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