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
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* dma-fence-util: misc functions for dma_fence objects
*
* Copyright (C) 2022 Advanced Micro Devices, Inc.
* Authors:
* Christian König <christian.koenig@amd.com>
*/
#include <linux/dma-fence.h>
#include <linux/dma-fence-array.h>
#include <linux/dma-fence-chain.h>
#include <linux/dma-fence-unwrap.h>
#include <linux/slab.h>
/* Internal helper to start new array iteration, don't use directly */
static struct dma_fence *
__dma_fence_unwrap_array(struct dma_fence_unwrap *cursor)
{
cursor->array = dma_fence_chain_contained(cursor->chain);
cursor->index = 0;
return dma_fence_array_first(cursor->array);
}
/**
* dma_fence_unwrap_first - return the first fence from fence containers
* @head: the entrypoint into the containers
* @cursor: current position inside the containers
*
* Unwraps potential dma_fence_chain/dma_fence_array containers and return the
* first fence.
*/
struct dma_fence *dma_fence_unwrap_first(struct dma_fence *head,
struct dma_fence_unwrap *cursor)
{
cursor->chain = dma_fence_get(head);
return __dma_fence_unwrap_array(cursor);
}
EXPORT_SYMBOL_GPL(dma_fence_unwrap_first);
/**
* dma_fence_unwrap_next - return the next fence from a fence containers
* @cursor: current position inside the containers
*
* Continue unwrapping the dma_fence_chain/dma_fence_array containers and return
* the next fence from them.
*/
struct dma_fence *dma_fence_unwrap_next(struct dma_fence_unwrap *cursor)
{
struct dma_fence *tmp;
++cursor->index;
tmp = dma_fence_array_next(cursor->array, cursor->index);
if (tmp)
return tmp;
cursor->chain = dma_fence_chain_walk(cursor->chain);
return __dma_fence_unwrap_array(cursor);
}
EXPORT_SYMBOL_GPL(dma_fence_unwrap_next);
/* Implementation for the dma_fence_merge() marco, don't use directly */
struct dma_fence *__dma_fence_unwrap_merge(unsigned int num_fences,
struct dma_fence **fences,
struct dma_fence_unwrap *iter)
{
struct dma_fence_array *result;
struct dma_fence *tmp, **array;
ktime_t timestamp;
unsigned int i;
size_t count;
count = 0;
timestamp = ns_to_ktime(0);
for (i = 0; i < num_fences; ++i) {
dma_fence_unwrap_for_each(tmp, &iter[i], fences[i]) {
if (!dma_fence_is_signaled(tmp)) {
++count;
} else if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT,
&tmp->flags)) {
if (ktime_after(tmp->timestamp, timestamp))
timestamp = tmp->timestamp;
} else {
/*
* Use the current time if the fence is
* currently signaling.
*/
timestamp = ktime_get();
}
}
}
/*
* If we couldn't find a pending fence just return a private signaled
* fence with the timestamp of the last signaled one.
*/
if (count == 0)
return dma_fence_allocate_private_stub(timestamp);
array = kmalloc_array(count, sizeof(*array), GFP_KERNEL);
if (!array)
return NULL;
/*
* This trashes the input fence array and uses it as position for the
* following merge loop. This works because the dma_fence_merge()
* wrapper macro is creating this temporary array on the stack together
* with the iterators.
*/
for (i = 0; i < num_fences; ++i)
fences[i] = dma_fence_unwrap_first(fences[i], &iter[i]);
count = 0;
do {
unsigned int sel;
restart:
tmp = NULL;
for (i = 0; i < num_fences; ++i) {
struct dma_fence *next;
while (fences[i] && dma_fence_is_signaled(fences[i]))
fences[i] = dma_fence_unwrap_next(&iter[i]);
next = fences[i];
if (!next)
continue;
/*
* We can't guarantee that inpute fences are ordered by
* context, but it is still quite likely when this
* function is used multiple times. So attempt to order
* the fences by context as we pass over them and merge
* fences with the same context.
*/
if (!tmp || tmp->context > next->context) {
tmp = next;
sel = i;
} else if (tmp->context < next->context) {
continue;
} else if (dma_fence_is_later(tmp, next)) {
fences[i] = dma_fence_unwrap_next(&iter[i]);
goto restart;
} else {
fences[sel] = dma_fence_unwrap_next(&iter[sel]);
goto restart;
}
}
if (tmp) {
array[count++] = dma_fence_get(tmp);
fences[sel] = dma_fence_unwrap_next(&iter[sel]);
}
} while (tmp);
if (count == 0) {
tmp = dma_fence_allocate_private_stub(ktime_get());
goto return_tmp;
}
if (count == 1) {
tmp = array[0];
goto return_tmp;
}
result = dma_fence_array_create(count, array,
dma_fence_context_alloc(1),
1, false);
if (!result) {
tmp = NULL;
goto return_tmp;
}
return &result->base;
return_tmp:
kfree(array);
return tmp;
}
EXPORT_SYMBOL_GPL(__dma_fence_unwrap_merge);
|
