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213 lines
6.4 KiB
213 lines
6.4 KiB
/* |
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* Header file for reservations for dma-buf and ttm |
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* |
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* Copyright(C) 2011 Linaro Limited. All rights reserved. |
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* Copyright (C) 2012-2013 Canonical Ltd |
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* Copyright (C) 2012 Texas Instruments |
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* |
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* Authors: |
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* Rob Clark <[email protected]> |
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* Maarten Lankhorst <[email protected]> |
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* Thomas Hellstrom <thellstrom-at-vmware-dot-com> |
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* |
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* Based on bo.c which bears the following copyright notice, |
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* but is dual licensed: |
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* |
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* Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA |
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* All Rights Reserved. |
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* |
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* Permission is hereby granted, free of charge, to any person obtaining a |
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* copy of this software and associated documentation files (the |
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* "Software"), to deal in the Software without restriction, including |
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* without limitation the rights to use, copy, modify, merge, publish, |
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* distribute, sub license, and/or sell copies of the Software, and to |
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* permit persons to whom the Software is furnished to do so, subject to |
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* the following conditions: |
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* |
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* The above copyright notice and this permission notice (including the |
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* next paragraph) shall be included in all copies or substantial portions |
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* of the Software. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
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* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, |
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* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
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* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
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* USE OR OTHER DEALINGS IN THE SOFTWARE. |
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*/ |
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#ifndef _LINUX_RESERVATION_H |
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#define _LINUX_RESERVATION_H |
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#include <linux/ww_mutex.h> |
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#include <linux/fence.h> |
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#include <linux/slab.h> |
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#include <linux/seqlock.h> |
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#include <linux/rcupdate.h> |
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extern struct ww_class reservation_ww_class; |
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extern struct lock_class_key reservation_seqcount_class; |
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extern const char reservation_seqcount_string[]; |
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/** |
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* struct reservation_object_list - a list of shared fences |
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* @rcu: for internal use |
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* @shared_count: table of shared fences |
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* @shared_max: for growing shared fence table |
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* @shared: shared fence table |
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*/ |
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struct reservation_object_list { |
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struct rcu_head rcu; |
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u32 shared_count, shared_max; |
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struct fence __rcu *shared[]; |
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}; |
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/** |
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* struct reservation_object - a reservation object manages fences for a buffer |
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* @lock: update side lock |
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* @seq: sequence count for managing RCU read-side synchronization |
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* @fence_excl: the exclusive fence, if there is one currently |
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* @fence: list of current shared fences |
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* @staged: staged copy of shared fences for RCU updates |
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*/ |
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struct reservation_object { |
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struct ww_mutex lock; |
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seqcount_t seq; |
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struct fence __rcu *fence_excl; |
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struct reservation_object_list __rcu *fence; |
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struct reservation_object_list *staged; |
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}; |
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#define reservation_object_held(obj) lockdep_is_held(&(obj)->lock.base) |
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#define reservation_object_assert_held(obj) \ |
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lockdep_assert_held(&(obj)->lock.base) |
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/** |
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* reservation_object_init - initialize a reservation object |
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* @obj: the reservation object |
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*/ |
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static inline void |
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reservation_object_init(struct reservation_object *obj) |
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{ |
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ww_mutex_init(&obj->lock, &reservation_ww_class); |
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__seqcount_init(&obj->seq, reservation_seqcount_string, &reservation_seqcount_class); |
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RCU_INIT_POINTER(obj->fence, NULL); |
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RCU_INIT_POINTER(obj->fence_excl, NULL); |
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obj->staged = NULL; |
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} |
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/** |
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* reservation_object_fini - destroys a reservation object |
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* @obj: the reservation object |
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*/ |
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static inline void |
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reservation_object_fini(struct reservation_object *obj) |
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{ |
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int i; |
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struct reservation_object_list *fobj; |
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struct fence *excl; |
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/* |
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* This object should be dead and all references must have |
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* been released to it, so no need to be protected with rcu. |
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*/ |
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excl = rcu_dereference_protected(obj->fence_excl, 1); |
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if (excl) |
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fence_put(excl); |
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fobj = rcu_dereference_protected(obj->fence, 1); |
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if (fobj) { |
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for (i = 0; i < fobj->shared_count; ++i) |
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fence_put(rcu_dereference_protected(fobj->shared[i], 1)); |
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kfree(fobj); |
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} |
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kfree(obj->staged); |
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ww_mutex_destroy(&obj->lock); |
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} |
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/** |
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* reservation_object_get_list - get the reservation object's |
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* shared fence list, with update-side lock held |
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* @obj: the reservation object |
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* |
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* Returns the shared fence list. Does NOT take references to |
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* the fence. The obj->lock must be held. |
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*/ |
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static inline struct reservation_object_list * |
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reservation_object_get_list(struct reservation_object *obj) |
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{ |
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return rcu_dereference_protected(obj->fence, |
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reservation_object_held(obj)); |
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} |
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/** |
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* reservation_object_get_excl - get the reservation object's |
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* exclusive fence, with update-side lock held |
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* @obj: the reservation object |
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* |
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* Returns the exclusive fence (if any). Does NOT take a |
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* reference. The obj->lock must be held. |
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* |
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* RETURNS |
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* The exclusive fence or NULL |
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*/ |
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static inline struct fence * |
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reservation_object_get_excl(struct reservation_object *obj) |
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{ |
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return rcu_dereference_protected(obj->fence_excl, |
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reservation_object_held(obj)); |
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} |
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/** |
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* reservation_object_get_excl_rcu - get the reservation object's |
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* exclusive fence, without lock held. |
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* @obj: the reservation object |
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* |
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* If there is an exclusive fence, this atomically increments it's |
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* reference count and returns it. |
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* |
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* RETURNS |
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* The exclusive fence or NULL if none |
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*/ |
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static inline struct fence * |
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reservation_object_get_excl_rcu(struct reservation_object *obj) |
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{ |
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struct fence *fence; |
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unsigned seq; |
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retry: |
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seq = read_seqcount_begin(&obj->seq); |
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rcu_read_lock(); |
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fence = rcu_dereference(obj->fence_excl); |
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if (read_seqcount_retry(&obj->seq, seq)) { |
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rcu_read_unlock(); |
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goto retry; |
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} |
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fence = fence_get(fence); |
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rcu_read_unlock(); |
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return fence; |
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} |
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int reservation_object_reserve_shared(struct reservation_object *obj); |
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void reservation_object_add_shared_fence(struct reservation_object *obj, |
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struct fence *fence); |
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void reservation_object_add_excl_fence(struct reservation_object *obj, |
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struct fence *fence); |
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int reservation_object_get_fences_rcu(struct reservation_object *obj, |
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struct fence **pfence_excl, |
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unsigned *pshared_count, |
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struct fence ***pshared); |
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long reservation_object_wait_timeout_rcu(struct reservation_object *obj, |
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bool wait_all, bool intr, |
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unsigned long timeout); |
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bool reservation_object_test_signaled_rcu(struct reservation_object *obj, |
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bool test_all); |
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#endif /* _LINUX_RESERVATION_H */
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