fence(struct reservation_object *obj, | |
196 | struct fence *fence); | |
197 | ||
198 | void reservation_object_add_excl_fence(struct reservation_object *obj, | |
199 | struct fence *fence); | |
200 | ||
3c3b177a ML |
201 | int reservation_object_get_fences_rcu(struct reservation_object *obj, |
202 | struct fence **pfence_excl, | |
203 | unsigned *pshared_count, | |
204 | struct fence ***pshared); | |
205 | ||
206 | long reservation_object_wait_timeout_rcu(struct reservation_object *obj, | |
207 | bool wait_all, bool intr, | |
208 | unsigned long timeout); | |
209 | ||
210 | bool reservation_object_test_signaled_rcu(struct reservation_object *obj, | |
211 | bool test_all); | |
212 | ||
786d7257 | 213 | #endif /* _LINUX_RESERVATION_H */ |