1/*
2 * Copyright © 2017 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 */
24
25#include "lib_sw_fence.h"
26
27/* Small library of different fence types useful for writing tests */
28
29static int
30nop_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
31{
32 return NOTIFY_DONE;
33}
34
35void __onstack_fence_init(struct i915_sw_fence *fence,
36 const char *name,
37 struct lock_class_key *key)
38{
39 debug_fence_init_onstack(fence);
40
41 __init_waitqueue_head(wq_head: &fence->wait, name, key);
42 atomic_set(v: &fence->pending, i: 1);
43 fence->error = 0;
44 fence->fn = nop_fence_notify;
45}
46
47void onstack_fence_fini(struct i915_sw_fence *fence)
48{
49 if (!fence->fn)
50 return;
51
52 i915_sw_fence_commit(fence);
53 i915_sw_fence_fini(fence);
54}
55
56static void timed_fence_wake(struct timer_list *t)
57{
58 struct timed_fence *tf = from_timer(tf, t, timer);
59
60 i915_sw_fence_commit(fence: &tf->fence);
61}
62
63void timed_fence_init(struct timed_fence *tf, unsigned long expires)
64{
65 onstack_fence_init(&tf->fence);
66
67 timer_setup_on_stack(&tf->timer, timed_fence_wake, 0);
68
69 if (time_after(expires, jiffies))
70 mod_timer(timer: &tf->timer, expires);
71 else
72 i915_sw_fence_commit(fence: &tf->fence);
73}
74
75void timed_fence_fini(struct timed_fence *tf)
76{
77 if (del_timer_sync(timer: &tf->timer))
78 i915_sw_fence_commit(fence: &tf->fence);
79
80 destroy_timer_on_stack(timer: &tf->timer);
81 i915_sw_fence_fini(fence: &tf->fence);
82}
83
84struct heap_fence {
85 struct i915_sw_fence fence;
86 union {
87 struct kref ref;
88 struct rcu_head rcu;
89 };
90};
91
92static int
93heap_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
94{
95 struct heap_fence *h = container_of(fence, typeof(*h), fence);
96
97 switch (state) {
98 case FENCE_COMPLETE:
99 break;
100
101 case FENCE_FREE:
102 heap_fence_put(fence: &h->fence);
103 }
104
105 return NOTIFY_DONE;
106}
107
108struct i915_sw_fence *heap_fence_create(gfp_t gfp)
109{
110 struct heap_fence *h;
111
112 h = kmalloc(size: sizeof(*h), flags: gfp);
113 if (!h)
114 return NULL;
115
116 i915_sw_fence_init(&h->fence, heap_fence_notify);
117 refcount_set(r: &h->ref.refcount, n: 2);
118
119 return &h->fence;
120}
121
122static void heap_fence_release(struct kref *ref)
123{
124 struct heap_fence *h = container_of(ref, typeof(*h), ref);
125
126 i915_sw_fence_fini(fence: &h->fence);
127
128 kfree_rcu(h, rcu);
129}
130
131void heap_fence_put(struct i915_sw_fence *fence)
132{
133 struct heap_fence *h = container_of(fence, typeof(*h), fence);
134
135 kref_put(kref: &h->ref, release: heap_fence_release);
136}
137

source code of linux/drivers/gpu/drm/i915/selftests/lib_sw_fence.c