LXR linux/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
  48extern struct ww_class reservation_ww_class;
  49extern struct lock_class_key reservation_seqcount_class;
  50extern const char reservation_seqcount_string[];
  51
  52struct reservation_object_list {
  53        struct rcu_head rcu;
  54        u32 shared_count, shared_max;
  55        struct fence __rcu *shared[];
  56};
  57
  58struct 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
  71static inline void
  72reservation_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
  82static inline void
  83reservation_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
 109static inline struct reservation_object_list *
 110reservation_object_get_list(struct reservation_object *obj)
 111{
 112        return rcu_dereference_protected(obj->fence,
 113                                         reservation_object_held(obj));
 114}
 115
 116static inline struct fence *
 117reservation_object_get_excl(struct reservation_object *obj)
 118{
 119        return rcu_dereference_protected(obj->fence_excl,
 120                                         reservation_object_held(obj));
 121}
 122
 123int reservation_object_reserve_shared(struct reservation_object *obj);
 124void reservation_object_add_shared_fence(struct reservation_object *obj,
 125                                         struct fence *fence);
 126
 127void reservation_object_add_excl_fence(struct reservation_object *obj,
 128                                       struct fence *fence);
 129
 130int reservation_object_get_fences_rcu(struct reservation_object *obj,
 131                                      struct fence **pfence_excl,
 132                                      unsigned *pshared_count,
 133                                      struct fence ***pshared);
 134
 135long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
 136                                         bool wait_all, bool intr,
 137                                         unsigned long timeout);
 138
 139bool reservation_object_test_signaled_rcu(struct reservation_object *obj,
 140                                          bool test_all);
 141
 142#endif /* _LINUX_RESERVATION_H */
 143