~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/reservation.h

Version: ~ [ linux-5.12 ] ~ [ linux-5.11.16 ] ~ [ linux-5.10.32 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.114 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.188 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.231 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.267 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.267 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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/dma-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 /**
 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  */
 59 struct reservation_object_list {
 60         struct rcu_head rcu;
 61         u32 shared_count, shared_max;
 62         struct dma_fence __rcu *shared[];
 63 };
 64 
 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  */
 73 struct reservation_object {
 74         struct ww_mutex lock;
 75         seqcount_t seq;
 76 
 77         struct dma_fence __rcu *fence_excl;
 78         struct reservation_object_list __rcu *fence;
 79         struct reservation_object_list *staged;
 80 };
 81 
 82 #define reservation_object_held(obj) lockdep_is_held(&(obj)->lock.base)
 83 #define reservation_object_assert_held(obj) \
 84         lockdep_assert_held(&(obj)->lock.base)
 85 
 86 /**
 87  * reservation_object_init - initialize a reservation object
 88  * @obj: the reservation object
 89  */
 90 static inline void
 91 reservation_object_init(struct reservation_object *obj)
 92 {
 93         ww_mutex_init(&obj->lock, &reservation_ww_class);
 94 
 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);
 98         obj->staged = NULL;
 99 }
100 
101 /**
102  * reservation_object_fini - destroys a reservation object
103  * @obj: the reservation object
104  */
105 static inline void
106 reservation_object_fini(struct reservation_object *obj)
107 {
108         int i;
109         struct reservation_object_list *fobj;
110         struct dma_fence *excl;
111 
112         /*
113          * This object should be dead and all references must have
114          * been released to it, so no need to be protected with rcu.
115          */
116         excl = rcu_dereference_protected(obj->fence_excl, 1);
117         if (excl)
118                 dma_fence_put(excl);
119 
120         fobj = rcu_dereference_protected(obj->fence, 1);
121         if (fobj) {
122                 for (i = 0; i < fobj->shared_count; ++i)
123                         dma_fence_put(rcu_dereference_protected(fobj->shared[i], 1));
124 
125                 kfree(fobj);
126         }
127         kfree(obj->staged);
128 
129         ww_mutex_destroy(&obj->lock);
130 }
131 
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  */
140 static inline struct reservation_object_list *
141 reservation_object_get_list(struct reservation_object *obj)
142 {
143         return rcu_dereference_protected(obj->fence,
144                                          reservation_object_held(obj));
145 }
146 
147 /**
148  * reservation_object_lock - lock the reservation object
149  * @obj: the reservation object
150  * @ctx: the locking context
151  *
152  * Locks the reservation object for exclusive access and modification. Note,
153  * that the lock is only against other writers, readers will run concurrently
154  * with a writer under RCU. The seqlock is used to notify readers if they
155  * overlap with a writer.
156  *
157  * As the reservation object may be locked by multiple parties in an
158  * undefined order, a #ww_acquire_ctx is passed to unwind if a cycle
159  * is detected. See ww_mutex_lock() and ww_acquire_init(). A reservation
160  * object may be locked by itself by passing NULL as @ctx.
161  */
162 static inline int
163 reservation_object_lock(struct reservation_object *obj,
164                         struct ww_acquire_ctx *ctx)
165 {
166         return ww_mutex_lock(&obj->lock, ctx);
167 }
168 
169 /**
170  * reservation_object_trylock - trylock the reservation object
171  * @obj: the reservation object
172  *
173  * Tries to lock the reservation object for exclusive access and modification.
174  * Note, that the lock is only against other writers, readers will run
175  * concurrently with a writer under RCU. The seqlock is used to notify readers
176  * if they overlap with a writer.
177  *
178  * Also note that since no context is provided, no deadlock protection is
179  * possible.
180  *
181  * Returns true if the lock was acquired, false otherwise.
182  */
183 static inline bool __must_check
184 reservation_object_trylock(struct reservation_object *obj)
185 {
186         return ww_mutex_trylock(&obj->lock);
187 }
188 
189 /**
190  * reservation_object_unlock - unlock the reservation object
191  * @obj: the reservation object
192  *
193  * Unlocks the reservation object following exclusive access.
194  */
195 static inline void
196 reservation_object_unlock(struct reservation_object *obj)
197 {
198         ww_mutex_unlock(&obj->lock);
199 }
200 
201 /**
202  * reservation_object_get_excl - get the reservation object's
203  * exclusive fence, with update-side lock held
204  * @obj: the reservation object
205  *
206  * Returns the exclusive fence (if any).  Does NOT take a
207  * reference.  The obj->lock must be held.
208  *
209  * RETURNS
210  * The exclusive fence or NULL
211  */
212 static inline struct dma_fence *
213 reservation_object_get_excl(struct reservation_object *obj)
214 {
215         return rcu_dereference_protected(obj->fence_excl,
216                                          reservation_object_held(obj));
217 }
218 
219 /**
220  * reservation_object_get_excl_rcu - get the reservation object's
221  * exclusive fence, without lock held.
222  * @obj: the reservation object
223  *
224  * If there is an exclusive fence, this atomically increments it's
225  * reference count and returns it.
226  *
227  * RETURNS
228  * The exclusive fence or NULL if none
229  */
230 static inline struct dma_fence *
231 reservation_object_get_excl_rcu(struct reservation_object *obj)
232 {
233         struct dma_fence *fence;
234 
235         if (!rcu_access_pointer(obj->fence_excl))
236                 return NULL;
237 
238         rcu_read_lock();
239         fence = dma_fence_get_rcu_safe(&obj->fence_excl);
240         rcu_read_unlock();
241 
242         return fence;
243 }
244 
245 int reservation_object_reserve_shared(struct reservation_object *obj);
246 void reservation_object_add_shared_fence(struct reservation_object *obj,
247                                          struct dma_fence *fence);
248 
249 void reservation_object_add_excl_fence(struct reservation_object *obj,
250                                        struct dma_fence *fence);
251 
252 int reservation_object_get_fences_rcu(struct reservation_object *obj,
253                                       struct dma_fence **pfence_excl,
254                                       unsigned *pshared_count,
255                                       struct dma_fence ***pshared);
256 
257 long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
258                                          bool wait_all, bool intr,
259                                          unsigned long timeout);
260 
261 bool reservation_object_test_signaled_rcu(struct reservation_object *obj,
262                                           bool test_all);
263 
264 #endif /* _LINUX_RESERVATION_H */
265 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp