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 
29 static int __i915_sw_fence_call
30 nop_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
31 {
32 	return NOTIFY_DONE;
33 }
34 
35 void __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(&fence->wait, name, key);
42 	atomic_set(&fence->pending, 1);
43 	fence->flags = (unsigned long)nop_fence_notify;
44 }
45 
46 void onstack_fence_fini(struct i915_sw_fence *fence)
47 {
48 	if (!fence->flags)
49 		return;
50 
51 	i915_sw_fence_commit(fence);
52 	i915_sw_fence_fini(fence);
53 }
54 
55 static void timed_fence_wake(struct timer_list *t)
56 {
57 	struct timed_fence *tf = from_timer(tf, t, timer);
58 
59 	i915_sw_fence_commit(&tf->fence);
60 }
61 
62 void timed_fence_init(struct timed_fence *tf, unsigned long expires)
63 {
64 	onstack_fence_init(&tf->fence);
65 
66 	timer_setup_on_stack(&tf->timer, timed_fence_wake, 0);
67 
68 	if (time_after(expires, jiffies))
69 		mod_timer(&tf->timer, expires);
70 	else
71 		i915_sw_fence_commit(&tf->fence);
72 }
73 
74 void timed_fence_fini(struct timed_fence *tf)
75 {
76 	if (del_timer_sync(&tf->timer))
77 		i915_sw_fence_commit(&tf->fence);
78 
79 	destroy_timer_on_stack(&tf->timer);
80 	i915_sw_fence_fini(&tf->fence);
81 }
82 
83 struct heap_fence {
84 	struct i915_sw_fence fence;
85 	union {
86 		struct kref ref;
87 		struct rcu_head rcu;
88 	};
89 };
90 
91 static int __i915_sw_fence_call
92 heap_fence_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
93 {
94 	struct heap_fence *h = container_of(fence, typeof(*h), fence);
95 
96 	switch (state) {
97 	case FENCE_COMPLETE:
98 		break;
99 
100 	case FENCE_FREE:
101 		heap_fence_put(&h->fence);
102 	}
103 
104 	return NOTIFY_DONE;
105 }
106 
107 struct i915_sw_fence *heap_fence_create(gfp_t gfp)
108 {
109 	struct heap_fence *h;
110 
111 	h = kmalloc(sizeof(*h), gfp);
112 	if (!h)
113 		return NULL;
114 
115 	i915_sw_fence_init(&h->fence, heap_fence_notify);
116 	refcount_set(&h->ref.refcount, 2);
117 
118 	return &h->fence;
119 }
120 
121 static void heap_fence_release(struct kref *ref)
122 {
123 	struct heap_fence *h = container_of(ref, typeof(*h), ref);
124 
125 	i915_sw_fence_fini(&h->fence);
126 
127 	kfree_rcu(h, rcu);
128 }
129 
130 void heap_fence_put(struct i915_sw_fence *fence)
131 {
132 	struct heap_fence *h = container_of(fence, typeof(*h), fence);
133 
134 	kref_put(&h->ref, heap_fence_release);
135 }
136