| 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 | static inline struct fence * |
| 124 | reservation_object_get_excl_rcu(struct reservation_object *obj) |
| 125 | { |
| 126 | struct fence *fence; |
| 127 | unsigned seq; |
| 128 | retry: |
| 129 | seq = read_seqcount_begin(&obj->seq); |
| 130 | rcu_read_lock(); |
| 131 | fence = rcu_dereference(obj->fence_excl); |
| 132 | if (read_seqcount_retry(&obj->seq, seq)) { |
| 133 | rcu_read_unlock(); |
| 134 | goto retry; |
| 135 | } |
| 136 | fence = fence_get(fence); |
| 137 | rcu_read_unlock(); |
| 138 | return fence; |
| 139 | } |
| 140 | |
| 141 | int reservation_object_reserve_shared(struct reservation_object *obj); |
| 142 | void reservation_object_add_shared_fence(struct reservation_object *obj, |
| 143 | struct fence *fence); |
| 144 | |
| 145 | void reservation_object_add_excl_fence(struct reservation_object *obj, |
| 146 | struct fence *fence); |
| 147 | |
| 148 | int reservation_object_get_fences_rcu(struct reservation_object *obj, |
| 149 | struct fence **pfence_excl, |
| 150 | unsigned *pshared_count, |
| 151 | struct fence ***pshared); |
| 152 | |
| 153 | long reservation_object_wait_timeout_rcu(struct reservation_object *obj, |
| 154 | bool wait_all, bool intr, |
| 155 | unsigned long timeout); |
| 156 | |
| 157 | bool reservation_object_test_signaled_rcu(struct reservation_object *obj, |
| 158 | bool test_all); |
| 159 | |
| 160 | #endif /* _LINUX_RESERVATION_H */ |