summaryrefslogtreecommitdiffstats
path: root/drivers/dma-buf/fence-array.c
blob: a8731c853da6a3551f405db83c2a9469fc235be3 (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
143
144
/*
 * fence-array: aggregate fences to be waited together
 *
 * Copyright (C) 2016 Collabora Ltd
 * Copyright (C) 2016 Advanced Micro Devices, Inc.
 * Authors:
 *	Gustavo Padovan <gustavo@padovan.org>
 *	Christian König <christian.koenig@amd.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/export.h>
#include <linux/slab.h>
#include <linux/fence-array.h>

static void fence_array_cb_func(struct fence *f, struct fence_cb *cb);

static const char *fence_array_get_driver_name(struct fence *fence)
{
	return "fence_array";
}

static const char *fence_array_get_timeline_name(struct fence *fence)
{
	return "unbound";
}

static void fence_array_cb_func(struct fence *f, struct fence_cb *cb)
{
	struct fence_array_cb *array_cb =
		container_of(cb, struct fence_array_cb, cb);
	struct fence_array *array = array_cb->array;

	if (atomic_dec_and_test(&array->num_pending))
		fence_signal(&array->base);
	fence_put(&array->base);
}

static bool fence_array_enable_signaling(struct fence *fence)
{
	struct fence_array *array = to_fence_array(fence);
	struct fence_array_cb *cb = (void *)(&array[1]);
	unsigned i;

	for (i = 0; i < array->num_fences; ++i) {
		cb[i].array = array;
		/*
		 * As we may report that the fence is signaled before all
		 * callbacks are complete, we need to take an additional
		 * reference count on the array so that we do not free it too
		 * early. The core fence handling will only hold the reference
		 * until we signal the array as complete (but that is now
		 * insufficient).
		 */
		fence_get(&array->base);
		if (fence_add_callback(array->fences[i], &cb[i].cb,
				       fence_array_cb_func)) {
			fence_put(&array->base);
			if (atomic_dec_and_test(&array->num_pending))
				return false;
		}
	}

	return true;
}

static bool fence_array_signaled(struct fence *fence)
{
	struct fence_array *array = to_fence_array(fence);

	return atomic_read(&array->num_pending) <= 0;
}

static void fence_array_release(struct fence *fence)
{
	struct fence_array *array = to_fence_array(fence);
	unsigned i;

	for (i = 0; i < array->num_fences; ++i)
		fence_put(array->fences[i]);

	kfree(array->fences);
	fence_free(fence);
}

const struct fence_ops fence_array_ops = {
	.get_driver_name = fence_array_get_driver_name,
	.get_timeline_name = fence_array_get_timeline_name,
	.enable_signaling = fence_array_enable_signaling,
	.signaled = fence_array_signaled,
	.wait = fence_default_wait,
	.release = fence_array_release,
};

/**
 * fence_array_create - Create a custom fence array
 * @num_fences:		[in]	number of fences to add in the array
 * @fences:		[in]	array containing the fences
 * @context:		[in]	fence context to use
 * @seqno:		[in]	sequence number to use
 * @signal_on_any	[in]	signal on any fence in the array
 *
 * Allocate a fence_array object and initialize the base fence with fence_init().
 * In case of error it returns NULL.
 *
 * The caller should allocte the fences array with num_fences size
 * and fill it with the fences it wants to add to the object. Ownership of this
 * array is take and fence_put() is used on each fence on release.
 *
 * If @signal_on_any is true the fence array signals if any fence in the array
 * signals, otherwise it signals when all fences in the array signal.
 */
struct fence_array *fence_array_create(int num_fences, struct fence **fences,
				       u64 context, unsigned seqno,
				       bool signal_on_any)
{
	struct fence_array *array;
	size_t size = sizeof(*array);

	/* Allocate the callback structures behind the array. */
	size += num_fences * sizeof(struct fence_array_cb);
	array = kzalloc(size, GFP_KERNEL);
	if (!array)
		return NULL;

	spin_lock_init(&array->lock);
	fence_init(&array->base, &fence_array_ops, &array->lock,
		   context, seqno);

	array->num_fences = num_fences;
	atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);
	array->fences = fences;

	return array;
}
EXPORT_SYMBOL(fence_array_create);
OpenPOWER on IntegriCloud