summaryrefslogtreecommitdiffstats
path: root/include/linux/reservation.h
blob: 5a0b64cf68b4a84683071669e3b9ab01765cecd7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
/*
 * Header file for reservations for dma-buf and ttm
 *
 * Copyright(C) 2011 Linaro Limited. All rights reserved.
 * Copyright (C) 2012-2013 Canonical Ltd
 * Copyright (C) 2012 Texas Instruments
 *
 * Authors:
 * Rob Clark <robdclark@gmail.com>
 * Maarten Lankhorst <maarten.lankhorst@canonical.com>
 * Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 *
 * Based on bo.c which bears the following copyright notice,
 * but is dual licensed:
 *
 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef _LINUX_RESERVATION_H
#define _LINUX_RESERVATION_H

#include <linux/ww_mutex.h>
#include <linux/fence.h>
#include <linux/slab.h>
#include <linux/seqlock.h>
#include <linux/rcupdate.h>

extern struct ww_class reservation_ww_class;
extern struct lock_class_key reservation_seqcount_class;
extern const char reservation_seqcount_string[];

struct reservation_object_list {
	struct rcu_head rcu;
	u32 shared_count, shared_max;
	struct fence __rcu *shared[];
};

struct reservation_object {
	struct ww_mutex lock;
	seqcount_t seq;

	struct fence __rcu *fence_excl;
	struct reservation_object_list __rcu *fence;
	struct reservation_object_list *staged;
};

#define reservation_object_held(obj) lockdep_is_held(&(obj)->lock.base)
#define reservation_object_assert_held(obj) \
	lockdep_assert_held(&(obj)->lock.base)

static inline void
reservation_object_init(struct reservation_object *obj)
{
	ww_mutex_init(&obj->lock, &reservation_ww_class);

	__seqcount_init(&obj->seq, reservation_seqcount_string, &reservation_seqcount_class);
	RCU_INIT_POINTER(obj->fence, NULL);
	RCU_INIT_POINTER(obj->fence_excl, NULL);
	obj->staged = NULL;
}

static inline void
reservation_object_fini(struct reservation_object *obj)
{
	int i;
	struct reservation_object_list *fobj;
	struct fence *excl;

	/*
	 * This object should be dead and all references must have
	 * been released to it, so no need to be protected with rcu.
	 */
	excl = rcu_dereference_protected(obj->fence_excl, 1);
	if (excl)
		fence_put(excl);

	fobj = rcu_dereference_protected(obj->fence, 1);
	if (fobj) {
		for (i = 0; i < fobj->shared_count; ++i)
			fence_put(rcu_dereference_protected(fobj->shared[i], 1));

		kfree(fobj);
	}
	kfree(obj->staged);

	ww_mutex_destroy(&obj->lock);
}

static inline struct reservation_object_list *
reservation_object_get_list(struct reservation_object *obj)
{
	return rcu_dereference_protected(obj->fence,
					 reservation_object_held(obj));
}

static inline struct fence *
reservation_object_get_excl(struct reservation_object *obj)
{
	return rcu_dereference_protected(obj->fence_excl,
					 reservation_object_held(obj));
}

int reservation_object_reserve_shared(struct reservation_object *obj);
void reservation_object_add_shared_fence(struct reservation_object *obj,
					 struct fence *fence);

void reservation_object_add_excl_fence(struct reservation_object *obj,
				       struct fence *fence);

int reservation_object_get_fences_rcu(struct reservation_object *obj,
				      struct fence **pfence_excl,
				      unsigned *pshared_count,
				      struct fence ***pshared);

long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
					 bool wait_all, bool intr,
					 unsigned long timeout);

bool reservation_object_test_signaled_rcu(struct reservation_object *obj,
					  bool test_all);

#endif /* _LINUX_RESERVATION_H */